From c14d26905d256565052dce99c35b02470162e679 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 30 May 2013 12:39:18 -0600 Subject: [PATCH] iommu/{vt-d,amd}: Remove multifunction assumption around grouping If a device is multifunction and does not have ACS enabled then we assume that the entire package lacks ACS and use function 0 as the base of the group. The PCIe spec however states that components are permitted to implement ACS on some, none, or all of their applicable functions. It's therefore conceivable that function 0 may be fully independent and support ACS while other functions do not. Instead use the lowest function of the slot that does not have ACS enabled as the base of the group. This may be the current device, which is intentional. So long as we use a consistent algorithm, all the non-ACS functions will be grouped together and ACS functions will get separate groups. Signed-off-by: Alex Williamson Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 25 +++++++++++++++++++------ drivers/iommu/intel-iommu.c | 25 +++++++++++++++++++------ 2 files changed, 38 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 21d02b0d907c..5a02d0776a66 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -287,14 +287,27 @@ static struct pci_dev *get_isolation_root(struct pci_dev *pdev) /* * If it's a multifunction device that does not support our - * required ACS flags, add to the same group as function 0. + * required ACS flags, add to the same group as lowest numbered + * function that also does not suport the required ACS flags. */ 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))); + !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) { + u8 i, slot = PCI_SLOT(dma_pdev->devfn); + + for (i = 0; i < 8; i++) { + struct pci_dev *tmp; + + tmp = pci_get_slot(dma_pdev->bus, PCI_DEVFN(slot, i)); + if (!tmp) + continue; + + if (!pci_acs_enabled(tmp, REQ_ACS_FLAGS)) { + swap_pci_ref(&dma_pdev, tmp); + break; + } + pci_dev_put(tmp); + } + } /* * Devices on the root bus go through the iommu. If that's not us, diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index b4f0e28dfa41..eec0d3e04bf5 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4182,14 +4182,27 @@ static int intel_iommu_add_device(struct device *dev) /* * If it's a multifunction device that does not support our - * required ACS flags, add to the same group as function 0. + * required ACS flags, add to the same group as lowest numbered + * function that also does not suport the required ACS flags. */ 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))); + !pci_acs_enabled(dma_pdev, REQ_ACS_FLAGS)) { + u8 i, slot = PCI_SLOT(dma_pdev->devfn); + + for (i = 0; i < 8; i++) { + struct pci_dev *tmp; + + tmp = pci_get_slot(dma_pdev->bus, PCI_DEVFN(slot, i)); + if (!tmp) + continue; + + if (!pci_acs_enabled(tmp, REQ_ACS_FLAGS)) { + swap_pci_ref(&dma_pdev, tmp); + break; + } + pci_dev_put(tmp); + } + } /* * Devices on the root bus go through the iommu. If that's not us, -- 2.20.1