| Message ID | 20160709020919.6760-6-mitchelh@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 09/07/16 03:09, Mitchel Humpherys wrote: > The newly added DMA_ATTR_PRIVILEGED_EXECUTABLE is useful for creating > mappings that are executable by 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 <mitchelh@codeaurora.org> > --- > arch/arm64/mm/dma-mapping.c | 6 +++--- > drivers/iommu/dma-iommu.c | 15 +++++++++++---- > include/linux/dma-iommu.h | 3 ++- > 3 files changed, 16 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index c566ec83719f..44f676268df6 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_direction_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_direction_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_direction_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..ccc6219da228 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -132,23 +132,30 @@ EXPORT_SYMBOL(iommu_dma_init_domain); > * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags Privilege really isn't a direction :( If we're going to cram more into this function it really wants renaming and redocumenting. > * @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_direction_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_EXECUTABLE, attrs)) { > + prot &= ~IOMMU_WRITE; Hey, we didn't say anything anywhere about anything being privileged read-only! Frankly, I think this is going to create more problems that it solves. Implementing IOMMU_PRIV as simply unprivileged no-access should be sufficient. Robin. > + 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..d5a37e58d29b 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_direction_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 >
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index c566ec83719f..44f676268df6 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_direction_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_direction_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_direction_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..ccc6219da228 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -132,23 +132,30 @@ EXPORT_SYMBOL(iommu_dma_init_domain); * dma_direction_to_prot - Translate DMA API directions 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_direction_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_EXECUTABLE, attrs)) { + prot &= ~IOMMU_WRITE; + 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..d5a37e58d29b 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_direction_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
The newly added DMA_ATTR_PRIVILEGED_EXECUTABLE is useful for creating mappings that are executable by 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 <mitchelh@codeaurora.org> --- arch/arm64/mm/dma-mapping.c | 6 +++--- drivers/iommu/dma-iommu.c | 15 +++++++++++---- include/linux/dma-iommu.h | 3 ++- 3 files changed, 16 insertions(+), 8 deletions(-)