[PATCH] x86: Fix gfp flags for coherent DMA memory allocation

From: Junichi Nomura
Date: Mon Sep 14 2015 - 03:40:44 EST


Commit 6894258eda2f reversed the order of gfp_flags adjustment in
dma_alloc_attrs() for x86 [arch/x86/kernel/pci-dma.c]
As a result, relevant flags set by dma_alloc_coherent_gfp_flags()
is just discarded and causes coherent DMA memory allocation failure
on some devices.

Fixes: 6894258eda2f ("dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}")
Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx>

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 84b8ef8..1b55de1 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -131,8 +131,8 @@ void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,

bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
{
- *gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);
*gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+ *gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);

if (!*dev)
*dev = &x86_dma_fallback_dev;--
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