Commit | Line | Data |
---|---|---|
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 | ||
1da177e4 LT |
18 | #include <linux/kernel.h> |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/notifier.h> | |
22 | #include <linux/cpufreq.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/device.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/completion.h> | |
3fc54d37 | 30 | #include <linux/mutex.h> |
1da177e4 LT |
31 | |
32 | #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg) | |
33 | ||
34 | /** | |
cd878479 | 35 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
36 | * level driver of CPUFreq support, and its spinlock. This lock |
37 | * also protects the cpufreq_cpu_data array. | |
38 | */ | |
7d5e350f DJ |
39 | static struct cpufreq_driver *cpufreq_driver; |
40 | static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; | |
1da177e4 LT |
41 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
42 | ||
1da177e4 LT |
43 | /* internal prototypes */ |
44 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); | |
65f27f38 | 45 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
46 | |
47 | /** | |
32ee8c3e DJ |
48 | * Two notifier lists: the "policy" list is involved in the |
49 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
50 | * "transition" list for kernel code that needs to handle |
51 | * changes to devices when the CPU clock speed changes. | |
52 | * The mutex locks both lists. | |
53 | */ | |
e041c683 | 54 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 55 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 56 | |
b4dfdbb3 AS |
57 | static int __init init_cpufreq_transition_notifier_list(void) |
58 | { | |
59 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
60 | return 0; | |
61 | } | |
b3438f82 | 62 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 LT |
63 | |
64 | static LIST_HEAD(cpufreq_governor_list); | |
7d5e350f | 65 | static DEFINE_MUTEX (cpufreq_governor_mutex); |
1da177e4 | 66 | |
7d5e350f | 67 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 LT |
68 | { |
69 | struct cpufreq_policy *data; | |
70 | unsigned long flags; | |
71 | ||
72 | if (cpu >= NR_CPUS) | |
73 | goto err_out; | |
74 | ||
75 | /* get the cpufreq driver */ | |
76 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
77 | ||
78 | if (!cpufreq_driver) | |
79 | goto err_out_unlock; | |
80 | ||
81 | if (!try_module_get(cpufreq_driver->owner)) | |
82 | goto err_out_unlock; | |
83 | ||
84 | ||
85 | /* get the CPU */ | |
86 | data = cpufreq_cpu_data[cpu]; | |
87 | ||
88 | if (!data) | |
89 | goto err_out_put_module; | |
90 | ||
91 | if (!kobject_get(&data->kobj)) | |
92 | goto err_out_put_module; | |
93 | ||
1da177e4 | 94 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
95 | return data; |
96 | ||
7d5e350f | 97 | err_out_put_module: |
1da177e4 | 98 | module_put(cpufreq_driver->owner); |
7d5e350f | 99 | err_out_unlock: |
1da177e4 | 100 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 101 | err_out: |
1da177e4 LT |
102 | return NULL; |
103 | } | |
104 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
105 | ||
7d5e350f | 106 | |
1da177e4 LT |
107 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
108 | { | |
109 | kobject_put(&data->kobj); | |
110 | module_put(cpufreq_driver->owner); | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
113 | ||
114 | ||
115 | /********************************************************************* | |
116 | * UNIFIED DEBUG HELPERS * | |
117 | *********************************************************************/ | |
118 | #ifdef CONFIG_CPU_FREQ_DEBUG | |
119 | ||
120 | /* what part(s) of the CPUfreq subsystem are debugged? */ | |
121 | static unsigned int debug; | |
122 | ||
123 | /* is the debug output ratelimit'ed using printk_ratelimit? User can | |
124 | * set or modify this value. | |
125 | */ | |
126 | static unsigned int debug_ratelimit = 1; | |
127 | ||
128 | /* is the printk_ratelimit'ing enabled? It's enabled after a successful | |
129 | * loading of a cpufreq driver, temporarily disabled when a new policy | |
130 | * is set, and disabled upon cpufreq driver removal | |
131 | */ | |
132 | static unsigned int disable_ratelimit = 1; | |
133 | static DEFINE_SPINLOCK(disable_ratelimit_lock); | |
134 | ||
858119e1 | 135 | static void cpufreq_debug_enable_ratelimit(void) |
1da177e4 LT |
136 | { |
137 | unsigned long flags; | |
138 | ||
139 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
140 | if (disable_ratelimit) | |
141 | disable_ratelimit--; | |
142 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
143 | } | |
144 | ||
858119e1 | 145 | static void cpufreq_debug_disable_ratelimit(void) |
1da177e4 LT |
146 | { |
147 | unsigned long flags; | |
148 | ||
149 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
150 | disable_ratelimit++; | |
151 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
152 | } | |
153 | ||
154 | void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...) | |
155 | { | |
156 | char s[256]; | |
157 | va_list args; | |
158 | unsigned int len; | |
159 | unsigned long flags; | |
32ee8c3e | 160 | |
1da177e4 LT |
161 | WARN_ON(!prefix); |
162 | if (type & debug) { | |
163 | spin_lock_irqsave(&disable_ratelimit_lock, flags); | |
164 | if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) { | |
165 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
166 | return; | |
167 | } | |
168 | spin_unlock_irqrestore(&disable_ratelimit_lock, flags); | |
169 | ||
170 | len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix); | |
171 | ||
172 | va_start(args, fmt); | |
173 | len += vsnprintf(&s[len], (256 - len), fmt, args); | |
174 | va_end(args); | |
175 | ||
176 | printk(s); | |
177 | ||
178 | WARN_ON(len < 5); | |
179 | } | |
180 | } | |
181 | EXPORT_SYMBOL(cpufreq_debug_printk); | |
182 | ||
183 | ||
184 | module_param(debug, uint, 0644); | |
185 | MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors."); | |
186 | ||
187 | module_param(debug_ratelimit, uint, 0644); | |
188 | MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting."); | |
189 | ||
190 | #else /* !CONFIG_CPU_FREQ_DEBUG */ | |
191 | ||
192 | static inline void cpufreq_debug_enable_ratelimit(void) { return; } | |
193 | static inline void cpufreq_debug_disable_ratelimit(void) { return; } | |
194 | ||
195 | #endif /* CONFIG_CPU_FREQ_DEBUG */ | |
196 | ||
197 | ||
198 | /********************************************************************* | |
199 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
200 | *********************************************************************/ | |
201 | ||
202 | /** | |
203 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
204 | * | |
205 | * This function alters the system "loops_per_jiffy" for the clock | |
206 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 207 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
208 | * per-CPU loops_per_jiffy value wherever possible. |
209 | */ | |
210 | #ifndef CONFIG_SMP | |
211 | static unsigned long l_p_j_ref; | |
212 | static unsigned int l_p_j_ref_freq; | |
213 | ||
858119e1 | 214 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
215 | { |
216 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
217 | return; | |
218 | ||
219 | if (!l_p_j_ref_freq) { | |
220 | l_p_j_ref = loops_per_jiffy; | |
221 | l_p_j_ref_freq = ci->old; | |
222 | dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
