net: dsa: deduplicate code adding / deleting the port address to fdb

The sequence
if (dsa_switch_supports_uc_filtering(ds))
dsa_port_standalone_host_fdb_add(dp, addr, 0);
if (!ether_addr_equal(addr, conduit->dev_addr))
dev_uc_add(conduit, addr);
is executed both in dsa_user_open() and dsa_user_set_mac_addr().

Its reverse is executed both in dsa_user_close() and
dsa_user_set_mac_addr().

Refactor these sequences into new functions dsa_user_host_uc_install()
and dsa_user_host_uc_uninstall().

Signed-off-by: Marek Behún <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/dsa/user.c

···
 	return READ_ONCE(dsa_user_to_conduit(dev)->ifindex);
 }
 
-static int dsa_user_open(struct net_device *dev)
+static int dsa_user_host_uc_install(struct net_device *dev, const u8 *addr)
 {
 	struct net_device *conduit = dsa_user_to_conduit(dev);
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct dsa_switch *ds = dp->ds;
+	int err;
+
+	if (dsa_switch_supports_uc_filtering(ds)) {
+		err = dsa_port_standalone_host_fdb_add(dp, addr, 0);
+		if (err)
+			goto out;
+	}
+
+	if (!ether_addr_equal(addr, conduit->dev_addr)) {
+		err = dev_uc_add(conduit, addr);
+		if (err < 0)
+			goto del_host_addr;
+	}
+
+	return 0;
+
+del_host_addr:
+	if (dsa_switch_supports_uc_filtering(ds))
+		dsa_port_standalone_host_fdb_del(dp, addr, 0);
+out:
+	return err;
+}
+
+static void dsa_user_host_uc_uninstall(struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
+	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
+		dev_uc_del(conduit, dev->dev_addr);
+
+	if (dsa_switch_supports_uc_filtering(ds))
+		dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
+}
+
+static int dsa_user_open(struct net_device *dev)
+{
+	struct net_device *conduit = dsa_user_to_conduit(dev);
+	struct dsa_port *dp = dsa_user_to_port(dev);
 	int err;
 
 	err = dev_open(conduit, NULL);
···
 		goto out;
 	}
 
-	if (dsa_switch_supports_uc_filtering(ds)) {
-		err = dsa_port_standalone_host_fdb_add(dp, dev->dev_addr, 0);
-		if (err)
-			goto out;
-	}
-
-	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr)) {
-		err = dev_uc_add(conduit, dev->dev_addr);
-		if (err < 0)
-			goto del_host_addr;
-	}
+	err = dsa_user_host_uc_install(dev, dev->dev_addr);
+	if (err)
+		goto out;
 
 	err = dsa_port_enable_rt(dp, dev->phydev);
 	if (err)
-		goto del_unicast;
+		goto out_del_host_uc;
 
 	return 0;
 
-del_unicast:
-	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
-		dev_uc_del(conduit, dev->dev_addr);
-del_host_addr:
-	if (dsa_switch_supports_uc_filtering(ds))
-		dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
+out_del_host_uc:
+	dsa_user_host_uc_uninstall(dev);
 out:
 	return err;
 }
 
 static int dsa_user_close(struct net_device *dev)
 {
-	struct net_device *conduit = dsa_user_to_conduit(dev);
 	struct dsa_port *dp = dsa_user_to_port(dev);
-	struct dsa_switch *ds = dp->ds;
 
 	dsa_port_disable_rt(dp);
 
-	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
-		dev_uc_del(conduit, dev->dev_addr);
-
-	if (dsa_switch_supports_uc_filtering(ds))
-		dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
+	dsa_user_host_uc_uninstall(dev);
 
 	return 0;
 }
···
 
 static int dsa_user_set_mac_address(struct net_device *dev, void *a)
 {
-	struct net_device *conduit = dsa_user_to_conduit(dev);
 	struct dsa_port *dp = dsa_user_to_port(dev);
 	struct dsa_switch *ds = dp->ds;
 	struct sockaddr *addr = a;
···
 	if (!(dev->flags & IFF_UP))
 		goto out_change_dev_addr;
 
-	if (dsa_switch_supports_uc_filtering(ds)) {
-		err = dsa_port_standalone_host_fdb_add(dp, addr->sa_data, 0);
-		if (err)
-			return err;
-	}
+	err = dsa_user_host_uc_install(dev, addr->sa_data);
+	if (err)
+		return err;
 
-	if (!ether_addr_equal(addr->sa_data, conduit->dev_addr)) {
-		err = dev_uc_add(conduit, addr->sa_data);
-		if (err < 0)
-			goto del_unicast;
-	}
-
-	if (!ether_addr_equal(dev->dev_addr, conduit->dev_addr))
-		dev_uc_del(conduit, dev->dev_addr);
-
-	if (dsa_switch_supports_uc_filtering(ds))
-		dsa_port_standalone_host_fdb_del(dp, dev->dev_addr, 0);
+	dsa_user_host_uc_uninstall(dev);
 
 out_change_dev_addr:
 	eth_hw_addr_set(dev, addr->sa_data);
 
 	return 0;
-
-del_unicast:
-	if (dsa_switch_supports_uc_filtering(ds))
-		dsa_port_standalone_host_fdb_del(dp, addr->sa_data, 0);
-
-	return err;
 }
 
 struct dsa_user_dump_ctx {