Intel IOMMU: Intel IOMMU driver

Actual intel IOMMU driver.  Hardware spec can be found at:
http://www.intel.com/technology/virtualization

This driver sets X86_64 'dma_ops', so hook into standard DMA APIs.  In this
way, PCI driver will get virtual DMA address.  This change is transparent to
PCI drivers.

[akpm@linux-foundation.org: remove unneeded cast]
[akpm@linux-foundation.org: build fix]
[bunk@stusta.de: fix duplicate CONFIG_DMAR Makefile line]
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1957 insertions, 0 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
new file mode 100644
index 000000000000..93ed771b3254
--- /dev/null
+++ b/drivers/pci/intel-iommu.c
@@ -0,0 +1,1957 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Copyright (C) Ashok Raj <ashok.raj@intel.com>
+ * Copyright (C) Shaohua Li <shaohua.li@intel.com>
+ * Copyright (C) Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ */
+
+#include <linux/init.h>
+#include <linux/bitmap.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/sysdev.h>
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/dmar.h>
+#include <linux/dma-mapping.h>
+#include <linux/mempool.h>
+#include "iova.h"
+#include "intel-iommu.h"
+#include <asm/proto.h> /* force_iommu in this header in x86-64*/
+#include <asm/cacheflush.h>
+#include <asm/iommu.h>
+#include "pci.h"
+
+#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
+#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
+
+#define IOAPIC_RANGE_START      (0xfee00000)
+#define IOAPIC_RANGE_END        (0xfeefffff)
+#define IOVA_START_ADDR         (0x1000)
+
+#define DEFAULT_DOMAIN_ADDRESS_WIDTH 48
+
+#define DMAR_OPERATION_TIMEOUT (HZ*60) /* 1m */
+
+#define DOMAIN_MAX_ADDR(gaw) ((((u64)1) << gaw) - 1)
+
+static void domain_remove_dev_info(struct dmar_domain *domain);
+
+static int dmar_disabled;
+static int __initdata dmar_map_gfx = 1;
+
+#define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
+static DEFINE_SPINLOCK(device_domain_lock);
+static LIST_HEAD(device_domain_list);
+
+static int __init intel_iommu_setup(char *str)
+{
+        if (!str)
+                return -EINVAL;
+        while (*str) {
+                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");
+                }
+
+                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 struct kmem_cache *iommu_iova_cache;
+
+static inline void *alloc_pgtable_page(void)
+{
+        return (void *)get_zeroed_page(GFP_ATOMIC);
+}
+
+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 inline 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);
+}
+
+struct iova *alloc_iova_mem(void)
+{
+        return kmem_cache_alloc(iommu_iova_cache, GFP_ATOMIC);
+}
+
+void free_iova_mem(struct iova *iova)
+{
+        kmem_cache_free(iommu_iova_cache, iova);
+}
+
+static inline void __iommu_flush_cache(
+        struct intel_iommu *iommu, void *addr, int size)
+{
+        if (!ecap_coherent(iommu->ecap))
+                clflush_cache_range(addr, size);
+}
+
+/* Gets context entry for a given bus and devfn */
+static struct context_entry * device_to_context_entry(struct intel_iommu *iommu,
+                u8 bus, u8 devfn)
+{
+        struct root_entry *root;
+        struct context_entry *context;
+        unsigned long phy_addr;
+        unsigned long flags;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        root = &iommu->root_entry[bus];
+        context = get_context_addr_from_root(root);
+        if (!context) {
+                context = (struct context_entry *)alloc_pgtable_page();
+                if (!context) {
+                        spin_unlock_irqrestore(&iommu->lock, flags);
+                        return NULL;
+                }
+                __iommu_flush_cache(iommu, (void *)context, PAGE_SIZE_4K);
+                phy_addr = virt_to_phys((void *)context);
+                set_root_value(root, phy_addr);
+                set_root_present(root);
+                __iommu_flush_cache(iommu, root, sizeof(*root));
+        }
+        spin_unlock_irqrestore(&iommu->lock, flags);
+        return &context[devfn];
+}
+
+static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+        struct root_entry *root;
+        struct context_entry *context;
+        int ret;
+        unsigned long flags;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        root = &iommu->root_entry[bus];
+        context = get_context_addr_from_root(root);
+        if (!context) {
+                ret = 0;
+                goto out;
+        }
+        ret = context_present(context[devfn]);
+out:
+        spin_unlock_irqrestore(&iommu->lock, flags);
+        return ret;
+}
+
+static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn)
+{
+        struct root_entry *root;
+        struct context_entry *context;
+        unsigned long flags;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        root = &iommu->root_entry[bus];
+        context = get_context_addr_from_root(root);
+        if (context) {
+                context_clear_entry(context[devfn]);
+                __iommu_flush_cache(iommu, &context[devfn], \
+                        sizeof(*context));
+        }
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void free_context_table(struct intel_iommu *iommu)
+{
+        struct root_entry *root;
+        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++) {
+                root = &iommu->root_entry[i];
+                context = get_context_addr_from_root(root);
+                if (context)
+                        free_pgtable_page(context);
+        }
+        free_pgtable_page(iommu->root_entry);
+        iommu->root_entry = NULL;
+out:
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+/* page table handling */
+#define LEVEL_STRIDE            (9)
+#define LEVEL_MASK              (((u64)1 << LEVEL_STRIDE) - 1)
+
+static inline int agaw_to_level(int agaw)
+{
+        return agaw + 2;
+}
+
+static inline int agaw_to_width(int agaw)
+{
+        return 30 + agaw * LEVEL_STRIDE;
+
+}
+
+static inline int width_to_agaw(int width)
+{
+        return (width - 30) / LEVEL_STRIDE;
+}
+
+static inline unsigned int level_to_offset_bits(int level)
+{
+        return (12 + (level - 1) * LEVEL_STRIDE);
+}
+
+static inline int address_level_offset(u64 addr, int level)
+{
+        return ((addr >> level_to_offset_bits(level)) & LEVEL_MASK);
+}
+
+static inline u64 level_mask(int level)
+{
+        return ((u64)-1 << level_to_offset_bits(level));
+}
+
+static inline u64 level_size(int level)
+{
+        return ((u64)1 << level_to_offset_bits(level));
+}
+
+static inline u64 align_to_level(u64 addr, int level)
+{
+        return ((addr + level_size(level) - 1) & level_mask(level));
+}
+
+static struct dma_pte * addr_to_dma_pte(struct dmar_domain *domain, u64 addr)
+{
+        int addr_width = agaw_to_width(domain->agaw);
+        struct dma_pte *parent, *pte = NULL;
+        int level = agaw_to_level(domain->agaw);
+        int offset;
+        unsigned long flags;
+
+        BUG_ON(!domain->pgd);
+
+        addr &= (((u64)1) << addr_width) - 1;
