All memory allocation functions have a pendant for allocating zeroed
memory, but dmam_alloc_coherent does not have such a pendant.
However, it is easier to read dmam_zalloc_coherent than passing an extra
flag or, even worse, see memset() after the allocation.
This patch adds an inline function dmam_zalloc_coherent(), exactly like
the implementation of dma_zalloc_coherent().

Signed-off-by: Michael Moese <>
 include/linux/dma-mapping.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 03c0196a6f24..cf6cbda76ee2 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -761,6 +761,15 @@ extern void dmam_free_coherent(struct device *dev, size_t 
size, void *vaddr,
 extern void *dmam_alloc_attrs(struct device *dev, size_t size,
                              dma_addr_t *dma_handle, gfp_t gfp,
                              unsigned long attrs);
+static inline void *dma_zalloc_coherent(struct device *dev, size_t size,
+                                       dma_addr_t *dma_handle, gfp_t flag)
+       void *ret = dmam_alloc_coherent(dev, size, dma_handle,
+                                       flag | __GFP_ZERO);
+       return ret;
 extern int dmam_declare_coherent_memory(struct device *dev,
                                        phys_addr_t phys_addr,

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