iommu/amd: Split IOMMU group allocation and attach

Add a WARN_ON to make it clear why we don't add dma_pdev->dev to the
group we're allocating.

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

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 3a00b5c..7fa97a5 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -325,6 +325,24 @@ static struct pci_dev *get_isolation_root(struct pci_dev *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 init_iommu_group(struct device *dev)
 {
        struct iommu_dev_data *dev_data;
@@ -353,18 +371,8 @@ static int init_iommu_group(struct device *dev)
                dma_pdev = pci_dev_get(to_pci_dev(dev));
 
        dma_pdev = get_isolation_root(dma_pdev);
-       group = iommu_group_get(&dma_pdev->dev);
+       ret = use_pdev_iommu_group(dma_pdev, dev);
        pci_dev_put(dma_pdev);
-       if (!group) {
-               group = iommu_group_alloc();
-               if (IS_ERR(group))
-                       return PTR_ERR(group);
-       }
-
-       ret = iommu_group_add_device(group, dev);
-
-       iommu_group_put(group);
-
        return ret;
 }