From: oulijun <oulijun@huawei.com>
Date: Wed, 3 Jan 2018 10:44:06 +0800
Subject: RDMA/hns: Filter for zero length of sge in hip08 kernel mode
Patch-mainline: v4.16-rc1
Git-commit: 52e3b42a2f587912f0558cd4989da160d8b1304a
References: bsc#1104427 FATE#326416

When the length of sge is zero, the driver need to filter it

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c |   29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -230,26 +230,37 @@ static int hns_roce_v2_post_send(struct
 				     V2_RC_SEND_WQE_BYTE_4_INLINE_S, 1);
 		} else {
 			if (wr->num_sge <= 2) {
-				for (i = 0; i < wr->num_sge; i++)
-					set_data_seg_v2(dseg + i,
-							wr->sg_list + i);
+				for (i = 0; i < wr->num_sge; i++) {
+					if (likely(wr->sg_list[i].length)) {
+						set_data_seg_v2(dseg,
+							       wr->sg_list + i);
+						dseg++;
+					}
+				}
 			} else {
 				roce_set_field(rc_sq_wqe->byte_20,
 				V2_RC_SEND_WQE_BYTE_20_MSG_START_SGE_IDX_M,
 				V2_RC_SEND_WQE_BYTE_20_MSG_START_SGE_IDX_S,
 				sge_ind & (qp->sge.sge_cnt - 1));
 
-				for (i = 0; i < 2; i++)
-					set_data_seg_v2(dseg + i,
-							wr->sg_list + i);
+				for (i = 0; i < 2; i++) {
+					if (likely(wr->sg_list[i].length)) {
+						set_data_seg_v2(dseg,
+							       wr->sg_list + i);
+						dseg++;
+					}
+				}
 
 				dseg = get_send_extend_sge(qp,
 					sge_ind & (qp->sge.sge_cnt - 1));
 
 				for (i = 0; i < wr->num_sge - 2; i++) {
-					set_data_seg_v2(dseg + i,
-							wr->sg_list + 2 + i);
-					sge_ind++;
+					if (likely(wr->sg_list[i + 2].length)) {
+						set_data_seg_v2(dseg,
+							   wr->sg_list + 2 + i);
+						dseg++;
+						sge_ind++;
+					}
 				}
 			}