net: dsa: move ageing time setter

Move the DSA port code which sets a port ageing time in port.c, where it
belongs.

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>
diff --git a/net/dsa/port.c b/net/dsa/port.c
index c9f95aa..3382fdc 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -127,3 +127,43 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
 
 	return 0;
 }
+
+static unsigned int dsa_fastest_ageing_time(struct dsa_switch *ds,
+					    unsigned int ageing_time)
+{
+	int i;
+
+	for (i = 0; i < ds->num_ports; ++i) {
+		struct dsa_port *dp = &ds->ports[i];
+
+		if (dp->ageing_time && dp->ageing_time < ageing_time)
+			ageing_time = dp->ageing_time;
+	}
+
+	return ageing_time;
+}
+
+int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
+			 struct switchdev_trans *trans)
+{
+	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)
+			return -ERANGE;
+		if (ds->ageing_time_max && ageing_time > ds->ageing_time_max)
+			return -ERANGE;
+		return 0;
+	}
+
+	/* Keep the fastest ageing time in case of multiple bridges */
+	dp->ageing_time = ageing_time;
+	ageing_time = dsa_fastest_ageing_time(ds, ageing_time);
+
+	if (ds->ops->set_ageing_time)
+		return ds->ops->set_ageing_time(ds, ageing_time);
+
+	return 0;
+}