mlxsw: spectrum: Add mlxsw_sp_port_egress_ethtype_set()

A subsequent patch will cause decapsulated packets to have their EtherType
determined by the egress port. Add mlxsw_sp_port_egress_ethtype_set() which
will be called when a port joins an 802.1ad bridge, so that it will set an
802.1ad EtherType on decapsulated packets transmitted through it, instead
of the default 802.1q EtherType.

Signed-off-by: Amit Cohen <[e-mail]>
Signed-off-by: Ido Schimmel <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

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

···
 	return 0;
 }
 
+int mlxsw_sp_port_egress_ethtype_set(struct mlxsw_sp_port *mlxsw_sp_port,
+				     u16 ethtype)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	char spevet_pl[MLXSW_REG_SPEVET_LEN];
+	u8 sver_type;
+	int err;
+
+	err = mlxsw_sp_ethtype_to_sver_type(ethtype, &sver_type);
+	if (err)
+		return err;
+
+	mlxsw_reg_spevet_pack(spevet_pl, mlxsw_sp_port->local_port, sver_type);
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(spevet), spevet_pl);
+}
+
 static int __mlxsw_sp_port_pvid_set(struct mlxsw_sp_port *mlxsw_sp_port,
 				    u16 vid, u16 ethtype)
 {

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

···
 int mlxsw_sp_port_vid_learning_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 vid,
 				   bool learn_enable);
 int mlxsw_sp_ethtype_to_sver_type(u16 ethtype, u8 *p_sver_type);
+int mlxsw_sp_port_egress_ethtype_set(struct mlxsw_sp_port *mlxsw_sp_port,
+				     u16 ethtype);
 int mlxsw_sp_port_pvid_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 vid,
 			   u16 ethtype);
 struct mlxsw_sp_port_vlan *