diff options
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 103 |
1 files changed, 73 insertions, 30 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index ff46dfa68a9..256ee1c9f51 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -15,20 +15,15 @@ * must not be used by drivers. */ #ifndef __arch_page_to_dma - -#if !defined(CONFIG_HIGHMEM) static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) { - return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page)); + return (dma_addr_t)__pfn_to_bus(page_to_pfn(page)); } -#elif defined(__pfn_to_bus) -static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) + +static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr) { - return (dma_addr_t)__pfn_to_bus(page_to_pfn(page)); + return pfn_to_page(__bus_to_pfn(addr)); } -#else -#error "this machine class needs to define __arch_page_to_dma to use HIGHMEM" -#endif static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) { @@ -45,6 +40,11 @@ static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) return __arch_page_to_dma(dev, page); } +static inline struct page *dma_to_page(struct device *dev, dma_addr_t addr) +{ + return __arch_dma_to_page(dev, addr); +} + static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) { return __arch_dma_to_virt(dev, addr); @@ -57,18 +57,58 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) #endif /* - * DMA-consistent mapping functions. These allocate/free a region of - * uncached, unwrite-buffered mapped memory space for use with DMA - * devices. This is the "generic" version. The PCI specific version - * is in pci.h + * The DMA API is built upon the notion of "buffer ownership". A buffer + * is either exclusively owned by the CPU (and therefore may be accessed + * by it) or exclusively owned by the DMA device. These helper functions + * represent the transitions between these two ownership states. + * + * Note, however, that on later ARMs, this notion does not work due to + * speculative prefetches. We model our approach on the assumption that + * the CPU does do speculative prefetches, which means we clean caches + * before transfers and delay cache invalidation until transfer completion. * - * Note: Drivers should NOT use this function directly, as it will break - * platforms with CONFIG_DMABOUNCE. - * Use the driver DMA support - see dma-mapping.h (dma_sync_*) + * Private support functions: these are not part of the API and are + * liable to change. Drivers must not use these. */ -extern void dma_cache_maint(const void *kaddr, size_t size, int rw); -extern void dma_cache_maint_page(struct page *page, unsigned long offset, - size_t size, int rw); +static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size, + enum dma_data_direction dir) +{ + extern void ___dma_single_cpu_to_dev(const void *, size_t, + enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_single_cpu_to_dev(kaddr, size, dir); +} + +static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size, + enum dma_data_direction dir) +{ + extern void ___dma_single_dev_to_cpu(const void *, size_t, + enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_single_dev_to_cpu(kaddr, size, dir); +} + +static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off, + size_t size, enum dma_data_direction dir) +{ + extern void ___dma_page_cpu_to_dev(struct page *, unsigned long, + size_t, enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_page_cpu_to_dev(page, off, size, dir); +} + +static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off, + size_t size, enum dma_data_direction dir) +{ + extern void ___dma_page_dev_to_cpu(struct page *, unsigned long, + size_t, enum dma_data_direction); + + if (!arch_is_coherent()) + ___dma_page_dev_to_cpu(page, off, size, dir); +} /* * Return whether the given device DMA address mask can be supported @@ -257,9 +297,11 @@ extern int dma_needs_bounce(struct device*, dma_addr_t, size_t); */ extern dma_addr_t dma_map_single(struct device *, void *, size_t, enum dma_data_direction); +extern void dma_unmap_single(struct device *, dma_addr_t, size_t, + enum dma_data_direction); extern dma_addr_t dma_map_page(struct device *, struct page *, unsigned long, size_t, enum dma_data_direction); -extern void dma_unmap_single(struct device *, dma_addr_t, size_t, +extern void dma_unmap_page(struct device *, dma_addr_t, size_t, enum dma_data_direction); /* @@ -302,8 +344,7 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, { BUG_ON(!valid_dma_direction(dir)); - if (!arch_is_coherent()) - dma_cache_maint(cpu_addr, size, dir); + __dma_single_cpu_to_dev(cpu_addr, size, dir); return virt_to_dma(dev, cpu_addr); } @@ -327,8 +368,7 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, { BUG_ON(!valid_dma_direction(dir)); - if (!arch_is_coherent()) - dma_cache_maint_page(page, offset, size, dir); + __dma_page_cpu_to_dev(page, offset, size, dir); return page_to_dma(dev, page) + offset; } @@ -350,9 +390,8 @@ static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, static inline void dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - /* nothing to do */ + __dma_single_dev_to_cpu(dma_to_virt(dev, handle), size, dir); } -#endif /* CONFIG_DMABOUNCE */ /** * dma_unmap_page - unmap a buffer previously mapped through dma_map_page() @@ -371,8 +410,10 @@ static inline void dma_unmap_single(struct device *dev, dma_addr_t handle, static inline void dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - dma_unmap_single(dev, handle, size, dir); + __dma_page_dev_to_cpu(dma_to_page(dev, handle), handle & ~PAGE_MASK, + size, dir); } +#endif /* CONFIG_DMABOUNCE */ /** * dma_sync_single_range_for_cpu @@ -398,7 +439,10 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev, { BUG_ON(!valid_dma_direction(dir)); - dmabounce_sync_for_cpu(dev, handle, offset, size, dir); + if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir)) + return; + + __dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir); } static inline void dma_sync_single_range_for_device(struct device *dev, @@ -410,8 +454,7 @@ static inline void dma_sync_single_range_for_device(struct device *dev, if (!dmabounce_sync_for_device(dev, handle, offset, size, dir)) return; - if (!arch_is_coherent()) - dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir); + __dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir); } static inline void dma_sync_single_for_cpu(struct device *dev, |