From 0d541064e8f58858e11cd34d81b6e83617f6eb4a Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sun, 12 Feb 2006 14:34:59 -0800 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/pci-gart.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c index 2fe23a6c361b..dd0718dc178b 100644 --- a/arch/x86_64/kernel/pci-gart.c +++ b/arch/x86_64/kernel/pci-gart.c @@ -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; } -- 2.20.1