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1da177e4 LT |
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/proc_fs.h> | |
34 | #include <linux/seq_file.h> | |
35 | ||
36 | #include <asm/uaccess.h> | |
37 | ||
38 | #include <acpi/acpi_bus.h> | |
39 | #include <acpi/processor.h> | |
40 | #include <acpi/acpi_drivers.h> | |
41 | ||
42 | #define ACPI_PROCESSOR_COMPONENT 0x01000000 | |
43 | #define ACPI_PROCESSOR_CLASS "processor" | |
44 | #define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver" | |
45 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT | |
4be44fcd | 46 | ACPI_MODULE_NAME("acpi_processor") |
1da177e4 LT |
47 | |
48 | /* -------------------------------------------------------------------------- | |
49 | Limit Interface | |
50 | -------------------------------------------------------------------------- */ | |
4be44fcd | 51 | static int acpi_processor_apply_limit(struct acpi_processor *pr) |
1da177e4 | 52 | { |
4be44fcd LB |
53 | int result = 0; |
54 | u16 px = 0; | |
55 | u16 tx = 0; | |
1da177e4 | 56 | |
1da177e4 LT |
57 | |
58 | if (!pr) | |
d550d98d | 59 | return -EINVAL; |
1da177e4 LT |
60 | |
61 | if (!pr->flags.limit) | |
d550d98d | 62 | return -ENODEV; |
1da177e4 LT |
63 | |
64 | if (pr->flags.throttling) { | |
65 | if (pr->limit.user.tx > tx) | |
66 | tx = pr->limit.user.tx; | |
67 | if (pr->limit.thermal.tx > tx) | |
68 | tx = pr->limit.thermal.tx; | |
69 | ||
70 | result = acpi_processor_set_throttling(pr, tx); | |
71 | if (result) | |
72 | goto end; | |
73 | } | |
74 | ||
75 | pr->limit.state.px = px; | |
76 | pr->limit.state.tx = tx; | |
77 | ||
4be44fcd LB |
78 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
79 | "Processor [%d] limit set to (P%d:T%d)\n", pr->id, | |
80 | pr->limit.state.px, pr->limit.state.tx)); | |
1da177e4 | 81 | |
4be44fcd | 82 | end: |
1da177e4 | 83 | if (result) |
6468463a | 84 | printk(KERN_ERR PREFIX "Unable to set limit\n"); |
1da177e4 | 85 | |
d550d98d | 86 | return result; |
1da177e4 LT |
87 | } |
88 | ||
1da177e4 LT |
89 | #ifdef CONFIG_CPU_FREQ |
90 | ||
91 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it | |
92 | * offers (in most cases) voltage scaling in addition to frequency scaling, and | |
93 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for | |
94 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. | |
95 | */ | |
96 | ||
97 | static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS]; | |
98 | static unsigned int acpi_thermal_cpufreq_is_init = 0; | |
99 | ||
1da177e4 LT |
100 | static int cpu_has_cpufreq(unsigned int cpu) |
101 | { | |
102 | struct cpufreq_policy policy; | |
1cbf4c56 | 103 | if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu)) |
75b245b3 TR |
104 | return 0; |
105 | return 1; | |
1da177e4 LT |
106 | } |
107 | ||
1da177e4 LT |
108 | static int acpi_thermal_cpufreq_increase(unsigned int cpu) |
109 | { | |
110 | if (!cpu_has_cpufreq(cpu)) | |
111 | return -ENODEV; | |
112 | ||
113 | if (cpufreq_thermal_reduction_pctg[cpu] < 60) { | |
114 | cpufreq_thermal_reduction_pctg[cpu] += 20; | |
115 | cpufreq_update_policy(cpu); | |
116 | return 0; | |
117 | } | |
118 | ||
119 | return -ERANGE; | |
120 | } | |
121 | ||
1da177e4 LT |
122 | static int acpi_thermal_cpufreq_decrease(unsigned int cpu) |
123 | { | |
124 | if (!cpu_has_cpufreq(cpu)) | |
125 | return -ENODEV; | |
126 | ||
1cbf4c56 | 127 | if (cpufreq_thermal_reduction_pctg[cpu] > 20) |
1da177e4 | 128 | cpufreq_thermal_reduction_pctg[cpu] -= 20; |
1cbf4c56 TR |
129 | else |
130 | cpufreq_thermal_reduction_pctg[cpu] = 0; | |
131 | cpufreq_update_policy(cpu); | |
132 | /* We reached max freq again and can leave passive mode */ | |
133 | return !cpufreq_thermal_reduction_pctg[cpu]; | |
1da177e4 LT |
134 | } |
135 | ||
4be44fcd LB |
136 | static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb, |
137 | unsigned long event, void *data) | |
1da177e4 LT |
138 | { |
139 | struct cpufreq_policy *policy = data; | |
140 | unsigned long max_freq = 0; | |
141 | ||
142 | if (event != CPUFREQ_ADJUST) | |
143 | goto out; | |
144 | ||
4be44fcd LB |
145 | max_freq = |
146 | (policy->cpuinfo.max_freq * | |
147 | (100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100; | |
1da177e4 LT |
148 | |
149 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
150 | ||
4be44fcd | 151 | out: |
1da177e4 LT |
152 | return 0; |
153 | } | |
154 | ||
1da177e4 LT |
155 | static struct notifier_block acpi_thermal_cpufreq_notifier_block = { |
156 | .notifier_call = acpi_thermal_cpufreq_notifier, | |
157 | }; | |
158 | ||
4be44fcd LB |
159 | void acpi_thermal_cpufreq_init(void) |
160 | { | |
1da177e4 LT |
161 | int i; |
162 | ||
4be44fcd | 163 | for (i = 0; i < NR_CPUS; i++) |
1da177e4 LT |
164 | cpufreq_thermal_reduction_pctg[i] = 0; |
165 | ||
4be44fcd LB |
166 | i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block, |
167 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
168 | if (!i) |
169 | acpi_thermal_cpufreq_is_init = 1; | |
170 | } | |
171 | ||
4be44fcd LB |
172 | void acpi_thermal_cpufreq_exit(void) |
173 | { | |
1da177e4 | 174 | if (acpi_thermal_cpufreq_is_init) |
4be44fcd LB |
175 | cpufreq_unregister_notifier |
176 | (&acpi_thermal_cpufreq_notifier_block, | |
177 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
178 | |
179 | acpi_thermal_cpufreq_is_init = 0; | |
180 | } | |
181 | ||
4be44fcd | 182 | #else /* ! CONFIG_CPU_FREQ */ |
1da177e4 | 183 | |
4be44fcd LB |
184 | static int acpi_thermal_cpufreq_increase(unsigned int cpu) |
185 | { | |
186 | return -ENODEV; | |
187 | } | |
188 | static int acpi_thermal_cpufreq_decrease(unsigned int cpu) | |
189 | { | |
190 | return -ENODEV; | |
191 | } | |
1da177e4 LT |
192 | |
193 | #endif | |
194 | ||
4be44fcd | 195 | int acpi_processor_set_thermal_limit(acpi_handle handle, int type) |
1da177e4 | 196 | { |
4be44fcd LB |
197 | int result = 0; |
198 | struct acpi_processor *pr = NULL; | |
199 | struct acpi_device *device = NULL; | |
1cbf4c56 | 200 | int tx = 0, max_tx_px = 0; |
1da177e4 | 201 | |
1da177e4 LT |
202 | |
203 | if ((type < ACPI_PROCESSOR_LIMIT_NONE) | |
4be44fcd | 204 | || (type > ACPI_PROCESSOR_LIMIT_DECREMENT)) |
d550d98d | 205 | return -EINVAL; |
1da177e4 LT |
206 | |
207 | result = acpi_bus_get_device(handle, &device); | |
208 | if (result) | |
d550d98d | 209 | return result; |
1da177e4 | 210 | |
50dd0969 | 211 | pr = acpi_driver_data(device); |
1da177e4 | 212 | if (!pr) |
d550d98d | 213 | return -ENODEV; |
1da177e4 LT |
214 | |
215 | /* Thermal limits are always relative to the current Px/Tx state. */ | |
216 | if (pr->flags.throttling) | |
217 | pr->limit.thermal.tx = pr->throttling.state; | |
218 | ||
219 | /* | |
220 | * Our default policy is to only use throttling at the lowest | |
221 | * performance state. | |
222 | */ | |
223 | ||
224 | tx = pr->limit.thermal.tx; | |
225 | ||
226 | switch (type) { | |
227 | ||
228 | case ACPI_PROCESSOR_LIMIT_NONE: | |
229 | do { | |
230 | result = acpi_thermal_cpufreq_decrease(pr->id); | |
231 | } while (!result); | |
232 | tx = 0; | |
233 | break; | |
234 | ||
235 | case ACPI_PROCESSOR_LIMIT_INCREMENT: | |
236 | /* if going up: P-states first, T-states later */ | |
237 | ||
238 | result = acpi_thermal_cpufreq_increase(pr->id); | |
239 | if (!result) | |
240 | goto end; | |
241 | else if (result == -ERANGE) | |
242 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
4be44fcd | 243 | "At maximum performance state\n")); |
1da177e4 LT |
244 | |
245 | if (pr->flags.throttling) { | |
246 | if (tx == (pr->throttling.state_count - 1)) | |
247 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
4be44fcd | 248 | "At maximum throttling state\n")); |
1da177e4 LT |
249 | else |
250 | tx++; | |
251 | } | |
252 | break; | |
253 | ||
254 | case ACPI_PROCESSOR_LIMIT_DECREMENT: | |
255 | /* if going down: T-states first, P-states later */ | |
256 | ||
257 | if (pr->flags.throttling) { | |
1cbf4c56 TR |
258 | if (tx == 0) { |
259 | max_tx_px = 1; | |
1da177e4 | 260 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
4be44fcd | 261 | "At minimum throttling state\n")); |
1cbf4c56 | 262 | } else { |
1da177e4 LT |
263 | tx--; |
264 | goto end; | |
265 | } | |
266 | } | |
267 | ||
268 | result = acpi_thermal_cpufreq_decrease(pr->id); | |
1cbf4c56 TR |
269 | if (result) { |
270 | /* | |
271 | * We only could get -ERANGE, 1 or 0. | |
272 | * In the first two cases we reached max freq again. | |
273 | */ | |
1da177e4 | 274 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
4be44fcd | 275 | "At minimum performance state\n")); |
1cbf4c56 TR |
276 | max_tx_px = 1; |
277 | } else | |
278 | max_tx_px = 0; | |
1da177e4 LT |
279 | |
280 | break; | |
281 | } | |
282 | ||
4be44fcd | 283 | end: |
1da177e4 LT |
284 | if (pr->flags.throttling) { |
285 | pr->limit.thermal.px = 0; | |
286 | pr->limit.thermal.tx = tx; | |
287 | ||
288 | result = acpi_processor_apply_limit(pr); | |
289 | if (result) | |
6468463a | 290 | printk(KERN_ERR PREFIX "Unable to set thermal limit\n"); |
1da177e4 LT |
291 | |
292 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n", | |
4be44fcd | 293 | pr->limit.thermal.px, pr->limit.thermal.tx)); |
1da177e4 LT |
294 | } else |
295 | result = 0; | |
1cbf4c56 | 296 | if (max_tx_px) |
d550d98d | 297 | return 1; |
1cbf4c56 | 298 | else |
d550d98d | 299 | return result; |
1da177e4 LT |
