diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index aab25f3..5c9aaed 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -750,6 +750,17 @@
 	depends on PCI
 	default y
 
+config DMAR
+	bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
+	depends on PCI_MSI && ACPI && EXPERIMENTAL
+	default y
+	help
+	  DMA remapping(DMAR) devices support enables independent address
+	  translations for Direct Memory Access(DMA) from Devices.
+	  These DMA remapping devices are reported via ACPI tables
+	  and includes pci device scope covered by these DMA
+	  remapping device.
+
 source "drivers/pci/pcie/Kconfig"
 
 source "drivers/pci/Kconfig"
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 006054a..836ab2f 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -20,6 +20,9 @@
 # Build the Hypertransport interrupt support
 obj-$(CONFIG_HT_IRQ) += htirq.o
 
+# Build Intel IOMMU support
+obj-$(CONFIG_DMAR) += dmar.o
+
 #
 # Some architectures use the generic PCI setup functions
 #
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
new file mode 100644
index 0000000..5dfdfda
--- /dev/null
+++ b/drivers/pci/dmar.c
@@ -0,0 +1,329 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * 	Copyright (C) Ashok Raj <ashok.raj@intel.com>
+ *	Copyright (C) Shaohua Li <shaohua.li@intel.com>
+ *	Copyright (C) Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *
+ * 	This file implements early detection/parsing of DMA Remapping Devices
+ * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
+ * tables.
+ */
+
+#include <linux/pci.h>
+#include <linux/dmar.h>
+
+#undef PREFIX
+#define PREFIX "DMAR:"
+
+/* No locks are needed as DMA remapping hardware unit
+ * list is constructed at boot time and hotplug of
+ * these units are not supported by the architecture.
+ */
+LIST_HEAD(dmar_drhd_units);
+LIST_HEAD(dmar_rmrr_units);
+
+static struct acpi_table_header * __initdata dmar_tbl;
+
+static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
+{
+	/*
+	 * add INCLUDE_ALL at the tail, so scan the list will find it at
+	 * the very end.
+	 */
+	if (drhd->include_all)
+		list_add_tail(&drhd->list, &dmar_drhd_units);
+	else
+		list_add(&drhd->list, &dmar_drhd_units);
+}
+
+static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
+{
+	list_add(&rmrr->list, &dmar_rmrr_units);
+}
+
+static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
+					   struct pci_dev **dev, u16 segment)
+{
+	struct pci_bus *bus;
+	struct pci_dev *pdev = NULL;
+	struct acpi_dmar_pci_path *path;
+	int count;
+
+	bus = pci_find_bus(segment, scope->bus);
+	path = (struct acpi_dmar_pci_path *)(scope + 1);
+	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
+		/ sizeof(struct acpi_dmar_pci_path);
+
+	while (count) {
+		if (pdev)
+			pci_dev_put(pdev);
+		/*
+		 * Some BIOSes list non-exist devices in DMAR table, just
+		 * ignore it
+		 */
+		if (!bus) {
+			printk(KERN_WARNING
+			PREFIX "Device scope bus [%d] not found\n",
+			scope->bus);
+			break;
+		}
+		pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
+		if (!pdev) {
+			printk(KERN_WARNING PREFIX
+			"Device scope device [%04x:%02x:%02x.%02x] not found\n",
+				segment, bus->number, path->dev, path->fn);
+			break;
+		}
+		path ++;
+		count --;
+		bus = pdev->subordinate;
+	}
+	if (!pdev) {
+		printk(KERN_WARNING PREFIX
+		"Device scope device [%04x:%02x:%02x.%02x] not found\n",
+		segment, scope->bus, path->dev, path->fn);
+		*dev = NULL;
+		return 0;
+	}
+	if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
+			pdev->subordinate) || (scope->entry_type == \
+			ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
+		pci_dev_put(pdev);
+		printk(KERN_WARNING PREFIX
+			"Device scope type does not match for %s\n",
+			 pci_name(pdev));
+		return -EINVAL;
+	}
+	*dev = pdev;
+	return 0;
+}
+
+static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
+				       struct pci_dev ***devices, u16 segment)
+{
+	struct acpi_dmar_device_scope *scope;
+	void * tmp = start;
+	int index;
+	int ret;
+
+	*cnt = 0;
+	while (start < end) {
+		scope = start;
+		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
+		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
+			(*cnt)++;
+		else
+			printk(KERN_WARNING PREFIX
+				"Unsupported device scope\n");
+		start += scope->length;
+	}
+	if (*cnt == 0)
+		return 0;
+
+	*devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
+	if (!*devices)
+		return -ENOMEM;
+
+	start = tmp;
+	index = 0;
+	while (start < end) {
+		scope = start;
+		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
+		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
+			ret = dmar_parse_one_dev_scope(scope,
+				&(*devices)[index], segment);
+			if (ret) {
+				kfree(*devices);
