-
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2023 Linaro Limited
#include <linux/mutex.h>
#include <linux/thermal.h>
+#include "thermal_core.h"
+
static struct dentry *d_root;
static struct dentry *d_cdev;
+static struct dentry *d_tz;
/*
* Length of the string containing the thermal zone id or the cooling
};
/**
- * struct cdev_value - Common structure for cooling device entry
+ * struct cdev_record - Common structure for cooling device entry
*
* The following common structure allows to store the information
* related to the transitions and to the state residencies. They are
};
};
+/**
+ * struct trip_stats - Thermal trip statistics
+ *
+ * The trip_stats structure has the relevant information to show the
+ * statistics related to temperature going above a trip point.
+ *
+ * @timestamp: the trip crossing timestamp
+ * @duration: total time when the zone temperature was above the trip point
+ * @count: the number of times the zone temperature was above the trip point
+ * @max: maximum recorded temperature above the trip point
+ * @min: minimum recorded temperature above the trip point
+ * @avg: average temperature above the trip point
+ */
+struct trip_stats {
+ ktime_t timestamp;
+ ktime_t duration;
+ int count;
+ int max;
+ int min;
+ int avg;
+};
+
+/**
+ * struct tz_episode - A mitigation episode information
+ *
+ * The tz_episode structure describes a mitigation episode. A
+ * mitigation episode begins the trip point with the lower temperature
+ * is crossed the way up and ends when it is crossed the way
+ * down. During this episode we can have multiple trip points crossed
+ * the way up and down if there are multiple trip described in the
+ * firmware after the lowest temperature trip point.
+ *
+ * @timestamp: first trip point crossed the way up
+ * @duration: total duration of the mitigation episode
+ * @node: a list element to be added to the list of tz events
+ * @trip_stats: per trip point statistics, flexible array
+ */
+struct tz_episode {
+ ktime_t timestamp;
+ ktime_t duration;
+ struct list_head node;
+ struct trip_stats trip_stats[];
+};
+
+/**
+ * struct tz_debugfs - Store all mitigation episodes for a thermal zone
+ *
+ * The tz_debugfs structure contains the list of the mitigation
+ * episodes and has to track which trip point has been crossed in
+ * order to handle correctly nested trip point mitigation episodes.
+ *
+ * We keep the history of the trip point crossed in an array and as we
+ * can go back and forth inside this history, eg. trip 0,1,2,1,2,1,0,
+ * we keep track of the current position in the history array.
+ *
+ * @tz_episodes: a list of thermal mitigation episodes
+ * @trips_crossed: an array of trip points crossed by id
+ * @nr_trips: the number of trip points currently being crossed
+ */
+struct tz_debugfs {
+ struct list_head tz_episodes;
+ int *trips_crossed;
+ int nr_trips;
+};
+
/**
* struct thermal_debugfs - High level structure for a thermal object in debugfs
*
* The thermal_debugfs structure is the common structure used by the
- * cooling device to compute the statistics.
+ * cooling device or the thermal zone to store the statistics.
*
* @d_top: top directory of the thermal object directory
* @lock: per object lock to protect the internals
*
- * @cdev: a cooling device debug structure
+ * @cdev_dbg: a cooling device debug structure
+ * @tz_dbg: a thermal zone debug structure
*/
struct thermal_debugfs {
struct dentry *d_top;
struct mutex lock;
union {
struct cdev_debugfs cdev_dbg;
+ struct tz_debugfs tz_dbg;
};
};
return;
d_cdev = debugfs_create_dir("cooling_devices", d_root);
+ if (!d_cdev)
+ return;
+
+ d_tz = debugfs_create_dir("thermal_zones", d_root);
}
static struct thermal_debugfs *thermal_debugfs_add_id(struct dentry *d, int id)
thermal_debugfs_remove_id(thermal_dbg);
}
+
+static struct tz_episode *thermal_debugfs_tz_event_alloc(struct thermal_zone_device *tz,
+ ktime_t now)
+{
+ struct tz_episode *tze;
+ int i;
+
+ tze = kzalloc(struct_size(tze, trip_stats, tz->num_trips), GFP_KERNEL);
+ if (!tze)
+ return NULL;
+
+ INIT_LIST_HEAD(&tze->node);
+ tze->timestamp = now;
+
+ for (i = 0; i < tz->num_trips; i++) {
+ tze->trip_stats[i].min = INT_MAX;
+ tze->trip_stats[i].max = INT_MIN;
+ }
+
+ return tze;
+}
+
+void thermal_debug_tz_trip_up(struct thermal_zone_device *tz,
+ const struct thermal_trip *trip)
+{
+ struct tz_episode *tze;
+ struct tz_debugfs *tz_dbg;
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+ int temperature = tz->temperature;
+ int trip_id = thermal_zone_trip_id(tz, trip);
+ ktime_t now = ktime_get();
+
+ if (!thermal_dbg)
+ return;
+
+ mutex_lock(&thermal_dbg->lock);
+
+ tz_dbg = &thermal_dbg->tz_dbg;
+
+ /*
+ * The mitigation is starting. A mitigation can contain
+ * several episodes where each of them is related to a
+ * temperature crossing a trip point. The episodes are
+ * nested. That means when the temperature is crossing the
+ * first trip point, the duration begins to be measured. If
+ * the temperature continues to increase and reaches the
+ * second trip point, the duration of the first trip must be
+ * also accumulated.
