Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / iommu / dmar.c
diff --git a/kernel/drivers/iommu/dmar.c b/kernel/drivers/iommu/dmar.c
new file mode 100644 (file)
index 0000000..9847613
--- /dev/null
@@ -0,0 +1,2000 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Copyright (C) 2006-2008 Intel Corporation
+ * Author: Ashok Raj <ashok.raj@intel.com>
+ * Author: Shaohua Li <shaohua.li@intel.com>
+ * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *
+ * This file implements early detection/parsing of Remapping Devices
+ * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
+ * tables.
+ *
+ * These routines are used by both DMA-remapping and Interrupt-remapping
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt /* has to precede printk.h */
+
+#include <linux/pci.h>
+#include <linux/dmar.h>
+#include <linux/iova.h>
+#include <linux/intel-iommu.h>
+#include <linux/timer.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/tboot.h>
+#include <linux/dmi.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <asm/irq_remapping.h>
+#include <asm/iommu_table.h>
+
+#include "irq_remapping.h"
+
+typedef int (*dmar_res_handler_t)(struct acpi_dmar_header *, void *);
+struct dmar_res_callback {
+       dmar_res_handler_t      cb[ACPI_DMAR_TYPE_RESERVED];
+       void                    *arg[ACPI_DMAR_TYPE_RESERVED];
+       bool                    ignore_unhandled;
+       bool                    print_entry;
+};
+
+/*
+ * Assumptions:
+ * 1) The hotplug framework guarentees that DMAR unit will be hot-added
+ *    before IO devices managed by that unit.
+ * 2) The hotplug framework guarantees that DMAR unit will be hot-removed
+ *    after IO devices managed by that unit.
+ * 3) Hotplug events are rare.
+ *
+ * Locking rules for DMA and interrupt remapping related global data structures:
+ * 1) Use dmar_global_lock in process context
+ * 2) Use RCU in interrupt context
+ */
+DECLARE_RWSEM(dmar_global_lock);
+LIST_HEAD(dmar_drhd_units);
+
+struct acpi_table_header * __initdata dmar_tbl;
+static acpi_size dmar_tbl_size;
+static int dmar_dev_scope_status = 1;
+static unsigned long dmar_seq_ids[BITS_TO_LONGS(DMAR_UNITS_SUPPORTED)];
+
+static int alloc_iommu(struct dmar_drhd_unit *drhd);
+static void free_iommu(struct intel_iommu *iommu);
+
+static void dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
+{
+       /*
+        * add INCLUDE_ALL at the tail, so scan the list will find it at
+        * the very end.
+        */
+       if (drhd->include_all)
+               list_add_tail_rcu(&drhd->list, &dmar_drhd_units);
+       else
+               list_add_rcu(&drhd->list, &dmar_drhd_units);
+}
+
+void *dmar_alloc_dev_scope(void *start, void *end, int *cnt)
+{
+       struct acpi_dmar_device_scope *scope;
+
+       *cnt = 0;
+       while (start < end) {
+               scope = start;
+               if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_NAMESPACE ||
+                   scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
+                   scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
+                       (*cnt)++;
+               else if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_IOAPIC &&
+                       scope->entry_type != ACPI_DMAR_SCOPE_TYPE_HPET) {
+                       pr_warn("Unsupported device scope\n");
+               }
+               start += scope->length;
+       }
+       if (*cnt == 0)
+               return NULL;
+
+       return kcalloc(*cnt, sizeof(struct dmar_dev_scope), GFP_KERNEL);
+}
+
+void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt)
+{
+       int i;
+       struct device *tmp_dev;
+
+       if (*devices && *cnt) {
+               for_each_active_dev_scope(*devices, *cnt, i, tmp_dev)
+                       put_device(tmp_dev);
+               kfree(*devices);
+       }
+
+       *devices = NULL;
+       *cnt = 0;
+}
+
+/* Optimize out kzalloc()/kfree() for normal cases */
+static char dmar_pci_notify_info_buf[64];
+
+static struct dmar_pci_notify_info *
+dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
+{
+       int level = 0;
+       size_t size;
+       struct pci_dev *tmp;
+       struct dmar_pci_notify_info *info;
+
+       BUG_ON(dev->is_virtfn);
+
+       /* Only generate path[] for device addition event */
+       if (event == BUS_NOTIFY_ADD_DEVICE)
+               for (tmp = dev; tmp; tmp = tmp->bus->self)
+                       level++;
+
+       size = sizeof(*info) + level * sizeof(struct acpi_dmar_pci_path);
+       if (size <= sizeof(dmar_pci_notify_info_buf)) {
+               info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf;
+       } else {
+               info = kzalloc(size, GFP_KERNEL);
+               if (!info) {
+                       pr_warn("Out of memory when allocating notify_info "
+                               "for %s.\n", pci_name(dev));
+                       if (dmar_dev_scope_status == 0)
+                               dmar_dev_scope_status = -ENOMEM;
+                       return NULL;
+               }
+       }
+
+       info->event = event;
+       info->dev = dev;
+       info->seg = pci_domain_nr(dev->bus);
+       info->level = level;
+       if (event == BUS_NOTIFY_ADD_DEVICE) {
+               for (tmp = dev; tmp; tmp = tmp->bus->self) {
+                       level--;
+                       info->path[level].bus = tmp->bus->number;
+                       info->path[level].device = PCI_SLOT(tmp->devfn);
+                       info->path[level].function = PCI_FUNC(tmp->devfn);
+                       if (pci_is_root_bus(tmp->bus))
+                               info->bus = tmp->bus->number;
+               }
+       }
+
+       return info;
+}
+
+static inline void dmar_free_pci_notify_info(struct dmar_pci_notify_info *info)
+{
+       if ((void *)info != dmar_pci_notify_info_buf)
+               kfree(info);
+}
+
+static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus,
+                               struct acpi_dmar_pci_path *path, int count)
+{
+       int i;
+
+       if (info->bus != bus)
+               goto fallback;
+       if (info->level != count)
+               goto fallback;
+
+       for (i = 0; i < count; i++) {
+               if (path[i].device != info->path[i].device ||
+                   path[i].function != info->path[i].function)
+                       goto fallback;
+       }
+
+       return true;
+
+fallback:
+
+       if (count != 1)
+               return false;
+
+       i = info->level - 1;
+       if (bus              == info->path[i].bus &&
+           path[0].device   == info->path[i].device &&
+           path[0].function == info->path[i].function) {
+               pr_info(FW_BUG "RMRR entry for device %02x:%02x.%x is broken - applying workaround\n",
+                       bus, path[0].device, path[0].function);
+               return true;
+       }
+
+       return false;
+}
+
+/* Return: > 0 if match found, 0 if no match found, < 0 if error happens */
+int dmar_insert_dev_scope(struct dmar_pci_notify_info *info,
+                         void *start, void*end, u16 segment,
+                         struct dmar_dev_scope *devices,
+                         int devices_cnt)
+{
+       int i, level;
+       struct device *tmp, *dev = &info->dev->dev;
+       struct acpi_dmar_device_scope *scope;
+       struct acpi_dmar_pci_path *path;
+
+       if (segment != info->seg)
+               return 0;
+
+       for (; start < end; start += scope->length) {
+               scope = start;
+               if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_ENDPOINT &&
+                   scope->entry_type != ACPI_DMAR_SCOPE_TYPE_BRIDGE)
+                       continue;
+
+               path = (struct acpi_dmar_pci_path *)(scope + 1);
+               level = (scope->length - sizeof(*scope)) / sizeof(*path);
+               if (!dmar_match_pci_path(info, scope->bus, path, level))
