x86: amd_iommu: move to drivers/iommu/

This should ease finding similarities with different platforms,
with the intention of solving problems once in a generic framework
which everyone can use.

Compile-tested on x86_64.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

3 files changed, 2794 insertions, 0 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 21a80bfbdb5..9246c5bf25a 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -17,3 +17,32 @@ config MSM_IOMMU
 config IOMMU_PGTABLES_L2
 	def_bool y
 	depends on MSM_IOMMU && MMU && SMP && CPU_DCACHE_DISABLE=n
+
+# AMD IOMMU support
+config AMD_IOMMU
+	bool "AMD IOMMU support"
+	select SWIOTLB
+	select PCI_MSI
+	select PCI_IOV
+	select IOMMU_API
+	depends on X86_64 && PCI && ACPI
+	---help---
+	  With this option you can enable support for AMD IOMMU hardware in
+	  your system. An IOMMU is a hardware component which provides
+	  remapping of DMA memory accesses from devices. With an AMD IOMMU you
+	  can isolate the the DMA memory of different devices and protect the
+	  system from misbehaving device drivers or hardware.
+
+	  You can find out if your system has an AMD IOMMU if you look into
+	  your BIOS for an option to enable it or if you have an IVRS ACPI
+	  table.
+
+config AMD_IOMMU_STATS
+	bool "Export AMD IOMMU statistics to debugfs"
+	depends on AMD_IOMMU
+	select DEBUG_FS
+	---help---
+	  This option enables code in the AMD IOMMU driver to collect various
+	  statistics about whats happening in the driver and exports that
+	  information to userspace via debugfs.
+	  If unsure, say N.
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 1a71c82b1af..4237eaf8460 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_IOMMU_API) += iommu.o
 obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
+obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
new file mode 100644
index 00000000000..7c3a95e54ec
--- /dev/null
+++ b/drivers/iommu/amd_iommu.c
@@ -0,0 +1,2764 @@
+/*
+ * Copyright (C) 2007-2010 Advanced Micro Devices, Inc.
+ * Author: Joerg Roedel <joerg.roedel@amd.com>
+ *         Leo Duran <leo.duran@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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
+ */
+
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
+#include <linux/bitmap.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
+#include <linux/iommu-helper.h>
+#include <linux/iommu.h>
+#include <linux/delay.h>
+#include <asm/proto.h>
+#include <asm/iommu.h>
+#include <asm/gart.h>
+#include <asm/dma.h>
+#include <asm/amd_iommu_proto.h>
+#include <asm/amd_iommu_types.h>
+#include <asm/amd_iommu.h>
+
+#define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
+
+#define LOOP_TIMEOUT	100000
+
+static DEFINE_RWLOCK(amd_iommu_devtable_lock);
+
+/* A list of preallocated protection domains */
+static LIST_HEAD(iommu_pd_list);
+static DEFINE_SPINLOCK(iommu_pd_list_lock);
+
+/*
+ * Domain for untranslated devices - only allocated
+ * if iommu=pt passed on kernel cmd line.
+ */
+static struct protection_domain *pt_domain;
+
+static struct iommu_ops amd_iommu_ops;
+
+/*
+ * general struct to manage commands send to an IOMMU
+ */
+struct iommu_cmd {
+	u32 data[4];
+};
+
+static void update_domain(struct protection_domain *domain);
+
+/****************************************************************************
+ *
+ * Helper functions
+ *
+ ****************************************************************************/
+
+static inline u16 get_device_id(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return calc_devid(pdev->bus->number, pdev->devfn);
+}
+
+static struct iommu_dev_data *get_dev_data(struct device *dev)
+{
+	return dev->archdata.iommu;
+}
+
+/*
+ * 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;
+	u16 alias = amd_iommu_alias_table[devid];
+
+	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 ||
+		    entry->target_dev == alias) {
+			ret = entry;
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&iommu_pd_list_lock, flags);
+
+	return ret;
+}
+
+/*
+ * 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)
+{
+	u16 devid;
+
+	if (!dev || !dev->dma_mask)
+		return false;
+
+	/* No device or no PCI device */
+	if (dev->bus != &pci_bus_type)
+		return false;
+
+	devid = get_device_id(dev);
+
+	/* Out of our scope? */
+	if (devid > amd_iommu_last_bdf)
+		return false;
+
+	if (amd_iommu_rlookup_table[devid] == NULL)
+		return false;
+
+	return true;
+}
+
+static int iommu_init_device(struct device *dev)
+{
+	struct iommu_dev_data *dev_data;
+	struct pci_dev *pdev;
+	u16 devid, alias;
+
+	if (dev->archdata.iommu)
+		return 0;
+
+	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
+	if (!dev_data)
+		return -ENOMEM;
+
+	dev_data->dev = dev;
+
+	devid = get_device_id(dev);
+	alias = amd_iommu_alias_table[devid];
+	pdev = pci_get_bus_and_slot(PCI_BUS(alias), alias & 0xff);
+	if (pdev)
+		dev_data->alias = &pdev->dev;
+	else {
+		kfree(dev_data);
+		return -ENOTSUPP;
+	}
+
+	atomic_set(&dev_data->bind, 0);
+
+	dev->archdata.iommu = dev_data;
+
+
+	return 0;
+}
+
+static void iommu_ignore_device(struct device *dev)
+{
+	u16 devid, alias;
+
+	devid = get_device_id(dev);
+	alias = amd_iommu_alias_table[devid];
+
+	memset(&amd_iommu_dev_table[devid], 0, sizeof(struct dev_table_entry));
+	memset(&amd_iommu_dev_table[alias], 0, sizeof(struct dev_table_entry));
+
+	amd_iommu_rlookup_table[devid] = NULL;
+	amd_iommu_rlookup_table[alias] = NULL;
+}
+
+static void iommu_uninit_device(struct device *dev)
+{
+	kfree(dev->archdata.iommu);
+}
+
+void __init amd_iommu_uninit_devices(void)
+{
+	struct pci_dev *pdev = NULL;
+
+	for_each_pci_dev(pdev) {
+
+		if (!check_device(&pdev->dev))
+			continue;
+
+		iommu_uninit_device(&pdev->dev);
+	}
+}
+
+int __init amd_iommu_init_devices(void)
+{
+	struct pci_dev *pdev = NULL;
+	int ret = 0;
+
+	for_each_pci_dev(pdev) {
+
+		if (!check_device(&pdev->dev))
+			continue;
+
+		ret = iommu_init_device(&pdev->dev);
+		if (ret == -ENOTSUPP)
+			iommu_ignore_device(&pdev->dev);
+		else if (ret)
+			goto out_free;
+	}
+
+	return 0;
+
+out_free:
+
+	amd_iommu_uninit_devices();
+
+	return ret;
+}
+#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_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_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
+
+/****************************************************************************
+ *
+ * Interrupt handling functions
+ *
+ ****************************************************************************/
+
+static void dump_dte_entry(u16 devid)
+{
+	int i;
+
+	for (i = 0; i < 8; ++i)
+		pr_err("AMD-Vi: DTE[%d]: %08x\n", i,
+			amd_iommu_dev_table[devid].data[i]);
+}
+
+static void dump_command(unsigned long phys_addr)
+{
+	struct iommu_cmd *cmd = phys_to_virt(phys_addr);
+	int i;
+
+	for (i = 0; i < 4; ++i)
+		pr_err("AMD-Vi: CMD[%d]: %08x\n", i, cmd->data[i]);
+}
+
+static void iommu_print_event(struct amd_iommu *iommu, 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-Vi: 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);
+		dump_dte_entry(devid);
+		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);
+		dump_command(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, 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_thread(int irq, void *data)
+{
+	struct amd_iommu *iommu;
+
+	for_each_iommu(iommu)
+		iommu_poll_events(iommu);
+
+	return IRQ_HANDLED;
+}
+
+irqreturn_t amd_iommu_int_handler(int irq, void *data)
+{
+	return IRQ_WAKE_THREAD;
+}
+
+/****************************************************************************
+ *
+ * IOMMU command queuing functions
+ *
+ ****************************************************************************/
+
+static int wait_on_sem(volatile u64 *sem)
