From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Alex Williamson Subject: [PATCH v2 5/7] amd_iommu: Make use of DMA quirks and ACS checks in IOMMU groups To: joerg.roedel@amd.com, dwmw2@infradead.org, iommu@lists.linux-foundation.org Cc: bhelgaas@google.com, benh@kernel.crashing.org, aik@ozlabs.ru, david@gibson.dropbear.id.au, konrad.wilk@oracle.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, gregkh@linuxfoundation.org, ddutile@redhat.com, alex.williamson@redhat.com, liuj97@gmail.com Date: Wed, 30 May 2012 14:19:31 -0600 Message-ID: <20120530201931.31527.57970.stgit@bling.home> In-Reply-To: <20120530201424.31527.33142.stgit@bling.home> References: <20120530201424.31527.33142.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: Work around broken devices and adhere to ACS support when determining IOMMU grouping. Signed-off-by: Alex Williamson --- drivers/iommu/amd_iommu.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index e072bd1..0e78d3c 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -254,6 +254,14 @@ static bool check_device(struct device *dev) return true; } +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 iommu_init_device(struct device *dev) { struct pci_dev *dma_pdev, *pdev = to_pci_dev(dev); @@ -286,6 +294,23 @@ static int iommu_init_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) {