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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 | ||
39 | /* we keep a copy of all ->add'ed CPU's struct sys_device here; | |
40 | * as it is only accessed in ->add and ->remove, no lock or reference | |
41 | * count is necessary. | |
42 | */ | |
43 | static struct sys_device *cpu_sys_devices[NR_CPUS]; | |
44 | ||
45 | ||
46 | /* internal prototypes */ | |
47 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
48 | static void handle_update(void *data); | |
49 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci); | |
50 | ||
51 | /** | |
52 | * Two notifier lists: the "policy" list is involved in the | |
53 | * validation process for a new CPU frequency policy; the | |
54 | * "transition" list for kernel code that needs to handle | |
55 | * changes to devices when the CPU clock speed changes. | |
56 | * The mutex locks both lists. | |
57 | */ | |
58 | static struct notifier_block *cpufreq_policy_notifier_list; | |
59 | static struct notifier_block *cpufreq_transition_notifier_list; | |
60 | static DECLARE_RWSEM (cpufreq_notifier_rwsem); | |
61 | ||
62 | ||
63 | static LIST_HEAD(cpufreq_governor_list); | |
64 | static DECLARE_MUTEX (cpufreq_governor_sem); | |
65 | ||
66 | struct cpufreq_policy * cpufreq_cpu_get(unsigned int cpu) | |
67 | { | |
68 | struct cpufreq_policy *data; | |
69 | unsigned long flags; | |
70 | ||
71 | if (cpu >= NR_CPUS) | |
72 | goto err_out; | |
73 | ||
74 | /* get the cpufreq driver */ | |
75 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
76 | ||
77 | if (!cpufreq_driver) | |
78 | goto err_out_unlock; | |
79 | ||
80 | if (!try_module_get(cpufreq_driver->owner)) | |
81 | goto err_out_unlock; | |
82 | ||
83 | ||
84 | /* get the CPU */ | |
85 | data = cpufreq_cpu_data[cpu]; | |
86 | ||
87 | if (!data) | |
88 | goto err_out_put_module; | |
89 | ||
90 | if (!kobject_get(&data->kobj)) | |
91 | goto err_out_put_module; | |
92 | ||
93 | ||
94 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
95 | ||
96 | return data; | |
97 | ||
98 | err_out_put_module: | |
99 | module_put(cpufreq_driver->owner); | |
100 | err_out_unlock: | |
101 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
102 | err_out: | |
103 | return NULL; | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
106 | ||
107 | void cpufreq_cpu_put(struct cpufreq_policy *data) | |
108 | { | |
109 | kobject_put(&data->kobj); | |
110 | module_put(cpufreq_driver->owner); | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
113 | ||
114 | ||
115 | /********************************************************************* | |
116 | * UNIFIED DEBUG HELPERS * | |
117 | *********************************************************************/ | |
118 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
119 | ||
120 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
121 | static unsigned int debug; | |
122 | ||
123 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
124 | * set or modify this value. | |
125 | */ | |
126 | static unsigned int debug_ratelimit = 1; | |
127 | ||
128 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
129 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
130 | * is set, and disabled upon cpufreq driver removal | |
131 | */ | |
132 | static unsigned int disable_ratelimit = 1; | |
133 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
134 | ||
135 | static inline void cpufreq_debug_enable_ratelimit(void) | |
136 | { | |
137 | unsigned long flags; | |
138 | ||
139 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
140 | if (disable_ratelimit) | |
141 | disable_ratelimit--; | |
142 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
143 | } | |
144 | ||
145 | static inline void cpufreq_debug_disable_ratelimit(void) | |
146 | { | |
147 | unsigned long flags; | |
148 | ||
149 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
150 | disable_ratelimit++; | |
151 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
152 | } | |
153 | ||
154 | void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...) | |
155 | { | |
156 | char s[256]; | |
157 | va_list args; | |
158 | unsigned int len; | |
159 | unsigned long flags; | |
160 | ||
161 | WARN_ON(!prefix); | |
162 | if (type & debug) { | |
163 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
164 | if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) { | |
165 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
166 | return; | |
167 | } | |
168 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
169 | ||
170 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
171 | ||
172 | va_start(args, fmt); | |
173 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
174 | va_end(args); | |
175 | ||
176 | printk(s); | |
177 | ||
178 | WARN_ON(len < 5); | |
179 | } | |
180 | } | |
181 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
182 | ||
183 | ||
184 | module_param(debug, uint, 0644); | |
185 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors."); | |
186 | ||
187 | module_param(debug_ratelimit, uint, 0644); | |
188 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting."); | |
189 | ||
190 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
191 | ||
192 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
193 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
194 | ||
195 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
196 | ||
197 | ||
198 | /********************************************************************* | |
199 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
200 | *********************************************************************/ | |
201 | ||
202 | /** | |
203 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
204 | * | |
205 | * This function alters the system "loops_per_jiffy" for the clock | |
206 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
207 | * systems as each CPU might be scaled differently. So, use the arch | |
208 | * per-CPU loops_per_jiffy value wherever possible. | |
209 | */ | |
210 | #ifndef CONFIG_SMP | |
211 | static unsigned long l_p_j_ref; | |
212 | static unsigned int l_p_j_ref_freq; | |
213 | ||
214 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) | |
215 | { | |
216 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
217 | return; | |
218 | ||
219 | if (!l_p_j_ref_freq) { | |
220 | l_p_j_ref = loops_per_jiffy; | |
221 | l_p_j_ref_freq = ci->old; | |
222 | dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
223 | } | |
224 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
225 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 226 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
1da177e4 LT |
227 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new); |
228 | dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
229 | } | |
230 | } | |
231 | #else | |
232 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; } | |
233 | #endif | |
234 | ||
235 | ||
236 | /** | |
237 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies on frequency transition | |
238 | * | |
239 | * This function calls the transition notifiers and the "adjust_jiffies" function. It is called | |
240 | * twice on all CPU frequency changes that have external effects. | |
241 | */ | |
242 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
243 | { | |
244 | BUG_ON(irqs_disabled()); | |
245 | ||
246 | freqs->flags = cpufreq_driver->flags; | |
247 | dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new); | |
248 | ||
249 | down_read(&cpufreq_notifier_rwsem); | |
250 | switch (state) { | |
251 | case CPUFREQ_PRECHANGE: | |
252 | /* detect if the driver reported a value as "old frequency" which | |
253 | * is not equal to what the cpufreq core thinks is "old frequency". | |
254 | */ | |
255 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
256 | if ((likely(cpufreq_cpu_data[freqs->cpu])) && | |
257 | (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)) && | |
258 | (likely(cpufreq_cpu_data[freqs->cpu]->cur)) && | |
259 | (unlikely(freqs->old != cpufreq_cpu_data[freqs->cpu]->cur))) | |
260 | { | |
78ee998f | 261 | dprintk(KERN_WARNING "Warning: CPU frequency is %u, " |
1da177e4 LT |
262 | "cpufreq assumed %u kHz.\n", freqs->old, cpufreq_cpu_data[freqs->cpu]->cur); |
263 | freqs->old = cpufreq_cpu_data[freqs->cpu]->cur; | |
264 | } | |
265 | } | |
266 | notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs); | |
267 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); | |
268 | break; | |
269 | case CPUFREQ_POSTCHANGE: | |
270 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
271 | notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_POSTCHANGE, freqs); | |
272 | if ((likely(cpufreq_cpu_data[freqs->cpu])) && | |
273 | (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu))) | |
274 | cpufreq_cpu_data[freqs->cpu]->cur = freqs->new; | |
275 | break; | |
276 | } | |
277 | up_read(&cpufreq_notifier_rwsem); | |
278 | } | |
279 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
280 | ||
281 | ||
282 | ||
283 | /********************************************************************* | |
284 | * SYSFS INTERFACE * | |
285 | *********************************************************************/ | |
286 | ||
287 | /** | |
288 | * cpufreq_parse_governor - parse a governor string | |
289 | */ | |
290 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
291 | struct cpufreq_governor **governor) | |
292 | { | |
293 | if (!cpufreq_driver) | |
294 | return -EINVAL; | |
295 | if (cpufreq_driver->setpolicy) { | |
296 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
297 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
298 | return 0; | |
299 | } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
300 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
301 | return 0; | |
302 | } | |
303 | return -EINVAL; | |
304 | } else { | |
305 | struct cpufreq_governor *t; | |
306 | down(&cpufreq_governor_sem); | |
307 | if (!cpufreq_driver || !cpufreq_driver->target) | |
308 | goto out; | |
309 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
310 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) { | |
311 | *governor = t; | |
312 | up(&cpufreq_governor_sem); | |
313 | return 0; | |
314 | } | |
315 | } | |
316 | out: | |
317 | up(&cpufreq_governor_sem); | |
318 | } | |
319 | return -EINVAL; | |
320 | } | |
321 | EXPORT_SYMBOL_GPL(cpufreq_parse_governor); | |
322 | ||
323 | ||
324 | /* drivers/base/cpu.c */ | |
325 | extern struct sysdev_class cpu_sysdev_class; | |
326 | ||
327 | ||
328 | /** | |
329 | * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information | |
330 | * | |
331 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
332 | * "unsigned int". | |
333 | */ | |
334 | ||
335 | #define show_one(file_name, object) \ | |
336 | static ssize_t show_##file_name \ | |
337 | (struct cpufreq_policy * policy, char *buf) \ | |
338 | { \ | |
339 | return sprintf (buf, "%u\n", policy->object); \ | |
340 | } | |
341 | ||
342 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
343 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
344 | show_one(scaling_min_freq, min); | |
345 | show_one(scaling_max_freq, max); | |
346 | show_one(scaling_cur_freq, cur); | |
347 | ||
348 | /** | |
349 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
350 | */ | |
351 | #define store_one(file_name, object) \ | |
352 | static ssize_t store_##file_name \ | |
353 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
354 | { \ | |
355 | unsigned int ret = -EINVAL; \ | |
356 | struct cpufreq_policy new_policy; \ | |
357 | \ | |
358 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
359 | if (ret) \ | |
360 | return -EINVAL; \ | |
361 | \ | |
362 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
363 | if (ret != 1) \ | |
364 | return -EINVAL; \ | |
365 | \ | |
366 | ret = cpufreq_set_policy(&new_policy); \ | |
367 | \ | |
368 | return ret ? ret : count; \ | |
369 | } | |
370 | ||
371 | store_one(scaling_min_freq,min); | |
372 | store_one(scaling_max_freq,max); | |
373 | ||
374 | /** | |
375 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
376 | */ | |
377 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf) | |
378 | { | |
379 | unsigned int cur_freq = cpufreq_get(policy->cpu); | |
380 | if (!cur_freq) | |
381 | return sprintf(buf, "<unknown>"); | |
382 | return sprintf(buf, "%u\n", cur_freq); | |