+{
+	int i = 0;
+
+	while (*sem == 0 && i < LOOP_TIMEOUT) {
+		udelay(1);
+		i += 1;
+	}
+
+	if (i == LOOP_TIMEOUT) {
+		pr_alert("AMD-Vi: Completion-Wait loop timed out\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void copy_cmd_to_buffer(struct amd_iommu *iommu,
+			       struct iommu_cmd *cmd,
+			       u32 tail)
+{
+	u8 *target;
+
+	target = iommu->cmd_buf + tail;
+	tail   = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
+
+	/* Copy command to buffer */
+	memcpy(target, cmd, sizeof(*cmd));
+
+	/* Tell the IOMMU about it */
+	writel(tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
+}
+
+static void build_completion_wait(struct iommu_cmd *cmd, u64 address)
+{
+	WARN_ON(address & 0x7ULL);
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[0] = lower_32_bits(__pa(address)) | CMD_COMPL_WAIT_STORE_MASK;
+	cmd->data[1] = upper_32_bits(__pa(address));
+	cmd->data[2] = 1;
+	CMD_SET_TYPE(cmd, CMD_COMPL_WAIT);
+}
+
+static void build_inv_dte(struct iommu_cmd *cmd, u16 devid)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[0] = devid;
+	CMD_SET_TYPE(cmd, CMD_INV_DEV_ENTRY);
+}
+
+static void build_inv_iommu_pages(struct iommu_cmd *cmd, u64 address,
+				  size_t size, u16 domid, int pde)
+{
+	u64 pages;
+	int s;
+
+	pages = iommu_num_pages(address, size, PAGE_SIZE);
+	s     = 0;
+
+	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;
+	}
+
+	address &= PAGE_MASK;
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[1] |= domid;
+	cmd->data[2]  = lower_32_bits(address);
+	cmd->data[3]  = upper_32_bits(address);
+	CMD_SET_TYPE(cmd, CMD_INV_IOMMU_PAGES);
+	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;
+}
+
+static void build_inv_iotlb_pages(struct iommu_cmd *cmd, u16 devid, int qdep,
+				  u64 address, size_t size)
+{
+	u64 pages;
+	int s;
+
+	pages = iommu_num_pages(address, size, PAGE_SIZE);
+	s     = 0;
+
+	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;
+	}
+
+	address &= PAGE_MASK;
+
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[0]  = devid;
+	cmd->data[0] |= (qdep & 0xff) << 24;
+	cmd->data[1]  = devid;
+	cmd->data[2]  = lower_32_bits(address);
+	cmd->data[3]  = upper_32_bits(address);
+	CMD_SET_TYPE(cmd, CMD_INV_IOTLB_PAGES);
+	if (s)
+		cmd->data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
+}
+
+static void build_inv_all(struct iommu_cmd *cmd)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	CMD_SET_TYPE(cmd, CMD_INV_ALL);
+}
+
+/*
+ * Writes the command to the IOMMUs command buffer and informs the
+ * hardware about the new command.
+ */
+static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
+{
+	u32 left, tail, head, next_tail;
+	unsigned long flags;
+
+	WARN_ON(iommu->cmd_buf_size & CMD_BUFFER_UNINITIALIZED);
+
+again:
+	spin_lock_irqsave(&iommu->lock, flags);
+
+	head      = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
+	tail      = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
+	next_tail = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
+	left      = (head - next_tail) % iommu->cmd_buf_size;
+
+	if (left <= 2) {
+		struct iommu_cmd sync_cmd;
+		volatile u64 sem = 0;
+		int ret;
+
+		build_completion_wait(&sync_cmd, (u64)&sem);
+		copy_cmd_to_buffer(iommu, &sync_cmd, tail);
+
+		spin_unlock_irqrestore(&iommu->lock, flags);
+
+		if ((ret = wait_on_sem(&sem)) != 0)
+			return ret;
+
+		goto again;
+	}
+
+	copy_cmd_to_buffer(iommu, cmd, tail);
+
+	/* We need to sync now to make sure all commands are processed */
+	iommu->need_sync = true;
+
+	spin_unlock_irqrestore(&iommu->lock, flags);
+
+	return 0;
+}
+
+/*
+ * 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;
+	volatile u64 sem = 0;
+	int ret;
+
+	if (!iommu->need_sync)
+		return 0;
+
+	build_completion_wait(&cmd, (u64)&sem);
+
+	ret = iommu_queue_command(iommu, &cmd);
+	if (ret)
+		return ret;
+
+	return wait_on_sem(&sem);
+}
+
+static int iommu_flush_dte(struct amd_iommu *iommu, u16 devid)
+{
+	struct iommu_cmd cmd;
+
+	build_inv_dte(&cmd, devid);
+
+	return iommu_queue_command(iommu, &cmd);
+}
+
+static void iommu_flush_dte_all(struct amd_iommu *iommu)
+{
+	u32 devid;
+
+	for (devid = 0; devid <= 0xffff; ++devid)
+		iommu_flush_dte(iommu, devid);
+
+	iommu_completion_wait(iommu);
+}
+
+/*
+ * This function uses heavy locking and may disable irqs for some time. But
+ * this is no issue because it is only called during resume.
+ */
+static void iommu_flush_tlb_all(struct amd_iommu *iommu)
+{
+	u32 dom_id;
+
+	for (dom_id = 0; dom_id <= 0xffff; ++dom_id) {
+		struct iommu_cmd cmd;
+		build_inv_iommu_pages(&cmd, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS,
+				      dom_id, 1);
+		iommu_queue_command(iommu, &cmd);
+	}
+
+	iommu_completion_wait(iommu);
+}
+
+static void iommu_flush_all(struct amd_iommu *iommu)
+{
+	struct iommu_cmd cmd;
+
+	build_inv_all(&cmd);
+
+	iommu_queue_command(iommu, &cmd);
+	iommu_completion_wait(iommu);
+}
+
+void iommu_flush_all_caches(struct amd_iommu *iommu)
+{
+	if (iommu_feature(iommu, FEATURE_IA)) {
+		iommu_flush_all(iommu);
+	} else {
+		iommu_flush_dte_all(iommu);
+		iommu_flush_tlb_all(iommu);
+	}
+}
+
+/*
+ * Command send function for flushing on-device TLB
+ */
+static int device_flush_iotlb(struct device *dev, u64 address, size_t size)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct amd_iommu *iommu;
+	struct iommu_cmd cmd;
+	u16 devid;
+	int qdep;
+
+	qdep  = pci_ats_queue_depth(pdev);
+	devid = get_device_id(dev);
+	iommu = amd_iommu_rlookup_table[devid];
+
+	build_inv_iotlb_pages(&cmd, devid, qdep, address, size);
+
+	return iommu_queue_command(iommu, &cmd);
+}
+
+/*
+ * Command send function for invalidating a device table entry
+ */
+static int device_flush_dte(struct device *dev)
+{
+	struct amd_iommu *iommu;
+	struct pci_dev *pdev;
+	u16 devid;
+	int ret;
+
+	pdev  = to_pci_dev(dev);
+	devid = get_device_id(dev);
+	iommu = amd_iommu_rlookup_table[devid];
+
+	ret = iommu_flush_dte(iommu, devid);
+	if (ret)
+		return ret;
+
+	if (pci_ats_enabled(pdev))
+		ret = device_flush_iotlb(dev, 0, ~0UL);
+
+	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 void __domain_flush_pages(struct protection_domain *domain,
+				 u64 address, size_t size, int pde)
+{
+	struct iommu_dev_data *dev_data;
+	struct iommu_cmd cmd;
+	int ret = 0, i;
+
+	build_inv_iommu_pages(&cmd, address, size, domain->id, pde);
+
+	for (i = 0; i < amd_iommus_present; ++i) {
+		if (!domain->dev_iommu[i])
+			continue;
+
+		/*
+		 * Devices of this domain are behind this IOMMU
+		 * We need a TLB flush
+		 */
+		ret |= iommu_queue_command(amd_iommus[i], &cmd);
+	}
+
+	list_for_each_entry(dev_data, &domain->dev_list, list) {
+		struct pci_dev *pdev = to_pci_dev(dev_data->dev);
+
+		if (!pci_ats_enabled(pdev))
+			continue;
+
+		ret |= device_flush_iotlb(dev_data->dev, address, size);
+	}
+
+	WARN_ON(ret);
+}
+
+static void domain_flush_pages(struct protection_domain *domain,
+			       u64 address, size_t size)
+{
+	__domain_flush_pages(domain, address, size, 0);
+}
+
+/* Flush the whole IO/TLB for a given protection domain */
+static void domain_flush_tlb(struct protection_domain *domain)
+{
+	__domain_flush_pages(domain, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS, 0);
+}
+
+/* Flush the whole IO/TLB for a given protection domain - including PDE */
+static void domain_flush_tlb_pde(struct protection_domain *domain)
+{
+	__domain_flush_pages(domain, 0, CMD_INV_IOMMU_ALL_PAGES_ADDRESS, 1);
+}
+
+static void domain_flush_complete(struct protection_domain *domain)
+{
+	int i;
+
+	for (i = 0; i < amd_iommus_present; ++i) {
+		if (!domain->dev_iommu[i])
+			continue;
+
+		/*
+		 * Devices of this domain are behind this IOMMU
+		 * We need to wait for completion of all commands.
