mlxsw: spectrum_buffers: Set a minimum quota for CPU port traffic

In commit 9ffcc372 ("mlxsw: spectrum: Allow packets to be trapped
from any PG") I fixed a problem where packets could not be trapped to
the CPU due to exceeded shared buffer quotas. The mentioned commit
explains the problem in detail.

The problem was fixed by assigning a minimum quota for the CPU port and
the traffic class used for scheduling traffic to the CPU.

However, commit 117b0dad ("mlxsw: Create a different trap group list
for each device") assigned different traffic classes to different
packet types and rendered the fix useless.

Fix the problem by assigning a minimum quota for the CPU port and all
the traffic classes that are currently in use.

Fixes: 117b0dad ("mlxsw: Create a different trap group list for each device")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Eddie Shklaer <eddies@mellanox.com>
Tested-by: Eddie Shklaer <eddies@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -385,13 +385,13 @@ static const struct mlxsw_sp_sb_cm mlxsw_sp_sb_cms_egress[] = {
 
 static const struct mlxsw_sp_sb_cm mlxsw_sp_cpu_port_sb_cms[] = {
 	MLXSW_SP_CPU_PORT_SB_CM,
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
 	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_CPU_PORT_SB_CM,
-	MLXSW_SP_SB_CM(10000, 0, 0),
+	MLXSW_SP_SB_CM(MLXSW_PORT_MAX_MTU, 0, 0),
 	MLXSW_SP_CPU_PORT_SB_CM,
 	MLXSW_SP_CPU_PORT_SB_CM,
 	MLXSW_SP_CPU_PORT_SB_CM,