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