223 | } | |
224 | if ((val == CPUFREQ_PRECHANGE && ci->old < ci->new) || | |
225 | (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) || | |
42d4dc3f | 226 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
1da177e4 LT |
227 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new); |
228 | dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
229 | } | |
230 | } | |
231 | #else | |
232 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; } | |
233 | #endif | |
234 | ||
235 | ||
236 | /** | |
e4472cb3 DJ |
237 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
238 | * on frequency transition. | |
1da177e4 | 239 | * |
e4472cb3 DJ |
240 | * This function calls the transition notifiers and the "adjust_jiffies" |
241 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 242 | * external effects. |
1da177e4 LT |
243 | */ |
244 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
245 | { | |
e4472cb3 DJ |
246 | struct cpufreq_policy *policy; |
247 | ||
1da177e4 LT |
248 | BUG_ON(irqs_disabled()); |
249 | ||
250 | freqs->flags = cpufreq_driver->flags; | |
e4472cb3 DJ |
251 | dprintk("notification %u of frequency transition to %u kHz\n", |
252 | state, freqs->new); | |
1da177e4 | 253 | |
e4472cb3 | 254 | policy = cpufreq_cpu_data[freqs->cpu]; |
1da177e4 | 255 | switch (state) { |
e4472cb3 | 256 | |
1da177e4 | 257 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 258 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
259 | * which is not equal to what the cpufreq core thinks is |
260 | * "old frequency". | |
1da177e4 LT |
261 | */ |
262 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
263 | if ((policy) && (policy->cpu == freqs->cpu) && |
264 | (policy->cur) && (policy->cur != freqs->old)) { | |
b10eec22 | 265 | dprintk("Warning: CPU frequency is" |
e4472cb3 DJ |
266 | " %u, cpufreq assumed %u kHz.\n", |
267 | freqs->old, policy->cur); | |
268 | freqs->old = policy->cur; | |
1da177e4 LT |
269 | } |
270 | } | |
b4dfdbb3 | 271 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 272 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
273 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
274 | break; | |
e4472cb3 | 275 | |
1da177e4 LT |
276 | case CPUFREQ_POSTCHANGE: |
277 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
b4dfdbb3 | 278 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 279 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
280 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
281 | policy->cur = freqs->new; | |
1da177e4 LT |
282 | break; |
283 | } | |
1da177e4 LT |
284 | } |
285 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
286 | ||
287 | ||
288 | ||
289 | /********************************************************************* | |
290 | * SYSFS INTERFACE * | |
291 | *********************************************************************/ | |
292 | ||
3bcb09a3 JF |
293 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
294 | { | |
295 | struct cpufreq_governor *t; | |
296 | ||
297 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
298 | if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) | |
299 | return t; | |
300 | ||
301 | return NULL; | |
302 | } | |
303 | ||
1da177e4 LT |
304 | /** |
305 | * cpufreq_parse_governor - parse a governor string | |
306 | */ | |
307 | static int cpufreq_parse_governor (char *str_governor, unsigned int *policy, | |
308 | struct cpufreq_governor **governor) | |
309 | { | |
3bcb09a3 JF |
310 | int err = -EINVAL; |
311 | ||
1da177e4 | 312 | if (!cpufreq_driver) |
3bcb09a3 JF |
313 | goto out; |
314 | ||
1da177e4 LT |
315 | if (cpufreq_driver->setpolicy) { |
316 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
317 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 318 | err = 0; |
1da177e4 LT |
319 | } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) { |
320 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
3bcb09a3 | 321 | err = 0; |
1da177e4 | 322 | } |
3bcb09a3 | 323 | } else if (cpufreq_driver->target) { |
1da177e4 | 324 | struct cpufreq_governor *t; |
3bcb09a3 | 325 | |
3fc54d37 | 326 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
327 | |
328 | t = __find_governor(str_governor); | |
329 | ||
ea714970 JF |
330 | if (t == NULL) { |
331 | char *name = kasprintf(GFP_KERNEL, "cpufreq_%s", str_governor); | |
332 | ||
333 | if (name) { | |
334 | int ret; | |
335 | ||
336 | mutex_unlock(&cpufreq_governor_mutex); | |
337 | ret = request_module(name); | |
338 | mutex_lock(&cpufreq_governor_mutex); | |
339 | ||
340 | if (ret == 0) | |
341 | t = __find_governor(str_governor); | |
342 | } | |
343 | ||
344 | kfree(name); | |
345 | } | |
346 | ||
3bcb09a3 JF |
347 | if (t != NULL) { |
348 | *governor = t; | |
349 | err = 0; | |
1da177e4 | 350 | } |
3bcb09a3 | 351 | |
3fc54d37 | 352 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 353 | } |
3bcb09a3 JF |
354 | out: |
355 | return err; | |
1da177e4 | 356 | } |
1da177e4 LT |
357 | |
358 | ||
359 | /* drivers/base/cpu.c */ | |
360 | extern struct sysdev_class cpu_sysdev_class; | |
361 | ||
362 | ||
363 | /** | |
364 | * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information | |
365 | * | |
366 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
367 | * "unsigned int". | |
368 | */ | |
369 | ||
32ee8c3e DJ |
370 | #define show_one(file_name, object) \ |
371 | static ssize_t show_##file_name \ | |
372 | (struct cpufreq_policy * policy, char *buf) \ | |
373 | { \ | |
374 | return sprintf (buf, "%u\n", policy->object); \ | |
1da177e4 LT |
375 | } |
376 | ||
377 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
378 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
379 | show_one(scaling_min_freq, min); | |
380 | show_one(scaling_max_freq, max); | |
381 | show_one(scaling_cur_freq, cur); | |
382 | ||
7970e08b TR |
383 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy); |
384 | ||
1da177e4 LT |
385 | /** |
386 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
387 | */ | |
388 | #define store_one(file_name, object) \ | |
389 | static ssize_t store_##file_name \ | |
390 | (struct cpufreq_policy * policy, const char *buf, size_t count) \ | |
391 | { \ | |
392 | unsigned int ret = -EINVAL; \ | |
393 | struct cpufreq_policy new_policy; \ | |
394 | \ | |
395 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
396 | if (ret) \ | |
397 | return -EINVAL; \ | |
398 | \ | |
399 | ret = sscanf (buf, "%u", &new_policy.object); \ | |
400 | if (ret != 1) \ | |
401 | return -EINVAL; \ | |
402 | \ | |
153d7f3f | 403 | lock_cpu_hotplug(); \ |
7970e08b TR |
404 | mutex_lock(&policy->lock); \ |
405 | ret = __cpufreq_set_policy(policy, &new_policy); \ | |
406 | policy->user_policy.object = policy->object; \ | |
407 | mutex_unlock(&policy->lock); \ | |
153d7f3f | 408 | unlock_cpu_hotplug(); \ |
1da177e4 LT |
409 | \ |
410 | return ret ? ret : count; \ | |
411 | } | |
412 | ||
413 | store_one(scaling_min_freq,min); | |
414 | store_one(scaling_max_freq,max); | |
415 | ||
416 | /** | |
417 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
418 | */ | |
419 | static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf) | |
420 | { | |
421 | unsigned int cur_freq = cpufreq_get(policy->cpu); | |
422 | if (!cur_freq) | |
423 | return sprintf(buf, "<unknown>"); | |
424 | return sprintf(buf, "%u\n", cur_freq); | |
425 | } | |
426 | ||
427 | ||
428 | /** | |