+				return ret;
+			}
+			index ++;
+		}
+		start += scope->length;
+	}
+
+	return 0;
+}
+
+/**
+ * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
+ * structure which uniquely represent one DMA remapping hardware unit
+ * present in the platform
+ */
+static int __init
+dmar_parse_one_drhd(struct acpi_dmar_header *header)
+{
+	struct acpi_dmar_hardware_unit *drhd;
+	struct dmar_drhd_unit *dmaru;
+	int ret = 0;
+	static int include_all;
+
+	dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
+	if (!dmaru)
+		return -ENOMEM;
+
+	drhd = (struct acpi_dmar_hardware_unit *)header;
+	dmaru->reg_base_addr = drhd->address;
+	dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
+
+	if (!dmaru->include_all)
+		ret = dmar_parse_dev_scope((void *)(drhd + 1),
+				((void *)drhd) + header->length,
+				&dmaru->devices_cnt, &dmaru->devices,
+				drhd->segment);
+	else {
+		/* Only allow one INCLUDE_ALL */
+		if (include_all) {
+			printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
+				"device scope is allowed\n");
+			ret = -EINVAL;
+		}
+		include_all = 1;
+	}
+
+	if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
+		kfree(dmaru);
+	else
+		dmar_register_drhd_unit(dmaru);
+	return ret;
+}
+
+static int __init
+dmar_parse_one_rmrr(struct acpi_dmar_header *header)
+{
+	struct acpi_dmar_reserved_memory *rmrr;
+	struct dmar_rmrr_unit *rmrru;
+	int ret = 0;
+
+	rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
+	if (!rmrru)
+		return -ENOMEM;
+
+	rmrr = (struct acpi_dmar_reserved_memory *)header;
+	rmrru->base_address = rmrr->base_address;
+	rmrru->end_address = rmrr->end_address;
+	ret = dmar_parse_dev_scope((void *)(rmrr + 1),
+		((void *)rmrr) + header->length,
+		&rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
+
+	if (ret || (rmrru->devices_cnt == 0))
+		kfree(rmrru);
+	else
+		dmar_register_rmrr_unit(rmrru);
+	return ret;
+}
+
+static void __init
+dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
+{
+	struct acpi_dmar_hardware_unit *drhd;
+	struct acpi_dmar_reserved_memory *rmrr;
+
+	switch (header->type) {
+	case ACPI_DMAR_TYPE_HARDWARE_UNIT:
+		drhd = (struct acpi_dmar_hardware_unit *)header;
+		printk (KERN_INFO PREFIX
+			"DRHD (flags: 0x%08x)base: 0x%016Lx\n",
+			drhd->flags, drhd->address);
+		break;
+	case ACPI_DMAR_TYPE_RESERVED_MEMORY:
+		rmrr = (struct acpi_dmar_reserved_memory *)header;
+
+		printk (KERN_INFO PREFIX
+			"RMRR base: 0x%016Lx end: 0x%016Lx\n",
+			rmrr->base_address, rmrr->end_address);
+		break;
+	}
+}
+
+/**
+ * parse_dmar_table - parses the DMA reporting table
+ */
+static int __init
+parse_dmar_table(void)
+{
+	struct acpi_table_dmar *dmar;
+	struct acpi_dmar_header *entry_header;
+	int ret = 0;
+
+	dmar = (struct acpi_table_dmar *)dmar_tbl;
+	if (!dmar)
+		return -ENODEV;
+
+	if (!dmar->width) {
+		printk (KERN_WARNING PREFIX "Zero: Invalid DMAR haw\n");
+		return -EINVAL;
+	}
+
+	printk (KERN_INFO PREFIX "Host address width %d\n",
+		dmar->width + 1);
+
+	entry_header = (struct acpi_dmar_header *)(dmar + 1);
+	while (((unsigned long)entry_header) <
+			(((unsigned long)dmar) + dmar_tbl->length)) {
+		dmar_table_print_dmar_entry(entry_header);
+
+		switch (entry_header->type) {
+		case ACPI_DMAR_TYPE_HARDWARE_UNIT:
+			ret = dmar_parse_one_drhd(entry_header);
+			break;
+		case ACPI_DMAR_TYPE_RESERVED_MEMORY:
+			ret = dmar_parse_one_rmrr(entry_header);
+			break;
+		default:
+			printk(KERN_WARNING PREFIX
+				"Unknown DMAR structure type\n");
+			ret = 0; /* for forward compatibility */
+			break;
+		}
+		if (ret)
+			break;
+
+		entry_header = ((void *)entry_header + entry_header->length);
+	}
+	return ret;
+}
+
+
+int __init dmar_table_init(void)
+{
+
+	parse_dmar_table();
+	if (list_empty(&dmar_drhd_units)) {
+		printk(KERN_INFO PREFIX "No DMAR devices found\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/**
+ * early_dmar_detect - checks to see if the platform supports DMAR devices
+ */
+int __init early_dmar_detect(void)
+{
+	acpi_status status = AE_OK;
+
+	/* if we could find DMAR table, then there are DMAR devices */
+	status = acpi_get_table(ACPI_SIG_DMAR, 0,
+				(struct acpi_table_header **)&dmar_tbl);
+
+	if (ACPI_SUCCESS(status) && !dmar_tbl) {
+		printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
+		status = AE_NOT_FOUND;
+	}
+
+	return (ACPI_SUCCESS(status) ? 1 : 0);
+}
diff --git a/include/acpi/actbl1.h b/include/acpi/actbl1.h
index 4e5d3ca..a1b1b2e 100644
--- a/include/acpi/actbl1.h
+++ b/include/acpi/actbl1.h
@@ -257,7 +257,8 @@
 struct acpi_table_dmar {
 	struct acpi_table_header header;	/* Common ACPI table header */
 	u8 width;		/* Host Address Width */
-	u8 reserved[11];
+	u8 flags;
+	u8 reserved[10];
 };
 
