cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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gov_fair_share.c (3366B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  fair_share.c - A simple weight based Thermal governor
      4 *
      5 *  Copyright (C) 2012 Intel Corp
      6 *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
      7 *
      8 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      9 *
     10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     11 */
     12
     13#include <linux/thermal.h>
     14#include <trace/events/thermal.h>
     15
     16#include "thermal_core.h"
     17
     18/**
     19 * get_trip_level: - obtains the current trip level for a zone
     20 * @tz:		thermal zone device
     21 */
     22static int get_trip_level(struct thermal_zone_device *tz)
     23{
     24	int count = 0;
     25	int trip_temp;
     26	enum thermal_trip_type trip_type;
     27
     28	if (tz->trips == 0 || !tz->ops->get_trip_temp)
     29		return 0;
     30
     31	for (count = 0; count < tz->trips; count++) {
     32		tz->ops->get_trip_temp(tz, count, &trip_temp);
     33		if (tz->temperature < trip_temp)
     34			break;
     35	}
     36
     37	/*
     38	 * count > 0 only if temperature is greater than first trip
     39	 * point, in which case, trip_point = count - 1
     40	 */
     41	if (count > 0) {
     42		tz->ops->get_trip_type(tz, count - 1, &trip_type);
     43		trace_thermal_zone_trip(tz, count - 1, trip_type);
     44	}
     45
     46	return count;
     47}
     48
     49static long get_target_state(struct thermal_zone_device *tz,
     50		struct thermal_cooling_device *cdev, int percentage, int level)
     51{
     52	unsigned long max_state;
     53
     54	cdev->ops->get_max_state(cdev, &max_state);
     55
     56	return (long)(percentage * level * max_state) / (100 * tz->trips);
     57}
     58
     59/**
     60 * fair_share_throttle - throttles devices associated with the given zone
     61 * @tz: thermal_zone_device
     62 * @trip: trip point index
     63 *
     64 * Throttling Logic: This uses three parameters to calculate the new
     65 * throttle state of the cooling devices associated with the given zone.
     66 *
     67 * Parameters used for Throttling:
     68 * P1. max_state: Maximum throttle state exposed by the cooling device.
     69 * P2. percentage[i]/100:
     70 *	How 'effective' the 'i'th device is, in cooling the given zone.
     71 * P3. cur_trip_level/max_no_of_trips:
     72 *	This describes the extent to which the devices should be throttled.
     73 *	We do not want to throttle too much when we trip a lower temperature,
     74 *	whereas the throttling is at full swing if we trip critical levels.
     75 *	(Heavily assumes the trip points are in ascending order)
     76 * new_state of cooling device = P3 * P2 * P1
     77 */
     78static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
     79{
     80	struct thermal_instance *instance;
     81	int total_weight = 0;
     82	int total_instance = 0;
     83	int cur_trip_level = get_trip_level(tz);
     84
     85	mutex_lock(&tz->lock);
     86
     87	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
     88		if (instance->trip != trip)
     89			continue;
     90
     91		total_weight += instance->weight;
     92		total_instance++;
     93	}
     94
     95	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
     96		int percentage;
     97		struct thermal_cooling_device *cdev = instance->cdev;
     98
     99		if (instance->trip != trip)
    100			continue;
    101
    102		if (!total_weight)
    103			percentage = 100 / total_instance;
    104		else
    105			percentage = (instance->weight * 100) / total_weight;
    106
    107		instance->target = get_target_state(tz, cdev, percentage,
    108						    cur_trip_level);
    109
    110		mutex_lock(&cdev->lock);
    111		__thermal_cdev_update(cdev);
    112		mutex_unlock(&cdev->lock);
    113	}
    114
    115	mutex_unlock(&tz->lock);
    116	return 0;
    117}
    118
    119static struct thermal_governor thermal_gov_fair_share = {
    120	.name		= "fair_share",
    121	.throttle	= fair_share_throttle,
    122};
    123THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share);