Loading...
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
34#include <asm/uaccess.h>
35
36#include <acpi/acpi_bus.h>
37#include <acpi/processor.h>
38#include <acpi/acpi_drivers.h>
39
40#define PREFIX "ACPI: "
41
42#define ACPI_PROCESSOR_CLASS "processor"
43#define _COMPONENT ACPI_PROCESSOR_COMPONENT
44ACPI_MODULE_NAME("processor_thermal");
45
46#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
54#define CPUFREQ_THERMAL_MIN_STEP 0
55#define CPUFREQ_THERMAL_MAX_STEP 3
56
57static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
58static unsigned int acpi_thermal_cpufreq_is_init = 0;
59
60#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
81static int cpu_has_cpufreq(unsigned int cpu)
82{
83 struct cpufreq_policy policy;
84 if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
85 return 0;
86 return 1;
87}
88
89static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
90 unsigned long event, void *data)
91{
92 struct cpufreq_policy *policy = data;
93 unsigned long max_freq = 0;
94
95 if (event != CPUFREQ_ADJUST)
96 goto out;
97
98 max_freq = (
99 policy->cpuinfo.max_freq *
100 (100 - reduction_pctg(policy->cpu) * 20)
101 ) / 100;
102
103 cpufreq_verify_within_limits(policy, 0, max_freq);
104
105 out:
106 return 0;
107}
108
109static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
110 .notifier_call = acpi_thermal_cpufreq_notifier,
111};
112
113static 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
126 return reduction_pctg(cpu);
127}
128
129static int cpufreq_set_cur_state(unsigned int cpu, int state)
130{
131 int i;
132
133 if (!cpu_has_cpufreq(cpu))
134 return 0;
135
136 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 }
148 return 0;
149}
150
151void acpi_thermal_cpufreq_init(void)
152{
153 int i;
154
155 i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
156 CPUFREQ_POLICY_NOTIFIER);
157 if (!i)
158 acpi_thermal_cpufreq_is_init = 1;
159}
160
161void acpi_thermal_cpufreq_exit(void)
162{
163 if (acpi_thermal_cpufreq_is_init)
164 cpufreq_unregister_notifier
165 (&acpi_thermal_cpufreq_notifier_block,
166 CPUFREQ_POLICY_NOTIFIER);
167
168 acpi_thermal_cpufreq_is_init = 0;
169}
170
171#else /* ! CONFIG_CPU_FREQ */
172static 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}
186
187#endif
188
189int acpi_processor_get_limit_info(struct acpi_processor *pr)
190{
191
192 if (!pr)
193 return -EINVAL;
194
195 if (pr->flags.throttling)
196 pr->flags.limit = 1;
197
198 return 0;
199}
200
201/* thermal coolign device callbacks */
202static int acpi_processor_max_state(struct acpi_processor *pr)
203{
204 int max_state = 0;
205
206 /*
207 * There exists four states according to
208 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
209 */
210 max_state += cpufreq_get_max_state(pr->id);
211 if (pr->flags.throttling)
212 max_state += (pr->throttling.state_count -1);
213
214 return max_state;
215}
216static int
217processor_get_max_state(struct thermal_cooling_device *cdev,
218 unsigned long *state)
219{
220 struct acpi_device *device = cdev->devdata;
221 struct acpi_processor *pr = acpi_driver_data(device);
222
223 if (!device || !pr)
224 return -EINVAL;
225
226 *state = acpi_processor_max_state(pr);
227 return 0;
228}
229
230static int
231processor_get_cur_state(struct thermal_cooling_device *cdev,
232 unsigned long *cur_state)
233{
234 struct acpi_device *device = cdev->devdata;
235 struct acpi_processor *pr = acpi_driver_data(device);
236
237 if (!device || !pr)
238 return -EINVAL;
239
240 *cur_state = cpufreq_get_cur_state(pr->id);
241 if (pr->flags.throttling)
242 *cur_state += pr->throttling.state;
243 return 0;
244}
245
246static int
247processor_set_cur_state(struct thermal_cooling_device *cdev,
248 unsigned long state)
249{
250 struct acpi_device *device = cdev->devdata;
251 struct acpi_processor *pr = acpi_driver_data(device);
252 int result = 0;
253 int max_pstate;
254
255 if (!device || !pr)
256 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)
265 result = acpi_processor_set_throttling(pr, 0, false);
266 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,
270 state - max_pstate, false);
271 }
272 return result;
273}
274
275const struct thermal_cooling_device_ops processor_cooling_ops = {
276 .get_max_state = processor_get_max_state,
277 .get_cur_state = processor_get_cur_state,
278 .set_cur_state = processor_set_cur_state,
279};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * processor_thermal.c - Passive cooling submodule of the ACPI processor driver
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9 * - Added processor hotplug support
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/cpufreq.h>
16#include <linux/acpi.h>
17#include <acpi/processor.h>
18#include <linux/uaccess.h>
19
20#include "internal.h"
21
22#ifdef CONFIG_CPU_FREQ
23
24/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
25 * offers (in most cases) voltage scaling in addition to frequency scaling, and
26 * thus a cubic (instead of linear) reduction of energy. Also, we allow for
27 * _any_ cpufreq driver and not only the acpi-cpufreq driver.
