Commit | Line | Data |
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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 | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/notifier.h> | |
23 | #include <linux/cpufreq.h> | |
24 | #include <linux/delay.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/device.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/cpu.h> | |
30 | #include <linux/completion.h> | |
3fc54d37 | 31 | #include <linux/mutex.h> |
1da177e4 LT |
32 | |
33 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg) | |
34 | ||
35 | /** | |
36 | * The "cpufreq driver" - the arch- or hardware-dependend low | |
37 | * level driver of CPUFreq support, and its spinlock. This lock | |
38 | * also protects the cpufreq_cpu_data array. | |
39 | */ | |
7d5e350f DJ |
40 | static struct cpufreq_driver *cpufreq_driver; |
41 | static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; | |
1da177e4 LT |
42 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
43 | ||
1da177e4 LT |
44 | /* internal prototypes */ |
45 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
46 | static void handle_update(void *data); | |
1da177e4 LT |
47 | |
48 | /** | |
32ee8c3e DJ |
49 | * Two notifier lists: the "policy" list is involved in the |
50 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
51 | * "transition" list for kernel code that needs to handle |
52 | * changes to devices when the CPU clock speed changes. | |
53 | * The mutex locks both lists. | |
54 | */ | |
7d5e350f DJ |
55 | static struct notifier_block *cpufreq_policy_notifier_list; |
56 | static struct notifier_block *cpufreq_transition_notifier_list; | |
57 | static DECLARE_RWSEM (cpufreq_notifier_rwsem); | |
1da177e4 LT |
58 | |
59 | ||
60 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 61 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 62 | |
7d5e350f | 63 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
64 | { |
65 | struct cpufreq_policy *data; | |
66 | unsigned long flags; | |
67 | ||
68 | if (cpu >= NR_CPUS) | |
69 | goto err_out; | |
70 | ||
71 | /* get the cpufreq driver */ | |
72 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
73 | ||
74 | if (!cpufreq_driver) | |
75 | goto err_out_unlock; | |
76 | ||
77 | if (!try_module_get(cpufreq_driver->owner)) | |
78 | goto err_out_unlock; | |
79 | ||
80 | ||
81 | /* get the CPU */ | |
82 | data = cpufreq_cpu_data[cpu]; | |
83 | ||
84 | if (!data) | |
85 | goto err_out_put_module; | |
86 | ||
87 | if (!kobject_get(&data->kobj)) | |
88 | goto err_out_put_module; | |
89 | ||
1da177e4 | 90 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
91 | return data; |
92 | ||
7d5e350f | 93 | err_out_put_module: |
1da177e4 | 94 | module_put(cpufreq_driver->owner); |
7d5e350f | 95 | err_out_unlock: |
1da177e4 | 96 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 97 | err_out: |
1da177e4 LT |
98 | return NULL; |
99 | } | |
100 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
101 | ||
7d5e350f | 102 | |
1da177e4 LT |
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 | ||
858119e1 | 131 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
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 | ||
858119e1 | 141 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
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; | |
32ee8c3e | 156 | |
1da177e4 LT |
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 | |
32ee8c3e | 203 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
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 | ||
858119e1 | 210 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
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 | /** | |
e4472cb3 DJ |
233 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
234 | * on frequency transition. | |
1da177e4 | 235 | * |
e4472cb3 DJ |
236 | * This function calls the transition notifiers and the "adjust_jiffies" |
237 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 238 | * external effects. |
1da177e4 LT |
239 | */ |
240 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
241 | { | |
e4472cb3 DJ |
242 | struct cpufreq_policy *policy; |
243 | ||
1da177e4 LT |
244 | BUG_ON(irqs_disabled()); |
245 | ||
246 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
247 | dprintk("notification %u of frequency transition to %u kHz\n", |
248 | state, freqs->new); | |
1da177e4 LT |
249 | |
250 | down_read(&cpufreq_notifier_rwsem); | |
e4472cb3 DJ |
251 | |
252 | policy = cpufreq_cpu_data[freqs->cpu]; | |
1da177e4 | 253 | switch (state) { |
e4472cb3 | 254 | |
1da177e4 | 255 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 256 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
257 | * which is not equal to what the cpufreq core thinks is |
258 | * "old frequency". | |
1da177e4 LT |
259 | */ |
260 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
261 | if ((policy) && (policy->cpu == freqs->cpu) && |
262 | (policy->cur) && (policy->cur != freqs->old)) { | |
263 | dprintk(KERN_WARNING "Warning: CPU frequency is" | |
264 | " %u, cpufreq assumed %u kHz.\n", | |
265 | freqs->old, policy->cur); | |
266 | freqs->old = policy->cur; | |
1da177e4 LT |
267 | } |
268 | } | |
e4472cb3 DJ |
269 | notifier_call_chain(&cpufreq_transition_notifier_list, |
270 | CPUFREQ_PRECHANGE, freqs); | |
1da177e4 LT |
271 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
272 | break; | |
e4472cb3 | 273 | |
1da177e4 LT |
274 | case CPUFREQ_POSTCHANGE: |
275 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e4472cb3 DJ |
276 | notifier_call_chain(&cpufreq_transition_notifier_list, |
277 | CPUFREQ_POSTCHANGE, freqs); | |
278 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) | |
279 | policy->cur = freqs->new; | |
1da177e4 LT |
280 | break; |
281 | } | |
282 | up_read(&cpufreq_notifier_rwsem); | |
283 | } | |
284 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
285 | ||
286 | ||
287 | ||
288 | /********************************************************************* | |
289 | * SYSFS INTERFACE * | |
290 | *********************************************************************/ | |
291 | ||
292 | /** | |
293 | * cpufreq_parse_governor - parse a governor string | |
294 | */ | |
295 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
296 | struct cpufreq_governor **governor) | |
297 | { | |
298 | if (!cpufreq_driver) | |
299 | return -EINVAL; | |
300 | if (cpufreq_driver->setpolicy) { | |
301 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
302 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
