drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

75 files changed, 20727 insertions, 0 deletions

diff --git a/drivers/of/.kunitconfig b/drivers/of/.kunitconfig
new file mode 100644
index 000000000..7d570cb92
--- /dev/null
+++ b/drivers/of/.kunitconfig
@@ -0,0 +1,5 @@
+CONFIG_KUNIT=y
+CONFIG_OF=y
+CONFIG_OF_KUNIT_TEST=y
+CONFIG_OF_OVERLAY=y
+CONFIG_OF_OVERLAY_KUNIT_TEST=y
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
new file mode 100644
index 000000000..50697cc3b
--- /dev/null
+++ b/drivers/of/Kconfig
@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: GPL-2.0
+config DTC
+	bool
+
+config GENERIC_BUILTIN_DTB
+	bool
+
+config BUILTIN_DTB_ALL
+	bool
+
+menuconfig OF
+	bool "Device Tree and Open Firmware support"
+	help
+	  This option enables the device tree infrastructure.
+	  It is automatically selected by platforms that need it or can
+	  be enabled manually for unittests, overlays or
+	  compile-coverage.
+
+if OF
+
+config OF_UNITTEST
+	bool "Device Tree runtime unit tests"
+	depends on OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
+	select OF_RESOLVE
+	help
+	  This option builds in test cases for the device tree infrastructure
+	  that are executed once at boot time, and the results dumped to the
+	  console.
+
+	  This option should only be enabled for a development kernel. The tests
+	  will taint the kernel with TAINT_TEST. The tests will cause ERROR and
+	  WARNING messages to print on the console. The tests will cause stack
+	  traces to print on the console.  It is possible that the tests will
+	  leave the devicetree in a corrupted state.
+
+	  The unittest output will be verbose.  Copy the output to a file
+	  via capturing the console output or via the dmesg command.  Process
+	  this file with scripts/dtc/of_unittest_expect to reduce the
+	  verbosity, test whether expected output is present, and to
+	  summarize the results.
+
+	  If unsure, say N here. This option is not safe to enable.
+
+config OF_KUNIT_TEST
+	tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option builds KUnit unit tests for device tree infrastructure.
+
+	  If unsure, say N here, but this option is safe to enable.
+
+config OF_ALL_DTBS
+	bool "Build all Device Tree Blobs"
+	depends on COMPILE_TEST
+	select DTC
+	help
+	  This option builds all possible Device Tree Blobs (DTBs) for the
+	  current architecture.
+
+	  If unsure, say N here, but this option is safe to enable.
+
+config OF_FLATTREE
+	bool
+	select DTC
+	select LIBFDT
+	select CRC32
+
+config OF_EARLY_FLATTREE
+	def_bool OF && !(SPARC || ALPHA || HEXAGON || M68K || PARISC || S390)
+	select DMA_DECLARE_COHERENT if HAS_DMA && HAS_IOMEM
+	select OF_FLATTREE
+
+config OF_PROMTREE
+	bool
+
+config OF_KOBJ
+	def_bool SYSFS
+
+# Hardly any platforms need this.  It is safe to select, but only do so if you
+# need it.
+config OF_DYNAMIC
+	bool "Support for dynamic device trees" if OF_UNITTEST
+	select OF_KOBJ
+	help
+	  On some platforms, the device tree can be manipulated at runtime.
+	  While this option is selected automatically on such platforms, you
+	  can enable it manually to improve device tree unit test coverage.
+
+config OF_ADDRESS
+	def_bool y
+	depends on !SPARC && (HAS_IOMEM || UML)
+
+config OF_IRQ
+	def_bool y
+	depends on !SPARC && IRQ_DOMAIN
+
+config OF_RESERVED_MEM
+	def_bool OF_EARLY_FLATTREE
+
+config OF_RESOLVE
+	bool
+
+config OF_OVERLAY
+	bool "Device Tree overlays"
+	select OF_DYNAMIC
+	select OF_FLATTREE
+	select OF_RESOLVE
+	help
+	  Overlays are a method to dynamically modify part of the kernel's
+	  device tree with dynamically loaded data.
+	  While this option is selected automatically when needed, you can
+	  enable it manually to improve device tree unit test coverage.
+
+config OF_OVERLAY_KUNIT_TEST
+	tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	select DTC
+	help
+	  This option builds KUnit unit tests for the device tree overlay code.
+
+	  If unsure, say N here, but this option is safe to enable.
+
+config OF_NUMA
+	bool
+
+endif # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
new file mode 100644
index 000000000..379a0afcb
--- /dev/null
+++ b/drivers/of/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y = base.o cpu.o device.o module.o platform.o property.o
+obj-$(CONFIG_OF_KOBJ) += kobj.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
+obj-$(CONFIG_OF_FLATTREE) += fdt.o empty_root.dtb.o
+obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
+obj-$(CONFIG_OF_PROMTREE) += pdt.o
+obj-$(CONFIG_OF_ADDRESS)  += address.o
+obj-$(CONFIG_OF_IRQ)    += irq.o
+obj-$(CONFIG_OF_UNITTEST) += unittest.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+obj-$(CONFIG_OF_RESOLVE)  += resolver.o
+obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o
+
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
+obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay-test.o
+overlay-test-y := overlay_test.o kunit_overlay_test.dtbo.o
+
+obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/address.c b/drivers/of/address.c
new file mode 100644
index 000000000..499d37cea
--- /dev/null
+++ b/drivers/of/address.c
@@ -0,0 +1,1180 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/device.h>
+#include <linux/fwnode.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/logic_pio.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/overflow.h>
+#include <linux/pci.h>
+#include <linux/pci_regs.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/dma-direct.h> /* for bus_dma_region */
+
+#include <kunit/visibility.h>
+
+/* Uncomment me to enable of_dump_addr() debugging output */
+// #define DEBUG
+
+#include "of_private.h"
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	const char	*name;
+	const char	*addresses;
+	int		(*match)(struct device_node *parent);
+	void		(*count_cells)(struct device_node *child,
+				       int *addrc, int *sizec);
+	u64		(*map)(__be32 *addr, const __be32 *range,
+				int na, int ns, int pna, int fna);
+	int		(*translate)(__be32 *addr, u64 offset, int na);
+	int		flag_cells;
+	unsigned int	(*get_flags)(const __be32 *addr);
+};
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_bus_default_count_cells(struct device_node *dev,
+				       int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = of_n_addr_cells(dev);
+	if (sizec)
+		*sizec = of_n_size_cells(dev);
+}
+
+static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
+		int na, int ns, int pna, int fna)
+{
+	u64 cp, s, da;
+
+	cp = of_read_number(range + fna, na - fna);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr + fna, na - fna);
+
+	pr_debug("default map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
+{
+	u64 a = of_read_number(addr, na);
+	memset(addr, 0, na * 4);
+	a += offset;
+	if (na > 1)
+		addr[na - 2] = cpu_to_be32(a >> 32);
+	addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
+
+	return 0;
+}
+
+static unsigned int of_bus_default_flags_get_flags(const __be32 *addr)
+{
+	return of_read_number(addr, 1);
+}
+
+static unsigned int of_bus_default_get_flags(const __be32 *addr)
+{
+	return IORESOURCE_MEM;
+}
+
+static u64 of_bus_default_flags_map(__be32 *addr, const __be32 *range, int na,
+				    int ns, int pna, int fna)
+{
+	/* Check that flags match */
+	if (*addr != *range)
+		return OF_BAD_ADDR;
+
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
+}
+
+static int of_bus_default_flags_translate(__be32 *addr, u64 offset, int na)
+{
+	/* Keep "flags" part (high cell) in translated address */
+	return of_bus_default_translate(addr + 1, offset, na - 1);
+}
+
+#ifdef CONFIG_PCI
+static unsigned int of_bus_pci_get_flags(const __be32 *addr)
+{
+	unsigned int flags = 0;
+	u32 w = be32_to_cpup(addr);
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return 0;
+
+	switch((w >> 24) & 0x03) {
+	case 0x01:
+		flags |= IORESOURCE_IO;
+		break;
+	case 0x02: /* 32 bits */
+		flags |= IORESOURCE_MEM;
+		break;
+
+	case 0x03: /* 64 bits */
+		flags |= IORESOURCE_MEM | IORESOURCE_MEM_64;
+		break;
+	}
+	if (w & 0x40000000)
+		flags |= IORESOURCE_PREFETCH;
+	return flags;
+}
+
+/*
+ * PCI bus specific translator
+ */
+
+static bool of_node_is_pcie(const struct device_node *np)
+{
+	bool is_pcie = of_node_name_eq(np, "pcie");
+
+	if (is_pcie)
+		pr_warn_once("%pOF: Missing device_type\n", np);
+
+	return is_pcie;
+}
+
+static int of_bus_pci_match(struct device_node *np)
+{
+	/*
+ 	 * "pciex" is PCI Express
+	 * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
+	 * "ht" is hypertransport
+	 *
+	 * If none of the device_type match, and that the node name is
+	 * "pcie", accept the device as PCI (with a warning).
+	 */
+	return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
+		of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
+		of_node_is_pcie(np);
+}
+
+static void of_bus_pci_count_cells(struct device_node *np,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 3;
+	if (sizec)
+		*sizec = 2;
+}
+
+static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
+		int pna, int fna)
+{
+	unsigned int af, rf;
+
+	af = of_bus_pci_get_flags(addr);
+	rf = of_bus_pci_get_flags(range);
+
+	/* Check address type match */
+	if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
+		return OF_BAD_ADDR;
+
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
+}
+
+#endif /* CONFIG_PCI */
+
+VISIBLE_IF_KUNIT int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
+{
+	if (overflows_type(start, r->start))
+		return -EOVERFLOW;
+
+	r->start = start;
+
+	if (!size)
+		r->end = wrapping_sub(typeof(r->end), r->start, 1);
+	else if (size && check_add_overflow(r->start, size - 1, &r->end))
+		return -EOVERFLOW;
+
+	return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(__of_address_resource_bounds);
+
+/*
+ * of_pci_range_to_resource - Create a resource from an of_pci_range
+ * @range:	the PCI range that describes the resource
+ * @np:		device node where the range belongs to
+ * @res:	pointer to a valid resource that will be updated to
+ *              reflect the values contained in the range.
+ *
+ * Returns -EINVAL if the range cannot be converted to resource.
+ *
+ * Note that if the range is an IO range, the resource will be converted
+ * using pci_address_to_pio() which can fail if it is called too early or
+ * if the range cannot be matched to any host bridge IO space (our case here).
+ * To guard against that we try to register the IO range first.
+ * If that fails we know that pci_address_to_pio() will do too.
+ */
+int of_pci_range_to_resource(const struct of_pci_range *range,
+			     const struct device_node *np, struct resource *res)
+{
+	u64 start;
+	int err;
+	res->flags = range->flags;
+	res->parent = res->child = res->sibling = NULL;
+	res->name = np->full_name;
+
+	if (res->flags & IORESOURCE_IO) {
+		unsigned long port;
+		err = pci_register_io_range(&np->fwnode, range->cpu_addr,
+				range->size);
+		if (err)
+			goto invalid_range;
+		port = pci_address_to_pio(range->cpu_addr);
+		if (port == (unsigned long)-1) {
+			err = -EINVAL;
+			goto invalid_range;
+		}
+		start = port;
+	} else {
+		start = range->cpu_addr;
+	}
+	return __of_address_resource_bounds(res, start, range->size);
+
+invalid_range:
+	res->start = (resource_size_t)OF_BAD_ADDR;
+	res->end = (resource_size_t)OF_BAD_ADDR;
+	return err;
+}
+EXPORT_SYMBOL(of_pci_range_to_resource);
+
+/*
+ * of_range_to_resource - Create a resource from a ranges entry
+ * @np:		device node where the range belongs to
+ * @index:	the 'ranges' index to convert to a resource
+ * @res:	pointer to a valid resource that will be updated to
+ *              reflect the values contained in the range.
+ *
+ * Returns -ENOENT if the entry is not found or -EOVERFLOW if the range
+ * cannot be converted to resource.
+ */
+int of_range_to_resource(struct device_node *np, int index, struct resource *res)
+{
+	int ret, i = 0;
+	struct of_range_parser parser;
+	struct of_range range;
+
+	ret = of_range_parser_init(&parser, np);
+	if (ret)
+		return ret;
+
+	for_each_of_range(&parser, &range)
+		if (i++ == index)
+			return of_pci_range_to_resource(&range, np, res);
+
+	return -ENOENT;
+}
+EXPORT_SYMBOL(of_range_to_resource);
+
+/*
+ * ISA bus specific translator
+ */
+
+static int of_bus_isa_match(struct device_node *np)
+{
+	return of_node_name_eq(np, "isa");
+}
+
+static void of_bus_isa_count_cells(struct device_node *child,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 2;
+	if (sizec)
+		*sizec = 1;
+}
+
+static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
+		int pna, int fna)
+{
+	/* Check address type match */
+	if ((addr[0] ^ range[0]) & cpu_to_be32(1))
+		return OF_BAD_ADDR;
+
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
+}
+
+static unsigned int of_bus_isa_get_flags(const __be32 *addr)
+{
+	unsigned int flags = 0;
+	u32 w = be32_to_cpup(addr);
+
+	if (w & 1)
+		flags |= IORESOURCE_IO;
+	else
+		flags |= IORESOURCE_MEM;
+	return flags;
+}
+
+static int of_bus_default_flags_match(struct device_node *np)
+{
+	/*
+	 * Check for presence first since of_bus_n_addr_cells() will warn when
+	 * walking parent nodes.
+	 */
+	return of_property_present(np, "#address-cells") && (of_bus_n_addr_cells(np) == 3);
+}
+
+static int of_bus_default_match(struct device_node *np)
+{
+	return of_property_present(np, "#address-cells");
+}
+
+/*
+ * Array of bus specific translators
+ */
+
+static const struct of_bus of_busses[] = {
+#ifdef CONFIG_PCI
+	/* PCI */
+	{
+		.name = "pci",
+		.addresses = "assigned-addresses",
+		.match = of_bus_pci_match,
+		.count_cells = of_bus_pci_count_cells,
+		.map = of_bus_pci_map,
+		.translate = of_bus_default_flags_translate,
+		.flag_cells = 1,
+		.get_flags = of_bus_pci_get_flags,
+	},
+#endif /* CONFIG_PCI */
+	/* ISA */
+	{
+		.name = "isa",
+		.addresses = "reg",
+		.match = of_bus_isa_match,
+		.count_cells = of_bus_isa_count_cells,
+		.map = of_bus_isa_map,
+		.translate = of_bus_default_flags_translate,
+		.flag_cells = 1,
+		.get_flags = of_bus_isa_get_flags,
+	},
+	/* Default with flags cell */
+	{
+		.name = "default-flags",
+		.addresses = "reg",
+		.match = of_bus_default_flags_match,
+		.count_cells = of_bus_default_count_cells,
+		.map = of_bus_default_flags_map,
+		.translate = of_bus_default_flags_translate,
+		.flag_cells = 1,
+		.get_flags = of_bus_default_flags_get_flags,
+	},
+	/* Default */
+	{
+		.name = "default",
+		.addresses = "reg",
+		.match = of_bus_default_match,
+		.count_cells = of_bus_default_count_cells,
+		.map = of_bus_default_map,
+		.translate = of_bus_default_translate,
+		.get_flags = of_bus_default_get_flags,
+	},
+};
+
+static const struct of_bus *of_match_bus(struct device_node *np)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(of_busses); i++)
+		if (!of_busses[i].match || of_busses[i].match(np))
+			return &of_busses[i];
+	return NULL;
+}
+
+static int of_empty_ranges_quirk(const struct device_node *np)
+{
+	if (IS_ENABLED(CONFIG_PPC)) {
+		/* To save cycles, we cache the result for global "Mac" setting */
+		static int quirk_state = -1;
+
+		/* PA-SEMI sdc DT bug */
+		if (of_device_is_compatible(np, "1682m-sdc"))
+			return true;
+
+		/* Make quirk cached */
+		if (quirk_state < 0)
+			quirk_state =
+				of_machine_is_compatible("Power Macintosh") ||
+				of_machine_is_compatible("MacRISC");
+		return quirk_state;
+	}
+	return false;
+}
+
+static int of_translate_one(const struct device_node *parent, const struct of_bus *bus,
+			    const struct of_bus *pbus, __be32 *addr,
+			    int na, int ns, int pna, const char *rprop)
+{
+	const __be32 *ranges;
+	unsigned int rlen;
+	int rone;
+	u64 offset = OF_BAD_ADDR;
+
+	/*
+	 * Normally, an absence of a "ranges" property means we are
+	 * crossing a non-translatable boundary, and thus the addresses
+	 * below the current cannot be converted to CPU physical ones.
+	 * Unfortunately, while this is very clear in the spec, it's not
+	 * what Apple understood, and they do have things like /uni-n or
+	 * /ht nodes with no "ranges" property and a lot of perfectly
+	 * useable mapped devices below them. Thus we treat the absence of
+	 * "ranges" as equivalent to an empty "ranges" property which means
+	 * a 1:1 translation at that level. It's up to the caller not to try
+	 * to translate addresses that aren't supposed to be translated in
+	 * the first place. --BenH.
+	 *
+	 * As far as we know, this damage only exists on Apple machines, so
+	 * This code is only enabled on powerpc. --gcl
+	 *
+	 * This quirk also applies for 'dma-ranges' which frequently exist in
+	 * child nodes without 'dma-ranges' in the parent nodes. --RobH
+	 */
+	ranges = of_get_property(parent, rprop, &rlen);
+	if (ranges == NULL && !of_empty_ranges_quirk(parent) &&
+	    strcmp(rprop, "dma-ranges")) {
+		pr_debug("no ranges; cannot translate\n");
+		return 1;
+	}
+	if (ranges == NULL || rlen == 0) {
+		offset = of_read_number(addr, na);
+		/* set address to zero, pass flags through */
+		memset(addr + pbus->flag_cells, 0, (pna - pbus->flag_cells) * 4);
+		pr_debug("empty ranges; 1:1 translation\n");
+		goto finish;
+	}
+
+	pr_debug("walking ranges...\n");
+
+	/* Now walk through the ranges */
+	rlen /= 4;
+	rone = na + pna + ns;
+	for (; rlen >= rone; rlen -= rone, ranges += rone) {
+		offset = bus->map(addr, ranges, na, ns, pna, bus->flag_cells);
+		if (offset != OF_BAD_ADDR)
+			break;
+	}
+	if (offset == OF_BAD_ADDR) {
+		pr_debug("not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("parent translation for:", addr, pna);
+	pr_debug("with offset: %llx\n", offset);
+
+	/* Translate it into parent bus space */
+	return pbus->translate(addr, offset, pna);
+}
+
+/*
+ * Translate an address from the device-tree into a CPU physical address,
+ * this walks up the tree and applies the various bus mappings on the
+ * way.
+ *
+ * Note: We consider that crossing any level with #size-cells == 0 to mean
+ * that translation is impossible (that is we are not dealing with a value
+ * that can be mapped to a cpu physical address). This is not really specified
+ * that way, but this is traditionally the way IBM at least do things
+ *
+ * Whenever the translation fails, the *host pointer will be set to the
+ * device that had registered logical PIO mapping, and the return code is
+ * relative to that node.
+ */
+static u64 __of_translate_address(struct device_node *node,
+				  struct device_node *(*get_parent)(const struct device_node *),
+				  const __be32 *in_addr, const char *rprop,
+				  struct device_node **host)
+{
+	struct device_node *dev __free(device_node) = of_node_get(node);
+	struct device_node *parent __free(device_node) = get_parent(dev);
+	const struct of_bus *bus, *pbus;
+	__be32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+
+	pr_debug("** translation for device %pOF **\n", dev);
+
+	*host = NULL;
+
+	if (parent == NULL)
+		return OF_BAD_ADDR;
+	bus = of_match_bus(parent);
+	if (!bus)
+		return OF_BAD_ADDR;
+
+	/* Count address cells & copy address locally */
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		pr_debug("Bad cell count for %pOF\n", dev);
+		return OF_BAD_ADDR;
+	}
+	memcpy(addr, in_addr, na * 4);
+
+	pr_debug("bus is %s (na=%d, ns=%d) on %pOF\n",
+	    bus->name, na, ns, parent);
+	of_dump_addr("translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		struct logic_pio_hwaddr *iorange;
+
+		/* Switch to parent bus */
+		of_node_put(dev);
+		dev = parent;
+		parent = get_parent(dev);
+
+		/* If root, we have finished */
+		if (parent == NULL) {
+			pr_debug("reached root node\n");
+			return of_read_number(addr, na);
+		}
+
+		/*
+		 * For indirectIO device which has no ranges property, get
+		 * the address from reg directly.
+		 */
+		iorange = find_io_range_by_fwnode(&dev->fwnode);
+		if (iorange && (iorange->flags != LOGIC_PIO_CPU_MMIO)) {
+			u64 result = of_read_number(addr + 1, na - 1);
+			pr_debug("indirectIO matched(%pOF) 0x%llx\n",
+				 dev, result);
+			*host = no_free_ptr(dev);
+			return result;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = of_match_bus(parent);
+		if (!pbus)
+			return OF_BAD_ADDR;
+		pbus->count_cells(dev, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			pr_err("Bad cell count for %pOF\n", dev);
+			return OF_BAD_ADDR;
+		}
+
+		pr_debug("parent bus is %s (na=%d, ns=%d) on %pOF\n",
+		    pbus->name, pna, pns, parent);
+
+		/* Apply bus translation */
+		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
+			return OF_BAD_ADDR;
+
+		/* Complete the move up one level */
+		na = pna;
+		ns = pns;
+		bus = pbus;
+
+		of_dump_addr("one level translation:", addr, na);
+	}
+
+	unreachable();
+}
+
+u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
+{
+	struct device_node *host;
+	u64 ret;
+
+	ret = __of_translate_address(dev, of_get_parent,
+				     in_addr, "ranges", &host);
+	if (host) {
+		of_node_put(host);
+		return OF_BAD_ADDR;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(of_translate_address);
+
+#ifdef CONFIG_HAS_DMA
+struct device_node *__of_get_dma_parent(const struct device_node *np)
+{
+	struct of_phandle_args args;
+	int ret, index;
+
+	index = of_property_match_string(np, "interconnect-names", "dma-mem");
+	if (index < 0)
+		return of_get_parent(np);
+
+	ret = of_parse_phandle_with_args(np, "interconnects",
+					 "#interconnect-cells",
+					 index, &args);
+	if (ret < 0)
+		return of_get_parent(np);
+
+	return args.np;
+}
+#endif
+
+static struct device_node *of_get_next_dma_parent(struct device_node *np)
+{
+	struct device_node *parent;
+
+	parent = __of_get_dma_parent(np);
+	of_node_put(np);
+
+	return parent;
+}
+
+u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
+{
+	struct device_node *host;
+	u64 ret;
+
+	ret = __of_translate_address(dev, __of_get_dma_parent,
+				     in_addr, "dma-ranges", &host);
+
+	if (host) {
+		of_node_put(host);
+		return OF_BAD_ADDR;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(of_translate_dma_address);
+
+/**
+ * of_translate_dma_region - Translate device tree address and size tuple
+ * @dev: device tree node for which to translate
+ * @prop: pointer into array of cells
+ * @start: return value for the start of the DMA range
+ * @length: return value for the length of the DMA range
+ *
+ * Returns a pointer to the cell immediately following the translated DMA region.
+ */
+const __be32 *of_translate_dma_region(struct device_node *dev, const __be32 *prop,
+				      phys_addr_t *start, size_t *length)
+{
+	struct device_node *parent __free(device_node) = __of_get_dma_parent(dev);
+	u64 address, size;
+	int na, ns;
+
+	if (!parent)
+		return NULL;
+
+	na = of_bus_n_addr_cells(parent);
+	ns = of_bus_n_size_cells(parent);
+
+	address = of_translate_dma_address(dev, prop);
+	if (address == OF_BAD_ADDR)
+		return NULL;
+
+	size = of_read_number(prop + na, ns);
+
+	if (start)
+		*start = address;
+
+	if (length)
+		*length = size;
+
+	return prop + na + ns;
+}
+EXPORT_SYMBOL(of_translate_dma_region);
+
+const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
+			       u64 *size, unsigned int *flags)
+{
+	const __be32 *prop;
+	unsigned int psize;
+	struct device_node *parent __free(device_node) = of_get_parent(dev);
+	const struct of_bus *bus;
+	int onesize, i, na, ns;
+
+	if (parent == NULL)
+		return NULL;
+
+	/* match the parent's bus type */
+	bus = of_match_bus(parent);
+	if (!bus || (strcmp(bus->name, "pci") && (bar_no >= 0)))
+		return NULL;
+
+	/* Get "reg" or "assigned-addresses" property */
+	prop = of_get_property(dev, bus->addresses, &psize);
+	if (prop == NULL)
+		return NULL;
+	psize /= 4;
+
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_ADDR_COUNT(na))
+		return NULL;
+
+	onesize = na + ns;
+	for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++) {
+		u32 val = be32_to_cpu(prop[0]);
+		/* PCI bus matches on BAR number instead of index */
+		if (((bar_no >= 0) && ((val & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0))) ||
+		    ((index >= 0) && (i == index))) {
+			if (size)
+				*size = of_read_number(prop + na, ns);
+			if (flags)
+				*flags = bus->get_flags(prop);
+			return prop;
+		}
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(__of_get_address);
+
+/**
+ * of_property_read_reg - Retrieve the specified "reg" entry index without translating
+ * @np: device tree node for which to retrieve "reg" from
+ * @idx: "reg" entry index to read
+ * @addr: return value for the untranslated address
+ * @size: return value for the entry size
+ *
+ * Returns -EINVAL if "reg" is not found. Returns 0 on success with addr and
+ * size values filled in.
+ */
+int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size)
+{
+	const __be32 *prop = of_get_address(np, idx, size, NULL);
+
+	if (!prop)
+		return -EINVAL;
+
+	*addr = of_read_number(prop, of_n_addr_cells(np));
+
+	return 0;
+}
+EXPORT_SYMBOL(of_property_read_reg);
+
+static int parser_init(struct of_pci_range_parser *parser,
+			struct device_node *node, const char *name)
+{
+	const __be32 *range;
+	int rlen;
+
+	parser->node = node;
+	parser->pna = of_n_addr_cells(node);
+	parser->na = of_bus_n_addr_cells(node);
+	parser->ns = of_bus_n_size_cells(node);
+	parser->dma = !strcmp(name, "dma-ranges");
+	parser->bus = of_match_bus(node);
+	parser->range = NULL;
+	parser->end = NULL;
+
+	range = of_get_property(node, name, &rlen);
+	if (!range)
+		return -ENOENT;
+
+	if (!parser->bus ||
+	    !OF_CHECK_COUNTS(parser->na, parser->ns) ||
+	    !OF_CHECK_ADDR_COUNT(parser->pna))
+		return -EINVAL;
+
+	parser->range = range;
+	parser->end = range + rlen / sizeof(__be32);
+
+	return 0;
+}
+
+int of_pci_range_parser_init(struct of_pci_range_parser *parser,
+				struct device_node *node)
+{
+	return parser_init(parser, node, "ranges");
+}
+EXPORT_SYMBOL_GPL(of_pci_range_parser_init);
+
+int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
+				struct device_node *node)
+{
+	return parser_init(parser, node, "dma-ranges");
+}
+EXPORT_SYMBOL_GPL(of_pci_dma_range_parser_init);
+#define of_dma_range_parser_init of_pci_dma_range_parser_init
+
+struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
+						struct of_pci_range *range)
+{
+	int na = parser->na;
+	int ns = parser->ns;
+	int np = parser->pna + na + ns;
+	int busflag_na;
+
+	if (!range)
+		return NULL;
+
+	if (!parser->range || parser->range + np > parser->end)
+		return NULL;
+
+	busflag_na = parser->bus->flag_cells;
+
+	range->flags = parser->bus->get_flags(parser->range);
+
+	range->bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
+
+	if (parser->dma)
+		range->cpu_addr = of_translate_dma_address(parser->node,
+				parser->range + na);
+	else
+		range->cpu_addr = of_translate_address(parser->node,
+				parser->range + na);
+
+	range->parent_bus_addr = of_read_number(parser->range + na, parser->pna);
+	range->size = of_read_number(parser->range + parser->pna + na, ns);
+
+	parser->range += np;
+
+	/* Now consume following elements while they are contiguous */
+	while (parser->range + np <= parser->end) {
+		u32 flags = 0;
+		u64 bus_addr, cpu_addr, size;
+
+		flags = parser->bus->get_flags(parser->range);
+		bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
+		if (parser->dma)
+			cpu_addr = of_translate_dma_address(parser->node,
+					parser->range + na);
+		else
+			cpu_addr = of_translate_address(parser->node,
+					parser->range + na);
+		size = of_read_number(parser->range + parser->pna + na, ns);
+
+		if (flags != range->flags)
+			break;
+		if (bus_addr != range->bus_addr + range->size ||
+		    cpu_addr != range->cpu_addr + range->size)
+			break;
+
+		range->size += size;
+		parser->range += np;
+	}
+
+	return range;
+}
+EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
+
+static u64 of_translate_ioport(struct device_node *dev, const __be32 *in_addr,
+			u64 size)
+{
+	u64 taddr;
+	unsigned long port;
+	struct device_node *host;
+
+	taddr = __of_translate_address(dev, of_get_parent,
+				       in_addr, "ranges", &host);
+	if (host) {
+		/* host-specific port access */
+		port = logic_pio_trans_hwaddr(&host->fwnode, taddr, size);
+		of_node_put(host);
+	} else {
+		/* memory-mapped I/O range */
+		port = pci_address_to_pio(taddr);
+	}
+
+	if (port == (unsigned long)-1)
+		return OF_BAD_ADDR;
+
+	return port;
+}
+
+#ifdef CONFIG_HAS_DMA
+/**
+ * of_dma_get_range - Get DMA range info and put it into a map array
+ * @np:		device node to get DMA range info
+ * @map:	dma range structure to return
+ *
+ * Look in bottom up direction for the first "dma-ranges" property
+ * and parse it.  Put the information into a DMA offset map array.
+ *
+ * dma-ranges format:
+ *	DMA addr (dma_addr)	: naddr cells
+ *	CPU addr (phys_addr_t)	: pna cells
+ *	size			: nsize cells
+ *
+ * It returns -ENODEV if "dma-ranges" property was not found for this
+ * device in the DT.
+ */
+int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
+{
+	struct device_node *node __free(device_node) = of_node_get(np);
+	const __be32 *ranges = NULL;
+	bool found_dma_ranges = false;
+	struct of_range_parser parser;
+	struct of_range range;
+	struct bus_dma_region *r;
+	int len, num_ranges = 0;
+
+	while (node) {
+		ranges = of_get_property(node, "dma-ranges", &len);
+
+		/* Ignore empty ranges, they imply no translation required */
+		if (ranges && len > 0)
+			break;
+
+		/* Once we find 'dma-ranges', then a missing one is an error */
+		if (found_dma_ranges && !ranges)
+			return -ENODEV;
+
+		found_dma_ranges = true;
+
+		node = of_get_next_dma_parent(node);
+	}
+
+	if (!node || !ranges) {
+		pr_debug("no dma-ranges found for node(%pOF)\n", np);
+		return -ENODEV;
+	}
+	of_dma_range_parser_init(&parser, node);
+	for_each_of_range(&parser, &range) {
+		if (range.cpu_addr == OF_BAD_ADDR) {
+			pr_err("translation of DMA address(%llx) to CPU address failed node(%pOF)\n",
+			       range.bus_addr, node);
+			continue;
+		}
+		num_ranges++;
+	}
+
+	if (!num_ranges)
+		return -EINVAL;
+
+	r = kzalloc_objs(*r, num_ranges + 1);
+	if (!r)
+		return -ENOMEM;
+
+	/*
+	 * Record all info in the generic DMA ranges array for struct device,
+	 * returning an error if we don't find any parsable ranges.
+	 */
+	*map = r;
+	of_dma_range_parser_init(&parser, node);
+	for_each_of_range(&parser, &range) {
+		pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
+			 range.bus_addr, range.cpu_addr, range.size);
+		if (range.cpu_addr == OF_BAD_ADDR)
+			continue;
+		r->cpu_start = range.cpu_addr;
+		r->dma_start = range.bus_addr;
+		r->size = range.size;
+		r++;
+	}
+	return 0;
+}
+#endif /* CONFIG_HAS_DMA */
+
+/**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+	phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+	struct of_range_parser parser;
+	phys_addr_t subtree_max_addr;
+	struct device_node *child;
+	struct of_range range;
+	const __be32 *ranges;
+	u64 cpu_end = 0;
+	int len;
+
+	if (!np)
+		np = of_root;
+
+	ranges = of_get_property(np, "dma-ranges", &len);
+	if (ranges && len && !of_dma_range_parser_init(&parser, np)) {
+		for_each_of_range(&parser, &range)
+			if (range.cpu_addr + range.size > cpu_end)
+				cpu_end = range.cpu_addr + range.size - 1;
+
+		if (max_cpu_addr > cpu_end)
+			max_cpu_addr = cpu_end;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		subtree_max_addr = of_dma_get_max_cpu_address(child);
+		if (max_cpu_addr > subtree_max_addr)
+			max_cpu_addr = subtree_max_addr;
+	}
+
+	return max_cpu_addr;
+}
+
+/**
+ * of_dma_is_coherent - Check if device is coherent
+ * @np:	device node
+ *
+ * It returns true if "dma-coherent" property was found
+ * for this device in the DT, or if DMA is coherent by
+ * default for OF devices on the current platform and no
+ * "dma-noncoherent" property was found for this device.
+ */
+bool of_dma_is_coherent(struct device_node *np)
+{
+	struct device_node *node __free(device_node) = of_node_get(np);
+
+	while (node) {
+		if (of_property_read_bool(node, "dma-coherent"))
+			return true;
+
+		if (of_property_read_bool(node, "dma-noncoherent"))
+			return false;
+
+		node = of_get_next_dma_parent(node);
+	}
+	return dma_default_coherent;
+}
+EXPORT_SYMBOL_GPL(of_dma_is_coherent);
+
+/**
+ * of_mmio_is_nonposted - Check if device uses non-posted MMIO
+ * @np:	device node
+ *
+ * Returns true if the "nonposted-mmio" property was found for
+ * the device's bus.
+ */
+static bool of_mmio_is_nonposted(const struct device_node *np)
+{
+	struct device_node *parent __free(device_node) = of_get_parent(np);
+
+	if (of_property_read_bool(np, "nonposted-mmio"))
+		return true;
+
+	return parent && of_property_read_bool(parent, "nonposted-mmio");
+}
+
+static int __of_address_to_resource(struct device_node *dev, int index, int bar_no,
+		struct resource *r)
+{
+	u64 taddr;
+	const __be32	*addrp;
+	u64		size;
+	unsigned int	flags;
+	const char	*name = NULL;
+
+	addrp = __of_get_address(dev, index, bar_no, &size, &flags);
+	if (addrp == NULL)
+		return -EINVAL;
+
+	/* Get optional "reg-names" property to add a name to a resource */
+	if (index >= 0)
+		of_property_read_string_index(dev, "reg-names",	index, &name);
+
+	if (flags & IORESOURCE_MEM)
+		taddr = of_translate_address(dev, addrp);
+	else if (flags & IORESOURCE_IO)
+		taddr = of_translate_ioport(dev, addrp, size);
+	else
+		return -EINVAL;
+
+	if (taddr == OF_BAD_ADDR)
+		return -EINVAL;
+	memset(r, 0, sizeof(struct resource));
+
+	if (of_mmio_is_nonposted(dev))
+		flags |= IORESOURCE_MEM_NONPOSTED;
+
+	r->flags = flags;
+	r->name = name ? name : dev->full_name;
+
+	return __of_address_resource_bounds(r, taddr, size);
+}
+
+/**
+ * of_address_to_resource - Translate device tree address and return as resource
+ * @dev:	Caller's Device Node
+ * @index:	Index into the array
+ * @r:		Pointer to resource array
+ *
+ * Returns -EINVAL if the range cannot be converted to resource.
+ *
+ * Note that if your address is a PIO address, the conversion will fail if
+ * the physical address can't be internally converted to an IO token with
+ * pci_address_to_pio(), that is because it's either called too early or it
+ * can't be matched to any host bridge IO space
+ */
+int of_address_to_resource(struct device_node *dev, int index,
+			   struct resource *r)
+{
+	return __of_address_to_resource(dev, index, -1, r);
+}
+EXPORT_SYMBOL_GPL(of_address_to_resource);
+
+int of_pci_address_to_resource(struct device_node *dev, int bar,
+			       struct resource *r)
+{
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return -ENOSYS;
+
+	return __of_address_to_resource(dev, -1, bar, r);
+}
+EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
+
+/**
+ * of_iomap - Maps the memory mapped IO for a given device_node
+ * @np:		the device whose io range will be mapped
+ * @index:	index of the io range
+ *
+ * Returns a pointer to the mapped memory
+ */
+void __iomem *of_iomap(struct device_node *np, int index)
+{
+	struct resource res;
+
+	if (of_address_to_resource(np, index, &res))
+		return NULL;
+
+	if (res.flags & IORESOURCE_MEM_NONPOSTED)
+		return ioremap_np(res.start, resource_size(&res));
+	else
+		return ioremap(res.start, resource_size(&res));
+}
+EXPORT_SYMBOL(of_iomap);
+
+/*
+ * of_io_request_and_map - Requests a resource and maps the memory mapped IO
+ *			   for a given device_node
+ * @device:	the device whose io range will be mapped
+ * @index:	index of the io range
+ * @name:	name "override" for the memory region request or NULL
+ *
+ * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
+ * error code on failure. Usage example:
+ *
+ *	base = of_io_request_and_map(node, 0, "foo");
+ *	if (IS_ERR(base))
+ *		return PTR_ERR(base);
+ */
+void __iomem *of_io_request_and_map(struct device_node *np, int index,
+				    const char *name)
+{
+	struct resource res;
+	void __iomem *mem;
+
+	if (of_address_to_resource(np, index, &res))
+		return IOMEM_ERR_PTR(-EINVAL);
+
+	if (!name)
+		name = res.name;
+	if (!request_mem_region(res.start, resource_size(&res), name))
+		return IOMEM_ERR_PTR(-EBUSY);
+
+	if (res.flags & IORESOURCE_MEM_NONPOSTED)
+		mem = ioremap_np(res.start, resource_size(&res));
+	else
+		mem = ioremap(res.start, resource_size(&res));
+
+	if (!mem) {
+		release_mem_region(res.start, resource_size(&res));
+		return IOMEM_ERR_PTR(-ENOMEM);
+	}
+
+	return mem;
+}
+EXPORT_SYMBOL(of_io_request_and_map);
diff --git a/drivers/of/base.c b/drivers/of/base.c
new file mode 100644
index 000000000..d71ae0449
--- /dev/null
+++ b/drivers/of/base.c
@@ -0,0 +1,2376 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Procedures for creating, accessing and interpreting the device tree.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
+ *
+ *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ *  Grant Likely.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/cleanup.h>
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+LIST_HEAD(aliases_lookup);
+
+struct device_node *of_root;
+EXPORT_SYMBOL(of_root);
+struct device_node *of_chosen;
+EXPORT_SYMBOL(of_chosen);
+struct device_node *of_aliases;
+struct device_node *of_stdout;
+EXPORT_SYMBOL_GPL(of_stdout);
+static const char *of_stdout_options;
+
+struct kset *of_kset;
+
+/*
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
+ * This mutex must be held whenever modifications are being made to the
+ * device tree. The of_{attach,detach}_node() and
+ * of_{add,remove,update}_property() helpers make sure this happens.
+ */
+DEFINE_MUTEX(of_mutex);
+
+/* use when traversing tree through the child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RAW_SPINLOCK(devtree_lock);
+
+bool of_node_name_eq(const struct device_node *np, const char *name)
+{
+	const char *node_name;
+	size_t len;
+
+	if (!np)
+		return false;
+
+	node_name = kbasename(np->full_name);
+	len = strchrnul(node_name, '@') - node_name;
+
+	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
+}
+EXPORT_SYMBOL(of_node_name_eq);
+
+bool of_node_name_prefix(const struct device_node *np, const char *prefix)
+{
+	if (!np)
+		return false;
+
+	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
+}
+EXPORT_SYMBOL(of_node_name_prefix);
+
+static bool __of_node_is_type(const struct device_node *np, const char *type)
+{
+	const char *match;
+	int len;
+
+	if (!np || !type)
+		return false;
+
+	match = __of_get_property(np, "device_type", &len);
+	if (!match || len <= 0 || strnlen(match, len) >= len)
+		return false;
+
+	return !strcmp(match, type);
+}
+
+#define EXCLUDED_DEFAULT_CELLS_PLATFORMS ( \
+	IS_ENABLED(CONFIG_SPARC) || \
+	of_find_compatible_node(NULL, NULL, "coreboot") \
+)
+
+int of_bus_n_addr_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent) {
+		if (!of_property_read_u32(np, "#address-cells", &cells))
+			return cells;
+		/*
+		 * Default root value and walking parent nodes for "#address-cells"
+		 * is deprecated. Any platforms which hit this warning should
+		 * be added to the excluded list.
+		 */
+		WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS,
+			  "Missing '#address-cells' in %pOF\n", np);
+	}
+	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+}
+
+int of_n_addr_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_addr_cells(np);
+}
+EXPORT_SYMBOL(of_n_addr_cells);
+
+int of_bus_n_size_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent) {
+		if (!of_property_read_u32(np, "#size-cells", &cells))
+			return cells;
+		/*
+		 * Default root value and walking parent nodes for "#size-cells"
+		 * is deprecated. Any platforms which hit this warning should
+		 * be added to the excluded list.
+		 */
+		WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS,
+			  "Missing '#size-cells' in %pOF\n", np);
+	}
+	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+}
+
+int of_n_size_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_size_cells(np);
+}
+EXPORT_SYMBOL(of_n_size_cells);
+
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return NUMA_NO_NODE;
+}
+#endif
+
+#define OF_PHANDLE_CACHE_BITS	7
+#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
+
+static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
+
+static u32 of_phandle_cache_hash(phandle handle)
+{
+	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
+}
+
+/*
+ * Caller must hold devtree_lock.
+ */
+void __of_phandle_cache_inv_entry(phandle handle)
+{
+	u32 handle_hash;
+	struct device_node *np;
+
+	if (!handle)
+		return;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	np = phandle_cache[handle_hash];
+	if (np && handle == np->phandle)
+		phandle_cache[handle_hash] = NULL;
+}
+
+void __init of_core_init(void)
+{
+	struct device_node *np;
+
+	of_platform_register_reconfig_notifier();
+
+	/* Create the kset, and register existing nodes */
+	mutex_lock(&of_mutex);
+	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
+	if (!of_kset) {
+		mutex_unlock(&of_mutex);
+		pr_err("failed to register existing nodes\n");
+		return;
+	}
+	for_each_of_allnodes(np) {
+		__of_attach_node_sysfs(np);
+		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
+			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
+	}
+	mutex_unlock(&of_mutex);
+
+	/* Symlink in /proc as required by userspace ABI */
+	if (of_root)
+		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+}
+
+static struct property *__of_find_property(const struct device_node *np,
+					   const char *name, int *lenp)
+{
+	struct property *pp;
+
+	if (!np)
+		return NULL;
+
+	for (pp = np->properties; pp; pp = pp->next) {
+		if (of_prop_cmp(pp->name, name) == 0) {
+			if (lenp)
+				*lenp = pp->length;
+			break;
+		}
+	}
+
+	return pp;
+}
+
+struct property *of_find_property(const struct device_node *np,
+				  const char *name,
+				  int *lenp)
+{
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	pp = __of_find_property(np, name, lenp);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
+struct device_node *__of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+	if (!prev) {
+		np = of_root;
+	} else if (prev->child) {
+		np = prev->child;
+	} else {
+		/* Walk back up looking for a sibling, or the end of the structure */
+		np = prev;
+		while (np->parent && !np->sibling)
+			np = np->parent;
+		np = np->sibling; /* Might be null at the end of the tree */
+	}
+	return np;
+}
+
+/**
+ * of_find_all_nodes - Get next node in global list
+ * @prev:	Previous node or NULL to start iteration
+ *		of_node_put() will be called on it
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = __of_find_all_nodes(prev);
+	of_node_get(np);
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_all_nodes);
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *__of_get_property(const struct device_node *np,
+			      const char *name, int *lenp)
+{
+	const struct property *pp = __of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *of_get_property(const struct device_node *np, const char *name,
+			    int *lenp)
+{
+	const struct property *pp = of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+EXPORT_SYMBOL(of_get_property);
+
+/**
+ * __of_device_is_compatible() - Check if the node matches given constraints
+ * @device: pointer to node
+ * @compat: required compatible string, NULL or "" for any match
+ * @type: required device_type value, NULL or "" for any match
+ * @name: required node name, NULL or "" for any match
+ *
+ * Checks if the given @compat, @type and @name strings match the
+ * properties of the given @device. A constraints can be skipped by
+ * passing NULL or an empty string as the constraint.
+ *
+ * Returns 0 for no match, and a positive integer on match. The return
+ * value is a relative score with larger values indicating better
+ * matches. The score is weighted for the most specific compatible value
+ * to get the highest score. Matching type is next, followed by matching
+ * name. Practically speaking, this results in the following priority
+ * order for matches:
+ *
+ * 1. specific compatible && type && name
+ * 2. specific compatible && type
+ * 3. specific compatible && name
+ * 4. specific compatible
+ * 5. general compatible && type && name
+ * 6. general compatible && type
+ * 7. general compatible && name
+ * 8. general compatible
+ * 9. type && name
+ * 10. type
+ * 11. name
+ */
+static int __of_device_is_compatible(const struct device_node *device,
+				     const char *compat, const char *type, const char *name)
+{
+	const struct property *prop;
+	const char *cp;
+	int index = 0, score = 0;
+
+	/* Compatible match has highest priority */
+	if (compat && compat[0]) {
+		prop = __of_find_property(device, "compatible", NULL);
+		for (cp = of_prop_next_string(prop, NULL); cp;
+		     cp = of_prop_next_string(prop, cp), index++) {
+			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
+				score = INT_MAX/2 - (index << 2);
+				break;
+			}
+		}
+		if (!score)
+			return 0;
+	}
+
+	/* Matching type is better than matching name */
+	if (type && type[0]) {
+		if (!__of_node_is_type(device, type))
+			return 0;
+		score += 2;
+	}
+
+	/* Matching name is a bit better than not */
+	if (name && name[0]) {
+		if (!of_node_name_eq(device, name))
+			return 0;
+		score++;
+	}
+
+	return score;
+}
+
+/** Checks if the given "compat" string matches one of the strings in
+ * the device's "compatible" property
+ */
+int of_device_is_compatible(const struct device_node *device,
+		const char *compat)
+{
+	unsigned long flags;
+	int res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_compatible(device, compat, NULL, NULL);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/** Checks if the device is compatible with any of the entries in
+ *  a NULL terminated array of strings. Returns the best match
+ *  score or 0.
+ */
+int of_device_compatible_match(const struct device_node *device,
+			       const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_device_is_compatible(device, *compat);
+		if (tmp > score)
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+EXPORT_SYMBOL_GPL(of_device_compatible_match);
+
+/**
+ * of_machine_compatible_match - Test root of device tree against a compatible array
+ * @compats: NULL terminated array of compatible strings to look for in root node's compatible property.
+ *
+ * Returns true if the root node has any of the given compatible values in its
+ * compatible property.
+ */
+bool of_machine_compatible_match(const char *const *compats)
+{
+	struct device_node *root;
+	int rc = 0;
+
+	root = of_find_node_by_path("/");
+	if (root) {
+		rc = of_device_compatible_match(root, compats);
+		of_node_put(root);
+	}
+
+	return rc != 0;
+}
+EXPORT_SYMBOL(of_machine_compatible_match);
+
+/**
+ * of_machine_read_compatible - Get the compatible string of this machine
+ * @compatible: address at which the address of the compatible string will be
+ *              stored
+ * @index: index of the compatible entry in the list
+ *
+ * Returns:
+ * 0 on success, negative error number on failure.
+ */
+int of_machine_read_compatible(const char **compatible, unsigned int index)
+{
+	return of_property_read_string_index(of_root, "compatible", index, compatible);
+}
+EXPORT_SYMBOL_GPL(of_machine_read_compatible);
+
+/**
+ * of_machine_read_model - Get the model string of this machine
+ * @model: address at which the address of the model string will be stored
+ *
+ * Returns:
+ * 0 on success, negative error number on failure.
+ */
+int of_machine_read_model(const char **model)
+{
+	return of_property_read_string(of_root, "model", model);
+}
+EXPORT_SYMBOL_GPL(of_machine_read_model);
+
+/**
+ * of_machine_get_match - Test root of device tree against an of_device_id array
+ * @matches:	NULL terminated array of of_device_id match structures to search in
+ *
+ * Returns matched entry or NULL
+ */
+const struct of_device_id *of_machine_get_match(const struct of_device_id *matches)
+{
+	struct device_node *root;
+	const struct of_device_id *match = NULL;
+
+	root = of_find_node_by_path("/");
+	if (root) {
+		match = of_match_node(matches, root);
+		of_node_put(root);
+	}
+
+	return match;
+}
+EXPORT_SYMBOL(of_machine_get_match);
+
+/**
+ * of_machine_get_match_data - Tell if root of device tree has a matching of_match structure
+ * @matches:	NULL terminated array of of_device_id match structures to search in
+ *
+ * Returns data associated with matched entry or NULL
+ */
+const void *of_machine_get_match_data(const struct of_device_id *matches)
+{
+	const struct of_device_id *match;
+
+	match = of_machine_get_match(matches);
+	if (!match)
+		return NULL;
+
+	return match->data;
+}
+EXPORT_SYMBOL(of_machine_get_match_data);
+
+static bool __of_device_is_status(const struct device_node *device,
+				  const char * const*strings)
+{
+	const char *status;
+	int statlen;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", &statlen);
+	if (!status || statlen <= 0)
+		return false;
+	if (strnlen(status, statlen) >= statlen)
+		return false;
+
+	while (*strings) {
+		unsigned int len = strlen(*strings);
+
+		if ((*strings)[len - 1] == '-') {
+			if (!strncmp(status, *strings, len))
+				return true;
+		} else {
+			if (!strcmp(status, *strings))
+				return true;
+		}
+		strings++;
+	}
+
+	return false;
+}
+
+/**
+ *  __of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Return: True if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool __of_device_is_available(const struct device_node *device)
+{
+	static const char * const ok[] = {"okay", "ok", NULL};
+
+	if (!device)
+		return false;
+
+	return !__of_get_property(device, "status", NULL) ||
+		__of_device_is_status(device, ok);
+}
+
+/**
+ *  __of_device_is_reserved - check if a device is reserved
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Return: True if the status property is set to "reserved", false otherwise
+ */
+static bool __of_device_is_reserved(const struct device_node *device)
+{
+	static const char * const reserved[] = {"reserved", NULL};
+
+	return __of_device_is_status(device, reserved);
+}
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Return: True if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+bool of_device_is_available(const struct device_node *device)
+{
+	unsigned long flags;
+	bool res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_available(device);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+
+}
+EXPORT_SYMBOL(of_device_is_available);
+
+/**
+ *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
+ *
+ *  @device: Node to check status for, with locks already held
+ *
+ *  Return: True if the status property is set to "fail" or "fail-..." (for any
+ *  error code suffix), false otherwise
+ */
+static bool __of_device_is_fail(const struct device_node *device)
+{
+	static const char * const fail[] = {"fail", "fail-", NULL};
+
+	return __of_device_is_status(device, fail);
+}
+
+/**
+ *  of_device_is_big_endian - check if a device has BE registers
+ *
+ *  @device: Node to check for endianness
+ *
+ *  Return: True if the device has a "big-endian" property, or if the kernel
+ *  was compiled for BE *and* the device has a "native-endian" property.
+ *  Returns false otherwise.
+ *
+ *  Callers would nominally use ioread32be/iowrite32be if
+ *  of_device_is_big_endian() == true, or readl/writel otherwise.
+ */
+bool of_device_is_big_endian(const struct device_node *device)
+{
+	if (of_property_read_bool(device, "big-endian"))
+		return true;
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+	    of_property_read_bool(device, "native-endian"))
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(of_device_is_big_endian);
+
+/**
+ * of_get_parent - Get a node's parent if any
+ * @node:	Node to get parent
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_get_parent(const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = of_node_get(node->parent);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_get_parent);
+
+/**
+ * of_get_next_parent - Iterate to a node's parent
+ * @node:	Node to get parent of
+ *
+ * This is like of_get_parent() except that it drops the
+ * refcount on the passed node, making it suitable for iterating
+ * through a node's parents.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_get_next_parent(struct device_node *node)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	parent = of_node_get(node->parent);
+	of_node_put(node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return parent;
+}
+EXPORT_SYMBOL(of_get_next_parent);
+
+static struct device_node *__of_get_next_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	struct device_node *next;
+
+	if (!node)
+		return NULL;
+
+	next = prev ? prev->sibling : node->child;
+	of_node_get(next);
+	of_node_put(prev);
+	return next;
+}
+#define __for_each_child_of_node(parent, child) \
+	for (child = __of_get_next_child(parent, NULL); child != NULL; \
+	     child = __of_get_next_child(parent, child))
+
+/**
+ * of_get_next_child - Iterate a node childs
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ *
+ * Return: A node pointer with refcount incremented, use of_node_put() on
+ * it when done. Returns NULL when prev is the last child. Decrements the
+ * refcount of prev.
+ */
+struct device_node *of_get_next_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = __of_get_next_child(node, prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_child);
+
+/**
+ * of_get_next_child_with_prefix - Find the next child node with prefix
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ * @prefix:	prefix that the node name should have
+ *
+ * This function is like of_get_next_child(), except that it automatically
+ * skips any nodes whose name doesn't have the given prefix.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_get_next_child_with_prefix(const struct device_node *node,
+						  struct device_node *prev,
+						  const char *prefix)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling) {
+		if (!of_node_name_prefix(next, prefix))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_child_with_prefix);
+
+static struct device_node *of_get_next_status_child(const struct device_node *node,
+						    struct device_node *prev,
+						    bool (*checker)(const struct device_node *))
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling) {
+		if (!checker(next))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+
+/**
+ * of_get_next_available_child - Find the next available child node
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ *
+ * This function is like of_get_next_child(), except that it
+ * automatically skips any disabled nodes (i.e. status = "disabled").
+ */
+struct device_node *of_get_next_available_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	return of_get_next_status_child(node, prev, __of_device_is_available);
+}
+EXPORT_SYMBOL(of_get_next_available_child);
+
+/**
+ * of_get_next_reserved_child - Find the next reserved child node
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ *
+ * This function is like of_get_next_child(), except that it
+ * automatically skips any disabled nodes (i.e. status = "disabled").
+ */
+struct device_node *of_get_next_reserved_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	return of_get_next_status_child(node, prev, __of_device_is_reserved);
+}
+EXPORT_SYMBOL(of_get_next_reserved_child);
+
+/**
+ * of_get_next_cpu_node - Iterate on cpu nodes
+ * @prev:	previous child of the /cpus node, or NULL to get first
+ *
+ * Unusable CPUs (those with the status property set to "fail" or "fail-...")
+ * will be skipped.
+ *
+ * Return: A cpu node pointer with refcount incremented, use of_node_put()
+ * on it when done. Returns NULL when prev is the last child. Decrements
+ * the refcount of prev.
+ */
+struct device_node *of_get_next_cpu_node(struct device_node *prev)
+{
+	struct device_node *next = NULL;
+	unsigned long flags;
+	struct device_node *node;
+
+	if (!prev)
+		node = of_find_node_by_path("/cpus");
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (prev)
+		next = prev->sibling;
+	else if (node) {
+		next = node->child;
+		of_node_put(node);
+	}
+	for (; next; next = next->sibling) {
+		if (__of_device_is_fail(next))
+			continue;
+		if (!(of_node_name_eq(next, "cpu") ||
+		      __of_node_is_type(next, "cpu")))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_cpu_node);
+
+/**
+ * of_get_compatible_child - Find compatible child node
+ * @parent:	parent node
+ * @compatible:	compatible string
+ *
+ * Lookup child node whose compatible property contains the given compatible
+ * string.
+ *
+ * Return: a node pointer with refcount incremented, use of_node_put() on it
+ * when done; or NULL if not found.
+ */
+struct device_node *of_get_compatible_child(const struct device_node *parent,
+				const char *compatible)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(parent, child) {
+		if (of_device_is_compatible(child, compatible))
+			break;
+	}
+
+	return child;
+}
+EXPORT_SYMBOL(of_get_compatible_child);
+
+/**
+ * of_get_child_by_name - Find the child node by name for a given parent
+ * @node:	parent node
+ * @name:	child name to look for.
+ *
+ * This function looks for child node for given matching name
+ *
+ * Return: A node pointer if found, with refcount incremented, use
+ * of_node_put() on it when done.
+ * Returns NULL if node is not found.
+ */
+struct device_node *of_get_child_by_name(const struct device_node *node,
+				const char *name)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(node, child)
+		if (of_node_name_eq(child, name))
+			break;
+	return child;
+}
+EXPORT_SYMBOL(of_get_child_by_name);
+
+/**
+ * of_get_available_child_by_name - Find the available child node by name for a given parent
+ * @node:	parent node
+ * @name:	child name to look for.
+ *
+ * This function looks for child node for given matching name and checks the
+ * device's availability for use.
+ *
+ * Return: A node pointer if found, with refcount incremented, use
+ * of_node_put() on it when done.
+ * Returns NULL if node is not found.
+ */
+struct device_node *of_get_available_child_by_name(const struct device_node *node,
+						   const char *name)
+{
+	struct device_node *child;
+
+	child = of_get_child_by_name(node, name);
+	if (child && !of_device_is_available(child)) {
+		of_node_put(child);
+		return NULL;
+	}
+
+	return child;
+}
+EXPORT_SYMBOL(of_get_available_child_by_name);
+
+struct device_node *__of_find_node_by_path(const struct device_node *parent,
+						const char *path)
+{
+	struct device_node *child;
+	int len;
+
+	len = strcspn(path, "/:");
+	if (!len)
+		return NULL;
+
+	__for_each_child_of_node(parent, child) {
+		const char *name = kbasename(child->full_name);
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
+struct device_node *__of_find_node_by_full_path(struct device_node *node,
+						const char *path)
+{
+	const char *separator = strchr(path, ':');
+
+	while (node && *path == '/') {
+		struct device_node *tmp = node;
+
+		path++; /* Increment past '/' delimiter */
+		node = __of_find_node_by_path(node, path);
+		of_node_put(tmp);
+		path = strchrnul(path, '/');
+		if (separator && separator < path)
+			break;
+	}
+	return node;
+}
+
+/**
+ * of_find_node_opts_by_path - Find a node matching a full OF path
+ * @path: Either the full path to match, or if the path does not
+ *       start with '/', the name of a property of the /aliases
+ *       node (an alias).  In the case of an alias, the node
+ *       matching the alias' value will be returned.
+ * @opts: Address of a pointer into which to store the start of
+ *       an options string appended to the end of the path with
+ *       a ':' separator.
+ *
+ * Valid paths:
+ *  * /foo/bar	Full path
+ *  * foo	Valid alias
+ *  * foo/bar	Valid alias + relative path
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
+{
+	struct device_node *np = NULL;
+	const struct property *pp;
+	unsigned long flags;
+	const char *separator = strchr(path, ':');
+
+	if (opts)
+		*opts = separator ? separator + 1 : NULL;
+
+	if (strcmp(path, "/") == 0)
+		return of_node_get(of_root);
+
+	/* The path could begin with an alias */
+	if (*path != '/') {
+		int len;
+		const char *p = strchrnul(path, '/');
+
+		if (separator && separator < p)
+			p = separator;
+		len = p - path;
+
+		/* of_aliases must not be NULL */
+		if (!of_aliases)
+			return NULL;
+
+		for_each_property_of_node(of_aliases, pp) {
+			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
+				np = of_find_node_by_path(pp->value);
+				break;
+			}
+		}
+		if (!np)
+			return NULL;
+		path = p;
+	}
+
+	/* Step down the tree matching path components */
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (!np)
+		np = of_node_get(of_root);
+	np = __of_find_node_by_full_path(np, path);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_opts_by_path);
+
+/**
+ * of_find_node_by_name - Find a node by its "name" property
+ * @from:	The node to start searching from or NULL; the node
+ *		you pass will not be searched, only the next one
+ *		will. Typically, you pass what the previous call
+ *		returned. of_node_put() will be called on @from.
+ * @name:	The name string to match against
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_name(struct device_node *from,
+	const char *name)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (of_node_name_eq(np, name) && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_name);
+
+/**
+ * of_find_node_by_type - Find a node by its "device_type" property
+ * @from:	The node to start searching from, or NULL to start searching
+ *		the entire device tree. The node you pass will not be
+ *		searched, only the next one will; typically, you pass
+ *		what the previous call returned. of_node_put() will be
+ *		called on from for you.
+ * @type:	The type string to match against
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_type(struct device_node *from,
+	const char *type)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (__of_node_is_type(np, type) && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_type);
+
+/**
+ * of_find_compatible_node - Find a node based on type and one of the
+ *                                tokens in its "compatible" property
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @type:	The type string to match "device_type" or NULL to ignore
+ * @compatible:	The string to match to one of the tokens in the device
+ *		"compatible" list.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_compatible_node(struct device_node *from,
+	const char *type, const char *compatible)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (__of_device_is_compatible(np, compatible, type, NULL) &&
+		    of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ * of_find_node_with_property - Find a node which has a property with
+ *                              the given name.
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @prop_name:	The name of the property to look for.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_with_property(struct device_node *from,
+	const char *prop_name)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		if (__of_find_property(np, prop_name, NULL)) {
+			of_node_get(np);
+			break;
+		}
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_with_property);
+
+static
+const struct of_device_id *__of_match_node(const struct of_device_id *matches,
+					   const struct device_node *node)
+{
+	const struct of_device_id *best_match = NULL;
+	int score, best_score = 0;
+
+	if (!matches)
+		return NULL;
+
+	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
+		score = __of_device_is_compatible(node, matches->compatible,
+						  matches->type, matches->name);
+		if (score > best_score) {
+			best_match = matches;
+			best_score = score;
+		}
+	}
+
+	return best_match;
+}
+
+/**
+ * of_match_node - Tell if a device_node has a matching of_match structure
+ * @matches:	array of of device match structures to search in
+ * @node:	the of device structure to match against
+ *
+ * Low level utility function used by device matching.
+ */
+const struct of_device_id *of_match_node(const struct of_device_id *matches,
+					 const struct device_node *node)
+{
+	const struct of_device_id *match;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	match = __of_match_node(matches, node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return match;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ * of_find_matching_node_and_match - Find a node based on an of_device_id
+ *				     match table.
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @matches:	array of of device match structures to search in
+ * @match:	Updated to point at the matches entry which matched
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_matching_node_and_match(struct device_node *from,
+					const struct of_device_id *matches,
+					const struct of_device_id **match)
+{
+	struct device_node *np;
+	const struct of_device_id *m;
+	unsigned long flags;
+
+	if (match)
+		*match = NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		m = __of_match_node(matches, np);
+		if (m && of_node_get(np)) {
+			if (match)
+				*match = m;
+			break;
+		}
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_matching_node_and_match);
+
+/**
+ * of_alias_from_compatible - Lookup appropriate alias for a device node
+ *			      depending on compatible
+ * @node:	pointer to a device tree node
+ * @alias:	Pointer to buffer that alias value will be copied into
+ * @len:	Length of alias value
+ *
+ * Based on the value of the compatible property, this routine will attempt
+ * to choose an appropriate alias value for a particular device tree node.
+ * It does this by stripping the manufacturer prefix (as delimited by a ',')
+ * from the first entry in the compatible list property.
+ *
+ * Note: The matching on just the "product" side of the compatible is a relic
+ * from I2C and SPI. Please do not add any new user.
+ *
+ * Return: This routine returns 0 on success, <0 on failure.
+ */
+int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
+{
+	const char *compatible, *p;
+	int ret;
+
+	ret = of_property_read_string_index(node, "compatible", 0,
+					    &compatible);
+	if (ret)
+		return -ENODEV;
+	p = strchr(compatible, ',');
+	strscpy(alias, p ? p + 1 : compatible, len);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_alias_from_compatible);
+
+/**
+ * of_find_node_by_phandle - Find a node given a phandle
+ * @handle:	phandle of the node to find
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_phandle(phandle handle)
+{
+	struct device_node *np = NULL;
+	unsigned long flags;
+	u32 handle_hash;
+
+	if (!handle)
+		return NULL;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (phandle_cache[handle_hash] &&
+	    handle == phandle_cache[handle_hash]->phandle)
+		np = phandle_cache[handle_hash];
+
+	if (!np) {
+		for_each_of_allnodes(np)
+			if (np->phandle == handle &&
+			    !of_node_check_flag(np, OF_DETACHED)) {
+				phandle_cache[handle_hash] = np;
+				break;
+			}
+	}
+
+	of_node_get(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_phandle);
+
+void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
+{
+	int i;
+	printk("%s %pOF", msg, args->np);
+	for (i = 0; i < args->args_count; i++) {
+		const char delim = i ? ',' : ':';
+
+		pr_cont("%c%08x", delim, args->args[i]);
+	}
+	pr_cont("\n");
+}
+
+int of_phandle_iterator_init(struct of_phandle_iterator *it,
+		const struct device_node *np,
+		const char *list_name,
+		const char *cells_name,
+		int cell_count)
+{
+	const __be32 *list;
+	int size;
+
+	memset(it, 0, sizeof(*it));
+
+	/*
+	 * one of cell_count or cells_name must be provided to determine the
+	 * argument length.
+	 */
+	if (cell_count < 0 && !cells_name)
+		return -EINVAL;
+
+	list = of_get_property(np, list_name, &size);
+	if (!list)
+		return -ENOENT;
+
+	it->cells_name = cells_name;
+	it->cell_count = cell_count;
+	it->parent = np;
+	it->list_end = list + size / sizeof(*list);
+	it->phandle_end = list;
+	it->cur = list;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
+
+int of_phandle_iterator_next(struct of_phandle_iterator *it)
+{
+	uint32_t count = 0;
+
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	if (!it->cur || it->phandle_end >= it->list_end)
+		return -ENOENT;
+
+	it->cur = it->phandle_end;
+
+	/* If phandle is 0, then it is an empty entry with no arguments. */
+	it->phandle = be32_to_cpup(it->cur++);
+
+	if (it->phandle) {
+
+		/*
+		 * Find the provider node and parse the #*-cells property to
+		 * determine the argument length.
+		 */
+		it->node = of_find_node_by_phandle(it->phandle);
+
+		if (it->cells_name) {
+			if (!it->node) {
+				pr_err("%pOF: could not find phandle %d\n",
+				       it->parent, it->phandle);
+				goto err;
+			}
+
+			if (of_property_read_u32(it->node, it->cells_name,
+						 &count)) {
+				/*
+				 * If both cell_count and cells_name is given,
+				 * fall back to cell_count in absence
+				 * of the cells_name property
+				 */
+				if (it->cell_count >= 0) {
+					count = it->cell_count;
+				} else {
+					pr_err("%pOF: could not get %s for %pOF\n",
+					       it->parent,
+					       it->cells_name,
+					       it->node);
+					goto err;
+				}
+			}
+		} else {
+			count = it->cell_count;
+		}
+
+		/*
+		 * Make sure that the arguments actually fit in the remaining
+		 * property data length
+		 */
+		if (it->cur + count > it->list_end) {
+			if (it->cells_name)
+				pr_err("%pOF: %s = %d found %td\n",
+					it->parent, it->cells_name,
+					count, it->list_end - it->cur);
+			else
+				pr_err("%pOF: phandle %s needs %d, found %td\n",
+					it->parent, of_node_full_name(it->node),
+					count, it->list_end - it->cur);
+			goto err;
+		}
+	}
+
+	it->phandle_end = it->cur + count;
+	it->cur_count = count;
+
+	return 0;
+
+err:
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
+
+int of_phandle_iterator_args(struct of_phandle_iterator *it,
+			     uint32_t *args,
+			     int size)
+{
+	int i, count;
+
+	count = it->cur_count;
+
+	if (WARN_ON(size < count))
+		count = size;
+
+	for (i = 0; i < count; i++)
+		args[i] = be32_to_cpup(it->cur++);
+
+	return count;
+}
+
+int __of_parse_phandle_with_args(const struct device_node *np,
+				 const char *list_name,
+				 const char *cells_name,
+				 int cell_count, int index,
+				 struct of_phandle_args *out_args)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	if (index < 0)
+		return -EINVAL;
+
+	/* Loop over the phandles until all the requested entry is found */
+	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
+		/*
+		 * All of the error cases bail out of the loop, so at
+		 * this point, the parsing is successful. If the requested
+		 * index matches, then fill the out_args structure and return,
+		 * or return -ENOENT for an empty entry.
