Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
c32b6b8e | 9 | * |
1da177e4 LT |
10 | * This program is free software; you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/config.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/notifier.h> | |
21 | #include <linux/cpufreq.h> | |
22 | #include <linux/delay.h> | |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/spinlock.h> | |
25 | #include <linux/device.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/cpu.h> | |
28 | #include <linux/completion.h> | |
3fc54d37 | 29 | #include <linux/mutex.h> |
1da177e4 LT |
30 | |
31 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg) | |
32 | ||
33 | /** | |
34 | * The "cpufreq driver" - the arch- or hardware-dependend low | |
35 | * level driver of CPUFreq support, and its spinlock. This lock | |
36 | * also protects the cpufreq_cpu_data array. | |
37 | */ | |
7d5e350f DJ |
38 | static struct cpufreq_driver *cpufreq_driver; |
39 | static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; | |
1da177e4 LT |
40 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
41 | ||
1da177e4 LT |
42 | /* internal prototypes */ |
43 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
44 | static void handle_update(void *data); | |
1da177e4 LT |
45 | |
46 | /** | |
32ee8c3e DJ |
47 | * Two notifier lists: the "policy" list is involved in the |
48 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
49 | * "transition" list for kernel code that needs to handle |
50 | * changes to devices when the CPU clock speed changes. | |
51 | * The mutex locks both lists. | |
52 | */ | |
7d5e350f DJ |
53 | static struct notifier_block *cpufreq_policy_notifier_list; |
54 | static struct notifier_block *cpufreq_transition_notifier_list; | |
55 | static DECLARE_RWSEM (cpufreq_notifier_rwsem); | |
1da177e4 LT |
56 | |
57 | ||
58 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 59 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 60 | |
7d5e350f | 61 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
62 | { |
63 | struct cpufreq_policy *data; | |
64 | unsigned long flags; | |
65 | ||
66 | if (cpu >= NR_CPUS) | |
67 | goto err_out; | |
68 | ||
69 | /* get the cpufreq driver */ | |
70 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
71 | ||
72 | if (!cpufreq_driver) | |
73 | goto err_out_unlock; | |
74 | ||
75 | if (!try_module_get(cpufreq_driver->owner)) | |
76 | goto err_out_unlock; | |
77 | ||
78 | ||
79 | /* get the CPU */ | |
80 | data = cpufreq_cpu_data[cpu]; | |
81 | ||
82 | if (!data) | |
83 | goto err_out_put_module; | |
84 | ||
85 | if (!kobject_get(&data->kobj)) | |
86 | goto err_out_put_module; | |
87 | ||
1da177e4 | 88 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
89 | return data; |
90 | ||
7d5e350f | 91 | err_out_put_module: |
1da177e4 | 92 | module_put(cpufreq_driver->owner); |
7d5e350f | 93 | err_out_unlock: |
1da177e4 | 94 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 95 | err_out: |
1da177e4 LT |
96 | return NULL; |
97 | } | |
98 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
99 | ||
7d5e350f | 100 | |
1da177e4 LT |
101 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
102 | { | |
103 | kobject_put(&data->kobj); | |
104 | module_put(cpufreq_driver->owner); | |
105 | } | |
106 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
107 | ||
108 | ||
109 | /********************************************************************* | |
110 | * UNIFIED DEBUG HELPERS * | |
111 | *********************************************************************/ | |
112 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
113 | ||
114 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
115 | static unsigned int debug; | |
116 | ||
117 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
118 | * set or modify this value. | |
119 | */ | |
120 | static unsigned int debug_ratelimit = 1; | |
121 | ||
122 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
123 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
124 | * is set, and disabled upon cpufreq driver removal | |
125 | */ | |
126 | static unsigned int disable_ratelimit = 1; | |
127 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
128 | ||
858119e1 | 129 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
130 | { |
131 | unsigned long flags; | |
132 | ||
133 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
134 | if (disable_ratelimit) | |
135 | disable_ratelimit--; | |
136 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
137 | } | |
138 | ||
858119e1 | 139 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
140 | { |
141 | unsigned long flags; | |
142 | ||
143 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
144 | disable_ratelimit++; | |
145 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
146 | } | |
147 | ||
148 | void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...) | |
149 | { | |
150 | char s[256]; | |
151 | va_list args; | |
152 | unsigned int len; | |
153 | unsigned long flags; | |
32ee8c3e | 154 | |
1da177e4 LT |
155 | WARN_ON(!prefix); |
156 | if (type & debug) { | |
157 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
158 | if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) { | |
159 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
160 | return; | |
161 | } | |
162 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
163 | ||
164 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
165 | ||
166 | va_start(args, fmt); | |
167 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
168 | va_end(args); | |
169 | ||
170 | printk(s); | |
171 | ||
172 | WARN_ON(len < 5); | |
173 | } | |
174 | } | |
175 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
176 | ||
177 | ||
178 | module_param(debug, uint, 0644); | |
179 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors."); | |
180 | ||
181 | module_param(debug_ratelimit, uint, 0644); | |
182 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting."); | |
183 | ||
184 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
185 | ||
186 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
187 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
188 | ||
189 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
190 | ||
191 | ||
192 | /********************************************************************* | |
193 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
194 | *********************************************************************/ | |
195 | ||
196 | /** | |
197 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
198 | * | |
199 | * This function alters the system "loops_per_jiffy" for the clock | |
200 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 201 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
202 | * per-CPU loops_per_jiffy value wherever possible. |
203 | */ | |
204 | #ifndef CONFIG_SMP | |
205 | static unsigned long l_p_j_ref; | |
206 | static unsigned int l_p_j_ref_freq; | |
207 | ||
858119e1 | 208 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
209 | { |
210 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
211 | return; | |
212 | ||
213 | if (!l_p_j_ref_freq) { | |
214 | l_p_j_ref = loops_per_jiffy; | |
215 | l_p_j_ref_freq = ci->old; | |
216 | dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
217 | } | |
218 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
219 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 220 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
1da177e4 LT |
221 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new); |
222 | dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
223 | } | |
224 | } | |
225 | #else | |
226 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; } | |
227 | #endif | |
228 | ||
229 | ||
230 | /** | |
e4472cb3 DJ |
231 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
232 | * on frequency transition. | |
1da177e4 | 233 | * |
e4472cb3 DJ |
234 | * This function calls the transition notifiers and the "adjust_jiffies" |
235 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 236 | * external effects. |
1da177e4 LT |
237 | */ |
238 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
239 | { | |
e4472cb3 DJ |
240 | struct cpufreq_policy *policy; |
241 | ||
1da177e4 LT |
242 | BUG_ON(irqs_disabled()); |
243 | ||
244 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
245 | dprintk("notification %u of frequency transition to %u kHz\n", |
246 | state, freqs->new); | |
1da177e4 LT |
247 | |
248 | down_read(&cpufreq_notifier_rwsem); | |
e4472cb3 DJ |
249 | |
250 | policy = cpufreq_cpu_data[freqs->cpu]; | |
1da177e4 | 251 | switch (state) { |
e4472cb3 | 252 | |
1da177e4 | 253 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 254 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
255 | * which is not equal to what the cpufreq core thinks is |
256 | * "old frequency". | |
1da177e4 LT |
257 | */ |
258 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
259 | if ((policy) && (policy->cpu == freqs->cpu) && |
260 | (policy->cur) && (policy->cur != freqs->old)) { | |
261 | dprintk(KERN_WARNING "Warning: CPU frequency is" | |
262 | " %u, cpufreq assumed %u kHz.\n", | |
263 | freqs->old, policy->cur); | |
264 | freqs->old = policy->cur; | |
1da177e4 LT |
265 | } |
266 | } | |
e4472cb3 DJ |
267 | notifier_call_chain(&cpufreq_transition_notifier_list, |
268 | CPUFREQ_PRECHANGE, freqs); | |
1da177e4 LT |
269 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
270 | break; | |
e4472cb3 | 271 | |
1da177e4 LT |
272 | case CPUFREQ_POSTCHANGE: |
273 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e4472cb3 DJ |
274 | notifier_call_chain(&cpufreq_transition_notifier_list, |
275 | CPUFREQ_POSTCHANGE, freqs); | |
276 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) | |
277 | policy->cur = freqs->new; | |
1da177e4 LT |
278 | break; |
279 | } | |
280 | up_read(&cpufreq_notifier_rwsem); | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
283 | ||
284 | ||
285 | ||
286 | /********************************************************************* | |
287 | * SYSFS INTERFACE * | |
288 | *********************************************************************/ | |
289 | ||
290 | /** | |
291 | * cpufreq_parse_governor - parse a governor string | |
292 | */ | |
293 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
294 | struct cpufreq_governor **governor) | |
295 | { | |
296 | if (!cpufreq_driver) | |
297 | return -EINVAL; | |
298 | if (cpufreq_driver->setpolicy) { | |
299 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
300 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
301 | return 0; | |
302 | } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
303 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
304 | return 0; | |
305 | } | |
306 | return -EINVAL; | |
307 | } else { | |
308 | struct cpufreq_governor *t; | |
3fc54d37 | 309 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 LT |
310 | if (!cpufreq_driver || !cpufreq_driver->target) |
311 | goto out; | |
312 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
313 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) { | |
314 | *governor = t; | |
3fc54d37 | 315 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
316 | return 0; |
317 | } | |
318 | } | |
7d5e350f | 319 | out: |
3fc54d37 | 320 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
321 | } |
322 | return -EINVAL; | |
323 | } | |
324 | EXPORT_SYMBOL_GPL(cpufreq_parse_governor); | |
325 | ||
326 | ||
327 | /* drivers/base/cpu.c */ | |
328 | extern struct sysdev_class cpu_sysdev_class; | |
329 | ||
330 | ||
331 | /** | |
332 | * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information | |
333 | * | |
334 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
335 | * "unsigned int". | |
336 | */ | |
337 | ||
32ee8c3e DJ |
338 | #define show_one(file_name, object) \ |
339 | static ssize_t show_##file_name \ | |
340 | (struct cpufreq_policy * policy, char *buf) \ | |
341 | { \ | |
342 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
343 | } |
344 | ||
345 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
346 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
347 | show_one(scaling_min_freq, min); | |
348 | show_one(scaling_max_freq, max); | |
349 | show_one(scaling_cur_freq, cur); | |
350 | ||
351 | /** | |
352 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
353 | */ | |
354 | #define store_one(file_name, object) \ | |
355 | static ssize_t store_##file_name \ | |
356 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
357 | { \ | |
358 | unsigned int ret = -EINVAL; \ | |
359 | struct cpufreq_policy new_policy; \ | |
360 | \ | |
361 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
362 | if (ret) \ | |
363 | return -EINVAL; \ | |
364 | \ | |
365 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
366 | if (ret != 1) \ | |
367 | return -EINVAL; \ | |
368 | \ | |
369 | ret = cpufreq_set_policy(&new_policy); \ | |
370 | \ | |
371 | return ret ? ret : count; \ | |
372 | } | |
373 | ||
374 | store_one(scaling_min_freq,min); | |
375 | store_one(scaling_max_freq,max); | |
376 | ||
377 | /** | |
378 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
379 | */ | |
380 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf) | |
381 | { | |
382 | unsigned int cur_freq = cpufreq_get(policy->cpu); | |
383 | if (!cur_freq) | |
384 | return sprintf(buf, "<unknown>"); | |
385 | return sprintf(buf, "%u\n", cur_freq); | |
386 | } | |
387 | ||
388 | ||
389 | /** | |
390 | * show_scaling_governor - show the current policy for the specified CPU | |
391 | */ | |
392 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf) | |
