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>
This commit is contained in:
Alex Williamson 2012-08-04 12:08:55 -06:00 committed by Joerg Roedel
parent 1adb7d31b0
commit a4ff1fc2cc

View File

@ -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) {