1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
/*
* fair_share.c - A simple weight based Thermal governor
*
* Copyright (C) 2012 Intel Corp
* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/thermal.h>
#include <trace/events/thermal.h>
#include "thermal_core.h"
/**
* get_trip_level: - obtains the current trip level for a zone
* @tz: thermal zone device
*/
static int get_trip_level(struct thermal_zone_device *tz)
{
int count = 0;
unsigned long trip_temp;
enum thermal_trip_type trip_type;
if (tz->trips == 0 || !tz->ops->get_trip_temp)
return 0;
for (count = 0; count < tz->trips; count++) {
tz->ops->get_trip_temp(tz, count, &trip_temp);
if (tz->temperature < trip_temp)
break;
}
/*
* count > 0 only if temperature is greater than first trip
* point, in which case, trip_point = count - 1
*/
if (count > 0) {
tz->ops->get_trip_type(tz, count - 1, &trip_type);
trace_thermal_zone_trip(tz, count - 1, trip_type);
}
return count;
}
static long get_target_state(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev, int weight, int level)
{
unsigned long max_state;
cdev->ops->get_max_state(cdev, &max_state);
return (long)(weight * level * max_state) / (100 * tz->trips);
}
/**
* fair_share_throttle - throttles devices asscciated with the given zone
* @tz - thermal_zone_device
*
* 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. weight[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, int trip)
{
const struct thermal_zone_params *tzp;
struct thermal_cooling_device *cdev;
struct thermal_instance *instance;
int i;
int cur_trip_level = get_trip_level(tz);
if (!tz->tzp || !tz->tzp->tbp)
return -EINVAL;
tzp = tz->tzp;
for (i = 0; i < tzp->num_tbps; i++) {
if (!tzp->tbp[i].cdev)
continue;
cdev = tzp->tbp[i].cdev;
instance = get_thermal_instance(tz, cdev, trip);
if (!instance)
continue;
instance->target = get_target_state(tz, cdev,
tzp->tbp[i].weight, cur_trip_level);
instance->cdev->updated = false;
thermal_cdev_update(cdev);
}
return 0;
}
static struct thermal_governor thermal_gov_fair_share = {
.name = "fair_share",
.throttle = fair_share_throttle,
};
int thermal_gov_fair_share_register(void)
{
return thermal_register_governor(&thermal_gov_fair_share);
}
void thermal_gov_fair_share_unregister(void)
{
thermal_unregister_governor(&thermal_gov_fair_share);
}
|