303 | return 0; | |
304 | } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
305 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
306 | return 0; | |
307 | } | |
308 | return -EINVAL; | |
309 | } else { | |
310 | struct cpufreq_governor *t; | |
3fc54d37 | 311 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 LT |
312 | if (!cpufreq_driver || !cpufreq_driver->target) |
313 | goto out; | |
314 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
315 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) { | |
316 | *governor = t; | |
3fc54d37 | 317 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
318 | return 0; |
319 | } | |
320 | } | |
7d5e350f | 321 | out: |
3fc54d37 | 322 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
323 | } |
324 | return -EINVAL; | |
325 | } | |
326 | EXPORT_SYMBOL_GPL(cpufreq_parse_governor); | |
327 | ||
328 | ||
329 | /* drivers/base/cpu.c */ | |
330 | extern struct sysdev_class cpu_sysdev_class; | |
331 | ||
332 | ||
333 | /** | |
334 | * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information | |
335 | * | |
336 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
337 | * "unsigned int". | |
338 | */ | |
339 | ||
32ee8c3e DJ |
340 | #define show_one(file_name, object) \ |
341 | static ssize_t show_##file_name \ | |
342 | (struct cpufreq_policy * policy, char *buf) \ | |
343 | { \ | |
344 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
345 | } |
346 | ||
347 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
348 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
349 | show_one(scaling_min_freq, min); | |
350 | show_one(scaling_max_freq, max); | |
351 | show_one(scaling_cur_freq, cur); | |
352 | ||
353 | /** | |
354 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
355 | */ | |
356 | #define store_one(file_name, object) \ | |
357 | static ssize_t store_##file_name \ | |
358 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
359 | { \ | |
360 | unsigned int ret = -EINVAL; \ | |
361 | struct cpufreq_policy new_policy; \ | |
362 | \ | |
363 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
364 | if (ret) \ | |
365 | return -EINVAL; \ | |
366 | \ | |
367 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
368 | if (ret != 1) \ | |
369 | return -EINVAL; \ | |
370 | \ | |
371 | ret = cpufreq_set_policy(&new_policy); \ | |
372 | \ | |
373 | return ret ? ret : count; \ | |
374 | } | |
375 | ||
376 | store_one(scaling_min_freq,min); | |
377 | store_one(scaling_max_freq,max); | |
378 | ||
379 | /** | |
380 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
381 | */ | |
382 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf) | |
383 | { | |
384 | unsigned int cur_freq = cpufreq_get(policy->cpu); | |
385 | if (!cur_freq) | |
386 | return sprintf(buf, "<unknown>"); | |
387 | return sprintf(buf, "%u\n", cur_freq); | |
388 | } | |
389 | ||
390 | ||
391 | /** | |
392 | * show_scaling_governor - show the current policy for the specified CPU | |
393 | */ | |
394 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf) | |
395 | { | |
396 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
397 | return sprintf(buf, "powersave\n"); | |
398 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
399 | return sprintf(buf, "performance\n"); | |
400 | else if (policy->governor) | |
401 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
402 | return -EINVAL; | |
403 | } | |
404 | ||
405 | ||
406 | /** | |
407 | * store_scaling_governor - store policy for the specified CPU | |
408 | */ | |
32ee8c3e DJ |
409 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
410 | const char *buf, size_t count) | |
1da177e4 LT |
411 | { |
412 | unsigned int ret = -EINVAL; | |
413 | char str_governor[16]; | |
414 | struct cpufreq_policy new_policy; | |
415 | ||
416 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
417 | if (ret) | |
418 | return ret; | |
419 | ||
420 | ret = sscanf (buf, "%15s", str_governor); | |
421 | if (ret != 1) | |
422 | return -EINVAL; | |
423 | ||
424 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor)) | |
425 | return -EINVAL; | |
426 | ||
427 | ret = cpufreq_set_policy(&new_policy); | |
1da177e4 LT |
428 | return ret ? ret : count; |
429 | } | |
430 | ||
431 | /** | |
432 | * show_scaling_driver - show the cpufreq driver currently loaded | |
433 | */ | |
434 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
435 | { | |
436 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
437 | } | |
438 | ||
439 | /** | |
440 | * show_scaling_available_governors - show the available CPUfreq governors | |
441 | */ | |
442 | static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy, | |
443 | char *buf) | |
444 | { | |
445 | ssize_t i = 0; | |
446 | struct cpufreq_governor *t; | |
447 | ||
448 | if (!cpufreq_driver->target) { | |
449 | i += sprintf(buf, "performance powersave"); | |
450 | goto out; | |
451 | } | |
452 | ||
453 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
454 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
455 | goto out; | |
456 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
457 | } | |
7d5e350f | 458 | out: |
1da177e4 LT |
459 | i += sprintf(&buf[i], "\n"); |
460 | return i; | |
461 | } | |
462 | /** | |
463 | * show_affected_cpus - show the CPUs affected by each transition | |
464 | */ | |
465 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
466 | { | |
467 | ssize_t i = 0; | |
468 | unsigned int cpu; | |
469 | ||
470 | for_each_cpu_mask(cpu, policy->cpus) { | |
471 | if (i) | |
472 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
473 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
474 | if (i >= (PAGE_SIZE - 5)) | |
475 | break; | |
476 | } | |
477 | i += sprintf(&buf[i], "\n"); | |
478 | return i; | |
479 | } | |
480 | ||
481 | ||
482 | #define define_one_ro(_name) \ | |
483 | static struct freq_attr _name = \ | |
484 | __ATTR(_name, 0444, show_##_name, NULL) | |
485 | ||
486 | #define define_one_ro0400(_name) \ | |
487 | static struct freq_attr _name = \ | |
488 | __ATTR(_name, 0400, show_##_name, NULL) | |
489 | ||
490 | #define define_one_rw(_name) \ | |
491 | static struct freq_attr _name = \ | |
492 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
493 | ||
494 | define_one_ro0400(cpuinfo_cur_freq); | |
495 | define_one_ro(cpuinfo_min_freq); | |
496 | define_one_ro(cpuinfo_max_freq); | |
497 | define_one_ro(scaling_available_governors); | |
498 | define_one_ro(scaling_driver); | |
499 | define_one_ro(scaling_cur_freq); | |