383 | } | |
384 | ||
385 | ||
386 | /** | |
387 | * show_scaling_governor - show the current policy for the specified CPU | |
388 | */ | |
389 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf) | |
390 | { | |
391 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
392 | return sprintf(buf, "powersave\n"); | |
393 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
394 | return sprintf(buf, "performance\n"); | |
395 | else if (policy->governor) | |
396 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | ||
401 | /** | |
402 | * store_scaling_governor - store policy for the specified CPU | |
403 | */ | |
404 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, | |
405 | const char *buf, size_t count) | |
406 | { | |
407 | unsigned int ret = -EINVAL; | |
408 | char str_governor[16]; | |
409 | struct cpufreq_policy new_policy; | |
410 | ||
411 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
412 | if (ret) | |
413 | return ret; | |
414 | ||
415 | ret = sscanf (buf, "%15s", str_governor); | |
416 | if (ret != 1) | |
417 | return -EINVAL; | |
418 | ||
419 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor)) | |
420 | return -EINVAL; | |
421 | ||
422 | ret = cpufreq_set_policy(&new_policy); | |
423 | ||
424 | return ret ? ret : count; | |
425 | } | |
426 | ||
427 | /** | |
428 | * show_scaling_driver - show the cpufreq driver currently loaded | |
429 | */ | |
430 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
431 | { | |
432 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
433 | } | |
434 | ||
435 | /** | |
436 | * show_scaling_available_governors - show the available CPUfreq governors | |
437 | */ | |
438 | static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy, | |
439 | char *buf) | |
440 | { | |
441 | ssize_t i = 0; | |
442 | struct cpufreq_governor *t; | |
443 | ||
444 | if (!cpufreq_driver->target) { | |
445 | i += sprintf(buf, "performance powersave"); | |
446 | goto out; | |
447 | } | |
448 | ||
449 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
450 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
451 | goto out; | |
452 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
453 | } | |
454 | out: | |
455 | i += sprintf(&buf[i], "\n"); | |
456 | return i; | |
457 | } | |
458 | /** | |
459 | * show_affected_cpus - show the CPUs affected by each transition | |
460 | */ | |
461 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
462 | { | |
463 | ssize_t i = 0; | |
464 | unsigned int cpu; | |
465 | ||
466 | for_each_cpu_mask(cpu, policy->cpus) { | |
467 | if (i) | |
468 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
469 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
470 | if (i >= (PAGE_SIZE - 5)) | |
471 | break; | |
472 | } | |
473 | i += sprintf(&buf[i], "\n"); | |
474 | return i; | |
475 | } | |
476 | ||
477 | ||
478 | #define define_one_ro(_name) \ | |
479 | static struct freq_attr _name = \ | |
480 | __ATTR(_name, 0444, show_##_name, NULL) | |
481 | ||
482 | #define define_one_ro0400(_name) \ | |
483 | static struct freq_attr _name = \ | |
484 | __ATTR(_name, 0400, show_##_name, NULL) | |
485 | ||
486 | #define define_one_rw(_name) \ | |
487 | static struct freq_attr _name = \ | |
488 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
489 | ||
490 | define_one_ro0400(cpuinfo_cur_freq); | |
491 | define_one_ro(cpuinfo_min_freq); | |
492 | define_one_ro(cpuinfo_max_freq); | |
493 | define_one_ro(scaling_available_governors); | |
494 | define_one_ro(scaling_driver); | |
495 | define_one_ro(scaling_cur_freq); | |
496 | define_one_ro(affected_cpus); | |
497 | define_one_rw(scaling_min_freq); | |
498 | define_one_rw(scaling_max_freq); | |
499 | define_one_rw(scaling_governor); | |
500 | ||
501 | static struct attribute * default_attrs[] = { | |
502 | &cpuinfo_min_freq.attr, | |
503 | &cpuinfo_max_freq.attr, | |
504 | &scaling_min_freq.attr, | |
505 | &scaling_max_freq.attr, | |
506 | &affected_cpus.attr, | |
507 | &scaling_governor.attr, | |
508 | &scaling_driver.attr, | |
509 | &scaling_available_governors.attr, | |
510 | NULL | |
511 | }; | |
512 | ||
513 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
514 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
515 | ||
516 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
517 | { | |
518 | struct cpufreq_policy * policy = to_policy(kobj); | |
519 | struct freq_attr * fattr = to_attr(attr); | |
520 | ssize_t ret; | |
521 | policy = cpufreq_cpu_get(policy->cpu); | |
522 | if (!policy) | |
523 | return -EINVAL; | |
524 | ret = fattr->show ? fattr->show(policy,buf) : 0; | |
525 | cpufreq_cpu_put(policy); | |
526 | return ret; | |
527 | } | |
528 | ||
529 | static ssize_t store(struct kobject * kobj, struct attribute * attr, | |
530 | const char * buf, size_t count) | |
531 | { | |
532 | struct cpufreq_policy * policy = to_policy(kobj); | |
533 | struct freq_attr * fattr = to_attr(attr); | |
534 | ssize_t ret; | |
535 | policy = cpufreq_cpu_get(policy->cpu); | |
536 | if (!policy) | |
537 | return -EINVAL; | |
538 | ret = fattr->store ? fattr->store(policy,buf,count) : 0; | |
539 | cpufreq_cpu_put(policy); | |
540 | return ret; | |
541 | } | |
542 | ||
543 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
544 | { | |
545 | struct cpufreq_policy * policy = to_policy(kobj); | |
546 | dprintk("last reference is dropped\n"); | |
547 | complete(&policy->kobj_unregister); | |
548 | } | |
549 | ||
550 | static struct sysfs_ops sysfs_ops = { | |
551 | .show = show, | |
552 | .store = store, | |
553 | }; | |
554 | ||
555 | static struct kobj_type ktype_cpufreq = { | |
556 | .sysfs_ops = &sysfs_ops, | |
557 | .default_attrs = default_attrs, | |
558 | .release = cpufreq_sysfs_release, | |
559 | }; | |
560 | ||
561 | ||
562 | /** | |
563 | * cpufreq_add_dev - add a CPU device | |
564 | * | |
565 | * Adds the cpufreq interface for a CPU device. | |
566 | */ | |
567 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
568 | { | |
569 | unsigned int cpu = sys_dev->id; | |
570 | int ret = 0; | |
571 | struct cpufreq_policy new_policy; | |
572 | struct cpufreq_policy *policy; | |
573 | struct freq_attr **drv_attr; | |
574 | unsigned long flags; | |
