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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/*
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};