+		 */
+		iommu_completion_wait(amd_iommus[i]);
+	}
+}
+
+
+/*
+ * This function flushes the DTEs for all devices in domain
+ */
+static void domain_flush_devices(struct protection_domain *domain)
+{
+	struct iommu_dev_data *dev_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	list_for_each_entry(dev_data, &domain->dev_list, list)
+		device_flush_dte(dev_data->dev);
+
+	spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/****************************************************************************
+ *
+ * The functions below are used the create the page table mappings for
+ * unity mapped regions.
+ *
+ ****************************************************************************/
+
+/*
+ * This function is used to add another level to an IO page table. Adding
+ * another level increases the size of the address space by 9 bits to a size up
+ * to 64 bits.
+ */
+static bool increase_address_space(struct protection_domain *domain,
+				   gfp_t gfp)
+{
+	u64 *pte;
+
+	if (domain->mode == PAGE_MODE_6_LEVEL)
+		/* address space already 64 bit large */
+		return false;
+
+	pte = (void *)get_zeroed_page(gfp);
+	if (!pte)
+		return false;
+
+	*pte             = PM_LEVEL_PDE(domain->mode,
+					virt_to_phys(domain->pt_root));
+	domain->pt_root  = pte;
+	domain->mode    += 1;
+	domain->updated  = true;
+
+	return true;
+}
+
+static u64 *alloc_pte(struct protection_domain *domain,
+		      unsigned long address,
+		      unsigned long page_size,
+		      u64 **pte_page,
+		      gfp_t gfp)
+{
+	int level, end_lvl;
+	u64 *pte, *page;
+
+	BUG_ON(!is_power_of_2(page_size));
+
+	while (address > PM_LEVEL_SIZE(domain->mode))
+		increase_address_space(domain, gfp);
+
+	level   = domain->mode - 1;
+	pte     = &domain->pt_root[PM_LEVEL_INDEX(level, address)];
+	address = PAGE_SIZE_ALIGN(address, page_size);
+	end_lvl = PAGE_SIZE_LEVEL(page_size);
+
+	while (level > end_lvl) {
+		if (!IOMMU_PTE_PRESENT(*pte)) {
+			page = (u64 *)get_zeroed_page(gfp);
+			if (!page)
+				return NULL;
+			*pte = PM_LEVEL_PDE(level, virt_to_phys(page));
+		}
+
+		/* No level skipping support yet */
+		if (PM_PTE_LEVEL(*pte) != level)
+			return NULL;
+
+		level -= 1;
+
+		pte = IOMMU_PTE_PAGE(*pte);
+
+		if (pte_page && level == end_lvl)
+			*pte_page = pte;
+
+		pte = &pte[PM_LEVEL_INDEX(level, address)];
+	}
+
+	return pte;
+}
+
+/*
+ * This function checks if there is a PTE for a given dma address. If
+ * there is one, it returns the pointer to it.
+ */
+static u64 *fetch_pte(struct protection_domain *domain, unsigned long address)
+{
+	int level;
+	u64 *pte;
+
+	if (address > PM_LEVEL_SIZE(domain->mode))
+		return NULL;
+
+	level   =  domain->mode - 1;
+	pte     = &domain->pt_root[PM_LEVEL_INDEX(level, address)];
+
+	while (level > 0) {
+
+		/* Not Present */
+		if (!IOMMU_PTE_PRESENT(*pte))
+			return NULL;
+
+		/* Large PTE */
+		if (PM_PTE_LEVEL(*pte) == 0x07) {
+			unsigned long pte_mask, __pte;
+
+			/*
+			 * If we have a series of large PTEs, make
+			 * sure to return a pointer to the first one.
+			 */
+			pte_mask = PTE_PAGE_SIZE(*pte);
+			pte_mask = ~((PAGE_SIZE_PTE_COUNT(pte_mask) << 3) - 1);
+			__pte    = ((unsigned long)pte) & pte_mask;
+
+			return (u64 *)__pte;
+		}
+
+		/* No level skipping support yet */
+		if (PM_PTE_LEVEL(*pte) != level)
+			return NULL;
+
+		level -= 1;
+
+		/* Walk to the next level */
+		pte = IOMMU_PTE_PAGE(*pte);
+		pte = &pte[PM_LEVEL_INDEX(level, address)];
+	}
+
+	return pte;
+}
+
+/*
+ * 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_page(struct protection_domain *dom,
+			  unsigned long bus_addr,
+			  unsigned long phys_addr,
+			  int prot,
+			  unsigned long page_size)
+{
+	u64 __pte, *pte;
+	int i, count;
+
+	if (!(prot & IOMMU_PROT_MASK))
+		return -EINVAL;
+
+	bus_addr  = PAGE_ALIGN(bus_addr);
+	phys_addr = PAGE_ALIGN(phys_addr);
+	count     = PAGE_SIZE_PTE_COUNT(page_size);
+	pte       = alloc_pte(dom, bus_addr, page_size, NULL, GFP_KERNEL);
+
+	for (i = 0; i < count; ++i)
+		if (IOMMU_PTE_PRESENT(pte[i]))
+			return -EBUSY;
+
+	if (page_size > PAGE_SIZE) {
+		__pte = PAGE_SIZE_PTE(phys_addr, page_size);
+		__pte |= PM_LEVEL_ENC(7) | IOMMU_PTE_P | IOMMU_PTE_FC;
+	} else
+		__pte = phys_addr | IOMMU_PTE_P | IOMMU_PTE_FC;
+
+	if (prot & IOMMU_PROT_IR)
+		__pte |= IOMMU_PTE_IR;
+	if (prot & IOMMU_PROT_IW)
+		__pte |= IOMMU_PTE_IW;
+
+	for (i = 0; i < count; ++i)
+		pte[i] = __pte;
+
+	update_domain(dom);
+
+	return 0;
+}
+
+static unsigned long iommu_unmap_page(struct protection_domain *dom,
+				      unsigned long bus_addr,
+				      unsigned long page_size)
+{
+	unsigned long long unmap_size, unmapped;
+	u64 *pte;
+
+	BUG_ON(!is_power_of_2(page_size));
+
+	unmapped = 0;
+
+	while (unmapped < page_size) {
+
+		pte = fetch_pte(dom, bus_addr);
+
+		if (!pte) {
+			/*
+			 * No PTE for this address
+			 * move forward in 4kb steps
+			 */
+			unmap_size = PAGE_SIZE;
+		} else if (PM_PTE_LEVEL(*pte) == 0) {
+			/* 4kb PTE found for this address */
+			unmap_size = PAGE_SIZE;
+			*pte       = 0ULL;
+		} else {
+			int count, i;
+
+			/* Large PTE found which maps this address */
+			unmap_size = PTE_PAGE_SIZE(*pte);
+			count      = PAGE_SIZE_PTE_COUNT(unmap_size);
+			for (i = 0; i < count; i++)
+				pte[i] = 0ULL;
+		}
+
+		bus_addr  = (bus_addr & ~(unmap_size - 1)) + unmap_size;
+		unmapped += unmap_size;
+	}
+
+	BUG_ON(!is_power_of_2(unmapped));
+
+	return unmapped;
+}
+
+/*
+ * 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)
+{
+	u16 bdf, i;
+
+	for (i = entry->devid_start; i <= entry->devid_end; ++i) {
+		bdf = amd_iommu_alias_table[i];
+		if (amd_iommu_rlookup_table[bdf] == iommu)
+			return 1;
+	}
+
+	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)
+{
+	u64 addr;
+	int ret;
+
+	for (addr = e->address_start; addr < e->address_end;
+	     addr += PAGE_SIZE) {
+		ret = iommu_map_page(&dma_dom->domain, addr, addr, e->prot,
+				     PAGE_SIZE);
+		if (ret)
+			return ret;
+		/*
+		 * if unity mapping is in aperture range mark the page
+		 * as allocated in the aperture
+		 */
+		if (addr < dma_dom->aperture_size)
+			__set_bit(addr >> PAGE_SHIFT,
+				  dma_dom->aperture[0]->bitmap);
+	}
+
+	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;
+	int ret;
+
+	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+		if (!iommu_for_unity_map(iommu, entry))
+			continue;
+		ret = dma_ops_unity_map(iommu->default_dom, entry);
+		if (ret)
+			return ret;
+	}
+
+	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)
+{
+	struct unity_map_entry *e;
+	int ret;
+
+	list_for_each_entry(e, &amd_iommu_unity_map, list) {
+		if (!(devid >= e->devid_start && devid <= e->devid_end))
+			continue;
+		ret = dma_ops_unity_map(dma_dom, e);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/****************************************************************************
+ *
+ * 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 functions.
