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a5a98a786e
Add and use a special guard for cooling devices. This allows quite a few error code paths to be simplified among other things and brings in code size reduction for a good measure. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/5837621.DvuYhMxLoT@rjwysocki.net Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
142 lines
4.1 KiB
C
142 lines
4.1 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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/*
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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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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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return clamp(cur_state + 1, instance->lower, instance->upper);
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return THERMAL_NO_TARGET;
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}
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if (throttle) {
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if (trend == THERMAL_TREND_RAISING)
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return clamp(cur_state + 1, instance->lower, instance->upper);
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} else if (trend == THERMAL_TREND_DROPPING) {
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if (cur_state <= instance->lower)
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return THERMAL_NO_TARGET;
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/*
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* If 'throttle' is false, no mitigation is necessary, so
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* request the lower state for this instance.
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*/
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return instance->lower;
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}
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return instance->target;
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}
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static void thermal_zone_trip_update(struct thermal_zone_device *tz,
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const struct thermal_trip_desc *td,
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int trip_threshold)
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{
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const struct thermal_trip *trip = &td->trip;
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enum thermal_trend trend = get_tz_trend(tz, trip);
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int trip_id = thermal_zone_trip_id(tz, trip);
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struct thermal_instance *instance;
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bool throttle = false;
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if (tz->temperature >= trip_threshold) {
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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_threshold, trend, throttle);
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list_for_each_entry(instance, &td->thermal_instances, trip_node) {
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int old_target;
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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=%ld\n",
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old_target, instance->target);
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if (instance->initialized && old_target == instance->target)
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continue;
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instance->initialized = true;
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scoped_guard(cooling_dev, instance->cdev) {
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instance->cdev->updated = false; /* cdev needs update */
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}
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}
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}
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static void step_wise_manage(struct thermal_zone_device *tz)
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{
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const struct thermal_trip_desc *td;
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struct thermal_instance *instance;
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lockdep_assert_held(&tz->lock);
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/*
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* Throttling Logic: Use the trend of the thermal zone to throttle.
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* If the thermal zone is 'heating up', throttle all of the cooling
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* devices associated with each trip point by one step. If the zone
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* is 'cooling down', it brings back the performance of the devices
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* by one step.
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*/
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for_each_trip_desc(tz, td) {
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const struct thermal_trip *trip = &td->trip;
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if (trip->temperature == THERMAL_TEMP_INVALID ||
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trip->type == THERMAL_TRIP_CRITICAL ||
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trip->type == THERMAL_TRIP_HOT)
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continue;
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thermal_zone_trip_update(tz, td, td->threshold);
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}
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for_each_trip_desc(tz, td) {
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list_for_each_entry(instance, &td->thermal_instances, trip_node)
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thermal_cdev_update(instance->cdev);
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}
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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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.manage = step_wise_manage,
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};
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THERMAL_GOVERNOR_DECLARE(thermal_gov_step_wise);
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