net: dsa: add port_fdb_prepare

Push the prepare phase for FDB operations down to the DSA drivers, with
a new port_fdb_prepare function. Currently only mv88e6xxx is affected.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6171.c

@@ -121,6 +121,7 @@ struct dsa_switch_driver mv88e6171_switch_driver = {
 	.port_vlan_add		= mv88e6xxx_port_vlan_add,
 	.port_vlan_del		= mv88e6xxx_port_vlan_del,
 	.vlan_getnext		= mv88e6xxx_vlan_getnext,
+	.port_fdb_prepare	= mv88e6xxx_port_fdb_prepare,
 	.port_fdb_add		= mv88e6xxx_port_fdb_add,
 	.port_fdb_del		= mv88e6xxx_port_fdb_del,
 	.port_fdb_getnext	= mv88e6xxx_port_fdb_getnext,

drivers/net/dsa/mv88e6352.c

@@ -348,6 +348,7 @@ struct dsa_switch_driver mv88e6352_switch_driver = {
 	.port_vlan_add		= mv88e6xxx_port_vlan_add,
 	.port_vlan_del		= mv88e6xxx_port_vlan_del,
 	.vlan_getnext		= mv88e6xxx_vlan_getnext,
+	.port_fdb_prepare	= mv88e6xxx_port_fdb_prepare,
 	.port_fdb_add		= mv88e6xxx_port_fdb_add,
 	.port_fdb_del		= mv88e6xxx_port_fdb_del,
 	.port_fdb_getnext	= mv88e6xxx_port_fdb_getnext,

drivers/net/dsa/mv88e6xxx.c

@@ -1841,6 +1841,16 @@ static int _mv88e6xxx_port_fdb_load(struct dsa_switch *ds, int port,
 	return _mv88e6xxx_atu_load(ds, &entry);
 }
 
+int mv88e6xxx_port_fdb_prepare(struct dsa_switch *ds, int port,
+			       const struct switchdev_obj_port_fdb *fdb,
+			       struct switchdev_trans *trans)
+{
+	/* We don't need any dynamic resource from the kernel (yet),
+	 * so skip the prepare phase.
+	 */
+	return 0;
+}
+
 int mv88e6xxx_port_fdb_add(struct dsa_switch *ds, int port,
 			   const unsigned char *addr, u16 vid)
 {

drivers/net/dsa/mv88e6xxx.h

@@ -474,6 +474,9 @@ int mv88e6xxx_port_vlan_add(struct dsa_switch *ds, int port, u16 vid,
 int mv88e6xxx_port_vlan_del(struct dsa_switch *ds, int port, u16 vid);
 int mv88e6xxx_vlan_getnext(struct dsa_switch *ds, u16 *vid,
 			   unsigned long *ports, unsigned long *untagged);
+int mv88e6xxx_port_fdb_prepare(struct dsa_switch *ds, int port,
+			       const struct switchdev_obj_port_fdb *fdb,
+			       struct switchdev_trans *trans);
 int mv88e6xxx_port_fdb_add(struct dsa_switch *ds, int port,
 			   const unsigned char *addr, u16 vid);
 int mv88e6xxx_port_fdb_del(struct dsa_switch *ds, int port,

include/net/dsa.h

@@ -197,6 +197,9 @@ static inline u8 dsa_upstream_port(struct dsa_switch *ds)
 		return ds->pd->rtable[dst->cpu_switch];
 }
 
+struct switchdev_trans;
+struct switchdev_obj_port_fdb;
+
 struct dsa_switch_driver {
 	struct list_head	list;
 
@@ -316,6 +319,9 @@ struct dsa_switch_driver {
 	/*
 	 * Forwarding database
 	 */
+	int	(*port_fdb_prepare)(struct dsa_switch *ds, int port,
+				    const struct switchdev_obj_port_fdb *fdb,
+				    struct switchdev_trans *trans);
 	int	(*port_fdb_add)(struct dsa_switch *ds, int port,
 				const unsigned char *addr, u16 vid);
 	int	(*port_fdb_del)(struct dsa_switch *ds, int port,

net/dsa/slave.c

@@ -346,10 +346,13 @@ static int dsa_slave_port_fdb_add(struct net_device *dev,
 {
 	struct dsa_slave_priv *p = netdev_priv(dev);
 	struct dsa_switch *ds = p->parent;
-	int ret = -EOPNOTSUPP;
+	int ret;
+
+	if (!ds->drv->port_fdb_prepare || !ds->drv->port_fdb_add)
+		return -EOPNOTSUPP;
 
 	if (switchdev_trans_ph_prepare(trans))
-		ret = ds->drv->port_fdb_add ? 0 : -EOPNOTSUPP;
+		ret = ds->drv->port_fdb_prepare(ds, p->port, fdb, trans);
 	else
 		ret = ds->drv->port_fdb_add(ds, p->port, fdb->addr, fdb->vid);