+ *
+ * called with domain->lock held
+ */
+
+/*
+ * 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)
+{
+	unsigned int i, last_page = dom->aperture_size >> PAGE_SHIFT;
+
+	if (start_page + pages > last_page)
+		pages = last_page - start_page;
+
+	for (i = start_page; i < start_page + pages; ++i) {
+		int index = i / APERTURE_RANGE_PAGES;
+		int page  = i % APERTURE_RANGE_PAGES;
+		__set_bit(page, dom->aperture[index]->bitmap);
+	}
+}
+
+/*
+ * This function is used to add a new aperture range to an existing
+ * aperture in case of dma_ops domain allocation or address allocation
+ * failure.
+ */
+static int alloc_new_range(struct dma_ops_domain *dma_dom,
+			   bool populate, gfp_t gfp)
+{
+	int index = dma_dom->aperture_size >> APERTURE_RANGE_SHIFT;
+	struct amd_iommu *iommu;
+	unsigned long i;
+
+#ifdef CONFIG_IOMMU_STRESS
+	populate = false;
+#endif
+
+	if (index >= APERTURE_MAX_RANGES)
+		return -ENOMEM;
+
+	dma_dom->aperture[index] = kzalloc(sizeof(struct aperture_range), gfp);
+	if (!dma_dom->aperture[index])
+		return -ENOMEM;
+
+	dma_dom->aperture[index]->bitmap = (void *)get_zeroed_page(gfp);
+	if (!dma_dom->aperture[index]->bitmap)
+		goto out_free;
+
+	dma_dom->aperture[index]->offset = dma_dom->aperture_size;
+
+	if (populate) {
+		unsigned long address = dma_dom->aperture_size;
+		int i, num_ptes = APERTURE_RANGE_PAGES / 512;
+		u64 *pte, *pte_page;
+
+		for (i = 0; i < num_ptes; ++i) {
+			pte = alloc_pte(&dma_dom->domain, address, PAGE_SIZE,
+					&pte_page, gfp);
+			if (!pte)
+				goto out_free;
+
+			dma_dom->aperture[index]->pte_pages[i] = pte_page;
+
+			address += APERTURE_RANGE_SIZE / 64;
+		}
+	}
+
+	dma_dom->aperture_size += APERTURE_RANGE_SIZE;
+
+	/* Initialize the exclusion range if necessary */
+	for_each_iommu(iommu) {
+		if (iommu->exclusion_start &&
+		    iommu->exclusion_start >= dma_dom->aperture[index]->offset
+		    && iommu->exclusion_start < dma_dom->aperture_size) {
+			unsigned long startpage;
+			int pages = iommu_num_pages(iommu->exclusion_start,
+						    iommu->exclusion_length,
+						    PAGE_SIZE);
+			startpage = iommu->exclusion_start >> PAGE_SHIFT;
+			dma_ops_reserve_addresses(dma_dom, startpage, pages);
+		}
+	}
+
+	/*
+	 * Check for areas already mapped as present in the new aperture
+	 * range and mark those pages as reserved in the allocator. Such
+	 * mappings may already exist as a result of requested unity
+	 * mappings for devices.
+	 */
+	for (i = dma_dom->aperture[index]->offset;
+	     i < dma_dom->aperture_size;
+	     i += PAGE_SIZE) {
+		u64 *pte = fetch_pte(&dma_dom->domain, i);
+		if (!pte || !IOMMU_PTE_PRESENT(*pte))
+			continue;
+
+		dma_ops_reserve_addresses(dma_dom, i << PAGE_SHIFT, 1);
+	}
+
+	update_domain(&dma_dom->domain);
+
+	return 0;
+
+out_free:
+	update_domain(&dma_dom->domain);
+
+	free_page((unsigned long)dma_dom->aperture[index]->bitmap);
+
+	kfree(dma_dom->aperture[index]);
+	dma_dom->aperture[index] = NULL;
+
+	return -ENOMEM;
+}
+
+static unsigned long dma_ops_area_alloc(struct device *dev,
+					struct dma_ops_domain *dom,
+					unsigned int pages,
+					unsigned long align_mask,
+					u64 dma_mask,
+					unsigned long start)
+{
+	unsigned long next_bit = dom->next_address % APERTURE_RANGE_SIZE;
+	int max_index = dom->aperture_size >> APERTURE_RANGE_SHIFT;
+	int i = start >> APERTURE_RANGE_SHIFT;
+	unsigned long boundary_size;
+	unsigned long address = -1;
+	unsigned long limit;
+
+	next_bit >>= PAGE_SHIFT;
+
+	boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
+			PAGE_SIZE) >> PAGE_SHIFT;
+
+	for (;i < max_index; ++i) {
+		unsigned long offset = dom->aperture[i]->offset >> PAGE_SHIFT;
+
+		if (dom->aperture[i]->offset >= dma_mask)
+			break;
+
+		limit = iommu_device_max_index(APERTURE_RANGE_PAGES, offset,
+					       dma_mask >> PAGE_SHIFT);
+
+		address = iommu_area_alloc(dom->aperture[i]->bitmap,
+					   limit, next_bit, pages, 0,
+					    boundary_size, align_mask);
+		if (address != -1) {
+			address = dom->aperture[i]->offset +
+				  (address << PAGE_SHIFT);
+			dom->next_address = address + (pages << PAGE_SHIFT);
+			break;
+		}
+
+		next_bit = 0;
+	}
+
+	return address;
+}
+
+static unsigned long dma_ops_alloc_addresses(struct device *dev,
+					     struct dma_ops_domain *dom,
+					     unsigned int pages,
+					     unsigned long align_mask,
+					     u64 dma_mask)
+{
+	unsigned long address;
+
+#ifdef CONFIG_IOMMU_STRESS
+	dom->next_address = 0;
+	dom->need_flush = true;
+#endif
+
+	address = dma_ops_area_alloc(dev, dom, pages, align_mask,
+				     dma_mask, dom->next_address);
+
+	if (address == -1) {
+		dom->next_address = 0;
+		address = dma_ops_area_alloc(dev, dom, pages, align_mask,
+					     dma_mask, 0);
+		dom->need_flush = true;
+	}
+
+	if (unlikely(address == -1))
+		address = DMA_ERROR_CODE;
+
+	WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
+
+	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)
+{
+	unsigned i = address >> APERTURE_RANGE_SHIFT;
+	struct aperture_range *range = dom->aperture[i];
+
+	BUG_ON(i >= APERTURE_MAX_RANGES || range == NULL);
+
+#ifdef CONFIG_IOMMU_STRESS
+	if (i < 4)
+		return;
+#endif
+
+	if (address >= dom->next_address)
+		dom->need_flush = true;
+
+	address = (address % APERTURE_RANGE_SIZE) >> PAGE_SHIFT;
+
+	bitmap_clear(range->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.
