From 23759dc6430428897a36c4d493f611eca55c9481 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sun, 2 Apr 2006 00:07:39 +0100 Subject: [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 Signed-off-by: Lennert Buytenhek Signed-off-by: Russell King --- include/asm-arm/dma-mapping.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'include/asm-arm/dma-mapping.h') diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h index e3e8541ee63..63ca7412a46 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 -- cgit v1.2.3-70-g09d2