[PATCH] x86_64: Fix CONFIG_IOMMU_DEBUG

If CONFIG_IOMMU_DEBUG is set force_iommu defaults to 1. In the case
where no HW IOMMU is present in the machine and we end up using nommu,
leaving force_iommu set to 1 causes dma_alloc_coherent to do the wrong
thing. Therefore, if we end up using nommu, make sure force_iommu is
0.

Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/pci-nommu.c b/arch/x86_64/kernel/pci-nommu.c
index c4c3cc36ac5b..aad7609d8e92 100644
--- a/arch/x86_64/kernel/pci-nommu.c
+++ b/arch/x86_64/kernel/pci-nommu.c
@@ -92,5 +92,7 @@ void __init no_iommu_init(void)
 {
         if (dma_ops)
                 return;
+
+        force_iommu = 0; /* no HW IOMMU */
         dma_ops = &nommu_dma_ops;
 }