+                       continue;
+
+               if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT) ^
+                   (info->dev->hdr_type == PCI_HEADER_TYPE_NORMAL)) {
+                       pr_warn("Device scope type does not match for %s\n",
+                               pci_name(info->dev));
+                       return -EINVAL;
+               }
+
+               for_each_dev_scope(devices, devices_cnt, i, tmp)
+                       if (tmp == NULL) {
+                               devices[i].bus = info->dev->bus->number;
+                               devices[i].devfn = info->dev->devfn;
+                               rcu_assign_pointer(devices[i].dev,
+                                                  get_device(dev));
+                               return 1;
+                       }
+               BUG_ON(i >= devices_cnt);
+       }
+
+       return 0;
+}
+
+int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment,
+                         struct dmar_dev_scope *devices, int count)
+{
+       int index;
+       struct device *tmp;
+
+       if (info->seg != segment)
+               return 0;
+
+       for_each_active_dev_scope(devices, count, index, tmp)
+               if (tmp == &info->dev->dev) {
+                       RCU_INIT_POINTER(devices[index].dev, NULL);
+                       synchronize_rcu();
+                       put_device(tmp);
+                       return 1;
+               }
+
+       return 0;
+}
+
+static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info)
+{
+       int ret = 0;
+       struct dmar_drhd_unit *dmaru;
+       struct acpi_dmar_hardware_unit *drhd;
+
+       for_each_drhd_unit(dmaru) {
+               if (dmaru->include_all)
+                       continue;
+
+               drhd = container_of(dmaru->hdr,
+                                   struct acpi_dmar_hardware_unit, header);
+               ret = dmar_insert_dev_scope(info, (void *)(drhd + 1),
+                               ((void *)drhd) + drhd->header.length,
+                               dmaru->segment,
+                               dmaru->devices, dmaru->devices_cnt);
+               if (ret != 0)
+                       break;
+       }
+       if (ret >= 0)
+               ret = dmar_iommu_notify_scope_dev(info);
+       if (ret < 0 && dmar_dev_scope_status == 0)
+               dmar_dev_scope_status = ret;
+
+       return ret;
+}
+
+static void  dmar_pci_bus_del_dev(struct dmar_pci_notify_info *info)
+{
+       struct dmar_drhd_unit *dmaru;
+
+       for_each_drhd_unit(dmaru)
+               if (dmar_remove_dev_scope(info, dmaru->segment,
+                       dmaru->devices, dmaru->devices_cnt))
+                       break;
+       dmar_iommu_notify_scope_dev(info);
+}
+
+static int dmar_pci_bus_notifier(struct notifier_block *nb,
+                                unsigned long action, void *data)
+{
+       struct pci_dev *pdev = to_pci_dev(data);
+       struct dmar_pci_notify_info *info;
+
+       /* Only care about add/remove events for physical functions */
+       if (pdev->is_virtfn)
+               return NOTIFY_DONE;
+       if (action != BUS_NOTIFY_ADD_DEVICE && action != BUS_NOTIFY_DEL_DEVICE)
+               return NOTIFY_DONE;
+
+       info = dmar_alloc_pci_notify_info(pdev, action);
+       if (!info)
+               return NOTIFY_DONE;
+
+       down_write(&dmar_global_lock);
+       if (action == BUS_NOTIFY_ADD_DEVICE)
+               dmar_pci_bus_add_dev(info);
+       else if (action == BUS_NOTIFY_DEL_DEVICE)
+               dmar_pci_bus_del_dev(info);
+       up_write(&dmar_global_lock);
+
+       dmar_free_pci_notify_info(info);
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block dmar_pci_bus_nb = {
+       .notifier_call = dmar_pci_bus_notifier,
+       .priority = INT_MIN,
+};
+
+static struct dmar_drhd_unit *
+dmar_find_dmaru(struct acpi_dmar_hardware_unit *drhd)
+{
+       struct dmar_drhd_unit *dmaru;
+
+       list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list)
+               if (dmaru->segment == drhd->segment &&
+                   dmaru->reg_base_addr == drhd->address)
+                       return dmaru;
+
+       return NULL;
+}
+
+/**
+ * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
+ * structure which uniquely represent one DMA remapping hardware unit
+ * present in the platform
+ */
+static int dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
+{
+       struct acpi_dmar_hardware_unit *drhd;
+       struct dmar_drhd_unit *dmaru;
+       int ret = 0;
+
+       drhd = (struct acpi_dmar_hardware_unit *)header;
+       dmaru = dmar_find_dmaru(drhd);
+       if (dmaru)
+               goto out;
+
+       dmaru = kzalloc(sizeof(*dmaru) + header->length, GFP_KERNEL);
+       if (!dmaru)
+               return -ENOMEM;
+
+       /*
+        * If header is allocated from slab by ACPI _DSM method, we need to
+        * copy the content because the memory buffer will be freed on return.
+        */
+       dmaru->hdr = (void *)(dmaru + 1);
+       memcpy(dmaru->hdr, header, header->length);
+       dmaru->reg_base_addr = drhd->address;
+       dmaru->segment = drhd->segment;
+       dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
+       dmaru->devices = dmar_alloc_dev_scope((void *)(drhd + 1),
+                                             ((void *)drhd) + drhd->header.length,
+                                             &dmaru->devices_cnt);
+       if (dmaru->devices_cnt && dmaru->devices == NULL) {
+               kfree(dmaru);
+               return -ENOMEM;
+       }
+
+       ret = alloc_iommu(dmaru);
+       if (ret) {
+               dmar_free_dev_scope(&dmaru->devices,
+                                   &dmaru->devices_cnt);
+               kfree(dmaru);
+               return ret;
+       }
+       dmar_register_drhd_unit(dmaru);
+
+out:
+       if (arg)
+               (*(int *)arg)++;
+
+       return 0;
+}
+
+static void dmar_free_drhd(struct dmar_drhd_unit *dmaru)
+{
+       if (dmaru->devices && dmaru->devices_cnt)
+               dmar_free_dev_scope(&dmaru->devices, &dmaru->devices_cnt);
+       if (dmaru->iommu)
+               free_iommu(dmaru->iommu);
+       kfree(dmaru);
+}
+
+static int __init dmar_parse_one_andd(struct acpi_dmar_header *header,
+                                     void *arg)
+{
+       struct acpi_dmar_andd *andd = (void *)header;
+
+       /* Check for NUL termination within the designated length */
+       if (strnlen(andd->device_name, header->length - 8) == header->length - 8) {
+               WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
+                          "Your BIOS is broken; ANDD object name is not NUL-terminated\n"
+                          "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+                          dmi_get_system_info(DMI_BIOS_VENDOR),
+                          dmi_get_system_info(DMI_BIOS_VERSION),
+                          dmi_get_system_info(DMI_PRODUCT_VERSION));
+               return -EINVAL;
+       }
+       pr_info("ANDD device: %x name: %s\n", andd->device_number,
+               andd->device_name);
+
+       return 0;
+}
+
+#ifdef CONFIG_ACPI_NUMA
+static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
+{
+       struct acpi_dmar_rhsa *rhsa;
+       struct dmar_drhd_unit *drhd;
+
+       rhsa = (struct acpi_dmar_rhsa *)header;
+       for_each_drhd_unit(drhd) {
+               if (drhd->reg_base_addr == rhsa->base_address) {
+                       int node = acpi_map_pxm_to_node(rhsa->proximity_domain);
+
+                       if (!node_online(node))
+                               node = -1;
+                       drhd->iommu->node = node;
+                       return 0;
+               }
+       }
+       WARN_TAINT(
+               1, TAINT_FIRMWARE_WORKAROUND,
+               "Your BIOS is broken; RHSA refers to non-existent DMAR unit at %llx\n"
