mlxsw: spectrum_router: Support RIF without device

Spectrum-2 underlay RIF is merely an auxiliary RIF that points to the
virtual router used for encapsulated packets lookup. It exists only when
its overlay RIF exists but may be shared with other overlay RIFs.
Hence it is undesired to mark any device as related to it.

Therefore allow usage of NULL device when allocating RIF.
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_dpipe.c

@@ -220,7 +220,7 @@ mlxsw_sp_dpipe_table_erif_entries_dump(void *priv, bool counters_enabled,
 	for (; i < rif_count; i++) {
 		struct mlxsw_sp_rif *rif = mlxsw_sp_rif_by_index(mlxsw_sp, i);
 
-		if (!rif)
+		if (!rif || !mlxsw_sp_rif_dev(rif))
 			continue;
 		err = mlxsw_sp_erif_entry_get(mlxsw_sp, &entry, rif,
 					      counters_enabled);

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -80,7 +80,7 @@ struct mlxsw_sp_router {
 struct mlxsw_sp_rif {
 	struct list_head nexthop_list;
 	struct list_head neigh_list;
-	struct net_device *dev;
+	struct net_device *dev; /* NULL for underlay RIF */
 	struct mlxsw_sp_fid *fid;
 	unsigned char addr[ETH_ALEN];
 	int mtu;
@@ -6224,10 +6224,12 @@ static struct mlxsw_sp_rif *mlxsw_sp_rif_alloc(size_t rif_size, u16 rif_index,
 
 	INIT_LIST_HEAD(&rif->nexthop_list);
 	INIT_LIST_HEAD(&rif->neigh_list);
+	if (l3_dev) {
 		ether_addr_copy(rif->addr, l3_dev->dev_addr);
 		rif->mtu = l3_dev->mtu;
-	rif->vr_id = vr_id;
 		rif->dev = l3_dev;
+	}
+	rif->vr_id = vr_id;
 	rif->rif_index = rif_index;
 
 	return rif;
@@ -6758,7 +6760,7 @@ static int mlxsw_sp_router_port_check_rif_addr(struct mlxsw_sp *mlxsw_sp,
 
 	for (i = 0; i < MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_RIFS); i++) {
 		rif = mlxsw_sp->router->rifs[i];
-		if (rif && rif->dev != dev &&
+		if (rif && rif->dev && rif->dev != dev &&
 		    !ether_addr_equal_masked(rif->dev->dev_addr, dev_addr,
 					     mlxsw_sp->mac_mask)) {
 			NL_SET_ERR_MSG_MOD(extack, "All router interface MAC addresses must have the same prefix");