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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>
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
Andi Kleen2815ab92012-02-06 08:17:11 -080060#define reduction_pctg(cpu) \
61 per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
62
63/*
64 * Emulate "per package data" using per cpu data (which should really be
65 * provided elsewhere)
66 *
67 * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
68 * temporarily. Fortunately that's not a big issue here (I hope)
69 */
70static int phys_package_first_cpu(int cpu)
71{
72 int i;
73 int id = topology_physical_package_id(cpu);
74
75 for_each_online_cpu(i)
76 if (topology_physical_package_id(i) == id)
77 return i;
78 return 0;
79}
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static int cpu_has_cpufreq(unsigned int cpu)
82{
83 struct cpufreq_policy policy;
Thomas Renninger1cbf4c52004-09-16 11:07:00 -040084 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
Thomas Renninger75b245b32005-12-21 01:29:00 -050085 return 0;
86 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
Len Brown4be44fc2005-08-05 00:44:28 -040089static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
90 unsigned long event, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 struct cpufreq_policy *policy = data;
93 unsigned long max_freq = 0;
94
95 if (event != CPUFREQ_ADJUST)
96 goto out;
97
Mike Travisc938ac22008-03-05 08:31:29 -080098 max_freq = (
99 policy->cpuinfo.max_freq *
Andi Kleen2815ab92012-02-06 08:17:11 -0800100 (100 - reduction_pctg(policy->cpu) * 20)
Mike Travisc938ac22008-03-05 08:31:29 -0800101 ) / 100;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103 cpufreq_verify_within_limits(policy, 0, max_freq);
104
Len Brown4be44fc2005-08-05 00:44:28 -0400105 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 return 0;
107}
108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
110 .notifier_call = acpi_thermal_cpufreq_notifier,
111};
112
Zhang Ruid9460fd222008-01-17 15:51:23 +0800113static int cpufreq_get_max_state(unsigned int cpu)
114{
115 if (!cpu_has_cpufreq(cpu))
116 return 0;
117
118 return CPUFREQ_THERMAL_MAX_STEP;
119}
120
121static int cpufreq_get_cur_state(unsigned int cpu)
122{
123 if (!cpu_has_cpufreq(cpu))
124 return 0;
125
Andi Kleen2815ab92012-02-06 08:17:11 -0800126 return reduction_pctg(cpu);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800127}
128
129static int cpufreq_set_cur_state(unsigned int cpu, int state)
130{
Andi Kleen2815ab92012-02-06 08:17:11 -0800131 int i;
132
Zhang Ruid9460fd222008-01-17 15:51:23 +0800133 if (!cpu_has_cpufreq(cpu))
134 return 0;
135
Andi Kleen2815ab92012-02-06 08:17:11 -0800136 reduction_pctg(cpu) = state;
137
138 /*
139 * Update all the CPUs in the same package because they all
140 * contribute to the temperature and often share the same
141 * frequency.
142 */
143 for_each_online_cpu(i) {
144 if (topology_physical_package_id(i) ==
145 topology_physical_package_id(cpu))
146 cpufreq_update_policy(i);
147 }
Zhang Ruid9460fd222008-01-17 15:51:23 +0800148 return 0;
149}
150
Len Brown4be44fc2005-08-05 00:44:28 -0400151void acpi_thermal_cpufreq_init(void)
152{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 int i;
154
Len Brown4be44fc2005-08-05 00:44:28 -0400155 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
156 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 if (!i)
158 acpi_thermal_cpufreq_is_init = 1;
159}
160
Len Brown4be44fc2005-08-05 00:44:28 -0400161void acpi_thermal_cpufreq_exit(void)
162{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 if (acpi_thermal_cpufreq_is_init)
Len Brown4be44fc2005-08-05 00:44:28 -0400164 cpufreq_unregister_notifier
165 (&acpi_thermal_cpufreq_notifier_block,
166 CPUFREQ_POLICY_NOTIFIER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 acpi_thermal_cpufreq_is_init = 0;
169}
170
Len Brown4be44fc2005-08-05 00:44:28 -0400171#else /* ! CONFIG_CPU_FREQ */
Zhang Ruid9460fd222008-01-17 15:51:23 +0800172static int cpufreq_get_max_state(unsigned int cpu)
173{
174 return 0;
175}
176
177static int cpufreq_get_cur_state(unsigned int cpu)
178{
179 return 0;
180}
181
182static int cpufreq_set_cur_state(unsigned int cpu, int state)
183{
184 return 0;
185}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187#endif
188
Zhang Ruid9460fd222008-01-17 15:51:23 +0800189/* thermal coolign device callbacks */
190static int acpi_processor_max_state(struct acpi_processor *pr)
191{
192 int max_state = 0;
193
194 /*
195 * There exists four states according to
196 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
197 */
198 max_state += cpufreq_get_max_state(pr->id);
199 if (pr->flags.throttling)
200 max_state += (pr->throttling.state_count -1);
201
202 return max_state;
203}
204static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000205processor_get_max_state(struct thermal_cooling_device *cdev,
206 unsigned long *state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800207{
208 struct acpi_device *device = cdev->devdata;
Colin Ian King99aa3632013-03-25 10:50:06 +0000209 struct acpi_processor *pr;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800210
Colin Ian King99aa3632013-03-25 10:50:06 +0000211 if (!device)
212 return -EINVAL;
213
214 pr = acpi_driver_data(device);
215 if (!pr)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800216 return -EINVAL;
217
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000218 *state = acpi_processor_max_state(pr);
219 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800220}
221
222static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000223processor_get_cur_state(struct thermal_cooling_device *cdev,
224 unsigned long *cur_state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800225{
226 struct acpi_device *device = cdev->devdata;
Colin Ian King99aa3632013-03-25 10:50:06 +0000227 struct acpi_processor *pr;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800228
Colin Ian King99aa3632013-03-25 10:50:06 +0000229 if (!device)
230 return -EINVAL;
231
232 pr = acpi_driver_data(device);
233 if (!pr)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800234 return -EINVAL;
235
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000236 *cur_state = cpufreq_get_cur_state(pr->id);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800237 if (pr->flags.throttling)
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000238 *cur_state += pr->throttling.state;
239 return 0;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800240}
241
242static int
Matthew Garrett6503e5d2008-11-27 17:48:13 +0000243processor_set_cur_state(struct thermal_cooling_device *cdev,
244 unsigned long state)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800245{
246 struct acpi_device *device = cdev->devdata;
Colin Ian King99aa3632013-03-25 10:50:06 +0000247 struct acpi_processor *pr;
Zhang Ruid9460fd222008-01-17 15:51:23 +0800248 int result = 0;
249 int max_pstate;
250
Colin Ian King99aa3632013-03-25 10:50:06 +0000251 if (!device)
252 return -EINVAL;
253
254 pr = acpi_driver_data(device);
255 if (!pr)
Zhang Ruid9460fd222008-01-17 15:51:23 +0800256 return -EINVAL;
257
258 max_pstate = cpufreq_get_max_state(pr->id);
259
260 if (state > acpi_processor_max_state(pr))
261 return -EINVAL;
262
263 if (state <= max_pstate) {
264 if (pr->flags.throttling && pr->throttling.state)
Frans Pop2a908002009-08-26 14:29:29 -0700265 result = acpi_processor_set_throttling(pr, 0, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800266 cpufreq_set_cur_state(pr->id, state);
267 } else {
268 cpufreq_set_cur_state(pr->id, max_pstate);
269 result = acpi_processor_set_throttling(pr,
Frans Pop2a908002009-08-26 14:29:29 -0700270 state - max_pstate, false);
Zhang Ruid9460fd222008-01-17 15:51:23 +0800271 }
272 return result;
273}
274
Vasiliy Kulikov9c8b04b2011-06-25 21:07:52 +0400275const struct thermal_cooling_device_ops processor_cooling_ops = {
Zhang Ruid9460fd222008-01-17 15:51:23 +0800276 .get_max_state = processor_get_max_state,
277 .get_cur_state = processor_get_cur_state,
278 .set_cur_state = processor_set_cur_state,
279};