575 | unsigned int j; | |
576 | ||
577 | cpufreq_debug_disable_ratelimit(); | |
578 | dprintk("adding CPU %u\n", cpu); | |
579 | ||
580 | #ifdef CONFIG_SMP | |
581 | /* check whether a different CPU already registered this | |
582 | * CPU because it is in the same boat. */ | |
583 | policy = cpufreq_cpu_get(cpu); | |
584 | if (unlikely(policy)) { | |
585 | cpu_sys_devices[cpu] = sys_dev; | |
586 | dprintk("CPU already managed, adding link\n"); | |
587 | sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq"); | |
588 | cpufreq_debug_enable_ratelimit(); | |
589 | return 0; | |
590 | } | |
591 | #endif | |
592 | ||
593 | if (!try_module_get(cpufreq_driver->owner)) { | |
594 | ret = -EINVAL; | |
595 | goto module_out; | |
596 | } | |
597 | ||
598 | policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); | |
599 | if (!policy) { | |
600 | ret = -ENOMEM; | |
601 | goto nomem_out; | |
602 | } | |
603 | memset(policy, 0, sizeof(struct cpufreq_policy)); | |
604 | ||
605 | policy->cpu = cpu; | |
606 | policy->cpus = cpumask_of_cpu(cpu); | |
607 | ||
608 | init_MUTEX_LOCKED(&policy->lock); | |
609 | init_completion(&policy->kobj_unregister); | |
610 | INIT_WORK(&policy->update, handle_update, (void *)(long)cpu); | |
611 | ||
612 | /* call driver. From then on the cpufreq must be able | |
613 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
614 | */ | |
615 | ret = cpufreq_driver->init(policy); | |
616 | if (ret) { | |
617 | dprintk("initialization failed\n"); | |
618 | goto err_out; | |
619 | } | |
620 | ||
621 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
622 | ||
623 | /* prepare interface data */ | |
624 | policy->kobj.parent = &sys_dev->kobj; | |
625 | policy->kobj.ktype = &ktype_cpufreq; | |
626 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
627 | ||
628 | ret = kobject_register(&policy->kobj); | |
629 | if (ret) | |
630 | goto err_out; | |
631 | ||
632 | /* set up files for this cpu device */ | |
633 | drv_attr = cpufreq_driver->attr; | |
634 | while ((drv_attr) && (*drv_attr)) { | |
635 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
636 | drv_attr++; | |
637 | } | |
638 | if (cpufreq_driver->get) | |
639 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
640 | if (cpufreq_driver->target) | |
641 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
642 | ||
643 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
644 | for_each_cpu_mask(j, policy->cpus) | |
645 | cpufreq_cpu_data[j] = policy; | |
646 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
647 | policy->governor = NULL; /* to assure that the starting sequence is | |
648 | * run in cpufreq_set_policy */ | |
649 | up(&policy->lock); | |
650 | ||
651 | /* set default policy */ | |
652 | ||
653 | ret = cpufreq_set_policy(&new_policy); | |
654 | if (ret) { | |
655 | dprintk("setting policy failed\n"); | |
656 | goto err_out_unregister; | |
657 | } | |
658 | ||
659 | module_put(cpufreq_driver->owner); | |
660 | cpu_sys_devices[cpu] = sys_dev; | |
661 | dprintk("initialization complete\n"); | |
662 | cpufreq_debug_enable_ratelimit(); | |
663 | ||
664 | return 0; | |
665 | ||
666 | ||
667 | err_out_unregister: | |
668 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
669 | for_each_cpu_mask(j, policy->cpus) | |
670 | cpufreq_cpu_data[j] = NULL; | |
671 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
672 | ||
673 | kobject_unregister(&policy->kobj); | |
674 | wait_for_completion(&policy->kobj_unregister); | |
675 | ||
676 | err_out: | |
677 | kfree(policy); | |
678 | ||
679 | nomem_out: | |
680 | module_put(cpufreq_driver->owner); | |
681 | module_out: | |
682 | cpufreq_debug_enable_ratelimit(); | |
683 | return ret; | |
684 | } | |
685 | ||
686 | ||
687 | /** | |
688 | * cpufreq_remove_dev - remove a CPU device | |
689 | * | |
690 | * Removes the cpufreq interface for a CPU device. | |
691 | */ | |
692 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
693 | { | |
694 | unsigned int cpu = sys_dev->id; | |
695 | unsigned long flags; | |
696 | struct cpufreq_policy *data; | |
697 | #ifdef CONFIG_SMP | |
698 | unsigned int j; | |
699 | #endif | |
700 | ||
701 | cpufreq_debug_disable_ratelimit(); | |
702 | dprintk("unregistering CPU %u\n", cpu); | |
703 | ||
704 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
705 | data = cpufreq_cpu_data[cpu]; | |
706 | ||
707 | if (!data) { | |
708 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
709 | cpu_sys_devices[cpu] = NULL; | |
710 | cpufreq_debug_enable_ratelimit(); | |
711 | return -EINVAL; | |
712 | } | |
713 | cpufreq_cpu_data[cpu] = NULL; | |
714 | ||
715 | ||
716 | #ifdef CONFIG_SMP | |
717 | /* if this isn't the CPU which is the parent of the kobj, we | |
718 | * only need to unlink, put and exit | |
719 | */ | |
720 | if (unlikely(cpu != data->cpu)) { | |
721 | dprintk("removing link\n"); | |
722 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
723 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
724 | cpu_sys_devices[cpu] = NULL; | |
725 | cpufreq_cpu_put(data); | |
726 | cpufreq_debug_enable_ratelimit(); | |
727 | return 0; | |
728 | } | |
729 | #endif | |
730 | ||
731 | cpu_sys_devices[cpu] = NULL; | |
732 | ||
733 | if (!kobject_get(&data->kobj)) { | |
734 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
735 | cpufreq_debug_enable_ratelimit(); | |
736 | return -EFAULT; | |
737 | } | |
738 | ||
739 | #ifdef CONFIG_SMP | |
740 | /* if we have other CPUs still registered, we need to unlink them, | |
741 | * or else wait_for_completion below will lock up. Clean the | |
742 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
743 | * links afterwards. | |
744 | */ | |
745 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
746 | for_each_cpu_mask(j, data->cpus) { | |
747 | if (j == cpu) | |
748 | continue; | |
749 | cpufreq_cpu_data[j] = NULL; | |
750 | } | |
751 | } | |
752 | ||
753 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
754 | ||
755 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
756 | for_each_cpu_mask(j, data->cpus) { | |
757 | if (j == cpu) | |
758 | continue; | |
759 | dprintk("removing link for cpu %u\n", j); | |
760 | sysfs_remove_link(&cpu_sys_devices[j]->kobj, "cpufreq"); | |
