Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

5 files changed, 617 insertions, 0 deletions

diff --git a/drivers/misc/cb710/Kconfig b/drivers/misc/cb710/Kconfig
new file mode 100644
index 000000000..a696d7509
--- /dev/null
+++ b/drivers/misc/cb710/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CB710_CORE
+	tristate "ENE CB710/720 Flash memory card reader support"
+	depends on PCI
+	help
+	  This option enables support for PCI ENE CB710/720 Flash memory card
+	  reader found in some laptops (ie. some versions of HP Compaq nx9500).
+
+	  You will also have to select some flash card format drivers (MMC/SD,
+	  MemoryStick).
+
+	  This driver can also be built as a module. If so, the module
+	  will be called cb710.
+
+config CB710_DEBUG
+	bool "Enable driver debugging"
+	depends on CB710_CORE != n
+	help
+	  This is an option for use by developers; most people should
+	  say N here.  This adds a lot of debugging output to dmesg.
+
+config CB710_DEBUG_ASSUMPTIONS
+	bool
+	depends on CB710_CORE != n
+	default y
diff --git a/drivers/misc/cb710/Makefile b/drivers/misc/cb710/Makefile
new file mode 100644
index 000000000..8a38c66eb
--- /dev/null
+++ b/drivers/misc/cb710/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ccflags-$(CONFIG_CB710_DEBUG)	:= -DDEBUG
+
+obj-$(CONFIG_CB710_CORE)	+= cb710.o
+
+cb710-y				:= core.o sgbuf2.o
+cb710-$(CONFIG_CB710_DEBUG)	+= debug.o
diff --git a/drivers/misc/cb710/core.c b/drivers/misc/cb710/core.c
new file mode 100644
index 000000000..8e0d11e59
--- /dev/null
+++ b/drivers/misc/cb710/core.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  cb710/core.c
+ *
+ *  Copyright by Michał Mirosław, 2008-2009
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/cb710.h>
+#include <linux/gfp.h>
+
+static DEFINE_IDA(cb710_ida);
+
+void cb710_pci_update_config_reg(struct pci_dev *pdev,
+	int reg, uint32_t mask, uint32_t xor)
+{
+	u32 rval;
+
+	pci_read_config_dword(pdev, reg, &rval);
+	rval = (rval & mask) ^ xor;
+	pci_write_config_dword(pdev, reg, rval);
+}
+EXPORT_SYMBOL_GPL(cb710_pci_update_config_reg);
+
+/* Some magic writes based on Windows driver init code */
+static int cb710_pci_configure(struct pci_dev *pdev)
+{
+	unsigned int devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
+	struct pci_dev *pdev0;
+	u32 val;
+
+	cb710_pci_update_config_reg(pdev, 0x48,
+		~0x000000FF, 0x0000003F);
+
+	pci_read_config_dword(pdev, 0x48, &val);
+	if (val & 0x80000000)
+		return 0;
+
+	pdev0 = pci_get_slot(pdev->bus, devfn);
+	if (!pdev0)
+		return -ENODEV;
+
+	if (pdev0->vendor == PCI_VENDOR_ID_ENE
+	    && pdev0->device == PCI_DEVICE_ID_ENE_720) {
+		cb710_pci_update_config_reg(pdev0, 0x8C,
+			~0x00F00000, 0x00100000);
+		cb710_pci_update_config_reg(pdev0, 0xB0,
+			~0x08000000, 0x08000000);
+	}
+
+	cb710_pci_update_config_reg(pdev0, 0x8C,
+		~0x00000F00, 0x00000200);
+	cb710_pci_update_config_reg(pdev0, 0x90,
+		~0x00060000, 0x00040000);
+
+	pci_dev_put(pdev0);
+
+	return 0;
+}
+
+static irqreturn_t cb710_irq_handler(int irq, void *data)
+{
+	struct cb710_chip *chip = data;
+	struct cb710_slot *slot = &chip->slot[0];
+	irqreturn_t handled = IRQ_NONE;
+	unsigned nr;
+
+	spin_lock(&chip->irq_lock); /* incl. smp_rmb() */
+
+	for (nr = chip->slots; nr; ++slot, --nr) {
+		cb710_irq_handler_t handler_func = slot->irq_handler;
+		if (handler_func && handler_func(slot))
+			handled = IRQ_HANDLED;
+	}
+
+	spin_unlock(&chip->irq_lock);
+
+	return handled;
