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authorAlex Williamson <alex.williamson@redhat.com>2012-08-04 20:08:55 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2012-08-06 18:09:51 +0200
commita4ff1fc2ccbd81e83ac51ea44570caa361c666af (patch)
treead667523a59057c1b608ff8b41b372e9086f6736 /drivers/iommu/intel-iommu.c
parentiommu/amd: Fix pci_request_acs() call-place (diff)
downloadlinux-a4ff1fc2ccbd81e83ac51ea44570caa361c666af.tar.xz
linux-a4ff1fc2ccbd81e83ac51ea44570caa361c666af.zip
iommu/intel: Fix ACS path checking
SR-IOV can create buses without a bridge. There may be other cases where this happens as well. In these cases skip to the parent bus and continue testing devices there. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
-rw-r--r--drivers/iommu/intel-iommu.c25
1 files changed, 22 insertions, 3 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0204b62480b0..2297ec193eb4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4125,8 +4125,13 @@ static int intel_iommu_add_device(struct device *dev)
} else
dma_pdev = pci_dev_get(pdev);
+ /* Account for quirked devices */
swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev));
+ /*
+ * If it's a multifunction device that does not support our
+ * required ACS flags, add to the same group as function 0.
+ */
if (dma_pdev->multifunction &&
!pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS))
swap_pci_ref(&dma_pdev,
@@ -4134,14 +4139,28 @@ static int intel_iommu_add_device(struct device *dev)
PCI_DEVFN(PCI_SLOT(dma_pdev->devfn),
0)));
+ /*
+ * Devices on the root bus go through the iommu. If that's not us,
+ * find the next upstream device and test ACS up to the root bus.
+ * Finding the next device may require skipping virtual buses.
+ */
while (!pci_is_root_bus(dma_pdev->bus)) {
- if (pci_acs_path_enabled(dma_pdev->bus->self,
- NULL, REQ_ACS_FLAGS))
+ struct pci_bus *bus = dma_pdev->bus;
+
+ while (!bus->self) {
+ if (!pci_is_root_bus(bus))
+ bus = bus->parent;
+ else
+ goto root_bus;
+ }
+
+ if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
break;
- swap_pci_ref(&dma_pdev, pci_dev_get(dma_pdev->bus->self));
+ swap_pci_ref(&dma_pdev, pci_dev_get(bus->self));
}
+root_bus:
group = iommu_group_get(&dma_pdev->dev);
pci_dev_put(dma_pdev);
if (!group) {