x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 624 insertions, 0 deletions

diff --git a/drivers/pci/controller/pcie-xilinx.c b/drivers/pci/controller/pcie-xilinx.c
new file mode 100644
index 000000000..4aa139aba
--- /dev/null
+++ b/drivers/pci/controller/pcie-xilinx.c
@@ -0,0 +1,624 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCIe host controller driver for Xilinx AXI PCIe Bridge
+ *
+ * Copyright (c) 2012 - 2014 Xilinx, Inc.
+ *
+ * Based on the Tegra PCIe driver
+ *
+ * Bits taken from Synopsys DesignWare Host controller driver and
+ * ARM PCI Host generic driver.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip/irq-msi-lib.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/pci-ecam.h>
+#include <linux/platform_device.h>
+
+#include "../pci.h"
+
+/* Register definitions */
+#define XILINX_PCIE_REG_BIR		0x00000130
+#define XILINX_PCIE_REG_IDR		0x00000138
+#define XILINX_PCIE_REG_IMR		0x0000013c
+#define XILINX_PCIE_REG_PSCR		0x00000144
+#define XILINX_PCIE_REG_RPSC		0x00000148
+#define XILINX_PCIE_REG_MSIBASE1	0x0000014c
+#define XILINX_PCIE_REG_MSIBASE2	0x00000150
+#define XILINX_PCIE_REG_RPEFR		0x00000154
+#define XILINX_PCIE_REG_RPIFR1		0x00000158
+#define XILINX_PCIE_REG_RPIFR2		0x0000015c
+
+/* Interrupt registers definitions */
+#define XILINX_PCIE_INTR_LINK_DOWN	BIT(0)
+#define XILINX_PCIE_INTR_ECRC_ERR	BIT(1)
+#define XILINX_PCIE_INTR_STR_ERR	BIT(2)
+#define XILINX_PCIE_INTR_HOT_RESET	BIT(3)
+#define XILINX_PCIE_INTR_CFG_TIMEOUT	BIT(8)
+#define XILINX_PCIE_INTR_CORRECTABLE	BIT(9)
+#define XILINX_PCIE_INTR_NONFATAL	BIT(10)
+#define XILINX_PCIE_INTR_FATAL		BIT(11)
+#define XILINX_PCIE_INTR_INTX		BIT(16)
+#define XILINX_PCIE_INTR_MSI		BIT(17)
+#define XILINX_PCIE_INTR_SLV_UNSUPP	BIT(20)
+#define XILINX_PCIE_INTR_SLV_UNEXP	BIT(21)
+#define XILINX_PCIE_INTR_SLV_COMPL	BIT(22)
+#define XILINX_PCIE_INTR_SLV_ERRP	BIT(23)
+#define XILINX_PCIE_INTR_SLV_CMPABT	BIT(24)
+#define XILINX_PCIE_INTR_SLV_ILLBUR	BIT(25)
+#define XILINX_PCIE_INTR_MST_DECERR	BIT(26)
+#define XILINX_PCIE_INTR_MST_SLVERR	BIT(27)
+#define XILINX_PCIE_INTR_MST_ERRP	BIT(28)
+#define XILINX_PCIE_IMR_ALL_MASK	0x1FF30FED
+#define XILINX_PCIE_IMR_ENABLE_MASK	0x1FF30F0D
+#define XILINX_PCIE_IDR_ALL_MASK	0xFFFFFFFF
+
+/* Root Port Error FIFO Read Register definitions */
+#define XILINX_PCIE_RPEFR_ERR_VALID	BIT(18)
+#define XILINX_PCIE_RPEFR_REQ_ID	GENMASK(15, 0)
+#define XILINX_PCIE_RPEFR_ALL_MASK	0xFFFFFFFF
+
+/* Root Port Interrupt FIFO Read Register 1 definitions */
+#define XILINX_PCIE_RPIFR1_INTR_VALID	BIT(31)
+#define XILINX_PCIE_RPIFR1_MSI_INTR	BIT(30)
+#define XILINX_PCIE_RPIFR1_INTR_MASK	GENMASK(28, 27)
+#define XILINX_PCIE_RPIFR1_ALL_MASK	0xFFFFFFFF
+#define XILINX_PCIE_RPIFR1_INTR_SHIFT	27
+
+/* Bridge Info Register definitions */
+#define XILINX_PCIE_BIR_ECAM_SZ_MASK	GENMASK(18, 16)
+#define XILINX_PCIE_BIR_ECAM_SZ_SHIFT	16
+
+/* Root Port Interrupt FIFO Read Register 2 definitions */
+#define XILINX_PCIE_RPIFR2_MSG_DATA	GENMASK(15, 0)
+
+/* Root Port Status/control Register definitions */
+#define XILINX_PCIE_REG_RPSC_BEN	BIT(0)
+
