[PATCH -mm 03/11] x86: make pci-gart iommu respect the segment size limits

FUJITA Tomonori
2007-10-24T10:57:32Z

This patch makes pci-gart iommu respect segment size limits when
merging sg lists.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
arch/x86/kernel/pci-gart_64.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index c56e9ee..dfe3828 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -384,6 +384,8 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
int start;
unsigned long pages = 0;
int need = 0, nextneed;
+ unsigned int seg_size;
+ unsigned int max_seg_size;
struct scatterlist *s, *ps, *start_sg, *sgmap;

if (nents == 0)
@@ -395,6 +397,8 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
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);
@@ -408,11 +412,13 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
/* Can only merge when the last chunk ends on a page
boundary and the new one doesn't have an 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;
@@ -420,6 +426,7 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
}
}

+ seg_size += s->length;
need = nextneed;
pages += to_pages(s->offset, s->length);
ps = s;
--
1.5.2.4