Revert "iommu/amd: Don't allocate with __GFP_ZERO in alloc_coherent"

This reverts commit 5fc872c7323534e8f7dc21bab635e7a9b9659e07.

The DMA-API does not strictly require that the memory
returned by dma_alloc_coherent is zeroed out. For that
another function (dma_zalloc_coherent) should be used. But
all other x86 DMA-API implementation I checked zero out the
memory, so that some drivers rely on it and break when it is
not.

It seems the (driver-)world is not yet ready for this
change, so revert it.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index e43d48956dea..e1c7e9e51045 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2930,6 +2930,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
         size      = PAGE_ALIGN(size);
         dma_mask  = dev->coherent_dma_mask;
         flag     &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+        flag     |= __GFP_ZERO;
 
         page = alloc_pages(flag | __GFP_NOWARN,  get_order(size));
         if (!page) {