+               "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+               drhd->reg_base_addr,
+               dmi_get_system_info(DMI_BIOS_VENDOR),
+               dmi_get_system_info(DMI_BIOS_VERSION),
+               dmi_get_system_info(DMI_PRODUCT_VERSION));
+
+       return 0;
+}
+#else
+#define        dmar_parse_one_rhsa             dmar_res_noop
+#endif
+
+static void __init
+dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
+{
+       struct acpi_dmar_hardware_unit *drhd;
+       struct acpi_dmar_reserved_memory *rmrr;
+       struct acpi_dmar_atsr *atsr;
+       struct acpi_dmar_rhsa *rhsa;
+
+       switch (header->type) {
+       case ACPI_DMAR_TYPE_HARDWARE_UNIT:
+               drhd = container_of(header, struct acpi_dmar_hardware_unit,
+                                   header);
+               pr_info("DRHD base: %#016Lx flags: %#x\n",
+                       (unsigned long long)drhd->address, drhd->flags);
+               break;
+       case ACPI_DMAR_TYPE_RESERVED_MEMORY:
+               rmrr = container_of(header, struct acpi_dmar_reserved_memory,
+                                   header);
+               pr_info("RMRR base: %#016Lx end: %#016Lx\n",
+                       (unsigned long long)rmrr->base_address,
+                       (unsigned long long)rmrr->end_address);
+               break;
+       case ACPI_DMAR_TYPE_ROOT_ATS:
+               atsr = container_of(header, struct acpi_dmar_atsr, header);
+               pr_info("ATSR flags: %#x\n", atsr->flags);
+               break;
+       case ACPI_DMAR_TYPE_HARDWARE_AFFINITY:
+               rhsa = container_of(header, struct acpi_dmar_rhsa, header);
+               pr_info("RHSA base: %#016Lx proximity domain: %#x\n",
+                      (unsigned long long)rhsa->base_address,
+                      rhsa->proximity_domain);
+               break;
+       case ACPI_DMAR_TYPE_NAMESPACE:
+               /* We don't print this here because we need to sanity-check
+                  it first. So print it in dmar_parse_one_andd() instead. */
+               break;
+       }
+}
+
+/**
+ * dmar_table_detect - checks to see if the platform supports DMAR devices
+ */
+static int __init dmar_table_detect(void)
+{
+       acpi_status status = AE_OK;
+
+       /* if we could find DMAR table, then there are DMAR devices */
+       status = acpi_get_table_with_size(ACPI_SIG_DMAR, 0,
+                               (struct acpi_table_header **)&dmar_tbl,
+                               &dmar_tbl_size);
+
+       if (ACPI_SUCCESS(status) && !dmar_tbl) {
+               pr_warn("Unable to map DMAR\n");
+               status = AE_NOT_FOUND;
+       }
+
+       return (ACPI_SUCCESS(status) ? 1 : 0);
+}
+
+static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
+                                      size_t len, struct dmar_res_callback *cb)
+{
+       int ret = 0;
+       struct acpi_dmar_header *iter, *next;
+       struct acpi_dmar_header *end = ((void *)start) + len;
+
+       for (iter = start; iter < end && ret == 0; iter = next) {
+               next = (void *)iter + iter->length;
+               if (iter->length == 0) {
+                       /* Avoid looping forever on bad ACPI tables */
+                       pr_debug(FW_BUG "Invalid 0-length structure\n");
+                       break;
+               } else if (next > end) {
+                       /* Avoid passing table end */
+                       pr_warn(FW_BUG "record passes table end\n");
+                       ret = -EINVAL;
+                       break;
+               }
+
+               if (cb->print_entry)
+                       dmar_table_print_dmar_entry(iter);
+
+               if (iter->type >= ACPI_DMAR_TYPE_RESERVED) {
+                       /* continue for forward compatibility */
+                       pr_debug("Unknown DMAR structure type %d\n",
+                                iter->type);
+               } else if (cb->cb[iter->type]) {
+                       ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
+               } else if (!cb->ignore_unhandled) {
+                       pr_warn("No handler for DMAR structure type %d\n",
+                               iter->type);
+                       ret = -EINVAL;
+               }
+       }
+
+       return ret;
+}
+
+static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
+                                      struct dmar_res_callback *cb)
+{
+       return dmar_walk_remapping_entries((void *)(dmar + 1),
+                       dmar->header.length - sizeof(*dmar), cb);
+}
+
+/**
+ * parse_dmar_table - parses the DMA reporting table
+ */
+static int __init
+parse_dmar_table(void)
+{
+       struct acpi_table_dmar *dmar;
+       int ret = 0;
+       int drhd_count = 0;
+       struct dmar_res_callback cb = {
+               .print_entry = true,
+               .ignore_unhandled = true,
+               .arg[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &drhd_count,
+               .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_parse_one_drhd,
+               .cb[ACPI_DMAR_TYPE_RESERVED_MEMORY] = &dmar_parse_one_rmrr,
+               .cb[ACPI_DMAR_TYPE_ROOT_ATS] = &dmar_parse_one_atsr,
+               .cb[ACPI_DMAR_TYPE_HARDWARE_AFFINITY] = &dmar_parse_one_rhsa,
+               .cb[ACPI_DMAR_TYPE_NAMESPACE] = &dmar_parse_one_andd,
+       };
+
+       /*
+        * Do it again, earlier dmar_tbl mapping could be mapped with
+        * fixed map.
+        */
+       dmar_table_detect();
+
+       /*
+        * ACPI tables may not be DMA protected by tboot, so use DMAR copy
+        * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
+        */
+       dmar_tbl = tboot_get_dmar_table(dmar_tbl);
+
+       dmar = (struct acpi_table_dmar *)dmar_tbl;
+       if (!dmar)
+               return -ENODEV;
+
+       if (dmar->width < PAGE_SHIFT - 1) {
+               pr_warn("Invalid DMAR haw\n");
+               return -EINVAL;
+       }
+
+       pr_info("Host address width %d\n", dmar->width + 1);
+       ret = dmar_walk_dmar_table(dmar, &cb);
+       if (ret == 0 && drhd_count == 0)
+               pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
+
+       return ret;
+}
+
+static int dmar_pci_device_match(struct dmar_dev_scope devices[],
+                                int cnt, struct pci_dev *dev)
+{
+       int index;
+       struct device *tmp;
+
+       while (dev) {
+               for_each_active_dev_scope(devices, cnt, index, tmp)
+                       if (dev_is_pci(tmp) && dev == to_pci_dev(tmp))
+                               return 1;
+
+               /* Check our parent */
+               dev = dev->bus->self;
+       }
+
+       return 0;
+}
+
+struct dmar_drhd_unit *
+dmar_find_matched_drhd_unit(struct pci_dev *dev)
+{
+       struct dmar_drhd_unit *dmaru;
+       struct acpi_dmar_hardware_unit *drhd;
+
+       dev = pci_physfn(dev);
+
+       rcu_read_lock();
+       for_each_drhd_unit(dmaru) {
+               drhd = container_of(dmaru->hdr,
+                                   struct acpi_dmar_hardware_unit,
+                                   header);
+
+               if (dmaru->include_all &&
+                   drhd->segment == pci_domain_nr(dev->bus))
+                       goto out;
+
+               if (dmar_pci_device_match(dmaru->devices,
+                                         dmaru->devices_cnt, dev))
+                       goto out;
+       }
+       dmaru = NULL;
+out:
+       rcu_read_unlock();
+
+       return dmaru;
+}
+
+static void __init dmar_acpi_insert_dev_scope(u8 device_number,
+                                             struct acpi_device *adev)
+{
+       struct dmar_drhd_unit *dmaru;
+       struct acpi_dmar_hardware_unit *drhd;
+       struct acpi_dmar_device_scope *scope;
+       struct device *tmp;
+       int i;
+       struct acpi_dmar_pci_path *path;
+
