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From: Fredrik Noring <noring@nocrew.org>
Date: Wed, 29 May 2019 13:28:39 +0300
Subject: lib/genalloc: add gen_pool_dma_zalloc() for zeroed DMA allocations
Origin: https://git.kernel.org/linus/da83a722959a82733c3ca60030cc364ca2318c5a
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>
---
include/linux/genalloc.h | 1 +
lib/genalloc.c | 29 ++++++++++++++++++++++++++++-
2 files changed, 29 insertions(+), 1 deletion(-)
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -121,6 +121,7 @@
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 *);
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -337,12 +337,14 @@
* 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 @@
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
|
