[PATCH -mm 08/11] parisc: make iommu respect the segment size limits

FUJITA Tomonori
2007-10-24T10:50:01Z

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

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
drivers/parisc/ccio-dma.c | 2 +-
drivers/parisc/iommu-helpers.h | 7 ++++++-
drivers/parisc/sba_iommu.c | 2 +-
3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 7c60cbd..2ec7db1 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -941,7 +941,7 @@ ccio_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
** w/o this association, we wouldn't have coherent DMA!
** Access to the virtual address is what forces a two pass algorithm.
*/
- coalesced = iommu_coalesce_chunks(ioc, sglist, nents, ccio_alloc_range);
+ coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, ccio_alloc_range);

/*
** Program the I/O Pdir
diff --git a/drivers/parisc/iommu-helpers.h b/drivers/parisc/iommu-helpers.h
index 0a1f99a..97ba828 100644
--- a/drivers/parisc/iommu-helpers.h
+++ b/drivers/parisc/iommu-helpers.h
@@ -95,12 +95,14 @@ iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents,
*/

static inline unsigned int
-iommu_coalesce_chunks(struct ioc *ioc, struct scatterlist *startsg, int nents,
+iommu_coalesce_chunks(struct ioc *ioc, struct device *dev,
+ struct scatterlist *startsg, int nents,
int (*iommu_alloc_range)(struct ioc *, size_t))
{
struct scatterlist *contig_sg; /* contig chunk head */
unsigned long dma_offset, dma_len; /* start/len of DMA stream */
unsigned int n_mappings = 0;
+ unsigned int max_seg_size = dma_get_max_seg_size(dev);

while (nents > 0) {

@@ -142,6 +144,9 @@ iommu_coalesce_chunks(struct ioc *ioc, struct scatterlist *startsg, int nents,
IOVP_SIZE) > DMA_CHUNK_SIZE))
break;

+ if (startsg->length + dma_len > max_seg_size)
+ break;
+
/*
** Next see if we can append the next chunk (i.e.
** it must end on one page and begin on another
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index e527a0e..d06627c 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -946,7 +946,7 @@ sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
** w/o this association, we wouldn't have coherent DMA!
** Access to the virtual address is what forces a two pass algorithm.
*/
- coalesced = iommu_coalesce_chunks(ioc, sglist, nents, sba_alloc_range);
+ coalesced = iommu_coalesce_chunks(ioc, dev, sglist, nents, sba_alloc_range);

/*
** Program the I/O Pdir
--
1.5.2.4