mlxsw: spectrum: Track used packet trap policer IDs

During initialization the driver configures various packet trap groups
and binds policers to them.

Currently, most of these groups are not exposed to user space and
therefore their policers should not be exposed as well. Otherwise, user
space will be able to alter policer parameters without knowing which
packet traps are policed by the policer.

Use a bitmap to track the used policer IDs so that these policers will
not be registered with devlink in a subsequent patch.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -43,6 +43,7 @@
 #include "spectrum_acl_flex_actions.h"
 #include "spectrum_span.h"
 #include "spectrum_ptp.h"
+#include "spectrum_trap.h"
 #include "../mlxfw/mlxfw.h"
 
 #define MLXSW_SP1_FWREV_MAJOR 13
@@ -4556,6 +4557,7 @@ static const struct mlxsw_listener mlxsw_sp1_listener[] = {
 
 static int mlxsw_sp_cpu_policers_set(struct mlxsw_core *mlxsw_core)
 {
+	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	char qpcr_pl[MLXSW_REG_QPCR_LEN];
 	enum mlxsw_reg_qpcr_ir_units ir_units;
 	int max_cpu_policers;
@@ -4619,6 +4621,7 @@ static int mlxsw_sp_cpu_policers_set(struct mlxsw_core *mlxsw_core)
 			continue;
 		}
 
+		__set_bit(i, mlxsw_sp->trap->policers_usage);
 		mlxsw_reg_qpcr_pack(qpcr_pl, i, ir_units, is_bytes, rate,
 				    burst_size);
 		err = mlxsw_reg_write(mlxsw_core, MLXSW_REG(qpcr), qpcr_pl);
@@ -4747,20 +4750,32 @@ static void mlxsw_sp_traps_unregister(struct mlxsw_sp *mlxsw_sp,
 
 static int mlxsw_sp_traps_init(struct mlxsw_sp *mlxsw_sp)
 {
+	struct mlxsw_sp_trap *trap;
+	u64 max_policers;
 	int err;
 
+	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_CPU_POLICERS))
+		return -EIO;
+	max_policers = MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_CPU_POLICERS);
+	trap = kzalloc(struct_size(trap, policers_usage,
+				   BITS_TO_LONGS(max_policers)), GFP_KERNEL);
+	if (!trap)
+		return -ENOMEM;
+	trap->max_policers = max_policers;
+	mlxsw_sp->trap = trap;
+
 	err = mlxsw_sp_cpu_policers_set(mlxsw_sp->core);
 	if (err)
-		return err;
+		goto err_cpu_policers_set;
 
 	err = mlxsw_sp_trap_groups_set(mlxsw_sp->core);
 	if (err)
-		return err;
+		goto err_trap_groups_set;
 
 	err = mlxsw_sp_traps_register(mlxsw_sp, mlxsw_sp_listener,
 				      ARRAY_SIZE(mlxsw_sp_listener));
 	if (err)
-		return err;
+		goto err_traps_register;
 
 	err = mlxsw_sp_traps_register(mlxsw_sp, mlxsw_sp->listeners,
 				      mlxsw_sp->listeners_count);
@@ -4772,6 +4787,10 @@ static int mlxsw_sp_traps_init(struct mlxsw_sp *mlxsw_sp)
 err_extra_traps_init:
 	mlxsw_sp_traps_unregister(mlxsw_sp, mlxsw_sp_listener,
 				  ARRAY_SIZE(mlxsw_sp_listener));
+err_traps_register:
+err_trap_groups_set:
+err_cpu_policers_set:
+	kfree(trap);
 	return err;
 }
 
@@ -4781,6 +4800,7 @@ static void mlxsw_sp_traps_fini(struct mlxsw_sp *mlxsw_sp)
 				  mlxsw_sp->listeners_count);
 	mlxsw_sp_traps_unregister(mlxsw_sp, mlxsw_sp_listener,
 				  ARRAY_SIZE(mlxsw_sp_listener));
+	kfree(mlxsw_sp->trap);
 }
 
 #define MLXSW_SP_LAG_SEED_INIT 0xcafecafe

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

@@ -176,6 +176,7 @@ struct mlxsw_sp {
 	struct mlxsw_sp_ptp_state *ptp_state;
 	struct mlxsw_sp_counter_pool *counter_pool;
 	struct mlxsw_sp_span *span;
+	struct mlxsw_sp_trap *trap;
 	const struct mlxsw_fw_rev *req_rev;
 	const char *fw_filename;
 	const struct mlxsw_sp_kvdl_ops *kvdl_ops;

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

@@ -8,6 +8,7 @@
 #include "core.h"
 #include "reg.h"
 #include "spectrum.h"
+#include "spectrum_trap.h"
 
 /* All driver-specific traps must be documented in
  * Documentation/networking/devlink/mlxsw.rst
@@ -309,6 +310,7 @@ static int mlxsw_sp_trap_cpu_policers_set(struct mlxsw_sp *mlxsw_sp)
 	/* The purpose of "thin" policer is to drop as many packets
 	 * as possible. The dummy group is using it.
 	 */
+	__set_bit(MLXSW_SP_THIN_POLICER_ID, mlxsw_sp->trap->policers_usage);
 	mlxsw_reg_qpcr_pack(qpcr_pl, MLXSW_SP_THIN_POLICER_ID,
 			    MLXSW_REG_QPCR_IR_UNITS_M, false, 1, 4);
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(qpcr), qpcr_pl);

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

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+/* Copyright (c) 2020 Mellanox Technologies. All rights reserved */
+
+#ifndef _MLXSW_SPECTRUM_TRAP_H
+#define _MLXSW_SPECTRUM_TRAP_H
+
+struct mlxsw_sp_trap {
+	u64 max_policers;
+	unsigned long policers_usage[]; /* Usage bitmap */
+};
+
+#endif