500 | define_one_ro(affected_cpus); | |
501 | define_one_rw(scaling_min_freq); | |
502 | define_one_rw(scaling_max_freq); | |
503 | define_one_rw(scaling_governor); | |
504 | ||
505 | static struct attribute * default_attrs[] = { | |
506 | &cpuinfo_min_freq.attr, | |
507 | &cpuinfo_max_freq.attr, | |
508 | &scaling_min_freq.attr, | |
509 | &scaling_max_freq.attr, | |
510 | &affected_cpus.attr, | |
511 | &scaling_governor.attr, | |
512 | &scaling_driver.attr, | |
513 | &scaling_available_governors.attr, | |
514 | NULL | |
515 | }; | |
516 | ||
517 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
518 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
519 | ||
520 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
521 | { | |
522 | struct cpufreq_policy * policy = to_policy(kobj); | |
523 | struct freq_attr * fattr = to_attr(attr); | |
524 | ssize_t ret; | |
525 | policy = cpufreq_cpu_get(policy->cpu); | |
526 | if (!policy) | |
527 | return -EINVAL; | |
70f2817a | 528 | ret = fattr->show ? fattr->show(policy,buf) : -EIO; |
1da177e4 LT |
529 | cpufreq_cpu_put(policy); |
530 | return ret; | |
531 | } | |
532 | ||
32ee8c3e | 533 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
534 | const char * buf, size_t count) |
535 | { | |
536 | struct cpufreq_policy * policy = to_policy(kobj); | |
537 | struct freq_attr * fattr = to_attr(attr); | |
538 | ssize_t ret; | |
539 | policy = cpufreq_cpu_get(policy->cpu); | |
540 | if (!policy) | |
541 | return -EINVAL; | |
70f2817a | 542 | ret = fattr->store ? fattr->store(policy,buf,count) : -EIO; |
1da177e4 LT |
543 | cpufreq_cpu_put(policy); |
544 | return ret; | |
545 | } | |
546 | ||
547 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
548 | { | |
549 | struct cpufreq_policy * policy = to_policy(kobj); | |
550 | dprintk("last reference is dropped\n"); | |
551 | complete(&policy->kobj_unregister); | |
552 | } | |
553 | ||
554 | static struct sysfs_ops sysfs_ops = { | |
555 | .show = show, | |
556 | .store = store, | |
557 | }; | |
558 | ||
559 | static struct kobj_type ktype_cpufreq = { | |
560 | .sysfs_ops = &sysfs_ops, | |
561 | .default_attrs = default_attrs, | |
562 | .release = cpufreq_sysfs_release, | |
563 | }; | |
564 | ||
565 | ||
566 | /** | |
567 | * cpufreq_add_dev - add a CPU device | |
568 | * | |
32ee8c3e | 569 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
570 | */ |
571 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
572 | { | |
573 | unsigned int cpu = sys_dev->id; | |
574 | int ret = 0; | |
575 | struct cpufreq_policy new_policy; | |
576 | struct cpufreq_policy *policy; | |
577 | struct freq_attr **drv_attr; | |
8ff69732 | 578 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
579 | unsigned long flags; |
580 | unsigned int j; | |
8ff69732 DJ |
581 | #ifdef CONFIG_SMP |
582 | struct cpufreq_policy *managed_policy; | |
583 | #endif | |
1da177e4 | 584 | |
c32b6b8e AR |
585 | if (cpu_is_offline(cpu)) |
586 | return 0; | |
587 | ||
1da177e4 LT |
588 | cpufreq_debug_disable_ratelimit(); |
589 | dprintk("adding CPU %u\n", cpu); | |
590 | ||
591 | #ifdef CONFIG_SMP | |
592 | /* check whether a different CPU already registered this | |
593 | * CPU because it is in the same boat. */ | |
594 | policy = cpufreq_cpu_get(cpu); | |
595 | if (unlikely(policy)) { | |
8ff69732 | 596 | cpufreq_cpu_put(policy); |
1da177e4 LT |
597 | cpufreq_debug_enable_ratelimit(); |
598 | return 0; | |
599 | } | |
600 | #endif | |
601 | ||
602 | if (!try_module_get(cpufreq_driver->owner)) { | |
603 | ret = -EINVAL; | |
604 | goto module_out; | |
605 | } | |
606 | ||
e98df50c | 607 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
608 | if (!policy) { |
609 | ret = -ENOMEM; | |
610 | goto nomem_out; | |
611 | } | |
1da177e4 LT |
612 | |
613 | policy->cpu = cpu; | |
614 | policy->cpus = cpumask_of_cpu(cpu); | |
615 | ||
83933af4 AV |
616 | mutex_init(&policy->lock); |
617 | mutex_lock(&policy->lock); | |
1da177e4 LT |
618 | init_completion(&policy->kobj_unregister); |
619 | INIT_WORK(&policy->update, handle_update, (void *)(long)cpu); | |
620 | ||
621 | /* call driver. From then on the cpufreq must be able | |
622 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
623 | */ | |
624 | ret = cpufreq_driver->init(policy); | |
625 | if (ret) { | |
626 | dprintk("initialization failed\n"); | |
f3876c1b | 627 | mutex_unlock(&policy->lock); |
1da177e4 LT |
628 | goto err_out; |
629 | } | |
630 | ||
8ff69732 DJ |
631 | #ifdef CONFIG_SMP |
632 | for_each_cpu_mask(j, policy->cpus) { | |
633 | if (cpu == j) | |
634 | continue; | |
635 | ||
636 | /* check for existing affected CPUs. They may not be aware | |
637 | * of it due to CPU Hotplug. | |
638 | */ | |
639 | managed_policy = cpufreq_cpu_get(j); | |
640 | if (unlikely(managed_policy)) { | |
641 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
642 | managed_policy->cpus = policy->cpus; | |
643 | cpufreq_cpu_data[cpu] = managed_policy; | |
644 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
645 | ||
646 | dprintk("CPU already managed, adding link\n"); | |
647 | sysfs_create_link(&sys_dev->kobj, | |
648 | &managed_policy->kobj, "cpufreq"); | |
649 | ||
650 | cpufreq_debug_enable_ratelimit(); | |
651 | mutex_unlock(&policy->lock); | |
652 | ret = 0; | |
653 | goto err_out_driver_exit; /* call driver->exit() */ | |
654 | } | |
655 | } | |
656 | #endif | |
1da177e4 LT |
657 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
658 | ||
659 | /* prepare interface data */ | |
660 | policy->kobj.parent = &sys_dev->kobj; | |
661 | policy->kobj.ktype = &ktype_cpufreq; | |
662 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
663 | ||
664 | ret = kobject_register(&policy->kobj); | |
f3876c1b AM |
665 | if (ret) { |
666 | mutex_unlock(&policy->lock); | |
8085e1f1 | 667 | goto err_out_driver_exit; |
f3876c1b | 668 | } |
1da177e4 LT |
669 | /* set up files for this cpu device */ |
670 | drv_attr = cpufreq_driver->attr; | |
671 | while ((drv_attr) && (*drv_attr)) { | |
672 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
673 | drv_attr++; | |
674 | } | |
675 | if (cpufreq_driver->get) | |
676 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
677 | if (cpufreq_driver->target) | |
678 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
679 | ||
680 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
681 | for_each_cpu_mask(j, policy->cpus) | |
682 | cpufreq_cpu_data[j] = policy; | |
683 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
8ff69732 DJ |
684 | |
