1 files changed, 143 insertions, 53 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 55074cb..c1c74e0 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -57,17 +57,9 @@
  * physically contiguous memory regions it is mapping into page sizes
  * that we support.
  *
- * Traditionally the IOMMU core just handed us the mappings directly,
- * after making sure the size is an order of a 4KiB page and that the
- * mapping has natural alignment.
- *
- * To retain this behavior, we currently advertise that we support
- * all page sizes that are an order of 4KiB.
- *
- * If at some point we'd like to utilize the IOMMU core's new behavior,
- * we could change this to advertise the real page sizes we support.
+ * 512GB Pages are not supported due to a hardware bug
  */
-#define AMD_IOMMU_PGSIZES	(~0xFFFUL)
+#define AMD_IOMMU_PGSIZES	((~0xFFFUL) & ~(2ULL << 38))
 
 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 
@@ -140,6 +132,9 @@ static void free_dev_data(struct iommu_dev_data *dev_data)
 	list_del(&dev_data->dev_data_list);
 	spin_unlock_irqrestore(&dev_data_list_lock, flags);
 
+	if (dev_data->group)
+		iommu_group_put(dev_data->group);
+
 	kfree(dev_data);
 }
 
@@ -274,41 +269,23 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to)
 	*from = to;
 }
 
-#define REQ_ACS_FLAGS	(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
-
-static int iommu_init_device(struct device *dev)
+static struct pci_bus *find_hosted_bus(struct pci_bus *bus)
 {
-	struct pci_dev *dma_pdev = NULL, *pdev = to_pci_dev(dev);
-	struct iommu_dev_data *dev_data;
-	struct iommu_group *group;
-	u16 alias;
-	int ret;
-
-	if (dev->archdata.iommu)
-		return 0;
-
-	dev_data = find_dev_data(get_device_id(dev));
-	if (!dev_data)
-		return -ENOMEM;
-
-	alias = amd_iommu_alias_table[dev_data->devid];
-	if (alias != dev_data->devid) {
-		struct iommu_dev_data *alias_data;
+	while (!bus->self) {
+		if (!pci_is_root_bus(bus))
+			bus = bus->parent;
+		else
+			return ERR_PTR(-ENODEV);
+	}
 
-		alias_data = find_dev_data(alias);
-		if (alias_data == NULL) {
-			pr_err("AMD-Vi: Warning: Unhandled device %s\n",
-					dev_name(dev));
-			free_dev_data(dev_data);
-			return -ENOTSUPP;
-		}
-		dev_data->alias_data = alias_data;
+	return bus;
+}
 
-		dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
-	}
+#define REQ_ACS_FLAGS	(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
 
-	if (dma_pdev == NULL)
-		dma_pdev = pci_dev_get(pdev);
+static struct pci_dev *get_isolation_root(struct pci_dev *pdev)
+{
+	struct pci_dev *dma_pdev = pdev;
 
 	/* Account for quirked devices */
 	swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
@@ -330,14 +307,9 @@ static int iommu_init_device(struct device *dev)
 	 * Finding the next device may require skipping virtual buses.
 	 */
 	while (!pci_is_root_bus(dma_pdev->bus)) {
-		struct pci_bus *bus = dma_pdev->bus;
-
-		while (!bus->self) {
-			if (!pci_is_root_bus(bus))
-				bus = bus->parent;
-			else
-				goto root_bus;
-		}
+		struct pci_bus *bus = find_hosted_bus(dma_pdev->bus);
+		if (IS_ERR(bus))
+			break;
 
 		if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
 			break;
@@ -345,19 +317,137 @@ static int iommu_init_device(struct device *dev)
 		swap_pci_ref(&dma_pdev, pci_dev_get(bus->self));
 	}
 