+		 */
+		rc = -ENOENT;
+		if (cur_index == index) {
+			if (!it.phandle)
+				goto err;
+
+			if (out_args) {
+				int c;
+
+				c = of_phandle_iterator_args(&it,
+							     out_args->args,
+							     MAX_PHANDLE_ARGS);
+				out_args->np = it.node;
+				out_args->args_count = c;
+			} else {
+				of_node_put(it.node);
+			}
+
+			/* Found it! return success */
+			return 0;
+		}
+
+		cur_index++;
+	}
+
+	/*
+	 * Unlock node before returning result; will be one of:
+	 * -ENOENT : index is for empty phandle
+	 * -EINVAL : parsing error on data
+	 */
+
+ err:
+	of_node_put(it.node);
+	return rc;
+}
+EXPORT_SYMBOL(__of_parse_phandle_with_args);
+
+/**
+ * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @stem_name:	stem of property names that specify phandles' arguments count
+ * @index:	index of a phandle to parse out
+ * @_out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills @_out_args, on error returns appropriate errno
+ * value. The difference between this function and of_parse_phandle_with_args()
+ * is that this API remaps a phandle if the node the phandle points to has
+ * a <@stem_name>-map property.
+ *
+ * Caller is responsible to call of_node_put() on the returned @_out_args->np
+ * pointer.
+ *
+ * Example::
+ *
+ *  phandle1: node1 {
+ *  	#list-cells = <2>;
+ *  };
+ *
+ *  phandle2: node2 {
+ *  	#list-cells = <1>;
+ *  };
+ *
+ *  phandle3: node3 {
+ *  	#list-cells = <1>;
+ *  	list-map = <0 &phandle2 3>,
+ *  		   <1 &phandle2 2>,
+ *  		   <2 &phandle1 5 1>;
+ *  	list-map-mask = <0x3>;
+ *  };
+ *
+ *  node4 {
+ *  	list = <&phandle1 1 2 &phandle3 0>;
+ *  };
+ *
+ * To get a device_node of the ``node2`` node you may call this:
+ * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
+ */
+int of_parse_phandle_with_args_map(const struct device_node *np,
+				   const char *list_name,
+				   const char *stem_name,
+				   int index, struct of_phandle_args *_out_args)
+{
+	char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
+	char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
+	char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
+	char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
+	struct device_node *cur, *new = NULL;
+	const __be32 *map, *mask, *pass;
+	static const __be32 dummy_mask[] = { [0 ... (MAX_PHANDLE_ARGS - 1)] = cpu_to_be32(~0) };
+	static const __be32 dummy_pass[] = { [0 ... (MAX_PHANDLE_ARGS - 1)] = cpu_to_be32(0) };
+	struct of_phandle_args _oa = {};
+	struct of_phandle_args *out_args = _out_args ? _out_args : &_oa;
+	__be32 initial_match_array[MAX_PHANDLE_ARGS];
+	const __be32 *match_array = initial_match_array;
+	int i, ret, map_len, match;
+	u32 list_size, new_size;
+
+	if (index < 0)
+		return -EINVAL;
+
+	if (!cells_name || !map_name || !mask_name || !pass_name)
+		return -ENOMEM;
+
+	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
+					   out_args);
+	if (ret)
+		return ret;
+
+	/* Get the #<list>-cells property */
+	cur = out_args->np;
+	ret = of_property_read_u32(cur, cells_name, &list_size);
+	if (ret < 0)
+		goto put;
+
+	/* Precalculate the match array - this simplifies match loop */
+	for (i = 0; i < list_size; i++)
+		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
+
+	ret = -EINVAL;
+	while (cur) {
+		/* Get the <list>-map property */
+		map = of_get_property(cur, map_name, &map_len);
+		if (!map) {
+			if (!_out_args)
+				of_node_put(out_args->np);
+			return 0;
+		}
+		map_len /= sizeof(u32);
+
+		/* Get the <list>-map-mask property (optional) */
+		mask = of_get_property(cur, mask_name, NULL);
+		if (!mask)
+			mask = dummy_mask;
+		/* Iterate through <list>-map property */
+		match = 0;
+		while (map_len > (list_size + 1) && !match) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < list_size; i++, map_len--)
+				match &= !((match_array[i] ^ *map++) & mask[i]);
+
+			of_node_put(new);
+			new = of_find_node_by_phandle(be32_to_cpup(map));
+			map++;
+			map_len--;
+
+			/* Check if not found */
+			if (!new) {
+				ret = -EINVAL;
+				goto put;
+			}
+
+			if (!of_device_is_available(new))
+				match = 0;
+
+			ret = of_property_read_u32(new, cells_name, &new_size);
+			if (ret)
+				goto put;
+
+			/* Check for malformed properties */
+			if (WARN_ON(new_size > MAX_PHANDLE_ARGS) ||
+			    map_len < new_size) {
+				ret = -EINVAL;
+				goto put;
+			}
+
+			/* Move forward by new node's #<list>-cells amount */
+			map += new_size;
+			map_len -= new_size;
+		}
+		if (!match) {
+			ret = -ENOENT;
+			goto put;
+		}
+
+		/* Get the <list>-map-pass-thru property (optional) */
+		pass = of_get_property(cur, pass_name, NULL);
+		if (!pass)
+			pass = dummy_pass;
+
+		/*
+		 * Successfully parsed a <list>-map translation; copy new
+		 * specifier into the out_args structure, keeping the
+		 * bits specified in <list>-map-pass-thru.
+		 */
+		for (i = 0; i < new_size; i++) {
+			__be32 val = *(map - new_size + i);
+
+			if (i < list_size) {
+				val &= ~pass[i];
+				val |= cpu_to_be32(out_args->args[i]) & pass[i];
+			}
+
+			initial_match_array[i] = val;
+			out_args->args[i] = be32_to_cpu(val);
+		}
+		out_args->args_count = list_size = new_size;
+		/* Iterate again with new provider */
+		out_args->np = new;
+		of_node_put(cur);
+		cur = new;
+		new = NULL;
+	}
+put:
+	of_node_put(cur);
+	of_node_put(new);
+	return ret;
+}
+EXPORT_SYMBOL(of_parse_phandle_with_args_map);
+
+/**
+ * of_count_phandle_with_args() - Find the number of phandles references in a property
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * Return: The number of phandle + argument tuples within a property. It
+ * is a typical pattern to encode a list of phandle and variable
+ * arguments into a single property. The number of arguments is encoded
+ * by a property in the phandle-target node. For example, a gpios
+ * property would contain a list of GPIO specifies consisting of a
+ * phandle and 1 or more arguments. The number of arguments are
+ * determined by the #gpio-cells property in the node pointed to by the
+ * phandle.
+ */
+int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
+				const char *cells_name)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	/*
+	 * If cells_name is NULL we assume a cell count of 0. This makes
+	 * counting the phandles trivial as each 32bit word in the list is a
+	 * phandle and no arguments are to consider. So we don't iterate through
+	 * the list but just use the length to determine the phandle count.
+	 */
+	if (!cells_name) {
+		const __be32 *list;
+		int size;
+
+		list = of_get_property(np, list_name, &size);
+		if (!list)
+			return -ENOENT;
+
+		return size / sizeof(*list);
+	}
+
+	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
+	if (rc)
+		return rc;
+
+	while ((rc = of_phandle_iterator_next(&it)) == 0)
+		cur_index += 1;
+
+	if (rc != -ENOENT)
+		return rc;
+
+	return cur_index;
+}
+EXPORT_SYMBOL(of_count_phandle_with_args);
+
+static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
+{
+	struct property **next;
+
+	for (next = list; *next; next = &(*next)->next) {
+		if (*next == prop) {
+			*next = prop->next;
+			prop->next = NULL;
+			return prop;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * __of_add_property - Add a property to a node without lock operations
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+int __of_add_property(struct device_node *np, struct property *prop)
+{
+	int rc = 0;
+	unsigned long flags;
+	struct property **next;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	__of_remove_property_from_list(&np->deadprops, prop);
+
+	prop->next = NULL;
+	next = &np->properties;
+	while (*next) {
+		if (of_prop_cmp(prop->name, (*next)->name) == 0) {
+			/* duplicate ! don't insert it */
+			rc = -EEXIST;
+			goto out_unlock;
+		}
+		next = &(*next)->next;
+	}
+	*next = prop;
+
+out_unlock:
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	if (rc)
+		return rc;
+
+	__of_add_property_sysfs(np, prop);
+	return 0;
+}
+
+/**
+ * of_add_property - Add a property to a node
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+int of_add_property(struct device_node *np, struct property *prop)
+{
+	int rc;
+
+	mutex_lock(&of_mutex);
+	rc = __of_add_property(np, prop);
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_add_property);
+
+int __of_remove_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc = -ENODEV;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (__of_remove_property_from_list(&np->properties, prop)) {
+		/* Found the property, add it to deadprops list */
+		prop->next = np->deadprops;
+		np->deadprops = prop;
+		rc = 0;
+	}
+
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	if (rc)
+		return rc;
+
+	__of_remove_property_sysfs(np, prop);
+	return 0;
+}
+
+/**
+ * of_remove_property - Remove a property from a node.
+ * @np:		Caller's Device Node
+ * @prop:	Property to remove
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties"
+ * list, so it won't be found any more.
+ */
+int of_remove_property(struct device_node *np, struct property *prop)
+{
+	int rc;
+
+	if (!prop)
+		return -ENODEV;
+
+	mutex_lock(&of_mutex);
+	rc = __of_remove_property(np, prop);
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_remove_property);
+
+int __of_update_property(struct device_node *np, struct property *newprop,
+		struct property **oldpropp)
+{
+	struct property **next, *oldprop;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	__of_remove_property_from_list(&np->deadprops, newprop);
+
+	for (next = &np->properties; *next; next = &(*next)->next) {
+		if (of_prop_cmp((*next)->name, newprop->name) == 0)
+			break;
+	}
+	*oldpropp = oldprop = *next;
+
+	if (oldprop) {
+		/* replace the node */
+		newprop->next = oldprop->next;
+		*next = newprop;
+		oldprop->next = np->deadprops;
+		np->deadprops = oldprop;
+	} else {
+		/* new node */
+		newprop->next = NULL;
+		*next = newprop;
+	}
+
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_update_property_sysfs(np, newprop, oldprop);
+
+	return 0;
+}
+
+/*
+ * of_update_property - Update a property in a node, if the property does
+ * not exist, add it.
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties" list,
+ * and add the new property to the property list
+ */
+int of_update_property(struct device_node *np, struct property *newprop)
+{
+	struct property *oldprop;
+	int rc;
+
+	if (!newprop->name)
+		return -EINVAL;
+
+	mutex_lock(&of_mutex);
+	rc = __of_update_property(np, newprop, &oldprop);
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
+
+	return rc;
+}
+
+static void of_alias_add(struct alias_prop *ap, struct device_node *np,
+			 int id, const char *stem, int stem_len)
+{
+	ap->np = np;
+	ap->id = id;
+	strscpy(ap->stem, stem, stem_len + 1);
+	list_add_tail(&ap->link, &aliases_lookup);
+	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
+		 ap->alias, ap->stem, ap->id, np);
+}
+
+/**
+ * of_alias_scan - Scan all properties of the 'aliases' node
+ * @dt_alloc:	An allocator that provides a virtual address to memory
+ *		for storing the resulting tree
+ *
+ * The function scans all the properties of the 'aliases' node and populates
+ * the global lookup table with the properties.
+ */
+void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
+{
+	const struct property *pp;
+
+	of_aliases = of_find_node_by_path("/aliases");
+	of_chosen = of_find_node_by_path("/chosen");
+	if (of_chosen == NULL)
+		of_chosen = of_find_node_by_path("/chosen@0");
+
+	if (of_chosen) {
+		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
+		const char *name = NULL;
+
+		if (of_property_read_string(of_chosen, "stdout-path", &name))
+			of_property_read_string(of_chosen, "linux,stdout-path",
+						&name);
+		if (IS_ENABLED(CONFIG_PPC) && !name)
+			of_property_read_string(of_aliases, "stdout", &name);
+		if (name)
+			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
+		if (of_stdout)
+			fwnode_set_flag(&of_stdout->fwnode, FWNODE_FLAG_BEST_EFFORT);
+	}
+
+	if (!of_aliases)
+		return;
+
+	for_each_property_of_node(of_aliases, pp) {
+		const char *start = pp->name;
+		const char *end = start + strlen(start);
+		struct device_node *np;
+		struct alias_prop *ap;
+		int id, len;
+
+		/* Skip those we do not want to proceed */
+		if (is_pseudo_property(pp->name))
+			continue;
+
+		np = of_find_node_by_path(pp->value);
+		if (!np)
+			continue;
+
+		/* walk the alias backwards to extract the id and work out
+		 * the 'stem' string */
+		while (end > start && isdigit(*(end - 1)))
+			end--;
+		len = end - start;
+
+		if (kstrtoint(end, 10, &id) < 0) {
+			of_node_put(np);
+			continue;
+		}
+
+		/* Allocate an alias_prop with enough space for the stem */
+		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
+		if (!ap) {
+			of_node_put(np);
+			continue;
+		}
+		memset(ap, 0, sizeof(*ap) + len + 1);
+		ap->alias = start;
+		of_alias_add(ap, np, id, start, len);
+	}
+}
+
+/**
+ * of_alias_get_id - Get alias id for the given device_node
+ * @np:		Pointer to the given device_node
+ * @stem:	Alias stem of the given device_node
+ *
+ * The function travels the lookup table to get the alias id for the given
+ * device_node and alias stem.
+ *
+ * Return: The alias id if found.
+ */
+int of_alias_get_id(const struct device_node *np, const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (np == app->np) {
+			id = app->id;
+			break;
+		}
+	}
+	mutex_unlock(&of_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_id);
+
+/**
+ * of_alias_get_highest_id - Get highest alias id for the given stem
+ * @stem:	Alias stem to be examined
+ *
+ * The function travels the lookup table to get the highest alias id for the
+ * given alias stem.  It returns the alias id if found.
+ */
+int of_alias_get_highest_id(const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (app->id > id)
+			id = app->id;
+	}
+	mutex_unlock(&of_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
+
+/**
+ * of_console_check() - Test and setup console for DT setup
+ * @dn: Pointer to device node
+ * @name: Name to use for preferred console without index. ex. "ttyS"
+ * @index: Index to use for preferred console.
+ *
+ * Check if the given device node matches the stdout-path property in the
+ * /chosen node. If it does then register it as the preferred console.
+ *
+ * Return: TRUE if console successfully setup. Otherwise return FALSE.
+ */
+bool of_console_check(const struct device_node *dn, char *name, int index)
+{
+	if (!dn || dn != of_stdout || console_set_on_cmdline)
+		return false;
+
+	/*
+	 * XXX: cast `options' to char pointer to suppress complication
+	 * warnings: printk, UART and console drivers expect char pointer.
+	 */
+	return !add_preferred_console(name, index, (char *)of_stdout_options);
+}
+EXPORT_SYMBOL_GPL(of_console_check);
+
+/**
+ * of_find_next_cache_node - Find a node's subsidiary cache
+ * @np:	node of type "cpu" or "cache"
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.  Caller should hold a reference
+ * to np.
+ */
+struct device_node *of_find_next_cache_node(const struct device_node *np)
+{
+	struct device_node *child, *cache_node;
+
+	cache_node = of_parse_phandle(np, "l2-cache", 0);
+	if (!cache_node)
+		cache_node = of_parse_phandle(np, "next-level-cache", 0);
+
+	if (cache_node)
+		return cache_node;
+
+	/* OF on pmac has nodes instead of properties named "l2-cache"
+	 * beneath CPU nodes.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
+		for_each_child_of_node(np, child)
+			if (of_node_is_type(child, "cache"))
+				return child;
+
+	return NULL;
+}
+
+/**
+ * of_find_last_cache_level - Find the level at which the last cache is
+ * 		present for the given logical cpu
+ *
+ * @cpu: cpu number(logical index) for which the last cache level is needed
+ *
+ * Return: The level at which the last cache is present. It is exactly
+ * same as  the total number of cache levels for the given logical cpu.
+ */
+int of_find_last_cache_level(unsigned int cpu)
+{
+	u32 cache_level = 0;
+	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
+
+	while (np) {
+		of_node_put(prev);
+		prev = np;
+		np = of_find_next_cache_node(np);
+	}
+
+	of_property_read_u32(prev, "cache-level", &cache_level);
+	of_node_put(prev);
+
+	return cache_level;
+}
+
+/*
+ * Some DTs have an iommu-map targeting a 2-cell IOMMU node while
+ * specifying only 1 cell. Fortunately they all consist of value '1'
+ * as the 2nd cell entry with the same target, so check for that pattern.
+ *
+ * Example:
+ *	IOMMU node:
+ *		#iommu-cells = <2>;
+ *
+ *	Device node:
+ *		iommu-map = <0x0000 &smmu 0x0000 0x1>,
+ *			    <0x0100 &smmu 0x0100 0x1>;
+ */
+static bool of_check_bad_map(const __be32 *map, int len)
+{
+	__be32 phandle = map[1];
+
+	if (len % 4)
+		return false;
+	for (int i = 0; i < len; i += 4) {
+		if (map[i + 1] != phandle || map[i + 3] != cpu_to_be32(1))
+			return false;
+	}
+	return true;
+}
+
+/**
+ * of_map_id - Translate an ID through a downstream mapping.
+ * @np: root complex device node.
+ * @id: device ID to map.
+ * @map_name: property name of the map to use.
+ * @cells_name: property name of target specifier cells.
+ * @map_mask_name: optional property name of the mask to use.
+ * @filter_np: pointer to an optional filter node, or NULL to allow bypass.
+ *	If non-NULL, the map property must exist (-ENODEV if absent). If
+ *	``*filter_np`` is also non-NULL, only entries targeting that node match.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args_count will be set to the number of output specifier cells
+ *	as defined by @cells_name in the target node, and
+ *	@arg->args[0..args_count-1] will contain the translated output
+ *	specifier values. If a map entry was matched, @arg->np will be set
+ *	to the target node with a reference held that the caller must release
+ *	with of_node_put().
+ *
+ * Given a device ID, look up the appropriate implementation-defined
+ * platform ID and/or the target device which receives transactions on that
+ * ID, as per the "iommu-map" and "msi-map" bindings.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_id(const struct device_node *np, u32 id,
+	       const char *map_name, const char *cells_name,
+	       const char *map_mask_name,
+	       struct device_node * const *filter_np, struct of_phandle_args *arg)
+{
+	u32 map_mask, masked_id;
+	int map_bytes, map_len, offset = 0;
+	bool bad_map = false;
+	const __be32 *map = NULL;
+
+	if (!np || !map_name || !cells_name || !arg)
+		return -EINVAL;
+	/* Ensure bypass/no-match success never returns a stale target node. */
+	arg->np = NULL;
+
+	map = of_get_property(np, map_name, &map_bytes);
+	if (!map) {
+		if (filter_np)
+			return -ENODEV;
+		/* Otherwise, no map implies no translation */
+		arg->args[0] = id;
+		arg->args_count = 1;
+		return 0;
+	}
+
+	if (map_bytes % sizeof(*map))
+		goto err_map_len;
+	map_len = map_bytes / sizeof(*map);
+
+	/* The default is to select all bits. */
+	map_mask = 0xffffffff;
+
+	/*
+	 * Can be overridden by "{iommu,msi}-map-mask" property.
+	 * If of_property_read_u32() fails, the default is used.
+	 */
+	if (map_mask_name)
+		of_property_read_u32(np, map_mask_name, &map_mask);
+
+	masked_id = map_mask & id;
+
+	while (offset < map_len) {
+		struct device_node *phandle_node;
+		u32 id_base, phandle, id_len, id_off, cells = 0;
+		const __be32 *out_base;
+
+		if (map_len - offset < 2)
+			goto err_map_len;
+
+		id_base = be32_to_cpup(map + offset);
+
+		if (id_base & ~map_mask) {
+			pr_err("%pOF: Invalid %s translation - %s (0x%x) ignores id-base (0x%x)\n",
+			       np, map_name, map_mask_name, map_mask, id_base);
+			return -EFAULT;
+		}
+
+		phandle = be32_to_cpup(map + offset + 1);
+		phandle_node = of_find_node_by_phandle(phandle);
+		if (!phandle_node)
+			return -ENODEV;
+
+		/*
+		 * Assume 1-cell output specifier if the target node lacks the
+		 * #cells property, for backward compatibility with controllers
+		 * that predate the property (e.g. arm,gic-v2m-frame).
+		 */
+		if (bad_map || of_property_read_u32(phandle_node, cells_name, &cells))
+			cells = 1;
+
+		if (cells > MAX_PHANDLE_ARGS) {
+			pr_err("%pOF: %s cell count %d exceeds maximum\n",
+			       phandle_node, cells_name, cells);
+			of_node_put(phandle_node);
+			return -EINVAL;
+		}
+
+		if (offset == 0 && cells == 2) {
+			bad_map = of_check_bad_map(map, map_len);
+			if (bad_map) {
+				pr_warn_once("%pOF: %s has 1-cell entries targeting 2-cell %s, treating as 1-cell output\n",
+					     np, map_name, cells_name);
+				cells = 1;
+			}
+		}
+
+		if (map_len - offset < 3 + cells) {
+			of_node_put(phandle_node);
+			goto err_map_len;
+		}
+
+		out_base = map + offset + 2;
+		offset += 3 + cells;
+
+		id_len = be32_to_cpup(map + offset - 1);
+		id_off = masked_id - id_base;
+		if (masked_id < id_base || id_off >= id_len) {
+			of_node_put(phandle_node);
+			continue;
+		}
+		if (id_len > 1 && cells > 1) {
+			/*
+			 * With 1 output cell we reasonably assume its value
+			 * has a linear relationship to the input; with more,
+			 * we'd need help from the provider to know what to do.
+			 */
+			pr_err("%pOF: Unsupported %s - cannot handle %d-ID range with %d-cell output specifier\n",
+			       np, map_name, id_len, cells);
+			of_node_put(phandle_node);
+			return -EINVAL;
+		}
+
+		if (filter_np && *filter_np && *filter_np != phandle_node) {
+			of_node_put(phandle_node);
+			continue;
+		}
+
+		arg->np = phandle_node;
+		for (int i = 0; i < cells; i++)
+			arg->args[i] = id_off + be32_to_cpu(out_base[i]);
+		arg->args_count = cells;
+
+		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
+			np, map_name, map_mask, id_base,
+			cells ? be32_to_cpup(out_base) : 0,
+			id_len, id,
+			cells ? id_off + be32_to_cpup(out_base) : id_off);
+		return 0;
+	}
+
+	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
+		id, filter_np && *filter_np ? *filter_np : NULL);
+
+	/* Bypasses translation */
+	arg->args[0] = id;
+	arg->args_count = 1;
+	return 0;
+
+err_map_len:
+	pr_err("%pOF: Error: Bad %s length: %d\n", np, map_name, map_bytes);
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_map_id);
+
+/**
+ * of_map_iommu_id - Translate an ID using "iommu-map" bindings.
+ * @np: root complex device node.
+ * @id: Requester ID of the device (e.g. PCI RID/BDF or a platform
+ *      stream/device ID) used as the lookup key in the iommu-map table.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args_count will be set to the number of output specifier cells
+ *	and @arg->args[0..args_count-1] will contain the translated output
+ *	specifier values. If a map entry was matched, @arg->np holds a
+ *	reference to the target node that the caller must release with
+ *	of_node_put().
+ *
+ * Convenience wrapper around of_map_id() using "iommu-map", "#iommu-cells",
+ * and "iommu-map-mask".
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_iommu_id(const struct device_node *np, u32 id,
+		    struct of_phandle_args *arg)
+{
+	return of_map_id(np, id, "iommu-map", "#iommu-cells", "iommu-map-mask", NULL, arg);
+}
+EXPORT_SYMBOL_GPL(of_map_iommu_id);
+
+/**
+ * of_map_msi_id - Translate an ID using "msi-map" bindings.
+ * @np: root complex device node.
+ * @id: Requester ID of the device (e.g. PCI RID/BDF or a platform
+ *      stream/device ID) used as the lookup key in the msi-map table.
+ * @filter_np: pointer to an optional filter node, or NULL to allow bypass.
+ *	If non-NULL, the map property must exist (-ENODEV if absent). If
+ *	``*filter_np`` is also non-NULL, only entries targeting that node match.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->args_count will be set to the number of output specifier cells
+ *	and @arg->args[0..args_count-1] will contain the translated output
+ *	specifier values. If a map entry was matched, @arg->np holds a
+ *	reference to the target node that the caller must release with
+ *	of_node_put().
+ *
+ * Convenience wrapper around of_map_id() using "msi-map", "#msi-cells",
+ * and "msi-map-mask".
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_msi_id(const struct device_node *np, u32 id,
+		  struct device_node * const *filter_np, struct of_phandle_args *arg)
+{
+	return of_map_id(np, id, "msi-map", "#msi-cells", "msi-map-mask", filter_np, arg);
+}
+EXPORT_SYMBOL_GPL(of_map_msi_id);
diff --git a/drivers/of/cpu.c b/drivers/of/cpu.c
new file mode 100644
index 000000000..bd0e918d6
--- /dev/null
+++ b/drivers/of/cpu.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+
+/**
+ * of_get_cpu_hwid - Get the hardware ID from a CPU device node
+ *
+ * @cpun: CPU number(logical index) for which device node is required
+ * @thread: The local thread number to get the hardware ID for.
+ *
+ * Return: The hardware ID for the CPU node or ~0ULL if not found.
+ */
+u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
+{
+	const __be32 *cell;
+	int ac, len;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, "reg", &len);
+	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
+		return ~0ULL;
+
+	cell += ac * thread;
+	return of_read_number(cell, ac);
+}
+
+/*
+ * arch_match_cpu_phys_id - Match the given logical CPU and physical id
+ *
+ * @cpu: logical cpu index of a core/thread
+ * @phys_id: physical identifier of a core/thread
+ *
+ * CPU logical to physical index mapping is architecture specific.
+ * However this __weak function provides a default match of physical
+ * id to logical cpu index. phys_id provided here is usually values read
+ * from the device tree which must match the hardware internal registers.
+ *
+ * Returns true if the physical identifier and the logical cpu index
+ * correspond to the same core/thread, false otherwise.
+ */
+bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (u32)phys_id == cpu;
+}
+
+/*
+ * Checks if the given "prop_name" property holds the physical id of the
+ * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
+ * NULL, local thread number within the core is returned in it.
+ */
+static bool __of_find_n_match_cpu_property(struct device_node *cpun,
+			const char *prop_name, int cpu, unsigned int *thread)
+{
+	const __be32 *cell;
+	int ac, prop_len, tid;
+	u64 hwid;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, prop_name, &prop_len);
+	if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
+		return true;
+	if (!cell || !ac || ac > 2)
+		return false;
+	prop_len /= sizeof(*cell) * ac;
+	for (tid = 0; tid < prop_len; tid++) {
+		hwid = of_read_number(cell, ac);
+		if (arch_match_cpu_phys_id(cpu, hwid)) {
+			if (thread)
+				*thread = tid;
+			return true;
+		}
+		cell += ac;
+	}
+	return false;
+}
+
+/*
+ * arch_find_n_match_cpu_physical_id - See if the given device node is
+ * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
+ * else false.  If 'thread' is non-NULL, the local thread number within the
+ * core is returned in it.
+ */
+bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+					      int cpu, unsigned int *thread)
+{
+	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
+	 * for thread ids on PowerPC. If it doesn't exist fallback to
+	 * standard "reg" property.
+	 */
+	if (IS_ENABLED(CONFIG_PPC) &&
+	    __of_find_n_match_cpu_property(cpun,
+					   "ibm,ppc-interrupt-server#s",
+					   cpu, thread))
+		return true;
+
+	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
+}
+
+/**
+ * of_get_cpu_node - Get device node associated with the given logical CPU
+ *
+ * @cpu: CPU number(logical index) for which device node is required
+ * @thread: if not NULL, local thread number within the physical core is
+ *          returned
+ *
+ * The main purpose of this function is to retrieve the device node for the
+ * given logical CPU index. It should be used to initialize the of_node in
+ * cpu device. Once of_node in cpu device is populated, all the further
+ * references can use that instead.
+ *
+ * CPU logical to physical index mapping is architecture specific and is built
+ * before booting secondary cores. This function uses arch_match_cpu_phys_id
+ * which can be overridden by architecture specific implementation.
+ *
+ * Return: A node pointer for the logical cpu with refcount incremented, use
+ * of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+	struct device_node *cpun;
+
+	for_each_of_cpu_node(cpun) {
+		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
+			return cpun;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_cpu_node);
+
+/**
+ * of_cpu_device_node_get: Get the CPU device_node for a given logical CPU number
+ *
+ * @cpu: The logical CPU number
+ *
+ * Return: Pointer to the device_node for CPU with its reference count
+ * incremented of the given logical CPU number or NULL if the CPU device_node
+ * is not found.
+ */
+struct device_node *of_cpu_device_node_get(int cpu)
+{
+	struct device *cpu_dev;
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev)
+		return of_get_cpu_node(cpu, NULL);
+	return of_node_get(cpu_dev->of_node);
+}
+EXPORT_SYMBOL(of_cpu_device_node_get);
+
+/**
+ * of_cpu_node_to_id: Get the logical CPU number for a given device_node
+ *
+ * @cpu_node: Pointer to the device_node for CPU.
+ *
+ * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
+ * CPU is not found.
+ */
+int of_cpu_node_to_id(struct device_node *cpu_node)
+{
+	int cpu;
+	bool found = false;
+	struct device_node *np;
+
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		found = (cpu_node == np);
+		of_node_put(np);
+		if (found)
+			return cpu;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(of_cpu_node_to_id);
+
+/**
+ * of_get_cpu_state_node - Get CPU's idle state node at the given index
+ *
+ * @cpu_node: The device node for the CPU
+ * @index: The index in the list of the idle states
+ *
+ * Two generic methods can be used to describe a CPU's idle states, either via
+ * a flattened description through the "cpu-idle-states" binding or via the
+ * hierarchical layout, using the "power-domains" and the "domain-idle-states"
+ * bindings. This function check for both and returns the idle state node for
+ * the requested index.
+ *
+ * Return: An idle state node if found at @index. The refcount is incremented
+ * for it, so call of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_state_node(const struct device_node *cpu_node,
+					  int index)
+{
+	struct of_phandle_args args;
+	int err;
+
+	err = of_parse_phandle_with_args(cpu_node, "power-domains",
+					"#power-domain-cells", 0, &args);
+	if (!err) {
+		struct device_node *state_node =
+			of_parse_phandle(args.np, "domain-idle-states", index);
+
+		of_node_put(args.np);
+		if (state_node)
+			return state_node;
+	}
+
+	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
+}
+EXPORT_SYMBOL(of_get_cpu_state_node);
diff --git a/drivers/of/device.c b/drivers/of/device.c
new file mode 100644
index 000000000..b3dc78f2f
--- /dev/null
+++ b/drivers/of/device.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_iommu.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/dma-direct.h> /* for bus_dma_region */
+#include <linux/dma-map-ops.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include <asm/errno.h>
+#include "of_private.h"
+
+/**
+ * of_match_device - Tell if a struct device matches an of_device_id list
+ * @matches: array of of_device_id match structures to search in
+ * @dev: the OF device structure to match against
+ *
+ * Used by a driver to check whether an platform_device present in the
+ * system is in its list of supported devices.
+ */
+const struct of_device_id *of_match_device(const struct of_device_id *matches,
+					   const struct device *dev)
+{
+	if (!matches || !dev->of_node || dev_of_node_reused(dev))
+		return NULL;
+	return of_match_node(matches, dev->of_node);
+}
+EXPORT_SYMBOL(of_match_device);
+
+static void
+of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
+{
+	struct device_node *of_node = dev->of_node;
+	struct of_phandle_iterator it;
+	int rc, i = 0;
+
+	if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
+		return;
+
+	/*
+	 * If dev->of_node doesn't exist or doesn't contain memory-region, try
+	 * the OF node having DMA configuration.
+	 */
+	if (!of_property_present(of_node, "memory-region"))
+		of_node = np;
+
+	of_for_each_phandle(&it, rc, of_node, "memory-region", NULL, 0) {
+		/*
+		 * There might be multiple memory regions, but only one
+		 * restricted-dma-pool region is allowed.
+		 */
+		if (of_device_is_compatible(it.node, "restricted-dma-pool") &&
+		    of_device_is_available(it.node)) {
+			if (of_reserved_mem_device_init_by_idx(dev, of_node, i))
+				dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
+			of_node_put(it.node);
+			break;
+		}
+		i++;
+	}
+
+}
+
+/**
+ * of_dma_configure_id - Setup DMA configuration
+ * @dev:	Device to apply DMA configuration
+ * @np:		Pointer to OF node having DMA configuration
+ * @force_dma:  Whether device is to be set up by of_dma_configure() even if
+ *		DMA capability is not explicitly described by firmware.
+ * @id:		Optional const pointer value input id
+ *
+ * Try to get devices's DMA configuration from DT and update it
+ * accordingly.
+ *
+ * If platform code needs to use its own special DMA configuration, it
+ * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
+ * to fix up DMA configuration.
+ */
+int of_dma_configure_id(struct device *dev, struct device_node *np,
+			bool force_dma, const u32 *id)
+{
+	const struct bus_dma_region *map = NULL;
+	struct device_node *bus_np;
+	u64 mask, end = 0;
+	bool coherent, set_map = false;
+	int ret;
+
+	if (dev->dma_range_map) {
+		dev_dbg(dev, "dma_range_map already set\n");
+		goto skip_map;
+	}
+
+	if (np == dev->of_node)
+		bus_np = __of_get_dma_parent(np);
+	else
+		bus_np = of_node_get(np);
+
+	ret = of_dma_get_range(bus_np, &map);
+	of_node_put(bus_np);
+	if (ret < 0) {
+		/*
+		 * For legacy reasons, we have to assume some devices need
+		 * DMA configuration regardless of whether "dma-ranges" is
+		 * correctly specified or not.
+		 */
+		if (!force_dma)
+			return ret == -ENODEV ? 0 : ret;
+	} else {
+		/* Determine the overall bounds of all DMA regions */
+		end = dma_range_map_max(map);
+		set_map = true;
+	}
+skip_map:
+	/*
+	 * If @dev is expected to be DMA-capable then the bus code that created
+	 * it should have initialised its dma_mask pointer by this point. For
+	 * now, we'll continue the legacy behaviour of coercing it to the
+	 * coherent mask if not, but we'll no longer do so quietly.
+	 */
+	if (!dev->dma_mask) {
+		dev_warn(dev, "DMA mask not set\n");
+		dev->dma_mask = &dev->coherent_dma_mask;
+	}
+
+	if (!end && dev->coherent_dma_mask)
+		end = dev->coherent_dma_mask;
+	else if (!end)
+		end = (1ULL << 32) - 1;
+
+	/*
+	 * Limit coherent and dma mask based on size and default mask
+	 * set by the driver.
+	 */
+	mask = DMA_BIT_MASK(ilog2(end) + 1);
+	dev->coherent_dma_mask &= mask;
+	*dev->dma_mask &= mask;
+	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
+	if (set_map) {
+		dev->bus_dma_limit = end;
+		dev->dma_range_map = map;
+	}
+
+	coherent = of_dma_is_coherent(np);
+	dev_dbg(dev, "device is%sdma coherent\n",
+		coherent ? " " : " not ");
+
+	ret = of_iommu_configure(dev, np, id);
+	if (ret == -EPROBE_DEFER) {
+		/* Don't touch range map if it wasn't set from a valid dma-ranges */
+		if (set_map)
+			dev->dma_range_map = NULL;
+		kfree(map);
+		return -EPROBE_DEFER;
+	}
+	/* Take all other IOMMU errors to mean we'll just carry on without it */
+	dev_dbg(dev, "device is%sbehind an iommu\n",
+		!ret ? " " : " not ");
+
+	arch_setup_dma_ops(dev, coherent);
+
+	if (ret)
+		of_dma_set_restricted_buffer(dev, np);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_dma_configure_id);
+
+const void *of_device_get_match_data(const struct device *dev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match)
+		return NULL;
+
+	return match->data;
+}
+EXPORT_SYMBOL(of_device_get_match_data);
+
+/**
+ * of_device_modalias - Fill buffer with newline terminated modalias string
+ * @dev:	Calling device
+ * @str:	Modalias string
+ * @len:	Size of @str
+ */
+ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
+{
+	ssize_t sl;
+
+	if (!dev || !dev->of_node || dev_of_node_reused(dev))
+		return -ENODEV;
+
+	sl = of_modalias(dev->of_node, str, len - 2);
+	if (sl < 0)
+		return sl;
+	if (sl > len - 2)
+		return -ENOMEM;
+
+	str[sl++] = '\n';
+	str[sl] = 0;
+	return sl;
+}
+EXPORT_SYMBOL_GPL(of_device_modalias);
+
+/**
+ * of_device_uevent - Display OF related uevent information
+ * @dev:	Device to display the uevent information for
+ * @env:	Kernel object's userspace event reference to fill up
+ */
+void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const char *compat, *type;
+	struct alias_prop *app;
+	struct property *p;
+	int seen = 0;
+
+	if ((!dev) || (!dev->of_node))
+		return;
+
+	add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
+	add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
+	type = of_node_get_device_type(dev->of_node);
+	if (type)
+		add_uevent_var(env, "OF_TYPE=%s", type);
+
+	/* Since the compatible field can contain pretty much anything
+	 * it's not really legal to split it out with commas. We split it
+	 * up using a number of environment variables instead. */
+	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
+		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
+		seen++;
+	}
+	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
+
+	seen = 0;
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (dev->of_node == app->np) {
+			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
+				       app->alias);
+			seen++;
+		}
+	}
+	mutex_unlock(&of_mutex);
+}
+EXPORT_SYMBOL_GPL(of_device_uevent);
+
+int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
+{
+	int sl;
+
+	if ((!dev) || (!dev->of_node) || dev_of_node_reused(dev))
+		return -ENODEV;
+
+	/* Devicetree modalias is tricky, we add it in 2 steps */
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
+			 sizeof(env->buf) - env->buflen);
+	if (sl < 0)
+		return sl;
+	if (sl >= (sizeof(env->buf) - env->buflen))
+		return -ENOMEM;
+	env->buflen += sl;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_device_uevent_modalias);
+
+/**
+ * of_device_make_bus_id - Use the device node data to assign a unique name
+ * @dev: pointer to device structure that is linked to a device tree node
+ *
+ * This routine will first try using the translated bus address to
+ * derive a unique name. If it cannot, then it will prepend names from
+ * parent nodes until a unique name can be derived.
+ */
+void of_device_make_bus_id(struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	const __be32 *reg;
+	u64 addr;
+	u32 mask;
+
+	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
+	while (node->parent) {
+		/*
+		 * If the address can be translated, then that is as much
+		 * uniqueness as we need. Make it the first component and return
+		 */
+		reg = of_get_property(node, "reg", NULL);
+		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
+			if (!of_property_read_u32(node, "mask", &mask))
+				dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
+					     addr, ffs(mask) - 1, node, dev_name(dev));
+
+			else
+				dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
+					     addr, node, dev_name(dev));
+			return;
+		}
+
+		/* format arguments only used if dev_name() resolves to NULL */
+		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
+			     kbasename(node->full_name), dev_name(dev));
+		node = node->parent;
+	}
+}
+EXPORT_SYMBOL_GPL(of_device_make_bus_id);
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
new file mode 100644
index 000000000..744ce0e1e
--- /dev/null
+++ b/drivers/of/dynamic.c
@@ -0,0 +1,1134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+static struct device_node *kobj_to_device_node(struct kobject *kobj)
+{
+	return container_of(kobj, struct device_node, kobj);
+}
+
+/**
+ * of_node_get() - Increment refcount of a node
+ * @node:	Node to inc refcount, NULL is supported to simplify writing of
+ *		callers
+ *
+ * Return: The node with refcount incremented.
+ */
+struct device_node *of_node_get(struct device_node *node)
+{
+	if (node)
+		kobject_get(&node->kobj);
+	return node;
+}
+EXPORT_SYMBOL(of_node_get);
+
+/**
+ * of_node_put() - Decrement refcount of a node
+ * @node:	Node to dec refcount, NULL is supported to simplify writing of
+ *		callers
+ */
+void of_node_put(struct device_node *node)
+{
+	if (node)
+		kobject_put(&node->kobj);
+}
+EXPORT_SYMBOL(of_node_put);
+
+static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
+
+int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
+
+static const char *action_names[] = {
+	[0] = "INVALID",
+	[OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
+	[OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
+	[OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
+	[OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
+	[OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
+};
+
+static bool of_property_status_ok(const struct property *prop)
+{
+	const char *status;
+
+	if (!prop || !prop->value || prop->length <= 0)
+		return false;
+
+	status = prop->value;
+	if (strnlen(status, prop->length) >= prop->length)
+		return false;
+
+	return !strcmp(status, "okay") || !strcmp(status, "ok");
+}
+
+#define _do_print(func, prefix, action, node, prop, ...) ({	\
+	func("changeset: " prefix "%-15s %pOF%s%s\n",		\
+	     ##__VA_ARGS__, action_names[action], node,		\
+	     prop ? ":" : "", prop ? prop->name : "");		\
+})
+#define of_changeset_action_err(...) _do_print(pr_err, __VA_ARGS__)
+#define of_changeset_action_debug(...) _do_print(pr_debug, __VA_ARGS__)
+
+int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
+{
+	int rc;
+	struct of_reconfig_data *pr = p;
+
+	of_changeset_action_debug("notify: ", action, pr->dn, pr->prop);
+
+	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
+	return notifier_to_errno(rc);
+}
+
+/*
+ * of_reconfig_get_state_change()	- Returns new state of device
+ * @action	- action of the of notifier
+ * @arg		- argument of the of notifier
+ *
+ * Returns the new state of a device based on the notifier used.
+ *
+ * Return: OF_RECONFIG_CHANGE_REMOVE on device going from enabled to
+ * disabled, OF_RECONFIG_CHANGE_ADD on device going from disabled to
+ * enabled and OF_RECONFIG_NO_CHANGE on no change.
+ */
+int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
+{
+	struct property *prop, *old_prop = NULL;
+	int is_status, status_state, old_status_state, prev_state, new_state;
+
+	/* figure out if a device should be created or destroyed */
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		prop = of_find_property(pr->dn, "status", NULL);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		prop = pr->prop;
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		prop = pr->prop;
+		old_prop = pr->old_prop;
+		break;
+	default:
+		return OF_RECONFIG_NO_CHANGE;
+	}
+
+	is_status = 0;
+	status_state = -1;
+	old_status_state = -1;
+	prev_state = -1;
+	new_state = -1;
+
+	if (prop && !strcmp(prop->name, "status")) {
+		is_status = 1;
+		status_state = of_property_status_ok(prop);
+		if (old_prop)
+			old_status_state = of_property_status_ok(old_prop);
+	}
+
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		prev_state = 0;
+		/* -1 & 0 status either missing or okay */
+		new_state = status_state != 0;
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		/* -1 & 0 status either missing or okay */
+		prev_state = status_state != 0;
+		new_state = 0;
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		if (is_status) {
+			/* no status property -> enabled (legacy) */
+			prev_state = 1;
+			new_state = status_state;
+		}
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		if (is_status) {
+			prev_state = status_state;
+			/* no status property -> enabled (legacy) */
+			new_state = 1;
+		}
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		if (is_status) {
+			prev_state = old_status_state != 0;
+			new_state = status_state != 0;
+		}
+		break;
+	}
+
+	if (prev_state == new_state)
+		return OF_RECONFIG_NO_CHANGE;
+
+	return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
+}
+EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
+
+int of_property_notify(int action, struct device_node *np,
+		       struct property *prop, struct property *oldprop)
+{
+	struct of_reconfig_data pr;
+
+	/* only call notifiers if the node is attached */
+	if (!of_node_is_attached(np))
+		return 0;
+
+	pr.dn = np;
+	pr.prop = prop;
+	pr.old_prop = oldprop;
+	return of_reconfig_notify(action, &pr);
+}
+
+static void __of_attach_node(struct device_node *np)
+{
+	const __be32 *phandle;
+	int sz;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (!of_node_check_flag(np, OF_OVERLAY)) {
+		np->name = __of_get_property(np, "name", NULL);
+		if (!np->name)
+			np->name = "<NULL>";
+
+		phandle = __of_get_property(np, "phandle", &sz);
+		if (!phandle)
+			phandle = __of_get_property(np, "linux,phandle", &sz);
+		if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
+			phandle = __of_get_property(np, "ibm,phandle", &sz);
+		if (phandle && (sz >= 4))
+			np->phandle = be32_to_cpup(phandle);
+		else
+			np->phandle = 0;
+	}
+
+	np->child = NULL;
+	np->sibling = np->parent->child;
+	np->parent->child = np;
+	of_node_clear_flag(np, OF_DETACHED);
+
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_attach_node_sysfs(np);
+}
+
+/**
+ * of_attach_node() - Plug a device node into the tree and global list.
+ * @np:		Pointer to the caller's Device Node
+ */
+int of_attach_node(struct device_node *np)
+{
+	struct of_reconfig_data rd;
+
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
+	mutex_lock(&of_mutex);
+	__of_attach_node(np);
+	mutex_unlock(&of_mutex);
+
+	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
+
+	return 0;
+}
+
+void __of_detach_node(struct device_node *np)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	parent = np->parent;
+	if (WARN_ON(of_node_check_flag(np, OF_DETACHED) || !parent)) {
+		raw_spin_unlock_irqrestore(&devtree_lock, flags);
+		return;
+	}
+
+	if (parent->child == np)
+		parent->child = np->sibling;
+	else {
+		struct device_node *prevsib;
+		for (prevsib = np->parent->child;
+		     prevsib->sibling != np;
+		     prevsib = prevsib->sibling)
+			;
+		prevsib->sibling = np->sibling;
+	}
+
+	of_node_set_flag(np, OF_DETACHED);
+
+	/* race with of_find_node_by_phandle() prevented by devtree_lock */
+	__of_phandle_cache_inv_entry(np->phandle);
+
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_detach_node_sysfs(np);
+}
+
+/**
+ * of_detach_node() - "Unplug" a node from the device tree.
+ * @np:		Pointer to the caller's Device Node
+ */
+int of_detach_node(struct device_node *np)
+{
+	struct of_reconfig_data rd;
+
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
+	mutex_lock(&of_mutex);
+	__of_detach_node(np);
+	mutex_unlock(&of_mutex);
+
+	of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_detach_node);
+
+void __of_prop_free(struct property *prop)
+{
+	kfree(prop->name);
+	kfree(prop->value);
+	kfree(prop);
+}
+
+static void property_list_free(struct property *prop_list)
+{
+	struct property *prop, *next;
+
+	for (prop = prop_list; prop != NULL; prop = next) {
+		next = prop->next;
+		__of_prop_free(prop);
+	}
+}
+
+/**
+ * of_node_release() - release a dynamically allocated node
+ * @kobj: kernel object of the node to be released
+ *
+ * In of_node_put() this function is passed to kref_put() as the destructor.
+ */
+void of_node_release(struct kobject *kobj)
+{
+	struct device_node *node = kobj_to_device_node(kobj);
+
+	/*
+	 * can not use '"%pOF", node' in pr_err() calls from this function
+	 * because an of_node_get(node) when refcount is already zero
+	 * will result in an error and a stack dump
+	 */
+
+	/* We should never be releasing nodes that haven't been detached. */
+	if (!of_node_check_flag(node, OF_DETACHED)) {
+
+		pr_err("ERROR: %s() detected bad of_node_put() on %pOF/%s\n",
+			__func__, node->parent, node->full_name);
+
+		/*
+		 * of unittests will test this path.  Do not print the stack
+		 * trace when the error is caused by unittest so that we do
+		 * not display what a normal developer might reasonably
+		 * consider a real bug.
+		 */
+		if (!IS_ENABLED(CONFIG_OF_UNITTEST) ||
+		    strcmp(node->parent->full_name, "testcase-data")) {
+			dump_stack();
+			pr_err("ERROR: next of_node_put() on this node will result in a kobject warning 'refcount_t: underflow; use-after-free.'\n");
+		}
+
+		return;
+	}
+	if (!of_node_check_flag(node, OF_DYNAMIC))
+		return;
+
+	if (of_node_check_flag(node, OF_OVERLAY)) {
+
+		if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) {
+			/* premature refcount of zero, do not free memory */
+			pr_err("ERROR: memory leak before free overlay changeset,  %pOF\n",
+			       node);
+			return;
+		}
+
+		/*
+		 * If node->properties non-empty then properties were added
+		 * to this node either by different overlay that has not
+		 * yet been removed, or by a non-overlay mechanism.
+		 */
+		if (node->properties)
+			pr_err("ERROR: %s(), unexpected properties in %pOF\n",
+			       __func__, node);
+	}
+
+	if (node->child)
+		pr_err("ERROR: %s() unexpected children for %pOF/%s\n",
+			__func__, node->parent, node->full_name);
+
+	property_list_free(node->properties);
+	property_list_free(node->deadprops);
+	fwnode_links_purge(of_fwnode_handle(node));
+
+	kfree(node->full_name);
+	kfree(node->data);
+	kfree(node);
+}
+
+/**
+ * __of_prop_dup - Copy a property dynamically.
+ * @prop:	Property to copy
+ * @allocflags:	Allocation flags (typically pass GFP_KERNEL)
+ *
+ * Copy a property by dynamically allocating the memory of both the
+ * property structure and the property name & contents. The property's
+ * flags have the OF_DYNAMIC bit set so that we can differentiate between
+ * dynamically allocated properties and not.
+ *
+ * Return: The newly allocated property or NULL on out of memory error.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
+{
+	struct property *new;
+
+	new = kzalloc_obj(*new, allocflags);
+	if (!new)
+		return NULL;
+
+	/*
+	 * NOTE: There is no check for zero length value.
+	 * In case of a boolean property, this will allocate a value
+	 * of zero bytes. We do this to work around the use
+	 * of of_get_property() calls on boolean values.
+	 */
+	new->name = kstrdup(prop->name, allocflags);
+	new->value = kmemdup(prop->value, prop->length, allocflags);
+	new->length = prop->length;
+	if (!new->name || !new->value)
+		goto err_free;
+
+	/* mark the property as dynamic */
+	of_property_set_flag(new, OF_DYNAMIC);
+
+	return new;
+
+ err_free:
+	__of_prop_free(new);
+	return NULL;
+}
+
+/**
+ * __of_node_dup() - Duplicate or create an empty device node dynamically.
+ * @np:		if not NULL, contains properties to be duplicated in new node
+ * @full_name:	string value to be duplicated into new node's full_name field
+ *
+ * Create a device tree node, optionally duplicating the properties of
+ * another node.  The node data are dynamically allocated and all the node
+ * flags have the OF_DYNAMIC & OF_DETACHED bits set.
+ *
+ * Return: The newly allocated node or NULL on out of memory error.  Use
+ * of_node_put() on it when done to free the memory allocated for it.
+ */
+struct device_node *__of_node_dup(const struct device_node *np,
+				  const char *full_name)
+{
+	struct device_node *node;
+
+	node = kzalloc_obj(*node);
+	if (!node)
+		return NULL;
+	node->full_name = kstrdup(full_name, GFP_KERNEL);
+	if (!node->full_name) {
+		kfree(node);
+		return NULL;
+	}
+
+	of_node_set_flag(node, OF_DYNAMIC);
+	of_node_set_flag(node, OF_DETACHED);
+	of_node_init(node);
+
+	/* Iterate over and duplicate all properties */
+	if (np) {
+		struct property *pp, *new_pp;
+		for_each_property_of_node(np, pp) {
+			new_pp = __of_prop_dup(pp, GFP_KERNEL);
+			if (!new_pp)
+				goto err_prop;
+			if (__of_add_property(node, new_pp)) {
+				__of_prop_free(new_pp);
+				goto err_prop;
+			}
+		}
+	}
+	return node;
+
+ err_prop:
+	of_node_put(node); /* Frees the node and properties */
+	return NULL;
+}
+
+/**
+ * of_changeset_create_node - Dynamically create a device node and attach to
+ * a given changeset.
+ *
+ * @ocs: Pointer to changeset
+ * @parent: Pointer to parent device node
+ * @full_name: Node full name
+ *
+ * Return: Pointer to the created device node or NULL in case of an error.
+ */
+struct device_node *of_changeset_create_node(struct of_changeset *ocs,
+					     struct device_node *parent,
+					     const char *full_name)
+{
+	struct device_node *np;
+	int ret;
+
+	np = __of_node_dup(NULL, full_name);
+	if (!np)
+		return NULL;
+	np->parent = parent;
+
+	ret = of_changeset_attach_node(ocs, np);
+	if (ret) {
+		of_node_put(np);
+		return NULL;
+	}
+
+	return np;
+}
+EXPORT_SYMBOL(of_changeset_create_node);
+
+static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
+{
+	if (ce->action == OF_RECONFIG_ATTACH_NODE &&
+	    of_node_check_flag(ce->np, OF_OVERLAY)) {
+		if (kref_read(&ce->np->kobj.kref) > 1) {
+			pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n",
+			       kref_read(&ce->np->kobj.kref), ce->np);
+		} else {
+			of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET);
+		}
+	}
+
+	of_node_put(ce->np);
+	list_del(&ce->node);
+	kfree(ce);
+}
+
+static void __of_changeset_entry_invert(const struct of_changeset_entry *ce,
+					  struct of_changeset_entry *rce)
+{
+	memcpy(rce, ce, sizeof(*rce));
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		rce->action = OF_RECONFIG_DETACH_NODE;
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		rce->action = OF_RECONFIG_ATTACH_NODE;
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		rce->action = OF_RECONFIG_REMOVE_PROPERTY;
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		rce->action = OF_RECONFIG_ADD_PROPERTY;
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		rce->old_prop = ce->prop;
+		rce->prop = ce->old_prop;
+		/* update was used but original property did not exist */
+		if (!rce->prop) {
+			rce->action = OF_RECONFIG_REMOVE_PROPERTY;
+			rce->prop = ce->prop;
+		}
+		break;
+	}
+}
+
+static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
+		bool revert)
+{
+	struct of_reconfig_data rd;
+	struct of_changeset_entry ce_inverted;
+	int ret = 0;
+
+	if (revert) {
+		__of_changeset_entry_invert(ce, &ce_inverted);
+		ce = &ce_inverted;
+	}
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		memset(&rd, 0, sizeof(rd));
+		rd.dn = ce->np;
+		ret = of_reconfig_notify(ce->action, &rd);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
+		break;
+	default:
+		pr_err("invalid devicetree changeset action: %i\n",
+			(int)ce->action);
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		pr_err("changeset notifier error @%pOF\n", ce->np);
+	return ret;
+}
+
+static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
+{
+	int ret = 0;
+
+	of_changeset_action_debug("apply: ", ce->action, ce->np, ce->prop);
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		__of_attach_node(ce->np);
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		__of_detach_node(ce->np);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		ret = __of_add_property(ce->np, ce->prop);
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		ret = __of_remove_property(ce->np, ce->prop);
+		break;
+
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		ret = __of_update_property(ce->np, ce->prop, &ce->old_prop);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret) {
+		of_changeset_action_err("apply failed: ", ce->action, ce->np, ce->prop);
+		return ret;
+	}
+
+	return 0;
+}
+
+static inline int __of_changeset_entry_revert(const struct of_changeset_entry *ce)
+{
+	struct of_changeset_entry ce_inverted;
+
+	__of_changeset_entry_invert(ce, &ce_inverted);
+	return __of_changeset_entry_apply(&ce_inverted);
+}
+
+/**
+ * of_changeset_init - Initialize a changeset for use
+ *
+ * @ocs:	changeset pointer
+ *
+ * Initialize a changeset structure
+ */
+void of_changeset_init(struct of_changeset *ocs)
+{
+	memset(ocs, 0, sizeof(*ocs));
+	INIT_LIST_HEAD(&ocs->entries);
+}
+EXPORT_SYMBOL_GPL(of_changeset_init);
+
+/**
+ * of_changeset_destroy - Destroy a changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Destroys a changeset. Note that if a changeset is applied,
+ * its changes to the tree cannot be reverted.
+ */
+void of_changeset_destroy(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce, *cen;
+
+	/*
+	 * When a device is deleted, the device links to/from it are also queued
+	 * for deletion. Until these device links are freed, the devices
+	 * themselves aren't freed. If the device being deleted is due to an
+	 * overlay change, this device might be holding a reference to a device
+	 * node that will be freed. So, wait until all already pending device
+	 * links are deleted before freeing a device node. This ensures we don't
+	 * free any device node that has a non-zero reference count.
+	 */
+	device_link_wait_removal();
+
+	list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
+		__of_changeset_entry_destroy(ce);
+}
+EXPORT_SYMBOL_GPL(of_changeset_destroy);
+
+/*
+ * Apply the changeset entries in @ocs.
+ * If apply fails, an attempt is made to revert the entries that were
+ * successfully applied.
+ *
+ * If multiple revert errors occur then only the final revert error is reported.
+ *
+ * Returns 0 on success, a negative error value in case of an error.
+ * If a revert error occurs, it is returned in *ret_revert.
+ */
+int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert)
+{
+	struct of_changeset_entry *ce;
+	int ret, ret_tmp;
+
+	pr_debug("changeset: applying...\n");
+	list_for_each_entry(ce, &ocs->entries, node) {
+		ret = __of_changeset_entry_apply(ce);
+		if (ret) {
+			pr_err("Error applying changeset (%d)\n", ret);
+			list_for_each_entry_continue_reverse(ce, &ocs->entries,
+							     node) {
+				ret_tmp = __of_changeset_entry_revert(ce);
+				if (ret_tmp)
+					*ret_revert = ret_tmp;
+			}
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Returns 0 on success, a negative error value in case of an error.
+ *
+ * If multiple changeset entry notification errors occur then only the
+ * final notification error is reported.
+ */
+int __of_changeset_apply_notify(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce;
+	int ret = 0, ret_tmp;
+
+	pr_debug("changeset: emitting notifiers.\n");
+
+	/* drop the global lock while emitting notifiers */
+	mutex_unlock(&of_mutex);
+	list_for_each_entry(ce, &ocs->entries, node) {
+		ret_tmp = __of_changeset_entry_notify(ce, 0);
+		if (ret_tmp)
+			ret = ret_tmp;
+	}
+	mutex_lock(&of_mutex);
+	pr_debug("changeset: notifiers sent.\n");
+
+	return ret;
+}
+
+/*
+ * Returns 0 on success, a negative error value in case of an error.
+ *
+ * If a changeset entry apply fails, an attempt is made to revert any
+ * previous entries in the changeset.  If any of the reverts fails,
+ * that failure is not reported.  Thus the state of the device tree
+ * is unknown if an apply error occurs.
+ */
+static int __of_changeset_apply(struct of_changeset *ocs)
+{
+	int ret, ret_revert = 0;
+
+	ret = __of_changeset_apply_entries(ocs, &ret_revert);
+	if (!ret)
+		ret = __of_changeset_apply_notify(ocs);
+
+	return ret;
+}
+
+/**
+ * of_changeset_apply - Applies a changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Applies a changeset to the live tree.
+ * Any side-effects of live tree state changes are applied here on
+ * success, like creation/destruction of devices and side-effects
+ * like creation of sysfs properties and directories.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ * On error the partially applied effects are reverted.
+ */
+int of_changeset_apply(struct of_changeset *ocs)
+{
+	int ret;
+
+	mutex_lock(&of_mutex);
+	ret = __of_changeset_apply(ocs);
+	mutex_unlock(&of_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_apply);
+
+/*
+ * Revert the changeset entries in @ocs.
+ * If revert fails, an attempt is made to re-apply the entries that were
+ * successfully removed.
+ *
+ * If multiple re-apply errors occur then only the final apply error is
+ * reported.
+ *
+ * Returns 0 on success, a negative error value in case of an error.
+ * If an apply error occurs, it is returned in *ret_apply.
+ */
+int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply)
+{
+	struct of_changeset_entry *ce;
+	int ret, ret_tmp;
+
+	pr_debug("changeset: reverting...\n");
+	list_for_each_entry_reverse(ce, &ocs->entries, node) {
+		ret = __of_changeset_entry_revert(ce);
+		if (ret) {
+			pr_err("Error reverting changeset (%d)\n", ret);
+			list_for_each_entry_continue(ce, &ocs->entries, node) {
+				ret_tmp = __of_changeset_entry_apply(ce);
+				if (ret_tmp)
+					*ret_apply = ret_tmp;
+			}
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * If multiple changeset entry notification errors occur then only the
+ * final notification error is reported.
+ */
+int __of_changeset_revert_notify(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce;
+	int ret = 0, ret_tmp;
+
+	pr_debug("changeset: emitting notifiers.\n");
+
+	/* drop the global lock while emitting notifiers */
+	mutex_unlock(&of_mutex);
+	list_for_each_entry_reverse(ce, &ocs->entries, node) {
+		ret_tmp = __of_changeset_entry_notify(ce, 1);
+		if (ret_tmp)
+			ret = ret_tmp;
+	}
+	mutex_lock(&of_mutex);
+	pr_debug("changeset: notifiers sent.\n");
+
+	return ret;
+}
+
+static int __of_changeset_revert(struct of_changeset *ocs)
+{
+	int ret, ret_reply;
+
+	ret_reply = 0;
+	ret = __of_changeset_revert_entries(ocs, &ret_reply);
+
+	if (!ret)
+		ret = __of_changeset_revert_notify(ocs);
+
+	return ret;
+}
+
+/**
+ * of_changeset_revert - Reverts an applied changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Reverts a changeset returning the state of the tree to what it
+ * was before the application.
+ * Any side-effects like creation/destruction of devices and
+ * removal of sysfs properties and directories are applied.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_revert(struct of_changeset *ocs)
+{
+	int ret;
+
+	mutex_lock(&of_mutex);
+	ret = __of_changeset_revert(ocs);
+	mutex_unlock(&of_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_revert);
+
+/**
+ * of_changeset_action - Add an action to the tail of the changeset list
+ *
+ * @ocs:	changeset pointer
+ * @action:	action to perform
+ * @np:		Pointer to device node
+ * @prop:	Pointer to property
+ *
+ * On action being one of:
+ * + OF_RECONFIG_ATTACH_NODE
+ * + OF_RECONFIG_DETACH_NODE,
+ * + OF_RECONFIG_ADD_PROPERTY
+ * + OF_RECONFIG_REMOVE_PROPERTY,
+ * + OF_RECONFIG_UPDATE_PROPERTY
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_action(struct of_changeset *ocs, unsigned long action,
+		struct device_node *np, struct property *prop)
+{
+	struct of_changeset_entry *ce;
+
+	if (WARN_ON(action >= ARRAY_SIZE(action_names)))
+		return -EINVAL;
+
+	ce = kzalloc_obj(*ce);
+	if (!ce)
+		return -ENOMEM;
+
+	/* get a reference to the node */
+	ce->action = action;
+	ce->np = of_node_get(np);
+	ce->prop = prop;
+
+	/* add it to the list */
+	list_add_tail(&ce->node, &ocs->entries);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_changeset_action);
+
+static int of_changeset_add_prop_helper(struct of_changeset *ocs,
+					struct device_node *np,
+					const struct property *pp)
+{
+	struct property *new_pp;
+	int ret;
+
+	new_pp = __of_prop_dup(pp, GFP_KERNEL);
+	if (!new_pp)
+		return -ENOMEM;
+
+	ret = of_changeset_add_property(ocs, np, new_pp);
+	if (ret) {
+		__of_prop_free(new_pp);
+		return ret;
+	}
+
+	new_pp->next = np->deadprops;
+	np->deadprops = new_pp;
+
+	return 0;
+}
+
+/**
+ * of_changeset_add_prop_string - Add a string property to a changeset
+ *
+ * @ocs:	changeset pointer
+ * @np:		device node pointer
+ * @prop_name:	name of the property to be added
+ * @str:	pointer to null terminated string
+ *
+ * Create a string property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string(struct of_changeset *ocs,
+				 struct device_node *np,
+				 const char *prop_name, const char *str)
+{
+	struct property prop;
+
+	prop.name = (char *)prop_name;
+	prop.length = strlen(str) + 1;
+	prop.value = (void *)str;
+
+	return of_changeset_add_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string);
+
+/**
+ * of_changeset_add_prop_string_array - Add a string list property to
+ * a changeset
+ *
+ * @ocs:	changeset pointer
+ * @np:		device node pointer
+ * @prop_name:	name of the property to be added
+ * @str_array:	pointer to an array of null terminated strings
+ * @sz:		number of string array elements
+ *
+ * Create a string list property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string_array(struct of_changeset *ocs,
+				       struct device_node *np,
+				       const char *prop_name,
+				       const char * const *str_array, size_t sz)
+{
+	struct property prop;
+	int i, ret;
+	char *vp;
+
+	prop.name = (char *)prop_name;
+
+	prop.length = 0;
+	for (i = 0; i < sz; i++)
+		prop.length += strlen(str_array[i]) + 1;
+
+	prop.value = kmalloc(prop.length, GFP_KERNEL);
+	if (!prop.value)
+		return -ENOMEM;
+
+	vp = prop.value;
+	for (i = 0; i < sz; i++) {
+		vp += snprintf(vp, (char *)prop.value + prop.length - vp, "%s",
+			       str_array[i]) + 1;
+	}
+	ret = of_changeset_add_prop_helper(ocs, np, &prop);
+	kfree(prop.value);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string_array);
+
+/**
+ * of_changeset_add_prop_u32_array - Add a property of 32 bit integers
+ * property to a changeset
+ *
+ * @ocs:	changeset pointer
+ * @np:		device node pointer
+ * @prop_name:	name of the property to be added
+ * @array:	pointer to an array of 32 bit integers
+ * @sz:		number of array elements
+ *
+ * Create a property of 32 bit integers and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
+				    struct device_node *np,
+				    const char *prop_name,
+				    const u32 *array, size_t sz)
+{
+	struct property prop;
+	__be32 *val __free(kfree) = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
+	int i;
+
+	if (!val)
+		return -ENOMEM;
+
+	for (i = 0; i < sz; i++)
+		val[i] = cpu_to_be32(array[i]);
+	prop.name = (char *)prop_name;
+	prop.length = sizeof(u32) * sz;
+	prop.value = (void *)val;
+
+	return of_changeset_add_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
+
+/**
+ * of_changeset_add_prop_bool - Add a boolean property (i.e. a property without
+ * any values) to a changeset.
+ *
+ * @ocs:	changeset pointer
+ * @np:		device node pointer
+ * @prop_name:	name of the property to be added
+ *
+ * Create a boolean property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_bool(struct of_changeset *ocs, struct device_node *np,
+			       const char *prop_name)
+{
+	struct property prop;
+
+	prop.name = (char *)prop_name;
+	prop.length = 0;
+	prop.value = NULL;
+
+	return of_changeset_add_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_bool);
+
+static int of_changeset_update_prop_helper(struct of_changeset *ocs,
+					   struct device_node *np,
+					   const struct property *pp)
+{
+	struct property *new_pp;
+	int ret;
+
+	new_pp = __of_prop_dup(pp, GFP_KERNEL);
+	if (!new_pp)
+		return -ENOMEM;
+
+	ret = of_changeset_update_property(ocs, np, new_pp);
+	if (ret)
+		__of_prop_free(new_pp);
+
+	return ret;
+}
+
+/**
+ * of_changeset_update_prop_string - Add a string property update to a changeset
+ *
+ * @ocs:	changeset pointer
+ * @np:		device node pointer
+ * @prop_name:	name of the property to be updated
+ * @str:	pointer to null terminated string
+ *
+ * Create a string property to be updated and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_update_prop_string(struct of_changeset *ocs,
+				    struct device_node *np,
+				    const char *prop_name, const char *str)
+{
+	struct property prop = {
+		.name = (char *)prop_name,
+		.length = strlen(str) + 1,
+		.value = (void *)str,
+	};
+
+	return of_changeset_update_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_update_prop_string);
diff --git a/drivers/of/empty_root.dts b/drivers/of/empty_root.dts
new file mode 100644
index 000000000..cbe169ba3
--- /dev/null
+++ b/drivers/of/empty_root.dts
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/dts-v1/;
+
+/ {
+	/*
+	 * #address-cells/#size-cells are required properties at root node.
+	 * Use 2 cells for both address cells and size cells in order to fully
+	 * support 64-bit addresses and sizes on systems using this empty root
+	 * node.