+        parent = domain->pgd;
+
+        spin_lock_irqsave(&domain->mapping_lock, flags);
+        while (level > 0) {
+                void *tmp_page;
+
+                offset = address_level_offset(addr, level);
+                pte = &parent[offset];
+                if (level == 1)
+                        break;
+
+                if (!dma_pte_present(*pte)) {
+                        tmp_page = alloc_pgtable_page();
+
+                        if (!tmp_page) {
+                                spin_unlock_irqrestore(&domain->mapping_lock,
+                                        flags);
+                                return NULL;
+                        }
+                        __iommu_flush_cache(domain->iommu, tmp_page,
+                                        PAGE_SIZE_4K);
+                        dma_set_pte_addr(*pte, virt_to_phys(tmp_page));
+                        /*
+                         * high level table always sets r/w, last level page
+                         * table control read/write
+                         */
+                        dma_set_pte_readable(*pte);
+                        dma_set_pte_writable(*pte);
+                        __iommu_flush_cache(domain->iommu, pte, sizeof(*pte));
+                }
+                parent = phys_to_virt(dma_pte_addr(*pte));
+                level--;
+        }
+
+        spin_unlock_irqrestore(&domain->mapping_lock, flags);
+        return pte;
+}
+
+/* return address's pte at specific level */
+static struct dma_pte *dma_addr_level_pte(struct dmar_domain *domain, u64 addr,
+                int level)
+{
+        struct dma_pte *parent, *pte = NULL;
+        int total = agaw_to_level(domain->agaw);
+        int offset;
+
+        parent = domain->pgd;
+        while (level <= total) {
+                offset = address_level_offset(addr, total);
+                pte = &parent[offset];
+                if (level == total)
+                        return pte;
+
+                if (!dma_pte_present(*pte))
+                        break;
+                parent = phys_to_virt(dma_pte_addr(*pte));
+                total--;
+        }
+        return NULL;
+}
+
+/* clear one page's page table */
+static void dma_pte_clear_one(struct dmar_domain *domain, u64 addr)
+{
+        struct dma_pte *pte = NULL;
+
+        /* get last level pte */
+        pte = dma_addr_level_pte(domain, addr, 1);
+
+        if (pte) {
+                dma_clear_pte(*pte);
+                __iommu_flush_cache(domain->iommu, pte, sizeof(*pte));
+        }
+}
+
+/* clear last level pte, a tlb flush should be followed */
+static void dma_pte_clear_range(struct dmar_domain *domain, u64 start, u64 end)
+{
+        int addr_width = agaw_to_width(domain->agaw);
+
+        start &= (((u64)1) << addr_width) - 1;
+        end &= (((u64)1) << addr_width) - 1;
+        /* in case it's partial page */
+        start = PAGE_ALIGN_4K(start);
+        end &= PAGE_MASK_4K;
+
+        /* we don't need lock here, nobody else touches the iova range */
+        while (start < end) {
+                dma_pte_clear_one(domain, start);
+                start += PAGE_SIZE_4K;
+        }
+}
+
+/* free page table pages. last level pte should already be cleared */
+static void dma_pte_free_pagetable(struct dmar_domain *domain,
+        u64 start, u64 end)
+{
+        int addr_width = agaw_to_width(domain->agaw);
+        struct dma_pte *pte;
+        int total = agaw_to_level(domain->agaw);
+        int level;
+        u64 tmp;
+
+        start &= (((u64)1) << addr_width) - 1;
+        end &= (((u64)1) << addr_width) - 1;
+
+        /* we don't need lock here, nobody else touches the iova range */
+        level = 2;
+        while (level <= total) {
+                tmp = align_to_level(start, level);
+                if (tmp >= end || (tmp + level_size(level) > end))
+                        return;
+
+                while (tmp < end) {
+                        pte = dma_addr_level_pte(domain, tmp, level);
+                        if (pte) {
+                                free_pgtable_page(
+                                        phys_to_virt(dma_pte_addr(*pte)));
+                                dma_clear_pte(*pte);
+                                __iommu_flush_cache(domain->iommu,
+                                                pte, sizeof(*pte));
+                        }
+                        tmp += level_size(level);
+                }
+                level++;
+        }
+        /* free pgd */
+        if (start == 0 && end >= ((((u64)1) << addr_width) - 1)) {
+                free_pgtable_page(domain->pgd);
+                domain->pgd = NULL;
+        }
+}
+
+/* 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();
+        if (!root)
+                return -ENOMEM;
+
+        __iommu_flush_cache(iommu, root, PAGE_SIZE_4K);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        iommu->root_entry = root;
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        return 0;
+}
+
+#define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \
+{\
+        unsigned long start_time = jiffies;\
+        while (1) {\
+                sts = op (iommu->reg + offset);\
+                if (cond)\
+                        break;\
+                if (time_after(jiffies, start_time + DMAR_OPERATION_TIMEOUT))\
+                        panic("DMAR hardware is malfunctioning\n");\
+                cpu_relax();\
+        }\
+}
+
+static void iommu_set_root_entry(struct intel_iommu *iommu)
+{
+        void *addr;
+        u32 cmd, sts;
+        unsigned long flag;
+
+        addr = iommu->root_entry;
+
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        dmar_writeq(iommu->reg + DMAR_RTADDR_REG, virt_to_phys(addr));
+
+        cmd = iommu->gcmd | DMA_GCMD_SRTP;
+        writel(cmd, iommu->reg + DMAR_GCMD_REG);
+
+        /* Make sure hardware complete it */
+        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                readl, (sts & DMA_GSTS_RTPS), sts);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+static void iommu_flush_write_buffer(struct intel_iommu *iommu)
+{
+        u32 val;
+        unsigned long flag;
+
+        if (!cap_rwbf(iommu->cap))
+                return;
+        val = iommu->gcmd | DMA_GCMD_WBF;
+
+        spin_lock_irqsave(&iommu->register_lock, flag);
+        writel(val, iommu->reg + DMAR_GCMD_REG);
+
+        /* Make sure hardware complete it */
+        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                        readl, (!(val & DMA_GSTS_WBFS)), val);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+/* return value determine if we need a write buffer flush */
+static int __iommu_flush_context(struct intel_iommu *iommu,
+        u16 did, u16 source_id, u8 function_mask, u64 type,
+        int non_present_entry_flush)
+{
+        u64 val = 0;
+        unsigned long flag;
+
+        /*
+         * In the non-present entry flush case, if hardware doesn't cache
+         * non-present entry we do nothing and if hardware cache non-present
