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Commit 2540c41c authored by Charan Teja Reddy's avatar Charan Teja Reddy Committed by Gerrit - the friendly Code Review server
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arm: dma_mapping: Support for DOMAIN_ATTR_S1_BYPASS attribute 



For iommus which do not use stage1 translation, stage2 may not be aware
of the device's dma_mask requirements. Choose the dma_ops such that
allocations are made within the dma_mask region and bounce buffers are
used as necessary.

Change-Id: I63ae3ff9e5ab608892d12db7a813264d234699ee
Signed-off-by: default avatarCharan Teja Reddy <charante@codeaurora.org>
parent e85bc8a8

arch/arm/mm/dma-mapping.c

+19 −2
Original line number Diff line number Diff line
@@ -2284,11 +2284,15 @@ int arm_iommu_attach_device(struct device *dev, 
			    struct dma_iommu_mapping *mapping)

{

	int err;

	int s1_bypass = 0;



	err = __arm_iommu_attach_device(dev, mapping);

	if (err)

		return err;



	iommu_domain_get_attr(mapping->domain, DOMAIN_ATTR_S1_BYPASS,

					&s1_bypass);

	if (!s1_bypass)

		set_dma_ops(dev, &iommu_ops);

	return 0;

}
@@ -2323,7 +2327,20 @@ static void __arm_iommu_detach_device(struct device *dev) 
 */

void arm_iommu_detach_device(struct device *dev)

{

	struct dma_iommu_mapping *mapping;

	int s1_bypass = 0;



	mapping = to_dma_iommu_mapping(dev);

	if (!mapping) {

		dev_warn(dev, "Not attached\n");

		return;

	}



	__arm_iommu_detach_device(dev);



	iommu_domain_get_attr(mapping->domain, DOMAIN_ATTR_S1_BYPASS,

					&s1_bypass);

	if (!s1_bypass)

		set_dma_ops(dev, NULL);

}

EXPORT_SYMBOL_GPL(arm_iommu_detach_device);