intel-iommu: Don't set identity mapping for bypassed graphics devices

We should check iommu_dummy() _first_, because that means it's attached
to an iommu that we've just disabled completely. At the moment, we might
try to put the device into the identity mapping domain.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index ad85e95d2dcc..3e3910127fc1 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2447,8 +2447,11 @@ static int iommu_no_mapping(struct pci_dev *pdev)
 {
         int found;
 
+        if (iommu_dummy(pdev))
+                return 1;
+
         if (!iommu_identity_mapping)
-                return iommu_dummy(pdev);
+                return 0;
 
         found = identity_mapping(pdev);
         if (found) {
@@ -2480,7 +2483,7 @@ static int iommu_no_mapping(struct pci_dev *pdev)
                 }
         }
 
-        return iommu_dummy(pdev);
+        return 0;
 }
 
 static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,