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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 | */ | |
e041c683 AS |
55 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
56 | static BLOCKING_NOTIFIER_HEAD(cpufreq_transition_notifier_list); | |
1da177e4 LT |
57 | |
58 | ||
59 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 60 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 61 | |
7d5e350f | 62 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
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 | ||
1da177e4 | 89 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
90 | return data; |
91 | ||
7d5e350f | 92 | err_out_put_module: |
1da177e4 | 93 | module_put(cpufreq_driver->owner); |
7d5e350f | 94 | err_out_unlock: |
1da177e4 | 95 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 96 | err_out: |
1da177e4 LT |
97 | return NULL; |
98 | } | |
99 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
100 | ||
7d5e350f | 101 | |
1da177e4 LT |
102 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
103 | { | |
104 | kobject_put(&data->kobj); | |
105 | module_put(cpufreq_driver->owner); | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
108 | ||
109 | ||
110 | /********************************************************************* | |
111 | * UNIFIED DEBUG HELPERS * | |
112 | *********************************************************************/ | |
113 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
114 | ||
115 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
116 | static unsigned int debug; | |
117 | ||
118 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
119 | * set or modify this value. | |
120 | */ | |
121 | static unsigned int debug_ratelimit = 1; | |
122 | ||
123 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
124 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
125 | * is set, and disabled upon cpufreq driver removal | |
126 | */ | |
127 | static unsigned int disable_ratelimit = 1; | |
128 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
129 | ||
858119e1 | 130 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
131 | { |
132 | unsigned long flags; | |
133 | ||
134 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
135 | if (disable_ratelimit) | |
136 | disable_ratelimit--; | |
137 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
138 | } | |
139 | ||
858119e1 | 140 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
141 | { |
142 | unsigned long flags; | |
143 | ||
144 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
145 | disable_ratelimit++; | |
146 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
147 | } | |
148 | ||
149 | void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...) | |
150 | { | |
151 | char s[256]; | |
152 | va_list args; | |
153 | unsigned int len; | |
154 | unsigned long flags; | |
32ee8c3e | 155 | |
1da177e4 LT |
156 | WARN_ON(!prefix); |
157 | if (type & debug) { | |
158 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
159 | if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) { | |
160 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
161 | return; | |
162 | } | |
163 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
164 | ||
165 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
166 | ||
167 | va_start(args, fmt); | |
168 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
169 | va_end(args); | |
170 | ||
171 | printk(s); | |
172 | ||
173 | WARN_ON(len < 5); | |
174 | } | |
175 | } | |
176 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
177 | ||
178 | ||
179 | module_param(debug, uint, 0644); | |
180 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors."); | |
181 | ||
182 | module_param(debug_ratelimit, uint, 0644); | |
183 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting."); | |
184 | ||
185 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
186 | ||
187 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
188 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
189 | ||
190 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
191 | ||
192 | ||
193 | /********************************************************************* | |
194 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
195 | *********************************************************************/ | |
196 | ||
197 | /** | |
198 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
199 | * | |
200 | * This function alters the system "loops_per_jiffy" for the clock | |
201 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 202 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
203 | * per-CPU loops_per_jiffy value wherever possible. |
204 | */ | |
205 | #ifndef CONFIG_SMP | |
206 | static unsigned long l_p_j_ref; | |
207 | static unsigned int l_p_j_ref_freq; | |
208 | ||
858119e1 | 209 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
210 | { |
211 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
212 | return; | |
213 | ||
214 | if (!l_p_j_ref_freq) { | |
215 | l_p_j_ref = loops_per_jiffy; | |
216 | l_p_j_ref_freq = ci->old; | |
217 | dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
218 | } | |
219 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
220 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 221 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
1da177e4 LT |
222 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new); |
223 | dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
224 | } | |
225 | } | |
226 | #else | |
227 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; } | |
228 | #endif | |
229 | ||
230 | ||
231 | /** | |
e4472cb3 DJ |
232 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
233 | * on frequency transition. | |
1da177e4 | 234 | * |
e4472cb3 DJ |
235 | * This function calls the transition notifiers and the "adjust_jiffies" |
236 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 237 | * external effects. |
1da177e4 LT |
238 | */ |
239 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
240 | { | |
e4472cb3 DJ |
241 | struct cpufreq_policy *policy; |
242 | ||
1da177e4 LT |
243 | BUG_ON(irqs_disabled()); |
244 | ||
245 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
246 | dprintk("notification %u of frequency transition to %u kHz\n", |
247 | state, freqs->new); | |
1da177e4 | 248 | |
e4472cb3 | 249 | policy = cpufreq_cpu_data[freqs->cpu]; |
1da177e4 | 250 | switch (state) { |
e4472cb3 | 251 | |
1da177e4 | 252 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 253 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
254 | * which is not equal to what the cpufreq core thinks is |
255 | * "old frequency". | |
1da177e4 LT |
256 | */ |
257 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
258 | if ((policy) && (policy->cpu == freqs->cpu) && |
