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1 | /* | |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> | |
8 | * Added handling for CPU hotplug | |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> | |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
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 version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/cpufreq.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/completion.h> | |
30 | #include <linux/mutex.h> | |
31 | ||
32 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, \ | |
33 | "cpufreq-core", msg) | |
34 | ||
35 | /** | |
36 | * The "cpufreq driver" - the arch- or hardware-dependent low | |
37 | * level driver of CPUFreq support, and its spinlock. This lock | |
38 | * also protects the cpufreq_cpu_data array. | |
39 | */ | |
40 | static struct cpufreq_driver *cpufreq_driver; | |
41 | static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; | |
42 | #ifdef CONFIG_HOTPLUG_CPU | |
43 | /* This one keeps track of the previously set governor of a removed CPU */ | |
44 | static struct cpufreq_governor *cpufreq_cpu_governor[NR_CPUS]; | |
45 | #endif | |
46 | static DEFINE_SPINLOCK(cpufreq_driver_lock); | |
47 | ||
48 | /* | |
49 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
50 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
51 | * | |
52 | * The rules for this semaphore: | |
53 | * - Any routine that wants to read from the policy structure will | |
54 | * do a down_read on this semaphore. | |
55 | * - Any routine that will write to the policy structure and/or may take away | |
56 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
57 | * mode before doing so. | |
58 | * | |
59 | * Additional rules: | |
60 | * - All holders of the lock should check to make sure that the CPU they | |
61 | * are concerned with are online after they get the lock. | |
62 | * - Governor routines that can be called in cpufreq hotplug path should not | |
63 | * take this sem as top level hotplug notifier handler takes this. | |
64 | */ | |
65 | static DEFINE_PER_CPU(int, policy_cpu); | |
66 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); | |
67 | ||
68 | #define lock_policy_rwsem(mode, cpu) \ | |
69 | int lock_policy_rwsem_##mode \ | |
70 | (int cpu) \ | |
71 | { \ | |
72 | int policy_cpu = per_cpu(policy_cpu, cpu); \ | |
73 | BUG_ON(policy_cpu == -1); \ | |
74 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
75 | if (unlikely(!cpu_online(cpu))) { \ | |
76 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
77 | return -1; \ | |
78 | } \ | |
79 | \ | |
80 | return 0; \ | |
81 | } | |
82 | ||
83 | lock_policy_rwsem(read, cpu); | |
84 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_read); | |
85 | ||
86 | lock_policy_rwsem(write, cpu); | |
87 | EXPORT_SYMBOL_GPL(lock_policy_rwsem_write); | |
88 | ||
89 | void unlock_policy_rwsem_read(int cpu) | |
90 | { | |
91 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
92 | BUG_ON(policy_cpu == -1); | |
93 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_read); | |
96 | ||
97 | void unlock_policy_rwsem_write(int cpu) | |
98 | { | |
99 | int policy_cpu = per_cpu(policy_cpu, cpu); | |
100 | BUG_ON(policy_cpu == -1); | |
101 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
102 | } | |
103 | EXPORT_SYMBOL_GPL(unlock_policy_rwsem_write); | |
104 | ||
105 | ||
106 | /* internal prototypes */ | |
107 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
108 | static unsigned int __cpufreq_get(unsigned int cpu); | |
109 | static void handle_update(struct work_struct *work); | |
110 | ||
111 | /** | |
112 | * Two notifier lists: the "policy" list is involved in the | |
113 | * validation process for a new CPU frequency policy; the | |
114 | * "transition" list for kernel code that needs to handle | |
115 | * changes to devices when the CPU clock speed changes. | |
116 | * The mutex locks both lists. | |
117 | */ | |
118 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); | |
119 | static struct srcu_notifier_head cpufreq_transition_notifier_list; | |
120 | ||
121 | static int __init init_cpufreq_transition_notifier_list(void) | |
122 | { | |
123 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
124 | return 0; | |
125 | } | |
126 | pure_initcall(init_cpufreq_transition_notifier_list); | |
127 | ||
128 | static LIST_HEAD(cpufreq_governor_list); | |
129 | static DEFINE_MUTEX (cpufreq_governor_mutex); | |
130 | ||
131 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
132 | { | |
133 | struct cpufreq_policy *data; | |
134 | unsigned long flags; | |
135 | ||
136 | if (cpu >= NR_CPUS) | |
137 | goto err_out; | |
138 | ||
139 | /* get the cpufreq driver */ | |
140 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
141 | ||
142 | if (!cpufreq_driver) | |
143 | goto err_out_unlock; | |
144 | ||
145 | if (!try_module_get(cpufreq_driver->owner)) | |
146 | goto err_out_unlock; | |
147 | ||
148 | ||
149 | /* get the CPU */ | |
150 | data = cpufreq_cpu_data[cpu]; | |
151 | ||
152 | if (!data) | |
153 | goto err_out_put_module; | |
154 | ||
155 | if (!kobject_get(&data->kobj)) | |
156 | goto err_out_put_module; | |
157 | ||
158 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
159 | return data; | |
160 | ||
161 | err_out_put_module: | |
162 | module_put(cpufreq_driver->owner); | |
163 | err_out_unlock: | |
164 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
165 | err_out: | |
166 | return NULL; | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
169 | ||
170 | ||
171 | void cpufreq_cpu_put(struct cpufreq_policy *data) | |
172 | { | |
173 | kobject_put(&data->kobj); | |
174 | module_put(cpufreq_driver->owner); | |
175 | } | |
176 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
177 | ||
178 | ||
179 | /********************************************************************* | |
180 | * UNIFIED DEBUG HELPERS * | |
181 | *********************************************************************/ | |
182 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
183 | ||
184 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
185 | static unsigned int debug; | |
186 | ||
187 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
188 | * set or modify this value. | |
189 | */ | |
190 | static unsigned int debug_ratelimit = 1; | |
191 | ||
192 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
193 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
194 | * is set, and disabled upon cpufreq driver removal | |
195 | */ | |
196 | static unsigned int disable_ratelimit = 1; | |
197 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
198 | ||
199 | static void cpufreq_debug_enable_ratelimit(void) | |
200 | { | |
201 | unsigned long flags; | |
202 | ||
203 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
204 | if (disable_ratelimit) | |
205 | disable_ratelimit--; | |
206 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
207 | } | |
208 | ||
209 | static void cpufreq_debug_disable_ratelimit(void) | |
210 | { | |
211 | unsigned long flags; | |
212 | ||
213 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
214 | disable_ratelimit++; | |
215 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
216 | } | |
217 | ||
218 | void cpufreq_debug_printk(unsigned int type, const char *prefix, | |
219 | const char *fmt, ...) | |
220 | { | |
221 | char s[256]; | |
222 | va_list args; | |
223 | unsigned int len; | |
224 | unsigned long flags; | |
225 | ||
226 | WARN_ON(!prefix); | |
227 | if (type & debug) { | |
228 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
229 | if (!disable_ratelimit && debug_ratelimit | |
230 | && !printk_ratelimit()) { | |
231 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
232 | return; | |
233 | } | |
234 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
235 | ||
236 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
237 | ||
238 | va_start(args, fmt); | |
239 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
240 | va_end(args); | |
241 | ||
242 | printk(s); | |
243 | ||
244 | WARN_ON(len < 5); | |
245 | } | |
246 | } | |
247 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
248 | ||
249 | ||
250 | module_param(debug, uint, 0644); | |
251 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core," | |
252 | " 2 to debug drivers, and 4 to debug governors."); | |
253 | ||
254 | module_param(debug_ratelimit, uint, 0644); | |
255 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging:" | |
256 | " set to 0 to disable ratelimiting."); | |
257 | ||
258 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
259 | ||
260 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
261 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
262 | ||
263 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
264 | ||
265 | ||
266 | /********************************************************************* | |
267 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
268 | *********************************************************************/ | |
269 | ||
270 | /** | |
271 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
272 | * | |
273 | * This function alters the system "loops_per_jiffy" for the clock | |
274 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
275 | * systems as each CPU might be scaled differently. So, use the arch | |
276 | * per-CPU loops_per_jiffy value wherever possible. | |
277 | */ | |
278 | #ifndef CONFIG_SMP | |
279 | static unsigned long l_p_j_ref; | |
280 | static unsigned int l_p_j_ref_freq; | |
281 | ||
282 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) | |
283 | { | |
284 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
285 | return; | |
286 | ||
287 | if (!l_p_j_ref_freq) { | |
288 | l_p_j_ref = loops_per_jiffy; | |
289 | l_p_j_ref_freq = ci->old; | |
290 | dprintk("saving %lu as reference value for loops_per_jiffy;" | |
291 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
292 | } | |
293 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
294 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
295 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { | |
296 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, | |
297 | ci->new); | |
298 | dprintk("scaling loops_per_jiffy to %lu" | |
299 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
300 | } | |
301 | } | |
302 | #else | |
303 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) | |
304 | { | |
305 | return; | |
306 | } | |
307 | #endif | |
308 | ||
309 | ||
310 | /** | |
311 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
312 | * on frequency transition. | |
313 | * | |
314 | * This function calls the transition notifiers and the "adjust_jiffies" | |
315 | * function. It is called twice on all CPU frequency changes that have | |
316 | * external effects. | |
317 | */ | |
318 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
319 | { | |
320 | struct cpufreq_policy *policy; | |
321 | ||
322 | BUG_ON(irqs_disabled()); | |
323 | ||
324 | freqs->flags = cpufreq_driver->flags; | |
325 | dprintk("notification %u of frequency transition to %u kHz\n", | |
326 | state, freqs->new); | |
327 | ||
328 | policy = cpufreq_cpu_data[freqs->cpu]; | |
329 | switch (state) { | |
330 | ||
331 | case CPUFREQ_PRECHANGE: | |
332 | /* detect if the driver reported a value as "old frequency" | |
333 | * which is not equal to what the cpufreq core thinks is | |
334 | * "old frequency". | |
335 | */ | |
336 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
337 | if ((policy) && (policy->cpu == freqs->cpu) && | |
338 | (policy->cur) && (policy->cur != freqs->old)) { | |
339 | dprintk("Warning: CPU frequency is" | |
340 | " %u, cpufreq assumed %u kHz.\n", | |
341 | freqs->old, policy->cur); | |
342 | freqs->old = policy->cur; | |
343 | } | |
344 | } | |
345 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
346 | CPUFREQ_PRECHANGE, freqs); | |
347 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); | |
348 | break; | |
349 | ||
350 | case CPUFREQ_POSTCHANGE: | |
351 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
352 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
353 | CPUFREQ_POSTCHANGE, freqs); | |
354 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) | |
355 | policy->cur = freqs->new; | |
356 | break; | |
357 | } | |
358 | } | |
359 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
360 | ||
361 | ||
362 | ||
363 | /********************************************************************* | |
364 | * SYSFS INTERFACE * | |
365 | *********************************************************************/ | |
366 | ||
367 | static struct cpufreq_governor *__find_governor(const char *str_governor) | |
368 | { | |
369 | struct cpufreq_governor *t; | |
370 | ||
371 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
372 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) | |
373 | return t; | |
374 | ||
375 | return NULL; | |
376 | } | |
377 | ||
378 | /** | |
379 | * cpufreq_parse_governor - parse a governor string | |
380 | */ | |
381 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
382 | struct cpufreq_governor **governor) | |
383 | { | |
384 | int err = -EINVAL; | |
385 | ||
386 | if (!cpufreq_driver) | |
387 | goto out; | |
388 | ||
389 | if (cpufreq_driver->setpolicy) { | |
390 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
391 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
392 | err = 0; | |
393 | } else if (!strnicmp(str_governor, "powersave", | |
394 | CPUFREQ_NAME_LEN)) { | |
395 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
396 | err = 0; | |
397 | } | |
398 | } else if (cpufreq_driver->target) { | |
399 | struct cpufreq_governor *t; | |
400 | ||
401 | mutex_lock(&cpufreq_governor_mutex); | |
402 | ||
403 | t = __find_governor(str_governor); | |
404 | ||
405 | if (t == NULL) { | |
406 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", | |
407 | str_governor); | |
408 | ||
409 | if (name) { | |
410 | int ret; | |
411 | ||
412 | mutex_unlock(&cpufreq_governor_mutex); | |
413 | ret = request_module(name); | |
414 | mutex_lock(&cpufreq_governor_mutex); | |
415 | ||
416 | if (ret == 0) | |
417 | t = __find_governor(str_governor); | |
418 | } | |
419 | ||
420 | kfree(name); | |
421 | } | |
422 | ||
423 | if (t != NULL) { | |
424 | *governor = t; | |
425 | err = 0; | |
426 | } | |
427 | ||
428 | mutex_unlock(&cpufreq_governor_mutex); | |
429 | } | |
430 | out: | |
431 | return err; | |
432 | } | |
433 | ||
434 | ||
435 | /* drivers/base/cpu.c */ | |
436 | extern struct sysdev_class cpu_sysdev_class; | |
437 | ||
438 | ||
439 | /** | |
440 | * cpufreq_per_cpu_attr_read() / show_##file_name() - | |
441 | * print out cpufreq information | |
442 | * | |
443 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
444 | * "unsigned int". | |
445 | */ | |
446 | ||
447 | #define show_one(file_name, object) \ | |
448 | static ssize_t show_##file_name \ | |
449 | (struct cpufreq_policy * policy, char *buf) \ | |
450 | { \ | |
451 | return sprintf (buf, "%u\n", policy->object); \ | |
452 | } | |
453 | ||
454 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
455 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
456 | show_one(scaling_min_freq, min); | |
457 | show_one(scaling_max_freq, max); | |
458 | show_one(scaling_cur_freq, cur); | |
459 | ||
460 | static int __cpufreq_set_policy(struct cpufreq_policy *data, | |
461 | struct cpufreq_policy *policy); | |
462 | ||
463 | /** | |
464 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
465 | */ | |
466 | #define store_one(file_name, object) \ | |
467 | static ssize_t store_##file_name \ | |
468 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
469 | { \ | |
470 | unsigned int ret = -EINVAL; \ | |
471 | struct cpufreq_policy new_policy; \ | |
472 | \ | |
473 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
474 | if (ret) \ | |
475 | return -EINVAL; \ | |
476 | \ | |
477 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
478 | if (ret != 1) \ | |
479 | return -EINVAL; \ | |
480 | \ | |
481 | ret = __cpufreq_set_policy(policy, &new_policy); \ | |
482 | policy->user_policy.object = policy->object; \ | |
483 | \ | |
484 | return ret ? ret : count; \ | |
485 | } | |
486 | ||
487 | store_one(scaling_min_freq,min); | |
488 | store_one(scaling_max_freq,max); | |
489 | ||
490 | /** | |
491 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
492 | */ | |
493 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, | |
494 | char *buf) | |
495 | { | |
496 | unsigned int cur_freq = __cpufreq_get(policy->cpu); | |
497 | if (!cur_freq) | |
498 | return sprintf(buf, "<unknown>"); | |
499 | return sprintf(buf, "%u\n", cur_freq); | |
500 | } | |
501 | ||
502 | ||
503 | /** | |
504 | * show_scaling_governor - show the current policy for the specified CPU | |
505 | */ | |
506 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, | |
507 | char *buf) | |
508 | { | |
509 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
510 | return sprintf(buf, "powersave\n"); | |
511 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
512 | return sprintf(buf, "performance\n"); | |
513 | else if (policy->governor) | |
514 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
515 | return -EINVAL; | |
516 | } | |
517 | ||
518 | ||
519 | /** | |
520 | * store_scaling_governor - store policy for the specified CPU | |
521 | */ | |
522 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, | |
523 | const char *buf, size_t count) | |
524 | { | |
525 | unsigned int ret = -EINVAL; | |
526 | char str_governor[16]; | |
527 | struct cpufreq_policy new_policy; | |
528 | ||
529 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
530 | if (ret) | |
531 | return ret; | |
532 | ||
533 | ret = sscanf (buf, "%15s", str_governor); | |
534 | if (ret != 1) | |
535 | return -EINVAL; | |
536 | ||
537 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, | |
538 | &new_policy.governor)) | |
539 | return -EINVAL; | |
540 | ||
541 | /* Do not use cpufreq_set_policy here or the user_policy.max | |
542 | will be wrongly overridden */ | |
543 | ret = __cpufreq_set_policy(policy, &new_policy); | |
544 | ||
545 | policy->user_policy.policy = policy->policy; | |
546 | policy->user_policy.governor = policy->governor; | |
547 | ||
548 | if (ret) | |
549 | return ret; | |
550 | else | |
551 | return count; | |
552 | } | |
553 | ||
554 | /** | |
555 | * show_scaling_driver - show the cpufreq driver currently loaded | |
556 | */ | |
557 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
558 | { | |
559 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
560 | } | |
561 | ||
562 | /** | |
563 | * show_scaling_available_governors - show the available CPUfreq governors | |
564 | */ | |
565 | static ssize_t show_scaling_available_governors (struct cpufreq_policy *policy, | |
566 | char *buf) | |
567 | { | |
568 | ssize_t i = 0; | |
569 | struct cpufreq_governor *t; | |
570 | ||
571 | if (!cpufreq_driver->target) { | |
572 | i += sprintf(buf, "performance powersave"); | |
573 | goto out; | |
574 | } | |
575 | ||
576 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
577 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
578 | goto out; | |
579 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
580 | } | |
581 | out: | |
582 | i += sprintf(&buf[i], "\n"); | |
583 | return i; | |
584 | } | |
585 | /** | |
586 | * show_affected_cpus - show the CPUs affected by each transition | |
587 | */ | |
588 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
589 | { | |
590 | ssize_t i = 0; | |
591 | unsigned int cpu; | |
592 | ||
593 | for_each_cpu_mask(cpu, policy->cpus) { | |
594 | if (i) | |
595 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
597 | if (i >= (PAGE_SIZE - 5)) | |
598 | break; | |
599 | } | |
600 | i += sprintf(&buf[i], "\n"); | |
601 | return i; | |
602 | } | |
603 | ||
604 | ||
605 | #define define_one_ro(_name) \ | |
606 | static struct freq_attr _name = \ | |
607 | __ATTR(_name, 0444, show_##_name, NULL) | |
608 | ||
609 | #define define_one_ro0400(_name) \ | |
610 | static struct freq_attr _name = \ | |
611 | __ATTR(_name, 0400, show_##_name, NULL) | |
612 | ||
613 | #define define_one_rw(_name) \ | |
614 | static struct freq_attr _name = \ | |
615 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
616 | ||
617 | define_one_ro0400(cpuinfo_cur_freq); | |
618 | define_one_ro(cpuinfo_min_freq); | |
619 | define_one_ro(cpuinfo_max_freq); | |
620 | define_one_ro(scaling_available_governors); | |
621 | define_one_ro(scaling_driver); | |
622 | define_one_ro(scaling_cur_freq); | |
623 | define_one_ro(affected_cpus); | |
624 | define_one_rw(scaling_min_freq); | |
625 | define_one_rw(scaling_max_freq); | |
626 | define_one_rw(scaling_governor); | |
627 | ||
628 | static struct attribute * default_attrs[] = { | |
629 | &cpuinfo_min_freq.attr, | |
630 | &cpuinfo_max_freq.attr, | |
631 | &scaling_min_freq.attr, | |
632 | &scaling_max_freq.attr, | |
633 | &affected_cpus.attr, | |
634 | &scaling_governor.attr, | |
635 | &scaling_driver.attr, | |
636 | &scaling_available_governors.attr, | |
637 | NULL | |
638 | }; | |
639 | ||
640 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
641 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
642 | ||
643 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
644 | { | |
645 | struct cpufreq_policy * policy = to_policy(kobj); | |
646 | struct freq_attr * fattr = to_attr(attr); | |
647 | ssize_t ret; | |
648 | policy = cpufreq_cpu_get(policy->cpu); | |
649 | if (!policy) | |
650 | return -EINVAL; | |
651 | ||
652 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
653 | return -EINVAL; | |
654 | ||
655 | if (fattr->show) | |
656 | ret = fattr->show(policy, buf); | |
657 | else | |
658 | ret = -EIO; | |
659 | ||
660 | unlock_policy_rwsem_read(policy->cpu); | |
661 | ||
662 | cpufreq_cpu_put(policy); | |
663 | return ret; | |
664 | } | |
665 | ||
666 | static ssize_t store(struct kobject * kobj, struct attribute * attr, | |
667 | const char * buf, size_t count) | |
668 | { | |
669 | struct cpufreq_policy * policy = to_policy(kobj); | |
670 | struct freq_attr * fattr = to_attr(attr); | |
671 | ssize_t ret; | |
672 | policy = cpufreq_cpu_get(policy->cpu); | |
673 | if (!policy) | |
674 | return -EINVAL; | |
675 | ||
676 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
677 | return -EINVAL; | |
678 | ||
679 | if (fattr->store) | |
680 | ret = fattr->store(policy, buf, count); | |
681 | else | |
682 | ret = -EIO; | |
683 | ||
684 | unlock_policy_rwsem_write(policy->cpu); | |
685 | ||
686 | cpufreq_cpu_put(policy); | |
687 | return ret; | |
688 | } | |
689 | ||
690 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
691 | { | |
692 | struct cpufreq_policy * policy = to_policy(kobj); | |
693 | dprintk("last reference is dropped\n"); | |
694 | complete(&policy->kobj_unregister); | |
695 | } | |
696 | ||
697 | static struct sysfs_ops sysfs_ops = { | |
698 | .show = show, | |
699 | .store = store, | |
700 | }; | |
701 | ||
702 | static struct kobj_type ktype_cpufreq = { | |
703 | .sysfs_ops = &sysfs_ops, | |
704 | .default_attrs = default_attrs, | |
705 | .release = cpufreq_sysfs_release, | |
706 | }; | |
707 | ||
708 | ||
709 | /** | |
710 | * cpufreq_add_dev - add a CPU device | |