+ *
+ ****************************************************************************/
+
+/*
+ * This function adds a protection domain to the global protection domain list
+ */
+static void add_domain_to_list(struct protection_domain *domain)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&amd_iommu_pd_lock, flags);
+	list_add(&domain->list, &amd_iommu_pd_list);
+	spin_unlock_irqrestore(&amd_iommu_pd_lock, flags);
+}
+
+/*
+ * This function removes a protection domain to the global
+ * protection domain list
+ */
+static void del_domain_from_list(struct protection_domain *domain)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&amd_iommu_pd_lock, flags);
+	list_del(&domain->list);
+	spin_unlock_irqrestore(&amd_iommu_pd_lock, flags);
+}
+
+static u16 domain_id_alloc(void)
+{
+	unsigned long flags;
+	int id;
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID);
+	BUG_ON(id == 0);
+	if (id > 0 && id < MAX_DOMAIN_ID)
+		__set_bit(id, amd_iommu_pd_alloc_bitmap);
+	else
+		id = 0;
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+	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);
+}
+
+static void free_pagetable(struct protection_domain *domain)
+{
+	int i, j;
+	u64 *p1, *p2, *p3;
+
+	p1 = domain->pt_root;
+
+	if (!p1)
+		return;
+
+	for (i = 0; i < 512; ++i) {
+		if (!IOMMU_PTE_PRESENT(p1[i]))
+			continue;
+
+		p2 = IOMMU_PTE_PAGE(p1[i]);
+		for (j = 0; j < 512; ++j) {
+			if (!IOMMU_PTE_PRESENT(p2[j]))
+				continue;
+			p3 = IOMMU_PTE_PAGE(p2[j]);
+			free_page((unsigned long)p3);
+		}
+
+		free_page((unsigned long)p2);
+	}
+
+	free_page((unsigned long)p1);
+
+	domain->pt_root = NULL;
+}
+
+/*
+ * 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)
+{
+	int i;
+
+	if (!dom)
+		return;
+
+	del_domain_from_list(&dom->domain);
+
+	free_pagetable(&dom->domain);
+
+	for (i = 0; i < APERTURE_MAX_RANGES; ++i) {
+		if (!dom->aperture[i])
+			continue;
+		free_page((unsigned long)dom->aperture[i]->bitmap);
+		kfree(dom->aperture[i]);
+	}
+
+	kfree(dom);
+}
+
+/*
+ * Allocates a new protection domain usable for the dma_ops functions.
+ * It also initializes the page table and the address allocator data
+ * structures required for the dma_ops interface
+ */
+static struct dma_ops_domain *dma_ops_domain_alloc(void)
+{
+	struct dma_ops_domain *dma_dom;
+
+	dma_dom = kzalloc(sizeof(struct dma_ops_domain), GFP_KERNEL);
+	if (!dma_dom)
+		return NULL;
+
+	spin_lock_init(&dma_dom->domain.lock);
+
+	dma_dom->domain.id = domain_id_alloc();
+	if (dma_dom->domain.id == 0)
+		goto free_dma_dom;
+	INIT_LIST_HEAD(&dma_dom->domain.dev_list);
+	dma_dom->domain.mode = PAGE_MODE_2_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;
+
+	dma_dom->need_flush = false;
+	dma_dom->target_dev = 0xffff;
+
+	add_domain_to_list(&dma_dom->domain);
+
+	if (alloc_new_range(dma_dom, true, GFP_KERNEL))
+		goto free_dma_dom;
+
+	/*
+	 * mark the first page as allocated so we never return 0 as
+	 * a valid dma-address. So we can use 0 as error value
+	 */
+	dma_dom->aperture[0]->bitmap[0] = 1;
+	dma_dom->next_address = 0;
+
+
+	return dma_dom;
+
+free_dma_dom:
+	dma_ops_domain_free(dma_dom);
+
+	return NULL;
+}
+
+/*
+ * 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;
+}
+
+static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
+{
+	u64 pte_root = virt_to_phys(domain->pt_root);
+	u32 flags = 0;
+
+	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;
+
+	if (ats)
+		flags |= DTE_FLAG_IOTLB;
+
+	amd_iommu_dev_table[devid].data[3] |= flags;
+	amd_iommu_dev_table[devid].data[2]  = domain->id;
+	amd_iommu_dev_table[devid].data[1]  = upper_32_bits(pte_root);
+	amd_iommu_dev_table[devid].data[0]  = lower_32_bits(pte_root);
+}
+
+static void clear_dte_entry(u16 devid)
+{
+	/* 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;
+
+	amd_iommu_apply_erratum_63(devid);
+}
+
+static void do_attach(struct device *dev, struct protection_domain *domain)
+{
+	struct iommu_dev_data *dev_data;
+	struct amd_iommu *iommu;
+	struct pci_dev *pdev;
+	bool ats = false;
+	u16 devid;
+
+	devid    = get_device_id(dev);
+	iommu    = amd_iommu_rlookup_table[devid];
+	dev_data = get_dev_data(dev);
+	pdev     = to_pci_dev(dev);
+
+	if (amd_iommu_iotlb_sup)
+		ats = pci_ats_enabled(pdev);
+
+	/* Update data structures */
+	dev_data->domain = domain;
+	list_add(&dev_data->list, &domain->dev_list);
+	set_dte_entry(devid, domain, ats);
+
+	/* Do reference counting */
+	domain->dev_iommu[iommu->index] += 1;
+	domain->dev_cnt                 += 1;
+
+	/* Flush the DTE entry */
+	device_flush_dte(dev);
+}
+
+static void do_detach(struct device *dev)
+{
+	struct iommu_dev_data *dev_data;
+	struct amd_iommu *iommu;
+	u16 devid;
+
+	devid    = get_device_id(dev);
+	iommu    = amd_iommu_rlookup_table[devid];
+	dev_data = get_dev_data(dev);
+
+	/* decrease reference counters */
+	dev_data->domain->dev_iommu[iommu->index] -= 1;
+	dev_data->domain->dev_cnt                 -= 1;
+
+	/* Update data structures */
+	dev_data->domain = NULL;
+	list_del(&dev_data->list);
+	clear_dte_entry(devid);
+
+	/* Flush the DTE entry */
+	device_flush_dte(dev);
+}
+
+/*
+ * If a device is not yet associated with a domain, this function does
+ * assigns it visible for the hardware
+ */
+static int __attach_device(struct device *dev,
+			   struct protection_domain *domain)
+{
+	struct iommu_dev_data *dev_data, *alias_data;
+	int ret;
+
+	dev_data   = get_dev_data(dev);
+	alias_data = get_dev_data(dev_data->alias);
+
+	if (!alias_data)
+		return -EINVAL;
+
+	/* lock domain */
+	spin_lock(&domain->lock);
+
+	/* Some sanity checks */
+	ret = -EBUSY;
+	if (alias_data->domain != NULL &&
+	    alias_data->domain != domain)
+		goto out_unlock;
+
+	if (dev_data->domain != NULL &&
+	    dev_data->domain != domain)
+		goto out_unlock;
+
+	/* Do real assignment */
+	if (dev_data->alias != dev) {
+		alias_data = get_dev_data(dev_data->alias);
+		if (alias_data->domain == NULL)
+			do_attach(dev_data->alias, domain);
+
+		atomic_inc(&alias_data->bind);
+	}
+
+	if (dev_data->domain == NULL)
+		do_attach(dev, domain);
+
+	atomic_inc(&dev_data->bind);
+
+	ret = 0;
+
+out_unlock:
+
+	/* ready */
+	spin_unlock(&domain->lock);
+
+	return ret;
+}
+
+/*
+ * If a device is not yet associated with a domain, this function does
+ * assigns it visible for the hardware
+ */
+static int attach_device(struct device *dev,
+			 struct protection_domain *domain)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	unsigned long flags;
+	int ret;
+
+	if (amd_iommu_iotlb_sup)
+		pci_enable_ats(pdev, PAGE_SHIFT);
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	ret = __attach_device(dev, domain);
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+	/*
+	 * We might boot into a crash-kernel here. The crashed kernel
+	 * left the caches in the IOMMU dirty. So we have to flush
+	 * here to evict all dirty stuff.