+	 */
+	#address-cells = <0x02>;
+	#size-cells = <0x02>;
+};
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
new file mode 100644
index 000000000..a64afc3de
--- /dev/null
+++ b/drivers/of/fdt.c
@@ -0,0 +1,1350 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for working with the Flattened Device Tree data format
+ *
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh@kernel.crashing.org
+ */
+
+#define pr_fmt(fmt)	"OF: fdt: " fmt
+
+#include <linux/crash_dump.h>
+#include <linux/crc32.h>
+#include <linux/kernel.h>
+#include <linux/initrd.h>
+#include <linux/memblock.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/libfdt.h>
+#include <linux/debugfs.h>
+#include <linux/serial_core.h>
+#include <linux/sysfs.h>
+#include <linux/random.h>
+#include <linux/kexec_handover.h>
+
+#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
+#include <asm/page.h>
+
+#include "of_private.h"
+
+/*
+ * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
+ * cmd_wrap_S_dtb in scripts/Makefile.dtbs
+ */
+extern uint8_t __dtb_empty_root_begin[];
+extern uint8_t __dtb_empty_root_end[];
+
+/*
+ * of_fdt_limit_memory - limit the number of regions in the /memory node
+ * @limit: maximum entries
+ *
+ * Adjust the flattened device tree to have at most 'limit' number of
+ * memory entries in the /memory node. This function may be called
+ * any time after initial_boot_param is set.
+ */
+void __init of_fdt_limit_memory(int limit)
+{
+	int memory;
+	int len;
+	const void *val;
+	int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells);
+
+	memory = fdt_path_offset(initial_boot_params, "/memory");
+	if (memory > 0) {
+		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
+		if (len > limit*cell_size) {
+			len = limit*cell_size;
+			pr_debug("Limiting number of entries to %d\n", limit);
+			fdt_setprop(initial_boot_params, memory, "reg", val,
+					len);
+		}
+	}
+}
+
+bool of_fdt_device_is_available(const void *blob, unsigned long node)
+{
+	const char *status = fdt_stringlist_get(blob, node, "status", 0, NULL);
+
+	if (!status)
+		return true;
+
+	if (!strcmp(status, "ok") || !strcmp(status, "okay"))
+		return true;
+
+	return false;
+}
+
+static void *unflatten_dt_alloc(void **mem, unsigned long size,
+				       unsigned long align)
+{
+	void *res;
+
+	*mem = PTR_ALIGN(*mem, align);
+	res = *mem;
+	*mem += size;
+
+	return res;
+}
+
+static void populate_properties(const void *blob,
+				int offset,
+				void **mem,
+				struct device_node *np,
+				const char *nodename,
+				bool dryrun)
+{
+	struct property *pp, **pprev = NULL;
+	int cur;
+	bool has_name = false;
+
+	pprev = &np->properties;
+	for (cur = fdt_first_property_offset(blob, offset);
+	     cur >= 0;
+	     cur = fdt_next_property_offset(blob, cur)) {
+		const __be32 *val;
+		const char *pname;
+		u32 sz;
+
+		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
+		if (!val) {
+			pr_warn("Cannot locate property at 0x%x\n", cur);
+			continue;
+		}
+
+		if (!pname) {
+			pr_warn("Cannot find property name at 0x%x\n", cur);
+			continue;
+		}
+
+		if (!strcmp(pname, "name"))
+			has_name = true;
+
+		pp = unflatten_dt_alloc(mem, sizeof(struct property),
+					__alignof__(struct property));
+		if (dryrun)
+			continue;
+
+		/* We accept flattened tree phandles either in
+		 * ePAPR-style "phandle" properties, or the
+		 * legacy "linux,phandle" properties.  If both
+		 * appear and have different values, things
+		 * will get weird. Don't do that.
+		 */
+		if (!strcmp(pname, "phandle") ||
+		    !strcmp(pname, "linux,phandle")) {
+			if (!np->phandle)
+				np->phandle = be32_to_cpup(val);
+		}
+
+		/* And we process the "ibm,phandle" property
+		 * used in pSeries dynamic device tree
+		 * stuff
+		 */
+		if (IS_ENABLED(CONFIG_PPC_PSERIES) && !strcmp(pname, "ibm,phandle"))
+			np->phandle = be32_to_cpup(val);
+
+		pp->name   = (char *)pname;
+		pp->length = sz;
+		pp->value  = (__be32 *)val;
+		*pprev     = pp;
+		pprev      = &pp->next;
+	}
+
+	/* With version 0x10 we may not have the name property,
+	 * recreate it here from the unit name if absent
+	 */
+	if (!has_name) {
+		const char *p = nodename, *ps = p, *pa = NULL;
+		int len;
+
+		while (*p) {
+			if ((*p) == '@')
+				pa = p;
+			else if ((*p) == '/')
+				ps = p + 1;
+			p++;
+		}
+
+		if (pa < ps)
+			pa = p;
+		len = (pa - ps) + 1;
+		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
+					__alignof__(struct property));
+		if (!dryrun) {
+			pp->name   = "name";
+			pp->length = len;
+			pp->value  = pp + 1;
+			*pprev     = pp;
+			memcpy(pp->value, ps, len - 1);
+			((char *)pp->value)[len - 1] = 0;
+			pr_debug("fixed up name for %s -> %s\n",
+				 nodename, (char *)pp->value);
+		}
+	}
+}
+
+static int populate_node(const void *blob,
+			  int offset,
+			  void **mem,
+			  struct device_node *dad,
+			  struct device_node **pnp,
+			  bool dryrun)
+{
+	struct device_node *np;
+	const char *pathp;
+	int len;
+
+	pathp = fdt_get_name(blob, offset, &len);
+	if (!pathp) {
+		*pnp = NULL;
+		return len;
+	}
+
+	len++;
+
+	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
+				__alignof__(struct device_node));
+	if (!dryrun) {
+		char *fn;
+		of_node_init(np);
+		np->full_name = fn = ((char *)np) + sizeof(*np);
+
+		memcpy(fn, pathp, len);
+
+		if (dad != NULL) {
+			np->parent = dad;
+			np->sibling = dad->child;
+			dad->child = np;
+		}
+	}
+
+	populate_properties(blob, offset, mem, np, pathp, dryrun);
+	if (!dryrun) {
+		np->name = of_get_property(np, "name", NULL);
+		if (!np->name)
+			np->name = "<NULL>";
+	}
+
+	*pnp = np;
+	return 0;
+}
+
+static void reverse_nodes(struct device_node *parent)
+{
+	struct device_node *child, *next;
+
+	/* In-depth first */
+	child = parent->child;
+	while (child) {
+		reverse_nodes(child);
+
+		child = child->sibling;
+	}
+
+	/* Reverse the nodes in the child list */
+	child = parent->child;
+	parent->child = NULL;
+	while (child) {
+		next = child->sibling;
+
+		child->sibling = parent->child;
+		parent->child = child;
+		child = next;
+	}
+}
+
+/**
+ * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
+ * @blob: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @dad: Parent struct device_node
+ * @nodepp: The device_node tree created by the call
+ *
+ * Return: The size of unflattened device tree or error code
+ */
+static int unflatten_dt_nodes(const void *blob,
+			      void *mem,
+			      struct device_node *dad,
+			      struct device_node **nodepp)
+{
+	struct device_node *root;
+	int offset = 0, depth = 0, initial_depth = 0;
+#define FDT_MAX_DEPTH	64
+	struct device_node *nps[FDT_MAX_DEPTH];
+	void *base = mem;
+	bool dryrun = !base;
+	int ret;
+
+	if (nodepp)
+		*nodepp = NULL;
+
+	/*
+	 * We're unflattening device sub-tree if @dad is valid. There are
+	 * possibly multiple nodes in the first level of depth. We need
+	 * set @depth to 1 to make fdt_next_node() happy as it bails
+	 * immediately when negative @depth is found. Otherwise, the device
+	 * nodes except the first one won't be unflattened successfully.
+	 */
+	if (dad)
+		depth = initial_depth = 1;
+
+	root = dad;
+	nps[depth] = dad;
+
+	for (offset = 0;
+	     offset >= 0 && depth >= initial_depth;
+	     offset = fdt_next_node(blob, offset, &depth)) {
+		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
+			continue;
+
+		if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
+		    !of_fdt_device_is_available(blob, offset))
+			continue;
+
+		ret = populate_node(blob, offset, &mem, nps[depth],
+				   &nps[depth+1], dryrun);
+		if (ret < 0)
+			return ret;
+
+		if (!dryrun && nodepp && !*nodepp)
+			*nodepp = nps[depth+1];
+		if (!dryrun && !root)
+			root = nps[depth+1];
+	}
+
+	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
+		pr_err("Error %d processing FDT\n", offset);
+		return -EINVAL;
+	}
+
+	/*
+	 * Reverse the child list. Some drivers assumes node order matches .dts
+	 * node order
+	 */
+	if (!dryrun)
+		reverse_nodes(root);
+
+	return mem - base;
+}
+
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ * @blob: The blob to expand
+ * @dad: Parent device node
+ * @mynodes: The device_node tree created by the call
+ * @dt_alloc: An allocator that provides a virtual address to memory
+ * for the resulting tree
+ * @detached: if true set OF_DETACHED on @mynodes
+ *
+ * unflattens a device-tree, creating the tree of struct device_node. It also
+ * fills the "name" and "type" pointers of the nodes so the normal device-tree
+ * walking functions can be used.
+ *
+ * Return: NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
+ */
+void *__unflatten_device_tree(const void *blob,
+			      struct device_node *dad,
+			      struct device_node **mynodes,
+			      void *(*dt_alloc)(u64 size, u64 align),
+			      bool detached)
+{
+	int size;
+	void *mem;
+	int ret;
+
+	if (mynodes)
+		*mynodes = NULL;
+
+	pr_debug(" -> unflatten_device_tree()\n");
+
+	if (!blob) {
+		pr_debug("No device tree pointer\n");
+		return NULL;
+	}
+
+	pr_debug("Unflattening device tree:\n");
+	pr_debug("magic: %08x\n", fdt_magic(blob));
+	pr_debug("size: %08x\n", fdt_totalsize(blob));
+	pr_debug("version: %08x\n", fdt_version(blob));
+
+	if (fdt_check_header(blob)) {
+		pr_err("Invalid device tree blob header\n");
+		return NULL;
+	}
+
+	/* First pass, scan for size */
+	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
+	if (size <= 0)
+		return NULL;
+
+	size = ALIGN(size, 4);
+	pr_debug("  size is %d, allocating...\n", size);
+
+	/* Allocate memory for the expanded device tree */
+	mem = dt_alloc(size + 4, __alignof__(struct device_node));
+	if (!mem)
+		return NULL;
+
+	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
+
+	pr_debug("  unflattening %p...\n", mem);
+
+	/* Second pass, do actual unflattening */
+	ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
+
+	if (be32_to_cpup(mem + size) != 0xdeadbeef)
+		pr_warn("End of tree marker overwritten: %08x\n",
+			be32_to_cpup(mem + size));
+
+	if (ret <= 0)
+		return NULL;
+
+	if (detached && mynodes && *mynodes) {
+		of_node_set_flag(*mynodes, OF_DETACHED);
+		pr_debug("unflattened tree is detached\n");
+	}
+
+	pr_debug(" <- unflatten_device_tree()\n");
+	return mem;
+}
+
+static void *kernel_tree_alloc(u64 size, u64 align)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+static DEFINE_MUTEX(of_fdt_unflatten_mutex);
+
+/**
+ * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
+ * @blob: Flat device tree blob
+ * @dad: Parent device node
+ * @mynodes: The device tree created by the call
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ *
+ * Return: NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
+ */
+void *of_fdt_unflatten_tree(const unsigned long *blob,
+			    struct device_node *dad,
+			    struct device_node **mynodes)
+{
+	void *mem;
+
+	mutex_lock(&of_fdt_unflatten_mutex);
+	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
+				      true);
+	mutex_unlock(&of_fdt_unflatten_mutex);
+
+	return mem;
+}
+EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+
+/* Everything below here references initial_boot_params directly. */
+int __initdata dt_root_addr_cells;
+int __initdata dt_root_size_cells;
+
+void *initial_boot_params __ro_after_init;
+phys_addr_t initial_boot_params_pa __ro_after_init;
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+static u32 of_fdt_crc32;
+
+/*
+ * fdt_reserve_elfcorehdr() - reserves memory for elf core header
+ *
+ * This function reserves the memory occupied by an elf core header
+ * described in the device tree. This region contains all the
+ * information about primary kernel's core image and is used by a dump
+ * capture kernel to access the system memory on primary kernel.
+ */
+static void __init fdt_reserve_elfcorehdr(void)
+{
+	if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
+		return;
+
+	if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
+		pr_warn("elfcorehdr is overlapped\n");
+		return;
+	}
+
+	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
+
+	pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
+		elfcorehdr_size >> 10, elfcorehdr_addr);
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+	int n;
+	int res;
+	u64 base, size;
+
+	if (!initial_boot_params)
+		return;
+
+	fdt_reserve_elfcorehdr();
+	fdt_scan_reserved_mem();
+
+	/* Process header /memreserve/ fields */
+	for (n = 0; ; n++) {
+		res = fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
+		if (res) {
+			pr_err("Invalid memory reservation block index %d\n", n);
+			break;
+		}
+		if (!size)
+			break;
+		memblock_reserve(base, size);
+	}
+}
+
+/**
+ * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
+ */
+void __init early_init_fdt_reserve_self(void)
+{
+	if (!initial_boot_params)
+		return;
+
+	/* Reserve the dtb region */
+	memblock_reserve(__pa(initial_boot_params),
+			 fdt_totalsize(initial_boot_params));
+}
+
+/**
+ * of_scan_flat_dt - scan flattened tree blob and call callback on each.
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree, it is
+ * used to extract the memory information at boot before we can
+ * unflatten the tree
+ */
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+				     const char *uname, int depth,
+				     void *data),
+			   void *data)
+{
+	const void *blob = initial_boot_params;
+	const char *pathp;
+	int offset, rc = 0, depth = -1;
+
+	if (!blob)
+		return 0;
+
+	for (offset = fdt_next_node(blob, -1, &depth);
+	     offset >= 0 && depth >= 0 && !rc;
+	     offset = fdt_next_node(blob, offset, &depth)) {
+
+		pathp = fdt_get_name(blob, offset, NULL);
+		rc = it(offset, pathp, depth, data);
+	}
+	return rc;
+}
+
+/**
+ * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
+ * @parent: parent node
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan sub-nodes of a node.
+ */
+int __init of_scan_flat_dt_subnodes(unsigned long parent,
+				    int (*it)(unsigned long node,
+					      const char *uname,
+					      void *data),
+				    void *data)
+{
+	const void *blob = initial_boot_params;
+	int node;
+
+	fdt_for_each_subnode(node, blob, parent) {
+		const char *pathp;
+		int rc;
+
+		pathp = fdt_get_name(blob, node, NULL);
+		rc = it(node, pathp, data);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+/**
+ * of_get_flat_dt_subnode_by_name - get the subnode by given name
+ *
+ * @node: the parent node
+ * @uname: the name of subnode
+ * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
+ */
+
+int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
+{
+	return fdt_subnode_offset(initial_boot_params, node, uname);
+}
+
+/*
+ * of_get_flat_dt_root - find the root node in the flat blob
+ */
+unsigned long __init of_get_flat_dt_root(void)
+{
+	return 0;
+}
+
+/*
+ * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
+ *
+ * This function can be used within scan_flattened_dt callback to get
+ * access to properties
+ */
+const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
+				       int *size)
+{
+	return fdt_getprop(initial_boot_params, node, name, size);
+}
+
+const __be32 *__init of_flat_dt_get_addr_size_prop(unsigned long node,
+						   const char *name,
+						   int *entries)
+{
+	const __be32 *prop;
+	int len, elen = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+
+	prop = of_get_flat_dt_prop(node, name, &len);
+	if (!prop || len % elen) {
+		*entries = 0;
+		return NULL;
+	}
+
+	*entries = len / elen;
+	return prop;
+}
+
+bool __init of_flat_dt_get_addr_size(unsigned long node, const char *name,
+				     u64 *addr, u64 *size)
+{
+	const __be32 *prop;
+	int entries;
+
+	prop = of_flat_dt_get_addr_size_prop(node, name, &entries);
+	if (!prop || entries != 1)
+		return false;
+
+	of_flat_dt_read_addr_size(prop, 0, addr, size);
+	return true;
+}
+
+void __init of_flat_dt_read_addr_size(const __be32 *prop, int entry_index,
+				      u64 *addr, u64 *size)
+{
+	int entry_cells = dt_root_addr_cells + dt_root_size_cells;
+	prop += entry_cells * entry_index;
+
+	*addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	*size = dt_mem_next_cell(dt_root_size_cells, &prop);
+}
+
+/**
+ * of_fdt_is_compatible - Return true if given node from the given blob has
+ * compat in its compatible list
+ * @blob: A device tree blob
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ *
+ * Return: a non-zero value on match with smaller values returned for more
+ * specific compatible values.
+ */
+static int of_fdt_is_compatible(const void *blob,
+			      unsigned long node, const char *compat)
+{
+	const char *cp;
+	int idx = 0, score = 0;
+
+	while ((cp = fdt_stringlist_get(blob, node, "compatible", idx++, NULL))) {
+		score++;
+		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+			return score;
+	}
+
+	return 0;
+}
+
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	return of_fdt_is_compatible(initial_boot_params, node, compat);
+}
+
+/*
+ * of_flat_dt_match - Return true if node matches a list of compatible values
+ */
+static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
+		if (tmp && (score == 0 || (tmp < score)))
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+
+/*
+ * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
+ */
+uint32_t __init of_get_flat_dt_phandle(unsigned long node)
+{
+	return fdt_get_phandle(initial_boot_params, node);
+}
+
+const char * __init of_flat_dt_get_machine_name(void)
+{
+	const char *name;
+	unsigned long dt_root = of_get_flat_dt_root();
+
+	name = fdt_stringlist_get(initial_boot_params, dt_root, "model", 0, NULL);
+	if (!name)
+		name = fdt_stringlist_get(initial_boot_params, dt_root,
+					  "compatible", 0, NULL);
+	return name;
+}
+
+/**
+ * of_flat_dt_match_machine - Iterate match tables to find matching machine.
+ *
+ * @default_match: A machine specific ptr to return in case of no match.
+ * @get_next_compat: callback function to return next compatible match table.
+ *
+ * Iterate through machine match tables to find the best match for the machine
+ * compatible string in the FDT.
+ */
+const void * __init of_flat_dt_match_machine(const void *default_match,
+		const void * (*get_next_compat)(const char * const**))
+{
+	const void *data = NULL;
+	const void *best_data = default_match;
+	const char *const *compat;
+	unsigned long dt_root;
+	unsigned int best_score = ~1, score = 0;
+
+	dt_root = of_get_flat_dt_root();
+	while ((data = get_next_compat(&compat))) {
+		score = of_flat_dt_match(dt_root, compat);
+		if (score > 0 && score < best_score) {
+			best_data = data;
+			best_score = score;
+		}
+	}
+	if (!best_data) {
+		const char *prop;
+		int idx = 0, size;
+
+		pr_err("\n unrecognized device tree list:\n[ ");
+
+		while ((prop = fdt_stringlist_get(initial_boot_params, dt_root,
+						  "compatible", idx++, &size)))
+			pr_err("'%s' ", prop);
+		pr_err("]\n\n");
+		return NULL;
+	}
+
+	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
+
+	return best_data;
+}
+
+static void __early_init_dt_declare_initrd(unsigned long start,
+					   unsigned long end)
+{
+	/*
+	 * __va() is not yet available this early on some platforms. In that
+	 * case, the platform uses phys_initrd_start/phys_initrd_size instead
+	 * and does the VA conversion itself.
+	 */
+	if (!IS_ENABLED(CONFIG_ARM64) &&
+	    !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
+		initrd_start = (unsigned long)__va(start);
+		initrd_end = (unsigned long)__va(end);
+		initrd_below_start_ok = 1;
+	}
+}
+
+/**
+ * early_init_dt_check_for_initrd - Decode initrd location from flat tree
+ * @node: reference to node containing initrd location ('chosen')
+ */
+static void __init early_init_dt_check_for_initrd(unsigned long node)
+{
+	u64 start, end;
+	int len;
+	const __be32 *prop;
+
+	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
+		return;
+
+	pr_debug("Looking for initrd properties... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
+	if (!prop)
+		return;
+	start = of_read_number(prop, len/4);
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
+	if (!prop)
+		return;
+	end = of_read_number(prop, len/4);
+	if (start > end)
+		return;
+
+	__early_init_dt_declare_initrd(start, end);
+	phys_initrd_start = start;
+	phys_initrd_size = end - start;
+
+	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n", start, end);
+}
+
+/**
+ * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
+ * tree
+ * @node: reference to node containing elfcorehdr location ('chosen')
+ */
+static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
+{
+	if (!IS_ENABLED(CONFIG_CRASH_DUMP))
+		return;
+
+	pr_debug("Looking for elfcorehdr property... ");
+
+	if (!of_flat_dt_get_addr_size(node, "linux,elfcorehdr",
+				      &elfcorehdr_addr, &elfcorehdr_size))
+		return;
+
+	pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
+		 elfcorehdr_addr, elfcorehdr_size);
+}
+
+static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node)
+{
+	const char *prop_name = "linux,dmcryptkeys";
+	const __be32 *prop;
+
+	if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT))
+		return;
+
+	pr_debug("Looking for dmcryptkeys property... ");
+
+	prop = of_get_flat_dt_prop(node, prop_name, NULL);
+	if (!prop)
+		return;
+
+	dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+
+	/* Property only accessible to crash dump kernel */
+	fdt_delprop(initial_boot_params, node, prop_name);
+}
+
+static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
+
+/*
+ * The main usage of linux,usable-memory-range is for crash dump kernel.
+ * Originally, the number of usable-memory regions is one. Now there may
+ * be 2 + CRASHK_CMA_RANGES_MAX regions, low region, high region and cma
+ * regions. To make compatibility with existing user-space and older kdump,
+ * the high and low region are always the first two ranges of
+ * linux,usable-memory-range if exist.
+ */
+#define MAX_USABLE_RANGES		(2 + CRASHK_CMA_RANGES_MAX)
+
+/**
+ * early_init_dt_check_for_usable_mem_range - Decode usable memory range
+ * location from flat tree
+ */
+void __init early_init_dt_check_for_usable_mem_range(void)
+{
+	struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
+	const __be32 *prop;
+	int len, i;
+	u64 base, size;
+	unsigned long node = chosen_node_offset;
+
+	if ((long)node < 0)
+		return;
+
+	pr_debug("Looking for usable-memory-range property... ");
+
+	prop = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory-range",
+					     &len);
+	if (!prop)
+		return;
+
+	len = min(len, MAX_USABLE_RANGES);
+
+	for (i = 0; i < len; i++) {
+		of_flat_dt_read_addr_size(prop, i, &base, &size);
+		rgn[i].base = base;
+		rgn[i].size = size;
+
+		pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
+			 i, &rgn[i].base, &rgn[i].size);
+	}
+
+	memblock_cap_memory_range(rgn[0].base, rgn[0].size);
+	for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
+		memblock_add(rgn[i].base, rgn[i].size);
+}
+
+/**
+ * early_init_dt_check_kho - Decode info required for kexec handover from DT
+ */
+static void __init early_init_dt_check_kho(void)
+{
+	unsigned long node = chosen_node_offset;
+	u64 fdt_start, fdt_size, scratch_start, scratch_size;
+
+	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0)
+		return;
+
+	if (!of_flat_dt_get_addr_size(node, "linux,kho-fdt",
+				      &fdt_start, &fdt_size))
+		return;
+
+	if (!of_flat_dt_get_addr_size(node, "linux,kho-scratch",
+				      &scratch_start, &scratch_size))
+		return;
+
+	kho_populate(fdt_start, fdt_size, scratch_start, scratch_size);
+}
+
+#ifdef CONFIG_SERIAL_EARLYCON
+
+int __init early_init_dt_scan_chosen_stdout(void)
+{
+	int offset;
+	const char *p, *q, *options = NULL;
+	int l;
+	const struct earlycon_id *match;
+	const void *fdt = initial_boot_params;
+	int ret;
+
+	offset = fdt_path_offset(fdt, "/chosen");
+	if (offset < 0)
+		offset = fdt_path_offset(fdt, "/chosen@0");
+	if (offset < 0)
+		return -ENOENT;
+
+	p = fdt_stringlist_get(fdt, offset, "stdout-path", 0, &l);
+	if (!p)
+		p = fdt_stringlist_get(fdt, offset, "linux,stdout-path", 0, &l);
+	if (!p || !l)
+		return -ENOENT;
+
+	q = strchrnul(p, ':');
+	if (*q != '\0')
+		options = q + 1;
+	l = q - p;
+
+	/* Get the node specified by stdout-path */
+	offset = fdt_path_offset_namelen(fdt, p, l);
+	if (offset < 0) {
+		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
+		return 0;
+	}
+
+	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
+		if (!match->compatible[0])
+			continue;
+
+		if (fdt_node_check_compatible(fdt, offset, match->compatible))
+			continue;
+
+		ret = of_setup_earlycon(match, offset, options);
+		if (!ret || ret == -EALREADY)
+			return 0;
+	}
+	return -ENODEV;
+}
+#endif
+
+/*
+ * early_init_dt_scan_root - fetch the top level address and size cells
+ */
+int __init early_init_dt_scan_root(void)
+{
+	const __be32 *prop;
+	const void *fdt = initial_boot_params;
+	int node = fdt_path_offset(fdt, "/");
+
+	if (node < 0)
+		return -ENODEV;
+
+	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!WARN(!prop, "No '#size-cells' in root node\n"))
+		dt_root_size_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!WARN(!prop, "No '#address-cells' in root node\n"))
+		dt_root_addr_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
+
+	return 0;
+}
+
+u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
+{
+	const __be32 *p = *cellp;
+
+	*cellp = p + s;
+	return of_read_number(p, s);
+}
+
+/*
+ * early_init_dt_scan_memory - Look for and parse memory nodes
+ */
+int __init early_init_dt_scan_memory(void)
+{
+	int node, found_memory = 0;
+	const void *fdt = initial_boot_params;
+
+	fdt_for_each_subnode(node, fdt, 0) {
+		const char *type = fdt_stringlist_get(fdt, node,
+						      "device_type", 0, NULL);
+		const __be32 *reg;
+		int i, l;
+		bool hotpluggable;
+
+		/* We are scanning "memory" nodes only */
+		if (type == NULL || strcmp(type, "memory") != 0)
+			continue;
+
+		if (!of_fdt_device_is_available(fdt, node))
+			continue;
+
+		reg = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory", &l);
+		if (reg == NULL)
+			reg = of_flat_dt_get_addr_size_prop(node, "reg", &l);
+		if (reg == NULL)
+			continue;
+
+		hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
+
+		pr_debug("memory scan node %s, reg {addr,size} entries %d,\n",
+			 fdt_get_name(fdt, node, NULL), l);
+
+		for (i = 0; i < l; i++) {
+			u64 base, size;
+
+			of_flat_dt_read_addr_size(reg, i, &base, &size);
+
+			if (size == 0)
+				continue;
+			pr_debug(" - %llx, %llx\n", base, size);
+
+			early_init_dt_add_memory_arch(base, size);
+
+			found_memory = 1;
+
+			if (!hotpluggable)
+				continue;
+
+			if (memblock_mark_hotplug(base, size))
+				pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
+					base, base + size);
+		}
+	}
+	return found_memory;
+}
+
+int __init early_init_dt_scan_chosen(char *cmdline)
+{
+	int l, node;
+	const char *p;
+	const void *rng_seed;
+	const void *fdt = initial_boot_params;
+
+	node = fdt_path_offset(fdt, "/chosen");
+	if (node < 0)
+		node = fdt_path_offset(fdt, "/chosen@0");
+	if (node < 0)
+		/* Handle the cmdline config options even if no /chosen node */
+		goto handle_cmdline;
+
+	chosen_node_offset = node;
+
+	early_init_dt_check_for_initrd(node);
+	early_init_dt_check_for_elfcorehdr(node);
+	early_init_dt_check_for_dmcryptkeys(node);
+
+	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
+	if (rng_seed && l > 0) {
+		add_bootloader_randomness(rng_seed, l);
+
+		/* try to clear seed so it won't be found. */
+		fdt_nop_property(initial_boot_params, node, "rng-seed");
+
+		/* update CRC check value */
+		of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
+	}
+
+	/* Retrieve command line */
+	p = of_get_flat_dt_prop(node, "bootargs", &l);
+	if (p != NULL && l > 0)
+		strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
+
+handle_cmdline:
+	/*
+	 * CONFIG_CMDLINE is meant to be a default in case nothing else
+	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
+	 * is set in which case we override whatever was found earlier.
+	 */
+#ifdef CONFIG_CMDLINE
+#if defined(CONFIG_CMDLINE_EXTEND)
+	strlcat(cmdline, " ", COMMAND_LINE_SIZE);
+	strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#elif defined(CONFIG_CMDLINE_FORCE)
+	strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#else
+	/* No arguments from boot loader, use kernel's  cmdl*/
+	if (!((char *)cmdline)[0])
+		strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#endif
+#endif /* CONFIG_CMDLINE */
+
+	pr_debug("Command line is: %s\n", (char *)cmdline);
+
+	return 0;
+}
+
+#ifndef MIN_MEMBLOCK_ADDR
+#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
+#endif
+#ifndef MAX_MEMBLOCK_ADDR
+#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
+#endif
+
+void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
+
+	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+
+	if (!PAGE_ALIGNED(base)) {
+		size -= PAGE_SIZE - (base & ~PAGE_MASK);
+		base = PAGE_ALIGN(base);
+	}
+	size &= PAGE_MASK;
+
+	if (base > MAX_MEMBLOCK_ADDR) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+
+	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
+		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
+			((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
+		size = MAX_MEMBLOCK_ADDR - base + 1;
+	}
+
+	if (base + size < phys_offset) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+	if (base < phys_offset) {
+		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
+			base, phys_offset);
+		size -= phys_offset - base;
+		base = phys_offset;
+	}
+	memblock_add(base, size);
+}
+
+static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return memblock_alloc_or_panic(size, align);
+}
+
+bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
+{
+	if (!dt_virt)
+		return false;
+
+	/* check device tree validity */
+	if (fdt_check_header(dt_virt))
+		return false;
+
+	/* Setup flat device-tree pointer */
+	initial_boot_params = dt_virt;
+	initial_boot_params_pa = dt_phys;
+	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
+
+	/* Initialize {size,address}-cells info */
+	early_init_dt_scan_root();
+
+	return true;
+}
+
+
+void __init early_init_dt_scan_nodes(void)
+{
+	int rc;
+
+	/* Retrieve various information from the /chosen node */
+	rc = early_init_dt_scan_chosen(boot_command_line);
+	if (rc)
+		pr_warn("No chosen node found, continuing without\n");
+
+	/* Setup memory, calling early_init_dt_add_memory_arch */
+	early_init_dt_scan_memory();
+
+	/* Handle linux,usable-memory-range property */
+	early_init_dt_check_for_usable_mem_range();
+
+	/* Handle kexec handover */
+	early_init_dt_check_kho();
+}
+
+bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
+{
+	bool status;
+
+	status = early_init_dt_verify(dt_virt, dt_phys);
+	if (!status)
+		return false;
+
+	early_init_dt_scan_nodes();
+	return true;
+}
+
+static void *__init copy_device_tree(void *fdt)
+{
+	int size;
+	void *dt;
+
+	size = fdt_totalsize(fdt);
+	dt = early_init_dt_alloc_memory_arch(size,
+					     roundup_pow_of_two(FDT_V17_SIZE));
+
+	if (dt)
+		memcpy(dt, fdt, size);
+
+	return dt;
+}
+
+/**
+ * unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void __init unflatten_device_tree(void)
+{
+	void *fdt = initial_boot_params;
+
+	/* Save the statically-placed regions in the reserved_mem array */
+	fdt_scan_reserved_mem_late();
+
+	/* Populate an empty root node when bootloader doesn't provide one */
+	if (!fdt) {
+		fdt = (void *) __dtb_empty_root_begin;
+		/* fdt_totalsize() will be used for copy size */
+		if (fdt_totalsize(fdt) >
+		    __dtb_empty_root_end - __dtb_empty_root_begin) {
+			pr_err("invalid size in dtb_empty_root\n");
+			return;
+		}
+		of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
+		fdt = copy_device_tree(fdt);
+	}
+
+	__unflatten_device_tree(fdt, NULL, &of_root,
+				early_init_dt_alloc_memory_arch, false);
+
+	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
+	of_alias_scan(early_init_dt_alloc_memory_arch);
+
+	unittest_unflatten_overlay_base();
+}
+
+/**
+ * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
+ *
+ * Copies and unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used. This should only be used when the FDT memory has not been
+ * reserved such is the case when the FDT is built-in to the kernel init
+ * section. If the FDT memory is reserved already then unflatten_device_tree
+ * should be used instead.
+ */
+void __init unflatten_and_copy_device_tree(void)
+{
+	if (initial_boot_params)
+		initial_boot_params = copy_device_tree(initial_boot_params);
+
+	unflatten_device_tree();
+}
+
+#ifdef CONFIG_SYSFS
+static int __init of_fdt_raw_init(void)
+{
+	static __ro_after_init BIN_ATTR_SIMPLE_ADMIN_RO(fdt);
+
+	if (!initial_boot_params)
+		return 0;
+
+	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
+				     fdt_totalsize(initial_boot_params))) {
+		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
+		return 0;
+	}
+	bin_attr_fdt.private = initial_boot_params;
+	bin_attr_fdt.size = fdt_totalsize(initial_boot_params);
+	return sysfs_create_bin_file(firmware_kobj, &bin_attr_fdt);
+}
+late_initcall(of_fdt_raw_init);
+#endif
+
+#endif /* CONFIG_OF_EARLY_FLATTREE */
diff --git a/drivers/of/fdt_address.c b/drivers/of/fdt_address.c
new file mode 100644
index 000000000..f358d2c80
--- /dev/null
+++ b/drivers/of/fdt_address.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FDT Address translation based on u-boot fdt_support.c which in turn was
+ * based on the kernel unflattened DT address translation code.
+ *
+ * (C) Copyright 2007
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
+ *
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: fdt: " fmt
+
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+
+/* Uncomment me to enable of_dump_addr() debugging output */
+// #define DEBUG
+
+#include "of_private.h"
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	void		(*count_cells)(const void *blob, int parentoffset,
+				int *addrc, int *sizec);
+	u64		(*map)(__be32 *addr, const __be32 *range,
+				int na, int ns, int pna);
+	int		(*translate)(__be32 *addr, u64 offset, int na);
+};
+
+/* Default translator (generic bus) */
+static void __init fdt_bus_default_count_cells(const void *blob, int parentoffset,
+					       int *addrc, int *sizec)
+{
+	const __be32 *prop;
+
+	if (addrc) {
+		prop = fdt_getprop(blob, parentoffset, "#address-cells", NULL);
+		if (prop)
+			*addrc = be32_to_cpup(prop);
+		else
+			*addrc = -1;
+	}
+
+	if (sizec) {
+		prop = fdt_getprop(blob, parentoffset, "#size-cells", NULL);
+		if (prop)
+			*sizec = be32_to_cpup(prop);
+		else
+			*sizec = -1;
+	}
+}
+
+static u64 __init fdt_bus_default_map(__be32 *addr, const __be32 *range,
+				      int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	cp = of_read_number(range, na);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr, na);
+
+	pr_debug("default map, cp=%llx, s=%llx, da=%llx\n",
+	    cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int __init fdt_bus_default_translate(__be32 *addr, u64 offset, int na)
+{
+	u64 a = of_read_number(addr, na);
+	memset(addr, 0, na * 4);
+	a += offset;
+	if (na > 1)
+		addr[na - 2] = cpu_to_fdt32(a >> 32);
+	addr[na - 1] = cpu_to_fdt32(a & 0xffffffffu);
+
+	return 0;
+}
+
+/* Array of bus specific translators */
+static const struct of_bus of_busses[] __initconst = {
+	/* Default */
+	{
+		.count_cells = fdt_bus_default_count_cells,
+		.map = fdt_bus_default_map,
+		.translate = fdt_bus_default_translate,
+	},
+};
+
+static int __init fdt_translate_one(const void *blob, int parent,
+				    const struct of_bus *bus,
+				    const struct of_bus *pbus, __be32 *addr,
+				    int na, int ns, int pna, const char *rprop)
+{
+	const __be32 *ranges;
+	int rlen;
+	int rone;
+	u64 offset = OF_BAD_ADDR;
+
+	ranges = fdt_getprop(blob, parent, rprop, &rlen);
+	if (!ranges)
+		return 1;
+	if (rlen == 0) {
+		offset = of_read_number(addr, na);
+		memset(addr, 0, pna * 4);
+		pr_debug("empty ranges, 1:1 translation\n");
+		goto finish;
+	}
+
+	pr_debug("walking ranges...\n");
+
+	/* Now walk through the ranges */
+	rlen /= 4;
+	rone = na + pna + ns;
+	for (; rlen >= rone; rlen -= rone, ranges += rone) {
+		offset = bus->map(addr, ranges, na, ns, pna);
+		if (offset != OF_BAD_ADDR)
+			break;
+	}
+	if (offset == OF_BAD_ADDR) {
+		pr_debug("not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("parent translation for:", addr, pna);
+	pr_debug("with offset: %llx\n", offset);
+
+	/* Translate it into parent bus space */
+	return pbus->translate(addr, offset, pna);
+}
+
+/*
+ * Translate an address from the device-tree into a CPU physical address,
+ * this walks up the tree and applies the various bus mappings on the
+ * way.
+ *
+ * Note: We consider that crossing any level with #size-cells == 0 to mean
+ * that translation is impossible (that is we are not dealing with a value
+ * that can be mapped to a cpu physical address). This is not really specified
+ * that way, but this is traditionally the way IBM at least do things
+ */
+static u64 __init fdt_translate_address(const void *blob, int node_offset)
+{
+	int parent, len;
+	const struct of_bus *bus, *pbus;
+	const __be32 *reg;
+	__be32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+	u64 result = OF_BAD_ADDR;
+
+	pr_debug("** translation for device %s **\n",
+		 fdt_get_name(blob, node_offset, NULL));
+
+	reg = fdt_getprop(blob, node_offset, "reg", &len);
+	if (!reg) {
+		pr_err("warning: device tree node '%s' has no address.\n",
+			fdt_get_name(blob, node_offset, NULL));
+		goto bail;
+	}
+
+	/* Get parent & match bus type */
+	parent = fdt_parent_offset(blob, node_offset);
+	if (parent < 0)
+		goto bail;
+	bus = &of_busses[0];
+
+	/* Cound address cells & copy address locally */
+	bus->count_cells(blob, parent, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		pr_err("Bad cell count for %s\n",
+		       fdt_get_name(blob, node_offset, NULL));
+		goto bail;
+	}
+	memcpy(addr, reg, na * 4);
+
+	pr_debug("bus (na=%d, ns=%d) on %s\n",
+		 na, ns, fdt_get_name(blob, parent, NULL));
+	of_dump_addr("translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		/* Switch to parent bus */
+		node_offset = parent;
+		parent = fdt_parent_offset(blob, node_offset);
+
+		/* If root, we have finished */
+		if (parent < 0) {
+			pr_debug("reached root node\n");
+			result = of_read_number(addr, na);
+			break;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = &of_busses[0];
+		pbus->count_cells(blob, parent, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			pr_err("Bad cell count for %s\n",
+				fdt_get_name(blob, node_offset, NULL));
+			break;
+		}
+
+		pr_debug("parent bus (na=%d, ns=%d) on %s\n",
+			 pna, pns, fdt_get_name(blob, parent, NULL));
+
+		/* Apply bus translation */
+		if (fdt_translate_one(blob, node_offset, bus, pbus,
+					addr, na, ns, pna, "ranges"))
+			break;
+
+		/* Complete the move up one level */
+		na = pna;
+		ns = pns;
+		bus = pbus;
+
+		of_dump_addr("one level translation:", addr, na);
+	}
+ bail:
+	return result;
+}
+
+/**
+ * of_flat_dt_translate_address - translate DT addr into CPU phys addr
+ * @node: node in the flat blob
+ */
+u64 __init of_flat_dt_translate_address(unsigned long node)
+{
+	return fdt_translate_address(initial_boot_params, node);
+}
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
new file mode 100644
index 000000000..ec035367c
--- /dev/null
+++ b/drivers/of/irq.c
@@ -0,0 +1,908 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Derived from arch/i386/kernel/irq.c
+ *    Copyright (C) 1992 Linus Torvalds
+ *  Adapted from arch/i386 by Gary Thomas
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
+ *    Copyright (C) 1996-2001 Cort Dougan
+ *  Adapted for Power Macintosh by Paul Mackerras
+ *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
+ *
+ * This file contains the code used to make IRQ descriptions in the
+ * device tree to actual irq numbers on an interrupt controller
+ * driver.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+
+#include "of_private.h"
+
+/**
+ * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
+ * @dev: Device node of the device whose interrupt is to be mapped
+ * @index: Index of the interrupt to map
+ *
+ * This function is a wrapper that chains of_irq_parse_one() and
+ * irq_create_of_mapping() to make things easier to callers
+ */
+unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
+{
+	struct of_phandle_args oirq;
+	unsigned int ret;
+
+	if (of_irq_parse_one(dev, index, &oirq))
+		return 0;
+
+	ret = irq_create_of_mapping(&oirq);
+	of_node_put(oirq.np);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
+
+/**
+ * of_irq_find_parent - Given a device node, find its interrupt parent node
+ * @child: pointer to device node
+ *
+ * Return: A pointer to the interrupt parent node with refcount increased
+ * or NULL if the interrupt parent could not be determined.
+ */
+struct device_node *of_irq_find_parent(struct device_node *child)
+{
+	struct device_node *p;
+	phandle parent;
+
+	if (!of_node_get(child))
+		return NULL;
+
+	do {
+		if (of_property_read_u32(child, "interrupt-parent", &parent)) {
+			p = of_get_parent(child);
+		} else	{
+			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+				p = of_node_get(of_irq_dflt_pic);
+			else
+				p = of_find_node_by_phandle(parent);
+		}
+		of_node_put(child);
+		child = p;
+	} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(of_irq_find_parent);
+
+/*
+ * These interrupt controllers abuse interrupt-map for unspeakable
+ * reasons and rely on the core code to *ignore* it (the drivers do
+ * their own parsing of the property). The PAsemi entry covers a
+ * non-sensical interrupt-map that is better left ignored.
+ *
+ * If you think of adding to the list for something *new*, think
+ * again. There is a high chance that you will be sent back to the
+ * drawing board.
+ */
+static const char * const of_irq_imap_abusers[] = {
+	"CBEA,platform-spider-pic",
+	"sti,platform-spider-pic",
+	"realtek,rtl-intc",
+	"fsl,ls1021a-extirq",
+	"fsl,ls1043a-extirq",
+	"fsl,ls1088a-extirq",
+	"renesas,rza1-irqc",
+	"pasemi,rootbus",
+	NULL,
+};
+
+const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_phandle_args *out_irq)
+{
+	u32 intsize, addrsize;
+	struct device_node *np;
+
+	/* Get the interrupt parent */
+	if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+		np = of_node_get(of_irq_dflt_pic);
+	else
+		np = of_find_node_by_phandle(be32_to_cpup(imap));
+	imap++;
+	len--;
+
+	/* Check if not found */
+	if (!np) {
+		pr_debug(" -> imap parent not found !\n");
+		return NULL;
+	}
+
+	/* Get #interrupt-cells and #address-cells of new parent */
+	if (of_property_read_u32(np, "#interrupt-cells",
+					&intsize)) {
+		pr_debug(" -> parent lacks #interrupt-cells!\n");
+		of_node_put(np);
+		return NULL;
+	}
+	if (of_property_read_u32(np, "#address-cells",
+					&addrsize))
+		addrsize = 0;
+
+	pr_debug(" -> intsize=%d, addrsize=%d\n",
+		intsize, addrsize);
+
+	/* Check for malformed properties */
+	if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)
+		|| (len < (addrsize + intsize))) {
+		of_node_put(np);
+		return NULL;
+	}
+
+	pr_debug(" -> imaplen=%d\n", len);
+
+	imap += addrsize + intsize;
+
+	out_irq->np = np;
+	for (int i = 0; i < intsize; i++)
+		out_irq->args[i] = be32_to_cpup(imap - intsize + i);
+	out_irq->args_count = intsize;
+
+	return imap;
+}
+
+int of_imap_parser_init(struct of_imap_parser *parser, struct device_node *node,
+			struct of_imap_item *item)
+{
+	int imaplen;
+	u32 tmp;
+	int ret;
+
+	/*
+	 * parent_offset is the offset where the parent part is starting.
+	 * In other words, the offset where the parent interrupt controller
+	 * phandle is present.
+	 *
+	 * Compute this offset (child #interrupt-cells + child #address-cells)
+	 */
+	parser->parent_offset = of_bus_n_addr_cells(node);
+
+	ret = of_property_read_u32(node, "#interrupt-cells", &tmp);
+	if (ret)
+		return ret;
+
+	parser->parent_offset += tmp;
+
+	if (WARN(parser->parent_offset > ARRAY_SIZE(item->child_imap),
+		 "child part size = %u, cannot fit in array of %zu items",
+		 parser->parent_offset, ARRAY_SIZE(item->child_imap)))
+		return -EINVAL;
+
+	parser->imap = of_get_property(node, "interrupt-map", &imaplen);
+	if (!parser->imap)
+		return -ENOENT;
+
+	imaplen /= sizeof(*parser->imap);
+	parser->imap_end = parser->imap + imaplen;
+
+	memset(item, 0, sizeof(*item));
+	item->child_imap_count = parser->parent_offset;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_imap_parser_init);
+
+struct of_imap_item *of_imap_parser_one(struct of_imap_parser *parser,
+					struct of_imap_item *item)
+{
+	const __be32 *imap_parent, *imap_next;
+	int i;
+
+	/* Release previously get parent node */
+	of_node_put(item->parent_args.np);
+
+	if (parser->imap + parser->parent_offset + 1 >= parser->imap_end)
+		return NULL;
+
+	imap_parent = parser->imap + parser->parent_offset;
+
+	imap_next = of_irq_parse_imap_parent(imap_parent,
+					     parser->imap_end - imap_parent,
+					     &item->parent_args);
+	if (!imap_next)
+		return NULL;
+
+	for (i = 0; i < parser->parent_offset; i++)
+		item->child_imap[i] = be32_to_cpu(*(parser->imap + i));
+
+	parser->imap = imap_next;
+
+	return item;
+}
+EXPORT_SYMBOL_GPL(of_imap_parser_one);
+
+/**
+ * of_irq_parse_raw - Low level interrupt tree parsing
+ * @addr:	address specifier (start of "reg" property of the device) in be32 format
+ * @out_irq:	structure of_phandle_args updated by this function
+ *
+ * This function is a low-level interrupt tree walking function. It
+ * can be used to do a partial walk with synthesized reg and interrupts
+ * properties, for example when resolving PCI interrupts when no device
+ * node exist for the parent. It takes an interrupt specifier structure as
+ * input, walks the tree looking for any interrupt-map properties, translates
+ * the specifier for each map, and then returns the translated map.
+ *
+ * Return: 0 on success and a negative number on error
+ *
+ * Note: refcount of node @out_irq->np is increased by 1 on success.
+ */
+int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
+{
+	struct device_node *ipar, *tnode, *old = NULL;
+	__be32 initial_match_array[MAX_PHANDLE_ARGS];
+	const __be32 *match_array = initial_match_array;
+	const __be32 *tmp, dummy_imask[] = { [0 ... (MAX_PHANDLE_ARGS - 1)] = cpu_to_be32(~0) };
+	u32 intsize = 1, addrsize;
+	int i, rc = -EINVAL;
+
+#ifdef DEBUG
+	of_print_phandle_args("of_irq_parse_raw: ", out_irq);
+#endif
+
+	ipar = of_node_get(out_irq->np);
+
+	/* First get the #interrupt-cells property of the current cursor
+	 * that tells us how to interpret the passed-in intspec. If there
+	 * is none, we are nice and just walk up the tree
+	 */
+	do {
+		if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
+			break;
+		tnode = ipar;
+		ipar = of_irq_find_parent(ipar);
+		of_node_put(tnode);
+	} while (ipar);
+	if (ipar == NULL) {
+		pr_debug(" -> no parent found !\n");
+		goto fail;
+	}
+
+	pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
+
+	if (out_irq->args_count != intsize)
+		goto fail;
+
+	/* Look for this #address-cells. We have to implement the old linux
+	 * trick of looking for the parent here as some device-trees rely on it
+	 */
+	old = of_node_get(ipar);
+	do {
+		tmp = of_get_property(old, "#address-cells", NULL);
+		tnode = of_get_parent(old);
+		of_node_put(old);
+		old = tnode;
+	} while (old && tmp == NULL);
+	of_node_put(old);
+	old = NULL;
+	addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
+
+	pr_debug(" -> addrsize=%d\n", addrsize);
+
+	/* Range check so that the temporary buffer doesn't overflow */
+	if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
+		rc = -EFAULT;
+		goto fail;
+	}
+
+	/* Precalculate the match array - this simplifies match loop */
+	for (i = 0; i < addrsize; i++)
+		initial_match_array[i] = addr ? addr[i] : 0;
+	for (i = 0; i < intsize; i++)
+		initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
+
+	/* Now start the actual "proper" walk of the interrupt tree */
+	while (ipar != NULL) {
+		int imaplen, match;
+		const __be32 *imap, *oldimap, *imask;
+		struct device_node *newpar;
+		/*
+		 * Now check if cursor is an interrupt-controller and
+		 * if it is then we are done, unless there is an
+		 * interrupt-map which takes precedence except on one
+		 * of these broken platforms that want to parse
+		 * interrupt-map themselves for $reason.
+		 */
+		bool intc = of_property_read_bool(ipar, "interrupt-controller");
+
+		imap = of_get_property(ipar, "interrupt-map", &imaplen);
+		if (intc &&
+		    (!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
+			pr_debug(" -> got it !\n");
+			return 0;
+		}
+
+		/*
+		 * interrupt-map parsing does not work without a reg
+		 * property when #address-cells != 0
+		 */
+		if (addrsize && !addr) {
+			pr_debug(" -> no reg passed in when needed !\n");
+			goto fail;
+		}
+
+		/* No interrupt map, check for an interrupt parent */
+		if (imap == NULL) {
+			pr_debug(" -> no map, getting parent\n");
+			newpar = of_irq_find_parent(ipar);
+			goto skiplevel;
+		}
+		imaplen /= sizeof(u32);
+
+		/* Look for a mask */
+		imask = of_get_property(ipar, "interrupt-map-mask", NULL);
+		if (!imask)
+			imask = dummy_imask;
+
+		/* Parse interrupt-map */
+		match = 0;
+		while (imaplen > (addrsize + intsize + 1)) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < (addrsize + intsize); i++, imaplen--)
+				match &= !((match_array[i] ^ *imap++) & imask[i]);
+
+			pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
+
+			oldimap = imap;
+			imap = of_irq_parse_imap_parent(oldimap, imaplen, out_irq);
+			if (!imap)
+				goto fail;
+
+			match &= of_device_is_available(out_irq->np);
+			if (match)
+				break;
+
+			of_node_put(out_irq->np);
+			imaplen -= imap - oldimap;
+			pr_debug(" -> imaplen=%d\n", imaplen);
+		}
+		if (!match)
+			goto fail;
+
+		/*
+		 * Successfully parsed an interrupt-map translation; copy new
+		 * interrupt specifier into the out_irq structure
+		 */
+		match_array = oldimap + 1;
+
+		newpar = out_irq->np;
+		intsize = out_irq->args_count;
+		addrsize = (imap - match_array) - intsize;
+
+		if (ipar == newpar) {
+			/*
+			 * We got @ipar's refcount, but the refcount was
+			 * gotten again by of_irq_parse_imap_parent() via its
+			 * alias @newpar.
+			 */
+			of_node_put(ipar);
+			pr_debug("%pOF interrupt-map entry to self\n", ipar);
+			return 0;
+		}
+
+	skiplevel:
+		/* Iterate again with new parent */
+		pr_debug(" -> new parent: %pOF\n", newpar);
+		of_node_put(ipar);
+		ipar = newpar;
+		newpar = NULL;
+	}
+	rc = -ENOENT; /* No interrupt-map found */
+
+ fail:
+	of_node_put(ipar);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_irq_parse_raw);
+
+/**
+ * of_irq_parse_one - Resolve an interrupt for a device
+ * @device: the device whose interrupt is to be resolved
+ * @index: index of the interrupt to resolve
+ * @out_irq: structure of_phandle_args filled by this function
+ *
+ * This function resolves an interrupt for a node by walking the interrupt tree,
+ * finding which interrupt controller node it is attached to, and returning the
+ * interrupt specifier that can be used to retrieve a Linux IRQ number.
+ *
+ * Note: refcount of node @out_irq->np is increased by 1 on success.
+ */
+int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
+{
+	struct device_node __free(device_node) *p = NULL;
+	const __be32 *addr;
+	u32 intsize;
+	int i, res, addr_len;
+	__be32 addr_buf[3] = { 0 };
+
+	pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
+
+	/* OldWorld mac stuff is "special", handle out of line */
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return of_irq_parse_oldworld(device, index, out_irq);
+
+	/* Get the reg property (if any) */
+	addr_len = 0;
+	addr = of_get_property(device, "reg", &addr_len);
+
+	/* Prevent out-of-bounds read in case of longer interrupt parent address size */
+	if (addr_len > sizeof(addr_buf))
+		addr_len = sizeof(addr_buf);
+	if (addr)
+		memcpy(addr_buf, addr, addr_len);
+
+	/* Try the new-style interrupts-extended first */
+	res = of_parse_phandle_with_args(device, "interrupts-extended",
+					"#interrupt-cells", index, out_irq);
+	if (!res) {
+		p = out_irq->np;
+	} else {
+		/* Look for the interrupt parent. */
+		p = of_irq_find_parent(device);
+		/* Get size of interrupt specifier */
+		if (!p || of_property_read_u32(p, "#interrupt-cells", &intsize))
+			return -EINVAL;
+
+		pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
+
+		/* Copy intspec into irq structure */
+		out_irq->np = p;
+		out_irq->args_count = intsize;
+		for (i = 0; i < intsize; i++) {
+			res = of_property_read_u32_index(device, "interrupts",
+							(index * intsize) + i,
+							out_irq->args + i);
+			if (res)
+				return res;
+		}
+
+		pr_debug(" intspec=%d\n", *out_irq->args);
+	}
+
+	/* Check if there are any interrupt-map translations to process */
+	return of_irq_parse_raw(addr_buf, out_irq);
+}
+EXPORT_SYMBOL_GPL(of_irq_parse_one);
+
+/**
+ * of_irq_to_resource - Decode a node's IRQ and return it as a resource
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the irq
+ * @r: pointer to resource structure to return result into.
+ */
+int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
+{
+	int irq = of_irq_get(dev, index);
+
+	if (irq < 0)
+		return irq;
+
+	/* Only dereference the resource if both the
+	 * resource and the irq are valid. */
+	if (r && irq) {
+		const char *name = NULL;
+
+		memset(r, 0, sizeof(*r));
+		/*
+		 * Get optional "interrupt-names" property to add a name
+		 * to the resource.
+		 */
+		of_property_read_string_index(dev, "interrupt-names", index,
+					      &name);
+
+		*r = DEFINE_RES_IRQ_NAMED(irq, name ?: of_node_full_name(dev));
+		r->flags |= irq_get_trigger_type(irq);
+	}
+
+	return irq;
+}
+EXPORT_SYMBOL_GPL(of_irq_to_resource);
+
+/**
+ * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the IRQ
+ *
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
+ * of any other failure.
+ */
+int of_irq_get(struct device_node *dev, int index)
+{
+	int rc;
+	struct of_phandle_args oirq;
+	struct irq_domain *domain;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return rc;
+
+	domain = irq_find_host(oirq.np);
+	if (!domain) {
+		rc = -EPROBE_DEFER;
+		goto out;
+	}
+
+	rc = irq_create_of_mapping(&oirq);
+out:
+	of_node_put(oirq.np);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_irq_get);
+
+const struct cpumask *of_irq_get_affinity(struct device_node *dev, int index)
+{
+	struct of_phandle_args oirq;
+	struct irq_fwspec_info info;
+	struct irq_fwspec fwspec;
+	int rc;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return NULL;
+
+	of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
+				  &fwspec);
+
+	rc = irq_populate_fwspec_info(&fwspec, &info);
+	of_node_put(oirq.np);
+	if (rc)
+		return NULL;
+
+	return info.affinity;
+}
+
+/**
+ * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
+ * @dev: pointer to device tree node
+ * @name: IRQ name
+ *
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
+ * of any other failure.
+ */
+int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	int index;
+
+	if (unlikely(!name))
+		return -EINVAL;
+
+	index = of_property_match_string(dev, "interrupt-names", name);
+	if (index < 0)
+		return index;
+
+	return of_irq_get(dev, index);
+}
+EXPORT_SYMBOL_GPL(of_irq_get_byname);
+
+/**
+ * of_irq_count - Count the number of IRQs a node uses
+ * @dev: pointer to device tree node
+ */
+int of_irq_count(struct device_node *dev)
+{
+	struct of_phandle_args irq;
+	int nr = 0;
+
+	while (of_irq_parse_one(dev, nr, &irq) == 0) {
+		of_node_put(irq.np);
+		nr++;
+	}
+
+	return nr;
+}
+EXPORT_SYMBOL_GPL(of_irq_count);
+
+/**
+ * of_irq_to_resource_table - Fill in resource table with node's IRQ info
+ * @dev: pointer to device tree node
+ * @res: array of resources to fill in
+ * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
+ *
+ * Return: The size of the filled in table (up to @nr_irqs).
+ */
+int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
+		int nr_irqs)
+{
+	int i;
+
+	for (i = 0; i < nr_irqs; i++, res++)
+		if (of_irq_to_resource(dev, i, res) <= 0)
+			break;
+
+	return i;
+}
+EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
+
+struct of_intc_desc {
+	struct list_head	list;
+	of_irq_init_cb_t	irq_init_cb;
+	struct device_node	*dev;
+	struct device_node	*interrupt_parent;
+};
+
+/**
+ * of_irq_init - Scan and init matching interrupt controllers in DT
+ * @matches: 0 terminated array of nodes to match and init function to call
+ *
+ * This function scans the device tree for matching interrupt controller nodes,
+ * and calls their initialization functions in order with parents first.
+ */
+void __init of_irq_init(const struct of_device_id *matches)
+{
+	const struct of_device_id *match;
+	struct device_node *np, *parent = NULL;
+	struct of_intc_desc *desc, *temp_desc;
+	struct list_head intc_desc_list, intc_parent_list;
+
+	INIT_LIST_HEAD(&intc_desc_list);
+	INIT_LIST_HEAD(&intc_parent_list);
+
+	for_each_matching_node_and_match(np, matches, &match) {
+		if (!of_property_read_bool(np, "interrupt-controller") ||
+				!of_device_is_available(np))
+			continue;
+
+		if (WARN(!match->data, "of_irq_init: no init function for %s\n",
+			 match->compatible))
+			continue;
+
+		/*
+		 * Here, we allocate and populate an of_intc_desc with the node
+		 * pointer, interrupt-parent device_node etc.
+		 */
+		desc = kzalloc_obj(*desc);
+		if (!desc) {
+			of_node_put(np);
+			goto err;
+		}
+
+		desc->irq_init_cb = match->data;
+		desc->dev = of_node_get(np);
+		/*
+		 * interrupts-extended can reference multiple parent domains.
+		 * Arbitrarily pick the first one; assume any other parents
+		 * are the same distance away from the root irq controller.
+		 */
+		desc->interrupt_parent = of_parse_phandle(np, "interrupts-extended", 0);
+		if (!desc->interrupt_parent && of_property_present(np, "interrupts"))
+			desc->interrupt_parent = of_irq_find_parent(np);
+		else if (!desc->interrupt_parent)
+			desc->interrupt_parent = of_parse_phandle(np, "interrupt-parent", 0);
+		if (desc->interrupt_parent == np) {
+			of_node_put(desc->interrupt_parent);
+			desc->interrupt_parent = NULL;
+		}
+		list_add_tail(&desc->list, &intc_desc_list);
+	}
+
+	/*
+	 * The root irq controller is the one without an interrupt-parent.
+	 * That one goes first, followed by the controllers that reference it,
+	 * followed by the ones that reference the 2nd level controllers, etc.
+	 */
+	while (!list_empty(&intc_desc_list)) {
+		/*
+		 * Process all controllers with the current 'parent'.
+		 * First pass will be looking for NULL as the parent.
+		 * The assumption is that NULL parent means a root controller.
+		 */
+		list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
+			int ret;
+
+			if (desc->interrupt_parent != parent)
+				continue;
+
+			list_del(&desc->list);
+
+			of_node_set_flag(desc->dev, OF_POPULATED);
+
+			pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
+				 desc->dev,
+				 desc->dev, desc->interrupt_parent);
+			ret = desc->irq_init_cb(desc->dev,
+						desc->interrupt_parent);
+			if (ret) {
+				pr_err("%s: Failed to init %pOF (%p), parent %p\n",
+				       __func__, desc->dev, desc->dev,
+				       desc->interrupt_parent);
+				of_node_clear_flag(desc->dev, OF_POPULATED);
+				of_node_put(desc->interrupt_parent);
+				of_node_put(desc->dev);
+				kfree(desc);
+				continue;
+			}
+
+			/*
+			 * This one is now set up; add it to the parent list so
+			 * its children can get processed in a subsequent pass.
+			 */
+			list_add_tail(&desc->list, &intc_parent_list);
+		}
+
+		/* Get the next pending parent that might have children */
+		desc = list_first_entry_or_null(&intc_parent_list,
+						typeof(*desc), list);
+		if (!desc) {
+			pr_err("of_irq_init: children remain, but no parents\n");
+			break;
+		}
+		list_del(&desc->list);
+		parent = desc->dev;
+		kfree(desc);
+	}
+
+	list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
+		list_del(&desc->list);
+		kfree(desc);
+	}
+err:
+	list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
+		list_del(&desc->list);
+		of_node_put(desc->interrupt_parent);
+		of_node_put(desc->dev);
+		kfree(desc);
+	}
+}
+
+static int of_check_msi_parent(struct device_node *dev_node, struct device_node **msi_node)
+{
+	struct of_phandle_args msi_spec;
+	int ret;
+
+	/*
+	 * An msi-parent phandle with a missing or == 0 #msi-cells
+	 * property identifies a 1:1 ID translation mapping.
+	 *
+	 * Set the msi controller node if the firmware matches this
+	 * condition.
+	 */
+	ret = of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi-cells",
+						  0, &msi_spec);
+	if (ret)
+		return ret;
+
+	if ((*msi_node && *msi_node != msi_spec.np) || msi_spec.args_count != 0)
+		ret = -EINVAL;
+
+	if (!ret) {
+		/* Return with a node reference held */
+		*msi_node = msi_spec.np;
+		return 0;
+	}
+	of_node_put(msi_spec.np);
+
+	return ret;
+}
+
+/**
+ * of_msi_xlate - map a MSI ID and find relevant MSI controller node
+ * @dev: device for which the mapping is to be done.
+ * @msi_np: Pointer to target MSI controller node, or NULL if the caller
+ *           only needs the translated ID without receiving the controller node.
+ *           If non-NULL and pointing to a non-NULL node, only entries targeting
+ *           that node will be matched. If non-NULL and pointing to NULL, it will
+ *           receive the first matching target node with a reference held.
+ * @id_in: Device ID.
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * or "msi-parent" property. If found, apply the mapping to @id_in.
+ *
+ * Returns: The mapped MSI id.
+ */
+u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
+{
+	struct device *parent_dev;
+	u32 id_out = id_in;
+
+	/*
+	 * Walk up the device parent links looking for one with a
+	 * "msi-map" or an "msi-parent" property.
+	 */
+	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
+		struct of_phandle_args msi_spec = {};
+
+		if (!of_map_msi_id(parent_dev->of_node, id_in, msi_np, &msi_spec)) {
+			if (msi_spec.np) {
+				/* msi-map matched: use the translated ID and target node */
+				if (msi_spec.args_count > 0)
+					id_out = msi_spec.args[0];
+				if (msi_np && !*msi_np)
+					*msi_np = of_node_get(msi_spec.np);
+				of_node_put(msi_spec.np);
+			}
+			/* msi-map present but no match → stop walking */
+			break;
+		}
+		/* -ENODEV: msi-map absent → check for msi-parent */
+		if (msi_np && !of_check_msi_parent(parent_dev->of_node, msi_np))
+			break;
+	}
+	return id_out;
+}
+EXPORT_SYMBOL_GPL(of_msi_xlate);
+
+/**
+ * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
+ * @dev: device for which the mapping is to be done.
+ * @id: Device ID.
+ * @bus_token: Bus token
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * property.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure)
+ */
+struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
+						u32 bus_token)
+{
+	struct device_node *np = NULL;
+	struct irq_domain *d;
+
+	of_msi_xlate(dev, &np, id);
+	d = irq_find_matching_host(np, bus_token);
+	of_node_put(np);
+	return d;
+}
+
+/**
+ * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
+ * @dev: device for which the domain is requested
+ * @np: device node for @dev
+ * @token: bus type for this domain
+ *
+ * Parse the msi-parent property and returns the corresponding MSI domain.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure).
+ */
+struct irq_domain *of_msi_get_domain(struct device *dev,
+				     const struct device_node *np,
+				     enum irq_domain_bus_token token)
+{
+	struct of_phandle_iterator it;
+	struct irq_domain *d;
+	int err;
+
+	of_for_each_phandle(&it, err, np, "msi-parent", "#msi-cells", 0) {
+		d = irq_find_matching_host(it.node, token);
+		if (d) {
+			of_node_put(it.node);
+			return d;
+		}
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_msi_get_domain);
+
+/**
+ * of_msi_configure - Set the msi_domain field of a device
+ * @dev: device structure to associate with an MSI irq domain
+ * @np: device node for that device
+ */
+void of_msi_configure(struct device *dev, const struct device_node *np)
+{
+	dev_set_msi_domain(dev,
+			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
+}
+EXPORT_SYMBOL_GPL(of_msi_configure);
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
index 000000000..029903b98
--- /dev/null
+++ b/drivers/of/kexec.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ *
+ * Based on arch/arm64/kernel/machine_kexec_file.c:
+ *  Copyright (C) 2018 Linaro Limited
+ *
+ * And arch/powerpc/kexec/file_load.c:
+ *  Copyright (C) 2016  IBM Corporation
+ */
+
+#include <linux/ima.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define RNG_SEED_SIZE		128
+
+/*
+ * Additional space needed for the FDT buffer so that we can add initrd,
+ * bootargs, kaslr-seed, rng-seed, useable-memory-range and elfcorehdr.
+ */
+#define FDT_EXTRA_SPACE 0x1000
+
+/**
+ * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt:	Flattened device tree for the current kernel.
+ * @start:	Starting address of the reserved memory.
+ * @size:	Size of the reserved memory.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+	for (i = 0; i < num_rsvs; i++) {
+		u64 rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == start && rsv_size == size) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting device tree reservation.\n");
+				return -EINVAL;
+			}
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/**
+ * get_addr_size_cells - Get address and size of root node
+ *
+ * @addr_cells: Return address of the root node
+ * @size_cells: Return size of the root node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int get_addr_size_cells(int *addr_cells, int *size_cells)
+{
+	struct device_node *root;
+
+	root = of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	*addr_cells = of_n_addr_cells(root);
+	*size_cells = of_n_size_cells(root);
+
+	of_node_put(root);
+
+	return 0;
+}
+
+/**
+ * do_get_kexec_buffer - Get address and size of device tree property
+ *
+ * @prop: Device tree property
+ * @len: Size of @prop
+ * @addr: Return address of the node
+ * @size: Return size of the node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
+			       size_t *size)
+{
+	int ret, addr_cells, size_cells;
+
+	ret = get_addr_size_cells(&addr_cells, &size_cells);
+	if (ret)
+		return ret;
+
+	if (len < 4 * (addr_cells + size_cells))
+		return -ENOENT;
+
+	*addr = of_read_number(prop, addr_cells);
+	*size = of_read_number(prop + 4 * addr_cells, size_cells);
+
+	return 0;
+}
+
+#ifdef CONFIG_HAVE_IMA_KEXEC
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr:	On successful return, set to point to the buffer contents.
