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-rw-r--r--arch/x86/kernel/amd_iommu.c25
1 files changed, 25 insertions, 0 deletions
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
@@ -1205,6 +1205,30 @@ free_mem:
}
/*
+ * 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.
*
* If the driver core informs the DMA layer if a driver grabs a device
@@ -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,
};
/*
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