1 files changed, 607 insertions, 59 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 2e2da717b350..5113c080f0c4 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -20,8 +20,12 @@
 #include <linux/pci.h>
 #include <linux/gfp.h>
 #include <linux/bitops.h>
+#include <linux/debugfs.h>
 #include <linux/scatterlist.h>
 #include <linux/iommu-helper.h>
+#ifdef CONFIG_IOMMU_API
+#include <linux/iommu.h>
+#endif
 #include <asm/proto.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
@@ -38,6 +42,10 @@ static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 static LIST_HEAD(iommu_pd_list);
 static DEFINE_SPINLOCK(iommu_pd_list_lock);
 
+#ifdef CONFIG_IOMMU_API
+static struct iommu_ops amd_iommu_ops;
+#endif
+
 /*
  * general struct to manage commands send to an IOMMU
  */
@@ -47,6 +55,68 @@ struct iommu_cmd {
 
 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
 			     struct unity_map_entry *e);
+static struct dma_ops_domain *find_protection_domain(u16 devid);
+
+
+#ifdef CONFIG_AMD_IOMMU_STATS
+
+/*
+ * Initialization code for statistics collection
+ */
+
+DECLARE_STATS_COUNTER(compl_wait);
+DECLARE_STATS_COUNTER(cnt_map_single);
+DECLARE_STATS_COUNTER(cnt_unmap_single);
+DECLARE_STATS_COUNTER(cnt_map_sg);
+DECLARE_STATS_COUNTER(cnt_unmap_sg);
+DECLARE_STATS_COUNTER(cnt_alloc_coherent);
+DECLARE_STATS_COUNTER(cnt_free_coherent);
+DECLARE_STATS_COUNTER(cross_page);
+DECLARE_STATS_COUNTER(domain_flush_single);
+DECLARE_STATS_COUNTER(domain_flush_all);
+DECLARE_STATS_COUNTER(alloced_io_mem);
+DECLARE_STATS_COUNTER(total_map_requests);
+
+static struct dentry *stats_dir;
+static struct dentry *de_isolate;
+static struct dentry *de_fflush;
+
+static void amd_iommu_stats_add(struct __iommu_counter *cnt)
+{
+	if (stats_dir == NULL)
+		return;
+
+	cnt->dent = debugfs_create_u64(cnt->name, 0444, stats_dir,
+				       &cnt->value);
+}
+
+static void amd_iommu_stats_init(void)
+{
+	stats_dir = debugfs_create_dir("amd-iommu", NULL);
+	if (stats_dir == NULL)
+		return;
+
+	de_isolate = debugfs_create_bool("isolation", 0444, stats_dir,
+					 (u32 *)&amd_iommu_isolate);
+
+	de_fflush  = debugfs_create_bool("fullflush", 0444, stats_dir,
+					 (u32 *)&amd_iommu_unmap_flush);
+
+	amd_iommu_stats_add(&compl_wait);
+	amd_iommu_stats_add(&cnt_map_single);
+	amd_iommu_stats_add(&cnt_unmap_single);
+	amd_iommu_stats_add(&cnt_map_sg);
+	amd_iommu_stats_add(&cnt_unmap_sg);
+	amd_iommu_stats_add(&cnt_alloc_coherent);
+	amd_iommu_stats_add(&cnt_free_coherent);
+	amd_iommu_stats_add(&cross_page);
+	amd_iommu_stats_add(&domain_flush_single);
+	amd_iommu_stats_add(&domain_flush_all);
+	amd_iommu_stats_add(&alloced_io_mem);
+	amd_iommu_stats_add(&total_map_requests);
+}
+
+#endif
 
