diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index c7d2fa1..ebf976a 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -96,3 +96,56 @@ Example:
 		      <0x2c006000 0x2000>;
 		interrupts = <1 9 0xf04>;
 	};
+
+
+* GICv2m extension for MSI/MSI-x support (Optional)
+
+Certain revisions of GIC-400 supports MSI/MSI-x via V2M register frame(s).
+This is enabled by specifying v2m sub-node(s).
+
+Required properties:
+
+- compatible        : The value here should contain "arm,gic-v2m-frame".
+
+- msi-controller    : Identifies the node as an MSI controller.
+
+- reg               : GICv2m MSI interface register base and size
+
+Optional properties:
+
+- arm,msi-base-spi  : When the MSI_TYPER register contains an incorrect
+                      value, this property should contain the SPI base of
+                      the MSI frame, overriding the HW value.
+
+- arm,msi-num-spis  : When the MSI_TYPER register contains an incorrect
+                      value, this property should contain the number of
+                      SPIs assigned to the frame, overriding the HW value.
+
+Example:
+
+	interrupt-controller@e1101000 {
+		compatible = "arm,gic-400";
+		#interrupt-cells = <3>;
+		#address-cells = <2>;
+		#size-cells = <2>;
+		interrupt-controller;
+		interrupts = <1 8 0xf04>;
+		ranges = <0 0 0 0xe1100000 0 0x100000>;
+		reg = <0x0 0xe1110000 0 0x01000>,
+		      <0x0 0xe112f000 0 0x02000>,
+		      <0x0 0xe1140000 0 0x10000>,
+		      <0x0 0xe1160000 0 0x10000>;
+		v2m0: v2m@0x8000 {
+			compatible = "arm,gic-v2m-frame";
+			msi-controller;
+			reg = <0x0 0x80000 0 0x1000>;
+		};
+
+		....
+
+		v2mN: v2m@0x9000 {
+			compatible = "arm,gic-v2m-frame";
+			msi-controller;
+			reg = <0x0 0x90000 0 0x1000>;
+		};
+	};
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index cde2f72..cbcde2d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -12,6 +12,7 @@ config ARM64
 	select ARM_ARCH_TIMER
 	select ARM_GIC
 	select AUDIT_ARCH_COMPAT_GENERIC
+	select ARM_GIC_V2M
 	select ARM_GIC_V3
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 2a48e0a..39ce065 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -8,6 +8,11 @@ config ARM_GIC
 	select IRQ_DOMAIN_HIERARCHY
 	select MULTI_IRQ_HANDLER
 
+config ARM_GIC_V2M
+	bool
+	depends on ARM_GIC
+	depends on PCI && PCI_MSI
+
 config GIC_NON_BANKED
 	bool
 
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 73052ba..3bda951 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_SUNXI)		+= irq-sun4i.o
 obj-$(CONFIG_ARCH_SUNXI)		+= irq-sunxi-nmi.o
 obj-$(CONFIG_ARCH_SPEAR3XX)		+= spear-shirq.o
 obj-$(CONFIG_ARM_GIC)			+= irq-gic.o irq-gic-common.o
+obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-common.o
 obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
 obj-$(CONFIG_ARM_VIC)			+= irq-vic.o
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
new file mode 100644
index 0000000..d82b668
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -0,0 +1,395 @@
+/*
+ * ARM GIC v2m MSI(-X) support
+ * Support for Message Signaled Interrupts for systems that
+ * implement ARM Generic Interrupt Controller: GICv2m.
+ *
+ * Copyright (C) 2014 Advanced Micro Devices, Inc.
+ * Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
+ *          Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
+ *          Brandon Anderson <brandon.anderson@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "GICv2m: " fmt
+
+#include <linux/bitmap.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <asm/hardirq.h>
+#include <asm/irq.h>
+
+#include "irqchip.h"
+#include "irq-gic-v2m.h"
+
+/*
+* MSI_TYPER:
+*     [31:26] Reserved
+*     [25:16] lowest SPI assigned to MSI
+*     [15:10] Reserved
+*     [9:0]   Numer of SPIs assigned to MSI
+*/
+#define V2M_MSI_TYPER			0x008
+#define V2M_MSI_TYPER_BASE_SHIFT	16
+#define V2M_MSI_TYPER_BASE_MASK		0x3FF
+#define V2M_MSI_TYPER_NUM_MASK		0x3FF
+#define V2M_MSI_SETSPI_NS		0x040
+#define V2M_MIN_SPI			32
+#define V2M_MAX_SPI			1019
+
+#define V2M_MSI_TYPER_BASE_SPI(x)	\
+		(((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
+
+#define V2M_MSI_TYPER_NUM_SPI(x)	((x) & V2M_MSI_TYPER_NUM_MASK)
+
+struct v2m_data {
+	struct list_head list;
+	spinlock_t msi_cnt_lock;
+	struct msi_chip msi_chip;
+	struct resource res;      /* GICv2m resource */
+	void __iomem *base;       /* GICv2m virt address */
+	unsigned int spi_start;   /* The SPI number that MSIs start */
+	unsigned int nr_spis;     /* The number of SPIs for MSIs */
+	unsigned long *bm;        /* MSI vector bitmap */
+	struct irq_domain *domain;
+};
+
+static struct irq_chip v2m_chip;
+
+/*
+ * alloc_msi_irq - Allocate MSIs from available MSI bitmap.
+ * @data: Pointer to v2m_data
+ * @nvec: Number of interrupts to allocate
+ * @irq: Pointer to the allocated irq
+ *
+ * Allocates interrupts only if the contiguous range of MSIs
+ * with specified nvec are available. Otherwise return the number
+ * of available interrupts. If none are available, then returns -ENOENT.
+ */
+static int alloc_msi_irq(struct v2m_data *data, int nvec, int *irq)
+{
+	int size = data->nr_spis;
+	int next = size, i = nvec, ret;
+
+	/* We should never allocate more than available nr_spis */
+	if (i >= size)
+		i = size;
+
+	spin_lock(&data->msi_cnt_lock);
+
+	for (; i > 0; i--) {
+		next = bitmap_find_next_zero_area(data->bm,
+					size, 0, i, 0);
+		if (next < size)
+			break;
+	}
+
+	if (i != nvec) {
+		ret = i ? : -ENOENT;
+	} else {
+		bitmap_set(data->bm, next, nvec);
+		*irq = data->spi_start + next;
+		ret = 0;
+	}
+
+	spin_unlock(&data->msi_cnt_lock);
+
+	return ret;
+}
+
+static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq)
+{
+	int pos;
+	struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
+
+	spin_lock(&data->msi_cnt_lock);
+
+	pos = irq - data->spi_start;
+	if (pos >= 0 && pos < data->nr_spis)
+		bitmap_clear(data->bm, pos, 1);
+
+	spin_unlock(&data->msi_cnt_lock);
+}
+
+static int gicv2m_setup_msi_irq(struct msi_chip *chip, struct pci_dev *pdev,
+				struct msi_desc *desc)
+{
+	int hwirq = 0, virq, avail;
+	struct v2m_data *v2m = container_of(chip, struct v2m_data, msi_chip);
+
+	if (!desc) {
+		dev_err(&pdev->dev,
+			"MSI setup failed. Invalid msi descriptor\n");
+		return -EINVAL;
+	}
+
+	avail = alloc_msi_irq(v2m, 1, &hwirq);
+	if (avail != 0) {
+		dev_err(&pdev->dev,
+			"MSI setup failed. Cannnot allocate IRQ\n");
+		return -ENOSPC;
+	}
+
+	virq = __irq_domain_alloc_irqs(v2m->domain, hwirq,
+				       1, NUMA_NO_NODE, v2m, true);
+	if (virq < 0)
+		return -EINVAL;
+
+	irq_domain_set_hwirq_and_chip(v2m->domain, virq, hwirq,
+				&v2m_chip, v2m);
+
+
+	irq_set_msi_desc(hwirq, desc);
+	irq_set_irq_type(hwirq, IRQ_TYPE_EDGE_RISING);
+
+	return 0;
+}
+
+static int gicv2m_domain_activate(struct irq_domain *domain,
+				      struct irq_data *data)
+{
+	struct msi_msg msg;
+	struct v2m_data *v2m;
+	phys_addr_t addr;
+
+	v2m = container_of(data->chip_data, struct v2m_data, msi_chip);
+	addr = v2m->res.start + V2M_MSI_SETSPI_NS;
+
+	msg.address_hi = (u32)(addr >> 32);
+	msg.address_lo = (u32)(addr);
+	msg.data = data->irq;
+	write_msi_msg(data->irq, &msg);
+
+	return 0;
+}
+
+static int gicv2m_domain_deactivate(struct irq_domain *domain,
+				    struct irq_data *data)
+{
+	struct msi_msg msg;
+
+	memset(&msg, 0, sizeof(msg));
+	write_msi_msg(data->irq, &msg);
+
+	return 0;
+}
+
+static int gicv2m_domain_alloc(struct irq_domain *d, unsigned int virq,
+			       unsigned int nr_irqs, void *arg)
+{
+	int i, ret, irq;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq = virq + i;
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+		irq_set_chip_and_handler_name(irq, &v2m_chip,
+			handle_fasteoi_irq, v2m_chip.name);
+	}
+
+	ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, NULL);
+	if (ret < 0)
+		pr_err("Failed to allocate parent IRQ domain\n");
+
+	return ret;
+}
+
+static void gicv2m_domain_free(struct irq_domain *d, unsigned int virq,
+			       unsigned int nr_irqs)
+{
+	int i, irq;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq = virq + i;
+		irq_set_handler(irq, NULL);
+		irq_domain_set_hwirq_and_chip(d, irq, 0, NULL, NULL);
+	}
+
+	irq_domain_free_irqs_parent(d, virq, nr_irqs);
+}
+
+static bool is_msi_spi_valid(u32 base, u32 num)
+{
+	if (base < V2M_MIN_SPI) {
+		pr_err("Invalid MSI base SPI (base:%u)\n", base);
+		return false;
+	}
+
+	if ((num == 0) || (base + num > V2M_MAX_SPI)) {
+		pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
+		       num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
+		return false;
+	}
+
+	return true;
+}
+
+static void gicv2m_mask_irq(struct irq_data *d)
+{
+	irq_chip_mask_parent(d);
+	if (d->msi_desc)
+		mask_msi_irq(d);
+}
+
+static void gicv2m_unmask_irq(struct irq_data *d)
+{
+	irq_chip_unmask_parent(d);
+	if (d->msi_desc)
+		unmask_msi_irq(d);
+}
+
+static struct irq_chip v2m_chip = {
+	.name             = "GICv2m",
+	.irq_mask         = gicv2m_mask_irq,
+	.irq_unmask       = gicv2m_unmask_irq,
+	.irq_eoi          = irq_chip_eoi_parent,
+	.irq_set_type     = irq_chip_set_type_parent,
+
+#ifdef CONFIG_SMP
+	.irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+};
+
+static const struct irq_domain_ops gicv2m_domain_ops = {
+	.alloc      = gicv2m_domain_alloc,
+	.free       = gicv2m_domain_free,
+	.activate   = gicv2m_domain_activate,
+	.deactivate = gicv2m_domain_deactivate,
+};
+
+static int __init
+gicv2m_init_one(struct device_node *node,
+		struct v2m_data **v,
+		struct irq_domain *parent)
+{
+	int ret;
+	struct v2m_data *v2m;
+
+	*v = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
+	if (!*v) {
+		pr_err("Failed to allocate struct v2m_data.\n");
+		return -ENOMEM;
+	}
+
+	v2m = *v;
+	v2m->msi_chip.owner = THIS_MODULE;
+	v2m->msi_chip.of_node = node;
+	v2m->msi_chip.setup_irq = gicv2m_setup_msi_irq;
+	v2m->msi_chip.teardown_irq = gicv2m_teardown_msi_irq;
+	ret = of_address_to_resource(node, 0, &v2m->res);
+	if (ret) {
+		pr_err("Failed to allocate v2m resource.\n");
+		goto err_out;
+	}
+
+	v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
+	if (!v2m->base) {
+		pr_err("Failed to map GICv2m resource\n");
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	ret = of_pci_msi_chip_add(&v2m->msi_chip);
+	if (ret) {
+		pr_info("Failed to add msi_chip.\n");
+		goto err_out;
+	}
+
+	if (!of_property_read_u32(node, "arm,msi-base-spi", &v2m->spi_start) &&
+	    !of_property_read_u32(node, "arm,msi-num-spis", &v2m->nr_spis)) {
+		pr_info("Overriding V2M MSI_TYPER (base:%u, num:%u)\n",
+			v2m->spi_start, v2m->nr_spis);
+	} else {
+		u32 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
+
+		v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
+		v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
+	}
+
+	if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
+			  GFP_KERNEL);
+	if (!v2m->bm) {
+		pr_err("Failed to allocate MSI bitmap\n");
+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	v2m->domain = irq_domain_add_simple(node, v2m->nr_spis, v2m->spi_start,
+					    &gicv2m_domain_ops, v2m);
+	if (!v2m->domain) {
+		pr_err("Failed to create GICv2m domain\n");
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	v2m->domain->parent = parent;
+
+	spin_lock_init(&v2m->msi_cnt_lock);
+
+	pr_info("Node %s: range[%#lx:%#lx], SPI[%d:%d]\n", node->name,
+		(unsigned long)v2m->res.start, (unsigned long)v2m->res.end,
+		v2m->spi_start, (v2m->spi_start + v2m->nr_spis));
+
+	return 0;
+err_out:
+	of_pci_msi_chip_remove(&v2m->msi_chip);
+	if (v2m->base)
+		iounmap(v2m->base);
+	if (v2m->bm)
+		kzfree(v2m->bm);
+	kfree(v2m);
+	return ret;
+}
+
+int __init gicv2m_of_init(struct device_node *node,
+			  struct irq_domain *parent,
+			  struct list_head *v2m_list)
+{
+	int ret = 0;
+	struct v2m_data *v2m;
+	struct device_node *child = NULL;
+
+	INIT_LIST_HEAD(v2m_list);
+
+	for (;;) {
+		child = of_get_next_child(node, child);
+		if (!child)
+			break;
+
+		if (!of_device_is_compatible(child, "arm,gic-v2m-frame"))
+			continue;
+
+		if (!of_find_property(child, "msi-controller", NULL))
+			continue;
+
+		ret = gicv2m_init_one(child, &v2m, parent);
+		if (ret) {
+			of_node_put(node);
+			break;
+		}
+
+		list_add_tail(&v2m->list, v2m_list);
+	}
+
+	if (ret && list_empty(v2m_list)) {
+		pr_warn("Warning: Failed to enable GICv2m support.\n");
+		return -EINVAL;
+	}
+
+	return ret;
+}
diff --git a/drivers/irqchip/irq-gic-v2m.h b/drivers/irqchip/irq-gic-v2m.h
new file mode 100644
index 0000000..b5ae787
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.h
@@ -0,0 +1,7 @@
+#ifndef _IRQ_GIC_V2M_H_
+#define _IRQ_GIC_V2M_H_
+
+extern int gicv2m_of_init(struct device_node *node, struct irq_domain *parent,
+			  struct list_head *v2m_list) __init;
+
+#endif /* _IRQ_GIC_V2M_H_ */
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index a99c211..4069eb3 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -46,6 +46,7 @@
 #include <asm/smp_plat.h>
 