761 | cpufreq_cpu_put(data); | |
762 | } | |
763 | } | |
764 | #else | |
765 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
766 | #endif | |
767 | ||
768 | down(&data->lock); | |
769 | if (cpufreq_driver->target) | |
770 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
771 | cpufreq_driver->target = NULL; | |
772 | up(&data->lock); | |
773 | ||
774 | kobject_unregister(&data->kobj); | |
775 | ||
776 | kobject_put(&data->kobj); | |
777 | ||
778 | /* we need to make sure that the underlying kobj is actually | |
779 | * not referenced anymore by anybody before we proceed with | |
780 | * unloading. | |
781 | */ | |
782 | dprintk("waiting for dropping of refcount\n"); | |
783 | wait_for_completion(&data->kobj_unregister); | |
784 | dprintk("wait complete\n"); | |
785 | ||
786 | if (cpufreq_driver->exit) | |
787 | cpufreq_driver->exit(data); | |
788 | ||
789 | kfree(data); | |
790 | ||
791 | cpufreq_debug_enable_ratelimit(); | |
792 | ||
793 | return 0; | |
794 | } | |
795 | ||
796 | ||
797 | static void handle_update(void *data) | |
798 | { | |
799 | unsigned int cpu = (unsigned int)(long)data; | |
800 | dprintk("handle_update for cpu %u called\n", cpu); | |
801 | cpufreq_update_policy(cpu); | |
802 | } | |
803 | ||
804 | /** | |
805 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
806 | * @cpu: cpu number | |
807 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
808 | * @new_freq: CPU frequency the CPU actually runs at | |
809 | * | |
810 | * We adjust to current frequency first, and need to clean up later. So either call | |
811 | * to cpufreq_update_policy() or schedule handle_update()). | |
812 | */ | |
813 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq) | |
814 | { | |
815 | struct cpufreq_freqs freqs; | |
816 | ||
78ee998f | 817 | dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
818 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
819 | ||
820 | freqs.cpu = cpu; | |
821 | freqs.old = old_freq; | |
822 | freqs.new = new_freq; | |
823 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
824 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
825 | } | |
826 | ||
827 | ||
828 | /** | |
829 | * cpufreq_get - get the current CPU frequency (in kHz) | |
830 | * @cpu: CPU number | |
831 | * | |
832 | * Get the CPU current (static) CPU frequency | |
833 | */ | |
834 | unsigned int cpufreq_get(unsigned int cpu) | |
835 | { | |
836 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
837 | unsigned int ret = 0; | |
838 | ||
839 | if (!policy) | |
840 | return 0; | |
841 | ||
842 | if (!cpufreq_driver->get) | |
843 | goto out; | |
844 | ||
845 | down(&policy->lock); | |
846 | ||
847 | ret = cpufreq_driver->get(cpu); | |
848 | ||
849 | if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) | |
850 | { | |
851 | /* verify no discrepancy between actual and saved value exists */ | |
852 | if (unlikely(ret != policy->cur)) { | |
853 | cpufreq_out_of_sync(cpu, policy->cur, ret); | |
854 | schedule_work(&policy->update); | |
855 | } | |
856 | } | |
857 | ||
858 | up(&policy->lock); | |
859 | ||
860 | out: | |
861 | cpufreq_cpu_put(policy); | |
862 | ||
863 | return (ret); | |
864 | } | |
865 | EXPORT_SYMBOL(cpufreq_get); | |
866 | ||
867 | ||
42d4dc3f BH |
868 | /** |
869 | * cpufreq_suspend - let the low level driver prepare for suspend | |
870 | */ | |
871 | ||
872 | static int cpufreq_suspend(struct sys_device * sysdev, u32 state) | |
873 | { | |
874 | int cpu = sysdev->id; | |
875 | unsigned int ret = 0; | |
876 | unsigned int cur_freq = 0; | |
877 | struct cpufreq_policy *cpu_policy; | |
878 | ||
879 | dprintk("resuming cpu %u\n", cpu); | |
880 | ||
881 | if (!cpu_online(cpu)) | |
882 | return 0; | |
883 | ||
884 | /* we may be lax here as interrupts are off. Nonetheless | |
885 | * we need to grab the correct cpu policy, as to check | |
886 | * whether we really run on this CPU. | |
887 | */ | |
888 | ||
889 | cpu_policy = cpufreq_cpu_get(cpu); | |
890 | if (!cpu_policy) | |
891 | return -EINVAL; | |
892 | ||
893 | /* only handle each CPU group once */ | |
894 | if (unlikely(cpu_policy->cpu != cpu)) { | |
895 | cpufreq_cpu_put(cpu_policy); | |
896 | return 0; | |
897 | } | |
898 | ||
899 | if (cpufreq_driver->suspend) { | |
900 | ret = cpufreq_driver->suspend(cpu_policy, state); | |
901 | if (ret) { | |
902 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
903 | "step on CPU %u\n", cpu_policy->cpu); | |
904 | cpufreq_cpu_put(cpu_policy); | |
905 | return ret; | |
906 | } | |
907 | } | |
908 | ||
909 | ||
910 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
911 | goto out; | |
912 | ||
913 | if (cpufreq_driver->get) | |
914 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
915 | ||
916 | if (!cur_freq || !cpu_policy->cur) { | |
917 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
918 | "frequency is what timing core thinks it is.\n"); | |
919 | goto out; | |
920 | } | |
921 | ||
922 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
923 | struct cpufreq_freqs freqs; | |
924 | ||
925 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
78ee998f | 926 | dprintk(KERN_DEBUG "Warning: CPU frequency is %u, " |
42d4dc3f BH |
927 | "cpufreq assumed %u kHz.\n", |
928 | cur_freq, cpu_policy->cur); | |
929 | ||
930 | freqs.cpu = cpu; | |
931 | freqs.old = cpu_policy->cur; | |
932 | freqs.new = cur_freq; | |
933 | ||
934 | notifier_call_chain(&cpufreq_transition_notifier_list, | |
935 | CPUFREQ_SUSPENDCHANGE, &freqs); | |
936 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
937 | ||
938 | cpu_policy->cur = cur_freq; | |
939 | } | |
940 | ||
941 | out: | |
942 | cpufreq_cpu_put(cpu_policy); | |
943 | return 0; | |
944 | } | |
945 | ||
1da177e4 LT |
946 | /** |
947 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
948 | * | |
949 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
950 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
951 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
952 | * restored. | |
1da177e4 LT |
953 | */ |
954 | static int cpufreq_resume(struct sys_device * sysdev) | |
955 | { | |
956 | int cpu = sysdev->id; | |
957 | unsigned int ret = 0; | |