28 */
29
30#define CPUFREQ_THERMAL_MIN_STEP 0
31
32static int cpufreq_thermal_max_step __read_mostly = 3;
33
34/*
35 * Minimum throttle percentage for processor_thermal cooling device.
36 * The processor_thermal driver uses it to calculate the percentage amount by
37 * which cpu frequency must be reduced for each cooling state. This is also used
38 * to calculate the maximum number of throttling steps or cooling states.
39 */
40static int cpufreq_thermal_reduction_pctg __read_mostly = 20;
41
42static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_step);
43
44#define reduction_step(cpu) \
45 per_cpu(cpufreq_thermal_reduction_step, phys_package_first_cpu(cpu))
46
47/*
48 * Emulate "per package data" using per cpu data (which should really be
49 * provided elsewhere)
50 *
51 * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
52 * temporarily. Fortunately that's not a big issue here (I hope)
53 */
54static int phys_package_first_cpu(int cpu)
55{
56 int i;
57 int id = topology_physical_package_id(cpu);
58
59 for_each_online_cpu(i)
60 if (topology_physical_package_id(i) == id)
61 return i;
62 return 0;
63}
64
65static int cpu_has_cpufreq(unsigned int cpu)
66{
67 struct cpufreq_policy *policy;
68
69 if (!acpi_processor_cpufreq_init)
70 return 0;
71
72 policy = cpufreq_cpu_get(cpu);
73 if (policy) {
74 cpufreq_cpu_put(policy);
75 return 1;
76 }
77 return 0;
78}
79
80static int cpufreq_get_max_state(unsigned int cpu)
81{
82 if (!cpu_has_cpufreq(cpu))
83 return 0;
84
85 return cpufreq_thermal_max_step;
86}
87
88static int cpufreq_get_cur_state(unsigned int cpu)
89{
90 if (!cpu_has_cpufreq(cpu))
91 return 0;
92
93 return reduction_step(cpu);
94}
95
96static int cpufreq_set_cur_state(unsigned int cpu, int state)
97{
98 struct cpufreq_policy *policy;
99 struct acpi_processor *pr;
100 unsigned long max_freq;
101 int i, ret;
102
103 if (!cpu_has_cpufreq(cpu))
104 return 0;
105
106 reduction_step(cpu) = state;
107
108 /*
109 * Update all the CPUs in the same package because they all
110 * contribute to the temperature and often share the same
111 * frequency.
112 */
113 for_each_online_cpu(i) {
114 if (topology_physical_package_id(i) !=
115 topology_physical_package_id(cpu))
116 continue;
117
118 pr = per_cpu(processors, i);
119
120 if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
121 continue;
122
123 policy = cpufreq_cpu_get(i);
124 if (!policy)
125 return -EINVAL;
126
127 max_freq = (policy->cpuinfo.max_freq *
128 (100 - reduction_step(i) * cpufreq_thermal_reduction_pctg)) / 100;
129
130 cpufreq_cpu_put(policy);
131
132 ret = freq_qos_update_request(&pr->thermal_req, max_freq);
133 if (ret < 0) {
134 pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
135 pr->id, ret);
136 }
137 }
138 return 0;
139}
140
141static void acpi_thermal_cpufreq_config(void)
142{
143 int cpufreq_pctg = acpi_arch_thermal_cpufreq_pctg();
144
145 if (!cpufreq_pctg)
146 return;
147
148 cpufreq_thermal_reduction_pctg = cpufreq_pctg;
149
150 /*
151 * Derive the MAX_STEP from minimum throttle percentage so that the reduction
152 * percentage doesn't end up becoming negative. Also, cap the MAX_STEP so that
153 * the CPU performance doesn't become 0.
