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