393 | { | |
394 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
395 | return sprintf(buf, "powersave\n"); | |
396 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
397 | return sprintf(buf, "performance\n"); | |
398 | else if (policy->governor) | |
399 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
400 | return -EINVAL; | |
401 | } | |
402 | ||
403 | ||
404 | /** | |
405 | * store_scaling_governor - store policy for the specified CPU | |
406 | */ | |
32ee8c3e DJ |
407 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
408 | const char *buf, size_t count) | |
1da177e4 LT |
409 | { |
410 | unsigned int ret = -EINVAL; | |
411 | char str_governor[16]; | |
412 | struct cpufreq_policy new_policy; | |
413 | ||
414 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
415 | if (ret) | |
416 | return ret; | |
417 | ||
418 | ret = sscanf (buf, "%15s", str_governor); | |
419 | if (ret != 1) | |
420 | return -EINVAL; | |
421 | ||
422 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor)) | |
423 | return -EINVAL; | |
424 | ||
425 | ret = cpufreq_set_policy(&new_policy); | |
1da177e4 LT |
426 | return ret ? ret : count; |
427 | } | |
428 | ||
429 | /** | |
430 | * show_scaling_driver - show the cpufreq driver currently loaded | |
431 | */ | |
432 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
433 | { | |
434 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
435 | } | |
436 | ||
437 | /** | |
438 | * show_scaling_available_governors - show the available CPUfreq governors | |
439 | */ | |
440 | static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy, | |
441 | char *buf) | |
442 | { | |
443 | ssize_t i = 0; | |
444 | struct cpufreq_governor *t; | |
445 | ||
446 | if (!cpufreq_driver->target) { | |
447 | i += sprintf(buf, "performance powersave"); | |
448 | goto out; | |
449 | } | |
450 | ||
451 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
452 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
453 | goto out; | |
454 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
455 | } | |
7d5e350f | 456 | out: |
1da177e4 LT |
457 | i += sprintf(&buf[i], "\n"); |
458 | return i; | |
459 | } | |
460 | /** | |
461 | * show_affected_cpus - show the CPUs affected by each transition | |
462 | */ | |
463 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
464 | { | |
465 | ssize_t i = 0; | |
466 | unsigned int cpu; | |
467 | ||
468 | for_each_cpu_mask(cpu, policy->cpus) { | |
469 | if (i) | |
470 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
471 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
472 | if (i >= (PAGE_SIZE - 5)) | |
473 | break; | |
474 | } | |
475 | i += sprintf(&buf[i], "\n"); | |
476 | return i; | |
477 | } | |
478 | ||
479 | ||
480 | #define define_one_ro(_name) \ | |
481 | static struct freq_attr _name = \ | |
482 | __ATTR(_name, 0444, show_##_name, NULL) | |
483 | ||
484 | #define define_one_ro0400(_name) \ | |
485 | static struct freq_attr _name = \ | |
486 | __ATTR(_name, 0400, show_##_name, NULL) | |
487 | ||
488 | #define define_one_rw(_name) \ | |
489 | static struct freq_attr _name = \ | |
490 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
491 | ||
492 | define_one_ro0400(cpuinfo_cur_freq); | |
493 | define_one_ro(cpuinfo_min_freq); | |
494 | define_one_ro(cpuinfo_max_freq); | |
495 | define_one_ro(scaling_available_governors); | |
496 | define_one_ro(scaling_driver); | |
497 | define_one_ro(scaling_cur_freq); | |
498 | define_one_ro(affected_cpus); | |
499 | define_one_rw(scaling_min_freq); | |
500 | define_one_rw(scaling_max_freq); | |
501 | define_one_rw(scaling_governor); | |
502 | ||
503 | static struct attribute * default_attrs[] = { | |
504 | &cpuinfo_min_freq.attr, | |
505 | &cpuinfo_max_freq.attr, | |
506 | &scaling_min_freq.attr, | |
507 | &scaling_max_freq.attr, | |
508 | &affected_cpus.attr, | |
509 | &scaling_governor.attr, | |
510 | &scaling_driver.attr, | |
511 | &scaling_available_governors.attr, | |
512 | NULL | |
513 | }; | |
514 | ||
515 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
516 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
517 | ||
518 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
519 | { | |
520 | struct cpufreq_policy * policy = to_policy(kobj); | |
521 | struct freq_attr * fattr = to_attr(attr); | |
522 | ssize_t ret; | |
523 | policy = cpufreq_cpu_get(policy->cpu); | |
524 | if (!policy) | |
525 | return -EINVAL; | |
70f2817a | 526 | ret = fattr->show ? fattr->show(policy,buf) : -EIO; |
1da177e4 LT |
527 | cpufreq_cpu_put(policy); |
528 | return ret; | |
529 | } | |
530 | ||
32ee8c3e | 531 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
532 | const char * buf, size_t count) |
533 | { | |
534 | struct cpufreq_policy * policy = to_policy(kobj); | |
535 | struct freq_attr * fattr = to_attr(attr); | |
536 | ssize_t ret; | |
537 | policy = cpufreq_cpu_get(policy->cpu); | |
538 | if (!policy) | |
539 | return -EINVAL; | |
70f2817a | 540 | ret = fattr->store ? fattr->store(policy,buf,count) : -EIO; |
1da177e4 LT |
541 | cpufreq_cpu_put(policy); |
542 | return ret; | |
543 | } | |
544 | ||
545 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
546 | { | |
547 | struct cpufreq_policy * policy = to_policy(kobj); | |
548 | dprintk("last reference is dropped\n"); | |
549 | complete(&policy->kobj_unregister); | |
550 | } | |
551 | ||
552 | static struct sysfs_ops sysfs_ops = { | |
553 | .show = show, | |
554 | .store = store, | |
555 | }; | |
556 | ||
557 | static struct kobj_type ktype_cpufreq = { | |
558 | .sysfs_ops = &sysfs_ops, | |
559 | .default_attrs = default_attrs, | |
560 | .release = cpufreq_sysfs_release, | |
561 | }; | |
562 | ||
563 | ||
564 | /** | |
565 | * cpufreq_add_dev - add a CPU device | |
566 | * | |
32ee8c3e | 567 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
568 | */ |
569 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
570 | { | |
571 | unsigned int cpu = sys_dev->id; | |
572 | int ret = 0; | |
573 | struct cpufreq_policy new_policy; | |
574 | struct cpufreq_policy *policy; | |
575 | struct freq_attr **drv_attr; | |
576 | unsigned long flags; | |
577 | unsigned int j; | |
578 | ||
c32b6b8e AR |
579 | if (cpu_is_offline(cpu)) |
580 | return 0; | |
581 | ||
1da177e4 LT |
582 | cpufreq_debug_disable_ratelimit(); |
583 | dprintk("adding CPU %u\n", cpu); | |
584 | ||
585 | #ifdef CONFIG_SMP | |
586 | /* check whether a different CPU already registered this | |
587 | * CPU because it is in the same boat. */ | |
588 | policy = cpufreq_cpu_get(cpu); | |
589 | if (unlikely(policy)) { | |
1da177e4 LT |
590 | dprintk("CPU already managed, adding link\n"); |
591 | sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq"); | |
592 | cpufreq_debug_enable_ratelimit(); | |
593 | return 0; | |
594 | } | |
595 | #endif | |
596 | ||
