net/mlx5e: Enabling aRFS mechanism

Accelerated RFS requires that ntuple filtering is enabled via
ethtool and driver supports ndo_rx_flow_steer.
When the ntuple filtering is enabled, we modify the l3_l4 ttc
rules to point on the aRFS flow tables and when the filtering
is disabled, we modify the l3_l4 ttc rules to point on the RSS
TIRs.

Signed-off-by: Maor Gottlieb <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Maor Gottlieb

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

@@ -690,9 +690,21 @@ static inline int mlx5e_arfs_create_tables(struct mlx5e_priv *priv)
 }
 
 static inline void mlx5e_arfs_destroy_tables(struct mlx5e_priv *priv) {}
+
+static inline int mlx5e_arfs_enable(struct mlx5e_priv *priv)
+{
+	return -ENOTSUPP;
+}
+
+static inline int mlx5e_arfs_disable(struct mlx5e_priv *priv)
+{
+	return -ENOTSUPP;
+}
 #else
 int mlx5e_arfs_create_tables(struct mlx5e_priv *priv);
 void mlx5e_arfs_destroy_tables(struct mlx5e_priv *priv);
+int mlx5e_arfs_enable(struct mlx5e_priv *priv);
+int mlx5e_arfs_disable(struct mlx5e_priv *priv);
 int mlx5e_rx_flow_steer(struct net_device *dev, const struct sk_buff *skb,
 			u16 rxq_index, u32 flow_id);
 #endif

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

@@ -72,14 +72,87 @@ struct arfs_rule {
 	for (j = 0; j < ARFS_HASH_SIZE; j++) \
 		hlist_for_each_entry_safe(hn, tmp, &hash[j], hlist)
 
+static enum mlx5e_traffic_types arfs_get_tt(enum arfs_type type)
+{
+	switch (type) {
+	case ARFS_IPV4_TCP:
+		return MLX5E_TT_IPV4_TCP;
+	case ARFS_IPV4_UDP:
+		return MLX5E_TT_IPV4_UDP;
+	case ARFS_IPV6_TCP:
+		return MLX5E_TT_IPV6_TCP;
+	case ARFS_IPV6_UDP:
+		return MLX5E_TT_IPV6_UDP;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int arfs_disable(struct mlx5e_priv *priv)
+{
+	struct mlx5_flow_destination dest;
+	u32 *tirn = priv->indir_tirn;
+	int err = 0;
+	int tt;
+	int i;
+
+	dest.type = MLX5_FLOW_DESTINATION_TYPE_TIR;
+	for (i = 0; i < ARFS_NUM_TYPES; i++) {
+		dest.tir_num = tirn[i];
+		tt = arfs_get_tt(i);
+		/* Modify ttc rules destination to bypass the aRFS tables*/
+		err = mlx5_modify_rule_destination(priv->fs.ttc.rules[tt],
+						   &dest);
+		if (err) {
+			netdev_err(priv->netdev,
+				   "%s: modify ttc destination failed\n",
+				   __func__);
+			return err;
+		}
+	}
+	return 0;
+}
+
+static void arfs_del_rules(struct mlx5e_priv *priv);
+
+int mlx5e_arfs_disable(struct mlx5e_priv *priv)
+{
+	arfs_del_rules(priv);
+
+	return arfs_disable(priv);
+}
+
+int mlx5e_arfs_enable(struct mlx5e_priv *priv)
+{
+	struct mlx5_flow_destination dest;
+	int err = 0;
+	int tt;
+	int i;
+
+	dest.type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
+	for (i = 0; i < ARFS_NUM_TYPES; i++) {
+		dest.ft = priv->fs.arfs.arfs_tables[i].ft.t;
+		tt = arfs_get_tt(i);
+		/* Modify ttc rules destination to point on the aRFS FTs */
+		err = mlx5_modify_rule_destination(priv->fs.ttc.rules[tt],
+						   &dest);
+		if (err) {
+			netdev_err(priv->netdev,
+				   "%s: modify ttc destination failed err=%d\n",
+				   __func__, err);
+			arfs_disable(priv);
+			return err;
+		}
+	}
+	return 0;
+}
+
 static void arfs_destroy_table(struct arfs_table *arfs_t)
 {
 	mlx5_del_flow_rule(arfs_t->default_rule);
 	mlx5e_destroy_flow_table(&arfs_t->ft);
 }
 
-static void arfs_del_rules(struct mlx5e_priv *priv);
-
 void mlx5e_arfs_destroy_tables(struct mlx5e_priv *priv)
 {
 	int i;

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

@@ -456,6 +456,7 @@ static int mlx5e_set_channels(struct net_device *dev,
 	struct mlx5e_priv *priv = netdev_priv(dev);
 	int ncv = mlx5e_get_max_num_channels(priv->mdev);
 	unsigned int count = ch->combined_count;
+	bool arfs_enabled;
 	bool was_opened;
 	int err = 0;
 
@@ -484,13 +485,27 @@ static int mlx5e_set_channels(struct net_device *dev,
 	if (was_opened)
 		mlx5e_close_locked(dev);
 
+	arfs_enabled = dev->features & NETIF_F_NTUPLE;
+	if (arfs_enabled)
+		mlx5e_arfs_disable(priv);
+
 	priv->params.num_channels = count;
 	mlx5e_build_default_indir_rqt(priv->mdev, priv->params.indirection_rqt,
 				      MLX5E_INDIR_RQT_SIZE, count);
 
 	if (was_opened)
 		err = mlx5e_open_locked(dev);
+	if (err)
+		goto out;
 
+	if (arfs_enabled) {
+		err = mlx5e_arfs_enable(priv);
+		if (err)
+			netdev_err(dev, "%s: mlx5e_arfs_enable failed: %d\n",
+				   __func__, err);
+	}
+
+out:
 	mutex_unlock(&priv->state_lock);
 
 	return err;

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

@@ -2308,6 +2308,21 @@ static int set_feature_rx_vlan(struct net_device *netdev, bool enable)
 	return err;
 }
 
+#ifdef CONFIG_RFS_ACCEL
+static int set_feature_arfs(struct net_device *netdev, bool enable)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	int err;
+
+	if (enable)
+		err = mlx5e_arfs_enable(priv);
+	else
+		err = mlx5e_arfs_disable(priv);
+
+	return err;
+}
+#endif
+
 static int mlx5e_handle_feature(struct net_device *netdev,
 				netdev_features_t wanted_features,
 				netdev_features_t feature,
@@ -2347,6 +2362,10 @@ static int mlx5e_set_features(struct net_device *netdev,
 				    set_feature_rx_all);
 	err |= mlx5e_handle_feature(netdev, features, NETIF_F_HW_VLAN_CTAG_RX,
 				    set_feature_rx_vlan);
+#ifdef CONFIG_RFS_ACCEL
+	err |= mlx5e_handle_feature(netdev, features, NETIF_F_NTUPLE,
+				    set_feature_arfs);
+#endif
 
 	return err ? -EINVAL : 0;
 }
@@ -2562,6 +2581,9 @@ static const struct net_device_ops mlx5e_netdev_ops_basic = {
 	.ndo_set_features        = mlx5e_set_features,
 	.ndo_change_mtu          = mlx5e_change_mtu,
 	.ndo_do_ioctl            = mlx5e_ioctl,
+#ifdef CONFIG_RFS_ACCEL
+	.ndo_rx_flow_steer	 = mlx5e_rx_flow_steer,
+#endif
 };
 
 static const struct net_device_ops mlx5e_netdev_ops_sriov = {
@@ -2581,6 +2603,9 @@ static const struct net_device_ops mlx5e_netdev_ops_sriov = {
 	.ndo_add_vxlan_port      = mlx5e_add_vxlan_port,
 	.ndo_del_vxlan_port      = mlx5e_del_vxlan_port,
 	.ndo_features_check      = mlx5e_features_check,
+#ifdef CONFIG_RFS_ACCEL
+	.ndo_rx_flow_steer	 = mlx5e_rx_flow_steer,
+#endif
 	.ndo_set_vf_mac          = mlx5e_set_vf_mac,
 	.ndo_set_vf_vlan         = mlx5e_set_vf_vlan,
 	.ndo_get_vf_config       = mlx5e_get_vf_config,