x86, um: ... and asm-x86 move
[safe/jmp/linux-2.6] / arch / x86 / kernel / amd_iommu.c
index 47e80b5..a8fd9eb 100644 (file)
 #include <linux/scatterlist.h>
 #include <linux/iommu-helper.h>
 #include <asm/proto.h>
-#include <asm/gart.h>
+#include <asm/iommu.h>
 #include <asm/amd_iommu_types.h>
+#include <asm/amd_iommu.h>
 
 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
 
-#define to_pages(addr, size) \
-        (round_up(((addr) & ~PAGE_MASK) + (size), PAGE_SIZE) >> PAGE_SHIFT)
+#define EXIT_LOOP_COUNT 10000000
 
 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 
-struct command {
+/* A list of preallocated protection domains */
+static LIST_HEAD(iommu_pd_list);
+static DEFINE_SPINLOCK(iommu_pd_list_lock);
+
+/*
+ * general struct to manage commands send to an IOMMU
+ */
+struct iommu_cmd {
        u32 data[4];
 };
 
 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
                             struct unity_map_entry *e);
 
-static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
+/* returns !0 if the IOMMU is caching non-present entries in its TLB */
+static int iommu_has_npcache(struct amd_iommu *iommu)
+{
+       return iommu->cap & IOMMU_CAP_NPCACHE;
+}
+
+/****************************************************************************
+ *
+ * Interrupt handling functions
+ *
+ ****************************************************************************/
+
+static void iommu_print_event(void *__evt)
+{
+       u32 *event = __evt;
+       int type  = (event[1] >> EVENT_TYPE_SHIFT)  & EVENT_TYPE_MASK;
+       int devid = (event[0] >> EVENT_DEVID_SHIFT) & EVENT_DEVID_MASK;
+       int domid = (event[1] >> EVENT_DOMID_SHIFT) & EVENT_DOMID_MASK;
+       int flags = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
+       u64 address = (u64)(((u64)event[3]) << 32) | event[2];
+
+       printk(KERN_ERR "AMD IOMMU: Event logged [");
+
+       switch (type) {
+       case EVENT_TYPE_ILL_DEV:
+               printk("ILLEGAL_DEV_TABLE_ENTRY device=%02x:%02x.%x "
+                      "address=0x%016llx flags=0x%04x]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      address, flags);
+               break;
+       case EVENT_TYPE_IO_FAULT:
+               printk("IO_PAGE_FAULT device=%02x:%02x.%x "
+                      "domain=0x%04x address=0x%016llx flags=0x%04x]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      domid, address, flags);
+               break;
+       case EVENT_TYPE_DEV_TAB_ERR:
+               printk("DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
+                      "address=0x%016llx flags=0x%04x]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      address, flags);
+               break;
+       case EVENT_TYPE_PAGE_TAB_ERR:
+               printk("PAGE_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
+                      "domain=0x%04x address=0x%016llx flags=0x%04x]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      domid, address, flags);
+               break;
+       case EVENT_TYPE_ILL_CMD:
+               printk("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address);
+               break;
+       case EVENT_TYPE_CMD_HARD_ERR:
+               printk("COMMAND_HARDWARE_ERROR address=0x%016llx "
+                      "flags=0x%04x]\n", address, flags);
+               break;
+       case EVENT_TYPE_IOTLB_INV_TO:
+               printk("IOTLB_INV_TIMEOUT device=%02x:%02x.%x "
+                      "address=0x%016llx]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      address);
+               break;
+       case EVENT_TYPE_INV_DEV_REQ:
+               printk("INVALID_DEVICE_REQUEST device=%02x:%02x.%x "
+                      "address=0x%016llx flags=0x%04x]\n",
+                      PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                      address, flags);
+               break;
+       default:
+               printk(KERN_ERR "UNKNOWN type=0x%02x]\n", type);
+       }
+}
+
+static void iommu_poll_events(struct amd_iommu *iommu)
+{
+       u32 head, tail;
+       unsigned long flags;
+
+       spin_lock_irqsave(&iommu->lock, flags);
+
+       head = readl(iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
+       tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);
+
+       while (head != tail) {
+               iommu_print_event(iommu->evt_buf + head);
+               head = (head + EVENT_ENTRY_SIZE) % iommu->evt_buf_size;
+       }
+
+       writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET);
+
+       spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+irqreturn_t amd_iommu_int_handler(int irq, void *data)
+{
+       struct amd_iommu *iommu;
+
+       list_for_each_entry(iommu, &amd_iommu_list, list)
+               iommu_poll_events(iommu);
+
+       return IRQ_HANDLED;
+}
+
+/****************************************************************************
+ *
+ * IOMMU command queuing functions
+ *
+ ****************************************************************************/
+
+/*
+ * Writes the command to the IOMMUs command buffer and informs the
+ * hardware about the new command. Must be called with iommu->lock held.
+ */
+static int __iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
 {
        u32 tail, head;
        u8 *target;
 
        tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
-       target = (iommu->cmd_buf + tail);
+       target = iommu->cmd_buf + tail;
        memcpy_toio(target, cmd, sizeof(*cmd));
        tail = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
        head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
@@ -57,7 +176,11 @@ static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
        return 0;
 }
 
-static int iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
+/*
+ * General queuing function for commands. Takes iommu->lock and calls
+ * __iommu_queue_command().
+ */
+static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
 {
        unsigned long flags;
        int ret;
@@ -69,35 +192,59 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
        return ret;
 }
 
+/*
+ * This function is called whenever we need to ensure that the IOMMU has
+ * completed execution of all commands we sent. It sends a
+ * COMPLETION_WAIT command and waits for it to finish. The IOMMU informs
+ * us about that by writing a value to a physical address we pass with
+ * the command.
+ */
 static int iommu_completion_wait(struct amd_iommu *iommu)
 {
-       int ret;
-       struct command cmd;
-       volatile u64 ready = 0;
-       unsigned long ready_phys = virt_to_phys(&ready);
+       int ret = 0, ready = 0;
+       unsigned status = 0;
+       struct iommu_cmd cmd;
+       unsigned long flags, i = 0;
 
        memset(&cmd, 0, sizeof(cmd));
-       cmd.data[0] = LOW_U32(ready_phys) | CMD_COMPL_WAIT_STORE_MASK;
-       cmd.data[1] = HIGH_U32(ready_phys);
-       cmd.data[2] = 1; /* value written to 'ready' */
+       cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
        CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
 
        iommu->need_sync = 0;
 
-       ret = iommu_queue_command(iommu, &cmd);
+       spin_lock_irqsave(&iommu->lock, flags);
+
+       ret = __iommu_queue_command(iommu, &cmd);
 
        if (ret)
-               return ret;
+               goto out;
+
+       while (!ready && (i < EXIT_LOOP_COUNT)) {
+               ++i;
+               /* wait for the bit to become one */
+               status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
+               ready = status & MMIO_STATUS_COM_WAIT_INT_MASK;
+       }
 
-       while (!ready)
-               cpu_relax();
+       /* set bit back to zero */
+       status &= ~MMIO_STATUS_COM_WAIT_INT_MASK;
+       writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET);
+
+       if (unlikely((i == EXIT_LOOP_COUNT) && printk_ratelimit()))
+               printk(KERN_WARNING "AMD IOMMU: Completion wait loop failed\n");
+out:
+       spin_unlock_irqrestore(&iommu->lock, flags);
 
        return 0;
 }
 
+/*
+ * Command send function for invalidating a device table entry
+ */
 static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
 {
-       struct command cmd;
+       struct iommu_cmd cmd;
+       int ret;
 
        BUG_ON(iommu == NULL);
 
@@ -105,48 +252,89 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
        CMD_SET_TYPE(&cmd, CMD_INV_DEV_ENTRY);
        cmd.data[0] = devid;
 
+       ret = iommu_queue_command(iommu, &cmd);
+
        iommu->need_sync = 1;
 
-       return iommu_queue_command(iommu, &cmd);
+       return ret;
 }
 
+/*
+ * Generic command send function for invalidaing TLB entries
+ */
 static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
                u64 address, u16 domid, int pde, int s)
 {
-       struct command cmd;
+       struct iommu_cmd cmd;
+       int ret;
 
        memset(&cmd, 0, sizeof(cmd));
        address &= PAGE_MASK;
        CMD_SET_TYPE(&cmd, CMD_INV_IOMMU_PAGES);
        cmd.data[1] |= domid;
-       cmd.data[2] = LOW_U32(address);
-       cmd.data[3] = HIGH_U32(address);
-       if (s)
+       cmd.data[2] = lower_32_bits(address);
+       cmd.data[3] = upper_32_bits(address);
+       if (s) /* size bit - we flush more than one 4kb page */
                cmd.data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
-       if (pde)
+       if (pde) /* PDE bit - we wan't flush everything not only the PTEs */
                cmd.data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
 
+       ret = iommu_queue_command(iommu, &cmd);
+
        iommu->need_sync = 1;
 
-       return iommu_queue_command(iommu, &cmd);
+       return ret;
 }
 
+/*
+ * TLB invalidation function which is called from the mapping functions.
+ * It invalidates a single PTE if the range to flush is within a single
+ * page. Otherwise it flushes the whole TLB of the IOMMU.
+ */
 static int iommu_flush_pages(struct amd_iommu *iommu, u16 domid,
                u64 address, size_t size)
 {
-       int i;
-       unsigned pages = to_pages(address, size);
+       int s = 0;
+       unsigned pages = iommu_num_pages(address, size, PAGE_SIZE);
 
        address &= PAGE_MASK;
 
-       for (i = 0; i < pages; ++i) {
-               iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 0);
-               address += PAGE_SIZE;
+       if (pages > 1) {
+               /*
+                * If we have to flush more than one page, flush all
+                * TLB entries for this domain
+                */
+               address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
+               s = 1;
        }
 
+       iommu_queue_inv_iommu_pages(iommu, address, domid, 0, s);
+
        return 0;
 }
 
+/* Flush the whole IO/TLB for a given protection domain */
+static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid)
+{
+       u64 address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
+
+       iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 1);
+}
+
+/****************************************************************************
+ *
+ * The functions below are used the create the page table mappings for
+ * unity mapped regions.
+ *
+ ****************************************************************************/
+
+/*
+ * Generic mapping functions. It maps a physical address into a DMA
+ * address space. It allocates the page table pages if necessary.
+ * In the future it can be extended to a generic mapping function
+ * supporting all features of AMD IOMMU page tables like level skipping
+ * and full 64 bit address spaces.
+ */
 static int iommu_map(struct protection_domain *dom,
                     unsigned long bus_addr,
                     unsigned long phys_addr,
@@ -197,6 +385,10 @@ static int iommu_map(struct protection_domain *dom,
        return 0;
 }
 
+/*
+ * This function checks if a specific unity mapping entry is needed for
+ * this specific IOMMU.
+ */
 static int iommu_for_unity_map(struct amd_iommu *iommu,
                               struct unity_map_entry *entry)
 {
@@ -211,6 +403,12 @@ static int iommu_for_unity_map(struct amd_iommu *iommu,
        return 0;
 }
 
+/*
+ * Init the unity mappings for a specific IOMMU in the system
+ *
+ * Basically iterates over all unity mapping entries and applies them to
+ * the default domain DMA of that IOMMU if necessary.
+ */
 static int iommu_init_unity_mappings(struct amd_iommu *iommu)
 {
        struct unity_map_entry *entry;
@@ -227,6 +425,10 @@ static int iommu_init_unity_mappings(struct amd_iommu *iommu)
        return 0;
 }
 
+/*
+ * This function actually applies the mapping to the page table of the
+ * dma_ops domain.
+ */
 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
                             struct unity_map_entry *e)
 {
@@ -249,6 +451,9 @@ static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
        return 0;
 }
 
+/*
+ * Inits the unity mappings required for a specific device
+ */
 static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
                                          u16 devid)
 {
@@ -266,36 +471,50 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
        return 0;
 }
 
-static unsigned long dma_mask_to_pages(unsigned long mask)
-{
-       return (mask >> PAGE_SHIFT) +
-               (PAGE_ALIGN(mask & ~PAGE_MASK) >> PAGE_SHIFT);
-}
+/****************************************************************************
+ *
+ * The next functions belong to the address allocator for the dma_ops
+ * interface functions. They work like the allocators in the other IOMMU
+ * drivers. Its basically a bitmap which marks the allocated pages in
+ * the aperture. Maybe it could be enhanced in the future to a more
+ * efficient allocator.
+ *
+ ****************************************************************************/
 
+/*
+ * The address allocator core function.
+ *
+ * called with domain->lock held
+ */
 static unsigned long dma_ops_alloc_addresses(struct device *dev,
                                             struct dma_ops_domain *dom,
-                                            unsigned int pages)
+                                            unsigned int pages,
+                                            unsigned long align_mask,
+                                            u64 dma_mask)
 {
-       unsigned long limit = dma_mask_to_pages(*dev->dma_mask);
+       unsigned long limit;
        unsigned long address;
-       unsigned long size = dom->aperture_size >> PAGE_SHIFT;
        unsigned long boundary_size;
 
        boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
                        PAGE_SIZE) >> PAGE_SHIFT;
-       limit = limit < size ? limit : size;
+       limit = iommu_device_max_index(dom->aperture_size >> PAGE_SHIFT, 0,
+                                      dma_mask >> PAGE_SHIFT);
 
