--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2024 Linaro Limited
+ *
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *
+ * Thermal thresholds
+ */
+#include <linux/list.h>
+#include <linux/list_sort.h>
+#include <linux/slab.h>
+
+#include "thermal_core.h"
+#include "thermal_thresholds.h"
+
+int thermal_thresholds_init(struct thermal_zone_device *tz)
+{
+ INIT_LIST_HEAD(&tz->user_thresholds);
+
+ return 0;
+}
+
+void thermal_thresholds_flush(struct thermal_zone_device *tz)
+{
+ struct list_head *thresholds = &tz->user_thresholds;
+ struct user_threshold *entry, *tmp;
+
+ lockdep_assert_held(&tz->lock);
+
+ list_for_each_entry_safe(entry, tmp, thresholds, list_node) {
+ list_del(&entry->list_node);
+ kfree(entry);
+ }
+
+ __thermal_zone_device_update(tz, THERMAL_TZ_FLUSH_THRESHOLDS);
+}
+
+void thermal_thresholds_exit(struct thermal_zone_device *tz)
+{
+ thermal_thresholds_flush(tz);
+}
+
+static int __thermal_thresholds_cmp(void *data,
+ const struct list_head *l1,
+ const struct list_head *l2)
+{
+ struct user_threshold *t1 = container_of(l1, struct user_threshold, list_node);
+ struct user_threshold *t2 = container_of(l2, struct user_threshold, list_node);
+
+ return t1->temperature - t2->temperature;
+}
+
+static struct user_threshold *__thermal_thresholds_find(const struct list_head *thresholds,
+ int temperature)
+{
+ struct user_threshold *t;
+
+ list_for_each_entry(t, thresholds, list_node)
+ if (t->temperature == temperature)
+ return t;
+
+ return NULL;
+}
+
+static bool __thermal_threshold_is_crossed(struct user_threshold *threshold, int temperature,
+ int last_temperature, int direction,
+ int *low, int *high)
+{
+
+ if (temperature >= threshold->temperature) {
+ if (threshold->temperature > *low &&
+ THERMAL_THRESHOLD_WAY_DOWN & threshold->direction)
+ *low = threshold->temperature;
+
+ if (last_temperature < threshold->temperature &&
+ threshold->direction & direction)
+ return true;
+ } else {
+ if (threshold->temperature < *high && THERMAL_THRESHOLD_WAY_UP
+ & threshold->direction)
+ *high = threshold->temperature;
+
+ if (last_temperature >= threshold->temperature &&
+ threshold->direction & direction)
+ return true;
+ }
+
+ return false;
+}
+
+static bool thermal_thresholds_handle_raising(struct list_head *thresholds, int temperature,
+ int last_temperature, int *low, int *high)
+{
+ struct user_threshold *t;
+
+ list_for_each_entry(t, thresholds, list_node) {
+ if (__thermal_threshold_is_crossed(t, temperature, last_temperature,
+ THERMAL_THRESHOLD_WAY_UP, low, high))
+ return true;
+ }
+
+ return false;
+}
+
+static bool thermal_thresholds_handle_dropping(struct list_head *thresholds, int temperature,
+ int last_temperature, int *low, int *high)
+{
+ struct user_threshold *t;
+
+ list_for_each_entry_reverse(t, thresholds, list_node) {
+ if (__thermal_threshold_is_crossed(t, temperature, last_temperature,
+ THERMAL_THRESHOLD_WAY_DOWN, low, high))
+ return true;
+ }
+
+ return false;
+}
+
+void thermal_thresholds_handle(struct thermal_zone_device *tz, int *low, int *high)
+{
+ struct list_head *thresholds = &tz->user_thresholds;
+
+ int temperature = tz->temperature;
+ int last_temperature = tz->last_temperature;
+ bool notify;
+
+ lockdep_assert_held(&tz->lock);
+
+ /*
+ * We need a second update in order to detect a threshold being crossed
+ */
+ if (last_temperature == THERMAL_TEMP_INVALID)
+ return;
+
+ /*
+ * The temperature is stable, so obviously we can not have
+ * crossed a threshold.
+ */
+ if (last_temperature == temperature)
+ return;
+
+ /*
+ * Since last update the temperature:
+ * - 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);
+}
+
+int thermal_thresholds_add(struct thermal_zone_device *tz, int temperature, int direction)
+{
+ struct list_head *thresholds = &tz->user_thresholds;
+ struct user_threshold *t;
+
+ lockdep_assert_held(&tz->lock);
+
+ t = __thermal_thresholds_find(thresholds, temperature);
+ if (t) {
+ if (t->direction == direction)
+ return -EEXIST;
+
+ t->direction |= direction;
+ } else {
+
+ t = kmalloc(sizeof(*t), GFP_KERNEL);
+ if (!t)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&t->list_node);
+ t->temperature = temperature;
+ t->direction = direction;
+ list_add(&t->list_node, thresholds);
+ list_sort(NULL, thresholds, __thermal_thresholds_cmp);
+ }
+
+ __thermal_zone_device_update(tz, THERMAL_TZ_ADD_THRESHOLD);
+
+ return 0;
+}
+
+int thermal_thresholds_delete(struct thermal_zone_device *tz, int temperature, int direction)
+{
+ struct list_head *thresholds = &tz->user_thresholds;
+ struct user_threshold *t;
+
+ lockdep_assert_held(&tz->lock);
+
+ t = __thermal_thresholds_find(thresholds, temperature);
+ if (!t)
+ return -ENOENT;
+
+ if (t->direction == direction) {
+ list_del(&t->list_node);
+ kfree(t);
+ } else {
+ t->direction &= ~direction;
+ }
+
+ __thermal_zone_device_update(tz, THERMAL_TZ_DEL_THRESHOLD);
+
+ return 0;
+}
+
+int thermal_thresholds_for_each(struct thermal_zone_device *tz,
+ int (*cb)(struct user_threshold *, void *arg), void *arg)
+{
+ struct list_head *thresholds = &tz->user_thresholds;
+ struct user_threshold *entry;
+ int ret;
+
+ lockdep_assert_held(&tz->lock);
+
+ list_for_each_entry(entry, thresholds, list_node) {
+ ret = cb(entry, arg);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
projects / thirdparty / kernel / linux.git / commitdiff
