arm64: Honor __GFP_ZERO in dma allocations

commit 7132813c384515c9dede1ae20e56f3895feb7f1e upstream.

Current implementation doesn't zero out the pages allocated.
Honor the __GFP_ZERO flag and zero out if set.

Cc: <stable@vger.kernel.org> # v3.14+
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index fbd76785c5db640bf511a9647380ebb1ae29b3ef..3974881388bbbe24be2f4c4822ac5adbd30c634a 100644 (file)
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -44,6 +44,7 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
                flags |= GFP_DMA32;
        if (IS_ENABLED(CONFIG_DMA_CMA)) {
                struct page *page;
+               void *addr;
 
                size = PAGE_ALIGN(size);
                page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
@@ -52,7 +53,10 @@ static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
                        return NULL;
 
                *dma_handle = phys_to_dma(dev, page_to_phys(page));
-               return page_address(page);
+               addr = page_address(page);
+               if (flags & __GFP_ZERO)
+                       memset(addr, 0, size);
+               return addr;
        } else {
                return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
        }