Merge branch 'net-dsa-mv88e6xxx-fix-IPv6'

Florian Fainelli says:

====================
net: dsa: mv88e6xxx: fix IPv6

We have had some emails in private over this issue, this is my current
patch set rebased on top of net-next which provides working IPv6 (and
probably other protocols as well) over mv88e6xxx DSA switches.

The problem comes down to mv88e6xxx defaulting to not flood unknown
unicast and multicast datagrams, as they would be by dumb switches,
and as the Linux bridge code does by default.

There is also the issue of IPv6 over a vlan that is transparent to the
bridge; the multicast querier will not reach inside the vlan, and so
the switch can not learn about multicast routing within the vlan.

These flood settings can be disabled via the Linux bridge code if it's
desired to make the switch behave more like a managed switch, eg, by
enabling the multicast querier.  However, the multicast querier
defaults to being disabled which effectively means that by default,
mv88e6xxx switches block all multicast traffic.  This is at odds with
the Linux bridge documentation, and the defaults that the Linux bridge
code adopts.

So, this patch set adds DSA support for Linux bridge flags, adds
mv88e6xxx support for the unicast and multicast flooding flags, and
lastly enables flooding of these frames by default to match the
Linux bridge defaults.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -4692,6 +4692,22 @@ static int mv88e6xxx_port_mdb_del(struct dsa_switch *ds, int port,
 	return err;
 }
 
+static int mv88e6xxx_port_egress_floods(struct dsa_switch *ds, int port,
+					 bool unicast, bool multicast)
+{
+	struct mv88e6xxx_chip *chip = ds->priv;
+	int err = -EOPNOTSUPP;
+
+	mutex_lock(&chip->reg_lock);
+	if (chip->info->ops->port_set_egress_floods)
+		err = chip->info->ops->port_set_egress_floods(chip, port,
+							      unicast,
+							      multicast);
+	mutex_unlock(&chip->reg_lock);
+
+	return err;
+}
+
 static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 #if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 	.probe			= mv88e6xxx_drv_probe,
@@ -4719,6 +4735,7 @@ static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
 	.set_ageing_time	= mv88e6xxx_set_ageing_time,
 	.port_bridge_join	= mv88e6xxx_port_bridge_join,
 	.port_bridge_leave	= mv88e6xxx_port_bridge_leave,
+	.port_egress_floods	= mv88e6xxx_port_egress_floods,
 	.port_stp_state_set	= mv88e6xxx_port_stp_state_set,
 	.port_fast_age		= mv88e6xxx_port_fast_age,
 	.port_vlan_filtering	= mv88e6xxx_port_vlan_filtering,

include/net/dsa.h

@@ -400,6 +400,8 @@ struct dsa_switch_ops {
 	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
 				      u8 state);
 	void	(*port_fast_age)(struct dsa_switch *ds, int port);
+	int	(*port_egress_floods)(struct dsa_switch *ds, int port,
+				      bool unicast, bool multicast);
 
 	/*
 	 * VLAN support

net/dsa/dsa_priv.h

@@ -160,6 +160,8 @@ int dsa_port_mdb_add(const struct dsa_port *dp,
 		     struct switchdev_trans *trans);
 int dsa_port_mdb_del(const struct dsa_port *dp,
 		     const struct switchdev_obj_port_mdb *mdb);
+int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
+			  struct switchdev_trans *trans);
 int dsa_port_vlan_add(struct dsa_port *dp,
 		      const struct switchdev_obj_port_vlan *vlan,
 		      struct switchdev_trans *trans);

net/dsa/port.c

@@ -105,16 +105,23 @@ int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
 	};
 	int err;
 
-	/* Here the port is already bridged. Reflect the current configuration
-	 * so that drivers can program their chips accordingly.
+	/* Set the flooding mode before joining the port in the switch */
+	err = dsa_port_bridge_flags(dp, BR_FLOOD | BR_MCAST_FLOOD, NULL);
+	if (err)
+		return err;
+
+	/* Here the interface is already bridged. Reflect the current
+	 * configuration so that drivers can program their chips accordingly.
 	 */
 	dp->bridge_dev = br;
 
 	err = dsa_port_notify(dp, DSA_NOTIFIER_BRIDGE_JOIN, &info);
 
 	/* The bridging is rolled back on error */
-	if (err)
+	if (err) {
+		dsa_port_bridge_flags(dp, 0, NULL);
 		dp->bridge_dev = NULL;
+	}
 
 	return err;
 }
@@ -137,6 +144,9 @@ void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br)
 	if (err)
 		pr_err("DSA: failed to notify DSA_NOTIFIER_BRIDGE_LEAVE\n");
 
+	/* Port is leaving the bridge, disable flooding */
+	dsa_port_bridge_flags(dp, 0, NULL);
+
 	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
 	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
 	 */
@@ -177,6 +187,23 @@ int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
 	return dsa_port_notify(dp, DSA_NOTIFIER_AGEING_TIME, &info);
 }
 
+int dsa_port_bridge_flags(const struct dsa_port *dp, unsigned long flags,
+			  struct switchdev_trans *trans)
+{
+	struct dsa_switch *ds = dp->ds;
+	int port = dp->index;
+	int err = 0;
+
+	if (switchdev_trans_ph_prepare(trans))
+		return 0;
+
+	if (ds->ops->port_egress_floods)
+		err = ds->ops->port_egress_floods(ds, port, flags & BR_FLOOD,
+						  flags & BR_MCAST_FLOOD);
+
+	return err;
+}
+
 int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
 		     u16 vid)
 {

net/dsa/slave.c

@@ -295,6 +295,9 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
 	case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
 		ret = dsa_port_ageing_time(dp, attr->u.ageing_time, trans);
 		break;
+	case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS:
+		ret = dsa_port_bridge_flags(dp, attr->u.brport_flags, trans);
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;
@@ -381,9 +384,15 @@ static int dsa_slave_get_port_parent_id(struct net_device *dev,
 static int dsa_slave_port_attr_get(struct net_device *dev,
 				   struct switchdev_attr *attr)
 {
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+	struct dsa_switch *ds = dp->ds;
+
 	switch (attr->id) {
 	case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS_SUPPORT:
 		attr->u.brport_flags_support = 0;
+		if (ds->ops->port_egress_floods)
+			attr->u.brport_flags_support |= BR_FLOOD |
+							BR_MCAST_FLOOD;
 		break;
 	default:
 		return -EOPNOTSUPP;