685 | /* symlink affected CPUs */ | |
686 | for_each_cpu_mask(j, policy->cpus) { | |
687 | if (j == cpu) | |
688 | continue; | |
689 | if (!cpu_online(j)) | |
690 | continue; | |
691 | ||
692 | dprintk("CPU already managed, adding link\n"); | |
693 | cpufreq_cpu_get(cpu); | |
694 | cpu_sys_dev = get_cpu_sysdev(j); | |
695 | sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
696 | "cpufreq"); | |
697 | } | |
698 | ||
1da177e4 LT |
699 | policy->governor = NULL; /* to assure that the starting sequence is |
700 | * run in cpufreq_set_policy */ | |
83933af4 | 701 | mutex_unlock(&policy->lock); |
1da177e4 LT |
702 | |
703 | /* set default policy */ | |
704 | ||
705 | ret = cpufreq_set_policy(&new_policy); | |
706 | if (ret) { | |
707 | dprintk("setting policy failed\n"); | |
708 | goto err_out_unregister; | |
709 | } | |
710 | ||
711 | module_put(cpufreq_driver->owner); | |
1da177e4 LT |
712 | dprintk("initialization complete\n"); |
713 | cpufreq_debug_enable_ratelimit(); | |
714 | ||
715 | return 0; | |
716 | ||
717 | ||
718 | err_out_unregister: | |
719 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
720 | for_each_cpu_mask(j, policy->cpus) | |
721 | cpufreq_cpu_data[j] = NULL; | |
722 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
723 | ||
724 | kobject_unregister(&policy->kobj); | |
725 | wait_for_completion(&policy->kobj_unregister); | |
726 | ||
8085e1f1 VP |
727 | err_out_driver_exit: |
728 | if (cpufreq_driver->exit) | |
729 | cpufreq_driver->exit(policy); | |
730 | ||
1da177e4 LT |
731 | err_out: |
732 | kfree(policy); | |
733 | ||
734 | nomem_out: | |
735 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 736 | module_out: |
1da177e4 LT |
737 | cpufreq_debug_enable_ratelimit(); |
738 | return ret; | |
739 | } | |
740 | ||
741 | ||
742 | /** | |
743 | * cpufreq_remove_dev - remove a CPU device | |
744 | * | |
745 | * Removes the cpufreq interface for a CPU device. | |
746 | */ | |
747 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
748 | { | |
749 | unsigned int cpu = sys_dev->id; | |
750 | unsigned long flags; | |
751 | struct cpufreq_policy *data; | |
752 | #ifdef CONFIG_SMP | |
e738cf6d | 753 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
754 | unsigned int j; |
755 | #endif | |
756 | ||
757 | cpufreq_debug_disable_ratelimit(); | |
758 | dprintk("unregistering CPU %u\n", cpu); | |
759 | ||
760 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
761 | data = cpufreq_cpu_data[cpu]; | |
762 | ||
763 | if (!data) { | |
764 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
765 | cpufreq_debug_enable_ratelimit(); |
766 | return -EINVAL; | |
767 | } | |
768 | cpufreq_cpu_data[cpu] = NULL; | |
769 | ||
770 | ||
771 | #ifdef CONFIG_SMP | |
772 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 773 | * only need to unlink, put and exit |
1da177e4 LT |
774 | */ |
775 | if (unlikely(cpu != data->cpu)) { | |
776 | dprintk("removing link\n"); | |
8ff69732 | 777 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
778 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
779 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
780 | cpufreq_cpu_put(data); |
781 | cpufreq_debug_enable_ratelimit(); | |
782 | return 0; | |
783 | } | |
784 | #endif | |
785 | ||
1da177e4 LT |
786 | |
787 | if (!kobject_get(&data->kobj)) { | |
788 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
789 | cpufreq_debug_enable_ratelimit(); | |
32ee8c3e | 790 | return -EFAULT; |
1da177e4 LT |
791 | } |
792 | ||
793 | #ifdef CONFIG_SMP | |
794 | /* if we have other CPUs still registered, we need to unlink them, | |
795 | * or else wait_for_completion below will lock up. Clean the | |
796 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
797 | * links afterwards. | |
798 | */ | |
799 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
800 | for_each_cpu_mask(j, data->cpus) { | |
801 | if (j == cpu) | |
802 | continue; | |
803 | cpufreq_cpu_data[j] = NULL; | |
804 | } | |
805 | } | |
806 | ||
807 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
808 | ||
809 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
810 | for_each_cpu_mask(j, data->cpus) { | |
811 | if (j == cpu) | |
812 | continue; | |
813 | dprintk("removing link for cpu %u\n", j); | |
d434fca7 AR |
814 | cpu_sys_dev = get_cpu_sysdev(j); |
815 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
816 | cpufreq_cpu_put(data); |
817 | } | |
818 | } | |
819 | #else | |
820 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
821 | #endif | |
822 | ||
83933af4 | 823 | mutex_lock(&data->lock); |
1da177e4 LT |
824 | if (cpufreq_driver->target) |
825 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
83933af4 | 826 | mutex_unlock(&data->lock); |
1da177e4 LT |
827 | |
828 | kobject_unregister(&data->kobj); | |
829 | ||
830 | kobject_put(&data->kobj); | |
831 | ||
832 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 833 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
834 | * unloading. |
835 | */ | |
836 | dprintk("waiting for dropping of refcount\n"); | |
837 | wait_for_completion(&data->kobj_unregister); | |
838 | dprintk("wait complete\n"); | |
839 | ||
840 | if (cpufreq_driver->exit) | |
841 | cpufreq_driver->exit(data); | |
842 | ||
843 | kfree(data); | |
844 | ||
845 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
846 | return 0; |
847 | } | |
848 | ||
849 | ||
850 | static void handle_update(void *data) | |
851 | { | |
852 | unsigned int cpu = (unsigned int)(long)data; | |
853 | dprintk("handle_update for cpu %u called\n", cpu); | |
854 | cpufreq_update_policy(cpu); | |
855 | } | |
856 | ||
857 | /** | |
858 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
859 | * @cpu: cpu number | |
860 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
861 | * @new_freq: CPU frequency the CPU actually runs at | |
862 | * | |
863 | * We adjust to current frequency first, and need to clean up later. So either call | |
864 | * to cpufreq_update_policy() or schedule handle_update()). | |
865 | */ | |
866 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq) | |
867 | { | |
868 | struct cpufreq_freqs freqs; | |
869 | ||
78ee998f | 870 | dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
871 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
872 | ||
873 | freqs.cpu = cpu; | |
874 | freqs.old = old_freq; | |
875 | freqs.new = new_freq; | |
876 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
877 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
878 | } | |
879 | ||
880 | ||
32ee8c3e | 881 | /** |