259 | (policy->cur) && (policy->cur != freqs->old)) { | |
260 | dprintk(KERN_WARNING "Warning: CPU frequency is" | |
261 | " %u, cpufreq assumed %u kHz.\n", | |
262 | freqs->old, policy->cur); | |
263 | freqs->old = policy->cur; | |
1da177e4 LT |
264 | } |
265 | } | |
e041c683 AS |
266 | blocking_notifier_call_chain(&cpufreq_transition_notifier_list, |
267 | CPUFREQ_PRECHANGE, freqs); | |
1da177e4 LT |
268 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
269 | break; | |
e4472cb3 | 270 | |
1da177e4 LT |
271 | case CPUFREQ_POSTCHANGE: |
272 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e041c683 AS |
273 | blocking_notifier_call_chain(&cpufreq_transition_notifier_list, |
274 | CPUFREQ_POSTCHANGE, freqs); | |
e4472cb3 DJ |
275 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
276 | policy->cur = freqs->new; | |
1da177e4 LT |
277 | break; |
278 | } | |
1da177e4 LT |
279 | } |
280 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
281 | ||
282 | ||
283 | ||
284 | /********************************************************************* | |
285 | * SYSFS INTERFACE * | |
286 | *********************************************************************/ | |
287 | ||
288 | /** | |
289 | * cpufreq_parse_governor - parse a governor string | |
290 | */ | |
291 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
292 | struct cpufreq_governor **governor) | |
293 | { | |
294 | if (!cpufreq_driver) | |
295 | return -EINVAL; | |
296 | if (cpufreq_driver->setpolicy) { | |
297 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
298 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
299 | return 0; | |
300 | } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { | |
301 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
302 | return 0; | |
303 | } | |
304 | return -EINVAL; | |
305 | } else { | |
306 | struct cpufreq_governor *t; | |
3fc54d37 | 307 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 LT |
308 | if (!cpufreq_driver || !cpufreq_driver->target) |
309 | goto out; | |
310 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
311 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) { | |
312 | *governor = t; | |
3fc54d37 | 313 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
314 | return 0; |
315 | } | |
316 | } | |
7d5e350f | 317 | out: |
3fc54d37 | 318 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
319 | } |
320 | return -EINVAL; | |
321 | } | |
322 | EXPORT_SYMBOL_GPL(cpufreq_parse_governor); | |
323 | ||
324 | ||
325 | /* drivers/base/cpu.c */ | |
326 | extern struct sysdev_class cpu_sysdev_class; | |
327 | ||
328 | ||
329 | /** | |
330 | * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information | |
331 | * | |
332 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
333 | * "unsigned int". | |
334 | */ | |
335 | ||
32ee8c3e DJ |
336 | #define show_one(file_name, object) \ |
337 | static ssize_t show_##file_name \ | |
338 | (struct cpufreq_policy * policy, char *buf) \ | |
339 | { \ | |
340 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
341 | } |
342 | ||
343 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
344 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
345 | show_one(scaling_min_freq, min); | |
346 | show_one(scaling_max_freq, max); | |
347 | show_one(scaling_cur_freq, cur); | |
348 | ||
349 | /** | |
350 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
351 | */ | |
352 | #define store_one(file_name, object) \ | |
353 | static ssize_t store_##file_name \ | |
354 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
355 | { \ | |
356 | unsigned int ret = -EINVAL; \ | |
357 | struct cpufreq_policy new_policy; \ | |
358 | \ | |
359 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
360 | if (ret) \ | |
361 | return -EINVAL; \ | |
362 | \ | |
363 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
364 | if (ret != 1) \ | |
365 | return -EINVAL; \ | |
366 | \ | |
367 | ret = cpufreq_set_policy(&new_policy); \ | |
368 | \ | |
369 | return ret ? ret : count; \ | |
370 | } | |
371 | ||
372 | store_one(scaling_min_freq,min); | |
373 | store_one(scaling_max_freq,max); | |
374 | ||
375 | /** | |
376 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
377 | */ | |
378 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf) | |
379 | { | |
380 | unsigned int cur_freq = cpufreq_get(policy->cpu); | |
381 | if (!cur_freq) | |
382 | return sprintf(buf, "<unknown>"); | |
383 | return sprintf(buf, "%u\n", cur_freq); | |
384 | } | |
385 | ||
386 | ||
387 | /** | |
388 | * show_scaling_governor - show the current policy for the specified CPU | |
389 | */ | |
390 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf) | |
391 | { | |
392 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
393 | return sprintf(buf, "powersave\n"); | |
394 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
395 | return sprintf(buf, "performance\n"); | |
396 | else if (policy->governor) | |
397 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
398 | return -EINVAL; | |
399 | } | |
400 | ||
401 | ||
402 | /** | |
403 | * store_scaling_governor - store policy for the specified CPU | |
404 | */ | |
32ee8c3e DJ |
405 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
406 | const char *buf, size_t count) | |
1da177e4 LT |
407 | { |
408 | unsigned int ret = -EINVAL; | |
409 | char str_governor[16]; | |
410 | struct cpufreq_policy new_policy; | |
411 | ||
412 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
413 | if (ret) | |
414 | return ret; | |
415 | ||
416 | ret = sscanf (buf, "%15s", str_governor); | |
417 | if (ret != 1) | |
418 | return -EINVAL; | |
419 | ||
420 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor)) | |
421 | return -EINVAL; | |
422 | ||
423 | ret = cpufreq_set_policy(&new_policy); | |
1da177e4 LT |
424 | return ret ? ret : count; |
425 | } | |
426 | ||
427 | /** | |
428 | * show_scaling_driver - show the cpufreq driver currently loaded | |
429 | */ | |
430 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
431 | { | |
432 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
433 | } | |
434 | ||
435 | /** | |
436 | * show_scaling_available_governors - show the available CPUfreq governors | |
437 | */ | |
438 | static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy, | |
439 | char *buf) | |
440 | { | |
441 | ssize_t i = 0; | |
442 | struct cpufreq_governor *t; | |
443 | ||
444 | if (!cpufreq_driver->target) { | |
445 | i += sprintf(buf, "performance powersave"); | |
446 | goto out; | |
447 | } | |
448 | ||
449 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
450 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
451 | goto out; | |
452 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
453 | } | |
7d5e350f | 454 | out: |