958 | struct cpufreq_policy *cpu_policy; | |
959 | ||
960 | dprintk("resuming cpu %u\n", cpu); | |
961 | ||
962 | if (!cpu_online(cpu)) | |
963 | return 0; | |
964 | ||
965 | /* we may be lax here as interrupts are off. Nonetheless | |
966 | * we need to grab the correct cpu policy, as to check | |
967 | * whether we really run on this CPU. | |
968 | */ | |
969 | ||
970 | cpu_policy = cpufreq_cpu_get(cpu); | |
971 | if (!cpu_policy) | |
972 | return -EINVAL; | |
973 | ||
974 | /* only handle each CPU group once */ | |
975 | if (unlikely(cpu_policy->cpu != cpu)) { | |
976 | cpufreq_cpu_put(cpu_policy); | |
977 | return 0; | |
978 | } | |
979 | ||
980 | if (cpufreq_driver->resume) { | |
981 | ret = cpufreq_driver->resume(cpu_policy); | |
982 | if (ret) { | |
983 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
984 | "step on CPU %u\n", cpu_policy->cpu); | |
985 | cpufreq_cpu_put(cpu_policy); | |
986 | return ret; | |
987 | } | |
988 | } | |
989 | ||
990 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
991 | unsigned int cur_freq = 0; | |
992 | ||
993 | if (cpufreq_driver->get) | |
994 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
995 | ||
996 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
997 | printk(KERN_ERR "cpufreq: resume failed to assert " |
998 | "current frequency is what timing core " | |
999 | "thinks it is.\n"); | |
1da177e4 LT |
1000 | goto out; |
1001 | } | |
1002 | ||
1003 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1004 | struct cpufreq_freqs freqs; | |
1005 | ||
ac09f698 | 1006 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
78ee998f | 1007 | dprintk(KERN_WARNING "Warning: CPU frequency" |
ac09f698 BH |
1008 | "is %u, cpufreq assumed %u kHz.\n", |
1009 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1010 | |
1011 | freqs.cpu = cpu; | |
1012 | freqs.old = cpu_policy->cur; | |
1013 | freqs.new = cur_freq; | |
1014 | ||
42d4dc3f BH |
1015 | notifier_call_chain(&cpufreq_transition_notifier_list, |
1016 | CPUFREQ_RESUMECHANGE, &freqs); | |
1da177e4 LT |
1017 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1018 | ||
1019 | cpu_policy->cur = cur_freq; | |
1020 | } | |
1021 | } | |
1022 | ||
1023 | out: | |
1024 | schedule_work(&cpu_policy->update); | |
1025 | cpufreq_cpu_put(cpu_policy); | |
1026 | return ret; | |
1027 | } | |
1028 | ||
1029 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1030 | .add = cpufreq_add_dev, | |
1031 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1032 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1033 | .resume = cpufreq_resume, |
1034 | }; | |
1035 | ||
1036 | ||
1037 | /********************************************************************* | |
1038 | * NOTIFIER LISTS INTERFACE * | |
1039 | *********************************************************************/ | |
1040 | ||
1041 | /** | |
1042 | * cpufreq_register_notifier - register a driver with cpufreq | |
1043 | * @nb: notifier function to register | |
1044 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1045 | * | |
1046 | * Add a driver to one of two lists: either a list of drivers that | |
1047 | * are notified about clock rate changes (once before and once after | |
1048 | * the transition), or a list of drivers that are notified about | |
1049 | * changes in cpufreq policy. | |
1050 | * | |
1051 | * This function may sleep, and has the same return conditions as | |
1052 | * notifier_chain_register. | |
1053 | */ | |
1054 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1055 | { | |
1056 | int ret; | |
1057 | ||
1058 | down_write(&cpufreq_notifier_rwsem); | |
1059 | switch (list) { | |
1060 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1061 | ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb); | |
1062 | break; | |
1063 | case CPUFREQ_POLICY_NOTIFIER: | |
1064 | ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb); | |
1065 | break; | |
1066 | default: | |
1067 | ret = -EINVAL; | |
1068 | } | |
1069 | up_write(&cpufreq_notifier_rwsem); | |
1070 | ||
1071 | return ret; | |
1072 | } | |
1073 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1074 | ||
1075 | ||
1076 | /** | |
1077 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1078 | * @nb: notifier block to be unregistered | |
1079 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1080 | * | |
1081 | * Remove a driver from the CPU frequency notifier list. | |
1082 | * | |
1083 | * This function may sleep, and has the same return conditions as | |
1084 | * notifier_chain_unregister. | |
1085 | */ | |
1086 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1087 | { | |
1088 | int ret; | |
1089 | ||
1090 | down_write(&cpufreq_notifier_rwsem); | |
1091 | switch (list) { | |
1092 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1093 | ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb); | |
1094 | break; | |
1095 | case CPUFREQ_POLICY_NOTIFIER: | |
1096 | ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb); | |
1097 | break; | |
1098 | default: | |
1099 | ret = -EINVAL; | |
1100 | } | |
1101 | up_write(&cpufreq_notifier_rwsem); | |
1102 | ||
1103 | return ret; | |
1104 | } | |
1105 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1106 | ||
1107 | ||
1108 | /********************************************************************* | |
1109 | * GOVERNORS * | |
1110 | *********************************************************************/ | |
1111 | ||
1112 | ||
1113 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1114 | unsigned int target_freq, | |
1115 | unsigned int relation) | |
1116 | { | |
1117 | int retval = -EINVAL; | |
1118 | lock_cpu_hotplug(); | |
1119 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, | |
1120 | target_freq, relation); | |
1121 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1122 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
1123 | unlock_cpu_hotplug(); | |
1124 | return retval; | |
1125 | } | |
1126 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1127 | ||
1128 | ||
1129 | int cpufreq_driver_target(struct cpufreq_policy *policy, | |
1130 | unsigned int target_freq, | |
1131 | unsigned int relation) | |
1132 | { | |
1133 | unsigned int ret; | |
1134 | ||
1135 | policy = cpufreq_cpu_get(policy->cpu); | |
