net: dsa: lantiq: Add fast age function

Fast aging per port is not supported directly by the hardware, it is
only possible to configure a global aging time.

Do the fast aging by iterating over the MAC forwarding table and remove
all dynamic entries for a given port.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/lantiq_gswip.c

@@ -213,6 +213,8 @@
 
 #define GSWIP_TABLE_ACTIVE_VLAN		0x01
 #define GSWIP_TABLE_VLAN_MAPPING	0x02
+#define GSWIP_TABLE_MAC_BRIDGE		0x0b
+#define  GSWIP_TABLE_MAC_BRIDGE_STATIC	0x01	/* Static not, aging entry */
 
 #define XRX200_GPHY_FW_ALIGN	(16 * 1024)
 
@@ -1220,6 +1222,43 @@ static int gswip_port_vlan_del(struct dsa_switch *ds, int port,
 	return 0;
 }
 
+static void gswip_port_fast_age(struct dsa_switch *ds, int port)
+{
+	struct gswip_priv *priv = ds->priv;
+	struct gswip_pce_table_entry mac_bridge = {0,};
+	int i;
+	int err;
+
+	for (i = 0; i < 2048; i++) {
+		mac_bridge.table = GSWIP_TABLE_MAC_BRIDGE;
+		mac_bridge.index = i;
+
+		err = gswip_pce_table_entry_read(priv, &mac_bridge);
+		if (err) {
+			dev_err(priv->dev, "failed to read mac brigde: %d\n",
+				err);
+			return;
+		}
+
+		if (!mac_bridge.valid)
+			continue;
+
+		if (mac_bridge.val[1] & GSWIP_TABLE_MAC_BRIDGE_STATIC)
+			continue;
+
+		if (((mac_bridge.val[0] & GENMASK(7, 4)) >> 4) != port)
+			continue;
+
+		mac_bridge.valid = false;
+		err = gswip_pce_table_entry_write(priv, &mac_bridge);
+		if (err) {
+			dev_err(priv->dev, "failed to write mac brigde: %d\n",
+				err);
+			return;
+		}
+	}
+}
+
 static void gswip_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 {
 	struct gswip_priv *priv = ds->priv;
@@ -1460,6 +1499,7 @@ static const struct dsa_switch_ops gswip_switch_ops = {
 	.port_disable		= gswip_port_disable,
 	.port_bridge_join	= gswip_port_bridge_join,
 	.port_bridge_leave	= gswip_port_bridge_leave,
+	.port_fast_age		= gswip_port_fast_age,
 	.port_vlan_filtering	= gswip_port_vlan_filtering,
 	.port_vlan_prepare	= gswip_port_vlan_prepare,
 	.port_vlan_add		= gswip_port_vlan_add,