+         * entry, we flush entries of domain 0 (the domain id is used to cache
+         * any non-present entries)
+         */
+        if (non_present_entry_flush) {
+                if (!cap_caching_mode(iommu->cap))
+                        return 1;
+                else
+                        did = 0;
+        }
+
+        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;
+
+        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);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+
+        /* flush context entry will implictly flush write buffer */
+        return 0;
+}
+
+static int inline iommu_flush_context_global(struct intel_iommu *iommu,
+        int non_present_entry_flush)
+{
+        return __iommu_flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL,
+                non_present_entry_flush);
+}
+
+static int inline iommu_flush_context_domain(struct intel_iommu *iommu, u16 did,
+        int non_present_entry_flush)
+{
+        return __iommu_flush_context(iommu, did, 0, 0, DMA_CCMD_DOMAIN_INVL,
+                non_present_entry_flush);
+}
+
+static int inline iommu_flush_context_device(struct intel_iommu *iommu,
+        u16 did, u16 source_id, u8 function_mask, int non_present_entry_flush)
+{
+        return __iommu_flush_context(iommu, did, source_id, function_mask,
+                DMA_CCMD_DEVICE_INVL, non_present_entry_flush);
+}
+
+/* return value determine if we need a write buffer flush */
+static int __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
+        u64 addr, unsigned int size_order, u64 type,
+        int non_present_entry_flush)
+{
+        int tlb_offset = ecap_iotlb_offset(iommu->ecap);
+        u64 val = 0, val_iva = 0;
+        unsigned long flag;
+
+        /*
+         * In the non-present entry flush case, if hardware doesn't cache
+         * non-present entry we do nothing and if hardware cache non-present
+         * entry, we flush entries of domain 0 (the domain id is used to cache
+         * any non-present entries)
+         */
+        if (non_present_entry_flush) {
+                if (!cap_caching_mode(iommu->cap))
+                        return 1;
+                else
+                        did = 0;
+        }
+
+        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);
+                /* Note: always flush non-leaf currently */
+                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;
+
+        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);
+
+        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",
+                        DMA_TLB_IIRG(type), DMA_TLB_IAIG(val));
+        /* flush context entry will implictly flush write buffer */
+        return 0;
+}
+
+static int inline iommu_flush_iotlb_global(struct intel_iommu *iommu,
+        int non_present_entry_flush)
+{
+        return __iommu_flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH,
+                non_present_entry_flush);
+}
+
+static int inline iommu_flush_iotlb_dsi(struct intel_iommu *iommu, u16 did,
+        int non_present_entry_flush)
+{
+        return __iommu_flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH,
+                non_present_entry_flush);
+}
+
+static int iommu_get_alignment(u64 base, unsigned int size)
+{
+        int t = 0;
+        u64 end;
+
+        end = base + size - 1;
+        while (base != end) {
+                t++;
+                base >>= 1;
+                end >>= 1;
+        }
+        return t;
+}
+
+static int iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
+        u64 addr, unsigned int pages, int non_present_entry_flush)
+{
+        unsigned int align;
+
+        BUG_ON(addr & (~PAGE_MASK_4K));
+        BUG_ON(pages == 0);
+
+        /* Fallback to domain selective flush if no PSI support */
+        if (!cap_pgsel_inv(iommu->cap))
+                return iommu_flush_iotlb_dsi(iommu, did,
+                        non_present_entry_flush);
+
+        /*
+         * PSI requires page size to be 2 ^ x, and the base address is naturally
+         * aligned to the size
+         */
+        align = iommu_get_alignment(addr >> PAGE_SHIFT_4K, pages);
+        /* Fallback to domain selective flush if size is too big */
+        if (align > cap_max_amask_val(iommu->cap))
+                return iommu_flush_iotlb_dsi(iommu, did,
+                        non_present_entry_flush);
+
+        addr >>= PAGE_SHIFT_4K + align;
+        addr <<= PAGE_SHIFT_4K + align;
+
+        return __iommu_flush_iotlb(iommu, did, addr, align,
+                DMA_TLB_PSI_FLUSH, non_present_entry_flush);
+}
+
+static int iommu_enable_translation(struct intel_iommu *iommu)
+{
+        u32 sts;
+        unsigned long flags;
+
+        spin_lock_irqsave(&iommu->register_lock, flags);
+        writel(iommu->gcmd|DMA_GCMD_TE, iommu->reg + DMAR_GCMD_REG);
+
+        /* Make sure hardware complete it */
+        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
+                readl, (sts & DMA_GSTS_TES), sts);
+
+        iommu->gcmd |= DMA_GCMD_TE;
+        spin_unlock_irqrestore(&iommu->register_lock, flags);
+        return 0;
+}
+
+static int iommu_disable_translation(struct intel_iommu *iommu)
+{
+        u32 sts;
+        unsigned long flag;
+
+        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);
+
+        spin_unlock_irqrestore(&iommu->register_lock, flag);
+        return 0;
+}
+
+static int iommu_init_domains(struct intel_iommu *iommu)
+{
+        unsigned long ndomains;
+        unsigned long nlongs;
+
+        ndomains = cap_ndoms(iommu->cap);
+        pr_debug("Number of Domains supportd <%ld>\n", ndomains);
+        nlongs = BITS_TO_LONGS(ndomains);
+
+        /* 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) {
+                printk(KERN_ERR "Allocating domain id array failed\n");
+                return -ENOMEM;
+        }
+        iommu->domains = kcalloc(ndomains, sizeof(struct dmar_domain *),
+                        GFP_KERNEL);
+        if (!iommu->domains) {
+                printk(KERN_ERR "Allocating domain array failed\n");
+                kfree(iommu->domain_ids);
+                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 struct intel_iommu *alloc_iommu(struct dmar_drhd_unit *drhd)
+{
+        struct intel_iommu *iommu;
+        int ret;
+        int map_size;
+        u32 ver;
+
+        iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+        if (!iommu)
+                return NULL;
+        iommu->reg = ioremap(drhd->reg_base_addr, PAGE_SIZE_4K);
+        if (!iommu->reg) {
+                printk(KERN_ERR "IOMMU: can't map the region\n");
+                goto error;
+        }
+        iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
+        iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
+
+        /* the registers might be more than one page */
+        map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
+                cap_max_fault_reg_offset(iommu->cap));
+        map_size = PAGE_ALIGN_4K(map_size);
+        if (map_size > PAGE_SIZE_4K) {
