mlxsw: spectrum_switchdev: Add support of QinQ traffic

802.1ad, also known as QinQ is an extension to the 802.1q standard, which
is concerned with passing possibly 802.1q-tagged packets through another
VLAN-like tunnel. The format of 802.1ad tag is the same as 802.1q, except
it uses the EtherType of 0x88a8, unlike 802.1q's 0x8100.

Add support for 802.1ad protocol. Most of the configuration is the same
as 802.1q. The difference is that before a port joins an 802.1ad bridge it
needs to be configured to recognize 802.1ad packets as tagged and other
packets (e.g., 802.1q) as untagged.

VXLAN is not currently supported with 802.1ad bridge, so return an error
with an appropriate extack message.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -1411,7 +1411,7 @@ static int mlxsw_sp_port_overheat_init_val_set(struct mlxsw_sp_port *mlxsw_sp_po
 	return 0;
 }
 
-static int
+int
 mlxsw_sp_port_vlan_classification_set(struct mlxsw_sp_port *mlxsw_sp_port,
 				      bool is_8021ad_tagged,
 				      bool is_8021q_tagged)

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -428,6 +428,10 @@ int mlxsw_sp_port_get_stats_raw(struct net_device *dev, int grp,
 				int prio, char *ppcnt_pl);
 int mlxsw_sp_port_admin_status_set(struct mlxsw_sp_port *mlxsw_sp_port,
 				   bool is_up);
+int
+mlxsw_sp_port_vlan_classification_set(struct mlxsw_sp_port *mlxsw_sp_port,
+				      bool is_8021ad_tagged,
+				      bool is_8021q_tagged);
 
 /* spectrum_buffers.c */
 struct mlxsw_sp_hdroom_prio {

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

@@ -41,6 +41,7 @@ struct mlxsw_sp_bridge {
 	DECLARE_BITMAP(mids_bitmap, MLXSW_SP_MID_MAX);
 	const struct mlxsw_sp_bridge_ops *bridge_8021q_ops;
 	const struct mlxsw_sp_bridge_ops *bridge_8021d_ops;
+	const struct mlxsw_sp_bridge_ops *bridge_8021ad_ops;
 };
 
 struct mlxsw_sp_bridge_device {
@@ -228,8 +229,14 @@ mlxsw_sp_bridge_device_create(struct mlxsw_sp_bridge *bridge,
 	bridge_device->mrouter = br_multicast_router(br_dev);
 	INIT_LIST_HEAD(&bridge_device->ports_list);
 	if (vlan_enabled) {
+		u16 proto;
+
 		bridge->vlan_enabled_exists = true;
-		bridge_device->ops = bridge->bridge_8021q_ops;
+		br_vlan_get_proto(br_dev, &proto);
+		if (proto == ETH_P_8021AD)
+			bridge_device->ops = bridge->bridge_8021ad_ops;
+		else
+			bridge_device->ops = bridge->bridge_8021q_ops;
 	} else {
 		bridge_device->ops = bridge->bridge_8021d_ops;
 	}
@@ -2266,6 +2273,57 @@ static const struct mlxsw_sp_bridge_ops mlxsw_sp_bridge_8021d_ops = {
 	.fid_vid	= mlxsw_sp_bridge_8021d_fid_vid,
 };
 
+static int
+mlxsw_sp_bridge_8021ad_port_join(struct mlxsw_sp_bridge_device *bridge_device,
+				 struct mlxsw_sp_bridge_port *bridge_port,
+				 struct mlxsw_sp_port *mlxsw_sp_port,
+				 struct netlink_ext_ack *extack)
+{
+	int err;
+
+	err = mlxsw_sp_port_vlan_classification_set(mlxsw_sp_port, true, false);
+	if (err)
+		return err;
+
+	err = mlxsw_sp_bridge_vlan_aware_port_join(bridge_port, mlxsw_sp_port,
+						   extack);
+	if (err)
+		goto err_bridge_vlan_aware_port_join;
+
+	return 0;
+
+err_bridge_vlan_aware_port_join:
+	mlxsw_sp_port_vlan_classification_set(mlxsw_sp_port, false, true);
+	return err;
+}
+
+static void
+mlxsw_sp_bridge_8021ad_port_leave(struct mlxsw_sp_bridge_device *bridge_device,
+				  struct mlxsw_sp_bridge_port *bridge_port,
+				  struct mlxsw_sp_port *mlxsw_sp_port)
+{
+	mlxsw_sp_bridge_vlan_aware_port_leave(mlxsw_sp_port);
+	mlxsw_sp_port_vlan_classification_set(mlxsw_sp_port, false, true);
+}
+
+static int
+mlxsw_sp_bridge_8021ad_vxlan_join(struct mlxsw_sp_bridge_device *bridge_device,
+				  const struct net_device *vxlan_dev, u16 vid,
+				  struct netlink_ext_ack *extack)
+{
+	NL_SET_ERR_MSG_MOD(extack, "VXLAN is not supported with 802.1ad");
+	return -EOPNOTSUPP;
+}
+
+static const struct mlxsw_sp_bridge_ops mlxsw_sp_bridge_8021ad_ops = {
+	.port_join	= mlxsw_sp_bridge_8021ad_port_join,
+	.port_leave	= mlxsw_sp_bridge_8021ad_port_leave,
+	.vxlan_join	= mlxsw_sp_bridge_8021ad_vxlan_join,
+	.fid_get	= mlxsw_sp_bridge_8021q_fid_get,
+	.fid_lookup	= mlxsw_sp_bridge_8021q_fid_lookup,
+	.fid_vid	= mlxsw_sp_bridge_8021q_fid_vid,
+};
+
 int mlxsw_sp_port_bridge_join(struct mlxsw_sp_port *mlxsw_sp_port,
 			      struct net_device *brport_dev,
 			      struct net_device *br_dev,
@@ -3527,6 +3585,7 @@ int mlxsw_sp_switchdev_init(struct mlxsw_sp *mlxsw_sp)
 
 	bridge->bridge_8021q_ops = &mlxsw_sp_bridge_8021q_ops;
 	bridge->bridge_8021d_ops = &mlxsw_sp_bridge_8021d_ops;
+	bridge->bridge_8021ad_ops = &mlxsw_sp_bridge_8021ad_ops;
 
 	return mlxsw_sp_fdb_init(mlxsw_sp);
 }