711 | * | |
712 | * Adds the cpufreq interface for a CPU device. | |
713 | */ | |
714 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
715 | { | |
716 | unsigned int cpu = sys_dev->id; | |
717 | int ret = 0; | |
718 | struct cpufreq_policy new_policy; | |
719 | struct cpufreq_policy *policy; | |
720 | struct freq_attr **drv_attr; | |
721 | struct sys_device *cpu_sys_dev; | |
722 | unsigned long flags; | |
723 | unsigned int j; | |
724 | #ifdef CONFIG_SMP | |
725 | struct cpufreq_policy *managed_policy; | |
726 | #endif | |
727 | ||
728 | if (cpu_is_offline(cpu)) | |
729 | return 0; | |
730 | ||
731 | cpufreq_debug_disable_ratelimit(); | |
732 | dprintk("adding CPU %u\n", cpu); | |
733 | ||
734 | #ifdef CONFIG_SMP | |
735 | /* check whether a different CPU already registered this | |
736 | * CPU because it is in the same boat. */ | |
737 | policy = cpufreq_cpu_get(cpu); | |
738 | if (unlikely(policy)) { | |
739 | cpufreq_cpu_put(policy); | |
740 | cpufreq_debug_enable_ratelimit(); | |
741 | return 0; | |
742 | } | |
743 | #endif | |
744 | ||
745 | if (!try_module_get(cpufreq_driver->owner)) { | |
746 | ret = -EINVAL; | |
747 | goto module_out; | |
748 | } | |
749 | ||
750 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); | |
751 | if (!policy) { | |
752 | ret = -ENOMEM; | |
753 | goto nomem_out; | |
754 | } | |
755 | ||
756 | policy->cpu = cpu; | |
757 | policy->cpus = cpumask_of_cpu(cpu); | |
758 | ||
759 | /* Initially set CPU itself as the policy_cpu */ | |
760 | per_cpu(policy_cpu, cpu) = cpu; | |
761 | lock_policy_rwsem_write(cpu); | |
762 | ||
763 | init_completion(&policy->kobj_unregister); | |
764 | INIT_WORK(&policy->update, handle_update); | |
765 | ||
766 | /* Set governor before ->init, so that driver could check it */ | |
767 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
768 | /* call driver. From then on the cpufreq must be able | |
769 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
770 | */ | |
771 | ret = cpufreq_driver->init(policy); | |
772 | if (ret) { | |
773 | dprintk("initialization failed\n"); | |
774 | unlock_policy_rwsem_write(cpu); | |
775 | goto err_out; | |
776 | } | |
777 | policy->user_policy.min = policy->cpuinfo.min_freq; | |
778 | policy->user_policy.max = policy->cpuinfo.max_freq; | |
779 | ||
780 | #ifdef CONFIG_SMP | |
781 | ||
782 | #ifdef CONFIG_HOTPLUG_CPU | |
783 | if (cpufreq_cpu_governor[cpu]){ | |
784 | policy->governor = cpufreq_cpu_governor[cpu]; | |
785 | dprintk("Restoring governor %s for cpu %d\n", | |
786 | policy->governor->name, cpu); | |
787 | } | |
788 | #endif | |
789 | ||
790 | for_each_cpu_mask(j, policy->cpus) { | |
791 | if (cpu == j) | |
792 | continue; | |
793 | ||
794 | /* check for existing affected CPUs. They may not be aware | |
795 | * of it due to CPU Hotplug. | |
796 | */ | |
797 | managed_policy = cpufreq_cpu_get(j); | |
798 | if (unlikely(managed_policy)) { | |
799 | ||
800 | /* Set proper policy_cpu */ | |
801 | unlock_policy_rwsem_write(cpu); | |
802 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
803 | ||
804 | if (lock_policy_rwsem_write(cpu) < 0) | |
805 | goto err_out_driver_exit; | |
806 | ||
807 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
808 | managed_policy->cpus = policy->cpus; | |
809 | cpufreq_cpu_data[cpu] = managed_policy; | |
810 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
811 | ||
812 | dprintk("CPU already managed, adding link\n"); | |
813 | ret = sysfs_create_link(&sys_dev->kobj, | |
814 | &managed_policy->kobj, | |
815 | "cpufreq"); | |
816 | if (ret) { | |
817 | unlock_policy_rwsem_write(cpu); | |
818 | goto err_out_driver_exit; | |
819 | } | |
820 | ||
821 | cpufreq_debug_enable_ratelimit(); | |
822 | ret = 0; | |
823 | unlock_policy_rwsem_write(cpu); | |
824 | goto err_out_driver_exit; /* call driver->exit() */ | |
825 | } | |
826 | } | |
827 | #endif | |
828 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
829 | ||
830 | /* prepare interface data */ | |
831 | policy->kobj.parent = &sys_dev->kobj; | |
832 | policy->kobj.ktype = &ktype_cpufreq; | |
833 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
834 | ||
835 | ret = kobject_register(&policy->kobj); | |
836 | if (ret) { | |
837 | unlock_policy_rwsem_write(cpu); | |
838 | goto err_out_driver_exit; | |
839 | } | |
840 | /* set up files for this cpu device */ | |
841 | drv_attr = cpufreq_driver->attr; | |
842 | while ((drv_attr) && (*drv_attr)) { | |
843 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
844 | if (ret) | |
845 | goto err_out_driver_exit; | |
846 | drv_attr++; | |
847 | } | |
848 | if (cpufreq_driver->get){ | |
849 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
850 | if (ret) | |
851 | goto err_out_driver_exit; | |
852 | } | |
853 | if (cpufreq_driver->target){ | |
854 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
855 | if (ret) | |
856 | goto err_out_driver_exit; | |
857 | } | |
858 | ||
859 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
860 | for_each_cpu_mask(j, policy->cpus) { | |
861 | cpufreq_cpu_data[j] = policy; | |
862 | per_cpu(policy_cpu, j) = policy->cpu; | |
863 | } | |
864 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
865 | ||
866 | /* symlink affected CPUs */ | |
867 | for_each_cpu_mask(j, policy->cpus) { | |
868 | if (j == cpu) | |
869 | continue; | |
870 | if (!cpu_online(j)) | |
871 | continue; | |
872 | ||
873 | dprintk("CPU %u already managed, adding link\n", j); | |
874 | cpufreq_cpu_get(cpu); | |
875 | cpu_sys_dev = get_cpu_sysdev(j); | |
876 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
877 | "cpufreq"); | |
878 | if (ret) { | |
879 | unlock_policy_rwsem_write(cpu); | |
880 | goto err_out_unregister; | |
881 | } | |
882 | } | |
883 | ||
884 | policy->governor = NULL; /* to assure that the starting sequence is | |
885 | * run in cpufreq_set_policy */ | |
886 | ||
887 | /* set default policy */ | |
888 | ret = __cpufreq_set_policy(policy, &new_policy); | |
889 | policy->user_policy.policy = policy->policy; | |
890 | policy->user_policy.governor = policy->governor; | |
891 | ||
892 | unlock_policy_rwsem_write(cpu); | |
893 | ||
894 | if (ret) { | |
895 | dprintk("setting policy failed\n"); | |
896 | goto err_out_unregister; | |
897 | } | |
898 | ||
899 | module_put(cpufreq_driver->owner); | |
900 | dprintk("initialization complete\n"); | |
901 | cpufreq_debug_enable_ratelimit(); | |
902 | ||
903 | return 0; | |
904 | ||
905 | ||
906 | err_out_unregister: | |
907 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
908 | for_each_cpu_mask(j, policy->cpus) | |
909 | cpufreq_cpu_data[j] = NULL; | |
910 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
911 | ||
912 | kobject_unregister(&policy->kobj); | |
913 | wait_for_completion(&policy->kobj_unregister); | |
914 | ||
915 | err_out_driver_exit: | |
916 | if (cpufreq_driver->exit) | |
917 | cpufreq_driver->exit(policy); | |
918 | ||
919 | err_out: | |
920 | kfree(policy); | |
921 | ||
922 | nomem_out: | |
923 | module_put(cpufreq_driver->owner); | |
924 | module_out: | |
925 | cpufreq_debug_enable_ratelimit(); | |
926 | return ret; | |
927 | } | |
928 | ||
929 | ||
930 | /** | |
931 | * __cpufreq_remove_dev - remove a CPU device | |
932 | * | |
933 | * Removes the cpufreq interface for a CPU device. | |
934 | * Caller should already have policy_rwsem in write mode for this CPU. | |
935 | * This routine frees the rwsem before returning. | |
936 | */ | |
937 | static int __cpufreq_remove_dev (struct sys_device * sys_dev) | |
938 | { | |
939 | unsigned int cpu = sys_dev->id; | |
940 | unsigned long flags; | |
941 | struct cpufreq_policy *data; | |
942 | #ifdef CONFIG_SMP | |
943 | struct sys_device *cpu_sys_dev; | |
944 | unsigned int j; | |
