net/mlx5e: Support MQPRIO channel mode

Add support for MQPRIO channel mode, in which a partition to TCs
is defined over the channels. We allow partitions with contiguous
queue indices, with no holes within. We do not allow modification
to the num of channels while this MQPRIO mode is active.

Signed-off-by: Tariq Toukan <[email protected]>
Reviewed-by: Maxim Mikityanskiy <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>

Author: Tariq Toukan

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

@@ -72,6 +72,7 @@ struct page_pool;
 #define MLX5E_SW2HW_MTU(params, swmtu) ((swmtu) + ((params)->hard_mtu))
 
 #define MLX5E_MAX_NUM_TC	8
+#define MLX5E_MAX_NUM_MQPRIO_CH_TC TC_QOPT_MAX_QUEUE
 
 #define MLX5_RX_HEADROOM NET_SKB_PAD
 #define MLX5_SKB_FRAG_SZ(len)	(SKB_DATA_ALIGN(len) +	\

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

@@ -467,6 +467,16 @@ int mlx5e_ethtool_set_channels(struct mlx5e_priv *priv,
 		goto out;
 	}
 
+	/* Don't allow changing the number of channels if MQPRIO mode channel offload is active,
+	 * because it defines a partition over the channels queues.
+	 */
+	if (cur_params->mqprio.mode == TC_MQPRIO_MODE_CHANNEL) {
+		err = -EINVAL;
+		netdev_err(priv->netdev, "%s: MQPRIO mode channel offload is active, cannot change the number of channels\n",
+			   __func__);
+		goto out;
+	}
+
 	new_params = *cur_params;
 	new_params.num_channels = count;
 

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

@@ -2263,7 +2263,8 @@ void mlx5e_set_netdev_mtu_boundaries(struct mlx5e_priv *priv)
 				ETH_MAX_MTU);
 }
 
-static int mlx5e_netdev_set_tcs(struct net_device *netdev, u16 nch, u8 ntc)
+static int mlx5e_netdev_set_tcs(struct net_device *netdev, u16 nch, u8 ntc,
+				struct tc_mqprio_qopt_offload *mqprio)
 {
 	int tc, err;
 
@@ -2278,11 +2279,16 @@ static int mlx5e_netdev_set_tcs(struct net_device *netdev, u16 nch, u8 ntc)
 		return err;
 	}
 
-	/* Map netdev TCs to offset 0
-	 * We have our own UP to TXQ mapping for QoS
-	 */
-	for (tc = 0; tc < ntc; tc++)
-		netdev_set_tc_queue(netdev, tc, nch, 0);
+	for (tc = 0; tc < ntc; tc++) {
+		u16 count, offset;
+
+		/* For DCB mode, map netdev TCs to offset 0
+		 * We have our own UP to TXQ mapping for QoS
+		 */
+		count = mqprio ? mqprio->qopt.count[tc] : nch;
+		offset = mqprio ? mqprio->qopt.offset[tc] : 0;
+		netdev_set_tc_queue(netdev, tc, count, offset);
+	}
 
 	return 0;
 }
@@ -2321,7 +2327,7 @@ static int mlx5e_update_netdev_queues(struct mlx5e_priv *priv)
 	ntc = mlx5e_get_dcb_num_tc(&priv->channels.params);
 	num_rxqs = nch * priv->profile->rq_groups;
 
-	err = mlx5e_netdev_set_tcs(netdev, nch, ntc);
+	err = mlx5e_netdev_set_tcs(netdev, nch, ntc, NULL);
 	if (err)
 		goto err_out;
 	err = mlx5e_update_tx_netdev_queues(priv);
@@ -2344,7 +2350,7 @@ static int mlx5e_update_netdev_queues(struct mlx5e_priv *priv)
 	WARN_ON_ONCE(netif_set_real_num_tx_queues(netdev, old_num_txqs));
 
 err_tcs:
-	mlx5e_netdev_set_tcs(netdev, old_num_txqs / old_ntc, old_ntc);
+	mlx5e_netdev_set_tcs(netdev, old_num_txqs / old_ntc, old_ntc, NULL);
 err_out:
 	return err;
 }
@@ -2879,6 +2885,81 @@ static int mlx5e_setup_tc_mqprio_dcb(struct mlx5e_priv *priv,
 	return err;
 }
 
