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