intel-iommu: Fix lookup in add device

We can't assume this device exists, fall back to the bridge itself.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Matthew Thode <prometheanfire@gentoo.org>
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <joro@8bytes.org>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d4a4cd445cabb40504bd2a1c7d5300656feceaff..0badfa48b32b7e84a16449ebc8804e461529c8b9 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4108,7 +4108,7 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to)
 static int intel_iommu_add_device(struct device *dev)
 {
        struct pci_dev *pdev = to_pci_dev(dev);
-       struct pci_dev *bridge, *dma_pdev;
+       struct pci_dev *bridge, *dma_pdev = NULL;
        struct iommu_group *group;
        int ret;
 
@@ -4122,7 +4122,7 @@ static int intel_iommu_add_device(struct device *dev)
                        dma_pdev = pci_get_domain_bus_and_slot(
                                                pci_domain_nr(pdev->bus),
                                                bridge->subordinate->number, 0);
-               else
+               if (!dma_pdev)
                        dma_pdev = pci_dev_get(bridge);
        } else
                dma_pdev = pci_dev_get(pdev);