Commit da83a722 authored by Fredrik Noring's avatar Fredrik Noring Committed by Christoph Hellwig
Browse files

lib/genalloc: add gen_pool_dma_zalloc() for zeroed DMA allocations 



gen_pool_dma_zalloc() is a zeroed memory variant of
gen_pool_dma_alloc().  Also document the return values of both, and
indicate NULL as a "%NULL" constant.

Signed-off-by: default avatarFredrik Noring <noring@nocrew.org>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent dd3dcede

include/linux/genalloc.h

+1 −0
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ extern unsigned long gen_pool_alloc_algo(struct gen_pool *, size_t, 
		genpool_algo_t algo, void *data);

extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,

		dma_addr_t *dma);

void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma);

extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);

extern void gen_pool_for_each_chunk(struct gen_pool *,

	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);

lib/genalloc.c

+28 −1
Original line number Diff line number Diff line
@@ -337,12 +337,14 @@ EXPORT_SYMBOL(gen_pool_alloc_algo); 
 * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage

 * @pool: pool to allocate from

 * @size: number of bytes to allocate from the pool

 * @dma: dma-view physical address return value.  Use NULL if unneeded.

 * @dma: dma-view physical address return value.  Use %NULL if unneeded.

 *

 * Allocate the requested number of bytes from the specified pool.

 * Uses the pool allocation function (with first-fit algorithm by default).

 * Can not be used in NMI handler on architectures without

 * NMI-safe cmpxchg implementation.

 *

 * Return: virtual address of the allocated memory, or %NULL on failure

 */

void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)

{
@@ -362,6 +364,31 @@ void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma) 
}

EXPORT_SYMBOL(gen_pool_dma_alloc);



/**

 * gen_pool_dma_zalloc - allocate special zeroed memory from the pool for

 * DMA usage

 * @pool: pool to allocate from

 * @size: number of bytes to allocate from the pool

 * @dma: dma-view physical address return value.  Use %NULL if unneeded.

 *

 * Allocate the requested number of zeroed bytes from the specified pool.

 * Uses the pool allocation function (with first-fit algorithm by default).

 * Can not be used in NMI handler on architectures without

 * NMI-safe cmpxchg implementation.

 *

 * Return: virtual address of the allocated zeroed memory, or %NULL on failure

 */

void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma)

{

	void *vaddr = gen_pool_dma_alloc(pool, size, dma);



	if (vaddr)

		memset(vaddr, 0, size);



	return vaddr;

}

EXPORT_SYMBOL(gen_pool_dma_zalloc);



/**

 * gen_pool_free - free allocated special memory back to the pool

 * @pool: pool to free to

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