+ *
+ * eg.
+ *
+ * temp
+ * ^
+ * | --------
+ * trip 2 / \ ------
+ * | /| |\ /| |\
+ * trip 1 / | | `---- | | \
+ * | /| | | | | |\
+ * trip 0 / | | | | | | \
+ * | /| | | | | | | |\
+ * | / | | | | | | | | `--
+ * | / | | | | | | | |
+ * |----- | | | | | | | |
+ * | | | | | | | | |
+ * --------|-|-|--------|--------|------|-|-|------------------> time
+ * | | |<--t2-->| |<-t2'>| | |
+ * | | | |
+ * | |<------------t1------------>| |
+ * | |
+ * |<-------------t0--------------->|
+ *
+ */
+ if (!tz_dbg->nr_trips) {
+ tze = thermal_debugfs_tz_event_alloc(tz, now);
+ if (!tze)
+ return;
+
+ list_add(&tze->node, &tz_dbg->tz_episodes);
+ }
+
+ /*
+ * Each time a trip point is crossed the way up, the trip_id
+ * is stored in the trip_crossed array and the nr_trips is
+ * incremented. A nr_trips equal to zero means we are entering
+ * a mitigation episode.
+ *
+ * The trip ids may not be in the ascending order but the
+ * result in the array trips_crossed will be in the ascending
+ * temperature order. The function detecting when a trip point
+ * is crossed the way down will handle the very rare case when
+ * the trip points may have been reordered during this
+ * mitigation episode.
+ */
+ tz_dbg->trips_crossed[tz_dbg->nr_trips++] = trip_id;
+
+ tze = list_first_entry(&tz_dbg->tz_episodes, struct tz_episode, node);
+ tze->trip_stats[trip_id].timestamp = now;
+ tze->trip_stats[trip_id].max = max(tze->trip_stats[trip_id].max, temperature);
+ tze->trip_stats[trip_id].min = min(tze->trip_stats[trip_id].min, temperature);
+ tze->trip_stats[trip_id].avg = tze->trip_stats[trip_id].avg +
+ (temperature - tze->trip_stats[trip_id].avg) /
+ tze->trip_stats[trip_id].count;
+
+ mutex_unlock(&thermal_dbg->lock);
+}
+
+void thermal_debug_tz_trip_down(struct thermal_zone_device *tz,
+ const struct thermal_trip *trip)
+{
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+ struct tz_episode *tze;
+ struct tz_debugfs *tz_dbg;
+ ktime_t delta, now = ktime_get();
+ int trip_id = thermal_zone_trip_id(tz, trip);
+ int i;
+
+ if (!thermal_dbg)
+ return;
+
+ mutex_lock(&thermal_dbg->lock);
+
+ tz_dbg = &thermal_dbg->tz_dbg;
+
+ /*
+ * The temperature crosses the way down but there was not
+ * mitigation detected before. That may happen when the
+ * temperature is greater than a trip point when registering a
+ * thermal zone, which is a common use case as the kernel has
+ * no mitigation mechanism yet at boot time.
+ */
+ if (!tz_dbg->nr_trips)
+ goto out;
+
+ for (i = tz_dbg->nr_trips - 1; i >= 0; i--) {
+ if (tz_dbg->trips_crossed[i] == trip_id)
+ break;
+ }
+
+ if (i < 0)
+ goto out;
+
+ tz_dbg->nr_trips--;
+
+ if (i < tz_dbg->nr_trips)
+ tz_dbg->trips_crossed[i] = tz_dbg->trips_crossed[tz_dbg->nr_trips];
+
+ tze = list_first_entry(&tz_dbg->tz_episodes, struct tz_episode, node);
+
+ delta = ktime_sub(now, tze->trip_stats[trip_id].timestamp);
+
+ tze->trip_stats[trip_id].duration =
+ ktime_add(delta, tze->trip_stats[trip_id].duration);
+
+ /*
+ * This event closes the mitigation as we are crossing the
+ * last trip point the way down.
+ */
+ if (!tz_dbg->nr_trips)
+ tze->duration = ktime_sub(now, tze->timestamp);
+
+out:
+ mutex_unlock(&thermal_dbg->lock);
+}
+
+void thermal_debug_update_temp(struct thermal_zone_device *tz)
+{
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+ struct tz_episode *tze;
+ struct tz_debugfs *tz_dbg;
+ int trip_id, i;
+
+ if (!thermal_dbg)
+ return;
+
+ mutex_lock(&thermal_dbg->lock);
+
+ tz_dbg = &thermal_dbg->tz_dbg;
+
+ if (!tz_dbg->nr_trips)
+ goto out;
+
+ for (i = 0; i < tz_dbg->nr_trips; i++) {
+ trip_id = tz_dbg->trips_crossed[i];
+ tze = list_first_entry(&tz_dbg->tz_episodes, struct tz_episode, node);
+ tze->trip_stats[trip_id].count++;
+ tze->trip_stats[trip_id].max = max(tze->trip_stats[trip_id].max, tz->temperature);
+ tze->trip_stats[trip_id].min = min(tze->trip_stats[trip_id].min, tz->temperature);
+ tze->trip_stats[trip_id].avg = tze->trip_stats[trip_id].avg +
+ (tz->temperature - tze->trip_stats[trip_id].avg) /
+ tze->trip_stats[trip_id].count;
+ }
+out:
+ mutex_unlock(&thermal_dbg->lock);
+}
+
+static void *tze_seq_start(struct seq_file *s, loff_t *pos)
+{
+ struct thermal_zone_device *tz = s->private;
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+ struct tz_debugfs *tz_dbg = &thermal_dbg->tz_dbg;
+
+ mutex_lock(&thermal_dbg->lock);
+
+ return seq_list_start(&tz_dbg->tz_episodes, *pos);
+}
+
+static void *tze_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct thermal_zone_device *tz = s->private;
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+ struct tz_debugfs *tz_dbg = &thermal_dbg->tz_dbg;
+
+ return seq_list_next(v, &tz_dbg->tz_episodes, pos);
+}
+
+static void tze_seq_stop(struct seq_file *s, void *v)
+{
+ struct thermal_zone_device *tz = s->private;
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+
+ mutex_unlock(&thermal_dbg->lock);
+}
+
+static int tze_seq_show(struct seq_file *s, void *v)
+{
+ struct thermal_zone_device *tz = s->private;
+ struct thermal_trip *trip;
+ struct tz_episode *tze;
+ const char *type;
+ int trip_id;
+
+ tze = list_entry((struct list_head *)v, struct tz_episode, node);
+
+ seq_printf(s, ",-Mitigation at %lluus, duration=%llums\n",
+ ktime_to_us(tze->timestamp),
+ ktime_to_ms(tze->duration));
+
+ seq_printf(s, "| trip | type | temp(°mC) | hyst(°mC) | duration | avg(°mC) | min(°mC) | max(°mC) |\n");
+
+ for_each_trip(tz, trip) {
+ /*
+ * There is no possible mitigation happening at the
+ * critical trip point, so the stats will be always
+ * zero, skip this trip point
+ */
+ if (trip->type == THERMAL_TRIP_CRITICAL)
+ continue;
+
+ if (trip->type == THERMAL_TRIP_PASSIVE)
+ type = "passive";
+ else if (trip->type == THERMAL_TRIP_ACTIVE)
+ type = "active";
+ else
+ type = "hot";
+
+ trip_id = thermal_zone_trip_id(tz, trip);
+
+ seq_printf(s, "| %*d | %*s | %*d | %*d | %*lld | %*d | %*d | %*d |\n",
+ 4 , trip_id,
+ 8, type,
+ 9, trip->temperature,
+ 9, trip->hysteresis,
+ 10, ktime_to_ms(tze->trip_stats[trip_id].duration),
+ 9, tze->trip_stats[trip_id].avg,
+ 9, tze->trip_stats[trip_id].min,
+ 9, tze->trip_stats[trip_id].max);
+ }
+
+ return 0;
+}
+
+static const struct seq_operations tze_sops = {
+ .start = tze_seq_start,
+ .next = tze_seq_next,
+ .stop = tze_seq_stop,
+ .show = tze_seq_show,
+};
+
+DEFINE_SEQ_ATTRIBUTE(tze);
+
+void thermal_debug_tz_add(struct thermal_zone_device *tz)
+{
+ struct thermal_debugfs *thermal_dbg;
+ struct tz_debugfs *tz_dbg;
+
+ thermal_dbg = thermal_debugfs_add_id(d_tz, tz->id);
+ if (!thermal_dbg)
+ return;
+
+ tz_dbg = &thermal_dbg->tz_dbg;
+
+ tz_dbg->trips_crossed = kzalloc(sizeof(int) * tz->num_trips, GFP_KERNEL);
+ if (!tz_dbg->trips_crossed) {
+ thermal_debugfs_remove_id(thermal_dbg);
+ return;
+ }
+
+ INIT_LIST_HEAD(&tz_dbg->tz_episodes);
+
+ debugfs_create_file("mitigations", 0400, thermal_dbg->d_top, tz, &tze_fops);
+
+ tz->debugfs = thermal_dbg;
+}
+
+void thermal_debug_tz_remove(struct thermal_zone_device *tz)
+{
+ struct thermal_debugfs *thermal_dbg = tz->debugfs;
+
+ if (!thermal_dbg)
+ return;
+
+ mutex_lock(&thermal_dbg->lock);
+
+ tz->debugfs = NULL;
+
+ mutex_unlock(&thermal_dbg->lock);
+
+ thermal_debugfs_remove_id(thermal_dbg);
+}
projects / users / willy / xarray.git / commitdiff