]>
Commit | Line | Data |
---|---|---|
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 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, | |
605 | const char *buf, size_t count) | |
606 | { | |
607 | unsigned int freq = 0; | |
608 | unsigned int ret; | |
609 | ||
610 | if (!policy->governor->store_setspeed) | |
611 | return -EINVAL; | |
612 | ||
613 | ret = sscanf(buf, "%u", &freq); | |
614 | if (ret != 1) | |
615 | return -EINVAL; | |
616 | ||
617 | policy->governor->store_setspeed(policy, freq); | |
618 | ||
619 | return count; | |
620 | } | |
621 | ||
622 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
623 | { | |
624 | if (!policy->governor->show_setspeed) | |
625 | return sprintf(buf, "<unsupported>\n"); | |
626 | ||
627 | return policy->governor->show_setspeed(policy, buf); | |
628 | } | |
629 | ||
630 | #define define_one_ro(_name) \ | |
631 | static struct freq_attr _name = \ | |
632 | __ATTR(_name, 0444, show_##_name, NULL) | |
633 | ||
634 | #define define_one_ro0400(_name) \ | |
635 | static struct freq_attr _name = \ | |
636 | __ATTR(_name, 0400, show_##_name, NULL) | |
637 | ||
638 | #define define_one_rw(_name) \ | |
639 | static struct freq_attr _name = \ | |
640 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
641 | ||
642 | define_one_ro0400(cpuinfo_cur_freq); | |
643 | define_one_ro(cpuinfo_min_freq); | |
644 | define_one_ro(cpuinfo_max_freq); | |
645 | define_one_ro(scaling_available_governors); | |
646 | define_one_ro(scaling_driver); | |
647 | define_one_ro(scaling_cur_freq); | |
648 | define_one_ro(affected_cpus); | |
649 | define_one_rw(scaling_min_freq); | |
650 | define_one_rw(scaling_max_freq); | |
651 | define_one_rw(scaling_governor); | |
652 | define_one_rw(scaling_setspeed); | |
653 | ||
654 | static struct attribute * default_attrs[] = { | |
655 | &cpuinfo_min_freq.attr, | |
656 | &cpuinfo_max_freq.attr, | |
657 | &scaling_min_freq.attr, | |
658 | &scaling_max_freq.attr, | |
659 | &affected_cpus.attr, | |
660 | &scaling_governor.attr, | |
661 | &scaling_driver.attr, | |
662 | &scaling_available_governors.attr, | |
663 | &scaling_setspeed.attr, | |
664 | NULL | |
665 | }; | |
666 | ||
667 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
668 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
669 | ||
670 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
671 | { | |
672 | struct cpufreq_policy * policy = to_policy(kobj); | |
673 | struct freq_attr * fattr = to_attr(attr); | |
674 | ssize_t ret = -EINVAL; | |
675 | policy = cpufreq_cpu_get(policy->cpu); | |
676 | if (!policy) | |
677 | goto no_policy; | |
678 | ||
679 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
680 | goto fail; | |
681 | ||
682 | if (fattr->show) | |
683 | ret = fattr->show(policy, buf); | |
684 | else | |
685 | ret = -EIO; | |
686 | ||
687 | unlock_policy_rwsem_read(policy->cpu); | |
688 | fail: | |
689 | cpufreq_cpu_put(policy); | |
690 | no_policy: | |
691 | return ret; | |
692 | } | |
693 | ||
694 | static ssize_t store(struct kobject * kobj, struct attribute * attr, | |
695 | const char * buf, size_t count) | |
696 | { | |
697 | struct cpufreq_policy * policy = to_policy(kobj); | |
698 | struct freq_attr * fattr = to_attr(attr); | |
699 | ssize_t ret = -EINVAL; | |
700 | policy = cpufreq_cpu_get(policy->cpu); | |
701 | if (!policy) | |
702 | goto no_policy; | |
703 | ||
704 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
705 | goto fail; | |
706 | ||
707 | if (fattr->store) | |
708 | ret = fattr->store(policy, buf, count); | |
709 | else | |
710 | ret = -EIO; | |
711 | ||
712 | unlock_policy_rwsem_write(policy->cpu); | |
713 | fail: | |
714 | cpufreq_cpu_put(policy); | |
715 | no_policy: | |
716 | return ret; | |
717 | } | |
718 | ||
719 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
720 | { | |
721 | struct cpufreq_policy * policy = to_policy(kobj); | |
722 | dprintk("last reference is dropped\n"); | |
723 | complete(&policy->kobj_unregister); | |
724 | } | |
725 | ||
726 | static struct sysfs_ops sysfs_ops = { | |
727 | .show = show, | |
728 | .store = store, | |
729 | }; | |
730 | ||
731 | static struct kobj_type ktype_cpufreq = { | |
732 | .sysfs_ops = &sysfs_ops, | |
733 | .default_attrs = default_attrs, | |
734 | .release = cpufreq_sysfs_release, | |
735 | }; | |
736 | ||
737 | ||
738 | /** | |
739 | * cpufreq_add_dev - add a CPU device | |
740 | * | |
741 | * Adds the cpufreq interface for a CPU device. | |
742 | */ | |
743 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
744 | { | |
745 | unsigned int cpu = sys_dev->id; | |
746 | int ret = 0; | |
747 | struct cpufreq_policy new_policy; | |
748 | struct cpufreq_policy *policy; | |
749 | struct freq_attr **drv_attr; | |
750 | struct sys_device *cpu_sys_dev; | |
751 | unsigned long flags; | |
752 | unsigned int j; | |
753 | #ifdef CONFIG_SMP | |
754 | struct cpufreq_policy *managed_policy; | |
755 | #endif | |
756 | ||
757 | if (cpu_is_offline(cpu)) | |
758 | return 0; | |
759 | ||
760 | cpufreq_debug_disable_ratelimit(); | |
761 | dprintk("adding CPU %u\n", cpu); | |
762 | ||
763 | #ifdef CONFIG_SMP | |
764 | /* check whether a different CPU already registered this | |
765 | * CPU because it is in the same boat. */ | |
766 | policy = cpufreq_cpu_get(cpu); | |
767 | if (unlikely(policy)) { | |
768 | cpufreq_cpu_put(policy); | |
769 | cpufreq_debug_enable_ratelimit(); | |
770 | return 0; | |
771 | } | |
772 | #endif | |
773 | ||
774 | if (!try_module_get(cpufreq_driver->owner)) { | |
775 | ret = -EINVAL; | |
776 | goto module_out; | |
777 | } | |
778 | ||
779 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); | |
780 | if (!policy) { | |
781 | ret = -ENOMEM; | |
782 | goto nomem_out; | |
783 | } | |
784 | ||
785 | policy->cpu = cpu; | |
786 | policy->cpus = cpumask_of_cpu(cpu); | |
787 | ||
788 | /* Initially set CPU itself as the policy_cpu */ | |
789 | per_cpu(policy_cpu, cpu) = cpu; | |
790 | lock_policy_rwsem_write(cpu); | |
791 | ||
792 | init_completion(&policy->kobj_unregister); | |
793 | INIT_WORK(&policy->update, handle_update); | |
794 | ||
795 | /* Set governor before ->init, so that driver could check it */ | |
796 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
797 | /* call driver. From then on the cpufreq must be able | |
798 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
799 | */ | |
800 | ret = cpufreq_driver->init(policy); | |
801 | if (ret) { | |
802 | dprintk("initialization failed\n"); | |
803 | unlock_policy_rwsem_write(cpu); | |
804 | goto err_out; | |
805 | } | |
806 | policy->user_policy.min = policy->cpuinfo.min_freq; | |
807 | policy->user_policy.max = policy->cpuinfo.max_freq; | |
808 | ||
809 | #ifdef CONFIG_SMP | |
810 | ||
811 | #ifdef CONFIG_HOTPLUG_CPU | |
812 | if (cpufreq_cpu_governor[cpu]){ | |
813 | policy->governor = cpufreq_cpu_governor[cpu]; | |
814 | dprintk("Restoring governor %s for cpu %d\n", | |
815 | policy->governor->name, cpu); | |
816 | } | |
817 | #endif | |
818 | ||
819 | for_each_cpu_mask(j, policy->cpus) { | |
820 | if (cpu == j) | |
821 | continue; | |
822 | ||
823 | /* check for existing affected CPUs. They may not be aware | |
824 | * of it due to CPU Hotplug. | |
825 | */ | |
826 | managed_policy = cpufreq_cpu_get(j); | |
827 | if (unlikely(managed_policy)) { | |
828 | ||
829 | /* Set proper policy_cpu */ | |
830 | unlock_policy_rwsem_write(cpu); | |
831 | per_cpu(policy_cpu, cpu) = managed_policy->cpu; | |
832 | ||
833 | if (lock_policy_rwsem_write(cpu) < 0) | |
834 | goto err_out_driver_exit; | |
835 | ||
836 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
837 | managed_policy->cpus = policy->cpus; | |
838 | cpufreq_cpu_data[cpu] = managed_policy; | |
839 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
840 | ||
841 | dprintk("CPU already managed, adding link\n"); | |
842 | ret = sysfs_create_link(&sys_dev->kobj, | |
843 | &managed_policy->kobj, | |
844 | "cpufreq"); | |
845 | if (ret) { | |
846 | unlock_policy_rwsem_write(cpu); | |
847 | goto err_out_driver_exit; | |
848 | } | |
849 | ||
850 | cpufreq_debug_enable_ratelimit(); | |
851 | ret = 0; | |
852 | unlock_policy_rwsem_write(cpu); | |
853 | goto err_out_driver_exit; /* call driver->exit() */ | |
854 | } | |
855 | } | |
856 | #endif | |
857 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
858 | ||
859 | /* prepare interface data */ | |
860 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj, | |
861 | "cpufreq"); | |
862 | if (ret) { | |
863 | unlock_policy_rwsem_write(cpu); | |
864 | goto err_out_driver_exit; | |
865 | } | |
866 | /* set up files for this cpu device */ | |
867 | drv_attr = cpufreq_driver->attr; | |
868 | while ((drv_attr) && (*drv_attr)) { | |
869 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
870 | if (ret) { | |
871 | unlock_policy_rwsem_write(cpu); | |
872 | goto err_out_driver_exit; | |
873 | } | |
874 | drv_attr++; | |
875 | } | |
876 | if (cpufreq_driver->get){ | |
877 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
878 | if (ret) { | |
879 | unlock_policy_rwsem_write(cpu); | |
880 | goto err_out_driver_exit; | |
881 | } | |
882 | } | |
883 | if (cpufreq_driver->target){ | |
884 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
885 | if (ret) { | |
886 | unlock_policy_rwsem_write(cpu); | |
887 | goto err_out_driver_exit; | |
888 | } | |
889 | } | |
890 | ||
891 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
892 | for_each_cpu_mask(j, policy->cpus) { | |
893 | cpufreq_cpu_data[j] = policy; | |
894 | per_cpu(policy_cpu, j) = policy->cpu; | |
895 | } | |
896 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
897 | ||
898 | /* symlink affected CPUs */ | |
899 | for_each_cpu_mask(j, policy->cpus) { | |
900 | if (j == cpu) | |
901 | continue; | |
902 | if (!cpu_online(j)) | |
903 | continue; | |
904 | ||
905 | dprintk("CPU %u already managed, adding link\n", j); | |
906 | cpufreq_cpu_get(cpu); | |
907 | cpu_sys_dev = get_cpu_sysdev(j); | |
908 | ret = sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
909 | "cpufreq"); | |
910 | if (ret) { | |
911 | unlock_policy_rwsem_write(cpu); | |
912 | goto err_out_unregister; | |
913 | } | |
914 | } | |
915 | ||
916 | policy->governor = NULL; /* to assure that the starting sequence is | |
917 | * run in cpufreq_set_policy */ | |
918 | ||
919 | /* set default policy */ | |
920 | ret = __cpufreq_set_policy(policy, &new_policy); | |
921 | policy->user_policy.policy = policy->policy; | |
922 | policy->user_policy.governor = policy->governor; | |
923 | ||
924 | unlock_policy_rwsem_write(cpu); | |
925 | ||
926 | if (ret) { | |
927 | dprintk("setting policy failed\n"); | |
928 | goto err_out_unregister; | |
929 | } | |
930 | ||
931 | kobject_uevent(&policy->kobj, KOBJ_ADD); | |
932 | module_put(cpufreq_driver->owner); | |
933 | dprintk("initialization complete\n"); | |
934 | cpufreq_debug_enable_ratelimit(); | |
935 | ||
936 | return 0; | |
937 | ||
938 | ||
939 | err_out_unregister: | |
940 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
941 | for_each_cpu_mask(j, policy->cpus) | |
942 | cpufreq_cpu_data[j] = NULL; | |
943 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
944 | ||
945 | kobject_put(&policy->kobj); | |
946 | wait_for_completion(&policy->kobj_unregister); | |
947 | ||
948 | err_out_driver_exit: | |
949 | if (cpufreq_driver->exit) | |
950 | cpufreq_driver->exit(policy); | |
951 | ||
952 | err_out: | |
953 | kfree(policy); | |
954 | ||
955 | nomem_out: | |
956 | module_put(cpufreq_driver->owner); | |
957 | module_out: | |
958 | cpufreq_debug_enable_ratelimit(); | |
959 | return ret; | |
960 | } | |
961 | ||
962 | ||
963 | /** | |
964 | * __cpufreq_remove_dev - remove a CPU device | |
965 | * | |
966 | * Removes the cpufreq interface for a CPU device. | |
967 | * Caller should already have policy_rwsem in write mode for this CPU. | |
968 | * This routine frees the rwsem before returning. | |
969 | */ | |
970 | static int __cpufreq_remove_dev (struct sys_device * sys_dev) | |
971 | { | |
972 | unsigned int cpu = sys_dev->id; | |
973 | unsigned long flags; | |
974 | struct cpufreq_policy *data; | |
975 | #ifdef CONFIG_SMP | |
976 | struct sys_device *cpu_sys_dev; | |
977 | unsigned int j; | |
978 | #endif | |
979 | ||
980 | cpufreq_debug_disable_ratelimit(); | |
981 | dprintk("unregistering CPU %u\n", cpu); | |
982 | ||
983 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
984 | data = cpufreq_cpu_data[cpu]; | |
985 | ||
986 | if (!data) { | |
987 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
988 | cpufreq_debug_enable_ratelimit(); | |
989 | unlock_policy_rwsem_write(cpu); | |
990 | return -EINVAL; | |
991 | } | |
992 | cpufreq_cpu_data[cpu] = NULL; | |
993 | ||
994 | ||
995 | #ifdef CONFIG_SMP | |
996 | /* if this isn't the CPU which is the parent of the kobj, we | |
997 | * only need to unlink, put and exit | |
998 | */ | |
999 | if (unlikely(cpu != data->cpu)) { | |
1000 | dprintk("removing link\n"); | |
1001 | cpu_clear(cpu, data->cpus); | |
1002 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1003 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1004 | cpufreq_cpu_put(data); | |
1005 | cpufreq_debug_enable_ratelimit(); | |
1006 | unlock_policy_rwsem_write(cpu); | |
1007 | return 0; | |
1008 | } | |
1009 | #endif | |
1010 | ||
1011 | #ifdef CONFIG_SMP | |
1012 | ||
1013 | #ifdef CONFIG_HOTPLUG_CPU | |
1014 | cpufreq_cpu_governor[cpu] = data->governor; | |
1015 | #endif | |
1016 | ||
1017 | /* if we have other CPUs still registered, we need to unlink them, | |
1018 | * or else wait_for_completion below will lock up. Clean the | |
1019 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
1020 | * links afterwards. | |
1021 | */ | |
1022 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1023 | for_each_cpu_mask(j, data->cpus) { | |
1024 | if (j == cpu) | |
1025 | continue; | |
1026 | cpufreq_cpu_data[j] = NULL; | |
1027 | } | |
1028 | } | |
1029 | ||
1030 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1031 | ||
1032 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
1033 | for_each_cpu_mask(j, data->cpus) { | |
1034 | if (j == cpu) | |
1035 | continue; | |
1036 | dprintk("removing link for cpu %u\n", j); | |
1037 | #ifdef CONFIG_HOTPLUG_CPU | |
1038 | cpufreq_cpu_governor[j] = data->governor; | |
1039 | #endif | |
1040 | cpu_sys_dev = get_cpu_sysdev(j); | |
1041 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1042 | cpufreq_cpu_put(data); | |
1043 | } | |
1044 | } | |
1045 | #else | |
1046 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1047 | #endif | |
1048 | ||
1049 | if (cpufreq_driver->target) | |
1050 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1051 | ||
1052 | unlock_policy_rwsem_write(cpu); | |
1053 | ||
1054 | kobject_put(&data->kobj); | |
1055 | ||
1056 | /* we need to make sure that the underlying kobj is actually | |
1057 | * not referenced anymore by anybody before we proceed with | |
1058 | * unloading. | |
1059 | */ | |
1060 | dprintk("waiting for dropping of refcount\n"); | |
1061 | wait_for_completion(&data->kobj_unregister); | |
1062 | dprintk("wait complete\n"); | |
1063 | ||
1064 | if (cpufreq_driver->exit) | |
1065 | cpufreq_driver->exit(data); | |
1066 | ||
1067 | kfree(data); | |
1068 | ||
1069 | cpufreq_debug_enable_ratelimit(); | |
1070 | return 0; | |
1071 | } | |
1072 | ||
1073 | ||
1074 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
1075 | { | |
1076 | unsigned int cpu = sys_dev->id; | |
1077 | int retval; | |
1078 | ||
1079 | if (cpu_is_offline(cpu)) | |
1080 | return 0; | |
1081 | ||
1082 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1083 | BUG(); | |
1084 | ||
1085 | retval = __cpufreq_remove_dev(sys_dev); | |
1086 | return retval; | |
1087 | } | |
1088 | ||
1089 | ||
1090 | static void handle_update(struct work_struct *work) | |
1091 | { | |
1092 | struct cpufreq_policy *policy = | |
1093 | container_of(work, struct cpufreq_policy, update); | |
1094 | unsigned int cpu = policy->cpu; | |
1095 | dprintk("handle_update for cpu %u called\n", cpu); | |
1096 | cpufreq_update_policy(cpu); | |
