mlxsw: core: Allow to enable/disable rx_listener for trap

For source traps, the "thin policer" is going to be used in order
to reduce the amount of trapped packets to minimum. However, there
will be still small number of packets coming in that need to be dropped
in the driver. Allow to enable/disable rx_listener related to specific
trap in order to prevent unwanted packets to go up the stack.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core.c

@@ -142,6 +142,7 @@ struct mlxsw_rx_listener_item {
 	struct list_head list;
 	struct mlxsw_rx_listener rxl;
 	void *priv;
+	bool enabled;
 };
 
 struct mlxsw_event_listener_item {
@@ -1470,7 +1471,7 @@ __find_rx_listener_item(struct mlxsw_core *mlxsw_core,
 
 int mlxsw_core_rx_listener_register(struct mlxsw_core *mlxsw_core,
 				    const struct mlxsw_rx_listener *rxl,
-				    void *priv)
+				    void *priv, bool enabled)
 {
 	struct mlxsw_rx_listener_item *rxl_item;
 
@@ -1482,6 +1483,7 @@ int mlxsw_core_rx_listener_register(struct mlxsw_core *mlxsw_core,
 		return -ENOMEM;
 	rxl_item->rxl = *rxl;
 	rxl_item->priv = priv;
+	rxl_item->enabled = enabled;
 
 	list_add_rcu(&rxl_item->list, &mlxsw_core->rx_listener_list);
 	return 0;
@@ -1502,6 +1504,19 @@ void mlxsw_core_rx_listener_unregister(struct mlxsw_core *mlxsw_core,
 }
 EXPORT_SYMBOL(mlxsw_core_rx_listener_unregister);
 
+static void
+mlxsw_core_rx_listener_state_set(struct mlxsw_core *mlxsw_core,
+				 const struct mlxsw_rx_listener *rxl,
+				 bool enabled)
+{
+	struct mlxsw_rx_listener_item *rxl_item;
+
+	rxl_item = __find_rx_listener_item(mlxsw_core, rxl);
+	if (WARN_ON(!rxl_item))
+		return;
+	rxl_item->enabled = enabled;
+}
+
 static void mlxsw_core_event_listener_func(struct sk_buff *skb, u8 local_port,
 					   void *priv)
 {
@@ -1563,7 +1578,7 @@ int mlxsw_core_event_listener_register(struct mlxsw_core *mlxsw_core,
 	el_item->el = *el;
 	el_item->priv = priv;
 
-	err = mlxsw_core_rx_listener_register(mlxsw_core, &rxl, el_item);
+	err = mlxsw_core_rx_listener_register(mlxsw_core, &rxl, el_item, true);
 	if (err)
 		goto err_rx_listener_register;
 
@@ -1601,16 +1616,18 @@ EXPORT_SYMBOL(mlxsw_core_event_listener_unregister);
 
 static int mlxsw_core_listener_register(struct mlxsw_core *mlxsw_core,
 					const struct mlxsw_listener *listener,
-					void *priv)
+					void *priv, bool enabled)
 {
-	if (listener->is_event)
+	if (listener->is_event) {
+		WARN_ON(!enabled);
 		return mlxsw_core_event_listener_register(mlxsw_core,
 						&listener->event_listener,
 						priv);
-	else
+	} else {
 		return mlxsw_core_rx_listener_register(mlxsw_core,
 						&listener->rx_listener,
-						priv);
+						priv, enabled);
+	}
 }
 
 static void mlxsw_core_listener_unregister(struct mlxsw_core *mlxsw_core,
@@ -1632,7 +1649,8 @@ int mlxsw_core_trap_register(struct mlxsw_core *mlxsw_core,
 	char hpkt_pl[MLXSW_REG_HPKT_LEN];
 	int err;
 
-	err = mlxsw_core_listener_register(mlxsw_core, listener, priv);
+	err = mlxsw_core_listener_register(mlxsw_core, listener, priv,
+					   listener->enabled_on_register);
 	if (err)
 		return err;
 
@@ -1675,11 +1693,22 @@ int mlxsw_core_trap_state_set(struct mlxsw_core *mlxsw_core,
 {
 	enum mlxsw_reg_hpkt_action action;
 	char hpkt_pl[MLXSW_REG_HPKT_LEN];
+	int err;
+
+	/* Not supported for event listener */
+	if (WARN_ON(listener->is_event))
+		return -EINVAL;
 
 	action = enabled ? listener->en_action : listener->dis_action;
 	mlxsw_reg_hpkt_pack(hpkt_pl, action, listener->trap_id,
 			    listener->trap_group, listener->is_ctrl);
-	return mlxsw_reg_write(mlxsw_core, MLXSW_REG(hpkt), hpkt_pl);
+	err = mlxsw_reg_write(mlxsw_core, MLXSW_REG(hpkt), hpkt_pl);
+	if (err)
+		return err;
+
+	mlxsw_core_rx_listener_state_set(mlxsw_core, &listener->rx_listener,
+					 enabled);
+	return 0;
 }
 EXPORT_SYMBOL(mlxsw_core_trap_state_set);
 
@@ -1939,7 +1968,8 @@ void mlxsw_core_skb_receive(struct mlxsw_core *mlxsw_core, struct sk_buff *skb,
 		if ((rxl->local_port == MLXSW_PORT_DONT_CARE ||
 		     rxl->local_port == local_port) &&
 		    rxl->trap_id == rx_info->trap_id) {
-			found = true;
+			if (rxl_item->enabled)
+				found = true;
 			break;
 		}
 	}

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -129,7 +129,7 @@ struct mlxsw_listener {
 
 int mlxsw_core_rx_listener_register(struct mlxsw_core *mlxsw_core,
 				    const struct mlxsw_rx_listener *rxl,
-				    void *priv);
+				    void *priv, bool enabled);
 void mlxsw_core_rx_listener_unregister(struct mlxsw_core *mlxsw_core,
 				       const struct mlxsw_rx_listener *rxl);