[RFC 5/5] ARM: dma-mapping: Introduce dma_map_linear_attrs() for IOVA linear map
From: Hiroshi Doyu <hidden>
Date: 2012-08-29 06:56:26
Also in:
linux-arm-kernel, linux-iommu, linux-mm, lkml
Subsystem:
arm port, generic include/asm header files, the rest · Maintainers:
Russell King, Arnd Bergmann, Linus Torvalds
Introduce a helper function, dma_map_linear(_attrs)() to create IOVA linear map, where IOVA and kernel virtual addresses are mapped at the same address linearly. This is useful to support legacy device drivers which expects no IOMMU. Signed-off-by: Hiroshi Doyu <redacted> --- arch/arm/include/asm/dma-mapping.h | 13 +++++++++++++ include/asm-generic/dma-mapping-common.h | 1 + 2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index f04a533..7a78dd4 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h@@ -212,6 +212,19 @@ static inline size_t dma_iova_get_free_max(struct device *dev) return ops->iova_get_free_max(dev); } +static inline dma_addr_t dma_map_linear_attrs(struct device *dev, void *va, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + dma_addr_t da; + + da = dma_iova_alloc_at(dev, (dma_addr_t)va, size); + if (da == DMA_ERROR_CODE) + return DMA_ERROR_CODE; + + return dma_map_single_at_attrs(dev, va, da, size, dir, attrs); +} + /** * arm_dma_mmap - map a coherent DMA allocation into user space * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index eada2d8..4564bf0 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h@@ -191,6 +191,7 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, #define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, NULL) #define dma_map_single_at(d, a, h, s, r) \ dma_map_single_at_attrs(d, a, h, s, r, NULL) +#define dma_map_linear(d, a, s, r) dma_map_linear_attrs(d, a, s, r, NULL) #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, NULL) #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL) #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)
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1.7.5.4