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Commit 6a709119 authored by Mitchel Humpherys's avatar Mitchel Humpherys Committed by Kyle Yan
Browse files

arm64: dma-mapping: Attach IOMMUs as groups 



Some devices behind IOMMUs might end up in IOMMU groups due to DMA
aliasing.  The iommu_attach_device API expects a single device in a
group all by its lonesome, so it fails when a device is passed in that's
part of a group.  Use iommu_attach_group to accommodate these types of
devices.

CRs-Fixed: 1023180
Change-Id: I9601efd300c7f428c4576e6ecf6d31791d0b47bd
Signed-off-by: default avatarMitchel Humpherys <mitchelh@codeaurora.org>
parent 78f42e35

arch/arm64/mm/dma-mapping.c

+16 −2
Original line number Diff line number Diff line
@@ -2114,12 +2114,19 @@ int arm_iommu_attach_device(struct device *dev, 
{

	int err;

	int s1_bypass = 0, is_fast = 0;

	struct iommu_group *group;



	iommu_domain_get_attr(mapping->domain, DOMAIN_ATTR_FAST, &is_fast);

	if (is_fast)

		return fast_smmu_attach_device(dev, mapping);



	err = iommu_attach_device(mapping->domain, dev);

	group = iommu_group_get(dev);

	if (!group) {

		dev_err(dev, "Couldn't get group\n");

		return -ENODEV;

	}



	err = iommu_attach_group(mapping->domain, group);

	if (err)

		return err;
@@ -2147,6 +2154,7 @@ void arm_iommu_detach_device(struct device *dev) 
{

	struct dma_iommu_mapping *mapping;

	int is_fast;

	struct iommu_group *group;



	mapping = to_dma_iommu_mapping(dev);

	if (!mapping) {
@@ -2160,7 +2168,13 @@ void arm_iommu_detach_device(struct device *dev) 
		return;

	}



	iommu_detach_device(mapping->domain, dev);

	group = iommu_group_get(dev);

	if (!group) {

		dev_err(dev, "Couldn't get group\n");

		return;

	}



	iommu_detach_group(mapping->domain, group);

	kref_put(&mapping->kref, release_iommu_mapping);

	dev->archdata.mapping = NULL;

	set_dma_ops(dev, NULL);