1da177e4 LT |
455 | i += sprintf(&buf[i], "\n"); |
456 | return i; | |
457 | } | |
458 | /** | |
459 | * show_affected_cpus - show the CPUs affected by each transition | |
460 | */ | |
461 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
462 | { | |
463 | ssize_t i = 0; | |
464 | unsigned int cpu; | |
465 | ||
466 | for_each_cpu_mask(cpu, policy->cpus) { | |
467 | if (i) | |
468 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
469 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
470 | if (i >= (PAGE_SIZE - 5)) | |
471 | break; | |
472 | } | |
473 | i += sprintf(&buf[i], "\n"); | |
474 | return i; | |
475 | } | |
476 | ||
477 | ||
478 | #define define_one_ro(_name) \ | |
479 | static struct freq_attr _name = \ | |
480 | __ATTR(_name, 0444, show_##_name, NULL) | |
481 | ||
482 | #define define_one_ro0400(_name) \ | |
483 | static struct freq_attr _name = \ | |
484 | __ATTR(_name, 0400, show_##_name, NULL) | |
485 | ||
486 | #define define_one_rw(_name) \ | |
487 | static struct freq_attr _name = \ | |
488 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
489 | ||
490 | define_one_ro0400(cpuinfo_cur_freq); | |
491 | define_one_ro(cpuinfo_min_freq); | |
492 | define_one_ro(cpuinfo_max_freq); | |
493 | define_one_ro(scaling_available_governors); | |
494 | define_one_ro(scaling_driver); | |
495 | define_one_ro(scaling_cur_freq); | |
496 | define_one_ro(affected_cpus); | |
497 | define_one_rw(scaling_min_freq); | |
498 | define_one_rw(scaling_max_freq); | |
499 | define_one_rw(scaling_governor); | |
500 | ||
501 | static struct attribute * default_attrs[] = { | |
502 | &cpuinfo_min_freq.attr, | |
503 | &cpuinfo_max_freq.attr, | |
504 | &scaling_min_freq.attr, | |
505 | &scaling_max_freq.attr, | |
506 | &affected_cpus.attr, | |
507 | &scaling_governor.attr, | |
508 | &scaling_driver.attr, | |
509 | &scaling_available_governors.attr, | |
510 | NULL | |
511 | }; | |
512 | ||
513 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
514 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
515 | ||
516 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
517 | { | |
518 | struct cpufreq_policy * policy = to_policy(kobj); | |
519 | struct freq_attr * fattr = to_attr(attr); | |
520 | ssize_t ret; | |
521 | policy = cpufreq_cpu_get(policy->cpu); | |
522 | if (!policy) | |
523 | return -EINVAL; | |
70f2817a | 524 | ret = fattr->show ? fattr->show(policy,buf) : -EIO; |
1da177e4 LT |
525 | cpufreq_cpu_put(policy); |
526 | return ret; | |
527 | } | |
528 | ||
32ee8c3e | 529 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
530 | const char * buf, size_t count) |
531 | { | |
532 | struct cpufreq_policy * policy = to_policy(kobj); | |
533 | struct freq_attr * fattr = to_attr(attr); | |
534 | ssize_t ret; | |
535 | policy = cpufreq_cpu_get(policy->cpu); | |
536 | if (!policy) | |
537 | return -EINVAL; | |
70f2817a | 538 | ret = fattr->store ? fattr->store(policy,buf,count) : -EIO; |
1da177e4 LT |
539 | cpufreq_cpu_put(policy); |
540 | return ret; | |
541 | } | |
542 | ||
543 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
544 | { | |
545 | struct cpufreq_policy * policy = to_policy(kobj); | |
546 | dprintk("last reference is dropped\n"); | |
547 | complete(&policy->kobj_unregister); | |
548 | } | |
549 | ||
550 | static struct sysfs_ops sysfs_ops = { | |
551 | .show = show, | |
552 | .store = store, | |
553 | }; | |
554 | ||
555 | static struct kobj_type ktype_cpufreq = { | |
556 | .sysfs_ops = &sysfs_ops, | |
557 | .default_attrs = default_attrs, | |
558 | .release = cpufreq_sysfs_release, | |
559 | }; | |
560 | ||
561 | ||
562 | /** | |
563 | * cpufreq_add_dev - add a CPU device | |
564 | * | |
32ee8c3e | 565 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
566 | */ |
567 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
568 | { | |
569 | unsigned int cpu = sys_dev->id; | |
570 | int ret = 0; | |
571 | struct cpufreq_policy new_policy; | |
572 | struct cpufreq_policy *policy; | |
573 | struct freq_attr **drv_attr; | |
8ff69732 | 574 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
575 | unsigned long flags; |
576 | unsigned int j; | |
8ff69732 DJ |
577 | #ifdef CONFIG_SMP |
578 | struct cpufreq_policy *managed_policy; | |
579 | #endif | |
1da177e4 | 580 | |
c32b6b8e AR |
581 | if (cpu_is_offline(cpu)) |
582 | return 0; | |
583 | ||
1da177e4 LT |
584 | cpufreq_debug_disable_ratelimit(); |
585 | dprintk("adding CPU %u\n", cpu); | |
586 | ||
587 | #ifdef CONFIG_SMP | |
588 | /* check whether a different CPU already registered this | |
589 | * CPU because it is in the same boat. */ | |
590 | policy = cpufreq_cpu_get(cpu); | |
591 | if (unlikely(policy)) { | |
8ff69732 | 592 | cpufreq_cpu_put(policy); |
1da177e4 LT |
593 | cpufreq_debug_enable_ratelimit(); |
594 | return 0; | |
595 | } | |
596 | #endif | |
597 | ||
598 | if (!try_module_get(cpufreq_driver->owner)) { | |
599 | ret = -EINVAL; | |
600 | goto module_out; | |
601 | } | |
602 | ||
e98df50c | 603 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
604 | if (!policy) { |
605 | ret = -ENOMEM; | |
606 | goto nomem_out; | |
607 | } | |
1da177e4 LT |
608 | |
609 | policy->cpu = cpu; | |
610 | policy->cpus = cpumask_of_cpu(cpu); | |
611 | ||
83933af4 AV |
612 | mutex_init(&policy->lock); |
613 | mutex_lock(&policy->lock); | |
1da177e4 LT |
614 | init_completion(&policy->kobj_unregister); |
615 | INIT_WORK(&policy->update, handle_update, (void *)(long)cpu); | |
616 | ||
617 | /* call driver. From then on the cpufreq must be able | |
618 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
619 | */ | |
620 | ret = cpufreq_driver->init(policy); | |
621 | if (ret) { | |
622 | dprintk("initialization failed\n"); | |
f3876c1b | 623 | mutex_unlock(&policy->lock); |
1da177e4 LT |
624 | goto err_out; |
625 | } | |
626 | ||
8ff69732 DJ |
627 | #ifdef CONFIG_SMP |
628 | for_each_cpu_mask(j, policy->cpus) { | |
629 | if (cpu == j) | |
630 | continue; | |
631 | ||
632 | /* check for existing affected CPUs. They may not be aware | |
633 | * of it due to CPU Hotplug. | |
634 | */ | |
635 | managed_policy = cpufreq_cpu_get(j); | |
636 | if (unlikely(managed_policy)) { | |
637 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
638 | managed_policy->cpus = policy->cpus; | |
639 | cpufreq_cpu_data[cpu] = managed_policy; | |
640 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
641 | ||
642 | dprintk("CPU already managed, adding link\n"); | |
643 | sysfs_create_link(&sys_dev->kobj, | |
644 | &managed_policy->kobj, "cpufreq"); | |
645 | ||
646 | cpufreq_debug_enable_ratelimit(); | |
647 | mutex_unlock(&policy->lock); | |
648 | ret = 0; | |
649 | goto err_out_driver_exit; /* call driver->exit() */ | |
650 | } | |
651 | } | |
652 | #endif | |
1da177e4 LT |