+	 */
+	domain_flush_tlb_pde(domain);
+
+	return ret;
+}
+
+/*
+ * Removes a device from a protection domain (unlocked)
+ */
+static void __detach_device(struct device *dev)
+{
+	struct iommu_dev_data *dev_data = get_dev_data(dev);
+	struct iommu_dev_data *alias_data;
+	struct protection_domain *domain;
+	unsigned long flags;
+
+	BUG_ON(!dev_data->domain);
+
+	domain = dev_data->domain;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	if (dev_data->alias != dev) {
+		alias_data = get_dev_data(dev_data->alias);
+		if (atomic_dec_and_test(&alias_data->bind))
+			do_detach(dev_data->alias);
+	}
+
+	if (atomic_dec_and_test(&dev_data->bind))
+		do_detach(dev);
+
+	spin_unlock_irqrestore(&domain->lock, flags);
+
+	/*
+	 * If we run in passthrough mode the device must be assigned to the
+	 * passthrough domain if it is detached from any other domain.
+	 * Make sure we can deassign from the pt_domain itself.
+	 */
+	if (iommu_pass_through &&
+	    (dev_data->domain == NULL && domain != pt_domain))
+		__attach_device(dev, pt_domain);
+}
+
+/*
+ * Removes a device from a protection domain (with devtable_lock held)
+ */
+static void detach_device(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	unsigned long flags;
+
+	/* lock device table */
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	__detach_device(dev);
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+	if (amd_iommu_iotlb_sup && pci_ats_enabled(pdev))
+		pci_disable_ats(pdev);
+}
+
+/*
+ * 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(struct device *dev)
+{
+	struct protection_domain *dom;
+	struct iommu_dev_data *dev_data, *alias_data;
+	unsigned long flags;
+	u16 devid;
+
+	devid      = get_device_id(dev);
+	dev_data   = get_dev_data(dev);
+	alias_data = get_dev_data(dev_data->alias);
+	if (!alias_data)
+		return NULL;
+
+	read_lock_irqsave(&amd_iommu_devtable_lock, flags);
+	dom = dev_data->domain;
+	if (dom == NULL &&
+	    alias_data->domain != NULL) {
+		__attach_device(dev, alias_data->domain);
+		dom = alias_data->domain;
+	}
+
+	read_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+
+	return dom;
+}
+
+static int device_change_notifier(struct notifier_block *nb,
+				  unsigned long action, void *data)
+{
+	struct device *dev = data;
+	u16 devid;
+	struct protection_domain *domain;
+	struct dma_ops_domain *dma_domain;
+	struct amd_iommu *iommu;
+	unsigned long flags;
+
+	if (!check_device(dev))
+		return 0;
+
+	devid  = get_device_id(dev);
+	iommu  = amd_iommu_rlookup_table[devid];
+
+	switch (action) {
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+
+		domain = domain_for_device(dev);
+
+		if (!domain)
+			goto out;
+		if (iommu_pass_through)
+			break;
+		detach_device(dev);
+		break;
+	case BUS_NOTIFY_ADD_DEVICE:
+
+		iommu_init_device(dev);
+
+		domain = domain_for_device(dev);
+
+		/* 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();
+		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;
+	case BUS_NOTIFY_DEL_DEVICE:
+
+		iommu_uninit_device(dev);
+
+	default:
+		goto out;
+	}
+
+	device_flush_dte(dev);
+	iommu_completion_wait(iommu);
+
+out:
+	return 0;
+}
+
+static struct notifier_block device_nb = {
+	.notifier_call = device_change_notifier,
+};
+
+void amd_iommu_init_notifier(void)
+{
+	bus_register_notifier(&pci_bus_type, &device_nb);
+}
+
+/*****************************************************************************
+ *
+ * The next functions belong to the dma_ops mapping/unmapping code.
+ *
+ *****************************************************************************/
+
+/*
+ * 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 struct protection_domain *get_domain(struct device *dev)
+{
+	struct protection_domain *domain;
+	struct dma_ops_domain *dma_dom;
+	u16 devid = get_device_id(dev);
+
+	if (!check_device(dev))
+		return ERR_PTR(-EINVAL);
+
+	domain = domain_for_device(dev);
+	if (domain != NULL && !dma_ops_domain(domain))
+		return ERR_PTR(-EBUSY);
+
+	if (domain != NULL)
+		return domain;
+
+	/* Device not bount yet - bind it */
+	dma_dom = find_protection_domain(devid);
+	if (!dma_dom)
+		dma_dom = amd_iommu_rlookup_table[devid]->default_dom;
+	attach_device(dev, &dma_dom->domain);
+	DUMP_printk("Using protection domain %d for device %s\n",
+		    dma_dom->domain.id, dev_name(dev));
+
+	return &dma_dom->domain;
+}
+
+static void update_device_table(struct protection_domain *domain)
+{
+	struct iommu_dev_data *dev_data;
+
+	list_for_each_entry(dev_data, &domain->dev_list, list) {
+		struct pci_dev *pdev = to_pci_dev(dev_data->dev);
+		u16 devid = get_device_id(dev_data->dev);
+		set_dte_entry(devid, domain, pci_ats_enabled(pdev));
+	}
+}
+
+static void update_domain(struct protection_domain *domain)
+{
+	if (!domain->updated)
+		return;
+
+	update_device_table(domain);
+
+	domain_flush_devices(domain);
+	domain_flush_tlb_pde(domain);
+
+	domain->updated = false;
+}
+
+/*
+ * This function fetches the PTE for a given address in the aperture
+ */
+static u64* dma_ops_get_pte(struct dma_ops_domain *dom,
+			    unsigned long address)
+{
+	struct aperture_range *aperture;
+	u64 *pte, *pte_page;
+
+	aperture = dom->aperture[APERTURE_RANGE_INDEX(address)];
+	if (!aperture)
+		return NULL;
+
+	pte = aperture->pte_pages[APERTURE_PAGE_INDEX(address)];
+	if (!pte) {
+		pte = alloc_pte(&dom->domain, address, PAGE_SIZE, &pte_page,
+				GFP_ATOMIC);
+		aperture->pte_pages[APERTURE_PAGE_INDEX(address)] = pte_page;
+	} else
+		pte += PM_LEVEL_INDEX(0, address);
+
+	update_domain(&dom->domain);
+
+	return pte;
+}
+
+/*
+ * 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 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  = dma_ops_get_pte(dom, address);
+	if (!pte)
+		return DMA_ERROR_CODE;
+
+	__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 dma_ops_domain *dom,
+				 unsigned long address)
+{
+	struct aperture_range *aperture;
+	u64 *pte;
+
+	if (address >= dom->aperture_size)
+		return;
+
+	aperture = dom->aperture[APERTURE_RANGE_INDEX(address)];
+	if (!aperture)
+		return;
+
+	pte  = aperture->pte_pages[APERTURE_PAGE_INDEX(address)];
+	if (!pte)
+		return;
+
+	pte += PM_LEVEL_INDEX(0, 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 used by all
+ * mapping functions provided with this IOMMU driver.
+ * Must be called with the domain lock held.
+ */
+static dma_addr_t __map_single(struct device *dev,
+			       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, ret;
+	unsigned int pages;
+	unsigned long align_mask = 0;
+	int i;
+
+	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;
+
+retry:
+	address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask,
+					  dma_mask);
+	if (unlikely(address == DMA_ERROR_CODE)) {
+		/*
+		 * setting next_address here will let the address
+		 * allocator only scan the new allocated range in the
+		 * first run. This is a small optimization.
+		 */
+		dma_dom->next_address = dma_dom->aperture_size;
+
+		if (alloc_new_range(dma_dom, false, GFP_ATOMIC))
+			goto out;
+
+		/*
+		 * aperture was successfully enlarged by 128 MB, try
+		 * allocation again
+		 */
+		goto retry;
+	}
+
+	start = address;
+	for (i = 0; i < pages; ++i) {
+		ret = dma_ops_domain_map(dma_dom, start, paddr, dir);
+		if (ret == DMA_ERROR_CODE)
+			goto out_unmap;
+
+		paddr += PAGE_SIZE;
+		start += PAGE_SIZE;
+	}
+	address += offset;
+
+	ADD_STATS_COUNTER(alloced_io_mem, size);
+
+	if (unlikely(dma_dom->need_flush && !amd_iommu_unmap_flush)) {
+		domain_flush_tlb(&dma_dom->domain);
+		dma_dom->need_flush = false;
+	} else if (unlikely(amd_iommu_np_cache))
+		domain_flush_pages(&dma_dom->domain, address, size);
+
+out:
+	return address;
+
+out_unmap:
+
+	for (--i; i >= 0; --i) {
+		start -= PAGE_SIZE;
+		dma_ops_domain_unmap(dma_dom, start);
+	}
+
+	dma_ops_free_addresses(dma_dom, address, pages);
+
+	return DMA_ERROR_CODE;
+}
+
+/*
+ * Does the reverse of the __map_single function. Must be called with
+ * the domain lock held too
+ */
+static void __unmap_single(struct dma_ops_domain *dma_dom,
+			   dma_addr_t dma_addr,
+			   size_t size,
+			   int dir)
+{
+	dma_addr_t flush_addr;
+	dma_addr_t i, start;
+	unsigned int pages;
+
+	if ((dma_addr == DMA_ERROR_CODE) ||
+	    (dma_addr + size > dma_dom->aperture_size))
+		return;
+
+	flush_addr = dma_addr;
+	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(dma_dom, start);
+		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) {
+		domain_flush_pages(&dma_dom->domain, flush_addr, size);
+		dma_dom->need_flush = false;
+	}
+}
+
+/*
+ * The exported map_single function for dma_ops.
+ */
+static dma_addr_t map_page(struct device *dev, struct page *page,
+			   unsigned long offset, size_t size,
+			   enum dma_data_direction dir,
+			   struct dma_attrs *attrs)
+{
+	unsigned long flags;
+	struct protection_domain *domain;
+	dma_addr_t addr;
+	u64 dma_mask;
+	phys_addr_t paddr = page_to_phys(page) + offset;
+
+	INC_STATS_COUNTER(cnt_map_single);
+
+	domain = get_domain(dev);
+	if (PTR_ERR(domain) == -EINVAL)
+		return (dma_addr_t)paddr;
+	else if (IS_ERR(domain))
+		return DMA_ERROR_CODE;
+
+	dma_mask = *dev->dma_mask;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	addr = __map_single(dev, domain->priv, paddr, size, dir, false,
+			    dma_mask);
+	if (addr == DMA_ERROR_CODE)
+		goto out;
+
+	domain_flush_complete(domain);
+
+out:
+	spin_unlock_irqrestore(&domain->lock, flags);
+
+	return addr;
+}
+
+/*
+ * The exported unmap_single function for dma_ops.
+ */
+static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
+		       enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+	unsigned long flags;
+	struct protection_domain *domain;
+
+	INC_STATS_COUNTER(cnt_unmap_single);
+
+	domain = get_domain(dev);
+	if (IS_ERR(domain))
+		return;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	__unmap_single(domain->priv, dma_addr, size, dir);
+
+	domain_flush_complete(domain);
+
+	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, enum dma_data_direction dir,
+		  struct dma_attrs *attrs)
+{
+	unsigned long flags;
+	struct protection_domain *domain;
+	int i;
+	struct scatterlist *s;
+	phys_addr_t paddr;
+	int mapped_elems = 0;
+	u64 dma_mask;
+
+	INC_STATS_COUNTER(cnt_map_sg);
+
+	domain = get_domain(dev);
+	if (PTR_ERR(domain) == -EINVAL)
+		return map_sg_no_iommu(dev, sglist, nelems, dir);
+	else if (IS_ERR(domain))
+		return 0;
+
+	dma_mask = *dev->dma_mask;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	for_each_sg(sglist, s, nelems, i) {
+		paddr = sg_phys(s);
+
+		s->dma_address = __map_single(dev, domain->priv,
+					      paddr, s->length, dir, false,
+					      dma_mask);
+
+		if (s->dma_address) {
+			s->dma_length = s->length;
+			mapped_elems++;
+		} else
+			goto unmap;
+	}
+
+	domain_flush_complete(domain);
+
+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(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, enum dma_data_direction dir,
+		     struct dma_attrs *attrs)
+{
+	unsigned long flags;
+	struct protection_domain *domain;
+	struct scatterlist *s;
+	int i;
+
+	INC_STATS_COUNTER(cnt_unmap_sg);
+
+	domain = get_domain(dev);
+	if (IS_ERR(domain))
+		return;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	for_each_sg(sglist, s, nelems, i) {
+		__unmap_single(domain->priv, s->dma_address,
+			       s->dma_length, dir);
+		s->dma_address = s->dma_length = 0;
+	}
+
+	domain_flush_complete(domain);
+
+	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 protection_domain *domain;
+	phys_addr_t paddr;
+	u64 dma_mask = dev->coherent_dma_mask;
+
+	INC_STATS_COUNTER(cnt_alloc_coherent);
+
+	domain = get_domain(dev);
+	if (PTR_ERR(domain) == -EINVAL) {
+		virt_addr = (void *)__get_free_pages(flag, get_order(size));
+		*dma_addr = __pa(virt_addr);
+		return virt_addr;
+	} else if (IS_ERR(domain))
+		return NULL;
+
+	dma_mask  = dev->coherent_dma_mask;
+	flag     &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+	flag     |= __GFP_ZERO;
+
+	virt_addr = (void *)__get_free_pages(flag, get_order(size));
+	if (!virt_addr)
+		return NULL;
+
+	paddr = virt_to_phys(virt_addr);
+
+	if (!dma_mask)
+		dma_mask = *dev->dma_mask;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	*dma_addr = __map_single(dev, domain->priv, paddr,
+				 size, DMA_BIDIRECTIONAL, true, dma_mask);
+
+	if (*dma_addr == DMA_ERROR_CODE) {
+		spin_unlock_irqrestore(&domain->lock, flags);
+		goto out_free;
+	}
+
+	domain_flush_complete(domain);
+
+	spin_unlock_irqrestore(&domain->lock, flags);
+
+	return virt_addr;
+
+out_free:
+
+	free_pages((unsigned long)virt_addr, get_order(size));
+
+	return NULL;
+}
+
+/*
+ * 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 protection_domain *domain;
+
+	INC_STATS_COUNTER(cnt_free_coherent);
+
+	domain = get_domain(dev);
+	if (IS_ERR(domain))
+		goto free_mem;
+
+	spin_lock_irqsave(&domain->lock, flags);
+
+	__unmap_single(domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
+
+	domain_flush_complete(domain);
+
+	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)
+{
+	return check_device(dev);
+}
+
+/*
+ * 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.
+ */
+static void prealloc_protection_domains(void)
+{
+	struct pci_dev *dev = NULL;
+	struct dma_ops_domain *dma_dom;
+	u16 devid;
+
+	for_each_pci_dev(dev) {
+
+		/* Do we handle this device? */
+		if (!check_device(&dev->dev))
+			continue;
+
+		/* Is there already any domain for it? */
+		if (domain_for_device(&dev->dev))
+			continue;
+
+		devid = get_device_id(&dev->dev);
+
+		dma_dom = dma_ops_domain_alloc();
+		if (!dma_dom)
+			continue;
+		init_unity_mappings_for_device(dma_dom, devid);
+		dma_dom->target_dev = devid;
+
+		attach_device(&dev->dev, &dma_dom->domain);
+
+		list_add_tail(&dma_dom->list, &iommu_pd_list);
+	}
+}
+
+static struct dma_map_ops amd_iommu_dma_ops = {
+	.alloc_coherent = alloc_coherent,
+	.free_coherent = free_coherent,
+	.map_page = map_page,
+	.unmap_page = unmap_page,
+	.map_sg = map_sg,
+	.unmap_sg = unmap_sg,
+	.dma_supported = amd_iommu_dma_supported,
+};
+
+static unsigned device_dma_ops_init(void)
+{
+	struct pci_dev *pdev = NULL;
+	unsigned unhandled = 0;
+
+	for_each_pci_dev(pdev) {
+		if (!check_device(&pdev->dev)) {
+			unhandled += 1;
+			continue;
+		}
+
+		pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
+	}
+
+	return unhandled;
+}
+
+/*
+ * The function which clues the AMD IOMMU driver into dma_ops.
