2 files changed, 77 insertions, 11 deletions

diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 22b02c6df854..e5f8fc164fd3 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -175,15 +175,6 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header)
         int ret = 0;
 
         drhd = (struct acpi_dmar_hardware_unit *)header;
-        if (!drhd->address) {
-                /* Promote an attitude of violence to a BIOS engineer today */
-                WARN(1, "Your BIOS is broken; DMAR reported at address zero!\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 -ENODEV;
-        }
         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
         if (!dmaru)
                 return -ENOMEM;
@@ -591,12 +582,50 @@ int __init dmar_table_init(void)
         return 0;
 }
 
+int __init check_zero_address(void)
+{
+        struct acpi_table_dmar *dmar;
+        struct acpi_dmar_header *entry_header;
+        struct acpi_dmar_hardware_unit *drhd;
+
+        dmar = (struct acpi_table_dmar *)dmar_tbl;
+        entry_header = (struct acpi_dmar_header *)(dmar + 1);
+
+        while (((unsigned long)entry_header) <
+                        (((unsigned long)dmar) + dmar_tbl->length)) {
+                /* Avoid looping forever on bad ACPI tables */
+                if (entry_header->length == 0) {
+                        printk(KERN_WARNING PREFIX
+                                "Invalid 0-length structure\n");
+                        return 0;
+                }
+
+                if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) {
+                        drhd = (void *)entry_header;
+                        if (!drhd->address) {
+                                /* Promote an attitude of violence to a BIOS engineer today */
+                                WARN(1, "Your BIOS is broken; DMAR reported at address zero!\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 0;
+                        }
+                        break;
+                }
+
+                entry_header = ((void *)entry_header + entry_header->length);
+        }
+        return 1;
+}
+
 void __init detect_intel_iommu(void)
 {
         int ret;
 
         ret = dmar_table_detect();
-
+        if (ret)
+                ret = check_zero_address();
         {
 #ifdef CONFIG_INTR_REMAP
                 struct acpi_table_dmar *dmar;
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index b1e97e682500..1840a0578a42 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2767,7 +2767,15 @@ static void *intel_alloc_coherent(struct device *hwdev, size_t size,
 
         size = PAGE_ALIGN(size);
         order = get_order(size);
-        flags &= ~(GFP_DMA | GFP_DMA32);
+
+        if (!iommu_no_mapping(hwdev))
+                flags &= ~(GFP_DMA | GFP_DMA32);
+        else if (hwdev->coherent_dma_mask < dma_get_required_mask(hwdev)) {
+                if (hwdev->coherent_dma_mask < DMA_BIT_MASK(32))
+                        flags |= GFP_DMA;
+                else
+                        flags |= GFP_DMA32;
+        }
 
         vaddr = (void *)__get_free_pages(flags, order);
         if (!vaddr)
@@ -3207,6 +3215,33 @@ static int __init init_iommu_sysfs(void)
 }
 #endif  /* CONFIG_PM */
 
+/*
+ * Here we only respond to action of unbound device from driver.
+ *
+ * Added device is not attached to its DMAR domain here yet. That will happen
+ * when mapping the device to iova.
+ */
+static int device_notifier(struct notifier_block *nb,
+                                  unsigned long action, void *data)
+{
+        struct device *dev = data;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct dmar_domain *domain;
+
+        domain = find_domain(pdev);
+        if (!domain)
+                return 0;
+
+        if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through)
+                domain_remove_one_dev_info(domain, pdev);
+
+        return 0;
+}
+
+static struct notifier_block device_nb = {
+        .notifier_call = device_notifier,
+};
+
 int __init intel_iommu_init(void)
 {
         int ret = 0;
@@ -3259,6 +3294,8 @@ int __init intel_iommu_init(void)
 
         register_iommu(&intel_iommu_ops);
 
+        bus_register_notifier(&pci_bus_type, &device_nb);
+
         return 0;
 }