+       for_each_drhd_unit(dmaru) {
+               drhd = container_of(dmaru->hdr,
+                                   struct acpi_dmar_hardware_unit,
+                                   header);
+
+               for (scope = (void *)(drhd + 1);
+                    (unsigned long)scope < ((unsigned long)drhd) + drhd->header.length;
+                    scope = ((void *)scope) + scope->length) {
+                       if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_NAMESPACE)
+                               continue;
+                       if (scope->enumeration_id != device_number)
+                               continue;
+
+                       path = (void *)(scope + 1);
+                       pr_info("ACPI device \"%s\" under DMAR at %llx as %02x:%02x.%d\n",
+                               dev_name(&adev->dev), dmaru->reg_base_addr,
+                               scope->bus, path->device, path->function);
+                       for_each_dev_scope(dmaru->devices, dmaru->devices_cnt, i, tmp)
+                               if (tmp == NULL) {
+                                       dmaru->devices[i].bus = scope->bus;
+                                       dmaru->devices[i].devfn = PCI_DEVFN(path->device,
+                                                                           path->function);
+                                       rcu_assign_pointer(dmaru->devices[i].dev,
+                                                          get_device(&adev->dev));
+                                       return;
+                               }
+                       BUG_ON(i >= dmaru->devices_cnt);
+               }
+       }
+       pr_warn("No IOMMU scope found for ANDD enumeration ID %d (%s)\n",
+               device_number, dev_name(&adev->dev));
+}
+
+static int __init dmar_acpi_dev_scope_init(void)
+{
+       struct acpi_dmar_andd *andd;
+
+       if (dmar_tbl == NULL)
+               return -ENODEV;
+
+       for (andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
+            ((unsigned long)andd) < ((unsigned long)dmar_tbl) + dmar_tbl->length;
+            andd = ((void *)andd) + andd->header.length) {
+               if (andd->header.type == ACPI_DMAR_TYPE_NAMESPACE) {
+                       acpi_handle h;
+                       struct acpi_device *adev;
+
+                       if (!ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT,
+                                                         andd->device_name,
+                                                         &h))) {
+                               pr_err("Failed to find handle for ACPI object %s\n",
+                                      andd->device_name);
+                               continue;
+                       }
+                       if (acpi_bus_get_device(h, &adev)) {
+                               pr_err("Failed to get device for ACPI object %s\n",
+                                      andd->device_name);
+                               continue;
+                       }
+                       dmar_acpi_insert_dev_scope(andd->device_number, adev);
+               }
+       }
+       return 0;
+}
+
+int __init dmar_dev_scope_init(void)
+{
+       struct pci_dev *dev = NULL;
+       struct dmar_pci_notify_info *info;
+
+       if (dmar_dev_scope_status != 1)
+               return dmar_dev_scope_status;
+
+       if (list_empty(&dmar_drhd_units)) {
+               dmar_dev_scope_status = -ENODEV;
+       } else {
+               dmar_dev_scope_status = 0;
+
+               dmar_acpi_dev_scope_init();
+
+               for_each_pci_dev(dev) {
+                       if (dev->is_virtfn)
+                               continue;
+
+                       info = dmar_alloc_pci_notify_info(dev,
+                                       BUS_NOTIFY_ADD_DEVICE);
+                       if (!info) {
+                               return dmar_dev_scope_status;
+                       } else {
+                               dmar_pci_bus_add_dev(info);
+                               dmar_free_pci_notify_info(info);
+                       }
+               }
+
+               bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb);
+       }
+
+       return dmar_dev_scope_status;
+}
+
+
+int __init dmar_table_init(void)
+{
+       static int dmar_table_initialized;
+       int ret;
+
+       if (dmar_table_initialized == 0) {
+               ret = parse_dmar_table();
+               if (ret < 0) {
+                       if (ret != -ENODEV)
+                               pr_info("parse DMAR table failure.\n");
+               } else  if (list_empty(&dmar_drhd_units)) {
+                       pr_info("No DMAR devices found\n");
+                       ret = -ENODEV;
+               }
+
+               if (ret < 0)
+                       dmar_table_initialized = ret;
+               else
+                       dmar_table_initialized = 1;
+       }
+
+       return dmar_table_initialized < 0 ? dmar_table_initialized : 0;
+}
+
+static void warn_invalid_dmar(u64 addr, const char *message)
+{
+       WARN_TAINT_ONCE(
+               1, TAINT_FIRMWARE_WORKAROUND,
+               "Your BIOS is broken; DMAR reported at address %llx%s!\n"
+               "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
+               addr, message,
+               dmi_get_system_info(DMI_BIOS_VENDOR),
+               dmi_get_system_info(DMI_BIOS_VERSION),
+               dmi_get_system_info(DMI_PRODUCT_VERSION));
+}
+
+static int __ref
+dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
+{
+       struct acpi_dmar_hardware_unit *drhd;
+       void __iomem *addr;
+       u64 cap, ecap;
+
+       drhd = (void *)entry;
+       if (!drhd->address) {
+               warn_invalid_dmar(0, "");
+               return -EINVAL;
+       }
+
+       if (arg)
+               addr = ioremap(drhd->address, VTD_PAGE_SIZE);
+       else
+               addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
+       if (!addr) {
+               pr_warn("IOMMU: can't validate: %llx\n", drhd->address);
+               return -EINVAL;
+       }
+
+       cap = dmar_readq(addr + DMAR_CAP_REG);
+       ecap = dmar_readq(addr + DMAR_ECAP_REG);
+
+       if (arg)
+               iounmap(addr);
+       else
+               early_iounmap(addr, VTD_PAGE_SIZE);
+
+       if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
+               warn_invalid_dmar(drhd->address, " returns all ones");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+int __init detect_intel_iommu(void)
+{
+       int ret;
+       struct dmar_res_callback validate_drhd_cb = {
+               .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_validate_one_drhd,
+               .ignore_unhandled = true,
+       };
+
+       down_write(&dmar_global_lock);
+       ret = dmar_table_detect();
+       if (ret)
+               ret = !dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
+                                           &validate_drhd_cb);
+       if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
+               iommu_detected = 1;
+               /* Make sure ACS will be enabled */
+               pci_request_acs();
+       }
+
+#ifdef CONFIG_X86
+       if (ret)
+               x86_init.iommu.iommu_init = intel_iommu_init;
+#endif
+
+       early_acpi_os_unmap_memory((void __iomem *)dmar_tbl, dmar_tbl_size);
+       dmar_tbl = NULL;
+       up_write(&dmar_global_lock);
+
+       return ret ? 1 : -ENODEV;
+}
+
+
+static void unmap_iommu(struct intel_iommu *iommu)
+{
+       iounmap(iommu->reg);
+       release_mem_region(iommu->reg_phys, iommu->reg_size);
+}
+
+/**
+ * map_iommu: map the iommu's registers
+ * @iommu: the iommu to map
+ * @phys_addr: the physical address of the base resgister
+ *
+ * Memory map the iommu's registers.  Start w/ a single page, and
+ * possibly expand if that turns out to be insufficent.
