RDMA/mlx5: Allow providing extra scatter CQE QP flag

Scatter CQE feature relies on two flags MLX5_QP_FLAG_SCATTER_CQE and
MLX5_QP_FLAG_ALLOW_SCATTER_CQE, both of them can be provided without
relation to device capability.

Relax global validity check to allow MLX5_QP_FLAG_ALLOW_SCATTER_CQE QP
flag.

Existing user applications are failing on this new validity check.

Fixes: 90ecb37a ("RDMA/mlx5: Change scatter CQE flag to be set like other vendor flags")
Fixes: 37518fa4 ("RDMA/mlx5: Process all vendor flags in one place")
Link: https://lore.kernel.org/r/20200728120255.805733-1-leon@kernel.orgReviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/mlx5/qp.c

@@ -1766,15 +1766,14 @@ static int create_rss_raw_qp_tir(struct mlx5_ib_dev *dev, struct ib_pd *pd,
 }
 
 static void configure_requester_scat_cqe(struct mlx5_ib_dev *dev,
+					 struct mlx5_ib_qp *qp,
 					 struct ib_qp_init_attr *init_attr,
-					 struct mlx5_ib_create_qp *ucmd,
 					 void *qpc)
 {
 	int scqe_sz;
 	bool allow_scat_cqe = false;
 
-	if (ucmd)
-		allow_scat_cqe = ucmd->flags & MLX5_QP_FLAG_ALLOW_SCATTER_CQE;
+	allow_scat_cqe = qp->flags_en & MLX5_QP_FLAG_ALLOW_SCATTER_CQE;
 
 	if (!allow_scat_cqe && init_attr->sq_sig_type != IB_SIGNAL_ALL_WR)
 		return;
@@ -2012,7 +2011,7 @@ static int create_user_qp(struct mlx5_ib_dev *dev, struct ib_pd *pd,
 	}
 	if ((qp->flags_en & MLX5_QP_FLAG_SCATTER_CQE) &&
 	    (qp->type == MLX5_IB_QPT_DCI || qp->type == IB_QPT_RC))
-		configure_requester_scat_cqe(dev, init_attr, ucmd, qpc);
+		configure_requester_scat_cqe(dev, qp, init_attr, qpc);
 
 	if (qp->rq.wqe_cnt) {
 		MLX5_SET(qpc, qpc, log_rq_stride, qp->rq.wqe_shift - 4);
@@ -2543,13 +2542,18 @@ static void process_vendor_flag(struct mlx5_ib_dev *dev, int *flags, int flag,
 		return;
 	}
 
-	if (flag == MLX5_QP_FLAG_SCATTER_CQE) {
+	switch (flag) {
+	case MLX5_QP_FLAG_SCATTER_CQE:
+	case MLX5_QP_FLAG_ALLOW_SCATTER_CQE:
 		/*
-		 * We don't return error if this flag was provided,
+			 * We don't return error if these flags were provided,
 			 * and mlx5 doesn't have right capability.
 			 */
-		*flags &= ~MLX5_QP_FLAG_SCATTER_CQE;
+		*flags &= ~(MLX5_QP_FLAG_SCATTER_CQE |
+			    MLX5_QP_FLAG_ALLOW_SCATTER_CQE);
 		return;
+	default:
+		break;
 	}
 	mlx5_ib_dbg(dev, "Vendor create QP flag 0x%X is not supported\n", flag);
 }
@@ -2589,6 +2593,8 @@ static int process_vendor_flags(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
 	process_vendor_flag(dev, &flags, MLX5_QP_FLAG_SIGNATURE, true, qp);
 	process_vendor_flag(dev, &flags, MLX5_QP_FLAG_SCATTER_CQE,
 			    MLX5_CAP_GEN(mdev, sctr_data_cqe), qp);
+	process_vendor_flag(dev, &flags, MLX5_QP_FLAG_ALLOW_SCATTER_CQE,
+			    MLX5_CAP_GEN(mdev, sctr_data_cqe), qp);
 
 	if (qp->type == IB_QPT_RAW_PACKET) {
 		cond = MLX5_CAP_ETH(mdev, tunnel_stateless_vxlan) ||