[PATCH] x86_64: Use the DMA32 zone for dma_alloc_coherent()/pci_alloc_consistent
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 88be97c..2e28e85 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -220,6 +220,12 @@
uses the normal dma_mask for alloc_coherent. */
dma_mask &= *dev->dma_mask;
+ /* Why <=? Even when the mask is smaller than 4GB it is often larger
+ than 16MB and in this case we have a chance of finding fitting memory
+ in the next higher zone first. If not retry with true GFP_DMA. -AK */
+ if (dma_mask <= 0xffffffff)
+ gfp |= GFP_DMA32;
+
again:
memory = dma_alloc_pages(dev, gfp, get_order(size));
if (memory == NULL)
@@ -245,7 +251,7 @@
}
if (!(gfp & GFP_DMA)) {
- gfp |= GFP_DMA;
+ gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
goto again;
}
return NULL;