 /* returns !0 if the IOMMU is caching non-present entries in its TLB */
 static int iommu_has_npcache(struct amd_iommu *iommu)
@@ -189,13 +259,55 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
 	spin_lock_irqsave(&iommu->lock, flags);
 	ret = __iommu_queue_command(iommu, cmd);
 	if (!ret)
-		iommu->need_sync = 1;
+		iommu->need_sync = true;
 	spin_unlock_irqrestore(&iommu->lock, flags);
 
 	return ret;
 }
 
 /*
+ * This function waits until an IOMMU has completed a completion
+ * wait command
+ */
+static void __iommu_wait_for_completion(struct amd_iommu *iommu)
+{
+	int ready = 0;
+	unsigned status = 0;
+	unsigned long i = 0;
+
+	INC_STATS_COUNTER(compl_wait);
+
+	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;
+	}
+
+	/* 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))
+		panic("AMD IOMMU: Completion wait loop failed\n");
+}
+
+/*
+ * This function queues a completion wait command into the command
+ * buffer of an IOMMU
+ */
+static int __iommu_completion_wait(struct amd_iommu *iommu)
+{
+	struct iommu_cmd cmd;
+
+	 memset(&cmd, 0, sizeof(cmd));
+	 cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
+	 CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
+
+	 return __iommu_queue_command(iommu, &cmd);
+}
+
+/*
  * 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
@@ -204,40 +316,22 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
  */
 static int iommu_completion_wait(struct amd_iommu *iommu)
 {
-	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] = CMD_COMPL_WAIT_INT_MASK;
-	CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
+	int ret = 0;
+	unsigned long flags;
 
 	spin_lock_irqsave(&iommu->lock, flags);
 
 	if (!iommu->need_sync)
 		goto out;
 
-	iommu->need_sync = 0;
+	ret = __iommu_completion_wait(iommu);
 
-	ret = __iommu_queue_command(iommu, &cmd);
+	iommu->need_sync = false;
 
 	if (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;
-	}
-
-	/* 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))
-		panic("AMD IOMMU: Completion wait loop failed\n");
+	__iommu_wait_for_completion(iommu);
 
 out:
 	spin_unlock_irqrestore(&iommu->lock, flags);
@@ -264,6 +358,21 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
 	return ret;
 }
 
+static void __iommu_build_inv_iommu_pages(struct iommu_cmd *cmd, u64 address,
+					  u16 domid, int pde, int s)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	address &= PAGE_MASK;
+	CMD_SET_TYPE(cmd, CMD_INV_IOMMU_PAGES);
+	cmd->data[1] |= domid;
+	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) /* PDE bit - we wan't flush everything not only the PTEs */
+		cmd->data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
+}
+
 /*
  * Generic command send function for invalidaing TLB entries
  */
@@ -273,16 +382,7 @@ static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
 	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] = 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) /* PDE bit - we wan't flush everything not only the PTEs */
-		cmd.data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
+	__iommu_build_inv_iommu_pages(&cmd, address, domid, pde, s);
 
 	ret = iommu_queue_command(iommu, &cmd);
 
@@ -321,9 +421,35 @@ static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid)
 {
 	u64 address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
 
+	INC_STATS_COUNTER(domain_flush_single);
+
 	iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 1);
 }
 
+/*
+ * This function is used to flush the IO/TLB for a given protection domain
+ * on every IOMMU in the system
+ */
+static void iommu_flush_domain(u16 domid)
+{
+	unsigned long flags;
+	struct amd_iommu *iommu;
+	struct iommu_cmd cmd;
+
+	INC_STATS_COUNTER(domain_flush_all);
+
+	__iommu_build_inv_iommu_pages(&cmd, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
+				      domid, 1, 1);
+
+	list_for_each_entry(iommu, &amd_iommu_list, list) {
+		spin_lock_irqsave(&iommu->lock, flags);
+		__iommu_queue_command(iommu, &cmd);
+		__iommu_completion_wait(iommu);
+		__iommu_wait_for_completion(iommu);
+		spin_unlock_irqrestore(&iommu->lock, flags);
+	}
+}
+
 /****************************************************************************
  *
  * The functions below are used the create the page table mappings for
@@ -338,10 +464,10 @@ static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid)
  * 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,
-		     int prot)
+static int iommu_map_page(struct protection_domain *dom,
+			  unsigned long bus_addr,
+			  unsigned long phys_addr,
+			  int prot)
 {
 	u64 __pte, *pte, *page;
 
@@ -388,6 +514,28 @@ static int iommu_map(struct protection_domain *dom,
 	return 0;
 }
 
+static void iommu_unmap_page(struct protection_domain *dom,
+			     unsigned long bus_addr)
+{
+	u64 *pte;
+
+	pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(bus_addr)];
+
+	if (!IOMMU_PTE_PRESENT(*pte))
+		return;
+
+	pte = IOMMU_PTE_PAGE(*pte);
+	pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
+
+	if (!IOMMU_PTE_PRESENT(*pte))
+		return;
+
+	pte = IOMMU_PTE_PAGE(*pte);
+	pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
+
+	*pte = 0;
+}
+
 /*
  * This function checks if a specific unity mapping entry is needed for
  * this specific IOMMU.
@@ -440,7 +588,7 @@ static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
 
 	for (addr = e->address_start; addr < e->address_end;
 	     addr += PAGE_SIZE) {
-		ret = iommu_map(&dma_dom->domain, addr, addr, e->prot);
+		ret = iommu_map_page(&dma_dom->domain, addr, addr, e->prot);
 		if (ret)
 			return ret;
 		/*
@@ -571,6 +719,16 @@ static u16 domain_id_alloc(void)
 	return id;
 }
 
+static void domain_id_free(int id)
+{
+	unsigned long flags;
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	if (id > 0 && id < MAX_DOMAIN_ID)
+		__clear_bit(id, amd_iommu_pd_alloc_bitmap);
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
+
 /*
  * Used to reserve address ranges in the aperture (e.g. for exclusion
  * ranges.
@@ -587,12 +745,12 @@ static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
 	iommu_area_reserve(dom->bitmap, start_page, pages);
 }
 
-static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
+static void free_pagetable(struct protection_domain *domain)
 {
 	int i, j;
 	u64 *p1, *p2, *p3;
 
-	p1 = dma_dom->domain.pt_root;
+	p1 = domain->pt_root;
 
 	if (!p1)
 		return;
@@ -613,6 +771,8 @@ static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
 	}
 
 	free_page((unsigned long)p1);
+
+	domain->pt_root = NULL;
 }
 
 /*
@@ -624,7 +784,7 @@ static void dma_ops_domain_free(struct dma_ops_domain *dom)
 	if (!dom)
 		return;
 
-	dma_ops_free_pagetable(dom);
+	free_pagetable(&dom->domain);
 
 	kfree(dom->pte_pages);
 
@@ -663,6 +823,7 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu,
 		goto free_dma_dom;
 	dma_dom->domain.mode = PAGE_MODE_3_LEVEL;
 	dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL);
+	dma_dom->domain.flags = PD_DMA_OPS_MASK;
 	dma_dom->domain.priv = dma_dom;
 	if (!dma_dom->domain.pt_root)
 		goto free_dma_dom;
@@ -725,6 +886,15 @@ free_dma_dom:
 }
 
 /*
+ * little helper function to check whether a given protection domain is a
+ * dma_ops domain
+ */
+static bool dma_ops_domain(struct protection_domain *domain)
+{
+	return domain->flags & PD_DMA_OPS_MASK;
+}
+
+/*
  * Find out the protection domain structure for a given PCI device. This
  * will give us the pointer to the page table root for example.
  */
@@ -744,14 +914,15 @@ static struct protection_domain *domain_for_device(u16 devid)
  * 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)
+static void attach_device(struct amd_iommu *iommu,
+			  struct protection_domain *domain,
+			  u16 devid)
 {
 	unsigned long flags;
-
 	u64 pte_root = virt_to_phys(domain->pt_root);
 
+	domain->dev_cnt += 1;
+
 	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;
@@ -767,6 +938,116 @@ static void set_device_domain(struct amd_iommu *iommu,
 	iommu_queue_inv_dev_entry(iommu, devid);
 }
 