653 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
654 | ||
655 | /* prepare interface data */ | |
656 | policy->kobj.parent = &sys_dev->kobj; | |
657 | policy->kobj.ktype = &ktype_cpufreq; | |
658 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
659 | ||
660 | ret = kobject_register(&policy->kobj); | |
f3876c1b AM |
661 | if (ret) { |
662 | mutex_unlock(&policy->lock); | |
8085e1f1 | 663 | goto err_out_driver_exit; |
f3876c1b | 664 | } |
1da177e4 LT |
665 | /* set up files for this cpu device */ |
666 | drv_attr = cpufreq_driver->attr; | |
667 | while ((drv_attr) && (*drv_attr)) { | |
668 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
669 | drv_attr++; | |
670 | } | |
671 | if (cpufreq_driver->get) | |
672 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
673 | if (cpufreq_driver->target) | |
674 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
675 | ||
676 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
677 | for_each_cpu_mask(j, policy->cpus) | |
678 | cpufreq_cpu_data[j] = policy; | |
679 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
8ff69732 DJ |
680 | |
681 | /* symlink affected CPUs */ | |
682 | for_each_cpu_mask(j, policy->cpus) { | |
683 | if (j == cpu) | |
684 | continue; | |
685 | if (!cpu_online(j)) | |
686 | continue; | |
687 | ||
1f8b2c9d | 688 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
689 | cpufreq_cpu_get(cpu); |
690 | cpu_sys_dev = get_cpu_sysdev(j); | |
691 | sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
692 | "cpufreq"); | |
693 | } | |
694 | ||
1da177e4 LT |
695 | policy->governor = NULL; /* to assure that the starting sequence is |
696 | * run in cpufreq_set_policy */ | |
83933af4 | 697 | mutex_unlock(&policy->lock); |
1da177e4 LT |
698 | |
699 | /* set default policy */ | |
700 | ||
701 | ret = cpufreq_set_policy(&new_policy); | |
702 | if (ret) { | |
703 | dprintk("setting policy failed\n"); | |
704 | goto err_out_unregister; | |
705 | } | |
706 | ||
707 | module_put(cpufreq_driver->owner); | |
1da177e4 LT |
708 | dprintk("initialization complete\n"); |
709 | cpufreq_debug_enable_ratelimit(); | |
710 | ||
711 | return 0; | |
712 | ||
713 | ||
714 | err_out_unregister: | |
715 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
716 | for_each_cpu_mask(j, policy->cpus) | |
717 | cpufreq_cpu_data[j] = NULL; | |
718 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
719 | ||
720 | kobject_unregister(&policy->kobj); | |
721 | wait_for_completion(&policy->kobj_unregister); | |
722 | ||
8085e1f1 VP |
723 | err_out_driver_exit: |
724 | if (cpufreq_driver->exit) | |
725 | cpufreq_driver->exit(policy); | |
726 | ||
1da177e4 LT |
727 | err_out: |
728 | kfree(policy); | |
729 | ||
730 | nomem_out: | |
731 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 732 | module_out: |
1da177e4 LT |
733 | cpufreq_debug_enable_ratelimit(); |
734 | return ret; | |
735 | } | |
736 | ||
737 | ||
738 | /** | |
739 | * cpufreq_remove_dev - remove a CPU device | |
740 | * | |
741 | * Removes the cpufreq interface for a CPU device. | |
742 | */ | |
743 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
744 | { | |
745 | unsigned int cpu = sys_dev->id; | |
746 | unsigned long flags; | |
747 | struct cpufreq_policy *data; | |
748 | #ifdef CONFIG_SMP | |
e738cf6d | 749 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
750 | unsigned int j; |
751 | #endif | |
752 | ||
753 | cpufreq_debug_disable_ratelimit(); | |
754 | dprintk("unregistering CPU %u\n", cpu); | |
755 | ||
756 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
757 | data = cpufreq_cpu_data[cpu]; | |
758 | ||
759 | if (!data) { | |
760 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
761 | cpufreq_debug_enable_ratelimit(); |
762 | return -EINVAL; | |
763 | } | |
764 | cpufreq_cpu_data[cpu] = NULL; | |
765 | ||
766 | ||
767 | #ifdef CONFIG_SMP | |
768 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 769 | * only need to unlink, put and exit |
1da177e4 LT |
770 | */ |
771 | if (unlikely(cpu != data->cpu)) { | |
772 | dprintk("removing link\n"); | |
8ff69732 | 773 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
774 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
775 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
776 | cpufreq_cpu_put(data); |
777 | cpufreq_debug_enable_ratelimit(); | |
778 | return 0; | |
779 | } | |
780 | #endif | |
781 | ||
1da177e4 LT |
782 | |
783 | if (!kobject_get(&data->kobj)) { | |
784 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
785 | cpufreq_debug_enable_ratelimit(); | |
32ee8c3e | 786 | return -EFAULT; |
1da177e4 LT |
787 | } |
788 | ||
789 | #ifdef CONFIG_SMP | |
790 | /* if we have other CPUs still registered, we need to unlink them, | |
791 | * or else wait_for_completion below will lock up. Clean the | |
792 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
793 | * links afterwards. | |
794 | */ | |
795 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
796 | for_each_cpu_mask(j, data->cpus) { | |
797 | if (j == cpu) | |
798 | continue; | |
799 | cpufreq_cpu_data[j] = NULL; | |
800 | } | |
801 | } | |
802 | ||
803 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
804 | ||
805 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
806 | for_each_cpu_mask(j, data->cpus) { | |
807 | if (j == cpu) | |
808 | continue; | |
809 | dprintk("removing link for cpu %u\n", j); | |
d434fca7 AR |
810 | cpu_sys_dev = get_cpu_sysdev(j); |
811 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
812 | cpufreq_cpu_put(data); |
813 | } | |
814 | } | |
815 | #else | |
816 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
817 | #endif | |
818 | ||
83933af4 | 819 | mutex_lock(&data->lock); |
1da177e4 LT |
820 | if (cpufreq_driver->target) |
821 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
83933af4 | 822 | mutex_unlock(&data->lock); |
1da177e4 LT |
823 | |
824 | kobject_unregister(&data->kobj); | |
825 | ||
826 | kobject_put(&data->kobj); | |
827 | ||
828 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 829 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
830 | * unloading. |
831 | */ | |
832 | dprintk("waiting for dropping of refcount\n"); | |
833 | wait_for_completion(&data->kobj_unregister); | |
834 | dprintk("wait complete\n"); | |
835 | ||
836 | if (cpufreq_driver->exit) | |
837 | cpufreq_driver->exit(data); | |
838 | ||
839 | kfree(data); | |
840 | ||
841 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
842 | return 0; |
843 | } | |
844 | ||
845 | ||
846 | static void handle_update(void *data) | |
847 | { | |
848 | unsigned int cpu = (unsigned int)(long)data; | |
849 | dprintk("handle_update for cpu %u called\n", cpu); | |
850 | cpufreq_update_policy(cpu); | |
851 | } | |
852 | ||
853 | /** | |
854 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
855 | * @cpu: cpu number | |
856 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
857 | * @new_freq: CPU frequency the CPU actually runs at | |
858 | * | |
859 | * We adjust to current frequency first, and need to clean up later. So either call | |
860 | * to cpufreq_update_policy() or schedule handle_update()). | |
861 | */ | |
862 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq) | |
863 | { | |
864 | struct cpufreq_freqs freqs; | |
865 | ||
78ee998f | 866 | dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
867 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
868 | ||
869 | freqs.cpu = cpu; | |
870 | freqs.old = old_freq; | |
871 | freqs.new = new_freq; | |
872 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
873 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
874 | } | |
875 | ||
876 | ||
32ee8c3e | 877 | /** |
95235ca2 VP |
878 | * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur |
879 | * @cpu: CPU number | |
880 | * | |
881 | * This is the last known freq, without actually getting it from the driver. | |
882 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
883 | */ | |
884 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
885 | { | |
886 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
887 | unsigned int ret = 0; | |
888 | ||
889 | if (policy) { | |
83933af4 | 890 | mutex_lock(&policy->lock); |
95235ca2 | 891 | ret = policy->cur; |
83933af4 | 892 | mutex_unlock(&policy->lock); |
95235ca2 VP |
893 | cpufreq_cpu_put(policy); |
894 | } | |
895 | ||
896 | return (ret); | |
897 | } | |
898 | EXPORT_SYMBOL(cpufreq_quick_get); | |
899 | ||
900 | ||
32ee8c3e | 901 | /** |
1da177e4 LT |
902 | * cpufreq_get - get the current CPU frequency (in kHz) |
903 | * @cpu: CPU number | |
904 | * | |
905 | * Get the CPU current (static) CPU frequency | |
906 | */ | |
907 | unsigned int cpufreq_get(unsigned int cpu) | |
908 | { | |
909 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
910 | unsigned int ret = 0; | |
911 | ||
912 | if (!policy) | |
913 | return 0; | |
914 | ||
915 | if (!cpufreq_driver->get) | |
916 | goto out; | |
917 | ||
83933af4 | 918 | mutex_lock(&policy->lock); |
1da177e4 LT |
919 | |
920 | ret = cpufreq_driver->get(cpu); | |
921 | ||
7d5e350f | 922 | if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
1da177e4 LT |
923 | /* verify no discrepancy between actual and saved value exists */ |
924 | if (unlikely(ret != policy->cur)) { | |
925 | cpufreq_out_of_sync(cpu, policy->cur, ret); | |
926 | schedule_work(&policy->update); | |
927 | } | |
928 | } | |
929 | ||
83933af4 | 930 | mutex_unlock(&policy->lock); |
1da177e4 | 931 | |
7d5e350f | 932 | out: |
1da177e4 LT |
933 | cpufreq_cpu_put(policy); |
934 | ||
935 | return (ret); | |
936 | } | |
937 | EXPORT_SYMBOL(cpufreq_get); | |
938 | ||
939 | ||
42d4dc3f BH |
940 | /** |
941 | * cpufreq_suspend - let the low level driver prepare for suspend | |
942 | */ | |
943 | ||
e00d9967 | 944 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
945 | { |
946 | int cpu = sysdev->id; | |
947 | unsigned int ret = 0; | |
948 | unsigned int cur_freq = 0; | |
949 | struct cpufreq_policy *cpu_policy; | |
950 | ||
951 | dprintk("resuming cpu %u\n", cpu); | |
952 | ||
953 | if (!cpu_online(cpu)) | |
954 | return 0; | |
955 | ||
956 | /* we may be lax here as interrupts are off. Nonetheless | |
957 | * we need to grab the correct cpu policy, as to check | |
958 | * whether we really run on this CPU. | |
959 | */ | |
960 | ||
961 | cpu_policy = cpufreq_cpu_get(cpu); | |
962 | if (!cpu_policy) | |
963 | return -EINVAL; | |
964 | ||
965 | /* only handle each CPU group once */ | |
966 | if (unlikely(cpu_policy->cpu != cpu)) { | |
967 | cpufreq_cpu_put(cpu_policy); | |
968 | return 0; | |
969 | } | |
970 | ||
971 | if (cpufreq_driver->suspend) { | |
e00d9967 | 972 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
973 | if (ret) { |
974 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
975 | "step on CPU %u\n", cpu_policy->cpu); | |
976 | cpufreq_cpu_put(cpu_policy); | |
977 | return ret; | |
978 | } | |
979 | } | |
980 | ||
981 | ||
982 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
983 | goto out; | |
984 | ||
985 | if (cpufreq_driver->get) | |
986 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
987 | ||
988 | if (!cur_freq || !cpu_policy->cur) { | |
989 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
990 | "frequency is what timing core thinks it is.\n"); | |
991 | goto out; | |
992 | } | |
993 | ||
994 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
995 | struct cpufreq_freqs freqs; | |
996 | ||
997 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
78ee998f | 998 | dprintk(KERN_DEBUG "Warning: CPU frequency is %u, " |
42d4dc3f BH |
999 | "cpufreq assumed %u kHz.\n", |
1000 | cur_freq, cpu_policy->cur); | |
1001 | ||
1002 | freqs.cpu = cpu; | |
1003 | freqs.old = cpu_policy->cur; | |
1004 | freqs.new = cur_freq; | |
1005 | ||
e041c683 | 1006 | blocking_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1007 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1008 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1009 | ||
1010 | cpu_policy->cur = cur_freq; | |
1011 | } | |
1012 | ||
7d5e350f | 1013 | out: |
42d4dc3f BH |
1014 | cpufreq_cpu_put(cpu_policy); |
1015 | return 0; | |
1016 | } | |
1017 | ||
1da177e4 LT |
1018 | /** |
1019 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1020 | * | |
1021 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1022 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1023 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1024 | * restored. | |
1da177e4 LT |
1025 | */ |
1026 | static int cpufreq_resume(struct sys_device * sysdev) | |
1027 | { | |
1028 | int cpu = sysdev->id; | |
1029 | unsigned int ret = 0; | |
1030 | struct cpufreq_policy *cpu_policy; | |
1031 | ||
1032 | dprintk("resuming cpu %u\n", cpu); | |
1033 | ||
1034 | if (!cpu_online(cpu)) | |
1035 | return 0; | |
1036 | ||
1037 | /* we may be lax here as interrupts are off. Nonetheless | |
1038 | * we need to grab the correct cpu policy, as to check | |
1039 | * whether we really run on this CPU. | |
1040 | */ | |
1041 | ||
1042 | cpu_policy = cpufreq_cpu_get(cpu); | |
1043 | if (!cpu_policy) | |
1044 | return -EINVAL; | |
1045 | ||
1046 | /* only handle each CPU group once */ | |
1047 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1048 | cpufreq_cpu_put(cpu_policy); | |
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | if (cpufreq_driver->resume) { | |
1053 | ret = cpufreq_driver->resume(cpu_policy); | |
1054 | if (ret) { | |
1055 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1056 | "step on CPU %u\n", cpu_policy->cpu); | |
