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author | Fredrik Noring <noring@nocrew.org> | 2019-05-29 13:28:39 +0300 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2019-06-03 16:00:07 +0200 |
commit | da83a722959a82733c3ca60030cc364ca2318c5a (patch) | |
tree | 010b99492c9ff68db6634b5f7f8cd1278b8f88d9 /lib/genalloc.c | |
parent | dd3dcede9fa0a0b661ac1f24843f4a1b1317fdb6 (diff) | |
download | linux-stable-da83a722959a82733c3ca60030cc364ca2318c5a.tar.gz linux-stable-da83a722959a82733c3ca60030cc364ca2318c5a.tar.bz2 linux-stable-da83a722959a82733c3ca60030cc364ca2318c5a.zip |
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: Fredrik Noring <noring@nocrew.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'lib/genalloc.c')
-rw-r--r-- | lib/genalloc.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/lib/genalloc.c b/lib/genalloc.c index 7e85d1e37a6e..5db43476a19b 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -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) { @@ -363,6 +365,31 @@ 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 * @addr: starting address of memory to free back to pool |