+/* Phy Status/Control Register definitions */
+#define XILINX_PCIE_REG_PSCR_LNKUP	BIT(11)
+
+/* Number of MSI IRQs */
+#define XILINX_NUM_MSI_IRQS		128
+
+/**
+ * struct xilinx_pcie - PCIe port information
+ * @dev: Device pointer
+ * @reg_base: IO Mapped Register Base
+ * @msi_map: Bitmap of allocated MSIs
+ * @map_lock: Mutex protecting the MSI allocation
+ * @msi_domain: MSI IRQ domain pointer
+ * @leg_domain: Legacy IRQ domain pointer
+ * @resources: Bus Resources
+ */
+struct xilinx_pcie {
+	struct device *dev;
+	void __iomem *reg_base;
+	unsigned long msi_map[BITS_TO_LONGS(XILINX_NUM_MSI_IRQS)];
+	struct mutex map_lock;
+	struct irq_domain *msi_domain;
+	struct irq_domain *leg_domain;
+	struct list_head resources;
+};
+
+static inline u32 pcie_read(struct xilinx_pcie *pcie, u32 reg)
+{
+	return readl(pcie->reg_base + reg);
+}
+
+static inline void pcie_write(struct xilinx_pcie *pcie, u32 val, u32 reg)
+{
+	writel(val, pcie->reg_base + reg);
+}
+
+static inline bool xilinx_pcie_link_up(struct xilinx_pcie *pcie)
+{
+	return (pcie_read(pcie, XILINX_PCIE_REG_PSCR) &
+		XILINX_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
+}
+
+/**
+ * xilinx_pcie_clear_err_interrupts - Clear Error Interrupts
+ * @pcie: PCIe port information
+ */
+static void xilinx_pcie_clear_err_interrupts(struct xilinx_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	unsigned long val = pcie_read(pcie, XILINX_PCIE_REG_RPEFR);
+
+	if (val & XILINX_PCIE_RPEFR_ERR_VALID) {
+		dev_dbg(dev, "Requester ID %lu\n",
+			val & XILINX_PCIE_RPEFR_REQ_ID);
+		pcie_write(pcie, XILINX_PCIE_RPEFR_ALL_MASK,
+			   XILINX_PCIE_REG_RPEFR);
+	}
+}
+
+/**
+ * xilinx_pcie_valid_device - Check if a valid device is present on bus
+ * @bus: PCI Bus structure
+ * @devfn: device/function
+ *
+ * Return: 'true' on success and 'false' if invalid device is found
+ */
+static bool xilinx_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
+{
+	struct xilinx_pcie *pcie = bus->sysdata;
+
+	/* Check if link is up when trying to access downstream pcie ports */
+	if (!pci_is_root_bus(bus)) {
+		if (!xilinx_pcie_link_up(pcie))
+			return false;
+	} else if (devfn > 0) {
+		/* Only one device down on each root port */
+		return false;
+	}
+	return true;
+}
+
+/**
+ * xilinx_pcie_map_bus - Get configuration base
+ * @bus: PCI Bus structure
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ *	   accessed.
+ */
+static void __iomem *xilinx_pcie_map_bus(struct pci_bus *bus,
+					 unsigned int devfn, int where)
+{
+	struct xilinx_pcie *pcie = bus->sysdata;
+
+	if (!xilinx_pcie_valid_device(bus, devfn))
+		return NULL;
+
+	return pcie->reg_base + PCIE_ECAM_OFFSET(bus->number, devfn, where);
+}
+
+/* PCIe operations */
+static struct pci_ops xilinx_pcie_ops = {
+	.map_bus = xilinx_pcie_map_bus,
+	.read	= pci_generic_config_read,
+	.write	= pci_generic_config_write,
+};
+
+/* MSI functions */
+
+static void xilinx_msi_top_irq_ack(struct irq_data *d)
+{
+	/*
+	 * xilinx_pcie_intr_handler() will have performed the Ack.
+	 * Eventually, this should be fixed and the Ack be moved in
+	 * the respective callbacks for INTx and MSI.