 /* DMAR subtable header */
@@ -265,8 +266,6 @@
 struct acpi_dmar_header {
 	u16 type;
 	u16 length;
-	u8 flags;
-	u8 reserved[3];
 };
 
 /* Values for subtable type in struct acpi_dmar_header */
@@ -274,13 +273,15 @@
 enum acpi_dmar_type {
 	ACPI_DMAR_TYPE_HARDWARE_UNIT = 0,
 	ACPI_DMAR_TYPE_RESERVED_MEMORY = 1,
-	ACPI_DMAR_TYPE_RESERVED = 2	/* 2 and greater are reserved */
+	ACPI_DMAR_TYPE_ATSR = 2,
+	ACPI_DMAR_TYPE_RESERVED = 3	/* 3 and greater are reserved */
 };
 
 struct acpi_dmar_device_scope {
 	u8 entry_type;
 	u8 length;
-	u8 segment;
+	u16 reserved;
+	u8 enumeration_id;
 	u8 bus;
 };
 
@@ -290,7 +291,14 @@
 	ACPI_DMAR_SCOPE_TYPE_NOT_USED = 0,
 	ACPI_DMAR_SCOPE_TYPE_ENDPOINT = 1,
 	ACPI_DMAR_SCOPE_TYPE_BRIDGE = 2,
-	ACPI_DMAR_SCOPE_TYPE_RESERVED = 3	/* 3 and greater are reserved */
+	ACPI_DMAR_SCOPE_TYPE_IOAPIC = 3,
+	ACPI_DMAR_SCOPE_TYPE_HPET = 4,
+	ACPI_DMAR_SCOPE_TYPE_RESERVED = 5	/* 5 and greater are reserved */
+};
+
+struct acpi_dmar_pci_path {
+	u8 dev;
+	u8 fn;
 };
 
 /*
@@ -301,6 +309,9 @@
 
 struct acpi_dmar_hardware_unit {
 	struct acpi_dmar_header header;
+	u8 flags;
+	u8 reserved;
+	u16 segment;
 	u64 address;		/* Register Base Address */
 };
 
@@ -312,7 +323,9 @@
 
 struct acpi_dmar_reserved_memory {
 	struct acpi_dmar_header header;
-	u64 address;		/* 4_k aligned base address */
+	u16 reserved;
+	u16 segment;
+	u64 base_address;		/* 4_k aligned base address */
 	u64 end_address;	/* 4_k aligned limit address */
 };
 
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
new file mode 100644
index 0000000..8d3e0e3
--- /dev/null
+++ b/include/linux/dmar.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Copyright (C) Ashok Raj <ashok.raj@intel.com>
+ * Copyright (C) Shaohua Li <shaohua.li@intel.com>
+ */
+
+#ifndef __DMAR_H__
+#define __DMAR_H__
+
+#include <linux/acpi.h>
+#include <linux/types.h>
+
+
+extern int dmar_table_init(void);
+extern int early_dmar_detect(void);
+
+extern struct list_head dmar_drhd_units;
+extern struct list_head dmar_rmrr_units;
+
+struct dmar_drhd_unit {
+	struct list_head list;		/* list of drhd units	*/
+	u64	reg_base_addr;		/* register base address*/
+	struct	pci_dev **devices; 	/* target device array	*/
+	int	devices_cnt;		/* target device count	*/
+	u8	ignored:1; 		/* ignore drhd		*/
+	u8	include_all:1;
+	struct intel_iommu *iommu;
+};
+
+struct dmar_rmrr_unit {
+	struct list_head list;		/* list of rmrr units	*/
+	u64	base_address;		/* reserved base address*/
+	u64	end_address;		/* reserved end address */
+	struct pci_dev **devices;	/* target devices */
+	int	devices_cnt;		/* target device count */
+};
+
+#endif /* __DMAR_H__ */