mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
f2675e588f
The computation in the fair share governor's get_trip_level() function currently works under the assumption that the temperature ordering of trips[] in a thermal zone is ascending, which need not be the case. However, get_trip_level() can be made work regardless of whether or not the trips table is ordered by temperature in any way, so change it accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
114 lines
3.1 KiB
C
114 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* fair_share.c - A simple weight based Thermal governor
|
|
*
|
|
* Copyright (C) 2012 Intel Corp
|
|
* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
|
|
*
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
*
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
*/
|
|
|
|
#include <linux/thermal.h>
|
|
#include "thermal_trace.h"
|
|
|
|
#include "thermal_core.h"
|
|
|
|
static int get_trip_level(struct thermal_zone_device *tz)
|
|
{
|
|
const struct thermal_trip *trip, *level_trip = NULL;
|
|
int trip_level = -1;
|
|
|
|
for_each_trip(tz, trip) {
|
|
if (trip->temperature >= tz->temperature)
|
|
continue;
|
|
|
|
trip_level++;
|
|
|
|
if (!level_trip || trip->temperature > level_trip->temperature)
|
|
level_trip = trip;
|
|
}
|
|
|
|
/* Bail out if the temperature is not greater than any trips. */
|
|
if (trip_level < 0)
|
|
return 0;
|
|
|
|
trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, level_trip),
|
|
level_trip->type);
|
|
|
|
return trip_level;
|
|
}
|
|
|
|
static long get_target_state(struct thermal_zone_device *tz,
|
|
struct thermal_cooling_device *cdev, int percentage, int level)
|
|
{
|
|
return (long)(percentage * level * cdev->max_state) / (100 * tz->num_trips);
|
|
}
|
|
|
|
/**
|
|
* fair_share_throttle - throttles devices associated with the given zone
|
|
* @tz: thermal_zone_device
|
|
* @trip: trip point
|
|
*
|
|
* Throttling Logic: This uses three parameters to calculate the new
|
|
* throttle state of the cooling devices associated with the given zone.
|
|
*
|
|
* Parameters used for Throttling:
|
|
* P1. max_state: Maximum throttle state exposed by the cooling device.
|
|
* P2. percentage[i]/100:
|
|
* How 'effective' the 'i'th device is, in cooling the given zone.
|
|
* P3. cur_trip_level/max_no_of_trips:
|
|
* This describes the extent to which the devices should be throttled.
|
|
* We do not want to throttle too much when we trip a lower temperature,
|
|
* whereas the throttling is at full swing if we trip critical levels.
|
|
* (Heavily assumes the trip points are in ascending order)
|
|
* new_state of cooling device = P3 * P2 * P1
|
|
*/
|
|
static int fair_share_throttle(struct thermal_zone_device *tz,
|
|
const struct thermal_trip *trip)
|
|
{
|
|
struct thermal_instance *instance;
|
|
int total_weight = 0;
|
|
int total_instance = 0;
|
|
int cur_trip_level = get_trip_level(tz);
|
|
|
|
lockdep_assert_held(&tz->lock);
|
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
if (instance->trip != trip)
|
|
continue;
|
|
|
|
total_weight += instance->weight;
|
|
total_instance++;
|
|
}
|
|
|
|
list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
|
|
int percentage;
|
|
struct thermal_cooling_device *cdev = instance->cdev;
|
|
|
|
if (instance->trip != trip)
|
|
continue;
|
|
|
|
if (!total_weight)
|
|
percentage = 100 / total_instance;
|
|
else
|
|
percentage = (instance->weight * 100) / total_weight;
|
|
|
|
instance->target = get_target_state(tz, cdev, percentage,
|
|
cur_trip_level);
|
|
|
|
mutex_lock(&cdev->lock);
|
|
__thermal_cdev_update(cdev);
|
|
mutex_unlock(&cdev->lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct thermal_governor thermal_gov_fair_share = {
|
|
.name = "fair_share",
|
|
.throttle = fair_share_throttle,
|
|
};
|
|
THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share);
|