1136 | if (!policy) | |
1137 | return -EINVAL; | |
1138 | ||
1139 | down(&policy->lock); | |
1140 | ||
1141 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1142 | ||
1143 | up(&policy->lock); | |
1144 | ||
1145 | cpufreq_cpu_put(policy); | |
1146 | ||
1147 | return ret; | |
1148 | } | |
1149 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1150 | ||
1151 | ||
1152 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) | |
1153 | { | |
1154 | int ret = -EINVAL; | |
1155 | ||
1156 | if (!try_module_get(policy->governor->owner)) | |
1157 | return -EINVAL; | |
1158 | ||
1159 | dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); | |
1160 | ret = policy->governor->governor(policy, event); | |
1161 | ||
1162 | /* we keep one module reference alive for each CPU governed by this CPU */ | |
1163 | if ((event != CPUFREQ_GOV_START) || ret) | |
1164 | module_put(policy->governor->owner); | |
1165 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1166 | module_put(policy->governor->owner); | |
1167 | ||
1168 | return ret; | |
1169 | } | |
1170 | ||
1171 | ||
1172 | int cpufreq_governor(unsigned int cpu, unsigned int event) | |
1173 | { | |
1174 | int ret = 0; | |
1175 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1176 | ||
1177 | if (!policy) | |
1178 | return -EINVAL; | |
1179 | ||
1180 | down(&policy->lock); | |
1181 | ret = __cpufreq_governor(policy, event); | |
1182 | up(&policy->lock); | |
1183 | ||
1184 | cpufreq_cpu_put(policy); | |
1185 | ||
1186 | return ret; | |
1187 | } | |
1188 | EXPORT_SYMBOL_GPL(cpufreq_governor); | |
1189 | ||
1190 | ||
1191 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1192 | { | |
1193 | struct cpufreq_governor *t; | |
1194 | ||
1195 | if (!governor) | |
1196 | return -EINVAL; | |
1197 | ||
1198 | down(&cpufreq_governor_sem); | |
1199 | ||
1200 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
1201 | if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) { | |
1202 | up(&cpufreq_governor_sem); | |
1203 | return -EBUSY; | |
1204 | } | |
1205 | } | |
1206 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1207 | ||
1208 | up(&cpufreq_governor_sem); | |
1209 | ||
1210 | return 0; | |
1211 | } | |
1212 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1213 | ||
1214 | ||
1215 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1216 | { | |
1217 | if (!governor) | |
1218 | return; | |
1219 | ||
1220 | down(&cpufreq_governor_sem); | |
1221 | list_del(&governor->governor_list); | |
1222 | up(&cpufreq_governor_sem); | |
1223 | return; | |
1224 | } | |
1225 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1226 | ||
1227 | ||
1228 | ||
1229 | /********************************************************************* | |
1230 | * POLICY INTERFACE * | |
1231 | *********************************************************************/ | |
1232 | ||
1233 | /** | |
1234 | * cpufreq_get_policy - get the current cpufreq_policy | |
1235 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1236 | * | |
1237 | * Reads the current cpufreq policy. | |
1238 | */ | |
1239 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1240 | { | |
1241 | struct cpufreq_policy *cpu_policy; | |
1242 | if (!policy) | |
1243 | return -EINVAL; | |
1244 | ||
1245 | cpu_policy = cpufreq_cpu_get(cpu); | |
1246 | if (!cpu_policy) | |
1247 | return -EINVAL; | |
1248 | ||
1249 | down(&cpu_policy->lock); | |
1250 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); | |
1251 | up(&cpu_policy->lock); | |
1252 | ||
1253 | cpufreq_cpu_put(cpu_policy); | |
1254 | ||
1255 | return 0; | |
1256 | } | |
1257 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1258 | ||
1259 | ||
1260 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) | |
1261 | { | |
1262 | int ret = 0; | |
1263 | ||
1264 | cpufreq_debug_disable_ratelimit(); | |
1265 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1266 | policy->min, policy->max); | |
1267 | ||
1268 | memcpy(&policy->cpuinfo, | |
1269 | &data->cpuinfo, | |
1270 | sizeof(struct cpufreq_cpuinfo)); | |
1271 | ||
1272 | /* verify the cpu speed can be set within this limit */ | |
1273 | ret = cpufreq_driver->verify(policy); | |
1274 | if (ret) | |
1275 | goto error_out; | |
1276 | ||
1277 | down_read(&cpufreq_notifier_rwsem); | |
1278 | ||
1279 | /* adjust if necessary - all reasons */ | |
1280 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST, | |
1281 | policy); | |
1282 | ||
1283 | /* adjust if necessary - hardware incompatibility*/ | |
1284 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE, | |
1285 | policy); | |
1286 | ||
1287 | /* verify the cpu speed can be set within this limit, | |
1288 | which might be different to the first one */ | |
1289 | ret = cpufreq_driver->verify(policy); | |
1290 | if (ret) { | |
1291 | up_read(&cpufreq_notifier_rwsem); | |
1292 | goto error_out; | |
1293 | } | |
1294 | ||
1295 | /* notification of the new policy */ | |
1296 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY, | |
1297 | policy); | |
1298 | ||
1299 | up_read(&cpufreq_notifier_rwsem); | |
1300 | ||
1301 | data->min = policy->min; | |
1302 | data->max = policy->max; | |
1303 | ||
1304 | dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); | |
1305 | ||
1306 | if (cpufreq_driver->setpolicy) { | |
1307 | data->policy = policy->policy; | |
1308 | dprintk("setting range\n"); | |
1309 | ret = cpufreq_driver->setpolicy(policy); | |
1310 | } else { | |
1311 | if (policy->governor != data->governor) { | |
1312 | /* save old, working values */ | |
1313 | struct cpufreq_governor *old_gov = data->governor; | |
1314 | ||
1315 | dprintk("governor switch\n"); | |
1316 | ||
1317 | /* end old governor */ | |
1318 | if (data->governor) | |
1319 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1320 | ||
1321 | /* start new governor */ | |
1322 | data->governor = policy->governor; | |
1323 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1324 | /* new governor failed, so re-start old one */ | |
1325 | dprintk("starting governor %s failed\n", data->governor->name); | |
1326 | if (old_gov) { | |
1327 | data->governor = old_gov; | |
1328 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1329 | } | |
1330 | ret = -EINVAL; | |
1331 | goto error_out; | |
1332 | } | |
1333 | /* might be a policy change, too, so fall through */ | |
1334 | } | |
1335 | dprintk("governor: change or update limits\n"); | |
1336 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1337 | } | |
1338 | ||
1339 | error_out: | |
1340 | cpufreq_debug_enable_ratelimit(); | |
1341 | return ret; | |
1342 | } | |
1343 | ||
1344 | /** | |
1345 | * cpufreq_set_policy - set a new CPUFreq policy | |
1346 | * @policy: policy to be set. | |
1347 | * | |
1348 | * Sets a new CPU frequency and voltage scaling policy. | |
1349 | */ | |
1350 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1351 | { | |
1352 | int ret = 0; | |
1353 | struct cpufreq_policy *data; | |
1354 | ||
1355 | if (!policy) | |
1356 | return -EINVAL; | |
1357 | ||
1358 | data = cpufreq_cpu_get(policy->cpu); | |
1359 | if (!data) | |
1360 | return -EINVAL; | |
1361 | ||
1362 | /* lock this CPU */ | |
1363 | down(&data->lock); | |
1364 | ||
1365 | ret = __cpufreq_set_policy(data, policy); | |
1366 | data->user_policy.min = data->min; | |
1367 | data->user_policy.max = data->max; | |
1368 | data->user_policy.policy = data->policy; | |
1369 | data->user_policy.governor = data->governor; | |
1370 | ||
1371 | up(&data->lock); | |
1372 | cpufreq_cpu_put(data); | |
1373 | ||
1374 | return ret; | |
1375 | } | |
1376 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1377 | ||
1378 | ||
1379 | /** | |
1380 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1381 | * @cpu: CPU which shall be re-evaluated | |
1382 | * | |
1383 | * Usefull for policy notifiers which have different necessities | |
1384 | * at different times. | |
1385 | */ | |
1386 | int cpufreq_update_policy(unsigned int cpu) | |
1387 | { | |
1388 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1389 | struct cpufreq_policy policy; | |
1390 | int ret = 0; | |
1391 | ||
1392 | if (!data) | |
1393 | return -ENODEV; | |
1394 | ||
1395 | down(&data->lock); | |
1396 | ||
1397 | dprintk("updating policy for CPU %u\n", cpu); | |
1398 | memcpy(&policy, | |
1399 | data, | |
1400 | sizeof(struct cpufreq_policy)); | |
1401 | policy.min = data->user_policy.min; | |
1402 | policy.max = data->user_policy.max; | |
1403 | policy.policy = data->user_policy.policy; | |
1404 | policy.governor = data->user_policy.governor; | |
1405 | ||
1406 | ret = __cpufreq_set_policy(data, &policy); | |
1407 | ||
1408 | up(&data->lock); | |
1409 | ||
1410 | cpufreq_cpu_put(data); | |
1411 | return ret; | |
1412 | } | |
1413 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1414 | ||
1415 | ||
1416 | /********************************************************************* | |
1417 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1418 | *********************************************************************/ | |
1419 | ||
1420 | /** | |
1421 | * cpufreq_register_driver - register a CPU Frequency driver | |
1422 | * @driver_data: A struct cpufreq_driver containing the values# | |
1423 | * submitted by the CPU Frequency driver. | |
1424 | * | |
1425 | * Registers a CPU Frequency driver to this core code. This code | |
1426 | * returns zero on success, -EBUSY when another driver got here first | |
1427 | * (and isn't unregistered in the meantime). | |
1428 | * | |
1429 | */ | |
1430 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1431 | { | |
1432 | unsigned long flags; | |
1433 | int ret; | |
1434 | ||
1435 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1436 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1437 | return -EINVAL; | |
1438 | ||
1439 | dprintk("trying to register driver %s\n", driver_data->name); | |
1440 | ||
1441 | if (driver_data->setpolicy) | |
1442 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1443 | ||
1444 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1445 | if (cpufreq_driver) { | |
1446 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1447 | return -EBUSY; | |
1448 | } | |
1449 | cpufreq_driver = driver_data; | |
1450 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1451 | ||
1452 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1453 | ||
1454 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1455 | int i; | |
1456 | ret = -ENODEV; | |
1457 | ||
1458 | /* check for at least one working CPU */ | |
1459 | for (i=0; i<NR_CPUS; i++) | |
1460 | if (cpufreq_cpu_data[i]) | |
1461 | ret = 0; | |
1462 | ||
1463 | /* if all ->init() calls failed, unregister */ | |
1464 | if (ret) { | |
1465 | dprintk("no CPU initialized for driver %s\n", driver_data->name); | |
1466 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1467 | ||
1468 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1469 | cpufreq_driver = NULL; | |
1470 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1471 | } | |
1472 | } | |
1473 | ||
1474 | if (!ret) { | |
1475 | dprintk("driver %s up and running\n", driver_data->name); | |
1476 | cpufreq_debug_enable_ratelimit(); | |
1477 | } | |
1478 | ||
1479 | return (ret); | |
1480 | } | |
1481 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1482 | ||
1483 | ||
1484 | /** | |
1485 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1486 | * | |
1487 | * Unregister the current CPUFreq driver. Only call this if you have | |
1488 | * the right to do so, i.e. if you have succeeded in initialising before! | |
1489 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1490 | * currently not initialised. | |
1491 | */ | |
1492 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1493 | { | |
1494 | unsigned long flags; | |
1495 | ||
1496 | cpufreq_debug_disable_ratelimit(); | |
1497 | ||
1498 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1499 | cpufreq_debug_enable_ratelimit(); | |
1500 | return -EINVAL; | |
1501 | } | |
1502 | ||
1503 | dprintk("unregistering driver %s\n", driver->name); | |
1504 | ||
1505 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1506 | ||
1507 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1508 | cpufreq_driver = NULL; | |
1509 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1510 | ||
1511 | return 0; | |
1512 | } | |
1513 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |