From a031bbcb8d7559d61f383880f23dd0e047247410 Mon Sep 17 00:00:00 2001
From: FUJITA Tomonori <tomof@acm.org>
Date: Mon, 4 Feb 2008 22:27:58 -0800
Subject: [PATCH] iommu sg merging: IA64: make sba_iommu respect the segment
size limits
This patch makes sba 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: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/ia64/hp/common/sba_iommu.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 45bf04eb7d70..c412fe63f8ec 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -1265,7 +1265,7 @@ sba_fill_pdir(
* the sglist do both.
*/
static SBA_INLINE int
-sba_coalesce_chunks( struct ioc *ioc,
+sba_coalesce_chunks(struct ioc *ioc, struct device *dev,
struct scatterlist *startsg,
int nents)
{
@@ -1275,6 +1275,7 @@ sba_coalesce_chunks( struct ioc *ioc,
struct scatterlist *dma_sg; /* next DMA stream head */
unsigned long dma_offset, dma_len; /* start/len of DMA stream */
int n_mappings = 0;
+ unsigned int max_seg_size = dma_get_max_seg_size(dev);
while (nents > 0) {
unsigned long vaddr = (unsigned long) sba_sg_address(startsg);
@@ -1314,6 +1315,9 @@ sba_coalesce_chunks( struct ioc *ioc,
> DMA_CHUNK_SIZE)
break;
+ if (dma_len + startsg->length > max_seg_size)
+ break;
+
/*
** Then look for virtually contiguous blocks.
**
@@ -1441,7 +1445,7 @@ int sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents, int di
** w/o this association, we wouldn't have coherent DMA!
** Access to the virtual address is what forces a two pass algorithm.
*/
- coalesced = sba_coalesce_chunks(ioc, sglist, nents);
+ coalesced = sba_coalesce_chunks(ioc, dev, sglist, nents);
/*
** Program the I/O Pdir