597 | if (!try_module_get(cpufreq_driver->owner)) { | |
598 | ret = -EINVAL; | |
599 | goto module_out; | |
600 | } | |
601 | ||
e98df50c | 602 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
603 | if (!policy) { |
604 | ret = -ENOMEM; | |
605 | goto nomem_out; | |
606 | } | |
1da177e4 LT |
607 | |
608 | policy->cpu = cpu; | |
609 | policy->cpus = cpumask_of_cpu(cpu); | |
610 | ||
83933af4 AV |
611 | mutex_init(&policy->lock); |
612 | mutex_lock(&policy->lock); | |
1da177e4 LT |
613 | init_completion(&policy->kobj_unregister); |
614 | INIT_WORK(&policy->update, handle_update, (void *)(long)cpu); | |
615 | ||
616 | /* call driver. From then on the cpufreq must be able | |
617 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
618 | */ | |
619 | ret = cpufreq_driver->init(policy); | |
620 | if (ret) { | |
621 | dprintk("initialization failed\n"); | |
f3876c1b | 622 | mutex_unlock(&policy->lock); |
1da177e4 LT |
623 | goto err_out; |
624 | } | |
625 | ||
626 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
627 | ||
628 | /* prepare interface data */ | |
629 | policy->kobj.parent = &sys_dev->kobj; | |
630 | policy->kobj.ktype = &ktype_cpufreq; | |
631 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
632 | ||
633 | ret = kobject_register(&policy->kobj); | |
f3876c1b AM |
634 | if (ret) { |
635 | mutex_unlock(&policy->lock); | |
8085e1f1 | 636 | goto err_out_driver_exit; |
f3876c1b | 637 | } |
1da177e4 LT |
638 | /* set up files for this cpu device */ |
639 | drv_attr = cpufreq_driver->attr; | |
640 | while ((drv_attr) && (*drv_attr)) { | |
641 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
642 | drv_attr++; | |
643 | } | |
644 | if (cpufreq_driver->get) | |
645 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
646 | if (cpufreq_driver->target) | |
647 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
648 | ||
649 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
650 | for_each_cpu_mask(j, policy->cpus) | |
651 | cpufreq_cpu_data[j] = policy; | |
652 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
653 | policy->governor = NULL; /* to assure that the starting sequence is | |
654 | * run in cpufreq_set_policy */ | |
83933af4 | 655 | mutex_unlock(&policy->lock); |
1da177e4 LT |
656 | |
657 | /* set default policy */ | |
658 | ||
659 | ret = cpufreq_set_policy(&new_policy); | |
660 | if (ret) { | |
661 | dprintk("setting policy failed\n"); | |
662 | goto err_out_unregister; | |
663 | } | |
664 | ||
665 | module_put(cpufreq_driver->owner); | |
1da177e4 LT |
666 | dprintk("initialization complete\n"); |
667 | cpufreq_debug_enable_ratelimit(); | |
668 | ||
669 | return 0; | |
670 | ||
671 | ||
672 | err_out_unregister: | |
673 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
674 | for_each_cpu_mask(j, policy->cpus) | |
675 | cpufreq_cpu_data[j] = NULL; | |
676 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
677 | ||
678 | kobject_unregister(&policy->kobj); | |
679 | wait_for_completion(&policy->kobj_unregister); | |
680 | ||
8085e1f1 VP |
681 | err_out_driver_exit: |
682 | if (cpufreq_driver->exit) | |
683 | cpufreq_driver->exit(policy); | |
684 | ||
1da177e4 LT |
685 | err_out: |
686 | kfree(policy); | |
687 | ||
688 | nomem_out: | |
689 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 690 | module_out: |
1da177e4 LT |
691 | cpufreq_debug_enable_ratelimit(); |
692 | return ret; | |
693 | } | |
694 | ||
695 | ||
696 | /** | |
697 | * cpufreq_remove_dev - remove a CPU device | |
698 | * | |
699 | * Removes the cpufreq interface for a CPU device. | |
700 | */ | |
701 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
702 | { | |
703 | unsigned int cpu = sys_dev->id; | |
704 | unsigned long flags; | |
705 | struct cpufreq_policy *data; | |
706 | #ifdef CONFIG_SMP | |
e738cf6d | 707 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
708 | unsigned int j; |
709 | #endif | |
710 | ||
711 | cpufreq_debug_disable_ratelimit(); | |
712 | dprintk("unregistering CPU %u\n", cpu); | |
713 | ||
714 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
715 | data = cpufreq_cpu_data[cpu]; | |
716 | ||
717 | if (!data) { | |
718 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
719 | cpufreq_debug_enable_ratelimit(); |
720 | return -EINVAL; | |
721 | } | |
722 | cpufreq_cpu_data[cpu] = NULL; | |
723 | ||
724 | ||
725 | #ifdef CONFIG_SMP | |
726 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 727 | * only need to unlink, put and exit |
1da177e4 LT |
728 | */ |
729 | if (unlikely(cpu != data->cpu)) { | |
730 | dprintk("removing link\n"); | |
731 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
732 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
733 | cpufreq_cpu_put(data); |
734 | cpufreq_debug_enable_ratelimit(); | |
735 | return 0; | |
736 | } | |
737 | #endif | |
738 | ||
1da177e4 LT |
739 | |
740 | if (!kobject_get(&data->kobj)) { | |
741 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
742 | cpufreq_debug_enable_ratelimit(); | |
32ee8c3e | 743 | return -EFAULT; |
1da177e4 LT |
744 | } |
745 | ||
746 | #ifdef CONFIG_SMP | |
747 | /* if we have other CPUs still registered, we need to unlink them, | |
748 | * or else wait_for_completion below will lock up. Clean the | |
749 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
750 | * links afterwards. | |
751 | */ | |
752 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
753 | for_each_cpu_mask(j, data->cpus) { | |
754 | if (j == cpu) | |
755 | continue; | |
756 | cpufreq_cpu_data[j] = NULL; | |
757 | } | |
758 | } | |
759 | ||
760 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
761 | ||
762 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
763 | for_each_cpu_mask(j, data->cpus) { | |
764 | if (j == cpu) | |
765 | continue; | |
766 | dprintk("removing link for cpu %u\n", j); | |
d434fca7 AR |
767 | cpu_sys_dev = get_cpu_sysdev(j); |
768 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
769 | cpufreq_cpu_put(data); |
770 | } | |
771 | } | |
772 | #else | |
773 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
774 | #endif | |
775 | ||
83933af4 | 776 | mutex_lock(&data->lock); |
1da177e4 LT |
777 | if (cpufreq_driver->target) |
778 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
83933af4 | 779 | mutex_unlock(&data->lock); |
1da177e4 LT |
780 | |
781 | kobject_unregister(&data->kobj); | |
782 | ||
783 | kobject_put(&data->kobj); | |
784 | ||
785 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 786 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
787 | * unloading. |
788 | */ | |
789 | dprintk("waiting for dropping of refcount\n"); | |
790 | wait_for_completion(&data->kobj_unregister); | |
791 | dprintk("wait complete\n"); | |
792 | ||
793 | if (cpufreq_driver->exit) | |
794 | cpufreq_driver->exit(data); | |
795 | ||
796 | kfree(data); | |
797 | ||
