net: mscc: ocelot: keep traps in a list

When using the ocelot-8021q tagging protocol, the CPU port isn't
configured as an NPI port, but is a regular port. So a "trap to CPU"
operation is actually a "redirect" operation. So DSA needs to set up the
trapping action one way or another, depending on the tagging protocol in
use.

To ease DSA's work of modifying the action, keep all currently installed
traps in a list, so that DSA can live-patch them when the tagging
protocol changes.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot.c

@@ -1495,6 +1495,7 @@ int ocelot_trap_add(struct ocelot *ocelot, int port, unsigned long cookie,
 		trap->action.cpu_copy_ena = true;
 		trap->action.mask_mode = OCELOT_MASK_MODE_PERMIT_DENY;
 		trap->action.port_mask = 0;
+		list_add_tail(&trap->trap_list, &ocelot->traps);
 		new = true;
 	}
 
@@ -1506,8 +1507,10 @@ int ocelot_trap_add(struct ocelot *ocelot, int port, unsigned long cookie,
 		err = ocelot_vcap_filter_replace(ocelot, trap);
 	if (err) {
 		trap->ingress_port_mask &= ~BIT(port);
-		if (!trap->ingress_port_mask)
+		if (!trap->ingress_port_mask) {
+			list_del(&trap->trap_list);
 			kfree(trap);
+		}
 		return err;
 	}
 
@@ -1527,8 +1530,11 @@ int ocelot_trap_del(struct ocelot *ocelot, int port, unsigned long cookie)
 		return 0;
 
 	trap->ingress_port_mask &= ~BIT(port);
-	if (!trap->ingress_port_mask)
+	if (!trap->ingress_port_mask) {
+		list_del(&trap->trap_list);
+
 		return ocelot_vcap_filter_del(ocelot, trap);
+	}
 
 	return ocelot_vcap_filter_replace(ocelot, trap);
 }

drivers/net/ethernet/mscc/ocelot_flower.c

@@ -279,6 +279,7 @@ static int ocelot_flower_parse_action(struct ocelot *ocelot, int port,
 			filter->action.cpu_copy_ena = true;
 			filter->action.cpu_qu_num = 0;
 			filter->type = OCELOT_VCAP_FILTER_OFFLOAD;
+			list_add_tail(&filter->trap_list, &ocelot->traps);
 			break;
 		case FLOW_ACTION_POLICE:
 			if (filter->block_id == PSFP_BLOCK_ID) {
@@ -840,6 +841,8 @@ int ocelot_cls_flower_replace(struct ocelot *ocelot, int port,
 
 	ret = ocelot_flower_parse(ocelot, port, ingress, f, filter);
 	if (ret) {
+		if (!list_empty(&filter->trap_list))
+			list_del(&filter->trap_list);
 		kfree(filter);
 		return ret;
 	}

drivers/net/ethernet/mscc/ocelot_vcap.c

@@ -1401,6 +1401,7 @@ int ocelot_vcap_init(struct ocelot *ocelot)
 	}
 
 	INIT_LIST_HEAD(&ocelot->dummy_rules);
+	INIT_LIST_HEAD(&ocelot->traps);
 	INIT_LIST_HEAD(&ocelot->vcap_pol.pol_list);
 
 	return 0;

include/soc/mscc/ocelot.h

@@ -689,6 +689,7 @@ struct ocelot {
 	u8				base_mac[ETH_ALEN];
 
 	struct list_head		vlans;
+	struct list_head		traps;
 
 	/* Switches like VSC9959 have flooding per traffic class */
 	int				num_flooding_pgids;

include/soc/mscc/ocelot_vcap.h

@@ -682,6 +682,7 @@ struct ocelot_vcap_id {
 
 struct ocelot_vcap_filter {
 	struct list_head list;
+	struct list_head trap_list;
 
 	enum ocelot_vcap_filter_type type;
 	int block_id;