blob: 3b599abf2b4049ab2cba7794bd654d38fa43a9c7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * processor_thermal.c - Passive cooling submodule of the ACPI processor driver
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
7 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
9 *
10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or (at
15 * your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License along
23 * with this program; if not, write to the Free Software Foundation, Inc.,
24 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25 *
26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27 */
28
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/init.h>
32#include <linux/cpufreq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#include <asm/uaccess.h>
35
36#include <acpi/acpi_bus.h>
37#include <acpi/processor.h>
38#include <acpi/acpi_drivers.h>
39
Len Browna192a952009-07-28 16:45:54 -040040#define PREFIX "ACPI: "
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#define ACPI_PROCESSOR_CLASS "processor"
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define _COMPONENT ACPI_PROCESSOR_COMPONENT
Len Brownf52fd662007-02-12 22:42:12 -050044ACPI_MODULE_NAME("processor_thermal");
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#ifdef CONFIG_CPU_FREQ
47
48/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
49 * offers (in most cases) voltage scaling in addition to frequency scaling, and
50 * thus a cubic (instead of linear) reduction of energy. Also, we allow for
51 * _any_ cpufreq driver and not only the acpi-cpufreq driver.
52 */
53
Zhang Ruid9460fd222008-01-17 15:51:23 +080054#define CPUFREQ_THERMAL_MIN_STEP 0
55#define CPUFREQ_THERMAL_MAX_STEP 3
56
Mike Travisc938ac22008-03-05 08:31:29 -080057static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058static unsigned int acpi_thermal_cpufreq_is_init = 0;
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060static int cpu_has_cpufreq(unsigned int cpu)
61{
62 struct cpufreq_policy policy;
Thomas Renninger1cbf4c52004-09-16 11:07:00 -040063 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
Thomas Renninger75b245b32005-12-21 01:29:00 -050064 return 0;
65 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066}
67
Len Brown4be44fc2005-08-05 00:44:28 -040068static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
69 unsigned long event, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070070{
71 struct cpufreq_policy *policy = data;
72 unsigned long max_freq = 0;
73
74 if (event != CPUFREQ_ADJUST)
75 goto out;
76
Mike Travisc938ac22008-03-05 08:31:29 -080077 max_freq = (
78 policy->cpuinfo.max_freq *
79 (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
80 ) / 100;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 cpufreq_verify_within_limits(policy, 0, max_freq);
83
Len Brown4be44fc2005-08-05 00:44:28 -040084 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 return 0;
86}
87
Linus Torvalds1da177e2005-04-16 15:20:36 -070088static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
89 .notifier_call = acpi_thermal_cpufreq_notifier,
90};
91
Zhang Ruid9460fd222008-01-17 15:51:23 +080092static int cpufreq_get_max_state(unsigned int cpu)
93{
94 if (!cpu_has_cpufreq(cpu))
95 return 0;
96
97 return CPUFREQ_THERMAL_MAX_STEP;
98}
99
100static int cpufreq_get_cur_state(unsigned int cpu)
101{
102 if (!cpu_has_cpufreq(cpu))
103 return 0;
104
Mike Travisc938ac22008-03-05 08:31:29 -0800105 return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800106}
107
108static int cpufreq_set_cur_state(unsigned int cpu, int state)
109{
110 if (!cpu_has_cpufreq(cpu))
111 return 0;
112
Mike Travisc938ac22008-03-05 08:31:29 -0800113 per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800114 cpufreq_update_policy(cpu);
115 return 0;
116}
117
Len Brown4be44fc2005-08-05 00:44:28 -0400118void acpi_thermal_cpufreq_init(void)
119{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 int i;
121
Mike Travisc938ac22008-03-05 08:31:29 -0800122 for (i = 0; i < nr_cpu_ids; i++)
123 if (cpu_present(i))
124 per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Len Brown4be44fc2005-08-05 00:44:28 -0400126 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
127 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 if (!i)
129 acpi_thermal_cpufreq_is_init = 1;
130}
131
Len Brown4be44fc2005-08-05 00:44:28 -0400132void acpi_thermal_cpufreq_exit(void)
133{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 if (acpi_thermal_cpufreq_is_init)
Len Brown4be44fc2005-08-05 00:44:28 -0400135 cpufreq_unregister_notifier
136 (&acpi_thermal_cpufreq_notifier_block,
137 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
139 acpi_thermal_cpufreq_is_init = 0;
140}
141
Len Brown4be44fc2005-08-05 00:44:28 -0400142#else /* ! CONFIG_CPU_FREQ */
Zhang Ruid9460fd222008-01-17 15:51:23 +0800143static int cpufreq_get_max_state(unsigned int cpu)
144{
145 return 0;
146}
147
148static int cpufreq_get_cur_state(unsigned int cpu)
149{
150 return 0;
151}
152
153static int cpufreq_set_cur_state(unsigned int cpu, int state)
154{
155 return 0;
156}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158#endif
159
Len Brown4be44fc2005-08-05 00:44:28 -0400160int acpi_processor_get_limit_info(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400164 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 if (pr->flags.throttling)
167 pr->flags.limit = 1;
168
Patrick Mocheld550d982006-06-27 00:41:40 -0400169 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170}
171
Zhang Ruid9460fd222008-01-17 15:51:23 +0800172/* thermal coolign device callbacks */
173static int acpi_processor_max_state(struct acpi_processor *pr)
174{
175 int max_state = 0;
176
177 /*
178 * There exists four states according to
179 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
180 */
181 max_state += cpufreq_get_max_state(pr->id);
182 if (pr->flags.throttling)
183 max_state += (pr->throttling.state_count -1);
184
185 return max_state;
186}
187static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000188processor_get_max_state(struct thermal_cooling_device *cdev,
189 unsigned long *state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800190{
191 struct acpi_device *device = cdev->devdata;
192 struct acpi_processor *pr = acpi_driver_data(device);
193
194 if (!device || !pr)
195 return -EINVAL;
196
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000197 *state = acpi_processor_max_state(pr);
198 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800199}
200
201static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000202processor_get_cur_state(struct thermal_cooling_device *cdev,
203 unsigned long *cur_state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800204{
205 struct acpi_device *device = cdev->devdata;
206 struct acpi_processor *pr = acpi_driver_data(device);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800207
208 if (!device || !pr)
209 return -EINVAL;
210
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000211 *cur_state = cpufreq_get_cur_state(pr->id);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800212 if (pr->flags.throttling)
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000213 *cur_state += pr->throttling.state;
214 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800215}
216
217static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000218processor_set_cur_state(struct thermal_cooling_device *cdev,
219 unsigned long state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800220{
221 struct acpi_device *device = cdev->devdata;
222 struct acpi_processor *pr = acpi_driver_data(device);
223 int result = 0;
224 int max_pstate;
225
226 if (!device || !pr)
227 return -EINVAL;
228
229 max_pstate = cpufreq_get_max_state(pr->id);
230
231 if (state > acpi_processor_max_state(pr))
232 return -EINVAL;
233
234 if (state <= max_pstate) {
235 if (pr->flags.throttling && pr->throttling.state)
Frans Pop2a908002009-08-26 14:29:29 -0700236 result = acpi_processor_set_throttling(pr, 0, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800237 cpufreq_set_cur_state(pr->id, state);
238 } else {
239 cpufreq_set_cur_state(pr->id, max_pstate);
240 result = acpi_processor_set_throttling(pr,
Frans Pop2a908002009-08-26 14:29:29 -0700241 state - max_pstate, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800242 }
243 return result;
244}
245
Vasiliy Kulikov9c8b04b2011-06-25 21:07:52 +0400246const struct thermal_cooling_device_ops processor_cooling_ops = {
Zhang Ruid9460fd222008-01-17 15:51:23 +0800247 .get_max_state = processor_get_max_state,
248 .get_cur_state = processor_get_cur_state,
249 .set_cur_state = processor_set_cur_state,
250};