+                iounmap(iommu->reg);
+                iommu->reg = ioremap(drhd->reg_base_addr, map_size);
+                if (!iommu->reg) {
+                        printk(KERN_ERR "IOMMU: can't map the region\n");
+                        goto error;
+                }
+        }
+
+        ver = readl(iommu->reg + DMAR_VER_REG);
+        pr_debug("IOMMU %llx: ver %d:%d cap %llx ecap %llx\n",
+                drhd->reg_base_addr, DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
+                iommu->cap, iommu->ecap);
+        ret = iommu_init_domains(iommu);
+        if (ret)
+                goto error_unmap;
+        spin_lock_init(&iommu->lock);
+        spin_lock_init(&iommu->register_lock);
+
+        drhd->iommu = iommu;
+        return iommu;
+error_unmap:
+        iounmap(iommu->reg);
+        iommu->reg = 0;
+error:
+        kfree(iommu);
+        return NULL;
+}
+
+static void domain_exit(struct dmar_domain *domain);
+static void free_iommu(struct intel_iommu *iommu)
+{
+        struct dmar_domain *domain;
+        int i;
+
+        if (!iommu)
+                return;
+
+        i = find_first_bit(iommu->domain_ids, cap_ndoms(iommu->cap));
+        for (; i < cap_ndoms(iommu->cap); ) {
+                domain = iommu->domains[i];
+                clear_bit(i, iommu->domain_ids);
+                domain_exit(domain);
+                i = find_next_bit(iommu->domain_ids,
+                        cap_ndoms(iommu->cap), i+1);
+        }
+
+        if (iommu->gcmd & DMA_GCMD_TE)
+                iommu_disable_translation(iommu);
+
+        if (iommu->irq) {
+                set_irq_data(iommu->irq, NULL);
+                /* This will mask the irq */
+                free_irq(iommu->irq, iommu);
+                destroy_irq(iommu->irq);
+        }
+
+        kfree(iommu->domains);
+        kfree(iommu->domain_ids);
+
+        /* free context mapping */
+        free_context_table(iommu);
+
+        if (iommu->reg)
+                iounmap(iommu->reg);
+        kfree(iommu);
+}
+
+static struct dmar_domain * iommu_alloc_domain(struct intel_iommu *iommu)
+{
+        unsigned long num;
+        unsigned long ndomains;
+        struct dmar_domain *domain;
+        unsigned long flags;
+
+        domain = alloc_domain_mem();
+        if (!domain)
+                return NULL;
+
+        ndomains = cap_ndoms(iommu->cap);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        num = find_first_zero_bit(iommu->domain_ids, ndomains);
+        if (num >= ndomains) {
+                spin_unlock_irqrestore(&iommu->lock, flags);
+                free_domain_mem(domain);
+                printk(KERN_ERR "IOMMU: no free domain ids\n");
+                return NULL;
+        }
+
+        set_bit(num, iommu->domain_ids);
+        domain->id = num;
+        domain->iommu = iommu;
+        iommu->domains[num] = domain;
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        return domain;
+}
+
+static void iommu_free_domain(struct dmar_domain *domain)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&domain->iommu->lock, flags);
+        clear_bit(domain->id, domain->iommu->domain_ids);
+        spin_unlock_irqrestore(&domain->iommu->lock, flags);
+}
+
+static struct iova_domain reserved_iova_list;
+
+static void dmar_init_reserved_ranges(void)
+{
+        struct pci_dev *pdev = NULL;
+        struct iova *iova;
+        int i;
+        u64 addr, size;
+
+        init_iova_domain(&reserved_iova_list);
+
+        /* 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");
+
+        /* 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;
+                        addr = r->start;
+                        addr &= PAGE_MASK_4K;
+                        size = r->end - addr;
+                        size = PAGE_ALIGN_4K(size);
+                        iova = reserve_iova(&reserved_iova_list, IOVA_PFN(addr),
+                                IOVA_PFN(size + addr) - 1);
+                        if (!iova)
+                                printk(KERN_ERR "Reserve iova failed\n");
+                }
+        }
+
+}
+
+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);
+        spin_lock_init(&domain->mapping_lock);
+
+        domain_reserve_special_ranges(domain);
+
+        /* calculate AGAW */
+        iommu = domain->iommu;
+        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;
+        INIT_LIST_HEAD(&domain->devices);
+
+        /* always allocate the top pgd */
+        domain->pgd = (struct dma_pte *)alloc_pgtable_page();
+        if (!domain->pgd)
+                return -ENOMEM;
+        __iommu_flush_cache(iommu, domain->pgd, PAGE_SIZE_4K);
+        return 0;
+}
+
+static void domain_exit(struct dmar_domain *domain)
+{
+        u64 end;
+
+        /* Domain 0 is reserved, so dont process it */
+        if (!domain)
+                return;
+
+        domain_remove_dev_info(domain);
+        /* destroy iovas */
+        put_iova_domain(&domain->iovad);
+        end = DOMAIN_MAX_ADDR(domain->gaw);
+        end = end & (~PAGE_MASK_4K);
+
+        /* clear ptes */
+        dma_pte_clear_range(domain, 0, end);
+
+        /* free page tables */
+        dma_pte_free_pagetable(domain, 0, end);
+
+        iommu_free_domain(domain);
+        free_domain_mem(domain);
+}
+
+static int domain_context_mapping_one(struct dmar_domain *domain,
+                u8 bus, u8 devfn)
+{
+        struct context_entry *context;
+        struct intel_iommu *iommu = domain->iommu;
+        unsigned long flags;
+
+        pr_debug("Set context mapping for %02x:%02x.%d\n",
+                bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+        BUG_ON(!domain->pgd);
+        context = device_to_context_entry(iommu, bus, devfn);
+        if (!context)
+                return -ENOMEM;
+        spin_lock_irqsave(&iommu->lock, flags);
+        if (context_present(*context)) {
+                spin_unlock_irqrestore(&iommu->lock, flags);
+                return 0;
+        }
+
+        context_set_domain_id(*context, domain->id);
+        context_set_address_width(*context, domain->agaw);
+        context_set_address_root(*context, virt_to_phys(domain->pgd));
+        context_set_translation_type(*context, CONTEXT_TT_MULTI_LEVEL);
+        context_set_fault_enable(*context);
+        context_set_present(*context);
+        __iommu_flush_cache(iommu, context, sizeof(*context));
+
+        /* it's a non-present to present mapping */
+        if (iommu_flush_context_device(iommu, domain->id,
+                        (((u16)bus) << 8) | devfn, DMA_CCMD_MASK_NOBIT, 1))
+                iommu_flush_write_buffer(iommu);
+        else
+                iommu_flush_iotlb_dsi(iommu, 0, 0);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+        return 0;
+}
+
+static int
+domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev)
+{
+        int ret;
+        struct pci_dev *tmp, *parent;
+
+        ret = domain_context_mapping_one(domain, pdev->bus->number,
+                pdev->devfn);
+        if (ret)
+                return ret;
+
