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Commit 842fa69f authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c736de60

Documentation/DMA-API.txt

+7 −0
Original line number Diff line number Diff line
@@ -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)

include/linux/dma-mapping.h

+10 −0
Original line number Diff line number Diff line 
#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)

{