Revert "x86-64: Avoid unnecessary double bouncing for swiotlb"

Commit id 6142891a0c0209c91aa4a98f725de0d6e2ed4918

Andi Kleen reports that it seems to break things for some people,
and since it's purely a small optimization, revert it for now.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/asm-x86_64/pci.h b/include/asm-x86_64/pci.h
index 5a82a6762c2183411c5af255c8c32f2140a0e8c0..eeb3088a1c9e3d2fbbff1140b94fad85c69777f9 100644 (file)
--- a/include/asm-x86_64/pci.h
+++ b/include/asm-x86_64/pci.h
@@ -50,10 +50,10 @@ extern int iommu_setup(char *opt);
  * address space.  The networking and block device layers use
  * this boolean for bounce buffer decisions
  *
- * On x86-64 it mostly equals, but we set it to zero to tell some subsystems
- * that an hard or soft IOMMU is available.
+ * On AMD64 it mostly equals, but we set it to zero to tell some subsystems
+ * that an IOMMU is available.
  */
-#define PCI_DMA_BUS_IS_PHYS 0
+#define PCI_DMA_BUS_IS_PHYS    (no_iommu ? 1 : 0)
 
 /*
  * x86-64 always supports DAC, but sometimes it is useful to force