945 | #endif | |
946 | ||
947 | cpufreq_debug_disable_ratelimit(); | |
948 | dprintk("unregistering CPU %u\n", cpu); | |
949 | ||
950 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
951 | data = cpufreq_cpu_data[cpu]; | |
952 | ||
953 | if (!data) { | |
954 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
955 | cpufreq_debug_enable_ratelimit(); | |
956 | unlock_policy_rwsem_write(cpu); | |
957 | return -EINVAL; | |
958 | } | |
959 | cpufreq_cpu_data[cpu] = NULL; | |
960 | ||
961 | ||
962 | #ifdef CONFIG_SMP | |
963 | /* if this isn't the CPU which is the parent of the kobj, we | |
964 | * only need to unlink, put and exit | |
965 | */ | |
966 | if (unlikely(cpu != data->cpu)) { | |
967 | dprintk("removing link\n"); | |
968 | cpu_clear(cpu, data->cpus); | |
969 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
970 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
971 | cpufreq_cpu_put(data); | |
972 | cpufreq_debug_enable_ratelimit(); | |
973 | unlock_policy_rwsem_write(cpu); | |
974 | return 0; | |
975 | } | |
976 | #endif | |
977 | ||
978 | ||
979 | if (!kobject_get(&data->kobj)) { | |
980 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
981 | cpufreq_debug_enable_ratelimit(); | |
982 | unlock_policy_rwsem_write(cpu); | |
983 | return -EFAULT; | |
984 | } | |
985 | ||
986 | #ifdef CONFIG_SMP | |
987 | ||
988 | #ifdef CONFIG_HOTPLUG_CPU | |
989 | cpufreq_cpu_governor[cpu] = data->governor; | |
990 | #endif | |
991 | ||
992 | /* if we have other CPUs still registered, we need to unlink them, | |
993 | * or else wait_for_completion below will lock up. Clean the | |
994 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
995 | * links afterwards. | |
996 | */ | |
997 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
998 | for_each_cpu_mask(j, data->cpus) { | |
999 | if (j == cpu) | |
1000 | continue; | |
1001 | cpufreq_cpu_data[j] = NULL; | |
1002 | } | |
1003 | } | |
1004 | ||
1005 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1006 | ||
1007 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1008 | for_each_cpu_mask(j, data->cpus) { | |
1009 | if (j == cpu) | |
1010 | continue; | |
1011 | dprintk("removing link for cpu %u\n", j); | |
1012 | #ifdef CONFIG_HOTPLUG_CPU | |
1013 | cpufreq_cpu_governor[j] = data->governor; | |
1014 | #endif | |
1015 | cpu_sys_dev = get_cpu_sysdev(j); | |
1016 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1017 | cpufreq_cpu_put(data); | |
1018 | } | |
1019 | } | |
1020 | #else | |
1021 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1022 | #endif | |
1023 | ||
1024 | if (cpufreq_driver->target) | |
1025 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1026 | ||
1027 | unlock_policy_rwsem_write(cpu); | |
1028 | ||
1029 | kobject_unregister(&data->kobj); | |
1030 | ||
1031 | kobject_put(&data->kobj); | |
1032 | ||
1033 | /* we need to make sure that the underlying kobj is actually | |
1034 | * not referenced anymore by anybody before we proceed with | |
1035 | * unloading. | |
1036 | */ | |
1037 | dprintk("waiting for dropping of refcount\n"); | |
1038 | wait_for_completion(&data->kobj_unregister); | |
1039 | dprintk("wait complete\n"); | |
1040 | ||
1041 | if (cpufreq_driver->exit) | |
1042 | cpufreq_driver->exit(data); | |
1043 | ||
1044 | kfree(data); | |
1045 | ||
1046 | cpufreq_debug_enable_ratelimit(); | |
1047 | return 0; | |
1048 | } | |
1049 | ||
1050 | ||
1051 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
1052 | { | |
1053 | unsigned int cpu = sys_dev->id; | |
1054 | int retval; | |
1055 | ||
1056 | if (cpu_is_offline(cpu)) | |
1057 | return 0; | |
1058 | ||
1059 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1060 | BUG(); | |
1061 | ||
1062 | retval = __cpufreq_remove_dev(sys_dev); | |
1063 | return retval; | |
1064 | } | |
1065 | ||
1066 | ||
1067 | static void handle_update(struct work_struct *work) | |
1068 | { | |
1069 | struct cpufreq_policy *policy = | |
1070 | container_of(work, struct cpufreq_policy, update); | |
1071 | unsigned int cpu = policy->cpu; | |
1072 | dprintk("handle_update for cpu %u called\n", cpu); | |
1073 | cpufreq_update_policy(cpu); | |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1078 | * @cpu: cpu number | |
1079 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1080 | * @new_freq: CPU frequency the CPU actually runs at | |
1081 | * | |
1082 | * We adjust to current frequency first, and need to clean up later. So either call | |
1083 | * to cpufreq_update_policy() or schedule handle_update()). | |
1084 | */ | |
1085 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, | |
1086 | unsigned int new_freq) | |
1087 | { | |
1088 | struct cpufreq_freqs freqs; | |
1089 | ||
1090 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " | |
1091 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); | |
1092 | ||
1093 | freqs.cpu = cpu; | |
1094 | freqs.old = old_freq; | |
1095 | freqs.new = new_freq; | |
1096 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1097 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1098 | } | |
1099 | ||
1100 | ||
1101 | /** | |
1102 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur | |
1103 | * @cpu: CPU number | |
1104 | * | |
1105 | * This is the last known freq, without actually getting it from the driver. | |
1106 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1107 | */ | |
1108 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1109 | { | |
1110 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1111 | unsigned int ret_freq = 0; | |
1112 | ||
1113 | if (policy) { | |
1114 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1115 | return ret_freq; | |
1116 | ||
1117 | ret_freq = policy->cur; | |
1118 | ||
1119 | unlock_policy_rwsem_read(cpu); | |
1120 | cpufreq_cpu_put(policy); | |
1121 | } | |
1122 | ||
1123 | return (ret_freq); | |
1124 | } | |
1125 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1126 | ||
1127 | ||
1128 | static unsigned int __cpufreq_get(unsigned int cpu) | |
1129 | { | |
1130 | struct cpufreq_policy *policy = cpufreq_cpu_data[cpu]; | |
1131 | unsigned int ret_freq = 0; | |
1132 | ||
1133 | if (!cpufreq_driver->get) | |
1134 | return (ret_freq); | |
1135 | ||
1136 | ret_freq = cpufreq_driver->get(cpu); | |
1137 | ||
1138 | if (ret_freq && policy->cur && | |
1139 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1140 | /* verify no discrepancy between actual and | |
1141 | saved value exists */ | |
1142 | if (unlikely(ret_freq != policy->cur)) { | |
1143 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1144 | schedule_work(&policy->update); | |
1145 | } | |
1146 | } | |
1147 | ||
1148 | return (ret_freq); | |
1149 | } | |
1150 | ||
1151 | /** | |
1152 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1153 | * @cpu: CPU number | |
1154 | * | |
1155 | * Get the CPU current (static) CPU frequency | |
1156 | */ | |
1157 | unsigned int cpufreq_get(unsigned int cpu) | |
1158 | { | |
1159 | unsigned int ret_freq = 0; | |
1160 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1161 | ||
1162 | if (!policy) | |
1163 | goto out; | |
1164 | ||
1165 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1166 | goto out_policy; | |
1167 | ||
1168 | ret_freq = __cpufreq_get(cpu); | |
1169 | ||
1170 | unlock_policy_rwsem_read(cpu); | |
1171 | ||
1172 | out_policy: | |
1173 | cpufreq_cpu_put(policy); | |
1174 | out: | |
1175 | return (ret_freq); | |
1176 | } | |
1177 | EXPORT_SYMBOL(cpufreq_get); | |
1178 | ||
1179 | ||
1180 | /** | |
1181 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1182 | */ | |
1183 | ||
1184 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) | |
1185 | { | |
1186 | int cpu = sysdev->id; | |
1187 | int ret = 0; | |
1188 | unsigned int cur_freq = 0; | |
