net: mscc: ocelot: offload per-flow mirroring using tc-mirred and VCAP IS2

Per-flow mirroring with the VCAP IS2 TCAM (in itself handled as an
offload for tc-flower) is done by setting the MIRROR_ENA bit from the
action vector of the filter. The packet is mirrored to the port mask
configured in the ANA:ANA:MIRRORPORTS register (the same port mask as
the destinations for port-based mirroring).

Functionality was tested with:

tc qdisc add dev swp3 clsact
tc filter add dev swp3 ingress protocol ip \
flower skip_sw ip_proto icmp \
action mirred egress mirror dev swp1

and pinging through swp3, while seeing that the ICMP replies are
mirrored towards swp1.

Signed-off-by: Vladimir Oltean <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/mscc/ocelot.c

···
 }
 EXPORT_SYMBOL_GPL(ocelot_port_del_dscp_prio);
 
-static struct ocelot_mirror *ocelot_mirror_get(struct ocelot *ocelot, int to,
-					       struct netlink_ext_ack *extack)
+struct ocelot_mirror *ocelot_mirror_get(struct ocelot *ocelot, int to,
+					struct netlink_ext_ack *extack)
 {
 	struct ocelot_mirror *m = ocelot->mirror;
 
···
 	return m;
 }
 
-static void ocelot_mirror_put(struct ocelot *ocelot)
+void ocelot_mirror_put(struct ocelot *ocelot)
 {
 	struct ocelot_mirror *m = ocelot->mirror;
 

drivers/net/ethernet/mscc/ocelot.h

···
 		    void (*populate)(struct ocelot_vcap_filter *f));
 int ocelot_trap_del(struct ocelot *ocelot, int port, unsigned long cookie);
 
+struct ocelot_mirror *ocelot_mirror_get(struct ocelot *ocelot, int to,
+					struct netlink_ext_ack *extack);
+void ocelot_mirror_put(struct ocelot *ocelot);
+
 extern struct notifier_block ocelot_netdevice_nb;
 extern struct notifier_block ocelot_switchdev_nb;
 extern struct notifier_block ocelot_switchdev_blocking_nb;

drivers/net/ethernet/mscc/ocelot_flower.c

···
 			filter->action.port_mask = BIT(egress_port);
 			filter->type = OCELOT_VCAP_FILTER_OFFLOAD;
 			break;
+		case FLOW_ACTION_MIRRED:
+			if (filter->block_id != VCAP_IS2) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Mirror action can only be offloaded to VCAP IS2");
+				return -EOPNOTSUPP;
+			}
+			if (filter->goto_target != -1) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Last action must be GOTO");
+				return -EOPNOTSUPP;
+			}
+			egress_port = ocelot->ops->netdev_to_port(a->dev);
+			if (egress_port < 0) {
+				NL_SET_ERR_MSG_MOD(extack,
+						   "Destination not an ocelot port");
+				return -EOPNOTSUPP;
+			}
+			filter->egress_port.value = egress_port;
+			filter->action.mirror_ena = true;
+			filter->type = OCELOT_VCAP_FILTER_OFFLOAD;
+			break;
 		case FLOW_ACTION_VLAN_POP:
 			if (filter->block_id != VCAP_IS1) {
 				NL_SET_ERR_MSG_MOD(extack,

drivers/net/ethernet/mscc/ocelot_vcap.c

···
 
 	vcap_action_set(vcap, data, VCAP_IS2_ACT_MASK_MODE, a->mask_mode);
 	vcap_action_set(vcap, data, VCAP_IS2_ACT_PORT_MASK, a->port_mask);
+	vcap_action_set(vcap, data, VCAP_IS2_ACT_MIRROR_ENA, a->mirror_ena);
 	vcap_action_set(vcap, data, VCAP_IS2_ACT_POLICE_ENA, a->police_ena);
 	vcap_action_set(vcap, data, VCAP_IS2_ACT_POLICE_IDX, a->pol_ix);
 	vcap_action_set(vcap, data, VCAP_IS2_ACT_CPU_QU_NUM, a->cpu_qu_num);
···
 				     struct ocelot_vcap_filter *filter,
 				     struct netlink_ext_ack *extack)
 {
+	struct ocelot_mirror *m;
 	int ret;
+
+	if (filter->block_id == VCAP_IS2 && filter->action.mirror_ena) {
+		m = ocelot_mirror_get(ocelot, filter->egress_port.value,
+				      extack);
+		if (IS_ERR(m))
+			return PTR_ERR(m);
+	}
 
 	if (filter->block_id == VCAP_IS2 && filter->action.police_ena) {
 		ret = ocelot_vcap_policer_add(ocelot, filter->action.pol_ix,
···
 {
 	if (filter->block_id == VCAP_IS2 && filter->action.police_ena)
 		ocelot_vcap_policer_del(ocelot, filter->action.pol_ix);
+
+	if (filter->block_id == VCAP_IS2 && filter->action.mirror_ena)
+		ocelot_mirror_put(ocelot);
 }
 
 static int ocelot_vcap_filter_add_to_block(struct ocelot *ocelot,

include/soc/mscc/ocelot_vcap.h

···
 			enum ocelot_mask_mode mask_mode;
 			unsigned long port_mask;
 			bool police_ena;
+			bool mirror_ena;
 			struct ocelot_policer pol;
 			u32 pol_ix;
 		};
···
 	unsigned long ingress_port_mask;
 	/* For VCAP ES0 */
 	struct ocelot_vcap_port ingress_port;
+	/* For VCAP IS2 mirrors and ES0 */
 	struct ocelot_vcap_port egress_port;
 
 	enum ocelot_vcap_bit dmac_mc;