From 2bff6a508eb2ba8b341c20db3099e050e5496e3d Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 8 Oct 2012 22:49:48 -0600 Subject: [PATCH] iommu/amd: Split upstream bus device lookup Signed-off-by: Alex Williamson Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 6edbd0edcae7..3a00b5ce73ab 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -274,6 +274,18 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to) *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 @@ static struct pci_dev *get_isolation_root(struct pci_dev *pdev) * 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 @@ static struct pci_dev *get_isolation_root(struct pci_dev *pdev) swap_pci_ref(&dma_pdev, pci_dev_get(bus->self)); } -root_bus: return dma_pdev; }