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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-11-24 16:27:17 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-02-15 15:22:11 +0000 |
commit | 4ea0d7371e808628d11154b0d44140b70f05b998 (patch) | |
tree | 7673b2fc850475a587144a02c9f568a2831f0c2f /arch/arm/include/asm/dma-mapping.h | |
parent | 18eabe2347ae7a11b3db768695913724166dfb0e (diff) | |
download | linux-3.10-4ea0d7371e808628d11154b0d44140b70f05b998.tar.gz linux-3.10-4ea0d7371e808628d11154b0d44140b70f05b998.tar.bz2 linux-3.10-4ea0d7371e808628d11154b0d44140b70f05b998.zip |
ARM: dma-mapping: push buffer ownership down into dma-mapping.c
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
-rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 39 |
1 files changed, 25 insertions, 14 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e850f5c1607..256ee1c9f51 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -57,46 +57,57 @@ 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); } /* |