+ * @size:	On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __init ima_get_kexec_buffer(void **addr, size_t *size)
+{
+	int ret, len;
+	unsigned long tmp_addr;
+	size_t tmp_size;
+	const void *prop;
+
+	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
+	if (!prop)
+		return -ENOENT;
+
+	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+	if (ret)
+		return ret;
+
+	/* Do some sanity on the returned size for the ima-kexec buffer */
+	if (!tmp_size)
+		return -ENOENT;
+
+	ret = ima_validate_range(tmp_addr, tmp_size);
+	if (ret)
+		return ret;
+
+	*addr = __va(tmp_addr);
+	*size = tmp_size;
+
+	return 0;
+}
+
+/**
+ * ima_free_kexec_buffer - free memory used by the IMA buffer
+ */
+int __init ima_free_kexec_buffer(void)
+{
+	int ret;
+	unsigned long addr;
+	size_t size;
+	struct property *prop;
+
+	prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
+	if (!prop)
+		return -ENOENT;
+
+	ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
+	if (ret)
+		return ret;
+
+	ret = of_remove_property(of_chosen, prop);
+	if (ret)
+		return ret;
+
+	memblock_phys_free(addr, size);
+	return 0;
+}
+#endif
+
+/**
+ * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
+ *
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
+ */
+static void remove_ima_buffer(void *fdt, int chosen_node)
+{
+	int ret, len;
+	unsigned long addr;
+	size_t size;
+	const void *prop;
+
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return;
+
+	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
+	if (!prop)
+		return;
+
+	ret = do_get_kexec_buffer(prop, len, &addr, &size);
+	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+	if (ret)
+		return;
+
+	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
+	if (!ret)
+		pr_debug("Removed old IMA buffer reservation.\n");
+}
+
+#ifdef CONFIG_IMA_KEXEC
+/**
+ * setup_ima_buffer - add IMA buffer information to the fdt
+ * @image:		kexec image being loaded.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @chosen_node:	Offset to the chosen node.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int setup_ima_buffer(const struct kimage *image, void *fdt,
+			    int chosen_node)
+{
+	int ret;
+
+	if (!image->ima_buffer_size)
+		return 0;
+
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				       "linux,ima-kexec-buffer",
+				       image->ima_buffer_addr,
+				       image->ima_buffer_size);
+	if (ret < 0)
+		return -EINVAL;
+
+	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
+			      image->ima_buffer_size);
+	if (ret)
+		return -EINVAL;
+
+	pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
+		 image->ima_buffer_addr, image->ima_buffer_size);
+
+	return 0;
+}
+#else /* CONFIG_IMA_KEXEC */
+static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
+				   int chosen_node)
+{
+	return 0;
+}
+#endif /* CONFIG_IMA_KEXEC */
+
+static int kho_add_chosen(const struct kimage *image, void *fdt, int chosen_node)
+{
+	int ret = 0;
+#ifdef CONFIG_KEXEC_HANDOVER
+	phys_addr_t fdt_mem = 0;
+	phys_addr_t fdt_len = 0;
+	phys_addr_t scratch_mem = 0;
+	phys_addr_t scratch_len = 0;
+
+	ret = fdt_delprop(fdt, chosen_node, "linux,kho-fdt");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		return ret;
+	ret = fdt_delprop(fdt, chosen_node, "linux,kho-scratch");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		return ret;
+
+	if (!image->kho.fdt || !image->kho.scratch)
+		return 0;
+
+	fdt_mem = image->kho.fdt;
+	fdt_len = PAGE_SIZE;
+	scratch_mem = image->kho.scratch->mem;
+	scratch_len = image->kho.scratch->bufsz;
+
+	pr_debug("Adding kho metadata to DT");
+
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-fdt",
+				       fdt_mem, fdt_len);
+	if (ret)
+		return ret;
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node, "linux,kho-scratch",
+				       scratch_mem, scratch_len);
+
+#endif /* CONFIG_KEXEC_HANDOVER */
+	return ret;
+}
+
+/*
+ * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
+ *
+ * @image:		kexec image being loaded.
+ * @initrd_load_addr:	Address where the next initrd will be loaded.
+ * @initrd_len:		Size of the next initrd, or 0 if there will be none.
+ * @cmdline:		Command line for the next kernel, or NULL if there will
+ *			be none.
+ * @extra_fdt_size:	Additional size for the new FDT buffer.
+ *
+ * Return: fdt on success, or NULL errno on error.
+ */
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline, size_t extra_fdt_size)
+{
+	void *fdt;
+	int ret, chosen_node, len;
+	const void *prop;
+	size_t fdt_size;
+
+	fdt_size = fdt_totalsize(initial_boot_params) +
+		   (cmdline ? strlen(cmdline) : 0) +
+		   FDT_EXTRA_SPACE +
+		   extra_fdt_size;
+	fdt = kvmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt)
+		return NULL;
+
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error %d setting up the new device tree.\n", ret);
+		goto out;
+	}
+
+	/* Remove memory reservation for the current device tree. */
+	ret = fdt_find_and_del_mem_rsv(fdt, initial_boot_params_pa,
+				       fdt_totalsize(initial_boot_params));
+	if (ret == -EINVAL) {
+		pr_err("Error removing memory reservation.\n");
+		goto out;
+	}
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node == -FDT_ERR_NOTFOUND)
+		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+					      "chosen");
+	if (chosen_node < 0) {
+		ret = chosen_node;
+		goto out;
+	}
+
+	ret = fdt_delprop(fdt, chosen_node, "linux,elfcorehdr");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+	ret = fdt_delprop(fdt, chosen_node, "linux,usable-memory-range");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+
+	/* Did we boot using an initrd? */
+	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", &len);
+	if (prop) {
+		u64 tmp_start, tmp_end, tmp_size;
+
+		tmp_start = of_read_number(prop, len / 4);
+
+		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", &len);
+		if (!prop) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		tmp_end = of_read_number(prop, len / 4);
+
+		/*
+		 * kexec reserves exact initrd size, while firmware may
+		 * reserve a multiple of PAGE_SIZE, so check for both.
+		 */
+		tmp_size = tmp_end - tmp_start;
+		ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size);
+		if (ret == -ENOENT)
+			ret = fdt_find_and_del_mem_rsv(fdt, tmp_start,
+						       round_up(tmp_size, PAGE_SIZE));
+		if (ret == -EINVAL)
+			goto out;
+	}
+
+	/* add initrd-* */
+	if (initrd_load_addr) {
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-start",
+				      initrd_load_addr);
+		if (ret)
+			goto out;
+
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+				      initrd_load_addr + initrd_len);
+		if (ret)
+			goto out;
+
+		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+		if (ret)
+			goto out;
+
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "linux,initrd-start");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+
+		ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	if (image->type == KEXEC_TYPE_CRASH) {
+		/* add linux,elfcorehdr */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				"linux,elfcorehdr", image->elf_load_addr,
+				image->elf_headers_sz);
+		if (ret)
+			goto out;
+
+		/*
+		 * Avoid elfcorehdr from being stomped on in kdump kernel by
+		 * setting up memory reserve map.
+		 */
+		ret = fdt_add_mem_rsv(fdt, image->elf_load_addr,
+				      image->elf_headers_sz);
+		if (ret)
+			goto out;
+
+		if (image->dm_crypt_keys_addr != 0) {
+			ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+						       "linux,dmcryptkeys",
+						       image->dm_crypt_keys_addr,
+						       image->dm_crypt_keys_sz);
+
+			if (ret)
+				goto out;
+
+			/*
+			 * Avoid dmcryptkeys from being stomped on in kdump kernel by
+			 * setting up memory reserve map.
+			 */
+			ret = fdt_add_mem_rsv(fdt, image->dm_crypt_keys_addr,
+					      image->dm_crypt_keys_sz);
+			if (ret)
+				goto out;
+		}
+
+#ifdef CONFIG_CRASH_DUMP
+		/* add linux,usable-memory-range */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				"linux,usable-memory-range", crashk_res.start,
+				crashk_res.end - crashk_res.start + 1);
+		if (ret)
+			goto out;
+
+		if (crashk_low_res.end) {
+			ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+					"linux,usable-memory-range",
+					crashk_low_res.start,
+					crashk_low_res.end - crashk_low_res.start + 1);
+			if (ret)
+				goto out;
+		}
+
+		for (int i = 0; i < crashk_cma_cnt; i++) {
+			ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+					"linux,usable-memory-range",
+					crashk_cma_ranges[i].start,
+					crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1);
+			if (ret)
+				goto out;
+		}
+#endif
+	}
+
+	/* Add kho metadata if this is a KHO image */
+	ret = kho_add_chosen(image, fdt, chosen_node);
+	if (ret)
+		goto out;
+
+	/* add bootargs */
+	if (cmdline) {
+		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+		if (ret)
+			goto out;
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "bootargs");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	/* add kaslr-seed */
+	ret = fdt_delprop(fdt, chosen_node, "kaslr-seed");
+	if (ret == -FDT_ERR_NOTFOUND)
+		ret = 0;
+	else if (ret)
+		goto out;
+
+	if (rng_is_initialized()) {
+		u64 seed = get_random_u64();
+
+		ret = fdt_setprop_u64(fdt, chosen_node, "kaslr-seed", seed);
+		if (ret)
+			goto out;
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+			  "kaslr-seed");
+	}
+
+	/* add rng-seed */
+	if (rng_is_initialized()) {
+		void *rng_seed;
+
+		ret = fdt_setprop_placeholder(fdt, chosen_node, "rng-seed",
+				RNG_SEED_SIZE, &rng_seed);
+		if (ret)
+			goto out;
+		get_random_bytes(rng_seed, RNG_SEED_SIZE);
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+			  "rng-seed");
+	}
+
+	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	if (ret)
+		goto out;
+
+	remove_ima_buffer(fdt, chosen_node);
+	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
+
+out:
+	if (ret) {
+		kvfree(fdt);
+		fdt = NULL;
+	}
+
+	return fdt;
+}
diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c
new file mode 100644
index 000000000..9f17305f1
--- /dev/null
+++ b/drivers/of/kobj.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <kunit/visibility.h>
+
+#include "of_private.h"
+
+/* true when node is initialized */
+static int of_node_is_initialized(const struct device_node *node)
+{
+	return node && node->kobj.state_initialized;
+}
+
+/* true when node is attached (i.e. present on sysfs) */
+int of_node_is_attached(const struct device_node *node)
+{
+	return node && node->kobj.state_in_sysfs;
+}
+
+
+#ifndef CONFIG_OF_DYNAMIC
+static void of_node_release(struct kobject *kobj)
+{
+	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+const struct kobj_type of_node_ktype = {
+	.release = of_node_release,
+};
+EXPORT_SYMBOL_IF_KUNIT(of_node_ktype);
+
+static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
+				const struct bin_attribute *bin_attr, char *buf,
+				loff_t offset, size_t count)
+{
+	struct property *pp = container_of(bin_attr, struct property, attr);
+	return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
+}
+
+/* always return newly allocated name, caller must free after use */
+static const char *safe_name(const struct kobject *kobj, const char *orig_name)
+{
+	const char *name = orig_name;
+	struct kernfs_node *kn;
+	int i = 0;
+
+	/* don't be a hero. After 16 tries give up */
+	while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
+		sysfs_put(kn);
+		if (name != orig_name)
+			kfree(name);
+		name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
+	}
+
+	if (name == orig_name) {
+		name = kstrdup(orig_name, GFP_KERNEL);
+	} else {
+		pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
+			kobject_name(kobj), name);
+	}
+	return name;
+}
+
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	int rc;
+
+	/* Important: Don't leak passwords */
+	bool secure = strncmp(pp->name, "security-", 9) == 0;
+
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return 0;
+
+	if (!of_kset || !of_node_is_attached(np))
+		return 0;
+
+	sysfs_bin_attr_init(&pp->attr);
+	pp->attr.attr.name = safe_name(&np->kobj, pp->name);
+	pp->attr.attr.mode = secure ? 0400 : 0444;
+	pp->attr.size = secure ? 0 : pp->length;
+	pp->attr.read = of_node_property_read;
+
+	rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
+	WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np);
+	return rc;
+}
+
+void __of_sysfs_remove_bin_file(struct device_node *np, const struct property *prop)
+{
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return;
+
+	sysfs_remove_bin_file(&np->kobj, &prop->attr);
+	kfree(prop->attr.attr.name);
+}
+
+void __of_remove_property_sysfs(struct device_node *np, const struct property *prop)
+{
+	/* at early boot, bail here and defer setup to of_init() */
+	if (of_kset && of_node_is_attached(np))
+		__of_sysfs_remove_bin_file(np, prop);
+}
+
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+		const struct property *oldprop)
+{
+	/* At early boot, bail out and defer setup to of_init() */
+	if (!of_kset)
+		return;
+
+	if (oldprop)
+		__of_sysfs_remove_bin_file(np, oldprop);
+	__of_add_property_sysfs(np, newprop);
+}
+
+int __of_attach_node_sysfs(struct device_node *np)
+{
+	const char *name;
+	struct kobject *parent;
+	struct property *pp;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_SYSFS) || !of_kset)
+		return 0;
+
+	np->kobj.kset = of_kset;
+	if (!np->parent) {
+		/* Nodes without parents are new top level trees */
+		name = safe_name(&of_kset->kobj, "base");
+		parent = NULL;
+	} else {
+		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+		parent = &np->parent->kobj;
+	}
+	if (!name)
+		return -ENOMEM;
+
+	rc = kobject_add(&np->kobj, parent, "%s", name);
+	kfree(name);
+	if (rc)
+		return rc;
+
+	for_each_property_of_node(np, pp)
+		__of_add_property_sysfs(np, pp);
+
+	of_node_get(np);
+	return 0;
+}
+
+void __of_detach_node_sysfs(struct device_node *np)
+{
+	struct property *pp;
+
+	BUG_ON(!of_node_is_initialized(np));
+	if (!of_kset)
+		return;
+
+	/* only remove properties if on sysfs */
+	if (of_node_is_attached(np)) {
+		for_each_property_of_node(np, pp)
+			__of_sysfs_remove_bin_file(np, pp);
+		kobject_del(&np->kobj);
+	}
+
+	of_node_put(np);
+}
diff --git a/drivers/of/kunit_overlay_test.dtso b/drivers/of/kunit_overlay_test.dtso
new file mode 100644
index 000000000..85f20b4b4
--- /dev/null
+++ b/drivers/of/kunit_overlay_test.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&{/} {
+	kunit-test {
+		compatible = "test,empty";
+	};
+};
diff --git a/drivers/of/module.c b/drivers/of/module.c
new file mode 100644
index 000000000..1e735fc13
--- /dev/null
+++ b/drivers/of/module.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Linux kernel module helpers.
+ */
+
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+ssize_t of_modalias(const struct device_node *np, char *str, ssize_t len)
+{
+	const char *compat;
+	char *c;
+	struct property *p;
+	ssize_t csize;
+	ssize_t tsize;
+
+	/*
+	 * Prevent a kernel oops in vsnprintf() -- it only allows passing a
+	 * NULL ptr when the length is also 0. Also filter out the negative
+	 * lengths...
+	 */
+	if ((len > 0 && !str) || len < 0)
+		return -EINVAL;
+
+	/* Name & Type */
+	/* %p eats all alphanum characters, so %c must be used here */
+	csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T',
+			 of_node_get_device_type(np));
+	tsize = csize;
+	if (csize >= len)
+		csize = len > 0 ? len - 1 : 0;
+	len -= csize;
+	str += csize;
+
+	of_property_for_each_string(np, "compatible", p, compat) {
+		csize = snprintf(str, len, "C%s", compat);
+		tsize += csize;
+		if (csize >= len)
+			continue;
+		for (c = str; c; ) {
+			c = strchr(c, ' ');
+			if (c)
+				*c++ = '_';
+		}
+		len -= csize;
+		str += csize;
+	}
+
+	return tsize;
+}
+
+int of_request_module(const struct device_node *np)
+{
+	char *str;
+	ssize_t size;
+	int ret;
+
+	if (!np)
+		return -ENODEV;
+
+	size = of_modalias(np, NULL, 0);
+	if (size < 0)
+		return size;
+
+	/* Reserve an additional byte for the trailing '\0' */
+	size++;
+
+	str = kmalloc(size, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	of_modalias(np, str, size);
+	str[size - 1] = '\0';
+	ret = request_module(str);
+	kfree(str);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_request_module);
diff --git a/drivers/of/of_kunit_helpers.c b/drivers/of/of_kunit_helpers.c
new file mode 100644
index 000000000..f6ed1af8b
--- /dev/null
+++ b/drivers/of/of_kunit_helpers.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test managed DeviceTree APIs
+ */
+
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+#include <kunit/resource.h>
+
+#include "of_private.h"
+
+/**
+ * of_root_kunit_skip() - Skip test if the root node isn't populated
+ * @test: test to skip if the root node isn't populated
+ */
+void of_root_kunit_skip(struct kunit *test)
+{
+	if ((IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_RISCV)) &&
+	    IS_ENABLED(CONFIG_ACPI) && !of_root)
+		kunit_skip(test, "arm64/riscv+acpi doesn't populate a root node");
+}
+EXPORT_SYMBOL_GPL(of_root_kunit_skip);
+
+#if defined(CONFIG_OF_OVERLAY) && defined(CONFIG_OF_EARLY_FLATTREE)
+
+static void of_overlay_fdt_apply_kunit_exit(void *ovcs_id)
+{
+	of_overlay_remove(ovcs_id);
+}
+
+/**
+ * of_overlay_fdt_apply_kunit() - Test managed of_overlay_fdt_apply()
+ * @test: test context
+ * @overlay_fdt: device tree overlay to apply
+ * @overlay_fdt_size: size in bytes of @overlay_fdt
+ * @ovcs_id: identifier of overlay, used to remove the overlay
+ *
+ * Just like of_overlay_fdt_apply(), except the overlay is managed by the test
+ * case and is automatically removed with of_overlay_remove() after the test
+ * case concludes.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt,
+			       u32 overlay_fdt_size, int *ovcs_id)
+{
+	int ret;
+	int *copy_id;
+
+	of_root_kunit_skip(test);
+
+	copy_id = kunit_kmalloc(test, sizeof(*copy_id), GFP_KERNEL);
+	if (!copy_id)
+		return -ENOMEM;
+
+	ret = of_overlay_fdt_apply(overlay_fdt, overlay_fdt_size,
+				   ovcs_id, NULL);
+	if (ret)
+		return ret;
+
+	*copy_id = *ovcs_id;
+
+	return kunit_add_action_or_reset(test, of_overlay_fdt_apply_kunit_exit,
+					 copy_id);
+}
+EXPORT_SYMBOL_GPL(of_overlay_fdt_apply_kunit);
+
+#endif
+
+KUNIT_DEFINE_ACTION_WRAPPER(of_node_put_wrapper, of_node_put, struct device_node *);
+
+/**
+ * of_node_put_kunit() - Test managed of_node_put()
+ * @test: test context
+ * @node: node to pass to `of_node_put()`
+ *
+ * Just like of_node_put(), except the node is managed by the test case and is
+ * automatically put with of_node_put() after the test case concludes.
+ */
+void of_node_put_kunit(struct kunit *test, struct device_node *node)
+{
+	if (kunit_add_action(test, of_node_put_wrapper, node)) {
+		KUNIT_FAIL(test,
+			   "Can't allocate a kunit resource to put of_node\n");
+	}
+}
+EXPORT_SYMBOL_GPL(of_node_put_kunit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Test managed DeviceTree APIs");
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
new file mode 100644
index 000000000..230d5f628
--- /dev/null
+++ b/drivers/of/of_numa.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OF NUMA Parsing support.
+ *
+ * Copyright (C) 2015 - 2016 Cavium Inc.
+ */
+
+#define pr_fmt(fmt) "OF: NUMA: " fmt
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/nodemask.h>
+#include <linux/numa_memblks.h>
+
+#include <asm/numa.h>
+
+/*
+ * Even though we connect cpus to numa domains later in SMP
+ * init, we need to know the node ids now for all cpus.
+*/
+static void __init of_numa_parse_cpu_nodes(void)
+{
+	u32 nid;
+	int r;
+	struct device_node *np;
+
+	for_each_of_cpu_node(np) {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		if (r)
+			continue;
+
+		pr_debug("CPU on %u\n", nid);
+		if (nid >= MAX_NUMNODES)
+			pr_warn("Node id %u exceeds maximum value\n", nid);
+		else
+			node_set(nid, numa_nodes_parsed);
+	}
+}
+
+static int __init of_numa_parse_memory_nodes(void)
+{
+	struct device_node *np = NULL;
+	struct resource rsrc;
+	u32 nid;
+	int i, r = -EINVAL;
+
+	for_each_node_by_type(np, "memory") {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		if (r == -EINVAL)
+			/*
+			 * property doesn't exist if -EINVAL, continue
+			 * looking for more memory nodes with
+			 * "numa-node-id" property
+			 */
+			continue;
+
+		if (nid >= MAX_NUMNODES) {
+			pr_warn("Node id %u exceeds maximum value\n", nid);
+			r = -EINVAL;
+		}
+
+		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
+			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
+
+		if (!i || r) {
+			of_node_put(np);
+			pr_err("bad property in memory node\n");
+			return r ? : -EINVAL;
+		}
+	}
+
+	return r;
+}
+
+static int __init of_numa_parse_distance_map_v1(struct device_node *map)
+{
+	const __be32 *matrix;
+	int entry_count;
+	int i;
+
+	pr_info("parsing numa-distance-map-v1\n");
+
+	matrix = of_get_property(map, "distance-matrix", NULL);
+	if (!matrix) {
+		pr_err("No distance-matrix property in distance-map\n");
+		return -EINVAL;
+	}
+
+	entry_count = of_property_count_u32_elems(map, "distance-matrix");
+	if (entry_count <= 0) {
+		pr_err("Invalid distance-matrix\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i + 2 < entry_count; i += 3) {
+		u32 nodea, nodeb, distance;
+
+		nodea = of_read_number(matrix, 1);
+		matrix++;
+		nodeb = of_read_number(matrix, 1);
+		matrix++;
+		distance = of_read_number(matrix, 1);
+		matrix++;
+
+		if ((nodea == nodeb && distance != LOCAL_DISTANCE) ||
+		    (nodea != nodeb && distance <= LOCAL_DISTANCE)) {
+			pr_err("Invalid distance[node%d -> node%d] = %d\n",
+			       nodea, nodeb, distance);
+			return -EINVAL;
+		}
+
+		node_set(nodea, numa_nodes_parsed);
+
+		numa_set_distance(nodea, nodeb, distance);
+
+		/* Set default distance of node B->A same as A->B */
+		if (nodeb > nodea)
+			numa_set_distance(nodeb, nodea, distance);
+	}
+
+	return 0;
+}
+
+static int __init of_numa_parse_distance_map(void)
+{
+	int ret = 0;
+	struct device_node *np;
+
+	np = of_find_compatible_node(NULL, NULL,
+				     "numa-distance-map-v1");
+	if (np)
+		ret = of_numa_parse_distance_map_v1(np);
+
+	of_node_put(np);
+	return ret;
+}
+
+int of_node_to_nid(struct device_node *device)
+{
+	struct device_node *np;
+	u32 nid;
+	int r = -ENODATA;
+
+	np = of_node_get(device);
+
+	while (np) {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		/*
+		 * -EINVAL indicates the property was not found, and
+		 *  we walk up the tree trying to find a parent with a
+		 *  "numa-node-id".  Any other type of error indicates
+		 *  a bad device tree and we give up.
+		 */
+		if (r != -EINVAL)
+			break;
+
+		np = of_get_next_parent(np);
+	}
+	if (np && r)
+		pr_warn("Invalid \"numa-node-id\" property in node %pOFn\n",
+			np);
+	of_node_put(np);
+
+	/*
+	 * If numa=off passed on command line, or with a defective
+	 * device tree, the nid may not be in the set of possible
+	 * nodes.  Check for this case and return NUMA_NO_NODE.
+	 */
+	if (!r && nid < MAX_NUMNODES && node_possible(nid))
+		return nid;
+
+	return NUMA_NO_NODE;
+}
+
+int __init of_numa_init(void)
+{
+	int r;
+
+	of_numa_parse_cpu_nodes();
+	r = of_numa_parse_memory_nodes();
+	if (r)
+		return r;
+	return of_numa_parse_distance_map();
+}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
new file mode 100644
index 000000000..0ae16da06
--- /dev/null
+++ b/drivers/of/of_private.h
@@ -0,0 +1,222 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef _LINUX_OF_PRIVATE_H
+#define _LINUX_OF_PRIVATE_H
+/*
+ * Private symbols used by OF support code
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ */
+
+#define FDT_ALIGN_SIZE 8
+#define MAX_RESERVED_REGIONS    64
+
+/**
+ * struct alias_prop - Alias property in 'aliases' node
+ * @link:	List node to link the structure in aliases_lookup list
+ * @alias:	Alias property name
+ * @np:		Pointer to device_node that the alias stands for
+ * @id:		Index value from end of alias name
+ * @stem:	Alias string without the index
+ *
+ * The structure represents one alias property of 'aliases' node as
+ * an entry in aliases_lookup list.
+ */
+struct alias_prop {
+	struct list_head link;
+	const char *alias;
+	struct device_node *np;
+	int id;
+	char stem[];
+};
+
+#if defined(CONFIG_SPARC)
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
+#else
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 1
+#endif
+
+#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
+
+extern struct mutex of_mutex;
+extern raw_spinlock_t devtree_lock;
+extern struct list_head aliases_lookup;
+extern struct kset *of_kset;
+
+struct kunit;
+extern void of_root_kunit_skip(struct kunit *test);
+
+#if defined(CONFIG_OF_DYNAMIC)
+extern int of_property_notify(int action, struct device_node *np,
+			      struct property *prop, struct property *old_prop);
+extern void of_node_release(struct kobject *kobj);
+extern int __of_changeset_apply_entries(struct of_changeset *ocs,
+					int *ret_revert);
+extern int __of_changeset_apply_notify(struct of_changeset *ocs);
+extern int __of_changeset_revert_entries(struct of_changeset *ocs,
+					 int *ret_apply);
+extern int __of_changeset_revert_notify(struct of_changeset *ocs);
+#else /* CONFIG_OF_DYNAMIC */
+static inline int of_property_notify(int action, struct device_node *np,
+				     struct property *prop, struct property *old_prop)
+{
+	return 0;
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+#if defined(CONFIG_OF_DYNAMIC) && defined(CONFIG_OF_ADDRESS)
+void of_platform_register_reconfig_notifier(void);
+#else
+static inline void of_platform_register_reconfig_notifier(void) { }
+#endif
+
+#if defined(CONFIG_OF_KOBJ)
+int of_node_is_attached(const struct device_node *node);
+int __of_add_property_sysfs(struct device_node *np, struct property *pp);
+void __of_remove_property_sysfs(struct device_node *np, const struct property *prop);
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+		const struct property *oldprop);
+int __of_attach_node_sysfs(struct device_node *np);
+void __of_detach_node_sysfs(struct device_node *np);
+#else
+static inline int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	return 0;
+}
+static inline void __of_remove_property_sysfs(struct device_node *np, const struct property *prop) {}
+static inline void __of_update_property_sysfs(struct device_node *np,
+		struct property *newprop, const struct property *oldprop) {}
+static inline int __of_attach_node_sysfs(struct device_node *np)
+{
+	return 0;
+}
+static inline void __of_detach_node_sysfs(struct device_node *np) {}
+#endif
+
+#if defined(CONFIG_OF_RESOLVE)
+int of_resolve_phandles(struct device_node *tree);
+#endif
+
+void __of_phandle_cache_inv_entry(phandle handle);
+
+#if defined(CONFIG_OF_OVERLAY)
+void of_overlay_mutex_lock(void);
+void of_overlay_mutex_unlock(void);
+#else
+static inline void of_overlay_mutex_lock(void) {};
+static inline void of_overlay_mutex_unlock(void) {};
+#endif
+
+#if defined(CONFIG_OF_UNITTEST) && defined(CONFIG_OF_OVERLAY)
+extern void __init unittest_unflatten_overlay_base(void);
+#else
+static inline void unittest_unflatten_overlay_base(void) {};
+#endif
+
+extern void *__unflatten_device_tree(const void *blob,
+			      struct device_node *dad,
+			      struct device_node **mynodes,
+			      void *(*dt_alloc)(u64 size, u64 align),
+			      bool detached);
+
+void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
+
+/**
+ * General utilities for working with live trees.
+ *
+ * All functions with two leading underscores operate
+ * without taking node references, so you either have to
+ * own the devtree lock or work on detached trees only.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
+void __of_prop_free(struct property *prop);
+struct device_node *__of_node_dup(const struct device_node *np,
+				  const char *full_name);
+
+struct device_node *__of_find_node_by_path(const struct device_node *parent,
+						const char *path);
+struct device_node *__of_find_node_by_full_path(struct device_node *node,
+						const char *path);
+
+extern const void *__of_get_property(const struct device_node *np,
+				     const char *name, int *lenp);
+extern int __of_add_property(struct device_node *np, struct property *prop);
+extern int __of_remove_property(struct device_node *np, struct property *prop);
+extern int __of_update_property(struct device_node *np,
+		struct property *newprop, struct property **oldprop);
+
+extern void __of_detach_node(struct device_node *np);
+
+extern void __of_sysfs_remove_bin_file(struct device_node *np,
+				       const struct property *prop);
+
+/* illegal phandle value (set when unresolved) */
+#define OF_PHANDLE_ILLEGAL	0xdeadbeef
+
+/* iterators for transactions, used for overlays */
+/* forward iterator */
+#define for_each_transaction_entry(_oft, _te) \
+	list_for_each_entry(_te, &(_oft)->te_list, node)
+
+/* reverse iterator */
+#define for_each_transaction_entry_reverse(_oft, _te) \
+	list_for_each_entry_reverse(_te, &(_oft)->te_list, node)
+
+extern int of_bus_n_addr_cells(struct device_node *np);
+extern int of_bus_n_size_cells(struct device_node *np);
+
+const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len,
+				       struct of_phandle_args *out_irq);
+
+struct bus_dma_region;
+#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
+int of_dma_get_range(struct device_node *np,
+		const struct bus_dma_region **map);
+struct device_node *__of_get_dma_parent(const struct device_node *np);
+#else
+static inline int of_dma_get_range(struct device_node *np,
+		const struct bus_dma_region **map)
+{
+	return -ENODEV;
+}
+static inline struct device_node *__of_get_dma_parent(const struct device_node *np)
+{
+	return of_get_parent(np);
+}
+#endif
+
+int fdt_scan_reserved_mem(void);
+void __init fdt_scan_reserved_mem_late(void);
+
+bool of_fdt_device_is_available(const void *blob, unsigned long node);
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+#define OF_CHECK_ADDR_COUNT(na)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
+#define OF_CHECK_COUNTS(na, ns)	(OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
+
+/* Debug utility */
+#ifdef DEBUG
+static void __maybe_unused of_dump_addr(const char *s, const __be32 *addr, int na)
+{
+	pr_debug("%s", s);
+	while (na--)
+		pr_cont(" %08x", be32_to_cpu(*(addr++)));
+	pr_cont("\n");
+}
+#else
+static void __maybe_unused of_dump_addr(const char *s, const __be32 *addr, int na) { }
+#endif
+
+static inline bool is_pseudo_property(const char *prop_name)
+{
+	return !of_prop_cmp(prop_name, "name") ||
+		!of_prop_cmp(prop_name, "phandle") ||
+		!of_prop_cmp(prop_name, "linux,phandle");
+}
+
+#if IS_ENABLED(CONFIG_KUNIT)
+int __of_address_resource_bounds(struct resource *r, u64 start, u64 size);
+#endif
+
+#endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
new file mode 100644
index 000000000..8c9d6395d
--- /dev/null
+++ b/drivers/of/of_reserved_mem.c
@@ -0,0 +1,948 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Device tree based initialization code for reserved memory.
+ *
+ * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Author: Marek Szyprowski <m.szyprowski@samsung.com>
+ * Author: Josh Cartwright <joshc@codeaurora.org>
+ */
+
+#define pr_fmt(fmt)	"OF: reserved mem: " fmt
+
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/kmemleak.h>
+
+#include "of_private.h"
+
+static struct reserved_mem reserved_mem_array[MAX_RESERVED_REGIONS] __initdata;
+static struct reserved_mem *reserved_mem __refdata = reserved_mem_array;
+static int total_reserved_mem_cnt = MAX_RESERVED_REGIONS;
+static int reserved_mem_count;
+
+static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	phys_addr_t base;
+	int err = 0;
+
+	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
+	align = !align ? SMP_CACHE_BYTES : align;
+	base = memblock_phys_alloc_range(size, align, start, end);
+	if (!base)
+		return -ENOMEM;
+
+	*res_base = base;
+	if (nomap) {
+		err = memblock_mark_nomap(base, size);
+		if (err)
+			memblock_phys_free(base, size);
+	}
+
+	if (!err)
+		kmemleak_ignore_phys(base);
+
+	return err;
+}
+
+/*
+ * alloc_reserved_mem_array() - allocate memory for the reserved_mem
+ * array using memblock
+ *
+ * This function is used to allocate memory for the reserved_mem
+ * array according to the total number of reserved memory regions
+ * defined in the DT.
+ * After the new array is allocated, the information stored in
+ * the initial static array is copied over to this new array and
+ * the new array is used from this point on.
+ */
+static int __init alloc_reserved_mem_array(void)
+{
+	struct reserved_mem *new_array;
+	size_t alloc_size, copy_size, memset_size;
+	int ret;
+
+	if (!total_reserved_mem_cnt)
+		return 0;
+
+	alloc_size = array_size(total_reserved_mem_cnt, sizeof(*new_array));
+	if (alloc_size == SIZE_MAX) {
+		ret = -EOVERFLOW;
+		goto fail;
+	}
+
+	new_array = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+	if (!new_array) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	copy_size = array_size(reserved_mem_count, sizeof(*new_array));
+	if (copy_size == SIZE_MAX) {
+		memblock_free(new_array, alloc_size);
+		ret = -EOVERFLOW;
+		goto fail;
+	}
+
+	memset_size = alloc_size - copy_size;
+
+	memcpy(new_array, reserved_mem, copy_size);
+	memset(new_array + reserved_mem_count, 0, memset_size);
+
+	reserved_mem = new_array;
+	return 0;
+
+fail:
+	pr_err("Failed to allocate memory for reserved_mem array with err: %d", ret);
+	reserved_mem_count = 0;
+	return ret;
+}
+
+static void fdt_init_reserved_mem_node(unsigned long node, const char *uname,
+				       phys_addr_t base, phys_addr_t size);
+static int fdt_validate_reserved_mem_node(unsigned long node,
+					  phys_addr_t *align);
+static int fdt_fixup_reserved_mem_node(unsigned long node,
+				       phys_addr_t base, phys_addr_t size);
+
+static int __init early_init_dt_reserve_memory(phys_addr_t base,
+					       phys_addr_t size, bool nomap)
+{
+	if (nomap) {
+		/*
+		 * If the memory is already reserved (by another region), we
+		 * should not allow it to be marked nomap, but don't worry
+		 * if the region isn't memory as it won't be mapped.
+		 */
+		if (memblock_overlaps_region(&memblock.memory, base, size) &&
+		    memblock_is_region_reserved(base, size))
+			return -EBUSY;
+
+		return memblock_mark_nomap(base, size);
+	}
+	return memblock_reserve(base, size);
+}
+
+/*
+ * __reserved_mem_reserve_reg() - reserve memory described in the
+ * first entry in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+					     const char *uname)
+{
+	phys_addr_t base, size;
+	int len, err;
+	const __be32 *prop;
+	bool nomap;
+	u64 b, s;
+
+	prop = of_flat_dt_get_addr_size_prop(node, "reg", &len);
+	if (!prop || !len)
+		return -ENOENT;
+
+	if (len > 1)
+		pr_warn("Reserved memory: node '%s' has %d <base size> entries, only the first is used\n",
+			uname, len);
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	err = fdt_validate_reserved_mem_node(node, NULL);
+	if (err && err != -ENODEV)
+		return err;
+
+	of_flat_dt_read_addr_size(prop, 0, &b, &s);
+	base = b;
+	size = s;
+
+	if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) {
+		fdt_fixup_reserved_mem_node(node, base, size);
+		pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
+			 uname, &base, (unsigned long)(size / SZ_1M));
+	} else {
+		pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
+		       uname, &base, (unsigned long)(size / SZ_1M));
+	}
+	return 0;
+}
+
+/*
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __init __reserved_mem_check_root(unsigned long node)
+{
+	const __be32 *prop;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "ranges", NULL);
+	if (!prop)
+		return -EINVAL;
+	return 0;
+}
+
+static int __init __rmem_cmp(const void *a, const void *b)
+{
+	const struct reserved_mem *ra = a, *rb = b;
+
+	if (ra->base < rb->base)
+		return -1;
+
+	if (ra->base > rb->base)
+		return 1;
+
+	/*
+	 * Put the dynamic allocations (address == 0, size == 0) before static
+	 * allocations at address 0x0 so that overlap detection works
+	 * correctly.
+	 */
+	if (ra->size < rb->size)
+		return -1;
+	if (ra->size > rb->size)
+		return 1;
+
+	return 0;
+}
+
+static void __init __rmem_check_for_overlap(void)
+{
+	int i;
+
+	if (reserved_mem_count < 2)
+		return;
+
+	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
+	     __rmem_cmp, NULL);
+	for (i = 0; i < reserved_mem_count - 1; i++) {
+		struct reserved_mem *this, *next;
+
+		this = &reserved_mem[i];
+		next = &reserved_mem[i + 1];
+
+		if (this->base + this->size > next->base) {
+			phys_addr_t this_end, next_end;
+
+			this_end = this->base + this->size;
+			next_end = next->base + next->size;
+			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
+			       this->name, &this->base, &this_end,
+			       next->name, &next->base, &next_end);
+		}
+	}
+}
+
+/**
+ * fdt_scan_reserved_mem_late() - Scan FDT and initialize remaining reserved
+ * memory regions.
+ *
+ * This function is used to scan again through the DT and initialize the
+ * "static" reserved memory regions, that are defined using the "reg"
+ * property. Each such region is then initialized with its specific init
+ * function and stored in the global reserved_mem array.
+ */
+void __init fdt_scan_reserved_mem_late(void)
+{
+	const void *fdt = initial_boot_params;
+	phys_addr_t base, size;
+	int node, child;
+
+	if (!fdt)
+		return;
+
+	node = fdt_path_offset(fdt, "/reserved-memory");
+	if (node < 0) {
+		pr_info("Reserved memory: No reserved-memory node in the DT\n");
+		return;
+	}
+
+	/* Attempt dynamic allocation of a new reserved_mem array */
+	if (alloc_reserved_mem_array())
+		return;
+
+	if (__reserved_mem_check_root(node)) {
+		pr_err("Reserved memory: unsupported node format, ignoring\n");
+		return;
+	}
+
+	fdt_for_each_subnode(child, fdt, node) {
+		const __be32 *prop;
+		const char *uname;
+		u64 b, s;
+		int ret;
+		int len;
+
+		if (!of_fdt_device_is_available(fdt, child))
+			continue;
+
+		prop = of_flat_dt_get_addr_size_prop(child, "reg", &len);
+		if (!prop || !len)
+			continue;
+
+		ret = fdt_validate_reserved_mem_node(child, NULL);
+		if (ret && ret != -ENODEV)
+			continue;
+
+		of_flat_dt_read_addr_size(prop, 0, &b, &s);
+		base = b;
+		size = s;
+
+		if (size) {
+			uname = fdt_get_name(fdt, child, NULL);
+			fdt_init_reserved_mem_node(child, uname, base, size);
+		}
+	}
+
+	/* check for overlapping reserved regions */
+	__rmem_check_for_overlap();
+}
+
+static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname);
+
+/*
+ * fdt_scan_reserved_mem() - reserve and allocate memory occupied by
+ * reserved memory regions.
+ *
+ * This function is used to scan through the FDT and mark memory occupied
+ * by all static (defined by the "reg" property) reserved memory regions.
+ * Then memory for all dynamic regions (defined by size & alignment) is
+ * allocated, a region specific init function is called and region information
+ * is stored in the reserved_mem array.
+ */
+int __init fdt_scan_reserved_mem(void)
+{
+	int node, child;
+	int dynamic_nodes_cnt = 0, count = 0;
+	int dynamic_nodes[MAX_RESERVED_REGIONS];
+	const void *fdt = initial_boot_params;
+
+	node = fdt_path_offset(fdt, "/reserved-memory");
+	if (node < 0) {
+		total_reserved_mem_cnt = 0;
+		return -ENODEV;
+	}
+
+	if (__reserved_mem_check_root(node) != 0) {
+		pr_err("Reserved memory: unsupported node format, ignoring\n");
+		total_reserved_mem_cnt = 0;
+		return -EINVAL;
+	}
+
+	fdt_for_each_subnode(child, fdt, node) {
+		const char *uname;
+		int err;
+
+		if (!of_fdt_device_is_available(fdt, child))
+			continue;
+
+		uname = fdt_get_name(fdt, child, NULL);
+
+		err = __reserved_mem_reserve_reg(child, uname);
+		if (!err)
+			count++;
+
+		/*
+		 * Save the nodes for the dynamically-placed regions
+		 * into an array which will be used for allocation right
+		 * after all the statically-placed regions are reserved
+		 * or marked as no-map. This is done to avoid dynamically
+		 * allocating from one of the statically-placed regions.
+		 */
+		if (err != -ENOENT || !of_get_flat_dt_prop(child, "size", NULL))
+			continue;
+
+		if (dynamic_nodes_cnt == MAX_RESERVED_REGIONS) {
+			pr_err("too many defined dynamic regions, skip '%s'\n",
+			       uname);
+			continue;
+		}
+
+		dynamic_nodes[dynamic_nodes_cnt] = child;
+		dynamic_nodes_cnt++;
+	}
+	for (int i = 0; i < dynamic_nodes_cnt; i++) {
+		const char *uname;
+		int err;
+
+		child = dynamic_nodes[i];
+		uname = fdt_get_name(fdt, child, NULL);
+		err = __reserved_mem_alloc_size(child, uname);
+		if (!err)
+			count++;
+	}
+	total_reserved_mem_cnt = count;
+	return 0;
+}
+
+/*
+ * __reserved_mem_alloc_in_range() - allocate reserved memory described with
+ *	'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
+ *	reserved regions to keep the reserved memory contiguous if possible.
+ */
+static int __init __reserved_mem_alloc_in_range(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	bool prev_bottom_up = memblock_bottom_up();
+	bool bottom_up = false, top_down = false;
+	int ret, i;
+
+	for (i = 0; i < reserved_mem_count; i++) {
+		struct reserved_mem *rmem = &reserved_mem[i];
+
+		/* Skip regions that were not reserved yet */
+		if (rmem->size == 0)
+			continue;
+
+		/*
+		 * If range starts next to an existing reservation, use bottom-up:
+		 *	|....RRRR................RRRRRRRR..............|
+		 *	       --RRRR------
+		 */
+		if (start >= rmem->base && start <= (rmem->base + rmem->size))
+			bottom_up = true;
+
+		/*
+		 * If range ends next to an existing reservation, use top-down:
+		 *	|....RRRR................RRRRRRRR..............|
+		 *	              -------RRRR-----
+		 */
+		if (end >= rmem->base && end <= (rmem->base + rmem->size))
+			top_down = true;
+	}
+
+	/* Change setting only if either bottom-up or top-down was selected */
+	if (bottom_up != top_down)
+		memblock_set_bottom_up(bottom_up);
+
+	ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+			start, end, nomap, res_base);
+
+	/* Restore old setting if needed */
+	if (bottom_up != top_down)
+		memblock_set_bottom_up(prev_bottom_up);
+
+	return ret;
+}
+
+/*
+ * __reserved_mem_alloc_size() - allocate reserved memory described by
+ *	'size', 'alignment'  and 'alloc-ranges' properties.
+ */
+static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname)
+{
+	phys_addr_t start = 0, end = 0;
+	phys_addr_t base = 0, align = 0, size;
+	int i, len;
+	const __be32 *prop;
+	bool nomap;
+	int ret;
+
+	prop = of_get_flat_dt_prop(node, "size", &len);
+	if (!prop)
+		return -EINVAL;
+
+	if (len != dt_root_size_cells * sizeof(__be32)) {
+		pr_err("invalid size property in '%s' node.\n", uname);
+		return -EINVAL;
+	}
+	size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+	prop = of_get_flat_dt_prop(node, "alignment", &len);
+	if (prop) {
+		if (len != dt_root_addr_cells * sizeof(__be32)) {
+			pr_err("invalid alignment property in '%s' node.\n",
+				uname);
+			return -EINVAL;
+		}
+		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	ret = fdt_validate_reserved_mem_node(node, &align);
+	if (ret && ret != -ENODEV)
+		return ret;
+
+	prop = of_flat_dt_get_addr_size_prop(node, "alloc-ranges", &len);
+	if (prop) {
+		for (i = 0; i < len; i++) {
+			u64 b, s;
+
+			of_flat_dt_read_addr_size(prop, i, &b, &s);
+
+			start = b;
+			end = b + s;
+
+			base = 0;
+			ret = __reserved_mem_alloc_in_range(size, align,
+					start, end, nomap, &base);
+			if (ret == 0) {
+				pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+					uname, &base,
+					(unsigned long)(size / SZ_1M));
+				break;
+			}
+		}
+	} else {
+		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+							0, 0, nomap, &base);
+		if (ret == 0)
+			pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+				uname, &base, (unsigned long)(size / SZ_1M));
+	}
+
+	if (base == 0) {
+		pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
+		       uname, (unsigned long)(size / SZ_1M));
+		return -ENOMEM;
+	}
+
+	fdt_fixup_reserved_mem_node(node, base, size);
+	fdt_init_reserved_mem_node(node, uname, base, size);
+
+	return 0;
+}
+
+extern const struct of_device_id __reservedmem_of_table[];
+static const struct of_device_id __rmem_of_table_sentinel
+	__used __section("__reservedmem_of_table_end");
+
+/**
+ * fdt_fixup_reserved_mem_node() - call fixup function for a reserved memory node
+ * @node: FDT node to fixup
+ * @base: base address of the reserved memory region
+ * @size: size of the reserved memory region
+ *
+ * This function iterates through the reserved memory drivers and calls
+ * the node_fixup callback for the compatible entry matching the node.
+ *
+ * Return: 0 on success, -ENODEV if no compatible match found
+ */
+static int __init fdt_fixup_reserved_mem_node(unsigned long node,
+					phys_addr_t base, phys_addr_t size)
+{
+	const struct of_device_id *i;
+	int ret = -ENODEV;
+
+	for (i = __reservedmem_of_table; ret == -ENODEV &&
+	     i < &__rmem_of_table_sentinel; i++) {
+		const struct reserved_mem_ops *ops = i->data;
+
+		if (!of_flat_dt_is_compatible(node, i->compatible))
+			continue;
+
+		if (ops->node_fixup)
+			ret = ops->node_fixup(node, base, size);
+	}
+	return ret;
+}
+
+/**
+ * fdt_validate_reserved_mem_node() - validate a reserved memory node
+ * @node: FDT node to validate
+ * @align: pointer to store the validated alignment (may be modified by callback)
+ *
+ * This function iterates through the reserved memory drivers and calls
+ * the node_validate callback for the compatible entry matching the node.
+ *
+ * Return: 0 on success, -ENODEV if no compatible match found
+ */
+static int __init fdt_validate_reserved_mem_node(unsigned long node, phys_addr_t *align)
+{
+	const struct of_device_id *i;
+	int ret = -ENODEV;
+
+	for (i = __reservedmem_of_table; ret == -ENODEV &&
+	     i < &__rmem_of_table_sentinel; i++) {
+		const struct reserved_mem_ops *ops = i->data;
+
+		if (!of_flat_dt_is_compatible(node, i->compatible))
+			continue;
+
+		if (ops->node_validate)
+			ret = ops->node_validate(node, align);
+	}
+	return ret;
+}
+
+/**
+ * __reserved_mem_init_node() - initialize a reserved memory region
+ * @rmem: reserved_mem structure to initialize
+ * @node: FDT node describing the reserved memory region
+ *
+ * This function iterates through the reserved memory drivers and calls the
+ * node_init callback for the compatible entry matching the node. On success,
+ * the operations pointer is stored in the reserved_mem structure.
+ *
+ * Return: 0 on success, -ENODEV if no compatible match found
+ */
+static int __init __reserved_mem_init_node(struct reserved_mem *rmem,
+					   unsigned long node)
+{
+	const struct of_device_id *i;
+	int ret = -ENODEV;
+
+	for (i = __reservedmem_of_table; ret == -ENODEV &&
+	     i < &__rmem_of_table_sentinel; i++) {
+		const struct reserved_mem_ops *ops = i->data;
+		const char *compat = i->compatible;
+
+		if (!of_flat_dt_is_compatible(node, compat))
+			continue;
+
+		ret = ops->node_init(node, rmem);
+		if (ret == 0) {
+			rmem->ops = ops;
+			pr_info("initialized node %s, compatible id %s\n",
+				rmem->name, compat);
+			return ret;
+		}
+	}
+	return ret;
+}
+
+/**
+ * fdt_init_reserved_mem_node() - Initialize a reserved memory region
+ * @node: fdt node of the initialized region
+ * @uname: name of the reserved memory node
+ * @base: base address of the reserved memory region
+ * @size: size of the reserved memory region
+ *
+ * This function calls the region-specific initialization function for a
+ * reserved memory region and saves all region-specific data to the
+ * reserved_mem array to allow of_reserved_mem_lookup() to find it.
+ */
+static void __init fdt_init_reserved_mem_node(unsigned long node, const char *uname,
+					      phys_addr_t base, phys_addr_t size)
+{
+	int err = 0;
+	bool nomap;
+
+	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
+
+	if (reserved_mem_count == total_reserved_mem_cnt) {
+		pr_err("not enough space for all defined regions, skip '%s'\n",
+		       uname);
+		return;
+	}
+
+	rmem->name = uname;
+	rmem->base = base;
+	rmem->size = size;
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	err = __reserved_mem_init_node(rmem, node);
+	if (err != 0 && err != -ENODEV) {
+		pr_info("node %s compatible matching fail\n", rmem->name);
+		rmem->name = NULL;
+
+		if (nomap)
+			memblock_clear_nomap(rmem->base, rmem->size);
+		else
+			memblock_phys_free(rmem->base, rmem->size);
+		return;
+	} else {
+		phys_addr_t end = rmem->base + rmem->size - 1;
+		bool reusable =
+			(of_get_flat_dt_prop(node, "reusable", NULL)) != NULL;
+
+		pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
+			&rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
+			nomap ? "nomap" : "map",
+			reusable ? "reusable" : "non-reusable",
+			rmem->name ? rmem->name : "unknown");
+	}
+
+	reserved_mem_count++;
+}
+
+struct rmem_assigned_device {
+	struct device *dev;
+	struct reserved_mem *rmem;
+	struct list_head list;
+};
+
+static LIST_HEAD(of_rmem_assigned_device_list);
+static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
+
+/**
+ * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
+ *					  given device
+ * @dev:	Pointer to the device to configure
+ * @np:		Pointer to the device_node with 'reserved-memory' property
+ * @idx:	Index of selected region
+ *
+ * This function assigns respective DMA-mapping operations based on reserved
+ * memory region specified by 'memory-region' property in @np node to the @dev
+ * device. When driver needs to use more than one reserved memory region, it
+ * should allocate child devices and initialize regions by name for each of
+ * child device.
+ *
+ * Returns error code or zero on success.
+ */
+int of_reserved_mem_device_init_by_idx(struct device *dev,
+				       struct device_node *np, int idx)
+{
+	struct rmem_assigned_device *rd;
+	struct device_node *target;
+	struct reserved_mem *rmem;
+	int ret;
+
+	if (!np || !dev)
+		return -EINVAL;
+
+	target = of_parse_phandle(np, "memory-region", idx);
+	if (!target)
+		return -ENODEV;
+
+	if (!of_device_is_available(target)) {
+		of_node_put(target);
+		return 0;
+	}
+
+	rmem = of_reserved_mem_lookup(target);
+	of_node_put(target);
+
+	if (!rmem || !rmem->ops || !rmem->ops->device_init)
+		return -EINVAL;
+
+	rd = kmalloc_obj(struct rmem_assigned_device);
+	if (!rd)
+		return -ENOMEM;
+
+	ret = rmem->ops->device_init(rmem, dev);
+	if (ret == 0) {
+		rd->dev = dev;
+		rd->rmem = rmem;
+
+		mutex_lock(&of_rmem_assigned_device_mutex);
+		list_add(&rd->list, &of_rmem_assigned_device_list);
+		mutex_unlock(&of_rmem_assigned_device_mutex);
+
+		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+	} else {
+		kfree(rd);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
+
+/**
+ * of_reserved_mem_device_init_by_name() - assign named reserved memory region
+ *					   to given device
+ * @dev: pointer to the device to configure
+ * @np: pointer to the device node with 'memory-region' property
+ * @name: name of the selected memory region
+ *
+ * Returns: 0 on success or a negative error-code on failure.
+ */
+int of_reserved_mem_device_init_by_name(struct device *dev,
+					struct device_node *np,
+					const char *name)
+{
+	int idx = of_property_match_string(np, "memory-region-names", name);
+
+	return of_reserved_mem_device_init_by_idx(dev, np, idx);
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ * @dev:	Pointer to the device to deconfigure
+ *
+ * This function releases structures allocated for memory region handling for
+ * the given device.
+ */
+void of_reserved_mem_device_release(struct device *dev)
+{
+	struct rmem_assigned_device *rd, *tmp;
+	LIST_HEAD(release_list);
+
+	mutex_lock(&of_rmem_assigned_device_mutex);
+	list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
+		if (rd->dev == dev)
+			list_move_tail(&rd->list, &release_list);
+	}
+	mutex_unlock(&of_rmem_assigned_device_mutex);
+
+	list_for_each_entry_safe(rd, tmp, &release_list, list) {
+		if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
+			rd->rmem->ops->device_release(rd->rmem, dev);
+
+		kfree(rd);
+	}
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
+
+static void devm_of_reserved_mem_device_release(struct device *dev, void *res)
+{
+	of_reserved_mem_device_release(*(struct device **)res);
+}
+
+static int devm_of_reserved_mem_device_init_by_idx(struct device *dev,
+						   struct device_node *np, int idx)
+{
+	struct device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_of_reserved_mem_device_release, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = of_reserved_mem_device_init_by_idx(dev, np, idx);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = dev;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+
+/**
+ * devm_of_reserved_mem_device_init() - Resource managed of_reserved_mem_device_init()
+ * @dev: Pointer to the device to configure
+ *
+ * This is a resource managed version of of_reserved_mem_device_init().
+ * The reserved memory region will be released automatically when the device
+ * is unbound.
+ *
+ * Returns: Negative errno on failure or zero on success.
+ */
+int devm_of_reserved_mem_device_init(struct device *dev)
+{
+	return devm_of_reserved_mem_device_init_by_idx(dev, dev->of_node, 0);
+}
+EXPORT_SYMBOL_GPL(devm_of_reserved_mem_device_init);
+
+/**
+ * of_reserved_mem_lookup() - acquire reserved_mem from a device node
+ * @np:		node pointer of the desired reserved-memory region
+ *
+ * This function allows drivers to acquire a reference to the reserved_mem
+ * struct based on a device node handle.
+ *
+ * Returns a reserved_mem reference, or NULL on error.
+ */
+struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
+{
+	const char *name;
+	int i;
+
+	if (!np->full_name)
+		return NULL;
+
+	name = kbasename(np->full_name);
+	for (i = 0; i < reserved_mem_count; i++)
+		if (reserved_mem[i].name &&
+		    !strcmp(reserved_mem[i].name, name))
+			return &reserved_mem[i];
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
+
+/**
+ * of_reserved_mem_region_to_resource() - Get a reserved memory region as a resource
+ * @np:		node containing 'memory-region' property
+ * @idx:	index of 'memory-region' property to lookup
+ * @res:	Pointer to a struct resource to fill in with reserved region
+ *
+ * This function allows drivers to lookup a node's 'memory-region' property
+ * entries by index and return a struct resource for the entry.
+ *
+ * Returns 0 on success with @res filled in. Returns -ENODEV if 'memory-region'
+ * is missing or unavailable, -EINVAL for any other error.
+ */
+int of_reserved_mem_region_to_resource(const struct device_node *np,
+				       unsigned int idx, struct resource *res)
+{
+	struct reserved_mem *rmem;
+
+	if (!np)
+		return -EINVAL;
+
+	struct device_node *target __free(device_node) = of_parse_phandle(np, "memory-region", idx);
+	if (!target || !of_device_is_available(target))
+		return -ENODEV;
+
+	rmem = of_reserved_mem_lookup(target);
+	if (!rmem)
+		return -EINVAL;
+
+	resource_set_range(res, rmem->base, rmem->size);
+	res->flags = IORESOURCE_MEM;
+	res->name = rmem->name;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource);
+
+/**
+ * of_reserved_mem_region_to_resource_byname() - Get a reserved memory region as a resource
+ * @np:		node containing 'memory-region' property
+ * @name:	name of 'memory-region' property entry to lookup
+ * @res:	Pointer to a struct resource to fill in with reserved region
+ *
+ * This function allows drivers to lookup a node's 'memory-region' property
+ * entries by name and return a struct resource for the entry.
+ *
+ * Returns 0 on success with @res filled in, or a negative error-code on
+ * failure.
+ */
+int of_reserved_mem_region_to_resource_byname(const struct device_node *np,
+					      const char *name,
+					      struct resource *res)
+{
+	int idx;
+
+	if (!name)
+		return -EINVAL;
+
+	idx = of_property_match_string(np, "memory-region-names", name);
+	if (idx < 0)
+		return idx;
+
+	return of_reserved_mem_region_to_resource(np, idx, res);
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource_byname);
+
+/**
+ * of_reserved_mem_region_count() - Return the number of 'memory-region' entries
+ * @np:		node containing 'memory-region' property
+ *
+ * This function allows drivers to retrieve the number of entries for a node's
+ * 'memory-region' property.
+ *
+ * Returns the number of entries on success, or negative error code on a
+ * malformed property.
+ */
+int of_reserved_mem_region_count(const struct device_node *np)
+{
+	return of_count_phandle_with_args(np, "memory-region", NULL);
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_region_count);
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
new file mode 100644
index 000000000..8bba5a72c
--- /dev/null
+++ b/drivers/of/of_test.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for OF APIs
+ */
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <kunit/test.h>
+
+#include "of_private.h"
+
+/*
+ * Test that the root node "/" can be found by path.
+ */
+static void of_dtb_root_node_found_by_path(struct kunit *test)
+{
+	struct device_node *np;
+
+	np = of_find_node_by_path("/");
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+	of_node_put(np);
+}
+
+/*
+ * Test that the 'of_root' global variable is always populated when DT code is
+ * enabled. Remove this test once of_root is removed from global access.
+ */
+static void of_dtb_root_node_populates_of_root(struct kunit *test)
+{
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, of_root);
+}
+
+static struct kunit_case of_dtb_test_cases[] = {
+	KUNIT_CASE(of_dtb_root_node_found_by_path),
+	KUNIT_CASE(of_dtb_root_node_populates_of_root),
+	{}
+};
+
+static int of_dtb_test_init(struct kunit *test)
+{
+	of_root_kunit_skip(test);
+	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE");
+
+	return 0;
+}
+
+/*
+ * Test suite to confirm a DTB is loaded.
+ */
+static struct kunit_suite of_dtb_suite = {
+	.name = "of_dtb",
+	.test_cases = of_dtb_test_cases,
+	.init = of_dtb_test_init,
+};
+
+struct of_address_resource_bounds_case {
+	u64 start;
+	u64 size;
+	int ret;
+
+	u64 res_start;
+	u64 res_end;
+};
+
+static void of_address_resource_bounds_case_desc(const struct of_address_resource_bounds_case *p,
+						 char *name)
+{
+	snprintf(name, KUNIT_PARAM_DESC_SIZE, "start=0x%016llx,size=0x%016llx", p->start, p->size);
+}
+
+static const struct of_address_resource_bounds_case of_address_resource_bounds_cases[] = {
+	{
+		.start = 0,
+		.size = 0,
+		.ret = 0,
+		.res_start = 0,
+		.res_end = -1,
+	},
+	{
+		.start = 0,
+		.size = 0x1000,
+		.ret = 0,
+		.res_start = 0,
+		.res_end = 0xfff,
+	},
+	{
+		.start = 0x1000,
+		.size = 0,
+		.ret = 0,
+		.res_start = 0x1000,
+		.res_end = 0xfff,
+	},
+	{
+		.start = 0x1000,
+		.size = 0x1000,
+		.ret = 0,
+		.res_start = 0x1000,
+		.res_end = 0x1fff,
+	},
+	{
+		.start = 1,
+		.size = RESOURCE_SIZE_MAX,
+		.ret = 0,
+		.res_start = 1,
+		.res_end = RESOURCE_SIZE_MAX,
+	},
+	{
+		.start = RESOURCE_SIZE_MAX,
+		.size = 1,
+		.ret = 0,
+		.res_start = RESOURCE_SIZE_MAX,
+		.res_end = RESOURCE_SIZE_MAX,
+	},
+	{
+		.start = 2,
+		.size = RESOURCE_SIZE_MAX,
+		.ret = -EOVERFLOW,
+	},
+	{
+		.start = RESOURCE_SIZE_MAX,
+		.size = 2,
+		.ret = -EOVERFLOW,
+	},
+	{
+		.start = ULL(0x100000000),
+		.size = 1,
+		.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
+		.res_start = ULL(0x100000000),
+		.res_end = ULL(0x100000000),
+	},
+	{
+		.start = 0x1000,
+		.size = 0xffffffff,
+		.ret = sizeof(resource_size_t) > sizeof(u32) ? 0 : -EOVERFLOW,
+		.res_start = 0x1000,
+		.res_end = ULL(0x100000ffe),
+	},
+};
+
+KUNIT_ARRAY_PARAM(of_address_resource_bounds,
+		  of_address_resource_bounds_cases, of_address_resource_bounds_case_desc);
+
+static void of_address_resource_bounds(struct kunit *test)
+{
+	const struct of_address_resource_bounds_case *param = test->param_value;
+	struct resource r; /* Intentionally uninitialized */
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_OF_ADDRESS))
+		kunit_skip(test, "CONFIG_OF_ADDRESS not enabled\n");
+
+	ret = __of_address_resource_bounds(&r, param->start, param->size);
+	KUNIT_EXPECT_EQ(test, param->ret, ret);
+	if (ret == 0) {
+		KUNIT_EXPECT_EQ(test, (resource_size_t)param->res_start, r.start);
+		KUNIT_EXPECT_EQ(test, (resource_size_t)param->res_end, r.end);
+		KUNIT_EXPECT_EQ(test, param->size, resource_size(&r));
+	}
+}
+
+static struct kunit_case of_address_test_cases[] = {
+	KUNIT_CASE_PARAM(of_address_resource_bounds, of_address_resource_bounds_gen_params),
+	{}
+};
+
+static struct kunit_suite of_address_suite = {
+	.name = "of_address",
+	.test_cases = of_address_test_cases,
+};
+
+kunit_test_suites(
+	&of_dtb_suite, &of_address_suite,
+);
+MODULE_DESCRIPTION("KUnit tests for OF APIs");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
new file mode 100644
index 000000000..08d535174
--- /dev/null
+++ b/drivers/of/overlay.c
@@ -0,0 +1,1298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for working with device tree overlays
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: overlay: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_fdt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/libfdt.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+
+#include "of_private.h"
+
+/**
+ * struct target - info about current target node as recursing through overlay
+ * @np:			node where current level of overlay will be applied
+ * @in_livetree:	@np is a node in the live devicetree
+ *
+ * Used in the algorithm to create the portion of a changeset that describes
+ * an overlay fragment, which is a devicetree subtree.  Initially @np is a node
+ * in the live devicetree where the overlay subtree is targeted to be grafted
+ * into.  When recursing to the next level of the overlay subtree, the target
+ * also recurses to the next level of the live devicetree, as long as overlay
+ * subtree node also exists in the live devicetree.  When a node in the overlay
+ * subtree does not exist at the same level in the live devicetree, target->np
+ * points to a newly allocated node, and all subsequent targets in the subtree
+ * will be newly allocated nodes.
+ */
+struct target {
+	struct device_node *np;
+	bool in_livetree;
+};
+
+/**
+ * struct fragment - info about fragment nodes in overlay expanded device tree
+ * @overlay:	pointer to the __overlay__ node
+ * @target:	target of the overlay operation
+ */
+struct fragment {
+	struct device_node *overlay;
+	struct device_node *target;
+};
+
+/**
+ * struct overlay_changeset
+ * @id:			changeset identifier
+ * @ovcs_list:		list on which we are located
+ * @new_fdt:		Memory allocated to hold unflattened aligned FDT
+ * @overlay_mem:	the memory chunk that contains @overlay_root
+ * @overlay_root:	expanded device tree that contains the fragment nodes
+ * @notify_state:	most recent notify action used on overlay
+ * @count:		count of fragment structures
+ * @fragments:		fragment nodes in the overlay expanded device tree
+ * @symbols_fragment:	last element of @fragments[] is the  __symbols__ node
+ * @cset:		changeset to apply fragments to live device tree
+ */
+struct overlay_changeset {
+	int id;
+	struct list_head ovcs_list;
+	const void *new_fdt;
+	const void *overlay_mem;
+	struct device_node *overlay_root;
+	enum of_overlay_notify_action notify_state;
+	int count;
+	struct fragment *fragments;
+	bool symbols_fragment;
+	struct of_changeset cset;
+};
+
+/* flags are sticky - once set, do not reset */
+static int devicetree_state_flags;
+#define DTSF_APPLY_FAIL		0x01
+#define DTSF_REVERT_FAIL	0x02
+
+static int of_prop_val_eq(const struct property *p1, const struct property *p2)
+{
+	return p1->length == p2->length &&
+	       !memcmp(p1->value, p2->value, (size_t)p1->length);
+}
+
+/*
+ * If a changeset apply or revert encounters an error, an attempt will
+ * be made to undo partial changes, but may fail.  If the undo fails
+ * we do not know the state of the devicetree.
+ */
+static int devicetree_corrupt(void)
+{
+	return devicetree_state_flags &
+		(DTSF_APPLY_FAIL | DTSF_REVERT_FAIL);
+}
+
+static int build_changeset_next_level(struct overlay_changeset *ovcs,
+		struct target *target, const struct device_node *overlay_node);
+
+/*
+ * of_resolve_phandles() finds the largest phandle in the live tree.
+ * of_overlay_apply() may add a larger phandle to the live tree.
+ * Do not allow race between two overlays being applied simultaneously:
+ *    mutex_lock(&of_overlay_phandle_mutex)
+ *    of_resolve_phandles()
+ *    of_overlay_apply()
+ *    mutex_unlock(&of_overlay_phandle_mutex)
+ */
+static DEFINE_MUTEX(of_overlay_phandle_mutex);
+
+void of_overlay_mutex_lock(void)
+{
+	mutex_lock(&of_overlay_phandle_mutex);
+}
+
+void of_overlay_mutex_unlock(void)
+{
+	mutex_unlock(&of_overlay_phandle_mutex);
+}
+
+static LIST_HEAD(ovcs_list);
+static DEFINE_IDR(ovcs_idr);
+
+static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain);
+
+/**
+ * of_overlay_notifier_register() - Register notifier for overlay operations
+ * @nb:		Notifier block to register
+ *
+ * Register for notification on overlay operations on device tree nodes. The
+ * reported actions defined by @of_reconfig_change. The notifier callback
+ * furthermore receives a pointer to the affected device tree node.
+ *
+ * Note that a notifier callback is not supposed to store pointers to a device
+ * tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the
+ * respective node it received.
+ */
+int of_overlay_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&overlay_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_overlay_notifier_register);
+
+/**
+ * of_overlay_notifier_unregister() - Unregister notifier for overlay operations
+ * @nb:		Notifier block to unregister
+ */
+int of_overlay_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&overlay_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister);
+
+static int overlay_notify(struct overlay_changeset *ovcs,
+		enum of_overlay_notify_action action)
+{
+	struct of_overlay_notify_data nd;
+	int i, ret;
+
+	ovcs->notify_state = action;
+
+	for (i = 0; i < ovcs->count; i++) {
+		struct fragment *fragment = &ovcs->fragments[i];
+
+		nd.target = fragment->target;
+		nd.overlay = fragment->overlay;
+
+		ret = blocking_notifier_call_chain(&overlay_notify_chain,
+						   action, &nd);
+		if (notifier_to_errno(ret)) {
+			ret = notifier_to_errno(ret);
+			pr_err("overlay changeset %s notifier error %d, target: %pOF\n",
+			       of_overlay_action_name(action), ret, nd.target);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void overlay_fw_devlink_refresh(struct overlay_changeset *ovcs)
+{
+	for (int i = 0; i < ovcs->count; i++) {
+		struct device_node *np = ovcs->fragments[i].target;
+
+		fw_devlink_refresh_fwnode(of_fwnode_handle(np));
+	}
+}
+
+/*
+ * The values of properties in the "/__symbols__" node are paths in
+ * the ovcs->overlay_root.  When duplicating the properties, the paths
+ * need to be adjusted to be the correct path for the live device tree.
