RDMA/mlx5: Define RoCEv2 udp source port when set path

Calculate and set UDP source port based on the flow label. If flow label
is not defined in GRH then calculate it based on lqpn/rqpn.

Link: https://lore.kernel.org/r/20200504051935.269708-4-leon@kernel.org
Signed-off-by: Mark Zhang <markz@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/qp.c

@@ -3133,6 +3133,21 @@ static int modify_raw_packet_tx_affinity(struct mlx5_core_dev *dev,
 	return err;
 }
 
+static void mlx5_set_path_udp_sport(struct mlx5_qp_path *path,
+				    const struct rdma_ah_attr *ah,
+				    u32 lqpn, u32 rqpn)
+
+{
+	u32 fl = ah->grh.flow_label;
+	u16 sport;
+
+	if (!fl)
+		fl = rdma_calc_flow_label(lqpn, rqpn);
+
+	sport = rdma_flow_label_to_udp_sport(fl);
+	path->udp_sport = cpu_to_be16(sport);
+}
+
 static int mlx5_set_path(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
 			 const struct rdma_ah_attr *ah,
 			 struct mlx5_qp_path *path, u8 port, int attr_mask,
@@ -3164,12 +3179,15 @@ static int mlx5_set_path(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
 			return -EINVAL;
 
 		memcpy(path->rmac, ah->roce.dmac, sizeof(ah->roce.dmac));
-		if (qp->ibqp.qp_type == IB_QPT_RC ||
-		    qp->ibqp.qp_type == IB_QPT_UC ||
-		    qp->ibqp.qp_type == IB_QPT_XRC_INI ||
-		    qp->ibqp.qp_type == IB_QPT_XRC_TGT)
-			path->udp_sport =
-				mlx5_get_roce_udp_sport(dev, ah->grh.sgid_attr);
+		if ((qp->ibqp.qp_type == IB_QPT_RC ||
+		     qp->ibqp.qp_type == IB_QPT_UC ||
+		     qp->ibqp.qp_type == IB_QPT_XRC_INI ||
+		     qp->ibqp.qp_type == IB_QPT_XRC_TGT) &&
+		    (grh->sgid_attr->gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP) &&
+		    (attr_mask & IB_QP_DEST_QPN))
+			mlx5_set_path_udp_sport(path, ah,
+						qp->ibqp.qp_num,
+						attr->dest_qp_num);
 		path->dci_cfi_prio_sl = (sl & 0x7) << 4;
 		gid_type = ah->grh.sgid_attr->gid_type;
 		if (gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP)