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[PATCH] x86-64: Avoid unnecessary double bouncing for swiotlb

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PCI_DMA_BUS_IS_PHYS has to be zero even when the GART IOMMU is disabled
and the swiotlb is used. Otherwise the block layer does unnecessary
double bouncing.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2005-09-12 18:49:24 +02:00 committed by Linus Torvalds
parent 357e11d4cb
commit 6142891a0c
1 changed files with 3 additions and 3 deletions
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6
include/asm-x86_64/pci.h
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@ -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 AMD64 it mostly equals, but we set it to zero to tell some subsystems
* that an IOMMU is available.
* On x86-64 it mostly equals, but we set it to zero to tell some subsystems
* that an hard or soft IOMMU is available.
*/
#define PCI_DMA_BUS_IS_PHYS (no_iommu ? 1 : 0)
#define PCI_DMA_BUS_IS_PHYS 0
/*
* x86-64 always supports DAC, but sometimes it is useful to force