300 | } |
301 | ||
4be44fcd | 302 | int acpi_processor_get_limit_info(struct acpi_processor *pr) |
1da177e4 | 303 | { |
1da177e4 LT |
304 | |
305 | if (!pr) | |
d550d98d | 306 | return -EINVAL; |
1da177e4 LT |
307 | |
308 | if (pr->flags.throttling) | |
309 | pr->flags.limit = 1; | |
310 | ||
d550d98d | 311 | return 0; |
1da177e4 LT |
312 | } |
313 | ||
1da177e4 LT |
314 | /* /proc interface */ |
315 | ||
316 | static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset) | |
317 | { | |
4be44fcd | 318 | struct acpi_processor *pr = (struct acpi_processor *)seq->private; |
1da177e4 | 319 | |
1da177e4 LT |
320 | |
321 | if (!pr) | |
322 | goto end; | |
323 | ||
324 | if (!pr->flags.limit) { | |
325 | seq_puts(seq, "<not supported>\n"); | |
326 | goto end; | |
327 | } | |
328 | ||
329 | seq_printf(seq, "active limit: P%d:T%d\n" | |
4be44fcd LB |
330 | "user limit: P%d:T%d\n" |
331 | "thermal limit: P%d:T%d\n", | |
332 | pr->limit.state.px, pr->limit.state.tx, | |
333 | pr->limit.user.px, pr->limit.user.tx, | |
334 | pr->limit.thermal.px, pr->limit.thermal.tx); | |
1da177e4 | 335 | |
4be44fcd | 336 | end: |
d550d98d | 337 | return 0; |
1da177e4 LT |
338 | } |
339 | ||
340 | static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file) | |
341 | { | |
342 | return single_open(file, acpi_processor_limit_seq_show, | |
4be44fcd | 343 | PDE(inode)->data); |
1da177e4 LT |
344 | } |
345 | ||
757b1866 AB |
346 | static ssize_t acpi_processor_write_limit(struct file * file, |
347 | const char __user * buffer, | |
348 | size_t count, loff_t * data) | |
1da177e4 | 349 | { |
4be44fcd | 350 | int result = 0; |
50dd0969 JE |
351 | struct seq_file *m = file->private_data; |
352 | struct acpi_processor *pr = m->private; | |
4be44fcd LB |
353 | char limit_string[25] = { '\0' }; |
354 | int px = 0; | |
355 | int tx = 0; | |
1da177e4 | 356 | |
1da177e4 LT |
357 | |
358 | if (!pr || (count > sizeof(limit_string) - 1)) { | |
d550d98d | 359 | return -EINVAL; |
1da177e4 LT |
360 | } |
361 | ||
362 | if (copy_from_user(limit_string, buffer, count)) { | |
d550d98d | 363 | return -EFAULT; |
1da177e4 LT |
364 | } |
365 | ||
366 | limit_string[count] = '\0'; | |
367 | ||
368 | if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) { | |
6468463a | 369 | printk(KERN_ERR PREFIX "Invalid data format\n"); |
d550d98d | 370 | return -EINVAL; |
1da177e4 LT |
371 | } |
372 | ||
373 | if (pr->flags.throttling) { | |
374 | if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) { | |
6468463a | 375 | printk(KERN_ERR PREFIX "Invalid tx\n"); |
d550d98d | 376 | return -EINVAL; |
1da177e4 LT |
377 | } |
378 | pr->limit.user.tx = tx; | |
379 | } | |
380 | ||
381 | result = acpi_processor_apply_limit(pr); | |
382 | ||
d550d98d | 383 | return count; |
1da177e4 LT |
384 | } |
385 | ||
1da177e4 | 386 | struct file_operations acpi_processor_limit_fops = { |
4be44fcd LB |
387 | .open = acpi_processor_limit_open_fs, |
388 | .read = seq_read, | |
d479e908 | 389 | .write = acpi_processor_write_limit, |
4be44fcd LB |
390 | .llseek = seq_lseek, |
391 | .release = single_release, | |
1da177e4 | 392 | }; |