+	 */
+}
+
+static void xilinx_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct xilinx_pcie *pcie = irq_data_get_irq_chip_data(data);
+	phys_addr_t pa = ALIGN_DOWN(virt_to_phys(pcie), SZ_4K);
+
+	msg->address_lo = lower_32_bits(pa);
+	msg->address_hi = upper_32_bits(pa);
+	msg->data = data->hwirq;
+}
+
+static struct irq_chip xilinx_msi_bottom_chip = {
+	.name			= "Xilinx MSI",
+	.irq_compose_msi_msg	= xilinx_compose_msi_msg,
+};
+
+static int xilinx_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs, void *args)
+{
+	struct xilinx_pcie *pcie = domain->host_data;
+	int hwirq, i;
+
+	mutex_lock(&pcie->map_lock);
+
+	hwirq = bitmap_find_free_region(pcie->msi_map, XILINX_NUM_MSI_IRQS, order_base_2(nr_irqs));
+
+	mutex_unlock(&pcie->map_lock);
+
+	if (hwirq < 0)
+		return -ENOSPC;
+
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &xilinx_msi_bottom_chip, domain->host_data,
+				    handle_edge_irq, NULL, NULL);
+
+	return 0;
+}
+
+static void xilinx_msi_domain_free(struct irq_domain *domain, unsigned int virq,
+				  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+	struct xilinx_pcie *pcie = domain->host_data;
+
+	mutex_lock(&pcie->map_lock);
+
+	bitmap_release_region(pcie->msi_map, d->hwirq, order_base_2(nr_irqs));
+
+	mutex_unlock(&pcie->map_lock);
+}
+
+static const struct irq_domain_ops xilinx_msi_domain_ops = {
+	.alloc	= xilinx_msi_domain_alloc,
+	.free	= xilinx_msi_domain_free,
+};
+
+static bool xilinx_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+				     struct irq_domain *real_parent, struct msi_domain_info *info)
+{
+	struct irq_chip *chip = info->chip;
+
+	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
+		return false;
+
+	chip->irq_ack = xilinx_msi_top_irq_ack;
+	return true;
+}
+
+#define XILINX_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS	| \
+				   MSI_FLAG_USE_DEF_CHIP_OPS	| \
+				   MSI_FLAG_NO_AFFINITY)
+
+static const struct msi_parent_ops xilinx_msi_parent_ops = {
+	.required_flags		= XILINX_MSI_FLAGS_REQUIRED,
+	.supported_flags	= MSI_GENERIC_FLAGS_MASK,
+	.bus_select_token	= DOMAIN_BUS_PCI_MSI,
+	.prefix			= "xilinx-",
+	.init_dev_msi_info	= xilinx_init_dev_msi_info,
+};
+
+static int xilinx_allocate_msi_domains(struct xilinx_pcie *pcie)
+{
+	struct irq_domain_info info = {
+		.fwnode		= dev_fwnode(pcie->dev),
+		.ops		= &xilinx_msi_domain_ops,
+		.host_data	= pcie,
+		.size		= XILINX_NUM_MSI_IRQS,
+	};
+
+	pcie->msi_domain = msi_create_parent_irq_domain(&info, &xilinx_msi_parent_ops);
+	if (!pcie->msi_domain) {
+		dev_err(pcie->dev, "failed to create MSI domain\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void xilinx_free_irq_domains(struct xilinx_pcie *pcie)
+{
+	irq_domain_remove(pcie->msi_domain);
+	irq_domain_remove(pcie->leg_domain);
+}
+
+/* INTx Functions */
+
+/**
+ * xilinx_pcie_intx_map - Set the handler for the INTx and mark IRQ as valid
+ * @domain: IRQ domain
+ * @irq: Virtual IRQ number
+ * @hwirq: HW interrupt number
+ *
+ * Return: Always returns 0.