1189 | struct cpufreq_policy *cpu_policy; | |
1190 | ||
1191 | dprintk("suspending cpu %u\n", cpu); | |
1192 | ||
1193 | if (!cpu_online(cpu)) | |
1194 | return 0; | |
1195 | ||
1196 | /* we may be lax here as interrupts are off. Nonetheless | |
1197 | * we need to grab the correct cpu policy, as to check | |
1198 | * whether we really run on this CPU. | |
1199 | */ | |
1200 | ||
1201 | cpu_policy = cpufreq_cpu_get(cpu); | |
1202 | if (!cpu_policy) | |
1203 | return -EINVAL; | |
1204 | ||
1205 | /* only handle each CPU group once */ | |
1206 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1207 | cpufreq_cpu_put(cpu_policy); | |
1208 | return 0; | |
1209 | } | |
1210 | ||
1211 | if (cpufreq_driver->suspend) { | |
1212 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); | |
1213 | if (ret) { | |
1214 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1215 | "step on CPU %u\n", cpu_policy->cpu); | |
1216 | cpufreq_cpu_put(cpu_policy); | |
1217 | return ret; | |
1218 | } | |
1219 | } | |
1220 | ||
1221 | ||
1222 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1223 | goto out; | |
1224 | ||
1225 | if (cpufreq_driver->get) | |
1226 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1227 | ||
1228 | if (!cur_freq || !cpu_policy->cur) { | |
1229 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1230 | "frequency is what timing core thinks it is.\n"); | |
1231 | goto out; | |
1232 | } | |
1233 | ||
1234 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1235 | struct cpufreq_freqs freqs; | |
1236 | ||
1237 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
1238 | dprintk("Warning: CPU frequency is %u, " | |
1239 | "cpufreq assumed %u kHz.\n", | |
1240 | cur_freq, cpu_policy->cur); | |
1241 | ||
1242 | freqs.cpu = cpu; | |
1243 | freqs.old = cpu_policy->cur; | |
1244 | freqs.new = cur_freq; | |
1245 | ||
1246 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
1247 | CPUFREQ_SUSPENDCHANGE, &freqs); | |
1248 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1249 | ||
1250 | cpu_policy->cur = cur_freq; | |
1251 | } | |
1252 | ||
1253 | out: | |
1254 | cpufreq_cpu_put(cpu_policy); | |
1255 | return 0; | |
1256 | } | |
1257 | ||
1258 | /** | |
1259 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1260 | * | |
1261 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1262 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
1263 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are | |
1264 | * restored. | |
1265 | */ | |
1266 | static int cpufreq_resume(struct sys_device * sysdev) | |
1267 | { | |
1268 | int cpu = sysdev->id; | |
1269 | int ret = 0; | |
1270 | struct cpufreq_policy *cpu_policy; | |
1271 | ||
1272 | dprintk("resuming cpu %u\n", cpu); | |
1273 | ||
1274 | if (!cpu_online(cpu)) | |
1275 | return 0; | |
1276 | ||
1277 | /* we may be lax here as interrupts are off. Nonetheless | |
1278 | * we need to grab the correct cpu policy, as to check | |
1279 | * whether we really run on this CPU. | |
1280 | */ | |
1281 | ||
1282 | cpu_policy = cpufreq_cpu_get(cpu); | |
1283 | if (!cpu_policy) | |
1284 | return -EINVAL; | |
1285 | ||
1286 | /* only handle each CPU group once */ | |
1287 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1288 | cpufreq_cpu_put(cpu_policy); | |
1289 | return 0; | |
1290 | } | |
1291 | ||
1292 | if (cpufreq_driver->resume) { | |
1293 | ret = cpufreq_driver->resume(cpu_policy); | |
1294 | if (ret) { | |
1295 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1296 | "step on CPU %u\n", cpu_policy->cpu); | |
1297 | cpufreq_cpu_put(cpu_policy); | |
1298 | return ret; | |
1299 | } | |
1300 | } | |
1301 | ||
1302 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1303 | unsigned int cur_freq = 0; | |
1304 | ||
1305 | if (cpufreq_driver->get) | |
1306 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1307 | ||
1308 | if (!cur_freq || !cpu_policy->cur) { | |
1309 | printk(KERN_ERR "cpufreq: resume failed to assert " | |
1310 | "current frequency is what timing core " | |
1311 | "thinks it is.\n"); | |
1312 | goto out; | |
1313 | } | |
1314 | ||
1315 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1316 | struct cpufreq_freqs freqs; | |
1317 | ||
1318 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
1319 | dprintk("Warning: CPU frequency" | |
1320 | "is %u, cpufreq assumed %u kHz.\n", | |
1321 | cur_freq, cpu_policy->cur); | |
1322 | ||
1323 | freqs.cpu = cpu; | |
1324 | freqs.old = cpu_policy->cur; | |
1325 | freqs.new = cur_freq; | |
1326 | ||
1327 | srcu_notifier_call_chain( | |
1328 | &cpufreq_transition_notifier_list, | |
1329 | CPUFREQ_RESUMECHANGE, &freqs); | |
1330 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); | |
1331 | ||
1332 | cpu_policy->cur = cur_freq; | |
1333 | } | |
1334 | } | |
1335 | ||
1336 | out: | |
1337 | schedule_work(&cpu_policy->update); | |
1338 | cpufreq_cpu_put(cpu_policy); | |
1339 | return ret; | |
1340 | } | |
1341 | ||
1342 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1343 | .add = cpufreq_add_dev, | |
1344 | .remove = cpufreq_remove_dev, | |
1345 | .suspend = cpufreq_suspend, | |
1346 | .resume = cpufreq_resume, | |
1347 | }; | |
1348 | ||
1349 | ||
1350 | /********************************************************************* | |
1351 | * NOTIFIER LISTS INTERFACE * | |
1352 | *********************************************************************/ | |
1353 | ||
1354 | /** | |
1355 | * cpufreq_register_notifier - register a driver with cpufreq | |
1356 | * @nb: notifier function to register | |
1357 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1358 | * | |
1359 | * Add a driver to one of two lists: either a list of drivers that | |
1360 | * are notified about clock rate changes (once before and once after | |
1361 | * the transition), or a list of drivers that are notified about | |
1362 | * changes in cpufreq policy. | |
1363 | * | |
1364 | * This function may sleep, and has the same return conditions as | |
1365 | * blocking_notifier_chain_register. | |
1366 | */ | |
1367 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1368 | { | |
1369 | int ret; | |
1370 | ||
1371 | switch (list) { | |
1372 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1373 | ret = srcu_notifier_chain_register( | |
1374 | &cpufreq_transition_notifier_list, nb); | |
1375 | break; | |
1376 | case CPUFREQ_POLICY_NOTIFIER: | |
1377 | ret = blocking_notifier_chain_register( | |
1378 | &cpufreq_policy_notifier_list, nb); | |
1379 | break; | |
1380 | default: | |
1381 | ret = -EINVAL; | |
1382 | } | |
1383 | ||
1384 | return ret; | |
1385 | } | |
1386 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1387 | ||
1388 | ||
1389 | /** | |
1390 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1391 | * @nb: notifier block to be unregistered | |
1392 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1393 | * | |
1394 | * Remove a driver from the CPU frequency notifier list. | |
1395 | * | |
1396 | * This function may sleep, and has the same return conditions as | |
1397 | * blocking_notifier_chain_unregister. | |
1398 | */ | |
1399 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1400 | { | |
1401 | int ret; | |
1402 | ||
1403 | switch (list) { | |
1404 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1405 | ret = srcu_notifier_chain_unregister( | |
1406 | &cpufreq_transition_notifier_list, nb); | |
1407 | break; | |
1408 | case CPUFREQ_POLICY_NOTIFIER: | |
1409 | ret = blocking_notifier_chain_unregister( | |
1410 | &cpufreq_policy_notifier_list, nb); | |
1411 | break; | |
1412 | default: | |
1413 | ret = -EINVAL; | |
1414 | } | |
1415 | ||
1416 | return ret; | |
1417 | } | |
1418 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1419 | ||
1420 | ||
