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873e65bc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4ccc5743 D |
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 | * | |
4ccc5743 D |
10 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
11 | */ | |
12 | ||
4ccc5743 | 13 | #include <linux/thermal.h> |
32a7a021 | 14 | #include "thermal_trace.h" |
4ccc5743 D |
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 | */ | |
22 | static int get_trip_level(struct thermal_zone_device *tz) | |
23 | { | |
7f725a23 DL |
24 | struct thermal_trip trip; |
25 | int count; | |
4ccc5743 | 26 | |
e5bfcd30 | 27 | for (count = 0; count < tz->num_trips; count++) { |
7f725a23 DL |
28 | __thermal_zone_get_trip(tz, count, &trip); |
29 | if (tz->temperature < trip.temperature) | |
4ccc5743 D |
30 | break; |
31 | } | |
208cd822 PA |
32 | |
33 | /* | |
34 | * count > 0 only if temperature is greater than first trip | |
35 | * point, in which case, trip_point = count - 1 | |
36 | */ | |
7f725a23 DL |
37 | if (count > 0) |
38 | trace_thermal_zone_trip(tz, count - 1, trip.type); | |
208cd822 | 39 | |
4ccc5743 D |
40 | return count; |
41 | } | |
42 | ||
43 | static long get_target_state(struct thermal_zone_device *tz, | |
bcdcbbc7 | 44 | struct thermal_cooling_device *cdev, int percentage, int level) |
4ccc5743 | 45 | { |
c408b3d1 | 46 | return (long)(percentage * level * cdev->max_state) / (100 * tz->num_trips); |
4ccc5743 D |
47 | } |
48 | ||
49 | /** | |
80b89172 | 50 | * fair_share_throttle - throttles devices associated with the given zone |
53d256e7 AK |
51 | * @tz: thermal_zone_device |
52 | * @trip: trip point index | |
4ccc5743 D |
53 | * |
54 | * Throttling Logic: This uses three parameters to calculate the new | |
55 | * throttle state of the cooling devices associated with the given zone. | |
56 | * | |
57 | * Parameters used for Throttling: | |
58 | * P1. max_state: Maximum throttle state exposed by the cooling device. | |
bcdcbbc7 | 59 | * P2. percentage[i]/100: |
4ccc5743 D |
60 | * How 'effective' the 'i'th device is, in cooling the given zone. |
61 | * P3. cur_trip_level/max_no_of_trips: | |
62 | * This describes the extent to which the devices should be throttled. | |
63 | * We do not want to throttle too much when we trip a lower temperature, | |
64 | * whereas the throttling is at full swing if we trip critical levels. | |
65 | * (Heavily assumes the trip points are in ascending order) | |
66 | * new_state of cooling device = P3 * P2 * P1 | |
67 | */ | |
62176933 | 68 | static int fair_share_throttle(struct thermal_zone_device *tz, int trip) |
4ccc5743 | 69 | { |
4ccc5743 | 70 | struct thermal_instance *instance; |
bcdcbbc7 JM |
71 | int total_weight = 0; |
72 | int total_instance = 0; | |
4ccc5743 D |
73 | int cur_trip_level = get_trip_level(tz); |
74 | ||
670a5e35 | 75 | lockdep_assert_held(&tz->lock); |
fef05776 | 76 | |
8b91e2cb | 77 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
bcdcbbc7 JM |
78 | if (instance->trip != trip) |
79 | continue; | |
80 | ||
81 | total_weight += instance->weight; | |
82 | total_instance++; | |
83 | } | |
84 | ||
85 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
86 | int percentage; | |
8b91e2cb | 87 | struct thermal_cooling_device *cdev = instance->cdev; |
4ccc5743 | 88 | |
8b91e2cb | 89 | if (instance->trip != trip) |
4ccc5743 D |
90 | continue; |
91 | ||
bcdcbbc7 JM |
92 | if (!total_weight) |
93 | percentage = 100 / total_instance; | |
94 | else | |
95 | percentage = (instance->weight * 100) / total_weight; | |
96 | ||
97 | instance->target = get_target_state(tz, cdev, percentage, | |
98 | cur_trip_level); | |
4ccc5743 | 99 | |
1a933698 LL |
100 | mutex_lock(&cdev->lock); |
101 | __thermal_cdev_update(cdev); | |
102 | mutex_unlock(&cdev->lock); | |
4ccc5743 | 103 | } |
fef05776 | 104 | |
4ccc5743 D |
105 | return 0; |
106 | } | |
107 | ||
62176933 | 108 | static struct thermal_governor thermal_gov_fair_share = { |
4ccc5743 D |
109 | .name = "fair_share", |
110 | .throttle = fair_share_throttle, | |
4ccc5743 | 111 | }; |
57c5b2ec | 112 | THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share); |