net: mscc: ocelot: set up the bonding mask in a way that avoids a net_device

Since this code should be called from pure switchdev as well as from
DSA, we must find a way to determine the bonding mask not by looking
directly at the net_device lowers of the bonding interface, since those
could have different private structures.

We keep a pointer to the bonding upper interface, if present, in struct
ocelot_port. Then the bonding mask becomes the bitwise OR of all ports
that have the same bonding upper interface. This adds a duplication of
functionality with the current "lags" array, but the duplication will be
short-lived, since further patches will remove the latter completely.
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

@@ -889,6 +889,24 @@ int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_get_ts_info);
 
+static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond)
+{
+	u32 mask = 0;
+	int port;
+
+	for (port = 0; port < ocelot->num_phys_ports; port++) {
+		struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+		if (!ocelot_port)
+			continue;
+
+		if (ocelot_port->bond == bond)
+			mask |= BIT(port);
+	}
+
+	return mask;
+}
+
 static u32 ocelot_get_dsa_8021q_cpu_mask(struct ocelot *ocelot)
 {
 	u32 mask = 0;
@@ -1319,20 +1337,15 @@ int ocelot_port_lag_join(struct ocelot *ocelot, int port,
 			 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);
+	ocelot->ports[port]->bond = bond;
 
-		bond_mask |= BIT(priv->chip_port);
-	}
-	rcu_read_unlock();
+	bond_mask = ocelot_get_bond_mask(ocelot, bond);
 
 	lp = __ffs(bond_mask);
 
@@ -1366,6 +1379,8 @@ void ocelot_port_lag_leave(struct ocelot *ocelot, int port,
 	u32 port_cfg;
 	int i;
 
+	ocelot->ports[port]->bond = NULL;
+
 	/* Remove port from any lag */
 	for (i = 0; i < ocelot->num_phys_ports; i++)
 		ocelot->lags[i] &= ~BIT(port);

include/soc/mscc/ocelot.h

@@ -611,6 +611,8 @@ struct ocelot_port {
 
 	u8				*xmit_template;
 	bool				is_dsa_8021q_cpu;
+
+	struct net_device		*bond;
 };
 
 struct ocelot {