net/mlx5e: XDP, Add user control for XDP TX MPWQE feature

Add ethtool private flag 'xdp_tx_mpwqe' to control the feature
from userspace.
Feature is set ON by default, if supported.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -216,6 +216,7 @@ enum mlx5e_priv_flag {
 	MLX5E_PFLAG_RX_CQE_COMPRESS,
 	MLX5E_PFLAG_RX_STRIDING_RQ,
 	MLX5E_PFLAG_RX_NO_CSUM_COMPLETE,
+	MLX5E_PFLAG_XDP_TX_MPWQE,
 	MLX5E_NUM_PFLAGS, /* Keep last */
 };
 

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c

@@ -1672,12 +1672,40 @@ static int set_pflag_rx_no_csum_complete(struct net_device *netdev, bool enable)
 	return 0;
 }
 
+static int set_pflag_xdp_tx_mpwqe(struct net_device *netdev, bool enable)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	struct mlx5e_channels new_channels = {};
+	int err;
+
+	if (enable && !MLX5_CAP_ETH(mdev, enhanced_multi_pkt_send_wqe))
+		return -EOPNOTSUPP;
+
+	new_channels.params = priv->channels.params;
+
+	MLX5E_SET_PFLAG(&new_channels.params, MLX5E_PFLAG_XDP_TX_MPWQE, enable);
+
+	if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
+		priv->channels.params = new_channels.params;
+		return 0;
+	}
+
+	err = mlx5e_open_channels(priv, &new_channels);
+	if (err)
+		return err;
+
+	mlx5e_switch_priv_channels(priv, &new_channels, NULL);
+	return 0;
+}
+
 static const struct pflag_desc mlx5e_priv_flags[MLX5E_NUM_PFLAGS] = {
 	{ "rx_cqe_moder",        set_pflag_rx_cqe_based_moder },
 	{ "tx_cqe_moder",        set_pflag_tx_cqe_based_moder },
 	{ "rx_cqe_compress",     set_pflag_rx_cqe_compress },
 	{ "rx_striding_rq",      set_pflag_rx_striding_rq },
 	{ "rx_no_csum_complete", set_pflag_rx_no_csum_complete },
+	{ "xdp_tx_mpwqe",        set_pflag_xdp_tx_mpwqe },
 };
 
 static int mlx5e_handle_pflag(struct net_device *netdev,

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -2341,7 +2341,7 @@ static void mlx5e_build_xdpsq_param(struct mlx5e_priv *priv,
 
 	mlx5e_build_sq_param_common(priv, param);
 	MLX5_SET(wq, wq, log_wq_sz, params->log_sq_size);
-	param->is_mpw = MLX5_CAP_ETH(priv->mdev, enhanced_multi_pkt_send_wqe);
+	param->is_mpw = MLX5E_GET_PFLAG(params, MLX5E_PFLAG_XDP_TX_MPWQE);
 }
 
 static void mlx5e_build_channel_param(struct mlx5e_priv *priv,
@@ -4595,6 +4595,10 @@ void mlx5e_build_nic_params(struct mlx5_core_dev *mdev,
 		MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE :
 		MLX5E_PARAMS_DEFAULT_LOG_SQ_SIZE;
 
+	/* XDP SQ */
+	MLX5E_SET_PFLAG(params, MLX5E_PFLAG_XDP_TX_MPWQE,
+			MLX5_CAP_ETH(mdev, enhanced_multi_pkt_send_wqe));
+
 	/* set CQE compression */
 	params->rx_cqe_compress_def = false;
 	if (MLX5_CAP_GEN(mdev, cqe_compression) &&