net: sparx5: support enabling/disabling of multicast snooping

L2 forwarding of ipv4 and ipv6 multicast frames is done by looking up
the equivalent l2 multicast address in the forwarding table. Add support
for enabling/disabling l2 forwarding of ipv4 and ipv6 traffic, by
using the SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED callback to dynamically
learn and forget entries.

Effectively, this means that based on the mcast_ena variable, multicast
frames are either forwarded according to the multicast PGID masks, or
the flood masks.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>

Author: Danielmachon

drivers/net/ethernet/microchip/sparx5/sparx5_main.h

@@ -300,6 +300,7 @@ struct sparx5_port {
 	u16 ts_id;
 	struct sk_buff_head tx_skbs;
 	bool is_mrouter;
+	bool mcast_ena;
 	/* QOS port configuration */
 	struct mchp_qos_port_conf qos_port_conf;
 	/* Frame preemption configuration */
@@ -1113,6 +1114,9 @@ int sparx5_handle_mdb_add(struct net_device *dev, struct notifier_block *nb,
 
 int sparx5_handle_mdb_del(struct net_device *dev, struct notifier_block *nb,
 			  const struct switchdev_obj_port_mdb *v);
+int sparx5_mdb_entries_clear(struct sparx5 *sparx5);
+int sparx5_mdb_entries_restore(struct sparx5 *sparx5);
+
 
 /* FDMA return action codes for checking if the frame is valid
  * FDMA_PASS, frame is valid and can be used

drivers/net/ethernet/microchip/sparx5/sparx5_mdb.c

@@ -12,6 +12,31 @@
 #include "sparx5_mrp.h"
 #include "sparx5_tc.h"
 
+int sparx5_mdb_entries_clear(struct sparx5 *sparx5)
+{
+	struct sparx5_mdb_entry *mdb_entry;
+
+	mutex_lock(&sparx5->mdb_lock);
+	list_for_each_entry(mdb_entry, &sparx5->mdb_entries, list)
+		sparx5_mact_forget(sparx5, mdb_entry->addr, mdb_entry->vid);
+	mutex_unlock(&sparx5->mdb_lock);
+
+	return 0;
+}
+
+int sparx5_mdb_entries_restore(struct sparx5 *sparx5)
+{
+	struct sparx5_mdb_entry *mdb_entry;
+
+	mutex_lock(&sparx5->mdb_lock);
+	list_for_each_entry(mdb_entry, &sparx5->mdb_entries, list)
+		sparx5_mact_learn(sparx5, mdb_entry->pgid_idx, mdb_entry->addr,
+				  mdb_entry->vid);
+	mutex_unlock(&sparx5->mdb_lock);
+
+	return 0;
+}
+
 static int sparx5_mdb_entry_alloc(struct sparx5 *sparx5,
 				  const unsigned char *addr,
 				  u16 vid,

drivers/net/ethernet/microchip/sparx5/sparx5_switchdev.c

@@ -138,6 +138,30 @@ static void sparx5_port_attr_mrouter_set(struct sparx5_port *port,
 	sparx5_port_update_mcast_ip_flood(port, flood_flag);
 }
 
+static void sparx5_port_attr_mc_set(struct sparx5_port *port, bool mcast_ena)
+{
+	struct sparx5 *sparx5 = port->sparx5;
+
+	port->mcast_ena = mcast_ena;
+
+	if (mcast_ena)
+		/* Forward multicast frames according to PGID mask. */
+		sparx5_mdb_entries_restore(sparx5);
+	else
+		/* Flood multicast frames according to MC flood mask. */
+		sparx5_mdb_entries_clear(sparx5);
+
+	spx5_rmw(ANA_CL_CAPTURE_CFG_CPU_IGMP_REDIR_ENA_SET(mcast_ena) |
+		 ANA_CL_CAPTURE_CFG_CPU_MLD_REDIR_ENA_SET(mcast_ena),
+		 ANA_CL_CAPTURE_CFG_CPU_IGMP_REDIR_ENA |
+		 ANA_CL_CAPTURE_CFG_CPU_MLD_REDIR_ENA,
+		 sparx5, ANA_CL_CAPTURE_CFG(port->portno));
+
+	spx5_rmw(ANA_L3_L3MC_CTRL_IPMC_TTL_COPY_ENA_SET(mcast_ena),
+		 ANA_L3_L3MC_CTRL_IPMC_TTL_COPY_ENA,
+		 sparx5, ANA_L3_L3MC_CTRL(port->portno));
+}
+
 static int sparx5_port_attr_set(struct net_device *dev, const void *ctx,
 				const struct switchdev_attr *attr,
 				struct netlink_ext_ack *extack)
@@ -174,6 +198,9 @@ static int sparx5_port_attr_set(struct net_device *dev, const void *ctx,
 	case SWITCHDEV_ATTR_ID_MRP_PORT_ROLE:
 		sparx5_handle_mrp_port_role(port, attr->u.mrp_port_role);
 		break;
+	case SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED:
+		sparx5_port_attr_mc_set(port, !attr->u.mc_disabled);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}