diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-09-25 23:16:22 +0200 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-09-29 11:40:22 +0200 |
commit | 125ab12acf64ff86b55d20e14db20becd917b7c4 (patch) | |
tree | ce39f81e6a3a409314735ce0cca1e366ea8fd94e /arch/arm/include/asm/dma-mapping.h | |
parent | [ARM] dma: use new dmabounce_sync_for_xxx() for dma_sync_single_xxx() (diff) | |
download | linux-125ab12acf64ff86b55d20e14db20becd917b7c4.tar.xz linux-125ab12acf64ff86b55d20e14db20becd917b7c4.zip |
[ARM] dma: fix dmabounce dma_sync_xxx() implementations
The dmabounce dma_sync_xxx() implementation have been broken for
quite some time; they all copy data between the DMA buffer and
the CPU visible buffer no irrespective of the change of ownership.
(IOW, a DMA_FROM_DEVICE mapping copies data from the DMA buffer
to the CPU buffer during a call to dma_sync_single_for_device().)
Fix it by getting rid of sync_single(), moving the contents into
the recently created dmabounce_sync_for_xxx() functions and adjusting
appropriately.
This also makes it possible to properly support the DMA range sync
functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/dma-mapping.h')
-rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index c003ad390def..1204dc958c43 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -242,6 +242,15 @@ extern void dmabounce_unregister_dev(struct device *); extern int dma_needs_bounce(struct device*, dma_addr_t, size_t); /* + * The DMA API, implemented by dmabounce.c. See below for descriptions. + */ +extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction); +extern dma_addr_t dma_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir); +extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction); + +/* * Private functions */ int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long, @@ -251,7 +260,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long, #else #define dmabounce_sync_for_cpu(dev,dma,off,sz,dir) (1) #define dmabounce_sync_for_device(dev,dma,off,sz,dir) (1) -#endif /* CONFIG_DMABOUNCE */ /** @@ -268,7 +276,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long, * can regain ownership by calling dma_unmap_single() or * dma_sync_single_for_cpu(). */ -#ifndef CONFIG_DMABOUNCE static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction dir) @@ -278,9 +285,7 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size, return virt_to_dma(dev, cpu_addr); } -#else -extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction); -#endif + /** * dma_map_page - map a portion of a page for streaming DMA @@ -297,7 +302,6 @@ extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_d * can regain ownership by calling dma_unmap_page() or * dma_sync_single_for_cpu(). */ -#ifndef CONFIG_DMABOUNCE static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, @@ -308,11 +312,6 @@ dma_map_page(struct device *dev, struct page *page, return page_to_dma(dev, page) + offset; } -#else -extern dma_addr_t dma_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, - enum dma_data_direction dir); -#endif /** * dma_unmap_single - unmap a single buffer previously mapped @@ -328,16 +327,13 @@ extern dma_addr_t dma_map_page(struct device *dev, struct page *page, * After this call, reads by the CPU to the buffer are guaranteed to see * whatever the device wrote there. */ -#ifndef CONFIG_DMABOUNCE static inline void dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { /* nothing to do */ } -#else -extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction); -#endif +#endif /* CONFIG_DMABOUNCE */ /** * dma_unmap_page - unmap a buffer previously mapped through dma_map_page() |