Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
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 | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/cpufreq.h> | |
8b48463f | 16 | #include <linux/acpi.h> |
1da177e4 | 17 | #include <acpi/processor.h> |
7c0f6ba6 | 18 | #include <linux/uaccess.h> |
1da177e4 | 19 | |
310293a2 SST |
20 | #include "internal.h" |
21 | ||
1da177e4 LT |
22 | #ifdef CONFIG_CPU_FREQ |
23 | ||
24 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it | |
25 | * offers (in most cases) voltage scaling in addition to frequency scaling, and | |
26 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for | |
27 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. | |
28 | */ | |
29 | ||
d9460fd2 | 30 | #define CPUFREQ_THERMAL_MIN_STEP 0 |
d9460fd2 | 31 | |
310293a2 SST |
32 | static int cpufreq_thermal_max_step __read_mostly = 3; |
33 | ||
34 | /* | |
35 | * Minimum throttle percentage for processor_thermal cooling device. | |
36 | * The processor_thermal driver uses it to calculate the percentage amount by | |
37 | * which cpu frequency must be reduced for each cooling state. This is also used | |
38 | * to calculate the maximum number of throttling steps or cooling states. | |
39 | */ | |
40 | static int cpufreq_thermal_reduction_pctg __read_mostly = 20; | |
1da177e4 | 41 | |
310293a2 SST |
42 | static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_step); |
43 | ||
44 | #define reduction_step(cpu) \ | |
45 | per_cpu(cpufreq_thermal_reduction_step, phys_package_first_cpu(cpu)) | |
2815ab92 AK |
46 | |
47 | /* | |
48 | * Emulate "per package data" using per cpu data (which should really be | |
49 | * provided elsewhere) | |
50 | * | |
51 | * Note we can lose a CPU on cpu hotunplug, in this case we forget the state | |
52 | * temporarily. Fortunately that's not a big issue here (I hope) | |
53 | */ | |
54 | static int phys_package_first_cpu(int cpu) | |
55 | { | |
56 | int i; | |
57 | int id = topology_physical_package_id(cpu); | |
58 | ||
59 | for_each_online_cpu(i) | |
60 | if (topology_physical_package_id(i) == id) | |
61 | return i; | |
62 | return 0; | |
63 | } | |
64 | ||
1da177e4 LT |
65 | static int cpu_has_cpufreq(unsigned int cpu) |
66 | { | |
8120832d MS |
67 | struct cpufreq_policy *policy; |
68 | ||
69 | if (!acpi_processor_cpufreq_init) | |
75b245b3 | 70 | return 0; |
8120832d MS |
71 | |
72 | policy = cpufreq_cpu_get(cpu); | |
73 | if (policy) { | |
74 | cpufreq_cpu_put(policy); | |
75 | return 1; | |
76 | } | |
77 | return 0; | |
1da177e4 LT |
78 | } |
79 | ||
d9460fd2 ZR |
80 | static int cpufreq_get_max_state(unsigned int cpu) |
81 | { | |
82 | if (!cpu_has_cpufreq(cpu)) | |
83 | return 0; | |
84 | ||
310293a2 | 85 | return cpufreq_thermal_max_step; |
d9460fd2 ZR |
86 | } |
87 | ||
88 | static int cpufreq_get_cur_state(unsigned int cpu) | |
89 | { | |
90 | if (!cpu_has_cpufreq(cpu)) | |
91 | return 0; | |
92 | ||
310293a2 | 93 | return reduction_step(cpu); |
d9460fd2 ZR |
94 | } |
95 | ||
96 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
97 | { | |
d15ce412 VK |
98 | struct cpufreq_policy *policy; |
99 | struct acpi_processor *pr; | |
100 | unsigned long max_freq; | |
101 | int i, ret; | |
2815ab92 | 102 | |
d9460fd2 ZR |
103 | if (!cpu_has_cpufreq(cpu)) |
104 | return 0; | |
105 | ||
310293a2 | 106 | reduction_step(cpu) = state; |
2815ab92 AK |
107 | |
108 | /* | |
109 | * Update all the CPUs in the same package because they all | |
110 | * contribute to the temperature and often share the same | |
111 | * frequency. | |
112 | */ | |
113 | for_each_online_cpu(i) { | |
d15ce412 | 114 | if (topology_physical_package_id(i) != |
2815ab92 | 115 | topology_physical_package_id(cpu)) |
d15ce412 VK |
116 | continue; |
117 | ||
118 | pr = per_cpu(processors, i); | |
119 | ||
3000ce3c | 120 | if (unlikely(!freq_qos_request_active(&pr->thermal_req))) |
d15ce412 VK |
121 | continue; |
122 | ||