429 | * show_scaling_governor - show the current policy for the specified CPU | |
430 | */ | |
431 | static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf) | |
432 | { | |
433 | if(policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
434 | return sprintf(buf, "powersave\n"); | |
435 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
436 | return sprintf(buf, "performance\n"); | |
437 | else if (policy->governor) | |
438 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name); | |
439 | return -EINVAL; | |
440 | } | |
441 | ||
442 | ||
443 | /** | |
444 | * store_scaling_governor - store policy for the specified CPU | |
445 | */ | |
32ee8c3e DJ |
446 | static ssize_t store_scaling_governor (struct cpufreq_policy * policy, |
447 | const char *buf, size_t count) | |
1da177e4 LT |
448 | { |
449 | unsigned int ret = -EINVAL; | |
450 | char str_governor[16]; | |
451 | struct cpufreq_policy new_policy; | |
452 | ||
453 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
454 | if (ret) | |
455 | return ret; | |
456 | ||
457 | ret = sscanf (buf, "%15s", str_governor); | |
458 | if (ret != 1) | |
459 | return -EINVAL; | |
460 | ||
461 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor)) | |
462 | return -EINVAL; | |
463 | ||
a496e25d DJ |
464 | lock_cpu_hotplug(); |
465 | ||
7970e08b TR |
466 | /* Do not use cpufreq_set_policy here or the user_policy.max |
467 | will be wrongly overridden */ | |
468 | mutex_lock(&policy->lock); | |
469 | ret = __cpufreq_set_policy(policy, &new_policy); | |
470 | ||
471 | policy->user_policy.policy = policy->policy; | |
472 | policy->user_policy.governor = policy->governor; | |
473 | mutex_unlock(&policy->lock); | |
474 | ||
a496e25d DJ |
475 | unlock_cpu_hotplug(); |
476 | ||
1da177e4 LT |
477 | return ret ? ret : count; |
478 | } | |
479 | ||
480 | /** | |
481 | * show_scaling_driver - show the cpufreq driver currently loaded | |
482 | */ | |
483 | static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf) | |
484 | { | |
485 | return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name); | |
486 | } | |
487 | ||
488 | /** | |
489 | * show_scaling_available_governors - show the available CPUfreq governors | |
490 | */ | |
491 | static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy, | |
492 | char *buf) | |
493 | { | |
494 | ssize_t i = 0; | |
495 | struct cpufreq_governor *t; | |
496 | ||
497 | if (!cpufreq_driver->target) { | |
498 | i += sprintf(buf, "performance powersave"); | |
499 | goto out; | |
500 | } | |
501 | ||
502 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
503 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2))) | |
504 | goto out; | |
505 | i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name); | |
506 | } | |
7d5e350f | 507 | out: |
1da177e4 LT |
508 | i += sprintf(&buf[i], "\n"); |
509 | return i; | |
510 | } | |
511 | /** | |
512 | * show_affected_cpus - show the CPUs affected by each transition | |
513 | */ | |
514 | static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf) | |
515 | { | |
516 | ssize_t i = 0; | |
517 | unsigned int cpu; | |
518 | ||
519 | for_each_cpu_mask(cpu, policy->cpus) { | |
520 | if (i) | |
521 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
522 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
523 | if (i >= (PAGE_SIZE - 5)) | |
524 | break; | |
525 | } | |
526 | i += sprintf(&buf[i], "\n"); | |
527 | return i; | |
528 | } | |
529 | ||
530 | ||
531 | #define define_one_ro(_name) \ | |
532 | static struct freq_attr _name = \ | |
533 | __ATTR(_name, 0444, show_##_name, NULL) | |
534 | ||
535 | #define define_one_ro0400(_name) \ | |
536 | static struct freq_attr _name = \ | |
537 | __ATTR(_name, 0400, show_##_name, NULL) | |
538 | ||
539 | #define define_one_rw(_name) \ | |
540 | static struct freq_attr _name = \ | |
541 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
542 | ||
543 | define_one_ro0400(cpuinfo_cur_freq); | |
544 | define_one_ro(cpuinfo_min_freq); | |
545 | define_one_ro(cpuinfo_max_freq); | |
546 | define_one_ro(scaling_available_governors); | |
547 | define_one_ro(scaling_driver); | |
548 | define_one_ro(scaling_cur_freq); | |
549 | define_one_ro(affected_cpus); | |
550 | define_one_rw(scaling_min_freq); | |
551 | define_one_rw(scaling_max_freq); | |
552 | define_one_rw(scaling_governor); | |
553 | ||
554 | static struct attribute * default_attrs[] = { | |
555 | &cpuinfo_min_freq.attr, | |
556 | &cpuinfo_max_freq.attr, | |
557 | &scaling_min_freq.attr, | |
558 | &scaling_max_freq.attr, | |
559 | &affected_cpus.attr, | |
560 | &scaling_governor.attr, | |
561 | &scaling_driver.attr, | |
562 | &scaling_available_governors.attr, | |
563 | NULL | |
564 | }; | |
565 | ||
566 | #define to_policy(k) container_of(k,struct cpufreq_policy,kobj) | |
567 | #define to_attr(a) container_of(a,struct freq_attr,attr) | |
568 | ||
569 | static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf) | |
570 | { | |
571 | struct cpufreq_policy * policy = to_policy(kobj); | |
572 | struct freq_attr * fattr = to_attr(attr); | |
573 | ssize_t ret; | |
574 | policy = cpufreq_cpu_get(policy->cpu); | |
575 | if (!policy) | |
576 | return -EINVAL; | |
70f2817a | 577 | ret = fattr->show ? fattr->show(policy,buf) : -EIO; |
1da177e4 LT |
578 | cpufreq_cpu_put(policy); |
579 | return ret; | |
580 | } | |
581 | ||
32ee8c3e | 582 | static ssize_t store(struct kobject * kobj, struct attribute * attr, |
1da177e4 LT |
583 | const char * buf, size_t count) |
584 | { | |
585 | struct cpufreq_policy * policy = to_policy(kobj); | |
586 | struct freq_attr * fattr = to_attr(attr); | |
587 | ssize_t ret; | |
588 | policy = cpufreq_cpu_get(policy->cpu); | |
589 | if (!policy) | |
590 | return -EINVAL; | |
70f2817a | 591 | ret = fattr->store ? fattr->store(policy,buf,count) : -EIO; |
1da177e4 LT |
592 | cpufreq_cpu_put(policy); |
593 | return ret; | |
594 | } | |
595 | ||
596 | static void cpufreq_sysfs_release(struct kobject * kobj) | |
597 | { | |
598 | struct cpufreq_policy * policy = to_policy(kobj); | |
599 | dprintk("last reference is dropped\n"); | |
600 | complete(&policy->kobj_unregister); | |
601 | } | |
602 | ||
603 | static struct sysfs_ops sysfs_ops = { | |
604 | .show = show, | |
605 | .store = store, | |
606 | }; | |
607 | ||
608 | static struct kobj_type ktype_cpufreq = { | |
609 | .sysfs_ops = &sysfs_ops, | |
610 | .default_attrs = default_attrs, | |
611 | .release = cpufreq_sysfs_release, | |
612 | }; | |
613 | ||
614 | ||
615 | /** | |
616 | * cpufreq_add_dev - add a CPU device | |
617 | * | |
32ee8c3e | 618 | * Adds the cpufreq interface for a CPU device. |
1da177e4 LT |
619 | */ |
620 | static int cpufreq_add_dev (struct sys_device * sys_dev) | |
621 | { | |
622 | unsigned int cpu = sys_dev->id; | |
623 | int ret = 0; | |
624 | struct cpufreq_policy new_policy; | |
625 | struct cpufreq_policy *policy; | |
626 | struct freq_attr **drv_attr; | |
8ff69732 | 627 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
628 | unsigned long flags; |
629 | unsigned int j; | |
8ff69732 DJ |
630 | #ifdef CONFIG_SMP |
631 | struct cpufreq_policy *managed_policy; | |
632 | #endif | |
1da177e4 | 633 | |
c32b6b8e AR |
634 | if (cpu_is_offline(cpu)) |
635 | return 0; | |
636 | ||
1da177e4 LT |
637 | cpufreq_debug_disable_ratelimit(); |
638 | dprintk("adding CPU %u\n", cpu); | |
639 | ||
640 | #ifdef CONFIG_SMP | |
