From 79b95a454bb5c1d9b7287d1016a70885ba3f346c Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@g5.osdl.org>
Date: Thu, 27 Oct 2005 16:28:39 -0700
Subject: [PATCH] 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>
---
 include/asm-x86_64/pci.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/asm-x86_64/pci.h b/include/asm-x86_64/pci.h
index 5a82a6762c218..eeb3088a1c9e3 100644
--- 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
-- 
2.30.2