net: dsa: change scope of ageing time setter

Change the scope of the switchdev bridge ageing time attribute setter
from the DSA slave device to the generic DSA port, so that the future
port-wide API can also be used for other port types, such as CPU and DSA
links.

Also ds->ports is now a contiguous array of dsa_port structures, thus
their addresses cannot be NULL. Remove the useless check in
dsa_fastest_ageing_time.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/slave.c

@@ -412,21 +412,19 @@ static unsigned int dsa_fastest_ageing_time(struct dsa_switch *ds,
 	for (i = 0; i < ds->num_ports; ++i) {
 		struct dsa_port *dp = &ds->ports[i];
 
-		if (dp && dp->ageing_time && dp->ageing_time < ageing_time)
+		if (dp->ageing_time && dp->ageing_time < ageing_time)
 			ageing_time = dp->ageing_time;
 	}
 
 	return ageing_time;
 }
 
-static int dsa_slave_ageing_time(struct net_device *dev,
-				 const struct switchdev_attr *attr,
-				 struct switchdev_trans *trans)
+static int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+				struct switchdev_trans *trans)
 {
-	struct dsa_slave_priv *p = netdev_priv(dev);
-	struct dsa_switch *ds = p->dp->ds;
-	unsigned long ageing_jiffies = clock_t_to_jiffies(attr->u.ageing_time);
+	unsigned long ageing_jiffies = clock_t_to_jiffies(ageing_clock);
 	unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
+	struct dsa_switch *ds = dp->ds;
 
 	if (switchdev_trans_ph_prepare(trans)) {
 		if (ds->ageing_time_min && ageing_time < ds->ageing_time_min)
@@ -437,7 +435,7 @@ static int dsa_slave_ageing_time(struct net_device *dev,
 	}
 
 	/* Keep the fastest ageing time in case of multiple bridges */
-	p->dp->ageing_time = ageing_time;
+	dp->ageing_time = ageing_time;
 	ageing_time = dsa_fastest_ageing_time(ds, ageing_time);
 
 	if (ds->ops->set_ageing_time)
@@ -463,7 +461,7 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
 					      trans);
 		break;
 	case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
-		ret = dsa_slave_ageing_time(dev, attr, trans);
+		ret = dsa_port_ageing_time(dp, attr->u.ageing_time, trans);
 		break;
 	default:
 		ret = -EOPNOTSUPP;