641 | /* check whether a different CPU already registered this | |
642 | * CPU because it is in the same boat. */ | |
643 | policy = cpufreq_cpu_get(cpu); | |
644 | if (unlikely(policy)) { | |
8ff69732 | 645 | cpufreq_cpu_put(policy); |
1da177e4 LT |
646 | cpufreq_debug_enable_ratelimit(); |
647 | return 0; | |
648 | } | |
649 | #endif | |
650 | ||
651 | if (!try_module_get(cpufreq_driver->owner)) { | |
652 | ret = -EINVAL; | |
653 | goto module_out; | |
654 | } | |
655 | ||
e98df50c | 656 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
1da177e4 LT |
657 | if (!policy) { |
658 | ret = -ENOMEM; | |
659 | goto nomem_out; | |
660 | } | |
1da177e4 LT |
661 | |
662 | policy->cpu = cpu; | |
663 | policy->cpus = cpumask_of_cpu(cpu); | |
664 | ||
83933af4 AV |
665 | mutex_init(&policy->lock); |
666 | mutex_lock(&policy->lock); | |
1da177e4 | 667 | init_completion(&policy->kobj_unregister); |
65f27f38 | 668 | INIT_WORK(&policy->update, handle_update); |
1da177e4 LT |
669 | |
670 | /* call driver. From then on the cpufreq must be able | |
671 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
672 | */ | |
673 | ret = cpufreq_driver->init(policy); | |
674 | if (ret) { | |
675 | dprintk("initialization failed\n"); | |
f3876c1b | 676 | mutex_unlock(&policy->lock); |
1da177e4 LT |
677 | goto err_out; |
678 | } | |
679 | ||
8ff69732 DJ |
680 | #ifdef CONFIG_SMP |
681 | for_each_cpu_mask(j, policy->cpus) { | |
682 | if (cpu == j) | |
683 | continue; | |
684 | ||
685 | /* check for existing affected CPUs. They may not be aware | |
686 | * of it due to CPU Hotplug. | |
687 | */ | |
688 | managed_policy = cpufreq_cpu_get(j); | |
689 | if (unlikely(managed_policy)) { | |
690 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
691 | managed_policy->cpus = policy->cpus; | |
692 | cpufreq_cpu_data[cpu] = managed_policy; | |
693 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
694 | ||
695 | dprintk("CPU already managed, adding link\n"); | |
696 | sysfs_create_link(&sys_dev->kobj, | |
697 | &managed_policy->kobj, "cpufreq"); | |
698 | ||
699 | cpufreq_debug_enable_ratelimit(); | |
700 | mutex_unlock(&policy->lock); | |
701 | ret = 0; | |
702 | goto err_out_driver_exit; /* call driver->exit() */ | |
703 | } | |
704 | } | |
705 | #endif | |
1da177e4 LT |
706 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); |
707 | ||
708 | /* prepare interface data */ | |
709 | policy->kobj.parent = &sys_dev->kobj; | |
710 | policy->kobj.ktype = &ktype_cpufreq; | |
711 | strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN); | |
712 | ||
713 | ret = kobject_register(&policy->kobj); | |
f3876c1b AM |
714 | if (ret) { |
715 | mutex_unlock(&policy->lock); | |
8085e1f1 | 716 | goto err_out_driver_exit; |
f3876c1b | 717 | } |
1da177e4 LT |
718 | /* set up files for this cpu device */ |
719 | drv_attr = cpufreq_driver->attr; | |
720 | while ((drv_attr) && (*drv_attr)) { | |
721 | sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
722 | drv_attr++; | |
723 | } | |
724 | if (cpufreq_driver->get) | |
725 | sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
726 | if (cpufreq_driver->target) | |
727 | sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
728 | ||
729 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
730 | for_each_cpu_mask(j, policy->cpus) | |
731 | cpufreq_cpu_data[j] = policy; | |
732 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
8ff69732 DJ |
733 | |
734 | /* symlink affected CPUs */ | |
735 | for_each_cpu_mask(j, policy->cpus) { | |
736 | if (j == cpu) | |
737 | continue; | |
738 | if (!cpu_online(j)) | |
739 | continue; | |
740 | ||
1f8b2c9d | 741 | dprintk("CPU %u already managed, adding link\n", j); |
8ff69732 DJ |
742 | cpufreq_cpu_get(cpu); |
743 | cpu_sys_dev = get_cpu_sysdev(j); | |
744 | sysfs_create_link(&cpu_sys_dev->kobj, &policy->kobj, | |
745 | "cpufreq"); | |
746 | } | |
747 | ||
1da177e4 LT |
748 | policy->governor = NULL; /* to assure that the starting sequence is |
749 | * run in cpufreq_set_policy */ | |
83933af4 | 750 | mutex_unlock(&policy->lock); |
87c32271 | 751 | |
1da177e4 | 752 | /* set default policy */ |
1da177e4 LT |
753 | ret = cpufreq_set_policy(&new_policy); |
754 | if (ret) { | |
755 | dprintk("setting policy failed\n"); | |
756 | goto err_out_unregister; | |
757 | } | |
758 | ||
759 | module_put(cpufreq_driver->owner); | |
1da177e4 LT |
760 | dprintk("initialization complete\n"); |
761 | cpufreq_debug_enable_ratelimit(); | |
87c32271 | 762 | |
1da177e4 LT |
763 | return 0; |
764 | ||
765 | ||
766 | err_out_unregister: | |
767 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
768 | for_each_cpu_mask(j, policy->cpus) | |
769 | cpufreq_cpu_data[j] = NULL; | |
770 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
771 | ||
772 | kobject_unregister(&policy->kobj); | |
773 | wait_for_completion(&policy->kobj_unregister); | |
774 | ||
8085e1f1 VP |
775 | err_out_driver_exit: |
776 | if (cpufreq_driver->exit) | |
777 | cpufreq_driver->exit(policy); | |
778 | ||
1da177e4 LT |
779 | err_out: |
780 | kfree(policy); | |
781 | ||
782 | nomem_out: | |
783 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 784 | module_out: |
1da177e4 LT |
785 | cpufreq_debug_enable_ratelimit(); |
786 | return ret; | |
787 | } | |
788 | ||
789 | ||
790 | /** | |
791 | * cpufreq_remove_dev - remove a CPU device | |
792 | * | |
793 | * Removes the cpufreq interface for a CPU device. | |
794 | */ | |
795 | static int cpufreq_remove_dev (struct sys_device * sys_dev) | |
796 | { | |
797 | unsigned int cpu = sys_dev->id; | |
798 | unsigned long flags; | |
799 | struct cpufreq_policy *data; | |
800 | #ifdef CONFIG_SMP | |
e738cf6d | 801 | struct sys_device *cpu_sys_dev; |
1da177e4 LT |
802 | unsigned int j; |
803 | #endif | |
804 | ||
805 | cpufreq_debug_disable_ratelimit(); | |
806 | dprintk("unregistering CPU %u\n", cpu); | |
807 | ||
808 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
809 | data = cpufreq_cpu_data[cpu]; | |
810 | ||
811 | if (!data) { | |
812 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1da177e4 LT |
813 | cpufreq_debug_enable_ratelimit(); |
814 | return -EINVAL; | |
815 | } | |
816 | cpufreq_cpu_data[cpu] = NULL; | |
817 | ||
818 | ||
819 | #ifdef CONFIG_SMP | |
820 | /* if this isn't the CPU which is the parent of the kobj, we | |
32ee8c3e | 821 | * only need to unlink, put and exit |
1da177e4 LT |
822 | */ |
823 | if (unlikely(cpu != data->cpu)) { | |
824 | dprintk("removing link\n"); | |
8ff69732 | 825 | cpu_clear(cpu, data->cpus); |
1da177e4 LT |
826 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
827 | sysfs_remove_link(&sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
828 | cpufreq_cpu_put(data); |
829 | cpufreq_debug_enable_ratelimit(); | |
830 | return 0; | |
831 | } | |
832 | #endif | |
833 | ||
1da177e4 LT |
834 | |
835 | if (!kobject_get(&data->kobj)) { | |
836 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
837 | cpufreq_debug_enable_ratelimit(); | |
32ee8c3e | 838 | return -EFAULT; |
1da177e4 LT |
839 | } |
840 | ||
841 | #ifdef CONFIG_SMP | |
842 | /* if we have other CPUs still registered, we need to unlink them, | |
843 | * or else wait_for_completion below will lock up. Clean the | |
844 | * cpufreq_cpu_data[] while holding the lock, and remove the sysfs | |
845 | * links afterwards. | |
846 | */ | |
847 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