+        /* dependent device mapping */
+        tmp = pci_find_upstream_pcie_bridge(pdev);
+        if (!tmp)
+                return 0;
+        /* Secondary interface's bus number and devfn 0 */
+        parent = pdev->bus->self;
+        while (parent != tmp) {
+                ret = domain_context_mapping_one(domain, parent->bus->number,
+                        parent->devfn);
+                if (ret)
+                        return ret;
+                parent = parent->bus->self;
+        }
+        if (tmp->is_pcie) /* this is a PCIE-to-PCI bridge */
+                return domain_context_mapping_one(domain,
+                        tmp->subordinate->number, 0);
+        else /* this is a legacy PCI bridge */
+                return domain_context_mapping_one(domain,
+                        tmp->bus->number, tmp->devfn);
+}
+
+static int domain_context_mapped(struct dmar_domain *domain,
+        struct pci_dev *pdev)
+{
+        int ret;
+        struct pci_dev *tmp, *parent;
+
+        ret = device_context_mapped(domain->iommu,
+                pdev->bus->number, pdev->devfn);
+        if (!ret)
+                return ret;
+        /* dependent device mapping */
+        tmp = pci_find_upstream_pcie_bridge(pdev);
+        if (!tmp)
+                return ret;
+        /* Secondary interface's bus number and devfn 0 */
+        parent = pdev->bus->self;
+        while (parent != tmp) {
+                ret = device_context_mapped(domain->iommu, parent->bus->number,
+                        parent->devfn);
+                if (!ret)
+                        return ret;
+                parent = parent->bus->self;
+        }
+        if (tmp->is_pcie)
+                return device_context_mapped(domain->iommu,
+                        tmp->subordinate->number, 0);
+        else
+                return device_context_mapped(domain->iommu,
+                        tmp->bus->number, tmp->devfn);
+}
+
+static int
+domain_page_mapping(struct dmar_domain *domain, dma_addr_t iova,
+                        u64 hpa, size_t size, int prot)
+{
+        u64 start_pfn, end_pfn;
+        struct dma_pte *pte;
+        int index;
+
+        if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
+                return -EINVAL;
+        iova &= PAGE_MASK_4K;
+        start_pfn = ((u64)hpa) >> PAGE_SHIFT_4K;
+        end_pfn = (PAGE_ALIGN_4K(((u64)hpa) + size)) >> PAGE_SHIFT_4K;
+        index = 0;
+        while (start_pfn < end_pfn) {
+                pte = addr_to_dma_pte(domain, iova + PAGE_SIZE_4K * index);
+                if (!pte)
+                        return -ENOMEM;
+                /* We don't need lock here, nobody else
+                 * touches the iova range
+                 */
+                BUG_ON(dma_pte_addr(*pte));
+                dma_set_pte_addr(*pte, start_pfn << PAGE_SHIFT_4K);
+                dma_set_pte_prot(*pte, prot);
+                __iommu_flush_cache(domain->iommu, pte, sizeof(*pte));
+                start_pfn++;
+                index++;
+        }
+        return 0;
+}
+
+static void detach_domain_for_dev(struct dmar_domain *domain, u8 bus, u8 devfn)
+{
+        clear_context_table(domain->iommu, bus, devfn);
+        iommu_flush_context_global(domain->iommu, 0);
+        iommu_flush_iotlb_global(domain->iommu, 0);
+}
+
+static void domain_remove_dev_info(struct dmar_domain *domain)
+{
+        struct device_domain_info *info;
+        unsigned long flags;
+
+        spin_lock_irqsave(&device_domain_lock, flags);
+        while (!list_empty(&domain->devices)) {
+                info = list_entry(domain->devices.next,
+                        struct device_domain_info, link);
+                list_del(&info->link);
+                list_del(&info->global);
+                if (info->dev)
+                        info->dev->sysdata = NULL;
+                spin_unlock_irqrestore(&device_domain_lock, flags);
+
+                detach_domain_for_dev(info->domain, info->bus, info->devfn);
+                free_devinfo_mem(info);
+
+                spin_lock_irqsave(&device_domain_lock, flags);
+        }
+        spin_unlock_irqrestore(&device_domain_lock, flags);
+}
+
+/*
+ * find_domain
+ * Note: we use struct pci_dev->sysdata stores the info
+ */
+struct dmar_domain *
+find_domain(struct pci_dev *pdev)
+{
+        struct device_domain_info *info;
+
+        /* No lock here, assumes no domain exit in normal case */
+        info = pdev->sysdata;
+        if (info)
+                return info->domain;
+        return NULL;
+}
+
+static int dmar_pci_device_match(struct pci_dev *devices[], int cnt,
+     struct pci_dev *dev)
+{
+        int index;
+
+        while (dev) {
+                for (index = 0; index < cnt; index ++)
+                        if (dev == devices[index])
+                                return 1;
+
+                /* Check our parent */
+                dev = dev->bus->self;
+        }
+
+        return 0;
+}
+
+static struct dmar_drhd_unit *
+dmar_find_matched_drhd_unit(struct pci_dev *dev)
+{
+        struct dmar_drhd_unit *drhd = NULL;
+
+        list_for_each_entry(drhd, &dmar_drhd_units, list) {
+                if (drhd->include_all || dmar_pci_device_match(drhd->devices,
+                                                drhd->devices_cnt, dev))
+                        return drhd;
+        }
+
+        return NULL;
+}
+
+/* domain is initialized */
+static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
+{
+        struct dmar_domain *domain, *found = NULL;
+        struct intel_iommu *iommu;
+        struct dmar_drhd_unit *drhd;
+        struct device_domain_info *info, *tmp;
+        struct pci_dev *dev_tmp;
+        unsigned long flags;
+        int bus = 0, devfn = 0;
+
+        domain = find_domain(pdev);
+        if (domain)
+                return domain;
+
+        dev_tmp = pci_find_upstream_pcie_bridge(pdev);
+        if (dev_tmp) {
+                if (dev_tmp->is_pcie) {
+                        bus = dev_tmp->subordinate->number;
+                        devfn = 0;
+                } else {
+                        bus = dev_tmp->bus->number;
+                        devfn = dev_tmp->devfn;
+                }
+                spin_lock_irqsave(&device_domain_lock, flags);
+                list_for_each_entry(info, &device_domain_list, global) {
+                        if (info->bus == bus && info->devfn == devfn) {
+                                found = info->domain;
+                                break;
+                        }
+                }
+                spin_unlock_irqrestore(&device_domain_lock, flags);
+                /* pcie-pci bridge already has a domain, uses it */
+                if (found) {
+                        domain = found;
+                        goto found_domain;
+                }
+        }
+
+        /* Allocate new domain for the device */
+        drhd = dmar_find_matched_drhd_unit(pdev);
+        if (!drhd) {
+                printk(KERN_ERR "IOMMU: can't find DMAR for device %s\n",
+                        pci_name(pdev));
+                return NULL;
+        }
+        iommu = drhd->iommu;
+
+        domain = iommu_alloc_domain(iommu);
+        if (!domain)
+                goto error;
+
+        if (domain_init(domain, gaw)) {
+                domain_exit(domain);
+                goto error;
+        }
+
+        /* register pcie-to-pci device */
+        if (dev_tmp) {
+                info = alloc_devinfo_mem();
+                if (!info) {
+                        domain_exit(domain);
+                        goto error;
+                }
+                info->bus = bus;
+                info->devfn = devfn;
+                info->dev = NULL;
+                info->domain = domain;
+                /* This domain is shared by devices under p2p bridge */
+                domain->flags |= DOMAIN_FLAG_MULTIPLE_DEVICES;
+
+                /* pcie-to-pci bridge already has a domain, uses it */
+                found = NULL;
+                spin_lock_irqsave(&device_domain_lock, flags);
+                list_for_each_entry(tmp, &device_domain_list, global) {
+                        if (tmp->bus == bus && tmp->devfn == devfn) {
+                                found = tmp->domain;
+                                break;
+                        }
+                }
+                if (found) {
+                        free_devinfo_mem(info);
+                        domain_exit(domain);
+                        domain = found;
+                } else {
+                        list_add(&info->link, &domain->devices);
+                        list_add(&info->global, &device_domain_list);
+                }
+                spin_unlock_irqrestore(&device_domain_lock, flags);
+        }
+
+found_domain:
+        info = alloc_devinfo_mem();
+        if (!info)
+                goto error;
+        info->bus = pdev->bus->number;
+        info->devfn = pdev->devfn;
+        info->dev = pdev;
+        info->domain = domain;
+        spin_lock_irqsave(&device_domain_lock, flags);
+        /* somebody is fast */
+        found = find_domain(pdev);
+        if (found != NULL) {
+                spin_unlock_irqrestore(&device_domain_lock, flags);
+                if (found != domain) {
+                        domain_exit(domain);
+                        domain = found;
+                }
+                free_devinfo_mem(info);
+                return domain;
+        }
+        list_add(&info->link, &domain->devices);
+        list_add(&info->global, &device_domain_list);
+        pdev->sysdata = info;
+        spin_unlock_irqrestore(&device_domain_lock, flags);
+        return domain;
+error:
+        /* recheck it here, maybe others set it */
+        return find_domain(pdev);
+}
+
+static int iommu_prepare_identity_map(struct pci_dev *pdev, u64 start, u64 end)
+{
+        struct dmar_domain *domain;
+        unsigned long size;
+        u64 base;
+        int ret;
+
+        printk(KERN_INFO
+                "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n",
+                pci_name(pdev), start, end);
+        /* page table init */
+        domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+        if (!domain)
+                return -ENOMEM;
+
+        /* The address might not be aligned */
+        base = start & PAGE_MASK_4K;
+        size = end - base;
+        size = PAGE_ALIGN_4K(size);
+        if (!reserve_iova(&domain->iovad, IOVA_PFN(base),
+                        IOVA_PFN(base + size) - 1)) {
+                printk(KERN_ERR "IOMMU: reserve iova failed\n");
+                ret = -ENOMEM;
+                goto error;
+        }
+
+        pr_debug("Mapping reserved region %lx@%llx for %s\n",
+                size, base, pci_name(pdev));
+        /*
+         * RMRR range might have overlap with physical memory range,
+         * clear it first
+         */
+        dma_pte_clear_range(domain, base, base + size);
+
+        ret = domain_page_mapping(domain, base, base, size,
+                DMA_PTE_READ|DMA_PTE_WRITE);
+        if (ret)
+                goto error;
+
+        /* context entry init */
+        ret = domain_context_mapping(domain, pdev);
+        if (!ret)
+                return 0;
+error:
+        domain_exit(domain);
+        return ret;
+
+}
+
+static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
+        struct pci_dev *pdev)
+{
+        if (pdev->sysdata == DUMMY_DEVICE_DOMAIN_INFO)
+                return 0;
+        return iommu_prepare_identity_map(pdev, rmrr->base_address,
+                rmrr->end_address + 1);
+}
+
+int __init init_dmars(void)
+{
+        struct dmar_drhd_unit *drhd;
+        struct dmar_rmrr_unit *rmrr;
+        struct pci_dev *pdev;
+        struct intel_iommu *iommu;
+        int ret, unit = 0;
+
+        /*
+         * for each drhd
+         *    allocate root
+         *    initialize and program root entry to not present
+         * endfor
+         */
+        for_each_drhd_unit(drhd) {
+                if (drhd->ignored)
+                        continue;
+                iommu = alloc_iommu(drhd);
+                if (!iommu) {
+                        ret = -ENOMEM;
+                        goto error;
+                }
+
+                /*
+                 * TBD:
+                 * we could share the same root & context tables
+                 * amoung all IOMMU's. Need to Split it later.
+                 */
+                ret = iommu_alloc_root_entry(iommu);
+                if (ret) {
+                        printk(KERN_ERR "IOMMU: allocate root entry failed\n");
+                        goto error;
+                }
+        }
+
+        /*
+         * 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
+         */
+        for_each_rmrr_units(rmrr) {
+                int i;
+                for (i = 0; i < rmrr->devices_cnt; i++) {
+                        pdev = rmrr->devices[i];
+                        /* some BIOS lists non-exist devices in DMAR table */
+                        if (!pdev)
+                                continue;
+                        ret = iommu_prepare_rmrr_dev(rmrr, pdev);
+                        if (ret)
+                                printk(KERN_ERR
+                                 "IOMMU: mapping reserved region failed\n");
+                }
+        }
+
+        /*
+         * for each drhd
+         *   enable fault log
+         *   global invalidate context cache
+         *   global invalidate iotlb
+         *   enable translation
+         */
+        for_each_drhd_unit(drhd) {
+                if (drhd->ignored)
+                        continue;
+                iommu = drhd->iommu;
+                sprintf (iommu->name, "dmar%d", unit++);
+
+                iommu_flush_write_buffer(iommu);
+
+                iommu_set_root_entry(iommu);
+
+                iommu_flush_context_global(iommu, 0);
+                iommu_flush_iotlb_global(iommu, 0);
+
+                ret = iommu_enable_translation(iommu);
+                if (ret)
+                        goto error;
+        }
+
+        return 0;
+error:
+        for_each_drhd_unit(drhd) {
+                if (drhd->ignored)
+                        continue;
+                iommu = drhd->iommu;
+                free_iommu(iommu);
+        }
+        return ret;
+}
+
+static inline u64 aligned_size(u64 host_addr, size_t size)
+{
+        u64 addr;
+        addr = (host_addr & (~PAGE_MASK_4K)) + size;
+        return PAGE_ALIGN_4K(addr);
+}
+
+struct iova *
+iommu_alloc_iova(struct dmar_domain *domain, void *host_addr, size_t size,
+                u64 start, u64 end)
+{
+        u64 start_addr;
+        struct iova *piova;
+
+        /* Make sure it's in range */
+        if ((start > DOMAIN_MAX_ADDR(domain->gaw)) || end < start)
+                return NULL;
+
+        end = min_t(u64, DOMAIN_MAX_ADDR(domain->gaw), end);
+        start_addr = PAGE_ALIGN_4K(start);
+        size = aligned_size((u64)host_addr, size);
+        if (!size || (start_addr + size > end))
+                return NULL;
+
+        piova = alloc_iova(&domain->iovad,
+                        size >> PAGE_SHIFT_4K, IOVA_PFN(end));
+
+        return piova;
+}
+
+static dma_addr_t __intel_map_single(struct device *dev, void *addr,
+        size_t size, int dir, u64 *flush_addr, unsigned int *flush_size)
+{
+        struct dmar_domain *domain;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        int ret;
+        int prot = 0;
+        struct iova *iova = NULL;
+        u64 start_addr;
+
+        addr = (void *)virt_to_phys(addr);
+
+        domain = get_domain_for_dev(pdev,
+                        DEFAULT_DOMAIN_ADDRESS_WIDTH);
+        if (!domain) {
+                printk(KERN_ERR
+                        "Allocating domain for %s failed", pci_name(pdev));
+                return 0;
+        }
+
+        start_addr = IOVA_START_ADDR;
+
+        if (pdev->dma_mask <= DMA_32BIT_MASK) {
+                iova = iommu_alloc_iova(domain, addr, size, start_addr,
+                        pdev->dma_mask);
+        } else  {
+                /*
+                 * First try to allocate an io virtual address in
+                 * DMA_32BIT_MASK and if that fails then try allocating
+                 * from higer range
+                 */
+                iova = iommu_alloc_iova(domain, addr, size, start_addr,
+                        DMA_32BIT_MASK);
+                if (!iova)
+                        iova = iommu_alloc_iova(domain, addr, size, start_addr,
+                        pdev->dma_mask);
+        }
+
+        if (!iova) {
+                printk(KERN_ERR"Allocating iova for %s failed", pci_name(pdev));
+                return 0;
+        }
+
+        /* make sure context mapping is ok */
+        if (unlikely(!domain_context_mapped(domain, pdev))) {
+                ret = domain_context_mapping(domain, pdev);
+                if (ret)
+                        goto error;
+        }
+
+        /*
+         * Check if DMAR supports zero-length reads on write only
+         * mappings..
+         */
+        if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
+                        !cap_zlr(domain->iommu->cap))
+                prot |= DMA_PTE_READ;
+        if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
+                prot |= DMA_PTE_WRITE;
+        /*
+         * addr - (addr + 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 addr, but this
+         * is not a big problem
+         */
+        ret = domain_page_mapping(domain, iova->pfn_lo << PAGE_SHIFT_4K,
+                ((u64)addr) & PAGE_MASK_4K,
+                (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT_4K, prot);
+        if (ret)
+                goto error;
+
+        pr_debug("Device %s request: %lx@%llx mapping: %lx@%llx, dir %d\n",
+                pci_name(pdev), size, (u64)addr,
+                (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT_4K,
+                (u64)(iova->pfn_lo << PAGE_SHIFT_4K), dir);
+
+        *flush_addr = iova->pfn_lo << PAGE_SHIFT_4K;
+        *flush_size = (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT_4K;
+        return (iova->pfn_lo << PAGE_SHIFT_4K) + ((u64)addr & (~PAGE_MASK_4K));
+error:
+        __free_iova(&domain->iovad, iova);
+        printk(KERN_ERR"Device %s request: %lx@%llx dir %d --- failed\n",
+                pci_name(pdev), size, (u64)addr, dir);
+        return 0;
+}
+
+static dma_addr_t intel_map_single(struct device *hwdev, void *addr,
+        size_t size, int dir)
+{
+        struct pci_dev *pdev = to_pci_dev(hwdev);
+        dma_addr_t ret;
+        struct dmar_domain *domain;
+        u64 flush_addr;
+        unsigned int flush_size;
+
+        BUG_ON(dir == DMA_NONE);
+        if (pdev->sysdata == DUMMY_DEVICE_DOMAIN_INFO)
+                return virt_to_bus(addr);
+
+        ret = __intel_map_single(hwdev, addr, size,
+                        dir, &flush_addr, &flush_size);
+        if (ret) {
+                domain = find_domain(pdev);
+                /* it's a non-present to present mapping */
+                if (iommu_flush_iotlb_psi(domain->iommu, domain->id,
+                                flush_addr, flush_size >> PAGE_SHIFT_4K, 1))
+                        iommu_flush_write_buffer(domain->iommu);
+        }
+        return ret;
+}
+
+static void __intel_unmap_single(struct device *dev, dma_addr_t dev_addr,
+        size_t size, int dir, u64 *flush_addr, unsigned int *flush_size)
+{
+        struct dmar_domain *domain;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct iova *iova;
+
+        domain = find_domain(pdev);
+        BUG_ON(!domain);
+
+        iova = find_iova(&domain->iovad, IOVA_PFN(dev_addr));
+        if (!iova) {
+                *flush_size = 0;
+                return;
+        }
+        pr_debug("Device %s unmapping: %lx@%llx\n",
+                pci_name(pdev),
+                (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT_4K,
+                (u64)(iova->pfn_lo << PAGE_SHIFT_4K));
+
+        *flush_addr = iova->pfn_lo << PAGE_SHIFT_4K;
+        *flush_size = (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT_4K;
+        /*  clear the whole page, not just dev_addr - (dev_addr + size) */
+        dma_pte_clear_range(domain, *flush_addr, *flush_addr + *flush_size);
+        /* free page tables */
+        dma_pte_free_pagetable(domain, *flush_addr, *flush_addr + *flush_size);
+        /* free iova */
+        __free_iova(&domain->iovad, iova);
+}
+
+static void intel_unmap_single(struct device *dev, dma_addr_t dev_addr,
+        size_t size, int dir)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct dmar_domain *domain;
+        u64 flush_addr;
+        unsigned int flush_size;
+
+        if (pdev->sysdata == DUMMY_DEVICE_DOMAIN_INFO)
+                return;
+
+        domain = find_domain(pdev);
+        __intel_unmap_single(dev, dev_addr, size,
+                dir, &flush_addr, &flush_size);
+        if (flush_size == 0)
+                return;
+        if (iommu_flush_iotlb_psi(domain->iommu, domain->id, flush_addr,
+                        flush_size >> PAGE_SHIFT_4K, 0))
+                iommu_flush_write_buffer(domain->iommu);
+}
+
+static void * intel_alloc_coherent(struct device *hwdev, size_t size,
+                       dma_addr_t *dma_handle, gfp_t flags)
+{
+        void *vaddr;
+        int order;
+
+        size = PAGE_ALIGN_4K(size);
+        order = get_order(size);
+        flags &= ~(GFP_DMA | GFP_DMA32);
+
+        vaddr = (void *)__get_free_pages(flags, order);
+        if (!vaddr)
+                return NULL;
+        memset(vaddr, 0, size);
+
+        *dma_handle = intel_map_single(hwdev, vaddr, size, DMA_BIDIRECTIONAL);
+        if (*dma_handle)
+                return vaddr;
+        free_pages((unsigned long)vaddr, order);
+        return NULL;
+}
+
+static void intel_free_coherent(struct device *hwdev, size_t size,
+        void *vaddr, dma_addr_t dma_handle)
+{
+        int order;
+
+        size = PAGE_ALIGN_4K(size);
+        order = get_order(size);
+
+        intel_unmap_single(hwdev, dma_handle, size, DMA_BIDIRECTIONAL);
+        free_pages((unsigned long)vaddr, order);
+}
+
+static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sg,
+        int nelems, int dir)
+{
+        int i;
+        struct pci_dev *pdev = to_pci_dev(hwdev);
+        struct dmar_domain *domain;
+        u64 flush_addr;
+        unsigned int flush_size;
+
+        if (pdev->sysdata == DUMMY_DEVICE_DOMAIN_INFO)
+                return;
+
+        domain = find_domain(pdev);
+        for (i = 0; i < nelems; i++, sg++)
+                __intel_unmap_single(hwdev, sg->dma_address,
+                        sg->dma_length, dir, &flush_addr, &flush_size);
+
+        if (iommu_flush_iotlb_dsi(domain->iommu, domain->id, 0))
+                iommu_flush_write_buffer(domain->iommu);
+}
+
+#define SG_ENT_VIRT_ADDRESS(sg) (page_address((sg)->page) + (sg)->offset)
+static int intel_nontranslate_map_sg(struct device *hddev,
+        struct scatterlist *sg, int nelems, int dir)
+{
+        int i;
+
+        for (i = 0; i < nelems; i++) {
+                struct scatterlist *s = &sg[i];
+                BUG_ON(!s->page);
+                s->dma_address = virt_to_bus(SG_ENT_VIRT_ADDRESS(s));
+                s->dma_length = s->length;
+        }
+        return nelems;
+}
+
+static int intel_map_sg(struct device *hwdev, struct scatterlist *sg,
+        int nelems, int dir)
+{
+        void *addr;
+        int i;
+        dma_addr_t dma_handle;
+        struct pci_dev *pdev = to_pci_dev(hwdev);
+        struct dmar_domain *domain;
+        u64 flush_addr;
+        unsigned int flush_size;
+
+        BUG_ON(dir == DMA_NONE);
+        if (pdev->sysdata == DUMMY_DEVICE_DOMAIN_INFO)
+                return intel_nontranslate_map_sg(hwdev, sg, nelems, dir);
+
+        for (i = 0; i < nelems; i++, sg++) {
+                addr = SG_ENT_VIRT_ADDRESS(sg);
+                dma_handle = __intel_map_single(hwdev, addr,
+                                sg->length, dir, &flush_addr, &flush_size);
+                if (!dma_handle) {
+                        intel_unmap_sg(hwdev, sg - i, i, dir);
+                        sg[0].dma_length = 0;
+                        return 0;
+                }
+                sg->dma_address = dma_handle;
+                sg->dma_length = sg->length;
+        }
+
+        domain = find_domain(pdev);
+
+        /* it's a non-present to present mapping */
+        if (iommu_flush_iotlb_dsi(domain->iommu, domain->id, 1))
+                iommu_flush_write_buffer(domain->iommu);
+        return nelems;
+}
+
+static struct dma_mapping_ops intel_dma_ops = {
+        .alloc_coherent = intel_alloc_coherent,
+        .free_coherent = intel_free_coherent,
+        .map_single = intel_map_single,
+        .unmap_single = intel_unmap_single,
+        .map_sg = intel_map_sg,
+        .unmap_sg = intel_unmap_sg,
+};
+
+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 inline int iommu_iova_cache_init(void)
+{
+        int ret = 0;
+
+        iommu_iova_cache = kmem_cache_create("iommu_iova",
+                                         sizeof(struct iova),
+                                         0,
+                                         SLAB_HWCACHE_ALIGN,
+
+                                         NULL);
+        if (!iommu_iova_cache) {
+                printk(KERN_ERR "Couldn't create iova 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:
+        kmem_cache_destroy(iommu_iova_cache);
+
+        return -ENOMEM;
+}
+
+static void __init iommu_exit_mempool(void)
+{
+        kmem_cache_destroy(iommu_devinfo_cache);
+        kmem_cache_destroy(iommu_domain_cache);
+        kmem_cache_destroy(iommu_iova_cache);
+
+}
+
+void __init detect_intel_iommu(void)
+{
+        if (swiotlb || no_iommu || iommu_detected || dmar_disabled)
+                return;
+        if (early_dmar_detect()) {
+                iommu_detected = 1;
+        }
+}
+
+static void __init init_no_remapping_devices(void)
+{
+        struct dmar_drhd_unit *drhd;
+
+        for_each_drhd_unit(drhd) {
+                if (!drhd->include_all) {
+                        int i;
+                        for (i = 0; i < drhd->devices_cnt; i++)
+                                if (drhd->devices[i] != NULL)
+                                        break;
+                        /* ignore DMAR unit if no pci devices exist */
+                        if (i == drhd->devices_cnt)
+                                drhd->ignored = 1;
+                }
+        }
+
+        if (dmar_map_gfx)
+                return;
+
+        for_each_drhd_unit(drhd) {
+                int i;
+                if (drhd->ignored || drhd->include_all)
+                        continue;
+
+                for (i = 0; i < drhd->devices_cnt; i++)
+                        if (drhd->devices[i] &&
+                                !IS_GFX_DEVICE(drhd->devices[i]))
+                                break;
+
+                if (i < drhd->devices_cnt)
+                        continue;
+
+                /* bypass IOMMU if it is just for gfx devices */
+                drhd->ignored = 1;
+                for (i = 0; i < drhd->devices_cnt; i++) {
+                        if (!drhd->devices[i])
+                                continue;
+                        drhd->devices[i]->sysdata = DUMMY_DEVICE_DOMAIN_INFO;
+                }
+        }
+}
+
+int __init intel_iommu_init(void)
+{
+        int ret = 0;
+
+        if (no_iommu || swiotlb || dmar_disabled)
+                return -ENODEV;
+
+        if (dmar_table_init())
+                return  -ENODEV;
+
+        iommu_init_mempool();
+        dmar_init_reserved_ranges();
+
+        init_no_remapping_devices();
+
+        ret = init_dmars();
+        if (ret) {
+                printk(KERN_ERR "IOMMU: dmar init failed\n");
+                put_iova_domain(&reserved_iova_list);
+                iommu_exit_mempool();
+                return ret;
+        }
+        printk(KERN_INFO
+        "PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
+
+        force_iommu = 1;
+        dma_ops = &intel_dma_ops;
+        return 0;
+}