-       if (dom->next_bit >= limit)
+       if (dom->next_bit >= limit) {
                dom->next_bit = 0;
+               dom->need_flush = true;
+       }
 
        address = iommu_area_alloc(dom->bitmap, limit, dom->next_bit, pages,
-                       0 , boundary_size, 0);
-       if (address == -1)
+                                  0 , boundary_size, align_mask);
+       if (address == -1) {
                address = iommu_area_alloc(dom->bitmap, limit, 0, pages,
-                               0, boundary_size, 0);
+                               0, boundary_size, align_mask);
+               dom->need_flush = true;
+       }
 
        if (likely(address != -1)) {
-               set_bit_string(dom->bitmap, address, pages);
                dom->next_bit = address + pages;
                address <<= PAGE_SHIFT;
        } else
@@ -306,6 +525,11 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev,
        return address;
 }
 
+/*
+ * The address free function.
+ *
+ * called with domain->lock held
+ */
 static void dma_ops_free_addresses(struct dma_ops_domain *dom,
                                   unsigned long address,
                                   unsigned int pages)
@@ -314,6 +538,16 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom,
        iommu_area_free(dom->bitmap, address, pages);
 }
 
+/****************************************************************************
+ *
+ * The next functions belong to the domain allocation. A domain is
+ * allocated for every IOMMU as the default domain. If device isolation
+ * is enabled, every device get its own domain. The most important thing
+ * about domains is the page table mapping the DMA address space they
+ * contain.
+ *
+ ****************************************************************************/
+
 static u16 domain_id_alloc(void)
 {
        unsigned long flags;
@@ -331,6 +565,10 @@ static u16 domain_id_alloc(void)
        return id;
 }
 
+/*
+ * Used to reserve address ranges in the aperture (e.g. for exclusion
+ * ranges.
+ */
 static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
                                      unsigned long start_page,
                                      unsigned int pages)
@@ -340,7 +578,7 @@ static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
        if (start_page + pages > last_page)
                pages = last_page - start_page;
 
-       set_bit_string(dom->bitmap, start_page, pages);
+       iommu_area_reserve(dom->bitmap, start_page, pages);
 }
 
 static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
@@ -371,6 +609,10 @@ static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
        free_page((unsigned long)p1);
 }
 
+/*
+ * Free a domain, only used if something went wrong in the
+ * allocation path and we need to free an already allocated page table
+ */
 static void dma_ops_domain_free(struct dma_ops_domain *dom)
 {
        if (!dom)
@@ -385,6 +627,11 @@ static void dma_ops_domain_free(struct dma_ops_domain *dom)
        kfree(dom);
 }
 
+/*
+ * Allocates a new protection domain usable for the dma_ops functions.
+ * It also intializes the page table and the address allocator data
+ * structures required for the dma_ops interface
+ */
 static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu,
                                                   unsigned order)
 {
@@ -425,14 +672,24 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu,
        dma_dom->bitmap[0] = 1;
        dma_dom->next_bit = 0;
 
+       dma_dom->need_flush = false;
+       dma_dom->target_dev = 0xffff;
+
+       /* Intialize the exclusion range if necessary */
        if (iommu->exclusion_start &&
            iommu->exclusion_start < dma_dom->aperture_size) {
                unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT;
-               int pages = to_pages(iommu->exclusion_start,
-                               iommu->exclusion_length);
+               int pages = iommu_num_pages(iommu->exclusion_start,
+                                           iommu->exclusion_length,
+                                           PAGE_SIZE);
                dma_ops_reserve_addresses(dma_dom, startpage, pages);
        }
 
+       /*
+        * At the last step, build the page tables so we don't need to
+        * allocate page table pages in the dma_ops mapping/unmapping
+        * path.
+        */
        num_pte_pages = dma_dom->aperture_size / (PAGE_SIZE * 512);
        dma_dom->pte_pages = kzalloc(num_pte_pages * sizeof(void *),
                        GFP_KERNEL);
@@ -461,6 +718,10 @@ free_dma_dom:
        return NULL;
 }
 
+/*
+ * Find out the protection domain structure for a given PCI device. This
+ * will give us the pointer to the page table root for example.
+ */
 static struct protection_domain *domain_for_device(u16 devid)
 {
        struct protection_domain *dom;
@@ -473,6 +734,10 @@ static struct protection_domain *domain_for_device(u16 devid)
        return dom;
 }
 
