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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>
Zhang Ruid9460fd222008-01-17 15:51:23 +080033#include <linux/sysdev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35#include <asm/uaccess.h>
36
37#include <acpi/acpi_bus.h>
38#include <acpi/processor.h>
39#include <acpi/acpi_drivers.h>
40
Len Browna192a952009-07-28 16:45:54 -040041#define PREFIX "ACPI: "
42
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define ACPI_PROCESSOR_CLASS "processor"
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#define _COMPONENT ACPI_PROCESSOR_COMPONENT
Len Brownf52fd662007-02-12 22:42:12 -050045ACPI_MODULE_NAME("processor_thermal");
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#ifdef CONFIG_CPU_FREQ
48
49/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
50 * offers (in most cases) voltage scaling in addition to frequency scaling, and
51 * thus a cubic (instead of linear) reduction of energy. Also, we allow for
52 * _any_ cpufreq driver and not only the acpi-cpufreq driver.
53 */
54
Zhang Ruid9460fd222008-01-17 15:51:23 +080055#define CPUFREQ_THERMAL_MIN_STEP 0
56#define CPUFREQ_THERMAL_MAX_STEP 3
57
Mike Travisc938ac22008-03-05 08:31:29 -080058static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059static unsigned int acpi_thermal_cpufreq_is_init = 0;
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061static int cpu_has_cpufreq(unsigned int cpu)
62{
63 struct cpufreq_policy policy;
Thomas Renninger1cbf4c52004-09-16 11:07:00 -040064 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
Thomas Renninger75b245b32005-12-21 01:29:00 -050065 return 0;
66 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067}
68
Len Brown4be44fc2005-08-05 00:44:28 -040069static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
70 unsigned long event, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
72 struct cpufreq_policy *policy = data;
73 unsigned long max_freq = 0;
74
75 if (event != CPUFREQ_ADJUST)
76 goto out;
77
Mike Travisc938ac22008-03-05 08:31:29 -080078 max_freq = (
79 policy->cpuinfo.max_freq *
80 (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
81 ) / 100;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 cpufreq_verify_within_limits(policy, 0, max_freq);
84
Len Brown4be44fc2005-08-05 00:44:28 -040085 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 return 0;
87}
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
90 .notifier_call = acpi_thermal_cpufreq_notifier,
91};
92
Zhang Ruid9460fd222008-01-17 15:51:23 +080093static int cpufreq_get_max_state(unsigned int cpu)
94{
95 if (!cpu_has_cpufreq(cpu))
96 return 0;
97
98 return CPUFREQ_THERMAL_MAX_STEP;
99}
100
101static int cpufreq_get_cur_state(unsigned int cpu)
102{
103 if (!cpu_has_cpufreq(cpu))
104 return 0;
105
Mike Travisc938ac22008-03-05 08:31:29 -0800106 return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800107}
108
109static int cpufreq_set_cur_state(unsigned int cpu, int state)
110{
111 if (!cpu_has_cpufreq(cpu))
112 return 0;
113
Mike Travisc938ac22008-03-05 08:31:29 -0800114 per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800115 cpufreq_update_policy(cpu);
116 return 0;
117}
118
Len Brown4be44fc2005-08-05 00:44:28 -0400119void acpi_thermal_cpufreq_init(void)
120{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 int i;
122
Mike Travisc938ac22008-03-05 08:31:29 -0800123 for (i = 0; i < nr_cpu_ids; i++)
124 if (cpu_present(i))
125 per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Len Brown4be44fc2005-08-05 00:44:28 -0400127 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
128 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 if (!i)
130 acpi_thermal_cpufreq_is_init = 1;
131}
132
Len Brown4be44fc2005-08-05 00:44:28 -0400133void acpi_thermal_cpufreq_exit(void)
134{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 if (acpi_thermal_cpufreq_is_init)
Len Brown4be44fc2005-08-05 00:44:28 -0400136 cpufreq_unregister_notifier
137 (&acpi_thermal_cpufreq_notifier_block,
138 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140 acpi_thermal_cpufreq_is_init = 0;
141}
142
Len Brown4be44fc2005-08-05 00:44:28 -0400143#else /* ! CONFIG_CPU_FREQ */
Zhang Ruid9460fd222008-01-17 15:51:23 +0800144static int cpufreq_get_max_state(unsigned int cpu)
145{
146 return 0;
147}
148
149static int cpufreq_get_cur_state(unsigned int cpu)
150{
151 return 0;
152}
153
154static int cpufreq_set_cur_state(unsigned int cpu, int state)
155{
156 return 0;
157}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159#endif
160
Len Brown4be44fc2005-08-05 00:44:28 -0400161int acpi_processor_get_limit_info(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400165 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 if (pr->flags.throttling)
168 pr->flags.limit = 1;
169
Patrick Mocheld550d982006-06-27 00:41:40 -0400170 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
172
Zhang Ruid9460fd222008-01-17 15:51:23 +0800173/* thermal coolign device callbacks */
174static int acpi_processor_max_state(struct acpi_processor *pr)
175{
176 int max_state = 0;
177
178 /*
179 * There exists four states according to
180 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
181 */
182 max_state += cpufreq_get_max_state(pr->id);
183 if (pr->flags.throttling)
184 max_state += (pr->throttling.state_count -1);
185
186 return max_state;
187}
188static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000189processor_get_max_state(struct thermal_cooling_device *cdev,
190 unsigned long *state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800191{
192 struct acpi_device *device = cdev->devdata;
193 struct acpi_processor *pr = acpi_driver_data(device);
194
195 if (!device || !pr)
196 return -EINVAL;
197
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000198 *state = acpi_processor_max_state(pr);
199 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800200}
201
202static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000203processor_get_cur_state(struct thermal_cooling_device *cdev,
204 unsigned long *cur_state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800205{
206 struct acpi_device *device = cdev->devdata;
207 struct acpi_processor *pr = acpi_driver_data(device);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800208
209 if (!device || !pr)
210 return -EINVAL;
211
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000212 *cur_state = cpufreq_get_cur_state(pr->id);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800213 if (pr->flags.throttling)
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000214 *cur_state += pr->throttling.state;
215 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800216}
217
218static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000219processor_set_cur_state(struct thermal_cooling_device *cdev,
220 unsigned long state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800221{
222 struct acpi_device *device = cdev->devdata;
223 struct acpi_processor *pr = acpi_driver_data(device);
224 int result = 0;
225 int max_pstate;
226
227 if (!device || !pr)
228 return -EINVAL;
229
230 max_pstate = cpufreq_get_max_state(pr->id);
231
232 if (state > acpi_processor_max_state(pr))
233 return -EINVAL;
234
235 if (state <= max_pstate) {
236 if (pr->flags.throttling && pr->throttling.state)
Frans Pop2a908002009-08-26 14:29:29 -0700237 result = acpi_processor_set_throttling(pr, 0, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800238 cpufreq_set_cur_state(pr->id, state);
239 } else {
240 cpufreq_set_cur_state(pr->id, max_pstate);
241 result = acpi_processor_set_throttling(pr,
Frans Pop2a908002009-08-26 14:29:29 -0700242 state - max_pstate, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800243 }
244 return result;
245}
246
Vasiliy Kulikov9c8b04b2011-06-25 21:07:52 +0400247const struct thermal_cooling_device_ops processor_cooling_ops = {
Zhang Ruid9460fd222008-01-17 15:51:23 +0800248 .get_max_state = processor_get_max_state,
249 .get_cur_state = processor_get_cur_state,
250 .set_cur_state = processor_set_cur_state,
251};