154 */
155 cpufreq_thermal_max_step = (100 / cpufreq_pctg) - 2;
156}
157
158void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
159{
160 unsigned int cpu;
161
162 acpi_thermal_cpufreq_config();
163
164 for_each_cpu(cpu, policy->related_cpus) {
165 struct acpi_processor *pr = per_cpu(processors, cpu);
166 int ret;
167
168 if (!pr)
169 continue;
170
171 ret = freq_qos_add_request(&policy->constraints,
172 &pr->thermal_req,
173 FREQ_QOS_MAX, INT_MAX);
174 if (ret < 0) {
175 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
176 cpu, ret);
177 continue;
178 }
179
180 thermal_cooling_device_update(pr->cdev);
181 }
182}
183
184void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
185{
186 unsigned int cpu;
187
188 for_each_cpu(cpu, policy->related_cpus) {
189 struct acpi_processor *pr = per_cpu(processors, cpu);
190
191 if (!pr)
192 continue;
193
194 freq_qos_remove_request(&pr->thermal_req);
195
196 thermal_cooling_device_update(pr->cdev);
197 }
198}
199#else /* ! CONFIG_CPU_FREQ */
200static int cpufreq_get_max_state(unsigned int cpu)
201{
202 return 0;
203}
204
205static int cpufreq_get_cur_state(unsigned int cpu)
206{
207 return 0;
208}
209
210static int cpufreq_set_cur_state(unsigned int cpu, int state)
211{
212 return 0;
213}
214
215#endif
216
217/* thermal cooling device callbacks */
218static int acpi_processor_max_state(struct acpi_processor *pr)
219{
220 int max_state = 0;
221
222 /*
223 * There exists four states according to
224 * cpufreq_thermal_reduction_step. 0, 1, 2, 3
225 */
226 max_state += cpufreq_get_max_state(pr->id);
227 if (pr->flags.throttling)
228 max_state += (pr->throttling.state_count -1);
229
230 return max_state;
231}
232static int
233processor_get_max_state(struct thermal_cooling_device *cdev,
234 unsigned long *state)
235{
236 struct acpi_device *device = cdev->devdata;
237 struct acpi_processor *pr;
238
239 if (!device)
240 return -EINVAL;
241
242 pr = acpi_driver_data(device);
243 if (!pr)
244 return -EINVAL;
245
246 *state = acpi_processor_max_state(pr);
247 return 0;
248}
249
250static int
251processor_get_cur_state(struct thermal_cooling_device *cdev,
252 unsigned long *cur_state)
253{
254 struct acpi_device *device = cdev->devdata;
255 struct acpi_processor *pr;
256
257 if (!device)
258 return -EINVAL;
259
260 pr = acpi_driver_data(device);
261 if (!pr)
262 return -EINVAL;
263
264 *cur_state = cpufreq_get_cur_state(pr->id);
265 if (pr->flags.throttling)
266 *cur_state += pr->throttling.state;
267 return 0;
268}
269
270static int
271processor_set_cur_state(struct thermal_cooling_device *cdev,
272 unsigned long state)
273{
274 struct acpi_device *device = cdev->devdata;
275 struct acpi_processor *pr;
276 int result = 0;
277 int max_pstate;
278
279 if (!device)
280 return -EINVAL;
281
282 pr = acpi_driver_data(device);
283 if (!pr)
284 return -EINVAL;
285
286 max_pstate = cpufreq_get_max_state(pr->id);
287
288 if (state > acpi_processor_max_state(pr))
289 return -EINVAL;
290
291 if (state <= max_pstate) {
292 if (pr->flags.throttling && pr->throttling.state)
293 result = acpi_processor_set_throttling(pr, 0, false);
294 cpufreq_set_cur_state(pr->id, state);
295 } else {
296 cpufreq_set_cur_state(pr->id, max_pstate);
297 result = acpi_processor_set_throttling(pr,
298 state - max_pstate, false);
299 }
300 return result;
301}
302
303const struct thermal_cooling_device_ops processor_cooling_ops = {
304 .get_max_state = processor_get_max_state,
305 .get_cur_state = processor_get_cur_state,
306 .set_cur_state = processor_set_cur_state,
307};
308
309int acpi_processor_thermal_init(struct acpi_processor *pr,
310 struct acpi_device *device)
311{
312 int result = 0;
313
314 pr->cdev = thermal_cooling_device_register("Processor", device,
315 &processor_cooling_ops);
316 if (IS_ERR(pr->cdev)) {
317 result = PTR_ERR(pr->cdev);
318 return result;
319 }
320
321 dev_dbg(&device->dev, "registered as cooling_device%d\n",
322 pr->cdev->id);
323
324 result = sysfs_create_link(&device->dev.kobj,
325 &pr->cdev->device.kobj,
326 "thermal_cooling");
327 if (result) {
328 dev_err(&device->dev,
329 "Failed to create sysfs link 'thermal_cooling'\n");
330 goto err_thermal_unregister;
331 }
332
333 result = sysfs_create_link(&pr->cdev->device.kobj,
334 &device->dev.kobj,
335 "device");
336 if (result) {
337 dev_err(&pr->cdev->device,
338 "Failed to create sysfs link 'device'\n");
339 goto err_remove_sysfs_thermal;
340 }
341
342 return 0;
343
344err_remove_sysfs_thermal:
345 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
346err_thermal_unregister:
347 thermal_cooling_device_unregister(pr->cdev);
348
349 return result;
350}
351
352void acpi_processor_thermal_exit(struct acpi_processor *pr,
353 struct acpi_device *device)
354{
355 if (pr->cdev) {
356 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
357 sysfs_remove_link(&pr->cdev->device.kobj, "device");
358 thermal_cooling_device_unregister(pr->cdev);
359 pr->cdev = NULL;
360 }
361}