diff options
Diffstat (limited to 'Documentation/DMA-API.txt')
| -rw-r--r-- | Documentation/DMA-API.txt | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 45b29326d719..ef3a04fcad65 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -515,14 +515,15 @@ API at all. :: void * - dma_alloc_noncoherent(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t flag) + dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t flag, unsigned long attrs) -Identical to dma_alloc_coherent() except that the platform will -choose to return either consistent or non-consistent memory as it sees -fit. By using this API, you are guaranteeing to the platform that you -have all the correct and necessary sync points for this memory in the -driver should it choose to return non-consistent memory. +Identical to dma_alloc_coherent() except that when the +DMA_ATTR_NON_CONSISTENT flags is passed in the attrs argument, the +platform will choose to return either consistent or non-consistent memory +as it sees fit. By using this API, you are guaranteeing to the platform +that you have all the correct and necessary sync points for this memory +in the driver should it choose to return non-consistent memory. Note: where the platform can return consistent memory, it will guarantee that the sync points become nops. @@ -535,12 +536,13 @@ that simply cannot make consistent memory. :: void - dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t dma_handle) + dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_handle, unsigned long attrs) -Free memory allocated by the nonconsistent API. All parameters must -be identical to those passed in (and returned by -dma_alloc_noncoherent()). +Free memory allocated by the dma_alloc_attrs(). All parameters common +parameters must identical to those otherwise passed to dma_fre_coherent, +and the attrs argument must be identical to the attrs passed to +dma_alloc_attrs(). :: @@ -564,8 +566,8 @@ memory or doing partial flushes. dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction direction) -Do a partial sync of memory that was allocated by -dma_alloc_noncoherent(), starting at virtual address vaddr and +Do a partial sync of memory that was allocated by dma_alloc_attrs() with +the DMA_ATTR_NON_CONSISTENT flag starting at virtual address vaddr and continuing on for size. Again, you *must* observe the cache line boundaries when doing this. |