+}
+
+static void cb710_release_slot(struct device *dev)
+{
+#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
+	struct cb710_slot *slot = cb710_pdev_to_slot(to_platform_device(dev));
+	struct cb710_chip *chip = cb710_slot_to_chip(slot);
+
+	/* slot struct can be freed now */
+	atomic_dec(&chip->slot_refs_count);
+#endif
+}
+
+static int cb710_register_slot(struct cb710_chip *chip,
+	unsigned slot_mask, unsigned io_offset, const char *name)
+{
+	int nr = chip->slots;
+	struct cb710_slot *slot = &chip->slot[nr];
+	int err;
+
+	dev_dbg(cb710_chip_dev(chip),
+		"register: %s.%d; slot %d; mask %d; IO offset: 0x%02X\n",
+		name, chip->platform_id, nr, slot_mask, io_offset);
+
+	/* slot->irq_handler == NULL here; this needs to be
+	 * seen before platform_device_register() */
+	++chip->slots;
+	smp_wmb();
+
+	slot->iobase = chip->iobase + io_offset;
+	slot->pdev.name = name;
+	slot->pdev.id = chip->platform_id;
+	slot->pdev.dev.parent = &chip->pdev->dev;
+	slot->pdev.dev.release = cb710_release_slot;
+
+	err = platform_device_register(&slot->pdev);
+
+#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
+	atomic_inc(&chip->slot_refs_count);
+#endif
+
+	if (err) {
+		/* device_initialize() called from platform_device_register()
+		 * wants this on error path */
+		platform_device_put(&slot->pdev);
+
+		/* slot->irq_handler == NULL here anyway, so no lock needed */
+		--chip->slots;
+		return err;
+	}
+
+	chip->slot_mask |= slot_mask;
+
+	return 0;
+}
+
+static void cb710_unregister_slot(struct cb710_chip *chip,
+	unsigned slot_mask)
+{
+	int nr = chip->slots - 1;
+
+	if (!(chip->slot_mask & slot_mask))
+		return;
+
+	platform_device_unregister(&chip->slot[nr].pdev);
+
+	/* complementary to spin_unlock() in cb710_set_irq_handler() */
+	smp_rmb();
+	BUG_ON(chip->slot[nr].irq_handler != NULL);
+
+	/* slot->irq_handler == NULL here, so no lock needed */
+	--chip->slots;
+	chip->slot_mask &= ~slot_mask;
+}
+
+void cb710_set_irq_handler(struct cb710_slot *slot,
+	cb710_irq_handler_t handler)
+{
+	struct cb710_chip *chip = cb710_slot_to_chip(slot);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chip->irq_lock, flags);
+	slot->irq_handler = handler;
+	spin_unlock_irqrestore(&chip->irq_lock, flags);
+}
+EXPORT_SYMBOL_GPL(cb710_set_irq_handler);
+
+static int __maybe_unused cb710_suspend(struct device *dev_d)
+{
+	struct pci_dev *pdev = to_pci_dev(dev_d);
+	struct cb710_chip *chip = pci_get_drvdata(pdev);
+
+	devm_free_irq(&pdev->dev, pdev->irq, chip);
+	return 0;
+}
+
+static int __maybe_unused cb710_resume(struct device *dev_d)
+{
+	struct pci_dev *pdev = to_pci_dev(dev_d);
+	struct cb710_chip *chip = pci_get_drvdata(pdev);
+
+	return devm_request_irq(&pdev->dev, pdev->irq,
+		cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
+}
+
+static int cb710_probe(struct pci_dev *pdev,
+	const struct pci_device_id *ent)
+{
+	struct cb710_chip *chip;
+	u32 val;
+	int err;
+	int n = 0;
+
+	err = cb710_pci_configure(pdev);
+	if (err)
+		return err;
+
+	/* this is actually magic... */
+	pci_read_config_dword(pdev, 0x48, &val);
+	if (!(val & 0x80000000)) {
+		pci_write_config_dword(pdev, 0x48, val|0x71000000);
+		pci_read_config_dword(pdev, 0x48, &val);
+	}
+
+	dev_dbg(&pdev->dev, "PCI config[0x48] = 0x%08X\n", val);
+	if (!(val & 0x70000000))
+		return -ENODEV;
+	val = (val >> 28) & 7;
+	if (val & CB710_SLOT_MMC)
+		++n;
+	if (val & CB710_SLOT_MS)
+		++n;
+	if (val & CB710_SLOT_SM)
