[PATCH v3 4/6] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
From: Mitchel Humpherys <hidden>
Date: 2016-07-19 20:37:31
Also in:
linux-iommu, lkml
Subsystem:
arm64 port (aarch64 architecture), iommu dma-api layer, iommu subsystem, the rest · Maintainers:
Catalin Marinas, Will Deacon, Robin Murphy, Joerg Roedel, Linus Torvalds
The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that
are only accessible to privileged DMA engines. Implement it in
dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it.
Signed-off-by: Mitchel Humpherys <redacted>
---
Notes:
v2..v3
- Renamed and redocumented dma_direction_to_prot.
- Dropped the stuff making all privileged mappings read-only.
arch/arm64/mm/dma-mapping.c | 6 +++---
drivers/iommu/dma-iommu.c | 16 +++++++++++-----
include/linux/dma-iommu.h | 3 ++-
3 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c566ec83719f..5da8946ead9e 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c@@ -543,7 +543,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, struct dma_attrs *attrs) { bool coherent = is_device_dma_coherent(dev); - int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent); + int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs); size_t iosize = size; void *addr;
@@ -697,7 +697,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page, struct dma_attrs *attrs) { bool coherent = is_device_dma_coherent(dev); - int prot = dma_direction_to_prot(dir, coherent); + int prot = dma_info_to_prot(dir, coherent, attrs); dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot); if (!iommu_dma_mapping_error(dev, dev_addr) &&
@@ -755,7 +755,7 @@ static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl, __iommu_sync_sg_for_device(dev, sgl, nelems, dir); return iommu_dma_map_sg(dev, sgl, nelems, - dma_direction_to_prot(dir, coherent)); + dma_info_to_prot(dir, coherent, attrs)); } static void __iommu_unmap_sg_attrs(struct device *dev,
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index ea5a9ebf0f78..cc2c9cccde1f 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c@@ -129,26 +129,32 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size EXPORT_SYMBOL(iommu_dma_init_domain); /** - * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags + * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API + * page flags. * @dir: Direction of DMA transfer * @coherent: Is the DMA master cache-coherent? + * @attrs: DMA attributes for the mapping * * Return: corresponding IOMMU API page protection flags */ -int dma_direction_to_prot(enum dma_data_direction dir, bool coherent) +int dma_info_to_prot(enum dma_data_direction dir, bool coherent, + struct dma_attrs *attrs) { int prot = coherent ? IOMMU_CACHE : 0; switch (dir) { case DMA_BIDIRECTIONAL: - return prot | IOMMU_READ | IOMMU_WRITE; + prot |= IOMMU_READ | IOMMU_WRITE; case DMA_TO_DEVICE: - return prot | IOMMU_READ; + prot |= IOMMU_READ; case DMA_FROM_DEVICE: - return prot | IOMMU_WRITE; + prot |= IOMMU_WRITE; default: return 0; } + if (dma_get_attr(DMA_ATTR_PRIVILEGED, attrs)) + prot |= IOMMU_PRIV; + return prot; } static struct iova *__alloc_iova(struct iova_domain *iovad, size_t size,
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 8443bbb5c071..b0dbcff2d73e 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h@@ -32,7 +32,8 @@ void iommu_put_dma_cookie(struct iommu_domain *domain); int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size); /* General helpers for DMA-API <-> IOMMU-API interaction */ -int dma_direction_to_prot(enum dma_data_direction dir, bool coherent); +int dma_info_to_prot(enum dma_data_direction dir, bool coherent, + struct dma_attrs *attrs); /* * These implement the bulk of the relevant DMA mapping callbacks, but require
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