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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 if (!acpi_processor_cpufreq_init || cpufreq_get_policy(&policy, cpu))
58 return 0;
59 return 1;
60}
61
62static int cpufreq_get_max_state(unsigned int cpu)
63{
64 if (!cpu_has_cpufreq(cpu))
65 return 0;
66
67 return CPUFREQ_THERMAL_MAX_STEP;
68}
69
70static int cpufreq_get_cur_state(unsigned int cpu)
71{
72 if (!cpu_has_cpufreq(cpu))
73 return 0;
74
75 return reduction_pctg(cpu);
76}
77
78static int cpufreq_set_cur_state(unsigned int cpu, int state)
79{
80 struct cpufreq_policy *policy;
81 struct acpi_processor *pr;
82 unsigned long max_freq;
83 int i, ret;
84
85 if (!cpu_has_cpufreq(cpu))
86 return 0;
87
88 reduction_pctg(cpu) = state;
89
90 /*
91 * Update all the CPUs in the same package because they all
92 * contribute to the temperature and often share the same
93 * frequency.
94 */
95 for_each_online_cpu(i) {
96 if (topology_physical_package_id(i) !=
97 topology_physical_package_id(cpu))
98 continue;
99
100 pr = per_cpu(processors, i);
101
102 if (unlikely(!freq_qos_request_active(&pr->thermal_req)))
103 continue;
104
105 policy = cpufreq_cpu_get(i);
106 if (!policy)
107 return -EINVAL;
108
109 max_freq = (policy->cpuinfo.max_freq * (100 - reduction_pctg(i) * 20)) / 100;
110
111 cpufreq_cpu_put(policy);
112
113 ret = freq_qos_update_request(&pr->thermal_req, max_freq);
114 if (ret < 0) {
115 pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n",
116 pr->id, ret);
117 }
118 }
119 return 0;
120}
121
122void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy)
123{
124 unsigned int cpu;
125
126 for_each_cpu(cpu, policy->related_cpus) {
127 struct acpi_processor *pr = per_cpu(processors, cpu);
128 int ret;
129
130 if (!pr)
131 continue;
132
133 ret = freq_qos_add_request(&policy->constraints,
134 &pr->thermal_req,
135 FREQ_QOS_MAX, INT_MAX);
136 if (ret < 0)
137 pr_err("Failed to add freq constraint for CPU%d (%d)\n",
138 cpu, ret);
139 }
140}
141
142void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy)
143{
144 unsigned int cpu;
145
146 for_each_cpu(cpu, policy->related_cpus) {
147 struct acpi_processor *pr = per_cpu(processors, policy->cpu);
148
149 if (pr)
150 freq_qos_remove_request(&pr->thermal_req);
151 }
152}
153#else /* ! CONFIG_CPU_FREQ */
154static int cpufreq_get_max_state(unsigned int cpu)
155{
156 return 0;
157}
158
159static int cpufreq_get_cur_state(unsigned int cpu)
160{
161 return 0;
162}
163
164static int cpufreq_set_cur_state(unsigned int cpu, int state)
165{
166 return 0;
167}
168
169#endif
170
171/* thermal cooling device callbacks */
172static int acpi_processor_max_state(struct acpi_processor *pr)
173{
174 int max_state = 0;
175
176 /*
177 * There exists four states according to
178 * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3
179 */
180 max_state += cpufreq_get_max_state(pr->id);
181 if (pr->flags.throttling)
182 max_state += (pr->throttling.state_count -1);
183
184 return max_state;
185}
186static int
187processor_get_max_state(struct thermal_cooling_device *cdev,
188 unsigned long *state)
189{
190 struct acpi_device *device = cdev->devdata;
191 struct acpi_processor *pr;
192
193 if (!device)
194 return -EINVAL;
195
196 pr = acpi_driver_data(device);
197 if (!pr)
198 return -EINVAL;
199
200 *state = acpi_processor_max_state(pr);
201 return 0;
202}
203
204static int
205processor_get_cur_state(struct thermal_cooling_device *cdev,
206 unsigned long *cur_state)
207{
208 struct acpi_device *device = cdev->devdata;
209 struct acpi_processor *pr;
210
211 if (!device)
212 return -EINVAL;
213
214 pr = acpi_driver_data(device);
215 if (!pr)
216 return -EINVAL;
217
218 *cur_state = cpufreq_get_cur_state(pr->id);
219 if (pr->flags.throttling)
220 *cur_state += pr->throttling.state;
221 return 0;
222}
223
224static int
225processor_set_cur_state(struct thermal_cooling_device *cdev,
226 unsigned long state)
227{
228 struct acpi_device *device = cdev->devdata;
229 struct acpi_processor *pr;
230 int result = 0;
231 int max_pstate;
232
233 if (!device)
234 return -EINVAL;
235
236 pr = acpi_driver_data(device);
237 if (!pr)
238 return -EINVAL;
239
240 max_pstate = cpufreq_get_max_state(pr->id);
241
242 if (state > acpi_processor_max_state(pr))
243 return -EINVAL;
244
245 if (state <= max_pstate) {
246 if (pr->flags.throttling && pr->throttling.state)
247 result = acpi_processor_set_throttling(pr, 0, false);
248 cpufreq_set_cur_state(pr->id, state);
249 } else {
250 cpufreq_set_cur_state(pr->id, max_pstate);
251 result = acpi_processor_set_throttling(pr,
252 state - max_pstate, false);
253 }
254 return result;
255}
256
257const struct thermal_cooling_device_ops processor_cooling_ops = {
258 .get_max_state = processor_get_max_state,
259 .get_cur_state = processor_get_cur_state,
260 .set_cur_state = processor_set_cur_state,
261};