+ *
+ * The paths refer to a node in the subtree of a fragment node's "__overlay__"
+ * node, for example "/fragment@0/__overlay__/symbol_path_tail",
+ * where symbol_path_tail can be a single node or it may be a multi-node path.
+ *
+ * The duplicated property value will be modified by replacing the
+ * "/fragment_name/__overlay/" portion of the value  with the target
+ * path from the fragment node.
+ */
+static struct property *dup_and_fixup_symbol_prop(
+		struct overlay_changeset *ovcs, const struct property *prop)
+{
+	struct fragment *fragment;
+	struct property *new_prop;
+	struct device_node *fragment_node;
+	struct device_node *overlay_node;
+	const char *path;
+	const char *path_tail;
+	const char *target_path;
+	int k;
+	int overlay_name_len;
+	int path_len;
+	int path_tail_len;
+	int target_path_len;
+
+	if (!prop->value)
+		return NULL;
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return NULL;
+	path = prop->value;
+	path_len = strlen(path);
+
+	if (path_len < 1)
+		return NULL;
+	fragment_node = __of_find_node_by_path(ovcs->overlay_root, path + 1);
+	overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/");
+	of_node_put(fragment_node);
+	of_node_put(overlay_node);
+
+	for (k = 0; k < ovcs->count; k++) {
+		fragment = &ovcs->fragments[k];
+		if (fragment->overlay == overlay_node)
+			break;
+	}
+	if (k >= ovcs->count)
+		return NULL;
+
+	overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay);
+
+	if (overlay_name_len > path_len)
+		return NULL;
+	path_tail = path + overlay_name_len;
+	path_tail_len = strlen(path_tail);
+
+	target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target);
+	if (!target_path)
+		return NULL;
+	target_path_len = strlen(target_path);
+
+	new_prop = kzalloc_obj(*new_prop);
+	if (!new_prop)
+		goto err_free_target_path;
+
+	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
+	new_prop->length = target_path_len + path_tail_len + 1;
+	new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
+	if (!new_prop->name || !new_prop->value)
+		goto err_free_new_prop;
+
+	memcpy(new_prop->value, target_path, target_path_len);
+	memcpy(new_prop->value + target_path_len, path_tail, path_tail_len);
+
+	of_property_set_flag(new_prop, OF_DYNAMIC);
+
+	kfree(target_path);
+
+	return new_prop;
+
+err_free_new_prop:
+	__of_prop_free(new_prop);
+err_free_target_path:
+	kfree(target_path);
+
+	return NULL;
+}
+
+/**
+ * add_changeset_property() - add @overlay_prop to overlay changeset
+ * @ovcs:		overlay changeset
+ * @target:		where @overlay_prop will be placed
+ * @overlay_prop:	property to add or update, from overlay tree
+ * @is_symbols_prop:	1 if @overlay_prop is from node "/__symbols__"
+ *
+ * If @overlay_prop does not already exist in live devicetree, add changeset
+ * entry to add @overlay_prop in @target, else add changeset entry to update
+ * value of @overlay_prop.
+ *
+ * @target may be either in the live devicetree or in a new subtree that
+ * is contained in the changeset.
+ *
+ * Some special properties are not added or updated (no error returned):
+ * "name", "phandle", "linux,phandle".
+ *
+ * Properties "#address-cells" and "#size-cells" are not updated if they
+ * are already in the live tree, but if present in the live tree, the values
+ * in the overlay must match the values in the live tree.
+ *
+ * Update of property in symbols node is not allowed.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay.
+ */
+static int add_changeset_property(struct overlay_changeset *ovcs,
+		struct target *target, const struct property *overlay_prop,
+		bool is_symbols_prop)
+{
+	struct property *new_prop = NULL;
+	const struct property *prop;
+	int ret = 0;
+
+	if (target->in_livetree)
+		if (is_pseudo_property(overlay_prop->name))
+			return 0;
+
+	if (target->in_livetree)
+		prop = of_find_property(target->np, overlay_prop->name, NULL);
+	else
+		prop = NULL;
+
+	if (prop) {
+		if (!of_prop_cmp(prop->name, "#address-cells")) {
+			if (!of_prop_val_eq(prop, overlay_prop)) {
+				pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
+				       target->np);
+				ret = -EINVAL;
+			}
+			return ret;
+
+		} else if (!of_prop_cmp(prop->name, "#size-cells")) {
+			if (!of_prop_val_eq(prop, overlay_prop)) {
+				pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
+				       target->np);
+				ret = -EINVAL;
+			}
+			return ret;
+		}
+	}
+
+	if (is_symbols_prop) {
+		if (prop)
+			return -EINVAL;
+		new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop);
+	} else {
+		new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL);
+	}
+
+	if (!new_prop)
+		return -ENOMEM;
+
+	if (!prop) {
+		if (!target->in_livetree) {
+			new_prop->next = target->np->deadprops;
+			target->np->deadprops = new_prop;
+		}
+		ret = of_changeset_add_property(&ovcs->cset, target->np,
+						new_prop);
+	} else {
+		ret = of_changeset_update_property(&ovcs->cset, target->np,
+						   new_prop);
+	}
+
+	if (!of_node_check_flag(target->np, OF_OVERLAY))
+		pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n",
+		       target->np, new_prop->name);
+
+	if (ret)
+		__of_prop_free(new_prop);
+	return ret;
+}
+
+/**
+ * add_changeset_node() - add @node (and children) to overlay changeset
+ * @ovcs:	overlay changeset
+ * @target:	where @node will be placed in live tree or changeset
+ * @node:	node from within overlay device tree fragment
+ *
+ * If @node does not already exist in @target, add changeset entry
+ * to add @node in @target.
+ *
+ * If @node already exists in @target, and the existing node has
+ * a phandle, the overlay node is not allowed to have a phandle.
+ *
+ * If @node has child nodes, add the children recursively via
+ * build_changeset_next_level().
+ *
+ * NOTE_1: A live devicetree created from a flattened device tree (FDT) will
+ *       not contain the full path in node->full_name.  Thus an overlay
+ *       created from an FDT also will not contain the full path in
+ *       node->full_name.  However, a live devicetree created from Open
+ *       Firmware may have the full path in node->full_name.
+ *
+ *       add_changeset_node() follows the FDT convention and does not include
+ *       the full path in node->full_name.  Even though it expects the overlay
+ *       to not contain the full path, it uses kbasename() to remove the
+ *       full path should it exist.  It also uses kbasename() in comparisons
+ *       to nodes in the live devicetree so that it can apply an overlay to
+ *       a live devicetree created from Open Firmware.
+ *
+ * NOTE_2: Multiple mods of created nodes not supported.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay.
+ */
+static int add_changeset_node(struct overlay_changeset *ovcs,
+		struct target *target, const struct device_node *node)
+{
+	const char *node_kbasename;
+	const __be32 *phandle;
+	struct device_node *tchild;
+	struct target target_child;
+	int ret = 0, size;
+
+	node_kbasename = kbasename(node->full_name);
+
+	for_each_child_of_node(target->np, tchild)
+		if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))
+			break;
+
+	if (!tchild) {
+		tchild = __of_node_dup(NULL, node_kbasename);
+		if (!tchild)
+			return -ENOMEM;
+
+		tchild->parent = target->np;
+		tchild->name = __of_get_property(node, "name", NULL);
+
+		if (!tchild->name)
+			tchild->name = "<NULL>";
+
+		/* ignore obsolete "linux,phandle" */
+		phandle = __of_get_property(node, "phandle", &size);
+		if (phandle && (size == 4))
+			tchild->phandle = be32_to_cpup(phandle);
+
+		of_node_set_flag(tchild, OF_OVERLAY);
+
+		ret = of_changeset_attach_node(&ovcs->cset, tchild);
+		if (ret)
+			return ret;
+
+		target_child.np = tchild;
+		target_child.in_livetree = false;
+
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+		of_node_put(tchild);
+		return ret;
+	}
+
+	if (node->phandle && tchild->phandle) {
+		ret = -EINVAL;
+	} else {
+		target_child.np = tchild;
+		target_child.in_livetree = target->in_livetree;
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+	}
+	of_node_put(tchild);
+
+	return ret;
+}
+
+/**
+ * build_changeset_next_level() - add level of overlay changeset
+ * @ovcs:		overlay changeset
+ * @target:		where to place @overlay_node in live tree
+ * @overlay_node:	node from within an overlay device tree fragment
+ *
+ * Add the properties (if any) and nodes (if any) from @overlay_node to the
+ * @ovcs->cset changeset.  If an added node has child nodes, they will
+ * be added recursively.
+ *
+ * Do not allow symbols node to have any children.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay_node.
+ */
+static int build_changeset_next_level(struct overlay_changeset *ovcs,
+		struct target *target, const struct device_node *overlay_node)
+{
+	struct property *prop;
+	int ret;
+
+	for_each_property_of_node(overlay_node, prop) {
+		ret = add_changeset_property(ovcs, target, prop, 0);
+		if (ret) {
+			pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
+				 target->np, prop->name, ret);
+			return ret;
+		}
+	}
+
+	for_each_child_of_node_scoped(overlay_node, child) {
+		ret = add_changeset_node(ovcs, target, child);
+		if (ret) {
+			pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n",
+				 target->np, child, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Add the properties from __overlay__ node to the @ovcs->cset changeset.
+ */
+static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
+		struct target *target,
+		const struct device_node *overlay_symbols_node)
+{
+	struct property *prop;
+	int ret;
+
+	for_each_property_of_node(overlay_symbols_node, prop) {
+		ret = add_changeset_property(ovcs, target, prop, 1);
+		if (ret) {
+			pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n",
+				 target->np, prop->name, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&
+	    ce_1->action != OF_RECONFIG_DETACH_NODE)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&
+		     ce_2->action != OF_RECONFIG_DETACH_NODE) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match) {
+			pr_err("ERROR: multiple fragments add and/or delete node %pOF\n",
+			       ce_1->np);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int find_dup_cset_prop(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match &&
+		    !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {
+			pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n",
+			       ce_1->np, ce_1->prop->name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * changeset_dup_entry_check() - check for duplicate entries
+ * @ovcs:	Overlay changeset
+ *
+ * Check changeset @ovcs->cset for multiple {add or delete} node entries for
+ * the same node or duplicate {add, delete, or update} properties entries
+ * for the same property.
+ *
+ * Return: 0 on success, or -EINVAL if duplicate changeset entry found.
+ */
+static int changeset_dup_entry_check(struct overlay_changeset *ovcs)
+{
+	struct of_changeset_entry *ce_1;
+	int dup_entry = 0;
+
+	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
+		dup_entry |= find_dup_cset_node_entry(ovcs, ce_1);
+		dup_entry |= find_dup_cset_prop(ovcs, ce_1);
+	}
+
+	return dup_entry ? -EINVAL : 0;
+}
+
+/**
+ * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
+ * @ovcs:	Overlay changeset
+ *
+ * Create changeset @ovcs->cset to contain the nodes and properties of the
+ * overlay device tree fragments in @ovcs->fragments[].  If an error occurs,
+ * any portions of the changeset that were successfully created will remain
+ * in @ovcs->cset.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid overlay in @ovcs->fragments[].
+ */
+static int build_changeset(struct overlay_changeset *ovcs)
+{
+	struct fragment *fragment;
+	struct target target;
+	int fragments_count, i, ret;
+
+	/*
+	 * if there is a symbols fragment in ovcs->fragments[i] it is
+	 * the final element in the array
+	 */
+	if (ovcs->symbols_fragment)
+		fragments_count = ovcs->count - 1;
+	else
+		fragments_count = ovcs->count;
+
+	for (i = 0; i < fragments_count; i++) {
+		fragment = &ovcs->fragments[i];
+
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_next_level(ovcs, &target,
+						 fragment->overlay);
+		if (ret) {
+			pr_debug("fragment apply failed '%pOF'\n",
+				 fragment->target);
+			return ret;
+		}
+	}
+
+	if (ovcs->symbols_fragment) {
+		fragment = &ovcs->fragments[ovcs->count - 1];
+
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_symbols_node(ovcs, &target,
+						   fragment->overlay);
+		if (ret) {
+			pr_debug("symbols fragment apply failed '%pOF'\n",
+				 fragment->target);
+			return ret;
+		}
+	}
+
+	return changeset_dup_entry_check(ovcs);
+}
+
+/*
+ * Find the target node using a number of different strategies
+ * in order of preference:
+ *
+ * 1) "target" property containing the phandle of the target
+ * 2) "target-path" property containing the path of the target
+ */
+static struct device_node *find_target(const struct device_node *info_node,
+				       const struct device_node *target_base)
+{
+	struct device_node *node;
+	char *target_path;
+	const char *path;
+	u32 val;
+	int ret;
+
+	ret = of_property_read_u32(info_node, "target", &val);
+	if (!ret) {
+		node = of_find_node_by_phandle(val);
+		if (!node)
+			pr_err("find target, node: %pOF, phandle 0x%x not found\n",
+			       info_node, val);
+		return node;
+	}
+
+	ret = of_property_read_string(info_node, "target-path", &path);
+	if (!ret) {
+		if (target_base) {
+			target_path = kasprintf(GFP_KERNEL, "%pOF%s", target_base, path);
+			if (!target_path)
+				return NULL;
+			node = of_find_node_by_path(target_path);
+			if (!node) {
+				pr_err("find target, node: %pOF, path '%s' not found\n",
+				       info_node, target_path);
+			}
+			kfree(target_path);
+		} else {
+			node =  of_find_node_by_path(path);
+			if (!node) {
+				pr_err("find target, node: %pOF, path '%s' not found\n",
+				       info_node, path);
+			}
+		}
+		return node;
+	}
+
+	pr_err("find target, node: %pOF, no target property\n", info_node);
+
+	return NULL;
+}
+
+/**
+ * init_overlay_changeset() - initialize overlay changeset from overlay tree
+ * @ovcs:		Overlay changeset to build
+ * @target_base:	Point to the target node to apply overlay
+ *
+ * Initialize @ovcs.  Populate @ovcs->fragments with node information from
+ * the top level of @overlay_root.  The relevant top level nodes are the
+ * fragment nodes and the __symbols__ node.  Any other top level node will
+ * be ignored.  Populate other @ovcs fields.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
+ * detected in @overlay_root.  On error return, the caller of
+ * init_overlay_changeset() must call free_overlay_changeset().
+ */
+static int init_overlay_changeset(struct overlay_changeset *ovcs,
+				  const struct device_node *target_base)
+{
+	struct device_node *node, *overlay_node;
+	struct fragment *fragment;
+	struct fragment *fragments;
+	int cnt, ret;
+
+	/*
+	 * None of the resources allocated by this function will be freed in
+	 * the error paths.  Instead the caller of this function is required
+	 * to call free_overlay_changeset() (which will free the resources)
+	 * if error return.
+	 */
+
+	/*
+	 * Warn for some issues.  Can not return -EINVAL for these until
+	 * of_unittest_apply_overlay() is fixed to pass these checks.
+	 */
+	if (!of_node_check_flag(ovcs->overlay_root, OF_DYNAMIC))
+		pr_debug("%s() ovcs->overlay_root is not dynamic\n", __func__);
+
+	if (!of_node_check_flag(ovcs->overlay_root, OF_DETACHED))
+		pr_debug("%s() ovcs->overlay_root is not detached\n", __func__);
+
+	if (!of_node_is_root(ovcs->overlay_root))
+		pr_debug("%s() ovcs->overlay_root is not root\n", __func__);
+
+	cnt = 0;
+
+	/* fragment nodes */
+	for_each_child_of_node(ovcs->overlay_root, node) {
+		overlay_node = of_get_child_by_name(node, "__overlay__");
+		if (overlay_node) {
+			cnt++;
+			of_node_put(overlay_node);
+		}
+	}
+
+	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");
+	if (node) {
+		cnt++;
+		of_node_put(node);
+	}
+
+	fragments = kzalloc_objs(*fragments, cnt);
+	if (!fragments) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+	ovcs->fragments = fragments;
+
+	cnt = 0;
+	for_each_child_of_node(ovcs->overlay_root, node) {
+		overlay_node = of_get_child_by_name(node, "__overlay__");
+		if (!overlay_node)
+			continue;
+
+		fragment = &fragments[cnt];
+		fragment->overlay = overlay_node;
+		fragment->target = find_target(node, target_base);
+		if (!fragment->target) {
+			of_node_put(fragment->overlay);
+			ret = -EINVAL;
+			of_node_put(node);
+			goto err_out;
+		}
+
+		cnt++;
+	}
+
+	/*
+	 * if there is a symbols fragment in ovcs->fragments[i] it is
+	 * the final element in the array
+	 */
+	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");
+	if (node) {
+		ovcs->symbols_fragment = 1;
+		fragment = &fragments[cnt];
+		fragment->overlay = node;
+		fragment->target = of_find_node_by_path("/__symbols__");
+
+		if (!fragment->target) {
+			pr_err("symbols in overlay, but not in live tree\n");
+			ret = -EINVAL;
+			of_node_put(node);
+			goto err_out;
+		}
+
+		cnt++;
+	}
+
+	if (!cnt) {
+		pr_err("no fragments or symbols in overlay\n");
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	ovcs->count = cnt;
+
+	return 0;
+
+err_out:
+	pr_err("%s() failed, ret = %d\n", __func__, ret);
+
+	return ret;
+}
+
+static void free_overlay_changeset(struct overlay_changeset *ovcs)
+{
+	int i;
+
+	if (ovcs->cset.entries.next)
+		of_changeset_destroy(&ovcs->cset);
+
+	if (ovcs->id) {
+		idr_remove(&ovcs_idr, ovcs->id);
+		list_del(&ovcs->ovcs_list);
+		ovcs->id = 0;
+	}
+
+
+	for (i = 0; i < ovcs->count; i++) {
+		of_node_put(ovcs->fragments[i].target);
+		of_node_put(ovcs->fragments[i].overlay);
+	}
+	kfree(ovcs->fragments);
+
+	/*
+	 * There should be no live pointers into ovcs->overlay_mem and
+	 * ovcs->new_fdt due to the policy that overlay notifiers are not
+	 * allowed to retain pointers into the overlay devicetree other
+	 * than during the window from OF_OVERLAY_PRE_APPLY overlay
+	 * notifiers until the OF_OVERLAY_POST_REMOVE overlay notifiers.
+	 *
+	 * A memory leak will occur here if within the window.
+	 */
+
+	if (ovcs->notify_state == OF_OVERLAY_INIT ||
+	    ovcs->notify_state == OF_OVERLAY_POST_REMOVE) {
+		kfree(ovcs->overlay_mem);
+		kfree(ovcs->new_fdt);
+	}
+	kfree(ovcs);
+}
+
+/*
+ * internal documentation
+ *
+ * of_overlay_apply() - Create and apply an overlay changeset
+ * @ovcs:	overlay changeset
+ * @base:	point to the target node to apply overlay
+ *
+ * Creates and applies an overlay changeset.
+ *
+ * If an error is returned by an overlay changeset pre-apply notifier
+ * then no further overlay changeset pre-apply notifier will be called.
+ *
+ * If an error is returned by an overlay changeset post-apply notifier
+ * then no further overlay changeset post-apply notifier will be called.
+ *
+ * If more than one notifier returns an error, then the last notifier
+ * error to occur is returned.
+ *
+ * If an error occurred while applying the overlay changeset, then an
+ * attempt is made to revert any changes that were made to the
+ * device tree.  If there were any errors during the revert attempt
+ * then the state of the device tree can not be determined, and any
+ * following attempt to apply or remove an overlay changeset will be
+ * refused.
+ *
+ * Returns 0 on success, or a negative error number.  On error return,
+ * the caller of of_overlay_apply() must call free_overlay_changeset().
+ */
+
+static int of_overlay_apply(struct overlay_changeset *ovcs,
+			    const struct device_node *base)
+{
+	int ret = 0, ret_revert, ret_tmp;
+
+	ret = of_resolve_phandles(ovcs->overlay_root);
+	if (ret)
+		goto out;
+
+	ret = init_overlay_changeset(ovcs, base);
+	if (ret)
+		goto out;
+
+	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
+	if (ret)
+		goto out;
+
+	ret = build_changeset(ovcs);
+	if (ret)
+		goto out;
+
+	ret_revert = 0;
+	ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);
+	if (ret) {
+		if (ret_revert) {
+			pr_debug("overlay changeset revert error %d\n",
+				 ret_revert);
+			devicetree_state_flags |= DTSF_APPLY_FAIL;
+		}
+		goto out;
+	}
+
+	ret = __of_changeset_apply_notify(&ovcs->cset);
+	if (ret)
+		pr_err("overlay apply changeset entry notify error %d\n", ret);
+	/* notify failure is not fatal, continue */
+
+	/*
+	 * Needs to happen after changeset notify to give the listeners a chance
+	 * to finish creating all the devices they need to create.
+	 */
+	overlay_fw_devlink_refresh(ovcs);
+
+	ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);
+	if (ret_tmp)
+		if (!ret)
+			ret = ret_tmp;
+
+out:
+	pr_debug("%s() err=%d\n", __func__, ret);
+
+	return ret;
+}
+
+/**
+ * of_overlay_fdt_apply() - Create and apply an overlay changeset
+ * @overlay_fdt:	pointer to overlay FDT
+ * @overlay_fdt_size:	number of bytes in @overlay_fdt
+ * @ret_ovcs_id:	pointer for returning created changeset id
+ * @base:		pointer for the target node to apply overlay
+ *
+ * Creates and applies an overlay changeset.
+ *
+ * See of_overlay_apply() for important behavior information.
+ *
+ * Return: 0 on success, or a negative error number.  *@ret_ovcs_id is set to
+ * the value of overlay changeset id, which can be passed to of_overlay_remove()
+ * to remove the overlay.
+ *
+ * On error return, the changeset may be partially applied.  This is especially
+ * likely if an OF_OVERLAY_POST_APPLY notifier returns an error.  In this case
+ * the caller should call of_overlay_remove() with the value in *@ret_ovcs_id.
+ */
+
+int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
+			 int *ret_ovcs_id, const struct device_node *base)
+{
+	void *new_fdt;
+	void *new_fdt_align;
+	void *overlay_mem;
+	int ret;
+	u32 size;
+	struct overlay_changeset *ovcs;
+
+	*ret_ovcs_id = 0;
+
+	if (devicetree_corrupt()) {
+		pr_err("devicetree state suspect, refuse to apply overlay\n");
+		return -EBUSY;
+	}
+
+	if (overlay_fdt_size < sizeof(struct fdt_header) ||
+	    fdt_check_header(overlay_fdt)) {
+		pr_err("Invalid overlay_fdt header\n");
+		return -EINVAL;
+	}
+
+	size = fdt_totalsize(overlay_fdt);
+	if (overlay_fdt_size < size)
+		return -EINVAL;
+
+	ovcs = kzalloc_obj(*ovcs);
+	if (!ovcs)
+		return -ENOMEM;
+
+	of_overlay_mutex_lock();
+	mutex_lock(&of_mutex);
+
+	/*
+	 * ovcs->notify_state must be set to OF_OVERLAY_INIT before allocating
+	 * ovcs resources, implicitly set by kzalloc() of ovcs
+	 */
+
+	ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);
+	if (ovcs->id <= 0) {
+		ret = ovcs->id;
+		goto err_free_ovcs;
+	}
+
+	INIT_LIST_HEAD(&ovcs->ovcs_list);
+	list_add_tail(&ovcs->ovcs_list, &ovcs_list);
+	of_changeset_init(&ovcs->cset);
+
+	/*
+	 * Must create permanent copy of FDT because of_fdt_unflatten_tree()
+	 * will create pointers to the passed in FDT in the unflattened tree.
+	 */
+	new_fdt = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
+	if (!new_fdt) {
+		ret = -ENOMEM;
+		goto err_free_ovcs;
+	}
+	ovcs->new_fdt = new_fdt;
+
+	new_fdt_align = PTR_ALIGN(new_fdt, FDT_ALIGN_SIZE);
+	memcpy(new_fdt_align, overlay_fdt, size);
+
+	overlay_mem = of_fdt_unflatten_tree(new_fdt_align, NULL,
+					    &ovcs->overlay_root);
+	if (!overlay_mem) {
+		pr_err("unable to unflatten overlay_fdt\n");
+		ret = -EINVAL;
+		goto err_free_ovcs;
+	}
+	ovcs->overlay_mem = overlay_mem;
+
+	ret = of_overlay_apply(ovcs, base);
+	/*
+	 * If of_overlay_apply() error, calling free_overlay_changeset() may
+	 * result in a memory leak if the apply partly succeeded, so do NOT
+	 * goto err_free_ovcs.  Instead, the caller of of_overlay_fdt_apply()
+	 * can call of_overlay_remove();
+	 */
+	*ret_ovcs_id = ovcs->id;
+	goto out_unlock;
+
+err_free_ovcs:
+	free_overlay_changeset(ovcs);
+
+out_unlock:
+	mutex_unlock(&of_mutex);
+	of_overlay_mutex_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_overlay_fdt_apply);
+
+/*
+ * Find @np in @tree.
+ *
+ * Returns 1 if @np is @tree or is contained in @tree, else 0
+ */
+static int find_node(const struct device_node *tree, struct device_node *np)
+{
+	if (tree == np)
+		return 1;
+
+	for_each_child_of_node_scoped(tree, child) {
+		if (find_node(child, np))
+			return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Is @remove_ce_node a child of, a parent of, or the same as any
+ * node in an overlay changeset more topmost than @remove_ovcs?
+ *
+ * Returns 1 if found, else 0
+ */
+static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs,
+		struct device_node *remove_ce_node)
+{
+	struct overlay_changeset *ovcs;
+	struct of_changeset_entry *ce;
+
+	list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) {
+		if (ovcs == remove_ovcs)
+			break;
+
+		list_for_each_entry(ce, &ovcs->cset.entries, node) {
+			if (find_node(ce->np, remove_ce_node)) {
+				pr_err("%s: #%d overlaps with #%d @%pOF\n",
+					__func__, remove_ovcs->id, ovcs->id,
+					remove_ce_node);
+				return 1;
+			}
+			if (find_node(remove_ce_node, ce->np)) {
+				pr_err("%s: #%d overlaps with #%d @%pOF\n",
+					__func__, remove_ovcs->id, ovcs->id,
+					remove_ce_node);
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * We can safely remove the overlay only if it's the top-most one.
+ * Newly applied overlays are inserted at the tail of the overlay list,
+ * so a top most overlay is the one that is closest to the tail.
+ *
+ * The topmost check is done by exploiting this property. For each
+ * affected device node in the log list we check if this overlay is
+ * the one closest to the tail. If another overlay has affected this
+ * device node and is closest to the tail, then removal is not permitted.
+ */
+static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs)
+{
+	struct of_changeset_entry *remove_ce;
+
+	list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) {
+		if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) {
+			pr_err("overlay #%d is not topmost\n", remove_ovcs->id);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/**
+ * of_overlay_remove() - Revert and free an overlay changeset
+ * @ovcs_id:	Pointer to overlay changeset id
+ *
+ * Removes an overlay if it is permissible.  @ovcs_id was previously returned
+ * by of_overlay_fdt_apply().
+ *
+ * If an error occurred while attempting to revert the overlay changeset,
+ * then an attempt is made to re-apply any changeset entry that was
+ * reverted.  If an error occurs on re-apply then the state of the device
+ * tree can not be determined, and any following attempt to apply or remove
+ * an overlay changeset will be refused.
+ *
+ * A non-zero return value will not revert the changeset if error is from:
+ *   - parameter checks
+ *   - overlay changeset pre-remove notifier
+ *   - overlay changeset entry revert
+ *
+ * If an error is returned by an overlay changeset pre-remove notifier
+ * then no further overlay changeset pre-remove notifier will be called.
+ *
+ * If more than one notifier returns an error, then the last notifier
+ * error to occur is returned.
+ *
+ * A non-zero return value will revert the changeset if error is from:
+ *   - overlay changeset entry notifier
+ *   - overlay changeset post-remove notifier
+ *
+ * If an error is returned by an overlay changeset post-remove notifier
+ * then no further overlay changeset post-remove notifier will be called.
+ *
+ * Return: 0 on success, or a negative error number.  *@ovcs_id is set to
+ * zero after reverting the changeset, even if a subsequent error occurs.
+ */
+int of_overlay_remove(int *ovcs_id)
+{
+	struct overlay_changeset *ovcs;
+	int ret, ret_apply, ret_tmp;
+
+	if (*ovcs_id == 0)
+		return 0;
+
+	if (devicetree_corrupt()) {
+		pr_err("suspect devicetree state, refuse to remove overlay\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	mutex_lock(&of_mutex);
+
+	ovcs = idr_find(&ovcs_idr, *ovcs_id);
+	if (!ovcs) {
+		ret = -ENODEV;
+		pr_err("remove: Could not find overlay #%d\n", *ovcs_id);
+		goto err_unlock;
+	}
+
+	if (!overlay_removal_is_ok(ovcs)) {
+		ret = -EBUSY;
+		goto err_unlock;
+	}
+
+	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE);
+	if (ret)
+		goto err_unlock;
+
+	ret_apply = 0;
+	ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);
+	if (ret) {
+		if (ret_apply)
+			devicetree_state_flags |= DTSF_REVERT_FAIL;
+		goto err_unlock;
+	}
+
+	ret = __of_changeset_revert_notify(&ovcs->cset);
+	if (ret)
+		pr_err("overlay remove changeset entry notify error %d\n", ret);
+	/* notify failure is not fatal, continue */
+
+	*ovcs_id = 0;
+
+	/*
+	 * Note that the overlay memory will be kfree()ed by
+	 * free_overlay_changeset() even if the notifier for
+	 * OF_OVERLAY_POST_REMOVE returns an error.
+	 */
+	ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE);
+	if (ret_tmp)
+		if (!ret)
+			ret = ret_tmp;
+
+	free_overlay_changeset(ovcs);
+
+err_unlock:
+	/*
+	 * If jumped over free_overlay_changeset(), then did not kfree()
+	 * overlay related memory.  This is a memory leak unless a subsequent
+	 * of_overlay_remove() of this overlay is successful.
+	 */
+	mutex_unlock(&of_mutex);
+
+out:
+	pr_debug("%s() err=%d\n", __func__, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_overlay_remove);
+
+/**
+ * of_overlay_remove_all() - Reverts and frees all overlay changesets
+ *
+ * Removes all overlays from the system in the correct order.
+ *
+ * Return: 0 on success, or a negative error number
+ */
+int of_overlay_remove_all(void)
+{
+	struct overlay_changeset *ovcs, *ovcs_n;
+	int ret;
+
+	/* the tail of list is guaranteed to be safe to remove */
+	list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) {
+		ret = of_overlay_remove(&ovcs->id);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_overlay_remove_all);
diff --git a/drivers/of/overlay_test.c b/drivers/of/overlay_test.c
new file mode 100644
index 000000000..c787524c5
--- /dev/null
+++ b/drivers/of/overlay_test.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for device tree overlays
+ */
+#include <linux/device/bus.h>
+#include <linux/kconfig.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+
+#include "of_private.h"
+
+static const char * const kunit_node_name = "kunit-test";
+static const char * const kunit_compatible = "test,empty";
+
+/* Test that of_overlay_apply_kunit() adds a node to the live tree */
+static void of_overlay_apply_kunit_apply(struct kunit *test)
+{
+	struct device_node *np;
+
+	KUNIT_ASSERT_EQ(test, 0,
+			of_overlay_apply_kunit(test, kunit_overlay_test));
+
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+	of_node_put(np);
+}
+
+/*
+ * Test that of_overlay_apply_kunit() creates platform devices with the
+ * expected device_node
+ */
+static void of_overlay_apply_kunit_platform_device(struct kunit *test)
+{
+	struct platform_device *pdev;
+	struct device_node *np;
+
+	KUNIT_ASSERT_EQ(test, 0,
+			of_overlay_apply_kunit(test, kunit_overlay_test));
+
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	of_node_put_kunit(test, np);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+	pdev = of_find_device_by_node(np);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pdev);
+	if (pdev)
+		put_device(&pdev->dev);
+}
+
+static int of_overlay_bus_match_compatible(struct device *dev, const void *data)
+{
+	return of_device_is_compatible(dev->of_node, data);
+}
+
+/* Test that of_overlay_apply_kunit() cleans up after the test is finished */
+static void of_overlay_apply_kunit_cleanup(struct kunit *test)
+{
+	struct kunit fake;
+	struct platform_device *pdev;
+	struct device *dev;
+	struct device_node *np;
+
+	of_root_kunit_skip(test);
+	if (!IS_ENABLED(CONFIG_OF_OVERLAY))
+		kunit_skip(test, "requires CONFIG_OF_OVERLAY to apply overlay");
+	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");
+
+	kunit_init_test(&fake, "fake test", NULL);
+	KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);
+
+	KUNIT_ASSERT_EQ(test, 0,
+			of_overlay_apply_kunit(&fake, kunit_overlay_test));
+
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+	of_node_put_kunit(&fake, np);
+
+	pdev = of_find_device_by_node(np);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+	put_device(&pdev->dev); /* Not derefing 'pdev' after this */
+
+	/* Remove overlay */
+	kunit_cleanup(&fake);
+
+	/* The node and device should be removed */
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, np);
+	of_node_put(np);
+
+	dev = bus_find_device(&platform_bus_type, NULL, kunit_compatible,
+			      of_overlay_bus_match_compatible);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, dev);
+	put_device(dev);
+}
+
+static struct kunit_case of_overlay_apply_kunit_test_cases[] = {
+	KUNIT_CASE(of_overlay_apply_kunit_apply),
+	KUNIT_CASE(of_overlay_apply_kunit_platform_device),
+	KUNIT_CASE(of_overlay_apply_kunit_cleanup),
+	{}
+};
+
+/*
+ * Test suite for test managed device tree overlays.
+ */
+static struct kunit_suite of_overlay_apply_kunit_suite = {
+	.name = "of_overlay_apply_kunit",
+	.test_cases = of_overlay_apply_kunit_test_cases,
+};
+
+kunit_test_suites(
+	&of_overlay_apply_kunit_suite,
+);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("KUnit tests for device tree overlays");
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
new file mode 100644
index 000000000..cb0cb374b
--- /dev/null
+++ b/drivers/of/pdt.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* pdt.c: OF PROM device tree support code.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc by David S. Miller davem@davemloft.net
+ *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
+
+#include "of_private.h"
+
+static struct of_pdt_ops *of_pdt_prom_ops __initdata;
+
+#if defined(CONFIG_SPARC)
+unsigned int of_pdt_unique_id __initdata;
+
+#define of_pdt_incr_unique_id(p) do { \
+	(p)->unique_id = of_pdt_unique_id++; \
+} while (0)
+
+static char * __init of_pdt_build_full_name(struct device_node *dp)
+{
+	return build_path_component(dp);
+}
+
+#else /* CONFIG_SPARC */
+
+static inline void of_pdt_incr_unique_id(void *p) { }
+static inline void irq_trans_init(struct device_node *dp) { }
+
+static char * __init of_pdt_build_full_name(struct device_node *dp)
+{
+	static int failsafe_id = 0; /* for generating unique names on failure */
+	const char *name;
+	char path[256];
+	char *buf;
+	int len;
+
+	if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
+		name = kbasename(path);
+		buf = prom_early_alloc(strlen(name) + 1);
+		strcpy(buf, name);
+		return buf;
+	}
+
+	name = of_get_property(dp, "name", &len);
+	buf = prom_early_alloc(len + 16);
+	sprintf(buf, "%s@unknown%i", name, failsafe_id++);
+	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
+	return buf;
+}
+
+#endif /* !CONFIG_SPARC */
+
+static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
+					       char *special_name,
+					       void *special_val,
+					       int special_len)
+{
+	static struct property *tmp = NULL;
+	struct property *p;
+	int err;
+
+	if (tmp) {
+		p = tmp;
+		memset(p, 0, sizeof(*p) + 32);
+		tmp = NULL;
+	} else {
+		p = prom_early_alloc(sizeof(struct property) + 32);
+		of_pdt_incr_unique_id(p);
+	}
+
+	p->name = (char *) (p + 1);
+	if (special_name) {
+		strcpy(p->name, special_name);
+		p->length = special_len;
+		p->value = prom_early_alloc(special_len);
+		memcpy(p->value, special_val, special_len);
+	} else {
+		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
+		if (err) {
+			tmp = p;
+			return NULL;
+		}
+		p->length = of_pdt_prom_ops->getproplen(node, p->name);
+		if (p->length <= 0) {
+			p->length = 0;
+		} else {
+			int len;
+
+			p->value = prom_early_alloc(p->length + 1);
+			len = of_pdt_prom_ops->getproperty(node, p->name,
+					p->value, p->length);
+			if (len <= 0)
+				p->length = 0;
+			((unsigned char *)p->value)[p->length] = '\0';
+		}
+	}
+	return p;
+}
+
+static struct property * __init of_pdt_build_prop_list(phandle node)
+{
+	struct property *head, *tail;
+
+	head = tail = of_pdt_build_one_prop(node, NULL,
+				     ".node", &node, sizeof(node));
+
+	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
+	tail = tail->next;
+	while(tail) {
+		tail->next = of_pdt_build_one_prop(node, tail->name,
+					    NULL, NULL, 0);
+		tail = tail->next;
+	}
+
+	return head;
+}
+
+static char * __init of_pdt_get_one_property(phandle node, const char *name)
+{
+	char *buf = "<NULL>";
+	int len;
+
+	len = of_pdt_prom_ops->getproplen(node, name);
+	if (len > 0) {
+		buf = prom_early_alloc(len);
+		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
+	}
+
+	return buf;
+}
+
+static struct device_node * __init of_pdt_create_node(phandle node,
+						    struct device_node *parent)
+{
+	struct device_node *dp;
+
+	if (!node)
+		return NULL;
+
+	dp = prom_early_alloc(sizeof(*dp));
+	of_node_init(dp);
+	of_pdt_incr_unique_id(dp);
+	dp->parent = parent;
+
+	dp->name = of_pdt_get_one_property(node, "name");
+	dp->phandle = node;
+
+	dp->properties = of_pdt_build_prop_list(node);
+
+	dp->full_name = of_pdt_build_full_name(dp);
+
+	irq_trans_init(dp);
+
+	return dp;
+}
+
+static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
+						   phandle node)
+{
+	struct device_node *ret = NULL, *prev_sibling = NULL;
+	struct device_node *dp;
+
+	while (1) {
+		dp = of_pdt_create_node(node, parent);
+		if (!dp)
+			break;
+
+		if (prev_sibling)
+			prev_sibling->sibling = dp;
+
+		if (!ret)
+			ret = dp;
+		prev_sibling = dp;
+
+		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
+
+		node = of_pdt_prom_ops->getsibling(node);
+	}
+
+	return ret;
+}
+
+static void * __init kernel_tree_alloc(u64 size, u64 align)
+{
+	return prom_early_alloc(size);
+}
+
+void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
+{
+	BUG_ON(!ops);
+	of_pdt_prom_ops = ops;
+
+	of_root = of_pdt_create_node(root_node, NULL);
+	of_root->full_name = "/";
+
+	of_root->child = of_pdt_build_tree(of_root,
+				of_pdt_prom_ops->getchild(of_root->phandle));
+
+	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
+	of_alias_scan(kernel_tree_alloc);
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
new file mode 100644
index 000000000..8b1e76407
--- /dev/null
+++ b/drivers/of/platform.c
@@ -0,0 +1,793 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
+ *			 <benh@kernel.crashing.org>
+ *    and		 Arnd Bergmann, IBM Corp.
+ *    Merged from powerpc/kernel/of_platform.c and
+ *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sysfb.h>
+
+#include "of_private.h"
+
+/**
+ * of_find_device_by_node - Find the platform_device associated with a node
+ * @np: Pointer to device tree node
+ *
+ * Takes a reference to the embedded struct device which needs to be dropped
+ * after use.
+ *
+ * Return: platform_device pointer, or NULL if not found
+ */
+struct platform_device *of_find_device_by_node(struct device_node *np)
+{
+	struct device *dev;
+
+	dev = bus_find_device_by_of_node(&platform_bus_type, np);
+	return dev ? to_platform_device(dev) : NULL;
+}
+EXPORT_SYMBOL(of_find_device_by_node);
+
+int of_device_add(struct platform_device *ofdev)
+{
+	BUG_ON(ofdev->dev.of_node == NULL);
+
+	/* name and id have to be set so that the platform bus doesn't get
+	 * confused on matching */
+	ofdev->name = dev_name(&ofdev->dev);
+	ofdev->id = PLATFORM_DEVID_NONE;
+
+	/*
+	 * If this device has not binding numa node in devicetree, that is
+	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
+	 * device is on the same node as the parent.
+	 */
+	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
+
+	return device_add(&ofdev->dev);
+}
+
+int of_device_register(struct platform_device *pdev)
+{
+	device_initialize(&pdev->dev);
+	return of_device_add(pdev);
+}
+EXPORT_SYMBOL(of_device_register);
+
+void of_device_unregister(struct platform_device *ofdev)
+{
+	device_unregister(&ofdev->dev);
+}
+EXPORT_SYMBOL(of_device_unregister);
+
+#ifdef CONFIG_OF_ADDRESS
+static const struct of_device_id of_skipped_node_table[] = {
+	{ .compatible = "operating-points-v2", },
+	{} /* Empty terminated list */
+};
+
+/*
+ * The following routines scan a subtree and registers a device for
+ * each applicable node.
+ *
+ * Note: sparc doesn't use these routines because it has a different
+ * mechanism for creating devices from device tree nodes.
+ */
+
+/**
+ * of_device_alloc - Allocate and initialize an of_device
+ * @np: device node to assign to device
+ * @bus_id: Name to assign to the device.  May be null to use default name.
+ * @parent: Parent device.
+ */
+struct platform_device *of_device_alloc(struct device_node *np,
+				  const char *bus_id,
+				  struct device *parent)
+{
+	struct platform_device *dev;
+	int rc, i, num_reg = 0;
+	struct resource *res;
+
+	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
+	if (!dev)
+		return NULL;
+
+	/* count the io resources */
+	num_reg = of_address_count(np);
+
+	/* Populate the resource table */
+	if (num_reg) {
+		res = kzalloc_objs(*res, num_reg);
+		if (!res) {
+			platform_device_put(dev);
+			return NULL;
+		}
+
+		dev->num_resources = num_reg;
+		dev->resource = res;
+		for (i = 0; i < num_reg; i++, res++) {
+			rc = of_address_to_resource(np, i, res);
+			WARN_ON(rc);
+		}
+	}
+
+	/* setup generic device info */
+	platform_device_set_of_node(dev, np);
+	dev->dev.parent = parent ? : &platform_bus;
+
+	if (bus_id)
+		dev_set_name(&dev->dev, "%s", bus_id);
+	else
+		of_device_make_bus_id(&dev->dev);
+
+	return dev;
+}
+EXPORT_SYMBOL(of_device_alloc);
+
+/**
+ * of_platform_device_create_pdata - Alloc, initialize and register an of_device
+ * @np: pointer to node to create device for
+ * @bus_id: name to assign device
+ * @platform_data: pointer to populate platform_data pointer with
+ * @parent: Linux device model parent device.
+ *
+ * Return: Pointer to created platform device, or NULL if a device was not
+ * registered.  Unavailable devices will not get registered.
+ */
+static struct platform_device *of_platform_device_create_pdata(
+					struct device_node *np,
+					const char *bus_id,
+					void *platform_data,
+					struct device *parent)
+{
+	struct platform_device *dev;
+
+	pr_debug("create platform device: %pOF\n", np);
+
+	if (!of_device_is_available(np) ||
+	    of_node_test_and_set_flag(np, OF_POPULATED))
+		return NULL;
+
+	dev = of_device_alloc(np, bus_id, parent);
+	if (!dev)
+		goto err_clear_flag;
+
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	if (!dev->dev.dma_mask)
+		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+	dev->dev.bus = &platform_bus_type;
+	dev->dev.platform_data = platform_data;
+	of_msi_configure(&dev->dev, dev->dev.of_node);
+
+	if (of_device_add(dev) != 0) {
+		platform_device_put(dev);
+		goto err_clear_flag;
+	}
+
+	return dev;
+
+err_clear_flag:
+	of_node_clear_flag(np, OF_POPULATED);
+	return NULL;
+}
+
+/**
+ * of_platform_device_create - Alloc, initialize and register an of_device
+ * @np: pointer to node to create device for
+ * @bus_id: name to assign device
+ * @parent: Linux device model parent device.
+ *
+ * Return: Pointer to created platform device, or NULL if a device was not
+ * registered.  Unavailable devices will not get registered.
+ */
+struct platform_device *of_platform_device_create(struct device_node *np,
+					    const char *bus_id,
+					    struct device *parent)
+{
+	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
+}
+EXPORT_SYMBOL(of_platform_device_create);
+
+#ifdef CONFIG_ARM_AMBA
+static struct amba_device *of_amba_device_create(struct device_node *node,
+						 const char *bus_id,
+						 void *platform_data,
+						 struct device *parent)
+{
+	struct amba_device *dev;
+	int ret;
+
+	pr_debug("Creating amba device %pOF\n", node);
+
+	if (!of_device_is_available(node) ||
+	    of_node_test_and_set_flag(node, OF_POPULATED))
+		return NULL;
+
+	dev = amba_device_alloc(NULL, 0, 0);
+	if (!dev)
+		goto err_clear_flag;
+
+	/* AMBA devices only support a single DMA mask */
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+
+	/* setup generic device info */
+	device_set_node(&dev->dev, of_fwnode_handle(node));
+	dev->dev.parent = parent ? : &platform_bus;
+	dev->dev.platform_data = platform_data;
+	if (bus_id)
+		dev_set_name(&dev->dev, "%s", bus_id);
+	else
+		of_device_make_bus_id(&dev->dev);
+
+	/* Allow the HW Peripheral ID to be overridden */
+	of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
+
+	ret = of_address_to_resource(node, 0, &dev->res);
+	if (ret) {
+		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
+		       ret, node);
+		goto err_free;
+	}
+
+	ret = amba_device_add(dev, &iomem_resource);
+	if (ret) {
+		pr_err("amba_device_add() failed (%d) for %pOF\n",
+		       ret, node);
+		goto err_free;
+	}
+
+	return dev;
+
+err_free:
+	amba_device_put(dev);
+err_clear_flag:
+	of_node_clear_flag(node, OF_POPULATED);
+	return NULL;
+}
+#else /* CONFIG_ARM_AMBA */
+static struct amba_device *of_amba_device_create(struct device_node *node,
+						 const char *bus_id,
+						 void *platform_data,
+						 struct device *parent)
+{
+	return NULL;
+}
+#endif /* CONFIG_ARM_AMBA */
+
+/*
+ * of_dev_lookup() - Given a device node, lookup the preferred Linux name
+ */
+static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
+				 struct device_node *np)
+{
+	const struct of_dev_auxdata *auxdata;
+	struct resource res;
+	int compatible = 0;
+
+	if (!lookup)
+		return NULL;
+
+	auxdata = lookup;
+	for (; auxdata->compatible; auxdata++) {
+		if (!of_device_is_compatible(np, auxdata->compatible))
+			continue;
+		compatible++;
+		if (!of_address_to_resource(np, 0, &res))
+			if (res.start != auxdata->phys_addr)
+				continue;
+		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
+		return auxdata;
+	}
+
+	if (!compatible)
+		return NULL;
+
+	/* Try compatible match if no phys_addr and name are specified */
+	auxdata = lookup;
+	for (; auxdata->compatible; auxdata++) {
+		if (!of_device_is_compatible(np, auxdata->compatible))
+			continue;
+		if (!auxdata->phys_addr && !auxdata->name) {
+			pr_debug("%pOF: compatible match\n", np);
+			return auxdata;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * of_platform_bus_create() - Create a device for a node and its children.
+ * @bus: device node of the bus to instantiate
+ * @matches: match table for bus nodes
+ * @lookup: auxdata table for matching id and platform_data with device nodes
+ * @parent: parent for new device, or NULL for top level.
+ * @strict: require compatible property
+ *
+ * Creates a platform_device for the provided device_node, and optionally
+ * recursively create devices for all the child nodes.
+ */
+static int of_platform_bus_create(struct device_node *bus,
+				  const struct of_device_id *matches,
+				  const struct of_dev_auxdata *lookup,
+				  struct device *parent, bool strict)
+{
+	const struct of_dev_auxdata *auxdata;
+	struct platform_device *dev;
+	const char *bus_id = NULL;
+	void *platform_data = NULL;
+	int rc = 0;
+
+	/* Make sure it has a compatible property */
+	if (strict && (!of_property_present(bus, "compatible"))) {
+		pr_debug("%s() - skipping %pOF, no compatible prop\n",
+			 __func__, bus);
+		return 0;
+	}
+
+	/* Skip nodes for which we don't want to create devices */
+	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
+		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
+		return 0;
+	}
+
+	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
+		pr_debug("%s() - skipping %pOF, already populated\n",
+			__func__, bus);
+		return 0;
+	}
+
+	auxdata = of_dev_lookup(lookup, bus);
+	if (auxdata) {
+		bus_id = auxdata->name;
+		platform_data = auxdata->platform_data;
+	}
+
+	if (of_device_is_compatible(bus, "arm,primecell")) {
+		/*
+		 * Don't return an error here to keep compatibility with older
+		 * device tree files.
+		 */
+		of_amba_device_create(bus, bus_id, platform_data, parent);
+		return 0;
+	}
+
+	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
+	if (!dev || !of_match_node(matches, bus))
+		return 0;
+
+	for_each_child_of_node_scoped(bus, child) {
+		pr_debug("   create child: %pOF\n", child);
+		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
+		if (rc)
+			break;
+	}
+	of_node_set_flag(bus, OF_POPULATED_BUS);
+	return rc;
+}
+
+/**
+ * of_platform_bus_probe() - Probe the device-tree for platform buses
+ * @root: parent of the first level to probe or NULL for the root of the tree
+ * @matches: match table for bus nodes
+ * @parent: parent to hook devices from, NULL for toplevel
+ *
+ * Note that children of the provided root are not instantiated as devices
+ * unless the specified root itself matches the bus list and is not NULL.
+ */
+int of_platform_bus_probe(struct device_node *root,
+			  const struct of_device_id *matches,
+			  struct device *parent)
+{
+	int rc = 0;
+
+	root = root ? of_node_get(root) : of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	pr_debug("%s()\n", __func__);
+	pr_debug(" starting at: %pOF\n", root);
+
+	/* Do a self check of bus type, if there's a match, create children */
+	if (of_match_node(matches, root)) {
+		rc = of_platform_bus_create(root, matches, NULL, parent, false);
+	} else {
+		for_each_child_of_node_scoped(root, child) {
+			if (!of_match_node(matches, child))
+				continue;
+			rc = of_platform_bus_create(child, matches, NULL, parent, false);
+			if (rc)
+				break;
+		}
+	}
+
+	of_node_put(root);
+	return rc;
+}
+EXPORT_SYMBOL(of_platform_bus_probe);
+
+/**
+ * of_platform_populate() - Populate platform_devices from device tree data
+ * @root: parent of the first level to probe or NULL for the root of the tree
+ * @matches: match table, NULL to use the default
+ * @lookup: auxdata table for matching id and platform_data with device nodes
+ * @parent: parent to hook devices from, NULL for toplevel
+ *
+ * Similar to of_platform_bus_probe(), this function walks the device tree
+ * and creates devices from nodes.  It differs in that it follows the modern
+ * convention of requiring all device nodes to have a 'compatible' property,
+ * and it is suitable for creating devices which are children of the root
+ * node (of_platform_bus_probe will only create children of the root which
+ * are selected by the @matches argument).
+ *
+ * New board support should be using this function instead of
+ * of_platform_bus_probe().
+ *
+ * Return: 0 on success, < 0 on failure.
+ */
+int of_platform_populate(struct device_node *root,
+			const struct of_device_id *matches,
+			const struct of_dev_auxdata *lookup,
+			struct device *parent)
+{
+	int rc = 0;
+
+	root = root ? of_node_get(root) : of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	pr_debug("%s()\n", __func__);
+	pr_debug(" starting at: %pOF\n", root);
+
+	device_links_supplier_sync_state_pause();
+	for_each_child_of_node_scoped(root, child) {
+		rc = of_platform_bus_create(child, matches, lookup, parent, true);
+		if (rc)
+			break;
+	}
+	device_links_supplier_sync_state_resume();
+
+	of_node_set_flag(root, OF_POPULATED_BUS);
+
+	of_node_put(root);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_platform_populate);
+
+int of_platform_default_populate(struct device_node *root,
+				 const struct of_dev_auxdata *lookup,
+				 struct device *parent)
+{
+	static const struct of_device_id match_table[] = {
+		{ .compatible = "simple-bus", },
+		{ .compatible = "simple-mfd", },
+		{ .compatible = "isa", },
+#ifdef CONFIG_ARM_AMBA
+		{ .compatible = "arm,amba-bus", },
+#endif /* CONFIG_ARM_AMBA */
+		{} /* Empty terminated list */
+	};
+
+	return of_platform_populate(root, match_table, lookup, parent);
+}
+EXPORT_SYMBOL_GPL(of_platform_default_populate);
+
+static const struct of_device_id reserved_mem_matches[] = {
+	{ .compatible = "phram" },
+	{ .compatible = "qcom,rmtfs-mem" },
+	{ .compatible = "qcom,cmd-db" },
+	{ .compatible = "qcom,smem" },
+	{ .compatible = "ramoops" },
+	{ .compatible = "nvmem-rmem" },
+	{ .compatible = "google,open-dice" },
+	{}
+};
+
+static int __init of_platform_default_populate_init(void)
+{
+	struct device_node *node, *reserved;
+
+	device_links_supplier_sync_state_pause();
+
+	if (IS_ENABLED(CONFIG_PPC)) {
+		struct device_node *boot_display = NULL;
+		struct platform_device *dev;
+		int display_number = 0;
+		int ret;
+
+		/* Check if we have a MacOS display without a node spec */
+		if (of_property_present(of_chosen, "linux,bootx-noscreen")) {
+			/*
+			 * The old code tried to work out which node was the MacOS
+			 * display based on the address. I'm dropping that since the
+			 * lack of a node spec only happens with old BootX versions
+			 * (users can update) and with this code, they'll still get
+			 * a display (just not the palette hacks).
+			 */
+			dev = platform_device_alloc("bootx-noscreen", 0);
+			if (WARN_ON(!dev))
+				return -ENOMEM;
+			ret = platform_device_add(dev);
+			if (WARN_ON(ret)) {
+				platform_device_put(dev);
+				return ret;
+			}
+		}
+
+		/*
+		 * For OF framebuffers, first create the device for the boot display,
+		 * then for the other framebuffers. Only fail for the boot display;
+		 * ignore errors for the rest.
+		 */
+		for_each_node_by_type(node, "display") {
+			if (!of_property_read_bool(node, "linux,opened") ||
+			    !of_property_read_bool(node, "linux,boot-display"))
+				continue;
+			dev = of_platform_device_create(node, "of-display", NULL);
+			of_node_put(node);
+			if (WARN_ON(!dev))
+				return -ENOMEM;
+			boot_display = node;
+			display_number++;
+			break;
+		}
+		for_each_node_by_type(node, "display") {
+			char buf[14];
+			const char *of_display_format = "of-display.%d";
+
+			if (!of_property_read_bool(node, "linux,opened") || node == boot_display)
+				continue;
+			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
+			if (ret < sizeof(buf))
+				of_platform_device_create(node, buf, NULL);
+		}
+
+	} else {
+		/*
+		 * Handle certain compatibles explicitly, since we don't want to create
+		 * platform_devices for every node in /reserved-memory with a
+		 * "compatible",
+		 */
+		reserved = of_find_node_by_path("/reserved-memory");
+		if (reserved) {
+			for_each_child_of_node(reserved, node) {
+				if (of_match_node(reserved_mem_matches, node))
+					of_platform_device_create(node, NULL, NULL);
+			}
+			of_node_put(reserved);
+		}
+
+		node = of_find_node_by_path("/firmware");
+		if (node) {
+			of_platform_default_populate(node, NULL, NULL);
+			of_node_put(node);
+		}
+
+		node = of_get_compatible_child(of_chosen, "simple-framebuffer");
+		if (node) {
+			/*
+			 * Since a "simple-framebuffer" device is already added
+			 * here, disable the Generic System Framebuffers (sysfb)
+			 * to prevent it from registering another device for the
+			 * system framebuffer later (e.g: using the screen_info
+			 * data that may had been filled as well).
+			 *
+			 * This can happen for example on DT systems that do EFI
+			 * booting and may provide a GOP handle to the EFI stub.
+			 */
+			sysfb_disable(NULL);
+			of_platform_device_create(node, NULL, NULL);
+			of_node_put(node);
+		}
+
+		/* Populate everything else. */
+		of_platform_default_populate(NULL, NULL, NULL);
+	}
+
+	return 0;
+}
+arch_initcall_sync(of_platform_default_populate_init);
+
+static int __init of_platform_sync_state_init(void)
+{
+	device_links_supplier_sync_state_resume();
+	return 0;
+}
+late_initcall_sync(of_platform_sync_state_init);
+
+int of_platform_device_destroy(struct device *dev, void *data)
+{
+	/* Do not touch devices not populated from the device tree */
+	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
+		return 0;
+
+	/* Recurse for any nodes that were treated as busses */
+	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
+		device_for_each_child(dev, NULL, of_platform_device_destroy);
+
+	of_node_clear_flag(dev->of_node, OF_POPULATED);
+	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
+
+	if (dev->bus == &platform_bus_type)
+		platform_device_unregister(to_platform_device(dev));
+#ifdef CONFIG_ARM_AMBA
+	else if (dev->bus == &amba_bustype)
+		amba_device_unregister(to_amba_device(dev));
+#endif
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_platform_device_destroy);
+
+/**
+ * of_platform_depopulate() - Remove devices populated from device tree
+ * @parent: device which children will be removed
+ *
+ * Complementary to of_platform_populate(), this function removes children
+ * of the given device (and, recursively, their children) that have been
+ * created from their respective device tree nodes (and only those,
+ * leaving others - eg. manually created - unharmed).
+ */
+void of_platform_depopulate(struct device *parent)
+{
+	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
+		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
+		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
+	}
+}
+EXPORT_SYMBOL_GPL(of_platform_depopulate);
+
+static void devm_of_platform_populate_release(struct device *dev, void *res)
+{
+	of_platform_depopulate(*(struct device **)res);
+}
+
+/**
+ * devm_of_platform_populate() - Populate platform_devices from device tree data
+ * @dev: device that requested to populate from device tree data
+ *
+ * Similar to of_platform_populate(), but will automatically call
+ * of_platform_depopulate() when the device is unbound from the bus.
+ *
+ * Return: 0 on success, < 0 on failure.
+ */
+int devm_of_platform_populate(struct device *dev)
+{
+	struct device **ptr;
+	int ret;
+
+	if (!dev)
+		return -EINVAL;
+
+	ptr = devres_alloc(devm_of_platform_populate_release,
+			   sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+	if (ret) {
+		devres_free(ptr);
+	} else {
+		*ptr = dev;
+		devres_add(dev, ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_of_platform_populate);
+
+static int devm_of_platform_match(struct device *dev, void *res, void *data)
+{
+	struct device **ptr = res;
+
+	if (!ptr) {
+		WARN_ON(!ptr);
+		return 0;
+	}
+
+	return *ptr == data;
+}
+
+/**
+ * devm_of_platform_depopulate() - Remove devices populated from device tree
+ * @dev: device that requested to depopulate from device tree data
+ *
+ * Complementary to devm_of_platform_populate(), this function removes children
+ * of the given device (and, recursively, their children) that have been
+ * created from their respective device tree nodes (and only those,
+ * leaving others - eg. manually created - unharmed).
+ */
+void devm_of_platform_depopulate(struct device *dev)
+{
+	int ret;
+
+	ret = devres_release(dev, devm_of_platform_populate_release,
+			     devm_of_platform_match, dev);
+
+	WARN_ON(ret);
+}
+EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
+
+#ifdef CONFIG_OF_DYNAMIC
+static int of_platform_notify(struct notifier_block *nb,
+				unsigned long action, void *arg)
+{
+	struct of_reconfig_data *rd = arg;
+	struct platform_device *pdev_parent, *pdev;
+	bool children_left;
+	struct device_node *parent;
+
+	switch (of_reconfig_get_state_change(action, rd)) {
+	case OF_RECONFIG_CHANGE_ADD:
+		parent = rd->dn->parent;
+		/* verify that the parent is a bus (or the root node) */
+		if (!of_node_is_root(parent) &&
+		    !of_node_check_flag(parent, OF_POPULATED_BUS))
+			return NOTIFY_OK;	/* not for us */
+
+		/* already populated? (driver using of_populate manually) */
+		if (of_node_check_flag(rd->dn, OF_POPULATED))
+			return NOTIFY_OK;
+
+		/* pdev_parent may be NULL when no bus platform device */
+		pdev_parent = of_find_device_by_node(parent);
+		pdev = of_platform_device_create(rd->dn, NULL,
+				pdev_parent ? &pdev_parent->dev : NULL);
+		platform_device_put(pdev_parent);
+
+		if (pdev == NULL) {
+			pr_err("%s: failed to create for '%pOF'\n",
+					__func__, rd->dn);
+			/* of_platform_device_create tosses the error code */
+			return notifier_from_errno(-EINVAL);
+		}
+		break;
+
+	case OF_RECONFIG_CHANGE_REMOVE:
+
+		/* already depopulated? */
+		if (!of_node_check_flag(rd->dn, OF_POPULATED))
+			return NOTIFY_OK;
+
+		/* find our device by node */
+		pdev = of_find_device_by_node(rd->dn);
+		if (pdev == NULL)
+			return NOTIFY_OK;	/* no? not meant for us */
+
+		/* unregister takes one ref away */
+		of_platform_device_destroy(&pdev->dev, &children_left);
+
+		/* and put the reference of the find */
+		platform_device_put(pdev);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block platform_of_notifier = {
+	.notifier_call = of_platform_notify,
+};
+
+void of_platform_register_reconfig_notifier(void)
+{
+	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+#endif /* CONFIG_OF_ADDRESS */
diff --git a/drivers/of/property.c b/drivers/of/property.c
new file mode 100644
index 000000000..72cf12907
--- /dev/null
+++ b/drivers/of/property.c
@@ -0,0 +1,1712 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/of/property.c - Procedures for accessing and interpreting
+ *			   Devicetree properties and graphs.
+ *
+ * Initially created by copying procedures from drivers/of/base.c. This
+ * file contains the OF property as well as the OF graph interface
+ * functions.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
+ *
+ *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ *  Grant Likely.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/ctype.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/of_irq.h>
+#include <linux/string.h>
+#include <linux/moduleparam.h>
+
+#include "of_private.h"
+
+/**
+ * of_property_read_bool - Find a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ *
+ * Search for a boolean property in a device node. Usage on non-boolean
+ * property types is deprecated.
+ *
+ * Return: true if the property exists false otherwise.
+ */
+bool of_property_read_bool(const struct device_node *np, const char *propname)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	/*
+	 * Boolean properties should not have a value. Testing for property
+	 * presence should either use of_property_present() or just read the
+	 * property value and check the returned error code.
+	 */
+	if (prop && prop->length)
+		pr_warn("%pOF: Read of boolean property '%s' with a value.\n", np, propname);
+
+	return prop ? true : false;
+}
+EXPORT_SYMBOL(of_property_read_bool);
+
+/**
+ * of_graph_is_present() - check graph's presence
+ * @node: pointer to device_node containing graph port
+ *
+ * Return: True if @node has a port or ports (with a port) sub-node,
+ * false otherwise.
+ */
+bool of_graph_is_present(const struct device_node *node)
+{
+	struct device_node *ports __free(device_node) = of_get_child_by_name(node, "ports");
+
+	if (ports)
+		node = ports;
+
+	struct device_node *port __free(device_node) = of_get_child_by_name(node, "port");
+
+	return !!port;
+}
+EXPORT_SYMBOL(of_graph_is_present);
+
+/**
+ * of_property_count_elems_of_size - Count the number of elements in a property
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @elem_size:	size of the individual element
+ *
+ * Search for a property in a device node and count the number of elements of
+ * size elem_size in it.
+ *
+ * Return: The number of elements on success, -EINVAL if the property does not
+ * exist or its length does not match a multiple of elem_size and -ENODATA if
+ * the property does not have a value.
+ */
+int of_property_count_elems_of_size(const struct device_node *np,
+				const char *propname, int elem_size)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	if (prop->length % elem_size != 0) {
+		pr_err("size of %s in node %pOF is not a multiple of %d\n",
+		       propname, np, elem_size);
+		return -EINVAL;
+	}
+
+	return prop->length / elem_size;
+}
+EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
+
+/**
+ * of_find_property_value_of_size
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @min:	minimum allowed length of property value
+ * @max:	maximum allowed length of property value (0 means unlimited)
+ * @len:	if !=NULL, actual length is written to here
+ *
+ * Search for a property in a device node and valid the requested size.
+ *
+ * Return: The property value on success, -EINVAL if the property does not
+ * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data is too small or too large.
+ *
+ */
+static void *of_find_property_value_of_size(const struct device_node *np,
+			const char *propname, u32 min, u32 max, size_t *len)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return ERR_PTR(-EINVAL);
+	if (!prop->value)
+		return ERR_PTR(-ENODATA);
+	if (prop->length < min)
+		return ERR_PTR(-EOVERFLOW);
+	if (max && prop->length > max)
+		return ERR_PTR(-EOVERFLOW);
+
+	if (len)
+		*len = prop->length;
+
+	return prop->value;
+}
+
+/**
+ * of_property_read_u8_index - Find and read a u8 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u8 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 8-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_u8_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u8 *out_value)
+{
+	const u8 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0, NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = val[index];
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u8_index);
+
+/**
+ * of_property_read_u16_index - Find and read a u16 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u16 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 16-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u16 value can be decoded.
+ */
+int of_property_read_u16_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u16 *out_value)
+{
+	const u16 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0, NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be16_to_cpup(((__be16 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u16_index);
+
+/**
+ * of_property_read_u32_index - Find and read a u32 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u32 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 32-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u32_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u32 *out_value)
+{
+	const u32 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0,
+					NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be32_to_cpup(((__be32 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_index);
+
+/**
+ * of_property_read_u64_index - Find and read a u64 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u64 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 64-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u64 *out_value)
+{
+	const u64 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0, NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be64_to_cpup(((__be64 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_index);
+
+/**
+ * of_property_read_variable_u8_array - Find and read an array of u8 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 8-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 8 <0x50 0x60 0x70>;``
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_variable_u8_array(const struct device_node *np,
+					const char *propname, u8 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const u8 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = *val++;
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
+
+/**
+ * of_property_read_variable_u16_array - Find and read an array of u16 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 16-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 16 <0x5000 0x6000 0x7000>;``
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u16 value can be decoded.
+ */
+int of_property_read_variable_u16_array(const struct device_node *np,
+					const char *propname, u16 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be16 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be16_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
+
+/**
+ * of_property_read_variable_u32_array - Find and read an array of 32 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it.
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_variable_u32_array(const struct device_node *np,
+			       const char *propname, u32 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be32_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
+
+/**
+ * of_property_read_u64 - Find and read a 64 bit integer from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_value:	pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read a 64-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64(const struct device_node *np, const char *propname,
+			 u64 *out_value)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						sizeof(*out_value),
+						0,
+						NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = of_read_number(val, 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64);
+
+/**
+ * of_property_read_variable_u64_array - Find and read an array of 64 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it.
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_variable_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--) {
+		*out_values++ = of_read_number(val, 2);
+		val += 2;
+	}
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
+
+/**
+ * of_property_read_string - Find and read a string from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_string:	pointer to null terminated return string, modified only if
+ *		return value is 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy).
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist, -ENODATA if
+ * property does not have a value, and -EILSEQ if the string is not
+ * null-terminated within the length of the property data.
+ *
+ * Note that the empty string "" has length of 1, thus -ENODATA cannot
+ * be interpreted as an empty string.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+int of_property_read_string(const struct device_node *np, const char *propname,
+				const char **out_string)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->length)
+		return -ENODATA;
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return -EILSEQ;
+	*out_string = prop->value;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string);
+
+/**
+ * of_property_match_string() - Find string in a list and return index
+ * @np: pointer to the node containing the string list property
+ * @propname: string list property name
+ * @string: pointer to the string to search for in the string list
+ *
+ * Search for an exact match of string in a device node property which is a
+ * string of lists.
+ *
+ * Return: the index of the first occurrence of the string on success, -EINVAL
+ * if the property does not exist, -ENODATA if the property does not have a
+ * value, and -EILSEQ if the string is not null-terminated within the length of
+ * the property data.
+ */
+int of_property_match_string(const struct device_node *np, const char *propname,
+			     const char *string)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+	size_t l;
+	int i;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end; i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		pr_debug("comparing %s with %s\n", string, p);
+		if (strcmp(string, p) == 0)
+			return i; /* Found it; return index */
+	}
+	return -ENODATA;
+}
+EXPORT_SYMBOL_GPL(of_property_match_string);
+
+/**
+ * of_property_read_string_helper() - Utility helper for parsing string properties
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_strs:	output array of string pointers.
+ * @sz:		number of array elements to read.
+ * @skip:	Number of strings to skip over at beginning of list.
+ *
+ * Don't call this function directly. It is a utility helper for the
+ * of_property_read_string*() family of functions.
+ */
+int of_property_read_string_helper(const struct device_node *np,
+				   const char *propname, const char **out_strs,
+				   size_t sz, int skip)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+	int l = 0, i = 0;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		if (out_strs && i >= skip)
+			*out_strs++ = p;
+	}
+	i -= skip;
+	return i <= 0 ? -ENODATA : i;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string_helper);
+
+const __be32 *of_prop_next_u32(const struct property *prop, const __be32 *cur,
+			       u32 *pu)
+{
+	const void *curv = cur;
+
+	if (!prop)
+		return NULL;
+
+	if (!cur) {
+		curv = prop->value;
+		goto out_val;
+	}
+
+	curv += sizeof(*cur);
+	if (curv >= prop->value + prop->length)
+		return NULL;
+
+out_val:
+	*pu = be32_to_cpup(curv);
+	return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_u32);
+
+const char *of_prop_next_string(const struct property *prop, const char *cur)
+{
+	const char *curv;
+	const char *end;
+	size_t len;
+
+	if (!prop || !prop->value || !prop->length)
+		return NULL;
+
+	curv = cur ? cur : prop->value;
+	end = prop->value + prop->length;
+
+	if (curv < (const char *)prop->value || curv >= end)
+		return NULL;
+
+	if (cur) {
+		len = strnlen(curv, end - curv);
+		if (len >= end - curv)
+			return NULL;
+
+		curv += len + 1;
+		if (curv >= end)
+			return NULL;
+	}
+
+	len = strnlen(curv, end - curv);
+	if (len >= end - curv)
+		return NULL;
+
+	return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_string);
+
+/**
+ * of_graph_parse_endpoint() - parse common endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the OF endpoint data structure
+ *
+ * The caller should hold a reference to @node.
+ */
+int of_graph_parse_endpoint(const struct device_node *node,
+			    struct of_endpoint *endpoint)
+{
+	struct device_node *port_node __free(device_node) =
+			    of_get_parent(node);
+
+	WARN_ONCE(!port_node, "%s(): endpoint %pOF has no parent node\n",
+		  __func__, node);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_node = node;
+	/*
+	 * It doesn't matter whether the two calls below succeed.
+	 * If they don't then the default value 0 is used.
+	 */
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_graph_parse_endpoint);
+
+/**
+ * of_graph_get_port_by_id() - get the port matching a given id
+ * @parent: pointer to the parent device node
+ * @id: id of the port
+ *
+ * Return: A 'port' node pointer with refcount incremented. The caller
+ * has to use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
+{
+	struct device_node *node __free(device_node) = of_get_child_by_name(parent, "ports");
+
+	if (node)
+		parent = node;
+
+	for_each_child_of_node_scoped(parent, port) {
+		u32 port_id = 0;
+
+		if (!of_node_name_eq(port, "port"))
+			continue;
+		of_property_read_u32(port, "reg", &port_id);
+		if (id == port_id)
+			return_ptr(port);
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_graph_get_port_by_id);
+
+/**
+ * of_graph_get_next_port() - get next port node.
+ * @parent: pointer to the parent device node, or parent ports node
+ * @prev: previous port node, or NULL to get first
+ *
+ * Parent device node can be used as @parent whether device node has ports node
+ * or not. It will work same as ports@0 node.
+ *
+ * Return: A 'port' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_port(const struct device_node *parent,
+					   struct device_node *prev)
+{
+	if (!parent)
+		return NULL;
+
+	if (!prev) {
+		struct device_node *node __free(device_node) =
+			of_get_child_by_name(parent, "ports");
+
+		if (node)
+			parent = node;
+
+		return of_get_child_by_name(parent, "port");
+	}
+
+	do {
+		prev = of_get_next_child(parent, prev);
+		if (!prev)
+			break;
+	} while (!of_node_name_eq(prev, "port"));
+
+	return prev;
+}
+EXPORT_SYMBOL(of_graph_get_next_port);
+
+/**
+ * of_graph_get_next_port_endpoint() - get next endpoint node in port.
+ * If it reached to end of the port, it will return NULL.
+ * @port: pointer to the target port node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_port_endpoint(const struct device_node *port,
+						    struct device_node *prev)
+{
+	while (1) {
+		prev = of_get_next_child(port, prev);
+		if (!prev)
+			break;
+		if (WARN(!of_node_name_eq(prev, "endpoint"),
+			 "non endpoint node is used (%pOF)", prev))
+			continue;
+
+		break;
+	}
+
+	return prev;
+}
+EXPORT_SYMBOL(of_graph_get_next_port_endpoint);
+
+/**
+ * of_graph_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+					struct device_node *prev)
+{
+	struct device_node *endpoint;
+	struct device_node *port;
+
+	if (!parent)
+		return NULL;
+
+	/*
+	 * Start by locating the port node. If no previous endpoint is specified
+	 * search for the first port node, otherwise get the previous endpoint
+	 * parent port node.
+	 */
+	if (!prev) {
+		port = of_graph_get_next_port(parent, NULL);
+		if (!port) {
+			pr_debug("graph: no port node found in %pOF\n", parent);
+			return NULL;
+		}
+	} else {
+		port = of_get_parent(prev);
+		if (WARN_ONCE(!port, "%s(): endpoint %pOF has no parent node\n",
+			      __func__, prev))
+			return NULL;
+	}
+
+	while (1) {
+		/*
+		 * Now that we have a port node, get the next endpoint by
+		 * getting the next child. If the previous endpoint is NULL this
+		 * will return the first child.
+		 */
+		endpoint = of_graph_get_next_port_endpoint(port, prev);
+		if (endpoint) {
+			of_node_put(port);
+			return endpoint;
+		}
+
+		/* No more endpoints under this port, try the next one. */
+		prev = NULL;
+
+		port = of_graph_get_next_port(parent, port);
+		if (!port)
+			return NULL;
+	}
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
+ * @parent: pointer to the parent device node
+ * @port_reg: identifier (value of reg property) of the parent port node
+ * @reg: identifier (value of reg property) of the endpoint node
+ *
+ * Return: An 'endpoint' node pointer which is identified by reg and at the same
+ * is the child of a port node identified by port_reg. reg and port_reg are
+ * ignored when they are -1. Use of_node_put() on the pointer when done.
+ */
+struct device_node *of_graph_get_endpoint_by_regs(
+	const struct device_node *parent, int port_reg, int reg)
+{
+	struct of_endpoint endpoint;
+	struct device_node *node = NULL;
+
+	for_each_endpoint_of_node(parent, node) {
+		of_graph_parse_endpoint(node, &endpoint);
+		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
+			((reg == -1) || (endpoint.id == reg)))
+			return node;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
+
+/**
+ * of_graph_get_remote_endpoint() - get remote endpoint node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote endpoint node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_endpoint(const struct device_node *node)
+{
+	/* Get remote endpoint node. */
+	return of_parse_phandle(node, "remote-endpoint", 0);
+}
+EXPORT_SYMBOL(of_graph_get_remote_endpoint);
+
+/**
+ * of_graph_get_port_parent() - get port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: device node associated with endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_port_parent(struct device_node *node)
+{
+	unsigned int depth;
+
+	if (!node)
+		return NULL;
+
+	/*
+	 * Preserve usecount for passed in node as of_get_next_parent()
+	 * will do of_node_put() on it.
+	 */
+	of_node_get(node);
+
+	/* Walk 3 levels up only if there is 'ports' node. */
+	for (depth = 3; depth && node; depth--) {
+		node = of_get_next_parent(node);
+		if (depth == 2 && !of_node_name_eq(node, "ports") &&
+		    !of_node_name_eq(node, "in-ports") &&
+		    !of_node_name_eq(node, "out-ports"))
+			break;
+	}
+	return node;
+}
+EXPORT_SYMBOL(of_graph_get_port_parent);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+			       const struct device_node *node)
+{
+	/* Get remote endpoint node. */
+	struct device_node *np __free(device_node) =
+		of_graph_get_remote_endpoint(node);
+
+	return of_graph_get_port_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+	struct device_node *np;
+
+	/* Get remote endpoint node. */
+	np = of_graph_get_remote_endpoint(node);
+	if (!np)
+		return NULL;
+	return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);
+
+/**
+ * of_graph_get_endpoint_count() - get the number of endpoints in a device node
+ * @np: parent device node containing ports and endpoints
+ *
+ * Return: count of endpoint of this device node
+ */
+unsigned int of_graph_get_endpoint_count(const struct device_node *np)
+{
+	struct device_node *endpoint;
+	unsigned int num = 0;
+
+	for_each_endpoint_of_node(np, endpoint)
+		num++;
+
+	return num;
+}
+EXPORT_SYMBOL(of_graph_get_endpoint_count);
+
+/**
+ * of_graph_get_port_count() - get the number of port in a device or ports node
+ * @np: pointer to the device or ports node
+ *
+ * Return: count of port of this device or ports node
+ */
+unsigned int of_graph_get_port_count(struct device_node *np)
+{
+	unsigned int num = 0;
+
+	for_each_of_graph_port(np, port)
+		num++;
+
+	return num;
+}
+EXPORT_SYMBOL(of_graph_get_port_count);
+
+/**
+ * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
+ * @node: pointer to parent device_node containing graph port/endpoint
+ * @port: identifier (value of reg property) of the parent port node
+ * @endpoint: identifier (value of reg property) of the endpoint node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_node(const struct device_node *node,
+					     u32 port, u32 endpoint)
+{
+	struct device_node *endpoint_node, *remote;
+
+	endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
+	if (!endpoint_node) {
+		pr_debug("no valid endpoint (%d, %d) for node %pOF\n",
+			 port, endpoint, node);
+		return NULL;
+	}
+
+	remote = of_graph_get_remote_port_parent(endpoint_node);
+	of_node_put(endpoint_node);
+	if (!remote) {
+		pr_debug("no valid remote node\n");
+		return NULL;
+	}
+
+	if (!of_device_is_available(remote)) {
+		pr_debug("not available for remote node\n");
+		of_node_put(remote);
+		return NULL;
+	}
+
+	return remote;
+}
+EXPORT_SYMBOL(of_graph_get_remote_node);
+
+static struct fwnode_handle *of_fwnode_get(struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(of_node_get(to_of_node(fwnode)));
+}
+
+static void of_fwnode_put(struct fwnode_handle *fwnode)
+{
+	of_node_put(to_of_node(fwnode));
+}
+
+static bool of_fwnode_device_is_available(const struct fwnode_handle *fwnode)
+{
+	return of_device_is_available(to_of_node(fwnode));
+}
+
+static bool of_fwnode_device_dma_supported(const struct fwnode_handle *fwnode)
+{
+	return true;
+}
+
+static enum dev_dma_attr
+of_fwnode_device_get_dma_attr(const struct fwnode_handle *fwnode)
+{
+	if (of_dma_is_coherent(to_of_node(fwnode)))
+		return DEV_DMA_COHERENT;
+	else
+		return DEV_DMA_NON_COHERENT;
+}
+
+static bool of_fwnode_property_present(const struct fwnode_handle *fwnode,
+				       const char *propname)
+{
+	return of_property_present(to_of_node(fwnode), propname);
+}
+
+static bool of_fwnode_property_read_bool(const struct fwnode_handle *fwnode,
+					 const char *propname)
+{
+	return of_property_read_bool(to_of_node(fwnode), propname);
+}
+
+static int of_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
+					     const char *propname,
+					     unsigned int elem_size, void *val,
+					     size_t nval)
+{
+	const struct device_node *node = to_of_node(fwnode);
+
+	if (!val)
+		return of_property_count_elems_of_size(node, propname,
+						       elem_size);
+
+	switch (elem_size) {
+	case sizeof(u8):
+		return of_property_read_u8_array(node, propname, val, nval);
+	case sizeof(u16):
+		return of_property_read_u16_array(node, propname, val, nval);
+	case sizeof(u32):
+		return of_property_read_u32_array(node, propname, val, nval);
+	case sizeof(u64):
+		return of_property_read_u64_array(node, propname, val, nval);
+	}
+
+	return -ENXIO;
+}
+
+static int
+of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
+				     const char *propname, const char **val,
+				     size_t nval)
+{
+	const struct device_node *node = to_of_node(fwnode);
+
+	return val ?
+		of_property_read_string_array(node, propname, val, nval) :
+		of_property_count_strings(node, propname);
+}
+
+static const char *of_fwnode_get_name(const struct fwnode_handle *fwnode)
+{
+	return kbasename(to_of_node(fwnode)->full_name);
+}
+
+static const char *of_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+	/* Root needs no prefix here (its name is "/"). */
+	if (!to_of_node(fwnode)->parent)
+		return "";
+
+	return "/";
+}
+
+static struct fwnode_handle *
+of_fwnode_get_parent(const struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(of_get_parent(to_of_node(fwnode)));
+}
+
+static struct fwnode_handle *
+of_fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
+			      struct fwnode_handle *child)
+{
+	return of_fwnode_handle(of_get_next_available_child(to_of_node(fwnode),
+							    to_of_node(child)));
+}
+
+static struct fwnode_handle *
+of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
+			       const char *childname)
+{
+	const struct device_node *node = to_of_node(fwnode);
+	struct device_node *child;
+
+	for_each_available_child_of_node(node, child)
+		if (of_node_name_eq(child, childname))
+			return of_fwnode_handle(child);
+
+	return NULL;
+}
+
+static int
+of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
+			     const char *prop, const char *nargs_prop,
+			     unsigned int nargs, unsigned int index,
+			     struct fwnode_reference_args *args)
+{
+	struct of_phandle_args of_args;
+	unsigned int i;
+	int ret;
+
+	/*
+	 * This function should return -ENOENT for out of bound indexes,
+	 * but the OF API uses signed indexes and consider negative indexes
+	 * as invalid. Catch them here to correctly implement the fwnode API.
+	 */
+	if ((int)index < 0)
+		return -ENOENT;
+
+	if (nargs_prop)
+		ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
+						 nargs_prop, index, &of_args);
+	else
+		ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
+						       nargs, index, &of_args);
+	if (ret < 0)
+		return ret;
+	if (!args) {
+		of_node_put(of_args.np);
+		return 0;
+	}
+
+	args->nargs = of_args.args_count;
+	args->fwnode = of_fwnode_handle(of_args.np);
+
+	for (i = 0; i < NR_FWNODE_REFERENCE_ARGS; i++)
+		args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;
+
+	return 0;
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
+				  struct fwnode_handle *prev)
+{
+	return of_fwnode_handle(of_graph_get_next_endpoint(to_of_node(fwnode),
+							   to_of_node(prev)));
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(
+		of_graph_get_remote_endpoint(to_of_node(fwnode)));
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_port_parent(struct fwnode_handle *fwnode)
+{
+	struct device_node *np;
+
+	/* Get the parent of the port */
+	np = of_get_parent(to_of_node(fwnode));
+	if (!np)
+		return NULL;
+
+	/* Is this the "ports" node? If not, it's the port parent. */
+	if (!of_node_name_eq(np, "ports"))
+		return of_fwnode_handle(np);
+
+	return of_fwnode_handle(of_get_next_parent(np));
+}
+
+static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
+					  struct fwnode_endpoint *endpoint)
+{
+	const struct device_node *node = to_of_node(fwnode);
+	struct device_node *port_node __free(device_node) = of_get_parent(node);
+
+	endpoint->local_fwnode = fwnode;
+
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	return 0;
+}
+
+static const void *
+of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
+				const struct device *dev)
+{
+	return of_device_get_match_data(dev);
+}
+
+static void of_link_to_phandle(struct device_node *con_np,
+			      struct device_node *sup_np,
+			      u8 flags)
+{
+	struct device_node *tmp_np __free(device_node) = of_node_get(sup_np);
+
+	/* Check that sup_np and its ancestors are available. */
+	while (tmp_np) {
+		if (of_fwnode_handle(tmp_np)->dev)
+			break;
+
+		if (!of_device_is_available(tmp_np))
+			return;
+
+		tmp_np = of_get_next_parent(tmp_np);
+	}
+
+	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np), flags);
+}
+
+/**
+ * parse_prop_cells - Property parsing function for suppliers
+ *
+ * @np:		Pointer to device tree node containing a list
+ * @prop_name:	Name of property to be parsed. Expected to hold phandle values
+ * @index:	For properties holding a list of phandles, this is the index
+ *		into the list.
+ * @list_name:	Property name that is known to contain list of phandle(s) to
+ *		supplier(s)
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * This is a helper function to parse properties that have a known fixed name
+ * and are a list of phandles and phandle arguments.
+ *
+ * Returns:
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+static struct device_node *parse_prop_cells(struct device_node *np,
+					    const char *prop_name, int index,
+					    const char *list_name,
+					    const char *cells_name)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, list_name))
+		return NULL;
+
+	if (__of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
+					 &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+#define DEFINE_SIMPLE_PROP(fname, name, cells)				  \
+static struct device_node *parse_##fname(struct device_node *np,	  \
+					const char *prop_name, int index) \
+{									  \
+	return parse_prop_cells(np, prop_name, index, name, cells);	  \
+}
+
+/**
+ * parse_suffix_prop_cells - Suffix property parsing function for suppliers
+ *
+ * @np:		Pointer to device tree node containing a list
+ * @prop_name:	Name of property to be parsed. Expected to hold phandle values
+ * @index:	For properties holding a list of phandles, this is the index
+ *		into the list.
+ * @suffix:	Property suffix that is known to contain list of phandle(s) to
+ *		supplier(s)
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * This is a helper function to parse properties that have a known fixed suffix
+ * and are a list of phandles and phandle arguments.
+ *
+ * Returns:
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+static struct device_node *parse_suffix_prop_cells(struct device_node *np,
+					    const char *prop_name, int index,
+					    const char *suffix,
+					    const char *cells_name)
+{
+	struct of_phandle_args sup_args;
+
+	if (!strends(prop_name, suffix))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, cells_name, index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+#define DEFINE_SUFFIX_PROP(fname, suffix, cells)			     \
+static struct device_node *parse_##fname(struct device_node *np,	     \
+					const char *prop_name, int index)    \
+{									     \
+	return parse_suffix_prop_cells(np, prop_name, index, suffix, cells); \
+}
+
+/**
+ * struct supplier_bindings - Property parsing functions for suppliers
+ *
+ * @parse_prop: function name
+ *	parse_prop() finds the node corresponding to a supplier phandle
+ *  parse_prop.np: Pointer to device node holding supplier phandle property
+ *  parse_prop.prop_name: Name of property holding a phandle value
+ *  parse_prop.index: For properties holding a list of phandles, this is the
+ *		      index into the list
+ * @get_con_dev: If the consumer node containing the property is never converted
+ *		 to a struct device, implement this ops so fw_devlink can use it
+ *		 to find the true consumer.
+ * @optional: Describes whether a supplier is mandatory or not
+ * @fwlink_flags: Optional fwnode link flags to use when creating a fwnode link
+ *		  for this property.
+ *
+ * Returns:
+ * parse_prop() return values are
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+struct supplier_bindings {
+	struct device_node *(*parse_prop)(struct device_node *np,
+					  const char *prop_name, int index);
+	struct device_node *(*get_con_dev)(struct device_node *np);
+	bool optional;
+	u8 fwlink_flags;
+};
+
+DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
+DEFINE_SIMPLE_PROP(interconnects, "interconnects", "#interconnect-cells")
+DEFINE_SIMPLE_PROP(iommus, "iommus", "#iommu-cells")
+DEFINE_SIMPLE_PROP(mboxes, "mboxes", "#mbox-cells")
+DEFINE_SIMPLE_PROP(io_channels, "io-channels", "#io-channel-cells")
+DEFINE_SIMPLE_PROP(io_backends, "io-backends", "#io-backend-cells")
+DEFINE_SIMPLE_PROP(dmas, "dmas", "#dma-cells")
+DEFINE_SIMPLE_PROP(power_domains, "power-domains", "#power-domain-cells")
+DEFINE_SIMPLE_PROP(hwlocks, "hwlocks", "#hwlock-cells")
+DEFINE_SIMPLE_PROP(extcon, "extcon", NULL)
+DEFINE_SIMPLE_PROP(nvmem_cells, "nvmem-cells", "#nvmem-cell-cells")
+DEFINE_SIMPLE_PROP(phys, "phys", "#phy-cells")
+DEFINE_SIMPLE_PROP(wakeup_parent, "wakeup-parent", NULL)
+DEFINE_SIMPLE_PROP(pwms, "pwms", "#pwm-cells")
+DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
+DEFINE_SIMPLE_PROP(leds, "leds", NULL)
+DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
+DEFINE_SIMPLE_PROP(panel, "panel", NULL)
+DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
+DEFINE_SIMPLE_PROP(post_init_providers, "post-init-providers", NULL)
+DEFINE_SIMPLE_PROP(access_controllers, "access-controllers", "#access-controller-cells")
+DEFINE_SIMPLE_PROP(pses, "pses", "#pse-cells")
+DEFINE_SIMPLE_PROP(power_supplies, "power-supplies", NULL)
+DEFINE_SIMPLE_PROP(mmc_pwrseq, "mmc-pwrseq", NULL)
+DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
+DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
+
+static struct device_node *parse_pinctrl_n(struct device_node *np,
+					   const char *prop_name, int index)
+{
+	if (!strstarts(prop_name, "pinctrl-"))
+		return NULL;
+
+	if (!isdigit(prop_name[strlen("pinctrl-")]))
+		return NULL;
+
+	return of_parse_phandle(np, prop_name, index);
+}
+
+static struct device_node *parse_gpios(struct device_node *np,
+				       const char *prop_name, int index)
+{
+	if (strends(prop_name, ",nr-gpios"))
+		return NULL;
+
+	return parse_suffix_prop_cells(np, prop_name, index, "-gpios",
+				       "#gpio-cells");
+}
+
+static struct device_node *parse_iommu_maps(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	if (strcmp(prop_name, "iommu-map"))
+		return NULL;
+
+	return of_parse_phandle(np, prop_name, (index * 4) + 1);
+}
+
+static struct device_node *parse_gpio_compat(struct device_node *np,
+					     const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, "gpio") && strcmp(prop_name, "gpios"))
+		return NULL;
+
+	/*
+	 * Ignore node with gpio-hog property since its gpios are all provided
+	 * by its parent.
+	 */
+	if (of_property_read_bool(np, "gpio-hog"))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, "#gpio-cells", index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+static struct device_node *parse_interrupts(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (!IS_ENABLED(CONFIG_OF_IRQ) || IS_ENABLED(CONFIG_PPC))
+		return NULL;
+
+	if (strcmp(prop_name, "interrupts") &&
+	    strcmp(prop_name, "interrupts-extended"))
+		return NULL;
+
+	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
+}
+
+static struct device_node *parse_interrupt_map(struct device_node *np,
+					       const char *prop_name, int index)
+{
+	const __be32 *imap, *imap_end;
+	struct of_phandle_args sup_args;
+	u32 addrcells, intcells;
+	int imaplen;
+
+	if (!IS_ENABLED(CONFIG_OF_IRQ))
+		return NULL;
+
+	if (strcmp(prop_name, "interrupt-map"))
+		return NULL;
+
+	if (of_property_read_u32(np, "#interrupt-cells", &intcells))
+		return NULL;
+	addrcells = of_bus_n_addr_cells(np);
+
+	imap = of_get_property(np, "interrupt-map", &imaplen);
+	if (!imap)
+		return NULL;
+	imaplen /= sizeof(*imap);
+
+	imap_end = imap + imaplen;
+
+	for (int i = 0; imap + addrcells + intcells + 1 < imap_end; i++) {
+		imap += addrcells + intcells;
+
+		imap = of_irq_parse_imap_parent(imap, imap_end - imap, &sup_args);
+		if (!imap)
+			return NULL;
+
+		if (i == index)
+			return sup_args.np;
+
+		of_node_put(sup_args.np);
+	}
+
+	return NULL;
+}
+
+static struct device_node *parse_remote_endpoint(struct device_node *np,
+						 const char *prop_name,
+						 int index)
+{
+	/* Return NULL for index > 0 to signify end of remote-endpoints. */
+	if (index > 0 || strcmp(prop_name, "remote-endpoint"))
+		return NULL;
+
+	return of_graph_get_remote_port_parent(np);
+}
+
+static const struct supplier_bindings of_supplier_bindings[] = {
+	{ .parse_prop = parse_clocks, },
+	{ .parse_prop = parse_interconnects, },
+	{ .parse_prop = parse_iommus, .optional = true, },
+	{ .parse_prop = parse_iommu_maps, .optional = true, },
+	{ .parse_prop = parse_mboxes, },
+	{ .parse_prop = parse_io_channels, },
+	{ .parse_prop = parse_io_backends, },
+	{ .parse_prop = parse_dmas, .optional = true, },
+	{ .parse_prop = parse_power_domains, },
+	{ .parse_prop = parse_hwlocks, },
+	{ .parse_prop = parse_extcon, },
+	{ .parse_prop = parse_nvmem_cells, },
+	{ .parse_prop = parse_phys, },
+	{ .parse_prop = parse_wakeup_parent, },
+	{ .parse_prop = parse_pinctrl_n, },
+	{
+		.parse_prop = parse_remote_endpoint,
+		.get_con_dev = of_graph_get_port_parent,
+	},
+	{ .parse_prop = parse_pwms, },
+	{ .parse_prop = parse_resets, },
+	{ .parse_prop = parse_leds, },
+	{ .parse_prop = parse_backlight, },
+	{ .parse_prop = parse_panel, },
+	{ .parse_prop = parse_msi_parent, },
+	{ .parse_prop = parse_pses, },
+	{ .parse_prop = parse_power_supplies, },
+	{ .parse_prop = parse_mmc_pwrseq, },
+	{ .parse_prop = parse_gpio_compat, },
+	{ .parse_prop = parse_interrupts, },
+	{ .parse_prop = parse_interrupt_map, },
+	{ .parse_prop = parse_access_controllers, },
+	{ .parse_prop = parse_regulators, },
+	{ .parse_prop = parse_gpio, },
+	{ .parse_prop = parse_gpios, },
+	{
+		.parse_prop = parse_post_init_providers,
+		.fwlink_flags = FWLINK_FLAG_IGNORE,
+	},
+	{}
+};
+
+/**
+ * of_link_property - Create device links to suppliers listed in a property
+ * @con_np: The consumer device tree node which contains the property
+ * @prop_name: Name of property to be parsed
+ *
+ * This function checks if the property @prop_name that is present in the
+ * @con_np device tree node is one of the known common device tree bindings
+ * that list phandles to suppliers. If @prop_name isn't one, this function
+ * doesn't do anything.
+ *
+ * If @prop_name is one, this function attempts to create fwnode links from the
+ * consumer device tree node @con_np to all the suppliers device tree nodes
+ * listed in @prop_name.
+ *
+ * Any failed attempt to create a fwnode link will NOT result in an immediate
+ * return.  of_link_property() must create links to all the available supplier
+ * device tree nodes even when attempts to create a link to one or more
+ * suppliers fail.
+ */
+static int of_link_property(struct device_node *con_np, const char *prop_name)
+{
+	struct device_node *phandle;
+	const struct supplier_bindings *s = of_supplier_bindings;
+	unsigned int i = 0;
+	bool matched = false;
+
+	/* Do not stop at first failed link, link all available suppliers. */
+	while (!matched && s->parse_prop) {
+		if (s->optional && !fw_devlink_is_strict()) {
+			s++;
+			continue;
+		}
+
+		while ((phandle = s->parse_prop(con_np, prop_name, i))) {
+			struct device_node *con_dev_np __free(device_node) =
+				s->get_con_dev ? s->get_con_dev(con_np) : of_node_get(con_np);
+
+			matched = true;
+			i++;
+			of_link_to_phandle(con_dev_np, phandle, s->fwlink_flags);
+			of_node_put(phandle);
+		}
+		s++;
+	}
+	return 0;
+}
+
+static void __iomem *of_fwnode_iomap(struct fwnode_handle *fwnode, int index)
+{
+#ifdef CONFIG_OF_ADDRESS
+	return of_iomap(to_of_node(fwnode), index);
+#else
+	return NULL;
+#endif
+}
+
+static int of_fwnode_irq_get(const struct fwnode_handle *fwnode,
+			     unsigned int index)
+{
+	return of_irq_get(to_of_node(fwnode), index);
+}
+
+static int match_property_by_path(const char *node_path, const char *prop_name,
+				  const char *value)
+{
+	struct device_node *np __free(device_node) = of_find_node_by_path(node_path);
+
+	return of_property_match_string(np, prop_name, value);
+}
+
+static bool of_is_fwnode_add_links_supported(void)
+{
+	static int is_supported = -1;
+
+	if (!IS_ENABLED(CONFIG_X86))
+		return true;
+
+	if (is_supported != -1)
+		return !!is_supported;
+
+	is_supported = !((match_property_by_path("/soc", "compatible", "intel,ce4100-cp") >= 0) ||
+			 (match_property_by_path("/", "architecture", "OLPC") >= 0));
+
+	return !!is_supported;
+}
+
+static int of_fwnode_add_links(struct fwnode_handle *fwnode)
+{
+	const struct property *p;
+	struct device_node *con_np = to_of_node(fwnode);
+
+	if (!of_is_fwnode_add_links_supported())
+		return 0;
+
+	if (!con_np)
+		return -EINVAL;
+
+	for_each_property_of_node(con_np, p)
+		of_link_property(con_np, p->name);
+
+	return 0;
+}
+
+const struct fwnode_operations of_fwnode_ops = {
+	.get = of_fwnode_get,
+	.put = of_fwnode_put,
+	.device_is_available = of_fwnode_device_is_available,
+	.device_get_match_data = of_fwnode_device_get_match_data,
+	.device_dma_supported = of_fwnode_device_dma_supported,
+	.device_get_dma_attr = of_fwnode_device_get_dma_attr,
+	.property_present = of_fwnode_property_present,
+	.property_read_bool = of_fwnode_property_read_bool,
+	.property_read_int_array = of_fwnode_property_read_int_array,
+	.property_read_string_array = of_fwnode_property_read_string_array,
+	.get_name = of_fwnode_get_name,
+	.get_name_prefix = of_fwnode_get_name_prefix,
+	.get_parent = of_fwnode_get_parent,
+	.get_next_child_node = of_fwnode_get_next_child_node,
+	.get_named_child_node = of_fwnode_get_named_child_node,
+	.get_reference_args = of_fwnode_get_reference_args,
+	.graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
+	.graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
+	.graph_get_port_parent = of_fwnode_graph_get_port_parent,
+	.graph_parse_endpoint = of_fwnode_graph_parse_endpoint,
+	.iomap = of_fwnode_iomap,
+	.irq_get = of_fwnode_irq_get,
+	.add_links = of_fwnode_add_links,
+};
+EXPORT_SYMBOL_GPL(of_fwnode_ops);
diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
new file mode 100644
index 000000000..86424e145
--- /dev/null
+++ b/drivers/of/resolver.c
@@ -0,0 +1,325 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for dealing with DT resolution
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: resolver: " fmt
+
+#include <linux/cleanup.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+
+#include "of_private.h"
+
+static phandle live_tree_max_phandle(void)
+{
+	struct device_node *node;
+	phandle phandle;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	phandle = 0;
+	for_each_of_allnodes(node) {
+		if (node->phandle != OF_PHANDLE_ILLEGAL &&
+				node->phandle > phandle)
+			phandle = node->phandle;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return phandle;
+}
+
+static void adjust_overlay_phandles(struct device_node *overlay,
+		int phandle_delta)
+{
+	struct device_node *child;
+	const struct property *prop;
+	phandle phandle;
+
+	/* adjust node's phandle in node */
+	if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL)
+		overlay->phandle += phandle_delta;
+
+	/* copy adjusted phandle into *phandle properties */
+	for_each_property_of_node(overlay, prop) {
+
+		if (of_prop_cmp(prop->name, "phandle") &&
+		    of_prop_cmp(prop->name, "linux,phandle"))
+			continue;
+
+		if (prop->length < 4)
+			continue;
+
+		phandle = be32_to_cpup(prop->value);
+		if (phandle == OF_PHANDLE_ILLEGAL)
+			continue;
+
+		*(__be32 *)prop->value = cpu_to_be32(overlay->phandle);
+	}
+
+	for_each_child_of_node(overlay, child)
+		adjust_overlay_phandles(child, phandle_delta);
+}
+
+static int update_usages_of_a_phandle_reference(struct device_node *overlay,
+		const struct property *prop_fixup, phandle phandle)
+{
+	struct device_node *refnode;
+	const struct property *prop;
+	char *value __free(kfree) = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
+	char *cur, *end, *node_path, *prop_name, *s;
+	int offset, len;
+	int err = 0;
+
+	if (!value)
+		return -ENOMEM;
+
+	/* prop_fixup contains a list of tuples of path:property_name:offset */
+	end = value + prop_fixup->length;
+	for (cur = value; cur < end; cur += len + 1) {
+		len = strlen(cur);
+
+		node_path = cur;
+		s = strchr(cur, ':');
+		if (!s)
+			return -EINVAL;
+		*s++ = '\0';
+
+		prop_name = s;
+		s = strchr(s, ':');
+		if (!s)
+			return -EINVAL;
+		*s++ = '\0';
+
+		err = kstrtoint(s, 10, &offset);
+		if (err)
+			return err;
+
+		refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path);
+		if (!refnode)
+			continue;
+
+		for_each_property_of_node(refnode, prop) {
+			if (!of_prop_cmp(prop->name, prop_name))
+				break;
+		}
+		of_node_put(refnode);
+
+		if (!prop)
+			return -ENOENT;
+
+		if (offset < 0 || offset + sizeof(__be32) > prop->length)
+			return -EINVAL;
+
+		*(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
+	}
+
+	return 0;
+}
+
+/* compare nodes taking into account that 'name' strips out the @ part */
+static int node_name_cmp(const struct device_node *dn1,
+		const struct device_node *dn2)
+{
+	const char *n1 = kbasename(dn1->full_name);
+	const char *n2 = kbasename(dn2->full_name);
+
+	return of_node_cmp(n1, n2);
+}
+
+/*
+ * Adjust the local phandle references by the given phandle delta.
+ *
+ * Subtree @local_fixups, which is overlay node __local_fixups__,
+ * mirrors the fragment node structure at the root of the overlay.
+ *
+ * For each property in the fragments that contains a phandle reference,
+ * @local_fixups has a property of the same name that contains a list
+ * of offsets of the phandle reference(s) within the respective property
+ * value(s).  The values at these offsets will be fixed up.
+ */
+static int adjust_local_phandle_references(const struct device_node *local_fixups,
+		const struct device_node *overlay, int phandle_delta)
+{
+	struct device_node *overlay_child;
+	const struct property *prop_fix, *prop;
+	int err, i, count;
+	unsigned int off;
+
+	if (!local_fixups)
+		return 0;
+
+	for_each_property_of_node(local_fixups, prop_fix) {
+
+		/* skip properties added automatically */
+		if (is_pseudo_property(prop_fix->name))
+			continue;
+
+		if ((prop_fix->length % 4) != 0 || prop_fix->length == 0)
+			return -EINVAL;
+		count = prop_fix->length / sizeof(__be32);
+
+		for_each_property_of_node(overlay, prop) {
+			if (!of_prop_cmp(prop->name, prop_fix->name))
+				break;
+		}
+
+		if (!prop)
+			return -EINVAL;
+
+		for (i = 0; i < count; i++) {
+			off = be32_to_cpu(((__be32 *)prop_fix->value)[i]);
+			if ((off + 4) > prop->length)
+				return -EINVAL;
+
+			be32_add_cpu(prop->value + off, phandle_delta);
+		}
+	}
+
+	/*
+	 * These nested loops recurse down two subtrees in parallel, where the
+	 * node names in the two subtrees match.
+	 *
+	 * The roots of the subtrees are the overlay's __local_fixups__ node
+	 * and the overlay's root node.
+	 */
+	for_each_child_of_node_scoped(local_fixups, child) {
+
+		for_each_child_of_node(overlay, overlay_child)
+			if (!node_name_cmp(child, overlay_child)) {
+				of_node_put(overlay_child);
+				break;
+			}
+
+		if (!overlay_child)
+			return -EINVAL;
+
+		err = adjust_local_phandle_references(child, overlay_child,
+				phandle_delta);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/**
+ * of_resolve_phandles - Relocate and resolve overlay against live tree
+ *
+ * @overlay:	Pointer to devicetree overlay to relocate and resolve
+ *
+ * Modify (relocate) values of local phandles in @overlay to a range that
+ * does not conflict with the live expanded devicetree.  Update references
+ * to the local phandles in @overlay.  Update (resolve) phandle references
+ * in @overlay that refer to the live expanded devicetree.
+ *
+ * Phandle values in the live tree are in the range of
+ * 1 .. live_tree_max_phandle().  The range of phandle values in the overlay
+ * also begin with at 1.  Adjust the phandle values in the overlay to begin
+ * at live_tree_max_phandle() + 1.  Update references to the phandles to
+ * the adjusted phandle values.
+ *
+ * The name of each property in the "__fixups__" node in the overlay matches
+ * the name of a symbol (a label) in the live tree.  The values of each
+ * property in the "__fixups__" node is a list of the property values in the
+ * overlay that need to be updated to contain the phandle reference
+ * corresponding to that symbol in the live tree.  Update the references in
+ * the overlay with the phandle values in the live tree.
+ *
+ * @overlay must be detached.
+ *
+ * Resolving and applying @overlay to the live expanded devicetree must be
+ * protected by a mechanism to ensure that multiple overlays are processed
+ * in a single threaded manner so that multiple overlays will not relocate
+ * phandles to overlapping ranges.  The mechanism to enforce this is not
+ * yet implemented.
+ *
+ * Return: %0 on success or a negative error value on error.
+ */
+int of_resolve_phandles(struct device_node *overlay)
+{
+	struct device_node *child, *refnode;
+	struct device_node *overlay_fixups;
+	struct device_node __free(device_node) *local_fixups = NULL;
+	struct property *prop;
+	const char *refpath;
+	phandle phandle, phandle_delta;
+	int err;
+
+	if (!overlay) {
+		pr_err("null overlay\n");
+		return -EINVAL;
+	}
+
+	if (!of_node_check_flag(overlay, OF_DETACHED)) {
+		pr_err("overlay not detached\n");
+		return -EINVAL;
+	}
+
+	phandle_delta = live_tree_max_phandle() + 1;
+	adjust_overlay_phandles(overlay, phandle_delta);
+
+	for_each_child_of_node(overlay, local_fixups)
+		if (of_node_name_eq(local_fixups, "__local_fixups__"))
+			break;
+
+	err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta);
+	if (err)
+		return err;
+
+	overlay_fixups = NULL;
+
+	for_each_child_of_node(overlay, child) {
+		if (of_node_name_eq(child, "__fixups__"))
+			overlay_fixups = child;
+	}
+
+	if (!overlay_fixups)
+		return 0;
+
+	struct device_node __free(device_node) *tree_symbols = of_find_node_by_path("/__symbols__");
+	if (!tree_symbols) {
+		pr_err("no symbols in root of device tree.\n");
+		return -EINVAL;
+	}
+
+	for_each_property_of_node(overlay_fixups, prop) {
+
+		/* skip properties added automatically */
+		if (!of_prop_cmp(prop->name, "name"))
+			continue;
+
+		err = of_property_read_string(tree_symbols,
+				prop->name, &refpath);
+		if (err) {
+			pr_err("node label '%s' not found in live devicetree symbols table\n",
+			       prop->name);
+			return err;
+		}
+
+		refnode = of_find_node_by_path(refpath);
+		if (!refnode)
+			return -ENOENT;
+
+		phandle = refnode->phandle;
+		of_node_put(refnode);
+
+		err = update_usages_of_a_phandle_reference(overlay, prop, phandle);
+		if (err)
+			break;
+	}
+
+	if (err)
+		pr_err("overlay phandle fixup failed: %d\n", err);
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_resolve_phandles);
diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
new file mode 100644
index 000000000..01a966e39
--- /dev/null
+++ b/drivers/of/unittest-data/Makefile
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y += testcases.dtbo.o
+
+obj-$(CONFIG_OF_OVERLAY) += overlay.dtbo.o \
+			    overlay_0.dtbo.o \
+			    overlay_1.dtbo.o \
+			    overlay_2.dtbo.o \
+			    overlay_3.dtbo.o \
+			    overlay_4.dtbo.o \
+			    overlay_5.dtbo.o \
+			    overlay_6.dtbo.o \
+			    overlay_7.dtbo.o \
+			    overlay_8.dtbo.o \
+			    overlay_9.dtbo.o \
+			    overlay_10.dtbo.o \
+			    overlay_11.dtbo.o \
+			    overlay_12.dtbo.o \
+			    overlay_13.dtbo.o \
+			    overlay_15.dtbo.o \
+			    overlay_16.dtbo.o \
+			    overlay_17.dtbo.o \
+			    overlay_18.dtbo.o \
+			    overlay_19.dtbo.o \
+			    overlay_20.dtbo.o \
+			    overlay_bad_add_dup_node.dtbo.o \
+			    overlay_bad_add_dup_prop.dtbo.o \
+			    overlay_bad_phandle.dtbo.o \
+			    overlay_bad_symbol.dtbo.o \
+			    overlay_base.dtbo.o \
+			    overlay_gpio_01.dtbo.o \
+			    overlay_gpio_02a.dtbo.o \
+			    overlay_gpio_02b.dtbo.o \
+			    overlay_gpio_03.dtbo.o \
+			    overlay_gpio_04a.dtbo.o \
+			    overlay_gpio_04b.dtbo.o \
+			    overlay_pci_node.dtbo.o \
+			    overlay_bad_unresolved.dtbo.o
+
+# enable creation of __symbols__ node
+DTC_FLAGS_overlay += -@
+DTC_FLAGS_overlay_bad_phandle += -@
+DTC_FLAGS_overlay_bad_symbol += -@
+DTC_FLAGS_overlay_base += -@
+DTC_FLAGS_testcases += -@
+
+# suppress warnings about intentional errors
+DTC_FLAGS_testcases += -Wno-interrupts_property \
+	-Wno-node_name_vs_property_name \
+	-Wno-interrupt_map
+
+# Apply overlays statically with fdtoverlay.  This is a build time test that
+# the overlays can be applied successfully by fdtoverlay.  This does not
+# guarantee that the overlays can be applied successfully at run time by
+# unittest, but it provides a bit of build time test coverage for those
+# who do not execute unittest.
+#
+# The overlays are applied on top of static_base_1.dtb and static_base_2.dtb to
+# create static_test_1.dtb and static_test_2.dtb.  If fdtoverlay detects an
+# error than the kernel build will fail.  static_test_1.dtb and
+# static_test_2.dtb are not consumed by unittest.
+#
+# Some unittest overlays deliberately contain errors that unittest checks for.
+# These overlays will cause fdtoverlay to fail, and are thus not included
+# in the static test:
+#			  overlay_bad_add_dup_node.dtbo \
+#			  overlay_bad_add_dup_prop.dtbo \
+#			  overlay_bad_phandle.dtbo \
+#			  overlay_bad_symbol.dtbo \
+
+apply_static_overlay_1 := overlay_0.dtbo \
+			  overlay_1.dtbo \
+			  overlay_2.dtbo \
+			  overlay_3.dtbo \
+			  overlay_4.dtbo \
+			  overlay_5.dtbo \
+			  overlay_6.dtbo \
+			  overlay_7.dtbo \
+			  overlay_8.dtbo \
+			  overlay_9.dtbo \
+			  overlay_10.dtbo \
+			  overlay_11.dtbo \
+			  overlay_12.dtbo \
+			  overlay_13.dtbo \
+			  overlay_15.dtbo \
+			  overlay_16.dtbo \
+			  overlay_17.dtbo \
+			  overlay_18.dtbo \
+			  overlay_19.dtbo \
+			  overlay_20.dtbo \
+			  overlay_gpio_01.dtbo \
+			  overlay_gpio_02a.dtbo \
+			  overlay_gpio_02b.dtbo \
+			  overlay_gpio_03.dtbo \
+			  overlay_gpio_04a.dtbo \
+			  overlay_gpio_04b.dtbo
+
+apply_static_overlay_2 := overlay.dtbo
+
+DTC_FLAGS_static_base_1 += -Wno-interrupts_property \
+	-Wno-node_name_vs_property_name \
+	-Wno-interrupt_map
+
+static_test_1-dtbs := static_base_1.dtb $(apply_static_overlay_1)
+static_test_2-dtbs := static_base_2.dtb $(apply_static_overlay_2)
+
+dtb-$(CONFIG_OF_OVERLAY) += static_test_1.dtb static_test_2.dtb
diff --git a/drivers/of/unittest-data/overlay.dtso b/drivers/of/unittest-data/overlay.dtso
new file mode 100644
index 000000000..b3e807b99
--- /dev/null
+++ b/drivers/of/unittest-data/overlay.dtso
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+	status = "okay";
+
+	hvac_2: hvac-large-1 {
+		compatible = "ot,hvac-large";
+		heat-range = <40 75>;
+		cool-range = <65 80>;
+	};
+};
+
+&rides_1 {
+
+	#address-cells = <1>;
+	#size-cells = <1>;
+	status = "okay";
+
+	ride@100 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		track@30 {
+			incline-up = <48 32 16>;
+		};
+
+		track@40 {
+			incline-up = <47 31 15>;
+		};
+	};
+
+	ride_200: ride@200 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "ot,ferris-wheel";
+		reg = <0x00000200 0x100>;
+		hvac-provider = <&hvac_2>;
+		hvac-thermostat = <27 32> ;
+		hvac-zones = <12 5>;
+		hvac-zone-names = "operator", "snack-bar";
+		spin-controller = <&spin_ctrl_1 3>;
+		spin-rph = <30>;
+		gondolas = <16>;
+		gondola-capacity = <6>;
+
+		ride_200_left: track@10 {
+			reg = <0x00000010 0x10>;
+		};
+
+		ride_200_right: track@20 {
+			reg = <0x00000020 0x10>;
+		};
+	};
+};
+
+&lights_2 {
+	status = "okay";
+	color = "purple", "white", "red", "green";
+	rate = <3 256>;
+};
diff --git a/drivers/of/unittest-data/overlay_0.dtso b/drivers/of/unittest-data/overlay_0.dtso
new file mode 100644
index 000000000..bb46582e0
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_0.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_0 - enable using absolute target path */
+
+&{/testcase-data/overlay-node/test-bus/test-unittest0} {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_1.dtso b/drivers/of/unittest-data/overlay_1.dtso
new file mode 100644
index 000000000..9c0fc8ffa
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_1.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_1 - disable using absolute target path */
+
+&{/testcase-data/overlay-node/test-bus/test-unittest1} {
+	status = "disabled";
+};
diff --git a/drivers/of/unittest-data/overlay_10.dtso b/drivers/of/unittest-data/overlay_10.dtso
new file mode 100644
index 000000000..73993bf23
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_10.dtso
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_10 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest_test_bus {
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest10 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <10>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		test-unittest101 {
+			compatible = "unittest";
+			status = "okay";
+			reg = <1>;
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_11.dtso b/drivers/of/unittest-data/overlay_11.dtso
new file mode 100644
index 000000000..7d04ff503
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_11.dtso
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_11 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest_test_bus {
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest11 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <11>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		test-unittest111 {
+			compatible = "unittest";
+			status = "okay";
+			reg = <1>;
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_12.dtso b/drivers/of/unittest-data/overlay_12.dtso
new file mode 100644
index 000000000..8d5087793
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_12.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_12 - enable using absolute target path (i2c) */
+
+&{/testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12} {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_13.dtso b/drivers/of/unittest-data/overlay_13.dtso
new file mode 100644
index 000000000..da200ae94
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_13.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_13 - disable using absolute target path (i2c) */
+
+&{/testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13} {
+	status = "disabled";
+};
diff --git a/drivers/of/unittest-data/overlay_15.dtso b/drivers/of/unittest-data/overlay_15.dtso
new file mode 100644
index 000000000..ba02ae1fe
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_15.dtso
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_15 - mux overlay */
+
+&unittest_i2c_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest15 {
+		reg = <11>;
+		compatible = "unittest-i2c-mux";
+		status = "okay";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		i2c@0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0>;
+
+			test-mux-dev@20 {
+				reg = <0x20>;
+				compatible = "unittest-i2c-dev";
+				status = "okay";
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_16.dtso b/drivers/of/unittest-data/overlay_16.dtso
new file mode 100644
index 000000000..80a46dc02
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_16.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_16 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest16 {
+		compatible = "unittest";
+		reg = <16>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_17.dtso b/drivers/of/unittest-data/overlay_17.dtso
new file mode 100644
index 000000000..5b8a22091
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_17.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_17 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest17 {
+		compatible = "unittest";
+		reg = <17>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_18.dtso b/drivers/of/unittest-data/overlay_18.dtso
new file mode 100644
index 000000000..dcddd5f6d
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_18.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_18 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest18 {
+		compatible = "unittest";
+		reg = <18>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_19.dtso b/drivers/of/unittest-data/overlay_19.dtso
new file mode 100644
index 000000000..32b3ba0b6
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_19.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_19 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest19 {
+		compatible = "unittest";
+		reg = <19>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_2.dtso b/drivers/of/unittest-data/overlay_2.dtso
new file mode 100644
index 000000000..db8684ba8
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_2.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_2 -  enable using label */
+
+&unittest2 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_20.dtso b/drivers/of/unittest-data/overlay_20.dtso
new file mode 100644
index 000000000..d4a4f2f32
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_20.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_20 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest20 {
+		compatible = "unittest";
+		reg = <20>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_3.dtso b/drivers/of/unittest-data/overlay_3.dtso
new file mode 100644
index 000000000..40f289e7c
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_3.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_3 - disable using label */
+
+&unittest3 {
+	status = "disabled";
+};
diff --git a/drivers/of/unittest-data/overlay_4.dtso b/drivers/of/unittest-data/overlay_4.dtso
new file mode 100644
index 000000000..9b9eadddb
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_4.dtso
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_4 - test insertion of a full node */
+
+&unittest_test_bus {
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest4 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <4>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_5.dtso b/drivers/of/unittest-data/overlay_5.dtso
new file mode 100644
index 000000000..706f5f1b7
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_5.dtso
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_5 - test overlay apply revert */
+
+&unittest5 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_6.dtso b/drivers/of/unittest-data/overlay_6.dtso
new file mode 100644
index 000000000..21a7fa4ca
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_6.dtso
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_6 */
+/* overlays 6, 7 application and removal in sequence */
+
+&unittest6 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_7.dtso b/drivers/of/unittest-data/overlay_7.dtso
new file mode 100644
index 000000000..58ba1bb51
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_7.dtso
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_7 */
+/* overlays 6, 7 application and removal in sequence */
+
+&unittest7 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_8.dtso b/drivers/of/unittest-data/overlay_8.dtso
new file mode 100644
index 000000000..e9718d118
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_8.dtso
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_8 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest8 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_9.dtso b/drivers/of/unittest-data/overlay_9.dtso
new file mode 100644
index 000000000..b35e23eda
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_9.dtso
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_9 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest8 {
+	property-foo = "bar";
+};
diff --git a/drivers/of/unittest-data/overlay_bad_add_dup_node.dtso b/drivers/of/unittest-data/overlay_bad_add_dup_node.dtso
new file mode 100644
index 000000000..9b53412b2
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_add_dup_node.dtso
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/*
+ * &electric_1/motor-1 and &spin_ctrl_1 are the same node:
+ *   /testcase-data-2/substation@100/motor-1
+ *
+ * Thus the new node "controller" in each fragment will
+ * result in an attempt to add the same node twice.
+ * This will result in an error and the overlay apply
+ * will fail.
+ */
+
+&electric_1 {
+	motor-1 {
+		controller {
+			power_bus = <0x1 0x2>;
+		};
+	};
+};
+
+&spin_ctrl_1 {
+	controller {
+		power_bus_emergency = <0x101 0x102>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_add_dup_prop.dtso b/drivers/of/unittest-data/overlay_bad_add_dup_prop.dtso
new file mode 100644
index 000000000..e03f79165
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_add_dup_prop.dtso
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/*
+ * &electric_1/motor-1/electric and &spin_ctrl_1/electric are the same node:
+ *   /testcase-data-2/substation@100/motor-1/electric
+ *
+ * Thus the property "rpm_avail" in each fragment will
+ * result in an attempt to update the same property twice.
+ * This will result in an error and the overlay apply
+ * will fail.
+ *
+ * The previous version of this test did not include the extra
+ * level of node 'electric'.  That resulted in the 'rpm_avail'
+ * property being located in the pre-existing node 'motor-1'.
+ * Modifying a property results in a WARNING that a memory leak
+ * will occur if the overlay is removed.  Since the overlay apply
+ * fails, the memory leak does actually occur, and kmemleak will
+ * further report the memory leak if CONFIG_DEBUG_KMEMLEAK is
+ * enabled.  Adding the overlay node 'electric' avoids the
+ * memory leak and thus people who use kmemleak will not
+ * have to debug this non-problem again.
+ */
+
+&electric_1 {
+	motor-1 {
+		electric {
+			rpm_avail = <100>;
+		};
+	};
+};
+
+&spin_ctrl_1 {
+	electric {
+		rpm_avail = <100 200>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_phandle.dtso b/drivers/of/unittest-data/overlay_bad_phandle.dtso
new file mode 100644
index 000000000..a61ffc073
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_phandle.dtso
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+	// This label should cause an error when the overlay
+	// is applied.  There is already a phandle value
+	// in the base tree for motor-1.
+	spin_ctrl_1_conflict: motor-1 {
+		accelerate = <3>;
+		decelerate = <5>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_symbol.dtso b/drivers/of/unittest-data/overlay_bad_symbol.dtso
new file mode 100644
index 000000000..07f730384
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_symbol.dtso
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+	// This label should cause an error when the overlay
+	// is applied.  There is already a symbol hvac_1
+	// in the base tree
+	hvac_1: hvac-medium-2 {
+		compatible = "ot,hvac-medium";
+		heat-range = <50 75>;
+		cool-range = <60 80>;
+	};
+
+};
diff --git a/drivers/of/unittest-data/overlay_bad_unresolved.dtso b/drivers/of/unittest-data/overlay_bad_unresolved.dtso
new file mode 100644
index 000000000..f34d8780d
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_unresolved.dtso
@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&this_label_does_not_exist {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_base.dtso b/drivers/of/unittest-data/overlay_base.dtso
new file mode 100644
index 000000000..ab9014589
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_base.dtso
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+#include "overlay_common.dtsi"
diff --git a/drivers/of/unittest-data/overlay_common.dtsi b/drivers/of/unittest-data/overlay_common.dtsi
new file mode 100644
index 000000000..a9d7cdbd5
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_common.dtsi
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Base device tree that overlays will be applied against.
+ *
+ * Do not add any properties in node "/".
+ * Do not add any nodes other than "/testcase-data-2" in node "/".
+ * Do not add anything that would result in dtc creating node "/__fixups__".
+ * dtc will create nodes "/__symbols__" and "/__local_fixups__".
+ */
+
+/ {
+	testcase-data-2 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		electric_1: substation@100 {
+			compatible = "ot,big-volts-control";
+			reg = <0x00000100 0x100>;
+			status = "disabled";
+
+			hvac_1: hvac-medium-1 {
+				compatible = "ot,hvac-medium";
+				heat-range = <50 75>;
+				cool-range = <60 80>;
+			};
+
+			spin_ctrl_1: motor-1 {
+				compatible = "ot,ferris-wheel-motor";
+				spin = "clockwise";
+				rpm_avail = <50>;
+			};
+
+			spin_ctrl_2: motor-8 {
+				compatible = "ot,roller-coaster-motor";
+			};
+		};
+
+		rides_1: fairway-1 {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			compatible = "ot,rides";
+			status = "disabled";
+			orientation = <127>;
+
+			ride@100 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				compatible = "ot,roller-coaster";
+				reg = <0x00000100 0x100>;
+				hvac-provider = <&hvac_1>;
+				hvac-thermostat = <29> ;
+				hvac-zones = <14>;
+				hvac-zone-names = "operator";
+				spin-controller = <&spin_ctrl_2 5 &spin_ctrl_2 7>;
+				spin-controller-names = "track_1", "track_2";
+				queues = <2>;
+
+				track@30 {
+					reg = <0x00000030 0x10>;
+				};
+
+				track@40 {
+					reg = <0x00000040 0x10>;
+				};
+
+			};
+		};
+
+		lights_1: lights@30000 {
+			compatible = "ot,work-lights";
+			reg = <0x00030000 0x1000>;
+			status = "disabled";
+		};
+
+		lights_2: lights@40000 {
+			compatible = "ot,show-lights";
+			reg = <0x00040000 0x1000>;
+			status = "disabled";
+			rate = <13 138>;
+		};
+
+		retail_1: vending@50000 {
+			reg = <0x00050000 0x1000>;
+			compatible = "ot,tickets";
+			status = "disabled";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_01.dtso b/drivers/of/unittest-data/overlay_gpio_01.dtso
new file mode 100644
index 000000000..bb3a31a21
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_01.dtso
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@0 {
+		compatible = "unittest-gpio";
+		reg = <0>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B";
+
+		line-b {
+			gpio-hog;
+			gpios = <2 0>;
+			input;
+			line-name = "line-B-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_02a.dtso b/drivers/of/unittest-data/overlay_gpio_02a.dtso
new file mode 100644
index 000000000..da955537d
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_02a.dtso
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@2 {
+		compatible = "unittest-gpio";
+		reg = <2>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B";
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_02b.dtso b/drivers/of/unittest-data/overlay_gpio_02b.dtso
new file mode 100644
index 000000000..79503965d
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_02b.dtso
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@2 {
+		line-a {
+			gpio-hog;
+			gpios = <1 0>;
+			input;
+			line-name = "line-A-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_03.dtso b/drivers/of/unittest-data/overlay_gpio_03.dtso
new file mode 100644
index 000000000..d8c709616
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_03.dtso
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@3 {
+		compatible = "unittest-gpio";
+		reg = <3>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B", "line-C", "line-D";
+
+		line-d {
+			gpio-hog;
+			gpios = <4 0>;
+			input;
+			line-name = "line-D-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_04a.dtso b/drivers/of/unittest-data/overlay_gpio_04a.dtso
new file mode 100644
index 000000000..de8651197
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_04a.dtso
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@4 {
+		compatible = "unittest-gpio";
+		reg = <4>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B", "line-C", "line-D";
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_04b.dtso b/drivers/of/unittest-data/overlay_gpio_04b.dtso
new file mode 100644
index 000000000..dc6eff22f
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_04b.dtso
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	gpio@4 {
+		line-c {
+			gpio-hog;
+			gpios = <3 0>;
+			input;
+			line-name = "line-C-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_pci_node.dtso b/drivers/of/unittest-data/overlay_pci_node.dtso
new file mode 100644
index 000000000..c05e52e9e
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_pci_node.dtso
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/ {
+	fragment@0 {
+		target-path="";
+		__overlay__ {
+			#address-cells = <3>;
+			#size-cells = <2>;
+			pci-ep-bus@0 {
+				compatible = "simple-bus";
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0x0 0x0 0x0 0x0 0x1000>;
+				reg = <0 0 0 0 0>;
+				unittest-pci@100 {
+					compatible = "unittest-pci";
+					reg = <0x100 0x200>;
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/static_base_1.dts b/drivers/of/unittest-data/static_base_1.dts
new file mode 100644
index 000000000..10556cb3f
--- /dev/null
+++ b/drivers/of/unittest-data/static_base_1.dts
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "testcases_common.dtsi"
diff --git a/drivers/of/unittest-data/static_base_2.dts b/drivers/of/unittest-data/static_base_2.dts
new file mode 100644
index 000000000..b0ea9504d
--- /dev/null
+++ b/drivers/of/unittest-data/static_base_2.dts
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "overlay_common.dtsi"
diff --git a/drivers/of/unittest-data/testcases.dtso b/drivers/of/unittest-data/testcases.dtso
new file mode 100644
index 000000000..61cdd3d5f
--- /dev/null
+++ b/drivers/of/unittest-data/testcases.dtso
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+#include "testcases_common.dtsi"
+
+/ {
+	/*
+	 * testcase data that intentionally results in an error is located here
+	 * instead of in testcases_common.dtsi so that the static overlay apply
+	 * tests will not include the error.
+	 */
+	testcase-data {
+		testcase-device2 {
+			compatible = "testcase-device";
+			interrupt-parent = <&test_intc2>;
+			interrupts = <1>; /* invalid specifier - too short */
+		};
+	};
+
+};
diff --git a/drivers/of/unittest-data/testcases_common.dtsi b/drivers/of/unittest-data/testcases_common.dtsi
new file mode 100644
index 000000000..1c2cdf353
--- /dev/null
+++ b/drivers/of/unittest-data/testcases_common.dtsi
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		changeset {
+			prop-update = "hello";
+			prop-remove = "world";
+
+			node-remove {
+			};
+		};
+	};
+};
+
+#include "tests-phandle.dtsi"
+#include "tests-interrupts.dtsi"
+#include "tests-match.dtsi"
+#include "tests-address.dtsi"
+#include "tests-platform.dtsi"
+#include "tests-overlay.dtsi"
+#include "tests-lifecycle.dtsi"
diff --git a/drivers/of/unittest-data/tests-address.dtsi b/drivers/of/unittest-data/tests-address.dtsi
new file mode 100644
index 000000000..f02a181bb
--- /dev/null
+++ b/drivers/of/unittest-data/tests-address.dtsi
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	testcase-data {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		address-tests {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			/* ranges here is to make sure we don't use it for
+			 * dma-ranges translation */
+			ranges = <0x70000000 0x70000000 0x50000000>,
+				 <0x00000000 0xd0000000 0x20000000>;
+			dma-ranges = <0x0 0x20000000 0x40000000>;
+
+			device@70000000 {
+				reg = <0x70000000 0x1000>;
+			};
+
+			bus@80000000 {
+				#address-cells = <2>;
+				#size-cells = <2>;
+				ranges = <0x0 0x0 0x80000000 0x0 0x100000>;
+				dma-ranges = <0x1 0x0 0x0 0x20 0x0>;
+
+				device@1000 {
+					reg = <0x0 0x1000 0x0 0x1000>;
+				};
+			};
+
+			pci@90000000 {
+				device_type = "pci";
+				#address-cells = <3>;
+				#size-cells = <2>;
+				reg = <0x90000000 0x1000>;
+				ranges = <0x42000000 0x0 0x40000000 0x40000000 0x0 0x10000000>;
+				dma-ranges = <0x42000000 0x0 0x80000000 0x00000000 0x0 0x10000000>,
+					     <0x42000000 0x0 0xc0000000 0x20000000 0x0 0x10000000>;
+			};
+
+			bus@a0000000 {
+				#address-cells = <3>;
+				#size-cells = <2>;
+				ranges = <0xf00baa 0x0 0x0 0xa0000000 0x0 0x100000>,
+					 <0xf00bee 0x1 0x0 0xb0000000 0x0 0x200000>;
+			};
+
+		};
+
+		address-tests2 {
+			#address-cells = <2>;
+			#size-cells = <1>;
+
+			ranges = <0x10000000 0x01000000 0xa0000000 0x01000000>,
+				 <0x10000000 0x02000000 0xb0000000 0x01000000>,
+				 <0x20000000 0x01000000 0xc0000000 0x01000000>,
+				 <0x20000000 0x02000000 0xd0000000 0x01000000>,
+				 <0x00000000 0xd1000000 0xd1000000 0x01000000>,
+				 <0x00000000 0xe8000000 0xe8000000 0x07f00000>,
+				 <0x00000000 0xefff0000 0xefff0000 0x00010000>;
+
+			bus-2cell@10000000 {
+				#address-cells = <2>;
+				#size-cells = <1>;
+				ranges = <0x100000 0x10000 0x10000000 0x1a00000 0x10000>,
+					 <0x100000 0x20000 0x10000000 0x1b00000 0x10000>,
+					 <0x200000 0x10000 0x20000000 0x1c00000 0x10000>,
+					 <0x200000 0x20000 0x20000000 0x2d00000 0x10000>;
+
+				device@100000 {
+					reg = <0x100000 0x11000 0x100>,
+					      <0x100000 0x12000 0x100>,
+					      <0x200000 0x11000 0x100>,
+					      <0x200000 0x21000 0x100>;
+				};
+			};
+
+			bus-3cell@20000000 {
+				#address-cells = <3>;
+				#size-cells = <1>;
+				ranges = <0x1 0x100000 0x10000 0x10000000 0x1a00000 0x10000>,
+					 <0x2 0x100000 0x10000 0x10000000 0x1b00000 0x10000>,
+					 <0x3 0x200000 0x10000 0x20000000 0x1c00000 0x10000>,
+					 <0x4 0x200000 0x20000 0x20000000 0x2d00000 0x10000>;
+
+				local-bus@100000 {
+					#address-cells = <1>;
+					#size-cells = <1>;
+					ranges = <0xf1000000 0x1 0x100000 0x10000 0x10000>,
+						 <0xf2000000 0x2 0x100000 0x10000 0x10000>,
+						 <0xf3000000 0x3 0x200000 0x10000 0x08000>,
+						 <0xf3800000 0x3 0x200000 0x18000 0x08000>,
+						 <0xf4000000 0x4 0x200000 0x20000 0x10000>;
+
+					device@f1001000 {
+						reg = <0xf1001000 0x100>,
+						      <0xf2002000 0x100>,
+						      <0xf3001000 0x100>,
+						      <0xf3801000 0x100>,
+						      <0xf4001000 0x100>;
+					};
+				};
+			};
+
+			pcie@d1070000 {
+				#address-cells = <0x03>;
+				#size-cells = <0x02>;
+				bus-range = <0x00 0xff>;
+				device_type = "pci";
+				ranges = <0x82000000 0 0xe8000000 0 0xe8000000 0 0x7f00000>,
+					 <0x81000000 0 0x00000000 0 0xefff0000 0 0x0010000>;
+				dma-ranges = <0x43000000 0x10 0x00 0x00 0x00 0x00 0x10000000>;
+				reg = <0x00000000 0xd1070000 0x20000>;
+
+				pci@0,0 {
+					#address-cells = <0x03>;
+					#size-cells = <0x02>;
+					bus-range = <0x01 0x01>;
+					device_type = "pci";
+					ranges = <0x82000000 0 0xe8000000
+						  0x82000000 0 0xe8000000
+						  0 0x4400000>;
+					reg = <0x00 0x00 0x00 0x00 0x00>;
+
+					dev@0,0 {
+						#address-cells = <0x03>;
+						#size-cells = <0x02>;
+						ranges = <0 0 0 0x82010000 0 0xe8000000 0 0x2000000>,
+							 <1 0 0 0x82010000 0 0xea000000 0 0x1000000>,
+							 <2 0 0 0x82010000 0 0xeb000000 0 0x0800000>,
+							 <3 0 0 0x82010000 0 0xeb800000 0 0x0800000>,
+							 <4 0 0 0x82010000 0 0xec000000 0 0x0020000>,
+							 <5 0 0 0x82010000 0 0xec020000 0 0x0002000>;
+						reg = <0x10000 0x00 0x00 0x00 0x00>;
+
+						local-bus@0 {
+							#address-cells = <0x01>;
+							#size-cells = <0x01>;
+							ranges = <0xa0000000 0 0 0 0x2000000>,
+								 <0xb0000000 1 0 0 0x1000000>;
+							dma-ranges = <0xc0000000 0x43000000 0x10 0x00 0x10000000>;
+
+							dev@e0000000 {
+								reg = <0xa0001000 0x1000>,
+								      <0xb0002000 0x2000>;
+							};
+						};
+					};
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-interrupts.dtsi b/drivers/of/unittest-data/tests-interrupts.dtsi
new file mode 100644
index 000000000..974f888c9
--- /dev/null
+++ b/drivers/of/unittest-data/tests-interrupts.dtsi
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		interrupts {
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			test_intc0: intc0 {
+				interrupt-controller;
+				#interrupt-cells = <1>;
+			};
+
+			test_intc1: intc1 {
+				interrupt-controller;
+				#interrupt-cells = <3>;
+			};
+
+			test_intc2: intc2 {
+				interrupt-controller;
+				#interrupt-cells = <2>;
+			};
+
+			test_intmap0: intmap0 {
+				#interrupt-cells = <1>;
+				#address-cells = <0>;
+				interrupt-map = <1 &test_intc0 9>,
+						<2 &test_intc1 10 11 12>,
+						<3 &test_intc2 13 14>,
+						<4 &test_intc2 15 16>;
+			};
+
+			test_intmap1: intmap1 {
+				#interrupt-cells = <2>;
+				/*
+				 * #address-cells is required
+				 *
+				 * The property is not provided in this node to
+				 * test that the code will properly handle
+				 * this case for legacy .dts files.