+/*
+ * Removes a device from a protection domain (unlocked)
+ */
+static void __detach_device(struct protection_domain *domain, u16 devid)
+{
+
+	/* lock domain */
+	spin_lock(&domain->lock);
+
+	/* remove domain from the lookup table */
+	amd_iommu_pd_table[devid] = NULL;
+
+	/* remove entry from the device table seen by the hardware */
+	amd_iommu_dev_table[devid].data[0] = IOMMU_PTE_P | IOMMU_PTE_TV;
+	amd_iommu_dev_table[devid].data[1] = 0;
+	amd_iommu_dev_table[devid].data[2] = 0;
+
+	/* decrease reference counter */
+	domain->dev_cnt -= 1;
+
+	/* ready */
+	spin_unlock(&domain->lock);
+}
+
+/*
+ * Removes a device from a protection domain (with devtable_lock held)
+ */
+static void detach_device(struct protection_domain *domain, u16 devid)
+{
+	unsigned long flags;
+
+	/* lock device table */
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	__detach_device(domain, devid);
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
+
+static int device_change_notifier(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	u16 devid = calc_devid(pdev->bus->number, pdev->devfn);
+	struct protection_domain *domain;
+	struct dma_ops_domain *dma_domain;
+	struct amd_iommu *iommu;
+	int order = amd_iommu_aperture_order;
+	unsigned long flags;
+
+	if (devid > amd_iommu_last_bdf)
+		goto out;
+
+	devid = amd_iommu_alias_table[devid];
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (iommu == NULL)
+		goto out;
+
+	domain = domain_for_device(devid);
+
+	if (domain && !dma_ops_domain(domain))
+		WARN_ONCE(1, "AMD IOMMU WARNING: device %s already bound "
+			  "to a non-dma-ops domain\n", dev_name(dev));
+
+	switch (action) {
+	case BUS_NOTIFY_BOUND_DRIVER:
+		if (domain)
+			goto out;
+		dma_domain = find_protection_domain(devid);
+		if (!dma_domain)
+			dma_domain = iommu->default_dom;
+		attach_device(iommu, &dma_domain->domain, devid);
+		printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
+		       "device %s\n", dma_domain->domain.id, dev_name(dev));
+		break;
+	case BUS_NOTIFY_UNBIND_DRIVER:
+		if (!domain)
+			goto out;
+		detach_device(domain, devid);
+		break;
+	case BUS_NOTIFY_ADD_DEVICE:
+		/* allocate a protection domain if a device is added */
+		dma_domain = find_protection_domain(devid);
+		if (dma_domain)
+			goto out;
+		dma_domain = dma_ops_domain_alloc(iommu, order);
+		if (!dma_domain)
+			goto out;
+		dma_domain->target_dev = devid;
+
+		spin_lock_irqsave(&iommu_pd_list_lock, flags);
+		list_add_tail(&dma_domain->list, &iommu_pd_list);
+		spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+
+		break;
+	default:
+		goto out;
+	}
+
+	iommu_queue_inv_dev_entry(iommu, devid);
+	iommu_completion_wait(iommu);
+
+out:
+	return 0;
+}
+
+struct notifier_block device_nb = {
+	.notifier_call = device_change_notifier,
+};
+
 /*****************************************************************************
  *
  * The next functions belong to the dma_ops mapping/unmapping code.
@@ -802,7 +1083,6 @@ static struct dma_ops_domain *find_protection_domain(u16 devid)
 	list_for_each_entry(entry, &iommu_pd_list, list) {
 		if (entry->target_dev == devid) {
 			ret = entry;
-			list_del(&ret->list);
 			break;
 		}
 	}
@@ -853,14 +1133,13 @@ static int get_device_resources(struct device *dev,
 		if (!dma_dom)
 			dma_dom = (*iommu)->default_dom;
 		*domain = &dma_dom->domain;
-		set_device_domain(*iommu, *domain, *bdf);
+		attach_device(*iommu, *domain, *bdf);
 		printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
-				"device ", (*domain)->id);
-		print_devid(_bdf, 1);
+				"device %s\n", (*domain)->id, dev_name(dev));
 	}
 
 	if (domain_for_device(_bdf) == NULL)
-		set_device_domain(*iommu, *domain, _bdf);
+		attach_device(*iommu, *domain, _bdf);
 
 	return 1;
 }
@@ -946,6 +1225,11 @@ static dma_addr_t __map_single(struct device *dev,
 	pages = iommu_num_pages(paddr, size, PAGE_SIZE);
 	paddr &= PAGE_MASK;
 
+	INC_STATS_COUNTER(total_map_requests);
+
+	if (pages > 1)
+		INC_STATS_COUNTER(cross_page);
+
 	if (align)
 		align_mask = (1UL << get_order(size)) - 1;
 
