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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// 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#ifdef CONFIG_CPU_FREQ
21
22/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
23 * offers (in most cases) voltage scaling in addition to frequency scaling, and
24 * thus a cubic (instead of linear) reduction of energy. Also, we allow for
25 * _any_ cpufreq driver and not only the acpi-cpufreq driver.
26 */
27
28#define CPUFREQ_THERMAL_MIN_STEP 0
29#define CPUFREQ_THERMAL_MAX_STEP 3
30
31static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
32
33#define reduction_pctg(cpu) \
34 per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
35
36/*
37 * Emulate "per package data" using per cpu data (which should really be
38 * provided elsewhere)
39 *
40 * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
41 * temporarily. Fortunately that's not a big issue here (I hope)
42 */
43static int phys_package_first_cpu(int cpu)
44{
45 int i;
46 int id = topology_physical_package_id(cpu);
47
48 for_each_online_cpu(i)
49 if (topology_physical_package_id(i) == id)
50 return i;
51 return 0;
52}
53
54static int cpu_has_cpufreq(unsigned int cpu)
55{
56 struct cpufreq_policy *policy;
57
58 if (!acpi_processor_cpufreq_init)
59 return 0;
60
61 policy = cpufreq_cpu_get(cpu);
62 if (policy) {
63 cpufreq_cpu_put(policy);
64 return 1;
65 }
66 return 0;
67}
68
69static int cpufreq_get_max_state(unsigned int cpu)
70{
71 if (!cpu_has_cpufreq(cpu))
72 return 0;
73
74 return CPUFREQ_THERMAL_MAX_STEP;
75}
76
77static int cpufreq_get_cur_state(unsigned int cpu)
78{
79 if (!cpu_has_cpufreq(cpu))
80 return 0;
81
82 return reduction_pctg(cpu);
83}
84
85static int cpufreq_set_cur_state(unsigned int cpu, int state)
86{
87 struct cpufreq_policy *policy;
88 struct acpi_processor *pr;
89 unsigned long max_freq;
90 int i, ret;
91
92 if (!cpu_has_cpufreq(cpu))
93 return 0;
94
95 reduction_pctg(cpu) = state;
96
97 /*
98 * Update all the CPUs in the same package because they all
99 * contribute to the temperature and often share the same
100 * frequency.
101 */
102 for_each_online_cpu(i) {
103 if (topology_physical_package_id(i) !=
104 topology_physical_package_id(cpu))
105 continue;
106
107 pr = per_cpu(processors, i);
108
109 if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
110 continue;
111
112 policy = cpufreq_cpu_get(i);
113 if (!policy)
114 return -EINVAL;
115
116 max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
117
118 cpufreq_cpu_put(policy);
119
120 ret = freq_qos_update_request(&pr->thermal_req, max_freq);
121 if (ret < 0) {
122 pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
123 pr->id, ret);
124 }
125 }
126 return 0;
127}
128
129void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
130{
131 unsigned int cpu;
132
133 for_each_cpu(cpu, policy->related_cpus) {
134 struct acpi_processor *pr = per_cpu(processors, cpu);
135 int ret;
136
137 if (!pr)
138 continue;
139
140 ret = freq_qos_add_request(&policy->constraints,
141 &pr->thermal_req,
142 FREQ_QOS_MAX, INT_MAX);
143 if (ret < 0)
144 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
145 cpu, ret);
146 }
147}
148
149void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
150{
151 unsigned int cpu;
152
153 for_each_cpu(cpu, policy->related_cpus) {
154 struct acpi_processor *pr = per_cpu(processors, cpu);
155
156 if (pr)
157 freq_qos_remove_request(&pr->thermal_req);
158 }
159}
160#else /* ! CONFIG_CPU_FREQ */
161static int cpufreq_get_max_state(unsigned int cpu)
162{
163 return 0;
164}
165
166static int cpufreq_get_cur_state(unsigned int cpu)
167{
168 return 0;
169}
170
171static int cpufreq_set_cur_state(unsigned int cpu, int state)
