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author | Lennert Buytenhek <buytenh@wantstofly.org> | 2006-04-02 00:07:39 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-04-02 00:07:39 +0100 |
commit | 23759dc6430428897a36c4d493f611eca55c9481 (patch) | |
tree | c62050927599b36ed223753c35fd737e3c0c6762 /include/asm-arm/dma-mapping.h | |
parent | d3f4c571b6e596f9d39c596426269006a309d3b8 (diff) | |
download | kernel_samsung_smdk4412-23759dc6430428897a36c4d493f611eca55c9481.zip kernel_samsung_smdk4412-23759dc6430428897a36c4d493f611eca55c9481.tar.gz kernel_samsung_smdk4412-23759dc6430428897a36c4d493f611eca55c9481.tar.bz2 |
[ARM] 3439/2: xsc3: add I/O coherency support
Patch from Lennert Buytenhek
This patch adds support for the I/O coherent cache available on the
xsc3. The approach is to provide a simple API to determine whether the
chipset supports coherency by calling arch_is_coherent() and then
setting the appropriate system memory PTE and PMD bits. In addition,
we call this API on dma_alloc_coherent() and dma_map_single() calls.
A generic version exists that will compile out all the coherency-related
code that is not needed on the majority of ARM systems.
Note that we do not check for coherency in the dma_alloc_writecombine()
function as that still requires a special PTE setting. We also don't
touch dma_mmap_coherent() as that is a special ARM-only API that is by
definition only used on non-coherent system.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'include/asm-arm/dma-mapping.h')
-rw-r--r-- | include/asm-arm/dma-mapping.h | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h index e3e8541..63ca741 100644 --- a/include/asm-arm/dma-mapping.h +++ b/include/asm-arm/dma-mapping.h @@ -47,7 +47,7 @@ static inline int dma_get_cache_alignment(void) static inline int dma_is_consistent(dma_addr_t handle) { - return 0; + return !!arch_is_coherent(); } /* @@ -145,7 +145,9 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction dir) { - consistent_sync(cpu_addr, size, dir); + if (!arch_is_coherent()) + consistent_sync(cpu_addr, size, dir); + return virt_to_dma(dev, (unsigned long)cpu_addr); } #else @@ -255,7 +257,9 @@ dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, sg->dma_address = page_to_dma(dev, sg->page) + sg->offset; virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } return nents; @@ -310,14 +314,16 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - consistent_sync((void *)dma_to_virt(dev, handle), size, dir); + if (!arch_is_coherent()) + consistent_sync((void *)dma_to_virt(dev, handle), size, dir); } static inline void dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - consistent_sync((void *)dma_to_virt(dev, handle), size, dir); + if (!arch_is_coherent()) + consistent_sync((void *)dma_to_virt(dev, handle), size, dir); } #else extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction); @@ -347,7 +353,8 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, for (i = 0; i < nents; i++, sg++) { char *virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } } @@ -359,7 +366,8 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, for (i = 0; i < nents; i++, sg++) { char *virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } } #else |