iommu/amd: Split upstream bus device lookup
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 6edbd0e..3a00b5ce 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -274,6 +274,18 @@
*from = to;
}
+static struct pci_bus *find_hosted_bus(struct pci_bus *bus)
+{
+ while (!bus->self) {
+ if (!pci_is_root_bus(bus))
+ bus = bus->parent;
+ else
+ return ERR_PTR(-ENODEV);
+ }
+
+ return bus;
+}
+
#define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
static struct pci_dev *get_isolation_root(struct pci_dev *pdev)
@@ -300,14 +312,9 @@
* Finding the next device may require skipping virtual buses.
*/
while (!pci_is_root_bus(dma_pdev->bus)) {
- struct pci_bus *bus = dma_pdev->bus;
-
- while (!bus->self) {
- if (!pci_is_root_bus(bus))
- bus = bus->parent;
- else
- goto root_bus;
- }
+ struct pci_bus *bus = find_hosted_bus(dma_pdev->bus);
+ if (IS_ERR(bus))
+ break;
if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
break;
@@ -315,7 +322,6 @@
swap_pci_ref(&dma_pdev, pci_dev_get(bus->self));
}
-root_bus:
return dma_pdev;
}