From da83a722959a82733c3ca60030cc364ca2318c5a Mon Sep 17 00:00:00 2001 From: Fredrik Noring Date: Wed, 29 May 2019 13:28:39 +0300 Subject: [PATCH] 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 Reviewed-by: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig --- include/linux/genalloc.h | 1 + lib/genalloc.c | 29 ++++++++++++++++++++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h index dd0a452373e7..6c62eeca754f 100644 --- a/include/linux/genalloc.h +++ b/include/linux/genalloc.h @@ -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 *); 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 -- 2.11.0