@@ -962,6 +1246,8 @@ static dma_addr_t __map_single(struct device *dev,
 	}
 	address += offset;
 
+	ADD_STATS_COUNTER(alloced_io_mem, size);
+
 	if (unlikely(dma_dom->need_flush && !amd_iommu_unmap_flush)) {
 		iommu_flush_tlb(iommu, dma_dom->domain.id);
 		dma_dom->need_flush = false;
@@ -998,6 +1284,8 @@ static void __unmap_single(struct amd_iommu *iommu,
 		start += PAGE_SIZE;
 	}
 
+	SUB_STATS_COUNTER(alloced_io_mem, size);
+
 	dma_ops_free_addresses(dma_dom, dma_addr, pages);
 
 	if (amd_iommu_unmap_flush || dma_dom->need_flush) {
@@ -1019,6 +1307,8 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
 	dma_addr_t addr;
 	u64 dma_mask;
 
+	INC_STATS_COUNTER(cnt_map_single);
+
 	if (!check_device(dev))
 		return bad_dma_address;
 
@@ -1030,6 +1320,9 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
 		/* device not handled by any AMD IOMMU */
 		return (dma_addr_t)paddr;
 
+	if (!dma_ops_domain(domain))
+		return bad_dma_address;
+
 	spin_lock_irqsave(&domain->lock, flags);
 	addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false,
 			    dma_mask);
@@ -1055,11 +1348,16 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
 	struct protection_domain *domain;
 	u16 devid;
 
+	INC_STATS_COUNTER(cnt_unmap_single);
+
 	if (!check_device(dev) ||
 	    !get_device_resources(dev, &iommu, &domain, &devid))
 		/* device not handled by any AMD IOMMU */
 		return;
 
+	if (!dma_ops_domain(domain))
+		return;
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	__unmap_single(iommu, domain->priv, dma_addr, size, dir);
@@ -1104,6 +1402,8 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
 	int mapped_elems = 0;
 	u64 dma_mask;
 
+	INC_STATS_COUNTER(cnt_map_sg);
+
 	if (!check_device(dev))
 		return 0;
 
@@ -1114,6 +1414,9 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
 	if (!iommu || !domain)
 		return map_sg_no_iommu(dev, sglist, nelems, dir);
 
+	if (!dma_ops_domain(domain))
+		return 0;
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	for_each_sg(sglist, s, nelems, i) {
@@ -1163,10 +1466,15 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
 	u16 devid;
 	int i;
 
+	INC_STATS_COUNTER(cnt_unmap_sg);
+
 	if (!check_device(dev) ||
 	    !get_device_resources(dev, &iommu, &domain, &devid))
 		return;
 
+	if (!dma_ops_domain(domain))
+		return;
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	for_each_sg(sglist, s, nelems, i) {
@@ -1194,6 +1502,8 @@ static void *alloc_coherent(struct device *dev, size_t size,
 	phys_addr_t paddr;
 	u64 dma_mask = dev->coherent_dma_mask;
 
+	INC_STATS_COUNTER(cnt_alloc_coherent);
+
 	if (!check_device(dev))
 		return NULL;
 
@@ -1212,6 +1522,9 @@ static void *alloc_coherent(struct device *dev, size_t size,
 		return virt_addr;
 	}
 
+	if (!dma_ops_domain(domain))
+		goto out_free;
+
 	if (!dma_mask)
 		dma_mask = *dev->dma_mask;
 
@@ -1220,18 +1533,20 @@ static void *alloc_coherent(struct device *dev, size_t size,
 	*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 (*dma_addr == bad_dma_address)
+		goto out_free;
 
 	iommu_completion_wait(iommu);
 
-out:
 	spin_unlock_irqrestore(&domain->lock, flags);
 
 	return virt_addr;
+
+out_free:
+
+	free_pages((unsigned long)virt_addr, get_order(size));
+
+	return NULL;
 }
 
 /*
@@ -1245,6 +1560,8 @@ static void free_coherent(struct device *dev, size_t size,
 	struct protection_domain *domain;
 	u16 devid;
 