1057 | cpufreq_cpu_put(cpu_policy); | |
1058 | return ret; | |
1059 | } | |
1060 | } | |
1061 | ||
1062 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1063 | unsigned int cur_freq = 0; | |
1064 | ||
1065 | if (cpufreq_driver->get) | |
1066 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1067 | ||
1068 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1069 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1070 | "current frequency is what timing core " | |
1071 | "thinks it is.\n"); | |
1da177e4 LT |
1072 | goto out; |
1073 | } | |
1074 | ||
1075 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1076 | struct cpufreq_freqs freqs; | |
1077 | ||
ac09f698 | 1078 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
78ee998f | 1079 | dprintk(KERN_WARNING "Warning: CPU frequency" |
ac09f698 BH |
1080 | "is %u, cpufreq assumed %u kHz.\n", |
1081 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1082 | |
1083 | freqs.cpu = cpu; | |
1084 | freqs.old = cpu_policy->cur; | |
1085 | freqs.new = cur_freq; | |
1086 | ||
e041c683 AS |
1087 | blocking_notifier_call_chain( |
1088 | &cpufreq_transition_notifier_list, | |
42d4dc3f | 1089 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1090 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1091 | ||
1092 | cpu_policy->cur = cur_freq; | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | out: | |
1097 | schedule_work(&cpu_policy->update); | |
1098 | cpufreq_cpu_put(cpu_policy); | |
1099 | return ret; | |
1100 | } | |
1101 | ||
1102 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1103 | .add = cpufreq_add_dev, | |
1104 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1105 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1106 | .resume = cpufreq_resume, |
1107 | }; | |
1108 | ||
1109 | ||
1110 | /********************************************************************* | |
1111 | * NOTIFIER LISTS INTERFACE * | |
1112 | *********************************************************************/ | |
1113 | ||
1114 | /** | |
1115 | * cpufreq_register_notifier - register a driver with cpufreq | |
1116 | * @nb: notifier function to register | |
1117 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1118 | * | |
32ee8c3e | 1119 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1120 | * are notified about clock rate changes (once before and once after |
1121 | * the transition), or a list of drivers that are notified about | |
1122 | * changes in cpufreq policy. | |
1123 | * | |
1124 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1125 | * blocking_notifier_chain_register. |
1da177e4 LT |
1126 | */ |
1127 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1128 | { | |
1129 | int ret; | |
1130 | ||
1da177e4 LT |
1131 | switch (list) { |
1132 | case CPUFREQ_TRANSITION_NOTIFIER: | |
e041c683 AS |
1133 | ret = blocking_notifier_chain_register( |
1134 | &cpufreq_transition_notifier_list, nb); | |
1da177e4 LT |
1135 | break; |
1136 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1137 | ret = blocking_notifier_chain_register( |
1138 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1139 | break; |
1140 | default: | |
1141 | ret = -EINVAL; | |
1142 | } | |
1da177e4 LT |
1143 | |
1144 | return ret; | |
1145 | } | |
1146 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1147 | ||
1148 | ||
1149 | /** | |
1150 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1151 | * @nb: notifier block to be unregistered | |
1152 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1153 | * | |
1154 | * Remove a driver from the CPU frequency notifier list. | |
1155 | * | |
1156 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1157 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1158 | */ |
1159 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1160 | { | |
1161 | int ret; | |
1162 | ||
1da177e4 LT |
1163 | switch (list) { |
1164 | case CPUFREQ_TRANSITION_NOTIFIER: | |
e041c683 AS |
1165 | ret = blocking_notifier_chain_unregister( |
1166 | &cpufreq_transition_notifier_list, nb); | |
1da177e4 LT |
1167 | break; |
1168 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1169 | ret = blocking_notifier_chain_unregister( |
1170 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1171 | break; |
1172 | default: | |
1173 | ret = -EINVAL; | |
1174 | } | |
1da177e4 LT |
1175 | |
1176 | return ret; | |
1177 | } | |
1178 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1179 | ||
1180 | ||
1181 | /********************************************************************* | |
1182 | * GOVERNORS * | |
1183 | *********************************************************************/ | |
1184 | ||
1185 | ||
1186 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1187 | unsigned int target_freq, | |
1188 | unsigned int relation) | |
1189 | { | |
1190 | int retval = -EINVAL; | |
c32b6b8e | 1191 | |
a9d9baa1 | 1192 | lock_cpu_hotplug(); |
1da177e4 LT |
1193 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1194 | target_freq, relation); | |
1195 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1196 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1197 | |
a9d9baa1 | 1198 | unlock_cpu_hotplug(); |
90d45d17 | 1199 | |
1da177e4 LT |
1200 | return retval; |
1201 | } | |
1202 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1203 | ||
1da177e4 LT |
1204 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1205 | unsigned int target_freq, | |
1206 | unsigned int relation) | |
1207 | { | |
cc993cab | 1208 | int ret; |
1da177e4 LT |
1209 | |
1210 | policy = cpufreq_cpu_get(policy->cpu); | |
1211 | if (!policy) | |
1212 | return -EINVAL; | |
1213 | ||
83933af4 | 1214 | mutex_lock(&policy->lock); |
1da177e4 LT |
1215 | |
1216 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1217 | ||
83933af4 | 1218 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1219 | |
1220 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1221 | return ret; |
1222 | } | |
1223 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1224 | ||
1225 | ||
1226 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) | |
1227 | { | |
cc993cab | 1228 | int ret; |
1da177e4 LT |
1229 | |
1230 | if (!try_module_get(policy->governor->owner)) | |
1231 | return -EINVAL; | |
1232 | ||
1233 | dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); | |
1234 | ret = policy->governor->governor(policy, event); | |
1235 | ||
1236 | /* we keep one module reference alive for each CPU governed by this CPU */ | |
1237 | if ((event != CPUFREQ_GOV_START) || ret) | |
1238 | module_put(policy->governor->owner); | |
1239 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1240 | module_put(policy->governor->owner); | |
1241 | ||
1242 | return ret; | |
1243 | } | |
1244 | ||
1245 | ||
1246 | int cpufreq_governor(unsigned int cpu, unsigned int event) | |
1247 | { | |
1248 | int ret = 0; | |
1249 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1250 | ||
1251 | if (!policy) | |
1252 | return -EINVAL; | |
1253 | ||
83933af4 | 1254 | mutex_lock(&policy->lock); |
1da177e4 | 1255 | ret = __cpufreq_governor(policy, event); |
83933af4 | 1256 | mutex_unlock(&policy->lock); |
1da177e4 LT |
1257 | |
1258 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1259 | return ret; |
1260 | } | |
1261 | EXPORT_SYMBOL_GPL(cpufreq_governor); | |
1262 | ||
1263 | ||
1264 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1265 | { | |
1266 | struct cpufreq_governor *t; | |
1267 | ||
1268 | if (!governor) | |
1269 | return -EINVAL; | |
1270 | ||
3fc54d37 | 1271 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1272 | |
1da177e4 LT |
1273 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { |
1274 | if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) { | |
3fc54d37 | 1275 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1276 | return -EBUSY; |
1277 | } | |
1278 | } | |
1279 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1280 | ||
32ee8c3e | 1281 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1282 | return 0; |
1283 | } | |
1284 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1285 | ||
1286 | ||
1287 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1288 | { | |
1289 | if (!governor) | |
1290 | return; | |
1291 | ||
3fc54d37 | 1292 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1293 | list_del(&governor->governor_list); |
3fc54d37 | 1294 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1295 | return; |
1296 | } | |
1297 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1298 | ||
1299 | ||
1300 | ||
1301 | /********************************************************************* | |
1302 | * POLICY INTERFACE * | |
1303 | *********************************************************************/ | |
1304 | ||
1305 | /** | |
1306 | * cpufreq_get_policy - get the current cpufreq_policy | |
1307 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1308 | * | |
1309 | * Reads the current cpufreq policy. | |
1310 | */ | |
1311 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1312 | { | |
1313 | struct cpufreq_policy *cpu_policy; | |
1314 | if (!policy) | |
1315 | return -EINVAL; | |
1316 | ||
1317 | cpu_policy = cpufreq_cpu_get(cpu); | |
1318 | if (!cpu_policy) | |
1319 | return -EINVAL; | |
1320 | ||
83933af4 | 1321 | mutex_lock(&cpu_policy->lock); |
1da177e4 | 1322 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
83933af4 | 1323 | mutex_unlock(&cpu_policy->lock); |
1da177e4 LT |
1324 | |
1325 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1326 | return 0; |
1327 | } | |
1328 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1329 | ||
1330 | ||
1331 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) | |
1332 | { | |
1333 | int ret = 0; | |
1334 | ||
1335 | cpufreq_debug_disable_ratelimit(); | |
1336 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1337 | policy->min, policy->max); | |
1338 | ||
7d5e350f | 1339 | memcpy(&policy->cpuinfo, &data->cpuinfo, sizeof(struct cpufreq_cpuinfo)); |
1da177e4 LT |
1340 | |
1341 | /* verify the cpu speed can be set within this limit */ | |
1342 | ret = cpufreq_driver->verify(policy); | |
1343 | if (ret) | |
1344 | goto error_out; | |
1345 | ||
1da177e4 | 1346 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1347 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1348 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1349 | |
1350 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1351 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1352 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1353 | |
1354 | /* verify the cpu speed can be set within this limit, | |
1355 | which might be different to the first one */ | |
1356 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1357 | if (ret) |
1da177e4 | 1358 | goto error_out; |
1da177e4 LT |
1359 | |
1360 | /* notification of the new policy */ | |
e041c683 AS |
1361 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1362 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1363 | |
7d5e350f DJ |
1364 | data->min = policy->min; |
1365 | data->max = policy->max; | |
1da177e4 LT |
1366 | |
1367 | dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); | |
1368 | ||
1369 | if (cpufreq_driver->setpolicy) { | |
1370 | data->policy = policy->policy; | |
1371 | dprintk("setting range\n"); | |
1372 | ret = cpufreq_driver->setpolicy(policy); | |
1373 | } else { | |
1374 | if (policy->governor != data->governor) { | |
1375 | /* save old, working values */ | |
1376 | struct cpufreq_governor *old_gov = data->governor; | |
1377 | ||
1378 | dprintk("governor switch\n"); | |
1379 | ||
1380 | /* end old governor */ | |
1381 | if (data->governor) | |
1382 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1383 | ||
1384 | /* start new governor */ | |
1385 | data->governor = policy->governor; | |
1386 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1387 | /* new governor failed, so re-start old one */ | |
1388 | dprintk("starting governor %s failed\n", data->governor->name); | |
1389 | if (old_gov) { | |
1390 | data->governor = old_gov; | |
1391 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1392 | } | |
1393 | ret = -EINVAL; | |
1394 | goto error_out; | |
1395 | } | |
1396 | /* might be a policy change, too, so fall through */ | |
1397 | } | |
1398 | dprintk("governor: change or update limits\n"); | |
1399 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1400 | } | |
1401 | ||
7d5e350f | 1402 | error_out: |
1da177e4 LT |
1403 | cpufreq_debug_enable_ratelimit(); |
1404 | return ret; | |
1405 | } | |
1406 | ||
1407 | /** | |
1408 | * cpufreq_set_policy - set a new CPUFreq policy | |
1409 | * @policy: policy to be set. | |
1410 | * | |
1411 | * Sets a new CPU frequency and voltage scaling policy. | |
1412 | */ | |
1413 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1414 | { | |
1415 | int ret = 0; | |
1416 | struct cpufreq_policy *data; | |
1417 | ||
1418 | if (!policy) | |
1419 | return -EINVAL; | |
1420 | ||
1421 | data = cpufreq_cpu_get(policy->cpu); | |
1422 | if (!data) | |
1423 | return -EINVAL; | |
1424 | ||
1425 | /* lock this CPU */ | |
83933af4 | 1426 | mutex_lock(&data->lock); |
1da177e4 LT |
1427 | |
1428 | ret = __cpufreq_set_policy(data, policy); | |
1429 | data->user_policy.min = data->min; | |
1430 | data->user_policy.max = data->max; | |
1431 | data->user_policy.policy = data->policy; | |
1432 | data->user_policy.governor = data->governor; | |
1433 | ||
83933af4 | 1434 | mutex_unlock(&data->lock); |
1da177e4 LT |
1435 | cpufreq_cpu_put(data); |
1436 | ||
1437 | return ret; | |
1438 | } | |
