Initial import

1 files changed, 4744 insertions, 0 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
new file mode 100644
index 000000000..5ecfaf299
--- /dev/null
+++ b/drivers/iommu/intel-iommu.c
@@ -0,0 +1,4744 @@
+/*
+ * Copyright © 2006-2014 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.
+ *
+ * Authors: David Woodhouse <dwmw2@infradead.org>,
+ *          Ashok Raj <ashok.raj@intel.com>,
+ *          Shaohua Li <shaohua.li@intel.com>,
+ *          Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
+ *          Fenghua Yu <fenghua.yu@intel.com>
+ */
+
+#include <linux/init.h>
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/dmar.h>
+#include <linux/dma-mapping.h>
+#include <linux/mempool.h>
+#include <linux/memory.h>
+#include <linux/timer.h>
+#include <linux/iova.h>
+#include <linux/iommu.h>
+#include <linux/intel-iommu.h>
+#include <linux/syscore_ops.h>
+#include <linux/tboot.h>
+#include <linux/dmi.h>
+#include <linux/pci-ats.h>
+#include <linux/memblock.h>
+#include <linux/dma-contiguous.h>
+#include <asm/irq_remapping.h>
+#include <asm/cacheflush.h>
+#include <asm/iommu.h>
+
+#include "irq_remapping.h"
+
+#define ROOT_SIZE		VTD_PAGE_SIZE
+#define CONTEXT_SIZE		VTD_PAGE_SIZE
+
+#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
+#define IS_USB_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_SERIAL_USB)
+#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
+#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
+
+#define IOAPIC_RANGE_START	(0xfee00000)
+#define IOAPIC_RANGE_END	(0xfeefffff)
+#define IOVA_START_ADDR		(0x1000)
+
+#define DEFAULT_DOMAIN_ADDRESS_WIDTH 48
+
+#define MAX_AGAW_WIDTH 64
+#define MAX_AGAW_PFN_WIDTH	(MAX_AGAW_WIDTH - VTD_PAGE_SHIFT)
+
+#define __DOMAIN_MAX_PFN(gaw)  ((((uint64_t)1) << (gaw-VTD_PAGE_SHIFT)) - 1)
+#define __DOMAIN_MAX_ADDR(gaw) ((((uint64_t)1) << gaw) - 1)
+
+/* We limit DOMAIN_MAX_PFN to fit in an unsigned long, and DOMAIN_MAX_ADDR
+   to match. That way, we can use 'unsigned long' for PFNs with impunity. */
+#define DOMAIN_MAX_PFN(gaw)	((unsigned long) min_t(uint64_t, \
+				__DOMAIN_MAX_PFN(gaw), (unsigned long)-1))
+#define DOMAIN_MAX_ADDR(gaw)	(((uint64_t)__DOMAIN_MAX_PFN(gaw)) << VTD_PAGE_SHIFT)
+
+/* IO virtual address start page frame number */
+#define IOVA_START_PFN		(1)
+
+#define IOVA_PFN(addr)		((addr) >> PAGE_SHIFT)
+#define DMA_32BIT_PFN		IOVA_PFN(DMA_BIT_MASK(32))
+#define DMA_64BIT_PFN		IOVA_PFN(DMA_BIT_MASK(64))
+
+/* page table handling */
+#define LEVEL_STRIDE		(9)
+#define LEVEL_MASK		(((u64)1 << LEVEL_STRIDE) - 1)
+
+/*
+ * This bitmap is used to advertise the page sizes our hardware support
+ * to the IOMMU core, which will then use this information to split
+ * physically contiguous memory regions it is mapping into page sizes
+ * that we support.
+ *
+ * Traditionally the IOMMU core just handed us the mappings directly,
+ * after making sure the size is an order of a 4KiB page and that the
+ * mapping has natural alignment.
+ *
+ * To retain this behavior, we currently advertise that we support
+ * all page sizes that are an order of 4KiB.
+ *
+ * If at some point we'd like to utilize the IOMMU core's new behavior,
+ * we could change this to advertise the real page sizes we support.
+ */
+#define INTEL_IOMMU_PGSIZES	(~0xFFFUL)
+
+static inline int agaw_to_level(int agaw)
+{
+	return agaw + 2;
+}
+
+static inline int agaw_to_width(int agaw)
+{
+	return min_t(int, 30 + agaw * LEVEL_STRIDE, MAX_AGAW_WIDTH);
+}
+
+static inline int width_to_agaw(int width)
+{
+	return DIV_ROUND_UP(width - 30, LEVEL_STRIDE);
+}
+
+static inline unsigned int level_to_offset_bits(int level)
+{
+	return (level - 1) * LEVEL_STRIDE;
+}
+
+static inline int pfn_level_offset(unsigned long pfn, int level)
+{
+	return (pfn >> level_to_offset_bits(level)) & LEVEL_MASK;
+}
+
+static inline unsigned long level_mask(int level)
+{
+	return -1UL << level_to_offset_bits(level);
+}
+
+static inline unsigned long level_size(int level)
+{
+	return 1UL << level_to_offset_bits(level);
+}
+
+static inline unsigned long align_to_level(unsigned long pfn, int level)
+{
+	return (pfn + level_size(level) - 1) & level_mask(level);
+}
+
+static inline unsigned long lvl_to_nr_pages(unsigned int lvl)
+{
+	return  1 << min_t(int, (lvl - 1) * LEVEL_STRIDE, MAX_AGAW_PFN_WIDTH);
+}
+
+/* VT-d pages must always be _smaller_ than MM pages. Otherwise things
+   are never going to work. */
+static inline unsigned long dma_to_mm_pfn(unsigned long dma_pfn)
+{
+	return dma_pfn >> (PAGE_SHIFT - VTD_PAGE_SHIFT);
+}
+
+static inline unsigned long mm_to_dma_pfn(unsigned long mm_pfn)
+{
+	return mm_pfn << (PAGE_SHIFT - VTD_PAGE_SHIFT);
+}
+static inline unsigned long page_to_dma_pfn(struct page *pg)
+{
+	return mm_to_dma_pfn(page_to_pfn(pg));
+}
+static inline unsigned long virt_to_dma_pfn(void *p)
+{
+	return page_to_dma_pfn(virt_to_page(p));
+}
+
+/* global iommu list, set NULL for ignored DMAR units */
+static struct intel_iommu **g_iommus;
+
+static void __init check_tylersburg_isoch(void);
+static int rwbf_quirk;
+
+/*
+ * set to 1 to panic kernel if can't successfully enable VT-d
+ * (used when kernel is launched w/ TXT)
+ */
+static int force_on = 0;
+
+/*
+ * 0: Present
+ * 1-11: Reserved
+ * 12-63: Context Ptr (12 - (haw-1))
+ * 64-127: Reserved
+ */
+struct root_entry {
+	u64	lo;
+	u64	hi;
+};
+#define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry))
+
+
+/*
+ * low 64 bits:
+ * 0: present
+ * 1: fault processing disable
+ * 2-3: translation type
+ * 12-63: address space root
+ * high 64 bits:
+ * 0-2: address width
+ * 3-6: aval
+ * 8-23: domain id
+ */
+struct context_entry {
+	u64 lo;
+	u64 hi;
+};
+
+static inline bool context_present(struct context_entry *context)
+{
+	return (context->lo & 1);
+}
+static inline void context_set_present(struct context_entry *context)
+{
+	context->lo |= 1;
+}
+
+static inline void context_set_fault_enable(struct context_entry *context)
+{
+	context->lo &= (((u64)-1) << 2) | 1;
+}
+
+static inline void context_set_translation_type(struct context_entry *context,
+						unsigned long value)
+{
+	context->lo &= (((u64)-1) << 4) | 3;
+	context->lo |= (value & 3) << 2;
+}
+
+static inline void context_set_address_root(struct context_entry *context,
+					    unsigned long value)
+{
+	context->lo &= ~VTD_PAGE_MASK;
+	context->lo |= value & VTD_PAGE_MASK;
+}
+
+static inline void context_set_address_width(struct context_entry *context,
+					     unsigned long value)
+{
+	context->hi |= value & 7;
+}
+
+static inline void context_set_domain_id(struct context_entry *context,
+					 unsigned long value)
+{
+	context->hi |= (value & ((1 << 16) - 1)) << 8;
+}
+
+static inline void context_clear_entry(struct context_entry *context)
+{
+	context->lo = 0;
+	context->hi = 0;
+}
+
+/*
+ * 0: readable
+ * 1: writable
+ * 2-6: reserved
+ * 7: super page
+ * 8-10: available
+ * 11: snoop behavior
+ * 12-63: Host physcial address
+ */
+struct dma_pte {
+	u64 val;
+};
+
+static inline void dma_clear_pte(struct dma_pte *pte)
+{
+	pte->val = 0;
+}
+
+static inline u64 dma_pte_addr(struct dma_pte *pte)
+{
+#ifdef CONFIG_64BIT
+	return pte->val & VTD_PAGE_MASK;
+#else
+	/* Must have a full atomic 64-bit read */
+	return  __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK;
+#endif
+}
+
+static inline bool dma_pte_present(struct dma_pte *pte)
+{
+	return (pte->val & 3) != 0;
+}
+
+static inline bool dma_pte_superpage(struct dma_pte *pte)
+{
+	return (pte->val & DMA_PTE_LARGE_PAGE);
+}
+
+static inline int first_pte_in_page(struct dma_pte *pte)
+{
+	return !((unsigned long)pte & ~VTD_PAGE_MASK);
+}
+
+/*
+ * This domain is a statically identity mapping domain.
+ *	1. This domain creats a static 1:1 mapping to all usable memory.
+ * 	2. It maps to each iommu if successful.
+ *	3. Each iommu mapps to this domain if successful.
+ */
+static struct dmar_domain *si_domain;
+static int hw_pass_through = 1;
+
+/* domain represents a virtual machine, more than one devices
+ * across iommus may be owned in one domain, e.g. kvm guest.
+ */
+#define DOMAIN_FLAG_VIRTUAL_MACHINE	(1 << 0)
+
+/* si_domain contains mulitple devices */
+#define DOMAIN_FLAG_STATIC_IDENTITY	(1 << 1)
+
+struct dmar_domain {
+	int	id;			/* domain id */
+	int	nid;			/* node id */
+	DECLARE_BITMAP(iommu_bmp, DMAR_UNITS_SUPPORTED);
+					/* bitmap of iommus this domain uses*/
+
+	struct list_head devices;	/* all devices' list */
+	struct iova_domain iovad;	/* iova's that belong to this domain */
+
+	struct dma_pte	*pgd;		/* virtual address */
+	int		gaw;		/* max guest address width */
+
+	/* adjusted guest address width, 0 is level 2 30-bit */
+	int		agaw;
+
+	int		flags;		/* flags to find out type of domain */
+
+	int		iommu_coherency;/* indicate coherency of iommu access */
+	int		iommu_snooping; /* indicate snooping control feature*/
+	int		iommu_count;	/* reference count of iommu */
+	int		iommu_superpage;/* Level of superpages supported:
+					   0 == 4KiB (no superpages), 1 == 2MiB,
+					   2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
+	spinlock_t	iommu_lock;	/* protect iommu set in domain */
+	u64		max_addr;	/* maximum mapped address */
+
+	struct iommu_domain domain;	/* generic domain data structure for
+					   iommu core */
+};
+
+/* PCI domain-device relationship */
+struct device_domain_info {
+	struct list_head link;	/* link to domain siblings */
+	struct list_head global; /* link to global list */
+	u8 bus;			/* PCI bus number */
+	u8 devfn;		/* PCI devfn number */
+	struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
+	struct intel_iommu *iommu; /* IOMMU used by this device */
+	struct dmar_domain *domain; /* pointer to domain */
+};
+
+struct dmar_rmrr_unit {
+	struct list_head list;		/* list of rmrr units	*/
+	struct acpi_dmar_header *hdr;	/* ACPI header		*/
+	u64	base_address;		/* reserved base address*/
+	u64	end_address;		/* reserved end address */
+	struct dmar_dev_scope *devices;	/* target devices */
+	int	devices_cnt;		/* target device count */
+};
+
+struct dmar_atsr_unit {
+	struct list_head list;		/* list of ATSR units */
+	struct acpi_dmar_header *hdr;	/* ACPI header */
+	struct dmar_dev_scope *devices;	/* target devices */
+	int devices_cnt;		/* target device count */
+	u8 include_all:1;		/* include all ports */
+};
+
+static LIST_HEAD(dmar_atsr_units);
+static LIST_HEAD(dmar_rmrr_units);
+
+#define for_each_rmrr_units(rmrr) \
+	list_for_each_entry(rmrr, &dmar_rmrr_units, list)
+
+static void flush_unmaps_timeout(unsigned long data);
+
+static DEFINE_TIMER(unmap_timer,  flush_unmaps_timeout, 0, 0);
+
+#define HIGH_WATER_MARK 250
+struct deferred_flush_tables {
+	int next;
+	struct iova *iova[HIGH_WATER_MARK];
+	struct dmar_domain *domain[HIGH_WATER_MARK];
+	struct page *freelist[HIGH_WATER_MARK];
+};
+
+static struct deferred_flush_tables *deferred_flush;
+
+/* bitmap for indexing intel_iommus */
+static int g_num_of_iommus;
+
+static DEFINE_SPINLOCK(async_umap_flush_lock);
+static LIST_HEAD(unmaps_to_do);
+
+static int timer_on;
+static long list_size;
+
+static void domain_exit(struct dmar_domain *domain);
+static void domain_remove_dev_info(struct dmar_domain *domain);
+static void domain_remove_one_dev_info(struct dmar_domain *domain,
+				       struct device *dev);
+static void iommu_detach_dependent_devices(struct intel_iommu *iommu,
+					   struct device *dev);
+static int domain_detach_iommu(struct dmar_domain *domain,
+			       struct intel_iommu *iommu);
+
+#ifdef CONFIG_INTEL_IOMMU_DEFAULT_ON
+int dmar_disabled = 0;
+#else
+int dmar_disabled = 1;
+#endif /*CONFIG_INTEL_IOMMU_DEFAULT_ON*/
+
+int intel_iommu_enabled = 0;
+EXPORT_SYMBOL_GPL(intel_iommu_enabled);
+
+static int dmar_map_gfx = 1;
+static int dmar_forcedac;
+static int intel_iommu_strict;
+static int intel_iommu_superpage = 1;
+static int intel_iommu_ecs = 1;
+
+/* We only actually use ECS when PASID support (on the new bit 40)
+ * is also advertised. Some early implementations — the ones with
+ * PASID support on bit 28 — have issues even when we *only* use
+ * extended root/context tables. */
+#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap) && \
+			    ecap_pasid(iommu->ecap))
+
+int intel_iommu_gfx_mapped;
+EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped);
+
+#define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
+static DEFINE_SPINLOCK(device_domain_lock);
+static LIST_HEAD(device_domain_list);
+
+static const struct iommu_ops intel_iommu_ops;
+
+/* Convert generic 'struct iommu_domain to private struct dmar_domain */
+static struct dmar_domain *to_dmar_domain(struct iommu_domain *dom)
+{
+	return container_of(dom, struct dmar_domain, domain);
+}
+
+static int __init intel_iommu_setup(char *str)
+{
+	if (!str)
+		return -EINVAL;
+	while (*str) {
+		if (!strncmp(str, "on", 2)) {
+			dmar_disabled = 0;
+			printk(KERN_INFO "Intel-IOMMU: enabled\n");
+		} else if (!strncmp(str, "off", 3)) {
+			dmar_disabled = 1;
+			printk(KERN_INFO "Intel-IOMMU: disabled\n");
+		} else if (!strncmp(str, "igfx_off", 8)) {
+			dmar_map_gfx = 0;
+			printk(KERN_INFO
+				"Intel-IOMMU: disable GFX device mapping\n");
+		} else if (!strncmp(str, "forcedac", 8)) {
+			printk(KERN_INFO
+				"Intel-IOMMU: Forcing DAC for PCI devices\n");
+			dmar_forcedac = 1;
+		} else if (!strncmp(str, "strict", 6)) {
+			printk(KERN_INFO
+				"Intel-IOMMU: disable batched IOTLB flush\n");
+			intel_iommu_strict = 1;
+		} else if (!strncmp(str, "sp_off", 6)) {
+			printk(KERN_INFO
+				"Intel-IOMMU: disable supported super page\n");
+			intel_iommu_superpage = 0;
+		} else if (!strncmp(str, "ecs_off", 7)) {
+			printk(KERN_INFO
+				"Intel-IOMMU: disable extended context table support\n");
+			intel_iommu_ecs = 0;
+		}
+
+		str += strcspn(str, ",");
+		while (*str == ',')
+			str++;
+	}
+	return 0;
+}
+__setup("intel_iommu=", intel_iommu_setup);
+
+static struct kmem_cache *iommu_domain_cache;
+static struct kmem_cache *iommu_devinfo_cache;
+
+static inline void *alloc_pgtable_page(int node)
+{
+	struct page *page;
+	void *vaddr = NULL;
+
+	page = alloc_pages_node(node, GFP_ATOMIC | __GFP_ZERO, 0);
+	if (page)
+		vaddr = page_address(page);
+	return vaddr;
+}
+
+static inline void free_pgtable_page(void *vaddr)
+{
+	free_page((unsigned long)vaddr);
+}
+
+static inline void *alloc_domain_mem(void)
+{
+	return kmem_cache_alloc(iommu_domain_cache, GFP_ATOMIC);
+}
+
+static void free_domain_mem(void *vaddr)
+{
+	kmem_cache_free(iommu_domain_cache, vaddr);
+}
+
+static inline void * alloc_devinfo_mem(void)
+{
+	return kmem_cache_alloc(iommu_devinfo_cache, GFP_ATOMIC);
+}
+
+static inline void free_devinfo_mem(void *vaddr)
+{
+	kmem_cache_free(iommu_devinfo_cache, vaddr);
+}
+
+static inline int domain_type_is_vm(struct dmar_domain *domain)
+{
+	return domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE;
+}
+
+static inline int domain_type_is_vm_or_si(struct dmar_domain *domain)
+{
+	return domain->flags & (DOMAIN_FLAG_VIRTUAL_MACHINE |
+				DOMAIN_FLAG_STATIC_IDENTITY);
+}
+
+static inline int domain_pfn_supported(struct dmar_domain *domain,
+				       unsigned long pfn)
+{
+	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
+
+	return !(addr_width < BITS_PER_LONG && pfn >> addr_width);
+}
+
+static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
+{
+	unsigned long sagaw;
+	int agaw = -1;
+
+	sagaw = cap_sagaw(iommu->cap);
+	for (agaw = width_to_agaw(max_gaw);
+	     agaw >= 0; agaw--) {
+		if (test_bit(agaw, &sagaw))
+			break;
+	}
+
+	return agaw;
+}
+
+/*
+ * Calculate max SAGAW for each iommu.
+ */
+int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
+{
+	return __iommu_calculate_agaw(iommu, MAX_AGAW_WIDTH);
+}
+
+/*
+ * calculate agaw for each iommu.
+ * "SAGAW" may be different across iommus, use a default agaw, and
+ * get a supported less agaw for iommus that don't support the default agaw.
+ */
+int iommu_calculate_agaw(struct intel_iommu *iommu)
+{
+	return __iommu_calculate_agaw(iommu, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+}
+
+/* This functionin only returns single iommu in a domain */
+static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
+{
+	int iommu_id;
+
+	/* si_domain and vm domain should not get here. */
+	BUG_ON(domain_type_is_vm_or_si(domain));
+	iommu_id = find_first_bit(domain->iommu_bmp, g_num_of_iommus);
+	if (iommu_id < 0 || iommu_id >= g_num_of_iommus)
+		return NULL;
+
+	return g_iommus[iommu_id];
+}
+
+static void domain_update_iommu_coherency(struct dmar_domain *domain)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	bool found = false;
+	int i;
+
+	domain->iommu_coherency = 1;
+
+	for_each_set_bit(i, domain->iommu_bmp, g_num_of_iommus) {
+		found = true;
+		if (!ecap_coherent(g_iommus[i]->ecap)) {
+			domain->iommu_coherency = 0;
+			break;
+		}
+	}
+	if (found)
+		return;
+
+	/* No hardware attached; use lowest common denominator */
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (!ecap_coherent(iommu->ecap)) {
+			domain->iommu_coherency = 0;
+			break;
+		}
+	}
+	rcu_read_unlock();
+}
+
+static int domain_update_iommu_snooping(struct intel_iommu *skip)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	int ret = 1;
+
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (iommu != skip) {
+			if (!ecap_sc_support(iommu->ecap)) {
+				ret = 0;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static int domain_update_iommu_superpage(struct intel_iommu *skip)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	int mask = 0xf;
+
+	if (!intel_iommu_superpage) {
+		return 0;
+	}
+
+	/* set iommu_superpage to the smallest common denominator */
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (iommu != skip) {
+			mask &= cap_super_page_val(iommu->cap);
+			if (!mask)
+				break;
+		}
+	}
+	rcu_read_unlock();
+
+	return fls(mask);
+}
+
+/* Some capabilities may be different across iommus */
+static void domain_update_iommu_cap(struct dmar_domain *domain)
+{
+	domain_update_iommu_coherency(domain);
+	domain->iommu_snooping = domain_update_iommu_snooping(NULL);
+	domain->iommu_superpage = domain_update_iommu_superpage(NULL);
+}
+
+static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu,
+						       u8 bus, u8 devfn, int alloc)
+{
+	struct root_entry *root = &iommu->root_entry[bus];
+	struct context_entry *context;
+	u64 *entry;
+
+	if (ecs_enabled(iommu)) {
+		if (devfn >= 0x80) {
+			devfn -= 0x80;
+			entry = &root->hi;
+		}
+		devfn *= 2;
+	}
+	entry = &root->lo;
+	if (*entry & 1)
+		context = phys_to_virt(*entry & VTD_PAGE_MASK);
+	else {
+		unsigned long phy_addr;
+		if (!alloc)
+			return NULL;
+
+		context = alloc_pgtable_page(iommu->node);
+		if (!context)
+			return NULL;
+
+		__iommu_flush_cache(iommu, (void *)context, CONTEXT_SIZE);
+		phy_addr = virt_to_phys((void *)context);
+		*entry = phy_addr | 1;
+		__iommu_flush_cache(iommu, entry, sizeof(*entry));
+	}
+	return &context[devfn];
+}
+
+static int iommu_dummy(struct device *dev)
+{
+	return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
+}
+
+static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
+{
+	struct dmar_drhd_unit *drhd = NULL;
+	struct intel_iommu *iommu;
+	struct device *tmp;
+	struct pci_dev *ptmp, *pdev = NULL;
+	u16 segment = 0;
+	int i;
+
+	if (iommu_dummy(dev))
+		return NULL;
+
+	if (dev_is_pci(dev)) {
+		pdev = to_pci_dev(dev);
+		segment = pci_domain_nr(pdev->bus);
+	} else if (has_acpi_companion(dev))
+		dev = &ACPI_COMPANION(dev)->dev;
+
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (pdev && segment != drhd->segment)
+			continue;
+
+		for_each_active_dev_scope(drhd->devices,
+					  drhd->devices_cnt, i, tmp) {
+			if (tmp == dev) {
+				*bus = drhd->devices[i].bus;
+				*devfn = drhd->devices[i].devfn;
+				goto out;
+			}
+
+			if (!pdev || !dev_is_pci(tmp))
+				continue;
+
+			ptmp = to_pci_dev(tmp);
+			if (ptmp->subordinate &&
+			    ptmp->subordinate->number <= pdev->bus->number &&
+			    ptmp->subordinate->busn_res.end >= pdev->bus->number)
+				goto got_pdev;
+		}
+
+		if (pdev && drhd->include_all) {
+		got_pdev:
+			*bus = pdev->bus->number;
+			*devfn = pdev->devfn;
+			goto out;
+		}
+	}
+	iommu = NULL;
+ out:
+	rcu_read_unlock();
+
+	return iommu;
+}
+
+static void domain_flush_cache(struct dmar_domain *domain,
+			       void *addr, int size)
+{
+	if (!domain->iommu_coherency)
+		clflush_cache_range(addr, size);
+}
+
+static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+	struct context_entry *context;
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	context = iommu_context_addr(iommu, bus, devfn, 0);
+	if (context)
+		ret = context_present(context);
+	spin_unlock_irqrestore(&iommu->lock, flags);
+	return ret;
+}
+
+static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+	struct context_entry *context;
+	unsigned long flags;
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	context = iommu_context_addr(iommu, bus, devfn, 0);
+	if (context) {
+		context_clear_entry(context);
+		__iommu_flush_cache(iommu, context, sizeof(*context));
+	}
+	spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void free_context_table(struct intel_iommu *iommu)
+{
+	int i;
+	unsigned long flags;
+	struct context_entry *context;
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	if (!iommu->root_entry) {
+		goto out;
+	}
+	for (i = 0; i < ROOT_ENTRY_NR; i++) {
+		context = iommu_context_addr(iommu, i, 0, 0);
+		if (context)
+			free_pgtable_page(context);
+
+		if (!ecs_enabled(iommu))
+			continue;
+
+		context = iommu_context_addr(iommu, i, 0x80, 0);
+		if (context)
+			free_pgtable_page(context);
+
+	}
+	free_pgtable_page(iommu->root_entry);
+	iommu->root_entry = NULL;
+out:
+	spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
+				      unsigned long pfn, int *target_level)
+{
+	struct dma_pte *parent, *pte = NULL;
+	int level = agaw_to_level(domain->agaw);
+	int offset;
+
+	BUG_ON(!domain->pgd);
+
+	if (!domain_pfn_supported(domain, pfn))
+		/* Address beyond IOMMU's addressing capabilities. */
+		return NULL;
+
+	parent = domain->pgd;
+
+	while (1) {
+		void *tmp_page;
+
+		offset = pfn_level_offset(pfn, level);
+		pte = &parent[offset];
+		if (!*target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))
+			break;
+		if (level == *target_level)
+			break;
+
+		if (!dma_pte_present(pte)) {
+			uint64_t pteval;
+
+			tmp_page = alloc_pgtable_page(domain->nid);
+
+			if (!tmp_page)
+				return NULL;
+
+			domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
+			pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
+			if (cmpxchg64(&pte->val, 0ULL, pteval))
+				/* Someone else set it while we were thinking; use theirs. */
+				free_pgtable_page(tmp_page);
+			else
+				domain_flush_cache(domain, pte, sizeof(*pte));
+		}
+		if (level == 1)
+			break;
+
+		parent = phys_to_virt(dma_pte_addr(pte));
+		level--;
+	}
+
+	if (!*target_level)
+		*target_level = level;
+
+	return pte;
+}
+
+
+/* return address's pte at specific level */
+static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
+					 unsigned long pfn,
+					 int level, int *large_page)
+{
+	struct dma_pte *parent, *pte = NULL;
+	int total = agaw_to_level(domain->agaw);
+	int offset;
+
+	parent = domain->pgd;
+	while (level <= total) {
+		offset = pfn_level_offset(pfn, total);
+		pte = &parent[offset];
+		if (level == total)
+			return pte;
+
+		if (!dma_pte_present(pte)) {
+			*large_page = total;
+			break;
+		}
+
+		if (dma_pte_superpage(pte)) {
+			*large_page = total;
+			return pte;
+		}
+
+		parent = phys_to_virt(dma_pte_addr(pte));
+		total--;
+	}
+	return NULL;
+}
+
+/* clear last level pte, a tlb flush should be followed */
+static void dma_pte_clear_range(struct dmar_domain *domain,
+				unsigned long start_pfn,
+				unsigned long last_pfn)
+{
+	unsigned int large_page = 1;
+	struct dma_pte *first_pte, *pte;
+
+	BUG_ON(!domain_pfn_supported(domain, start_pfn));
+	BUG_ON(!domain_pfn_supported(domain, last_pfn));
+	BUG_ON(start_pfn > last_pfn);
+
+	/* we don't need lock here; nobody else touches the iova range */
+	do {
+		large_page = 1;
+		first_pte = pte = dma_pfn_level_pte(domain, start_pfn, 1, &large_page);
+		if (!pte) {
+			start_pfn = align_to_level(start_pfn + 1, large_page + 1);
+			continue;
+		}
+		do {
+			dma_clear_pte(pte);
+			start_pfn += lvl_to_nr_pages(large_page);
+			pte++;
+		} while (start_pfn <= last_pfn && !first_pte_in_page(pte));
+
+		domain_flush_cache(domain, first_pte,
+				   (void *)pte - (void *)first_pte);
+
+	} while (start_pfn && start_pfn <= last_pfn);
+}
+
+static void dma_pte_free_level(struct dmar_domain *domain, int level,
+			       struct dma_pte *pte, unsigned long pfn,
+			       unsigned long start_pfn, unsigned long last_pfn)
+{
+	pfn = max(start_pfn, pfn);
+	pte = &pte[pfn_level_offset(pfn, level)];
+
+	do {
+		unsigned long level_pfn;
+		struct dma_pte *level_pte;
+
+		if (!dma_pte_present(pte) || dma_pte_superpage(pte))
+			goto next;
+
+		level_pfn = pfn & level_mask(level - 1);
+		level_pte = phys_to_virt(dma_pte_addr(pte));
+
+		if (level > 2)
+			dma_pte_free_level(domain, level - 1, level_pte,
+					   level_pfn, start_pfn, last_pfn);
+
+		/* If range covers entire pagetable, free it */
+		if (!(start_pfn > level_pfn ||
+		      last_pfn < level_pfn + level_size(level) - 1)) {
+			dma_clear_pte(pte);
+			domain_flush_cache(domain, pte, sizeof(*pte));
+			free_pgtable_page(level_pte);
+		}
+next:
+		pfn += level_size(level);
+	} while (!first_pte_in_page(++pte) && pfn <= last_pfn);
+}
+
+/* free page table pages. last level pte should already be cleared */
+static void dma_pte_free_pagetable(struct dmar_domain *domain,
+				   unsigned long start_pfn,
+				   unsigned long last_pfn)
+{
+	BUG_ON(!domain_pfn_supported(domain, start_pfn));
+	BUG_ON(!domain_pfn_supported(domain, last_pfn));
+	BUG_ON(start_pfn > last_pfn);
+
+	dma_pte_clear_range(domain, start_pfn, last_pfn);
+
+	/* We don't need lock here; nobody else touches the iova range */
+	dma_pte_free_level(domain, agaw_to_level(domain->agaw),
+			   domain->pgd, 0, start_pfn, last_pfn);
+
+	/* free pgd */
+	if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
+		free_pgtable_page(domain->pgd);
+		domain->pgd = NULL;
+	}
+}
+
+/* When a page at a given level is being unlinked from its parent, we don't
+   need to *modify* it at all. All we need to do is make a list of all the
+   pages which can be freed just as soon as we've flushed the IOTLB and we
+   know the hardware page-walk will no longer touch them.
+   The 'pte' argument is the *parent* PTE, pointing to the page that is to
+   be freed. */
+static struct page *dma_pte_list_pagetables(struct dmar_domain *domain,
+					    int level, struct dma_pte *pte,
+					    struct page *freelist)
+{
+	struct page *pg;
+
+	pg = pfn_to_page(dma_pte_addr(pte) >> PAGE_SHIFT);
+	pg->freelist = freelist;
+	freelist = pg;
+
+	if (level == 1)
+		return freelist;
+
+	pte = page_address(pg);
+	do {
+		if (dma_pte_present(pte) && !dma_pte_superpage(pte))
+			freelist = dma_pte_list_pagetables(domain, level - 1,
+							   pte, freelist);
+		pte++;
+	} while (!first_pte_in_page(pte));
+
+	return freelist;
+}
+
+static struct page *dma_pte_clear_level(struct dmar_domain *domain, int level,
+					struct dma_pte *pte, unsigned long pfn,
+					unsigned long start_pfn,
+					unsigned long last_pfn,
+					struct page *freelist)
+{
+	struct dma_pte *first_pte = NULL, *last_pte = NULL;
+
+	pfn = max(start_pfn, pfn);
+	pte = &pte[pfn_level_offset(pfn, level)];
+
+	do {
+		unsigned long level_pfn;
+
+		if (!dma_pte_present(pte))
+			goto next;
+
+		level_pfn = pfn & level_mask(level);
+
+		/* If range covers entire pagetable, free it */
+		if (start_pfn <= level_pfn &&
+		    last_pfn >= level_pfn + level_size(level) - 1) {
+			/* These suborbinate page tables are going away entirely. Don't
+			   bother to clear them; we're just going to *free* them. */
+			if (level > 1 && !dma_pte_superpage(pte))
+				freelist = dma_pte_list_pagetables(domain, level - 1, pte, freelist);
+
+			dma_clear_pte(pte);
+			if (!first_pte)
+				first_pte = pte;
+			last_pte = pte;
+		} else if (level > 1) {
+			/* Recurse down into a level that isn't *entirely* obsolete */
+			freelist = dma_pte_clear_level(domain, level - 1,
+						       phys_to_virt(dma_pte_addr(pte)),
+						       level_pfn, start_pfn, last_pfn,
+						       freelist);
+		}
+next:
+		pfn += level_size(level);
+	} while (!first_pte_in_page(++pte) && pfn <= last_pfn);
+
+	if (first_pte)
+		domain_flush_cache(domain, first_pte,
+				   (void *)++last_pte - (void *)first_pte);
+
+	return freelist;
+}
+
+/* We can't just free the pages because the IOMMU may still be walking
+   the page tables, and may have cached the intermediate levels. The
+   pages can only be freed after the IOTLB flush has been done. */
+struct page *domain_unmap(struct dmar_domain *domain,
+			  unsigned long start_pfn,
+			  unsigned long last_pfn)
+{
+	struct page *freelist = NULL;
+
+	BUG_ON(!domain_pfn_supported(domain, start_pfn));
+	BUG_ON(!domain_pfn_supported(domain, last_pfn));
+	BUG_ON(start_pfn > last_pfn);
+
+	/* we don't need lock here; nobody else touches the iova range */
+	freelist = dma_pte_clear_level(domain, agaw_to_level(domain->agaw),
+				       domain->pgd, 0, start_pfn, last_pfn, NULL);
+
+	/* free pgd */
+	if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
+		struct page *pgd_page = virt_to_page(domain->pgd);
+		pgd_page->freelist = freelist;
+		freelist = pgd_page;
+
+		domain->pgd = NULL;
+	}
+
+	return freelist;
+}
+
+void dma_free_pagelist(struct page *freelist)
+{
+	struct page *pg;
+
+	while ((pg = freelist)) {
+		freelist = pg->freelist;
+		free_pgtable_page(page_address(pg));
+	}
+}
+
+/* iommu handling */
+static int iommu_alloc_root_entry(struct intel_iommu *iommu)
+{
+	struct root_entry *root;
+	unsigned long flags;
+
+	root = (struct root_entry *)alloc_pgtable_page(iommu->node);
+	if (!root) {
+		pr_err("IOMMU: allocating root entry for %s failed\n",
+			iommu->name);
+		return -ENOMEM;
+	}
+
+	__iommu_flush_cache(iommu, root, ROOT_SIZE);
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	iommu->root_entry = root;
+	spin_unlock_irqrestore(&iommu->lock, flags);
+
+	return 0;
+}
+
+static void iommu_set_root_entry(struct intel_iommu *iommu)
+{
+	u64 addr;
+	u32 sts;
+	unsigned long flag;
+
+	addr = virt_to_phys(iommu->root_entry);
+	if (ecs_enabled(iommu))
+		addr |= DMA_RTADDR_RTT;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flag);
+	dmar_writeq(iommu->reg + DMAR_RTADDR_REG, addr);
+
+	writel(iommu->gcmd | DMA_GCMD_SRTP, iommu->reg + DMAR_GCMD_REG);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+		      readl, (sts & DMA_GSTS_RTPS), sts);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+static void iommu_flush_write_buffer(struct intel_iommu *iommu)
+{
+	u32 val;
+	unsigned long flag;
+
+	if (!rwbf_quirk && !cap_rwbf(iommu->cap))
+		return;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flag);
+	writel(iommu->gcmd | DMA_GCMD_WBF, iommu->reg + DMAR_GCMD_REG);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+		      readl, (!(val & DMA_GSTS_WBFS)), val);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+/* return value determine if we need a write buffer flush */
+static void __iommu_flush_context(struct intel_iommu *iommu,
+				  u16 did, u16 source_id, u8 function_mask,
+				  u64 type)
+{
+	u64 val = 0;
+	unsigned long flag;
+
+	switch (type) {
+	case DMA_CCMD_GLOBAL_INVL:
+		val = DMA_CCMD_GLOBAL_INVL;
+		break;
+	case DMA_CCMD_DOMAIN_INVL:
+		val = DMA_CCMD_DOMAIN_INVL|DMA_CCMD_DID(did);
+		break;
+	case DMA_CCMD_DEVICE_INVL:
+		val = DMA_CCMD_DEVICE_INVL|DMA_CCMD_DID(did)
+			| DMA_CCMD_SID(source_id) | DMA_CCMD_FM(function_mask);
+		break;
+	default:
+		BUG();
+	}
+	val |= DMA_CCMD_ICC;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flag);
+	dmar_writeq(iommu->reg + DMAR_CCMD_REG, val);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, DMAR_CCMD_REG,
+		dmar_readq, (!(val & DMA_CCMD_ICC)), val);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+/* return value determine if we need a write buffer flush */
+static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
+				u64 addr, unsigned int size_order, u64 type)
+{
+	int tlb_offset = ecap_iotlb_offset(iommu->ecap);
+	u64 val = 0, val_iva = 0;
+	unsigned long flag;
+
+	switch (type) {
+	case DMA_TLB_GLOBAL_FLUSH:
+		/* global flush doesn't need set IVA_REG */
+		val = DMA_TLB_GLOBAL_FLUSH|DMA_TLB_IVT;
+		break;
+	case DMA_TLB_DSI_FLUSH:
+		val = DMA_TLB_DSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
+		break;
+	case DMA_TLB_PSI_FLUSH:
+		val = DMA_TLB_PSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
+		/* IH bit is passed in as part of address */
+		val_iva = size_order | addr;
+		break;
+	default:
+		BUG();
+	}
+	/* Note: set drain read/write */
+#if 0
+	/*
+	 * This is probably to be super secure.. Looks like we can
+	 * ignore it without any impact.
+	 */
+	if (cap_read_drain(iommu->cap))
+		val |= DMA_TLB_READ_DRAIN;
+#endif
+	if (cap_write_drain(iommu->cap))
+		val |= DMA_TLB_WRITE_DRAIN;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flag);
+	/* Note: Only uses first TLB reg currently */
+	if (val_iva)
+		dmar_writeq(iommu->reg + tlb_offset, val_iva);
+	dmar_writeq(iommu->reg + tlb_offset + 8, val);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, tlb_offset + 8,
+		dmar_readq, (!(val & DMA_TLB_IVT)), val);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+
+	/* check IOTLB invalidation granularity */
+	if (DMA_TLB_IAIG(val) == 0)
+		printk(KERN_ERR"IOMMU: flush IOTLB failed\n");
+	if (DMA_TLB_IAIG(val) != DMA_TLB_IIRG(type))
+		pr_debug("IOMMU: tlb flush request %Lx, actual %Lx\n",
+			(unsigned long long)DMA_TLB_IIRG(type),
+			(unsigned long long)DMA_TLB_IAIG(val));
+}
+
+static struct device_domain_info *
+iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
+			 u8 bus, u8 devfn)
+{
+	bool found = false;
+	unsigned long flags;
+	struct device_domain_info *info;
+	struct pci_dev *pdev;
+
+	if (!ecap_dev_iotlb_support(iommu->ecap))
+		return NULL;
+
+	if (!iommu->qi)
+		return NULL;
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	list_for_each_entry(info, &domain->devices, link)
+		if (info->iommu == iommu && info->bus == bus &&
+		    info->devfn == devfn) {
+			found = true;
+			break;
+		}
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+
+	if (!found || !info->dev || !dev_is_pci(info->dev))
+		return NULL;
+
+	pdev = to_pci_dev(info->dev);
+
+	if (!pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS))
+		return NULL;
+
+	if (!dmar_find_matched_atsr_unit(pdev))
+		return NULL;
+
+	return info;
+}
+
+static void iommu_enable_dev_iotlb(struct device_domain_info *info)
+{
+	if (!info || !dev_is_pci(info->dev))
+		return;
+
+	pci_enable_ats(to_pci_dev(info->dev), VTD_PAGE_SHIFT);
+}
+
+static void iommu_disable_dev_iotlb(struct device_domain_info *info)
+{
+	if (!info->dev || !dev_is_pci(info->dev) ||
+	    !pci_ats_enabled(to_pci_dev(info->dev)))
+		return;
+
+	pci_disable_ats(to_pci_dev(info->dev));
+}
+
+static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
+				  u64 addr, unsigned mask)
+{
+	u16 sid, qdep;
+	unsigned long flags;
+	struct device_domain_info *info;
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	list_for_each_entry(info, &domain->devices, link) {
+		struct pci_dev *pdev;
+		if (!info->dev || !dev_is_pci(info->dev))
+			continue;
+
+		pdev = to_pci_dev(info->dev);
+		if (!pci_ats_enabled(pdev))
+			continue;
+
+		sid = info->bus << 8 | info->devfn;
+		qdep = pci_ats_queue_depth(pdev);
+		qi_flush_dev_iotlb(info->iommu, sid, qdep, addr, mask);
+	}
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+}
+
+static void iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
+				  unsigned long pfn, unsigned int pages, int ih, int map)
+{
+	unsigned int mask = ilog2(__roundup_pow_of_two(pages));
+	uint64_t addr = (uint64_t)pfn << VTD_PAGE_SHIFT;
+
+	BUG_ON(pages == 0);
+
+	if (ih)
+		ih = 1 << 6;
+	/*
+	 * Fallback to domain selective flush if no PSI support or the size is
+	 * too big.
+	 * PSI requires page size to be 2 ^ x, and the base address is naturally
+	 * aligned to the size
+	 */
+	if (!cap_pgsel_inv(iommu->cap) || mask > cap_max_amask_val(iommu->cap))
+		iommu->flush.flush_iotlb(iommu, did, 0, 0,
+						DMA_TLB_DSI_FLUSH);
+	else
+		iommu->flush.flush_iotlb(iommu, did, addr | ih, mask,
+						DMA_TLB_PSI_FLUSH);
+
+	/*
+	 * In caching mode, changes of pages from non-present to present require
+	 * flush. However, device IOTLB doesn't need to be flushed in this case.
+	 */
+	if (!cap_caching_mode(iommu->cap) || !map)
+		iommu_flush_dev_iotlb(iommu->domains[did], addr, mask);
+}
+
+static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu)
+{
+	u32 pmen;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flags);
+	pmen = readl(iommu->reg + DMAR_PMEN_REG);
+	pmen &= ~DMA_PMEN_EPM;
+	writel(pmen, iommu->reg + DMAR_PMEN_REG);
+
+	/* wait for the protected region status bit to clear */
+	IOMMU_WAIT_OP(iommu, DMAR_PMEN_REG,
+		readl, !(pmen & DMA_PMEN_PRS), pmen);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
+}
+
+static void iommu_enable_translation(struct intel_iommu *iommu)
+{
+	u32 sts;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flags);
+	iommu->gcmd |= DMA_GCMD_TE;
+	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+		      readl, (sts & DMA_GSTS_TES), sts);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
+}
+
+static void iommu_disable_translation(struct intel_iommu *iommu)
+{
+	u32 sts;
+	unsigned long flag;
+
+	raw_spin_lock_irqsave(&iommu->register_lock, flag);
+	iommu->gcmd &= ~DMA_GCMD_TE;
+	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
+
+	/* Make sure hardware complete it */
+	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+		      readl, (!(sts & DMA_GSTS_TES)), sts);
+
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+
+static int iommu_init_domains(struct intel_iommu *iommu)
+{
+	unsigned long ndomains;
+	unsigned long nlongs;
+
+	ndomains = cap_ndoms(iommu->cap);
+	pr_debug("IOMMU%d: Number of Domains supported <%ld>\n",
+		 iommu->seq_id, ndomains);
+	nlongs = BITS_TO_LONGS(ndomains);
+
+	spin_lock_init(&iommu->lock);
+
+	/* TBD: there might be 64K domains,
+	 * consider other allocation for future chip
+	 */
+	iommu->domain_ids = kcalloc(nlongs, sizeof(unsigned long), GFP_KERNEL);
+	if (!iommu->domain_ids) {
+		pr_err("IOMMU%d: allocating domain id array failed\n",
+		       iommu->seq_id);
+		return -ENOMEM;
+	}
+	iommu->domains = kcalloc(ndomains, sizeof(struct dmar_domain *),
+			GFP_KERNEL);
+	if (!iommu->domains) {
+		pr_err("IOMMU%d: allocating domain array failed\n",
+		       iommu->seq_id);
+		kfree(iommu->domain_ids);
+		iommu->domain_ids = NULL;
+		return -ENOMEM;
+	}
+
+	/*
+	 * if Caching mode is set, then invalid translations are tagged
+	 * with domainid 0. Hence we need to pre-allocate it.
+	 */
+	if (cap_caching_mode(iommu->cap))
+		set_bit(0, iommu->domain_ids);
+	return 0;
+}
+
+static void disable_dmar_iommu(struct intel_iommu *iommu)
+{
+	struct dmar_domain *domain;
+	int i;
+
+	if ((iommu->domains) && (iommu->domain_ids)) {
+		for_each_set_bit(i, iommu->domain_ids, cap_ndoms(iommu->cap)) {
+			/*
+			 * Domain id 0 is reserved for invalid translation
+			 * if hardware supports caching mode.
+			 */
+			if (cap_caching_mode(iommu->cap) && i == 0)
+				continue;
+
+			domain = iommu->domains[i];
+			clear_bit(i, iommu->domain_ids);
+			if (domain_detach_iommu(domain, iommu) == 0 &&
+			    !domain_type_is_vm(domain))
+				domain_exit(domain);
+		}
+	}
+
+	if (iommu->gcmd & DMA_GCMD_TE)
+		iommu_disable_translation(iommu);
+}
+
+static void free_dmar_iommu(struct intel_iommu *iommu)
+{
+	if ((iommu->domains) && (iommu->domain_ids)) {
+		kfree(iommu->domains);
+		kfree(iommu->domain_ids);
+		iommu->domains = NULL;
+		iommu->domain_ids = NULL;
+	}
+
+	g_iommus[iommu->seq_id] = NULL;
+
+	/* free context mapping */
+	free_context_table(iommu);
+}
+
+static struct dmar_domain *alloc_domain(int flags)
+{
+	/* domain id for virtual machine, it won't be set in context */
+	static atomic_t vm_domid = ATOMIC_INIT(0);
+	struct dmar_domain *domain;
+
+	domain = alloc_domain_mem();
+	if (!domain)
+		return NULL;
+
+	memset(domain, 0, sizeof(*domain));
+	domain->nid = -1;
+	domain->flags = flags;
+	spin_lock_init(&domain->iommu_lock);
+	INIT_LIST_HEAD(&domain->devices);
+	if (flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
+		domain->id = atomic_inc_return(&vm_domid);
+
+	return domain;
+}
+
+static int __iommu_attach_domain(struct dmar_domain *domain,
+				 struct intel_iommu *iommu)
+{
+	int num;
+	unsigned long ndomains;
+
+	ndomains = cap_ndoms(iommu->cap);
+	num = find_first_zero_bit(iommu->domain_ids, ndomains);
+	if (num < ndomains) {
+		set_bit(num, iommu->domain_ids);
+		iommu->domains[num] = domain;
+	} else {
+		num = -ENOSPC;
+	}
+
+	return num;
+}
+
+static int iommu_attach_domain(struct dmar_domain *domain,
+			       struct intel_iommu *iommu)
+{
+	int num;
+	unsigned long flags;
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	num = __iommu_attach_domain(domain, iommu);
+	spin_unlock_irqrestore(&iommu->lock, flags);
+	if (num < 0)
+		pr_err("IOMMU: no free domain ids\n");
+
+	return num;
+}
+
+static int iommu_attach_vm_domain(struct dmar_domain *domain,
+				  struct intel_iommu *iommu)
+{
+	int num;
+	unsigned long ndomains;
+
+	ndomains = cap_ndoms(iommu->cap);
+	for_each_set_bit(num, iommu->domain_ids, ndomains)
+		if (iommu->domains[num] == domain)
+			return num;
+
+	return __iommu_attach_domain(domain, iommu);
+}
+
+static void iommu_detach_domain(struct dmar_domain *domain,
+				struct intel_iommu *iommu)
+{
+	unsigned long flags;
+	int num, ndomains;
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	if (domain_type_is_vm_or_si(domain)) {
+		ndomains = cap_ndoms(iommu->cap);
+		for_each_set_bit(num, iommu->domain_ids, ndomains) {
+			if (iommu->domains[num] == domain) {
+				clear_bit(num, iommu->domain_ids);
+				iommu->domains[num] = NULL;
+				break;
+			}
+		}
+	} else {
+		clear_bit(domain->id, iommu->domain_ids);
+		iommu->domains[domain->id] = NULL;
+	}
+	spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void domain_attach_iommu(struct dmar_domain *domain,
+			       struct intel_iommu *iommu)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&domain->iommu_lock, flags);
+	if (!test_and_set_bit(iommu->seq_id, domain->iommu_bmp)) {
+		domain->iommu_count++;
+		if (domain->iommu_count == 1)
+			domain->nid = iommu->node;
+		domain_update_iommu_cap(domain);
+	}
+	spin_unlock_irqrestore(&domain->iommu_lock, flags);
+}
+
+static int domain_detach_iommu(struct dmar_domain *domain,
+			       struct intel_iommu *iommu)
+{
+	unsigned long flags;
+	int count = INT_MAX;
+
+	spin_lock_irqsave(&domain->iommu_lock, flags);
+	if (test_and_clear_bit(iommu->seq_id, domain->iommu_bmp)) {
+		count = --domain->iommu_count;
+		domain_update_iommu_cap(domain);
+	}
+	spin_unlock_irqrestore(&domain->iommu_lock, flags);
+
+	return count;
+}
+
+static struct iova_domain reserved_iova_list;
+static struct lock_class_key reserved_rbtree_key;
+
+static int dmar_init_reserved_ranges(void)
+{
+	struct pci_dev *pdev = NULL;
+	struct iova *iova;
+	int i;
+
+	init_iova_domain(&reserved_iova_list, VTD_PAGE_SIZE, IOVA_START_PFN,
+			DMA_32BIT_PFN);
+
+	lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
+		&reserved_rbtree_key);
+
+	/* IOAPIC ranges shouldn't be accessed by DMA */
+	iova = reserve_iova(&reserved_iova_list, IOVA_PFN(IOAPIC_RANGE_START),
+		IOVA_PFN(IOAPIC_RANGE_END));
+	if (!iova) {
+		printk(KERN_ERR "Reserve IOAPIC range failed\n");
+		return -ENODEV;
+	}
+
+	/* Reserve all PCI MMIO to avoid peer-to-peer access */
+	for_each_pci_dev(pdev) {
+		struct resource *r;
+
+		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+			r = &pdev->resource[i];
+			if (!r->flags || !(r->flags & IORESOURCE_MEM))
+				continue;
+			iova = reserve_iova(&reserved_iova_list,
+					    IOVA_PFN(r->start),
+					    IOVA_PFN(r->end));
+			if (!iova) {
+				printk(KERN_ERR "Reserve iova failed\n");
+				return -ENODEV;
+			}
+		}
+	}
+	return 0;
+}
+
+static void domain_reserve_special_ranges(struct dmar_domain *domain)
+{
+	copy_reserved_iova(&reserved_iova_list, &domain->iovad);
+}
+
+static inline int guestwidth_to_adjustwidth(int gaw)
+{
+	int agaw;
+	int r = (gaw - 12) % 9;
+
+	if (r == 0)
+		agaw = gaw;
+	else
+		agaw = gaw + 9 - r;
+	if (agaw > 64)
+		agaw = 64;
+	return agaw;
+}
+
+static int domain_init(struct dmar_domain *domain, int guest_width)
+{
+	struct intel_iommu *iommu;
+	int adjust_width, agaw;
+	unsigned long sagaw;
+
+	init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN,
+			DMA_32BIT_PFN);
+	domain_reserve_special_ranges(domain);
+
+	/* calculate AGAW */
+	iommu = domain_get_iommu(domain);
+	if (guest_width > cap_mgaw(iommu->cap))
+		guest_width = cap_mgaw(iommu->cap);
+	domain->gaw = guest_width;
+	adjust_width = guestwidth_to_adjustwidth(guest_width);
+	agaw = width_to_agaw(adjust_width);
+	sagaw = cap_sagaw(iommu->cap);
+	if (!test_bit(agaw, &sagaw)) {
+		/* hardware doesn't support it, choose a bigger one */
+		pr_debug("IOMMU: hardware doesn't support agaw %d\n", agaw);
+		agaw = find_next_bit(&sagaw, 5, agaw);
+		if (agaw >= 5)
+			return -ENODEV;
+	}
+	domain->agaw = agaw;
+
+	if (ecap_coherent(iommu->ecap))
+		domain->iommu_coherency = 1;
+	else
+		domain->iommu_coherency = 0;
+
+	if (ecap_sc_support(iommu->ecap))
+		domain->iommu_snooping = 1;
+	else
+		domain->iommu_snooping = 0;
+
+	if (intel_iommu_superpage)
+		domain->iommu_superpage = fls(cap_super_page_val(iommu->cap));
+	else
+		domain->iommu_superpage = 0;
+
+	domain->nid = iommu->node;
+
+	/* always allocate the top pgd */
+	domain->pgd = (struct dma_pte *)alloc_pgtable_page(domain->nid);
+	if (!domain->pgd)
+		return -ENOMEM;
+	__iommu_flush_cache(iommu, domain->pgd, PAGE_SIZE);
+	return 0;
+}
+
+static void domain_exit(struct dmar_domain *domain)
+{
+	struct page *freelist = NULL;
+	int i;
+
+	/* Domain 0 is reserved, so dont process it */
+	if (!domain)
+		return;
+
+	/* Flush any lazy unmaps that may reference this domain */
+	if (!intel_iommu_strict)
+		flush_unmaps_timeout(0);
+
+	/* remove associated devices */
+	domain_remove_dev_info(domain);
+
+	/* destroy iovas */
+	put_iova_domain(&domain->iovad);
+
+	freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
+
+	/* clear attached or cached domains */
+	rcu_read_lock();
+	for_each_set_bit(i, domain->iommu_bmp, g_num_of_iommus)
+		iommu_detach_domain(domain, g_iommus[i]);
+	rcu_read_unlock();
+
+	dma_free_pagelist(freelist);
+
+	free_domain_mem(domain);
+}
+
+static int domain_context_mapping_one(struct dmar_domain *domain,
+				      struct intel_iommu *iommu,
+				      u8 bus, u8 devfn, int translation)
+{
+	struct context_entry *context;
+	unsigned long flags;
+	struct dma_pte *pgd;
+	int id;
+	int agaw;
+	struct device_domain_info *info = NULL;
+
+	pr_debug("Set context mapping for %02x:%02x.%d\n",
+		bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+	BUG_ON(!domain->pgd);
+	BUG_ON(translation != CONTEXT_TT_PASS_THROUGH &&
+	       translation != CONTEXT_TT_MULTI_LEVEL);
+
+	spin_lock_irqsave(&iommu->lock, flags);
+	context = iommu_context_addr(iommu, bus, devfn, 1);
+	spin_unlock_irqrestore(&iommu->lock, flags);
+	if (!context)
+		return -ENOMEM;
+	spin_lock_irqsave(&iommu->lock, flags);
+	if (context_present(context)) {
+		spin_unlock_irqrestore(&iommu->lock, flags);
+		return 0;
+	}
+
+	id = domain->id;
+	pgd = domain->pgd;
+
+	if (domain_type_is_vm_or_si(domain)) {
+		if (domain_type_is_vm(domain)) {
+			id = iommu_attach_vm_domain(domain, iommu);
+			if (id < 0) {
+				spin_unlock_irqrestore(&iommu->lock, flags);
+				pr_err("IOMMU: no free domain ids\n");
+				return -EFAULT;
+			}
+		}
+
+		/* Skip top levels of page tables for
+		 * iommu which has less agaw than default.
+		 * Unnecessary for PT mode.
+		 */
+		if (translation != CONTEXT_TT_PASS_THROUGH) {
+			for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) {
+				pgd = phys_to_virt(dma_pte_addr(pgd));
+				if (!dma_pte_present(pgd)) {
+					spin_unlock_irqrestore(&iommu->lock, flags);
+					return -ENOMEM;
+				}
+			}
+		}
+	}
+
+	context_set_domain_id(context, id);
+
+	if (translation != CONTEXT_TT_PASS_THROUGH) {
+		info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
+		translation = info ? CONTEXT_TT_DEV_IOTLB :
+				     CONTEXT_TT_MULTI_LEVEL;
+	}
+	/*
+	 * In pass through mode, AW must be programmed to indicate the largest
+	 * AGAW value supported by hardware. And ASR is ignored by hardware.
+	 */
+	if (unlikely(translation == CONTEXT_TT_PASS_THROUGH))
+		context_set_address_width(context, iommu->msagaw);
+	else {
+		context_set_address_root(context, virt_to_phys(pgd));
+		context_set_address_width(context, iommu->agaw);
+	}
+
+	context_set_translation_type(context, translation);
+	context_set_fault_enable(context);
+	context_set_present(context);
+	domain_flush_cache(domain, context, sizeof(*context));
+
+	/*
+	 * It's a non-present to present mapping. If hardware doesn't cache
+	 * non-present entry we only need to flush the write-buffer. If the
+	 * _does_ cache non-present entries, then it does so in the special
+	 * domain #0, which we have to flush:
+	 */
+	if (cap_caching_mode(iommu->cap)) {
+		iommu->flush.flush_context(iommu, 0,
+					   (((u16)bus) << 8) | devfn,
+					   DMA_CCMD_MASK_NOBIT,
+					   DMA_CCMD_DEVICE_INVL);
+		iommu->flush.flush_iotlb(iommu, id, 0, 0, DMA_TLB_DSI_FLUSH);
+	} else {
+		iommu_flush_write_buffer(iommu);
+	}
+	iommu_enable_dev_iotlb(info);
+	spin_unlock_irqrestore(&iommu->lock, flags);
+
+	domain_attach_iommu(domain, iommu);
+
+	return 0;
+}
+
+struct domain_context_mapping_data {
+	struct dmar_domain *domain;
+	struct intel_iommu *iommu;
+	int translation;
+};
+
+static int domain_context_mapping_cb(struct pci_dev *pdev,
+				     u16 alias, void *opaque)
+{
+	struct domain_context_mapping_data *data = opaque;
+
+	return domain_context_mapping_one(data->domain, data->iommu,
+					  PCI_BUS_NUM(alias), alias & 0xff,
+					  data->translation);
+}
+
+static int
+domain_context_mapping(struct dmar_domain *domain, struct device *dev,
+		       int translation)
+{
+	struct intel_iommu *iommu;
+	u8 bus, devfn;
+	struct domain_context_mapping_data data;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	if (!dev_is_pci(dev))
+		return domain_context_mapping_one(domain, iommu, bus, devfn,
+						  translation);
+
+	data.domain = domain;
+	data.iommu = iommu;
+	data.translation = translation;
+
+	return pci_for_each_dma_alias(to_pci_dev(dev),
+				      &domain_context_mapping_cb, &data);
+}
+
+static int domain_context_mapped_cb(struct pci_dev *pdev,
+				    u16 alias, void *opaque)
+{
+	struct intel_iommu *iommu = opaque;
+
+	return !device_context_mapped(iommu, PCI_BUS_NUM(alias), alias & 0xff);
+}
+
+static int domain_context_mapped(struct device *dev)
+{
+	struct intel_iommu *iommu;
+	u8 bus, devfn;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	if (!dev_is_pci(dev))
+		return device_context_mapped(iommu, bus, devfn);
+
+	return !pci_for_each_dma_alias(to_pci_dev(dev),
+				       domain_context_mapped_cb, iommu);
+}
+
+/* Returns a number of VTD pages, but aligned to MM page size */
+static inline unsigned long aligned_nrpages(unsigned long host_addr,
+					    size_t size)
+{
+	host_addr &= ~PAGE_MASK;
+	return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
+}
+
+/* Return largest possible superpage level for a given mapping */
+static inline int hardware_largepage_caps(struct dmar_domain *domain,
+					  unsigned long iov_pfn,
+					  unsigned long phy_pfn,
+					  unsigned long pages)
+{
+	int support, level = 1;
+	unsigned long pfnmerge;
+
+	support = domain->iommu_superpage;
+
+	/* To use a large page, the virtual *and* physical addresses
+	   must be aligned to 2MiB/1GiB/etc. Lower bits set in either
+	   of them will mean we have to use smaller pages. So just
+	   merge them and check both at once. */
+	pfnmerge = iov_pfn | phy_pfn;
+
+	while (support && !(pfnmerge & ~VTD_STRIDE_MASK)) {
+		pages >>= VTD_STRIDE_SHIFT;
+		if (!pages)
+			break;
+		pfnmerge >>= VTD_STRIDE_SHIFT;
+		level++;
+		support--;
+	}
+	return level;
+}
+
+static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
+			    struct scatterlist *sg, unsigned long phys_pfn,
+			    unsigned long nr_pages, int prot)
+{
+	struct dma_pte *first_pte = NULL, *pte = NULL;
+	phys_addr_t uninitialized_var(pteval);
+	unsigned long sg_res = 0;
+	unsigned int largepage_lvl = 0;
+	unsigned long lvl_pages = 0;
+
+	BUG_ON(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1));
+
+	if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
+		return -EINVAL;
+
+	prot &= DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP;
+
+	if (!sg) {
+		sg_res = nr_pages;
+		pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | prot;
+	}
+
+	while (nr_pages > 0) {
+		uint64_t tmp;
+
+		if (!sg_res) {
+			sg_res = aligned_nrpages(sg->offset, sg->length);
+			sg->dma_address = ((dma_addr_t)iov_pfn << VTD_PAGE_SHIFT) + sg->offset;
+			sg->dma_length = sg->length;
+			pteval = page_to_phys(sg_page(sg)) | prot;
+			phys_pfn = pteval >> VTD_PAGE_SHIFT;
+		}
+
+		if (!pte) {
+			largepage_lvl = hardware_largepage_caps(domain, iov_pfn, phys_pfn, sg_res);
+
+			first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, &largepage_lvl);
+			if (!pte)
+				return -ENOMEM;
+			/* It is large page*/
+			if (largepage_lvl > 1) {
+				pteval |= DMA_PTE_LARGE_PAGE;
+				lvl_pages = lvl_to_nr_pages(largepage_lvl);
+				/*
+				 * Ensure that old small page tables are
+				 * removed to make room for superpage,
+				 * if they exist.
+				 */
+				dma_pte_free_pagetable(domain, iov_pfn,
+						       iov_pfn + lvl_pages - 1);
+			} else {
+				pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
+			}
+
+		}
+		/* We don't need lock here, nobody else
+		 * touches the iova range
+		 */
+		tmp = cmpxchg64_local(&pte->val, 0ULL, pteval);
+		if (tmp) {
+			static int dumps = 5;
+			printk(KERN_CRIT "ERROR: DMA PTE for vPFN 0x%lx already set (to %llx not %llx)\n",
+			       iov_pfn, tmp, (unsigned long long)pteval);
+			if (dumps) {
+				dumps--;
+				debug_dma_dump_mappings(NULL);
+			}
+			WARN_ON(1);
+		}
+
+		lvl_pages = lvl_to_nr_pages(largepage_lvl);
+
+		BUG_ON(nr_pages < lvl_pages);
+		BUG_ON(sg_res < lvl_pages);
+
+		nr_pages -= lvl_pages;
+		iov_pfn += lvl_pages;
+		phys_pfn += lvl_pages;
+		pteval += lvl_pages * VTD_PAGE_SIZE;
+		sg_res -= lvl_pages;
+
+		/* If the next PTE would be the first in a new page, then we
+		   need to flush the cache on the entries we've just written.
+		   And then we'll need to recalculate 'pte', so clear it and
+		   let it get set again in the if (!pte) block above.
+
+		   If we're done (!nr_pages) we need to flush the cache too.
+
+		   Also if we've been setting superpages, we may need to
+		   recalculate 'pte' and switch back to smaller pages for the
+		   end of the mapping, if the trailing size is not enough to
+		   use another superpage (i.e. sg_res < lvl_pages). */
+		pte++;
+		if (!nr_pages || first_pte_in_page(pte) ||
+		    (largepage_lvl > 1 && sg_res < lvl_pages)) {
+			domain_flush_cache(domain, first_pte,
+					   (void *)pte - (void *)first_pte);
+			pte = NULL;
+		}
+
+		if (!sg_res && nr_pages)
+			sg = sg_next(sg);
+	}
+	return 0;
+}
+
+static inline int domain_sg_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
+				    struct scatterlist *sg, unsigned long nr_pages,
+				    int prot)
+{
+	return __domain_mapping(domain, iov_pfn, sg, 0, nr_pages, prot);
+}
+
+static inline int domain_pfn_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
+				     unsigned long phys_pfn, unsigned long nr_pages,
+				     int prot)
+{
+	return __domain_mapping(domain, iov_pfn, NULL, phys_pfn, nr_pages, prot);
+}
+
+static void iommu_detach_dev(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+	if (!iommu)
+		return;
+
+	clear_context_table(iommu, bus, devfn);
+	iommu->flush.flush_context(iommu, 0, 0, 0,
+					   DMA_CCMD_GLOBAL_INVL);
+	iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+}
+
+static inline void unlink_domain_info(struct device_domain_info *info)
+{
+	assert_spin_locked(&device_domain_lock);
+	list_del(&info->link);
+	list_del(&info->global);
+	if (info->dev)
+		info->dev->archdata.iommu = NULL;
+}
+
+static void domain_remove_dev_info(struct dmar_domain *domain)
+{
+	struct device_domain_info *info, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	list_for_each_entry_safe(info, tmp, &domain->devices, link) {
+		unlink_domain_info(info);
+		spin_unlock_irqrestore(&device_domain_lock, flags);
+
+		iommu_disable_dev_iotlb(info);
+		iommu_detach_dev(info->iommu, info->bus, info->devfn);
+
+		if (domain_type_is_vm(domain)) {
+			iommu_detach_dependent_devices(info->iommu, info->dev);
+			domain_detach_iommu(domain, info->iommu);
+		}
+
+		free_devinfo_mem(info);
+		spin_lock_irqsave(&device_domain_lock, flags);
+	}
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+}
+
+/*
+ * find_domain
+ * Note: we use struct device->archdata.iommu stores the info
+ */
+static struct dmar_domain *find_domain(struct device *dev)
+{
+	struct device_domain_info *info;
+
+	/* No lock here, assumes no domain exit in normal case */
+	info = dev->archdata.iommu;
+	if (info)
+		return info->domain;
+	return NULL;
+}
+
+static inline struct device_domain_info *
+dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
+{
+	struct device_domain_info *info;
+
+	list_for_each_entry(info, &device_domain_list, global)
+		if (info->iommu->segment == segment && info->bus == bus &&
+		    info->devfn == devfn)
+			return info;
+
+	return NULL;
+}
+
+static struct dmar_domain *dmar_insert_dev_info(struct intel_iommu *iommu,
+						int bus, int devfn,
+						struct device *dev,
+						struct dmar_domain *domain)
+{
+	struct dmar_domain *found = NULL;
+	struct device_domain_info *info;
+	unsigned long flags;
+
+	info = alloc_devinfo_mem();
+	if (!info)
+		return NULL;
+
+	info->bus = bus;
+	info->devfn = devfn;
+	info->dev = dev;
+	info->domain = domain;
+	info->iommu = iommu;
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	if (dev)
+		found = find_domain(dev);
+	else {
+		struct device_domain_info *info2;
+		info2 = dmar_search_domain_by_dev_info(iommu->segment, bus, devfn);
+		if (info2)
+			found = info2->domain;
+	}
+	if (found) {
+		spin_unlock_irqrestore(&device_domain_lock, flags);
+		free_devinfo_mem(info);
+		/* Caller must free the original domain */
+		return found;
+	}
+
+	list_add(&info->link, &domain->devices);
+	list_add(&info->global, &device_domain_list);
+	if (dev)
+		dev->archdata.iommu = info;
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+
+	return domain;
+}
+
+static int get_last_alias(struct pci_dev *pdev, u16 alias, void *opaque)
+{
+	*(u16 *)opaque = alias;
+	return 0;
+}
+
+/* domain is initialized */
+static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
+{
+	struct dmar_domain *domain, *tmp;
+	struct intel_iommu *iommu;
+	struct device_domain_info *info;
+	u16 dma_alias;
+	unsigned long flags;
+	u8 bus, devfn;
+
+	domain = find_domain(dev);
+	if (domain)
+		return domain;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return NULL;
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		pci_for_each_dma_alias(pdev, get_last_alias, &dma_alias);
+
+		spin_lock_irqsave(&device_domain_lock, flags);
+		info = dmar_search_domain_by_dev_info(pci_domain_nr(pdev->bus),
+						      PCI_BUS_NUM(dma_alias),
+						      dma_alias & 0xff);
+		if (info) {
+			iommu = info->iommu;
+			domain = info->domain;
+		}
+		spin_unlock_irqrestore(&device_domain_lock, flags);
+
+		/* DMA alias already has a domain, uses it */
+		if (info)
+			goto found_domain;
+	}
+
+	/* Allocate and initialize new domain for the device */
+	domain = alloc_domain(0);
+	if (!domain)
+		return NULL;
+	domain->id = iommu_attach_domain(domain, iommu);
+	if (domain->id < 0) {
+		free_domain_mem(domain);
+		return NULL;
+	}
+	domain_attach_iommu(domain, iommu);
+	if (domain_init(domain, gaw)) {
+		domain_exit(domain);
+		return NULL;
+	}
+
+	/* register PCI DMA alias device */
+	if (dev_is_pci(dev)) {
+		tmp = dmar_insert_dev_info(iommu, PCI_BUS_NUM(dma_alias),
+					   dma_alias & 0xff, NULL, domain);
+
+		if (!tmp || tmp != domain) {
+			domain_exit(domain);
+			domain = tmp;
+		}
+
+		if (!domain)
+			return NULL;
+	}
+
+found_domain:
+	tmp = dmar_insert_dev_info(iommu, bus, devfn, dev, domain);
+
+	if (!tmp || tmp != domain) {
+		domain_exit(domain);
+		domain = tmp;
+	}
+
+	return domain;
+}
+
+static int iommu_identity_mapping;
+#define IDENTMAP_ALL		1
+#define IDENTMAP_GFX		2
+#define IDENTMAP_AZALIA		4
+
+static int iommu_domain_identity_map(struct dmar_domain *domain,
+				     unsigned long long start,
+				     unsigned long long end)
+{
+	unsigned long first_vpfn = start >> VTD_PAGE_SHIFT;
+	unsigned long last_vpfn = end >> VTD_PAGE_SHIFT;
+
+	if (!reserve_iova(&domain->iovad, dma_to_mm_pfn(first_vpfn),
+			  dma_to_mm_pfn(last_vpfn))) {
+		printk(KERN_ERR "IOMMU: reserve iova failed\n");
+		return -ENOMEM;
+	}
+
+	pr_debug("Mapping reserved region %llx-%llx for domain %d\n",
+		 start, end, domain->id);
+	/*
+	 * RMRR range might have overlap with physical memory range,
+	 * clear it first
+	 */
+	dma_pte_clear_range(domain, first_vpfn, last_vpfn);
+
+	return domain_pfn_mapping(domain, first_vpfn, first_vpfn,
+				  last_vpfn - first_vpfn + 1,
+				  DMA_PTE_READ|DMA_PTE_WRITE);
+}
+
+static int iommu_prepare_identity_map(struct device *dev,
+				      unsigned long long start,
+				      unsigned long long end)
+{
+	struct dmar_domain *domain;
+	int ret;
+
+	domain = get_domain_for_dev(dev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+	if (!domain)
+		return -ENOMEM;
+
+	/* For _hardware_ passthrough, don't bother. But for software
+	   passthrough, we do it anyway -- it may indicate a memory
+	   range which is reserved in E820, so which didn't get set
+	   up to start with in si_domain */
+	if (domain == si_domain && hw_pass_through) {
+		printk("Ignoring identity map for HW passthrough device %s [0x%Lx - 0x%Lx]\n",
+		       dev_name(dev), start, end);
+		return 0;
+	}
+
+	printk(KERN_INFO
+	       "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n",
+	       dev_name(dev), start, end);
+	
+	if (end < start) {
+		WARN(1, "Your BIOS is broken; RMRR ends before it starts!\n"
+			"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+			dmi_get_system_info(DMI_BIOS_VENDOR),
+			dmi_get_system_info(DMI_BIOS_VERSION),
+		     dmi_get_system_info(DMI_PRODUCT_VERSION));
+		ret = -EIO;
+		goto error;
+	}
+
+	if (end >> agaw_to_width(domain->agaw)) {
+		WARN(1, "Your BIOS is broken; RMRR exceeds permitted address width (%d bits)\n"
+		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+		     agaw_to_width(domain->agaw),
+		     dmi_get_system_info(DMI_BIOS_VENDOR),
+		     dmi_get_system_info(DMI_BIOS_VERSION),
+		     dmi_get_system_info(DMI_PRODUCT_VERSION));
+		ret = -EIO;
+		goto error;
+	}
+
+	ret = iommu_domain_identity_map(domain, start, end);
+	if (ret)
+		goto error;
+
+	/* context entry init */
+	ret = domain_context_mapping(domain, dev, CONTEXT_TT_MULTI_LEVEL);
+	if (ret)
+		goto error;
+
+	return 0;
+
+ error:
+	domain_exit(domain);
+	return ret;
+}
+
+static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
+					 struct device *dev)
+{
+	if (dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)
+		return 0;
+	return iommu_prepare_identity_map(dev, rmrr->base_address,
+					  rmrr->end_address);
+}
+
+#ifdef CONFIG_INTEL_IOMMU_FLOPPY_WA
+static inline void iommu_prepare_isa(void)
+{
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
+	if (!pdev)
+		return;
+
+	printk(KERN_INFO "IOMMU: Prepare 0-16MiB unity mapping for LPC\n");
+	ret = iommu_prepare_identity_map(&pdev->dev, 0, 16*1024*1024 - 1);
+
+	if (ret)
+		printk(KERN_ERR "IOMMU: Failed to create 0-16MiB identity map; "
+		       "floppy might not work\n");
+
+	pci_dev_put(pdev);
+}
+#else
+static inline void iommu_prepare_isa(void)
+{
+	return;
+}
+#endif /* !CONFIG_INTEL_IOMMU_FLPY_WA */
+
+static int md_domain_init(struct dmar_domain *domain, int guest_width);
+
+static int __init si_domain_init(int hw)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	int nid, ret = 0;
+	bool first = true;
+
+	si_domain = alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY);
+	if (!si_domain)
+		return -EFAULT;
+
+	for_each_active_iommu(iommu, drhd) {
+		ret = iommu_attach_domain(si_domain, iommu);
+		if (ret < 0) {
+			domain_exit(si_domain);
+			return -EFAULT;
+		} else if (first) {
+			si_domain->id = ret;
+			first = false;
+		} else if (si_domain->id != ret) {
+			domain_exit(si_domain);
+			return -EFAULT;
+		}
+		domain_attach_iommu(si_domain, iommu);
+	}
+
+	if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
+		domain_exit(si_domain);
+		return -EFAULT;
+	}
+
+	pr_debug("IOMMU: identity mapping domain is domain %d\n",
+		 si_domain->id);
+
+	if (hw)
+		return 0;
+
+	for_each_online_node(nid) {
+		unsigned long start_pfn, end_pfn;
+		int i;
+
+		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
+			ret = iommu_domain_identity_map(si_domain,
+					PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int identity_mapping(struct device *dev)
+{
+	struct device_domain_info *info;
+
+	if (likely(!iommu_identity_mapping))
+		return 0;
+
+	info = dev->archdata.iommu;
+	if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
+		return (info->domain == si_domain);
+
+	return 0;
+}
+
+static int domain_add_dev_info(struct dmar_domain *domain,
+			       struct device *dev, int translation)
+{
+	struct dmar_domain *ndomain;
+	struct intel_iommu *iommu;
+	u8 bus, devfn;
+	int ret;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	ndomain = dmar_insert_dev_info(iommu, bus, devfn, dev, domain);
+	if (ndomain != domain)
+		return -EBUSY;
+
+	ret = domain_context_mapping(domain, dev, translation);
+	if (ret) {
+		domain_remove_one_dev_info(domain, dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static bool device_has_rmrr(struct device *dev)
+{
+	struct dmar_rmrr_unit *rmrr;
+	struct device *tmp;
+	int i;
+
+	rcu_read_lock();
+	for_each_rmrr_units(rmrr) {
+		/*
+		 * Return TRUE if this RMRR contains the device that
+		 * is passed in.
+		 */
+		for_each_active_dev_scope(rmrr->devices,
+					  rmrr->devices_cnt, i, tmp)
+			if (tmp == dev) {
+				rcu_read_unlock();
+				return true;
+			}
+	}
+	rcu_read_unlock();
+	return false;
+}
+
+/*
+ * There are a couple cases where we need to restrict the functionality of
+ * devices associated with RMRRs.  The first is when evaluating a device for
+ * identity mapping because problems exist when devices are moved in and out
+ * of domains and their respective RMRR information is lost.  This means that
+ * a device with associated RMRRs will never be in a "passthrough" domain.
+ * The second is use of the device through the IOMMU API.  This interface
+ * expects to have full control of the IOVA space for the device.  We cannot
+ * satisfy both the requirement that RMRR access is maintained and have an
+ * unencumbered IOVA space.  We also have no ability to quiesce the device's
+ * use of the RMRR space or even inform the IOMMU API user of the restriction.
+ * We therefore prevent devices associated with an RMRR from participating in
+ * the IOMMU API, which eliminates them from device assignment.
+ *
+ * In both cases we assume that PCI USB devices with RMRRs have them largely
+ * for historical reasons and that the RMRR space is not actively used post
+ * boot.  This exclusion may change if vendors begin to abuse it.
+ *
+ * The same exception is made for graphics devices, with the requirement that
+ * any use of the RMRR regions will be torn down before assigning the device
+ * to a guest.
+ */
+static bool device_is_rmrr_locked(struct device *dev)
+{
+	if (!device_has_rmrr(dev))
+		return false;
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		if (IS_USB_DEVICE(pdev) || IS_GFX_DEVICE(pdev))
+			return false;
+	}
+
+	return true;
+}
+
+static int iommu_should_identity_map(struct device *dev, int startup)
+{
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		if (device_is_rmrr_locked(dev))
+			return 0;
+
+		if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
+			return 1;
+
+		if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
+			return 1;
+
+		if (!(iommu_identity_mapping & IDENTMAP_ALL))
+			return 0;
+
+		/*
+		 * We want to start off with all devices in the 1:1 domain, and
+		 * take them out later if we find they can't access all of memory.
+		 *
+		 * However, we can't do this for PCI devices behind bridges,
+		 * because all PCI devices behind the same bridge will end up
+		 * with the same source-id on their transactions.
+		 *
+		 * Practically speaking, we can't change things around for these
+		 * devices at run-time, because we can't be sure there'll be no
+		 * DMA transactions in flight for any of their siblings.
+		 *
+		 * So PCI devices (unless they're on the root bus) as well as
+		 * their parent PCI-PCI or PCIe-PCI bridges must be left _out_ of
+		 * the 1:1 domain, just in _case_ one of their siblings turns out
+		 * not to be able to map all of memory.
+		 */
+		if (!pci_is_pcie(pdev)) {
+			if (!pci_is_root_bus(pdev->bus))
+				return 0;
+			if (pdev->class >> 8 == PCI_CLASS_BRIDGE_PCI)
+				return 0;
+		} else if (pci_pcie_type(pdev) == PCI_EXP_TYPE_PCI_BRIDGE)
+			return 0;
+	} else {
+		if (device_has_rmrr(dev))
+			return 0;
+	}
+
+	/*
+	 * At boot time, we don't yet know if devices will be 64-bit capable.
+	 * Assume that they will — if they turn out not to be, then we can
+	 * take them out of the 1:1 domain later.
+	 */
+	if (!startup) {
+		/*
+		 * If the device's dma_mask is less than the system's memory
+		 * size then this is not a candidate for identity mapping.
+		 */
+		u64 dma_mask = *dev->dma_mask;
+
+		if (dev->coherent_dma_mask &&
+		    dev->coherent_dma_mask < dma_mask)
+			dma_mask = dev->coherent_dma_mask;
+
+		return dma_mask >= dma_get_required_mask(dev);
+	}
+
+	return 1;
+}
+
+static int __init dev_prepare_static_identity_mapping(struct device *dev, int hw)
+{
+	int ret;
+
+	if (!iommu_should_identity_map(dev, 1))
+		return 0;
+
+	ret = domain_add_dev_info(si_domain, dev,
+				  hw ? CONTEXT_TT_PASS_THROUGH :
+				       CONTEXT_TT_MULTI_LEVEL);
+	if (!ret)
+		pr_info("IOMMU: %s identity mapping for device %s\n",
+			hw ? "hardware" : "software", dev_name(dev));
+	else if (ret == -ENODEV)
+		/* device not associated with an iommu */
+		ret = 0;
+
+	return ret;
+}
+
+
+static int __init iommu_prepare_static_identity_mapping(int hw)
+{
+	struct pci_dev *pdev = NULL;
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	struct device *dev;
+	int i;
+	int ret = 0;
+
+	ret = si_domain_init(hw);
+	if (ret)
+		return -EFAULT;
+
+	for_each_pci_dev(pdev) {
+		ret = dev_prepare_static_identity_mapping(&pdev->dev, hw);
+		if (ret)
+			return ret;
+	}
+
+	for_each_active_iommu(iommu, drhd)
+		for_each_active_dev_scope(drhd->devices, drhd->devices_cnt, i, dev) {
+			struct acpi_device_physical_node *pn;
+			struct acpi_device *adev;
+
+			if (dev->bus != &acpi_bus_type)
+				continue;
+				
+			adev= to_acpi_device(dev);
+			mutex_lock(&adev->physical_node_lock);
+			list_for_each_entry(pn, &adev->physical_node_list, node) {
+				ret = dev_prepare_static_identity_mapping(pn->dev, hw);
+				if (ret)
+					break;
+			}
+			mutex_unlock(&adev->physical_node_lock);
+			if (ret)
+				return ret;
+		}
+
+	return 0;
+}
+
+static void intel_iommu_init_qi(struct intel_iommu *iommu)
+{
+	/*
+	 * Start from the sane iommu hardware state.
+	 * If the queued invalidation is already initialized by us
+	 * (for example, while enabling interrupt-remapping) then
+	 * we got the things already rolling from a sane state.
+	 */
+	if (!iommu->qi) {
+		/*
+		 * Clear any previous faults.
+		 */
+		dmar_fault(-1, iommu);
+		/*
+		 * Disable queued invalidation if supported and already enabled
+		 * before OS handover.
+		 */
+		dmar_disable_qi(iommu);
+	}
+
+	if (dmar_enable_qi(iommu)) {
+		/*
+		 * Queued Invalidate not enabled, use Register Based Invalidate
+		 */
+		iommu->flush.flush_context = __iommu_flush_context;
+		iommu->flush.flush_iotlb = __iommu_flush_iotlb;
+		pr_info("IOMMU: %s using Register based invalidation\n",
+			iommu->name);
+	} else {
+		iommu->flush.flush_context = qi_flush_context;
+		iommu->flush.flush_iotlb = qi_flush_iotlb;
+		pr_info("IOMMU: %s using Queued invalidation\n", iommu->name);
+	}
+}
+
+static int __init init_dmars(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct dmar_rmrr_unit *rmrr;
+	struct device *dev;
+	struct intel_iommu *iommu;
+	int i, ret;
+
+	/*
+	 * for each drhd
+	 *    allocate root
+	 *    initialize and program root entry to not present
+	 * endfor
+	 */
+	for_each_drhd_unit(drhd) {
+		/*
+		 * lock not needed as this is only incremented in the single
+		 * threaded kernel __init code path all other access are read
+		 * only
+		 */
+		if (g_num_of_iommus < DMAR_UNITS_SUPPORTED) {
+			g_num_of_iommus++;
+			continue;
+		}
+		printk_once(KERN_ERR "intel-iommu: exceeded %d IOMMUs\n",
+			  DMAR_UNITS_SUPPORTED);
+	}
+
+	/* Preallocate enough resources for IOMMU hot-addition */
+	if (g_num_of_iommus < DMAR_UNITS_SUPPORTED)
+		g_num_of_iommus = DMAR_UNITS_SUPPORTED;
+
+	g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *),
+			GFP_KERNEL);
+	if (!g_iommus) {
+		printk(KERN_ERR "Allocating global iommu array failed\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	deferred_flush = kzalloc(g_num_of_iommus *
+		sizeof(struct deferred_flush_tables), GFP_KERNEL);
+	if (!deferred_flush) {
+		ret = -ENOMEM;
+		goto free_g_iommus;
+	}
+
+	for_each_active_iommu(iommu, drhd) {
+		g_iommus[iommu->seq_id] = iommu;
+
+		ret = iommu_init_domains(iommu);
+		if (ret)
+			goto free_iommu;
+
+		/*
+		 * TBD:
+		 * we could share the same root & context tables
+		 * among all IOMMU's. Need to Split it later.
+		 */
+		ret = iommu_alloc_root_entry(iommu);
+		if (ret)
+			goto free_iommu;
+		if (!ecap_pass_through(iommu->ecap))
+			hw_pass_through = 0;
+	}
+
+	for_each_active_iommu(iommu, drhd)
+		intel_iommu_init_qi(iommu);
+
+	if (iommu_pass_through)
+		iommu_identity_mapping |= IDENTMAP_ALL;
+
+#ifdef CONFIG_INTEL_IOMMU_BROKEN_GFX_WA
+	iommu_identity_mapping |= IDENTMAP_GFX;
+#endif
+
+	check_tylersburg_isoch();
+
+	/*
+	 * If pass through is not set or not enabled, setup context entries for
+	 * identity mappings for rmrr, gfx, and isa and may fall back to static
+	 * identity mapping if iommu_identity_mapping is set.
+	 */
+	if (iommu_identity_mapping) {
+		ret = iommu_prepare_static_identity_mapping(hw_pass_through);
+		if (ret) {
+			printk(KERN_CRIT "Failed to setup IOMMU pass-through\n");
+			goto free_iommu;
+		}
+	}
+	/*
+	 * For each rmrr
+	 *   for each dev attached to rmrr
+	 *   do
+	 *     locate drhd for dev, alloc domain for dev
+	 *     allocate free domain
+	 *     allocate page table entries for rmrr
+	 *     if context not allocated for bus
+	 *           allocate and init context
+	 *           set present in root table for this bus
+	 *     init context with domain, translation etc
+	 *    endfor
+	 * endfor
+	 */
+	printk(KERN_INFO "IOMMU: Setting RMRR:\n");
+	for_each_rmrr_units(rmrr) {
+		/* some BIOS lists non-exist devices in DMAR table. */
+		for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
+					  i, dev) {
+			ret = iommu_prepare_rmrr_dev(rmrr, dev);
+			if (ret)
+				printk(KERN_ERR
+				       "IOMMU: mapping reserved region failed\n");
+		}
+	}
+
+	iommu_prepare_isa();
+
+	/*
+	 * for each drhd
+	 *   enable fault log
+	 *   global invalidate context cache
+	 *   global invalidate iotlb
+	 *   enable translation
+	 */
+	for_each_iommu(iommu, drhd) {
+		if (drhd->ignored) {
+			/*
+			 * we always have to disable PMRs or DMA may fail on
+			 * this device
+			 */
+			if (force_on)
+				iommu_disable_protect_mem_regions(iommu);
+			continue;
+		}
+
+		iommu_flush_write_buffer(iommu);
+
+		ret = dmar_set_interrupt(iommu);
+		if (ret)
+			goto free_iommu;
+
+		iommu_set_root_entry(iommu);
+
+		iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+		iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+		iommu_enable_translation(iommu);
+		iommu_disable_protect_mem_regions(iommu);
+	}
+
+	return 0;
+
+free_iommu:
+	for_each_active_iommu(iommu, drhd) {
+		disable_dmar_iommu(iommu);
+		free_dmar_iommu(iommu);
+	}
+	kfree(deferred_flush);
+free_g_iommus:
+	kfree(g_iommus);
+error:
+	return ret;
+}
+
+/* This takes a number of _MM_ pages, not VTD pages */
+static struct iova *intel_alloc_iova(struct device *dev,
+				     struct dmar_domain *domain,
+				     unsigned long nrpages, uint64_t dma_mask)
+{
+	struct iova *iova = NULL;
+
+	/* Restrict dma_mask to the width that the iommu can handle */
+	dma_mask = min_t(uint64_t, DOMAIN_MAX_ADDR(domain->gaw), dma_mask);
+
+	if (!dmar_forcedac && dma_mask > DMA_BIT_MASK(32)) {
+		/*
+		 * First try to allocate an io virtual address in
+		 * DMA_BIT_MASK(32) and if that fails then try allocating
+		 * from higher range
+		 */
+		iova = alloc_iova(&domain->iovad, nrpages,
+				  IOVA_PFN(DMA_BIT_MASK(32)), 1);
+		if (iova)
+			return iova;
+	}
+	iova = alloc_iova(&domain->iovad, nrpages, IOVA_PFN(dma_mask), 1);
+	if (unlikely(!iova)) {
+		printk(KERN_ERR "Allocating %ld-page iova for %s failed",
+		       nrpages, dev_name(dev));
+		return NULL;
+	}
+
+	return iova;
+}
+
+static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
+{
+	struct dmar_domain *domain;
+	int ret;
+
+	domain = get_domain_for_dev(dev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+	if (!domain) {
+		printk(KERN_ERR "Allocating domain for %s failed",
+		       dev_name(dev));
+		return NULL;
+	}
+
+	/* make sure context mapping is ok */
+	if (unlikely(!domain_context_mapped(dev))) {
+		ret = domain_context_mapping(domain, dev, CONTEXT_TT_MULTI_LEVEL);
+		if (ret) {
+			printk(KERN_ERR "Domain context map for %s failed",
+			       dev_name(dev));
+			return NULL;
+		}
+	}
+
+	return domain;
+}
+
+static inline struct dmar_domain *get_valid_domain_for_dev(struct device *dev)
+{
+	struct device_domain_info *info;
+
+	/* No lock here, assumes no domain exit in normal case */
+	info = dev->archdata.iommu;
+	if (likely(info))
+		return info->domain;
+
+	return __get_valid_domain_for_dev(dev);
+}
+
+/* Check if the dev needs to go through non-identity map and unmap process.*/
+static int iommu_no_mapping(struct device *dev)
+{
+	int found;
+
+	if (iommu_dummy(dev))
+		return 1;
+
+	if (!iommu_identity_mapping)
+		return 0;
+
+	found = identity_mapping(dev);
+	if (found) {
+		if (iommu_should_identity_map(dev, 0))
+			return 1;
+		else {
+			/*
+			 * 32 bit DMA is removed from si_domain and fall back
+			 * to non-identity mapping.
+			 */
+			domain_remove_one_dev_info(si_domain, dev);
+			printk(KERN_INFO "32bit %s uses non-identity mapping\n",
+			       dev_name(dev));
+			return 0;
+		}
+	} else {
+		/*
+		 * In case of a detached 64 bit DMA device from vm, the device
+		 * is put into si_domain for identity mapping.
+		 */
+		if (iommu_should_identity_map(dev, 0)) {
+			int ret;
+			ret = domain_add_dev_info(si_domain, dev,
+						  hw_pass_through ?
+						  CONTEXT_TT_PASS_THROUGH :
+						  CONTEXT_TT_MULTI_LEVEL);
+			if (!ret) {
+				printk(KERN_INFO "64bit %s uses identity mapping\n",
+				       dev_name(dev));
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
+				     size_t size, int dir, u64 dma_mask)
+{
+	struct dmar_domain *domain;
+	phys_addr_t start_paddr;
+	struct iova *iova;
+	int prot = 0;
+	int ret;
+	struct intel_iommu *iommu;
+	unsigned long paddr_pfn = paddr >> PAGE_SHIFT;
+
+	BUG_ON(dir == DMA_NONE);
+
+	if (iommu_no_mapping(dev))
+		return paddr;
+
+	domain = get_valid_domain_for_dev(dev);
+	if (!domain)
+		return 0;
+
+	iommu = domain_get_iommu(domain);
+	size = aligned_nrpages(paddr, size);
+
+	iova = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size), dma_mask);
+	if (!iova)
+		goto error;
+
+	/*
+	 * Check if DMAR supports zero-length reads on write only
+	 * mappings..
+	 */
+	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
+			!cap_zlr(iommu->cap))
+		prot |= DMA_PTE_READ;
+	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
+		prot |= DMA_PTE_WRITE;
+	/*
+	 * paddr - (paddr + size) might be partial page, we should map the whole
+	 * page.  Note: if two part of one page are separately mapped, we
+	 * might have two guest_addr mapping to the same host paddr, but this
+	 * is not a big problem
+	 */
+	ret = domain_pfn_mapping(domain, mm_to_dma_pfn(iova->pfn_lo),
+				 mm_to_dma_pfn(paddr_pfn), size, prot);
+	if (ret)
+		goto error;
+
+	/* it's a non-present to present mapping. Only flush if caching mode */
+	if (cap_caching_mode(iommu->cap))
+		iommu_flush_iotlb_psi(iommu, domain->id, mm_to_dma_pfn(iova->pfn_lo), size, 0, 1);
+	else
+		iommu_flush_write_buffer(iommu);
+
+	start_paddr = (phys_addr_t)iova->pfn_lo << PAGE_SHIFT;
+	start_paddr += paddr & ~PAGE_MASK;
+	return start_paddr;
+
+error:
+	if (iova)
+		__free_iova(&domain->iovad, iova);
+	printk(KERN_ERR"Device %s request: %zx@%llx dir %d --- failed\n",
+		dev_name(dev), size, (unsigned long long)paddr, dir);
+	return 0;
+}
+
+static dma_addr_t intel_map_page(struct device *dev, struct page *page,
+				 unsigned long offset, size_t size,
+				 enum dma_data_direction dir,
+				 struct dma_attrs *attrs)
+{
+	return __intel_map_single(dev, page_to_phys(page) + offset, size,
+				  dir, *dev->dma_mask);
+}
+
+static void flush_unmaps(void)
+{
+	int i, j;
+
+	timer_on = 0;
+
+	/* just flush them all */
+	for (i = 0; i < g_num_of_iommus; i++) {
+		struct intel_iommu *iommu = g_iommus[i];
+		if (!iommu)
+			continue;
+
+		if (!deferred_flush[i].next)
+			continue;
+
+		/* In caching mode, global flushes turn emulation expensive */
+		if (!cap_caching_mode(iommu->cap))
+			iommu->flush.flush_iotlb(iommu, 0, 0, 0,
+					 DMA_TLB_GLOBAL_FLUSH);
+		for (j = 0; j < deferred_flush[i].next; j++) {
+			unsigned long mask;
+			struct iova *iova = deferred_flush[i].iova[j];
+			struct dmar_domain *domain = deferred_flush[i].domain[j];
+
+			/* On real hardware multiple invalidations are expensive */
+			if (cap_caching_mode(iommu->cap))
+				iommu_flush_iotlb_psi(iommu, domain->id,
+					iova->pfn_lo, iova_size(iova),
+					!deferred_flush[i].freelist[j], 0);
+			else {
+				mask = ilog2(mm_to_dma_pfn(iova_size(iova)));
+				iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
+						(uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
+			}
+			__free_iova(&deferred_flush[i].domain[j]->iovad, iova);
+			if (deferred_flush[i].freelist[j])
+				dma_free_pagelist(deferred_flush[i].freelist[j]);
+		}
+		deferred_flush[i].next = 0;
+	}
+
+	list_size = 0;
+}
+
+static void flush_unmaps_timeout(unsigned long data)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&async_umap_flush_lock, flags);
+	flush_unmaps();
+	spin_unlock_irqrestore(&async_umap_flush_lock, flags);
+}
+
+static void add_unmap(struct dmar_domain *dom, struct iova *iova, struct page *freelist)
+{
+	unsigned long flags;
+	int next, iommu_id;
+	struct intel_iommu *iommu;
+
+	spin_lock_irqsave(&async_umap_flush_lock, flags);
+	if (list_size == HIGH_WATER_MARK)
+		flush_unmaps();
+
+	iommu = domain_get_iommu(dom);
+	iommu_id = iommu->seq_id;
+
+	next = deferred_flush[iommu_id].next;
+	deferred_flush[iommu_id].domain[next] = dom;
+	deferred_flush[iommu_id].iova[next] = iova;
+	deferred_flush[iommu_id].freelist[next] = freelist;
+	deferred_flush[iommu_id].next++;
+
+	if (!timer_on) {
+		mod_timer(&unmap_timer, jiffies + msecs_to_jiffies(10));
+		timer_on = 1;
+	}
+	list_size++;
+	spin_unlock_irqrestore(&async_umap_flush_lock, flags);
+}
+
+static void intel_unmap(struct device *dev, dma_addr_t dev_addr)
+{
+	struct dmar_domain *domain;
+	unsigned long start_pfn, last_pfn;
+	struct iova *iova;
+	struct intel_iommu *iommu;
+	struct page *freelist;
+
+	if (iommu_no_mapping(dev))
+		return;
+
+	domain = find_domain(dev);
+	BUG_ON(!domain);
+
+	iommu = domain_get_iommu(domain);
+
+	iova = find_iova(&domain->iovad, IOVA_PFN(dev_addr));
+	if (WARN_ONCE(!iova, "Driver unmaps unmatched page at PFN %llx\n",
+		      (unsigned long long)dev_addr))
+		return;
+
+	start_pfn = mm_to_dma_pfn(iova->pfn_lo);
+	last_pfn = mm_to_dma_pfn(iova->pfn_hi + 1) - 1;
+
+	pr_debug("Device %s unmapping: pfn %lx-%lx\n",
+		 dev_name(dev), start_pfn, last_pfn);
+
+	freelist = domain_unmap(domain, start_pfn, last_pfn);
+
+	if (intel_iommu_strict) {
+		iommu_flush_iotlb_psi(iommu, domain->id, start_pfn,
+				      last_pfn - start_pfn + 1, !freelist, 0);
+		/* free iova */
+		__free_iova(&domain->iovad, iova);
+		dma_free_pagelist(freelist);
+	} else {
+		add_unmap(domain, iova, freelist);
+		/*
+		 * queue up the release of the unmap to save the 1/6th of the
+		 * cpu used up by the iotlb flush operation...
+		 */
+	}
+}
+
+static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
+			     size_t size, enum dma_data_direction dir,
+			     struct dma_attrs *attrs)
+{
+	intel_unmap(dev, dev_addr);
+}
+
+static void *intel_alloc_coherent(struct device *dev, size_t size,
+				  dma_addr_t *dma_handle, gfp_t flags,
+				  struct dma_attrs *attrs)
+{
+	struct page *page = NULL;
+	int order;
+
+	size = PAGE_ALIGN(size);
+	order = get_order(size);
+
+	if (!iommu_no_mapping(dev))
+		flags &= ~(GFP_DMA | GFP_DMA32);
+	else if (dev->coherent_dma_mask < dma_get_required_mask(dev)) {
+		if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
+			flags |= GFP_DMA;
+		else
+			flags |= GFP_DMA32;
+	}
+
+	if (flags & __GFP_WAIT) {
+		unsigned int count = size >> PAGE_SHIFT;
+
+		page = dma_alloc_from_contiguous(dev, count, order);
+		if (page && iommu_no_mapping(dev) &&
+		    page_to_phys(page) + size > dev->coherent_dma_mask) {
+			dma_release_from_contiguous(dev, page, count);
+			page = NULL;
+		}
+	}
+
+	if (!page)
+		page = alloc_pages(flags, order);
+	if (!page)
+		return NULL;
+	memset(page_address(page), 0, size);
+
+	*dma_handle = __intel_map_single(dev, page_to_phys(page), size,
+					 DMA_BIDIRECTIONAL,
+					 dev->coherent_dma_mask);
+	if (*dma_handle)
+		return page_address(page);
+	if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
+		__free_pages(page, order);
+
+	return NULL;
+}
+
+static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
+				dma_addr_t dma_handle, struct dma_attrs *attrs)
+{
+	int order;
+	struct page *page = virt_to_page(vaddr);
+
+	size = PAGE_ALIGN(size);
+	order = get_order(size);
+
+	intel_unmap(dev, dma_handle);
+	if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
+		__free_pages(page, order);
+}
+
+static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
+			   int nelems, enum dma_data_direction dir,
+			   struct dma_attrs *attrs)
+{
+	intel_unmap(dev, sglist[0].dma_address);
+}
+
+static int intel_nontranslate_map_sg(struct device *hddev,
+	struct scatterlist *sglist, int nelems, int dir)
+{
+	int i;
+	struct scatterlist *sg;
+
+	for_each_sg(sglist, sg, nelems, i) {
+		BUG_ON(!sg_page(sg));
+		sg->dma_address = page_to_phys(sg_page(sg)) + sg->offset;
+		sg->dma_length = sg->length;
+	}
+	return nelems;
+}
+
+static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nelems,
+			enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+	int i;
+	struct dmar_domain *domain;
+	size_t size = 0;
+	int prot = 0;
+	struct iova *iova = NULL;
+	int ret;
+	struct scatterlist *sg;
+	unsigned long start_vpfn;
+	struct intel_iommu *iommu;
+
+	BUG_ON(dir == DMA_NONE);
+	if (iommu_no_mapping(dev))
+		return intel_nontranslate_map_sg(dev, sglist, nelems, dir);
+
+	domain = get_valid_domain_for_dev(dev);
+	if (!domain)
+		return 0;
+
+	iommu = domain_get_iommu(domain);
+
+	for_each_sg(sglist, sg, nelems, i)
+		size += aligned_nrpages(sg->offset, sg->length);
+
+	iova = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size),
+				*dev->dma_mask);
+	if (!iova) {
+		sglist->dma_length = 0;
+		return 0;
+	}
+
+	/*
+	 * Check if DMAR supports zero-length reads on write only
+	 * mappings..
+	 */
+	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
+			!cap_zlr(iommu->cap))
+		prot |= DMA_PTE_READ;
+	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
+		prot |= DMA_PTE_WRITE;
+
+	start_vpfn = mm_to_dma_pfn(iova->pfn_lo);
+
+	ret = domain_sg_mapping(domain, start_vpfn, sglist, size, prot);
+	if (unlikely(ret)) {
+		dma_pte_free_pagetable(domain, start_vpfn,
+				       start_vpfn + size - 1);
+		__free_iova(&domain->iovad, iova);
+		return 0;
+	}
+
+	/* it's a non-present to present mapping. Only flush if caching mode */
+	if (cap_caching_mode(iommu->cap))
+		iommu_flush_iotlb_psi(iommu, domain->id, start_vpfn, size, 0, 1);
+	else
+		iommu_flush_write_buffer(iommu);
+
+	return nelems;
+}
+
+static int intel_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return !dma_addr;
+}
+
+struct dma_map_ops intel_dma_ops = {
+	.alloc = intel_alloc_coherent,
+	.free = intel_free_coherent,
+	.map_sg = intel_map_sg,
+	.unmap_sg = intel_unmap_sg,
+	.map_page = intel_map_page,
+	.unmap_page = intel_unmap_page,
+	.mapping_error = intel_mapping_error,
+};
+
+static inline int iommu_domain_cache_init(void)
+{
+	int ret = 0;
+
+	iommu_domain_cache = kmem_cache_create("iommu_domain",
+					 sizeof(struct dmar_domain),
+					 0,
+					 SLAB_HWCACHE_ALIGN,
+
+					 NULL);
+	if (!iommu_domain_cache) {
+		printk(KERN_ERR "Couldn't create iommu_domain cache\n");
+		ret = -ENOMEM;
+	}
+
+	return ret;
+}
+
+static inline int iommu_devinfo_cache_init(void)
+{
+	int ret = 0;
+
+	iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
+					 sizeof(struct device_domain_info),
+					 0,
+					 SLAB_HWCACHE_ALIGN,
+					 NULL);
+	if (!iommu_devinfo_cache) {
+		printk(KERN_ERR "Couldn't create devinfo cache\n");
+		ret = -ENOMEM;
+	}
+
+	return ret;
+}
+
+static int __init iommu_init_mempool(void)
+{
+	int ret;
+	ret = iommu_iova_cache_init();
+	if (ret)
+		return ret;
+
+	ret = iommu_domain_cache_init();
+	if (ret)
+		goto domain_error;
+
+	ret = iommu_devinfo_cache_init();
+	if (!ret)
+		return ret;
+
+	kmem_cache_destroy(iommu_domain_cache);
+domain_error:
+	iommu_iova_cache_destroy();
+
+	return -ENOMEM;
+}
+
+static void __init iommu_exit_mempool(void)
+{
+	kmem_cache_destroy(iommu_devinfo_cache);
+	kmem_cache_destroy(iommu_domain_cache);
+	iommu_iova_cache_destroy();
+}
+
+static void quirk_ioat_snb_local_iommu(struct pci_dev *pdev)
+{
+	struct dmar_drhd_unit *drhd;
+	u32 vtbar;
+	int rc;
+
+	/* We know that this device on this chipset has its own IOMMU.
+	 * If we find it under a different IOMMU, then the BIOS is lying
+	 * to us. Hope that the IOMMU for this device is actually
+	 * disabled, and it needs no translation...
+	 */
+	rc = pci_bus_read_config_dword(pdev->bus, PCI_DEVFN(0, 0), 0xb0, &vtbar);
+	if (rc) {
+		/* "can't" happen */
+		dev_info(&pdev->dev, "failed to run vt-d quirk\n");
+		return;
+	}
+	vtbar &= 0xffff0000;
+
+	/* we know that the this iommu should be at offset 0xa000 from vtbar */
+	drhd = dmar_find_matched_drhd_unit(pdev);
+	if (WARN_TAINT_ONCE(!drhd || drhd->reg_base_addr - vtbar != 0xa000,
+			    TAINT_FIRMWARE_WORKAROUND,
+			    "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n"))
+		pdev->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
+}
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB, quirk_ioat_snb_local_iommu);
+
+static void __init init_no_remapping_devices(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct device *dev;
+	int i;
+
+	for_each_drhd_unit(drhd) {
+		if (!drhd->include_all) {
+			for_each_active_dev_scope(drhd->devices,
+						  drhd->devices_cnt, i, dev)
+				break;
+			/* ignore DMAR unit if no devices exist */
+			if (i == drhd->devices_cnt)
+				drhd->ignored = 1;
+		}
+	}
+
+	for_each_active_drhd_unit(drhd) {
+		if (drhd->include_all)
+			continue;
+
+		for_each_active_dev_scope(drhd->devices,
+					  drhd->devices_cnt, i, dev)
+			if (!dev_is_pci(dev) || !IS_GFX_DEVICE(to_pci_dev(dev)))
+				break;
+		if (i < drhd->devices_cnt)
+			continue;
+
+		/* This IOMMU has *only* gfx devices. Either bypass it or
+		   set the gfx_mapped flag, as appropriate */
+		if (dmar_map_gfx) {
+			intel_iommu_gfx_mapped = 1;
+		} else {
+			drhd->ignored = 1;
+			for_each_active_dev_scope(drhd->devices,
+						  drhd->devices_cnt, i, dev)
+				dev->archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
+		}
+	}
+}
+
+#ifdef CONFIG_SUSPEND
+static int init_iommu_hw(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu = NULL;
+
+	for_each_active_iommu(iommu, drhd)
+		if (iommu->qi)
+			dmar_reenable_qi(iommu);
+
+	for_each_iommu(iommu, drhd) {
+		if (drhd->ignored) {
+			/*
+			 * we always have to disable PMRs or DMA may fail on
+			 * this device
+			 */
+			if (force_on)
+				iommu_disable_protect_mem_regions(iommu);
+			continue;
+		}
+	
+		iommu_flush_write_buffer(iommu);
+
+		iommu_set_root_entry(iommu);
+
+		iommu->flush.flush_context(iommu, 0, 0, 0,
+					   DMA_CCMD_GLOBAL_INVL);
+		iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+		iommu_enable_translation(iommu);
+		iommu_disable_protect_mem_regions(iommu);
+	}
+
+	return 0;
+}
+
+static void iommu_flush_all(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+
+	for_each_active_iommu(iommu, drhd) {
+		iommu->flush.flush_context(iommu, 0, 0, 0,
+					   DMA_CCMD_GLOBAL_INVL);
+		iommu->flush.flush_iotlb(iommu, 0, 0, 0,
+					 DMA_TLB_GLOBAL_FLUSH);
+	}
+}
+
+static int iommu_suspend(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu = NULL;
+	unsigned long flag;
+
+	for_each_active_iommu(iommu, drhd) {
+		iommu->iommu_state = kzalloc(sizeof(u32) * MAX_SR_DMAR_REGS,
+						 GFP_ATOMIC);
+		if (!iommu->iommu_state)
+			goto nomem;
+	}
+
+	iommu_flush_all();
+
+	for_each_active_iommu(iommu, drhd) {
+		iommu_disable_translation(iommu);
+
+		raw_spin_lock_irqsave(&iommu->register_lock, flag);
+
+		iommu->iommu_state[SR_DMAR_FECTL_REG] =
+			readl(iommu->reg + DMAR_FECTL_REG);
+		iommu->iommu_state[SR_DMAR_FEDATA_REG] =
+			readl(iommu->reg + DMAR_FEDATA_REG);
+		iommu->iommu_state[SR_DMAR_FEADDR_REG] =
+			readl(iommu->reg + DMAR_FEADDR_REG);
+		iommu->iommu_state[SR_DMAR_FEUADDR_REG] =
+			readl(iommu->reg + DMAR_FEUADDR_REG);
+
+		raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+	}
+	return 0;
+
+nomem:
+	for_each_active_iommu(iommu, drhd)
+		kfree(iommu->iommu_state);
+
+	return -ENOMEM;
+}
+
+static void iommu_resume(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu = NULL;
+	unsigned long flag;
+
+	if (init_iommu_hw()) {
+		if (force_on)
+			panic("tboot: IOMMU setup failed, DMAR can not resume!\n");
+		else
+			WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
+		return;
+	}
+
+	for_each_active_iommu(iommu, drhd) {
+
+		raw_spin_lock_irqsave(&iommu->register_lock, flag);
+
+		writel(iommu->iommu_state[SR_DMAR_FECTL_REG],
+			iommu->reg + DMAR_FECTL_REG);
+		writel(iommu->iommu_state[SR_DMAR_FEDATA_REG],
+			iommu->reg + DMAR_FEDATA_REG);
+		writel(iommu->iommu_state[SR_DMAR_FEADDR_REG],
+			iommu->reg + DMAR_FEADDR_REG);
+		writel(iommu->iommu_state[SR_DMAR_FEUADDR_REG],
+			iommu->reg + DMAR_FEUADDR_REG);
+
+		raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+	}
+
+	for_each_active_iommu(iommu, drhd)
+		kfree(iommu->iommu_state);
+}
+
+static struct syscore_ops iommu_syscore_ops = {
+	.resume		= iommu_resume,
+	.suspend	= iommu_suspend,
+};
+
+static void __init init_iommu_pm_ops(void)
+{
+	register_syscore_ops(&iommu_syscore_ops);
+}
+
+#else
+static inline void init_iommu_pm_ops(void) {}
+#endif	/* CONFIG_PM */
+
+
+int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
+{
+	struct acpi_dmar_reserved_memory *rmrr;
+	struct dmar_rmrr_unit *rmrru;
+
+	rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
+	if (!rmrru)
+		return -ENOMEM;
+
+	rmrru->hdr = header;
+	rmrr = (struct acpi_dmar_reserved_memory *)header;
+	rmrru->base_address = rmrr->base_address;
+	rmrru->end_address = rmrr->end_address;
+	rmrru->devices = dmar_alloc_dev_scope((void *)(rmrr + 1),
+				((void *)rmrr) + rmrr->header.length,
+				&rmrru->devices_cnt);
+	if (rmrru->devices_cnt && rmrru->devices == NULL) {
+		kfree(rmrru);
+		return -ENOMEM;
+	}
+
+	list_add(&rmrru->list, &dmar_rmrr_units);
+
+	return 0;
+}
+
+static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr)
+{
+	struct dmar_atsr_unit *atsru;
+	struct acpi_dmar_atsr *tmp;
+
+	list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) {
+		tmp = (struct acpi_dmar_atsr *)atsru->hdr;
+		if (atsr->segment != tmp->segment)
+			continue;
+		if (atsr->header.length != tmp->header.length)
+			continue;
+		if (memcmp(atsr, tmp, atsr->header.length) == 0)
+			return atsru;
+	}
+
+	return NULL;
+}
+
+int dmar_parse_one_atsr(struct acpi_dmar_header *hdr, void *arg)
+{
+	struct acpi_dmar_atsr *atsr;
+	struct dmar_atsr_unit *atsru;
+
+	if (system_state != SYSTEM_BOOTING && !intel_iommu_enabled)
+		return 0;
+
+	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
+	atsru = dmar_find_atsr(atsr);
+	if (atsru)
+		return 0;
+
+	atsru = kzalloc(sizeof(*atsru) + hdr->length, GFP_KERNEL);
+	if (!atsru)
+		return -ENOMEM;
+
+	/*
+	 * If memory is allocated from slab by ACPI _DSM method, we need to
+	 * copy the memory content because the memory buffer will be freed
+	 * on return.
+	 */
+	atsru->hdr = (void *)(atsru + 1);
+	memcpy(atsru->hdr, hdr, hdr->length);
+	atsru->include_all = atsr->flags & 0x1;
+	if (!atsru->include_all) {
+		atsru->devices = dmar_alloc_dev_scope((void *)(atsr + 1),
+				(void *)atsr + atsr->header.length,
+				&atsru->devices_cnt);
+		if (atsru->devices_cnt && atsru->devices == NULL) {
+			kfree(atsru);
+			return -ENOMEM;
+		}
+	}
+
+	list_add_rcu(&atsru->list, &dmar_atsr_units);
+
+	return 0;
+}
+
+static void intel_iommu_free_atsr(struct dmar_atsr_unit *atsru)
+{
+	dmar_free_dev_scope(&atsru->devices, &atsru->devices_cnt);
+	kfree(atsru);
+}
+
+int dmar_release_one_atsr(struct acpi_dmar_header *hdr, void *arg)
+{
+	struct acpi_dmar_atsr *atsr;
+	struct dmar_atsr_unit *atsru;
+
+	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
+	atsru = dmar_find_atsr(atsr);
+	if (atsru) {
+		list_del_rcu(&atsru->list);
+		synchronize_rcu();
+		intel_iommu_free_atsr(atsru);
+	}
+
+	return 0;
+}
+
+int dmar_check_one_atsr(struct acpi_dmar_header *hdr, void *arg)
+{
+	int i;
+	struct device *dev;
+	struct acpi_dmar_atsr *atsr;
+	struct dmar_atsr_unit *atsru;
+
+	atsr = container_of(hdr, struct acpi_dmar_atsr, header);
+	atsru = dmar_find_atsr(atsr);
+	if (!atsru)
+		return 0;
+
+	if (!atsru->include_all && atsru->devices && atsru->devices_cnt)
+		for_each_active_dev_scope(atsru->devices, atsru->devices_cnt,
+					  i, dev)
+			return -EBUSY;
+
+	return 0;
+}
+
+static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
+{
+	int sp, ret = 0;
+	struct intel_iommu *iommu = dmaru->iommu;
+
+	if (g_iommus[iommu->seq_id])
+		return 0;
+
+	if (hw_pass_through && !ecap_pass_through(iommu->ecap)) {
+		pr_warn("IOMMU: %s doesn't support hardware pass through.\n",
+			iommu->name);
+		return -ENXIO;
+	}
+	if (!ecap_sc_support(iommu->ecap) &&
+	    domain_update_iommu_snooping(iommu)) {
+		pr_warn("IOMMU: %s doesn't support snooping.\n",
+			iommu->name);
+		return -ENXIO;
+	}
+	sp = domain_update_iommu_superpage(iommu) - 1;
+	if (sp >= 0 && !(cap_super_page_val(iommu->cap) & (1 << sp))) {
+		pr_warn("IOMMU: %s doesn't support large page.\n",
+			iommu->name);
+		return -ENXIO;
+	}
+
+	/*
+	 * Disable translation if already enabled prior to OS handover.
+	 */
+	if (iommu->gcmd & DMA_GCMD_TE)
+		iommu_disable_translation(iommu);
+
+	g_iommus[iommu->seq_id] = iommu;
+	ret = iommu_init_domains(iommu);
+	if (ret == 0)
+		ret = iommu_alloc_root_entry(iommu);
+	if (ret)
+		goto out;
+
+	if (dmaru->ignored) {
+		/*
+		 * we always have to disable PMRs or DMA may fail on this device
+		 */
+		if (force_on)
+			iommu_disable_protect_mem_regions(iommu);
+		return 0;
+	}
+
+	intel_iommu_init_qi(iommu);
+	iommu_flush_write_buffer(iommu);
+	ret = dmar_set_interrupt(iommu);
+	if (ret)
+		goto disable_iommu;
+
+	iommu_set_root_entry(iommu);
+	iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+	iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+	iommu_enable_translation(iommu);
+
+	if (si_domain) {
+		ret = iommu_attach_domain(si_domain, iommu);
+		if (ret < 0 || si_domain->id != ret)
+			goto disable_iommu;
+		domain_attach_iommu(si_domain, iommu);
+	}
+
+	iommu_disable_protect_mem_regions(iommu);
+	return 0;
+
+disable_iommu:
+	disable_dmar_iommu(iommu);
+out:
+	free_dmar_iommu(iommu);
+	return ret;
+}
+
+int dmar_iommu_hotplug(struct dmar_drhd_unit *dmaru, bool insert)
+{
+	int ret = 0;
+	struct intel_iommu *iommu = dmaru->iommu;
+
+	if (!intel_iommu_enabled)
+		return 0;
+	if (iommu == NULL)
+		return -EINVAL;
+
+	if (insert) {
+		ret = intel_iommu_add(dmaru);
+	} else {
+		disable_dmar_iommu(iommu);
+		free_dmar_iommu(iommu);
+	}
+
+	return ret;
+}
+
+static void intel_iommu_free_dmars(void)
+{
+	struct dmar_rmrr_unit *rmrru, *rmrr_n;
+	struct dmar_atsr_unit *atsru, *atsr_n;
+
+	list_for_each_entry_safe(rmrru, rmrr_n, &dmar_rmrr_units, list) {
+		list_del(&rmrru->list);
+		dmar_free_dev_scope(&rmrru->devices, &rmrru->devices_cnt);
+		kfree(rmrru);
+	}
+
+	list_for_each_entry_safe(atsru, atsr_n, &dmar_atsr_units, list) {
+		list_del(&atsru->list);
+		intel_iommu_free_atsr(atsru);
+	}
+}
+
+int dmar_find_matched_atsr_unit(struct pci_dev *dev)
+{
+	int i, ret = 1;
+	struct pci_bus *bus;
+	struct pci_dev *bridge = NULL;
+	struct device *tmp;
+	struct acpi_dmar_atsr *atsr;
+	struct dmar_atsr_unit *atsru;
+
+	dev = pci_physfn(dev);
+	for (bus = dev->bus; bus; bus = bus->parent) {
+		bridge = bus->self;
+		if (!bridge || !pci_is_pcie(bridge) ||
+		    pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE)
+			return 0;
+		if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT)
+			break;
+	}
+	if (!bridge)
+		return 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) {
+		atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
+		if (atsr->segment != pci_domain_nr(dev->bus))
+			continue;
+
+		for_each_dev_scope(atsru->devices, atsru->devices_cnt, i, tmp)
+			if (tmp == &bridge->dev)
+				goto out;
+
+		if (atsru->include_all)
+			goto out;
+	}
+	ret = 0;
+out:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
+{
+	int ret = 0;
+	struct dmar_rmrr_unit *rmrru;
+	struct dmar_atsr_unit *atsru;
+	struct acpi_dmar_atsr *atsr;
+	struct acpi_dmar_reserved_memory *rmrr;
+
+	if (!intel_iommu_enabled && system_state != SYSTEM_BOOTING)
+		return 0;
+
+	list_for_each_entry(rmrru, &dmar_rmrr_units, list) {
+		rmrr = container_of(rmrru->hdr,
+				    struct acpi_dmar_reserved_memory, header);
+		if (info->event == BUS_NOTIFY_ADD_DEVICE) {
+			ret = dmar_insert_dev_scope(info, (void *)(rmrr + 1),
+				((void *)rmrr) + rmrr->header.length,
+				rmrr->segment, rmrru->devices,
+				rmrru->devices_cnt);
+			if(ret < 0)
+				return ret;
+		} else if (info->event == BUS_NOTIFY_DEL_DEVICE) {
+			dmar_remove_dev_scope(info, rmrr->segment,
+				rmrru->devices, rmrru->devices_cnt);
+		}
+	}
+
+	list_for_each_entry(atsru, &dmar_atsr_units, list) {
+		if (atsru->include_all)
+			continue;
+
+		atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
+		if (info->event == BUS_NOTIFY_ADD_DEVICE) {
+			ret = dmar_insert_dev_scope(info, (void *)(atsr + 1),
+					(void *)atsr + atsr->header.length,
+					atsr->segment, atsru->devices,
+					atsru->devices_cnt);
+			if (ret > 0)
+				break;
+			else if(ret < 0)
+				return ret;
+		} else if (info->event == BUS_NOTIFY_DEL_DEVICE) {
+			if (dmar_remove_dev_scope(info, atsr->segment,
+					atsru->devices, atsru->devices_cnt))
+				break;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Here we only respond to action of unbound device from driver.
+ *
+ * Added device is not attached to its DMAR domain here yet. That will happen
+ * when mapping the device to iova.
+ */
+static int device_notifier(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct dmar_domain *domain;
+
+	if (iommu_dummy(dev))
+		return 0;
+
+	if (action != BUS_NOTIFY_REMOVED_DEVICE)
+		return 0;
+
+	domain = find_domain(dev);
+	if (!domain)
+		return 0;
+
+	down_read(&dmar_global_lock);
+	domain_remove_one_dev_info(domain, dev);
+	if (!domain_type_is_vm_or_si(domain) && list_empty(&domain->devices))
+		domain_exit(domain);
+	up_read(&dmar_global_lock);
+
+	return 0;
+}
+
+static struct notifier_block device_nb = {
+	.notifier_call = device_notifier,
+};
+
+static int intel_iommu_memory_notifier(struct notifier_block *nb,
+				       unsigned long val, void *v)
+{
+	struct memory_notify *mhp = v;
+	unsigned long long start, end;
+	unsigned long start_vpfn, last_vpfn;
+
+	switch (val) {
+	case MEM_GOING_ONLINE:
+		start = mhp->start_pfn << PAGE_SHIFT;
+		end = ((mhp->start_pfn + mhp->nr_pages) << PAGE_SHIFT) - 1;
+		if (iommu_domain_identity_map(si_domain, start, end)) {
+			pr_warn("dmar: failed to build identity map for [%llx-%llx]\n",
+				start, end);
+			return NOTIFY_BAD;
+		}
+		break;
+
+	case MEM_OFFLINE:
+	case MEM_CANCEL_ONLINE:
+		start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
+		last_vpfn = mm_to_dma_pfn(mhp->start_pfn + mhp->nr_pages - 1);
+		while (start_vpfn <= last_vpfn) {
+			struct iova *iova;
+			struct dmar_drhd_unit *drhd;
+			struct intel_iommu *iommu;
+			struct page *freelist;
+
+			iova = find_iova(&si_domain->iovad, start_vpfn);
+			if (iova == NULL) {
+				pr_debug("dmar: failed get IOVA for PFN %lx\n",
+					 start_vpfn);
+				break;
+			}
+
+			iova = split_and_remove_iova(&si_domain->iovad, iova,
+						     start_vpfn, last_vpfn);
+			if (iova == NULL) {
+				pr_warn("dmar: failed to split IOVA PFN [%lx-%lx]\n",
+					start_vpfn, last_vpfn);
+				return NOTIFY_BAD;
+			}
+
+			freelist = domain_unmap(si_domain, iova->pfn_lo,
+					       iova->pfn_hi);
+
+			rcu_read_lock();
+			for_each_active_iommu(iommu, drhd)
+				iommu_flush_iotlb_psi(iommu, si_domain->id,
+					iova->pfn_lo, iova_size(iova),
+					!freelist, 0);
+			rcu_read_unlock();
+			dma_free_pagelist(freelist);
+
+			start_vpfn = iova->pfn_hi + 1;
+			free_iova_mem(iova);
+		}
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block intel_iommu_memory_nb = {
+	.notifier_call = intel_iommu_memory_notifier,
+	.priority = 0
+};
+
+
+static ssize_t intel_iommu_show_version(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct intel_iommu *iommu = dev_get_drvdata(dev);
+	u32 ver = readl(iommu->reg + DMAR_VER_REG);
+	return sprintf(buf, "%d:%d\n",
+		       DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver));
+}
+static DEVICE_ATTR(version, S_IRUGO, intel_iommu_show_version, NULL);
+
+static ssize_t intel_iommu_show_address(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct intel_iommu *iommu = dev_get_drvdata(dev);
+	return sprintf(buf, "%llx\n", iommu->reg_phys);
+}
+static DEVICE_ATTR(address, S_IRUGO, intel_iommu_show_address, NULL);
+
+static ssize_t intel_iommu_show_cap(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct intel_iommu *iommu = dev_get_drvdata(dev);
+	return sprintf(buf, "%llx\n", iommu->cap);
+}
+static DEVICE_ATTR(cap, S_IRUGO, intel_iommu_show_cap, NULL);
+
+static ssize_t intel_iommu_show_ecap(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct intel_iommu *iommu = dev_get_drvdata(dev);
+	return sprintf(buf, "%llx\n", iommu->ecap);
+}
+static DEVICE_ATTR(ecap, S_IRUGO, intel_iommu_show_ecap, NULL);
+
+static struct attribute *intel_iommu_attrs[] = {
+	&dev_attr_version.attr,
+	&dev_attr_address.attr,
+	&dev_attr_cap.attr,
+	&dev_attr_ecap.attr,
+	NULL,
+};
+
+static struct attribute_group intel_iommu_group = {
+	.name = "intel-iommu",
+	.attrs = intel_iommu_attrs,
+};
+
+const struct attribute_group *intel_iommu_groups[] = {
+	&intel_iommu_group,
+	NULL,
+};
+
+int __init intel_iommu_init(void)
+{
+	int ret = -ENODEV;
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+
+	/* VT-d is required for a TXT/tboot launch, so enforce that */
+	force_on = tboot_force_iommu();
+
+	if (iommu_init_mempool()) {
+		if (force_on)
+			panic("tboot: Failed to initialize iommu memory\n");
+		return -ENOMEM;
+	}
+
+	down_write(&dmar_global_lock);
+	if (dmar_table_init()) {
+		if (force_on)
+			panic("tboot: Failed to initialize DMAR table\n");
+		goto out_free_dmar;
+	}
+
+	/*
+	 * Disable translation if already enabled prior to OS handover.
+	 */
+	for_each_active_iommu(iommu, drhd)
+		if (iommu->gcmd & DMA_GCMD_TE)
+			iommu_disable_translation(iommu);
+
+	if (dmar_dev_scope_init() < 0) {
+		if (force_on)
+			panic("tboot: Failed to initialize DMAR device scope\n");
+		goto out_free_dmar;
+	}
+
+	if (no_iommu || dmar_disabled)
+		goto out_free_dmar;
+
+	if (list_empty(&dmar_rmrr_units))
+		printk(KERN_INFO "DMAR: No RMRR found\n");
+
+	if (list_empty(&dmar_atsr_units))
+		printk(KERN_INFO "DMAR: No ATSR found\n");
+
+	if (dmar_init_reserved_ranges()) {
+		if (force_on)
+			panic("tboot: Failed to reserve iommu ranges\n");
+		goto out_free_reserved_range;
+	}
+
+	init_no_remapping_devices();
+
+	ret = init_dmars();
+	if (ret) {
+		if (force_on)
+			panic("tboot: Failed to initialize DMARs\n");
+		printk(KERN_ERR "IOMMU: dmar init failed\n");
+		goto out_free_reserved_range;
+	}
+	up_write(&dmar_global_lock);
+	printk(KERN_INFO
+	"PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
+
+	init_timer(&unmap_timer);
+#ifdef CONFIG_SWIOTLB
+	swiotlb = 0;
+#endif
+	dma_ops = &intel_dma_ops;
+
+	init_iommu_pm_ops();
+
+	for_each_active_iommu(iommu, drhd)
+		iommu->iommu_dev = iommu_device_create(NULL, iommu,
+						       intel_iommu_groups,
+						       iommu->name);
+
+	bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
+	bus_register_notifier(&pci_bus_type, &device_nb);
+	if (si_domain && !hw_pass_through)
+		register_memory_notifier(&intel_iommu_memory_nb);
+
+	intel_iommu_enabled = 1;
+
+	return 0;
+
+out_free_reserved_range:
+	put_iova_domain(&reserved_iova_list);
+out_free_dmar:
+	intel_iommu_free_dmars();
+	up_write(&dmar_global_lock);
+	iommu_exit_mempool();
+	return ret;
+}
+
+static int iommu_detach_dev_cb(struct pci_dev *pdev, u16 alias, void *opaque)
+{
+	struct intel_iommu *iommu = opaque;
+
+	iommu_detach_dev(iommu, PCI_BUS_NUM(alias), alias & 0xff);
+	return 0;
+}
+
+/*
+ * NB - intel-iommu lacks any sort of reference counting for the users of
+ * dependent devices.  If multiple endpoints have intersecting dependent
+ * devices, unbinding the driver from any one of them will possibly leave
+ * the others unable to operate.
+ */
+static void iommu_detach_dependent_devices(struct intel_iommu *iommu,
+					   struct device *dev)
+{
+	if (!iommu || !dev || !dev_is_pci(dev))
+		return;
+
+	pci_for_each_dma_alias(to_pci_dev(dev), &iommu_detach_dev_cb, iommu);
+}
+
+static void domain_remove_one_dev_info(struct dmar_domain *domain,
+				       struct device *dev)
+{
+	struct device_domain_info *info, *tmp;
+	struct intel_iommu *iommu;
+	unsigned long flags;
+	bool found = false;
+	u8 bus, devfn;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return;
+
+	spin_lock_irqsave(&device_domain_lock, flags);
+	list_for_each_entry_safe(info, tmp, &domain->devices, link) {
+		if (info->iommu == iommu && info->bus == bus &&
+		    info->devfn == devfn) {
+			unlink_domain_info(info);
+			spin_unlock_irqrestore(&device_domain_lock, flags);
+
+			iommu_disable_dev_iotlb(info);
+			iommu_detach_dev(iommu, info->bus, info->devfn);
+			iommu_detach_dependent_devices(iommu, dev);
+			free_devinfo_mem(info);
+
+			spin_lock_irqsave(&device_domain_lock, flags);
+
+			if (found)
+				break;
+			else
+				continue;
+		}
+
+		/* if there is no other devices under the same iommu
+		 * owned by this domain, clear this iommu in iommu_bmp
+		 * update iommu count and coherency
+		 */
+		if (info->iommu == iommu)
+			found = true;
+	}
+
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+
+	if (found == 0) {
+		domain_detach_iommu(domain, iommu);
+		if (!domain_type_is_vm_or_si(domain))
+			iommu_detach_domain(domain, iommu);
+	}
+}
+
+static int md_domain_init(struct dmar_domain *domain, int guest_width)
+{
+	int adjust_width;
+
+	init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN,
+			DMA_32BIT_PFN);
+	domain_reserve_special_ranges(domain);
+
+	/* calculate AGAW */
+	domain->gaw = guest_width;
+	adjust_width = guestwidth_to_adjustwidth(guest_width);
+	domain->agaw = width_to_agaw(adjust_width);
+
+	domain->iommu_coherency = 0;
+	domain->iommu_snooping = 0;
+	domain->iommu_superpage = 0;
+	domain->max_addr = 0;
+
+	/* always allocate the top pgd */
+	domain->pgd = (struct dma_pte *)alloc_pgtable_page(domain->nid);
+	if (!domain->pgd)
+		return -ENOMEM;
+	domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
+	return 0;
+}
+
+static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
+{
+	struct dmar_domain *dmar_domain;
+	struct iommu_domain *domain;
+
+	if (type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	dmar_domain = alloc_domain(DOMAIN_FLAG_VIRTUAL_MACHINE);
+	if (!dmar_domain) {
+		printk(KERN_ERR
+			"intel_iommu_domain_init: dmar_domain == NULL\n");
+		return NULL;
+	}
+	if (md_domain_init(dmar_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
+		printk(KERN_ERR
+			"intel_iommu_domain_init() failed\n");
+		domain_exit(dmar_domain);
+		return NULL;
+	}
+	domain_update_iommu_cap(dmar_domain);
+
+	domain = &dmar_domain->domain;
+	domain->geometry.aperture_start = 0;
+	domain->geometry.aperture_end   = __DOMAIN_MAX_ADDR(dmar_domain->gaw);
+	domain->geometry.force_aperture = true;
+
+	return domain;
+}
+
+static void intel_iommu_domain_free(struct iommu_domain *domain)
+{
+	domain_exit(to_dmar_domain(domain));
+}
+
+static int intel_iommu_attach_device(struct iommu_domain *domain,
+				     struct device *dev)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct intel_iommu *iommu;
+	int addr_width;
+	u8 bus, devfn;
+
+	if (device_is_rmrr_locked(dev)) {
+		dev_warn(dev, "Device is ineligible for IOMMU domain attach due to platform RMRR requirement.  Contact your platform vendor.\n");
+		return -EPERM;
+	}
+
+	/* normally dev is not mapped */
+	if (unlikely(domain_context_mapped(dev))) {
+		struct dmar_domain *old_domain;
+
+		old_domain = find_domain(dev);
+		if (old_domain) {
+			if (domain_type_is_vm_or_si(dmar_domain))
+				domain_remove_one_dev_info(old_domain, dev);
+			else
+				domain_remove_dev_info(old_domain);
+
+			if (!domain_type_is_vm_or_si(old_domain) &&
+			     list_empty(&old_domain->devices))
+				domain_exit(old_domain);
+		}
+	}
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	/* check if this iommu agaw is sufficient for max mapped address */
+	addr_width = agaw_to_width(iommu->agaw);
+	if (addr_width > cap_mgaw(iommu->cap))
+		addr_width = cap_mgaw(iommu->cap);
+
+	if (dmar_domain->max_addr > (1LL << addr_width)) {
+		printk(KERN_ERR "%s: iommu width (%d) is not "
+		       "sufficient for the mapped address (%llx)\n",
+		       __func__, addr_width, dmar_domain->max_addr);
+		return -EFAULT;
+	}
+	dmar_domain->gaw = addr_width;
+
+	/*
+	 * Knock out extra levels of page tables if necessary
+	 */
+	while (iommu->agaw < dmar_domain->agaw) {
+		struct dma_pte *pte;
+
+		pte = dmar_domain->pgd;
+		if (dma_pte_present(pte)) {
+			dmar_domain->pgd = (struct dma_pte *)
+				phys_to_virt(dma_pte_addr(pte));
+			free_pgtable_page(pte);
+		}
+		dmar_domain->agaw--;
+	}
+
+	return domain_add_dev_info(dmar_domain, dev, CONTEXT_TT_MULTI_LEVEL);
+}
+
+static void intel_iommu_detach_device(struct iommu_domain *domain,
+				      struct device *dev)
+{
+	domain_remove_one_dev_info(to_dmar_domain(domain), dev);
+}
+
+static int intel_iommu_map(struct iommu_domain *domain,
+			   unsigned long iova, phys_addr_t hpa,
+			   size_t size, int iommu_prot)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	u64 max_addr;
+	int prot = 0;
+	int ret;
+
+	if (iommu_prot & IOMMU_READ)
+		prot |= DMA_PTE_READ;
+	if (iommu_prot & IOMMU_WRITE)
+		prot |= DMA_PTE_WRITE;
+	if ((iommu_prot & IOMMU_CACHE) && dmar_domain->iommu_snooping)
+		prot |= DMA_PTE_SNP;
+
+	max_addr = iova + size;
+	if (dmar_domain->max_addr < max_addr) {
+		u64 end;
+
+		/* check if minimum agaw is sufficient for mapped address */
+		end = __DOMAIN_MAX_ADDR(dmar_domain->gaw) + 1;
+		if (end < max_addr) {
+			printk(KERN_ERR "%s: iommu width (%d) is not "
+			       "sufficient for the mapped address (%llx)\n",
+			       __func__, dmar_domain->gaw, max_addr);
+			return -EFAULT;
+		}
+		dmar_domain->max_addr = max_addr;
+	}
+	/* Round up size to next multiple of PAGE_SIZE, if it and
+	   the low bits of hpa would take us onto the next page */
+	size = aligned_nrpages(hpa, size);
+	ret = domain_pfn_mapping(dmar_domain, iova >> VTD_PAGE_SHIFT,
+				 hpa >> VTD_PAGE_SHIFT, size, prot);
+	return ret;
+}
+
+static size_t intel_iommu_unmap(struct iommu_domain *domain,
+				unsigned long iova, size_t size)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct page *freelist = NULL;
+	struct intel_iommu *iommu;
+	unsigned long start_pfn, last_pfn;
+	unsigned int npages;
+	int iommu_id, num, ndomains, level = 0;
+
+	/* Cope with horrid API which requires us to unmap more than the
+	   size argument if it happens to be a large-page mapping. */
+	if (!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level))
+		BUG();
+
+	if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
+		size = VTD_PAGE_SIZE << level_to_offset_bits(level);
+
+	start_pfn = iova >> VTD_PAGE_SHIFT;
+	last_pfn = (iova + size - 1) >> VTD_PAGE_SHIFT;
+
+	freelist = domain_unmap(dmar_domain, start_pfn, last_pfn);
+
+	npages = last_pfn - start_pfn + 1;
+
+	for_each_set_bit(iommu_id, dmar_domain->iommu_bmp, g_num_of_iommus) {
+               iommu = g_iommus[iommu_id];
+
+               /*
+                * find bit position of dmar_domain
+                */
+               ndomains = cap_ndoms(iommu->cap);
+               for_each_set_bit(num, iommu->domain_ids, ndomains) {
+                       if (iommu->domains[num] == dmar_domain)
+                               iommu_flush_iotlb_psi(iommu, num, start_pfn,
+						     npages, !freelist, 0);
+	       }
+
+	}
+
+	dma_free_pagelist(freelist);
+
+	if (dmar_domain->max_addr == iova + size)
+		dmar_domain->max_addr = iova;
+
+	return size;
+}
+
+static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
+					    dma_addr_t iova)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct dma_pte *pte;
+	int level = 0;
+	u64 phys = 0;
+
+	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level);
+	if (pte)
+		phys = dma_pte_addr(pte);
+
+	return phys;
+}
+
+static bool intel_iommu_capable(enum iommu_cap cap)
+{
+	if (cap == IOMMU_CAP_CACHE_COHERENCY)
+		return domain_update_iommu_snooping(NULL) == 1;
+	if (cap == IOMMU_CAP_INTR_REMAP)
+		return irq_remapping_enabled == 1;
+
+	return false;
+}
+
+static int intel_iommu_add_device(struct device *dev)
+{
+	struct intel_iommu *iommu;
+	struct iommu_group *group;
+	u8 bus, devfn;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	iommu_device_link(iommu->iommu_dev, dev);
+
+	group = iommu_group_get_for_dev(dev);
+
+	if (IS_ERR(group))
+		return PTR_ERR(group);
+
+	iommu_group_put(group);
+	return 0;
+}
+
+static void intel_iommu_remove_device(struct device *dev)
+{
+	struct intel_iommu *iommu;
+	u8 bus, devfn;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return;
+
+	iommu_group_remove_device(dev);
+
+	iommu_device_unlink(iommu->iommu_dev, dev);
+}
+
+static const struct iommu_ops intel_iommu_ops = {
+	.capable	= intel_iommu_capable,
+	.domain_alloc	= intel_iommu_domain_alloc,
+	.domain_free	= intel_iommu_domain_free,
+	.attach_dev	= intel_iommu_attach_device,
+	.detach_dev	= intel_iommu_detach_device,
+	.map		= intel_iommu_map,
+	.unmap		= intel_iommu_unmap,
+	.map_sg		= default_iommu_map_sg,
+	.iova_to_phys	= intel_iommu_iova_to_phys,
+	.add_device	= intel_iommu_add_device,
+	.remove_device	= intel_iommu_remove_device,
+	.pgsize_bitmap	= INTEL_IOMMU_PGSIZES,
+};
+
+static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
+{
+	/* G4x/GM45 integrated gfx dmar support is totally busted. */
+	printk(KERN_INFO "DMAR: Disabling IOMMU for graphics on this chipset\n");
+	dmar_map_gfx = 0;
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e10, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e20, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e30, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_g4x_gfx);
+
+static void quirk_iommu_rwbf(struct pci_dev *dev)
+{
+	/*
+	 * Mobile 4 Series Chipset neglects to set RWBF capability,
+	 * but needs it. Same seems to hold for the desktop versions.
+	 */
+	printk(KERN_INFO "DMAR: Forcing write-buffer flush capability\n");
+	rwbf_quirk = 1;
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e10, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e20, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e30, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_rwbf);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_rwbf);
+
+#define GGC 0x52
+#define GGC_MEMORY_SIZE_MASK	(0xf << 8)
+#define GGC_MEMORY_SIZE_NONE	(0x0 << 8)
+#define GGC_MEMORY_SIZE_1M	(0x1 << 8)
+#define GGC_MEMORY_SIZE_2M	(0x3 << 8)
+#define GGC_MEMORY_VT_ENABLED	(0x8 << 8)
+#define GGC_MEMORY_SIZE_2M_VT	(0x9 << 8)
+#define GGC_MEMORY_SIZE_3M_VT	(0xa << 8)
+#define GGC_MEMORY_SIZE_4M_VT	(0xb << 8)
+
+static void quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
+{
+	unsigned short ggc;
+
+	if (pci_read_config_word(dev, GGC, &ggc))
+		return;
+
+	if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
+		printk(KERN_INFO "DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
+		dmar_map_gfx = 0;
+	} else if (dmar_map_gfx) {
+		/* we have to ensure the gfx device is idle before we flush */
+		printk(KERN_INFO "DMAR: Disabling batched IOTLB flush on Ironlake\n");
+		intel_iommu_strict = 1;
+       }
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, quirk_calpella_no_shadow_gtt);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_calpella_no_shadow_gtt);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0062, quirk_calpella_no_shadow_gtt);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x006a, quirk_calpella_no_shadow_gtt);
+
+/* On Tylersburg chipsets, some BIOSes have been known to enable the
+   ISOCH DMAR unit for the Azalia sound device, but not give it any
+   TLB entries, which causes it to deadlock. Check for that.  We do
+   this in a function called from init_dmars(), instead of in a PCI
+   quirk, because we don't want to print the obnoxious "BIOS broken"
+   message if VT-d is actually disabled.
+*/
+static void __init check_tylersburg_isoch(void)
+{
+	struct pci_dev *pdev;
+	uint32_t vtisochctrl;
+
+	/* If there's no Azalia in the system anyway, forget it. */
+	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x3a3e, NULL);
+	if (!pdev)
+		return;
+	pci_dev_put(pdev);
+
+	/* System Management Registers. Might be hidden, in which case
+	   we can't do the sanity check. But that's OK, because the
+	   known-broken BIOSes _don't_ actually hide it, so far. */
+	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x342e, NULL);
+	if (!pdev)
+		return;
+
+	if (pci_read_config_dword(pdev, 0x188, &vtisochctrl)) {
+		pci_dev_put(pdev);
+		return;
+	}
+
+	pci_dev_put(pdev);
+
+	/* If Azalia DMA is routed to the non-isoch DMAR unit, fine. */
+	if (vtisochctrl & 1)
+		return;
+
+	/* Drop all bits other than the number of TLB entries */
+	vtisochctrl &= 0x1c;
+
+	/* If we have the recommended number of TLB entries (16), fine. */
+	if (vtisochctrl == 0x10)
+		return;
+
+	/* Zero TLB entries? You get to ride the short bus to school. */
+	if (!vtisochctrl) {
+		WARN(1, "Your BIOS is broken; DMA routed to ISOCH DMAR unit but no TLB space.\n"
+		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+		     dmi_get_system_info(DMI_BIOS_VENDOR),
+		     dmi_get_system_info(DMI_BIOS_VERSION),
+		     dmi_get_system_info(DMI_PRODUCT_VERSION));
+		iommu_identity_mapping |= IDENTMAP_AZALIA;
+		return;
+	}
+	
+	printk(KERN_WARNING "DMAR: Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n",
+	       vtisochctrl);
+}