123 | policy = cpufreq_cpu_get(i); | |
124 | if (!policy) | |
125 | return -EINVAL; | |
126 | ||
310293a2 SST |
127 | max_freq = (policy->cpuinfo.max_freq * |
128 | (100 - reduction_step(i) * cpufreq_thermal_reduction_pctg)) / 100; | |
d15ce412 VK |
129 | |
130 | cpufreq_cpu_put(policy); | |
131 | ||
3000ce3c | 132 | ret = freq_qos_update_request(&pr->thermal_req, max_freq); |
d15ce412 VK |
133 | if (ret < 0) { |
134 | pr_warn("Failed to update thermal freq constraint: CPU%d (%d)\n", | |
135 | pr->id, ret); | |
136 | } | |
2815ab92 | 137 | } |
d9460fd2 ZR |
138 | return 0; |
139 | } | |
140 | ||
310293a2 SST |
141 | static void acpi_thermal_cpufreq_config(void) |
142 | { | |
143 | int cpufreq_pctg = acpi_arch_thermal_cpufreq_pctg(); | |
144 | ||
145 | if (!cpufreq_pctg) | |
146 | return; | |
147 | ||
148 | cpufreq_thermal_reduction_pctg = cpufreq_pctg; | |
149 | ||
150 | /* | |
151 | * Derive the MAX_STEP from minimum throttle percentage so that the reduction | |
152 | * percentage doesn't end up becoming negative. Also, cap the MAX_STEP so that | |
153 | * the CPU performance doesn't become 0. | |
154 | */ | |
155 | cpufreq_thermal_max_step = (100 / cpufreq_pctg) - 2; | |
156 | } | |
157 | ||
3000ce3c | 158 | void acpi_thermal_cpufreq_init(struct cpufreq_policy *policy) |
4be44fcd | 159 | { |
a1bb46c3 RW |
160 | unsigned int cpu; |
161 | ||
310293a2 SST |
162 | acpi_thermal_cpufreq_config(); |
163 | ||
a1bb46c3 RW |
164 | for_each_cpu(cpu, policy->related_cpus) { |
165 | struct acpi_processor *pr = per_cpu(processors, cpu); | |
166 | int ret; | |
167 | ||
168 | if (!pr) | |
169 | continue; | |
170 | ||
171 | ret = freq_qos_add_request(&policy->constraints, | |
172 | &pr->thermal_req, | |
173 | FREQ_QOS_MAX, INT_MAX); | |
22c52fa5 | 174 | if (ret < 0) { |
a1bb46c3 RW |
175 | pr_err("Failed to add freq constraint for CPU%d (%d)\n", |
176 | cpu, ret); | |
22c52fa5 RW |
177 | continue; |
178 | } | |
179 | ||
180 | thermal_cooling_device_update(pr->cdev); | |
a1bb46c3 | 181 | } |
1da177e4 LT |
182 | } |
183 | ||
3000ce3c | 184 | void acpi_thermal_cpufreq_exit(struct cpufreq_policy *policy) |
4be44fcd | 185 | { |
a1bb46c3 RW |
186 | unsigned int cpu; |
187 | ||
188 | for_each_cpu(cpu, policy->related_cpus) { | |
36527b9d | 189 | struct acpi_processor *pr = per_cpu(processors, cpu); |
1da177e4 | 190 | |
22c52fa5 RW |
191 | if (!pr) |
192 | continue; | |
193 | ||
194 | freq_qos_remove_request(&pr->thermal_req); | |
195 | ||
196 | thermal_cooling_device_update(pr->cdev); | |
a1bb46c3 | 197 | } |
1da177e4 | 198 | } |
4be44fcd | 199 | #else /* ! CONFIG_CPU_FREQ */ |
d9460fd2 ZR |
200 | static int cpufreq_get_max_state(unsigned int cpu) |
201 | { | |
202 | return 0; | |
203 | } | |
204 | ||
205 | static int cpufreq_get_cur_state(unsigned int cpu) | |
206 | { | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
211 | { | |
212 | return 0; | |
213 | } | |
1da177e4 | 214 | |
1da177e4 LT |
215 | #endif |
216 | ||
6dd7aca8 | 217 | /* thermal cooling device callbacks */ |
d9460fd2 ZR |
218 | static int acpi_processor_max_state(struct acpi_processor *pr) |
219 | { | |
220 | int max_state = 0; | |
221 | ||
222 | /* | |
223 | * There exists four states according to | |
310293a2 | 224 | * cpufreq_thermal_reduction_step. 0, 1, 2, 3 |
d9460fd2 ZR |
225 | */ |
226 | max_state += cpufreq_get_max_state(pr->id); | |
227 | if (pr->flags.throttling) | |
228 | max_state += (pr->throttling.state_count -1); | |
229 | ||
230 | return max_state; | |
231 | } | |
232 | static int | |
6503e5df MG |
233 | processor_get_max_state(struct thermal_cooling_device *cdev, |
234 | unsigned long *state) | |
d9460fd2 ZR |
235 | { |
236 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 237 | struct acpi_processor *pr; |
d9460fd2 | 238 | |
99aa3638 CIK |
239 | if (!device) |
240 | return -EINVAL; | |
241 | ||
242 | pr = acpi_driver_data(device); | |
243 | if (!pr) | |
d9460fd2 ZR |
244 | return -EINVAL; |
245 | ||
6503e5df MG |
246 | *state = acpi_processor_max_state(pr); |
247 | return 0; | |
d9460fd2 ZR |
248 | } |
249 | ||
250 | static int | |
6503e5df MG |
251 | processor_get_cur_state(struct thermal_cooling_device *cdev, |
252 | unsigned long *cur_state) | |
d9460fd2 ZR |
253 | { |
254 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 255 | struct acpi_processor *pr; |
d9460fd2 | 256 | |
99aa3638 CIK |
257 | if (!device) |
258 | return -EINVAL; | |
259 | ||
260 | pr = acpi_driver_data(device); | |
261 | if (!pr) | |
d9460fd2 ZR |
262 | return -EINVAL; |
263 | ||
6503e5df | 264 | *cur_state = cpufreq_get_cur_state(pr->id); |
d9460fd2 | 265 | if (pr->flags.throttling) |
6503e5df MG |
266 | *cur_state += pr->throttling.state; |
267 | return 0; | |
d9460fd2 ZR |
268 | } |
269 | ||
270 | static int | |
6503e5df MG |
271 | processor_set_cur_state(struct thermal_cooling_device *cdev, |
272 | unsigned long state) | |
d9460fd2 ZR |
273 | { |
274 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 275 | struct acpi_processor *pr; |
d9460fd2 ZR |
276 | int result = 0; |
277 | int max_pstate; | |
278 | ||
99aa3638 CIK |
279 | if (!device) |
280 | return -EINVAL; | |
281 | ||
282 | pr = acpi_driver_data(device); | |
283 | if (!pr) | |
d9460fd2 ZR |
284 | return -EINVAL; |
285 | ||
286 | max_pstate = cpufreq_get_max_state(pr->id); | |
287 | ||
288 | if (state > acpi_processor_max_state(pr)) | |
289 | return -EINVAL; | |
290 | ||
291 | if (state <= max_pstate) { | |
292 | if (pr->flags.throttling && pr->throttling.state) | |
2a908002 | 293 | result = acpi_processor_set_throttling(pr, 0, false); |
d9460fd2 ZR |
294 | cpufreq_set_cur_state(pr->id, state); |
295 | } else { | |
296 | cpufreq_set_cur_state(pr->id, max_pstate); | |
297 | result = acpi_processor_set_throttling(pr, | |
2a908002 | 298 | state - max_pstate, false); |
d9460fd2 ZR |
299 | } |
300 | return result; | |
301 | } | |
302 | ||
9c8b04be | 303 | const struct thermal_cooling_device_ops processor_cooling_ops = { |
d9460fd2 ZR |
304 | .get_max_state = processor_get_max_state, |
305 | .get_cur_state = processor_get_cur_state, | |
306 | .set_cur_state = processor_set_cur_state, | |
307 | }; | |
7fdc74da RL |
308 | |
309 | int acpi_processor_thermal_init(struct acpi_processor *pr, | |
310 | struct acpi_device *device) | |
311 | { | |
312 | int result = 0; | |
313 | ||
314 | pr->cdev = thermal_cooling_device_register("Processor", device, | |
315 | &processor_cooling_ops); | |
316 | if (IS_ERR(pr->cdev)) { | |
317 | result = PTR_ERR(pr->cdev); | |
318 | return result; | |
319 | } | |
320 | ||
321 | dev_dbg(&device->dev, "registered as cooling_device%d\n", | |
322 | pr->cdev->id); | |
323 | ||
324 | result = sysfs_create_link(&device->dev.kobj, | |
325 | &pr->cdev->device.kobj, | |
326 | "thermal_cooling"); | |
327 | if (result) { | |
328 | dev_err(&device->dev, | |
329 | "Failed to create sysfs link 'thermal_cooling'\n"); | |
330 | goto err_thermal_unregister; | |
331 | } | |
332 | ||
333 | result = sysfs_create_link(&pr->cdev->device.kobj, | |
334 | &device->dev.kobj, | |
335 | "device"); | |
336 | if (result) { | |
337 | dev_err(&pr->cdev->device, | |
338 | "Failed to create sysfs link 'device'\n"); | |
339 | goto err_remove_sysfs_thermal; | |
340 | } | |
341 | ||
342 | return 0; | |
343 | ||
344 | err_remove_sysfs_thermal: | |
345 | sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); | |
346 | err_thermal_unregister: | |
347 | thermal_cooling_device_unregister(pr->cdev); | |
348 | ||
349 | return result; | |
350 | } | |
351 | ||
352 | void acpi_processor_thermal_exit(struct acpi_processor *pr, | |
353 | struct acpi_device *device) | |
354 | { | |
355 | if (pr->cdev) { | |
356 | sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); | |
357 | sysfs_remove_link(&pr->cdev->device.kobj, "device"); | |
358 | thermal_cooling_device_unregister(pr->cdev); | |
359 | pr->cdev = NULL; | |
360 | } | |
361 | } |