iommu/amd: Split IOMMU Group topology walk

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 33 insertions, 25 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index b65b377815ac..6edbd0edcae7 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -276,32 +276,9 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to)
 
 #define REQ_ACS_FLAGS   (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
 
-static int init_iommu_group(struct device *dev)
+static struct pci_dev *get_isolation_root(struct pci_dev *pdev)
 {
-        struct iommu_dev_data *dev_data;
-        struct iommu_group *group;
-        struct pci_dev *dma_pdev = NULL;
-        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;
-
-                alias = amd_iommu_alias_table[dev_data->devid];
-                dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
-        }
-
-        if (!dma_pdev)
-                dma_pdev = pci_dev_get(to_pci_dev(dev));
+        struct pci_dev *dma_pdev = pdev;
 
         /* Account for quirked devices */
         swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
@@ -339,6 +316,37 @@ static int init_iommu_group(struct device *dev)
         }
 
 root_bus:
+        return dma_pdev;
+}
+
+static int init_iommu_group(struct device *dev)
+{
+        struct iommu_dev_data *dev_data;
+        struct iommu_group *group;
+        struct pci_dev *dma_pdev = NULL;
+        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;
+
+                alias = amd_iommu_alias_table[dev_data->devid];
+                dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
+        }
+
+        if (!dma_pdev)
+                dma_pdev = pci_dev_get(to_pci_dev(dev));
+
+        dma_pdev = get_isolation_root(dma_pdev);
         group = iommu_group_get(&dma_pdev->dev);
         pci_dev_put(dma_pdev);
         if (!group) {