From: Brian King <[EMAIL PROTECTED]>
(Looks quite bad, should probably get in right away)
The patch below fixes a bug in the PPC64 iommu vmerge code
which results in the potential for iommu_unmap_sg to go off
unmapping more than it should. This was found on a test system
which resulted in PCI bus errors due to PCI memory being
unmapped while DMAs were still in progress.
Signed-off-by: Brian King <[EMAIL PROTECTED]>
Signed-off-by: Benjamin Herrenschmidt <[EMAIL PROTECTED]>
---
linux-2.6-bjking1/arch/ppc64/kernel/iommu.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff -puN arch/ppc64/kernel/iommu.c~ppc64_iommu_vmerge_fix
arch/ppc64/kernel/iommu.c
--- linux-2.6/arch/ppc64/kernel/iommu.c~ppc64_iommu_vmerge_fix 2005-08-17
15:34:50.000000000 -0500
+++ linux-2.6-bjking1/arch/ppc64/kernel/iommu.c 2005-08-17 15:35:19.000000000
-0500
@@ -242,7 +242,7 @@ int iommu_map_sg(struct device *dev, str
dma_addr_t dma_next = 0, dma_addr;
unsigned long flags;
struct scatterlist *s, *outs, *segstart;
- int outcount;
+ int outcount, incount;
unsigned long handle;
BUG_ON(direction == DMA_NONE);
@@ -252,6 +252,7 @@ int iommu_map_sg(struct device *dev, str
outs = s = segstart = &sglist[0];
outcount = 1;
+ incount = nelems;
handle = 0;
/* Init first segment length for backout at failure */
@@ -338,10 +339,10 @@ int iommu_map_sg(struct device *dev, str
DBG("mapped %d elements:\n", outcount);
- /* For the sake of iommu_free_sg, we clear out the length in the
+ /* For the sake of iommu_unmap_sg, we clear out the length in the
* next entry of the sglist if we didn't fill the list completely
*/
- if (outcount < nelems) {
+ if (outcount < incount) {
outs++;
outs->dma_address = DMA_ERROR_CODE;
outs->dma_length = 0;
_
-
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