848 | for_each_cpu_mask(j, data->cpus) { | |
849 | if (j == cpu) | |
850 | continue; | |
851 | cpufreq_cpu_data[j] = NULL; | |
852 | } | |
853 | } | |
854 | ||
855 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
856 | ||
857 | if (unlikely(cpus_weight(data->cpus) > 1)) { | |
858 | for_each_cpu_mask(j, data->cpus) { | |
859 | if (j == cpu) | |
860 | continue; | |
861 | dprintk("removing link for cpu %u\n", j); | |
d434fca7 AR |
862 | cpu_sys_dev = get_cpu_sysdev(j); |
863 | sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); | |
1da177e4 LT |
864 | cpufreq_cpu_put(data); |
865 | } | |
866 | } | |
867 | #else | |
868 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
869 | #endif | |
870 | ||
83933af4 | 871 | mutex_lock(&data->lock); |
1da177e4 LT |
872 | if (cpufreq_driver->target) |
873 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
83933af4 | 874 | mutex_unlock(&data->lock); |
1da177e4 LT |
875 | |
876 | kobject_unregister(&data->kobj); | |
877 | ||
878 | kobject_put(&data->kobj); | |
879 | ||
880 | /* we need to make sure that the underlying kobj is actually | |
32ee8c3e | 881 | * not referenced anymore by anybody before we proceed with |
1da177e4 LT |
882 | * unloading. |
883 | */ | |
884 | dprintk("waiting for dropping of refcount\n"); | |
885 | wait_for_completion(&data->kobj_unregister); | |
886 | dprintk("wait complete\n"); | |
887 | ||
888 | if (cpufreq_driver->exit) | |
889 | cpufreq_driver->exit(data); | |
890 | ||
891 | kfree(data); | |
892 | ||
893 | cpufreq_debug_enable_ratelimit(); | |
1da177e4 LT |
894 | return 0; |
895 | } | |
896 | ||
897 | ||
65f27f38 | 898 | static void handle_update(struct work_struct *work) |
1da177e4 | 899 | { |
65f27f38 DH |
900 | struct cpufreq_policy *policy = |
901 | container_of(work, struct cpufreq_policy, update); | |
902 | unsigned int cpu = policy->cpu; | |
1da177e4 LT |
903 | dprintk("handle_update for cpu %u called\n", cpu); |
904 | cpufreq_update_policy(cpu); | |
905 | } | |
906 | ||
907 | /** | |
908 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
909 | * @cpu: cpu number | |
910 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
911 | * @new_freq: CPU frequency the CPU actually runs at | |
912 | * | |
913 | * We adjust to current frequency first, and need to clean up later. So either call | |
914 | * to cpufreq_update_policy() or schedule handle_update()). | |
915 | */ | |
916 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq) | |
917 | { | |
918 | struct cpufreq_freqs freqs; | |
919 | ||
b10eec22 | 920 | dprintk("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
921 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
922 | ||
923 | freqs.cpu = cpu; | |
924 | freqs.old = old_freq; | |
925 | freqs.new = new_freq; | |
926 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
927 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
928 | } | |
929 | ||
930 | ||
32ee8c3e | 931 | /** |
95235ca2 VP |
932 | * cpufreq_quick_get - get the CPU frequency (in kHz) frpm policy->cur |
933 | * @cpu: CPU number | |
934 | * | |
935 | * This is the last known freq, without actually getting it from the driver. | |
936 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
937 | */ | |
938 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
939 | { | |
940 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
941 | unsigned int ret = 0; | |
942 | ||
943 | if (policy) { | |
83933af4 | 944 | mutex_lock(&policy->lock); |
95235ca2 | 945 | ret = policy->cur; |
83933af4 | 946 | mutex_unlock(&policy->lock); |
95235ca2 VP |
947 | cpufreq_cpu_put(policy); |
948 | } | |
949 | ||
950 | return (ret); | |
951 | } | |
952 | EXPORT_SYMBOL(cpufreq_quick_get); | |
953 | ||
954 | ||
32ee8c3e | 955 | /** |
1da177e4 LT |
956 | * cpufreq_get - get the current CPU frequency (in kHz) |
957 | * @cpu: CPU number | |
958 | * | |
959 | * Get the CPU current (static) CPU frequency | |
960 | */ | |
961 | unsigned int cpufreq_get(unsigned int cpu) | |
962 | { | |
963 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
964 | unsigned int ret = 0; | |
965 | ||
966 | if (!policy) | |
967 | return 0; | |
968 | ||
969 | if (!cpufreq_driver->get) | |
970 | goto out; | |
971 | ||
83933af4 | 972 | mutex_lock(&policy->lock); |
1da177e4 LT |
973 | |
974 | ret = cpufreq_driver->get(cpu); | |
975 | ||
7d5e350f | 976 | if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
1da177e4 LT |
977 | /* verify no discrepancy between actual and saved value exists */ |
978 | if (unlikely(ret != policy->cur)) { | |
979 | cpufreq_out_of_sync(cpu, policy->cur, ret); | |
980 | schedule_work(&policy->update); | |
981 | } | |
982 | } | |
983 | ||
83933af4 | 984 | mutex_unlock(&policy->lock); |
1da177e4 | 985 | |
7d5e350f | 986 | out: |
1da177e4 LT |
987 | cpufreq_cpu_put(policy); |
988 | ||
989 | return (ret); | |
990 | } | |
991 | EXPORT_SYMBOL(cpufreq_get); | |
992 | ||
993 | ||
42d4dc3f BH |
994 | /** |
995 | * cpufreq_suspend - let the low level driver prepare for suspend | |
996 | */ | |
997 | ||
e00d9967 | 998 | static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg) |
42d4dc3f BH |
999 | { |
1000 | int cpu = sysdev->id; | |
1001 | unsigned int ret = 0; | |
1002 | unsigned int cur_freq = 0; | |
1003 | struct cpufreq_policy *cpu_policy; | |
1004 | ||
0e37b159 | 1005 | dprintk("suspending cpu %u\n", cpu); |
42d4dc3f BH |
1006 | |
1007 | if (!cpu_online(cpu)) | |
1008 | return 0; | |
1009 | ||
1010 | /* we may be lax here as interrupts are off. Nonetheless | |
1011 | * we need to grab the correct cpu policy, as to check | |
1012 | * whether we really run on this CPU. | |
1013 | */ | |
1014 | ||
1015 | cpu_policy = cpufreq_cpu_get(cpu); | |
1016 | if (!cpu_policy) | |
1017 | return -EINVAL; | |
1018 | ||
1019 | /* only handle each CPU group once */ | |
1020 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1021 | cpufreq_cpu_put(cpu_policy); | |
1022 | return 0; | |
1023 | } | |
1024 | ||
1025 | if (cpufreq_driver->suspend) { | |
e00d9967 | 1026 | ret = cpufreq_driver->suspend(cpu_policy, pmsg); |
42d4dc3f BH |
1027 | if (ret) { |
1028 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1029 | "step on CPU %u\n", cpu_policy->cpu); | |
1030 | cpufreq_cpu_put(cpu_policy); | |
1031 | return ret; | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | ||
1036 | if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS) | |
1037 | goto out; | |
1038 | ||
1039 | if (cpufreq_driver->get) | |
1040 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1041 | ||
1042 | if (!cur_freq || !cpu_policy->cur) { | |
1043 | printk(KERN_ERR "cpufreq: suspend failed to assert current " | |
1044 | "frequency is what timing core thinks it is.\n"); | |
1045 | goto out; | |
1046 | } | |
1047 | ||
1048 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1049 | struct cpufreq_freqs freqs; | |
1050 | ||
1051 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) | |
b10eec22 | 1052 | dprintk("Warning: CPU frequency is %u, " |
42d4dc3f BH |
1053 | "cpufreq assumed %u kHz.\n", |
1054 | cur_freq, cpu_policy->cur); | |
1055 | ||
1056 | freqs.cpu = cpu; | |
1057 | freqs.old = cpu_policy->cur; | |
1058 | freqs.new = cur_freq; | |
1059 | ||
b4dfdbb3 | 1060 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
42d4dc3f BH |
1061 | CPUFREQ_SUSPENDCHANGE, &freqs); |
1062 | adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs); | |
1063 | ||
1064 | cpu_policy->cur = cur_freq; | |
1065 | } | |
1066 | ||
7d5e350f | 1067 | out: |
42d4dc3f BH |
1068 | cpufreq_cpu_put(cpu_policy); |
1069 | return 0; | |
1070 | } | |
1071 | ||
1da177e4 LT |
1072 | /** |
1073 | * cpufreq_resume - restore proper CPU frequency handling after resume | |
1074 | * | |
1075 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1076 | * 2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync | |
42d4dc3f BH |
1077 | * 3.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1078 | * restored. | |
1da177e4 LT |
1079 | */ |
1080 | static int cpufreq_resume(struct sys_device * sysdev) | |
1081 | { | |
1082 | int cpu = sysdev->id; | |
1083 | unsigned int ret = 0; | |
1084 | struct cpufreq_policy *cpu_policy; | |
1085 | ||
1086 | dprintk("resuming cpu %u\n", cpu); | |
1087 | ||
1088 | if (!cpu_online(cpu)) | |
1089 | return 0; | |
1090 | ||
1091 | /* we may be lax here as interrupts are off. Nonetheless | |
1092 | * we need to grab the correct cpu policy, as to check | |
1093 | * whether we really run on this CPU. | |
1094 | */ | |
1095 | ||
1096 | cpu_policy = cpufreq_cpu_get(cpu); | |
1097 | if (!cpu_policy) | |
1098 | return -EINVAL; | |
1099 | ||
1100 | /* only handle each CPU group once */ | |
1101 | if (unlikely(cpu_policy->cpu != cpu)) { | |
1102 | cpufreq_cpu_put(cpu_policy); | |
1103 | return 0; | |
1104 | } | |
1105 | ||
1106 | if (cpufreq_driver->resume) { | |
1107 | ret = cpufreq_driver->resume(cpu_policy); | |
1108 | if (ret) { | |
1109 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1110 | "step on CPU %u\n", cpu_policy->cpu); | |
1111 | cpufreq_cpu_put(cpu_policy); | |
1112 | return ret; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1117 | unsigned int cur_freq = 0; | |
1118 | ||
1119 | if (cpufreq_driver->get) | |
1120 | cur_freq = cpufreq_driver->get(cpu_policy->cpu); | |
1121 | ||
1122 | if (!cur_freq || !cpu_policy->cur) { | |
42d4dc3f BH |
1123 | printk(KERN_ERR "cpufreq: resume failed to assert " |
1124 | "current frequency is what timing core " | |
1125 | "thinks it is.\n"); | |
1da177e4 LT |
1126 | goto out; |
1127 | } | |
1128 | ||
1129 | if (unlikely(cur_freq != cpu_policy->cur)) { | |
1130 | struct cpufreq_freqs freqs; | |
1131 | ||
ac09f698 | 1132 | if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN)) |
b10eec22 | 1133 | dprintk("Warning: CPU frequency" |
ac09f698 BH |
1134 | "is %u, cpufreq assumed %u kHz.\n", |
1135 | cur_freq, cpu_policy->cur); | |
1da177e4 LT |
1136 | |
1137 | freqs.cpu = cpu; | |
1138 | freqs.old = cpu_policy->cur; | |
1139 | freqs.new = cur_freq; | |
1140 | ||
b4dfdbb3 | 1141 | srcu_notifier_call_chain( |
e041c683 | 1142 | &cpufreq_transition_notifier_list, |
42d4dc3f | 1143 | CPUFREQ_RESUMECHANGE, &freqs); |
1da177e4 LT |
1144 | adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs); |
1145 | ||
1146 | cpu_policy->cur = cur_freq; | |
1147 | } | |
1148 | } | |
1149 | ||
1150 | out: | |
1151 | schedule_work(&cpu_policy->update); | |
1152 | cpufreq_cpu_put(cpu_policy); | |
1153 | return ret; | |
1154 | } | |
1155 | ||
1156 | static struct sysdev_driver cpufreq_sysdev_driver = { | |
1157 | .add = cpufreq_add_dev, | |
1158 | .remove = cpufreq_remove_dev, | |
42d4dc3f | 1159 | .suspend = cpufreq_suspend, |
1da177e4 LT |
1160 | .resume = cpufreq_resume, |
1161 | }; | |
1162 | ||
1163 | ||
1164 | /********************************************************************* | |
1165 | * NOTIFIER LISTS INTERFACE * | |
1166 | *********************************************************************/ | |
1167 | ||
1168 | /** | |
1169 | * cpufreq_register_notifier - register a driver with cpufreq | |
1170 | * @nb: notifier function to register | |
1171 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1172 | * | |
32ee8c3e | 1173 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1174 | * are notified about clock rate changes (once before and once after |
1175 | * the transition), or a list of drivers that are notified about | |
1176 | * changes in cpufreq policy. | |
1177 | * | |
1178 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1179 | * blocking_notifier_chain_register. |
1da177e4 LT |
1180 | */ |
1181 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1182 | { | |
1183 | int ret; | |
1184 | ||
1da177e4 LT |
1185 | switch (list) { |
1186 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1187 | ret = srcu_notifier_chain_register( |
e041c683 | 1188 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1189 | break; |
1190 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1191 | ret = blocking_notifier_chain_register( |
1192 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1193 | break; |
1194 | default: | |
1195 | ret = -EINVAL; | |
1196 | } | |
1da177e4 LT |
1197 | |
1198 | return ret; | |
1199 | } | |
1200 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1201 | ||
1202 | ||
1203 | /** | |
1204 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1205 | * @nb: notifier block to be unregistered | |
1206 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1207 | * | |
1208 | * Remove a driver from the CPU frequency notifier list. | |
1209 | * | |
1210 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1211 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1212 | */ |
1213 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1214 | { | |
1215 | int ret; | |
1216 | ||
1da177e4 LT |
1217 | switch (list) { |
1218 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1219 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1220 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1221 | break; |
1222 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1223 | ret = blocking_notifier_chain_unregister( |
1224 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1225 | break; |
1226 | default: | |
1227 | ret = -EINVAL; | |
1228 | } | |
1da177e4 LT |
1229 | |
1230 | return ret; | |
1231 | } | |
1232 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1233 | ||
1234 | ||
1235 | /********************************************************************* | |
1236 | * GOVERNORS * | |
1237 | *********************************************************************/ | |
1238 | ||
1239 | ||
153d7f3f | 1240 | /* Must be called with lock_cpu_hotplug held */ |
1da177e4 LT |
1241 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1242 | unsigned int target_freq, | |
1243 | unsigned int relation) | |
1244 | { | |
1245 | int retval = -EINVAL; | |
c32b6b8e | 1246 | |
1da177e4 LT |
1247 | dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu, |
1248 | target_freq, relation); | |
1249 | if (cpu_online(policy->cpu) && cpufreq_driver->target) | |
1250 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1251 | |
1da177e4 LT |
1252 | return retval; |
1253 | } | |
1254 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1255 | ||
1da177e4 LT |
1256 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1257 | unsigned int target_freq, | |
1258 | unsigned int relation) | |
1259 | { | |
cc993cab | 1260 | int ret; |
1da177e4 LT |
1261 | |
1262 | policy = cpufreq_cpu_get(policy->cpu); | |
1263 | if (!policy) | |
1264 | return -EINVAL; | |
1265 | ||
153d7f3f | 1266 | lock_cpu_hotplug(); |
83933af4 | 1267 | mutex_lock(&policy->lock); |
1da177e4 LT |
1268 | |
1269 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1270 | ||
83933af4 | 1271 | mutex_unlock(&policy->lock); |
153d7f3f | 1272 | unlock_cpu_hotplug(); |
1da177e4 LT |
1273 | |
1274 | cpufreq_cpu_put(policy); | |
1da177e4 LT |
1275 | return ret; |
1276 | } | |
1277 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1278 | ||
153d7f3f AV |
1279 | /* |
1280 | * Locking: Must be called with the lock_cpu_hotplug() lock held | |
1281 | * when "event" is CPUFREQ_GOV_LIMITS | |
1282 | */ | |
1da177e4 LT |
1283 | |
1284 | static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) | |
1285 | { | |
cc993cab | 1286 | int ret; |
1da177e4 LT |
1287 | |
1288 | if (!try_module_get(policy->governor->owner)) | |
1289 | return -EINVAL; | |
1290 | ||
1291 | dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event); | |
1292 | ret = policy->governor->governor(policy, event); | |
1293 | ||
1294 | /* we keep one module reference alive for each CPU governed by this CPU */ | |
1295 | if ((event != CPUFREQ_GOV_START) || ret) | |
1296 | module_put(policy->governor->owner); | |
1297 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1298 | module_put(policy->governor->owner); | |
1299 | ||
1300 | return ret; | |
1301 | } | |
1302 | ||
1303 | ||
1da177e4 LT |
1304 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1305 | { | |
3bcb09a3 | 1306 | int err; |
1da177e4 LT |
1307 | |
1308 | if (!governor) | |
1309 | return -EINVAL; | |
1310 | ||
3fc54d37 | 1311 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1312 | |
3bcb09a3 JF |
1313 | err = -EBUSY; |
1314 | if (__find_governor(governor->name) == NULL) { | |
1315 | err = 0; | |
1316 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1317 | } |
1da177e4 | 1318 | |
32ee8c3e | 1319 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1320 | return err; |
1da177e4 LT |
1321 | } |
1322 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1323 | ||
1324 | ||
1325 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1326 | { | |
1327 | if (!governor) | |
1328 | return; | |
1329 | ||
3fc54d37 | 1330 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1331 | list_del(&governor->governor_list); |
3fc54d37 | 1332 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1333 | return; |
1334 | } | |
1335 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1336 | ||
1337 | ||
1338 | ||
1339 | /********************************************************************* | |
1340 | * POLICY INTERFACE * | |
1341 | *********************************************************************/ | |
1342 | ||
1343 | /** | |
1344 | * cpufreq_get_policy - get the current cpufreq_policy | |
1345 | * @policy: struct cpufreq_policy into which the current cpufreq_policy is written | |
1346 | * | |
1347 | * Reads the current cpufreq policy. | |
1348 | */ | |
1349 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1350 | { | |
1351 | struct cpufreq_policy *cpu_policy; | |
1352 | if (!policy) | |
1353 | return -EINVAL; | |
1354 | ||
1355 | cpu_policy = cpufreq_cpu_get(cpu); | |
1356 | if (!cpu_policy) | |
1357 | return -EINVAL; | |
1358 | ||
83933af4 | 1359 | mutex_lock(&cpu_policy->lock); |
1da177e4 | 1360 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
83933af4 | 1361 | mutex_unlock(&cpu_policy->lock); |
1da177e4 LT |
1362 | |
1363 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1364 | return 0; |
1365 | } | |
1366 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1367 | ||
1368 | ||
153d7f3f AV |
1369 | /* |
1370 | * Locking: Must be called with the lock_cpu_hotplug() lock held | |
1371 | */ | |
1da177e4 LT |
1372 | static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy) |
1373 | { | |
1374 | int ret = 0; | |
1375 | ||
1376 | cpufreq_debug_disable_ratelimit(); | |
1377 | dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1378 | policy->min, policy->max); | |
1379 | ||
7d5e350f | 1380 | memcpy(&policy->cpuinfo, &data->cpuinfo, sizeof(struct cpufreq_cpuinfo)); |
1da177e4 | 1381 | |
9c9a43ed MD |
1382 | if (policy->min > data->min && policy->min > policy->max) { |
1383 | ret = -EINVAL; | |
1384 | goto error_out; | |
1385 | } | |
1386 | ||
1da177e4 LT |
1387 | /* verify the cpu speed can be set within this limit */ |
1388 | ret = cpufreq_driver->verify(policy); | |
1389 | if (ret) | |
1390 | goto error_out; | |
1391 | ||
1da177e4 | 1392 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1393 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1394 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1395 | |
1396 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1397 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1398 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1399 | |
1400 | /* verify the cpu speed can be set within this limit, | |
1401 | which might be different to the first one */ | |
1402 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1403 | if (ret) |
1da177e4 | 1404 | goto error_out; |
1da177e4 LT |
1405 | |
1406 | /* notification of the new policy */ | |
e041c683 AS |
1407 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1408 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1409 | |
7d5e350f DJ |
1410 | data->min = policy->min; |
1411 | data->max = policy->max; | |
1da177e4 LT |
1412 | |
1413 | dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max); | |
1414 | ||
1415 | if (cpufreq_driver->setpolicy) { | |
1416 | data->policy = policy->policy; | |
1417 | dprintk("setting range\n"); | |
1418 | ret = cpufreq_driver->setpolicy(policy); | |
1419 | } else { | |
1420 | if (policy->governor != data->governor) { | |
1421 | /* save old, working values */ | |
1422 | struct cpufreq_governor *old_gov = data->governor; | |
1423 | ||
1424 | dprintk("governor switch\n"); | |
1425 | ||
1426 | /* end old governor */ | |
1427 | if (data->governor) | |
1428 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1429 | ||
1430 | /* start new governor */ | |
1431 | data->governor = policy->governor; | |
1432 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1433 | /* new governor failed, so re-start old one */ | |
1434 | dprintk("starting governor %s failed\n", data->governor->name); | |
1435 | if (old_gov) { | |
1436 | data->governor = old_gov; | |
1437 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1438 | } | |
1439 | ret = -EINVAL; | |
1440 | goto error_out; | |
1441 | } | |
1442 | /* might be a policy change, too, so fall through */ | |
1443 | } | |
1444 | dprintk("governor: change or update limits\n"); | |
1445 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1446 | } | |
1447 | ||
7d5e350f | 1448 | error_out: |
1da177e4 LT |
1449 | cpufreq_debug_enable_ratelimit(); |
1450 | return ret; | |
1451 | } | |
1452 | ||
1453 | /** | |
1454 | * cpufreq_set_policy - set a new CPUFreq policy | |
1455 | * @policy: policy to be set. | |
1456 | * | |
1457 | * Sets a new CPU frequency and voltage scaling policy. | |
1458 | */ | |
1459 | int cpufreq_set_policy(struct cpufreq_policy *policy) | |
1460 | { | |
1461 | int ret = 0; | |
1462 | struct cpufreq_policy *data; | |
1463 | ||
1464 | if (!policy) | |
1465 | return -EINVAL; | |
1466 | ||
1467 | data = cpufreq_cpu_get(policy->cpu); | |
1468 | if (!data) | |
1469 | return -EINVAL; | |
1470 | ||
153d7f3f AV |
1471 | lock_cpu_hotplug(); |
1472 | ||
1da177e4 | 1473 | /* lock this CPU */ |
83933af4 | 1474 | mutex_lock(&data->lock); |
1da177e4 LT |
1475 | |
1476 | ret = __cpufreq_set_policy(data, policy); | |
1477 | data->user_policy.min = data->min; | |
