net: mscc: ocelot: don't refuse bonding interfaces we can't offload

Since switchdev/DSA exposes network interfaces that fulfill many of the
same user space expectations that dedicated NICs do, it makes sense to
not deny bonding interfaces with a bonding policy that we cannot offload,
but instead allow the bonding driver to select the egress interface in
software.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mscc/ocelot.c

@@ -1316,12 +1316,16 @@ static void ocelot_setup_lag(struct ocelot *ocelot, int lag)
 }
 
 int ocelot_port_lag_join(struct ocelot *ocelot, int port,
-			 struct net_device *bond)
+			 struct net_device *bond,
+			 struct netdev_lag_upper_info *info)
 {
 	struct net_device *ndev;
 	u32 bond_mask = 0;
 	int lag, lp;
 
+	if (info->tx_type != NETDEV_LAG_TX_TYPE_HASH)
+		return -EOPNOTSUPP;
+
 	rcu_read_lock();
 	for_each_netdev_in_bond_rcu(bond, ndev) {
 		struct ocelot_port_private *priv = netdev_priv(ndev);

drivers/net/ethernet/mscc/ocelot.h

@@ -110,7 +110,8 @@ int ocelot_mact_learn(struct ocelot *ocelot, int port,
 int ocelot_mact_forget(struct ocelot *ocelot,
 		       const unsigned char mac[ETH_ALEN], unsigned int vid);
 int ocelot_port_lag_join(struct ocelot *ocelot, int port,
-			 struct net_device *bond);
+			 struct net_device *bond,
+			 struct netdev_lag_upper_info *info);
 void ocelot_port_lag_leave(struct ocelot *ocelot, int port,
 			   struct net_device *bond);
 struct net_device *ocelot_port_to_netdev(struct ocelot *ocelot, int port);

drivers/net/ethernet/mscc/ocelot_net.c

@@ -1129,12 +1129,19 @@ static int ocelot_netdevice_changeupper(struct net_device *dev,
 		}
 	}
 	if (netif_is_lag_master(info->upper_dev)) {
-		if (info->linking)
+		if (info->linking) {
 			err = ocelot_port_lag_join(ocelot, port,
-						   info->upper_dev);
-		else
+						   info->upper_dev,
+						   info->upper_info);
+			if (err == -EOPNOTSUPP) {
+				NL_SET_ERR_MSG_MOD(info->info.extack,
+						   "Offloading not supported");
+				err = 0;
+			}
+		} else {
 			ocelot_port_lag_leave(ocelot, port,
 					      info->upper_dev);
+		}
 	}
 
 	return notifier_from_errno(err);
@@ -1163,29 +1170,6 @@ static int ocelot_netdevice_event(struct notifier_block *unused,
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
 	switch (event) {
-	case NETDEV_PRECHANGEUPPER: {
-		struct netdev_notifier_changeupper_info *info = ptr;
-		struct netdev_lag_upper_info *lag_upper_info;
-		struct netlink_ext_ack *extack;
-
-		if (!ocelot_netdevice_dev_check(dev))
-			break;
-
-		if (!netif_is_lag_master(info->upper_dev))
-			break;
-
-		lag_upper_info = info->upper_info;
-
-		if (lag_upper_info &&
-		    lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH) {
-			extack = netdev_notifier_info_to_extack(&info->info);
-			NL_SET_ERR_MSG_MOD(extack, "LAG device using unsupported Tx type");
-
-			return notifier_from_errno(-EINVAL);
-		}
-
-		break;
-	}
 	case NETDEV_CHANGEUPPER: {
 		struct netdev_notifier_changeupper_info *info = ptr;