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arm: dma_mapping: Support for DOMAIN_ATTR_S1_BYPASS attribute

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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: Charan Teja Reddy <charante@codeaurora.org>
This commit is contained in:
Charan Teja Reddy 2016-12-07 18:40:57 +05:30
parent 69352ff8b4
commit 55889f2e5f
1 changed files with 19 additions and 2 deletions
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21
arch/arm/mm/dma-mapping.c
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@ -2160,12 +2160,16 @@ 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;
set_dma_ops(dev, &iommu_ops);
iommu_domain_get_attr(mapping->domain, DOMAIN_ATTR_S1_BYPASS,
&s1_bypass);
if (!s1_bypass)
set_dma_ops(dev, &iommu_ops);
return 0;
}
EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
@ -2199,8 +2203,21 @@ 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);
set_dma_ops(dev, NULL);
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);