net: mscc: ocelot: set up tag_8021q CPU ports independent of user port affinity

This is a partial revert of commit c295f9831f ("net: mscc: ocelot:
switch from {,un}set to {,un}assign for tag_8021q CPU ports"), because
as it turns out, this isn't how tag_8021q CPU ports under a LAG are
supposed to work.

Under that scenario, all user ports are "assigned" to the single
tag_8021q CPU port represented by the logical port corresponding to the
bonding interface. So one CPU port in a LAG would have is_dsa_8021q_cpu
set to true (the one whose physical port ID is equal to the logical port
ID), and the other one to false.

In turn, this makes 2 undesirable things happen:

(1) PGID_CPU contains only the first physical CPU port, rather than both
(2) only the first CPU port will be added to the private VLANs used by
    ocelot for VLAN-unaware bridging

To make the driver behave in the same way for both bonded CPU ports, we
need to bring back the old concept of setting up a port as a tag_8021q
CPU port, and this is what deals with VLAN membership and PGID_CPU
updating. But we also need the CPU port "assignment" (the user to CPU
port affinity), and this is what updates the PGID_SRC forwarding rules.

All DSA CPU ports are statically configured for tag_8021q mode when the
tagging protocol is changed to ocelot-8021q. User ports are "assigned"
to one CPU port or the other dynamically (this will be handled by a
future change).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/dsa/ocelot/felix.c

@@ -445,6 +445,9 @@ static int felix_tag_8021q_setup(struct dsa_switch *ds)
 	if (err)
 		return err;
 
+	dsa_switch_for_each_cpu_port(dp, ds)
+		ocelot_port_setup_dsa_8021q_cpu(ocelot, dp->index);
+
 	dsa_switch_for_each_user_port(dp, ds)
 		ocelot_port_assign_dsa_8021q_cpu(ocelot, dp->index,
 						 dp->cpu_dp->index);
@@ -493,6 +496,9 @@ static void felix_tag_8021q_teardown(struct dsa_switch *ds)
 	dsa_switch_for_each_user_port(dp, ds)
 		ocelot_port_unassign_dsa_8021q_cpu(ocelot, dp->index);
 
+	dsa_switch_for_each_cpu_port(dp, ds)
+		ocelot_port_teardown_dsa_8021q_cpu(ocelot, dp->index);
+
 	dsa_tag_8021q_unregister(ds);
 }
 

drivers/net/ethernet/mscc/ocelot.c

@@ -2214,25 +2214,50 @@ static void ocelot_update_pgid_cpu(struct ocelot *ocelot)
 	ocelot_write_rix(ocelot, pgid_cpu, ANA_PGID_PGID, PGID_CPU);
 }
 
-void ocelot_port_assign_dsa_8021q_cpu(struct ocelot *ocelot, int port,
-				      int cpu)
+void ocelot_port_setup_dsa_8021q_cpu(struct ocelot *ocelot, int cpu)
 {
 	struct ocelot_port *cpu_port = ocelot->ports[cpu];
 	u16 vid;
 
 	mutex_lock(&ocelot->fwd_domain_lock);
 
-	ocelot->ports[port]->dsa_8021q_cpu = cpu_port;
-
-	if (!cpu_port->is_dsa_8021q_cpu) {
 	cpu_port->is_dsa_8021q_cpu = true;
 
 	for (vid = OCELOT_RSV_VLAN_RANGE_START; vid < VLAN_N_VID; vid++)
 		ocelot_vlan_member_add(ocelot, cpu, vid, true);
 
 	ocelot_update_pgid_cpu(ocelot);
-	}
 
+	mutex_unlock(&ocelot->fwd_domain_lock);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_setup_dsa_8021q_cpu);
+
+void ocelot_port_teardown_dsa_8021q_cpu(struct ocelot *ocelot, int cpu)
+{
+	struct ocelot_port *cpu_port = ocelot->ports[cpu];
+	u16 vid;
+
+	mutex_lock(&ocelot->fwd_domain_lock);
+
+	cpu_port->is_dsa_8021q_cpu = false;
+
+	for (vid = OCELOT_RSV_VLAN_RANGE_START; vid < VLAN_N_VID; vid++)
+		ocelot_vlan_member_del(ocelot, cpu_port->index, vid);
+
+	ocelot_update_pgid_cpu(ocelot);
+
+	mutex_unlock(&ocelot->fwd_domain_lock);
+}
+EXPORT_SYMBOL_GPL(ocelot_port_teardown_dsa_8021q_cpu);
+
+void ocelot_port_assign_dsa_8021q_cpu(struct ocelot *ocelot, int port,
+				      int cpu)
+{
+	struct ocelot_port *cpu_port = ocelot->ports[cpu];
+
+	mutex_lock(&ocelot->fwd_domain_lock);
+
+	ocelot->ports[port]->dsa_8021q_cpu = cpu_port;
 	ocelot_apply_bridge_fwd_mask(ocelot, true);
 
 	mutex_unlock(&ocelot->fwd_domain_lock);
@@ -2241,34 +2266,9 @@ EXPORT_SYMBOL_GPL(ocelot_port_assign_dsa_8021q_cpu);
 
 void ocelot_port_unassign_dsa_8021q_cpu(struct ocelot *ocelot, int port)
 {
-	struct ocelot_port *cpu_port = ocelot->ports[port]->dsa_8021q_cpu;
-	bool keep = false;
-	u16 vid;
-	int p;
-
 	mutex_lock(&ocelot->fwd_domain_lock);
 
 	ocelot->ports[port]->dsa_8021q_cpu = NULL;
-
-	for (p = 0; p < ocelot->num_phys_ports; p++) {
-		if (!ocelot->ports[p])
-			continue;
-
-		if (ocelot->ports[p]->dsa_8021q_cpu == cpu_port) {
-			keep = true;
-			break;
-		}
-	}
-
-	if (!keep) {
-		cpu_port->is_dsa_8021q_cpu = false;
-
-		for (vid = OCELOT_RSV_VLAN_RANGE_START; vid < VLAN_N_VID; vid++)
-			ocelot_vlan_member_del(ocelot, cpu_port->index, vid);
-
-		ocelot_update_pgid_cpu(ocelot);
-	}
-
 	ocelot_apply_bridge_fwd_mask(ocelot, true);
 
 	mutex_unlock(&ocelot->fwd_domain_lock);

include/soc/mscc/ocelot.h

@@ -1024,6 +1024,8 @@ void ocelot_deinit(struct ocelot *ocelot);
 void ocelot_init_port(struct ocelot *ocelot, int port);
 void ocelot_deinit_port(struct ocelot *ocelot, int port);
 
+void ocelot_port_setup_dsa_8021q_cpu(struct ocelot *ocelot, int cpu);
+void ocelot_port_teardown_dsa_8021q_cpu(struct ocelot *ocelot, int cpu);
 void ocelot_port_assign_dsa_8021q_cpu(struct ocelot *ocelot, int port, int cpu);
 void ocelot_port_unassign_dsa_8021q_cpu(struct ocelot *ocelot, int port);
 u32 ocelot_port_assigned_dsa_8021q_cpu_mask(struct ocelot *ocelot, int port);