1097 | } | |
1098 | ||
1099 | /** | |
1100 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1101 | * @cpu: cpu number | |
1102 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1103 | * @new_freq: CPU frequency the CPU actually runs at | |
1104 | * | |
1105 | * We adjust to current frequency first, and need to clean up later. So either call | |
1106 | * to cpufreq_update_policy() or schedule handle_update()). | |
1107 | */ | |
1108 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, | |
1109 | unsigned int new_freq) | |
1110 | { | |
1111 | struct cpufreq_freqs freqs; | |
1112 | ||
1113 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " | |
1114 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); | |
1115 | ||
1116 | freqs.cpu = cpu; | |
1117 | freqs.old = old_freq; | |
1118 | freqs.new = new_freq; | |
1119 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1120 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1121 | } | |
1122 | ||
1123 | ||
1124 | /** | |
1125 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur | |
1126 | * @cpu: CPU number | |
1127 | * | |
1128 | * This is the last known freq, without actually getting it from the driver. | |
1129 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1130 | */ | |
1131 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1132 | { | |
1133 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1134 | unsigned int ret_freq = 0; | |
1135 | ||
1136 | if (policy) { | |
1137 | ret_freq = policy->cur; | |
1138 | cpufreq_cpu_put(policy); | |
1139 | } | |
1140 | ||
1141 | return (ret_freq); | |
1142 | } | |
1143 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1144 | ||
1145 | ||
1146 | static unsigned int __cpufreq_get(unsigned int cpu) | |
1147 | { | |
1148 | struct cpufreq_policy *policy = cpufreq_cpu_data[cpu]; | |
1149 | unsigned int ret_freq = 0; | |
1150 | ||
1151 | if (!cpufreq_driver->get) | |
1152 | return (ret_freq); | |
1153 | ||
1154 | ret_freq = cpufreq_driver->get(cpu); | |
1155 | ||
1156 | if (ret_freq && policy->cur && | |
1157 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1158 | /* verify no discrepancy between actual and | |
1159 | saved value exists */ | |
1160 | if (unlikely(ret_freq != policy->cur)) { | |
1161 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1162 | schedule_work(&policy->update); | |
1163 | } | |
1164 | } | |
1165 | ||
1166 | return (ret_freq); | |
1167 | } | |
1168 | ||
1169 | /** | |
1170 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1171 | * @cpu: CPU number | |
1172 | * | |
1173 | * Get the CPU current (static) CPU frequency | |
1174 | */ | |
1175 | unsigned int cpufreq_get(unsigned int cpu) | |
1176 | { | |
1177 | unsigned int ret_freq = 0; | |
1178 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1179 | ||
1180 | if (!policy) | |
1181 | goto out; | |
1182 | ||
1183 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1184 | goto out_policy; | |
1185 | ||
1186 | ret_freq = __cpufreq_get(cpu); | |
1187 | ||
1188 | unlock_policy_rwsem_read(cpu); | |
1189 | ||
1190 | out_policy: | |
1191 | cpufreq_cpu_put(policy); | |
1192 | out: | |
1193 | return (ret_freq); | |
1194 | } | |
1195 | EXPORT_SYMBOL(cpufreq_get); | |
1196 | ||
1197 | ||
1198 | /** | |
1199 | * cpufreq_suspend - let the low level driver prepare for suspend | |
1200 | */ | |
1201 | ||
1202 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) | |
1203 | { | |
1204 | int cpu = sysdev->id; | |
1205 | int ret = 0; | |
1206 | unsigned int cur_freq = 0; | |
1207 | struct cpufreq_policy *cpu_policy; | |
1208 | ||
1209 | dprintk("suspending cpu %u\n", cpu); | |
1210 | ||
1211 | if (!cpu_online(cpu)) | |
1212 | return 0; | |
1213 | ||
1214 | /* we may be lax here as interrupts are off. Nonetheless | |
1215 | * we need to grab the correct cpu policy, as to check | |
1216 | * whether we really run on this CPU. | |
1217 | */ | |
1218 | ||
1219 | cpu_policy = cpufreq_cpu_get(cpu); | |
1220 | if (!cpu_policy) | |
1221 | return -EINVAL; | |
1222 | ||
1223 | /* only handle each CPU group once */ | |
1224 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1225 | cpufreq_cpu_put(cpu_policy); | |
1226 | return 0; | |
1227 | } | |
1228 | ||
1229 | if (cpufreq_driver->suspend) { | |
1230 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); | |
1231 | if (ret) { | |
1232 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1233 | "step on CPU %u\n", cpu_policy->cpu); | |
1234 | cpufreq_cpu_put(cpu_policy); | |
1235 | return ret; | |
1236 | } | |
1237 | } | |
1238 | ||
1239 | ||
1240 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1241 | goto out; | |
1242 | ||
1243 | if (cpufreq_driver->get) | |
1244 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1245 | ||
1246 | if (!cur_freq || !cpu_policy->cur) { | |
1247 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1248 | "frequency is what timing core thinks it is.\n"); | |
1249 | goto out; | |
1250 | } | |
1251 | ||
1252 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1253 | struct cpufreq_freqs freqs; | |
1254 | ||
1255 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
1256 | dprintk("Warning: CPU frequency is %u, " | |
1257 | "cpufreq assumed %u kHz.\n", | |
1258 | cur_freq, cpu_policy->cur); | |
1259 | ||
1260 | freqs.cpu = cpu; | |
1261 | freqs.old = cpu_policy->cur; | |