+ */
+static int xilinx_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+				irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+/* INTx IRQ Domain operations */
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = xilinx_pcie_intx_map,
+	.xlate = pci_irqd_intx_xlate,
+};
+
+/* PCIe HW Functions */
+
+/**
+ * xilinx_pcie_intr_handler - Interrupt Service Handler
+ * @irq: IRQ number
+ * @data: PCIe port information
+ *
+ * Return: IRQ_HANDLED on success and IRQ_NONE on failure
+ */
+static irqreturn_t xilinx_pcie_intr_handler(int irq, void *data)
+{
+	struct xilinx_pcie *pcie = (struct xilinx_pcie *)data;
+	struct device *dev = pcie->dev;
+	u32 val, mask, status;
+
+	/* Read interrupt decode and mask registers */
+	val = pcie_read(pcie, XILINX_PCIE_REG_IDR);
+	mask = pcie_read(pcie, XILINX_PCIE_REG_IMR);
+
+	status = val & mask;
+	if (!status)
+		return IRQ_NONE;
+
+	if (status & XILINX_PCIE_INTR_LINK_DOWN)
+		dev_warn(dev, "Link Down\n");
+
+	if (status & XILINX_PCIE_INTR_ECRC_ERR)
+		dev_warn(dev, "ECRC failed\n");
+
+	if (status & XILINX_PCIE_INTR_STR_ERR)
+		dev_warn(dev, "Streaming error\n");
+
+	if (status & XILINX_PCIE_INTR_HOT_RESET)
+		dev_info(dev, "Hot reset\n");
+
+	if (status & XILINX_PCIE_INTR_CFG_TIMEOUT)
+		dev_warn(dev, "ECAM access timeout\n");
+
+	if (status & XILINX_PCIE_INTR_CORRECTABLE) {
+		dev_warn(dev, "Correctable error message\n");
+		xilinx_pcie_clear_err_interrupts(pcie);
+	}
+
+	if (status & XILINX_PCIE_INTR_NONFATAL) {
+		dev_warn(dev, "Non fatal error message\n");
+		xilinx_pcie_clear_err_interrupts(pcie);
+	}
+
+	if (status & XILINX_PCIE_INTR_FATAL) {
+		dev_warn(dev, "Fatal error message\n");
+		xilinx_pcie_clear_err_interrupts(pcie);
+	}
+
+	if (status & (XILINX_PCIE_INTR_INTX | XILINX_PCIE_INTR_MSI)) {
+		struct irq_domain *domain;
+
+		val = pcie_read(pcie, XILINX_PCIE_REG_RPIFR1);
+
+		/* Check whether interrupt valid */
+		if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID)) {
+			dev_warn(dev, "RP Intr FIFO1 read error\n");
+			goto error;
+		}
+
+		/* Decode the IRQ number */
+		if (val & XILINX_PCIE_RPIFR1_MSI_INTR) {
+			val = pcie_read(pcie, XILINX_PCIE_REG_RPIFR2) &
+				XILINX_PCIE_RPIFR2_MSG_DATA;
+			domain = pcie->msi_domain;
+		} else {
+			val = (val & XILINX_PCIE_RPIFR1_INTR_MASK) >>
+				XILINX_PCIE_RPIFR1_INTR_SHIFT;
+			domain = pcie->leg_domain;
+		}
+
+		/* Clear interrupt FIFO register 1 */
+		pcie_write(pcie, XILINX_PCIE_RPIFR1_ALL_MASK,
+			   XILINX_PCIE_REG_RPIFR1);
+
+		generic_handle_domain_irq(domain, val);
+	}
+
+	if (status & XILINX_PCIE_INTR_SLV_UNSUPP)
+		dev_warn(dev, "Slave unsupported request\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_UNEXP)
+		dev_warn(dev, "Slave unexpected completion\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_COMPL)
+		dev_warn(dev, "Slave completion timeout\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_ERRP)
+		dev_warn(dev, "Slave Error Poison\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_CMPABT)
+		dev_warn(dev, "Slave Completer Abort\n");
+
+	if (status & XILINX_PCIE_INTR_SLV_ILLBUR)
+		dev_warn(dev, "Slave Illegal Burst\n");
+
+	if (status & XILINX_PCIE_INTR_MST_DECERR)
+		dev_warn(dev, "Master decode error\n");
+
+	if (status & XILINX_PCIE_INTR_MST_SLVERR)
+		dev_warn(dev, "Master slave error\n");
+
+	if (status & XILINX_PCIE_INTR_MST_ERRP)
+		dev_warn(dev, "Master error poison\n");
+
+error:
+	/* Clear the Interrupt Decode register */
+	pcie_write(pcie, status, XILINX_PCIE_REG_IDR);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * xilinx_pcie_init_irq_domain - Initialize IRQ domain
+ * @pcie: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_init_irq_domain(struct xilinx_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *pcie_intc_node;
