From 42d00284e16bf998f8f93ce5d061df81b0ff283e Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 4 Feb 2008 22:27:56 -0800 Subject: [PATCH] iommu sg merging: x86: make pci-gart iommu respect the segment size limits This patch makes pci-gart iommu respect segment size limits when merging sg lists. Signed-off-by: FUJITA Tomonori Cc: Jeff Garzik Cc: James Bottomley Acked-by: Jens Axboe Cc: Dave Airlie Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/pci-gart_64.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index 845cbecd68e9..5ee700f0844d 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -416,6 +416,8 @@ gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir) struct scatterlist *s, *ps, *start_sg, *sgmap; int need = 0, nextneed, i, out, start; unsigned long pages = 0; + unsigned int seg_size; + unsigned int max_seg_size; if (nents == 0) return 0; @@ -426,6 +428,8 @@ gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir) out = 0; start = 0; start_sg = sgmap = sg; + seg_size = 0; + max_seg_size = dma_get_max_seg_size(dev); ps = NULL; /* shut up gcc */ for_each_sg(sg, s, nents, i) { dma_addr_t addr = sg_phys(s); @@ -443,11 +447,13 @@ gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir) * offset. */ if (!iommu_merge || !nextneed || !need || s->offset || + (s->length + seg_size > max_seg_size) || (ps->offset + ps->length) % PAGE_SIZE) { if (dma_map_cont(start_sg, i - start, sgmap, pages, need) < 0) goto error; out++; + seg_size = 0; sgmap = sg_next(sgmap); pages = 0; start = i; @@ -455,6 +461,7 @@ gart_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir) } } + seg_size += s->length; need = nextneed; pages += to_pages(s->offset, s->length); ps = s; -- 2.20.1