1262 | freqs.new = cur_freq; | |
1263 | ||
1264 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
1265 | CPUFREQ_SUSPENDCHANGE, &freqs); | |
1266 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1267 | ||
1268 | cpu_policy->cur = cur_freq; | |
1269 | } | |
1270 | ||
1271 | out: | |
1272 | cpufreq_cpu_put(cpu_policy); | |
1273 | return 0; | |
1274 | } | |
1275 | ||
1276 | /** | |
1277 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1278 | * | |
1279 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1280 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
1281 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are | |
1282 | * restored. | |
1283 | */ | |
1284 | static int cpufreq_resume(struct sys_device * sysdev) | |
1285 | { | |
1286 | int cpu = sysdev->id; | |
1287 | int ret = 0; | |
1288 | struct cpufreq_policy *cpu_policy; | |
1289 | ||
1290 | dprintk("resuming cpu %u\n", cpu); | |
1291 | ||
1292 | if (!cpu_online(cpu)) | |
1293 | return 0; | |
1294 | ||
1295 | /* we may be lax here as interrupts are off. Nonetheless | |
1296 | * we need to grab the correct cpu policy, as to check | |
1297 | * whether we really run on this CPU. | |
1298 | */ | |
1299 | ||
1300 | cpu_policy = cpufreq_cpu_get(cpu); | |
1301 | if (!cpu_policy) | |
1302 | return -EINVAL; | |
1303 | ||
1304 | /* only handle each CPU group once */ | |
1305 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1306 | cpufreq_cpu_put(cpu_policy); | |
1307 | return 0; | |
1308 | } | |
1309 | ||
1310 | if (cpufreq_driver->resume) { | |
1311 | ret = cpufreq_driver->resume(cpu_policy); | |
1312 | if (ret) { | |
1313 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1314 | "step on CPU %u\n", cpu_policy->cpu); | |
1315 | cpufreq_cpu_put(cpu_policy); | |
1316 | return ret; | |
1317 | } | |
1318 | } | |
1319 | ||
1320 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1321 | unsigned int cur_freq = 0; | |
1322 | ||
1323 | if (cpufreq_driver->get) | |
1324 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1325 | ||
1326 | if (!cur_freq || !cpu_policy->cur) { | |
1327 | printk(KERN_ERR "cpufreq: resume failed to assert " | |
1328 | "current frequency is what timing core " | |
1329 | "thinks it is.\n"); | |
1330 | goto out; | |
1331 | } | |
1332 | ||
1333 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1334 | struct cpufreq_freqs freqs; | |
1335 | ||
1336 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
1337 | dprintk("Warning: CPU frequency " | |
1338 | "is %u, cpufreq assumed %u kHz.\n", | |
1339 | cur_freq, cpu_policy->cur); | |
1340 | ||
1341 | freqs.cpu = cpu; | |
1342 | freqs.old = cpu_policy->cur; | |
1343 | freqs.new = cur_freq; | |
1344 | ||
1345 | srcu_notifier_call_chain( | |
1346 | &cpufreq_transition_notifier_list, | |
1347 | CPUFREQ_RESUMECHANGE, &freqs); | |
1348 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); | |
1349 | ||
1350 | cpu_policy->cur = cur_freq; | |
1351 | } | |
1352 | } | |
1353 | ||
1354 | out: | |
1355 | schedule_work(&cpu_policy->update); | |
1356 | cpufreq_cpu_put(cpu_policy); | |
1357 | return ret; | |
1358 | } | |
1359 | ||
1360 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1361 | .add = cpufreq_add_dev, | |
1362 | .remove = cpufreq_remove_dev, | |
1363 | .suspend = cpufreq_suspend, | |
1364 | .resume = cpufreq_resume, | |
1365 | }; | |
1366 | ||
1367 | ||
1368 | /********************************************************************* | |
1369 | * NOTIFIER LISTS INTERFACE * | |
1370 | *********************************************************************/ | |
1371 | ||
1372 | /** | |
1373 | * cpufreq_register_notifier - register a driver with cpufreq | |
1374 | * @nb: notifier function to register | |
1375 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1376 | * | |
1377 | * Add a driver to one of two lists: either a list of drivers that | |
1378 | * are notified about clock rate changes (once before and once after | |
1379 | * the transition), or a list of drivers that are notified about | |
1380 | * changes in cpufreq policy. | |
1381 | * | |
1382 | * This function may sleep, and has the same return conditions as | |
1383 | * blocking_notifier_chain_register. | |
1384 | */ | |
1385 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1386 | { | |
1387 | int ret; | |
1388 | ||
1389 | switch (list) { | |
1390 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1391 | ret = srcu_notifier_chain_register( | |
1392 | &cpufreq_transition_notifier_list, nb); | |
1393 | break; | |
1394 | case CPUFREQ_POLICY_NOTIFIER: | |
1395 | ret = blocking_notifier_chain_register( | |
1396 | &cpufreq_policy_notifier_list, nb); | |
1397 | break; | |
1398 | default: | |
1399 | ret = -EINVAL; | |
1400 | } | |
1401 | ||
1402 | return ret; | |
1403 | } | |
1404 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1405 | ||
1406 | ||
1407 | /** | |
1408 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1409 | * @nb: notifier block to be unregistered | |
1410 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1411 | * | |
1412 | * Remove a driver from the CPU frequency notifier list. | |
1413 | * | |
1414 | * This function may sleep, and has the same return conditions as | |
1415 | * blocking_notifier_chain_unregister. | |
1416 | */ | |
1417 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1418 | { | |
1419 | int ret; | |
1420 | ||