+	int ret;
+
+	/* Setup INTx */
+	pcie_intc_node = of_get_next_child(dev->of_node, NULL);
+	if (!pcie_intc_node) {
+		dev_err(dev, "No PCIe Intc node found\n");
+		return -ENODEV;
+	}
+
+	pcie->leg_domain = irq_domain_create_linear(of_fwnode_handle(pcie_intc_node), PCI_NUM_INTX,
+						    &intx_domain_ops, pcie);
+	of_node_put(pcie_intc_node);
+	if (!pcie->leg_domain) {
+		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		return -ENODEV;
+	}
+
+	/* Setup MSI */
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		phys_addr_t pa = ALIGN_DOWN(virt_to_phys(pcie), SZ_4K);
+
+		ret = xilinx_allocate_msi_domains(pcie);
+		if (ret) {
+			irq_domain_remove(pcie->leg_domain);
+			return ret;
+		}
+
+		pcie_write(pcie, upper_32_bits(pa), XILINX_PCIE_REG_MSIBASE1);
+		pcie_write(pcie, lower_32_bits(pa), XILINX_PCIE_REG_MSIBASE2);
+	}
+
+	return 0;
+}
+
+/**
+ * xilinx_pcie_init_port - Initialize hardware
+ * @pcie: PCIe port information
+ */
+static void xilinx_pcie_init_port(struct xilinx_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+
+	if (xilinx_pcie_link_up(pcie))
+		dev_info(dev, "PCIe Link is UP\n");
+	else
+		dev_info(dev, "PCIe Link is DOWN\n");
+
+	/* Disable all interrupts */
+	pcie_write(pcie, ~XILINX_PCIE_IDR_ALL_MASK,
+		   XILINX_PCIE_REG_IMR);
+
+	/* Clear pending interrupts */
+	pcie_write(pcie, pcie_read(pcie, XILINX_PCIE_REG_IDR) &
+			 XILINX_PCIE_IMR_ALL_MASK,
+		   XILINX_PCIE_REG_IDR);
+
+	/* Enable all interrupts we handle */
+	pcie_write(pcie, XILINX_PCIE_IMR_ENABLE_MASK, XILINX_PCIE_REG_IMR);
+
+	/* Enable the Bridge enable bit */
+	pcie_write(pcie, pcie_read(pcie, XILINX_PCIE_REG_RPSC) |
+			 XILINX_PCIE_REG_RPSC_BEN,
+		   XILINX_PCIE_REG_RPSC);
+}
+
+/**
+ * xilinx_pcie_parse_dt - Parse Device tree
+ * @pcie: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_parse_dt(struct xilinx_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *node = dev->of_node;
+	struct resource regs;
+	unsigned int irq;
+	int err;
+
+	err = of_address_to_resource(node, 0, &regs);
+	if (err) {
+		dev_err(dev, "missing \"reg\" property\n");
+		return err;
+	}
+
+	pcie->reg_base = devm_pci_remap_cfg_resource(dev, &regs);
+	if (IS_ERR(pcie->reg_base))
+		return PTR_ERR(pcie->reg_base);
+
+	irq = irq_of_parse_and_map(node, 0);
+	err = devm_request_irq(dev, irq, xilinx_pcie_intr_handler,
+			       IRQF_SHARED | IRQF_NO_THREAD,
+			       "xilinx-pcie", pcie);
+	if (err) {
+		dev_err(dev, "unable to request irq %d\n", irq);
+		return err;
+	}
+
+	return 0;
+}
+
+/**
+ * xilinx_pcie_probe - Probe function
+ * @pdev: Platform device pointer
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct xilinx_pcie *pcie;
+	struct pci_host_bridge *bridge;
+	int err;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+	if (!bridge)
+		return -ENODEV;
+
+	pcie = pci_host_bridge_priv(bridge);
+	mutex_init(&pcie->map_lock);
+	pcie->dev = dev;
+
+	err = xilinx_pcie_parse_dt(pcie);
+	if (err) {
+		dev_err(dev, "Parsing DT failed\n");
+		return err;
+	}
+
+	xilinx_pcie_init_port(pcie);
+
+	err = xilinx_pcie_init_irq_domain(pcie);
+	if (err) {
+		dev_err(dev, "Failed creating IRQ Domain\n");
+		return err;
+	}
+
+	bridge->sysdata = pcie;
+	bridge->ops = &xilinx_pcie_ops;
+
+	err = pci_host_probe(bridge);
+	if (err)
+		xilinx_free_irq_domains(pcie);
+
+	return err;
+}
+
+static const struct of_device_id xilinx_pcie_of_match[] = {
+	{ .compatible = "xlnx,axi-pcie-host-1.00.a", },
+	{}
+};
+
+static struct platform_driver xilinx_pcie_driver = {
+	.driver = {
+		.name = "xilinx-pcie",
+		.of_match_table = xilinx_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = xilinx_pcie_probe,
+};
+builtin_platform_driver(xilinx_pcie_driver);