160 строки
4.7 KiB
C
160 строки
4.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* step_wise.c - A step-by-step Thermal throttling governor
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*
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* Copyright (C) 2012 Intel Corp
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* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/thermal.h>
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#include <linux/minmax.h>
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#include "thermal_trace.h"
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#include "thermal_core.h"
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/*
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* If the temperature is higher than a trip point,
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* a. if the trend is THERMAL_TREND_RAISING, use higher cooling
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* state for this trip point
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* b. if the trend is THERMAL_TREND_DROPPING, do nothing
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* If the temperature is lower than a trip point,
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* a. if the trend is THERMAL_TREND_RAISING, do nothing
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* b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
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* state for this trip point, if the cooling state already
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* equals lower limit, deactivate the thermal instance
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*/
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static unsigned long get_target_state(struct thermal_instance *instance,
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enum thermal_trend trend, bool throttle)
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{
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struct thermal_cooling_device *cdev = instance->cdev;
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unsigned long cur_state;
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unsigned long next_target;
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/*
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* We keep this instance the way it is by default.
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* Otherwise, we use the current state of the
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* cdev in use to determine the next_target.
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*/
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cdev->ops->get_cur_state(cdev, &cur_state);
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next_target = instance->target;
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dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state);
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if (!instance->initialized) {
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if (throttle) {
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next_target = clamp((cur_state + 1), instance->lower, instance->upper);
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} else {
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next_target = THERMAL_NO_TARGET;
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}
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return next_target;
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}
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if (throttle) {
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if (trend == THERMAL_TREND_RAISING)
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next_target = clamp((cur_state + 1), instance->lower, instance->upper);
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} else {
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if (trend == THERMAL_TREND_DROPPING) {
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if (cur_state <= instance->lower)
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next_target = THERMAL_NO_TARGET;
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else
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next_target = clamp((cur_state - 1), instance->lower, instance->upper);
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}
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}
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return next_target;
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}
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static void update_passive_instance(struct thermal_zone_device *tz,
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enum thermal_trip_type type, int value)
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{
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/*
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* If value is +1, activate a passive instance.
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* If value is -1, deactivate a passive instance.
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*/
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if (type == THERMAL_TRIP_PASSIVE)
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tz->passive += value;
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}
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static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip_id)
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{
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enum thermal_trend trend;
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struct thermal_instance *instance;
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struct thermal_trip trip;
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bool throttle = false;
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int old_target;
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__thermal_zone_get_trip(tz, trip_id, &trip);
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trend = get_tz_trend(tz, trip_id);
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if (tz->temperature >= trip.temperature) {
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throttle = true;
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trace_thermal_zone_trip(tz, trip_id, trip.type);
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}
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dev_dbg(&tz->device, "Trip%d[type=%d,temp=%d]:trend=%d,throttle=%d\n",
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trip_id, trip.type, trip.temperature, trend, throttle);
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list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
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if (instance->trip != trip_id)
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continue;
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old_target = instance->target;
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instance->target = get_target_state(instance, trend, throttle);
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dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n",
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old_target, (int)instance->target);
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if (instance->initialized && old_target == instance->target)
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continue;
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/* Activate a passive thermal instance */
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if (old_target == THERMAL_NO_TARGET &&
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instance->target != THERMAL_NO_TARGET)
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update_passive_instance(tz, trip.type, 1);
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/* Deactivate a passive thermal instance */
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else if (old_target != THERMAL_NO_TARGET &&
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instance->target == THERMAL_NO_TARGET)
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update_passive_instance(tz, trip.type, -1);
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instance->initialized = true;
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mutex_lock(&instance->cdev->lock);
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instance->cdev->updated = false; /* cdev needs update */
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mutex_unlock(&instance->cdev->lock);
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}
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}
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/**
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* step_wise_throttle - throttles devices associated with the given zone
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* @tz: thermal_zone_device
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* @trip: trip point index
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*
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* Throttling Logic: This uses the trend of the thermal zone to throttle.
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* If the thermal zone is 'heating up' this throttles all the cooling
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* devices associated with the zone and its particular trip point, by one
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* step. If the zone is 'cooling down' it brings back the performance of
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* the devices by one step.
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*/
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static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
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{
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struct thermal_instance *instance;
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lockdep_assert_held(&tz->lock);
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thermal_zone_trip_update(tz, trip);
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list_for_each_entry(instance, &tz->thermal_instances, tz_node)
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thermal_cdev_update(instance->cdev);
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return 0;
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}
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static struct thermal_governor thermal_gov_step_wise = {
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.name = "step_wise",
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.throttle = step_wise_throttle,
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};
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THERMAL_GOVERNOR_DECLARE(thermal_gov_step_wise);
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