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 <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 845cbec..5ee700f 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -416,6 +416,8 @@
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 @@
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 @@
* 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 @@
}
}
+ seg_size += s->length;
need = nextneed;
pages += to_pages(s->offset, s->length);
ps = s;