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Commit 56dc6075 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 884e8488

arch/arm/mm/dma-mapping.c

+8 −2
Original line number Diff line number Diff line
@@ -2332,11 +2332,15 @@ 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;

}
@@ -2352,6 +2356,7 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device); 
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) {
@@ -2362,6 +2367,7 @@ void arm_iommu_detach_device(struct device *dev) 
	iommu_detach_device(mapping->domain, dev);

	kref_put(&mapping->kref, release_iommu_mapping);

	to_dma_iommu_mapping(dev) = NULL;

	if (!s1_bypass)

		set_dma_ops(dev, NULL);



	pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));