mlxsw: spectrum: Add lowest_shaper_bs to struct mlxsw_sp

Lower limit of burst size configuration is dependent on system type. Add a
datum to track the value. Initialize as appropriate in mlxsw_spX_init().
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -5173,6 +5173,7 @@ static int mlxsw_sp1_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->span_ops = &mlxsw_sp1_span_ops;
 	mlxsw_sp->listeners = mlxsw_sp1_listener;
 	mlxsw_sp->listeners_count = ARRAY_SIZE(mlxsw_sp1_listener);
+	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP1;
 
 	return mlxsw_sp_init(mlxsw_core, mlxsw_bus_info, extack);
 }
@@ -5197,6 +5198,7 @@ static int mlxsw_sp2_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->port_type_speed_ops = &mlxsw_sp2_port_type_speed_ops;
 	mlxsw_sp->ptp_ops = &mlxsw_sp2_ptp_ops;
 	mlxsw_sp->span_ops = &mlxsw_sp2_span_ops;
+	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP2;
 
 	return mlxsw_sp_init(mlxsw_core, mlxsw_bus_info, extack);
 }
@@ -5219,6 +5221,7 @@ static int mlxsw_sp3_init(struct mlxsw_core *mlxsw_core,
 	mlxsw_sp->port_type_speed_ops = &mlxsw_sp2_port_type_speed_ops;
 	mlxsw_sp->ptp_ops = &mlxsw_sp2_ptp_ops;
 	mlxsw_sp->span_ops = &mlxsw_sp2_span_ops;
+	mlxsw_sp->lowest_shaper_bs = MLXSW_REG_QEEC_LOWEST_SHAPER_BS_SP3;
 
 	return mlxsw_sp_init(mlxsw_core, mlxsw_bus_info, extack);
 }

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

@@ -189,6 +189,7 @@ struct mlxsw_sp {
 	const struct mlxsw_sp_span_ops *span_ops;
 	const struct mlxsw_listener *listeners;
 	size_t listeners_count;
+	u32 lowest_shaper_bs;
 };
 
 static inline struct mlxsw_sp_upper *