From: Vadim Pasternak <vadimp@mellanox.com>
Date: Sun, 6 Oct 2019 09:34:49 +0300
Subject: mlxsw: hwmon: Provide optimization for QSFP modules number detection
Patch-mainline: v5.5-rc1
Git-commit: ea30a92a4674eab955aee7bb8a017791f0e7d002
References: bsc#1154488

Use new field "num_of_modules" of MGPIR register for "hwmon" 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.

Reading this info through MGPIR register is faster and does not depend
on possible dynamic re-configuration of ports.
In case of port dynamic re-configuration some modules can logically
"disappear" as a result of port split and un-spilt operations, which
can cause missing of some modules, in case this info is taken 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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c |   64 ++++++++++-------------
 1 file changed, 29 insertions(+), 35 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c
@@ -41,7 +41,7 @@ struct mlxsw_hwmon {
 	struct mlxsw_hwmon_attr hwmon_attrs[MLXSW_HWMON_ATTR_COUNT];
 	unsigned int attrs_count;
 	u8 sensor_count;
-	u8 module_sensor_count;
+	u8 module_sensor_max;
 };
 
 static ssize_t mlxsw_hwmon_temp_show(struct device *dev,
@@ -56,7 +56,7 @@ static ssize_t mlxsw_hwmon_temp_show(str
 	int err;
 
 	index = mlxsw_hwmon_get_attr_index(mlwsw_hwmon_attr->type_index,
-					   mlxsw_hwmon->module_sensor_count);
+					   mlxsw_hwmon->module_sensor_max);
 	mlxsw_reg_mtmp_pack(mtmp_pl, index, false, false);
 	err = mlxsw_reg_query(mlxsw_hwmon->core, MLXSW_REG(mtmp), mtmp_pl);
 	if (err) {
@@ -79,7 +79,7 @@ static ssize_t mlxsw_hwmon_temp_max_show
 	int err;
 
 	index = mlxsw_hwmon_get_attr_index(mlwsw_hwmon_attr->type_index,
-					   mlxsw_hwmon->module_sensor_count);
+					   mlxsw_hwmon->module_sensor_max);
 	mlxsw_reg_mtmp_pack(mtmp_pl, index, false, false);
 	err = mlxsw_reg_query(mlxsw_hwmon->core, MLXSW_REG(mtmp), mtmp_pl);
 	if (err) {
@@ -109,7 +109,7 @@ static ssize_t mlxsw_hwmon_temp_rst_stor
 		return -EINVAL;
 
 	index = mlxsw_hwmon_get_attr_index(mlwsw_hwmon_attr->type_index,
-					   mlxsw_hwmon->module_sensor_count);
+					   mlxsw_hwmon->module_sensor_max);
 	mlxsw_reg_mtmp_pack(mtmp_pl, index, true, true);
 	err = mlxsw_reg_write(mlxsw_hwmon->core, MLXSW_REG(mtmp), mtmp_pl);
 	if (err) {
@@ -336,7 +336,7 @@ mlxsw_hwmon_gbox_temp_label_show(struct
 			container_of(attr, struct mlxsw_hwmon_attr, dev_attr);
 	struct mlxsw_hwmon *mlxsw_hwmon = mlwsw_hwmon_attr->hwmon;
 	int index = mlwsw_hwmon_attr->type_index -
-		    mlxsw_hwmon->module_sensor_count + 1;
+		    mlxsw_hwmon->module_sensor_max + 1;
 
 	return sprintf(buf, "gearbox %03u\n", index);
 }
@@ -528,51 +528,45 @@ static int mlxsw_hwmon_fans_init(struct
 
 static int mlxsw_hwmon_module_init(struct mlxsw_hwmon *mlxsw_hwmon)
 {
-	unsigned int module_count = mlxsw_core_max_ports(mlxsw_hwmon->core);
-	char pmlp_pl[MLXSW_REG_PMLP_LEN] = {0};
-	int i, index;
-	u8 width;
-	int err;
+	char mgpir_pl[MLXSW_REG_MGPIR_LEN];
+	u8 module_sensor_max;
+	int i, err;
 
 	if (!mlxsw_core_res_query_enabled(mlxsw_hwmon->core))
 		return 0;
 
+	mlxsw_reg_mgpir_pack(mgpir_pl);
+	err = mlxsw_reg_query(mlxsw_hwmon->core, MLXSW_REG(mgpir), mgpir_pl);
+	if (err)
+		return err;
+
+	mlxsw_reg_mgpir_unpack(mgpir_pl, NULL, NULL, NULL,
+			       &module_sensor_max);
+
 	/* Add extra attributes for module temperature. Sensor index is
 	 * assigned to sensor_count value, while all indexed before
 	 * sensor_count are already utilized by the sensors connected through
 	 * mtmp register by mlxsw_hwmon_temp_init().
 	 */
-	index = mlxsw_hwmon->sensor_count;
-	for (i = 1; i < module_count; i++) {
-		mlxsw_reg_pmlp_pack(pmlp_pl, i);
-		err = mlxsw_reg_query(mlxsw_hwmon->core, MLXSW_REG(pmlp),
-				      pmlp_pl);
-		if (err) {
-			dev_err(mlxsw_hwmon->bus_info->dev, "Failed to read module index %d\n",
-				i);
-			return err;
-		}
-		width = mlxsw_reg_pmlp_width_get(pmlp_pl);
-		if (!width)
-			continue;
+	mlxsw_hwmon->module_sensor_max = mlxsw_hwmon->sensor_count +
+					 module_sensor_max;
+	for (i = mlxsw_hwmon->sensor_count;
+	     i < mlxsw_hwmon->module_sensor_max; i++) {
 		mlxsw_hwmon_attr_add(mlxsw_hwmon,
-				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE, index,
-				     index);
+				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE, i, i);
 		mlxsw_hwmon_attr_add(mlxsw_hwmon,
 				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE_FAULT,
-				     index, index);
+				     i, i);
 		mlxsw_hwmon_attr_add(mlxsw_hwmon,
-				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE_CRIT,
-				     index, index);
+				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE_CRIT, i,
+				     i);
 		mlxsw_hwmon_attr_add(mlxsw_hwmon,
 				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE_EMERG,
-				     index, index);
+				     i, i);
 		mlxsw_hwmon_attr_add(mlxsw_hwmon,
 				     MLXSW_HWMON_ATTR_TYPE_TEMP_MODULE_LABEL,
-				     index, index);
-		index++;
+				     i, i);
 	}
-	mlxsw_hwmon->module_sensor_count = index;
 
 	return 0;
 }
@@ -594,10 +588,10 @@ static int mlxsw_hwmon_gearbox_init(stru
 	if (!gbox_num)
 		return 0;
 
-	index = mlxsw_hwmon->module_sensor_count;
-	max_index = mlxsw_hwmon->module_sensor_count + gbox_num;
+	index = mlxsw_hwmon->module_sensor_max;
+	max_index = mlxsw_hwmon->module_sensor_max + gbox_num;
 	while (index < max_index) {
-		sensor_index = index % mlxsw_hwmon->module_sensor_count +
+		sensor_index = index % mlxsw_hwmon->module_sensor_max +
 			       MLXSW_REG_MTMP_GBOX_INDEX_MIN;
 		mlxsw_reg_mtmp_pack(mtmp_pl, sensor_index, true, true);
 		err = mlxsw_reg_write(mlxsw_hwmon->core,