From 7363590d2c4691593fd280f94b3deaeb5e83dbbd Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 21 May 2013 17:35:19 +0100 Subject: [PATCH] arm64: Implement coherent DMA API based on swiotlb This patch adds support for DMA API cache maintenance on SoCs without hardware device cache coherency. Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/cacheflush.h | 7 ++ arch/arm64/include/asm/dma-mapping.h | 7 ++ arch/arm64/mm/cache.S | 78 +++++++++++++++++ arch/arm64/mm/dma-mapping.c | 162 ++++++++++++++++++++++++++++++++++- 4 files changed, 253 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 88932498..4c60e64 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -85,6 +85,13 @@ static inline void flush_cache_page(struct vm_area_struct *vma, } /* + * Cache maintenance functions used by the DMA API. No to be used directly. + */ +extern void __dma_map_area(const void *, size_t, int); +extern void __dma_unmap_area(const void *, size_t, int); +extern void __dma_flush_range(const void *, const void *); + +/* * Copy user data from/to a page which is mapped into a different * processes address space. Really, we want to allow our "user * space" model to handle this. diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index fd0c0c0..3a4572e 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -30,6 +30,8 @@ #define DMA_ERROR_CODE (~(dma_addr_t)0) extern struct dma_map_ops *dma_ops; +extern struct dma_map_ops coherent_swiotlb_dma_ops; +extern struct dma_map_ops noncoherent_swiotlb_dma_ops; static inline struct dma_map_ops *__generic_dma_ops(struct device *dev) { @@ -47,6 +49,11 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev) return __generic_dma_ops(dev); } +static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops) +{ + dev->archdata.dma_ops = ops; +} + #include static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 1ea9f26..97fcef5 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -166,3 +166,81 @@ ENTRY(__flush_dcache_area) dsb sy ret ENDPROC(__flush_dcache_area) + +/* + * __dma_inv_range(start, end) + * - start - virtual start address of region + * - end - virtual end address of region + */ +__dma_inv_range: + dcache_line_size x2, x3 + sub x3, x2, #1 + bic x0, x0, x3 + bic x1, x1, x3 +1: dc ivac, x0 // invalidate D / U line + add x0, x0, x2 + cmp x0, x1 + b.lo 1b + dsb sy + ret +ENDPROC(__dma_inv_range) + +/* + * __dma_clean_range(start, end) + * - start - virtual start address of region + * - end - virtual end address of region + */ +__dma_clean_range: + dcache_line_size x2, x3 + sub x3, x2, #1 + bic x0, x0, x3 +1: dc cvac, x0 // clean D / U line + add x0, x0, x2 + cmp x0, x1 + b.lo 1b + dsb sy + ret +ENDPROC(__dma_clean_range) + +/* + * __dma_flush_range(start, end) + * - start - virtual start address of region + * - end - virtual end address of region + */ +ENTRY(__dma_flush_range) + dcache_line_size x2, x3 + sub x3, x2, #1 + bic x0, x0, x3 +1: dc civac, x0 // clean & invalidate D / U line + add x0, x0, x2 + cmp x0, x1 + b.lo 1b + dsb sy + ret +ENDPROC(__dma_flush_range) + +/* + * __dma_map_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +ENTRY(__dma_map_area) + add x1, x1, x0 + cmp w2, #DMA_FROM_DEVICE + b.eq __dma_inv_range + b __dma_clean_range +ENDPROC(__dma_map_area) + +/* + * __dma_unmap_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +ENTRY(__dma_unmap_area) + add x1, x1, x0 + cmp w2, #DMA_TO_DEVICE + b.ne __dma_inv_range + ret +ENDPROC(__dma_unmap_area) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index afa91a2..88fbc5e 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -78,7 +78,166 @@ static void __dma_free_coherent(struct device *dev, size_t size, } } -static struct dma_map_ops coherent_swiotlb_dma_ops = { +static void *__dma_alloc_noncoherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flags, + struct dma_attrs *attrs) +{ + struct page *page, **map; + void *ptr, *coherent_ptr; + int order, i; + + size = PAGE_ALIGN(size); + order = get_order(size); + + ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs); + if (!ptr) + goto no_mem; + map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA); + if (!map) + goto no_map; + + /* remove any dirty cache lines on the kernel alias */ + __dma_flush_range(ptr, ptr + size); + + /* create a coherent mapping */ + page = virt_to_page(ptr); + for (i = 0; i < (size >> PAGE_SHIFT); i++) + map[i] = page + i; + coherent_ptr = vmap(map, size >> PAGE_SHIFT, VM_MAP, + pgprot_dmacoherent(pgprot_default)); + kfree(map); + if (!coherent_ptr) + goto no_map; + + return coherent_ptr; + +no_map: + __dma_free_coherent(dev, size, ptr, *dma_handle, attrs); +no_mem: + *dma_handle = ~0; + return NULL; +} + +static void __dma_free_noncoherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_handle, + struct dma_attrs *attrs) +{ + void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); + + vunmap(vaddr); + __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); +} + +static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + dma_addr_t dev_addr; + + dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs); + __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); + + return dev_addr; +} + + +static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); + swiotlb_unmap_page(dev, dev_addr, size, dir, attrs); +} + +static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i, ret; + + ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs); + for_each_sg(sgl, sg, ret, i) + __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), + sg->length, dir); + + return ret; +} + +static void __swiotlb_unmap_sg_attrs(struct device *dev, + struct scatterlist *sgl, int nelems, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nelems, i) + __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), + sg->length, dir); + swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs); +} + +static void __swiotlb_sync_single_for_cpu(struct device *dev, + dma_addr_t dev_addr, size_t size, + enum dma_data_direction dir) +{ + __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); + swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir); +} + +static void __swiotlb_sync_single_for_device(struct device *dev, + dma_addr_t dev_addr, size_t size, + enum dma_data_direction dir) +{ + swiotlb_sync_single_for_device(dev, dev_addr, size, dir); + __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); +} + +static void __swiotlb_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + struct scatterlist *sg; + int i; + + for_each_sg(sgl, sg, nelems, i) + __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), + sg->length, dir); + swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir); +} + +static void __swiotlb_sync_sg_for_device(struct device *dev, + struct scatterlist *sgl, int nelems, + enum dma_data_direction dir) +{ + struct scatterlist *sg; + int i; + + swiotlb_sync_sg_for_device(dev, sgl, nelems, dir); + for_each_sg(sgl, sg, nelems, i) + __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), + sg->length, dir); +} + +struct dma_map_ops noncoherent_swiotlb_dma_ops = { + .alloc = __dma_alloc_noncoherent, + .free = __dma_free_noncoherent, + .map_page = __swiotlb_map_page, + .unmap_page = __swiotlb_unmap_page, + .map_sg = __swiotlb_map_sg_attrs, + .unmap_sg = __swiotlb_unmap_sg_attrs, + .sync_single_for_cpu = __swiotlb_sync_single_for_cpu, + .sync_single_for_device = __swiotlb_sync_single_for_device, + .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = __swiotlb_sync_sg_for_device, + .dma_supported = swiotlb_dma_supported, + .mapping_error = swiotlb_dma_mapping_error, +}; +EXPORT_SYMBOL(noncoherent_swiotlb_dma_ops); + +struct dma_map_ops coherent_swiotlb_dma_ops = { .alloc = __dma_alloc_coherent, .free = __dma_free_coherent, .map_page = swiotlb_map_page, @@ -92,6 +251,7 @@ static struct dma_map_ops coherent_swiotlb_dma_ops = { .dma_supported = swiotlb_dma_supported, .mapping_error = swiotlb_dma_mapping_error, }; +EXPORT_SYMBOL(coherent_swiotlb_dma_ops); extern int swiotlb_late_init_with_default_size(size_t default_size); -- 2.7.4