+ */
+static int map_iommu(struct intel_iommu *iommu, u64 phys_addr)
+{
+       int map_size, err=0;
+
+       iommu->reg_phys = phys_addr;
+       iommu->reg_size = VTD_PAGE_SIZE;
+
+       if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name)) {
+               pr_err("IOMMU: can't reserve memory\n");
+               err = -EBUSY;
+               goto out;
+       }
+
+       iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
+       if (!iommu->reg) {
+               pr_err("IOMMU: can't map the region\n");
+               err = -ENOMEM;
+               goto release;
+       }
+
+       iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
+       iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
+
+       if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
+               err = -EINVAL;
+               warn_invalid_dmar(phys_addr, " returns all ones");
+               goto unmap;
+       }
+
+       /* the registers might be more than one page */
+       map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
+                        cap_max_fault_reg_offset(iommu->cap));
+       map_size = VTD_PAGE_ALIGN(map_size);
+       if (map_size > iommu->reg_size) {
+               iounmap(iommu->reg);
+               release_mem_region(iommu->reg_phys, iommu->reg_size);
+               iommu->reg_size = map_size;
+               if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
+                                       iommu->name)) {
+                       pr_err("IOMMU: can't reserve memory\n");
+                       err = -EBUSY;
+                       goto out;
+               }
+               iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
+               if (!iommu->reg) {
+                       pr_err("IOMMU: can't map the region\n");
+                       err = -ENOMEM;
+                       goto release;
+               }
+       }
+       err = 0;
+       goto out;
+
+unmap:
+       iounmap(iommu->reg);
+release:
+       release_mem_region(iommu->reg_phys, iommu->reg_size);
+out:
+       return err;
+}
+
+static int dmar_alloc_seq_id(struct intel_iommu *iommu)
+{
+       iommu->seq_id = find_first_zero_bit(dmar_seq_ids,
+                                           DMAR_UNITS_SUPPORTED);
+       if (iommu->seq_id >= DMAR_UNITS_SUPPORTED) {
+               iommu->seq_id = -1;
+       } else {
+               set_bit(iommu->seq_id, dmar_seq_ids);
+               sprintf(iommu->name, "dmar%d", iommu->seq_id);
+       }
+
+       return iommu->seq_id;
+}
+
+static void dmar_free_seq_id(struct intel_iommu *iommu)
+{
+       if (iommu->seq_id >= 0) {
+               clear_bit(iommu->seq_id, dmar_seq_ids);
+               iommu->seq_id = -1;
+       }
+}
+
+static int alloc_iommu(struct dmar_drhd_unit *drhd)
+{
+       struct intel_iommu *iommu;
+       u32 ver, sts;
+       int agaw = 0;
+       int msagaw = 0;
+       int err;
+
+       if (!drhd->reg_base_addr) {
+               warn_invalid_dmar(0, "");
+               return -EINVAL;
+       }
+
+       iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+       if (!iommu)
+               return -ENOMEM;
+
+       if (dmar_alloc_seq_id(iommu) < 0) {
+               pr_err("IOMMU: failed to allocate seq_id\n");
+               err = -ENOSPC;
+               goto error;
+       }
+
+       err = map_iommu(iommu, drhd->reg_base_addr);
+       if (err) {
+               pr_err("IOMMU: failed to map %s\n", iommu->name);
+               goto error_free_seq_id;
+       }
+
+       err = -EINVAL;
+       agaw = iommu_calculate_agaw(iommu);
+       if (agaw < 0) {
+               pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
+                       iommu->seq_id);
+               goto err_unmap;
+       }
+       msagaw = iommu_calculate_max_sagaw(iommu);
+       if (msagaw < 0) {
+               pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
+                       iommu->seq_id);
+               goto err_unmap;
+       }
+       iommu->agaw = agaw;
+       iommu->msagaw = msagaw;
+       iommu->segment = drhd->segment;
+
+       iommu->node = -1;
+
+       ver = readl(iommu->reg + DMAR_VER_REG);
+       pr_info("IOMMU %d: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
+               iommu->seq_id,
+               (unsigned long long)drhd->reg_base_addr,
+               DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
+               (unsigned long long)iommu->cap,
+               (unsigned long long)iommu->ecap);
+
+       /* Reflect status in gcmd */
+       sts = readl(iommu->reg + DMAR_GSTS_REG);
+       if (sts & DMA_GSTS_IRES)
+               iommu->gcmd |= DMA_GCMD_IRE;
+       if (sts & DMA_GSTS_TES)
+               iommu->gcmd |= DMA_GCMD_TE;
+       if (sts & DMA_GSTS_QIES)
+               iommu->gcmd |= DMA_GCMD_QIE;
+
+       raw_spin_lock_init(&iommu->register_lock);
+
+       drhd->iommu = iommu;
+
+       if (intel_iommu_enabled)
+               iommu->iommu_dev = iommu_device_create(NULL, iommu,
+                                                      intel_iommu_groups,
+                                                      iommu->name);
+
+       return 0;
+
+err_unmap:
+       unmap_iommu(iommu);
+error_free_seq_id:
+       dmar_free_seq_id(iommu);
+error:
+       kfree(iommu);
+       return err;
+}
+
+static void free_iommu(struct intel_iommu *iommu)
+{
+       iommu_device_destroy(iommu->iommu_dev);
+
+       if (iommu->irq) {
+               free_irq(iommu->irq, iommu);
+               irq_set_handler_data(iommu->irq, NULL);
+               dmar_free_hwirq(iommu->irq);
+       }
+
+       if (iommu->qi) {
+               free_page((unsigned long)iommu->qi->desc);
+               kfree(iommu->qi->desc_status);
+               kfree(iommu->qi);
+       }
+
+       if (iommu->reg)
+               unmap_iommu(iommu);
+
+       dmar_free_seq_id(iommu);
+       kfree(iommu);
+}
+
+/*
+ * Reclaim all the submitted descriptors which have completed its work.
+ */
+static inline void reclaim_free_desc(struct q_inval *qi)
+{
+       while (qi->desc_status[qi->free_tail] == QI_DONE ||
+              qi->desc_status[qi->free_tail] == QI_ABORT) {
+               qi->desc_status[qi->free_tail] = QI_FREE;
+               qi->free_tail = (qi->free_tail + 1) % QI_LENGTH;
+               qi->free_cnt++;
+       }
+}
+
+static int qi_check_fault(struct intel_iommu *iommu, int index)
+{
+       u32 fault;
+       int head, tail;
+       struct q_inval *qi = iommu->qi;
+       int wait_index = (index + 1) % QI_LENGTH;
+
+       if (qi->desc_status[wait_index] == QI_ABORT)
+               return -EAGAIN;
+
+       fault = readl(iommu->reg + DMAR_FSTS_REG);
+
+       /*
+        * If IQE happens, the head points to the descriptor associated
+        * with the error. No new descriptors are fetched until the IQE
+        * is cleared.
+        */
+       if (fault & DMA_FSTS_IQE) {
+               head = readl(iommu->reg + DMAR_IQH_REG);
+               if ((head >> DMAR_IQ_SHIFT) == index) {
+                       pr_err("VT-d detected invalid descriptor: "
+                               "low=%llx, high=%llx\n",
+                               (unsigned long long)qi->desc[index].low,
+                               (unsigned long long)qi->desc[index].high);
+                       memcpy(&qi->desc[index], &qi->desc[wait_index],
+                                       sizeof(struct qi_desc));
+                       __iommu_flush_cache(iommu, &qi->desc[index],
+                                       sizeof(struct qi_desc));
+                       writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
+                       return -EINVAL;
+               }
+       }
+
+       /*
+        * If ITE happens, all pending wait_desc commands are aborted.
+        * No new descriptors are fetched until the ITE is cleared.
+        */
+       if (fault & DMA_FSTS_ITE) {
+               head = readl(iommu->reg + DMAR_IQH_REG);
+               head = ((head >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
+               head |= 1;
+               tail = readl(iommu->reg + DMAR_IQT_REG);
+               tail = ((tail >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
+
+               writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
+
+               do {
+                       if (qi->desc_status[head] == QI_IN_USE)
+                               qi->desc_status[head] = QI_ABORT;
+                       head = (head - 2 + QI_LENGTH) % QI_LENGTH;
+               } while (head != tail);
+
+               if (qi->desc_status[wait_index] == QI_ABORT)
+                       return -EAGAIN;
+       }
+
+       if (fault & DMA_FSTS_ICE)
+               writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
+
+       return 0;
+}
+
+/*
+ * Submit the queued invalidation descriptor to the remapping
+ * hardware unit and wait for its completion.
+ */
+int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
+{
+       int rc;
+       struct q_inval *qi = iommu->qi;
+       struct qi_desc *hw, wait_desc;
+       int wait_index, index;
+       unsigned long flags;
+
+       if (!qi)
+               return 0;
+
+       hw = qi->desc;
+
+restart:
+       rc = 0;
+
+       raw_spin_lock_irqsave(&qi->q_lock, flags);
+       while (qi->free_cnt < 3) {
+               raw_spin_unlock_irqrestore(&qi->q_lock, flags);
+               cpu_relax();
+               raw_spin_lock_irqsave(&qi->q_lock, flags);
+       }
+
+       index = qi->free_head;
+       wait_index = (index + 1) % QI_LENGTH;
+
+       qi->desc_status[index] = qi->desc_status[wait_index] = QI_IN_USE;
+
+       hw[index] = *desc;
+
+       wait_desc.low = QI_IWD_STATUS_DATA(QI_DONE) |
+                       QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
+       wait_desc.high = virt_to_phys(&qi->desc_status[wait_index]);
+
+       hw[wait_index] = wait_desc;
+
+       __iommu_flush_cache(iommu, &hw[index], sizeof(struct qi_desc));
+       __iommu_flush_cache(iommu, &hw[wait_index], sizeof(struct qi_desc));
+
+       qi->free_head = (qi->free_head + 2) % QI_LENGTH;
+       qi->free_cnt -= 2;
+
+       /*
+        * update the HW tail register indicating the presence of
+        * new descriptors.