+	INC_STATS_COUNTER(cnt_free_coherent);
+
 	if (!check_device(dev))
 		return;
 
@@ -1253,6 +1570,9 @@ static void free_coherent(struct device *dev, size_t size,
 	if (!iommu || !domain)
 		goto free_mem;
 
+	if (!dma_ops_domain(domain))
+		goto free_mem;
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	__unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
@@ -1296,7 +1616,7 @@ static int amd_iommu_dma_supported(struct device *dev, u64 mask)
  * we don't need to preallocate the protection domains anymore.
  * For now we have to.
  */
-void prealloc_protection_domains(void)
+static void prealloc_protection_domains(void)
 {
 	struct pci_dev *dev = NULL;
 	struct dma_ops_domain *dma_dom;
@@ -1305,7 +1625,7 @@ void prealloc_protection_domains(void)
 	u16 devid;
 
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
-		devid = (dev->bus->number << 8) | dev->devfn;
+		devid = calc_devid(dev->bus->number, dev->devfn);
 		if (devid > amd_iommu_last_bdf)
 			continue;
 		devid = amd_iommu_alias_table[devid];
@@ -1352,6 +1672,7 @@ int __init amd_iommu_init_dma_ops(void)
 		iommu->default_dom = dma_ops_domain_alloc(iommu, order);
 		if (iommu->default_dom == NULL)
 			return -ENOMEM;
+		iommu->default_dom->domain.flags |= PD_DEFAULT_MASK;
 		ret = iommu_init_unity_mappings(iommu);
 		if (ret)
 			goto free_domains;
@@ -1375,6 +1696,12 @@ int __init amd_iommu_init_dma_ops(void)
 	/* Make the driver finally visible to the drivers */
 	dma_ops = &amd_iommu_dma_ops;
 
+	register_iommu(&amd_iommu_ops);
+
+	bus_register_notifier(&pci_bus_type, &device_nb);
+
+	amd_iommu_stats_init();
+
 	return 0;
 
 free_domains:
@@ -1386,3 +1713,224 @@ free_domains:
 