 #include "irq-gic-common.h"
+#include "irq-gic-v2m.h"
 #include "irqchip.h"
 
 union gic_base {
@@ -68,6 +69,9 @@ struct gic_chip_data {
 #ifdef CONFIG_GIC_NON_BANKED
 	void __iomem *(*get_base)(union gic_base *);
 #endif
+#ifdef CONFIG_ARM_GIC_V2M
+	struct list_head v2m_list;
+#endif
 };
 
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
@@ -843,10 +847,14 @@ static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 	unsigned int type = IRQ_TYPE_NONE;
 	struct of_phandle_args *irq_data = arg;
 
-	ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
-				   irq_data->args_count, &hwirq, &type);
-	if (ret)
-		return ret;
+	if (irq_data) {
+		ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
+					   irq_data->args_count, &hwirq, &type);
+		if (ret)
+			return ret;
+	} else {
+		hwirq = virq;
+	}
 
 	for (i = 0; i < nr_irqs; i++)
 		gic_irq_domain_map(domain, virq+i, hwirq+i);
@@ -1055,6 +1063,11 @@ gic_of_init(struct device_node *node, struct device_node *parent)
 		irq = irq_of_parse_and_map(node, 0);
 		gic_cascade_irq(gic_cnt, irq);
 	}
+
+	if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
+		gicv2m_of_init(node, gic_data[gic_cnt].domain,
+			       &gic_data[gic_cnt].v2m_list);
+
 	gic_cnt++;
 	return 0;
 }
