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| author | Andrew Morton <akpm@linux-foundation.org> | 2011-11-02 13:39:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-11-02 16:07:02 -0700 |
| commit | 842fa69f3e0c9a178b294e7af7c07f4c9d9e7af2 (patch) | |
| tree | 5c7b18074454b5ffa8e11175cfe7de08e6549ca7 | |
| parent | c736de60aed869df8a9aba512cdaf89e32545b00 (diff) | |
| download | lwn-842fa69f3e0c9a178b294e7af7c07f4c9d9e7af2.tar.gz lwn-842fa69f3e0c9a178b294e7af7c07f4c9d9e7af2.zip | |
include/linux/dma-mapping.h: add dma_zalloc_coherent()
Lots of driver code does a dma_alloc_coherent() and then zeroes out the
memory with a memset. Make it easy for them.
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | Documentation/DMA-API.txt | 7 | ||||
| -rw-r--r-- | include/linux/dma-mapping.h | 10 |
2 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index fe2326906610..66bd97a95f10 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -50,6 +50,13 @@ specify the GFP_ flags (see kmalloc) for the allocation (the implementation may choose to ignore flags that affect the location of the returned memory, like GFP_DMA). +void * +dma_zalloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag) + +Wraps dma_alloc_coherent() and also zeroes the returned memory if the +allocation attempt succeeded. + void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 347fdc32177a..be86ae13893f 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -1,6 +1,7 @@ #ifndef _LINUX_DMA_MAPPING_H #define _LINUX_DMA_MAPPING_H +#include <linux/string.h> #include <linux/device.h> #include <linux/err.h> #include <linux/dma-attrs.h> @@ -117,6 +118,15 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask) return -EIO; } +static inline void *dma_zalloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t flag) +{ + void *ret = dma_alloc_coherent(dev, size, dma_handle, flag); + if (ret) + memset(ret, 0, size); + return ret; +} + #ifdef CONFIG_HAS_DMA static inline int dma_get_cache_alignment(void) { |