1421 | switch (list) { | |
1422 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1423 | ret = srcu_notifier_chain_unregister( | |
1424 | &cpufreq_transition_notifier_list, nb); | |
1425 | break; | |
1426 | case CPUFREQ_POLICY_NOTIFIER: | |
1427 | ret = blocking_notifier_chain_unregister( | |
1428 | &cpufreq_policy_notifier_list, nb); | |
1429 | break; | |
1430 | default: | |
1431 | ret = -EINVAL; | |
1432 | } | |
1433 | ||
1434 | return ret; | |
1435 | } | |
1436 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1437 | ||
1438 | ||
1439 | /********************************************************************* | |
1440 | * GOVERNORS * | |
1441 | *********************************************************************/ | |
1442 | ||
1443 | ||
1444 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1445 | unsigned int target_freq, | |
1446 | unsigned int relation) | |
1447 | { | |
1448 | int retval = -EINVAL; | |
1449 | ||
1450 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, | |
1451 | target_freq, relation); | |
1452 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1453 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
1454 | ||
1455 | return retval; | |
1456 | } | |
1457 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1458 | ||
1459 | int cpufreq_driver_target(struct cpufreq_policy *policy, | |
1460 | unsigned int target_freq, | |
1461 | unsigned int relation) | |
1462 | { | |
1463 | int ret; | |
1464 | ||
1465 | policy = cpufreq_cpu_get(policy->cpu); | |
1466 | if (!policy) | |
1467 | return -EINVAL; | |
1468 | ||
1469 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) | |
1470 | return -EINVAL; | |
1471 | ||
1472 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1473 | ||
1474 | unlock_policy_rwsem_write(policy->cpu); | |
1475 | ||
1476 | cpufreq_cpu_put(policy); | |
1477 | return ret; | |
1478 | } | |
1479 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1480 | ||
1481 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy) | |
1482 | { | |
1483 | int ret = 0; | |
1484 | ||
1485 | policy = cpufreq_cpu_get(policy->cpu); | |
1486 | if (!policy) | |
1487 | return -EINVAL; | |
1488 | ||
1489 | if (cpu_online(policy->cpu) && cpufreq_driver->getavg) | |
1490 | ret = cpufreq_driver->getavg(policy->cpu); | |
1491 | ||
1492 | cpufreq_cpu_put(policy); | |
1493 | return ret; | |
1494 | } | |
1495 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); | |
1496 | ||
1497 | /* | |
1498 | * when "event" is CPUFREQ_GOV_LIMITS | |
1499 | */ | |
1500 | ||
1501 | static int __cpufreq_governor(struct cpufreq_policy *policy, | |
1502 | unsigned int event) | |
1503 | { | |
1504 | int ret; | |
1505 | ||
1506 | /* Only must be defined when default governor is known to have latency | |
1507 | restrictions, like e.g. conservative or ondemand. | |
1508 | That this is the case is already ensured in Kconfig | |
1509 | */ | |
1510 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1511 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1512 | #else | |
1513 | struct cpufreq_governor *gov = NULL; | |
1514 | #endif | |
1515 | ||
1516 | if (policy->governor->max_transition_latency && | |
1517 | policy->cpuinfo.transition_latency > | |
1518 | policy->governor->max_transition_latency) { | |
1519 | if (!gov) | |
1520 | return -EINVAL; | |
1521 | else { | |
1522 | printk(KERN_WARNING "%s governor failed, too long" | |
1523 | " transition latency of HW, fallback" | |
1524 | " to %s governor\n", | |
1525 | policy->governor->name, | |
1526 | gov->name); | |
1527 | policy->governor = gov; | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | if (!try_module_get(policy->governor->owner)) | |
1532 | return -EINVAL; | |
1533 | ||
1534 | dprintk("__cpufreq_governor for CPU %u, event %u\n", | |
1535 | policy->cpu, event); | |
1536 | ret = policy->governor->governor(policy, event); | |
1537 | ||
1538 | /* we keep one module reference alive for | |
1539 | each CPU governed by this CPU */ | |
1540 | if ((event != CPUFREQ_GOV_START) || ret) | |
1541 | module_put(policy->governor->owner); | |
1542 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1543 | module_put(policy->governor->owner); | |
1544 | ||
1545 | return ret; | |
1546 | } | |
1547 | ||
1548 | ||
1549 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1550 | { | |
1551 | int err; | |
1552 | ||
1553 | if (!governor) | |
1554 | return -EINVAL; | |
1555 | ||
1556 | mutex_lock(&cpufreq_governor_mutex); | |
1557 | ||
1558 | err = -EBUSY; | |
1559 | if (__find_governor(governor->name) == NULL) { | |
1560 | err = 0; | |
1561 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1562 | } | |
1563 | ||
1564 | mutex_unlock(&cpufreq_governor_mutex); | |
1565 | return err; | |
1566 | } | |
1567 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1568 | ||
1569 | ||
1570 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1571 | { | |
1572 | if (!governor) | |
1573 | return; | |
1574 | ||
1575 | mutex_lock(&cpufreq_governor_mutex); | |
1576 | list_del(&governor->governor_list); | |
1577 | mutex_unlock(&cpufreq_governor_mutex); | |
1578 | return; | |
1579 | } | |
1580 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1581 | ||
1582 | ||
1583 | ||
1584 | /********************************************************************* | |
1585 | * POLICY INTERFACE * | |
1586 | *********************************************************************/ | |