+        */
+       writel(qi->free_head << DMAR_IQ_SHIFT, iommu->reg + DMAR_IQT_REG);
+
+       while (qi->desc_status[wait_index] != QI_DONE) {
+               /*
+                * We will leave the interrupts disabled, to prevent interrupt
+                * context to queue another cmd while a cmd is already submitted
+                * and waiting for completion on this cpu. This is to avoid
+                * a deadlock where the interrupt context can wait indefinitely
+                * for free slots in the queue.
+                */
+               rc = qi_check_fault(iommu, index);
+               if (rc)
+                       break;
+
+               raw_spin_unlock(&qi->q_lock);
+               cpu_relax();
+               raw_spin_lock(&qi->q_lock);
+       }
+
+       qi->desc_status[index] = QI_DONE;
+
+       reclaim_free_desc(qi);
+       raw_spin_unlock_irqrestore(&qi->q_lock, flags);
+
+       if (rc == -EAGAIN)
+               goto restart;
+
+       return rc;
+}
+
+/*
+ * Flush the global interrupt entry cache.
+ */
+void qi_global_iec(struct intel_iommu *iommu)
+{
+       struct qi_desc desc;
+
+       desc.low = QI_IEC_TYPE;
+       desc.high = 0;
+
+       /* should never fail */
+       qi_submit_sync(&desc, iommu);
+}
+
+void qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
+                     u64 type)
+{
+       struct qi_desc desc;
+
+       desc.low = QI_CC_FM(fm) | QI_CC_SID(sid) | QI_CC_DID(did)
+                       | QI_CC_GRAN(type) | QI_CC_TYPE;
+       desc.high = 0;
+
+       qi_submit_sync(&desc, iommu);
+}
+
+void qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
+                   unsigned int size_order, u64 type)
+{
+       u8 dw = 0, dr = 0;
+
+       struct qi_desc desc;
+       int ih = 0;
+
+       if (cap_write_drain(iommu->cap))
+               dw = 1;
+
+       if (cap_read_drain(iommu->cap))
+               dr = 1;
+
+       desc.low = QI_IOTLB_DID(did) | QI_IOTLB_DR(dr) | QI_IOTLB_DW(dw)
+               | QI_IOTLB_GRAN(type) | QI_IOTLB_TYPE;
+       desc.high = QI_IOTLB_ADDR(addr) | QI_IOTLB_IH(ih)
+               | QI_IOTLB_AM(size_order);
+
+       qi_submit_sync(&desc, iommu);
+}
+
+void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 qdep,
+                       u64 addr, unsigned mask)
+{
+       struct qi_desc desc;
+
+       if (mask) {
+               BUG_ON(addr & ((1 << (VTD_PAGE_SHIFT + mask)) - 1));
+               addr |= (1 << (VTD_PAGE_SHIFT + mask - 1)) - 1;
+               desc.high = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
+       } else
+               desc.high = QI_DEV_IOTLB_ADDR(addr);
+
+       if (qdep >= QI_DEV_IOTLB_MAX_INVS)
+               qdep = 0;
+
+       desc.low = QI_DEV_IOTLB_SID(sid) | QI_DEV_IOTLB_QDEP(qdep) |
+                  QI_DIOTLB_TYPE;
+
+       qi_submit_sync(&desc, iommu);
+}
+
+/*
+ * Disable Queued Invalidation interface.
+ */
+void dmar_disable_qi(struct intel_iommu *iommu)
+{
+       unsigned long flags;
+       u32 sts;
+       cycles_t start_time = get_cycles();
+
+       if (!ecap_qis(iommu->ecap))
+               return;
+
+       raw_spin_lock_irqsave(&iommu->register_lock, flags);
+
+       sts =  dmar_readq(iommu->reg + DMAR_GSTS_REG);
+       if (!(sts & DMA_GSTS_QIES))
+               goto end;
+
+       /*
+        * Give a chance to HW to complete the pending invalidation requests.
+        */
+       while ((readl(iommu->reg + DMAR_IQT_REG) !=
+               readl(iommu->reg + DMAR_IQH_REG)) &&
+               (DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time)))
+               cpu_relax();
+
+       iommu->gcmd &= ~DMA_GCMD_QIE;
+       writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
+
+       IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl,
+                     !(sts & DMA_GSTS_QIES), sts);
+end:
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
+}
+
+/*
+ * Enable queued invalidation.
+ */
+static void __dmar_enable_qi(struct intel_iommu *iommu)
+{
+       u32 sts;
+       unsigned long flags;
+       struct q_inval *qi = iommu->qi;
+
+       qi->free_head = qi->free_tail = 0;
+       qi->free_cnt = QI_LENGTH;
+
+       raw_spin_lock_irqsave(&iommu->register_lock, flags);
+
+       /* write zero to the tail reg */
+       writel(0, iommu->reg + DMAR_IQT_REG);
+
+       dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));
+
+       iommu->gcmd |= DMA_GCMD_QIE;
+       writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
+
+       /* Make sure hardware complete it */
+       IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);
+
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
+}
+
+/*
+ * Enable Queued Invalidation interface. This is a must to support
+ * interrupt-remapping. Also used by DMA-remapping, which replaces
+ * register based IOTLB invalidation.
+ */
+int dmar_enable_qi(struct intel_iommu *iommu)
+{
+       struct q_inval *qi;
+       struct page *desc_page;
+
+       if (!ecap_qis(iommu->ecap))
+               return -ENOENT;
+
+       /*
+        * queued invalidation is already setup and enabled.
+        */
+       if (iommu->qi)
+               return 0;
+
+       iommu->qi = kmalloc(sizeof(*qi), GFP_ATOMIC);
+       if (!iommu->qi)
+               return -ENOMEM;
+
+       qi = iommu->qi;
+
+
+       desc_page = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO, 0);
+       if (!desc_page) {
+               kfree(qi);
+               iommu->qi = NULL;
+               return -ENOMEM;
+       }
+
+       qi->desc = page_address(desc_page);
+
+       qi->desc_status = kzalloc(QI_LENGTH * sizeof(int), GFP_ATOMIC);
+       if (!qi->desc_status) {
+               free_page((unsigned long) qi->desc);
+               kfree(qi);
+               iommu->qi = NULL;
+               return -ENOMEM;
+       }
+
+       raw_spin_lock_init(&qi->q_lock);
+
+       __dmar_enable_qi(iommu);
+
+       return 0;
+}
+
+/* iommu interrupt handling. Most stuff are MSI-like. */
+
+enum faulttype {
+       DMA_REMAP,
+       INTR_REMAP,
+       UNKNOWN,
+};
+
+static const char *dma_remap_fault_reasons[] =
+{
+       "Software",
+       "Present bit in root entry is clear",
+       "Present bit in context entry is clear",
+       "Invalid context entry",
+       "Access beyond MGAW",
+       "PTE Write access is not set",
+       "PTE Read access is not set",
+       "Next page table ptr is invalid",
+       "Root table address invalid",
+       "Context table ptr is invalid",
+       "non-zero reserved fields in RTP",
+       "non-zero reserved fields in CTP",
+       "non-zero reserved fields in PTE",
+       "PCE for translation request specifies blocking",
+};
+
+static const char *irq_remap_fault_reasons[] =
+{
+       "Detected reserved fields in the decoded interrupt-remapped request",
+       "Interrupt index exceeded the interrupt-remapping table size",
+       "Present field in the IRTE entry is clear",
+       "Error accessing interrupt-remapping table pointed by IRTA_REG",
+       "Detected reserved fields in the IRTE entry",
+       "Blocked a compatibility format interrupt request",
+       "Blocked an interrupt request due to source-id verification failure",
+};
+
+static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
+{
+       if (fault_reason >= 0x20 && (fault_reason - 0x20 <
+                                       ARRAY_SIZE(irq_remap_fault_reasons))) {
+               *fault_type = INTR_REMAP;
+               return irq_remap_fault_reasons[fault_reason - 0x20];
+       } else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
+               *fault_type = DMA_REMAP;
+               return dma_remap_fault_reasons[fault_reason];
+       } else {
+               *fault_type = UNKNOWN;
+               return "Unknown";
+       }
+}
+
+void dmar_msi_unmask(struct irq_data *data)
+{
+       struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
+       unsigned long flag;
+
+       /* unmask it */
+       raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       writel(0, iommu->reg + DMAR_FECTL_REG);
+       /* Read a reg to force flush the post write */
+       readl(iommu->reg + DMAR_FECTL_REG);
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_mask(struct irq_data *data)
+{
+       unsigned long flag;
+       struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
+
+       /* mask it */
+       raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       writel(DMA_FECTL_IM, iommu->reg + DMAR_FECTL_REG);
+       /* Read a reg to force flush the post write */
+       readl(iommu->reg + DMAR_FECTL_REG);
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_write(int irq, struct msi_msg *msg)
+{
+       struct intel_iommu *iommu = irq_get_handler_data(irq);
+       unsigned long flag;
+
+       raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       writel(msg->data, iommu->reg + DMAR_FEDATA_REG);
+       writel(msg->address_lo, iommu->reg + DMAR_FEADDR_REG);
+       writel(msg->address_hi, iommu->reg + DMAR_FEUADDR_REG);
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+void dmar_msi_read(int irq, struct msi_msg *msg)
+{
+       struct intel_iommu *iommu = irq_get_handler_data(irq);
+       unsigned long flag;
+
+       raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       msg->data = readl(iommu->reg + DMAR_FEDATA_REG);
+       msg->address_lo = readl(iommu->reg + DMAR_FEADDR_REG);
+       msg->address_hi = readl(iommu->reg + DMAR_FEUADDR_REG);
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+}
+
+static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
+               u8 fault_reason, u16 source_id, unsigned long long addr)
+{
+       const char *reason;
+       int fault_type;
+
+       reason = dmar_get_fault_reason(fault_reason, &fault_type);
+
+       if (fault_type == INTR_REMAP)
+               pr_err("INTR-REMAP: Request device [[%02x:%02x.%d] "
+                      "fault index %llx\n"
+                       "INTR-REMAP:[fault reason %02d] %s\n",
+                       (source_id >> 8), PCI_SLOT(source_id & 0xFF),
+                       PCI_FUNC(source_id & 0xFF), addr >> 48,
+                       fault_reason, reason);
+       else
+               pr_err("DMAR:[%s] Request device [%02x:%02x.%d] "
+                      "fault addr %llx \n"
+                      "DMAR:[fault reason %02d] %s\n",
+                      (type ? "DMA Read" : "DMA Write"),
+                      (source_id >> 8), PCI_SLOT(source_id & 0xFF),
+                      PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
+       return 0;
+}
+
+#define PRIMARY_FAULT_REG_LEN (16)
+irqreturn_t dmar_fault(int irq, void *dev_id)
+{
+       struct intel_iommu *iommu = dev_id;
+       int reg, fault_index;
+       u32 fault_status;
+       unsigned long flag;
+
+       raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+       if (fault_status)
+               pr_err("DRHD: handling fault status reg %x\n", fault_status);
+
+       /* TBD: ignore advanced fault log currently */
+       if (!(fault_status & DMA_FSTS_PPF))
+               goto unlock_exit;
+
+       fault_index = dma_fsts_fault_record_index(fault_status);
+       reg = cap_fault_reg_offset(iommu->cap);
+       while (1) {
+               u8 fault_reason;
+               u16 source_id;
+               u64 guest_addr;
+               int type;
+               u32 data;
+
+               /* highest 32 bits */
+               data = readl(iommu->reg + reg +
+                               fault_index * PRIMARY_FAULT_REG_LEN + 12);
+               if (!(data & DMA_FRCD_F))
+                       break;
+
+               fault_reason = dma_frcd_fault_reason(data);
+               type = dma_frcd_type(data);
+
+               data = readl(iommu->reg + reg +
+                               fault_index * PRIMARY_FAULT_REG_LEN + 8);
+               source_id = dma_frcd_source_id(data);
+
+               guest_addr = dmar_readq(iommu->reg + reg +
+                               fault_index * PRIMARY_FAULT_REG_LEN);
+               guest_addr = dma_frcd_page_addr(guest_addr);
+               /* clear the fault */
+               writel(DMA_FRCD_F, iommu->reg + reg +
+                       fault_index * PRIMARY_FAULT_REG_LEN + 12);
+
+               raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+
+               dmar_fault_do_one(iommu, type, fault_reason,
+                               source_id, guest_addr);
+
+               fault_index++;
+               if (fault_index >= cap_num_fault_regs(iommu->cap))
+                       fault_index = 0;
+               raw_spin_lock_irqsave(&iommu->register_lock, flag);
+       }
+
+       writel(DMA_FSTS_PFO | DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);
+
+unlock_exit:
+       raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
+       return IRQ_HANDLED;
+}
+
+int dmar_set_interrupt(struct intel_iommu *iommu)
+{
+       int irq, ret;
+
+       /*
+        * Check if the fault interrupt is already initialized.
+        */
+       if (iommu->irq)
+               return 0;
+
+       irq = dmar_alloc_hwirq();
+       if (irq <= 0) {
+               pr_err("IOMMU: no free vectors\n");
+               return -EINVAL;
+       }
+
+       irq_set_handler_data(irq, iommu);
+       iommu->irq = irq;
+
+       ret = arch_setup_dmar_msi(irq);
+       if (ret) {
+               irq_set_handler_data(irq, NULL);
+               iommu->irq = 0;
+               dmar_free_hwirq(irq);
+               return ret;
+       }
+
+       ret = request_irq(irq, dmar_fault, IRQF_NO_THREAD, iommu->name, iommu);
+       if (ret)
+               pr_err("IOMMU: can't request irq\n");
+       return ret;
+}
+
+int __init enable_drhd_fault_handling(void)
+{
+       struct dmar_drhd_unit *drhd;
+       struct intel_iommu *iommu;
+
+       /*
+        * Enable fault control interrupt.
+        */
+       for_each_iommu(iommu, drhd) {
+               u32 fault_status;
+               int ret = dmar_set_interrupt(iommu);
+
+               if (ret) {
+                       pr_err("DRHD %Lx: failed to enable fault, interrupt, ret %d\n",
+                              (unsigned long long)drhd->reg_base_addr, ret);
+                       return -1;
+               }
+
+               /*
+                * Clear any previous faults.
+                */
+               dmar_fault(iommu->irq, iommu);
+               fault_status = readl(iommu->reg + DMAR_FSTS_REG);
+               writel(fault_status, iommu->reg + DMAR_FSTS_REG);
+       }
+
+       return 0;
+}
+
+/*
+ * Re-enable Queued Invalidation interface.
+ */
+int dmar_reenable_qi(struct intel_iommu *iommu)
+{
+       if (!ecap_qis(iommu->ecap))
+               return -ENOENT;
+
+       if (!iommu->qi)
+               return -ENOENT;
+
+       /*
+        * First disable queued invalidation.
+        */
+       dmar_disable_qi(iommu);
+       /*
+        * Then enable queued invalidation again. Since there is no pending
+        * invalidation requests now, it's safe to re-enable queued
+        * invalidation.
+        */
+       __dmar_enable_qi(iommu);
+
+       return 0;
+}
+
+/*
+ * Check interrupt remapping support in DMAR table description.
