From dd37e9405a8e85be49a60b2530efeb5f06bcb753 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Tue, 21 Aug 2012 12:20:17 +0200 Subject: [PATCH] ARM: add coherent dma ops arch_is_coherent is problematic as it is a global symbol. This doesn't work for multi-platform kernels or platforms which can support per device coherent DMA. This adds arm_coherent_dma_ops to be used for devices which connected coherently (i.e. to the ACP port on Cortex-A9 or A15). The arm_dma_ops are modified at boot when arch_is_coherent is true. Signed-off-by: Rob Herring Cc: Russell King Cc: Marek Szyprowski Signed-off-by: Marek Szyprowski --- arch/arm/include/asm/dma-mapping.h | 1 + arch/arm/mm/dma-mapping.c | 71 +++++++++++++++++++++++++++++++------- 2 files changed, 60 insertions(+), 12 deletions(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 5c44dcb..2300484 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -13,6 +13,7 @@ #define DMA_ERROR_CODE (~0) extern struct dma_map_ops arm_dma_ops; +extern struct dma_map_ops arm_coherent_dma_ops; static inline struct dma_map_ops *get_dma_ops(struct device *dev) { diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 13f555d..7d772c0 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -73,11 +73,18 @@ static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_cpu_to_dev(page, offset, size, dir); return pfn_to_dma(dev, page_to_pfn(page)) + offset; } +static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + return pfn_to_dma(dev, page_to_pfn(page)) + offset; +} + /** * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page() * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices @@ -96,7 +103,7 @@ static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)), handle & ~PAGE_MASK, size, dir); } @@ -106,8 +113,7 @@ static void arm_dma_sync_single_for_cpu(struct device *dev, { unsigned int offset = handle & (PAGE_SIZE - 1); struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset)); - if (!arch_is_coherent()) - __dma_page_dev_to_cpu(page, offset, size, dir); + __dma_page_dev_to_cpu(page, offset, size, dir); } static void arm_dma_sync_single_for_device(struct device *dev, @@ -115,8 +121,7 @@ static void arm_dma_sync_single_for_device(struct device *dev, { unsigned int offset = handle & (PAGE_SIZE - 1); struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset)); - if (!arch_is_coherent()) - __dma_page_cpu_to_dev(page, offset, size, dir); + __dma_page_cpu_to_dev(page, offset, size, dir); } static int arm_dma_set_mask(struct device *dev, u64 dma_mask); @@ -138,6 +143,22 @@ struct dma_map_ops arm_dma_ops = { }; EXPORT_SYMBOL(arm_dma_ops); +static void *arm_coherent_dma_alloc(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs); +static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs); + +struct dma_map_ops arm_coherent_dma_ops = { + .alloc = arm_coherent_dma_alloc, + .free = arm_coherent_dma_free, + .mmap = arm_dma_mmap, + .get_sgtable = arm_dma_get_sgtable, + .map_page = arm_coherent_dma_map_page, + .map_sg = arm_dma_map_sg, + .set_dma_mask = arm_dma_set_mask, +}; +EXPORT_SYMBOL(arm_coherent_dma_ops); + static u64 get_coherent_dma_mask(struct device *dev) { u64 mask = (u64)arm_dma_limit; @@ -586,7 +607,7 @@ static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp, static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, - gfp_t gfp, pgprot_t prot, const void *caller) + gfp_t gfp, pgprot_t prot, bool is_coherent, const void *caller) { u64 mask = get_coherent_dma_mask(dev); struct page *page; @@ -619,7 +640,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, *handle = DMA_ERROR_CODE; size = PAGE_ALIGN(size); - if (arch_is_coherent() || nommu()) + if (is_coherent || nommu()) addr = __alloc_simple_buffer(dev, size, gfp, &page); else if (gfp & GFP_ATOMIC) addr = __alloc_from_pool(size, &page); @@ -647,7 +668,20 @@ void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, if (dma_alloc_from_coherent(dev, size, handle, &memory)) return memory; - return __dma_alloc(dev, size, handle, gfp, prot, + return __dma_alloc(dev, size, handle, gfp, prot, false, + __builtin_return_address(0)); +} + +static void *arm_coherent_dma_alloc(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) +{ + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel); + void *memory; + + if (dma_alloc_from_coherent(dev, size, handle, &memory)) + return memory; + + return __dma_alloc(dev, size, handle, gfp, prot, true, __builtin_return_address(0)); } @@ -684,8 +718,9 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, /* * Free a buffer as defined by the above mapping. */ -void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t handle, struct dma_attrs *attrs) +static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs, + bool is_coherent) { struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); @@ -694,7 +729,7 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, size = PAGE_ALIGN(size); - if (arch_is_coherent() || nommu()) { + if (is_coherent || nommu()) { __dma_free_buffer(page, size); } else if (__free_from_pool(cpu_addr, size)) { return; @@ -710,6 +745,18 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, } } +void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) +{ + __arm_dma_free(dev, size, cpu_addr, handle, attrs, false); +} + +static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t handle, struct dma_attrs *attrs) +{ + __arm_dma_free(dev, size, cpu_addr, handle, attrs, true); +} + int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t handle, size_t size, struct dma_attrs *attrs) -- 2.7.4