+				 *
+				 * Not having #address-cells will result in a
+				 * warning from dtc starting with
+				 * version v1.6.1-19-g0a3a9d3449c8
+				 * The warning is suppressed by adding
+				 * -Wno-interrupt_map to the Makefile for all
+				 * .dts files this include this .dtsi
+				#address-cells = <1>;
+				 */
+				interrupt-map = <0x5000 1 2 &test_intc0 15>;
+			};
+
+			intmap2 {
+				#interrupt-cells = <2>;
+				#address-cells = <0>;
+				interrupt-map = <1 11 &test_intc0 100>,
+						<2 22 &test_intc1 200 201 202>,
+						<3 33 &test_intc2 300 301>,
+						<4 44 &test_intc2 400 401>;
+			};
+
+			test_intc_intmap0: intc-intmap0 {
+				#interrupt-cells = <1>;
+				#address-cells = <1>;
+				interrupt-controller;
+				interrupt-map = <0x6000 1 &test_intc_intmap0 0x7000 2>;
+			};
+
+			interrupts0 {
+				interrupt-parent = <&test_intc0>;
+				interrupts = <1>, <2>, <3>, <4>;
+			};
+
+			interrupts1 {
+				interrupt-parent = <&test_intmap0>;
+				interrupts = <1>, <2>, <3>, <4>;
+			};
+
+			interrupts2 {
+				reg = <0x6000 0x100>;
+				interrupt-parent = <&test_intc_intmap0>;
+				interrupts = <1>;
+			};
+
+			interrupts-extended0 {
+				reg = <0x5000 0x100>;
+				/*
+				 * Do not remove &test_intmap1 from this
+				 * property - see comment in node intmap1
+				 */
+				interrupts-extended = <&test_intc0 1>,
+						      <&test_intc1 2 3 4>,
+						      <&test_intc2 5 6>,
+						      <&test_intmap0 1>,
+						      <&test_intmap0 2>,
+						      <&test_intmap0 3>,
+						      <&test_intmap1 1 2>;
+			};
+		};
+
+		testcase-device1 {
+			compatible = "testcase-device";
+			interrupt-parent = <&test_intc0>;
+			interrupts = <1>;
+		};
+
+		/*
+		 * testcase data that intentionally results in an error is
+		 * located in testcases.dts instead of in this file so that the
+		 * static overlay apply tests will not include the error.
+		 */
+	};
+};
diff --git a/drivers/of/unittest-data/tests-lifecycle.dtsi b/drivers/of/unittest-data/tests-lifecycle.dtsi
new file mode 100644
index 000000000..28509a878
--- /dev/null
+++ b/drivers/of/unittest-data/tests-lifecycle.dtsi
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		refcount-node {
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-match.dtsi b/drivers/of/unittest-data/tests-match.dtsi
new file mode 100644
index 000000000..1fd3b2131
--- /dev/null
+++ b/drivers/of/unittest-data/tests-match.dtsi
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		match-node {
+			name0 { };
+			name1 { device_type = "type1"; };
+			a { name2 { device_type = "type1"; }; };
+			b { name2 { }; };
+			c { name2 { device_type = "type2"; }; };
+			name3 { compatible = "compat3"; };
+			name4 { compatible = "compat2", "compat3"; };
+			name5 { compatible = "compat2", "compat3"; };
+			name6 { compatible = "compat1", "compat2", "compat3"; };
+			name7 { compatible = "compat2"; device_type = "type1"; };
+			name8 { compatible = "compat2"; device_type = "type1"; };
+			name9 { compatible = "compat2"; };
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-overlay.dtsi b/drivers/of/unittest-data/tests-overlay.dtsi
new file mode 100644
index 000000000..eb35e8aa5
--- /dev/null
+++ b/drivers/of/unittest-data/tests-overlay.dtsi
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		overlay-node {
+			/* test bus */
+			unittest_test_bus: test-bus {
+				compatible = "simple-bus";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				unittest100: test-unittest100 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <100>;
+				};
+
+				unittest101: test-unittest101 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <101>;
+				};
+
+				unittest0: test-unittest0 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <0>;
+				};
+
+				unittest1: test-unittest1 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <1>;
+				};
+
+				unittest2: test-unittest2 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <2>;
+				};
+
+				unittest3: test-unittest3 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <3>;
+				};
+
+				unittest5: test-unittest5 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <5>;
+				};
+
+				unittest6: test-unittest6 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <6>;
+				};
+
+				unittest7: test-unittest7 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <7>;
+				};
+
+				unittest8: test-unittest8 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <8>;
+				};
+
+				unittest_i2c_test_bus: i2c-test-bus {
+					compatible = "unittest-i2c-bus";
+					status = "okay";
+					reg = <50>;
+
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					test-unittest12 {
+						reg = <8>;
+						compatible = "unittest-i2c-dev";
+						status = "disabled";
+					};
+
+					test-unittest13 {
+						reg = <9>;
+						compatible = "unittest-i2c-dev";
+						status = "okay";
+					};
+
+					test-unittest14 {
+						reg = <10>;
+						compatible = "unittest-i2c-mux";
+						status = "okay";
+
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						i2c@0 {
+							#address-cells = <1>;
+							#size-cells = <0>;
+							reg = <0>;
+
+							test-mux-dev@20 {
+								reg = <0x20>;
+								compatible = "unittest-i2c-dev";
+								status = "okay";
+							};
+						};
+					};
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-phandle.dtsi b/drivers/of/unittest-data/tests-phandle.dtsi
new file mode 100644
index 000000000..554a996b2
--- /dev/null
+++ b/drivers/of/unittest-data/tests-phandle.dtsi
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	aliases {
+		testcase-alias = &testcase;
+	};
+
+	testcase: testcase-data {
+		security-password = "password";
+		duplicate-name = "duplicate";
+
+		duplicate-name { };
+
+		phandle-tests {
+			provider0: provider0 {
+				#phandle-cells = <0>;
+			};
+
+			provider1: provider1 {
+				#phandle-cells = <1>;
+			};
+
+			provider2: provider2 {
+				#phandle-cells = <2>;
+			};
+
+			provider3: provider3 {
+				#phandle-cells = <3>;
+			};
+
+			provider4: provider4 {
+				#phandle-cells = <2>;
+				phandle-map = <0 1 &provider1 3>,
+					      <4 0 &provider0>,
+					      <16 5 &provider3 3 5 0>,
+					      <200 8 &provider2 23 6>,
+					      <19 0 &provider2 15 0>,
+					      <2 3 &provider3 2 5 3>;
+				phandle-map-mask = <0xff 0xf>;
+				phandle-map-pass-thru = <0x0 0xf0>;
+			};
+
+			provider5: provider5 {
+				#phandle-cells = <2>;
+				phandle-map = <2 7 &provider4 2 3>;
+				phandle-map-mask = <0xff 0xf>;
+				phandle-map-pass-thru = <0x0 0xf0>;
+			};
+
+			consumer-a {
+				phandle-list =	<&provider1 1>,
+						<&provider2 2 0>,
+						<0>,
+						<&provider3 4 4 3>,
+						<&provider2 5 100>,
+						<&provider0>,
+						<&provider1 7>;
+				phandle-list-names = "first", "second", "third";
+
+				phandle-list-bad-phandle = <12345678 0 0>;
+				phandle-list-bad-args = <&provider2 1 0>,
+							<&provider3 0>;
+				empty-property;
+				string-property = "foobar";
+				unterminated-string = [40 41 42 43];
+				unterminated-string-list = "first", "second", [40 41 42 43];
+			};
+
+			consumer-b {
+				phandle-list =	<&provider1 1>,
+						<&provider4 2 3>,
+						<0>,
+						<&provider4 4 0x100>,
+						<&provider4 0 0x61>,
+						<&provider0>,
+						<&provider4 19 0x20>,
+						<&provider5 2 7>;
+				phandle-list-bad-phandle = <12345678 0 0>;
+				phandle-list-bad-args = <&provider2 1 0>,
+							<&provider4 0>;
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
new file mode 100644
index 000000000..59aa2a973
--- /dev/null
+++ b/drivers/of/unittest-data/tests-platform.dtsi
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		platform-tests {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			test-device@0 {
+				compatible = "test-device";
+				reg = <0x0>;
+
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				dev@100 {
+					compatible = "test-sub-device";
+					reg = <0x100>;
+				};
+			};
+
+			test-device@1 {
+				compatible = "test-device";
+				reg = <0x1>;
+
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				dev@100 {
+					compatible = "test-sub-device",
+						     "test-compat2",
+						     "test-compat3";
+					reg = <0x100>;
+				};
+			};
+
+			test-device@2 {
+				compatible = "test,rust-device";
+				reg = <0x2>;
+
+				test,u32-prop = <0xdeadbeef>;
+				test,i16-array = /bits/ 16 <1 2 (-3) (-4)>;
+
+				ref_child_0: child-0 {
+					test,ref-arg = <&ref_child_1 0x20 0x32>;
+				};
+				ref_child_1: child-1 {
+					test,ref-arg = <&ref_child_0 0x10 0x64>;
+				};
+			};
+		};
+
+		platform-tests-2 {
+			// No #address-cells or #size-cells
+			node {
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				test-device@100 {
+					compatible = "test-sub-device";
+					reg = <0x100 1>;
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
new file mode 100644
index 000000000..e255f54f4
--- /dev/null
+++ b/drivers/of/unittest.c
@@ -0,0 +1,4569 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Self tests for device tree subsystem
+ */
+
+#define pr_fmt(fmt) "### dt-test ### " fmt
+
+#include <linux/memblock.h>
+#include <linux/clk.h>
+#include <linux/dma-direct.h> /* to test phys_to_dma/dma_to_phys */
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/hashtable.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/gpio/driver.h>
+
+#include <linux/bitops.h>
+
+#include "of_private.h"
+
+static struct unittest_results {
+	int passed;
+	int failed;
+} unittest_results;
+
+#define unittest(result, fmt, ...) ({ \
+	bool failed = !(result); \
+	if (failed) { \
+		unittest_results.failed++; \
+		pr_err("FAIL %s():%i " fmt, __func__, __LINE__, ##__VA_ARGS__); \
+	} else { \
+		unittest_results.passed++; \
+		pr_info("pass %s():%i\n", __func__, __LINE__); \
+	} \
+	failed; \
+})
+
+#ifdef CONFIG_OF_KOBJ
+#define OF_KREF_READ(NODE) kref_read(&(NODE)->kobj.kref)
+#else
+#define OF_KREF_READ(NODE) 1
+#endif
+
+/*
+ * Expected message may have a message level other than KERN_INFO.
+ * Print the expected message only if the current loglevel will allow
+ * the actual message to print.
+ *
+ * Do not use EXPECT_BEGIN(), EXPECT_END(), EXPECT_NOT_BEGIN(), or
+ * EXPECT_NOT_END() to report messages expected to be reported or not
+ * reported by pr_debug().
+ */
+#define EXPECT_BEGIN(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT \\ : ") fmt, ##__VA_ARGS__)
+
+#define EXPECT_END(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT / : ") fmt, ##__VA_ARGS__)
+
+#define EXPECT_NOT_BEGIN(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT_NOT \\ : ") fmt, ##__VA_ARGS__)
+
+#define EXPECT_NOT_END(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT_NOT / : ") fmt, ##__VA_ARGS__)
+
+static void __init of_unittest_find_node_by_name(void)
+{
+	struct device_node *np;
+	const char *options, *name;
+
+	np = of_find_node_by_path("/testcase-data");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data", name),
+		"find /testcase-data failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	/* Test if trailing '/' works */
+	np = of_find_node_by_path("/testcase-data/");
+	unittest(!np, "trailing '/' on /testcase-data/ should fail\n");
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data/phandle-tests/consumer-a", name),
+		"find /testcase-data/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	np = of_find_node_by_path("testcase-alias");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data", name),
+		"find testcase-alias failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	/* Test if trailing '/' works on aliases */
+	np = of_find_node_by_path("testcase-alias/");
+	unittest(!np, "trailing '/' on testcase-alias/ should fail\n");
+
+	np = of_find_node_by_path("testcase-alias/phandle-tests/consumer-a");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data/phandle-tests/consumer-a", name),
+		"find testcase-alias/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	np = of_find_node_by_path("/testcase-data/missing-path");
+	unittest(!np, "non-existent path returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_by_path("missing-alias");
+	unittest(!np, "non-existent alias returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_by_path("testcase-alias/missing-path");
+	unittest(!np, "non-existent alias with relative path returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", &options);
+	unittest(np && !strcmp("testoption", options),
+		 "option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:test/option", &options);
+	unittest(np && !strcmp("test/option", options),
+		 "option path test, subcase #1 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data/testcase-device1:test/option", &options);
+	unittest(np && !strcmp("test/option", options),
+		 "option path test, subcase #2 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", NULL);
+	unittest(np, "NULL option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption",
+				       &options);
+	unittest(np && !strcmp("testaliasoption", options),
+		 "option alias path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:test/alias/option",
+				       &options);
+	unittest(np && !strcmp("test/alias/option", options),
+		 "option alias path test, subcase #1 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias/phandle-tests/consumer-a:testaliasoption",
+				       &options);
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data/phandle-tests/consumer-a", name) &&
+		 !strcmp("testaliasoption", options),
+		 "option alias path test, subcase #2 failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption", NULL);
+	unittest(np, "NULL option alias path test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("testcase-alias", &options);
+	unittest(np && !options, "option clearing test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("/", &options);
+	unittest(np && !options, "option clearing root node test failed\n");
+	of_node_put(np);
+}
+
+static void __init of_unittest_dynamic(void)
+{
+	struct device_node *np;
+	struct property *prop;
+
+	np = of_find_node_by_path("/testcase-data");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	/* Array of 4 properties for the purpose of testing */
+	prop = kzalloc_objs(*prop, 4);
+	if (!prop) {
+		unittest(0, "kzalloc() failed\n");
+		return;
+	}
+
+	/* Add a new property - should pass*/
+	prop->name = "new-property";
+	prop->value = "new-property-data";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_add_property(np, prop) == 0, "Adding a new property failed\n");
+
+	/* Try to add an existing property - should fail */
+	prop++;
+	prop->name = "new-property";
+	prop->value = "new-property-data-should-fail";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_add_property(np, prop) != 0,
+		 "Adding an existing property should have failed\n");
+
+	/* Try to modify an existing property - should pass */
+	prop->value = "modify-property-data-should-pass";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_update_property(np, prop) == 0,
+		 "Updating an existing property should have passed\n");
+
+	/* Try to modify non-existent property - should pass*/
+	prop++;
+	prop->name = "modify-property";
+	prop->value = "modify-missing-property-data-should-pass";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_update_property(np, prop) == 0,
+		 "Updating a missing property should have passed\n");
+
+	/* Remove property - should pass */
+	unittest(of_remove_property(np, prop) == 0,
+		 "Removing a property should have passed\n");
+
+	/* Adding very large property - should pass */
+	prop++;
+	prop->name = "large-property-PAGE_SIZEx8";
+	prop->length = PAGE_SIZE * 8;
+	prop->value = kzalloc(prop->length, GFP_KERNEL);
+	unittest(prop->value != NULL, "Unable to allocate large buffer\n");
+	if (prop->value)
+		unittest(of_add_property(np, prop) == 0,
+			 "Adding a large property should have passed\n");
+}
+
+static int __init of_unittest_check_node_linkage(struct device_node *np)
+{
+	int count = 0, rc;
+
+	for_each_child_of_node_scoped(np, child) {
+		if (child->parent != np) {
+			pr_err("Child node %pOFn links to wrong parent %pOFn\n",
+				 child, np);
+			return -EINVAL;
+		}
+
+		rc = of_unittest_check_node_linkage(child);
+		if (rc < 0)
+			return rc;
+		count += rc;
+	}
+
+	return count + 1;
+}
+
+static void __init of_unittest_check_tree_linkage(void)
+{
+	struct device_node *np;
+	int allnode_count = 0, child_count;
+
+	if (!of_root)
+		return;
+
+	for_each_of_allnodes(np)
+		allnode_count++;
+	child_count = of_unittest_check_node_linkage(of_root);
+
+	unittest(child_count > 0, "Device node data structure is corrupted\n");
+	unittest(child_count == allnode_count,
+		 "allnodes list size (%i) doesn't match sibling lists size (%i)\n",
+		 allnode_count, child_count);
+	pr_debug("allnodes list size (%i); sibling lists size (%i)\n", allnode_count, child_count);
+}
+
+static void __init of_unittest_printf_one(struct device_node *np, const char *fmt,
+					  const char *expected)
+{
+	unsigned char *buf;
+	int buf_size;
+	int size, i;
+
+	buf_size = strlen(expected) + 10;
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	/* Baseline; check conversion with a large size limit */
+	memset(buf, 0xff, buf_size);
+	size = snprintf(buf, buf_size - 2, fmt, np);
+
+	/* use strcmp() instead of strncmp() here to be absolutely sure strings match */
+	unittest((strcmp(buf, expected) == 0) && (buf[size+1] == 0xff),
+		"sprintf failed; fmt='%s' expected='%s' rslt='%s'\n",
+		fmt, expected, buf);
+
+	/* Make sure length limits work */
+	size++;
+	for (i = 0; i < 2; i++, size--) {
+		/* Clear the buffer, and make sure it works correctly still */
+		memset(buf, 0xff, buf_size);
+		snprintf(buf, size+1, fmt, np);
+		unittest(strncmp(buf, expected, size) == 0 && (buf[size+1] == 0xff),
+			"snprintf failed; size=%i fmt='%s' expected='%s' rslt='%s'\n",
+			size, fmt, expected, buf);
+	}
+	kfree(buf);
+}
+
+static void __init of_unittest_printf(void)
+{
+	struct device_node *np;
+	const char *full_name = "/testcase-data/platform-tests/test-device@1/dev@100";
+	char phandle_str[16] = "";
+
+	np = of_find_node_by_path(full_name);
+	if (!np) {
+		unittest(np, "testcase data missing\n");
+		return;
+	}
+
+	num_to_str(phandle_str, sizeof(phandle_str), np->phandle, 0);
+
+	of_unittest_printf_one(np, "%pOF",  full_name);
+	of_unittest_printf_one(np, "%pOFf", full_name);
+	of_unittest_printf_one(np, "%pOFn", "dev");
+	of_unittest_printf_one(np, "%2pOFn", "dev");
+	of_unittest_printf_one(np, "%5pOFn", "  dev");
+	of_unittest_printf_one(np, "%pOFnc", "dev:test-sub-device");
+	of_unittest_printf_one(np, "%pOFp", phandle_str);
+	of_unittest_printf_one(np, "%pOFP", "dev@100");
+	of_unittest_printf_one(np, "ABC %pOFP ABC", "ABC dev@100 ABC");
+	of_unittest_printf_one(np, "%10pOFP", "   dev@100");
+	of_unittest_printf_one(np, "%-10pOFP", "dev@100   ");
+	of_unittest_printf_one(of_root, "%pOFP", "/");
+	of_unittest_printf_one(np, "%pOFF", "----");
+	of_unittest_printf_one(np, "%pOFPF", "dev@100:----");
+	of_unittest_printf_one(np, "%pOFPFPc", "dev@100:----:dev@100:test-sub-device");
+	of_unittest_printf_one(np, "%pOFc", "test-sub-device");
+	of_unittest_printf_one(np, "%pOFC",
+			"\"test-sub-device\",\"test-compat2\",\"test-compat3\"");
+}
+
+struct node_hash {
+	struct hlist_node node;
+	struct device_node *np;
+};
+
+static DEFINE_HASHTABLE(phandle_ht, 8);
+static void __init of_unittest_check_phandles(void)
+{
+	struct device_node *np;
+	struct node_hash *nh;
+	struct hlist_node *tmp;
+	int i, dup_count = 0, phandle_count = 0;
+
+	for_each_of_allnodes(np) {
+		if (!np->phandle)
+			continue;
+
+		hash_for_each_possible(phandle_ht, nh, node, np->phandle) {
+			if (nh->np->phandle == np->phandle) {
+				pr_info("Duplicate phandle! %i used by %pOF and %pOF\n",
+					np->phandle, nh->np, np);
+				dup_count++;
+				break;
+			}
+		}
+
+		nh = kzalloc_obj(*nh);
+		if (!nh)
+			return;
+
+		nh->np = np;
+		hash_add(phandle_ht, &nh->node, np->phandle);
+		phandle_count++;
+	}
+	unittest(dup_count == 0, "Found %i duplicates in %i phandles\n",
+		 dup_count, phandle_count);
+
+	/* Clean up */
+	hash_for_each_safe(phandle_ht, i, tmp, nh, node) {
+		hash_del(&nh->node);
+		kfree(nh);
+	}
+}
+
+static void __init of_unittest_parse_phandle_with_args(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells");
+	unittest(rc == 7, "of_count_phandle_with_args() returned %i, expected 7\n", rc);
+
+	for (i = 0; i < 8; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_parse_phandle_with_args(np, "phandle-list",
+						"#phandle-cells", i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == (i + 1));
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 0);
+			break;
+		case 2:
+			passed &= (rc == -ENOENT);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 4);
+			passed &= (args.args[2] == 3);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 100);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.args_count == 0);
+			break;
+		case 6:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == (i + 1));
+			break;
+		case 7:
+			passed &= (rc == -ENOENT);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+
+		if (rc == 0)
+			of_node_put(args.np);
+	}
+
+	/* Check for missing list property */
+	memset(&args, 0, sizeof(args));
+	rc = of_parse_phandle_with_args(np, "phandle-list-missing",
+					"#phandle-cells", 0, &args);
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+	rc = of_count_phandle_with_args(np, "phandle-list-missing",
+					"#phandle-cells");
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+
+	/* Check for missing cells property */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list",
+					"#phandle-cells-missing", 0, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	rc = of_count_phandle_with_args(np, "phandle-list",
+					"#phandle-cells-missing");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for bad phandle in list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list-bad-phandle",
+					"#phandle-cells", 0, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	rc = of_count_phandle_with_args(np, "phandle-list-bad-phandle",
+					"#phandle-cells");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for incorrectly formed argument list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list-bad-args",
+					"#phandle-cells", 1, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	rc = of_count_phandle_with_args(np, "phandle-list-bad-args",
+					"#phandle-cells");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+}
+
+static void __init of_unittest_parse_phandle_with_args_map(void)
+{
+	struct device_node *np, *p[6] = {};
+	struct of_phandle_args args;
+	unsigned int prefs[6];
+	int i, rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-b");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	p[0] = of_find_node_by_path("/testcase-data/phandle-tests/provider0");
+	p[1] = of_find_node_by_path("/testcase-data/phandle-tests/provider1");
+	p[2] = of_find_node_by_path("/testcase-data/phandle-tests/provider2");
+	p[3] = of_find_node_by_path("/testcase-data/phandle-tests/provider3");
+	p[4] = of_find_node_by_path("/testcase-data/phandle-tests/provider4");
+	p[5] = of_find_node_by_path("/testcase-data/phandle-tests/provider5");
+	for (i = 0; i < ARRAY_SIZE(p); ++i) {
+		if (!p[i]) {
+			pr_err("missing testcase data\n");
+			return;
+		}
+		prefs[i] = OF_KREF_READ(p[i]);
+	}
+
+	rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells");
+	unittest(rc == 8, "of_count_phandle_with_args() returned %i, expected 8\n", rc);
+
+	for (i = 0; i < 9; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_parse_phandle_with_args_map(np, "phandle-list",
+						    "phandle", i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.np == p[1]);
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 1);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.np == p[3]);
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 5);
+			passed &= (args.args[2] == 3);
+			break;
+		case 2:
+			passed &= (rc == -ENOENT);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.np == p[0]);
+			passed &= (args.args_count == 0);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.np == p[1]);
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 3);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.np == p[0]);
+			passed &= (args.args_count == 0);
+			break;
+		case 6:
+			passed &= !rc;
+			passed &= (args.np == p[2]);
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 15);
+			passed &= (args.args[1] == 0x20);
+			break;
+		case 7:
+			passed &= !rc;
+			passed &= (args.np == p[3]);
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 5);
+			passed &= (args.args[2] == 3);
+			break;
+		case 8:
+			passed &= (rc == -ENOENT);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %s rc=%i\n",
+			 i, args.np->full_name, rc);
+
+		if (rc == 0)
+			of_node_put(args.np);
+	}
+
+	/* Check for missing list property */
+	memset(&args, 0, sizeof(args));
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-missing",
+					    "phandle", 0, &args);
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+
+	/* Check for missing cells,map,mask property */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: could not get #phandle-missing-cells for /testcase-data/phandle-tests/provider1");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list",
+					    "phandle-missing", 0, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: could not get #phandle-missing-cells for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for bad phandle in list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: could not find phandle 12345678");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-bad-phandle",
+					    "phandle", 0, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: could not find phandle 12345678");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for incorrectly formed argument list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: #phandle-cells = 2 found 1");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-bad-args",
+					    "phandle", 1, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: #phandle-cells = 2 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	for (i = 0; i < ARRAY_SIZE(p); ++i) {
+		unittest(prefs[i] == OF_KREF_READ(p[i]),
+			 "provider%d: expected:%d got:%d\n",
+			 i, prefs[i], OF_KREF_READ(p[i]));
+		of_node_put(p[i]);
+	}
+}
+
+static void __init of_unittest_property_string(void)
+{
+	const char *strings[4];
+	const struct property *prop;
+	struct device_node *np;
+	int rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_err("No testcase data in device tree\n");
+		return;
+	}
+
+	rc = of_property_match_string(np, "phandle-list-names", "first");
+	unittest(rc == 0, "first expected:0 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "second");
+	unittest(rc == 1, "second expected:1 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "third");
+	unittest(rc == 2, "third expected:2 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "fourth");
+	unittest(rc == -ENODATA, "unmatched string; rc=%i\n", rc);
+	rc = of_property_match_string(np, "missing-property", "blah");
+	unittest(rc == -EINVAL, "missing property; rc=%i\n", rc);
+	rc = of_property_match_string(np, "empty-property", "blah");
+	unittest(rc == -ENODATA, "empty property; rc=%i\n", rc);
+	rc = of_property_match_string(np, "unterminated-string", "blah");
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+
+	/* of_property_count_strings() tests */
+	rc = of_property_count_strings(np, "string-property");
+	unittest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "phandle-list-names");
+	unittest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "unterminated-string");
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "unterminated-string-list");
+	unittest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+
+	/* of_property_read_string_index() tests */
+	rc = of_property_read_string_index(np, "string-property", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "foobar"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "string-property", 1, strings);
+	unittest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 1, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "second"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 2, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "third"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "phandle-list-names", 3, strings);
+	unittest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "unterminated-string", 0, strings);
+	unittest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "unterminated-string-list", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "unterminated-string-list", 2, strings); /* should fail */
+	unittest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[1] = NULL;
+
+	/* of_property_read_string_array() tests */
+	rc = of_property_read_string_array(np, "string-property", strings, 4);
+	unittest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_read_string_array(np, "phandle-list-names", strings, 4);
+	unittest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_read_string_array(np, "unterminated-string", strings, 4);
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+	/* -- An incorrectly formed string should cause a failure */
+	rc = of_property_read_string_array(np, "unterminated-string-list", strings, 4);
+	unittest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+	/* -- parsing the correctly formed strings should still work: */
+	strings[2] = NULL;
+	rc = of_property_read_string_array(np, "unterminated-string-list", strings, 2);
+	unittest(rc == 2 && strings[2] == NULL, "of_property_read_string_array() failure; rc=%i\n", rc);
+	strings[1] = NULL;
+	rc = of_property_read_string_array(np, "phandle-list-names", strings, 1);
+	unittest(rc == 1 && strings[1] == NULL, "Overwrote end of string array; rc=%i, str='%s'\n", rc, strings[1]);
+
+	/* of_prop_next_string() tests */
+	prop = of_find_property(np, "phandle-list-names", NULL);
+	strings[0] = of_prop_next_string(prop, NULL);
+	unittest(strings[0] && !strcmp(strings[0], "first"),
+		 "of_prop_next_string() failure; got '%s'\n", strings[0]);
+	strings[0] = of_prop_next_string(prop, strings[0]);
+	unittest(strings[0] && !strcmp(strings[0], "second"),
+		 "of_prop_next_string() failure; got '%s'\n", strings[0]);
+	strings[0] = of_prop_next_string(prop, strings[0]);
+	unittest(strings[0] && !strcmp(strings[0], "third"),
+		 "of_prop_next_string() failure; got '%s'\n", strings[0]);
+	strings[0] = of_prop_next_string(prop, strings[0]);
+	unittest(!strings[0],
+		 "of_prop_next_string() should return NULL at end of list\n");
+
+	prop = of_find_property(np, "unterminated-string", NULL);
+	strings[0] = of_prop_next_string(prop, NULL);
+	unittest(!strings[0],
+		 "of_prop_next_string() should reject unterminated first string\n");
+
+	prop = of_find_property(np, "unterminated-string-list", NULL);
+	strings[0] = of_prop_next_string(prop, NULL);
+	unittest(strings[0] && !strcmp(strings[0], "first"),
+		 "of_prop_next_string() failure; got '%s'\n", strings[0]);
+	strings[0] = of_prop_next_string(prop, strings[0]);
+	unittest(strings[0] && !strcmp(strings[0], "second"),
+		 "of_prop_next_string() failure; got '%s'\n", strings[0]);
+	strings[0] = of_prop_next_string(prop, strings[0]);
+	unittest(!strings[0],
+		 "of_prop_next_string() should reject unterminated trailing string\n");
+}
+
+#define propcmp(p1, p2) (((p1)->length == (p2)->length) && \
+			(p1)->value && (p2)->value && \
+			!memcmp((p1)->value, (p2)->value, (p1)->length) && \
+			!strcmp((p1)->name, (p2)->name))
+static void __init of_unittest_property_copy(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	struct property p1 = { .name = "p1", .length = 0, .value = "" };
+	struct property p2 = { .name = "p2", .length = 5, .value = "abcd" };
+	struct property *new;
+
+	new = __of_prop_dup(&p1, GFP_KERNEL);
+	unittest(new && propcmp(&p1, new), "empty property didn't copy correctly\n");
+	if (new)
+		__of_prop_free(new);
+
+	new = __of_prop_dup(&p2, GFP_KERNEL);
+	unittest(new && propcmp(&p2, new), "non-empty property didn't copy correctly\n");
+	if (new)
+		__of_prop_free(new);
+#endif
+}
+
+static void __init of_unittest_changeset(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	int ret;
+	struct property *ppadd, padd = { .name = "prop-add", .length = 1, .value = "" };
+	struct property *ppname_n1,  pname_n1  = { .name = "name", .length = 3, .value = "n1"  };
+	struct property *ppname_n2,  pname_n2  = { .name = "name", .length = 3, .value = "n2"  };
+	struct property *ppname_n21, pname_n21 = { .name = "name", .length = 3, .value = "n21" };
+	struct property *ppupdate, pupdate = { .name = "prop-update", .length = 5, .value = "abcd" };
+	struct property *ppremove;
+	struct device_node *n1, *n2, *n21, *n22, *nchangeset, *nremove, *parent, *np;
+	static const char * const str_array[] = { "str1", "str2", "str3" };
+	const u32 u32_array[] = { 1, 2, 3 };
+	struct of_changeset chgset;
+	const char *propstr = NULL;
+
+	n1 = __of_node_dup(NULL, "n1");
+	unittest(n1, "testcase setup failure\n");
+
+	n2 = __of_node_dup(NULL, "n2");
+	unittest(n2, "testcase setup failure\n");
+
+	n21 = __of_node_dup(NULL, "n21");
+	unittest(n21, "testcase setup failure %p\n", n21);
+
+	nchangeset = of_find_node_by_path("/testcase-data/changeset");
+	nremove = of_get_child_by_name(nchangeset, "node-remove");
+	unittest(nremove, "testcase setup failure\n");
+
+	ppadd = __of_prop_dup(&padd, GFP_KERNEL);
+	unittest(ppadd, "testcase setup failure\n");
+
+	ppname_n1  = __of_prop_dup(&pname_n1, GFP_KERNEL);
+	unittest(ppname_n1, "testcase setup failure\n");
+
+	ppname_n2  = __of_prop_dup(&pname_n2, GFP_KERNEL);
+	unittest(ppname_n2, "testcase setup failure\n");
+
+	ppname_n21 = __of_prop_dup(&pname_n21, GFP_KERNEL);
+	unittest(ppname_n21, "testcase setup failure\n");
+
+	ppupdate = __of_prop_dup(&pupdate, GFP_KERNEL);
+	unittest(ppupdate, "testcase setup failure\n");
+
+	parent = nchangeset;
+	n1->parent = parent;
+	n2->parent = parent;
+	n21->parent = n2;
+
+	ppremove = of_find_property(parent, "prop-remove", NULL);
+	unittest(ppremove, "failed to find removal prop");
+
+	of_changeset_init(&chgset);
+
+	unittest(!of_changeset_attach_node(&chgset, n1), "fail attach n1\n");
+	unittest(!of_changeset_add_property(&chgset, n1, ppname_n1), "fail add prop name\n");
+
+	unittest(!of_changeset_attach_node(&chgset, n2), "fail attach n2\n");
+	unittest(!of_changeset_add_property(&chgset, n2, ppname_n2), "fail add prop name\n");
+
+	unittest(!of_changeset_detach_node(&chgset, nremove), "fail remove node\n");
+	unittest(!of_changeset_add_property(&chgset, n21, ppname_n21), "fail add prop name\n");
+
+	unittest(!of_changeset_attach_node(&chgset, n21), "fail attach n21\n");
+
+	unittest(!of_changeset_add_property(&chgset, parent, ppadd), "fail add prop prop-add\n");
+	unittest(!of_changeset_update_property(&chgset, parent, ppupdate), "fail update prop\n");
+	unittest(!of_changeset_remove_property(&chgset, parent, ppremove), "fail remove prop\n");
+	n22 = of_changeset_create_node(&chgset, n2, "n22");
+	unittest(n22, "fail create n22\n");
+	unittest(!of_changeset_add_prop_string(&chgset, n22, "prop-str", "abcd"),
+		 "fail add prop prop-str");
+	unittest(!of_changeset_add_prop_string_array(&chgset, n22, "prop-str-array",
+						     (const char **)str_array,
+						     ARRAY_SIZE(str_array)),
+		 "fail add prop prop-str-array");
+	unittest(!of_changeset_add_prop_u32_array(&chgset, n22, "prop-u32-array",
+						  u32_array, ARRAY_SIZE(u32_array)),
+		 "fail add prop prop-u32-array");
+
+	unittest(!of_changeset_apply(&chgset), "apply failed\n");
+
+	/* Make sure node names are constructed correctly */
+	unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n21")),
+		 "'%pOF' not added\n", n21);
+	of_node_put(np);
+	unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n22")),
+		 "'%pOF' not added\n", n22);
+	of_node_put(np);
+
+	unittest(!of_changeset_revert(&chgset), "revert failed\n");
+
+	unittest(!of_find_node_by_path("/testcase-data/changeset/n2/n21"),
+		 "'%pOF' still present after revert\n", n21);
+
+	unittest(of_property_present(parent, "prop-remove"),
+		 "failed to find removed prop after revert\n");
+
+	ret = of_property_read_string(parent, "prop-update", &propstr);
+	unittest(!ret, "failed to find updated prop after revert\n");
+	if (!ret)
+		unittest(strcmp(propstr, "hello") == 0, "original value not in updated property after revert");
+
+	of_node_put(nchangeset);
+	of_changeset_destroy(&chgset);
+
+	of_node_put(n1);
+	of_node_put(n2);
+	of_node_put(n21);
+	of_node_put(n22);
+#endif
+}
+
+static void __init __maybe_unused changeset_check_string(struct device_node *np,
+							 const char *prop_name,
+							 const char *expected_str)
+{
+	const char *str;
+	int ret;
+
+	ret = of_property_read_string(np, prop_name, &str);
+	if (unittest(ret == 0, "failed to read %s\n", prop_name))
+		return;
+
+	unittest(strcmp(str, expected_str) == 0,
+		 "%s value mismatch (read '%s', exp '%s')\n",
+		 prop_name, str, expected_str);
+}
+
+static void __init __maybe_unused changeset_check_string_array(struct device_node *np,
+							       const char *prop_name,
+							       const char * const *expected_array,
+							       unsigned int count)
+{
+	const char *str;
+	unsigned int i;
+	int ret;
+	int cnt;
+
+	cnt = of_property_count_strings(np, prop_name);
+	if (unittest(cnt >= 0, "failed to get %s count\n", prop_name))
+		return;
+
+	if (unittest(cnt == count,
+		     "%s count mismatch (read %d, exp %u)\n",
+		     prop_name, cnt, count))
+		return;
+
+	for (i = 0; i < count; i++) {
+		ret = of_property_read_string_index(np, prop_name, i, &str);
+		if (unittest(ret == 0, "failed to read %s[%d]\n", prop_name, i))
+			continue;
+
+		unittest(strcmp(str, expected_array[i]) == 0,
+			 "%s[%d] value mismatch (read '%s', exp '%s')\n",
+			 prop_name, i, str, expected_array[i]);
+	}
+}
+
+static void __init __maybe_unused changeset_check_u32(struct device_node *np,
+						      const char *prop_name,
+						      u32 expected_u32)
+{
+	u32 val32;
+	int ret;
+
+	ret = of_property_read_u32(np, prop_name, &val32);
+	if (unittest(ret == 0, "failed to read %s\n", prop_name))
+		return;
+
+	unittest(val32 == expected_u32,
+		 "%s value mismatch (read '%u', exp '%u')\n",
+		 prop_name, val32, expected_u32);
+}
+
+static void __init __maybe_unused changeset_check_u32_array(struct device_node *np,
+							    const char *prop_name,
+							    const u32 *expected_array,
+							    unsigned int count)
+{
+	unsigned int i;
+	u32 val32;
+	int ret;
+	int cnt;
+
+	cnt = of_property_count_u32_elems(np, prop_name);
+	if (unittest(cnt >= 0, "failed to get %s count\n", prop_name))
+		return;
+
+	if (unittest(cnt == count,
+		     "%s count mismatch (read %d, exp %u)\n",
+		     prop_name, cnt, count))
+		return;
+
+	for (i = 0; i < count; i++) {
+		ret = of_property_read_u32_index(np, prop_name, i, &val32);
+		if (unittest(ret == 0, "failed to read %s[%d]\n", prop_name, i))
+			continue;
+
+		unittest(val32 == expected_array[i],
+			 "%s[%d] value mismatch (read '%u', exp '%u')\n",
+			 prop_name, i, val32, expected_array[i]);
+	}
+}
+
+static void __init __maybe_unused changeset_check_bool(struct device_node *np,
+						       const char *prop_name)
+{
+	unittest(of_property_read_bool(np, prop_name),
+		 "%s value mismatch (read 'false', exp 'true')\n", prop_name);
+}
+
+static void __init of_unittest_changeset_prop(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	static const char * const str_array[] = { "abc", "defg", "hij" };
+	static const u32 u32_array[] = { 123, 4567, 89, 10, 11 };
+	struct device_node *nchangeset, *np;
+	struct of_changeset chgset;
+	int ret;
+
+	nchangeset = of_find_node_by_path("/testcase-data/changeset");
+	if (!nchangeset) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	of_changeset_init(&chgset);
+
+	np = of_changeset_create_node(&chgset, nchangeset, "test-prop");
+	if (unittest(np, "failed to create test-prop node\n"))
+		goto end_changeset_destroy;
+
+	ret = of_changeset_add_prop_string(&chgset, np, "prop-string", "abcde");
+	unittest(ret == 0, "failed to add prop-string\n");
+
+	ret = of_changeset_add_prop_string_array(&chgset, np, "prop-string-array",
+						 str_array, ARRAY_SIZE(str_array));
+	unittest(ret == 0, "failed to add prop-string-array\n");
+
+	ret = of_changeset_add_prop_u32(&chgset, np, "prop-u32", 1234);
+	unittest(ret == 0, "failed to add prop-u32\n");
+
+	ret = of_changeset_add_prop_u32_array(&chgset, np, "prop-u32-array",
+					      u32_array, ARRAY_SIZE(u32_array));
+	unittest(ret == 0, "failed to add prop-u32-array\n");
+
+	ret = of_changeset_add_prop_bool(&chgset, np, "prop-bool");
+	unittest(ret == 0, "failed to add prop-bool\n");
+
+	of_node_put(np);
+
+	ret = of_changeset_apply(&chgset);
+	if (unittest(ret == 0, "failed to apply changeset\n"))
+		goto end_changeset_destroy;
+
+	np = of_find_node_by_path("/testcase-data/changeset/test-prop");
+	if (unittest(np, "failed to find test-prop node\n"))
+		goto end_revert_changeset;
+
+	changeset_check_string(np, "prop-string", "abcde");
+	changeset_check_string_array(np, "prop-string-array", str_array, ARRAY_SIZE(str_array));
+	changeset_check_u32(np, "prop-u32", 1234);
+	changeset_check_u32_array(np, "prop-u32-array", u32_array, ARRAY_SIZE(u32_array));
+	changeset_check_bool(np, "prop-bool");
+
+	of_node_put(np);
+
+end_revert_changeset:
+	ret = of_changeset_revert(&chgset);
+	unittest(ret == 0, "failed to revert changeset\n");
+
+end_changeset_destroy:
+	of_changeset_destroy(&chgset);
+	of_node_put(nchangeset);
+#endif
+}
+
+static void __init of_unittest_dma_get_max_cpu_address(void)
+{
+	struct device_node *np;
+	phys_addr_t cpu_addr;
+
+	if (!IS_ENABLED(CONFIG_OF_ADDRESS))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	cpu_addr = of_dma_get_max_cpu_address(np);
+	unittest(cpu_addr == 0x4fffffff,
+		 "of_dma_get_max_cpu_address: wrong CPU addr %pad (expecting %x)\n",
+		 &cpu_addr, 0x4fffffff);
+}
+
+static void __init of_unittest_dma_ranges_one(const char *path,
+		u64 expect_dma_addr, u64 expect_paddr)
+{
+#ifdef CONFIG_HAS_DMA
+	struct device_node *np;
+	const struct bus_dma_region *map = NULL;
+	int rc;
+
+	np = of_find_node_by_path(path);
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	rc = of_dma_get_range(np, &map);
+
+	unittest(!rc, "of_dma_get_range failed on node %pOF rc=%i\n", np, rc);
+
+	if (!rc) {
+		phys_addr_t	paddr;
+		dma_addr_t	dma_addr;
+		struct device	*dev_bogus;
+
+		dev_bogus = kzalloc_obj(struct device);
+		if (!dev_bogus) {
+			unittest(0, "kzalloc() failed\n");
+			kfree(map);
+			return;
+		}
+
+		dev_bogus->dma_range_map = map;
+		paddr = dma_to_phys(dev_bogus, expect_dma_addr);
+		dma_addr = phys_to_dma(dev_bogus, expect_paddr);
+
+		unittest(paddr == expect_paddr,
+			 "of_dma_get_range: wrong phys addr %pap (expecting %llx) on node %pOF\n",
+			 &paddr, expect_paddr, np);
+		unittest(dma_addr == expect_dma_addr,
+			 "of_dma_get_range: wrong DMA addr %pad (expecting %llx) on node %pOF\n",
+			 &dma_addr, expect_dma_addr, np);
+
+		kfree(map);
+		kfree(dev_bogus);
+	}
+	of_node_put(np);
+#endif
+}
+
+static void __init of_unittest_parse_dma_ranges(void)
+{
+	of_unittest_dma_ranges_one("/testcase-data/address-tests/device@70000000",
+		0x0, 0x20000000);
+	if (IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT))
+		of_unittest_dma_ranges_one("/testcase-data/address-tests/bus@80000000/device@1000",
+			0x100000000, 0x20000000);
+	of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
+		0x80000000, 0x20000000);
+}
+
+static void __init of_unittest_pci_dma_ranges(void)
+{
+	struct device_node *np;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	int i = 0;
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests/pci@90000000");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		pr_err("missing dma-ranges property\n");
+		return;
+	}
+
+	/*
+	 * Get the dma-ranges from the device tree
+	 */
+	for_each_of_pci_range(&parser, &range) {
+		if (!i) {
+			unittest(range.size == 0x10000000,
+				 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0x20000000,
+				 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.pci_addr == 0x80000000,
+				 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		} else {
+			unittest(range.size == 0x10000000,
+				 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0x40000000,
+				 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.pci_addr == 0xc0000000,
+				 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		}
+		i++;
+	}
+
+	of_node_put(np);
+}
+
+static void __init of_unittest_pci_empty_dma_ranges(void)
+{
+	struct device_node *np;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests2/pcie@d1070000/pci@0,0/dev@0,0/local-bus@0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		pr_err("missing dma-ranges property\n");
+		return;
+	}
+
+	/*
+	 * Get the dma-ranges from the device tree
+	 */
+	for_each_of_pci_range(&parser, &range) {
+		unittest(range.size == 0x10000000,
+			 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+			 np, range.size);
+		unittest(range.cpu_addr == 0x00000000,
+			 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+			 range.cpu_addr, np);
+		unittest(range.pci_addr == 0xc0000000,
+			 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+			 range.pci_addr, np);
+	}
+
+	of_node_put(np);
+}
+
+static void __init of_unittest_bus_ranges(void)
+{
+	struct device_node *np;
+	struct of_range range;
+	struct of_range_parser parser;
+	struct resource res;
+	int ret, count, i = 0;
+
+	np = of_find_node_by_path("/testcase-data/address-tests");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_range_parser_init(&parser, np)) {
+		pr_err("missing ranges property\n");
+		return;
+	}
+
+	ret = of_range_to_resource(np, 1, &res);
+	unittest(!ret, "of_range_to_resource returned error (%d) node %pOF\n",
+		ret, np);
+	unittest(resource_type(&res) == IORESOURCE_MEM,
+		"of_range_to_resource wrong resource type on node %pOF res=%pR\n",
+		np, &res);
+	unittest(res.start == 0xd0000000,
+		"of_range_to_resource wrong resource start address on node %pOF res=%pR\n",
+		np, &res);
+	unittest(resource_size(&res) == 0x20000000,
+		"of_range_to_resource wrong resource start address on node %pOF res=%pR\n",
+		np, &res);
+
+	count = of_range_count(&parser);
+	unittest(count == 2,
+		"of_range_count wrong size on node %pOF count=%d\n",
+		np, count);
+
+	/*
+	 * Get the "ranges" from the device tree
+	 */
+	for_each_of_range(&parser, &range) {
+		unittest(range.flags == IORESOURCE_MEM,
+			"for_each_of_range wrong flags on node %pOF flags=%x (expected %x)\n",
+			np, range.flags, IORESOURCE_MEM);
+		if (!i) {
+			unittest(range.size == 0x50000000,
+				 "for_each_of_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0x70000000,
+				 "for_each_of_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.bus_addr == 0x70000000,
+				 "for_each_of_range wrong bus addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		} else {
+			unittest(range.size == 0x20000000,
+				 "for_each_of_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0xd0000000,
+				 "for_each_of_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.bus_addr == 0x00000000,
+				 "for_each_of_range wrong bus addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		}
+		i++;
+	}
+
+	of_node_put(np);
+}
+
+static void __init of_unittest_bus_3cell_ranges(void)
+{
+	struct device_node *np;
+	struct of_range range;
+	struct of_range_parser parser;
+	int i = 0;
+
+	np = of_find_node_by_path("/testcase-data/address-tests/bus@a0000000");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_range_parser_init(&parser, np)) {
+		pr_err("missing ranges property\n");
+		return;
+	}
+
+	/*
+	 * Get the "ranges" from the device tree
+	 */
+	for_each_of_range(&parser, &range) {
+		if (!i) {
+			unittest(range.flags == 0xf00baa,
+				 "for_each_of_range wrong flags on node %pOF flags=%x\n",
+				 np, range.flags);
+			unittest(range.size == 0x100000,
+				 "for_each_of_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0xa0000000,
+				 "for_each_of_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.bus_addr == 0x0,
+				 "for_each_of_range wrong bus addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		} else {
+			unittest(range.flags == 0xf00bee,
+				 "for_each_of_range wrong flags on node %pOF flags=%x\n",
+				 np, range.flags);
+			unittest(range.size == 0x200000,
+				 "for_each_of_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0xb0000000,
+				 "for_each_of_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.bus_addr == 0x100000000,
+				 "for_each_of_range wrong bus addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		}
+		i++;
+	}
+
+	of_node_put(np);
+}
+
+static void __init of_unittest_reg(void)
+{
+	struct device_node *np;
+	struct resource res;
+	int ret;
+	u64 addr, size;
+
+	np = of_find_node_by_path("/testcase-data/address-tests/bus@80000000/device@1000");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	ret = of_property_read_reg(np, 0, &addr, &size);
+	unittest(!ret, "of_property_read_reg(%pOF) returned error %d\n",
+		np, ret);
+	unittest(addr == 0x1000, "of_property_read_reg(%pOF) untranslated address (%llx) incorrect\n",
+		np, addr);
+
+	of_node_put(np);
+
+	np = of_find_node_by_path("/testcase-data/platform-tests-2/node/test-device@100");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	ret = of_address_to_resource(np, 0, &res);
+	unittest(ret == -EINVAL, "of_address_to_resource(%pOF) expected error on untranslatable address\n",
+		 np);
+
+	of_node_put(np);
+
+}
+
+struct of_unittest_expected_res {
+	int index;
+	struct resource res;
+};
+
+static void __init of_unittest_check_addr(const char *node_path,
+					  const struct of_unittest_expected_res *tab_exp,
+					  unsigned int tab_exp_count)
+{
+	const struct of_unittest_expected_res *expected;
+	struct device_node *np;
+	struct resource res;
+	unsigned int count;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_OF_ADDRESS))
+		return;
+
+	np = of_find_node_by_path(node_path);
+	if (!np) {
+		pr_err("missing testcase data (%s)\n", node_path);
+		return;
+	}
+
+	expected = tab_exp;
+	count = tab_exp_count;
+	while (count--) {
+		ret = of_address_to_resource(np, expected->index, &res);
+		unittest(!ret, "of_address_to_resource(%pOF, %d) returned error %d\n",
+			 np, expected->index, ret);
+		unittest(resource_type(&res) == resource_type(&expected->res) &&
+			 res.start == expected->res.start &&
+			 resource_size(&res) == resource_size(&expected->res),
+			"of_address_to_resource(%pOF, %d) wrong resource %pR, expected %pR\n",
+			np, expected->index, &res, &expected->res);
+		expected++;
+	}
+
+	of_node_put(np);
+}
+
+static const struct of_unittest_expected_res of_unittest_reg_2cell_expected_res[] = {
+	{.index = 0, .res = DEFINE_RES_MEM(0xa0a01000, 0x100) },
+	{.index = 1, .res = DEFINE_RES_MEM(0xa0a02000, 0x100) },
+	{.index = 2, .res = DEFINE_RES_MEM(0xc0c01000, 0x100) },
+	{.index = 3, .res = DEFINE_RES_MEM(0xd0d01000, 0x100) },
+};
+
+static const struct of_unittest_expected_res of_unittest_reg_3cell_expected_res[] = {
+	{.index = 0, .res = DEFINE_RES_MEM(0xa0a01000, 0x100) },
+	{.index = 1, .res = DEFINE_RES_MEM(0xa0b02000, 0x100) },
+	{.index = 2, .res = DEFINE_RES_MEM(0xc0c01000, 0x100) },
+	{.index = 3, .res = DEFINE_RES_MEM(0xc0c09000, 0x100) },
+	{.index = 4, .res = DEFINE_RES_MEM(0xd0d01000, 0x100) },
+};
+
+static const struct of_unittest_expected_res of_unittest_reg_pci_expected_res[] = {
+	{.index = 0, .res = DEFINE_RES_MEM(0xe8001000, 0x1000) },
+	{.index = 1, .res = DEFINE_RES_MEM(0xea002000, 0x2000) },
+};
+
+static void __init of_unittest_translate_addr(void)
+{
+	of_unittest_check_addr("/testcase-data/address-tests2/bus-2cell@10000000/device@100000",
+			       of_unittest_reg_2cell_expected_res,
+			       ARRAY_SIZE(of_unittest_reg_2cell_expected_res));
+
+	of_unittest_check_addr("/testcase-data/address-tests2/bus-3cell@20000000/local-bus@100000/device@f1001000",
+			       of_unittest_reg_3cell_expected_res,
+			       ARRAY_SIZE(of_unittest_reg_3cell_expected_res));
+
+	of_unittest_check_addr("/testcase-data/address-tests2/pcie@d1070000/pci@0,0/dev@0,0/local-bus@0/dev@e0000000",
+			       of_unittest_reg_pci_expected_res,
+			       ARRAY_SIZE(of_unittest_reg_pci_expected_res));
+}
+
+static void __init of_unittest_parse_interrupts(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return;
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 4; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		passed &= !rc;
+		passed &= (args.args_count == 1);
+		passed &= (args.args[0] == (i + 1));
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts1");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 4; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 9);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 10);
+			passed &= (args.args[1] == 11);
+			passed &= (args.args[2] == 12);
+			break;
+		case 2:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 13);
+			passed &= (args.args[1] == 14);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 15);
+			passed &= (args.args[1] == 16);
+			break;
+		default:
+			passed = false;
+		}
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+}
+
+static void __init of_unittest_parse_interrupts_extended(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return;
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts-extended0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 7; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 1);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 3);
+			passed &= (args.args[2] == 4);
+			break;
+		case 2:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 5);
+			passed &= (args.args[1] == 6);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 9);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 10);
+			passed &= (args.args[1] == 11);
+			passed &= (args.args[2] == 12);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 13);
+			passed &= (args.args[1] == 14);
+			break;
+		case 6:
+			/*
+			 * Tests child node that is missing property
+			 * #address-cells.  See the comments in
+			 * drivers/of/unittest-data/tests-interrupts.dtsi
+			 * nodes intmap1 and interrupts-extended0
+			 */
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 15);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+}
+
+struct of_unittest_expected_imap_item {
+	u32 child_imap_count;
+	u32 child_imap[2];
+	const char *parent_path;
+	int parent_args_count;
+	u32 parent_args[3];
+};
+
+static const struct of_unittest_expected_imap_item of_unittest_expected_imap_items[] = {
+	{
+		.child_imap_count = 2,
+		.child_imap = {1, 11},
+		.parent_path = "/testcase-data/interrupts/intc0",
+		.parent_args_count = 1,
+		.parent_args = {100},
+	}, {
+		.child_imap_count = 2,
+		.child_imap = {2, 22},
+		.parent_path = "/testcase-data/interrupts/intc1",
+		.parent_args_count = 3,
+		.parent_args = {200, 201, 202},
+	}, {
+		.child_imap_count = 2,
+		.child_imap = {3, 33},
+		.parent_path = "/testcase-data/interrupts/intc2",
+		.parent_args_count = 2,
+		.parent_args = {300, 301},
+	}, {
+		.child_imap_count = 2,
+		.child_imap = {4, 44},
+		.parent_path = "/testcase-data/interrupts/intc2",
+		.parent_args_count = 2,
+		.parent_args = {400, 401},
+	}
+};
+
+static void __init of_unittest_parse_interrupt_map(void)
+{
+	const struct of_unittest_expected_imap_item *expected_item;
+	struct device_node *imap_np, *expected_parent_np;
+	struct of_imap_parser imap_parser;
+	struct of_imap_item imap_item;
+	int count, ret, i;
+
+	if (of_irq_workarounds & (OF_IMAP_NO_PHANDLE | OF_IMAP_OLDWORLD_MAC))
+		return;
+
+	imap_np = of_find_node_by_path("/testcase-data/interrupts/intmap2");
+	if (!imap_np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	ret = of_imap_parser_init(&imap_parser, imap_np, &imap_item);
+	if (unittest(!ret, "of_imap_parser_init(%pOF) returned error %d\n",
+		     imap_np, ret))
+		goto end;
+
+	expected_item = of_unittest_expected_imap_items;
+	count = 0;
+
+	for_each_of_imap_item(&imap_parser, &imap_item) {
+		if (unittest(count < ARRAY_SIZE(of_unittest_expected_imap_items),
+			     "imap item number %d not expected. Max number %zu\n",
+			     count, ARRAY_SIZE(of_unittest_expected_imap_items) - 1)) {
+			of_node_put(imap_item.parent_args.np);
+			goto end;
+		}
+
+		expected_parent_np = of_find_node_by_path(expected_item->parent_path);
+		if (unittest(expected_parent_np,
+			     "missing dependent testcase data (%s)\n",
+			     expected_item->parent_path)) {
+			of_node_put(imap_item.parent_args.np);
+			goto end;
+		}
+
+		unittest(imap_item.child_imap_count == expected_item->child_imap_count,
+			 "imap[%d] child_imap_count = %u, expected %u\n",
+			 count, imap_item.child_imap_count,
+			 expected_item->child_imap_count);
+
+		for (i = 0; i < expected_item->child_imap_count; i++)
+			unittest(imap_item.child_imap[i] == expected_item->child_imap[i],
+				 "imap[%d] child_imap[%d] = %u, expected %u\n",
+				 count, i, imap_item.child_imap[i],
+				 expected_item->child_imap[i]);
+
+		unittest(imap_item.parent_args.np == expected_parent_np,
+			 "imap[%d] parent np = %pOF, expected %pOF\n",
+			 count, imap_item.parent_args.np, expected_parent_np);
+
+		unittest(imap_item.parent_args.args_count == expected_item->parent_args_count,
+			 "imap[%d] parent param_count = %d, expected %d\n",
+			 count, imap_item.parent_args.args_count,
+			 expected_item->parent_args_count);
+
+		for (i = 0; i < expected_item->parent_args_count; i++)
+			unittest(imap_item.parent_args.args[i] == expected_item->parent_args[i],
+				 "imap[%d] parent param[%d] = %u, expected %u\n",
+				 count, i, imap_item.parent_args.args[i],
+				 expected_item->parent_args[i]);
+
+		of_node_put(expected_parent_np);
+		count++;
+		expected_item++;
+	}
+
+	unittest(count == ARRAY_SIZE(of_unittest_expected_imap_items),
+		 "Missing items. %d parsed, expected %zu\n",
+		 count, ARRAY_SIZE(of_unittest_expected_imap_items));
+end:
+	of_node_put(imap_np);
+}
+
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static void __init of_unittest_irq_refcount(void)
+{
+	struct of_phandle_args args;
+	struct device_node *intc0, *int_ext0;
+	struct device_node *int2, *intc_intmap0;
+	unsigned int ref_c0, ref_c1, ref_c2;
+	int rc;
+	bool passed;
+
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return;
+
+	intc0 = of_find_node_by_path("/testcase-data/interrupts/intc0");
+	int_ext0 = of_find_node_by_path("/testcase-data/interrupts/interrupts-extended0");
+	intc_intmap0 = of_find_node_by_path("/testcase-data/interrupts/intc-intmap0");
+	int2 = of_find_node_by_path("/testcase-data/interrupts/interrupts2");
+	if (!intc0 || !int_ext0 || !intc_intmap0 || !int2) {
+		pr_err("missing testcase data\n");
+		goto out;
+	}
+
+	/* Test refcount for API of_irq_parse_one() */
+	passed = true;
+	ref_c0 = OF_KREF_READ(intc0);
+	ref_c1 = ref_c0 + 1;
+	memset(&args, 0, sizeof(args));
+	rc = of_irq_parse_one(int_ext0, 0, &args);
+	ref_c2 = OF_KREF_READ(intc0);
+	of_node_put(args.np);
+
+	passed &= !rc;
+	passed &= (args.np == intc0);
+	passed &= (args.args_count == 1);
+	passed &= (args.args[0] == 1);
+	passed &= (ref_c1 == ref_c2);
+	unittest(passed, "IRQ refcount case #1 failed, original(%u) expected(%u) got(%u)\n",
+		 ref_c0, ref_c1, ref_c2);
+
+	/* Test refcount for API of_irq_parse_raw() */
+	passed = true;
+	ref_c0 = OF_KREF_READ(intc_intmap0);
+	ref_c1 = ref_c0 + 1;
+	memset(&args, 0, sizeof(args));
+	rc = of_irq_parse_one(int2, 0, &args);
+	ref_c2 = OF_KREF_READ(intc_intmap0);
+	of_node_put(args.np);
+
+	passed &= !rc;
+	passed &= (args.np == intc_intmap0);
+	passed &= (args.args_count == 1);
+	passed &= (args.args[0] == 2);
+	passed &= (ref_c1 == ref_c2);
+	unittest(passed, "IRQ refcount case #2 failed, original(%u) expected(%u) got(%u)\n",
+		 ref_c0, ref_c1, ref_c2);
+
+out:
+	of_node_put(int2);
+	of_node_put(intc_intmap0);
+	of_node_put(int_ext0);
+	of_node_put(intc0);
+}
+#else
+static inline void __init of_unittest_irq_refcount(void) { }
+#endif
+
+static const struct of_device_id match_node_table[] = {
+	{ .data = "A", .name = "name0", }, /* Name alone is lowest priority */
+	{ .data = "B", .type = "type1", }, /* followed by type alone */
+
+	{ .data = "Ca", .name = "name2", .type = "type1", }, /* followed by both together */
+	{ .data = "Cb", .name = "name2", }, /* Only match when type doesn't match */
+	{ .data = "Cc", .name = "name2", .type = "type2", },
+
+	{ .data = "E", .compatible = "compat3" },
+	{ .data = "G", .compatible = "compat2", },
+	{ .data = "H", .compatible = "compat2", .name = "name5", },
+	{ .data = "I", .compatible = "compat2", .type = "type1", },
+	{ .data = "J", .compatible = "compat2", .type = "type1", .name = "name8", },
+	{ .data = "K", .compatible = "compat2", .name = "name9", },
+	{}
+};
+
+static struct {
+	const char *path;
+	const char *data;
+} match_node_tests[] = {
+	{ .path = "/testcase-data/match-node/name0", .data = "A", },
+	{ .path = "/testcase-data/match-node/name1", .data = "B", },
+	{ .path = "/testcase-data/match-node/a/name2", .data = "Ca", },
+	{ .path = "/testcase-data/match-node/b/name2", .data = "Cb", },
+	{ .path = "/testcase-data/match-node/c/name2", .data = "Cc", },
+	{ .path = "/testcase-data/match-node/name3", .data = "E", },
+	{ .path = "/testcase-data/match-node/name4", .data = "G", },
+	{ .path = "/testcase-data/match-node/name5", .data = "H", },
+	{ .path = "/testcase-data/match-node/name6", .data = "G", },
+	{ .path = "/testcase-data/match-node/name7", .data = "I", },
+	{ .path = "/testcase-data/match-node/name8", .data = "J", },
+	{ .path = "/testcase-data/match-node/name9", .data = "K", },
+};
+
+static void __init of_unittest_match_node(void)
+{
+	struct device_node *np;
+	const struct of_device_id *match;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(match_node_tests); i++) {
+		np = of_find_node_by_path(match_node_tests[i].path);
+		if (!np) {
+			unittest(0, "missing testcase node %s\n",
+				match_node_tests[i].path);
+			continue;
+		}
+
+		match = of_match_node(match_node_table, np);
+		if (!match) {
+			unittest(0, "%s didn't match anything\n",
+				match_node_tests[i].path);
+			continue;
+		}
+
+		if (strcmp(match->data, match_node_tests[i].data) != 0) {
+			unittest(0, "%s got wrong match. expected %s, got %s\n",
+				match_node_tests[i].path, match_node_tests[i].data,
+				(const char *)match->data);
+			continue;
+		}
+		unittest(1, "passed");
+	}
+}
+
+static struct resource test_bus_res = DEFINE_RES_MEM(0xfffffff8, 2);
+static const struct platform_device_info test_bus_info = {
+	.name = "unittest-bus",
+};
+static void __init of_unittest_platform_populate(void)
+{
+	int irq, rc;
+	struct device_node *np, *child, *grandchild;
+	struct platform_device *pdev, *test_bus;
+	const struct of_device_id match[] = {
+		{ .compatible = "test-device", },
+		{}
+	};
+
+	np = of_find_node_by_path("/testcase-data");
+	of_platform_default_populate(np, NULL, NULL);
+
+	/* Test that a missing irq domain returns -EPROBE_DEFER */
+	np = of_find_node_by_path("/testcase-data/testcase-device1");
+	pdev = of_find_device_by_node(np);
+	unittest(pdev, "device 1 creation failed\n");
+
+	if (!(of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)) {
+		irq = platform_get_irq(pdev, 0);
+		unittest(irq == -EPROBE_DEFER,
+			 "device deferred probe failed - %d\n", irq);
+
+		/* Test that a parsing failure does not return -EPROBE_DEFER */
+		np = of_find_node_by_path("/testcase-data/testcase-device2");
+		pdev = of_find_device_by_node(np);
+		unittest(pdev, "device 2 creation failed\n");
+
+		EXPECT_BEGIN(KERN_INFO,
+			     "platform testcase-data:testcase-device2: error -ENXIO: IRQ index 0 not found");
+
+		irq = platform_get_irq(pdev, 0);
+
+		EXPECT_END(KERN_INFO,
+			   "platform testcase-data:testcase-device2: error -ENXIO: IRQ index 0 not found");
+
+		unittest(irq < 0 && irq != -EPROBE_DEFER,
+			 "device parsing error failed - %d\n", irq);
+	}
+
+	np = of_find_node_by_path("/testcase-data/platform-tests");
+	unittest(np, "No testcase data in device tree\n");
+	if (!np)
+		return;
+
+	test_bus = platform_device_register_full(&test_bus_info);
+	rc = PTR_ERR_OR_ZERO(test_bus);
+	unittest(!rc, "testbus registration failed; rc=%i\n", rc);
+	if (rc) {
+		of_node_put(np);
+		return;
+	}
+	test_bus->dev.of_node = np;
+
+	/*
+	 * Add a dummy resource to the test bus node after it is
+	 * registered to catch problems with un-inserted resources. The
+	 * DT code doesn't insert the resources, and it has caused the
+	 * kernel to oops in the past. This makes sure the same bug
+	 * doesn't crop up again.
+	 */
+	platform_device_add_resources(test_bus, &test_bus_res, 1);
+
+	of_platform_populate(np, match, NULL, &test_bus->dev);
+	for_each_child_of_node(np, child) {
+		for_each_child_of_node(child, grandchild) {
+			if (!of_property_present(grandchild, "compatible"))
+				continue;
+			pdev = of_find_device_by_node(grandchild);
+			unittest(pdev,
+				 "Could not create device for node '%pOFn'\n",
+				 grandchild);
+			platform_device_put(pdev);
+		}
+	}
+
+	of_platform_depopulate(&test_bus->dev);
+	for_each_child_of_node(np, child) {
+		for_each_child_of_node(child, grandchild)
+			unittest(!of_find_device_by_node(grandchild),
+				 "device didn't get destroyed '%pOFn'\n",
+				 grandchild);
+	}
+
+	platform_device_unregister(test_bus);
+	of_node_put(np);
+}
+
+/**
+ *	update_node_properties - adds the properties
+ *	of np into dup node (present in live tree) and
+ *	updates parent of children of np to dup.
+ *
+ *	@np:	node whose properties are being added to the live tree
+ *	@dup:	node present in live tree to be updated
+ */
+static void update_node_properties(struct device_node *np,
+					struct device_node *dup)
+{
+	struct property *prop;
+	struct property *save_next;
+	struct device_node *child;
+	int ret;
+
+	for_each_child_of_node(np, child)
+		child->parent = dup;
+
+	/*
+	 * "unittest internal error: unable to add testdata property"
+	 *
+	 *    If this message reports a property in node '/__symbols__' then
+	 *    the respective unittest overlay contains a label that has the
+	 *    same name as a label in the live devicetree.  The label will
+	 *    be in the live devicetree only if the devicetree source was
+	 *    compiled with the '-@' option.  If you encounter this error,
+	 *    please consider renaming __all__ of the labels in the unittest
+	 *    overlay dts files with an odd prefix that is unlikely to be
+	 *    used in a real devicetree.
