tools/lib/thermal: Add the threshold netlink ABI

The thermal framework supports the thresholds and allows the userspace
to create, delete, flush, get the list of the thresholds as well as
getting the list of the thresholds set for a specific thermal zone.

Add the netlink abstraction in the thermal library to take full
advantage of thresholds for the userspace program.

Signed-off-by: Daniel Lezcano <[e-mail]>
Reviewed-by: Lukasz Luba <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Rafael J. Wysocki <[e-mail]>

tools/lib/thermal/commands.c

···
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <limits.h>
 
 #include <thermal.h>
 #include "thermal_nl.h"
···
 	[THERMAL_GENL_ATTR_CDEV_CUR_STATE]      = { .type = NLA_U32 },
 	[THERMAL_GENL_ATTR_CDEV_MAX_STATE]      = { .type = NLA_U32 },
 	[THERMAL_GENL_ATTR_CDEV_NAME]           = { .type = NLA_STRING },
+
+        /* Thresholds */
+        [THERMAL_GENL_ATTR_THRESHOLD]      	= { .type = NLA_NESTED },
+        [THERMAL_GENL_ATTR_THRESHOLD_TEMP]      = { .type = NLA_U32 },
+        [THERMAL_GENL_ATTR_THRESHOLD_DIRECTION] = { .type = NLA_U32 },
 };
 
 static int parse_tz_get(struct genl_info *info, struct thermal_zone **tz)
···
 	return THERMAL_SUCCESS;
 }
 
+static int parse_threshold_get(struct genl_info *info, struct thermal_zone *tz)
+{
+	struct nlattr *attr;
+	struct thermal_threshold *__tt = NULL;
+	size_t size = 0;
+	int rem;
+
+	/*
+	 * The size contains the size of the array and we want to
+	 * access the last element, size - 1.
+	 *
+	 * The variable size is initialized to zero but it will be
+	 * then incremented by the first if() statement. The message
+	 * attributes are ordered, so the first if() statement will be
+	 * always called before the second one. If it happens that is
+	 * not the case, then it is a kernel bug.
+	 */
+	nla_for_each_nested(attr, info->attrs[THERMAL_GENL_ATTR_THRESHOLD], rem) {
+
+		if (nla_type(attr) == THERMAL_GENL_ATTR_THRESHOLD_TEMP) {
+
+			size++;
+
+			__tt = realloc(__tt, sizeof(*__tt) * (size + 2));
+			if (!__tt)
+				return THERMAL_ERROR;
+
+			__tt[size - 1].temperature = nla_get_u32(attr);
+		}
+
+		if (nla_type(attr) == THERMAL_GENL_ATTR_THRESHOLD_DIRECTION)
+			__tt[size - 1].direction = nla_get_u32(attr);
+	}
+
+	if (__tt)
+		__tt[size].temperature = INT_MAX;
+
+	tz->thresholds = __tt;
+
+	return THERMAL_SUCCESS;
+}
+
 static int handle_netlink(struct nl_cache_ops *unused,
 			  struct genl_cmd *cmd,
 			  struct genl_info *info, void *arg)
···
 
 	case THERMAL_GENL_CMD_TZ_GET_GOV:
 		ret = parse_tz_get_gov(info, arg);
+		break;
+
+	case THERMAL_GENL_CMD_THRESHOLD_GET:
+		ret = parse_threshold_get(info, arg);
 		break;
 
 	default:
···
 		.c_maxattr	= THERMAL_GENL_ATTR_MAX,
 		.c_attr_policy	= thermal_genl_policy,
 	},
+        {
+                .c_id           = THERMAL_GENL_CMD_THRESHOLD_GET,
+                .c_name         = (char *)"Get thresholds list",
+                .c_msg_parser   = handle_netlink,
+                .c_maxattr      = THERMAL_GENL_ATTR_MAX,
+                .c_attr_policy  = thermal_genl_policy,
+        },
+        {
+                .c_id           = THERMAL_GENL_CMD_THRESHOLD_ADD,
+                .c_name         = (char *)"Add a threshold",
+                .c_msg_parser   = handle_netlink,
+                .c_maxattr      = THERMAL_GENL_ATTR_MAX,
+                .c_attr_policy  = thermal_genl_policy,
+        },
+        {
+                .c_id           = THERMAL_GENL_CMD_THRESHOLD_DELETE,
+                .c_name         = (char *)"Delete a threshold",
+                .c_msg_parser   = handle_netlink,
+                .c_maxattr      = THERMAL_GENL_ATTR_MAX,
+                .c_attr_policy  = thermal_genl_policy,
+        },
+        {
+                .c_id           = THERMAL_GENL_CMD_THRESHOLD_FLUSH,
+                .c_name         = (char *)"Flush the thresholds",
+                .c_msg_parser   = handle_netlink,
+                .c_maxattr      = THERMAL_GENL_ATTR_MAX,
+                .c_attr_policy  = thermal_genl_policy,
+        },
 };
 
 static struct genl_ops thermal_cmd_ops = {
···
 
 struct cmd_param {
 	int tz_id;
+	int temp;
+	int direction;
 };
 
 typedef int (*cmd_cb_t)(struct nl_msg *, struct cmd_param *);
 
 static int thermal_genl_tz_id_encode(struct nl_msg *msg, struct cmd_param *p)
 {
-	if (p->tz_id >= 0 && nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id))
+	if (nla_put_u32(msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id))
+		return -1;
+
+	return 0;
+}
+
+static int thermal_genl_threshold_encode(struct nl_msg *msg, struct cmd_param *p)
+{
+	if (thermal_genl_tz_id_encode(msg, p))
+		return -1;
+
+	if (nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_TEMP, p->temp))
+		return -1;
+
+	if (nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_DIRECTION, p->direction))
 		return -1;
 
 	return 0;
···
 
 	return thermal_genl_auto(th, thermal_genl_tz_id_encode, &p,
 				 THERMAL_GENL_CMD_TZ_GET_TEMP, 0, tz);
+}
+
+thermal_error_t thermal_cmd_threshold_get(struct thermal_handler *th,
+                                          struct thermal_zone *tz)
+{
+	struct cmd_param p = { .tz_id = tz->id };
+
+        return thermal_genl_auto(th, thermal_genl_tz_id_encode, &p,
+				 THERMAL_GENL_CMD_THRESHOLD_GET, 0, tz);
+}
+
+thermal_error_t thermal_cmd_threshold_add(struct thermal_handler *th,
+                                          struct thermal_zone *tz,
+                                          int temperature,
+                                          int direction)
+{
+	struct cmd_param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };
+
+        return thermal_genl_auto(th, thermal_genl_threshold_encode, &p,
+				 THERMAL_GENL_CMD_THRESHOLD_ADD, 0, tz);
+}
+
+thermal_error_t thermal_cmd_threshold_delete(struct thermal_handler *th,
+                                             struct thermal_zone *tz,
+                                             int temperature,
+                                             int direction)
+{
+	struct cmd_param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };
+
+        return thermal_genl_auto(th, thermal_genl_threshold_encode, &p,
+				 THERMAL_GENL_CMD_THRESHOLD_DELETE, 0, tz);
+}
+
+thermal_error_t thermal_cmd_threshold_flush(struct thermal_handler *th,
+                                            struct thermal_zone *tz)
+{
+	struct cmd_param p = { .tz_id = tz->id };
+
+        return thermal_genl_auto(th, thermal_genl_tz_id_encode, &p,
+				 THERMAL_GENL_CMD_THRESHOLD_FLUSH, 0, tz);
 }
 
 thermal_error_t thermal_cmd_exit(struct thermal_handler *th)

tools/lib/thermal/events.c

···
 	case THERMAL_GENL_EVENT_TZ_GOV_CHANGE:
 		return ops->gov_change(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
 				       nla_get_string(attrs[THERMAL_GENL_ATTR_GOV_NAME]), arg);
+
+	case THERMAL_GENL_EVENT_THRESHOLD_ADD:
+		return ops->threshold_add(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+					  nla_get_u32(attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]),
+					  nla_get_u32(attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]), arg);
+
+	case THERMAL_GENL_EVENT_THRESHOLD_DELETE:
+		return ops->threshold_delete(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+					     nla_get_u32(attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]),
+					     nla_get_u32(attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]), arg);
+
+	case THERMAL_GENL_EVENT_THRESHOLD_FLUSH:
+		return ops->threshold_flush(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]), arg);
+
+	case THERMAL_GENL_EVENT_THRESHOLD_UP:
+		return ops->threshold_up(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+					 nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_TEMP]),
+					 nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_PREV_TEMP]), arg);
+
+	case THERMAL_GENL_EVENT_THRESHOLD_DOWN:
+		return ops->threshold_down(nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+					   nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_TEMP]),
+					   nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_PREV_TEMP]), arg);
+
 	default:
 		return -1;
 	}
···
 
 static void thermal_events_ops_init(struct thermal_events_ops *ops)
 {
-	enabled_ops[THERMAL_GENL_EVENT_TZ_CREATE]	= !!ops->tz_create;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_DELETE]	= !!ops->tz_delete;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_DISABLE]	= !!ops->tz_disable;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_ENABLE]	= !!ops->tz_enable;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_UP]	= !!ops->trip_high;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_DOWN]	= !!ops->trip_low;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_CHANGE]	= !!ops->trip_change;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_ADD]	= !!ops->trip_add;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_DELETE]	= !!ops->trip_delete;
-	enabled_ops[THERMAL_GENL_EVENT_CDEV_ADD]	= !!ops->cdev_add;
-	enabled_ops[THERMAL_GENL_EVENT_CDEV_DELETE]	= !!ops->cdev_delete;
-	enabled_ops[THERMAL_GENL_EVENT_CDEV_STATE_UPDATE] = !!ops->cdev_update;
-	enabled_ops[THERMAL_GENL_EVENT_TZ_GOV_CHANGE]	= !!ops->gov_change;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_CREATE]		= !!ops->tz_create;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_DELETE]		= !!ops->tz_delete;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_DISABLE]		= !!ops->tz_disable;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_ENABLE]		= !!ops->tz_enable;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_UP]		= !!ops->trip_high;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_DOWN]		= !!ops->trip_low;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_CHANGE]		= !!ops->trip_change;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_ADD]		= !!ops->trip_add;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_TRIP_DELETE]		= !!ops->trip_delete;
+	enabled_ops[THERMAL_GENL_EVENT_CDEV_ADD]		= !!ops->cdev_add;
+	enabled_ops[THERMAL_GENL_EVENT_CDEV_DELETE]		= !!ops->cdev_delete;
+	enabled_ops[THERMAL_GENL_EVENT_CDEV_STATE_UPDATE] 	= !!ops->cdev_update;
+	enabled_ops[THERMAL_GENL_EVENT_TZ_GOV_CHANGE]		= !!ops->gov_change;
+	enabled_ops[THERMAL_GENL_EVENT_THRESHOLD_ADD]		= !!ops->threshold_add;
+	enabled_ops[THERMAL_GENL_EVENT_THRESHOLD_DELETE]	= !!ops->threshold_delete;
+	enabled_ops[THERMAL_GENL_EVENT_THRESHOLD_FLUSH]		= !!ops->threshold_flush;
+	enabled_ops[THERMAL_GENL_EVENT_THRESHOLD_UP]		= !!ops->threshold_up;
+	enabled_ops[THERMAL_GENL_EVENT_THRESHOLD_DOWN]		= !!ops->threshold_down;
 }
 
 thermal_error_t thermal_events_handle(struct thermal_handler *th, void *arg)

tools/lib/thermal/include/thermal.h

···
 #define __LIBTHERMAL_H
 
 #include <linux/thermal.h>
+#include <sys/types.h>
 
 #ifndef LIBTHERMAL_API
 #define LIBTHERMAL_API __attribute__((visibility("default")))
+#endif
+
+#ifndef THERMAL_THRESHOLD_WAY_UP
+#define THERMAL_THRESHOLD_WAY_UP 0x1
+#endif
+
+#ifndef THERMAL_THRESHOLD_WAY_DOWN
+#define THERMAL_THRESHOLD_WAY_DOWN 0x2
 #endif
 
 #ifdef __cplusplus
···
 	int (*cdev_delete)(int cdev_id, void *arg);
 	int (*cdev_update)(int cdev_id, int cur_state, void *arg);
 	int (*gov_change)(int tz_id, const char *gov_name, void *arg);
+	int (*threshold_add)(int tz_id, int temperature, int direction, void *arg);
+	int (*threshold_delete)(int tz_id, int temperature, int direction, void *arg);
+	int (*threshold_flush)(int tz_id, void *arg);
+	int (*threshold_up)(int tz_id, int temp, int prev_temp, void *arg);
+	int (*threshold_down)(int tz_id, int temp, int prev_temp, void *arg);
 };
 
 struct thermal_ops {
···
 	int hyst;
 };
 
+struct thermal_threshold {
+	int temperature;
+	int direction;
+};
+
 struct thermal_zone {
 	int id;
 	int temp;
 	char name[THERMAL_NAME_LENGTH];
 	char governor[THERMAL_NAME_LENGTH];
 	struct thermal_trip *trip;
+	struct thermal_threshold *thresholds;
 };
 
 struct thermal_cdev {
···
 
 typedef int (*cb_tc_t)(struct thermal_cdev *, void *);
 
+typedef int (*cb_th_t)(struct thermal_threshold *, void *);
+
 LIBTHERMAL_API int for_each_thermal_zone(struct thermal_zone *tz, cb_tz_t cb, void *arg);
 
 LIBTHERMAL_API int for_each_thermal_trip(struct thermal_trip *tt, cb_tt_t cb, void *arg);
 
 LIBTHERMAL_API int for_each_thermal_cdev(struct thermal_cdev *cdev, cb_tc_t cb, void *arg);
+
+LIBTHERMAL_API int for_each_thermal_threshold(struct thermal_threshold *th, cb_th_t cb, void *arg);
 
 LIBTHERMAL_API struct thermal_zone *thermal_zone_find_by_name(struct thermal_zone *tz,
 							      const char *name);
···
 
 LIBTHERMAL_API thermal_error_t thermal_cmd_get_temp(struct thermal_handler *th,
 						    struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_get(struct thermal_handler *th,
+							 struct thermal_zone *tz);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_add(struct thermal_handler *th,
+                                                         struct thermal_zone *tz,
+                                                         int temperature,
+                                                         int direction);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_delete(struct thermal_handler *th,
+                                                            struct thermal_zone *tz,
+                                                            int temperature,
+                                                            int direction);
+
+LIBTHERMAL_API thermal_error_t thermal_cmd_threshold_flush(struct thermal_handler *th,
+                                                           struct thermal_zone *tz);
 
 /*
  * Netlink thermal samples

tools/lib/thermal/libthermal.map

···
 		for_each_thermal_zone;
 		for_each_thermal_trip;
 		for_each_thermal_cdev;
+		for_each_thermal_threshold;
 		thermal_zone_find_by_name;
 		thermal_zone_find_by_id;
 		thermal_zone_discover;
···
 		thermal_cmd_get_trip;
 		thermal_cmd_get_governor;
 		thermal_cmd_get_temp;
+		thermal_cmd_threshold_get;
+		thermal_cmd_threshold_add;
+		thermal_cmd_threshold_delete;
+		thermal_cmd_threshold_flush;
 		thermal_sampling_init;
 		thermal_sampling_handle;
 		thermal_sampling_fd;

tools/lib/thermal/thermal.c

···
 // SPDX-License-Identifier: LGPL-2.1+
 // Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <[e-mail]>
 #include <stdio.h>
+#include <limits.h>
 #include <thermal.h>
 
 #include "thermal_nl.h"
+
+int for_each_thermal_threshold(struct thermal_threshold *th, cb_th_t cb, void *arg)
+{
+	int i, ret = 0;
+
+	if (!th)
+		return 0;
+
+	for (i = 0; th[i].temperature != INT_MAX; i++)
+		ret |= cb(&th[i], arg);
+
+	return ret;
+}
 
 int for_each_thermal_cdev(struct thermal_cdev *cdev, cb_tc_t cb, void *arg)
 {
···
 static int __thermal_zone_discover(struct thermal_zone *tz, void *th)
 {
 	if (thermal_cmd_get_trip(th, tz) < 0)
+		return -1;
+
+	if (thermal_cmd_threshold_get(th, tz))
 		return -1;
 
 	if (thermal_cmd_get_governor(th, tz))

tools/thermal/lib/Makefile

···
 
 LIBTHERMAL_TOOLS_VERSION = 0
 LIBTHERMAL_TOOLS_PATCHLEVEL = 0
-LIBTHERMAL_TOOLS_EXTRAVERSION = 1
+LIBTHERMAL_TOOLS_EXTRAVERSION = 2
 
 MAKEFLAGS += --no-print-directory