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