mlxsw: thermal: Provide optimization for QSFP modules number detection

Use new field "num_of_modules" of MGPIR register for "thermal" interface
in order to get the number of modules supported by system directly from
the system configuration, instead of getting it from port to module
mapping info.

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

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

@@ -112,6 +112,7 @@ struct mlxsw_thermal {
 	struct mlxsw_thermal_trip trips[MLXSW_THERMAL_NUM_TRIPS];
 	enum thermal_device_mode mode;
 	struct mlxsw_thermal_module *tz_module_arr;
+	u8 tz_module_num;
 	struct mlxsw_thermal_module *tz_gearbox_arr;
 	u8 tz_gearbox_num;
 	unsigned int tz_highest_score;
@@ -775,23 +776,10 @@ static void mlxsw_thermal_module_tz_fini(struct thermal_zone_device *tzdev)
 
 static int
 mlxsw_thermal_module_init(struct device *dev, struct mlxsw_core *core,
-			  struct mlxsw_thermal *thermal, u8 local_port)
+			  struct mlxsw_thermal *thermal, u8 module)
 {
 	struct mlxsw_thermal_module *module_tz;
-	char pmlp_pl[MLXSW_REG_PMLP_LEN];
-	u8 width, module;
-	int err;
-
-	mlxsw_reg_pmlp_pack(pmlp_pl, local_port);
-	err = mlxsw_reg_query(core, MLXSW_REG(pmlp), pmlp_pl);
-	if (err)
-		return err;
 
-	width = mlxsw_reg_pmlp_width_get(pmlp_pl);
-	if (!width)
-		return 0;
-
-	module = mlxsw_reg_pmlp_module_get(pmlp_pl, 0);
 	module_tz = &thermal->tz_module_arr[module];
 	/* Skip if parent is already set (case of port split). */
 	if (module_tz->parent)
@@ -819,26 +807,34 @@ static int
 mlxsw_thermal_modules_init(struct device *dev, struct mlxsw_core *core,
 			   struct mlxsw_thermal *thermal)
 {
-	unsigned int module_count = mlxsw_core_max_ports(core);
 	struct mlxsw_thermal_module *module_tz;
+	char mgpir_pl[MLXSW_REG_MGPIR_LEN];
 	int i, err;
 
 	if (!mlxsw_core_res_query_enabled(core))
 		return 0;
 
-	thermal->tz_module_arr = kcalloc(module_count,
+	mlxsw_reg_mgpir_pack(mgpir_pl);
+	err = mlxsw_reg_query(core, MLXSW_REG(mgpir), mgpir_pl);
+	if (err)
+		return err;
+
+	mlxsw_reg_mgpir_unpack(mgpir_pl, NULL, NULL, NULL,
+			       &thermal->tz_module_num);
+
+	thermal->tz_module_arr = kcalloc(thermal->tz_module_num,
 					 sizeof(*thermal->tz_module_arr),
 					 GFP_KERNEL);
 	if (!thermal->tz_module_arr)
 		return -ENOMEM;
 
-	for (i = 1; i < module_count; i++) {
+	for (i = 0; i < thermal->tz_module_num; i++) {
 		err = mlxsw_thermal_module_init(dev, core, thermal, i);
 		if (err)
 			goto err_unreg_tz_module_arr;
 	}
 
-	for (i = 0; i < module_count - 1; i++) {
+	for (i = 0; i < thermal->tz_module_num; i++) {
 		module_tz = &thermal->tz_module_arr[i];
 		if (!module_tz->parent)
 			continue;
@@ -850,7 +846,7 @@ mlxsw_thermal_modules_init(struct device *dev, struct mlxsw_core *core,
 	return 0;
 
 err_unreg_tz_module_arr:
-	for (i = module_count - 1; i >= 0; i--)
+	for (i = thermal->tz_module_num - 1; i >= 0; i--)
 		mlxsw_thermal_module_fini(&thermal->tz_module_arr[i]);
 	kfree(thermal->tz_module_arr);
 	return err;
@@ -859,13 +855,12 @@ mlxsw_thermal_modules_init(struct device *dev, struct mlxsw_core *core,
 static void
 mlxsw_thermal_modules_fini(struct mlxsw_thermal *thermal)
 {
-	unsigned int module_count = mlxsw_core_max_ports(thermal->core);
 	int i;
 
 	if (!mlxsw_core_res_query_enabled(thermal->core))
 		return;
 
-	for (i = module_count - 1; i >= 0; i--)
+	for (i = thermal->tz_module_num - 1; i >= 0; i--)
 		mlxsw_thermal_module_fini(&thermal->tz_module_arr[i]);
 	kfree(thermal->tz_module_arr);
 }