+	 */
+
+	/*
+	 * open code for_each_property_of_node() because of_add_property()
+	 * sets prop->next to NULL
+	 */
+	for (prop = np->properties; prop != NULL; prop = save_next) {
+		save_next = prop->next;
+		ret = of_add_property(dup, prop);
+		if (ret) {
+			if (ret == -EEXIST && !strcmp(prop->name, "name"))
+				continue;
+			pr_err("unittest internal error: unable to add testdata property %pOF/%s",
+			       np, prop->name);
+		}
+	}
+}
+
+/**
+ *	attach_node_and_children - attaches nodes
+ *	and its children to live tree.
+ *	CAUTION: misleading function name - if node @np already exists in
+ *	the live tree then children of @np are *not* attached to the live
+ *	tree.  This works for the current test devicetree nodes because such
+ *	nodes do not have child nodes.
+ *
+ *	@np:	Node to attach to live tree
+ */
+static void attach_node_and_children(struct device_node *np)
+{
+	struct device_node *next, *dup, *child;
+	unsigned long flags;
+	const char *full_name;
+
+	full_name = kasprintf(GFP_KERNEL, "%pOF", np);
+	if (!full_name)
+		return;
+
+	if (!strcmp(full_name, "/__local_fixups__") ||
+	    !strcmp(full_name, "/__fixups__")) {
+		kfree(full_name);
+		return;
+	}
+
+	dup = of_find_node_by_path(full_name);
+	kfree(full_name);
+	if (dup) {
+		update_node_properties(np, dup);
+		return;
+	}
+
+	child = np->child;
+	np->child = NULL;
+
+	mutex_lock(&of_mutex);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np->sibling = np->parent->child;
+	np->parent->child = np;
+	of_node_clear_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_attach_node_sysfs(np);
+	mutex_unlock(&of_mutex);
+
+	while (child) {
+		next = child->sibling;
+		attach_node_and_children(child);
+		child = next;
+	}
+}
+
+/**
+ *	unittest_data_add - Reads, copies data from
+ *	linked tree and attaches it to the live tree
+ */
+static int __init unittest_data_add(void)
+{
+	void *unittest_data_align;
+	struct device_node *unittest_data_node = NULL, *np;
+	/*
+	 * __dtbo_testcases_begin[] and __dtbo_testcases_end[] are magically
+	 * created by cmd_wrap_S_dtbo in scripts/Makefile.dtbs
+	 */
+	extern uint8_t __dtbo_testcases_begin[];
+	extern uint8_t __dtbo_testcases_end[];
+	const int size = __dtbo_testcases_end - __dtbo_testcases_begin;
+	int rc;
+	void *ret;
+
+	if (!size) {
+		pr_warn("%s: testcases is empty\n", __func__);
+		return -ENODATA;
+	}
+
+	/* creating copy */
+	void *unittest_data __free(kfree) = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
+	if (!unittest_data)
+		return -ENOMEM;
+
+	unittest_data_align = PTR_ALIGN(unittest_data, FDT_ALIGN_SIZE);
+	memcpy(unittest_data_align, __dtbo_testcases_begin, size);
+
+	ret = of_fdt_unflatten_tree(unittest_data_align, NULL, &unittest_data_node);
+	if (!ret) {
+		pr_warn("%s: unflatten testcases tree failed\n", __func__);
+		return -ENODATA;
+	}
+	if (!unittest_data_node) {
+		pr_warn("%s: testcases tree is empty\n", __func__);
+		return -ENODATA;
+	}
+
+	/*
+	 * This lock normally encloses of_resolve_phandles()
+	 */
+	of_overlay_mutex_lock();
+
+	rc = of_resolve_phandles(unittest_data_node);
+	if (rc) {
+		pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc);
+		rc = -EINVAL;
+		goto unlock;
+	}
+
+	/* attach the sub-tree to live tree */
+	if (!of_root) {
+		pr_warn("%s: no live tree to attach sub-tree\n", __func__);
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
+
+	np = unittest_data_node->child;
+	while (np) {
+		struct device_node *next = np->sibling;
+
+		np->parent = of_root;
+		/* this will clear OF_DETACHED in np and children */
+		attach_node_and_children(np);
+		np = next;
+	}
+
+	EXPECT_END(KERN_INFO,
+		   "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
+
+	retain_and_null_ptr(unittest_data);
+
+unlock:
+	of_overlay_mutex_unlock();
+
+	return rc;
+}
+
+#ifdef CONFIG_OF_OVERLAY
+static int __init overlay_data_apply(const char *overlay_name, int *ovcs_id);
+
+static int unittest_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	if (np == NULL) {
+		dev_err(dev, "No OF data for device\n");
+		return -EINVAL;
+
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	of_platform_populate(np, NULL, NULL, &pdev->dev);
+
+	return 0;
+}
+
+static void unittest_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+}
+
+static const struct of_device_id unittest_match[] = {
+	{ .compatible = "unittest", },
+	{},
+};
+
+static struct platform_driver unittest_driver = {
+	.probe			= unittest_probe,
+	.remove			= unittest_remove,
+	.driver = {
+		.name		= "unittest",
+		.of_match_table	= unittest_match,
+	},
+};
+
+/* get the platform device instantiated at the path */
+static struct platform_device *of_path_to_platform_device(const char *path)
+{
+	struct device_node *np;
+	struct platform_device *pdev;
+
+	np = of_find_node_by_path(path);
+	if (np == NULL)
+		return NULL;
+
+	pdev = of_find_device_by_node(np);
+	of_node_put(np);
+
+	return pdev;
+}
+
+/* find out if a platform device exists at that path */
+static int of_path_platform_device_exists(const char *path)
+{
+	struct platform_device *pdev;
+
+	pdev = of_path_to_platform_device(path);
+	platform_device_put(pdev);
+	return pdev != NULL;
+}
+
+#ifdef CONFIG_OF_GPIO
+
+struct unittest_gpio_dev {
+	struct gpio_chip chip;
+};
+
+static int unittest_gpio_chip_request_count;
+static int unittest_gpio_probe_count;
+static int unittest_gpio_probe_pass_count;
+
+static int unittest_gpio_chip_request(struct gpio_chip *chip, unsigned int offset)
+{
+	unittest_gpio_chip_request_count++;
+
+	pr_debug("%s(): %s %d %d\n", __func__, chip->label, offset,
+		 unittest_gpio_chip_request_count);
+	return 0;
+}
+
+static int unittest_gpio_probe(struct platform_device *pdev)
+{
+	struct unittest_gpio_dev *devptr;
+	int ret;
+
+	unittest_gpio_probe_count++;
+
+	devptr = kzalloc_obj(*devptr);
+	if (!devptr)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, devptr);
+
+	devptr->chip.fwnode = dev_fwnode(&pdev->dev);
+	devptr->chip.label = "of-unittest-gpio";
+	devptr->chip.base = -1; /* dynamic allocation */
+	devptr->chip.ngpio = 5;
+	devptr->chip.request = unittest_gpio_chip_request;
+
+	ret = gpiochip_add_data(&devptr->chip, NULL);
+
+	unittest(!ret,
+		 "gpiochip_add_data() for node @%pfw failed, ret = %d\n", devptr->chip.fwnode, ret);
+
+	if (!ret)
+		unittest_gpio_probe_pass_count++;
+	return ret;
+}
+
+static void unittest_gpio_remove(struct platform_device *pdev)
+{
+	struct unittest_gpio_dev *devptr = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	dev_dbg(dev, "%s for node @%pfw\n", __func__, devptr->chip.fwnode);
+
+	if (devptr->chip.base != -1)
+		gpiochip_remove(&devptr->chip);
+
+	kfree(devptr);
+}
+
+static const struct of_device_id unittest_gpio_id[] = {
+	{ .compatible = "unittest-gpio", },
+	{}
+};
+
+static struct platform_driver unittest_gpio_driver = {
+	.probe	= unittest_gpio_probe,
+	.remove = unittest_gpio_remove,
+	.driver	= {
+		.name		= "unittest-gpio",
+		.of_match_table	= unittest_gpio_id,
+	},
+};
+
+static void __init of_unittest_overlay_gpio(void)
+{
+	int chip_request_count;
+	int probe_pass_count;
+	int ret;
+
+	/*
+	 * tests: apply overlays before registering driver
+	 * Similar to installing a driver as a module, the
+	 * driver is registered after applying the overlays.
+	 *
+	 * The overlays are applied by overlay_data_apply()
+	 * instead of of_unittest_apply_overlay() so that they
+	 * will not be tracked.  Thus they will not be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 *
+	 * - apply overlay_gpio_01
+	 * - apply overlay_gpio_02a
+	 * - apply overlay_gpio_02b
+	 * - register driver
+	 *
+	 * register driver will result in
+	 *   - probe and processing gpio hog for overlay_gpio_01
+	 *   - probe for overlay_gpio_02a
+	 *   - processing gpio for overlay_gpio_02b
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	/*
+	 * overlay_gpio_01 contains gpio node and child gpio hog node
+	 * overlay_gpio_02a contains gpio node
+	 * overlay_gpio_02b contains child gpio hog node
+	 */
+
+	unittest(overlay_data_apply("overlay_gpio_01", NULL),
+		 "Adding overlay 'overlay_gpio_01' failed\n");
+
+	unittest(overlay_data_apply("overlay_gpio_02a", NULL),
+		 "Adding overlay 'overlay_gpio_02a' failed\n");
+
+	unittest(overlay_data_apply("overlay_gpio_02b", NULL),
+		 "Adding overlay 'overlay_gpio_02b' failed\n");
+
+	ret = platform_driver_register(&unittest_gpio_driver);
+	if (unittest(ret == 0, "could not register unittest gpio driver\n"))
+		return;
+
+	unittest(probe_pass_count + 2 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	unittest(chip_request_count + 2 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+
+	/*
+	 * tests: apply overlays after registering driver
+	 *
+	 * Similar to a driver built-in to the kernel, the
+	 * driver is registered before applying the overlays.
+	 *
+	 * overlay_gpio_03 contains gpio node and child gpio hog node
+	 *
+	 * - apply overlay_gpio_03
+	 *
+	 * apply overlay will result in
+	 *   - probe and processing gpio hog.
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	/* overlay_gpio_03 contains gpio node and child gpio hog node */
+
+	unittest(overlay_data_apply("overlay_gpio_03", NULL),
+		 "Adding overlay 'overlay_gpio_03' failed\n");
+
+	unittest(probe_pass_count + 1 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	unittest(chip_request_count + 1 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+
+	/*
+	 * overlay_gpio_04a contains gpio node
+	 *
+	 * - apply overlay_gpio_04a
+	 *
+	 * apply the overlay will result in
+	 *   - probe for overlay_gpio_04a
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	/* overlay_gpio_04a contains gpio node */
+
+	unittest(overlay_data_apply("overlay_gpio_04a", NULL),
+		 "Adding overlay 'overlay_gpio_04a' failed\n");
+
+	unittest(probe_pass_count + 1 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	/*
+	 * overlay_gpio_04b contains child gpio hog node
+	 *
+	 * - apply overlay_gpio_04b
+	 *
+	 * apply the overlay will result in
+	 *   - processing gpio for overlay_gpio_04b
+	 */
+
+	/* overlay_gpio_04b contains child gpio hog node */
+
+	unittest(overlay_data_apply("overlay_gpio_04b", NULL),
+		 "Adding overlay 'overlay_gpio_04b' failed\n");
+
+	unittest(chip_request_count + 1 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+}
+
+#else
+
+static void __init of_unittest_overlay_gpio(void)
+{
+	/* skip tests */
+}
+
+#endif
+
+#if IS_BUILTIN(CONFIG_I2C)
+
+/* get the i2c client device instantiated at the path */
+static struct i2c_client *of_path_to_i2c_client(const char *path)
+{
+	struct device_node *np;
+	struct i2c_client *client;
+
+	np = of_find_node_by_path(path);
+	if (np == NULL)
+		return NULL;
+
+	client = of_find_i2c_device_by_node(np);
+	of_node_put(np);
+
+	return client;
+}
+
+/* find out if a i2c client device exists at that path */
+static int of_path_i2c_client_exists(const char *path)
+{
+	struct i2c_client *client;
+
+	client = of_path_to_i2c_client(path);
+	if (client)
+		put_device(&client->dev);
+	return client != NULL;
+}
+#else
+static int of_path_i2c_client_exists(const char *path)
+{
+	return 0;
+}
+#endif
+
+enum overlay_type {
+	PDEV_OVERLAY,
+	I2C_OVERLAY
+};
+
+static int of_path_device_type_exists(const char *path,
+		enum overlay_type ovtype)
+{
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		return of_path_platform_device_exists(path);
+	case I2C_OVERLAY:
+		return of_path_i2c_client_exists(path);
+	}
+	return 0;
+}
+
+static const char *unittest_path(int nr, enum overlay_type ovtype)
+{
+	const char *base;
+	static char buf[256];
+
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		base = "/testcase-data/overlay-node/test-bus";
+		break;
+	case I2C_OVERLAY:
+		base = "/testcase-data/overlay-node/test-bus/i2c-test-bus";
+		break;
+	default:
+		buf[0] = '\0';
+		return buf;
+	}
+	snprintf(buf, sizeof(buf) - 1, "%s/test-unittest%d", base, nr);
+	buf[sizeof(buf) - 1] = '\0';
+	return buf;
+}
+
+static int of_unittest_device_exists(int unittest_nr, enum overlay_type ovtype)
+{
+	const char *path;
+
+	path = unittest_path(unittest_nr, ovtype);
+
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		return of_path_platform_device_exists(path);
+	case I2C_OVERLAY:
+		return of_path_i2c_client_exists(path);
+	}
+	return 0;
+}
+
+static const char *overlay_name_from_nr(int nr)
+{
+	static char buf[256];
+
+	snprintf(buf, sizeof(buf) - 1,
+		"overlay_%d", nr);
+	buf[sizeof(buf) - 1] = '\0';
+
+	return buf;
+}
+
+static const char *bus_path = "/testcase-data/overlay-node/test-bus";
+
+#define MAX_TRACK_OVCS_IDS 256
+
+static int track_ovcs_id[MAX_TRACK_OVCS_IDS];
+static int track_ovcs_id_overlay_nr[MAX_TRACK_OVCS_IDS];
+static int track_ovcs_id_cnt;
+
+static void of_unittest_track_overlay(int ovcs_id, int overlay_nr)
+{
+	if (WARN_ON(track_ovcs_id_cnt >= MAX_TRACK_OVCS_IDS))
+		return;
+
+	track_ovcs_id[track_ovcs_id_cnt] = ovcs_id;
+	track_ovcs_id_overlay_nr[track_ovcs_id_cnt] = overlay_nr;
+	track_ovcs_id_cnt++;
+}
+
+static void of_unittest_untrack_overlay(int ovcs_id)
+{
+	if (WARN_ON(track_ovcs_id_cnt < 1))
+		return;
+
+	track_ovcs_id_cnt--;
+
+	/* If out of synch then test is broken.  Do not try to recover. */
+	WARN_ON(track_ovcs_id[track_ovcs_id_cnt] != ovcs_id);
+}
+
+static void of_unittest_remove_tracked_overlays(void)
+{
+	int ret, ovcs_id, overlay_nr, save_ovcs_id;
+	const char *overlay_name;
+
+	while (track_ovcs_id_cnt > 0) {
+
+		ovcs_id = track_ovcs_id[track_ovcs_id_cnt - 1];
+		overlay_nr = track_ovcs_id_overlay_nr[track_ovcs_id_cnt - 1];
+		save_ovcs_id = ovcs_id;
+		ret = of_overlay_remove(&ovcs_id);
+		if (ret == -ENODEV) {
+			overlay_name = overlay_name_from_nr(overlay_nr);
+			pr_warn("%s: of_overlay_remove() for overlay \"%s\" failed, ret = %d\n",
+				__func__, overlay_name, ret);
+		}
+		of_unittest_untrack_overlay(save_ovcs_id);
+	}
+
+}
+
+static int __init of_unittest_apply_overlay(int overlay_nr, int *ovcs_id)
+{
+	/*
+	 * The overlay will be tracked, thus it will be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 */
+
+	const char *overlay_name;
+
+	overlay_name = overlay_name_from_nr(overlay_nr);
+
+	if (!overlay_data_apply(overlay_name, ovcs_id)) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+		return -EFAULT;
+	}
+	of_unittest_track_overlay(*ovcs_id, overlay_nr);
+
+	return 0;
+}
+
+static int __init __of_unittest_apply_overlay_check(int overlay_nr,
+		int unittest_nr, int before, int after,
+		enum overlay_type ovtype)
+{
+	int ret, ovcs_id;
+
+	/* unittest device must be in before state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!before ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	/* apply the overlay */
+	ovcs_id = 0;
+	ret = of_unittest_apply_overlay(overlay_nr, &ovcs_id);
+	if (ret != 0) {
+		/* of_unittest_apply_overlay already called unittest() */
+		return ret;
+	}
+
+	/* unittest device must be in after state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != after) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!after ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	return ovcs_id;
+}
+
+/* apply an overlay while checking before and after states */
+static int __init of_unittest_apply_overlay_check(int overlay_nr,
+		int unittest_nr, int before, int after,
+		enum overlay_type ovtype)
+{
+	int ovcs_id = __of_unittest_apply_overlay_check(overlay_nr,
+				unittest_nr, before, after, ovtype);
+	if (ovcs_id < 0)
+		return ovcs_id;
+
+	return 0;
+}
+
+/* apply an overlay and then revert it while checking before, after states */
+static int __init of_unittest_apply_revert_overlay_check(int overlay_nr,
+		int unittest_nr, int before, int after,
+		enum overlay_type ovtype)
+{
+	int ret, ovcs_id, save_ovcs_id;
+
+	ovcs_id = __of_unittest_apply_overlay_check(overlay_nr, unittest_nr,
+						    before, after, ovtype);
+	if (ovcs_id < 0)
+		return ovcs_id;
+
+	/* remove the overlay */
+	save_ovcs_id = ovcs_id;
+	ret = of_overlay_remove(&ovcs_id);
+	if (ret != 0) {
+		unittest(0, "%s failed to be destroyed @\"%s\"\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype));
+		return ret;
+	}
+	of_unittest_untrack_overlay(save_ovcs_id);
+
+	/* unittest device must be again in before state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!before ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* test activation of device */
+static void __init of_unittest_overlay_0(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status");
+
+	/* device should enable */
+	ret = of_unittest_apply_overlay_check(0, 0, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 0);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_1(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(1, 1, 1, 0, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 1);
+
+}
+
+/* test activation of device */
+static void __init of_unittest_overlay_2(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status");
+
+	/* device should enable */
+	ret = of_unittest_apply_overlay_check(2, 2, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status");
+
+	if (ret)
+		return;
+	unittest(1, "overlay test %d passed\n", 2);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_3(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(3, 3, 1, 0, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 3);
+}
+
+/* test activation of a full device node */
+static void __init of_unittest_overlay_4(void)
+{
+	/* device should disable */
+	if (of_unittest_apply_overlay_check(4, 4, 0, 1, PDEV_OVERLAY))
+		return;
+
+	unittest(1, "overlay test %d passed\n", 4);
+}
+
+/* test overlay apply/revert sequence */
+static void __init of_unittest_overlay_5(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_revert_overlay_check(5, 5, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 5);
+}
+
+/* test overlay application in sequence */
+static void __init of_unittest_overlay_6(void)
+{
+	int i, save_ovcs_id[2], ovcs_id;
+	int overlay_nr = 6, unittest_nr = 6;
+	int before = 0, after = 1;
+	const char *overlay_name;
+
+	int ret;
+
+	/* unittest device must be in before state */
+	for (i = 0; i < 2; i++) {
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= before) {
+			unittest(0, "%s with device @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!before ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	/* apply the overlays */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 0);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+			return;
+	}
+	save_ovcs_id[0] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 0);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status");
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 1);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+			return;
+	}
+	save_ovcs_id[1] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 1);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status");
+
+
+	for (i = 0; i < 2; i++) {
+		/* unittest device must be in after state */
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= after) {
+			unittest(0, "overlay @\"%s\" failed @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!after ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	for (i = 1; i >= 0; i--) {
+		ovcs_id = save_ovcs_id[i];
+		if (of_overlay_remove(&ovcs_id)) {
+			unittest(0, "%s failed destroy @\"%s\"\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY));
+			return;
+		}
+		of_unittest_untrack_overlay(save_ovcs_id[i]);
+	}
+
+	for (i = 0; i < 2; i++) {
+		/* unittest device must be again in before state */
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= before) {
+			unittest(0, "%s with device @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!before ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	unittest(1, "overlay test %d passed\n", 6);
+
+}
+
+/* test overlay application in sequence */
+static void __init of_unittest_overlay_8(void)
+{
+	int i, save_ovcs_id[2], ovcs_id;
+	int overlay_nr = 8, unittest_nr = 8;
+	const char *overlay_name;
+	int ret;
+
+	/* we don't care about device state in this test */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 0);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+	if (!ret)
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status");
+
+	if (!ret)
+		return;
+
+	save_ovcs_id[0] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 0);
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 1);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo");
+
+	/* apply the overlays */
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo");
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+		return;
+	}
+
+	save_ovcs_id[1] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 1);
+
+	/* now try to remove first overlay (it should fail) */
+	ovcs_id = save_ovcs_id[0];
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8");
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: overlay #6 is not topmost");
+
+	ret = of_overlay_remove(&ovcs_id);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: overlay #6 is not topmost");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8");
+
+	if (!ret) {
+		/*
+		 * Should never get here.  If we do, expect a lot of
+		 * subsequent tracking and overlay removal related errors.
+		 */
+		unittest(0, "%s was destroyed @\"%s\"\n",
+				overlay_name_from_nr(overlay_nr + 0),
+				unittest_path(unittest_nr,
+					PDEV_OVERLAY));
+		return;
+	}
+
+	/* removing them in order should work */
+	for (i = 1; i >= 0; i--) {
+		ovcs_id = save_ovcs_id[i];
+		if (of_overlay_remove(&ovcs_id)) {
+			unittest(0, "%s not destroyed @\"%s\"\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr,
+						PDEV_OVERLAY));
+			return;
+		}
+		of_unittest_untrack_overlay(save_ovcs_id[i]);
+	}
+
+	unittest(1, "overlay test %d passed\n", 8);
+}
+
+/* test insertion of a bus with parent devices */
+static void __init of_unittest_overlay_10(void)
+{
+	int ret;
+	char *child_path;
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(10, 10, 0, 1, PDEV_OVERLAY);
+
+	if (unittest(ret == 0,
+			"overlay test %d failed; overlay application\n", 10))
+		return;
+
+	child_path = kasprintf(GFP_KERNEL, "%s/test-unittest101",
+			unittest_path(10, PDEV_OVERLAY));
+	if (unittest(child_path, "overlay test %d failed; kasprintf\n", 10))
+		return;
+
+	ret = of_path_device_type_exists(child_path, PDEV_OVERLAY);
+	kfree(child_path);
+
+	unittest(ret, "overlay test %d failed; no child device\n", 10);
+}
+
+/* test insertion of a bus with parent devices (and revert) */
+static void __init of_unittest_overlay_11(void)
+{
+	int ret;
+
+	/* device should disable */
+	ret = of_unittest_apply_revert_overlay_check(11, 11, 0, 1,
+			PDEV_OVERLAY);
+
+	unittest(ret == 0, "overlay test %d failed; overlay apply\n", 11);
+}
+
+#if IS_BUILTIN(CONFIG_I2C) && IS_ENABLED(CONFIG_OF_OVERLAY)
+
+struct unittest_i2c_bus_data {
+	struct platform_device	*pdev;
+	struct i2c_adapter	adap;
+};
+
+static int unittest_i2c_master_xfer(struct i2c_adapter *adap,
+		struct i2c_msg *msgs, int num)
+{
+	struct unittest_i2c_bus_data *std = i2c_get_adapdata(adap);
+
+	(void)std;
+
+	return num;
+}
+
+static u32 unittest_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm unittest_i2c_algo = {
+	.master_xfer	= unittest_i2c_master_xfer,
+	.functionality	= unittest_i2c_functionality,
+};
+
+static int unittest_i2c_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct unittest_i2c_bus_data *std;
+	struct i2c_adapter *adap;
+	int ret;
+
+	if (np == NULL) {
+		dev_err(dev, "No OF data for device\n");
+		return -EINVAL;
+
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	std = devm_kzalloc(dev, sizeof(*std), GFP_KERNEL);
+	if (!std)
+		return -ENOMEM;
+
+	/* link them together */
+	std->pdev = pdev;
+	platform_set_drvdata(pdev, std);
+
+	adap = &std->adap;
+	i2c_set_adapdata(adap, std);
+	adap->nr = -1;
+	strscpy(adap->name, pdev->name, sizeof(adap->name));
+	adap->class = I2C_CLASS_DEPRECATED;
+	adap->algo = &unittest_i2c_algo;
+	adap->dev.parent = dev;
+	adap->dev.of_node = dev->of_node;
+	adap->timeout = 5 * HZ;
+	adap->retries = 3;
+
+	ret = i2c_add_numbered_adapter(adap);
+	if (ret != 0) {
+		dev_err(dev, "Failed to add I2C adapter\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void unittest_i2c_bus_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct unittest_i2c_bus_data *std = platform_get_drvdata(pdev);
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+	i2c_del_adapter(&std->adap);
+}
+
+static const struct of_device_id unittest_i2c_bus_match[] = {
+	{ .compatible = "unittest-i2c-bus", },
+	{},
+};
+
+static struct platform_driver unittest_i2c_bus_driver = {
+	.probe			= unittest_i2c_bus_probe,
+	.remove			= unittest_i2c_bus_remove,
+	.driver = {
+		.name		= "unittest-i2c-bus",
+		.of_match_table	= unittest_i2c_bus_match,
+	},
+};
+
+static int unittest_i2c_dev_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+
+	if (!np) {
+		dev_err(dev, "No OF node\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	return 0;
+};
+
+static void unittest_i2c_dev_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+}
+
+static const struct i2c_device_id unittest_i2c_dev_id[] = {
+	{ .name = "unittest-i2c-dev" },
+	{ }
+};
+
+static struct i2c_driver unittest_i2c_dev_driver = {
+	.driver = {
+		.name = "unittest-i2c-dev",
+	},
+	.probe = unittest_i2c_dev_probe,
+	.remove = unittest_i2c_dev_remove,
+	.id_table = unittest_i2c_dev_id,
+};
+
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+
+static int unittest_i2c_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+	return 0;
+}
+
+static int unittest_i2c_mux_probe(struct i2c_client *client)
+{
+	int i, nchans;
+	struct device *dev = &client->dev;
+	struct i2c_adapter *adap = client->adapter;
+	struct device_node *np = client->dev.of_node, *child;
+	struct i2c_mux_core *muxc;
+	u32 reg, max_reg;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	if (!np) {
+		dev_err(dev, "No OF node\n");
+		return -EINVAL;
+	}
+
+	max_reg = (u32)-1;
+	for_each_child_of_node(np, child) {
+		if (of_property_read_u32(child, "reg", &reg))
+			continue;
+		if (max_reg == (u32)-1 || reg > max_reg)
+			max_reg = reg;
+	}
+	nchans = max_reg == (u32)-1 ? 0 : max_reg + 1;
+	if (nchans == 0) {
+		dev_err(dev, "No channels\n");
+		return -EINVAL;
+	}
+
+	muxc = i2c_mux_alloc(adap, dev, nchans, 0, 0,
+			     unittest_i2c_mux_select_chan, NULL);
+	if (!muxc)
+		return -ENOMEM;
+	for (i = 0; i < nchans; i++) {
+		if (i2c_mux_add_adapter(muxc, 0, i)) {
+			dev_err(dev, "Failed to register mux #%d\n", i);
+			i2c_mux_del_adapters(muxc);
+			return -ENODEV;
+		}
+	}
+
+	i2c_set_clientdata(client, muxc);
+
+	return 0;
+};
+
+static void unittest_i2c_mux_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+	i2c_mux_del_adapters(muxc);
+}
+
+static const struct i2c_device_id unittest_i2c_mux_id[] = {
+	{ .name = "unittest-i2c-mux" },
+	{ }
+};
+
+static struct i2c_driver unittest_i2c_mux_driver = {
+	.driver = {
+		.name = "unittest-i2c-mux",
+	},
+	.probe = unittest_i2c_mux_probe,
+	.remove = unittest_i2c_mux_remove,
+	.id_table = unittest_i2c_mux_id,
+};
+
+#endif
+
+static int of_unittest_overlay_i2c_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&unittest_i2c_dev_driver);
+	if (unittest(ret == 0,
+			"could not register unittest i2c device driver\n"))
+		return ret;
+
+	ret = platform_driver_register(&unittest_i2c_bus_driver);
+
+	if (unittest(ret == 0,
+			"could not register unittest i2c bus driver\n"))
+		return ret;
+
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "i2c i2c-1: Added multiplexed i2c bus 2");
+
+	ret = i2c_add_driver(&unittest_i2c_mux_driver);
+
+	EXPECT_END(KERN_INFO,
+		   "i2c i2c-1: Added multiplexed i2c bus 2");
+
+	if (unittest(ret == 0,
+			"could not register unittest i2c mux driver\n"))
+		return ret;
+#endif
+
+	return 0;
+}
+
+static void of_unittest_overlay_i2c_cleanup(void)
+{
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+	i2c_del_driver(&unittest_i2c_mux_driver);
+#endif
+	platform_driver_unregister(&unittest_i2c_bus_driver);
+	i2c_del_driver(&unittest_i2c_dev_driver);
+}
+
+static void __init of_unittest_overlay_i2c_12(void)
+{
+	int ret;
+
+	/* device should enable */
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status");
+
+	ret = of_unittest_apply_overlay_check(12, 12, 0, 1, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 12);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_i2c_13(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(13, 13, 1, 0, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 13);
+}
+
+/* just check for i2c mux existence */
+static void of_unittest_overlay_i2c_14(void)
+{
+}
+
+static void __init of_unittest_overlay_i2c_15(void)
+{
+	int ret;
+
+	/* device should enable */
+	EXPECT_BEGIN(KERN_INFO,
+		     "i2c i2c-1: Added multiplexed i2c bus 3");
+
+	ret = of_unittest_apply_overlay_check(15, 15, 0, 1, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "i2c i2c-1: Added multiplexed i2c bus 3");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 15);
+}
+
+#else
+
+static inline void of_unittest_overlay_i2c_14(void) { }
+static inline void of_unittest_overlay_i2c_15(void) { }
+
+#endif
+
+static int of_notify(struct notifier_block *nb, unsigned long action,
+		     void *arg)
+{
+	struct of_overlay_notify_data *nd = arg;
+	struct device_node *found;
+	int ret;
+
+	/*
+	 * For overlay_16 .. overlay_19, check that returning an error
+	 * works for each of the actions by setting an arbitrary return
+	 * error number that matches the test number.  e.g. for unittest16,
+	 * ret = -EBUSY which is -16.
+	 *
+	 * OVERLAY_INFO() for the overlays is declared to expect the same
+	 * error number, so overlay_data_apply() will return no error.
+	 *
+	 * overlay_20 will return NOTIFY_DONE
+	 */
+
+	ret = 0;
+	of_node_get(nd->overlay);
+
+	switch (action) {
+
+	case OF_OVERLAY_PRE_APPLY:
+		found = of_find_node_by_name(nd->overlay, "test-unittest16");
+		if (found) {
+			of_node_put(found);
+			ret = -EBUSY;
+		}
+		break;
+
+	case OF_OVERLAY_POST_APPLY:
+		found = of_find_node_by_name(nd->overlay, "test-unittest17");
+		if (found) {
+			of_node_put(found);
+			ret = -EEXIST;
+		}
+		break;
+
+	case OF_OVERLAY_PRE_REMOVE:
+		found = of_find_node_by_name(nd->overlay, "test-unittest18");
+		if (found) {
+			of_node_put(found);
+			ret = -EXDEV;
+		}
+		break;
+
+	case OF_OVERLAY_POST_REMOVE:
+		found = of_find_node_by_name(nd->overlay, "test-unittest19");
+		if (found) {
+			of_node_put(found);
+			ret = -ENODEV;
+		}
+		break;
+
+	default:			/* should not happen */
+		of_node_put(nd->overlay);
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret)
+		return notifier_from_errno(ret);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block of_nb = {
+	.notifier_call = of_notify,
+};
+
+static void __init of_unittest_overlay_notify(void)
+{
+	int ovcs_id;
+	int ret;
+
+	ret = of_overlay_notifier_register(&of_nb);
+	unittest(!ret,
+		 "of_overlay_notifier_register() failed, ret = %d\n", ret);
+	if (ret)
+		return;
+
+	/*
+	 * The overlays are applied by overlay_data_apply()
+	 * instead of of_unittest_apply_overlay() so that they
+	 * will not be tracked.  Thus they will not be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 *
+	 * Applying overlays 16 - 19 will each trigger an error for a
+	 * different action in of_notify().
+	 *
+	 * Applying overlay 20 will not trigger any error in of_notify().
+	 */
+
+	/* ---  overlay 16  --- */
+
+	EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset pre-apply notifier error -16, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(overlay_data_apply("overlay_16", &ovcs_id),
+		 "test OF_OVERLAY_PRE_APPLY notify injected error\n");
+
+	EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset pre-apply notifier error -16, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_16\n");
+
+	/* ---  overlay 17  --- */
+
+	EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset post-apply notifier error -17, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(overlay_data_apply("overlay_17", &ovcs_id),
+		 "test OF_OVERLAY_POST_APPLY notify injected error\n");
+
+	EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset post-apply notifier error -17, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_17\n");
+
+	/* ---  overlay 18  --- */
+
+	unittest(overlay_data_apply("overlay_18", &ovcs_id),
+		 "OF_OVERLAY_PRE_REMOVE notify injected error\n");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_18\n");
+
+	if (ovcs_id) {
+		EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset pre-remove notifier error -18, target: /testcase-data/overlay-node/test-bus");
+
+		ret = of_overlay_remove(&ovcs_id);
+		EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset pre-remove notifier error -18, target: /testcase-data/overlay-node/test-bus");
+		if (ret == -EXDEV) {
+			/*
+			 * change set ovcs_id should still exist
+			 */
+			unittest(1, "overlay_18 of_overlay_remove() injected error for OF_OVERLAY_PRE_REMOVE\n");
+		} else {
+			unittest(0, "overlay_18 of_overlay_remove() injected error for OF_OVERLAY_PRE_REMOVE not returned\n");
+		}
+	} else {
+		unittest(1, "ovcs_id not created for overlay_18\n");
+	}
+
+	unittest(ovcs_id, "ovcs_id removed for overlay_18\n");
+
+	/* ---  overlay 19  --- */
+
+	unittest(overlay_data_apply("overlay_19", &ovcs_id),
+		 "OF_OVERLAY_POST_REMOVE notify injected error\n");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_19\n");
+
+	if (ovcs_id) {
+		EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset post-remove notifier error -19, target: /testcase-data/overlay-node/test-bus");
+		ret = of_overlay_remove(&ovcs_id);
+		EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset post-remove notifier error -19, target: /testcase-data/overlay-node/test-bus");
+		if (ret == -ENODEV)
+			unittest(1, "overlay_19 of_overlay_remove() injected error for OF_OVERLAY_POST_REMOVE\n");
+		else
+			unittest(0, "overlay_19 of_overlay_remove() injected error for OF_OVERLAY_POST_REMOVE not returned\n");
+	} else {
+		unittest(1, "ovcs_id removed for overlay_19\n");
+	}
+
+	unittest(!ovcs_id, "changeset ovcs_id = %d not removed for overlay_19\n",
+		 ovcs_id);
+
+	/* ---  overlay 20  --- */
+
+	unittest(overlay_data_apply("overlay_20", &ovcs_id),
+		 "overlay notify no injected error\n");
+
+	if (ovcs_id) {
+		ret = of_overlay_remove(&ovcs_id);
+		if (ret)
+			unittest(1, "overlay_20 failed to be destroyed, ret = %d\n",
+				 ret);
+	} else {
+		unittest(1, "ovcs_id not created for overlay_20\n");
+	}
+
+	unittest(!of_overlay_notifier_unregister(&of_nb),
+		 "of_overlay_notifier_unregister() failed, ret = %d\n", ret);
+}
+
+static void __init of_unittest_overlay(void)
+{
+	struct device_node *bus_np = NULL;
+	unsigned int i;
+
+	if (platform_driver_register(&unittest_driver)) {
+		unittest(0, "could not register unittest driver\n");
+		goto out;
+	}
+
+	bus_np = of_find_node_by_path(bus_path);
+	if (bus_np == NULL) {
+		unittest(0, "could not find bus_path \"%s\"\n", bus_path);
+		goto out;
+	}
+
+	if (of_platform_default_populate(bus_np, NULL, NULL)) {
+		unittest(0, "could not populate bus @ \"%s\"\n", bus_path);
+		goto out;
+	}
+
+	if (!of_unittest_device_exists(100, PDEV_OVERLAY)) {
+		unittest(0, "could not find unittest0 @ \"%s\"\n",
+				unittest_path(100, PDEV_OVERLAY));
+		goto out;
+	}
+
+	if (of_unittest_device_exists(101, PDEV_OVERLAY)) {
+		unittest(0, "unittest1 @ \"%s\" should not exist\n",
+				unittest_path(101, PDEV_OVERLAY));
+		goto out;
+	}
+
+	unittest(1, "basic infrastructure of overlays passed");
+
+	/* tests in sequence */
+	of_unittest_overlay_0();
+	of_unittest_overlay_1();
+	of_unittest_overlay_2();
+	of_unittest_overlay_3();
+	of_unittest_overlay_4();
+	for (i = 0; i < 3; i++)
+		of_unittest_overlay_5();
+	of_unittest_overlay_6();
+	of_unittest_overlay_8();
+
+	of_unittest_overlay_10();
+	of_unittest_overlay_11();
+
+#if IS_BUILTIN(CONFIG_I2C)
+	if (unittest(of_unittest_overlay_i2c_init() == 0, "i2c init failed\n"))
+		goto out;
+
+	of_unittest_overlay_i2c_12();
+	of_unittest_overlay_i2c_13();
+	of_unittest_overlay_i2c_14();
+	of_unittest_overlay_i2c_15();
+
+	of_unittest_overlay_i2c_cleanup();
+#endif
+
+	of_unittest_overlay_gpio();
+
+	of_unittest_remove_tracked_overlays();
+
+	of_unittest_overlay_notify();
+
+out:
+	of_node_put(bus_np);
+}
+
+#else
+static inline void __init of_unittest_overlay(void) { }
+#endif
+
+static void __init of_unittest_lifecycle(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	unsigned int refcount;
+	int found_refcount_one = 0;
+	int put_count = 0;
+	struct device_node *np;
+	struct device_node *prev_sibling, *next_sibling;
+	const char *refcount_path = "/testcase-data/refcount-node";
+	const char *refcount_parent_path = "/testcase-data";
+
+	/*
+	 * Node lifecycle tests, non-dynamic node:
+	 *
+	 * - Decrementing refcount to zero via of_node_put() should cause the
+	 *   attempt to free the node memory by of_node_release() to fail
+	 *   because the node is not a dynamic node.
+	 *
+	 * - Decrementing refcount past zero should result in additional
+	 *   errors reported.
+	 */
+
+	np = of_find_node_by_path(refcount_path);
+	unittest(np, "find refcount_path \"%s\"\n", refcount_path);
+	if (np == NULL)
+		goto out_skip_tests;
+
+	while (!found_refcount_one) {
+
+		if (put_count++ > 10) {
+			unittest(0, "guardrail to avoid infinite loop\n");
+			goto out_skip_tests;
+		}
+
+		refcount = kref_read(&np->kobj.kref);
+		if (refcount == 1)
+			found_refcount_one = 1;
+		else
+			of_node_put(np);
+	}
+
+	EXPECT_BEGIN(KERN_INFO, "OF: ERROR: of_node_release() detected bad of_node_put() on /testcase-data/refcount-node");
+
+	/*
+	 * refcount is now one, decrementing to zero will result in a call to
+	 * of_node_release() to free the node's memory, which should result
+	 * in an error
+	 */
+	unittest(1, "/testcase-data/refcount-node is one");
+	of_node_put(np);
+
+	EXPECT_END(KERN_INFO, "OF: ERROR: of_node_release() detected bad of_node_put() on /testcase-data/refcount-node");
+
+
+	/*
+	 * expect stack trace for subsequent of_node_put():
+	 *   __refcount_sub_and_test() calls:
+	 *   refcount_warn_saturate(r, REFCOUNT_SUB_UAF)
+	 *
+	 * Not capturing entire WARN_ONCE() trace with EXPECT_*(), just
+	 * the first three lines, and the last line.
+	 */
+	EXPECT_BEGIN(KERN_INFO, "------------[ cut here ]------------");
+	EXPECT_BEGIN(KERN_INFO, "WARNING: <<all>>");
+	EXPECT_BEGIN(KERN_INFO, "refcount_t: underflow; use-after-free.");
+	EXPECT_BEGIN(KERN_INFO, "---[ end trace <<int>> ]---");
+
+	/* refcount is now zero, this should fail */
+	unittest(1, "/testcase-data/refcount-node is zero");
+	of_node_put(np);
+
+	EXPECT_END(KERN_INFO, "---[ end trace <<int>> ]---");
+	EXPECT_END(KERN_INFO, "refcount_t: underflow; use-after-free.");
+	EXPECT_END(KERN_INFO, "WARNING: <<all>>");
+	EXPECT_END(KERN_INFO, "------------[ cut here ]------------");
+
+	/*
+	 * Q. do we expect to get yet another warning?
+	 * A. no, the WARNING is from WARN_ONCE()
+	 */
+	EXPECT_NOT_BEGIN(KERN_INFO, "------------[ cut here ]------------");
+	EXPECT_NOT_BEGIN(KERN_INFO, "WARNING: <<all>>");
+	EXPECT_NOT_BEGIN(KERN_INFO, "refcount_t: underflow; use-after-free.");
+	EXPECT_NOT_BEGIN(KERN_INFO, "---[ end trace <<int>> ]---");
+
+	unittest(1, "/testcase-data/refcount-node is zero, second time");
+	of_node_put(np);
+
+	EXPECT_NOT_END(KERN_INFO, "---[ end trace <<int>> ]---");
+	EXPECT_NOT_END(KERN_INFO, "refcount_t: underflow; use-after-free.");
+	EXPECT_NOT_END(KERN_INFO, "WARNING: <<all>>");
+	EXPECT_NOT_END(KERN_INFO, "------------[ cut here ]------------");
+
+	/*
+	 * refcount of zero will trigger stack traces from any further
+	 * attempt to of_node_get() node "refcount-node". One example of
+	 * this is where of_unittest_check_node_linkage() will recursively
+	 * scan the tree, with 'for_each_child_of_node()' doing an
+	 * of_node_get() of the children of a node.
+	 *
+	 * Prevent the stack trace by removing node "refcount-node" from
+	 * its parent's child list.
+	 *
+	 * WARNING:  EVIL, EVIL, EVIL:
+	 *
+	 *   Directly manipulate the child list of node /testcase-data to
+	 *   remove child refcount-node.  This is ignoring all proper methods
+	 *   of removing a child and will leak a small amount of memory.
+	 */
+
+	np = of_find_node_by_path(refcount_parent_path);
+	unittest(np, "find refcount_parent_path \"%s\"\n", refcount_parent_path);
+	unittest(np, "ERROR: devicetree live tree left in a 'bad state' if test fail\n");
+	if (np == NULL)
+		return;
+
+	prev_sibling = np->child;
+	next_sibling = prev_sibling->sibling;
+	if (!strcmp(prev_sibling->full_name, "refcount-node")) {
+		np->child = next_sibling;
+		next_sibling = next_sibling->sibling;
+	}
+	while (next_sibling) {
+		if (!strcmp(next_sibling->full_name, "refcount-node"))
+			prev_sibling->sibling = next_sibling->sibling;
+		prev_sibling = next_sibling;
+		next_sibling = next_sibling->sibling;
+	}
+	of_node_put(np);
+
+	return;
+
+out_skip_tests:
+#endif
+	unittest(0, "One or more lifecycle tests skipped\n");
+}
+
+#ifdef CONFIG_OF_OVERLAY
+
+/*
+ * __dtbo_##overlay_name##_begin[] and __dtbo_##overlay_name##_end[] are
+ * created by cmd_wrap_S_dtbo in scripts/Makefile.dtbs
+ */
+
+#define OVERLAY_INFO_EXTERN(overlay_name) \
+	extern uint8_t __dtbo_##overlay_name##_begin[]; \
+	extern uint8_t __dtbo_##overlay_name##_end[]
+
+#define OVERLAY_INFO(overlay_name, expected, expected_remove) \
+{	.dtbo_begin		= __dtbo_##overlay_name##_begin, \
+	.dtbo_end		= __dtbo_##overlay_name##_end, \
+	.expected_result	= expected, \
+	.expected_result_remove	= expected_remove, \
+	.name			= #overlay_name, \
+}
+
+struct overlay_info {
+	uint8_t		*dtbo_begin;
+	uint8_t		*dtbo_end;
+	int		expected_result;
+	int		expected_result_remove;	/* if apply failed */
+	int		ovcs_id;
+	char		*name;
+};
+
+OVERLAY_INFO_EXTERN(overlay_base);
+OVERLAY_INFO_EXTERN(overlay);
+OVERLAY_INFO_EXTERN(overlay_0);
+OVERLAY_INFO_EXTERN(overlay_1);
+OVERLAY_INFO_EXTERN(overlay_2);
+OVERLAY_INFO_EXTERN(overlay_3);
+OVERLAY_INFO_EXTERN(overlay_4);
+OVERLAY_INFO_EXTERN(overlay_5);
+OVERLAY_INFO_EXTERN(overlay_6);
+OVERLAY_INFO_EXTERN(overlay_7);
+OVERLAY_INFO_EXTERN(overlay_8);
+OVERLAY_INFO_EXTERN(overlay_9);
+OVERLAY_INFO_EXTERN(overlay_10);
+OVERLAY_INFO_EXTERN(overlay_11);
+OVERLAY_INFO_EXTERN(overlay_12);
+OVERLAY_INFO_EXTERN(overlay_13);
+OVERLAY_INFO_EXTERN(overlay_15);
+OVERLAY_INFO_EXTERN(overlay_16);
+OVERLAY_INFO_EXTERN(overlay_17);
+OVERLAY_INFO_EXTERN(overlay_18);
+OVERLAY_INFO_EXTERN(overlay_19);
+OVERLAY_INFO_EXTERN(overlay_20);
+OVERLAY_INFO_EXTERN(overlay_gpio_01);
+OVERLAY_INFO_EXTERN(overlay_gpio_02a);
+OVERLAY_INFO_EXTERN(overlay_gpio_02b);
+OVERLAY_INFO_EXTERN(overlay_gpio_03);
+OVERLAY_INFO_EXTERN(overlay_gpio_04a);
+OVERLAY_INFO_EXTERN(overlay_gpio_04b);
+OVERLAY_INFO_EXTERN(overlay_pci_node);
+OVERLAY_INFO_EXTERN(overlay_bad_add_dup_node);
+OVERLAY_INFO_EXTERN(overlay_bad_add_dup_prop);
+OVERLAY_INFO_EXTERN(overlay_bad_phandle);
+OVERLAY_INFO_EXTERN(overlay_bad_symbol);
+OVERLAY_INFO_EXTERN(overlay_bad_unresolved);
+
+/* entries found by name */
+static struct overlay_info overlays[] = {
+	OVERLAY_INFO(overlay_base, -9999, 0),
+	OVERLAY_INFO(overlay, 0, 0),
+	OVERLAY_INFO(overlay_0, 0, 0),
+	OVERLAY_INFO(overlay_1, 0, 0),
+	OVERLAY_INFO(overlay_2, 0, 0),
+	OVERLAY_INFO(overlay_3, 0, 0),
+	OVERLAY_INFO(overlay_4, 0, 0),
+	OVERLAY_INFO(overlay_5, 0, 0),
+	OVERLAY_INFO(overlay_6, 0, 0),
+	OVERLAY_INFO(overlay_7, 0, 0),
+	OVERLAY_INFO(overlay_8, 0, 0),
+	OVERLAY_INFO(overlay_9, 0, 0),
+	OVERLAY_INFO(overlay_10, 0, 0),
+	OVERLAY_INFO(overlay_11, 0, 0),
+	OVERLAY_INFO(overlay_12, 0, 0),
+	OVERLAY_INFO(overlay_13, 0, 0),
+	OVERLAY_INFO(overlay_15, 0, 0),
+	OVERLAY_INFO(overlay_16, -EBUSY, 0),
+	OVERLAY_INFO(overlay_17, -EEXIST, 0),
+	OVERLAY_INFO(overlay_18, 0, 0),
+	OVERLAY_INFO(overlay_19, 0, 0),
+	OVERLAY_INFO(overlay_20, 0, 0),
+	OVERLAY_INFO(overlay_gpio_01, 0, 0),
+	OVERLAY_INFO(overlay_gpio_02a, 0, 0),
+	OVERLAY_INFO(overlay_gpio_02b, 0, 0),
+	OVERLAY_INFO(overlay_gpio_03, 0, 0),
+	OVERLAY_INFO(overlay_gpio_04a, 0, 0),
+	OVERLAY_INFO(overlay_gpio_04b, 0, 0),
+	OVERLAY_INFO(overlay_pci_node, 0, 0),
+	OVERLAY_INFO(overlay_bad_add_dup_node, -EINVAL, -ENODEV),
+	OVERLAY_INFO(overlay_bad_add_dup_prop, -EINVAL, -ENODEV),
+	OVERLAY_INFO(overlay_bad_phandle, -EINVAL, 0),
+	OVERLAY_INFO(overlay_bad_symbol, -EINVAL, -ENODEV),
+	OVERLAY_INFO(overlay_bad_unresolved, -EINVAL, 0),
+	/* end marker */
+	{ }
+};
+
+static struct device_node *overlay_base_root;
+
+static void * __init dt_alloc_memory(u64 size, u64 align)
+{
+	return memblock_alloc_or_panic(size, align);
+}
+
+/*
+ * Create base device tree for the overlay unittest.
+ *
+ * This is called from very early boot code.
+ *
+ * Do as much as possible the same way as done in __unflatten_device_tree
+ * and other early boot steps for the normal FDT so that the overlay base
+ * unflattened tree will have the same characteristics as the real tree
+ * (such as having memory allocated by the early allocator).  The goal
+ * is to test "the real thing" as much as possible, and test "test setup
+ * code" as little as possible.
+ *
+ * Have to stop before resolving phandles, because that uses kmalloc.
+ */
+void __init unittest_unflatten_overlay_base(void)
+{
+	struct overlay_info *info;
+	u32 data_size;
+	void *new_fdt;
+	u32 size;
+	int found = 0;
+	const char *overlay_name = "overlay_base";
+
+	for (info = overlays; info && info->name; info++) {
+		if (!strcmp(overlay_name, info->name)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		pr_err("no overlay data for %s\n", overlay_name);
+		return;
+	}
+
+	info = &overlays[0];
+
+	if (info->expected_result != -9999) {
+		pr_err("No dtb 'overlay_base' to attach\n");
+		return;
+	}
+
+	data_size = info->dtbo_end - info->dtbo_begin;
+	if (!data_size) {
+		pr_err("No dtb 'overlay_base' to attach\n");
+		return;
+	}
+
+	size = fdt_totalsize(info->dtbo_begin);
+	if (size != data_size) {
+		pr_err("dtb 'overlay_base' header totalsize != actual size");
+		return;
+	}
+
+	new_fdt = dt_alloc_memory(size, roundup_pow_of_two(FDT_V17_SIZE));
+	if (!new_fdt) {
+		pr_err("alloc for dtb 'overlay_base' failed");
+		return;
+	}
+
+	memcpy(new_fdt, info->dtbo_begin, size);
+
+	__unflatten_device_tree(new_fdt, NULL, &overlay_base_root,
+				dt_alloc_memory, true);
+}
+
+/*
+ * The purpose of of_unittest_overlay_data_add is to add an
+ * overlay in the normal fashion.  This is a test of the whole
+ * picture, instead of testing individual elements.
+ *
+ * A secondary purpose is to be able to verify that the contents of
+ * /proc/device-tree/ contains the updated structure and values from
+ * the overlay.  That must be verified separately in user space.
+ *
+ * Return 0 on unexpected error.
+ */
+static int __init overlay_data_apply(const char *overlay_name, int *ovcs_id)
+{
+	struct overlay_info *info;
+	int passed = 1;
+	int found = 0;
+	int ret, ret2;
+	u32 size;
+
+	for (info = overlays; info && info->name; info++) {
+		if (!strcmp(overlay_name, info->name)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		pr_err("no overlay data for %s\n", overlay_name);
+		return 0;
+	}
+
+	size = info->dtbo_end - info->dtbo_begin;
+	if (!size)
+		pr_err("no overlay data for %s\n", overlay_name);
+
+	ret = of_overlay_fdt_apply(info->dtbo_begin, size, &info->ovcs_id,
+				   NULL);
+	if (ovcs_id)
+		*ovcs_id = info->ovcs_id;
+	if (ret < 0)
+		goto out;
+
+	pr_debug("%s applied\n", overlay_name);
+
+out:
+	if (ret != info->expected_result) {
+		pr_err("of_overlay_fdt_apply() expected %d, ret=%d, %s\n",
+		       info->expected_result, ret, overlay_name);
+		passed = 0;
+	}
+
+	if (ret < 0) {
+		/* changeset may be partially applied */
+		ret2 = of_overlay_remove(&info->ovcs_id);
+		if (ret2 != info->expected_result_remove) {
+			pr_err("of_overlay_remove() expected %d, ret=%d, %s\n",
+			       info->expected_result_remove, ret2,
+			       overlay_name);
+			passed = 0;
+		}
+	}
+
+	return passed;
+}
+
+/*
+ * The purpose of of_unittest_overlay_high_level is to add an overlay
+ * in the normal fashion.  This is a test of the whole picture,
+ * instead of individual elements.
+ *
+ * The first part of the function is _not_ normal overlay usage; it is
+ * finishing splicing the base overlay device tree into the live tree.
+ */
+static __init void of_unittest_overlay_high_level(void)
+{
+	struct device_node *last_sibling;
+	struct device_node *np;
+	struct device_node *of_symbols;
+	struct device_node *overlay_base_symbols;
+	struct device_node **pprev;
+	struct property *prop;
+	int ret;
+
+	if (!overlay_base_root) {
+		unittest(0, "overlay_base_root not initialized\n");
+		return;
+	}
+
+	/*
+	 * Could not fixup phandles in unittest_unflatten_overlay_base()
+	 * because kmalloc() was not yet available.
+	 */
+	of_overlay_mutex_lock();
+	of_resolve_phandles(overlay_base_root);
+	of_overlay_mutex_unlock();
+
+
+	/*
+	 * do not allow overlay_base to duplicate any node already in
+	 * tree, this greatly simplifies the code
+	 */
+
+	/*
+	 * remove overlay_base_root node "__local_fixups", after
+	 * being used by of_resolve_phandles()
+	 */
+	pprev = &overlay_base_root->child;
+	for (np = overlay_base_root->child; np; np = np->sibling) {
+		if (of_node_name_eq(np, "__local_fixups__")) {
+			*pprev = np->sibling;
+			break;
+		}
+		pprev = &np->sibling;
+	}
+
+	/* remove overlay_base_root node "__symbols__" if in live tree */
+	of_symbols = of_get_child_by_name(of_root, "__symbols__");
+	if (of_symbols) {
+		/* will have to graft properties from node into live tree */
+		pprev = &overlay_base_root->child;
+		for (np = overlay_base_root->child; np; np = np->sibling) {
+			if (of_node_name_eq(np, "__symbols__")) {
+				overlay_base_symbols = np;
+				*pprev = np->sibling;
+				break;
+			}
+			pprev = &np->sibling;
+		}
+	}
+
+	for_each_child_of_node(overlay_base_root, np) {
+		struct device_node *base_child;
+		for_each_child_of_node(of_root, base_child) {
+			if (!strcmp(np->full_name, base_child->full_name)) {
+				unittest(0, "illegal node name in overlay_base %pOFn",
+					 np);
+				of_node_put(np);
+				of_node_put(base_child);
+				return;
+			}
+		}
+	}
+
+	/*
+	 * overlay 'overlay_base' is not allowed to have root
+	 * properties, so only need to splice nodes into main device tree.
+	 *
+	 * root node of *overlay_base_root will not be freed, it is lost
+	 * memory.
+	 */
+
+	for (np = overlay_base_root->child; np; np = np->sibling)
+		np->parent = of_root;
+
+	mutex_lock(&of_mutex);
+
+	for (last_sibling = np = of_root->child; np; np = np->sibling)
+		last_sibling = np;
+
+	if (last_sibling)
+		last_sibling->sibling = overlay_base_root->child;
+	else
+		of_root->child = overlay_base_root->child;
+
+	for_each_of_allnodes_from(overlay_base_root, np)
+		__of_attach_node_sysfs(np);
+
+	if (of_symbols) {
+		struct property *new_prop;
+		for_each_property_of_node(overlay_base_symbols, prop) {
+
+			new_prop = __of_prop_dup(prop, GFP_KERNEL);
+			if (!new_prop) {
+				unittest(0, "__of_prop_dup() of '%s' from overlay_base node __symbols__",
+					 prop->name);
+				goto err_unlock;
+			}
+			if (__of_add_property(of_symbols, new_prop)) {
+				__of_prop_free(new_prop);
+				/* "name" auto-generated by unflatten */
+				if (!strcmp(prop->name, "name"))
+					continue;
+				unittest(0, "duplicate property '%s' in overlay_base node __symbols__",
+					 prop->name);
+				goto err_unlock;
+			}
+			if (__of_add_property_sysfs(of_symbols, new_prop)) {
+				unittest(0, "unable to add property '%s' in overlay_base node __symbols__ to sysfs",
+					 prop->name);
+				goto err_unlock;
+			}
+		}
+	}
+
+	mutex_unlock(&of_mutex);
+
+
+	/* now do the normal overlay usage test */
+
+	/* ---  overlay  --- */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/substation@100/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@30/incline-up");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@40/incline-up");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/color");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/rate");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/hvac_2");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_left");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_right");
+
+	ret = overlay_data_apply("overlay", NULL);
+
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_right");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_left");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/hvac_2");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/rate");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/color");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/status");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@40/incline-up");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@30/incline-up");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/status");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/substation@100/status");
+
+	unittest(ret, "Adding overlay 'overlay' failed\n");
+
+	/* ---  overlay_bad_add_dup_node  --- */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/controller/name");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/motor-1/controller:name");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: Error reverting changeset (-19)");
+
+	unittest(overlay_data_apply("overlay_bad_add_dup_node", NULL),
+		 "Adding overlay 'overlay_bad_add_dup_node' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		   "OF: Error reverting changeset (-19)");
+	EXPECT_END(KERN_ERR,
+		   "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/motor-1/controller:name");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/controller/name");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller");
+
+	/* ---  overlay_bad_add_dup_prop  --- */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/electric");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/rpm_avail");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/name");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/motor-1/electric:name");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: Error reverting changeset (-19)");
+
+	unittest(overlay_data_apply("overlay_bad_add_dup_prop", NULL),
+		 "Adding overlay 'overlay_bad_add_dup_prop' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		   "OF: Error reverting changeset (-19)");
+	EXPECT_END(KERN_ERR,
+		   "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/motor-1/electric:name");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/name");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/rpm_avail");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/electric");
+
+	/* ---  overlay_bad_phandle  --- */
+
+	unittest(overlay_data_apply("overlay_bad_phandle", NULL),
+		 "Adding overlay 'overlay_bad_phandle' failed\n");
+
+	/* ---  overlay_bad_symbol  --- */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/hvac-medium-2:name");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: Error reverting changeset (-19)");
+
+	unittest(overlay_data_apply("overlay_bad_symbol", NULL),
+		 "Adding overlay 'overlay_bad_symbol' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		   "OF: Error reverting changeset (-19)");
+	EXPECT_END(KERN_ERR,
+		   "OF: changeset: apply failed: REMOVE_PROPERTY /testcase-data-2/substation@100/hvac-medium-2:name");
+
+	/* ---  overlay_bad_unresolved  --- */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: resolver: node label 'this_label_does_not_exist' not found in live devicetree symbols table");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: resolver: overlay phandle fixup failed: -22");
+
+	unittest(overlay_data_apply("overlay_bad_unresolved", NULL),
+		 "Adding overlay 'overlay_bad_unresolved' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		   "OF: resolver: overlay phandle fixup failed: -22");
+	EXPECT_END(KERN_ERR,
+		   "OF: resolver: node label 'this_label_does_not_exist' not found in live devicetree symbols table");
+
+	return;
+
+err_unlock:
+	mutex_unlock(&of_mutex);
+}
+
+static int of_unittest_pci_dev_num;
+static int of_unittest_pci_child_num;
+
+/*
+ * PCI device tree node test driver
+ */
+static const struct pci_device_id testdrv_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT, 0x5), }, /* PCI_VENDOR_ID_REDHAT */
+	{ 0, }
+};
+
+static int testdrv_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct overlay_info *info;
+	struct device_node *dn;
+	int ret, ovcs_id;
+	u32 size;
+
+	dn = pdev->dev.of_node;
+	if (!dn) {
+		dev_err(&pdev->dev, "does not find bus endpoint");
+		return -EINVAL;
+	}
+
+	for (info = overlays; info && info->name; info++) {
+		if (!strcmp(info->name, "overlay_pci_node"))
+			break;
+	}
+	if (!info || !info->name) {
+		dev_err(&pdev->dev, "no overlay data for overlay_pci_node");
+		return -ENODEV;
+	}
+
+	size = info->dtbo_end - info->dtbo_begin;
+	ret = of_overlay_fdt_apply(info->dtbo_begin, size, &ovcs_id, dn);
+	if (ret)
+		return ret;
+
+	of_platform_default_populate(dn, NULL, &pdev->dev);
+	pci_set_drvdata(pdev, (void *)(uintptr_t)ovcs_id);
+
+	return 0;
+}
+
+static void testdrv_remove(struct pci_dev *pdev)
+{
+	int ovcs_id = (int)(uintptr_t)pci_get_drvdata(pdev);
+
+	of_platform_depopulate(&pdev->dev);
+	of_overlay_remove(&ovcs_id);
+}
+
+static struct pci_driver testdrv_driver = {
+	.name = "pci_dt_testdrv",
+	.id_table = testdrv_pci_ids,
+	.probe = testdrv_probe,
+	.remove = testdrv_remove,
+};
+
+static int unittest_pci_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct device *dev;
+	u64 exp_addr;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	dev = &pdev->dev;
+	while (dev && !dev_is_pci(dev))
+		dev = dev->parent;
+	if (!dev) {
+		pr_err("unable to find parent device\n");
+		return -ENODEV;
+	}
+
+	exp_addr = pci_resource_start(to_pci_dev(dev), 0) + 0x100;
+	unittest(res->start == exp_addr, "Incorrect translated address %llx, expected %llx\n",
+		 (u64)res->start, exp_addr);
+
+	of_unittest_pci_child_num++;
+
+	return 0;
+}
+
+static const struct of_device_id unittest_pci_of_match[] = {
+	{ .compatible = "unittest-pci" },
+	{ }
+};
+
+static struct platform_driver unittest_pci_driver = {
+	.probe = unittest_pci_probe,
+	.driver = {
+		.name = "unittest-pci",
+		.of_match_table = unittest_pci_of_match,
+	},
+};
+
+static int of_unittest_pci_node_verify(struct pci_dev *pdev, bool add)
+{
+	struct device_node *pnp, *np = NULL;
+	struct device *child_dev;
+	char *path = NULL;
+	const __be32 *reg;
+	int rc = 0;
+
+	pnp = pdev->dev.of_node;
+	unittest(pnp, "Failed creating PCI dt node\n");
+	if (!pnp)
+		return -ENODEV;
+
+	if (add) {
+		path = kasprintf(GFP_KERNEL, "%pOF/pci-ep-bus@0/unittest-pci@100", pnp);
+		np = of_find_node_by_path(path);
+		unittest(np, "Failed to get unittest-pci node under PCI node\n");
+		if (!np) {
+			rc = -ENODEV;
+			goto failed;
+		}
+
+		reg = of_get_property(np, "reg", NULL);
+		unittest(reg, "Failed to get reg property\n");
+		if (!reg)
+			rc = -ENODEV;
+	} else {
+		path = kasprintf(GFP_KERNEL, "%pOF/pci-ep-bus@0", pnp);
+		np = of_find_node_by_path(path);
+		unittest(!np, "Child device tree node is not removed\n");
+		child_dev = device_find_any_child(&pdev->dev);
+		unittest(!child_dev, "Child device is not removed\n");
+		put_device(child_dev);
+	}
+
+failed:
+	kfree(path);
+	if (np)
+		of_node_put(np);
+
+	return rc;
+}
+
+static void __init of_unittest_pci_node(void)
+{
+	struct pci_dev *pdev = NULL;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_PCI_DYNAMIC_OF_NODES))
+		return;
+
+	rc = pci_register_driver(&testdrv_driver);
+	unittest(!rc, "Failed to register pci test driver; rc = %d\n", rc);
+	if (rc)
+		return;
+
+	rc = platform_driver_register(&unittest_pci_driver);
+	if (unittest(!rc, "Failed to register unittest pci driver\n")) {
+		pci_unregister_driver(&testdrv_driver);
+		return;
+	}
+
+	while ((pdev = pci_get_device(PCI_VENDOR_ID_REDHAT, 0x5, pdev)) != NULL) {
+		of_unittest_pci_node_verify(pdev, true);
+		of_unittest_pci_dev_num++;
+	}
+	if (pdev)
+		pci_dev_put(pdev);
+
+	unittest(of_unittest_pci_dev_num,
+		 "No test PCI device been found. Please run QEMU with '-device pci-testdev'\n");
+	unittest(of_unittest_pci_dev_num == of_unittest_pci_child_num,
+		 "Child device number %d is not expected %d", of_unittest_pci_child_num,
+		 of_unittest_pci_dev_num);
+
+	platform_driver_unregister(&unittest_pci_driver);
+	pci_unregister_driver(&testdrv_driver);
+
+	while ((pdev = pci_get_device(PCI_VENDOR_ID_REDHAT, 0x5, pdev)) != NULL)
+		of_unittest_pci_node_verify(pdev, false);
+	if (pdev)
+		pci_dev_put(pdev);
+}
+#else
+
+static inline __init void of_unittest_overlay_high_level(void) {}
+static inline __init void of_unittest_pci_node(void) { }
+
+#endif
+
+static int __init of_unittest(void)
+{
+	struct device_node *np;
+	int res;
+
+	pr_info("start of unittest - you will see error messages\n");
+
+	/* Taint the kernel so we know we've run tests. */
+	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
+
+	/* adding data for unittest */
+	res = unittest_data_add();
+	if (res)
+		return res;
+	if (!of_aliases)
+		of_aliases = of_find_node_by_path("/aliases");
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_info("No testcase data in device tree; not running tests\n");
+		return 0;
+	}
+	of_node_put(np);
+
+	of_unittest_check_tree_linkage();
+	of_unittest_check_phandles();
+	of_unittest_find_node_by_name();
+	of_unittest_dynamic();
+	of_unittest_parse_phandle_with_args();
+	of_unittest_parse_phandle_with_args_map();
+	of_unittest_printf();
+	of_unittest_property_string();
+	of_unittest_property_copy();
+	of_unittest_changeset();
+	of_unittest_changeset_prop();
+	of_unittest_parse_interrupts();
+	of_unittest_parse_interrupts_extended();
+	of_unittest_parse_interrupt_map();
+	of_unittest_irq_refcount();
+	of_unittest_dma_get_max_cpu_address();
+	of_unittest_parse_dma_ranges();
+	of_unittest_pci_dma_ranges();
+	of_unittest_pci_empty_dma_ranges();
+	of_unittest_bus_ranges();
+	of_unittest_bus_3cell_ranges();
+	of_unittest_reg();
+	of_unittest_translate_addr();
+	of_unittest_match_node();
+	of_unittest_platform_populate();
+	of_unittest_overlay();
+	of_unittest_lifecycle();
+	of_unittest_pci_node();
+
+	/* Double check linkage after removing testcase data */
+	of_unittest_check_tree_linkage();
+
+	of_unittest_overlay_high_level();
+
+	pr_info("end of unittest - %i passed, %i failed\n",
+		unittest_results.passed, unittest_results.failed);
+
+	return 0;
+}
+late_initcall(of_unittest);