IA64: iommu uses sg_next with an invalid sg element
sg list elements might not be continuous.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 4338f41..3c95f41 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -1179,7 +1179,6 @@
u64 *pdirp = NULL;
unsigned long dma_offset = 0;
- dma_sg--;
while (nents-- > 0) {
int cnt = startsg->dma_length;
startsg->dma_length = 0;
@@ -1201,7 +1200,8 @@
u32 pide = startsg->dma_address & ~PIDE_FLAG;
dma_offset = (unsigned long) pide & ~iovp_mask;
startsg->dma_address = 0;
- dma_sg = sg_next(dma_sg);
+ if (n_mappings)
+ dma_sg = sg_next(dma_sg);
dma_sg->dma_address = pide | ioc->ibase;
pdirp = &(ioc->pdir_base[pide >> iovp_shift]);
n_mappings++;