net: dsa: qca8k: make learning configurable and keep off if standalone

Address learning should initially be turned off by the driver for port
operation in standalone mode, then the DSA core handles changes to it
via ds->ops->port_bridge_flags().

Currently this is not the case for qca8k where learning is enabled
unconditionally in qca8k_setup for every user port.

Handle ports configured in standalone mode by making the learning
configurable and not enabling it by default.

Implement .port_pre_bridge_flags and .port_bridge_flags dsa ops to
enable learning for bridge that request it and tweak
.port_stp_state_set to correctly disable learning when port is
configured in standalone mode.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20230730074113.21889-2-ansuelsmth@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/dsa/qca/qca8k-8xxx.c

@@ -1870,9 +1870,8 @@ qca8k_setup(struct dsa_switch *ds)
 			if (ret)
 				return ret;
 
-			/* Enable ARP Auto-learning by default */
-			ret = regmap_set_bits(priv->regmap, QCA8K_PORT_LOOKUP_CTRL(i),
-					      QCA8K_PORT_LOOKUP_LEARN);
+			ret = regmap_clear_bits(priv->regmap, QCA8K_PORT_LOOKUP_CTRL(i),
+						QCA8K_PORT_LOOKUP_LEARN);
 			if (ret)
 				return ret;
 
@@ -1978,6 +1977,8 @@ static const struct dsa_switch_ops qca8k_switch_ops = {
 	.port_change_mtu	= qca8k_port_change_mtu,
 	.port_max_mtu		= qca8k_port_max_mtu,
 	.port_stp_state_set	= qca8k_port_stp_state_set,
+	.port_pre_bridge_flags	= qca8k_port_pre_bridge_flags,
+	.port_bridge_flags	= qca8k_port_bridge_flags,
 	.port_bridge_join	= qca8k_port_bridge_join,
 	.port_bridge_leave	= qca8k_port_bridge_leave,
 	.port_fast_age		= qca8k_port_fast_age,

drivers/net/dsa/qca/qca8k-common.c

@@ -565,9 +565,26 @@ int qca8k_get_mac_eee(struct dsa_switch *ds, int port,
 	return 0;
 }
 
+static int qca8k_port_configure_learning(struct dsa_switch *ds, int port,
+					 bool learning)
+{
+	struct qca8k_priv *priv = ds->priv;
+
+	if (learning)
+		return regmap_set_bits(priv->regmap,
+				       QCA8K_PORT_LOOKUP_CTRL(port),
+				       QCA8K_PORT_LOOKUP_LEARN);
+	else
+		return regmap_clear_bits(priv->regmap,
+					 QCA8K_PORT_LOOKUP_CTRL(port),
+					 QCA8K_PORT_LOOKUP_LEARN);
+}
+
 void qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 {
+	struct dsa_port *dp = dsa_to_port(ds, port);
 	struct qca8k_priv *priv = ds->priv;
+	bool learning = false;
 	u32 stp_state;
 
 	switch (state) {
@@ -582,8 +599,11 @@ void qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 		break;
 	case BR_STATE_LEARNING:
 		stp_state = QCA8K_PORT_LOOKUP_STATE_LEARNING;
+		learning = dp->learning;
 		break;
 	case BR_STATE_FORWARDING:
+		learning = dp->learning;
+		fallthrough;
 	default:
 		stp_state = QCA8K_PORT_LOOKUP_STATE_FORWARD;
 		break;
@@ -591,6 +611,34 @@ void qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 
 	qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(port),
 		  QCA8K_PORT_LOOKUP_STATE_MASK, stp_state);
+
+	qca8k_port_configure_learning(ds, port, learning);
+}
+
+int qca8k_port_pre_bridge_flags(struct dsa_switch *ds, int port,
+				struct switchdev_brport_flags flags,
+				struct netlink_ext_ack *extack)
+{
+	if (flags.mask & ~BR_LEARNING)
+		return -EINVAL;
+
+	return 0;
+}
+
+int qca8k_port_bridge_flags(struct dsa_switch *ds, int port,
+			    struct switchdev_brport_flags flags,
+			    struct netlink_ext_ack *extack)
+{
+	int ret;
+
+	if (flags.mask & BR_LEARNING) {
+		ret = qca8k_port_configure_learning(ds, port,
+						    flags.val & BR_LEARNING);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 int qca8k_port_bridge_join(struct dsa_switch *ds, int port,

drivers/net/dsa/qca/qca8k.h

@@ -522,6 +522,12 @@ int qca8k_get_mac_eee(struct dsa_switch *ds, int port, struct ethtool_eee *e);
 
 /* Common bridge function */
 void qca8k_port_stp_state_set(struct dsa_switch *ds, int port, u8 state);
+int qca8k_port_pre_bridge_flags(struct dsa_switch *ds, int port,
+				struct switchdev_brport_flags flags,
+				struct netlink_ext_ack *extack);
+int qca8k_port_bridge_flags(struct dsa_switch *ds, int port,
+			    struct switchdev_brport_flags flags,
+			    struct netlink_ext_ack *extack);
 int qca8k_port_bridge_join(struct dsa_switch *ds, int port,
 			   struct dsa_bridge bridge,
 			   bool *tx_fwd_offload,