+		++n;
+
+	chip = devm_kzalloc(&pdev->dev, struct_size(chip, slot, n),
+			    GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	err = pcim_enable_device(pdev);
+	if (err)
+		return err;
+
+	spin_lock_init(&chip->irq_lock);
+	chip->pdev = pdev;
+	chip->iobase = pcim_iomap_region(pdev, 0, KBUILD_MODNAME);
+	if (IS_ERR(chip->iobase))
+		return PTR_ERR(chip->iobase);
+
+	pci_set_drvdata(pdev, chip);
+
+	err = devm_request_irq(&pdev->dev, pdev->irq,
+		cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
+	if (err)
+		return err;
+
+	err = ida_alloc(&cb710_ida, GFP_KERNEL);
+	if (err < 0)
+		return err;
+	chip->platform_id = err;
+
+	dev_info(&pdev->dev, "id %d, IO 0x%p, IRQ %d\n",
+		chip->platform_id, chip->iobase, pdev->irq);
+
+	if (val & CB710_SLOT_MMC) {	/* MMC/SD slot */
+		err = cb710_register_slot(chip,
+			CB710_SLOT_MMC, 0x00, "cb710-mmc");
+		if (err)
+			return err;
+	}
+
+	if (val & CB710_SLOT_MS) {	/* MemoryStick slot */
+		err = cb710_register_slot(chip,
+			CB710_SLOT_MS, 0x40, "cb710-ms");
+		if (err)
+			goto unreg_mmc;
+	}
+
+	if (val & CB710_SLOT_SM) {	/* SmartMedia slot */
+		err = cb710_register_slot(chip,
+			CB710_SLOT_SM, 0x60, "cb710-sm");
+		if (err)
+			goto unreg_ms;
+	}
+
+	return 0;
+unreg_ms:
+	cb710_unregister_slot(chip, CB710_SLOT_MS);
+unreg_mmc:
+	cb710_unregister_slot(chip, CB710_SLOT_MMC);
+
+#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
+	BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
+#endif
+	return err;
+}
+
+static void cb710_remove_one(struct pci_dev *pdev)
+{
+	struct cb710_chip *chip = pci_get_drvdata(pdev);
+
+	cb710_unregister_slot(chip, CB710_SLOT_SM);
+	cb710_unregister_slot(chip, CB710_SLOT_MS);
+	cb710_unregister_slot(chip, CB710_SLOT_MMC);
+#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
+	BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
+#endif
+
+	ida_free(&cb710_ida, chip->platform_id);
+}
+
+static const struct pci_device_id cb710_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_ENE, PCI_DEVICE_ID_ENE_CB710_FLASH) },
+	{ }
+};
+
+static SIMPLE_DEV_PM_OPS(cb710_pm_ops, cb710_suspend, cb710_resume);
+
+static struct pci_driver cb710_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = cb710_pci_tbl,
+	.probe = cb710_probe,
+	.remove = cb710_remove_one,
+	.driver.pm = &cb710_pm_ops,
+};
+
+static int __init cb710_init_module(void)
+{
+	return pci_register_driver(&cb710_driver);
+}
+
+static void __exit cb710_cleanup_module(void)
+{
+	pci_unregister_driver(&cb710_driver);
+	ida_destroy(&cb710_ida);
+}
+
+module_init(cb710_init_module);
+module_exit(cb710_cleanup_module);
+
+MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
+MODULE_DESCRIPTION("ENE CB710 memory card reader driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, cb710_pci_tbl);
diff --git a/drivers/misc/cb710/debug.c b/drivers/misc/cb710/debug.c
new file mode 100644
index 000000000..20d672edf
--- /dev/null
+++ b/drivers/misc/cb710/debug.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  cb710/debug.c
+ *
+ *  Copyright by Michał Mirosław, 2008-2009
+ */
+#include <linux/cb710.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#define CB710_REG_COUNT		0x80
+
+static const u16 allow[CB710_REG_COUNT/16] = {
+	0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF,
+	0xFFF0, 0xFFFF, 0xFFFF, 0xFFFF,
+};
+static const char *const prefix[ARRAY_SIZE(allow)] = {
+	"MMC", "MMC", "MMC", "MMC",
+	"MS?", "MS?", "SM?", "SM?"
+};
+
+static inline int allow_reg_read(unsigned block, unsigned offset, unsigned bits)
+{
+	unsigned mask = (1 << bits/8) - 1;
+	offset *= bits/8;
+	return ((allow[block] >> offset) & mask) == mask;
+}
+
+#define CB710_READ_REGS_TEMPLATE(t)					\
+static void cb710_read_regs_##t(void __iomem *iobase,			\
+	u##t *reg, unsigned select)					\
+{									\
+	unsigned i, j;							\
+									\
+	for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) {	\
+		if (!(select & (1 << i)))					\
+			continue;					\
+									\
+		for (j = 0; j < 0x10/(t/8); ++j) {			\
+			if (!allow_reg_read(i, j, t))			\
+				continue;				\
+			reg[j] = ioread##t(iobase			\
+				+ (i << 4) + (j * (t/8)));		\
+		}							\
+	}								\
+}
+
+static const char cb710_regf_8[] = "%02X";
+static const char cb710_regf_16[] = "%04X";
+static const char cb710_regf_32[] = "%08X";
+static const char cb710_xes[] = "xxxxxxxx";
+
+#define CB710_DUMP_REGS_TEMPLATE(t)					\
+static void cb710_dump_regs_##t(struct device *dev,			\
+	const u##t *reg, unsigned select)				\
+{									\
+	const char *const xp = &cb710_xes[8 - t/4];			\
+	const char *const format = cb710_regf_##t;			\
+									\
+	char msg[100], *p;						\
+	unsigned i, j;							\
+									\
+	for (i = 0; i < ARRAY_SIZE(allow); ++i, reg += 16/(t/8)) {	\
+		if (!(select & (1 << i)))				\
+			continue;					\
+		p = msg;						\
+		for (j = 0; j < 0x10/(t/8); ++j) {			\
+			*p++ = ' ';					\
+			if (j == 8/(t/8))				\
+				*p++ = ' ';				\
+			if (allow_reg_read(i, j, t))			\
+				p += sprintf(p, format, reg[j]);	\
+			else						\
+				p += sprintf(p, "%s", xp);		\
+		}							\
+		dev_dbg(dev, "%s 0x%02X %s\n", prefix[i], i << 4, msg);	\
+	}								\
+}
+
+#define CB710_READ_AND_DUMP_REGS_TEMPLATE(t)				\
+static void cb710_read_and_dump_regs_##t(struct cb710_chip *chip,	\
+	unsigned select)						\
+{									\
+	u##t regs[CB710_REG_COUNT/sizeof(u##t)];			\
+									\
+	memset(&regs, 0, sizeof(regs));					\
+	cb710_read_regs_##t(chip->iobase, regs, select);		\
+	cb710_dump_regs_##t(cb710_chip_dev(chip), regs, select);	\
+}
+
+#define CB710_REG_ACCESS_TEMPLATES(t)		\
+  CB710_READ_REGS_TEMPLATE(t)			\
+  CB710_DUMP_REGS_TEMPLATE(t)			\
+  CB710_READ_AND_DUMP_REGS_TEMPLATE(t)
+
+CB710_REG_ACCESS_TEMPLATES(8)
+CB710_REG_ACCESS_TEMPLATES(16)
+CB710_REG_ACCESS_TEMPLATES(32)
+
+void cb710_dump_regs(struct cb710_chip *chip, unsigned select)
+{
+	if (!(select & CB710_DUMP_REGS_MASK))
+		select = CB710_DUMP_REGS_ALL;
+	if (!(select & CB710_DUMP_ACCESS_MASK))
+		select |= CB710_DUMP_ACCESS_8;
+
+	if (select & CB710_DUMP_ACCESS_32)
+		cb710_read_and_dump_regs_32(chip, select);
+	if (select & CB710_DUMP_ACCESS_16)
+		cb710_read_and_dump_regs_16(chip, select);
+	if (select & CB710_DUMP_ACCESS_8)
+		cb710_read_and_dump_regs_8(chip, select);
+}
+EXPORT_SYMBOL_GPL(cb710_dump_regs);
+
diff --git a/drivers/misc/cb710/sgbuf2.c b/drivers/misc/cb710/sgbuf2.c
new file mode 100644
index 000000000..a798fad5f
--- /dev/null
+++ b/drivers/misc/cb710/sgbuf2.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  cb710/sgbuf2.c
+ *
+ *  Copyright by Michał Mirosław, 2008-2009
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/cb710.h>
+
+static bool sg_dwiter_next(struct sg_mapping_iter *miter)
+{
