/* * linux/include/asm-arm/proc-armv/io.h */ /* * The caches on some architectures aren't dma-coherent and have need to * handle this in software. There are two types of operations that * can be applied to dma buffers. * * - dma_cache_wback_inv(start, size) makes caches and RAM coherent by * writing the content of the caches back to memory, if necessary. * The function also invalidates the affected part of the caches as * necessary before DMA transfers from outside to memory. * - dma_cache_inv(start, size) invalidates the affected parts of the * caches. Dirty lines of the caches may be written back or simply * be discarded. This operation is necessary before dma operations * to the memory. * - dma_cache_wback(start, size) writes back any dirty lines but does * not invalidate the cache. This can be used before DMA reads from * memory, */ #include #define dma_cache_inv(start, size) \ do { cpu_cache_purge_area((unsigned long)(start), \ ((unsigned long)(start)+(size))); } while (0) #define dma_cache_wback(start, size) \ do { cpu_cache_wback_area((unsigned long)(start), \ ((unsigned long)(start)+(size))); } while (0) #define dma_cache_wback_inv(start, size) \ do { cpu_flush_cache_area((unsigned long)(start), \ ((unsigned long)(start)+(size)), 0); } while (0)