1587 | ||
1588 | /** | |
1589 | * cpufreq_get_policy - get the current cpufreq_policy | |
1590 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1591 | * | |
1592 | * Reads the current cpufreq policy. | |
1593 | */ | |
1594 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1595 | { | |
1596 | struct cpufreq_policy *cpu_policy; | |
1597 | if (!policy) | |
1598 | return -EINVAL; | |
1599 | ||
1600 | cpu_policy = cpufreq_cpu_get(cpu); | |
1601 | if (!cpu_policy) | |
1602 | return -EINVAL; | |
1603 | ||
1604 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); | |
1605 | ||
1606 | cpufreq_cpu_put(cpu_policy); | |
1607 | return 0; | |
1608 | } | |
1609 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1610 | ||
1611 | ||
1612 | /* | |
1613 | * data : current policy. | |
1614 | * policy : policy to be set. | |
1615 | */ | |
1616 | static int __cpufreq_set_policy(struct cpufreq_policy *data, | |
1617 | struct cpufreq_policy *policy) | |
1618 | { | |
1619 | int ret = 0; | |
1620 | ||
1621 | cpufreq_debug_disable_ratelimit(); | |
1622 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1623 | policy->min, policy->max); | |
1624 | ||
1625 | memcpy(&policy->cpuinfo, &data->cpuinfo, | |
1626 | sizeof(struct cpufreq_cpuinfo)); | |
1627 | ||
1628 | if (policy->min > data->max || policy->max < data->min) { | |
1629 | ret = -EINVAL; | |
1630 | goto error_out; | |
1631 | } | |
1632 | ||
1633 | /* verify the cpu speed can be set within this limit */ | |
1634 | ret = cpufreq_driver->verify(policy); | |
1635 | if (ret) | |
1636 | goto error_out; | |
1637 | ||
1638 | /* adjust if necessary - all reasons */ | |
1639 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1640 | CPUFREQ_ADJUST, policy); | |
1641 | ||
1642 | /* adjust if necessary - hardware incompatibility*/ | |
1643 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1644 | CPUFREQ_INCOMPATIBLE, policy); | |
1645 | ||
1646 | /* verify the cpu speed can be set within this limit, | |
1647 | which might be different to the first one */ | |
1648 | ret = cpufreq_driver->verify(policy); | |
1649 | if (ret) | |
1650 | goto error_out; | |
1651 | ||
1652 | /* notification of the new policy */ | |
1653 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1654 | CPUFREQ_NOTIFY, policy); | |
1655 | ||
1656 | data->min = policy->min; | |
1657 | data->max = policy->max; | |
1658 | ||
1659 | dprintk("new min and max freqs are %u - %u kHz\n", | |
1660 | data->min, data->max); | |
1661 | ||
1662 | if (cpufreq_driver->setpolicy) { | |
1663 | data->policy = policy->policy; | |
1664 | dprintk("setting range\n"); | |
1665 | ret = cpufreq_driver->setpolicy(policy); | |
1666 | } else { | |
1667 | if (policy->governor != data->governor) { | |
1668 | /* save old, working values */ | |
1669 | struct cpufreq_governor *old_gov = data->governor; | |
1670 | ||
1671 | dprintk("governor switch\n"); | |
1672 | ||
1673 | /* end old governor */ | |
1674 | if (data->governor) | |
1675 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1676 | ||
1677 | /* start new governor */ | |
1678 | data->governor = policy->governor; | |
1679 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1680 | /* new governor failed, so re-start old one */ | |
1681 | dprintk("starting governor %s failed\n", | |
1682 | data->governor->name); | |
1683 | if (old_gov) { | |
1684 | data->governor = old_gov; | |
1685 | __cpufreq_governor(data, | |
1686 | CPUFREQ_GOV_START); | |
1687 | } | |
1688 | ret = -EINVAL; | |
1689 | goto error_out; | |
1690 | } | |
1691 | /* might be a policy change, too, so fall through */ | |
1692 | } | |
1693 | dprintk("governor: change or update limits\n"); | |
1694 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1695 | } | |
1696 | ||
1697 | error_out: | |
1698 | cpufreq_debug_enable_ratelimit(); | |
1699 | return ret; | |
1700 | } | |
1701 | ||
1702 | /** | |
1703 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1704 | * @cpu: CPU which shall be re-evaluated | |
1705 | * | |
1706 | * Usefull for policy notifiers which have different necessities | |
1707 | * at different times. | |
1708 | */ | |
1709 | int cpufreq_update_policy(unsigned int cpu) | |
1710 | { | |
1711 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1712 | struct cpufreq_policy policy; | |
1713 | int ret = 0; | |
1714 | ||
1715 | if (!data) | |
1716 | return -ENODEV; | |
1717 | ||
1718 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1719 | return -EINVAL; | |
1720 | ||
1721 | dprintk("updating policy for CPU %u\n", cpu); | |
1722 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); | |
1723 | policy.min = data->user_policy.min; | |
1724 | policy.max = data->user_policy.max; | |
1725 | policy.policy = data->user_policy.policy; | |
1726 | policy.governor = data->user_policy.governor; | |
1727 | ||
1728 | /* BIOS might change freq behind our back | |
1729 | -> ask driver for current freq and notify governors about a change */ | |
1730 | if (cpufreq_driver->get) { | |
1731 | policy.cur = cpufreq_driver->get(cpu); | |
1732 | if (!data->cur) { | |
1733 | dprintk("Driver did not initialize current freq"); | |
1734 | data->cur = policy.cur; | |
1735 | } else { | |
1736 | if (data->cur != policy.cur) | |
1737 | cpufreq_out_of_sync(cpu, data->cur, | |
1738 | policy.cur); | |
1739 | } | |
1740 | } | |
1741 | ||
1742 | ret = __cpufreq_set_policy(data, &policy); | |
1743 | ||
1744 | unlock_policy_rwsem_write(cpu); | |
1745 | ||
1746 | cpufreq_cpu_put(data); | |
1747 | return ret; | |
1748 | } | |
1749 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1750 | ||
1751 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, | |
1752 | unsigned long action, void *hcpu) | |
1753 | { | |
1754 | unsigned int cpu = (unsigned long)hcpu; | |
1755 | struct sys_device *sys_dev; | |
1756 | ||
1757 | sys_dev = get_cpu_sysdev(cpu); | |
1758 | if (sys_dev) { | |
1759 | switch (action) { | |
1760 | case CPU_ONLINE: | |
1761 | case CPU_ONLINE_FROZEN: | |
1762 | cpufreq_add_dev(sys_dev); | |
1763 | break; | |
1764 | case CPU_DOWN_PREPARE: | |
1765 | case CPU_DOWN_PREPARE_FROZEN: | |
1766 | if (unlikely(lock_policy_rwsem_write(cpu))) | |
1767 | BUG(); | |
1768 | ||
1769 | __cpufreq_remove_dev(sys_dev); | |
1770 | break; | |
1771 | case CPU_DOWN_FAILED: | |
1772 | case CPU_DOWN_FAILED_FROZEN: | |
1773 | cpufreq_add_dev(sys_dev); | |
1774 | break; | |
1775 | } | |
1776 | } | |
1777 | return NOTIFY_OK; | |
1778 | } | |
1779 | ||
1780 | static struct notifier_block __refdata cpufreq_cpu_notifier = | |
1781 | { | |
1782 | .notifier_call = cpufreq_cpu_callback, | |
1783 | }; | |
1784 | ||
1785 | /********************************************************************* | |
1786 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1787 | *********************************************************************/ | |
1788 | ||
1789 | /** | |
1790 | * cpufreq_register_driver - register a CPU Frequency driver | |
1791 | * @driver_data: A struct cpufreq_driver containing the values# | |
1792 | * submitted by the CPU Frequency driver. | |
1793 | * | |
1794 | * Registers a CPU Frequency driver to this core code. This code | |
1795 | * returns zero on success, -EBUSY when another driver got here first | |
1796 | * (and isn't unregistered in the meantime). | |
1797 | * | |
1798 | */ | |
1799 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1800 | { | |
1801 | unsigned long flags; | |
1802 | int ret; | |
1803 | ||
1804 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1805 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1806 | return -EINVAL; | |
1807 | ||
1808 | dprintk("trying to register driver %s\n", driver_data->name); | |
1809 | ||
1810 | if (driver_data->setpolicy) | |
1811 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1812 | ||
1813 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1814 | if (cpufreq_driver) { | |
1815 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1816 | return -EBUSY; | |
1817 | } | |
1818 | cpufreq_driver = driver_data; | |
1819 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1820 | ||
1821 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1822 | ||
1823 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1824 | int i; | |
1825 | ret = -ENODEV; | |
1826 | ||
1827 | /* check for at least one working CPU */ | |
1828 | for (i=0; i<NR_CPUS; i++) | |
1829 | if (cpufreq_cpu_data[i]) | |
1830 | ret = 0; | |
1831 | ||
1832 | /* if all ->init() calls failed, unregister */ | |
1833 | if (ret) { | |
1834 | dprintk("no CPU initialized for driver %s\n", | |
1835 | driver_data->name); | |
1836 | sysdev_driver_unregister(&cpu_sysdev_class, | |
1837 | &cpufreq_sysdev_driver); | |
1838 | ||
1839 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1840 | cpufreq_driver = NULL; | |
1841 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1842 | } | |
1843 | } | |
1844 | ||
1845 | if (!ret) { | |
1846 | register_hotcpu_notifier(&cpufreq_cpu_notifier); | |
1847 | dprintk("driver %s up and running\n", driver_data->name); | |
1848 | cpufreq_debug_enable_ratelimit(); | |
1849 | } | |
1850 | ||
1851 | return (ret); | |
1852 | } | |
1853 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1854 | ||
1855 | ||
1856 | /** | |
1857 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1858 | * | |
1859 | * Unregister the current CPUFreq driver. Only call this if you have | |
1860 | * the right to do so, i.e. if you have succeeded in initialising before! | |
1861 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1862 | * currently not initialised. | |
1863 | */ | |
1864 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1865 | { | |
1866 | unsigned long flags; | |
1867 | ||
1868 | cpufreq_debug_disable_ratelimit(); | |
1869 | ||
1870 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1871 | cpufreq_debug_enable_ratelimit(); | |
1872 | return -EINVAL; | |
1873 | } | |
1874 | ||
1875 | dprintk("unregistering driver %s\n", driver->name); | |
1876 | ||
1877 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1878 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); | |
1879 | ||
1880 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1881 | cpufreq_driver = NULL; | |
1882 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1883 | ||
1884 | return 0; | |
1885 | } | |
1886 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
1887 | ||
1888 | static int __init cpufreq_core_init(void) | |
1889 | { | |
1890 | int cpu; | |
1891 | ||
1892 | for_each_possible_cpu(cpu) { | |
1893 | per_cpu(policy_cpu, cpu) = -1; | |
1894 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
1895 | } | |
1896 | return 0; | |
1897 | } | |
1898 | ||
1899 | core_initcall(cpufreq_core_init); |