+	if (sg_miter_next(miter)) {
+		miter->consumed = 0;
+		return true;
+	} else
+		return false;
+}
+
+static bool sg_dwiter_is_at_end(struct sg_mapping_iter *miter)
+{
+	return miter->length == miter->consumed && !sg_dwiter_next(miter);
+}
+
+static uint32_t sg_dwiter_read_buffer(struct sg_mapping_iter *miter)
+{
+	size_t len, left = 4;
+	uint32_t data;
+	void *addr = &data;
+
+	do {
+		len = min(miter->length - miter->consumed, left);
+		memcpy(addr, miter->addr + miter->consumed, len);
+		miter->consumed += len;
+		left -= len;
+		if (!left)
+			return data;
+		addr += len;
+	} while (sg_dwiter_next(miter));
+
+	memset(addr, 0, left);
+	return data;
+}
+
+static inline bool needs_unaligned_copy(const void *ptr)
+{
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	return false;
+#else
+	return ((uintptr_t)ptr & 3) != 0;
+#endif
+}
+
+static bool sg_dwiter_get_next_block(struct sg_mapping_iter *miter, uint32_t **ptr)
+{
+	size_t len;
+
+	if (sg_dwiter_is_at_end(miter))
+		return true;
+
+	len = miter->length - miter->consumed;
+
+	if (likely(len >= 4 && !needs_unaligned_copy(
+			miter->addr + miter->consumed))) {
+		*ptr = miter->addr + miter->consumed;
+		miter->consumed += 4;
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * cb710_sg_dwiter_read_next_block() - get next 32-bit word from sg buffer
+ * @miter: sg mapping iterator used for reading
+ *
+ * Description:
+ *   Returns 32-bit word starting at byte pointed to by @miter@
+ *   handling any alignment issues.  Bytes past the buffer's end
+ *   are not accessed (read) but are returned as zeroes.  @miter@
+ *   is advanced by 4 bytes or to the end of buffer whichever is
+ *   closer.
+ *
+ * Context:
+ *   Same requirements as in sg_miter_next().
+ *
+ * Returns:
+ *   32-bit word just read.
+ */
+uint32_t cb710_sg_dwiter_read_next_block(struct sg_mapping_iter *miter)
+{
+	uint32_t *ptr = NULL;
+
+	if (likely(sg_dwiter_get_next_block(miter, &ptr)))
+		return ptr ? *ptr : 0;
+
+	return sg_dwiter_read_buffer(miter);
+}
+EXPORT_SYMBOL_GPL(cb710_sg_dwiter_read_next_block);
+
+static void sg_dwiter_write_slow(struct sg_mapping_iter *miter, uint32_t data)
+{
+	size_t len, left = 4;
+	void *addr = &data;
+
+	do {
+		len = min(miter->length - miter->consumed, left);
+		memcpy(miter->addr, addr, len);
+		miter->consumed += len;
+		left -= len;
+		if (!left)
+			return;
+		addr += len;
+	} while (sg_dwiter_next(miter));
+}
+
+/**
+ * cb710_sg_dwiter_write_next_block() - write next 32-bit word to sg buffer
+ * @miter: sg mapping iterator used for writing
+ * @data: data to write to sg buffer
+ *
+ * Description:
+ *   Writes 32-bit word starting at byte pointed to by @miter@
+ *   handling any alignment issues.  Bytes which would be written
+ *   past the buffer's end are silently discarded. @miter@ is
+ *   advanced by 4 bytes or to the end of buffer whichever is closer.
+ *
+ * Context:
+ *   Same requirements as in sg_miter_next().
+ */
+void cb710_sg_dwiter_write_next_block(struct sg_mapping_iter *miter, uint32_t data)
+{
+	uint32_t *ptr = NULL;
+
+	if (likely(sg_dwiter_get_next_block(miter, &ptr))) {
+		if (ptr)
+			*ptr = data;
+		else
+			return;
+	} else
+		sg_dwiter_write_slow(miter, data);
+}
+EXPORT_SYMBOL_GPL(cb710_sg_dwiter_write_next_block);
+