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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 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};