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[PATCH] x86_64: GART DMA merging fix 

Don't touch the non DMA members in the sg list in dma_map_sg in the IOMMU

Some drivers (in particular ST) ran into problems because they reused the sg
lists after passing them to pci_map_sg().  The merging procedure in the K8
GART IOMMU corrupted the state.  This patch changes it to only touch the dma*
entries during merging, but not the other fields.  Approach suggested by Dave
Miller.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2006-02-12 14:34:59 -08:00 committed by Linus Torvalds
parent a65d17c9d2
commit 0d541064e8
1 changed files with 2 additions and 4 deletions
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6
arch/x86_64/kernel/pci-gart.c
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@ -310,7 +310,7 @@ void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int di
for (i = 0; i < nents; i++) {
struct scatterlist *s = &sg[i];
if (!s->dma_length || !s->length)
if (!s->dma_length)
break;
dma_unmap_single(dev, s->dma_address, s->dma_length, dir);
}
@ -364,7 +364,6 @@ static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
BUG_ON(i > start && s->offset);
if (i == start) {
*sout = *s;
sout->dma_address = iommu_bus_base;
sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
sout->dma_length = s->length;
@ -379,7 +378,7 @@ static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
SET_LEAK(iommu_page);
addr += PAGE_SIZE;
iommu_page++;
}
}
}
BUG_ON(iommu_page - iommu_start != pages);
return 0;
@ -391,7 +390,6 @@ static inline int dma_map_cont(struct scatterlist *sg, int start, int stopat,
{
if (!need) {
BUG_ON(stopat - start != 1);
*sout = sg[start];
sout->dma_length = sg[start].length;
return 0;
}