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Commit 42d00284 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
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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: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: default avatarJens 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4d57cdfa

arch/x86/kernel/pci-gart_64.c

+7 −0
Original line number Diff line number Diff line
@@ -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;