1478 | data->user_policy.max = data->max; | |
1479 | data->user_policy.policy = data->policy; | |
1480 | data->user_policy.governor = data->governor; | |
1481 | ||
83933af4 | 1482 | mutex_unlock(&data->lock); |
153d7f3f AV |
1483 | |
1484 | unlock_cpu_hotplug(); | |
1da177e4 LT |
1485 | cpufreq_cpu_put(data); |
1486 | ||
1487 | return ret; | |
1488 | } | |
1489 | EXPORT_SYMBOL(cpufreq_set_policy); | |
1490 | ||
1491 | ||
1492 | /** | |
1493 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1494 | * @cpu: CPU which shall be re-evaluated | |
1495 | * | |
1496 | * Usefull for policy notifiers which have different necessities | |
1497 | * at different times. | |
1498 | */ | |
1499 | int cpufreq_update_policy(unsigned int cpu) | |
1500 | { | |
1501 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1502 | struct cpufreq_policy policy; | |
1503 | int ret = 0; | |
1504 | ||
1505 | if (!data) | |
1506 | return -ENODEV; | |
1507 | ||
153d7f3f | 1508 | lock_cpu_hotplug(); |
83933af4 | 1509 | mutex_lock(&data->lock); |
1da177e4 LT |
1510 | |
1511 | dprintk("updating policy for CPU %u\n", cpu); | |
7d5e350f | 1512 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1513 | policy.min = data->user_policy.min; |
1514 | policy.max = data->user_policy.max; | |
1515 | policy.policy = data->user_policy.policy; | |
1516 | policy.governor = data->user_policy.governor; | |
1517 | ||
0961dd0d TR |
1518 | /* BIOS might change freq behind our back |
1519 | -> ask driver for current freq and notify governors about a change */ | |
1520 | if (cpufreq_driver->get) { | |
1521 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 TR |
1522 | if (!data->cur) { |
1523 | dprintk("Driver did not initialize current freq"); | |
1524 | data->cur = policy.cur; | |
1525 | } else { | |
1526 | if (data->cur != policy.cur) | |
1527 | cpufreq_out_of_sync(cpu, data->cur, policy.cur); | |
1528 | } | |
0961dd0d TR |
1529 | } |
1530 | ||
1da177e4 LT |
1531 | ret = __cpufreq_set_policy(data, &policy); |
1532 | ||
83933af4 | 1533 | mutex_unlock(&data->lock); |
153d7f3f | 1534 | unlock_cpu_hotplug(); |
1da177e4 LT |
1535 | cpufreq_cpu_put(data); |
1536 | return ret; | |
1537 | } | |
1538 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1539 | ||
65edc68c CS |
1540 | #ifdef CONFIG_HOTPLUG_CPU |
1541 | static int cpufreq_cpu_callback(struct notifier_block *nfb, | |
c32b6b8e AR |
1542 | unsigned long action, void *hcpu) |
1543 | { | |
1544 | unsigned int cpu = (unsigned long)hcpu; | |
1545 | struct cpufreq_policy *policy; | |
1546 | struct sys_device *sys_dev; | |
1547 | ||
1548 | sys_dev = get_cpu_sysdev(cpu); | |
1549 | ||
1550 | if (sys_dev) { | |
1551 | switch (action) { | |
1552 | case CPU_ONLINE: | |
1553 | cpufreq_add_dev(sys_dev); | |
1554 | break; | |
1555 | case CPU_DOWN_PREPARE: | |
1556 | /* | |
1557 | * We attempt to put this cpu in lowest frequency | |
1558 | * possible before going down. This will permit | |
1559 | * hardware-managed P-State to switch other related | |
1560 | * threads to min or higher speeds if possible. | |
1561 | */ | |
1562 | policy = cpufreq_cpu_data[cpu]; | |
1563 | if (policy) { | |
1564 | cpufreq_driver_target(policy, policy->min, | |
1565 | CPUFREQ_RELATION_H); | |
1566 | } | |
1567 | break; | |
1568 | case CPU_DEAD: | |
1569 | cpufreq_remove_dev(sys_dev); | |
1570 | break; | |
1571 | } | |
1572 | } | |
1573 | return NOTIFY_OK; | |
1574 | } | |
1575 | ||
74b85f37 | 1576 | static struct notifier_block __cpuinitdata cpufreq_cpu_notifier = |
c32b6b8e AR |
1577 | { |
1578 | .notifier_call = cpufreq_cpu_callback, | |
1579 | }; | |
65edc68c | 1580 | #endif /* CONFIG_HOTPLUG_CPU */ |
1da177e4 LT |
1581 | |
1582 | /********************************************************************* | |
1583 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1584 | *********************************************************************/ | |
1585 | ||
1586 | /** | |
1587 | * cpufreq_register_driver - register a CPU Frequency driver | |
1588 | * @driver_data: A struct cpufreq_driver containing the values# | |
1589 | * submitted by the CPU Frequency driver. | |
1590 | * | |
32ee8c3e | 1591 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1592 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1593 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1594 | * |
1595 | */ | |
1596 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
1597 | { | |
1598 | unsigned long flags; | |
1599 | int ret; | |
1600 | ||
1601 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
1602 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1603 | return -EINVAL; | |
1604 | ||
1605 | dprintk("trying to register driver %s\n", driver_data->name); | |
1606 | ||
1607 | if (driver_data->setpolicy) | |
1608 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1609 | ||
1610 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1611 | if (cpufreq_driver) { | |
1612 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1613 | return -EBUSY; | |
1614 | } | |
1615 | cpufreq_driver = driver_data; | |
1616 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1617 | ||
1618 | ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver); | |
1619 | ||
1620 | if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
1621 | int i; | |
1622 | ret = -ENODEV; | |
1623 | ||
1624 | /* check for at least one working CPU */ | |
1625 | for (i=0; i<NR_CPUS; i++) | |
1626 | if (cpufreq_cpu_data[i]) | |
1627 | ret = 0; | |
1628 | ||
1629 | /* if all ->init() calls failed, unregister */ | |
1630 | if (ret) { | |
1631 | dprintk("no CPU initialized for driver %s\n", driver_data->name); | |
1632 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
1633 | ||
1634 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1635 | cpufreq_driver = NULL; | |
1636 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1637 | } | |
1638 | } | |
1639 | ||
1640 | if (!ret) { | |
65edc68c | 1641 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1642 | dprintk("driver %s up and running\n", driver_data->name); |
1643 | cpufreq_debug_enable_ratelimit(); | |
1644 | } | |
1645 | ||
1646 | return (ret); | |
1647 | } | |
1648 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1649 | ||
1650 | ||
1651 | /** | |
1652 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1653 | * | |
32ee8c3e | 1654 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1655 | * the right to do so, i.e. if you have succeeded in initialising before! |
1656 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1657 | * currently not initialised. | |
1658 | */ | |
1659 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
1660 | { | |
1661 | unsigned long flags; | |
1662 | ||
1663 | cpufreq_debug_disable_ratelimit(); | |
1664 | ||
1665 | if (!cpufreq_driver || (driver != cpufreq_driver)) { | |
1666 | cpufreq_debug_enable_ratelimit(); | |
1667 | return -EINVAL; | |
1668 | } | |
1669 | ||
1670 | dprintk("unregistering driver %s\n", driver->name); | |
1671 | ||
1672 | sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver); | |
65edc68c | 1673 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1674 | |
1675 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1676 | cpufreq_driver = NULL; | |
1677 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1678 | ||
1679 | return 0; | |
1680 | } | |
1681 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); |