thermal: netlink: Add the commands and the events for the thresholds

The thresholds exist but there is no notification neither action code
related to them yet.

These changes implement the netlink for the notifications when the
thresholds are crossed, added, deleted or flushed as well as the
commands which allows to get the list of the thresholds, flush them,
add and delete.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20241022155147.463475-3-daniel.lezcano@linaro.org
[ rjw: Use the thermal_zone guard for locking, subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/thermal/thermal_netlink.c

@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/kernel.h>
+#include <net/sock.h>
 #include <net/genetlink.h>
 #include <uapi/linux/thermal.h>
 
@@ -49,6 +50,11 @@ static const struct nla_policy thermal_genl_policy[THERMAL_GENL_ATTR_MAX + 1] =
 	[THERMAL_GENL_ATTR_CPU_CAPABILITY_ID]		= { .type = NLA_U32 },
 	[THERMAL_GENL_ATTR_CPU_CAPABILITY_PERFORMANCE]	= { .type = NLA_U32 },
 	[THERMAL_GENL_ATTR_CPU_CAPABILITY_EFFICIENCY]	= { .type = NLA_U32 },
+
+	/* Thresholds */
+	[THERMAL_GENL_ATTR_THRESHOLD]		= { .type = NLA_NESTED },
+	[THERMAL_GENL_ATTR_THRESHOLD_TEMP]	= { .type = NLA_U32 },
+	[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]	= { .type = NLA_U32 },
 };
 
 struct param {
@@ -62,6 +68,8 @@ struct param {
 	int trip_type;
 	int trip_hyst;
 	int temp;
+	int prev_temp;
+	int direction;
 	int cdev_state;
 	int cdev_max_state;
 	struct thermal_genl_cpu_caps *cpu_capabilities;
@@ -234,6 +242,34 @@ static int thermal_genl_event_cpu_capability_change(struct param *p)
 	return -EMSGSIZE;
 }
 
+static int thermal_genl_event_threshold_add(struct param *p)
+{
+	if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
+	    nla_put_u32(p->msg, THERMAL_GENL_ATTR_THRESHOLD_TEMP, p->temp) ||
+	    nla_put_u32(p->msg, THERMAL_GENL_ATTR_THRESHOLD_DIRECTION, p->direction))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int thermal_genl_event_threshold_flush(struct param *p)
+{
+	if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int thermal_genl_event_threshold_up(struct param *p)
+{
+	if (nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_ID, p->tz_id) ||
+	    nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_PREV_TEMP, p->prev_temp) ||
+	    nla_put_u32(p->msg, THERMAL_GENL_ATTR_TZ_TEMP, p->temp))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 int thermal_genl_event_tz_delete(struct param *p)
 	__attribute__((alias("thermal_genl_event_tz")));
 
@@ -246,6 +282,12 @@ int thermal_genl_event_tz_disable(struct param *p)
 int thermal_genl_event_tz_trip_down(struct param *p)
 	__attribute__((alias("thermal_genl_event_tz_trip_up")));
 
+int thermal_genl_event_threshold_delete(struct param *p)
+	__attribute__((alias("thermal_genl_event_threshold_add")));
+
+int thermal_genl_event_threshold_down(struct param *p)
+	__attribute__((alias("thermal_genl_event_threshold_up")));
+
 static cb_t event_cb[] = {
 	[THERMAL_GENL_EVENT_TZ_CREATE]		= thermal_genl_event_tz_create,
 	[THERMAL_GENL_EVENT_TZ_DELETE]		= thermal_genl_event_tz_delete,
@@ -259,6 +301,11 @@ static cb_t event_cb[] = {
 	[THERMAL_GENL_EVENT_CDEV_STATE_UPDATE]	= thermal_genl_event_cdev_state_update,
 	[THERMAL_GENL_EVENT_TZ_GOV_CHANGE]	= thermal_genl_event_gov_change,
 	[THERMAL_GENL_EVENT_CPU_CAPABILITY_CHANGE] = thermal_genl_event_cpu_capability_change,
+	[THERMAL_GENL_EVENT_THRESHOLD_ADD]	= thermal_genl_event_threshold_add,
+	[THERMAL_GENL_EVENT_THRESHOLD_DELETE]	= thermal_genl_event_threshold_delete,
+	[THERMAL_GENL_EVENT_THRESHOLD_FLUSH]	= thermal_genl_event_threshold_flush,
+	[THERMAL_GENL_EVENT_THRESHOLD_DOWN]	= thermal_genl_event_threshold_down,
+	[THERMAL_GENL_EVENT_THRESHOLD_UP]	= thermal_genl_event_threshold_up,
 };
 
 /*
@@ -401,6 +448,43 @@ int thermal_genl_cpu_capability_event(int count,
 }
 EXPORT_SYMBOL_GPL(thermal_genl_cpu_capability_event);
 
+int thermal_notify_threshold_add(const struct thermal_zone_device *tz,
+				 int temperature, int direction)
+{
+	struct param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };
+
+	return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_ADD, &p);
+}
+
+int thermal_notify_threshold_delete(const struct thermal_zone_device *tz,
+				    int temperature, int direction)
+{
+	struct param p = { .tz_id = tz->id, .temp = temperature, .direction = direction };
+
+	return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_DELETE, &p);
+}
+
+int thermal_notify_threshold_flush(const struct thermal_zone_device *tz)
+{
+	struct param p = { .tz_id = tz->id };
+
+	return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_FLUSH, &p);
+}
+
+int thermal_notify_threshold_down(const struct thermal_zone_device *tz)
+{
+	struct param p = { .tz_id = tz->id, .temp = tz->temperature, .prev_temp = tz->last_temperature };
+
+	return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_DOWN, &p);
+}
+
+int thermal_notify_threshold_up(const struct thermal_zone_device *tz)
+{
+	struct param p = { .tz_id = tz->id, .temp = tz->temperature, .prev_temp = tz->last_temperature };
+
+	return thermal_genl_send_event(THERMAL_GENL_EVENT_THRESHOLD_UP, &p);
+}
+
 /*************************** Command encoding ********************************/
 
 static int __thermal_genl_cmd_tz_get_id(struct thermal_zone_device *tz,
@@ -563,12 +647,128 @@ static int thermal_genl_cmd_cdev_get(struct param *p)
 	return ret;
 }
 
+static int __thermal_genl_cmd_threshold_get(struct user_threshold *threshold, void *arg)
+{
+	struct sk_buff *msg = arg;
+
+	if (nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_TEMP, threshold->temperature) ||
+	    nla_put_u32(msg, THERMAL_GENL_ATTR_THRESHOLD_DIRECTION, threshold->direction))
+		return -1;
+
+	return 0;
+}
+
+static int thermal_genl_cmd_threshold_get(struct param *p)
+{
+	struct sk_buff *msg = p->msg;
+	struct nlattr *start_trip;
+	int id, ret;
+
+	if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
+		return -EINVAL;
+
+	id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
+
+	CLASS(thermal_zone_get_by_id, tz)(id);
+	if (!tz)
+		return -EINVAL;
+
+	start_trip = nla_nest_start(msg, THERMAL_GENL_ATTR_THRESHOLD);
+	if (!start_trip)
+		return -EMSGSIZE;
+
+	ret = thermal_thresholds_for_each(tz, __thermal_genl_cmd_threshold_get, msg);
+	if (ret)
+		return -EMSGSIZE;
+
+	nla_nest_end(msg, start_trip);
+
+	return 0;
+}
+
+static int thermal_genl_cmd_threshold_add(struct param *p)
+{
+	int id, temp, direction;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID] ||
+	    !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP] ||
+	    !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION])
+		return -EINVAL;
+
+	id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
+	temp = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]);
+	direction = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]);
+
+	CLASS(thermal_zone_get_by_id, tz)(id);
+	if (!tz)
+		return -EINVAL;
+
+	guard(thermal_zone)(tz);
+
+	return thermal_thresholds_add(tz, temp, direction);
+}
+
+static int thermal_genl_cmd_threshold_delete(struct param *p)
+{
+	int id, temp, direction;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID] ||
+	    !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP] ||
+	    !p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION])
+		return -EINVAL;
+
+	id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
+	temp = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_TEMP]);
+	direction = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_THRESHOLD_DIRECTION]);
+
+	CLASS(thermal_zone_get_by_id, tz)(id);
+	if (!tz)
+		return -EINVAL;
+
+	guard(thermal_zone)(tz);
+
+	return thermal_thresholds_delete(tz, temp, direction);
+}
+
+static int thermal_genl_cmd_threshold_flush(struct param *p)
+{
+	int id;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (!p->attrs[THERMAL_GENL_ATTR_TZ_ID])
+		return -EINVAL;
+
+	id = nla_get_u32(p->attrs[THERMAL_GENL_ATTR_TZ_ID]);
+
+	CLASS(thermal_zone_get_by_id, tz)(id);
+	if (!tz)
+		return -EINVAL;
+
+	guard(thermal_zone)(tz);
+
+	thermal_thresholds_flush(tz);
+
+	return 0;
+}
+
 static cb_t cmd_cb[] = {
 	[THERMAL_GENL_CMD_TZ_GET_ID]		= thermal_genl_cmd_tz_get_id,
 	[THERMAL_GENL_CMD_TZ_GET_TRIP]		= thermal_genl_cmd_tz_get_trip,
 	[THERMAL_GENL_CMD_TZ_GET_TEMP]		= thermal_genl_cmd_tz_get_temp,
 	[THERMAL_GENL_CMD_TZ_GET_GOV]		= thermal_genl_cmd_tz_get_gov,
 	[THERMAL_GENL_CMD_CDEV_GET]		= thermal_genl_cmd_cdev_get,
+	[THERMAL_GENL_CMD_THRESHOLD_GET]	= thermal_genl_cmd_threshold_get,
+	[THERMAL_GENL_CMD_THRESHOLD_ADD]	= thermal_genl_cmd_threshold_add,
+	[THERMAL_GENL_CMD_THRESHOLD_DELETE]	= thermal_genl_cmd_threshold_delete,
+	[THERMAL_GENL_CMD_THRESHOLD_FLUSH]	= thermal_genl_cmd_threshold_flush,
 };
 
 static int thermal_genl_cmd_dumpit(struct sk_buff *skb,
@@ -679,6 +879,26 @@ static const struct genl_small_ops thermal_genl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.dumpit = thermal_genl_cmd_dumpit,
 	},
+	{
+		.cmd = THERMAL_GENL_CMD_THRESHOLD_GET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = thermal_genl_cmd_doit,
+	},
+	{
+		.cmd = THERMAL_GENL_CMD_THRESHOLD_ADD,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = thermal_genl_cmd_doit,
+	},
+	{
+		.cmd = THERMAL_GENL_CMD_THRESHOLD_DELETE,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = thermal_genl_cmd_doit,
+	},
+	{
+		.cmd = THERMAL_GENL_CMD_THRESHOLD_FLUSH,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = thermal_genl_cmd_doit,
+	},
 };
 
 static struct genl_family thermal_genl_family __ro_after_init = {
@@ -691,7 +911,7 @@ static struct genl_family thermal_genl_family __ro_after_init = {
 	.unbind		= thermal_genl_unbind,
 	.small_ops	= thermal_genl_ops,
 	.n_small_ops	= ARRAY_SIZE(thermal_genl_ops),
-	.resv_start_op	= THERMAL_GENL_CMD_CDEV_GET + 1,
+	.resv_start_op	= __THERMAL_GENL_CMD_MAX,
 	.mcgrps		= thermal_genl_mcgrps,
 	.n_mcgrps	= ARRAY_SIZE(thermal_genl_mcgrps),
 };

drivers/thermal/thermal_netlink.h

@@ -53,6 +53,13 @@ int thermal_notify_tz_gov_change(const struct thermal_zone_device *tz,
 int thermal_genl_sampling_temp(int id, int temp);
 int thermal_genl_cpu_capability_event(int count,
 				      struct thermal_genl_cpu_caps *caps);
+int thermal_notify_threshold_add(const struct thermal_zone_device *tz,
+				 int temperature, int direction);
+int thermal_notify_threshold_delete(const struct thermal_zone_device *tz,
+				    int temperature, int direction);
+int thermal_notify_threshold_flush(const struct thermal_zone_device *tz);
+int thermal_notify_threshold_down(const struct thermal_zone_device *tz);
+int thermal_notify_threshold_up(const struct thermal_zone_device *tz);
 #else
 static inline int thermal_netlink_init(void)
 {
@@ -139,6 +146,33 @@ static inline int thermal_genl_cpu_capability_event(int count, struct thermal_ge
 	return 0;
 }
 
+static inline int thermal_notify_threshold_add(const struct thermal_zone_device *tz,
+					       int temperature, int direction)
+{
+	return 0;
+}
+
+static inline int thermal_notify_threshold_delete(const struct thermal_zone_device *tz,
+						  int temperature, int direction)
+{
+	return 0;
+}
+
+static inline int thermal_notify_threshold_flush(const struct thermal_zone_device *tz)
+{
+	return 0;
+}
+
+static inline int thermal_notify_threshold_down(const struct thermal_zone_device *tz)
+{
+	return 0;
+}
+
+static inline int thermal_notify_threshold_up(const struct thermal_zone_device *tz)
+{
+	return 0;
+}
+
 static inline void __init thermal_netlink_exit(void) {}
 
 #endif /* CONFIG_THERMAL_NETLINK */

drivers/thermal/thermal_thresholds.c

@@ -32,6 +32,8 @@ void thermal_thresholds_flush(struct thermal_zone_device *tz)
 		kfree(entry);
 	}
 
+	thermal_notify_threshold_flush(tz);
+
 	__thermal_zone_device_update(tz, THERMAL_TZ_FLUSH_THRESHOLDS);
 }
 
@@ -122,7 +124,6 @@ void thermal_thresholds_handle(struct thermal_zone_device *tz, int *low, int *hi
 
 	int temperature = tz->temperature;
 	int last_temperature = tz->last_temperature;
-	bool notify;
 
 	lockdep_assert_held(&tz->lock);
 
@@ -144,19 +145,19 @@ void thermal_thresholds_handle(struct thermal_zone_device *tz, int *low, int *hi
 	 * - increased : thresholds are crossed the way up
 	 * - decreased : thresholds are crossed the way down
 	 */
-	if (temperature > last_temperature)
-		notify = thermal_thresholds_handle_raising(thresholds, temperature,
-							   last_temperature, low, high);
-	else
-		notify = thermal_thresholds_handle_dropping(thresholds, temperature,
-							    last_temperature, low, high);
-
-	if (notify)
-		pr_debug("A threshold has been crossed the way %s, with a temperature=%d, last_temperature=%d\n",
-			 temperature > last_temperature ? "up" : "down", temperature, last_temperature);
+	if (temperature > last_temperature) {
+		if (thermal_thresholds_handle_raising(thresholds, temperature,
+						      last_temperature, low, high))
+			thermal_notify_threshold_up(tz);
+	} else {
+		if (thermal_thresholds_handle_dropping(thresholds, temperature,
+						       last_temperature, low, high))
+			thermal_notify_threshold_down(tz);
+	}
 }
 
-int thermal_thresholds_add(struct thermal_zone_device *tz, int temperature, int direction)
+int thermal_thresholds_add(struct thermal_zone_device *tz,
+			   int temperature, int direction)
 {
 	struct list_head *thresholds = &tz->user_thresholds;
 	struct user_threshold *t;
@@ -182,12 +183,15 @@ int thermal_thresholds_add(struct thermal_zone_device *tz, int temperature, int
 		list_sort(NULL, thresholds, __thermal_thresholds_cmp);
 	}
 
+	thermal_notify_threshold_add(tz, temperature, direction);
+
 	__thermal_zone_device_update(tz, THERMAL_TZ_ADD_THRESHOLD);
 
 	return 0;
 }
 
-int thermal_thresholds_delete(struct thermal_zone_device *tz, int temperature, int direction)
+int thermal_thresholds_delete(struct thermal_zone_device *tz,
+			      int temperature, int direction)
 {
 	struct list_head *thresholds = &tz->user_thresholds;
 	struct user_threshold *t;
@@ -205,6 +209,8 @@ int thermal_thresholds_delete(struct thermal_zone_device *tz, int temperature, i
 		t->direction &= ~direction;
 	}
 
+	thermal_notify_threshold_delete(tz, temperature, direction);
+
 	__thermal_zone_device_update(tz, THERMAL_TZ_DEL_THRESHOLD);
 
 	return 0;
@@ -217,7 +223,7 @@ int thermal_thresholds_for_each(struct thermal_zone_device *tz,
 	struct user_threshold *entry;
 	int ret;
 
-	lockdep_assert_held(&tz->lock);
+	guard(thermal_zone)(tz);
 
 	list_for_each_entry(entry, thresholds, list_node) {
 		ret = cb(entry, arg);

drivers/thermal/thermal_thresholds.h

@@ -10,8 +10,8 @@ struct user_threshold {
 
 int thermal_thresholds_init(struct thermal_zone_device *tz);
 void thermal_thresholds_exit(struct thermal_zone_device *tz);
-void thermal_thresholds_flush(struct thermal_zone_device *tz);
 void thermal_thresholds_handle(struct thermal_zone_device *tz, int *low, int *high);
+void thermal_thresholds_flush(struct thermal_zone_device *tz);
 int thermal_thresholds_add(struct thermal_zone_device *tz, int temperature, int direction);
 int thermal_thresholds_delete(struct thermal_zone_device *tz, int temperature, int direction);
 int thermal_thresholds_for_each(struct thermal_zone_device *tz,

include/uapi/linux/thermal.h

@@ -20,7 +20,7 @@ enum thermal_trip_type {
 
 /* Adding event notification support elements */
 #define THERMAL_GENL_FAMILY_NAME		"thermal"
-#define THERMAL_GENL_VERSION			0x01
+#define THERMAL_GENL_VERSION			0x02
 #define THERMAL_GENL_SAMPLING_GROUP_NAME	"sampling"
 #define THERMAL_GENL_EVENT_GROUP_NAME		"event"
 
@@ -30,6 +30,7 @@ enum thermal_genl_attr {
 	THERMAL_GENL_ATTR_TZ,
 	THERMAL_GENL_ATTR_TZ_ID,
 	THERMAL_GENL_ATTR_TZ_TEMP,
+	THERMAL_GENL_ATTR_TZ_PREV_TEMP,
 	THERMAL_GENL_ATTR_TZ_TRIP,
 	THERMAL_GENL_ATTR_TZ_TRIP_ID,
 	THERMAL_GENL_ATTR_TZ_TRIP_TYPE,
@@ -50,6 +51,9 @@ enum thermal_genl_attr {
 	THERMAL_GENL_ATTR_CPU_CAPABILITY_ID,
 	THERMAL_GENL_ATTR_CPU_CAPABILITY_PERFORMANCE,
 	THERMAL_GENL_ATTR_CPU_CAPABILITY_EFFICIENCY,
+	THERMAL_GENL_ATTR_THRESHOLD,
+	THERMAL_GENL_ATTR_THRESHOLD_TEMP,
+	THERMAL_GENL_ATTR_THRESHOLD_DIRECTION,
 	__THERMAL_GENL_ATTR_MAX,
 };
 #define THERMAL_GENL_ATTR_MAX (__THERMAL_GENL_ATTR_MAX - 1)
@@ -77,6 +81,11 @@ enum thermal_genl_event {
 	THERMAL_GENL_EVENT_CDEV_STATE_UPDATE,	/* Cdev state updated */
 	THERMAL_GENL_EVENT_TZ_GOV_CHANGE,	/* Governor policy changed  */
 	THERMAL_GENL_EVENT_CPU_CAPABILITY_CHANGE,	/* CPU capability changed */
+	THERMAL_GENL_EVENT_THRESHOLD_ADD,	/* A thresold has been added */
+	THERMAL_GENL_EVENT_THRESHOLD_DELETE,	/* A thresold has been deleted */
+	THERMAL_GENL_EVENT_THRESHOLD_FLUSH,	/* All thresolds have been deleted */
+	THERMAL_GENL_EVENT_THRESHOLD_UP,	/* A thresold has been crossed the way up */
+	THERMAL_GENL_EVENT_THRESHOLD_DOWN,	/* A thresold has been crossed the way down */
 	__THERMAL_GENL_EVENT_MAX,
 };
 #define THERMAL_GENL_EVENT_MAX (__THERMAL_GENL_EVENT_MAX - 1)
@@ -90,6 +99,10 @@ enum thermal_genl_cmd {
 	THERMAL_GENL_CMD_TZ_GET_GOV,		/* Get the thermal zone governor */
 	THERMAL_GENL_CMD_TZ_GET_MODE,		/* Get the thermal zone mode */
 	THERMAL_GENL_CMD_CDEV_GET,		/* List of cdev id */
+	THERMAL_GENL_CMD_THRESHOLD_GET,		/* List of thresholds */
+	THERMAL_GENL_CMD_THRESHOLD_ADD,		/* Add a threshold */
+	THERMAL_GENL_CMD_THRESHOLD_DELETE,	/* Delete a threshold */
+	THERMAL_GENL_CMD_THRESHOLD_FLUSH,	/* Flush all the thresholds */
 	__THERMAL_GENL_CMD_MAX,
 };
 #define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)