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>
This commit is contained in:
Andrew Morton 2011-11-02 13:39:33 -07:00 committed by Linus Torvalds
parent c736de60ae
commit 842fa69f3e
2 changed files with 17 additions and 0 deletions

View File

@ -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)

View File

@ -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)
{