1421 | /********************************************************************* | |
1422 | * GOVERNORS * | |
1423 | *********************************************************************/ | |
1424 | ||
1425 | ||
1426 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1427 | unsigned int target_freq, | |
1428 | unsigned int relation) | |
1429 | { | |
1430 | int retval = -EINVAL; | |
1431 | ||
1432 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, | |
1433 | target_freq, relation); | |
1434 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1435 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
1436 | ||
1437 | return retval; | |
1438 | } | |
1439 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1440 | ||
1441 | int cpufreq_driver_target(struct cpufreq_policy *policy, | |
1442 | unsigned int target_freq, | |
1443 | unsigned int relation) | |
1444 | { | |
1445 | int ret; | |
1446 | ||
1447 | policy = cpufreq_cpu_get(policy->cpu); | |
1448 | if (!policy) | |
1449 | return -EINVAL; | |
1450 | ||
1451 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) | |
1452 | return -EINVAL; | |
1453 | ||
1454 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1455 | ||
1456 | unlock_policy_rwsem_write(policy->cpu); | |
1457 | ||
1458 | cpufreq_cpu_put(policy); | |
1459 | return ret; | |
1460 | } | |
1461 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1462 | ||
1463 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) | |
1464 | { | |
1465 | int ret = 0; | |
1466 | ||
1467 | policy = cpufreq_cpu_get(policy->cpu); | |
1468 | if (!policy) | |
1469 | return -EINVAL; | |
1470 | ||
1471 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) | |
1472 | ret = cpufreq_driver->getavg(policy->cpu); | |
1473 | ||
1474 | cpufreq_cpu_put(policy); | |
1475 | return ret; | |
1476 | } | |
1477 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); | |
1478 | ||
1479 | /* | |
1480 | * when "event" is CPUFREQ_GOV_LIMITS | |
1481 | */ | |
1482 | ||
1483 | static int __cpufreq_governor(struct cpufreq_policy *policy, | |
1484 | unsigned int event) | |
1485 | { | |
1486 | int ret; | |
1487 | ||
1488 | /* Only must be defined when default governor is known to have latency | |
1489 | restrictions, like e.g. conservative or ondemand. | |
1490 | That this is the case is already ensured in Kconfig | |
1491 | */ | |
1492 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1493 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1494 | #else | |
1495 | struct cpufreq_governor *gov = NULL; | |
1496 | #endif | |
1497 | ||
1498 | if (policy->governor->max_transition_latency && | |
1499 | policy->cpuinfo.transition_latency > | |
1500 | policy->governor->max_transition_latency) { | |
1501 | if (!gov) | |
1502 | return -EINVAL; | |
1503 | else { | |
1504 | printk(KERN_WARNING "%s governor failed, too long" | |
1505 | " transition latency of HW, fallback" | |
1506 | " to %s governor\n", | |
1507 | policy->governor->name, | |
1508 | gov->name); | |
1509 | policy->governor = gov; | |
1510 | } | |
1511 | } | |
1512 | ||
1513 | if (!try_module_get(policy->governor->owner)) | |
1514 | return -EINVAL; | |
1515 | ||
1516 | dprintk("__cpufreq_governor for CPU %u, event %u\n", | |
1517 | policy->cpu, event); | |
1518 | ret = policy->governor->governor(policy, event); | |
1519 | ||
1520 | /* we keep one module reference alive for | |
1521 | each CPU governed by this CPU */ | |
1522 | if ((event != CPUFREQ_GOV_START) || ret) | |
1523 | module_put(policy->governor->owner); | |
1524 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1525 | module_put(policy->governor->owner); | |
1526 | ||
1527 | return ret; | |
1528 | } | |
1529 | ||
1530 | ||
1531 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1532 | { | |
1533 | int err; | |
1534 | ||
1535 | if (!governor) | |
1536 | return -EINVAL; | |
1537 | ||
1538 | mutex_lock(&cpufreq_governor_mutex); | |
1539 | ||
1540 | err = -EBUSY; | |
1541 | if (__find_governor(governor->name) == NULL) { | |
1542 | err = 0; | |
1543 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1544 | } | |
1545 | ||
1546 | mutex_unlock(&cpufreq_governor_mutex); | |
1547 | return err; | |
1548 | } | |
1549 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1550 | ||
1551 | ||
1552 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1553 | { | |
1554 | if (!governor) | |
1555 | return; | |
1556 | ||
1557 | mutex_lock(&cpufreq_governor_mutex); | |
1558 | list_del(&governor->governor_list); | |
1559 | mutex_unlock(&cpufreq_governor_mutex); | |
1560 | return; | |
1561 | } | |
1562 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1563 | ||
1564 | ||
1565 | ||
1566 | /********************************************************************* | |
1567 | * POLICY INTERFACE * | |
1568 | *********************************************************************/ | |
1569 | ||
1570 | /** | |
1571 | * cpufreq_get_policy - get the current cpufreq_policy | |
1572 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1573 | * | |
1574 | * Reads the current cpufreq policy. | |
1575 | */ | |
1576 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1577 | { | |
1578 | struct cpufreq_policy *cpu_policy; | |
1579 | if (!policy) | |
1580 | return -EINVAL; | |
1581 | ||
1582 | cpu_policy = cpufreq_cpu_get(cpu); | |
1583 | if (!cpu_policy) | |
1584 | return -EINVAL; | |
1585 | ||
1586 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); | |
1587 | ||
1588 | cpufreq_cpu_put(cpu_policy); | |
1589 | return 0; | |
1590 | } | |
1591 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1592 | ||
1593 | ||
1594 | /* | |
1595 | * data : current policy. | |
1596 | * policy : policy to be set. | |
1597 | */ | |
1598 | static int __cpufreq_set_policy(struct cpufreq_policy *data, | |
1599 | struct cpufreq_policy *policy) | |
1600 | { | |
1601 | int ret = 0; | |
1602 | ||
1603 | cpufreq_debug_disable_ratelimit(); | |
1604 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1605 | policy->min, policy->max); | |
1606 | ||
1607 | memcpy(&policy->cpuinfo, &data->cpuinfo, | |
1608 | sizeof(struct cpufreq_cpuinfo)); | |
1609 | ||
1610 | if (policy->min > data->min && policy->min > policy->max) { | |
1611 | ret = -EINVAL; | |
1612 | goto error_out; | |
1613 | } | |
1614 | ||
1615 | /* verify the cpu speed can be set within this limit */ | |
1616 | ret = cpufreq_driver->verify(policy); | |
1617 | if (ret) | |
1618 | goto error_out; | |
1619 | ||
1620 | /* adjust if necessary - all reasons */ | |
1621 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1622 | CPUFREQ_ADJUST, policy); | |
1623 | ||
1624 | /* adjust if necessary - hardware incompatibility*/ | |
1625 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1626 | CPUFREQ_INCOMPATIBLE, policy); | |
1627 | ||
1628 | /* verify the cpu speed can be set within this limit, | |
1629 | which might be different to the first one */ | |
1630 | ret = cpufreq_driver->verify(policy); | |
1631 | if (ret) | |
1632 | goto error_out; | |
1633 | ||
1634 | /* notification of the new policy */ | |
1635 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1636 | CPUFREQ_NOTIFY, policy); | |
1637 | ||
1638 | data->min = policy->min; | |
1639 | data->max = policy->max; | |
1640 | ||
1641 | dprintk("new min and max freqs are %u - %u kHz\n", | |
1642 | data->min, data->max); | |
1643 | ||
1644 | if (cpufreq_driver->setpolicy) { | |
1645 | data->policy = policy->policy; | |
1646 | dprintk("setting range\n"); | |
1647 | ret = cpufreq_driver->setpolicy(policy); | |
1648 | } else { | |
1649 | if (policy->governor != data->governor) { | |
1650 | /* save old, working values */ | |
1651 | struct cpufreq_governor *old_gov = data->governor; | |
1652 | ||
1653 | dprintk("governor switch\n"); | |
1654 | ||
1655 | /* end old governor */ | |
1656 | if (data->governor) | |