798 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
799 | return 0; |
800 | } | |
801 | ||
802 | ||
803 | static void handle_update(void *data) | |
804 | { | |
805 | unsigned int cpu = (unsigned int)(long)data; | |
806 | dprintk("handle_update for cpu %u called\n", cpu); | |
807 | cpufreq_update_policy(cpu); | |
808 | } | |
809 | ||
810 | /** | |
811 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
812 | * @cpu: cpu number | |
813 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
814 | * @new_freq: CPU frequency the CPU actually runs at | |
815 | * | |
816 | * We adjust to current frequency first, and need to clean up later. So either call | |
817 | * to cpufreq_update_policy() or schedule handle_update()). | |
818 | */ | |
819 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq) | |
820 | { | |
821 | struct cpufreq_freqs freqs; | |
822 | ||
78ee998f | 823 | dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
824 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
825 | ||
826 | freqs.cpu = cpu; | |
827 | freqs.old = old_freq; | |
828 | freqs.new = new_freq; | |
829 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
830 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
831 | } | |
832 | ||
833 | ||
32ee8c3e | 834 | /** |
95235ca2 VP |
835 | * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur |
836 | * @cpu: CPU number | |
837 | * | |
838 | * This is the last known freq, without actually getting it from the driver. | |
839 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
840 | */ | |
841 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
842 | { | |
843 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
844 | unsigned int ret = 0; | |
845 | ||
846 | if (policy) { | |
83933af4 | 847 | mutex_lock(&policy->lock); |
95235ca2 | 848 | ret = policy->cur; |
83933af4 | 849 | mutex_unlock(&policy->lock); |
95235ca2 VP |
850 | cpufreq_cpu_put(policy); |
851 | } | |
852 | ||
853 | return (ret); | |
854 | } | |
855 | EXPORT_SYMBOL(cpufreq_quick_get); | |
856 | ||
857 | ||
32ee8c3e | 858 | /** |
1da177e4 LT |
859 | * cpufreq_get - get the current CPU frequency (in kHz) |
860 | * @cpu: CPU number | |
861 | * | |
862 | * Get the CPU current (static) CPU frequency | |
863 | */ | |
864 | unsigned int cpufreq_get(unsigned int cpu) | |
865 | { | |
866 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
867 | unsigned int ret = 0; | |
868 | ||
869 | if (!policy) | |
870 | return 0; | |
871 | ||
872 | if (!cpufreq_driver->get) | |
873 | goto out; | |
874 | ||
83933af4 | 875 | mutex_lock(&policy->lock); |
1da177e4 LT |
876 | |
877 | ret = cpufreq_driver->get(cpu); | |
878 | ||
7d5e350f | 879 | if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
1da177e4 LT |
880 | /* verify no discrepancy between actual and saved value exists */ |
881 | if (unlikely(ret != policy->cur)) { | |
882 | cpufreq_out_of_sync(cpu, policy->cur, ret); | |
883 | schedule_work(&policy->update); | |
884 | } | |
885 | } | |
886 | ||
83933af4 | 887 | mutex_unlock(&policy->lock); |
1da177e4 | 888 | |
7d5e350f | 889 | out: |
1da177e4 LT |
890 | cpufreq_cpu_put(policy); |
891 | ||
892 | return (ret); | |
893 | } | |
894 | EXPORT_SYMBOL(cpufreq_get); | |
895 | ||
896 | ||
42d4dc3f BH |
897 | /** |
898 | * cpufreq_suspend - let the low level driver prepare for suspend | |
899 | */ | |
900 | ||
e00d9967 | 901 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
902 | { |
903 | int cpu = sysdev->id; | |
904 | unsigned int ret = 0; | |
905 | unsigned int cur_freq = 0; | |
906 | struct cpufreq_policy *cpu_policy; | |
907 | ||
908 | dprintk("resuming cpu %u\n", cpu); | |
909 | ||
910 | if (!cpu_online(cpu)) | |
911 | return 0; | |
912 | ||
913 | /* we may be lax here as interrupts are off. Nonetheless | |
914 | * we need to grab the correct cpu policy, as to check | |
915 | * whether we really run on this CPU. | |
916 | */ | |
917 | ||
918 | cpu_policy = cpufreq_cpu_get(cpu); | |
919 | if (!cpu_policy) | |
920 | return -EINVAL; | |
921 | ||
922 | /* only handle each CPU group once */ | |
923 | if (unlikely(cpu_policy->cpu != cpu)) { | |
924 | cpufreq_cpu_put(cpu_policy); | |
925 | return 0; | |
926 | } | |
927 | ||
928 | if (cpufreq_driver->suspend) { | |
e00d9967 | 929 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
930 | if (ret) { |
931 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
932 | "step on CPU %u\n", cpu_policy->cpu); | |
933 | cpufreq_cpu_put(cpu_policy); | |
934 | return ret; | |
935 | } | |
936 | } | |
937 | ||
938 | ||
939 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
940 | goto out; | |
941 | ||
942 | if (cpufreq_driver->get) | |
943 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
944 | ||
945 | if (!cur_freq || !cpu_policy->cur) { | |
946 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
947 | "frequency is what timing core thinks it is.\n"); | |
948 | goto out; | |
949 | } | |
950 | ||
951 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
952 | struct cpufreq_freqs freqs; | |
953 | ||
954 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
78ee998f | 955 | dprintk(KERN_DEBUG "Warning: CPU frequency is %u, " |
42d4dc3f BH |
956 | "cpufreq assumed %u kHz.\n", |
957 | cur_freq, cpu_policy->cur); | |
958 | ||
959 | freqs.cpu = cpu; | |
960 | freqs.old = cpu_policy->cur; | |
961 | freqs.new = cur_freq; | |
962 | ||
963 | notifier_call_chain(&cpufreq_transition_notifier_list, | |
964 | CPUFREQ_SUSPENDCHANGE, &freqs); | |
965 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
966 | ||
967 | cpu_policy->cur = cur_freq; | |
968 | } | |
969 | ||
7d5e350f | 970 | out: |
42d4dc3f BH |
971 | cpufreq_cpu_put(cpu_policy); |
972 | return 0; | |
973 | } | |
974 | ||
1da177e4 LT |
975 | /** |
976 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
977 | * | |
978 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
979 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
980 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
981 | * restored. | |
1da177e4 LT |
982 | */ |
983 | static int cpufreq_resume(struct sys_device * sysdev) | |
984 | { | |
985 | int cpu = sysdev->id; | |
986 | unsigned int ret = 0; | |
987 | struct cpufreq_policy *cpu_policy; | |
988 | ||
989 | dprintk("resuming cpu %u\n", cpu); | |
990 | ||
991 | if (!cpu_online(cpu)) | |
992 | return 0; | |
993 | ||
994 | /* we may be lax here as interrupts are off. Nonetheless | |
995 | * we need to grab the correct cpu policy, as to check | |
996 | * whether we really run on this CPU. | |
997 | */ | |
998 | ||
999 | cpu_policy = cpufreq_cpu_get(cpu); | |
1000 | if (!cpu_policy) | |
1001 | return -EINVAL; | |
1002 | ||
1003 | /* only handle each CPU group once */ | |
1004 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1005 | cpufreq_cpu_put(cpu_policy); | |
1006 | return 0; | |
1007 | } | |
