From 842fa69f3e0c9a178b294e7af7c07f4c9d9e7af2 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 2 Nov 2011 13:39:33 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/DMA-API.txt | 7 +++++++ include/linux/dma-mapping.h | 10 ++++++++++ 2 files changed, 17 insertions(+) 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 #include #include #include @@ -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) { -- 2.39.2