172{
173 return 0;
174}
175
176#endif
177
178/* thermal cooling device callbacks */
179static int acpi_processor_max_state(struct acpi_processor *pr)
180{
181 int max_state = 0;
182
183 /*
184 * There exists four states according to
185 * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
186 */
187 max_state += cpufreq_get_max_state(pr->id);
188 if (pr->flags.throttling)
189 max_state += (pr->throttling.state_count -1);
190
191 return max_state;
192}
193static int
194processor_get_max_state(struct thermal_cooling_device *cdev,
195 unsigned long *state)
196{
197 struct acpi_device *device = cdev->devdata;
198 struct acpi_processor *pr;
199
200 if (!device)
201 return -EINVAL;
202
203 pr = acpi_driver_data(device);
204 if (!pr)
205 return -EINVAL;
206
207 *state = acpi_processor_max_state(pr);
208 return 0;
209}
210
211static int
212processor_get_cur_state(struct thermal_cooling_device *cdev,
213 unsigned long *cur_state)
214{
215 struct acpi_device *device = cdev->devdata;
216 struct acpi_processor *pr;
217
218 if (!device)
219 return -EINVAL;
220
221 pr = acpi_driver_data(device);
222 if (!pr)
223 return -EINVAL;
224
225 *cur_state = cpufreq_get_cur_state(pr->id);
226 if (pr->flags.throttling)
227 *cur_state += pr->throttling.state;
228 return 0;
229}
230
231static int
232processor_set_cur_state(struct thermal_cooling_device *cdev,
233 unsigned long state)
234{
235 struct acpi_device *device = cdev->devdata;
236 struct acpi_processor *pr;
237 int result = 0;
238 int max_pstate;
239
240 if (!device)
241 return -EINVAL;
242
243 pr = acpi_driver_data(device);
244 if (!pr)
245 return -EINVAL;
246
247 max_pstate = cpufreq_get_max_state(pr->id);
248
249 if (state > acpi_processor_max_state(pr))
250 return -EINVAL;
251
252 if (state <= max_pstate) {
253 if (pr->flags.throttling && pr->throttling.state)
254 result = acpi_processor_set_throttling(pr, 0, false);
255 cpufreq_set_cur_state(pr->id, state);
256 } else {
257 cpufreq_set_cur_state(pr->id, max_pstate);
258 result = acpi_processor_set_throttling(pr,
259 state - max_pstate, false);
260 }
261 return result;
262}
263
264const struct thermal_cooling_device_ops processor_cooling_ops = {
265 .get_max_state = processor_get_max_state,
266 .get_cur_state = processor_get_cur_state,
267 .set_cur_state = processor_set_cur_state,
268};
269
270int acpi_processor_thermal_init(struct acpi_processor *pr,
271 struct acpi_device *device)
272{
273 int result = 0;
274
275 pr->cdev = thermal_cooling_device_register("Processor", device,
276 &processor_cooling_ops);
277 if (IS_ERR(pr->cdev)) {
278 result = PTR_ERR(pr->cdev);
279 return result;
280 }
281
282 dev_dbg(&device->dev, "registered as cooling_device%d\n",
283 pr->cdev->id);
284
285 result = sysfs_create_link(&device->dev.kobj,
286 &pr->cdev->device.kobj,
287 "thermal_cooling");
288 if (result) {
289 dev_err(&device->dev,
290 "Failed to create sysfs link 'thermal_cooling'\n");
291 goto err_thermal_unregister;
292 }
293
294 result = sysfs_create_link(&pr->cdev->device.kobj,
295 &device->dev.kobj,
296 "device");
297 if (result) {
298 dev_err(&pr->cdev->device,
299 "Failed to create sysfs link 'device'\n");
300 goto err_remove_sysfs_thermal;
301 }
302
303 return 0;
304
305err_remove_sysfs_thermal:
306 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
307err_thermal_unregister:
308 thermal_cooling_device_unregister(pr->cdev);
309
310 return result;
311}
312
313void acpi_processor_thermal_exit(struct acpi_processor *pr,
314 struct acpi_device *device)
315{
316 if (pr->cdev) {
317 sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
318 sysfs_remove_link(&pr->cdev->device.kobj, "device");
319 thermal_cooling_device_unregister(pr->cdev);
320 pr->cdev = NULL;
321 }
322}