diff options
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 4a434528cd1..ebf2b310cdd 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4090,6 +4090,14 @@ static int intel_iommu_domain_has_cap(struct iommu_domain *domain, return 0; } +static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to) +{ + pci_dev_put(*from); + *from = to; +} + +#define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF) + static int intel_iommu_add_device(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); @@ -4112,6 +4120,23 @@ static int intel_iommu_add_device(struct device *dev) } else dma_pdev = pci_dev_get(pdev); + swap_pci_ref(&dma_pdev, pci_get_dma_source(dma_pdev)); + + if (dma_pdev->multifunction && + !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) + swap_pci_ref(&dma_pdev, + pci_get_slot(dma_pdev->bus, + PCI_DEVFN(PCI_SLOT(dma_pdev->devfn), + 0))); + + while (!pci_is_root_bus(dma_pdev->bus)) { + if (pci_acs_path_enabled(dma_pdev->bus->self, + NULL, REQ_ACS_FLAGS)) + break; + + swap_pci_ref(&dma_pdev, pci_dev_get(dma_pdev->bus->self)); + } + group = iommu_group_get(&dma_pdev->dev); pci_dev_put(dma_pdev); if (!group) { |