IB/mlx5: Expose multi-packet RQ capabilities

This patch reports the device's striding RQ capabilities to
the user-space:
- min/max_single_stride_log_num_of_bytes: Log of min/max number of
  bytes in a single stride.
- min/max_single_wqe_log_num_of_strides: Log of min/max number of
  strides in a single WQE.
- supported_qpts: A bit mask to know which QP types support multi-
  packet RQ, for now only Raw Packet QPs.
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/main.c

@@ -848,6 +848,22 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 		}
 	}
 
+	if (field_avail(typeof(resp), striding_rq_caps, uhw->outlen)) {
+		resp.response_length += sizeof(resp.striding_rq_caps);
+		if (MLX5_CAP_GEN(mdev, striding_rq)) {
+			resp.striding_rq_caps.min_single_stride_log_num_of_bytes =
+				MLX5_MIN_SINGLE_STRIDE_LOG_NUM_BYTES;
+			resp.striding_rq_caps.max_single_stride_log_num_of_bytes =
+				MLX5_MAX_SINGLE_STRIDE_LOG_NUM_BYTES;
+			resp.striding_rq_caps.min_single_wqe_log_num_of_strides =
+				MLX5_MIN_SINGLE_WQE_LOG_NUM_STRIDES;
+			resp.striding_rq_caps.max_single_wqe_log_num_of_strides =
+				MLX5_MAX_SINGLE_WQE_LOG_NUM_STRIDES;
+			resp.striding_rq_caps.supported_qpts =
+				BIT(IB_QPT_RAW_PACKET);
+		}
+	}
+
 	if (uhw->outlen) {
 		err = ib_copy_to_udata(uhw, &resp, resp.response_length);
 

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -256,6 +256,11 @@ enum mlx5_ib_wq_flags {
 	MLX5_IB_WQ_FLAGS_DELAY_DROP = 0x1,
 };
 
+#define MLX5_MIN_SINGLE_WQE_LOG_NUM_STRIDES 9
+#define MLX5_MAX_SINGLE_WQE_LOG_NUM_STRIDES 16
+#define MLX5_MIN_SINGLE_STRIDE_LOG_NUM_BYTES 6
+#define MLX5_MAX_SINGLE_STRIDE_LOG_NUM_BYTES 13
+
 struct mlx5_ib_rwq {
 	struct ib_wq		ibwq;
 	struct mlx5_core_qp	core_qp;

include/uapi/rdma/mlx5-abi.h

@@ -190,6 +190,19 @@ struct mlx5_ib_sw_parsing_caps {
 	__u32 supported_qpts;
 };
 
+struct mlx5_ib_striding_rq_caps {
+	__u32 min_single_stride_log_num_of_bytes;
+	__u32 max_single_stride_log_num_of_bytes;
+	__u32 min_single_wqe_log_num_of_strides;
+	__u32 max_single_wqe_log_num_of_strides;
+
+	/* Corresponding bit will be set if qp type from
+	 * 'enum ib_qp_type' is supported, e.g.
+	 * supported_qpts |= 1 << IB_QPT_RAW_PACKET
+	 */
+	__u32 supported_qpts;
+};
+
 struct mlx5_ib_query_device_resp {
 	__u32	comp_mask;
 	__u32	response_length;
@@ -200,6 +213,7 @@ struct mlx5_ib_query_device_resp {
 	__u32	mlx5_ib_support_multi_pkt_send_wqes;
 	__u32	reserved;
 	struct mlx5_ib_sw_parsing_caps sw_parsing_caps;
+	struct mlx5_ib_striding_rq_caps striding_rq_caps;
 };
 
 struct mlx5_ib_create_cq {