+/*
+ * If a device is not yet associated with a domain, this function does
+ * assigns it visible for the hardware
+ */
 static void set_device_domain(struct amd_iommu *iommu,
                              struct protection_domain *domain,
                              u16 devid)
@@ -481,12 +746,13 @@ static void set_device_domain(struct amd_iommu *iommu,
 
        u64 pte_root = virt_to_phys(domain->pt_root);
 
-       pte_root |= (domain->mode & 0x07) << 9;
-       pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | 2;
+       pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK)
+                   << DEV_ENTRY_MODE_SHIFT;
+       pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV;
 
        write_lock_irqsave(&amd_iommu_devtable_lock, flags);
-       amd_iommu_dev_table[devid].data[0] = pte_root;
-       amd_iommu_dev_table[devid].data[1] = pte_root >> 32;
+       amd_iommu_dev_table[devid].data[0] = lower_32_bits(pte_root);
+       amd_iommu_dev_table[devid].data[1] = upper_32_bits(pte_root);
        amd_iommu_dev_table[devid].data[2] = domain->id;
 
        amd_iommu_pd_table[devid] = domain;
@@ -497,6 +763,58 @@ static void set_device_domain(struct amd_iommu *iommu,
        iommu->need_sync = 1;
 }
 
+/*****************************************************************************
+ *
+ * The next functions belong to the dma_ops mapping/unmapping code.
+ *
+ *****************************************************************************/
+
+/*
+ * This function checks if the driver got a valid device from the caller to
+ * avoid dereferencing invalid pointers.
+ */
+static bool check_device(struct device *dev)
+{
+       if (!dev || !dev->dma_mask)
+               return false;
+
+       return true;
+}
+
+/*
+ * In this function the list of preallocated protection domains is traversed to
+ * find the domain for a specific device
+ */
+static struct dma_ops_domain *find_protection_domain(u16 devid)
+{
+       struct dma_ops_domain *entry, *ret = NULL;
+       unsigned long flags;
+
+       if (list_empty(&iommu_pd_list))
+               return NULL;
+
+       spin_lock_irqsave(&iommu_pd_list_lock, flags);
+
+       list_for_each_entry(entry, &iommu_pd_list, list) {
+               if (entry->target_dev == devid) {
+                       ret = entry;
+                       list_del(&ret->list);
+                       break;
+               }
+       }
+
+       spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+
+       return ret;
+}
+
+/*
+ * In the dma_ops path we only have the struct device. This function
+ * finds the corresponding IOMMU, the protection domain and the
+ * requestor id for a given device.
+ * If the device is not yet associated with a domain this is also done
+ * in this function.
+ */
 static int get_device_resources(struct device *dev,
                                struct amd_iommu **iommu,
                                struct protection_domain **domain,
@@ -506,26 +824,30 @@ static int get_device_resources(struct device *dev,
        struct pci_dev *pcidev;
        u16 _bdf;
 
-       BUG_ON(!dev || dev->bus != &pci_bus_type || !dev->dma_mask);
+       *iommu = NULL;
+       *domain = NULL;
+       *bdf = 0xffff;
+
+       if (dev->bus != &pci_bus_type)
+               return 0;
 
        pcidev = to_pci_dev(dev);
-       _bdf = (pcidev->bus->number << 8) | pcidev->devfn;
+       _bdf = calc_devid(pcidev->bus->number, pcidev->devfn);
 
-       if (_bdf >= amd_iommu_last_bdf) {
-               *iommu = NULL;
-               *domain = NULL;
-               *bdf = 0xffff;
+       /* device not translated by any IOMMU in the system? */
+       if (_bdf > amd_iommu_last_bdf)
                return 0;
-       }
 
        *bdf = amd_iommu_alias_table[_bdf];
 
        *iommu = amd_iommu_rlookup_table[*bdf];
        if (*iommu == NULL)
                return 0;
-       dma_dom = (*iommu)->default_dom;
        *domain = domain_for_device(*bdf);
        if (*domain == NULL) {
+               dma_dom = find_protection_domain(*bdf);
+               if (!dma_dom)
+                       dma_dom = (*iommu)->default_dom;
                *domain = &dma_dom->domain;
                set_device_domain(*iommu, *domain, *bdf);
                printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
@@ -536,3 +858,527 @@ static int get_device_resources(struct device *dev,
        return 1;
 }
 
+/*
+ * This is the generic map function. It maps one 4kb page at paddr to
+ * the given address in the DMA address space for the domain.
+ */
+static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
+                                    struct dma_ops_domain *dom,
+                                    unsigned long address,
+                                    phys_addr_t paddr,
+                                    int direction)
+{
+       u64 *pte, __pte;
+
+       WARN_ON(address > dom->aperture_size);
+
+       paddr &= PAGE_MASK;
+
+       pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
+       pte += IOMMU_PTE_L0_INDEX(address);
+
+       __pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
+
+       if (direction == DMA_TO_DEVICE)
+               __pte |= IOMMU_PTE_IR;
+       else if (direction == DMA_FROM_DEVICE)
+               __pte |= IOMMU_PTE_IW;
+       else if (direction == DMA_BIDIRECTIONAL)
+               __pte |= IOMMU_PTE_IR | IOMMU_PTE_IW;
+
+       WARN_ON(*pte);
+
+       *pte = __pte;
+
+       return (dma_addr_t)address;
+}
+
+/*
+ * The generic unmapping function for on page in the DMA address space.
+ */
+static void dma_ops_domain_unmap(struct amd_iommu *iommu,
+                                struct dma_ops_domain *dom,
+                                unsigned long address)
+{
+       u64 *pte;
+
+       if (address >= dom->aperture_size)
+               return;
+
+       WARN_ON(address & 0xfffULL || address > dom->aperture_size);
+
+       pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
+       pte += IOMMU_PTE_L0_INDEX(address);
+
+       WARN_ON(!*pte);
+
+       *pte = 0ULL;
+}
+
+/*
+ * This function contains common code for mapping of a physically
+ * contiguous memory region into DMA address space. It is uses by all
+ * mapping functions provided by this IOMMU driver.
+ * Must be called with the domain lock held.
+ */
+static dma_addr_t __map_single(struct device *dev,
+                              struct amd_iommu *iommu,
+                              struct dma_ops_domain *dma_dom,
+                              phys_addr_t paddr,
+                              size_t size,
+                              int dir,
+                              bool align,
+                              u64 dma_mask)
+{
+       dma_addr_t offset = paddr & ~PAGE_MASK;
+       dma_addr_t address, start;
+       unsigned int pages;
+       unsigned long align_mask = 0;
+       int i;
+
+       pages = iommu_num_pages(paddr, size, PAGE_SIZE);
+       paddr &= PAGE_MASK;
+
+       if (align)
+               align_mask = (1UL << get_order(size)) - 1;
+
+       address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask,
+                                         dma_mask);
+       if (unlikely(address == bad_dma_address))
+               goto out;
+
+       start = address;
+       for (i = 0; i < pages; ++i) {
+               dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
+               paddr += PAGE_SIZE;
+               start += PAGE_SIZE;
+       }
+       address += offset;
+
+       if (unlikely(dma_dom->need_flush && !amd_iommu_unmap_flush)) {
+               iommu_flush_tlb(iommu, dma_dom->domain.id);
+               dma_dom->need_flush = false;
+       } else if (unlikely(iommu_has_npcache(iommu)))
+               iommu_flush_pages(iommu, dma_dom->domain.id, address, size);
+
+out:
+       return address;
+}
+
+/*
+ * Does the reverse of the __map_single function. Must be called with
+ * the domain lock held too
+ */
+static void __unmap_single(struct amd_iommu *iommu,
+                          struct dma_ops_domain *dma_dom,
+                          dma_addr_t dma_addr,
+                          size_t size,
+                          int dir)
+{
+       dma_addr_t i, start;
+       unsigned int pages;
+
+       if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size))
+               return;
+
+       pages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
+       dma_addr &= PAGE_MASK;
+       start = dma_addr;
+
+       for (i = 0; i < pages; ++i) {
+               dma_ops_domain_unmap(iommu, dma_dom, start);
+               start += PAGE_SIZE;
+       }
+
+       dma_ops_free_addresses(dma_dom, dma_addr, pages);
+
+       if (amd_iommu_unmap_flush)
+               iommu_flush_pages(iommu, dma_dom->domain.id, dma_addr, size);
+}
+
+/*
+ * The exported map_single function for dma_ops.
+ */
+static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
+                            size_t size, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+       dma_addr_t addr;
+       u64 dma_mask;
+
+       if (!check_device(dev))
+               return bad_dma_address;
+
+       dma_mask = *dev->dma_mask;
+
+       get_device_resources(dev, &iommu, &domain, &devid);
+
+       if (iommu == NULL || domain == NULL)
+               /* device not handled by any AMD IOMMU */
+               return (dma_addr_t)paddr;
+
