net: dsa: mt7530: rework mt7530_hw_vlan_{add,del}

Rework vlan_add/vlan_del functions in preparation for dynamic cpu port.

Currently BIT(MT7530_CPU_PORT) is added to new_members, even though
mt7530_port_vlan_add() will be called on the CPU port too.

Let DSA core decide when to call port_vlan_add for the CPU port, rather
than doing it implicitly.

We can do autonomous forwarding in a certain VLAN, but not add br0 to that
VLAN and avoid flooding the CPU with those packets, if software knows it
doesn't need to process them.
Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mt7530.c

@@ -1527,11 +1527,11 @@ static void
 mt7530_hw_vlan_add(struct mt7530_priv *priv,
 		   struct mt7530_hw_vlan_entry *entry)
 {
+	struct dsa_port *dp = dsa_to_port(priv->ds, entry->port);
 	u8 new_members;
 	u32 val;
 
-	new_members = entry->old_members | BIT(entry->port) |
-		      BIT(MT7530_CPU_PORT);
+	new_members = entry->old_members | BIT(entry->port);
 
 	/* Validate the entry with independent learning, create egress tag per
 	 * VLAN and joining the port as one of the port members.
@@ -1542,22 +1542,20 @@ mt7530_hw_vlan_add(struct mt7530_priv *priv,
 
 	/* Decide whether adding tag or not for those outgoing packets from the
 	 * port inside the VLAN.
-	 */
-	val = entry->untagged ? MT7530_VLAN_EGRESS_UNTAG :
-				MT7530_VLAN_EGRESS_TAG;
-	mt7530_rmw(priv, MT7530_VAWD2,
-		   ETAG_CTRL_P_MASK(entry->port),
-		   ETAG_CTRL_P(entry->port, val));
-
-	/* CPU port is always taken as a tagged port for serving more than one
+	 * CPU port is always taken as a tagged port for serving more than one
 	 * VLANs across and also being applied with egress type stack mode for
 	 * that VLAN tags would be appended after hardware special tag used as
 	 * DSA tag.
 	 */
+	if (dsa_port_is_cpu(dp))
+		val = MT7530_VLAN_EGRESS_STACK;
+	else if (entry->untagged)
+		val = MT7530_VLAN_EGRESS_UNTAG;
+	else
+		val = MT7530_VLAN_EGRESS_TAG;
 	mt7530_rmw(priv, MT7530_VAWD2,
-		   ETAG_CTRL_P_MASK(MT7530_CPU_PORT),
-		   ETAG_CTRL_P(MT7530_CPU_PORT,
-			       MT7530_VLAN_EGRESS_STACK));
+		   ETAG_CTRL_P_MASK(entry->port),
+		   ETAG_CTRL_P(entry->port, val));
 }
 
 static void
@@ -1576,11 +1574,7 @@ mt7530_hw_vlan_del(struct mt7530_priv *priv,
 		return;
 	}
 
-	/* If certain member apart from CPU port is still alive in the VLAN,
-	 * the entry would be kept valid. Otherwise, the entry is got to be
-	 * disabled.
-	 */
-	if (new_members && new_members != BIT(MT7530_CPU_PORT)) {
+	if (new_members) {
 		val = IVL_MAC | VTAG_EN | PORT_MEM(new_members) |
 		      VLAN_VALID;
 		mt7530_write(priv, MT7530_VAWD1, val);