95235ca2 VP |
882 | * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur |
883 | * @cpu: CPU number | |
884 | * | |
885 | * This is the last known freq, without actually getting it from the driver. | |
886 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
887 | */ | |
888 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
889 | { | |
890 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
891 | unsigned int ret = 0; | |
892 | ||
893 | if (policy) { | |
83933af4 | 894 | mutex_lock(&policy->lock); |
95235ca2 | 895 | ret = policy->cur; |
83933af4 | 896 | mutex_unlock(&policy->lock); |
95235ca2 VP |
897 | cpufreq_cpu_put(policy); |
898 | } | |
899 | ||
900 | return (ret); | |
901 | } | |
902 | EXPORT_SYMBOL(cpufreq_quick_get); | |
903 | ||
904 | ||
32ee8c3e | 905 | /** |
1da177e4 LT |
906 | * cpufreq_get - get the current CPU frequency (in kHz) |
907 | * @cpu: CPU number | |
908 | * | |
909 | * Get the CPU current (static) CPU frequency | |
910 | */ | |
911 | unsigned int cpufreq_get(unsigned int cpu) | |
912 | { | |
913 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
914 | unsigned int ret = 0; | |
915 | ||
916 | if (!policy) | |
917 | return 0; | |
918 | ||
919 | if (!cpufreq_driver->get) | |
920 | goto out; | |
921 | ||
83933af4 | 922 | mutex_lock(&policy->lock); |
1da177e4 LT |
923 | |
924 | ret = cpufreq_driver->get(cpu); | |
925 | ||
7d5e350f | 926 | if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
1da177e4 LT |
927 | /* verify no discrepancy between actual and saved value exists */ |
928 | if (unlikely(ret != policy->cur)) { | |
929 | cpufreq_out_of_sync(cpu, policy->cur, ret); | |
930 | schedule_work(&policy->update); | |
931 | } | |
932 | } | |
933 | ||
83933af4 | 934 | mutex_unlock(&policy->lock); |
1da177e4 | 935 | |
7d5e350f | 936 | out: |
1da177e4 LT |
937 | cpufreq_cpu_put(policy); |
938 | ||
939 | return (ret); | |
940 | } | |
941 | EXPORT_SYMBOL(cpufreq_get); | |
942 | ||
943 | ||
42d4dc3f BH |
944 | /** |
945 | * cpufreq_suspend - let the low level driver prepare for suspend | |
946 | */ | |
947 | ||
e00d9967 | 948 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
949 | { |
950 | int cpu = sysdev->id; | |
951 | unsigned int ret = 0; | |
952 | unsigned int cur_freq = 0; | |
953 | struct cpufreq_policy *cpu_policy; | |
954 | ||
955 | dprintk("resuming cpu %u\n", cpu); | |
956 | ||
957 | if (!cpu_online(cpu)) | |
958 | return 0; | |
959 | ||
960 | /* we may be lax here as interrupts are off. Nonetheless | |
961 | * we need to grab the correct cpu policy, as to check | |
962 | * whether we really run on this CPU. | |
963 | */ | |
964 | ||
965 | cpu_policy = cpufreq_cpu_get(cpu); | |
966 | if (!cpu_policy) | |
967 | return -EINVAL; | |
968 | ||
969 | /* only handle each CPU group once */ | |
970 | if (unlikely(cpu_policy->cpu != cpu)) { | |
971 | cpufreq_cpu_put(cpu_policy); | |
972 | return 0; | |
973 | } | |
974 | ||
975 | if (cpufreq_driver->suspend) { | |
e00d9967 | 976 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
977 | if (ret) { |
978 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
979 | "step on CPU %u\n", cpu_policy->cpu); | |
980 | cpufreq_cpu_put(cpu_policy); | |
981 | return ret; | |
982 | } | |
983 | } | |
984 | ||
985 | ||
986 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
987 | goto out; | |
988 | ||
989 | if (cpufreq_driver->get) | |
990 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
991 | ||
992 | if (!cur_freq || !cpu_policy->cur) { | |
993 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
994 | "frequency is what timing core thinks it is.\n"); | |
995 | goto out; | |
996 | } | |
997 | ||
998 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
999 | struct cpufreq_freqs freqs; | |
1000 | ||
1001 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
78ee998f | 1002 | dprintk(KERN_DEBUG "Warning: CPU frequency is %u, " |
42d4dc3f BH |
1003 | "cpufreq assumed %u kHz.\n", |
1004 | cur_freq, cpu_policy->cur); | |
1005 | ||
1006 | freqs.cpu = cpu; | |
1007 | freqs.old = cpu_policy->cur; | |
1008 | freqs.new = cur_freq; | |
1009 | ||
1010 | notifier_call_chain(&cpufreq_transition_notifier_list, | |
1011 | CPUFREQ_SUSPENDCHANGE, &freqs); | |
1012 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1013 | ||
1014 | cpu_policy->cur = cur_freq; | |
1015 | } | |
1016 | ||
7d5e350f | 1017 | out: |
42d4dc3f BH |
1018 | cpufreq_cpu_put(cpu_policy); |
1019 | return 0; | |
1020 | } | |
1021 | ||
1da177e4 LT |
1022 | /** |
1023 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1024 | * | |
1025 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1026 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1027 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1028 | * restored. | |
1da177e4 LT |
1029 | */ |
1030 | static int cpufreq_resume(struct sys_device * sysdev) | |
1031 | { | |
1032 | int cpu = sysdev->id; | |
1033 | unsigned int ret = 0; | |
1034 | struct cpufreq_policy *cpu_policy; | |
1035 | ||
1036 | dprintk("resuming cpu %u\n", cpu); | |
1037 | ||
1038 | if (!cpu_online(cpu)) | |
1039 | return 0; | |
1040 | ||
1041 | /* we may be lax here as interrupts are off. Nonetheless | |
1042 | * we need to grab the correct cpu policy, as to check | |
1043 | * whether we really run on this CPU. | |
1044 | */ | |
1045 | ||
1046 | cpu_policy = cpufreq_cpu_get(cpu); | |
1047 | if (!cpu_policy) | |
1048 | return -EINVAL; | |
1049 | ||
1050 | /* only handle each CPU group once */ | |
1051 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1052 | cpufreq_cpu_put(cpu_policy); | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | if (cpufreq_driver->resume) { | |
1057 | ret = cpufreq_driver->resume(cpu_policy); | |
1058 | if (ret) { | |
1059 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1060 | "step on CPU %u\n", cpu_policy->cpu); | |
1061 | cpufreq_cpu_put(cpu_policy); | |
1062 | return ret; | |
1063 | } | |
1064 | } | |
1065 | ||
1066 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1067 | unsigned int cur_freq = 0; | |
1068 | ||
1069 | if (cpufreq_driver->get) | |
1070 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1071 | ||
1072 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1073 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1074 | "current frequency is what timing core " | |
1075 | "thinks it is.\n"); | |
1da177e4 LT |
1076 | goto out; |
1077 | } | |
1078 | ||
1079 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1080 | struct cpufreq_freqs freqs; | |
1081 | ||
ac09f698 | 1082 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
78ee998f | 1083 | dprintk(KERN_WARNING "Warning: CPU frequency" |
ac09f698 BH |
1084 | "is %u, cpufreq assumed %u kHz.\n", |
1085 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1086 | |
1087 | freqs.cpu = cpu; | |
1088 | freqs.old = cpu_policy->cur; | |
1089 | freqs.new = cur_freq; | |
1090 | ||
42d4dc3f BH |
1091 | notifier_call_chain(&cpufreq_transition_notifier_list, |
1092 | CPUFREQ_RESUMECHANGE, &freqs); | |
1da177e4 LT |
1093 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1094 | ||
1095 | cpu_policy->cur = cur_freq; | |
1096 | } | |
1097 | } | |
1098 | ||
1099 | out: | |
1100 | schedule_work(&cpu_policy->update); | |
1101 | cpufreq_cpu_put(cpu_policy); | |
1102 | return ret; | |
1103 | } | |
1104 | ||
1105 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1106 | .add = cpufreq_add_dev, | |
1107 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1108 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1109 | .resume = cpufreq_resume, |
1110 | }; | |
1111 | ||
1112 | ||
1113 | /********************************************************************* | |
1114 | * NOTIFIER LISTS INTERFACE * | |
1115 | *********************************************************************/ | |
1116 | ||
1117 | /** | |
1118 | * cpufreq_register_notifier - register a driver with cpufreq | |
1119 | * @nb: notifier function to register | |
1120 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1121 | * | |
32ee8c3e | 1122 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1123 | * are notified about clock rate changes (once before and once after |
1124 | * the transition), or a list of drivers that are notified about | |
1125 | * changes in cpufreq policy. | |
1126 | * | |
1127 | * This function may sleep, and has the same return conditions as | |
1128 | * notifier_chain_register. | |
1129 | */ | |
1130 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1131 | { | |
1132 | int ret; | |
1133 | ||
1134 | down_write(&cpufreq_notifier_rwsem); | |
1135 | switch (list) { | |
1136 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1137 | ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb); | |
1138 | break; | |
1139 | case CPUFREQ_POLICY_NOTIFIER: | |
1140 | ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb); | |
1141 | break; | |
1142 | default: | |
1143 | ret = -EINVAL; | |
1144 | } | |
1145 | up_write(&cpufreq_notifier_rwsem); | |
1146 | ||
1147 | return ret; | |
1148 | } | |
1149 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1150 | ||
1151 | ||
1152 | /** | |
1153 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1154 | * @nb: notifier block to be unregistered | |
1155 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1156 | * | |
1157 | * Remove a driver from the CPU frequency notifier list. | |
1158 | * | |
1159 | * This function may sleep, and has the same return conditions as | |
1160 | * notifier_chain_unregister. | |
1161 | */ | |
1162 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1163 | { | |
1164 | int ret; | |
1165 | ||
1166 | down_write(&cpufreq_notifier_rwsem); | |
1167 | switch (list) { | |
1168 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1169 | ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb); | |
1170 | break; | |
1171 | case CPUFREQ_POLICY_NOTIFIER: | |
1172 | ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb); | |
1173 | break; | |
1174 | default: | |
1175 | ret = -EINVAL; | |
1176 | } | |
1177 | up_write(&cpufreq_notifier_rwsem); | |
1178 | ||
1179 | return ret; | |
1180 | } | |
1181 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1182 | ||
1183 | ||
1184 | /********************************************************************* | |
1185 | * GOVERNORS * | |
1186 | *********************************************************************/ | |
1187 | ||
1188 | ||
1189 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1190 | unsigned int target_freq, | |
1191 | unsigned int relation) | |
1192 | { | |
1193 | int retval = -EINVAL; | |
c32b6b8e | 1194 | |
a9d9baa1 | 1195 | lock_cpu_hotplug(); |
1da177e4 LT |
1196 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1197 | target_freq, relation); | |
1198 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1199 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1200 | |
a9d9baa1 | 1201 | unlock_cpu_hotplug(); |
90d45d17 | 1202 | |
1da177e4 LT |
1203 | return retval; |
1204 | } | |
1205 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1206 | ||
1da177e4 LT |
1207 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1208 | unsigned int target_freq, | |
1209 | unsigned int relation) | |
1210 | { | |
cc993cab | 1211 | int ret; |
1da177e4 LT |
1212 | |
1213 | policy = cpufreq_cpu_get(policy->cpu); | |
1214 | if (!policy) | |
1215 | return -EINVAL; | |
1216 | ||
83933af4 | 1217 | mutex_lock(&policy->lock); |
1da177e4 LT |
1218 | |
1219 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1220 | ||
83933af4 | 1221 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1222 | |
1223 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1224 | return ret; |
1225 | } | |
1226 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1227 | ||
1228 | ||
1229 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) | |
1230 | { | |
cc993cab | 1231 | int ret; |
1da177e4 LT |
1232 | |
1233 | if (!try_module_get(policy->governor->owner)) | |
1234 | return -EINVAL; | |
1235 | ||
1236 | dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); | |
1237 | ret = policy->governor->governor(policy, event); | |
1238 | ||
1239 | /* we keep one module reference alive for each CPU governed by this CPU */ | |
1240 | if ((event != CPUFREQ_GOV_START) || ret) | |
1241 | module_put(policy->governor->owner); | |
1242 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1243 | module_put(policy->governor->owner); | |
1244 | ||
1245 | return ret; | |
1246 | } | |
1247 | ||
1248 | ||
1249 | int cpufreq_governor(unsigned int cpu, unsigned int event) | |
1250 | { | |
1251 | int ret = 0; | |
1252 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1253 | ||
1254 | if (!policy) | |
1255 | return -EINVAL; | |
1256 | ||
83933af4 | 1257 | mutex_lock(&policy->lock); |
1da177e4 | 1258 | ret = __cpufreq_governor(policy, event); |
83933af4 | 1259 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1260 | |
1261 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1262 | return ret; |
1263 | } | |
1264 | EXPORT_SYMBOL_GPL(cpufreq_governor); | |
1265 | ||
1266 | ||
1267 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1268 | { | |
1269 | struct cpufreq_governor *t; | |
1270 | ||
1271 | if (!governor) | |
1272 | return -EINVAL; | |
1273 | ||
3fc54d37 | 1274 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1275 | |
1da177e4 LT |
1276 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { |
1277 | if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) { | |
3fc54d37 | 1278 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1279 | return -EBUSY; |
1280 | } | |
1281 | } | |
1282 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1283 | ||
32ee8c3e | 1284 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1285 | return 0; |
1286 | } | |
1287 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1288 | ||
1289 | ||
1290 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1291 | { | |
1292 | if (!governor) | |
1293 | return; | |
1294 | ||
3fc54d37 | 1295 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1296 | list_del(&governor->governor_list); |
3fc54d37 | 1297 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1298 | return; |
1299 | } | |
1300 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1301 | ||
1302 | ||
1303 | ||
1304 | /********************************************************************* | |
1305 | * POLICY INTERFACE * | |
1306 | *********************************************************************/ | |
1307 | ||
1308 | /** | |
1309 | * cpufreq_get_policy - get the current cpufreq_policy | |
1310 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1311 | * | |
1312 | * Reads the current cpufreq policy. | |
1313 | */ | |
1314 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1315 | { | |
1316 | struct cpufreq_policy *cpu_policy; | |
1317 | if (!policy) | |
1318 | return -EINVAL; | |
1319 | ||
1320 | cpu_policy = cpufreq_cpu_get(cpu); | |
1321 | if (!cpu_policy) | |
1322 | return -EINVAL; | |
1323 | ||
83933af4 | 1324 | mutex_lock(&cpu_policy->lock); |
1da177e4 | 1325 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
83933af4 | 1326 | mutex_unlock(&cpu_policy->lock); |
1da177e4 LT |
1327 | |
1328 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1329 | return 0; |
1330 | } | |
1331 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1332 | ||
1333 | ||
1334 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) | |
1335 | { | |
1336 | int ret = 0; | |
1337 | ||
1338 | cpufreq_debug_disable_ratelimit(); | |
1339 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1340 | policy->min, policy->max); | |
1341 | ||
7d5e350f | 1342 | memcpy(&policy->cpuinfo, &data->cpuinfo, sizeof(struct cpufreq_cpuinfo)); |
1da177e4 LT |
1343 | |
1344 | /* verify the cpu speed can be set within this limit */ | |
1345 | ret = cpufreq_driver->verify(policy); | |
1346 | if (ret) | |
1347 | goto error_out; | |
1348 | ||
1349 | down_read(&cpufreq_notifier_rwsem); | |
1350 | ||
1351 | /* adjust if necessary - all reasons */ | |
1352 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST, | |
1353 | policy); | |
1354 | ||
1355 | /* adjust if necessary - hardware incompatibility*/ | |
1356 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE, | |
1357 | policy); | |
1358 | ||
1359 | /* verify the cpu speed can be set within this limit, | |
1360 | which might be different to the first one */ | |
1361 | ret = cpufreq_driver->verify(policy); | |
1362 | if (ret) { | |
1363 | up_read(&cpufreq_notifier_rwsem); | |
1364 | goto error_out; | |
1365 | } | |
1366 | ||
1367 | /* notification of the new policy */ | |
1368 | notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY, | |
1369 | policy); | |
1370 | ||
1371 | up_read(&cpufreq_notifier_rwsem); | |
1372 | ||
7d5e350f DJ |
1373 | data->min = policy->min; |
1374 | data->max = policy->max; | |
1da177e4 LT |
1375 | |
1376 | dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); | |
1377 | ||
1378 | if (cpufreq_driver->setpolicy) { | |
1379 | data->policy = policy->policy; | |
1380 | dprintk("setting range\n"); | |
1381 | ret = cpufreq_driver->setpolicy(policy); | |
1382 | } else { | |
1383 | if (policy->governor != data->governor) { | |
1384 | /* save old, working values */ | |
1385 | struct cpufreq_governor *old_gov = data->governor; | |
1386 | ||
1387 | dprintk("governor switch\n"); | |
1388 | ||
1389 | /* end old governor */ | |
1390 | if (data->governor) | |
1391 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1392 | ||
1393 | /* start new governor */ | |
1394 | data->governor = policy->governor; | |
1395 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1396 | /* new governor failed, so re-start old one */ | |
1397 | dprintk("starting governor %s failed\n", data->governor->name); | |
1398 | if (old_gov) { | |
1399 | data->governor = old_gov; | |
1400 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1401 | } | |
1402 | ret = -EINVAL; | |
1403 | goto error_out; | |
1404 | } | |
1405 | /* might be a policy change, too, so fall through */ | |
1406 | } | |
1407 | dprintk("governor: change or update limits\n"); | |
1408 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1409 | } | |
1410 | ||
7d5e350f | 1411 | error_out: |
1da177e4 LT |
1412 | cpufreq_debug_enable_ratelimit(); |
1413 | return ret; | |
1414 | } | |
1415 | ||
1416 | /** | |
1417 | * cpufreq_set_policy - set a new CPUFreq policy | |
1418 | * @policy: policy to be set. | |
1419 | * | |
1420 | * Sets a new CPU frequency and voltage scaling policy. | |
1421 | */ | |
1422 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1423 | { | |
1424 | int ret = 0; | |
1425 | struct cpufreq_policy *data; | |
1426 | ||
1427 | if (!policy) | |
1428 | return -EINVAL; | |
1429 | ||
1430 | data = cpufreq_cpu_get(policy->cpu); | |
1431 | if (!data) | |
1432 | return -EINVAL; | |
1433 | ||
1434 | /* lock this CPU */ | |
83933af4 | 1435 | mutex_lock(&data->lock); |
1da177e4 LT |
1436 | |
1437 | ret = __cpufreq_set_policy(data, policy); | |
1438 | data->user_policy.min = data->min; | |
1439 | data->user_policy.max = data->max; | |
1440 | data->user_policy.policy = data->policy; | |
1441 | data->user_policy.governor = data->governor; | |
1442 | ||
83933af4 | 1443 | mutex_unlock(&data->lock); |
1da177e4 LT |
1444 | cpufreq_cpu_put(data); |
1445 | ||
1446 | return ret; | |
1447 | } | |
1448 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1449 | ||
1450 | ||
1451 | /** | |
1452 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1453 | * @cpu: CPU which shall be re-evaluated | |
1454 | * | |
1455 | * Usefull for policy notifiers which have different necessities | |
