[PATCH] x86_64: Fix swiotlb dma_alloc_coherent fallback

This avoids BUG_ONs in the low level allocator when an illegal
GFP mask is added.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 2f5d832..4ed391e 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -107,6 +107,9 @@
 				goto again;
 			}
 
+			/* Let low level make its own zone decisions */
+			gfp &= ~(GFP_DMA32|GFP_DMA);
+
 			if (dma_ops->alloc_coherent)
 				return dma_ops->alloc_coherent(dev, size,
 							   dma_handle, gfp);