Commit 664b6003 authored by Alex Williamson's avatar Alex Williamson Committed by Joerg Roedel
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amd_iommu: Make use of DMA quirks and ACS checks in IOMMU groups 



Work around broken devices and adhere to ACS support when determining
IOMMU grouping.

Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent abdfdde2

drivers/iommu/amd_iommu.c

+25 −0
Original line number Diff line number Diff line
@@ -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) {