diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 0cb8fd2359f5..a6a6f8ed1cf5 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -1204,6 +1204,30 @@ free_mem: free_pages((unsigned long)virt_addr, get_order(size)); } +/* + * This function is called by the DMA layer to find out if we can handle a + * particular device. It is part of the dma_ops. + */ +static int amd_iommu_dma_supported(struct device *dev, u64 mask) +{ + u16 bdf; + struct pci_dev *pcidev; + + /* No device or no PCI device */ + if (!dev || dev->bus != &pci_bus_type) + return 0; + + pcidev = to_pci_dev(dev); + + bdf = calc_devid(pcidev->bus->number, pcidev->devfn); + + /* Out of our scope? */ + if (bdf > amd_iommu_last_bdf) + return 0; + + return 1; +} + /* * The function for pre-allocating protection domains. * @@ -1247,6 +1271,7 @@ static struct dma_mapping_ops amd_iommu_dma_ops = { .unmap_single = unmap_single, .map_sg = map_sg, .unmap_sg = unmap_sg, + .dma_supported = amd_iommu_dma_supported, }; /*