-root_bus:
-	group = iommu_group_get(&dma_pdev->dev);
-	pci_dev_put(dma_pdev);
+	return dma_pdev;
+}
+
+static int use_pdev_iommu_group(struct pci_dev *pdev, struct device *dev)
+{
+	struct iommu_group *group = iommu_group_get(&pdev->dev);
+	int ret;
+
 	if (!group) {
 		group = iommu_group_alloc();
 		if (IS_ERR(group))
 			return PTR_ERR(group);
+
+		WARN_ON(&pdev->dev != dev);
 	}
 
 	ret = iommu_group_add_device(group, dev);
-
 	iommu_group_put(group);
+	return ret;
+}
+
+static int use_dev_data_iommu_group(struct iommu_dev_data *dev_data,
+				    struct device *dev)
+{
+	if (!dev_data->group) {
+		struct iommu_group *group = iommu_group_alloc();
+		if (IS_ERR(group))
+			return PTR_ERR(group);
+
+		dev_data->group = group;
+	}
+
+	return iommu_group_add_device(dev_data->group, dev);
+}
+
+static int init_iommu_group(struct device *dev)
+{
+	struct iommu_dev_data *dev_data;
+	struct iommu_group *group;
+	struct pci_dev *dma_pdev;
+	int ret;
+
+	group = iommu_group_get(dev);
+	if (group) {
+		iommu_group_put(group);
+		return 0;
+	}
+
+	dev_data = find_dev_data(get_device_id(dev));
+	if (!dev_data)
+		return -ENOMEM;
+
+	if (dev_data->alias_data) {
+		u16 alias;
+		struct pci_bus *bus;
+
+		if (dev_data->alias_data->group)
+			goto use_group;
+
+		/*
+		 * If the alias device exists, it's effectively just a first
+		 * level quirk for finding the DMA source.
+		 */
+		alias = amd_iommu_alias_table[dev_data->devid];
+		dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
+		if (dma_pdev) {
+			dma_pdev = get_isolation_root(dma_pdev);
+			goto use_pdev;
+		}
+
+		/*
+		 * If the alias is virtual, try to find a parent device
+		 * and test whether the IOMMU group is actualy rooted above
+		 * the alias.  Be careful to also test the parent device if
+		 * we think the alias is the root of the group.
+		 */
+		bus = pci_find_bus(0, alias >> 8);
+		if (!bus)
+			goto use_group;
+
+		bus = find_hosted_bus(bus);
+		if (IS_ERR(bus) || !bus->self)
+			goto use_group;
+
+		dma_pdev = get_isolation_root(pci_dev_get(bus->self));
+		if (dma_pdev != bus->self || (dma_pdev->multifunction &&
+		    !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)))
+			goto use_pdev;
+
+		pci_dev_put(dma_pdev);
+		goto use_group;
+	}
+
+	dma_pdev = get_isolation_root(pci_dev_get(to_pci_dev(dev)));
+use_pdev:
+	ret = use_pdev_iommu_group(dma_pdev, dev);
+	pci_dev_put(dma_pdev);
+	return ret;
+use_group:
+	return use_dev_data_iommu_group(dev_data->alias_data, dev);
+}
+
+static int iommu_init_device(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct iommu_dev_data *dev_data;
+	u16 alias;
+	int ret;
+
+	if (dev->archdata.iommu)
+		return 0;
+
+	dev_data = find_dev_data(get_device_id(dev));
+	if (!dev_data)
+		return -ENOMEM;
+
+	alias = amd_iommu_alias_table[dev_data->devid];
+	if (alias != dev_data->devid) {
+		struct iommu_dev_data *alias_data;
+
+		alias_data = find_dev_data(alias);
+		if (alias_data == NULL) {
+			pr_err("AMD-Vi: Warning: Unhandled device %s\n",
+					dev_name(dev));
+			free_dev_data(dev_data);
+			return -ENOTSUPP;
+		}
+		dev_data->alias_data = alias_data;
+	}
 
+	ret = init_iommu_group(dev);
 	if (ret)
 		return ret;