+ */
+int __init dmar_ir_support(void)
+{
+       struct acpi_table_dmar *dmar;
+       dmar = (struct acpi_table_dmar *)dmar_tbl;
+       if (!dmar)
+               return 0;
+       return dmar->flags & 0x1;
+}
+
+/* Check whether DMAR units are in use */
+static inline bool dmar_in_use(void)
+{
+       return irq_remapping_enabled || intel_iommu_enabled;
+}
+
+static int __init dmar_free_unused_resources(void)
+{
+       struct dmar_drhd_unit *dmaru, *dmaru_n;
+
+       if (dmar_in_use())
+               return 0;
+
+       if (dmar_dev_scope_status != 1 && !list_empty(&dmar_drhd_units))
+               bus_unregister_notifier(&pci_bus_type, &dmar_pci_bus_nb);
+
+       down_write(&dmar_global_lock);
+       list_for_each_entry_safe(dmaru, dmaru_n, &dmar_drhd_units, list) {
+               list_del(&dmaru->list);
+               dmar_free_drhd(dmaru);
+       }
+       up_write(&dmar_global_lock);
+
+       return 0;
+}
+
+late_initcall(dmar_free_unused_resources);
+IOMMU_INIT_POST(detect_intel_iommu);
+
+/*
+ * DMAR Hotplug Support
+ * For more details, please refer to Intel(R) Virtualization Technology
+ * for Directed-IO Architecture Specifiction, Rev 2.2, Section 8.8
+ * "Remapping Hardware Unit Hot Plug".
+ */
+static u8 dmar_hp_uuid[] = {
+       /* 0000 */    0xA6, 0xA3, 0xC1, 0xD8, 0x9B, 0xBE, 0x9B, 0x4C,
+       /* 0008 */    0x91, 0xBF, 0xC3, 0xCB, 0x81, 0xFC, 0x5D, 0xAF
+};
+
+/*
+ * Currently there's only one revision and BIOS will not check the revision id,
+ * so use 0 for safety.
+ */
+#define        DMAR_DSM_REV_ID                 0
+#define        DMAR_DSM_FUNC_DRHD              1
+#define        DMAR_DSM_FUNC_ATSR              2
+#define        DMAR_DSM_FUNC_RHSA              3
+
+static inline bool dmar_detect_dsm(acpi_handle handle, int func)
+{
+       return acpi_check_dsm(handle, dmar_hp_uuid, DMAR_DSM_REV_ID, 1 << func);
+}
+
+static int dmar_walk_dsm_resource(acpi_handle handle, int func,
+                                 dmar_res_handler_t handler, void *arg)
+{
+       int ret = -ENODEV;
+       union acpi_object *obj;
+       struct acpi_dmar_header *start;
+       struct dmar_res_callback callback;
+       static int res_type[] = {
+               [DMAR_DSM_FUNC_DRHD] = ACPI_DMAR_TYPE_HARDWARE_UNIT,
+               [DMAR_DSM_FUNC_ATSR] = ACPI_DMAR_TYPE_ROOT_ATS,
+               [DMAR_DSM_FUNC_RHSA] = ACPI_DMAR_TYPE_HARDWARE_AFFINITY,
+       };
+
+       if (!dmar_detect_dsm(handle, func))
+               return 0;
+
+       obj = acpi_evaluate_dsm_typed(handle, dmar_hp_uuid, DMAR_DSM_REV_ID,
+                                     func, NULL, ACPI_TYPE_BUFFER);
+       if (!obj)
+               return -ENODEV;
+
+       memset(&callback, 0, sizeof(callback));
+       callback.cb[res_type[func]] = handler;
+       callback.arg[res_type[func]] = arg;
+       start = (struct acpi_dmar_header *)obj->buffer.pointer;
+       ret = dmar_walk_remapping_entries(start, obj->buffer.length, &callback);
+
+       ACPI_FREE(obj);
+
+       return ret;
+}
+
+static int dmar_hp_add_drhd(struct acpi_dmar_header *header, void *arg)
+{
+       int ret;
+       struct dmar_drhd_unit *dmaru;
+
+       dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
+       if (!dmaru)
+               return -ENODEV;
+
+       ret = dmar_ir_hotplug(dmaru, true);
+       if (ret == 0)
+               ret = dmar_iommu_hotplug(dmaru, true);
+
+       return ret;
+}
+
+static int dmar_hp_remove_drhd(struct acpi_dmar_header *header, void *arg)
+{
+       int i, ret;
+       struct device *dev;
+       struct dmar_drhd_unit *dmaru;
+
+       dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
+       if (!dmaru)
+               return 0;
+
+       /*
+        * All PCI devices managed by this unit should have been destroyed.
+        */
+       if (!dmaru->include_all && dmaru->devices && dmaru->devices_cnt)
+               for_each_active_dev_scope(dmaru->devices,
+                                         dmaru->devices_cnt, i, dev)
+                       return -EBUSY;
+
+       ret = dmar_ir_hotplug(dmaru, false);
+       if (ret == 0)
+               ret = dmar_iommu_hotplug(dmaru, false);
+
+       return ret;
+}
+
+static int dmar_hp_release_drhd(struct acpi_dmar_header *header, void *arg)
+{
+       struct dmar_drhd_unit *dmaru;
+
+       dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
+       if (dmaru) {
+               list_del_rcu(&dmaru->list);
+               synchronize_rcu();
+               dmar_free_drhd(dmaru);
+       }
+
+       return 0;
+}
+
+static int dmar_hotplug_insert(acpi_handle handle)
+{
+       int ret;
+       int drhd_count = 0;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                    &dmar_validate_one_drhd, (void *)1);
+       if (ret)
+               goto out;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                    &dmar_parse_one_drhd, (void *)&drhd_count);
+       if (ret == 0 && drhd_count == 0) {
+               pr_warn(FW_BUG "No DRHD structures in buffer returned by _DSM method\n");
+               goto out;
+       } else if (ret) {
+               goto release_drhd;
+       }
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_RHSA,
+                                    &dmar_parse_one_rhsa, NULL);
+       if (ret)
+               goto release_drhd;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
+                                    &dmar_parse_one_atsr, NULL);
+       if (ret)
+               goto release_atsr;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                    &dmar_hp_add_drhd, NULL);
+       if (!ret)
+               return 0;
+
+       dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                              &dmar_hp_remove_drhd, NULL);
+release_atsr:
+       dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
+                              &dmar_release_one_atsr, NULL);
+release_drhd:
+       dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                              &dmar_hp_release_drhd, NULL);
+out:
+       return ret;
+}
+
+static int dmar_hotplug_remove(acpi_handle handle)
+{
+       int ret;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
+                                    &dmar_check_one_atsr, NULL);
+       if (ret)
+               return ret;
+
+       ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                    &dmar_hp_remove_drhd, NULL);
+       if (ret == 0) {
+               WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
+                                              &dmar_release_one_atsr, NULL));
+               WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                              &dmar_hp_release_drhd, NULL));
+       } else {
+               dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
+                                      &dmar_hp_add_drhd, NULL);
+       }
+
+       return ret;
+}
+
+static acpi_status dmar_get_dsm_handle(acpi_handle handle, u32 lvl,
+                                      void *context, void **retval)
+{
+       acpi_handle *phdl = retval;
+
+       if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
+               *phdl = handle;
+               return AE_CTRL_TERMINATE;
+       }
+
+       return AE_OK;
+}
+
+static int dmar_device_hotplug(acpi_handle handle, bool insert)
+{
+       int ret;
+       acpi_handle tmp = NULL;
+       acpi_status status;
+
+       if (!dmar_in_use())
+               return 0;
+
+       if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
+               tmp = handle;
+       } else {
+               status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
+                                            ACPI_UINT32_MAX,
+                                            dmar_get_dsm_handle,
+                                            NULL, NULL, &tmp);
+               if (ACPI_FAILURE(status)) {
+                       pr_warn("Failed to locate _DSM method.\n");
+                       return -ENXIO;
+               }
+       }
+       if (tmp == NULL)
+               return 0;
+
+       down_write(&dmar_global_lock);
+       if (insert)
+               ret = dmar_hotplug_insert(tmp);
+       else
+               ret = dmar_hotplug_remove(tmp);
+       up_write(&dmar_global_lock);
+
+       return ret;
+}
+
+int dmar_device_add(acpi_handle handle)
+{
+       return dmar_device_hotplug(handle, true);
+}
+
+int dmar_device_remove(acpi_handle handle)
+{
+       return dmar_device_hotplug(handle, false);
+}