iommu sg merging: ppc: make iommu respect the segment size limits
This patch makes 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: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index a3c406a..d0e6fac 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -270,16 +270,18 @@
spin_unlock_irqrestore(&(tbl->it_lock), flags);
}
-int iommu_map_sg(struct iommu_table *tbl, struct scatterlist *sglist,
+int iommu_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, unsigned long mask,
enum dma_data_direction direction)
{
+ struct iommu_table *tbl = dev->archdata.dma_data;
dma_addr_t dma_next = 0, dma_addr;
unsigned long flags;
struct scatterlist *s, *outs, *segstart;
int outcount, incount, i;
unsigned int align;
unsigned long handle;
+ unsigned int max_seg_size;
BUG_ON(direction == DMA_NONE);
@@ -298,6 +300,7 @@
spin_lock_irqsave(&(tbl->it_lock), flags);
+ max_seg_size = dma_get_max_seg_size(dev);
for_each_sg(sglist, s, nelems, i) {
unsigned long vaddr, npages, entry, slen;
@@ -344,7 +347,8 @@
/* We cannot merge if:
* - allocated dma_addr isn't contiguous to previous allocation
*/
- if (novmerge || (dma_addr != dma_next)) {
+ if (novmerge || (dma_addr != dma_next) ||
+ (outs->dma_length + s->length > max_seg_size)) {
/* Can't merge: create a new segment */
segstart = s;
outcount++;