 	return ret;
 }
+
+/*****************************************************************************
+ *
+ * The following functions belong to the exported interface of AMD IOMMU
+ *
+ * This interface allows access to lower level functions of the IOMMU
+ * like protection domain handling and assignement of devices to domains
+ * which is not possible with the dma_ops interface.
+ *
+ *****************************************************************************/
+
+static void cleanup_domain(struct protection_domain *domain)
+{
+	unsigned long flags;
+	u16 devid;
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+
+	for (devid = 0; devid <= amd_iommu_last_bdf; ++devid)
+		if (amd_iommu_pd_table[devid] == domain)
+			__detach_device(domain, devid);
+
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
+
+static int amd_iommu_domain_init(struct iommu_domain *dom)
+{
+	struct protection_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return -ENOMEM;
+
+	spin_lock_init(&domain->lock);
+	domain->mode = PAGE_MODE_3_LEVEL;
+	domain->id = domain_id_alloc();
+	if (!domain->id)
+		goto out_free;
+	domain->pt_root = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!domain->pt_root)
+		goto out_free;
+
+	dom->priv = domain;
+
+	return 0;
+
+out_free:
+	kfree(domain);
+
+	return -ENOMEM;
+}
+
+static void amd_iommu_domain_destroy(struct iommu_domain *dom)
+{
+	struct protection_domain *domain = dom->priv;
+
+	if (!domain)
+		return;
+
+	if (domain->dev_cnt > 0)
+		cleanup_domain(domain);
+
+	BUG_ON(domain->dev_cnt != 0);
+
+	free_pagetable(domain);
+
+	domain_id_free(domain->id);
+
+	kfree(domain);
+
+	dom->priv = NULL;
+}
+
+static void amd_iommu_detach_device(struct iommu_domain *dom,
+				    struct device *dev)
+{
+	struct protection_domain *domain = dom->priv;
+	struct amd_iommu *iommu;
+	struct pci_dev *pdev;
+	u16 devid;
+
+	if (dev->bus != &pci_bus_type)
+		return;
+
+	pdev = to_pci_dev(dev);
+
+	devid = calc_devid(pdev->bus->number, pdev->devfn);
+
+	if (devid > 0)
+		detach_device(domain, devid);
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		return;
+
+	iommu_queue_inv_dev_entry(iommu, devid);
+	iommu_completion_wait(iommu);
+}
+
+static int amd_iommu_attach_device(struct iommu_domain *dom,
+				   struct device *dev)
+{
+	struct protection_domain *domain = dom->priv;
+	struct protection_domain *old_domain;
+	struct amd_iommu *iommu;
+	struct pci_dev *pdev;
+	u16 devid;
+
+	if (dev->bus != &pci_bus_type)
+		return -EINVAL;
+
+	pdev = to_pci_dev(dev);
+
+	devid = calc_devid(pdev->bus->number, pdev->devfn);
+
+	if (devid >= amd_iommu_last_bdf ||
+			devid != amd_iommu_alias_table[devid])
+		return -EINVAL;
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		return -EINVAL;
+
+	old_domain = domain_for_device(devid);
+	if (old_domain)
+		return -EBUSY;
+
+	attach_device(iommu, domain, devid);
+
+	iommu_completion_wait(iommu);
+
+	return 0;
+}
+
+static int amd_iommu_map_range(struct iommu_domain *dom,
+			       unsigned long iova, phys_addr_t paddr,
+			       size_t size, int iommu_prot)
+{
+	struct protection_domain *domain = dom->priv;
+	unsigned long i,  npages = iommu_num_pages(paddr, size, PAGE_SIZE);
+	int prot = 0;
+	int ret;
+
+	if (iommu_prot & IOMMU_READ)
+		prot |= IOMMU_PROT_IR;
+	if (iommu_prot & IOMMU_WRITE)
+		prot |= IOMMU_PROT_IW;
+
+	iova  &= PAGE_MASK;
+	paddr &= PAGE_MASK;
+
+	for (i = 0; i < npages; ++i) {
+		ret = iommu_map_page(domain, iova, paddr, prot);
+		if (ret)
+			return ret;
+
+		iova  += PAGE_SIZE;
+		paddr += PAGE_SIZE;
+	}
+
+	return 0;
+}
+
+static void amd_iommu_unmap_range(struct iommu_domain *dom,
+				  unsigned long iova, size_t size)
+{
+
+	struct protection_domain *domain = dom->priv;
+	unsigned long i,  npages = iommu_num_pages(iova, size, PAGE_SIZE);
+
+	iova  &= PAGE_MASK;
+
+	for (i = 0; i < npages; ++i) {
+		iommu_unmap_page(domain, iova);
+		iova  += PAGE_SIZE;
+	}
+
+	iommu_flush_domain(domain->id);
+}
+
+static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
+					  unsigned long iova)
+{
+	struct protection_domain *domain = dom->priv;
+	unsigned long offset = iova & ~PAGE_MASK;
+	phys_addr_t paddr;
+	u64 *pte;
+
+	pte = &domain->pt_root[IOMMU_PTE_L2_INDEX(iova)];
+
+	if (!IOMMU_PTE_PRESENT(*pte))
+		return 0;
+
+	pte = IOMMU_PTE_PAGE(*pte);
+	pte = &pte[IOMMU_PTE_L1_INDEX(iova)];
+
+	if (!IOMMU_PTE_PRESENT(*pte))
+		return 0;
+
+	pte = IOMMU_PTE_PAGE(*pte);
+	pte = &pte[IOMMU_PTE_L0_INDEX(iova)];
+
+	if (!IOMMU_PTE_PRESENT(*pte))
+		return 0;
+
+	paddr  = *pte & IOMMU_PAGE_MASK;
+	paddr |= offset;
+
+	return paddr;
+}
+
+static struct iommu_ops amd_iommu_ops = {
+	.domain_init = amd_iommu_domain_init,
+	.domain_destroy = amd_iommu_domain_destroy,
+	.attach_dev = amd_iommu_attach_device,
+	.detach_dev = amd_iommu_detach_device,
+	.map = amd_iommu_map_range,
+	.unmap = amd_iommu_unmap_range,
+	.iova_to_phys = amd_iommu_iova_to_phys,
+};
+