+       spin_lock_irqsave(&domain->lock, flags);
+       addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
+                           dma_mask);
+       if (addr == bad_dma_address)
+               goto out;
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+out:
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return addr;
+}
+
+/*
+ * The exported unmap_single function for dma_ops.
+ */
+static void unmap_single(struct device *dev, dma_addr_t dma_addr,
+                        size_t size, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+
+       if (!check_device(dev) ||
+           !get_device_resources(dev, &iommu, &domain, &devid))
+               /* device not handled by any AMD IOMMU */
+               return;
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       __unmap_single(iommu, domain->priv, dma_addr, size, dir);
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+       spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/*
+ * This is a special map_sg function which is used if we should map a
+ * device which is not handled by an AMD IOMMU in the system.
+ */
+static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist,
+                          int nelems, int dir)
+{
+       struct scatterlist *s;
+       int i;
+
+       for_each_sg(sglist, s, nelems, i) {
+               s->dma_address = (dma_addr_t)sg_phys(s);
+               s->dma_length  = s->length;
+       }
+
+       return nelems;
+}
+
+/*
+ * The exported map_sg function for dma_ops (handles scatter-gather
+ * lists).
+ */
+static int map_sg(struct device *dev, struct scatterlist *sglist,
+                 int nelems, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+       int i;
+       struct scatterlist *s;
+       phys_addr_t paddr;
+       int mapped_elems = 0;
+       u64 dma_mask;
+
+       if (!check_device(dev))
+               return 0;
+
+       dma_mask = *dev->dma_mask;
+
+       get_device_resources(dev, &iommu, &domain, &devid);
+
+       if (!iommu || !domain)
+               return map_sg_no_iommu(dev, sglist, nelems, dir);
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       for_each_sg(sglist, s, nelems, i) {
+               paddr = sg_phys(s);
+
+               s->dma_address = __map_single(dev, iommu, domain->priv,
+                                             paddr, s->length, dir, false,
+                                             dma_mask);
+
+               if (s->dma_address) {
+                       s->dma_length = s->length;
+                       mapped_elems++;
+               } else
+                       goto unmap;
+       }
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+out:
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return mapped_elems;
+unmap:
+       for_each_sg(sglist, s, mapped_elems, i) {
+               if (s->dma_address)
+                       __unmap_single(iommu, domain->priv, s->dma_address,
+                                      s->dma_length, dir);
+               s->dma_address = s->dma_length = 0;
+       }
+
+       mapped_elems = 0;
+
+       goto out;
+}
+
+/*
+ * The exported map_sg function for dma_ops (handles scatter-gather
+ * lists).
+ */
+static void unmap_sg(struct device *dev, struct scatterlist *sglist,
+                    int nelems, int dir)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       struct scatterlist *s;
+       u16 devid;
+       int i;
+
+       if (!check_device(dev) ||
+           !get_device_resources(dev, &iommu, &domain, &devid))
+               return;
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       for_each_sg(sglist, s, nelems, i) {
+               __unmap_single(iommu, domain->priv, s->dma_address,
+                              s->dma_length, dir);
+               s->dma_address = s->dma_length = 0;
+       }
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+       spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/*
+ * The exported alloc_coherent function for dma_ops.
+ */
+static void *alloc_coherent(struct device *dev, size_t size,
+                           dma_addr_t *dma_addr, gfp_t flag)
+{
+       unsigned long flags;
+       void *virt_addr;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+       phys_addr_t paddr;
+       u64 dma_mask = dev->coherent_dma_mask;
+
+       if (!check_device(dev))
+               return NULL;
+
+       if (!get_device_resources(dev, &iommu, &domain, &devid))
+               flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+
+       flag |= __GFP_ZERO;
+       virt_addr = (void *)__get_free_pages(flag, get_order(size));
+       if (!virt_addr)
+               return 0;
+
+       paddr = virt_to_phys(virt_addr);
+
+       if (!iommu || !domain) {
+               *dma_addr = (dma_addr_t)paddr;
+               return virt_addr;
+       }
+
+       if (!dma_mask)
+               dma_mask = *dev->dma_mask;
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       *dma_addr = __map_single(dev, iommu, domain->priv, paddr,
+                                size, DMA_BIDIRECTIONAL, true, dma_mask);
+
+       if (*dma_addr == bad_dma_address) {
+               free_pages((unsigned long)virt_addr, get_order(size));
+               virt_addr = NULL;
+               goto out;
+       }
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+out:
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+       return virt_addr;
+}
+
+/*
+ * The exported free_coherent function for dma_ops.
+ */
+static void free_coherent(struct device *dev, size_t size,
+                         void *virt_addr, dma_addr_t dma_addr)
+{
+       unsigned long flags;
+       struct amd_iommu *iommu;
+       struct protection_domain *domain;
+       u16 devid;
+
+       if (!check_device(dev))
+               return;
+
+       get_device_resources(dev, &iommu, &domain, &devid);
+
+       if (!iommu || !domain)
+               goto free_mem;
+
+       spin_lock_irqsave(&domain->lock, flags);
+
+       __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
+
+       if (unlikely(iommu->need_sync))
+               iommu_completion_wait(iommu);
+
+       spin_unlock_irqrestore(&domain->lock, flags);
+
+free_mem:
+       free_pages((unsigned long)virt_addr, get_order(size));
+}
+
+/*
+ * This function is called by the DMA layer to find out if we can handle a
+ * particular device. It is part of the dma_ops.
+ */
+static int amd_iommu_dma_supported(struct device *dev, u64 mask)
+{
+       u16 bdf;
+       struct pci_dev *pcidev;
+
+       /* No device or no PCI device */
+       if (!dev || dev->bus != &pci_bus_type)
+               return 0;
+
+       pcidev = to_pci_dev(dev);
+
+       bdf = calc_devid(pcidev->bus->number, pcidev->devfn);
+
+       /* Out of our scope? */
+       if (bdf > amd_iommu_last_bdf)
+               return 0;
+
+       return 1;
+}
+
+/*
+ * The function for pre-allocating protection domains.
+ *
+ * If the driver core informs the DMA layer if a driver grabs a device
+ * we don't need to preallocate the protection domains anymore.
+ * For now we have to.
+ */
+void prealloc_protection_domains(void)
+{
+       struct pci_dev *dev = NULL;
+       struct dma_ops_domain *dma_dom;
+       struct amd_iommu *iommu;
+       int order = amd_iommu_aperture_order;
+       u16 devid;
+
+       while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
+               devid = (dev->bus->number << 8) | dev->devfn;
+               if (devid > amd_iommu_last_bdf)
+                       continue;
+               devid = amd_iommu_alias_table[devid];
+               if (domain_for_device(devid))
+                       continue;
+               iommu = amd_iommu_rlookup_table[devid];
+               if (!iommu)
+                       continue;
+               dma_dom = dma_ops_domain_alloc(iommu, order);
+               if (!dma_dom)
+                       continue;
+               init_unity_mappings_for_device(dma_dom, devid);
+               dma_dom->target_dev = devid;
+
+               list_add_tail(&dma_dom->list, &iommu_pd_list);
+       }
+}
+
+static struct dma_mapping_ops amd_iommu_dma_ops = {
+       .alloc_coherent = alloc_coherent,
+       .free_coherent = free_coherent,
+       .map_single = map_single,
+       .unmap_single = unmap_single,
+       .map_sg = map_sg,
+       .unmap_sg = unmap_sg,
+       .dma_supported = amd_iommu_dma_supported,
+};
+
+/*
+ * The function which clues the AMD IOMMU driver into dma_ops.
+ */
+int __init amd_iommu_init_dma_ops(void)
+{
+       struct amd_iommu *iommu;
+       int order = amd_iommu_aperture_order;
+       int ret;
+
+       /*
+        * first allocate a default protection domain for every IOMMU we
+        * found in the system. Devices not assigned to any other
+        * protection domain will be assigned to the default one.
+        */
+       list_for_each_entry(iommu, &amd_iommu_list, list) {
+               iommu->default_dom = dma_ops_domain_alloc(iommu, order);
+               if (iommu->default_dom == NULL)
+                       return -ENOMEM;
+               ret = iommu_init_unity_mappings(iommu);
+               if (ret)
+                       goto free_domains;
+       }
+
+       /*
+        * If device isolation is enabled, pre-allocate the protection
+        * domains for each device.
+        */
+       if (amd_iommu_isolate)
+               prealloc_protection_domains();
+
+       iommu_detected = 1;
+       force_iommu = 1;
+       bad_dma_address = 0;
+#ifdef CONFIG_GART_IOMMU
+       gart_iommu_aperture_disabled = 1;
+       gart_iommu_aperture = 0;
+#endif
+
+       /* Make the driver finally visible to the drivers */
+       dma_ops = &amd_iommu_dma_ops;
+
+       return 0;
+
+free_domains:
+
+       list_for_each_entry(iommu, &amd_iommu_list, list) {
+               if (iommu->default_dom)
+                       dma_ops_domain_free(iommu->default_dom);
+       }
+
+       return ret;
+}