+ */
+
+void __init amd_iommu_init_api(void)
+{
+	register_iommu(&amd_iommu_ops);
+}
+
+int __init amd_iommu_init_dma_ops(void)
+{
+	struct amd_iommu *iommu;
+	int ret, unhandled;
+
+	/*
+	 * 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.
+	 */
+	for_each_iommu(iommu) {
+		iommu->default_dom = dma_ops_domain_alloc();
+		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;
+	}
+
+	/*
+	 * Pre-allocate the protection domains for each device.
+	 */
+	prealloc_protection_domains();
+
+	iommu_detected = 1;
+	swiotlb = 0;
+
+	/* Make the driver finally visible to the drivers */
+	unhandled = device_dma_ops_init();
+	if (unhandled && max_pfn > MAX_DMA32_PFN) {
+		/* There are unhandled devices - initialize swiotlb for them */
+		swiotlb = 1;
+	}
+
+	amd_iommu_stats_init();
+
+	return 0;
+
+free_domains:
+
+	for_each_iommu(iommu) {
+		if (iommu->default_dom)
+			dma_ops_domain_free(iommu->default_dom);
+	}
+
+	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)
+{
+	struct iommu_dev_data *dev_data, *next;
+	unsigned long flags;
+
+	write_lock_irqsave(&amd_iommu_devtable_lock, flags);
+
+	list_for_each_entry_safe(dev_data, next, &domain->dev_list, list) {
+		struct device *dev = dev_data->dev;
+
+		__detach_device(dev);
+		atomic_set(&dev_data->bind, 0);
+	}
+
+	write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
+}
+
+static void protection_domain_free(struct protection_domain *domain)
+{
+	if (!domain)
+		return;
+
+	del_domain_from_list(domain);
+
+	if (domain->id)
+		domain_id_free(domain->id);
+
+	kfree(domain);
+}
+
+static struct protection_domain *protection_domain_alloc(void)
+{
+	struct protection_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return NULL;
+
+	spin_lock_init(&domain->lock);
+	mutex_init(&domain->api_lock);
+	domain->id = domain_id_alloc();
+	if (!domain->id)
+		goto out_err;
+	INIT_LIST_HEAD(&domain->dev_list);
+
+	add_domain_to_list(domain);
+
+	return domain;
+
+out_err:
+	kfree(domain);
+
+	return NULL;
+}
+
+static int amd_iommu_domain_init(struct iommu_domain *dom)
+{
+	struct protection_domain *domain;
+
+	domain = protection_domain_alloc();
+	if (!domain)
+		goto out_free;
+
+	domain->mode    = PAGE_MODE_3_LEVEL;
+	domain->pt_root = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!domain->pt_root)
+		goto out_free;
+
+	dom->priv = domain;
+
+	return 0;
+
+out_free:
+	protection_domain_free(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);
+
+	protection_domain_free(domain);
+
+	dom->priv = NULL;
+}
+
+static void amd_iommu_detach_device(struct iommu_domain *dom,
+				    struct device *dev)
+{
+	struct iommu_dev_data *dev_data = dev->archdata.iommu;
+	struct amd_iommu *iommu;
+	u16 devid;
+
+	if (!check_device(dev))
+		return;
+
+	devid = get_device_id(dev);
+
+	if (dev_data->domain != NULL)
+		detach_device(dev);
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		return;
+
+	device_flush_dte(dev);
+	iommu_completion_wait(iommu);
+}
+
+static int amd_iommu_attach_device(struct iommu_domain *dom,
+				   struct device *dev)
+{
+	struct protection_domain *domain = dom->priv;
+	struct iommu_dev_data *dev_data;
+	struct amd_iommu *iommu;
+	int ret;
+	u16 devid;
+
+	if (!check_device(dev))
+		return -EINVAL;
+
+	dev_data = dev->archdata.iommu;
+
+	devid = get_device_id(dev);
+
+	iommu = amd_iommu_rlookup_table[devid];
+	if (!iommu)
+		return -EINVAL;
+
+	if (dev_data->domain)
+		detach_device(dev);
+
+	ret = attach_device(dev, domain);
+
+	iommu_completion_wait(iommu);
+
+	return ret;
+}
+
+static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
+			 phys_addr_t paddr, int gfp_order, int iommu_prot)
+{
+	unsigned long page_size = 0x1000UL << gfp_order;
+	struct protection_domain *domain = dom->priv;
+	int prot = 0;
+	int ret;
+
+	if (iommu_prot & IOMMU_READ)
+		prot |= IOMMU_PROT_IR;
+	if (iommu_prot & IOMMU_WRITE)
+		prot |= IOMMU_PROT_IW;
+
+	mutex_lock(&domain->api_lock);
+	ret = iommu_map_page(domain, iova, paddr, prot, page_size);
+	mutex_unlock(&domain->api_lock);
+
+	return ret;
+}
+
+static int amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
+			   int gfp_order)
+{
+	struct protection_domain *domain = dom->priv;
+	unsigned long page_size, unmap_size;
+
+	page_size  = 0x1000UL << gfp_order;
+
+	mutex_lock(&domain->api_lock);
+	unmap_size = iommu_unmap_page(domain, iova, page_size);
+	mutex_unlock(&domain->api_lock);
+
+	domain_flush_tlb_pde(domain);
+
+	return get_order(unmap_size);
+}
+
+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_mask;
+	phys_addr_t paddr;
+	u64 *pte, __pte;
+
+	pte = fetch_pte(domain, iova);
+
+	if (!pte || !IOMMU_PTE_PRESENT(*pte))
+		return 0;
+
+	if (PM_PTE_LEVEL(*pte) == 0)
+		offset_mask = PAGE_SIZE - 1;
+	else
+		offset_mask = PTE_PAGE_SIZE(*pte) - 1;
+
+	__pte = *pte & PM_ADDR_MASK;
+	paddr = (__pte & ~offset_mask) | (iova & offset_mask);
+
+	return paddr;
+}
+
+static int amd_iommu_domain_has_cap(struct iommu_domain *domain,
+				    unsigned long cap)
+{
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
+		return 1;
+	}
+
+	return 0;
+}
+
+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,
+	.unmap = amd_iommu_unmap,
+	.iova_to_phys = amd_iommu_iova_to_phys,
+	.domain_has_cap = amd_iommu_domain_has_cap,
+};
+
+/*****************************************************************************
+ *
+ * The next functions do a basic initialization of IOMMU for pass through
+ * mode
+ *
+ * In passthrough mode the IOMMU is initialized and enabled but not used for
+ * DMA-API translation.
+ *
+ *****************************************************************************/
+
+int __init amd_iommu_init_passthrough(void)
+{
+	struct amd_iommu *iommu;
+	struct pci_dev *dev = NULL;
+	u16 devid;
+
+	/* allocate passthrough domain */
+	pt_domain = protection_domain_alloc();
+	if (!pt_domain)
+		return -ENOMEM;
+
+	pt_domain->mode |= PAGE_MODE_NONE;
+
+	for_each_pci_dev(dev) {
+		if (!check_device(&dev->dev))
+			continue;
+
+		devid = get_device_id(&dev->dev);
+
+		iommu = amd_iommu_rlookup_table[devid];
+		if (!iommu)
+			continue;
+
+		attach_device(&dev->dev, pt_domain);
+	}
+
+	pr_info("AMD-Vi: Initialized for Passthrough Mode\n");
+
+	return 0;
+}