+static int mlx5e_mqprio_channel_validate(struct mlx5e_priv *priv,
+					 struct tc_mqprio_qopt_offload *mqprio)
+{
+	struct net_device *netdev = priv->netdev;
+	int agg_count = 0;
+	int i;
+
+	if (mqprio->qopt.offset[0] != 0 || mqprio->qopt.num_tc < 1 ||
+	    mqprio->qopt.num_tc > MLX5E_MAX_NUM_MQPRIO_CH_TC)
+		return -EINVAL;
+
+	for (i = 0; i < mqprio->qopt.num_tc; i++) {
+		if (!mqprio->qopt.count[i]) {
+			netdev_err(netdev, "Zero size for queue-group (%d) is not supported\n", i);
+			return -EINVAL;
+		}
+		if (mqprio->min_rate[i]) {
+			netdev_err(netdev, "Min tx rate is not supported\n");
+			return -EINVAL;
+		}
+		if (mqprio->max_rate[i]) {
+			netdev_err(netdev, "Max tx rate is not supported\n");
+			return -EINVAL;
+		}
+
+		if (mqprio->qopt.offset[i] != agg_count) {
+			netdev_err(netdev, "Discontinuous queues config is not supported\n");
+			return -EINVAL;
+		}
+		agg_count += mqprio->qopt.count[i];
+	}
+
+	if (priv->channels.params.num_channels < agg_count) {
+		netdev_err(netdev, "Num of queues (%d) exceeds available (%d)\n",
+			   agg_count, priv->channels.params.num_channels);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int mlx5e_mqprio_channel_set_tcs_ctx(struct mlx5e_priv *priv, void *ctx)
+{
+	struct tc_mqprio_qopt_offload *mqprio = (struct tc_mqprio_qopt_offload *)ctx;
+	struct net_device *netdev = priv->netdev;
+	u8 num_tc;
+
+	if (priv->channels.params.mqprio.mode != TC_MQPRIO_MODE_CHANNEL)
+		return -EINVAL;
+
+	num_tc = priv->channels.params.mqprio.num_tc;
+	mlx5e_netdev_set_tcs(netdev, 0, num_tc, mqprio);
+
+	return 0;
+}
+
+static int mlx5e_setup_tc_mqprio_channel(struct mlx5e_priv *priv,
+					 struct tc_mqprio_qopt_offload *mqprio)
+{
+	struct mlx5e_params new_params;
+	int err;
+
+	err = mlx5e_mqprio_channel_validate(priv, mqprio);
+	if (err)
+		return err;
+
+	new_params = priv->channels.params;
+	new_params.mqprio.mode = TC_MQPRIO_MODE_CHANNEL;
+	new_params.mqprio.num_tc = mqprio->qopt.num_tc;
+	err = mlx5e_safe_switch_params(priv, &new_params,
+				       mlx5e_mqprio_channel_set_tcs_ctx, mqprio, true);
+
+	return err;
+}
+
 static int mlx5e_setup_tc_mqprio(struct mlx5e_priv *priv,
 				 struct tc_mqprio_qopt_offload *mqprio)
 {
@@ -2891,6 +2972,8 @@ static int mlx5e_setup_tc_mqprio(struct mlx5e_priv *priv,
 	switch (mqprio->mode) {
 	case TC_MQPRIO_MODE_DCB:
 		return mlx5e_setup_tc_mqprio_dcb(priv, &mqprio->qopt);
+	case TC_MQPRIO_MODE_CHANNEL:
+		return mlx5e_setup_tc_mqprio_channel(priv, mqprio);
 	default:
 		return -EOPNOTSUPP;
 	}