[PATCH v5 4/6] arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED
From: Mitchel Humpherys <hidden>
Date: 2016-07-27 23:42:33
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.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Mitchel Humpherys <redacted>
---
Notes:
v4..v5
- Simplified (suggested by Robin Murphy)
v3..v4
- Reworked against the new dma attrs format
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 | 10 ++++++++--
include/linux/dma-iommu.h | 3 ++-
3 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c4284c432ae8..1c6f85c56115 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c@@ -556,7 +556,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, unsigned long 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;
@@ -710,7 +710,7 @@ static dma_addr_t __iommu_map_page(struct device *dev, struct page *page, unsigned long 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) &&
@@ -768,7 +768,7 @@ 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 08a1e2f3690f..279764305005 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c@@ -129,16 +129,22 @@ 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, + unsigned long attrs) { int prot = coherent ? IOMMU_CACHE : 0; + if (attrs & DMA_ATTR_PRIVILEGED) + prot |= IOMMU_PRIV; + switch (dir) { case DMA_BIDIRECTIONAL: return prot | IOMMU_READ | IOMMU_WRITE;
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 81c5c8d167ad..b367613d49ba 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, + unsigned long attrs); /* * These implement the bulk of the relevant DMA mapping callbacks, but require
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