1456 | * at different times. | |
1457 | */ | |
1458 | int cpufreq_update_policy(unsigned int cpu) | |
1459 | { | |
1460 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1461 | struct cpufreq_policy policy; | |
1462 | int ret = 0; | |
1463 | ||
1464 | if (!data) | |
1465 | return -ENODEV; | |
1466 | ||
83933af4 | 1467 | mutex_lock(&data->lock); |
1da177e4 LT |
1468 | |
1469 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1470 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1471 | policy.min = data->user_policy.min; |
1472 | policy.max = data->user_policy.max; | |
1473 | policy.policy = data->user_policy.policy; | |
1474 | policy.governor = data->user_policy.governor; | |
1475 | ||
0961dd0d TR |
1476 | /* BIOS might change freq behind our back |
1477 | -> ask driver for current freq and notify governors about a change */ | |
1478 | if (cpufreq_driver->get) { | |
1479 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1480 | if (!data->cur) { |
1481 | dprintk("Driver did not initialize current freq"); | |
1482 | data->cur = policy.cur; | |
1483 | } else { | |
1484 | if (data->cur != policy.cur) | |
1485 | cpufreq_out_of_sync(cpu, data->cur, policy.cur); | |
1486 | } | |
0961dd0d TR |
1487 | } |
1488 | ||
1da177e4 LT |
1489 | ret = __cpufreq_set_policy(data, &policy); |
1490 | ||
83933af4 | 1491 | mutex_unlock(&data->lock); |
1da177e4 LT |
1492 | |
1493 | cpufreq_cpu_put(data); | |
1494 | return ret; | |
1495 | } | |
1496 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1497 | ||
c32b6b8e AR |
1498 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
1499 | unsigned long action, void *hcpu) | |
1500 | { | |
1501 | unsigned int cpu = (unsigned long)hcpu; | |
1502 | struct cpufreq_policy *policy; | |
1503 | struct sys_device *sys_dev; | |
1504 | ||
1505 | sys_dev = get_cpu_sysdev(cpu); | |
1506 | ||
1507 | if (sys_dev) { | |
1508 | switch (action) { | |
1509 | case CPU_ONLINE: | |
1510 | cpufreq_add_dev(sys_dev); | |
1511 | break; | |
1512 | case CPU_DOWN_PREPARE: | |
1513 | /* | |
1514 | * We attempt to put this cpu in lowest frequency | |
1515 | * possible before going down. This will permit | |
1516 | * hardware-managed P-State to switch other related | |
1517 | * threads to min or higher speeds if possible. | |
1518 | */ | |
1519 | policy = cpufreq_cpu_data[cpu]; | |
1520 | if (policy) { | |
1521 | cpufreq_driver_target(policy, policy->min, | |
1522 | CPUFREQ_RELATION_H); | |
1523 | } | |
1524 | break; | |
1525 | case CPU_DEAD: | |
1526 | cpufreq_remove_dev(sys_dev); | |
1527 | break; | |
1528 | } | |
1529 | } | |
1530 | return NOTIFY_OK; | |
1531 | } | |
1532 | ||
1533 | static struct notifier_block cpufreq_cpu_notifier = | |
1534 | { | |
1535 | .notifier_call = cpufreq_cpu_callback, | |
1536 | }; | |
1da177e4 LT |
1537 | |
1538 | /********************************************************************* | |
1539 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1540 | *********************************************************************/ | |
1541 | ||
1542 | /** | |
1543 | * cpufreq_register_driver - register a CPU Frequency driver | |
1544 | * @driver_data: A struct cpufreq_driver containing the values# | |
1545 | * submitted by the CPU Frequency driver. | |
1546 | * | |
32ee8c3e | 1547 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1548 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1549 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1550 | * |
1551 | */ | |
1552 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1553 | { | |
1554 | unsigned long flags; | |
1555 | int ret; | |
1556 | ||
1557 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1558 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1559 | return -EINVAL; | |
1560 | ||
1561 | dprintk("trying to register driver %s\n", driver_data->name); | |
1562 | ||
1563 | if (driver_data->setpolicy) | |
1564 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1565 | ||
1566 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1567 | if (cpufreq_driver) { | |
1568 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1569 | return -EBUSY; | |
1570 | } | |
1571 | cpufreq_driver = driver_data; | |
1572 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1573 | ||
1574 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1575 | ||
1576 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1577 | int i; | |
1578 | ret = -ENODEV; | |
1579 | ||
1580 | /* check for at least one working CPU */ | |
1581 | for (i=0; i<NR_CPUS; i++) | |
1582 | if (cpufreq_cpu_data[i]) | |
1583 | ret = 0; | |
1584 | ||
1585 | /* if all ->init() calls failed, unregister */ | |
1586 | if (ret) { | |
1587 | dprintk("no CPU initialized for driver %s\n", driver_data->name); | |
1588 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1589 | ||
1590 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1591 | cpufreq_driver = NULL; | |
1592 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1593 | } | |
1594 | } | |
1595 | ||
1596 | if (!ret) { | |
c32b6b8e | 1597 | register_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1598 | dprintk("driver %s up and running\n", driver_data->name); |
1599 | cpufreq_debug_enable_ratelimit(); | |
1600 | } | |
1601 | ||
1602 | return (ret); | |
1603 | } | |
1604 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1605 | ||
1606 | ||
1607 | /** | |
1608 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1609 | * | |
32ee8c3e | 1610 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1611 | * the right to do so, i.e. if you have succeeded in initialising before! |
1612 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1613 | * currently not initialised. | |
1614 | */ | |
1615 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1616 | { | |
1617 | unsigned long flags; | |
1618 | ||
1619 | cpufreq_debug_disable_ratelimit(); | |
1620 | ||
1621 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1622 | cpufreq_debug_enable_ratelimit(); | |
1623 | return -EINVAL; | |
1624 | } | |
1625 | ||
1626 | dprintk("unregistering driver %s\n", driver->name); | |
1627 | ||
1628 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
c32b6b8e | 1629 | unregister_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1630 | |
1631 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1632 | cpufreq_driver = NULL; | |
1633 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1634 | ||
1635 | return 0; | |
1636 | } | |
1637 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |