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1/*
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>
33#include <linux/sysdev.h>
34
35#include <asm/uaccess.h>
36
37#include <acpi/acpi_bus.h>
38#include <acpi/processor.h>
39#include <acpi/acpi_drivers.h>
40
41#define PREFIX "ACPI: "
42
43#define ACPI_PROCESSOR_CLASS "processor"
44#define _COMPONENT ACPI_PROCESSOR_COMPONENT
45ACPI_MODULE_NAME("processor_thermal");
46
47#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
55#define CPUFREQ_THERMAL_MIN_STEP 0
56#define CPUFREQ_THERMAL_MAX_STEP 3
57
58static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
59static unsigned int acpi_thermal_cpufreq_is_init = 0;
60
61static int cpu_has_cpufreq(unsigned int cpu)
62{
63 struct cpufreq_policy policy;
64 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
65 return 0;
66 return 1;
67}
68
69static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
70 unsigned long event, void *data)
71{
72 struct cpufreq_policy *policy = data;
73 unsigned long max_freq = 0;
74
75 if (event != CPUFREQ_ADJUST)
76 goto out;
77
78 max_freq = (
79 policy->cpuinfo.max_freq *
80 (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
81 ) / 100;
82
83 cpufreq_verify_within_limits(policy, 0, max_freq);
84
85 out:
86 return 0;
87}
88
89static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
90 .notifier_call = acpi_thermal_cpufreq_notifier,
91};
92
93static 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
106 return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
107}
108
109static int cpufreq_set_cur_state(unsigned int cpu, int state)
110{
111 if (!cpu_has_cpufreq(cpu))
112 return 0;
113
114 per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
115 cpufreq_update_policy(cpu);
116 return 0;
117}
118
119void acpi_thermal_cpufreq_init(void)
120{
121 int i;
122
123 for (i = 0; i < nr_cpu_ids; i++)
124 if (cpu_present(i))
125 per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
126
127 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
128 CPUFREQ_POLICY_NOTIFIER);
129 if (!i)
130 acpi_thermal_cpufreq_is_init = 1;
131}
132
133void acpi_thermal_cpufreq_exit(void)
134{
135 if (acpi_thermal_cpufreq_is_init)
136 cpufreq_unregister_notifier
137 (&acpi_thermal_cpufreq_notifier_block,
138 CPUFREQ_POLICY_NOTIFIER);
139
140 acpi_thermal_cpufreq_is_init = 0;
141}
142
143#else /* ! CONFIG_CPU_FREQ */
144static 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}
158
159#endif
160
161int acpi_processor_get_limit_info(struct acpi_processor *pr)
162{
163
164 if (!pr)
165 return -EINVAL;
166
167 if (pr->flags.throttling)
168 pr->flags.limit = 1;
169
170 return 0;
171}
172
173/* 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
189processor_get_max_state(struct thermal_cooling_device *cdev,
190 unsigned long *state)
191{
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
198 *state = acpi_processor_max_state(pr);
199 return 0;
200}
201
202static int
203processor_get_cur_state(struct thermal_cooling_device *cdev,
204 unsigned long *cur_state)
205{
206 struct acpi_device *device = cdev->devdata;
207 struct acpi_processor *pr = acpi_driver_data(device);
208
209 if (!device || !pr)
210 return -EINVAL;
211
212 *cur_state = cpufreq_get_cur_state(pr->id);
213 if (pr->flags.throttling)
214 *cur_state += pr->throttling.state;
215 return 0;
216}
217
218static int
219processor_set_cur_state(struct thermal_cooling_device *cdev,
220 unsigned long state)
221{
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)
237 result = acpi_processor_set_throttling(pr, 0, false);
238 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,
242 state - max_pstate, false);
243 }
244 return result;
245}
246
247const struct thermal_cooling_device_ops processor_cooling_ops = {
248 .get_max_state = processor_get_max_state,
249 .get_cur_state = processor_get_cur_state,
250 .set_cur_state = processor_set_cur_state,
251};
1/*
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>
33#include <linux/acpi.h>
34#include <acpi/processor.h>
35#include <asm/uaccess.h>
36
37#define PREFIX "ACPI: "
38
39#define ACPI_PROCESSOR_CLASS "processor"
40#define _COMPONENT ACPI_PROCESSOR_COMPONENT
41ACPI_MODULE_NAME("processor_thermal");
42
43#ifdef CONFIG_CPU_FREQ
44
45/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
46 * offers (in most cases) voltage scaling in addition to frequency scaling, and
47 * thus a cubic (instead of linear) reduction of energy. Also, we allow for
48 * _any_ cpufreq driver and not only the acpi-cpufreq driver.
49 */
50
51#define CPUFREQ_THERMAL_MIN_STEP 0
52#define CPUFREQ_THERMAL_MAX_STEP 3
53
54static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
55static unsigned int acpi_thermal_cpufreq_is_init = 0;
56
57#define reduction_pctg(cpu) \
58 per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
59
60/*
61 * Emulate "per package data" using per cpu data (which should really be
62 * provided elsewhere)
63 *
64 * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
65 * temporarily. Fortunately that's not a big issue here (I hope)
66 */
67static int phys_package_first_cpu(int cpu)
68{
69 int i;
70 int id = topology_physical_package_id(cpu);
71
72 for_each_online_cpu(i)
73 if (topology_physical_package_id(i) == id)
74 return i;
75 return 0;
76}
77
78static int cpu_has_cpufreq(unsigned int cpu)
79{
80 struct cpufreq_policy policy;
81 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
82 return 0;
83 return 1;
84}
85
86static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
87 unsigned long event, void *data)
88{
89 struct cpufreq_policy *policy = data;
90 unsigned long max_freq = 0;
91
92 if (event != CPUFREQ_ADJUST)
93 goto out;
94
95 max_freq = (
96 policy->cpuinfo.max_freq *
97 (100 - reduction_pctg(policy->cpu) * 20)
98 ) / 100;
99
100 cpufreq_verify_within_limits(policy, 0, max_freq);
101
102 out:
103 return 0;
104}
105
106static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
107 .notifier_call = acpi_thermal_cpufreq_notifier,
108};
109
110static int cpufreq_get_max_state(unsigned int cpu)
111{
112 if (!cpu_has_cpufreq(cpu))
113 return 0;
114
115 return CPUFREQ_THERMAL_MAX_STEP;
116}
117
118static int cpufreq_get_cur_state(unsigned int cpu)
119{
120 if (!cpu_has_cpufreq(cpu))
121 return 0;
122
123 return reduction_pctg(cpu);
124}
125
126static int cpufreq_set_cur_state(unsigned int cpu, int state)
127{
128 int i;
129
130 if (!cpu_has_cpufreq(cpu))
131 return 0;
132
133 reduction_pctg(cpu) = state;
134
135 /*
136 * Update all the CPUs in the same package because they all
137 * contribute to the temperature and often share the same
138 * frequency.
139 */
140 for_each_online_cpu(i) {
141 if (topology_physical_package_id(i) ==
142 topology_physical_package_id(cpu))
143 cpufreq_update_policy(i);
144 }
145 return 0;
146}
147
148void acpi_thermal_cpufreq_init(void)
149{
150 int i;
151
152 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
153 CPUFREQ_POLICY_NOTIFIER);
154 if (!i)
155 acpi_thermal_cpufreq_is_init = 1;
156}
157
158void acpi_thermal_cpufreq_exit(void)
159{
160 if (acpi_thermal_cpufreq_is_init)
161 cpufreq_unregister_notifier
162 (&acpi_thermal_cpufreq_notifier_block,
163 CPUFREQ_POLICY_NOTIFIER);
164
165 acpi_thermal_cpufreq_is_init = 0;
166}
167
168#else /* ! CONFIG_CPU_FREQ */
169static int cpufreq_get_max_state(unsigned int cpu)
170{
171 return 0;
172}
173
174static int cpufreq_get_cur_state(unsigned int cpu)
175{
176 return 0;
177}
178
179static int cpufreq_set_cur_state(unsigned int cpu, int state)
180{
181 return 0;
182}
183
184#endif
185
186/* thermal cooling device callbacks */
187static int acpi_processor_max_state(struct acpi_processor *pr)
188{
189 int max_state = 0;
190
191 /*
192 * There exists four states according to
193 * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
194 */
195 max_state += cpufreq_get_max_state(pr->id);
196 if (pr->flags.throttling)
197 max_state += (pr->throttling.state_count -1);
198
199 return max_state;
200}
201static int
202processor_get_max_state(struct thermal_cooling_device *cdev,
203 unsigned long *state)
204{
205 struct acpi_device *device = cdev->devdata;
206 struct acpi_processor *pr;
207
208 if (!device)
209 return -EINVAL;
210
211 pr = acpi_driver_data(device);
212 if (!pr)
213 return -EINVAL;
214
215 *state = acpi_processor_max_state(pr);
216 return 0;
217}
218
219static int
220processor_get_cur_state(struct thermal_cooling_device *cdev,
221 unsigned long *cur_state)
222{
223 struct acpi_device *device = cdev->devdata;
224 struct acpi_processor *pr;
225
226 if (!device)
227 return -EINVAL;
228
229 pr = acpi_driver_data(device);
230 if (!pr)
231 return -EINVAL;
232
233 *cur_state = cpufreq_get_cur_state(pr->id);
234 if (pr->flags.throttling)
235 *cur_state += pr->throttling.state;
236 return 0;
237}
238
239static int
240processor_set_cur_state(struct thermal_cooling_device *cdev,
241 unsigned long state)
242{
243 struct acpi_device *device = cdev->devdata;
244 struct acpi_processor *pr;
245 int result = 0;
246 int max_pstate;
247
248 if (!device)
249 return -EINVAL;
250
251 pr = acpi_driver_data(device);
252 if (!pr)
253 return -EINVAL;
254
255 max_pstate = cpufreq_get_max_state(pr->id);
256
257 if (state > acpi_processor_max_state(pr))
258 return -EINVAL;
259
260 if (state <= max_pstate) {
261 if (pr->flags.throttling && pr->throttling.state)
262 result = acpi_processor_set_throttling(pr, 0, false);
263 cpufreq_set_cur_state(pr->id, state);
264 } else {
265 cpufreq_set_cur_state(pr->id, max_pstate);
266 result = acpi_processor_set_throttling(pr,
267 state - max_pstate, false);
268 }
269 return result;
270}
271
272const struct thermal_cooling_device_ops processor_cooling_ops = {
273 .get_max_state = processor_get_max_state,
274 .get_cur_state = processor_get_cur_state,
275 .set_cur_state = processor_set_cur_state,
276};