net: dsa: felix: add port fast age support

Add support for flushing the MAC table on a given port in the ocelot
switch library, and use this functionality in the felix DSA driver.

This operation is needed when a port leaves a bridge to become
standalone, and when the learning is disabled, and when the STP state
changes to a state where no FDB entry should be present.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220107144229.244584-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/ocelot/felix.c

@@ -639,6 +639,17 @@ static int felix_set_ageing_time(struct dsa_switch *ds,
 	return 0;
 }
 
+static void felix_port_fast_age(struct dsa_switch *ds, int port)
+{
+	struct ocelot *ocelot = ds->priv;
+	int err;
+
+	err = ocelot_mact_flush(ocelot, port);
+	if (err)
+		dev_err(ds->dev, "Flushing MAC table on port %d returned %pe\n",
+			port, ERR_PTR(err));
+}
+
 static int felix_fdb_dump(struct dsa_switch *ds, int port,
 			  dsa_fdb_dump_cb_t *cb, void *data)
 {
@@ -1622,6 +1633,7 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.phylink_mac_config		= felix_phylink_mac_config,
 	.phylink_mac_link_down		= felix_phylink_mac_link_down,
 	.phylink_mac_link_up		= felix_phylink_mac_link_up,
+	.port_fast_age			= felix_port_fast_age,
 	.port_fdb_dump			= felix_fdb_dump,
 	.port_fdb_add			= felix_fdb_add,
 	.port_fdb_del			= felix_fdb_del,

drivers/net/ethernet/mscc/ocelot.c

@@ -1341,6 +1341,43 @@ static int ocelot_mact_read(struct ocelot *ocelot, int port, int row, int col,
 	return 0;
 }
 
+int ocelot_mact_flush(struct ocelot *ocelot, int port)
+{
+	int err;
+
+	mutex_lock(&ocelot->mact_lock);
+
+	/* Program ageing filter for a single port */
+	ocelot_write(ocelot, ANA_ANAGEFIL_PID_EN | ANA_ANAGEFIL_PID_VAL(port),
+		     ANA_ANAGEFIL);
+
+	/* Flushing dynamic FDB entries requires two successive age scans */
+	ocelot_write(ocelot,
+		     ANA_TABLES_MACACCESS_MAC_TABLE_CMD(MACACCESS_CMD_AGE),
+		     ANA_TABLES_MACACCESS);
+
+	err = ocelot_mact_wait_for_completion(ocelot);
+	if (err) {
+		mutex_unlock(&ocelot->mact_lock);
+		return err;
+	}
+
+	/* And second... */
+	ocelot_write(ocelot,
+		     ANA_TABLES_MACACCESS_MAC_TABLE_CMD(MACACCESS_CMD_AGE),
+		     ANA_TABLES_MACACCESS);
+
+	err = ocelot_mact_wait_for_completion(ocelot);
+
+	/* Restore ageing filter */
+	ocelot_write(ocelot, 0, ANA_ANAGEFIL);
+
+	mutex_unlock(&ocelot->mact_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(ocelot_mact_flush);
+
 int ocelot_fdb_dump(struct ocelot *ocelot, int port,
 		    dsa_fdb_dump_cb_t *cb, void *data)
 {

include/soc/mscc/ocelot.h

@@ -833,6 +833,7 @@ void ocelot_port_bridge_join(struct ocelot *ocelot, int port,
 			     struct net_device *bridge);
 void ocelot_port_bridge_leave(struct ocelot *ocelot, int port,
 			      struct net_device *bridge);
+int ocelot_mact_flush(struct ocelot *ocelot, int port);
 int ocelot_fdb_dump(struct ocelot *ocelot, int port,
 		    dsa_fdb_dump_cb_t *cb, void *data);
 int ocelot_fdb_add(struct ocelot *ocelot, int port,