From 4ea0d7371e808628d11154b0d44140b70f05b998 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 24 Nov 2009 16:27:17 +0000 Subject: ARM: dma-mapping: push buffer ownership down into dma-mapping.c Signed-off-by: Russell King Tested-By: Santosh Shilimkar --- arch/arm/include/asm/dma-mapping.h | 39 ++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e850f5c1607b..256ee1c9f51a 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -56,47 +56,58 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) } #endif -/* - * 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); - /* * 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. * - * As above, these are private support functions and not part of the API. - * Drivers must not use these. + * 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. + * + * Private support functions: these are not part of the API and are + * liable to change. Drivers must not use these. */ 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_cache_maint(kaddr, size, dir); + ___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) { - /* nothing to do */ + 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_cache_maint_page(page, off, size, dir); + ___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) { - /* nothing to do */ + 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); } /* -- cgit v1.2.3