1439 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1440 | ||
1441 | ||
1442 | /** | |
1443 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1444 | * @cpu: CPU which shall be re-evaluated | |
1445 | * | |
1446 | * Usefull for policy notifiers which have different necessities | |
1447 | * at different times. | |
1448 | */ | |
1449 | int cpufreq_update_policy(unsigned int cpu) | |
1450 | { | |
1451 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1452 | struct cpufreq_policy policy; | |
1453 | int ret = 0; | |
1454 | ||
1455 | if (!data) | |
1456 | return -ENODEV; | |
1457 | ||
83933af4 | 1458 | mutex_lock(&data->lock); |
1da177e4 LT |
1459 | |
1460 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1461 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1462 | policy.min = data->user_policy.min; |
1463 | policy.max = data->user_policy.max; | |
1464 | policy.policy = data->user_policy.policy; | |
1465 | policy.governor = data->user_policy.governor; | |
1466 | ||
0961dd0d TR |
1467 | /* BIOS might change freq behind our back |
1468 | -> ask driver for current freq and notify governors about a change */ | |
1469 | if (cpufreq_driver->get) { | |
1470 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1471 | if (!data->cur) { |
1472 | dprintk("Driver did not initialize current freq"); | |
1473 | data->cur = policy.cur; | |
1474 | } else { | |
1475 | if (data->cur != policy.cur) | |
1476 | cpufreq_out_of_sync(cpu, data->cur, policy.cur); | |
1477 | } | |
0961dd0d TR |
1478 | } |
1479 | ||
1da177e4 LT |
1480 | ret = __cpufreq_set_policy(data, &policy); |
1481 | ||
83933af4 | 1482 | mutex_unlock(&data->lock); |
1da177e4 LT |
1483 | |
1484 | cpufreq_cpu_put(data); | |
1485 | return ret; | |
1486 | } | |
1487 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1488 | ||
c32b6b8e AR |
1489 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
1490 | unsigned long action, void *hcpu) | |
1491 | { | |
1492 | unsigned int cpu = (unsigned long)hcpu; | |
1493 | struct cpufreq_policy *policy; | |
1494 | struct sys_device *sys_dev; | |
1495 | ||
1496 | sys_dev = get_cpu_sysdev(cpu); | |
1497 | ||
1498 | if (sys_dev) { | |
1499 | switch (action) { | |
1500 | case CPU_ONLINE: | |
1501 | cpufreq_add_dev(sys_dev); | |
1502 | break; | |
1503 | case CPU_DOWN_PREPARE: | |
1504 | /* | |
1505 | * We attempt to put this cpu in lowest frequency | |
1506 | * possible before going down. This will permit | |
1507 | * hardware-managed P-State to switch other related | |
1508 | * threads to min or higher speeds if possible. | |
1509 | */ | |
1510 | policy = cpufreq_cpu_data[cpu]; | |
1511 | if (policy) { | |
1512 | cpufreq_driver_target(policy, policy->min, | |
1513 | CPUFREQ_RELATION_H); | |
1514 | } | |
1515 | break; | |
1516 | case CPU_DEAD: | |
1517 | cpufreq_remove_dev(sys_dev); | |
1518 | break; | |
1519 | } | |
1520 | } | |
1521 | return NOTIFY_OK; | |
1522 | } | |
1523 | ||
1524 | static struct notifier_block cpufreq_cpu_notifier = | |
1525 | { | |
1526 | .notifier_call = cpufreq_cpu_callback, | |
1527 | }; | |
1da177e4 LT |
1528 | |
1529 | /********************************************************************* | |
1530 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1531 | *********************************************************************/ | |
1532 | ||
1533 | /** | |
1534 | * cpufreq_register_driver - register a CPU Frequency driver | |
1535 | * @driver_data: A struct cpufreq_driver containing the values# | |
1536 | * submitted by the CPU Frequency driver. | |
1537 | * | |
32ee8c3e | 1538 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1539 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1540 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1541 | * |
1542 | */ | |
1543 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1544 | { | |
1545 | unsigned long flags; | |
1546 | int ret; | |
1547 | ||
1548 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1549 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1550 | return -EINVAL; | |
1551 | ||
1552 | dprintk("trying to register driver %s\n", driver_data->name); | |
1553 | ||
1554 | if (driver_data->setpolicy) | |
1555 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1556 | ||
1557 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1558 | if (cpufreq_driver) { | |
1559 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1560 | return -EBUSY; | |
1561 | } | |
1562 | cpufreq_driver = driver_data; | |
1563 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1564 | ||
1565 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1566 | ||
1567 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1568 | int i; | |
1569 | ret = -ENODEV; | |
1570 | ||
1571 | /* check for at least one working CPU */ | |
1572 | for (i=0; i<NR_CPUS; i++) | |
1573 | if (cpufreq_cpu_data[i]) | |
1574 | ret = 0; | |
1575 | ||
1576 | /* if all ->init() calls failed, unregister */ | |
1577 | if (ret) { | |
1578 | dprintk("no CPU initialized for driver %s\n", driver_data->name); | |
1579 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1580 | ||
1581 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1582 | cpufreq_driver = NULL; | |
1583 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1584 | } | |
1585 | } | |
1586 | ||
1587 | if (!ret) { | |
c32b6b8e | 1588 | register_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1589 | dprintk("driver %s up and running\n", driver_data->name); |
1590 | cpufreq_debug_enable_ratelimit(); | |
1591 | } | |
1592 | ||
1593 | return (ret); | |
1594 | } | |
1595 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1596 | ||
1597 | ||
1598 | /** | |
1599 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1600 | * | |
32ee8c3e | 1601 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1602 | * the right to do so, i.e. if you have succeeded in initialising before! |
1603 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1604 | * currently not initialised. | |
1605 | */ | |
1606 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1607 | { | |
1608 | unsigned long flags; | |
1609 | ||
1610 | cpufreq_debug_disable_ratelimit(); | |
1611 | ||
1612 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1613 | cpufreq_debug_enable_ratelimit(); | |
1614 | return -EINVAL; | |
1615 | } | |
1616 | ||
1617 | dprintk("unregistering driver %s\n", driver->name); | |
1618 | ||
1619 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
c32b6b8e | 1620 | unregister_cpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1621 | |
1622 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1623 | cpufreq_driver = NULL; | |
1624 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1625 | ||
1626 | return 0; | |
1627 | } | |
1628 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |