diff options
Diffstat (limited to 'drivers/thermal/thermal_thresholds.c')
| -rw-r--r-- | drivers/thermal/thermal_thresholds.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_thresholds.c b/drivers/thermal/thermal_thresholds.c new file mode 100644 index 000000000000..38f5fd0e8930 --- /dev/null +++ b/drivers/thermal/thermal_thresholds.c @@ -0,0 +1,244 @@ +// 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; +} + +static void __thermal_thresholds_flush(struct thermal_zone_device *tz) +{ + struct list_head *thresholds = &tz->user_thresholds; + struct user_threshold *entry, *tmp; + + list_for_each_entry_safe(entry, tmp, thresholds, list_node) { + list_del(&entry->list_node); + kfree(entry); + } +} + +void thermal_thresholds_flush(struct thermal_zone_device *tz) +{ + lockdep_assert_held(&tz->lock); + + __thermal_thresholds_flush(tz); + + thermal_notify_threshold_flush(tz); + + __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_thresholds_handle_raising(struct list_head *thresholds, int temperature, + int last_temperature) +{ + struct user_threshold *t; + + list_for_each_entry(t, thresholds, list_node) { + + if (!(t->direction & THERMAL_THRESHOLD_WAY_UP)) + continue; + + if (temperature >= t->temperature && + last_temperature < t->temperature) + return true; + } + + return false; +} + +static bool thermal_thresholds_handle_dropping(struct list_head *thresholds, int temperature, + int last_temperature) +{ + struct user_threshold *t; + + list_for_each_entry_reverse(t, thresholds, list_node) { + + if (!(t->direction & THERMAL_THRESHOLD_WAY_DOWN)) + continue; + + if (temperature <= t->temperature && + last_temperature > t->temperature) + return true; + } + + return false; +} + +static void thermal_threshold_find_boundaries(struct list_head *thresholds, int temperature, + int *low, int *high) +{ + struct user_threshold *t; + + list_for_each_entry(t, thresholds, list_node) { + if (temperature < t->temperature && + (t->direction & THERMAL_THRESHOLD_WAY_UP) && + *high > t->temperature) + *high = t->temperature; + } + + list_for_each_entry_reverse(t, thresholds, list_node) { + if (temperature > t->temperature && + (t->direction & THERMAL_THRESHOLD_WAY_DOWN) && + *low < t->temperature) + *low = t->temperature; + } +} + +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; + + lockdep_assert_held(&tz->lock); + + thermal_threshold_find_boundaries(thresholds, temperature, low, high); + + /* + * 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) { + if (thermal_thresholds_handle_raising(thresholds, + temperature, last_temperature)) + thermal_notify_threshold_up(tz); + } else { + if (thermal_thresholds_handle_dropping(thresholds, + temperature, last_temperature)) + thermal_notify_threshold_down(tz); + } +} + +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_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) +{ + 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_notify_threshold_delete(tz, temperature, 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; + + guard(thermal_zone)(tz); + + list_for_each_entry(entry, thresholds, list_node) { + ret = cb(entry, arg); + if (ret) + return ret; + } + + return 0; +} |