RDMA/hns: RDMA/hns: Assign rq head pointer when enable rq record db

When flush cqe, it needs to get the pointer of rq and sq from db address
space of user and update it into qp context by modified qp. if rq does not
exist, it will not get the value from db address space of user.
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_qp.c

@@ -675,6 +675,10 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
 				dev_err(dev, "rq record doorbell map failed!\n");
 				goto err_sq_dbmap;
 			}
+
+			/* indicate kernel supports rq record db */
+			resp.cap_flags |= HNS_ROCE_SUPPORT_RQ_RECORD_DB;
+			hr_qp->rdb_en = 1;
 		}
 	} else {
 		if (init_attr->create_flags &
@@ -783,16 +787,11 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
 	else
 		hr_qp->doorbell_qpn = cpu_to_le64(hr_qp->qpn);
 
-	if (udata && (udata->outlen >= sizeof(resp)) &&
-		(hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB)) {
-
-		/* indicate kernel supports rq record db */
-		resp.cap_flags |= HNS_ROCE_SUPPORT_RQ_RECORD_DB;
-		ret = ib_copy_to_udata(udata, &resp, sizeof(resp));
+	if (udata) {
+		ret = ib_copy_to_udata(udata, &resp,
+				       min(udata->outlen, sizeof(resp)));
 		if (ret)
 			goto err_qp;
-
-		hr_qp->rdb_en = 1;
 	}
 	hr_qp->event = hns_roce_ib_qp_event;
 
@@ -969,7 +968,9 @@ int hns_roce_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	    (attr_mask & IB_QP_STATE) && new_state == IB_QPS_ERR) {
 		if (hr_qp->sdb_en == 1) {
 			hr_qp->sq.head = *(int *)(hr_qp->sdb.virt_addr);
-			hr_qp->rq.head = *(int *)(hr_qp->rdb.virt_addr);
+
+			if (hr_qp->rdb_en == 1)
+				hr_qp->rq.head = *(int *)(hr_qp->rdb.virt_addr);
 		} else {
 			dev_warn(dev, "flush cqe is not supported in userspace!\n");
 			goto out;