1657 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1658 | ||
1659 | /* start new governor */ | |
1660 | data->governor = policy->governor; | |
1661 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1662 | /* new governor failed, so re-start old one */ | |
1663 | dprintk("starting governor %s failed\n", | |
1664 | data->governor->name); | |
1665 | if (old_gov) { | |
1666 | data->governor = old_gov; | |
1667 | __cpufreq_governor(data, | |
1668 | CPUFREQ_GOV_START); | |
1669 | } | |
1670 | ret = -EINVAL; | |
1671 | goto error_out; | |
1672 | } | |
1673 | /* might be a policy change, too, so fall through */ | |
1674 | } | |
1675 | dprintk("governor: change or update limits\n"); | |
1676 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1677 | } | |
1678 | ||
1679 | error_out: | |
1680 | cpufreq_debug_enable_ratelimit(); | |
1681 | return ret; | |
1682 | } | |
1683 | ||
1684 | /** | |
1685 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1686 | * @cpu: CPU which shall be re-evaluated | |
1687 | * | |
1688 | * Usefull for policy notifiers which have different necessities | |
1689 | * at different times. | |
1690 | */ | |
1691 | int cpufreq_update_policy(unsigned int cpu) | |
1692 | { | |
1693 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1694 | struct cpufreq_policy policy; | |
1695 | int ret = 0; | |
1696 | ||
1697 | if (!data) | |
1698 | return -ENODEV; | |
1699 | ||
1700 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1701 | return -EINVAL; | |
1702 | ||
1703 | dprintk("updating policy for CPU %u\n", cpu); | |
1704 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); | |
1705 | policy.min = data->user_policy.min; | |
1706 | policy.max = data->user_policy.max; | |
1707 | policy.policy = data->user_policy.policy; | |
1708 | policy.governor = data->user_policy.governor; | |
1709 | ||
1710 | /* BIOS might change freq behind our back | |
1711 | -> ask driver for current freq and notify governors about a change */ | |
1712 | if (cpufreq_driver->get) { | |
1713 | policy.cur = cpufreq_driver->get(cpu); | |
1714 | if (!data->cur) { | |
1715 | dprintk("Driver did not initialize current freq"); | |
1716 | data->cur = policy.cur; | |
1717 | } else { | |
1718 | if (data->cur != policy.cur) | |
1719 | cpufreq_out_of_sync(cpu, data->cur, | |
1720 | policy.cur); | |
1721 | } | |
1722 | } | |
1723 | ||
1724 | ret = __cpufreq_set_policy(data, &policy); | |
1725 | ||
1726 | unlock_policy_rwsem_write(cpu); | |
1727 | ||
1728 | cpufreq_cpu_put(data); | |
1729 | return ret; | |
1730 | } | |
1731 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1732 | ||
1733 | static int cpufreq_cpu_callback(struct notifier_block *nfb, | |
1734 | unsigned long action, void *hcpu) | |
1735 | { | |
1736 | unsigned int cpu = (unsigned long)hcpu; | |
1737 | struct sys_device *sys_dev; | |
1738 | ||
1739 | sys_dev = get_cpu_sysdev(cpu); | |
1740 | if (sys_dev) { | |
1741 | switch (action) { | |
1742 | case CPU_ONLINE: | |
1743 | case CPU_ONLINE_FROZEN: | |
1744 | cpufreq_add_dev(sys_dev); | |
1745 | break; | |
1746 | case CPU_DOWN_PREPARE: | |
1747 | case CPU_DOWN_PREPARE_FROZEN: | |
1748 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1749 | BUG(); | |
1750 | ||
1751 | __cpufreq_remove_dev(sys_dev); | |
1752 | break; | |
1753 | case CPU_DOWN_FAILED: | |
1754 | case CPU_DOWN_FAILED_FROZEN: | |
1755 | cpufreq_add_dev(sys_dev); | |
1756 | break; | |
1757 | } | |
1758 | } | |
1759 | return NOTIFY_OK; | |
1760 | } | |
1761 | ||
1762 | static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = | |
1763 | { | |
1764 | .notifier_call = cpufreq_cpu_callback, | |
1765 | }; | |
1766 | ||
1767 | /********************************************************************* | |
1768 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1769 | *********************************************************************/ | |
1770 | ||
1771 | /** | |
1772 | * cpufreq_register_driver - register a CPU Frequency driver | |
1773 | * @driver_data: A struct cpufreq_driver containing the values# | |
1774 | * submitted by the CPU Frequency driver. | |
1775 | * | |
1776 | * Registers a CPU Frequency driver to this core code. This code | |
1777 | * returns zero on success, -EBUSY when another driver got here first | |
1778 | * (and isn't unregistered in the meantime). | |
1779 | * | |
1780 | */ | |
1781 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1782 | { | |
1783 | unsigned long flags; | |
1784 | int ret; | |
1785 | ||
1786 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1787 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1788 | return -EINVAL; | |
1789 | ||
1790 | dprintk("trying to register driver %s\n", driver_data->name); | |
1791 | ||
1792 | if (driver_data->setpolicy) | |
1793 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1794 | ||
1795 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1796 | if (cpufreq_driver) { | |
1797 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1798 | return -EBUSY; | |
1799 | } | |
1800 | cpufreq_driver = driver_data; | |
1801 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1802 | ||
1803 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1804 | ||
1805 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1806 | int i; | |
1807 | ret = -ENODEV; | |
1808 | ||
1809 | /* check for at least one working CPU */ | |
1810 | for (i=0; i<NR_CPUS; i++) | |
1811 | if (cpufreq_cpu_data[i]) | |
1812 | ret = 0; | |
1813 | ||
1814 | /* if all ->init() calls failed, unregister */ | |
1815 | if (ret) { | |
1816 | dprintk("no CPU initialized for driver %s\n", | |
1817 | driver_data->name); | |
1818 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1819 | &cpufreq_sysdev_driver); | |
1820 | ||
1821 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1822 | cpufreq_driver = NULL; | |
1823 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1824 | } | |
1825 | } | |
1826 | ||
1827 | if (!ret) { | |
1828 | register_hotcpu_notifier(&cpufreq_cpu_notifier); | |
1829 | dprintk("driver %s up and running\n", driver_data->name); | |
1830 | cpufreq_debug_enable_ratelimit(); | |
1831 | } | |
1832 | ||
1833 | return (ret); | |
1834 | } | |
1835 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1836 | ||
1837 | ||
1838 | /** | |
1839 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1840 | * | |
1841 | * Unregister the current CPUFreq driver. Only call this if you have | |
1842 | * the right to do so, i.e. if you have succeeded in initialising before! | |
1843 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1844 | * currently not initialised. | |
1845 | */ | |
1846 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1847 | { | |
1848 | unsigned long flags; | |
1849 | ||
1850 | cpufreq_debug_disable_ratelimit(); | |
1851 | ||
1852 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1853 | cpufreq_debug_enable_ratelimit(); | |
1854 | return -EINVAL; | |
1855 | } | |
1856 | ||
1857 | dprintk("unregistering driver %s\n", driver->name); | |
1858 | ||
1859 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1860 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); | |
1861 | ||
1862 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1863 | cpufreq_driver = NULL; | |
1864 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1865 | ||
1866 | return 0; | |
1867 | } | |
1868 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
1869 | ||
1870 | static int __init cpufreq_core_init(void) | |
1871 | { | |
1872 | int cpu; | |
1873 | ||
1874 | for_each_possible_cpu(cpu) { | |
1875 | per_cpu(policy_cpu, cpu) = -1; | |
1876 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1877 | } | |
1878 | return 0; | |
1879 | } | |
1880 | ||
1881 | core_initcall(cpufreq_core_init); |