1008 | ||
1009 | if (cpufreq_driver->resume) { | |
1010 | ret = cpufreq_driver->resume(cpu_policy); | |
1011 | if (ret) { | |
1012 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1013 | "step on CPU %u\n", cpu_policy->cpu); | |
1014 | cpufreq_cpu_put(cpu_policy); | |
1015 | return ret; | |
1016 | } | |
1017 | } | |
1018 | ||
1019 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1020 | unsigned int cur_freq = 0; | |
1021 | ||
1022 | if (cpufreq_driver->get) | |
1023 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1024 | ||
1025 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1026 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1027 | "current frequency is what timing core " | |
1028 | "thinks it is.\n"); | |
1da177e4 LT |
1029 | goto out; |
1030 | } | |
1031 | ||
1032 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1033 | struct cpufreq_freqs freqs; | |
1034 | ||
ac09f698 | 1035 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
78ee998f | 1036 | dprintk(KERN_WARNING "Warning: CPU frequency" |
ac09f698 BH |
1037 | "is %u, cpufreq assumed %u kHz.\n", |
1038 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1039 | |
1040 | freqs.cpu = cpu; | |
1041 | freqs.old = cpu_policy->cur; | |
1042 | freqs.new = cur_freq; | |
1043 | ||
42d4dc3f BH |
1044 | notifier_call_chain(&cpufreq_transition_notifier_list, |
1045 | CPUFREQ_RESUMECHANGE, &freqs); | |
1da177e4 LT |
1046 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1047 | ||
1048 | cpu_policy->cur = cur_freq; | |
1049 | } | |
1050 | } | |
1051 | ||
1052 | out: | |
1053 | schedule_work(&cpu_policy->update); | |
1054 | cpufreq_cpu_put(cpu_policy); | |
1055 | return ret; | |
1056 | } | |
1057 | ||
1058 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1059 | .add = cpufreq_add_dev, | |
1060 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1061 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1062 | .resume = cpufreq_resume, |
1063 | }; | |
1064 | ||
1065 | ||
1066 | /********************************************************************* | |
1067 | * NOTIFIER LISTS INTERFACE * | |
1068 | *********************************************************************/ | |
1069 | ||
1070 | /** | |
1071 | * cpufreq_register_notifier - register a driver with cpufreq | |
1072 | * @nb: notifier function to register | |
1073 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1074 | * | |
32ee8c3e | 1075 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1076 | * are notified about clock rate changes (once before and once after |
1077 | * the transition), or a list of drivers that are notified about | |
1078 | * changes in cpufreq policy. | |
1079 | * | |
1080 | * This function may sleep, and has the same return conditions as | |
1081 | * notifier_chain_register. | |
1082 | */ | |
1083 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1084 | { | |
1085 | int ret; | |
1086 | ||
1087 | down_write(&cpufreq_notifier_rwsem); | |
1088 | switch (list) { | |
1089 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1090 | ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb); | |
1091 | break; | |
1092 | case CPUFREQ_POLICY_NOTIFIER: | |
1093 | ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb); | |
1094 | break; | |
1095 | default: | |
1096 | ret = -EINVAL; | |
1097 | } | |
1098 | up_write(&cpufreq_notifier_rwsem); | |
1099 | ||
1100 | return ret; | |
1101 | } | |
1102 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1103 | ||
1104 | ||
1105 | /** | |
1106 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1107 | * @nb: notifier block to be unregistered | |
1108 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1109 | * | |
1110 | * Remove a driver from the CPU frequency notifier list. | |
1111 | * | |
1112 | * This function may sleep, and has the same return conditions as | |
1113 | * notifier_chain_unregister. | |
1114 | */ | |
1115 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1116 | { | |
1117 | int ret; | |
1118 | ||
1119 | down_write(&cpufreq_notifier_rwsem); | |
1120 | switch (list) { | |
1121 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1122 | ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb); | |
1123 | break; | |
1124 | case CPUFREQ_POLICY_NOTIFIER: | |
1125 | ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb); | |
1126 | break; | |
1127 | default: | |
1128 | ret = -EINVAL; | |
1129 | } | |
1130 | up_write(&cpufreq_notifier_rwsem); | |
1131 | ||
1132 | return ret; | |
1133 | } | |
1134 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1135 | ||
1136 | ||
1137 | /********************************************************************* | |
1138 | * GOVERNORS * | |
1139 | *********************************************************************/ | |
1140 | ||
1141 | ||
1142 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1143 | unsigned int target_freq, | |
1144 | unsigned int relation) | |
1145 | { | |
1146 | int retval = -EINVAL; | |
c32b6b8e | 1147 | |
a9d9baa1 | 1148 | lock_cpu_hotplug(); |
1da177e4 LT |
1149 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1150 | target_freq, relation); | |
1151 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1152 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1153 | |
a9d9baa1 | 1154 | unlock_cpu_hotplug(); |
90d45d17 | 1155 | |
1da177e4 LT |
1156 | return retval; |
1157 | } | |
1158 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1159 | ||
1da177e4 LT |
1160 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1161 | unsigned int target_freq, | |
1162 | unsigned int relation) | |
1163 | { | |
cc993cab | 1164 | int ret; |
1da177e4 LT |
1165 | |
1166 | policy = cpufreq_cpu_get(policy->cpu); | |
1167 | if (!policy) | |
1168 | return -EINVAL; | |
1169 | ||
83933af4 | 1170 | mutex_lock(&policy->lock); |
1da177e4 LT |
1171 | |
1172 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1173 | ||
83933af4 | 1174 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1175 | |
1176 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1177 | return ret; |
1178 | } | |
1179 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1180 | ||
1181 | ||
1182 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) | |
1183 | { | |
cc993cab | 1184 | int ret; |
1da177e4 LT |
1185 | |
1186 | if (!try_module_get(policy->governor->owner)) | |
1187 | return -EINVAL; | |
1188 | ||
1189 | dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); | |
1190 | ret = policy->governor->governor(policy, event); | |
1191 | ||
1192 | /* we keep one module reference alive for each CPU governed by this CPU */ | |
1193 | if ((event != CPUFREQ_GOV_START) || ret) | |
1194 | module_put(policy->governor->owner); | |
1195 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1196 | module_put(policy->governor->owner); | |
1197 | ||
1198 | return ret; | |
1199 | } | |
1200 | ||
1201 | ||
1202 | int cpufreq_governor(unsigned int cpu, unsigned int event) | |
1203 | { | |
1204 | int ret = 0; | |
1205 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1206 | ||
1207 | if (!policy) | |
1208 | return -EINVAL; | |
1209 | ||
83933af4 | 1210 | mutex_lock(&policy->lock); |
1da177e4 | 1211 | ret = __cpufreq_governor(policy, event); |
83933af4 | 1212 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1213 | |
1214 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1215 | return ret; |
1216 | } | |
1217 | EXPORT_SYMBOL_GPL(cpufreq_governor); | |
1218 | ||
1219 | ||
1220 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1221 | { | |
1222 | struct cpufreq_governor *t; | |
1223 | ||
1224 | if (!governor) | |
1225 | return -EINVAL; | |
1226 | ||
3fc54d37 | 1227 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1228 | |
1da177e4 LT |
1229 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { |
1230 | if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) { | |
3fc54d37 | 1231 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1232 | return -EBUSY; |
1233 | } | |
1234 | } | |
1235 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1236 | ||
32ee8c3e | 1237 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1238 | return 0; |
1239 | } | |
1240 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1241 | ||
1242 | ||
1243 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1244 | { | |
1245 | if (!governor) | |
1246 | return; | |
1247 | ||
3fc54d37 | 1248 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1249 | list_del(&governor->governor_list); |
3fc54d37 | 1250 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1251 | return; |
1252 | } | |
1253 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1254 | ||
1255 | ||
1256 | ||
1257 | /********************************************************************* | |
1258 | * POLICY INTERFACE * | |
1259 | *********************************************************************/ | |
1260 | ||
1261 | /** | |
1262 | * cpufreq_get_policy - get the current cpufreq_policy | |
1263 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1264 | * | |
1265 | * Reads the current cpufreq policy. | |
1266 | */ | |
1267 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1268 | { | |
1269 | struct cpufreq_policy *cpu_policy; | |
1270 | if (!policy) | |
1271 | return -EINVAL; | |
1272 | ||
1273 | cpu_policy = cpufreq_cpu_get(cpu); | |
1274 | if (!cpu_policy) | |
1275 | return -EINVAL; | |
1276 | ||
83933af4 | 1277 | mutex_lock(&cpu_policy->lock); |
1da177e4 | 1278 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
83933af4 | 1279 | mutex_unlock(&cpu_policy->lock); |
1da177e4 LT |
1280 | |
1281 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1282 | return 0; |
1283 | } | |
1284 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1285 | ||
1286 | ||
1287 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) | |
1288 | { | |
1289 | int ret = 0; | |
1290 | ||
1291 | cpufreq_debug_disable_ratelimit(); | |
1292 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1293 | policy->min, policy->max); | |
1294 | ||
7d5e350f | 1295 | memcpy(&policy->cpuinfo, &data->cpuinfo, sizeof(struct cpufreq_cpuinfo)); |
1da177e4 LT |
1296 | |
1297 | /* verify the cpu speed can be set within this limit */ | |
1298 | ret = cpufreq_driver->verify(policy); | |
1299 | if (ret) | |
1300 | goto error_out; | |
1301 | ||
1302 | down_read(&cpufreq_notifier_rwsem); | |
1303 | ||
1304 | /* adjust if necessary - all reasons */ | |
1305 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST, | |
1306 | policy); | |
1307 | ||
1308 | /* adjust if necessary - hardware incompatibility*/ | |
1309 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE, | |
1310 | policy); | |
1311 | ||
1312 | /* verify the cpu speed can be set within this limit, | |
1313 | which might be different to the first one */ | |
1314 | ret = cpufreq_driver->verify(policy); | |
1315 | if (ret) { | |
1316 | up_read(&cpufreq_notifier_rwsem); | |
1317 | goto error_out; | |
1318 | } | |
1319 | ||
1320 | /* notification of the new policy */ | |
1321 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY, | |
1322 | policy); | |
1323 | ||
1324 | up_read(&cpufreq_notifier_rwsem); | |
1325 | ||
7d5e350f DJ |
1326 | data->min = policy->min; |
1327 | data->max = policy->max; | |
1da177e4 LT |
1328 | |
1329 | dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); | |
1330 | ||
1331 | if (cpufreq_driver->setpolicy) { | |
1332 | data->policy = policy->policy; | |
1333 | dprintk("setting range\n"); | |
1334 | ret = cpufreq_driver->setpolicy(policy); | |
1335 | } else { | |
1336 | if (policy->governor != data->governor) { | |
1337 | /* save old, working values */ | |
1338 | struct cpufreq_governor *old_gov = data->governor; | |
1339 | ||
1340 | dprintk("governor switch\n"); | |
1341 | ||
1342 | /* end old governor */ | |
1343 | if (data->governor) | |
1344 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1345 | ||
1346 | /* start new governor */ | |
1347 | data->governor = policy->governor; | |
1348 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1349 | /* new governor failed, so re-start old one */ | |
1350 | dprintk("starting governor %s failed\n", data->governor->name); | |
1351 | if (old_gov) { | |
1352 | data->governor = old_gov; | |
1353 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1354 | } | |
1355 | ret = -EINVAL; | |
1356 | goto error_out; | |
1357 | } | |
1358 | /* might be a policy change, too, so fall through */ | |
1359 | } | |
1360 | dprintk("governor: change or update limits\n"); | |
1361 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1362 | } | |
1363 | ||
7d5e350f | 1364 | error_out: |
1da177e4 LT |
1365 | cpufreq_debug_enable_ratelimit(); |
1366 | return ret; | |
1367 | } | |
1368 | ||
1369 | /** | |
1370 | * cpufreq_set_policy - set a new CPUFreq policy | |
1371 | * @policy: policy to be set. | |
1372 | * | |
1373 | * Sets a new CPU frequency and voltage scaling policy. | |
1374 | */ | |
1375 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1376 | { | |
1377 | int ret = 0; | |
1378 | struct cpufreq_policy *data; | |
1379 | ||
1380 | if (!policy) | |
1381 | return -EINVAL; | |
1382 | ||
1383 | data = cpufreq_cpu_get(policy->cpu); | |
1384 | if (!data) | |
1385 | return -EINVAL; | |
1386 | ||
1387 | /* lock this CPU */ | |
83933af4 | 1388 | mutex_lock(&data->lock); |
1da177e4 LT |
1389 | |
1390 | ret = __cpufreq_set_policy(data, policy); | |
1391 | data->user_policy.min = data->min; | |
1392 | data->user_policy.max = data->max; | |
1393 | data->user_policy.policy = data->policy; | |
1394 | data->user_policy.governor = data->governor; | |
1395 | ||
83933af4 | 1396 | mutex_unlock(&data->lock); |
1da177e4 LT |
1397 | cpufreq_cpu_put(data); |
1398 | ||
1399 | return ret; | |
1400 | } | |
1401 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1402 | ||
1403 | ||
1404 | /** | |
1405 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1406 | * @cpu: CPU which shall be re-evaluated | |
1407 | * | |
1408 | * Usefull for policy notifiers which have different necessities | |
1409 | * at different times. | |
1410 | */ | |
1411 | int cpufreq_update_policy(unsigned int cpu) | |
1412 | { | |
1413 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1414 | struct cpufreq_policy policy; | |
1415 | int ret = 0; | |
1416 | ||
1417 | if (!data) | |
1418 | return -ENODEV; | |
1419 | ||
83933af4 | 1420 | mutex_lock(&data->lock); |
1da177e4 LT |
1421 | |
1422 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1423 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1424 | policy.min = data->user_policy.min; |
1425 | policy.max = data->user_policy.max; | |
1426 | policy.policy = data->user_policy.policy; | |
1427 | policy.governor = data->user_policy.governor; | |
1428 | ||
0961dd0d TR |
1429 | /* BIOS might change freq behind our back |
1430 | -> ask driver for current freq and notify governors about a change */ | |
1431 | if (cpufreq_driver->get) { | |
1432 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1433 | if (!data->cur) { |
1434 | dprintk("Driver did not initialize current freq"); | |
1435 | data->cur = policy.cur; | |
1436 | } else { | |
1437 | if (data->cur != policy.cur) | |
1438 | cpufreq_out_of_sync(cpu, data->cur, policy.cur); | |
1439 | } | |
0961dd0d TR |
1440 | } |
1441 | ||
1da177e4 LT |
1442 | ret = __cpufreq_set_policy(data, &policy); |
1443 | ||
83933af4 | 1444 | mutex_unlock(&data->lock); |
1da177e4 LT |
1445 | |
1446 | cpufreq_cpu_put(data); | |
1447 | return ret; | |
1448 | } | |
1449 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1450 | ||
c32b6b8e AR |
1451 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
1452 | unsigned long action, void *hcpu) | |
1453 | { | |
1454 | unsigned int cpu = (unsigned long)hcpu; | |
1455 | struct cpufreq_policy *policy; | |
1456 | struct sys_device *sys_dev; | |
1457 | ||
1458 | sys_dev = get_cpu_sysdev(cpu); | |
1459 | ||
1460 | if (sys_dev) { | |
1461 | switch (action) { | |
1462 | case CPU_ONLINE: | |
1463 | cpufreq_add_dev(sys_dev); | |
1464 | break; | |
1465 | case CPU_DOWN_PREPARE: | |
1466 | /* | |
1467 | * We attempt to put this cpu in lowest frequency | |
1468 | * possible before going down. This will permit | |
1469 | * hardware-managed P-State to switch other related | |
1470 | * threads to min or higher speeds if possible. | |
1471 | */ | |
1472 | policy = cpufreq_cpu_data[cpu]; | |
1473 | if (policy) { | |
1474 | cpufreq_driver_target(policy, policy->min, | |
1475 | CPUFREQ_RELATION_H); | |
1476 | } | |
1477 | break; | |
1478 | case CPU_DEAD: | |
1479 | cpufreq_remove_dev(sys_dev); | |
1480 | break; | |
1481 | } | |
1482 | } | |
1483 | return NOTIFY_OK; | |
1484 | } | |
1485 | ||
1486 | static struct notifier_block cpufreq_cpu_notifier = | |
1487 | { | |
1488 | .notifier_call = cpufreq_cpu_callback, | |
1489 | }; | |
1da177e4 LT |
1490 | |
1491 | /********************************************************************* | |
1492 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1493 | *********************************************************************/ | |
1494 | ||
1495 | /** | |
1496 | * cpufreq_register_driver - register a CPU Frequency driver | |
1497 | * @driver_data: A struct cpufreq_driver containing the values# | |
1498 | * submitted by the CPU Frequency driver. | |
1499 | * | |
32ee8c3e | 1500 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1501 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1502 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1503 | * |
1504 | */ | |
1505 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1506 | { | |
1507 | unsigned long flags; | |
1508 | int ret; | |
1509 | ||
1510 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1511 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1512 | return -EINVAL; | |
1513 | ||
1514 | dprintk("trying to register driver %s\n", driver_data->name); | |
1515 | ||
1516 | if (driver_data->setpolicy) | |
1517 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1518 | ||
1519 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1520 | if (cpufreq_driver) { | |
1521 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1522 | return -EBUSY; | |
1523 | } | |
1524 | cpufreq_driver = driver_data; | |
1525 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1526 | ||
1527 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1528 | ||
1529 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1530 | int i; | |
1531 | ret = -ENODEV; | |
1532 | ||
1533 | /* check for at least one working CPU */ | |
1534 | for (i=0; i<NR_CPUS; i++) | |
1535 | if (cpufreq_cpu_data[i]) | |
1536 | ret = 0; | |
1537 | ||
1538 | /* if all ->init() calls failed, unregister */ | |
1539 | if (ret) { | |
1540 | dprintk("no CPU initialized for driver %s\n", driver_data->name); | |
1541 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1542 | ||
1543 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1544 | cpufreq_driver = NULL; | |
1545 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1546 | } | |
1547 | } | |
1548 | ||
1549 | if (!ret) { | |
c32b6b8e | 1550 | register_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1551 | dprintk("driver %s up and running\n", driver_data->name); |
1552 | cpufreq_debug_enable_ratelimit(); | |
1553 | } | |
1554 | ||
1555 | return (ret); | |
1556 | } | |
1557 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1558 | ||
1559 | ||
1560 | /** | |
1561 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1562 | * | |
32ee8c3e | 1563 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1564 | * the right to do so, i.e. if you have succeeded in initialising before! |
1565 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1566 | * currently not initialised. | |
1567 | */ | |
1568 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1569 | { | |
1570 | unsigned long flags; | |
1571 | ||
1572 | cpufreq_debug_disable_ratelimit(); | |
1573 | ||
1574 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1575 | cpufreq_debug_enable_ratelimit(); | |
1576 | return -EINVAL; | |
1577 | } | |
1578 | ||
1579 | dprintk("unregistering driver %s\n", driver->name); | |
1580 | ||
1581 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
c32b6b8e | 1582 | unregister_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1583 | |
1584 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1585 | cpufreq_driver = NULL; | |
1586 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1587 | ||
1588 | return 0; | |
1589 | } | |
1590 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |