sparc64: zero out dma_length

zero out dma_length in the entry immediately following the last mapped
entry for unmap_sg.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/iommu_common.c b/arch/sparc64/kernel/iommu_common.c
index 78e8277df655..b70324e0d83d 100644
--- a/arch/sparc64/kernel/iommu_common.c
+++ b/arch/sparc64/kernel/iommu_common.c
@@ -233,6 +233,11 @@ unsigned long prepare_sg(struct scatterlist *sg, int nents)
         dma_sg->dma_address = dent_addr;
         dma_sg->dma_length = dent_len;
 
+        if (dma_sg != sg) {
+                dma_sg = next_sg(dma_sg);
+                dma_sg->dma_length = 0;
+        }
+
         return ((unsigned long) dent_addr +
                 (unsigned long) dent_len +
                 (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT;