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1 | /* | |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> | |
7 | * | |
8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> | |
9 | * Added handling for CPU hotplug | |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> | |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
16 | */ | |
17 | ||
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
19 | ||
20 | #include <asm/cputime.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/kernel_stat.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/notifier.h> | |
26 | #include <linux/cpufreq.h> | |
27 | #include <linux/delay.h> | |
28 | #include <linux/interrupt.h> | |
29 | #include <linux/spinlock.h> | |
30 | #include <linux/tick.h> | |
31 | #include <linux/device.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/cpu.h> | |
34 | #include <linux/completion.h> | |
35 | #include <linux/mutex.h> | |
36 | #include <linux/syscore_ops.h> | |
37 | ||
38 | #include <trace/events/power.h> | |
39 | ||
40 | /** | |
41 | * The "cpufreq driver" - the arch- or hardware-dependent low | |
42 | * level driver of CPUFreq support, and its spinlock. This lock | |
43 | * also protects the cpufreq_cpu_data array. | |
44 | */ | |
45 | static struct cpufreq_driver *cpufreq_driver; | |
46 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); | |
47 | static DEFINE_RWLOCK(cpufreq_driver_lock); | |
48 | static DEFINE_MUTEX(cpufreq_governor_lock); | |
49 | ||
50 | #ifdef CONFIG_HOTPLUG_CPU | |
51 | /* This one keeps track of the previously set governor of a removed CPU */ | |
52 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); | |
53 | #endif | |
54 | ||
55 | /* | |
56 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
57 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
58 | * | |
59 | * The rules for this semaphore: | |
60 | * - Any routine that wants to read from the policy structure will | |
61 | * do a down_read on this semaphore. | |
62 | * - Any routine that will write to the policy structure and/or may take away | |
63 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
64 | * mode before doing so. | |
65 | * | |
66 | * Additional rules: | |
67 | * - Governor routines that can be called in cpufreq hotplug path should not | |
68 | * take this sem as top level hotplug notifier handler takes this. | |
69 | * - Lock should not be held across | |
70 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
71 | */ | |
72 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); | |
73 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); | |
74 | ||
75 | #define lock_policy_rwsem(mode, cpu) \ | |
76 | static int lock_policy_rwsem_##mode(int cpu) \ | |
77 | { \ | |
78 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
79 | BUG_ON(policy_cpu == -1); \ | |
80 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
81 | \ | |
82 | return 0; \ | |
83 | } | |
84 | ||
85 | lock_policy_rwsem(read, cpu); | |
86 | lock_policy_rwsem(write, cpu); | |
87 | ||
88 | #define unlock_policy_rwsem(mode, cpu) \ | |
89 | static void unlock_policy_rwsem_##mode(int cpu) \ | |
90 | { \ | |
91 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ | |
92 | BUG_ON(policy_cpu == -1); \ | |
93 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
94 | } | |
95 | ||
96 | unlock_policy_rwsem(read, cpu); | |
97 | unlock_policy_rwsem(write, cpu); | |
98 | ||
99 | /* internal prototypes */ | |
100 | static int __cpufreq_governor(struct cpufreq_policy *policy, | |
101 | unsigned int event); | |
102 | static unsigned int __cpufreq_get(unsigned int cpu); | |
103 | static void handle_update(struct work_struct *work); | |
104 | ||
105 | /** | |
106 | * Two notifier lists: the "policy" list is involved in the | |
107 | * validation process for a new CPU frequency policy; the | |
108 | * "transition" list for kernel code that needs to handle | |
109 | * changes to devices when the CPU clock speed changes. | |
110 | * The mutex locks both lists. | |
111 | */ | |
112 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); | |
113 | static struct srcu_notifier_head cpufreq_transition_notifier_list; | |
114 | ||
115 | static bool init_cpufreq_transition_notifier_list_called; | |
116 | static int __init init_cpufreq_transition_notifier_list(void) | |
117 | { | |
118 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
119 | init_cpufreq_transition_notifier_list_called = true; | |
120 | return 0; | |
121 | } | |
122 | pure_initcall(init_cpufreq_transition_notifier_list); | |
123 | ||
124 | static int off __read_mostly; | |
125 | static int cpufreq_disabled(void) | |
126 | { | |
127 | return off; | |
128 | } | |
129 | void disable_cpufreq(void) | |
130 | { | |
131 | off = 1; | |
132 | } | |
133 | static LIST_HEAD(cpufreq_governor_list); | |
134 | static DEFINE_MUTEX(cpufreq_governor_mutex); | |
135 | ||
136 | bool have_governor_per_policy(void) | |
137 | { | |
138 | return cpufreq_driver->have_governor_per_policy; | |
139 | } | |
140 | EXPORT_SYMBOL_GPL(have_governor_per_policy); | |
141 | ||
142 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) | |
143 | { | |
144 | if (have_governor_per_policy()) | |
145 | return &policy->kobj; | |
146 | else | |
147 | return cpufreq_global_kobject; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
150 | ||
151 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) | |
152 | { | |
153 | u64 idle_time; | |
154 | u64 cur_wall_time; | |
155 | u64 busy_time; | |
156 | ||
157 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
158 | ||
159 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
160 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
161 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
162 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
163 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
164 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
165 | ||
166 | idle_time = cur_wall_time - busy_time; | |
167 | if (wall) | |
168 | *wall = cputime_to_usecs(cur_wall_time); | |
169 | ||
170 | return cputime_to_usecs(idle_time); | |
171 | } | |
172 | ||
173 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
174 | { | |
175 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
176 | ||
177 | if (idle_time == -1ULL) | |
178 | return get_cpu_idle_time_jiffy(cpu, wall); | |
179 | else if (!io_busy) | |
180 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
181 | ||
182 | return idle_time; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
185 | ||
186 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) | |
187 | { | |
188 | struct cpufreq_policy *data; | |
189 | unsigned long flags; | |
190 | ||
191 | if (cpu >= nr_cpu_ids) | |
192 | goto err_out; | |
193 | ||
194 | /* get the cpufreq driver */ | |
195 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
196 | ||
197 | if (!cpufreq_driver) | |
198 | goto err_out_unlock; | |
199 | ||
200 | if (!try_module_get(cpufreq_driver->owner)) | |
201 | goto err_out_unlock; | |
202 | ||
203 | /* get the CPU */ | |
204 | data = per_cpu(cpufreq_cpu_data, cpu); | |
205 | ||
206 | if (!data) | |
207 | goto err_out_put_module; | |
208 | ||
209 | if (!sysfs && !kobject_get(&data->kobj)) | |
210 | goto err_out_put_module; | |
211 | ||
212 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
213 | return data; | |
214 | ||
215 | err_out_put_module: | |
216 | module_put(cpufreq_driver->owner); | |
217 | err_out_unlock: | |
218 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
219 | err_out: | |
220 | return NULL; | |
221 | } | |
222 | ||
223 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
224 | { | |
225 | if (cpufreq_disabled()) | |
226 | return NULL; | |
227 | ||
228 | return __cpufreq_cpu_get(cpu, false); | |
229 | } | |
230 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); | |
231 | ||
232 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) | |
233 | { | |
234 | return __cpufreq_cpu_get(cpu, true); | |
235 | } | |
236 | ||
237 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
238 | { | |
239 | if (!sysfs) | |
240 | kobject_put(&data->kobj); | |
241 | module_put(cpufreq_driver->owner); | |
242 | } | |
243 | ||
244 | void cpufreq_cpu_put(struct cpufreq_policy *data) | |
245 | { | |
246 | if (cpufreq_disabled()) | |
247 | return; | |
248 | ||
249 | __cpufreq_cpu_put(data, false); | |
250 | } | |
251 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
252 | ||
253 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) | |
254 | { | |
255 | __cpufreq_cpu_put(data, true); | |
256 | } | |
257 | ||
258 | /********************************************************************* | |
259 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
260 | *********************************************************************/ | |
261 | ||
262 | /** | |
263 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
264 | * | |
265 | * This function alters the system "loops_per_jiffy" for the clock | |
266 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
267 | * systems as each CPU might be scaled differently. So, use the arch | |
268 | * per-CPU loops_per_jiffy value wherever possible. | |
269 | */ | |
270 | #ifndef CONFIG_SMP | |
271 | static unsigned long l_p_j_ref; | |
272 | static unsigned int l_p_j_ref_freq; | |
273 | ||
274 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) | |
275 | { | |
276 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
277 | return; | |
278 | ||
279 | if (!l_p_j_ref_freq) { | |
280 | l_p_j_ref = loops_per_jiffy; | |
281 | l_p_j_ref_freq = ci->old; | |
282 | pr_debug("saving %lu as reference value for loops_per_jiffy; " | |
283 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); | |
284 | } | |
285 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || | |
286 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { | |
287 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, | |
288 | ci->new); | |
289 | pr_debug("scaling loops_per_jiffy to %lu " | |
290 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); | |
291 | } | |
292 | } | |
293 | #else | |
294 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) | |
295 | { | |
296 | return; | |
297 | } | |
298 | #endif | |
299 | ||
300 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, | |
301 | struct cpufreq_freqs *freqs, unsigned int state) | |
302 | { | |
303 | BUG_ON(irqs_disabled()); | |
304 | ||
305 | if (cpufreq_disabled()) | |
306 | return; | |
307 | ||
308 | freqs->flags = cpufreq_driver->flags; | |
309 | pr_debug("notification %u of frequency transition to %u kHz\n", | |
310 | state, freqs->new); | |
311 | ||
312 | switch (state) { | |
313 | ||
314 | case CPUFREQ_PRECHANGE: | |
315 | if (WARN(policy->transition_ongoing == | |
316 | cpumask_weight(policy->cpus), | |
317 | "In middle of another frequency transition\n")) | |
318 | return; | |
319 | ||
320 | policy->transition_ongoing++; | |
321 | ||
322 | /* detect if the driver reported a value as "old frequency" | |
323 | * which is not equal to what the cpufreq core thinks is | |
324 | * "old frequency". | |
325 | */ | |
326 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
327 | if ((policy) && (policy->cpu == freqs->cpu) && | |
328 | (policy->cur) && (policy->cur != freqs->old)) { | |
329 | pr_debug("Warning: CPU frequency is" | |
330 | " %u, cpufreq assumed %u kHz.\n", | |
331 | freqs->old, policy->cur); | |
332 | freqs->old = policy->cur; | |
333 | } | |
334 | } | |
335 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
336 | CPUFREQ_PRECHANGE, freqs); | |
337 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); | |
338 | break; | |
339 | ||
340 | case CPUFREQ_POSTCHANGE: | |
341 | if (WARN(!policy->transition_ongoing, | |
342 | "No frequency transition in progress\n")) | |
343 | return; | |
344 | ||
345 | policy->transition_ongoing--; | |
346 | ||
347 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
348 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, | |
349 | (unsigned long)freqs->cpu); | |
350 | trace_cpu_frequency(freqs->new, freqs->cpu); | |
351 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, | |
352 | CPUFREQ_POSTCHANGE, freqs); | |
353 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) | |
354 | policy->cur = freqs->new; | |
355 | break; | |
356 | } | |
357 | } | |
358 | ||
359 | /** | |
360 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
361 | * on frequency transition. | |
362 | * | |
363 | * This function calls the transition notifiers and the "adjust_jiffies" | |
364 | * function. It is called twice on all CPU frequency changes that have | |
365 | * external effects. | |
366 | */ | |
367 | void cpufreq_notify_transition(struct cpufreq_policy *policy, | |
368 | struct cpufreq_freqs *freqs, unsigned int state) | |
369 | { | |
370 | for_each_cpu(freqs->cpu, policy->cpus) | |
371 | __cpufreq_notify_transition(policy, freqs, state); | |
372 | } | |
373 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
374 | ||
375 | ||
376 | /********************************************************************* | |
377 | * SYSFS INTERFACE * | |
378 | *********************************************************************/ | |
379 | ||
380 | static struct cpufreq_governor *__find_governor(const char *str_governor) | |
381 | { | |
382 | struct cpufreq_governor *t; | |
383 | ||
384 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
385 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) | |
386 | return t; | |
387 | ||
388 | return NULL; | |
389 | } | |
390 | ||
391 | /** | |
392 | * cpufreq_parse_governor - parse a governor string | |
393 | */ | |
394 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, | |
395 | struct cpufreq_governor **governor) | |
396 | { | |
397 | int err = -EINVAL; | |
398 | ||
399 | if (!cpufreq_driver) | |
400 | goto out; | |
401 | ||
402 | if (cpufreq_driver->setpolicy) { | |
403 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
404 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
405 | err = 0; | |
406 | } else if (!strnicmp(str_governor, "powersave", | |
407 | CPUFREQ_NAME_LEN)) { | |
408 | *policy = CPUFREQ_POLICY_POWERSAVE; | |
409 | err = 0; | |
410 | } | |
411 | } else if (cpufreq_driver->target) { | |
412 | struct cpufreq_governor *t; | |
413 | ||
414 | mutex_lock(&cpufreq_governor_mutex); | |
415 | ||
416 | t = __find_governor(str_governor); | |
417 | ||
418 | if (t == NULL) { | |
419 | int ret; | |
420 | ||
421 | mutex_unlock(&cpufreq_governor_mutex); | |
422 | ret = request_module("cpufreq_%s", str_governor); | |
423 | mutex_lock(&cpufreq_governor_mutex); | |
424 | ||
425 | if (ret == 0) | |
426 | t = __find_governor(str_governor); | |
427 | } | |
428 | ||
429 | if (t != NULL) { | |
430 | *governor = t; | |
431 | err = 0; | |
432 | } | |
433 | ||
434 | mutex_unlock(&cpufreq_governor_mutex); | |
435 | } | |
436 | out: | |
437 | return err; | |
438 | } | |
439 | ||
440 | /** | |
441 | * cpufreq_per_cpu_attr_read() / show_##file_name() - | |
442 | * print out cpufreq information | |
443 | * | |
444 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
445 | * "unsigned int". | |
446 | */ | |
447 | ||
448 | #define show_one(file_name, object) \ | |
449 | static ssize_t show_##file_name \ | |
450 | (struct cpufreq_policy *policy, char *buf) \ | |
451 | { \ | |
452 | return sprintf(buf, "%u\n", policy->object); \ | |
453 | } | |
454 | ||
455 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
456 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
457 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); | |
458 | show_one(scaling_min_freq, min); | |
459 | show_one(scaling_max_freq, max); | |
460 | show_one(scaling_cur_freq, cur); | |
461 | ||
462 | static int __cpufreq_set_policy(struct cpufreq_policy *data, | |
463 | struct cpufreq_policy *policy); | |
464 | ||
465 | /** | |
466 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
467 | */ | |
468 | #define store_one(file_name, object) \ | |
469 | static ssize_t store_##file_name \ | |
470 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ | |
471 | { \ | |
472 | unsigned int ret; \ | |
473 | struct cpufreq_policy new_policy; \ | |
474 | \ | |
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
476 | if (ret) \ | |
477 | return -EINVAL; \ | |
478 | \ | |
479 | ret = sscanf(buf, "%u", &new_policy.object); \ | |
480 | if (ret != 1) \ | |
481 | return -EINVAL; \ | |
482 | \ | |
483 | ret = __cpufreq_set_policy(policy, &new_policy); \ | |
484 | policy->user_policy.object = policy->object; \ | |
485 | \ | |
486 | return ret ? ret : count; \ | |
487 | } | |
488 | ||
489 | store_one(scaling_min_freq, min); | |
490 | store_one(scaling_max_freq, max); | |
491 | ||
492 | /** | |
493 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
494 | */ | |
495 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, | |
496 | char *buf) | |
497 | { | |
498 | unsigned int cur_freq = __cpufreq_get(policy->cpu); | |
499 | if (!cur_freq) | |
500 | return sprintf(buf, "<unknown>"); | |
501 | return sprintf(buf, "%u\n", cur_freq); | |
502 | } | |
503 | ||
504 | /** | |
505 | * show_scaling_governor - show the current policy for the specified CPU | |
506 | */ | |
507 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) | |
508 | { | |
509 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) | |
510 | return sprintf(buf, "powersave\n"); | |
511 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
512 | return sprintf(buf, "performance\n"); | |
513 | else if (policy->governor) | |
514 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", | |
515 | policy->governor->name); | |
516 | return -EINVAL; | |
517 | } | |
518 | ||
519 | /** | |
520 | * store_scaling_governor - store policy for the specified CPU | |
521 | */ | |
522 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, | |
523 | const char *buf, size_t count) | |
524 | { | |
525 | unsigned int ret; | |
526 | char str_governor[16]; | |
527 | struct cpufreq_policy new_policy; | |
528 | ||
529 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
530 | if (ret) | |
531 | return ret; | |
532 | ||
533 | ret = sscanf(buf, "%15s", str_governor); | |
534 | if (ret != 1) | |
535 | return -EINVAL; | |
536 | ||
537 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, | |
538 | &new_policy.governor)) | |
539 | return -EINVAL; | |
540 | ||
541 | /* | |
542 | * Do not use cpufreq_set_policy here or the user_policy.max | |
543 | * will be wrongly overridden | |
544 | */ | |
545 | ret = __cpufreq_set_policy(policy, &new_policy); | |
546 | ||
547 | policy->user_policy.policy = policy->policy; | |
548 | policy->user_policy.governor = policy->governor; | |
549 | ||
550 | if (ret) | |
551 | return ret; | |
552 | else | |
553 | return count; | |
554 | } | |
555 | ||
556 | /** | |
557 | * show_scaling_driver - show the cpufreq driver currently loaded | |
558 | */ | |
559 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) | |
560 | { | |
561 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); | |
562 | } | |
563 | ||
564 | /** | |
565 | * show_scaling_available_governors - show the available CPUfreq governors | |
566 | */ | |
567 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, | |
568 | char *buf) | |
569 | { | |
570 | ssize_t i = 0; | |
571 | struct cpufreq_governor *t; | |
572 | ||
573 | if (!cpufreq_driver->target) { | |
574 | i += sprintf(buf, "performance powersave"); | |
575 | goto out; | |
576 | } | |
577 | ||
578 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
579 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) | |
580 | - (CPUFREQ_NAME_LEN + 2))) | |
581 | goto out; | |
582 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); | |
583 | } | |
584 | out: | |
585 | i += sprintf(&buf[i], "\n"); | |
586 | return i; | |
587 | } | |
588 | ||
589 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) | |
590 | { | |
591 | ssize_t i = 0; | |
592 | unsigned int cpu; | |
593 | ||
594 | for_each_cpu(cpu, mask) { | |
595 | if (i) | |
596 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
597 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
598 | if (i >= (PAGE_SIZE - 5)) | |
599 | break; | |
600 | } | |
601 | i += sprintf(&buf[i], "\n"); | |
602 | return i; | |
603 | } | |
604 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); | |
605 | ||
606 | /** | |
607 | * show_related_cpus - show the CPUs affected by each transition even if | |
608 | * hw coordination is in use | |
609 | */ | |
610 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
611 | { | |
612 | return cpufreq_show_cpus(policy->related_cpus, buf); | |
613 | } | |
614 | ||
615 | /** | |
616 | * show_affected_cpus - show the CPUs affected by each transition | |
617 | */ | |
618 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
619 | { | |
620 | return cpufreq_show_cpus(policy->cpus, buf); | |
621 | } | |
622 | ||
623 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, | |
624 | const char *buf, size_t count) | |
625 | { | |
626 | unsigned int freq = 0; | |
627 | unsigned int ret; | |
628 | ||
629 | if (!policy->governor || !policy->governor->store_setspeed) | |
630 | return -EINVAL; | |
631 | ||
632 | ret = sscanf(buf, "%u", &freq); | |
633 | if (ret != 1) | |
634 | return -EINVAL; | |
635 | ||
636 | policy->governor->store_setspeed(policy, freq); | |
637 | ||
638 | return count; | |
639 | } | |
640 | ||
641 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
642 | { | |
643 | if (!policy->governor || !policy->governor->show_setspeed) | |
644 | return sprintf(buf, "<unsupported>\n"); | |
645 | ||
646 | return policy->governor->show_setspeed(policy, buf); | |
647 | } | |
648 | ||
649 | /** | |
650 | * show_bios_limit - show the current cpufreq HW/BIOS limitation | |
651 | */ | |
652 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
653 | { | |
654 | unsigned int limit; | |
655 | int ret; | |
656 | if (cpufreq_driver->bios_limit) { | |
657 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
658 | if (!ret) | |
659 | return sprintf(buf, "%u\n", limit); | |
660 | } | |
661 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
662 | } | |
663 | ||
664 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); | |
665 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
666 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
667 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
668 | cpufreq_freq_attr_ro(scaling_available_governors); | |
669 | cpufreq_freq_attr_ro(scaling_driver); | |
670 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
671 | cpufreq_freq_attr_ro(bios_limit); | |
672 | cpufreq_freq_attr_ro(related_cpus); | |
673 | cpufreq_freq_attr_ro(affected_cpus); | |
674 | cpufreq_freq_attr_rw(scaling_min_freq); | |
675 | cpufreq_freq_attr_rw(scaling_max_freq); | |
676 | cpufreq_freq_attr_rw(scaling_governor); | |
677 | cpufreq_freq_attr_rw(scaling_setspeed); | |
678 | ||
679 | static struct attribute *default_attrs[] = { | |
680 | &cpuinfo_min_freq.attr, | |
681 | &cpuinfo_max_freq.attr, | |
682 | &cpuinfo_transition_latency.attr, | |
683 | &scaling_min_freq.attr, | |
684 | &scaling_max_freq.attr, | |
685 | &affected_cpus.attr, | |
686 | &related_cpus.attr, | |
687 | &scaling_governor.attr, | |
688 | &scaling_driver.attr, | |
689 | &scaling_available_governors.attr, | |
690 | &scaling_setspeed.attr, | |
691 | NULL | |
692 | }; | |
693 | ||
694 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) | |
695 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
696 | ||
697 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) | |
698 | { | |
699 | struct cpufreq_policy *policy = to_policy(kobj); | |
700 | struct freq_attr *fattr = to_attr(attr); | |
701 | ssize_t ret = -EINVAL; | |
702 | policy = cpufreq_cpu_get_sysfs(policy->cpu); | |
703 | if (!policy) | |
704 | goto no_policy; | |
705 | ||
706 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
707 | goto fail; | |
708 | ||
709 | if (fattr->show) | |
710 | ret = fattr->show(policy, buf); | |
711 | else | |
712 | ret = -EIO; | |
713 | ||
714 | unlock_policy_rwsem_read(policy->cpu); | |
715 | fail: | |
716 | cpufreq_cpu_put_sysfs(policy); | |
717 | no_policy: | |
718 | return ret; | |
719 | } | |
720 | ||
721 | static ssize_t store(struct kobject *kobj, struct attribute *attr, | |
722 | const char *buf, size_t count) | |
723 | { | |
724 | struct cpufreq_policy *policy = to_policy(kobj); | |
725 | struct freq_attr *fattr = to_attr(attr); | |
726 | ssize_t ret = -EINVAL; | |
727 | policy = cpufreq_cpu_get_sysfs(policy->cpu); | |
728 | if (!policy) | |
729 | goto no_policy; | |
730 | ||
731 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
732 | goto fail; | |
733 | ||
734 | if (fattr->store) | |
735 | ret = fattr->store(policy, buf, count); | |
736 | else | |
737 | ret = -EIO; | |
738 | ||
739 | unlock_policy_rwsem_write(policy->cpu); | |
740 | fail: | |
741 | cpufreq_cpu_put_sysfs(policy); | |
742 | no_policy: | |
743 | return ret; | |
744 | } | |
745 | ||
746 | static void cpufreq_sysfs_release(struct kobject *kobj) | |
747 | { | |
748 | struct cpufreq_policy *policy = to_policy(kobj); | |
749 | pr_debug("last reference is dropped\n"); | |
750 | complete(&policy->kobj_unregister); | |
751 | } | |
752 | ||
753 | static const struct sysfs_ops sysfs_ops = { | |
754 | .show = show, | |
755 | .store = store, | |
756 | }; | |
757 | ||
758 | static struct kobj_type ktype_cpufreq = { | |
759 | .sysfs_ops = &sysfs_ops, | |
760 | .default_attrs = default_attrs, | |
761 | .release = cpufreq_sysfs_release, | |
762 | }; | |
763 | ||
764 | struct kobject *cpufreq_global_kobject; | |
765 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
766 | ||
767 | static int cpufreq_global_kobject_usage; | |
768 | ||
769 | int cpufreq_get_global_kobject(void) | |
770 | { | |
771 | if (!cpufreq_global_kobject_usage++) | |
772 | return kobject_add(cpufreq_global_kobject, | |
773 | &cpu_subsys.dev_root->kobj, "%s", "cpufreq"); | |
774 | ||
775 | return 0; | |
776 | } | |
777 | EXPORT_SYMBOL(cpufreq_get_global_kobject); | |
778 | ||
779 | void cpufreq_put_global_kobject(void) | |
780 | { | |
781 | if (!--cpufreq_global_kobject_usage) | |
782 | kobject_del(cpufreq_global_kobject); | |
783 | } | |
784 | EXPORT_SYMBOL(cpufreq_put_global_kobject); | |
785 | ||
786 | int cpufreq_sysfs_create_file(const struct attribute *attr) | |
787 | { | |
788 | int ret = cpufreq_get_global_kobject(); | |
789 | ||
790 | if (!ret) { | |
791 | ret = sysfs_create_file(cpufreq_global_kobject, attr); | |
792 | if (ret) | |
793 | cpufreq_put_global_kobject(); | |
794 | } | |
795 | ||
796 | return ret; | |
797 | } | |
798 | EXPORT_SYMBOL(cpufreq_sysfs_create_file); | |
799 | ||
800 | void cpufreq_sysfs_remove_file(const struct attribute *attr) | |
801 | { | |
802 | sysfs_remove_file(cpufreq_global_kobject, attr); | |
803 | cpufreq_put_global_kobject(); | |
804 | } | |
805 | EXPORT_SYMBOL(cpufreq_sysfs_remove_file); | |
806 | ||
807 | /* symlink affected CPUs */ | |
808 | static int cpufreq_add_dev_symlink(unsigned int cpu, | |
809 | struct cpufreq_policy *policy) | |
810 | { | |
811 | unsigned int j; | |
812 | int ret = 0; | |
813 | ||
814 | for_each_cpu(j, policy->cpus) { | |
815 | struct cpufreq_policy *managed_policy; | |
816 | struct device *cpu_dev; | |
817 | ||
818 | if (j == cpu) | |
819 | continue; | |
820 | ||
821 | pr_debug("CPU %u already managed, adding link\n", j); | |
822 | managed_policy = cpufreq_cpu_get(cpu); | |
823 | cpu_dev = get_cpu_device(j); | |
824 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
825 | "cpufreq"); | |
826 | if (ret) { | |
827 | cpufreq_cpu_put(managed_policy); | |
828 | return ret; | |
829 | } | |
830 | } | |
831 | return ret; | |
832 | } | |
833 | ||
834 | static int cpufreq_add_dev_interface(unsigned int cpu, | |
835 | struct cpufreq_policy *policy, | |
836 | struct device *dev) | |
837 | { | |
838 | struct freq_attr **drv_attr; | |
839 | int ret = 0; | |
840 | ||
841 | /* prepare interface data */ | |
842 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
843 | &dev->kobj, "cpufreq"); | |
844 | if (ret) | |
845 | return ret; | |
846 | ||
847 | /* set up files for this cpu device */ | |
848 | drv_attr = cpufreq_driver->attr; | |
849 | while ((drv_attr) && (*drv_attr)) { | |
850 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
851 | if (ret) | |
852 | goto err_out_kobj_put; | |
853 | drv_attr++; | |
854 | } | |
855 | if (cpufreq_driver->get) { | |
856 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
857 | if (ret) | |
858 | goto err_out_kobj_put; | |
859 | } | |
860 | if (cpufreq_driver->target) { | |
861 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
862 | if (ret) | |
863 | goto err_out_kobj_put; | |
864 | } | |
865 | if (cpufreq_driver->bios_limit) { | |
866 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
867 | if (ret) | |
868 | goto err_out_kobj_put; | |
869 | } | |
870 | ||
871 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
872 | if (ret) | |
873 | goto err_out_kobj_put; | |
874 | ||
875 | return ret; | |
876 | ||
877 | err_out_kobj_put: | |
878 | kobject_put(&policy->kobj); | |
879 | wait_for_completion(&policy->kobj_unregister); | |
880 | return ret; | |
881 | } | |
882 | ||
883 | static void cpufreq_init_policy(struct cpufreq_policy *policy) | |
884 | { | |
885 | struct cpufreq_policy new_policy; | |
886 | int ret = 0; | |
887 | ||
888 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
889 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
890 | policy->governor = NULL; | |
891 | ||
892 | /* set default policy */ | |
893 | ret = __cpufreq_set_policy(policy, &new_policy); | |
894 | policy->user_policy.policy = policy->policy; | |
895 | policy->user_policy.governor = policy->governor; | |
896 | ||
897 | if (ret) { | |
898 | pr_debug("setting policy failed\n"); | |
899 | if (cpufreq_driver->exit) | |
900 | cpufreq_driver->exit(policy); | |
901 | } | |
902 | } | |
903 | ||
904 | #ifdef CONFIG_HOTPLUG_CPU | |
905 | static int cpufreq_add_policy_cpu(unsigned int cpu, unsigned int sibling, | |
906 | struct device *dev) | |
907 | { | |
908 | struct cpufreq_policy *policy; | |
909 | int ret = 0, has_target = !!cpufreq_driver->target; | |
910 | unsigned long flags; | |
911 | ||
912 | policy = cpufreq_cpu_get(sibling); | |
913 | WARN_ON(!policy); | |
914 | ||
915 | if (has_target) | |
916 | __cpufreq_governor(policy, CPUFREQ_GOV_STOP); | |
917 | ||
918 | lock_policy_rwsem_write(sibling); | |
919 | ||
920 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
921 | ||
922 | cpumask_set_cpu(cpu, policy->cpus); | |
923 | per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu; | |
924 | per_cpu(cpufreq_cpu_data, cpu) = policy; | |
925 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
926 | ||
927 | unlock_policy_rwsem_write(sibling); | |
928 | ||
929 | if (has_target) { | |
930 | __cpufreq_governor(policy, CPUFREQ_GOV_START); | |
931 | __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); | |
932 | } | |
933 | ||
934 | ret = sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"); | |
935 | if (ret) { | |
936 | cpufreq_cpu_put(policy); | |
937 | return ret; | |
938 | } | |
939 | ||
940 | return 0; | |
941 | } | |
942 | #endif | |
943 | ||
944 | static struct cpufreq_policy *cpufreq_policy_alloc(void) | |
945 | { | |
946 | struct cpufreq_policy *policy; | |
947 | ||
948 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
949 | if (!policy) | |
950 | return NULL; | |
951 | ||
952 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
953 | goto err_free_policy; | |
954 | ||
955 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
956 | goto err_free_cpumask; | |
957 | ||
958 | return policy; | |
959 | ||
960 | err_free_cpumask: | |
961 | free_cpumask_var(policy->cpus); | |
962 | err_free_policy: | |
963 | kfree(policy); | |
964 | ||
965 | return NULL; | |
966 | } | |
967 | ||
968 | static void cpufreq_policy_free(struct cpufreq_policy *policy) | |
969 | { | |
970 | free_cpumask_var(policy->related_cpus); | |
971 | free_cpumask_var(policy->cpus); | |
972 | kfree(policy); | |
973 | } | |
974 | ||
975 | /** | |
976 | * cpufreq_add_dev - add a CPU device | |
977 | * | |
978 | * Adds the cpufreq interface for a CPU device. | |
979 | * | |
980 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
981 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
982 | * mess up, but more thorough testing is needed. - Mathieu | |
983 | */ | |
984 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
985 | { | |
986 | unsigned int j, cpu = dev->id; | |
987 | int ret = -ENOMEM; | |
988 | struct cpufreq_policy *policy; | |
989 | unsigned long flags; | |
990 | #ifdef CONFIG_HOTPLUG_CPU | |
991 | struct cpufreq_governor *gov; | |
992 | int sibling; | |
993 | #endif | |
994 | ||
995 | if (cpu_is_offline(cpu)) | |
996 | return 0; | |
997 | ||
998 | pr_debug("adding CPU %u\n", cpu); | |
999 | ||
1000 | #ifdef CONFIG_SMP | |
1001 | /* check whether a different CPU already registered this | |
1002 | * CPU because it is in the same boat. */ | |
1003 | policy = cpufreq_cpu_get(cpu); | |
1004 | if (unlikely(policy)) { | |
1005 | cpufreq_cpu_put(policy); | |
1006 | return 0; | |
1007 | } | |
1008 | ||
1009 | #ifdef CONFIG_HOTPLUG_CPU | |
1010 | /* Check if this cpu was hot-unplugged earlier and has siblings */ | |
1011 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1012 | for_each_online_cpu(sibling) { | |
1013 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
1014 | if (cp && cpumask_test_cpu(cpu, cp->related_cpus)) { | |
1015 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1016 | return cpufreq_add_policy_cpu(cpu, sibling, dev); | |
1017 | } | |
1018 | } | |
1019 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1020 | #endif | |
1021 | #endif | |
1022 | ||
1023 | if (!try_module_get(cpufreq_driver->owner)) { | |
1024 | ret = -EINVAL; | |
1025 | goto module_out; | |
1026 | } | |
1027 | ||
1028 | policy = cpufreq_policy_alloc(); | |
1029 | if (!policy) | |
1030 | goto nomem_out; | |
1031 | ||
1032 | policy->cpu = cpu; | |
1033 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1034 | cpumask_copy(policy->cpus, cpumask_of(cpu)); | |
1035 | ||
1036 | /* Initially set CPU itself as the policy_cpu */ | |
1037 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; | |
1038 | ||
1039 | init_completion(&policy->kobj_unregister); | |
1040 | INIT_WORK(&policy->update, handle_update); | |
1041 | ||
1042 | /* call driver. From then on the cpufreq must be able | |
1043 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1044 | */ | |
1045 | ret = cpufreq_driver->init(policy); | |
1046 | if (ret) { | |
1047 | pr_debug("initialization failed\n"); | |
1048 | goto err_set_policy_cpu; | |
1049 | } | |
1050 | ||
1051 | /* related cpus should atleast have policy->cpus */ | |
1052 | cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus); | |
1053 | ||
1054 | /* | |
1055 | * affected cpus must always be the one, which are online. We aren't | |
1056 | * managing offline cpus here. | |
1057 | */ | |
1058 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1059 | ||
1060 | policy->user_policy.min = policy->min; | |
1061 | policy->user_policy.max = policy->max; | |
1062 | ||
1063 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1064 | CPUFREQ_START, policy); | |
1065 | ||
1066 | #ifdef CONFIG_HOTPLUG_CPU | |
1067 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
1068 | if (gov) { | |
1069 | policy->governor = gov; | |
1070 | pr_debug("Restoring governor %s for cpu %d\n", | |
1071 | policy->governor->name, cpu); | |
1072 | } | |
1073 | #endif | |
1074 | ||
1075 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1076 | for_each_cpu(j, policy->cpus) { | |
1077 | per_cpu(cpufreq_cpu_data, j) = policy; | |
1078 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; | |
1079 | } | |
1080 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1081 | ||
1082 | ret = cpufreq_add_dev_interface(cpu, policy, dev); | |
1083 | if (ret) | |
1084 | goto err_out_unregister; | |
1085 | ||
1086 | cpufreq_init_policy(policy); | |
1087 | ||
1088 | kobject_uevent(&policy->kobj, KOBJ_ADD); | |
1089 | module_put(cpufreq_driver->owner); | |
1090 | pr_debug("initialization complete\n"); | |
1091 | ||
1092 | return 0; | |
1093 | ||
1094 | err_out_unregister: | |
1095 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1096 | for_each_cpu(j, policy->cpus) { | |
1097 | per_cpu(cpufreq_cpu_data, j) = NULL; | |
1098 | if (j != cpu) | |
1099 | per_cpu(cpufreq_policy_cpu, j) = -1; | |
1100 | } | |
1101 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1102 | ||
1103 | kobject_put(&policy->kobj); | |
1104 | wait_for_completion(&policy->kobj_unregister); | |
1105 | ||
1106 | err_set_policy_cpu: | |
1107 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
1108 | cpufreq_policy_free(policy); | |
1109 | nomem_out: | |
1110 | module_put(cpufreq_driver->owner); | |
1111 | module_out: | |
1112 | return ret; | |
1113 | } | |
1114 | ||
1115 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) | |
1116 | { | |
1117 | int j; | |
1118 | ||
1119 | policy->last_cpu = policy->cpu; | |
1120 | policy->cpu = cpu; | |
1121 | ||
1122 | for_each_cpu(j, policy->cpus) | |
1123 | per_cpu(cpufreq_policy_cpu, j) = cpu; | |
1124 | ||
1125 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1126 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1127 | #endif | |
1128 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1129 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1130 | } | |
1131 | ||
1132 | static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data, | |
1133 | unsigned int old_cpu) | |
1134 | { | |
1135 | struct device *cpu_dev; | |
1136 | unsigned long flags; | |
1137 | int ret; | |
1138 | ||
1139 | /* first sibling now owns the new sysfs dir */ | |
1140 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1141 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1142 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1143 | if (ret) { | |
1144 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1145 | ||
1146 | WARN_ON(lock_policy_rwsem_write(old_cpu)); | |
1147 | cpumask_set_cpu(old_cpu, data->cpus); | |
1148 | ||
1149 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1150 | per_cpu(cpufreq_cpu_data, old_cpu) = data; | |
1151 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1152 | ||
1153 | unlock_policy_rwsem_write(old_cpu); | |
1154 | ||
1155 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1156 | "cpufreq"); | |
1157 | ||
1158 | return -EINVAL; | |
1159 | } | |
1160 | ||
1161 | return cpu_dev->id; | |
1162 | } | |
1163 | ||
1164 | /** | |
1165 | * __cpufreq_remove_dev - remove a CPU device | |
1166 | * | |
1167 | * Removes the cpufreq interface for a CPU device. | |
1168 | * Caller should already have policy_rwsem in write mode for this CPU. | |
1169 | * This routine frees the rwsem before returning. | |
1170 | */ | |
1171 | static int __cpufreq_remove_dev(struct device *dev, | |
1172 | struct subsys_interface *sif) | |
1173 | { | |
1174 | unsigned int cpu = dev->id, cpus; | |
1175 | int new_cpu; | |
1176 | unsigned long flags; | |
1177 | struct cpufreq_policy *data; | |
1178 | struct kobject *kobj; | |
1179 | struct completion *cmp; | |
1180 | ||
1181 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); | |
1182 | ||
1183 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1184 | ||
1185 | data = per_cpu(cpufreq_cpu_data, cpu); | |
1186 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1187 | ||
1188 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1189 | ||
1190 | if (!data) { | |
1191 | pr_debug("%s: No cpu_data found\n", __func__); | |
1192 | return -EINVAL; | |
1193 | } | |
1194 | ||
1195 | if (cpufreq_driver->target) | |
1196 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1197 | ||
1198 | #ifdef CONFIG_HOTPLUG_CPU | |
1199 | if (!cpufreq_driver->setpolicy) | |
1200 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), | |
1201 | data->governor->name, CPUFREQ_NAME_LEN); | |
1202 | #endif | |
1203 | ||
1204 | WARN_ON(lock_policy_rwsem_write(cpu)); | |
1205 | cpus = cpumask_weight(data->cpus); | |
1206 | ||
1207 | if (cpus > 1) | |
1208 | cpumask_clear_cpu(cpu, data->cpus); | |
1209 | unlock_policy_rwsem_write(cpu); | |
1210 | ||
1211 | if (cpu != data->cpu) { | |
1212 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
1213 | } else if (cpus > 1) { | |
1214 | ||
1215 | new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu); | |
1216 | if (new_cpu >= 0) { | |
1217 | WARN_ON(lock_policy_rwsem_write(cpu)); | |
1218 | update_policy_cpu(data, new_cpu); | |
1219 | unlock_policy_rwsem_write(cpu); | |
1220 | pr_debug("%s: policy Kobject moved to cpu: %d " | |
1221 | "from: %d\n",__func__, new_cpu, cpu); | |
1222 | } | |
1223 | } | |
1224 | ||
1225 | /* If cpu is last user of policy, free policy */ | |
1226 | if (cpus == 1) { | |
1227 | if (cpufreq_driver->target) | |
1228 | __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); | |
1229 | ||
1230 | lock_policy_rwsem_read(cpu); | |
1231 | kobj = &data->kobj; | |
1232 | cmp = &data->kobj_unregister; | |
1233 | unlock_policy_rwsem_read(cpu); | |
1234 | kobject_put(kobj); | |
1235 | ||
1236 | /* we need to make sure that the underlying kobj is actually | |
1237 | * not referenced anymore by anybody before we proceed with | |
1238 | * unloading. | |
1239 | */ | |
1240 | pr_debug("waiting for dropping of refcount\n"); | |
1241 | wait_for_completion(cmp); | |
1242 | pr_debug("wait complete\n"); | |
1243 | ||
1244 | if (cpufreq_driver->exit) | |
1245 | cpufreq_driver->exit(data); | |
1246 | ||
1247 | cpufreq_policy_free(data); | |
1248 | } else { | |
1249 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); | |
1250 | cpufreq_cpu_put(data); | |
1251 | if (cpufreq_driver->target) { | |
1252 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1253 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1254 | } | |
1255 | } | |
1256 | ||
1257 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
1258 | return 0; | |
1259 | } | |
1260 | ||
1261 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) | |
1262 | { | |
1263 | unsigned int cpu = dev->id; | |
1264 | int retval; | |
1265 | ||
1266 | if (cpu_is_offline(cpu)) | |
1267 | return 0; | |
1268 | ||
1269 | retval = __cpufreq_remove_dev(dev, sif); | |
1270 | return retval; | |
1271 | } | |
1272 | ||
1273 | static void handle_update(struct work_struct *work) | |
1274 | { | |
1275 | struct cpufreq_policy *policy = | |
1276 | container_of(work, struct cpufreq_policy, update); | |
1277 | unsigned int cpu = policy->cpu; | |
1278 | pr_debug("handle_update for cpu %u called\n", cpu); | |
1279 | cpufreq_update_policy(cpu); | |
1280 | } | |
1281 | ||
1282 | /** | |
1283 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're | |
1284 | * in deep trouble. | |
1285 | * @cpu: cpu number | |
1286 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1287 | * @new_freq: CPU frequency the CPU actually runs at | |
1288 | * | |
1289 | * We adjust to current frequency first, and need to clean up later. | |
1290 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1291 | */ | |
1292 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, | |
1293 | unsigned int new_freq) | |
1294 | { | |
1295 | struct cpufreq_policy *policy; | |
1296 | struct cpufreq_freqs freqs; | |
1297 | unsigned long flags; | |
1298 | ||
1299 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " | |
1300 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); | |
1301 | ||
1302 | freqs.old = old_freq; | |
1303 | freqs.new = new_freq; | |
1304 | ||
1305 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
1306 | policy = per_cpu(cpufreq_cpu_data, cpu); | |
1307 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1308 | ||
1309 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); | |
1310 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); | |
1311 | } | |
1312 | ||
1313 | /** | |
1314 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur | |
1315 | * @cpu: CPU number | |
1316 | * | |
1317 | * This is the last known freq, without actually getting it from the driver. | |
1318 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1319 | */ | |
1320 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1321 | { | |
1322 | struct cpufreq_policy *policy; | |
1323 | unsigned int ret_freq = 0; | |
1324 | ||
1325 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) | |
1326 | return cpufreq_driver->get(cpu); | |
1327 | ||
1328 | policy = cpufreq_cpu_get(cpu); | |
1329 | if (policy) { | |
1330 | ret_freq = policy->cur; | |
1331 | cpufreq_cpu_put(policy); | |
1332 | } | |
1333 | ||
1334 | return ret_freq; | |
1335 | } | |
1336 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1337 | ||
1338 | /** | |
1339 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1340 | * @cpu: CPU number | |
1341 | * | |
1342 | * Just return the max possible frequency for a given CPU. | |
1343 | */ | |
1344 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1345 | { | |
1346 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1347 | unsigned int ret_freq = 0; | |
1348 | ||
1349 | if (policy) { | |
1350 | ret_freq = policy->max; | |
1351 | cpufreq_cpu_put(policy); | |
1352 | } | |
1353 | ||
1354 | return ret_freq; | |
1355 | } | |
1356 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1357 | ||
1358 | static unsigned int __cpufreq_get(unsigned int cpu) | |
1359 | { | |
1360 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
1361 | unsigned int ret_freq = 0; | |
1362 | ||
1363 | if (!cpufreq_driver->get) | |
1364 | return ret_freq; | |
1365 | ||
1366 | ret_freq = cpufreq_driver->get(cpu); | |
1367 | ||
1368 | if (ret_freq && policy->cur && | |
1369 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1370 | /* verify no discrepancy between actual and | |
1371 | saved value exists */ | |
1372 | if (unlikely(ret_freq != policy->cur)) { | |
1373 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1374 | schedule_work(&policy->update); | |
1375 | } | |
1376 | } | |
1377 | ||
1378 | return ret_freq; | |
1379 | } | |
1380 | ||
1381 | /** | |
1382 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1383 | * @cpu: CPU number | |
1384 | * | |
1385 | * Get the CPU current (static) CPU frequency | |
1386 | */ | |
1387 | unsigned int cpufreq_get(unsigned int cpu) | |
1388 | { | |
1389 | unsigned int ret_freq = 0; | |
1390 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1391 | ||
1392 | if (!policy) | |
1393 | goto out; | |
1394 | ||
1395 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1396 | goto out_policy; | |
1397 | ||
1398 | ret_freq = __cpufreq_get(cpu); | |
1399 | ||
1400 | unlock_policy_rwsem_read(cpu); | |
1401 | ||
1402 | out_policy: | |
1403 | cpufreq_cpu_put(policy); | |
1404 | out: | |
1405 | return ret_freq; | |
1406 | } | |
1407 | EXPORT_SYMBOL(cpufreq_get); | |
1408 | ||
1409 | static struct subsys_interface cpufreq_interface = { | |
1410 | .name = "cpufreq", | |
1411 | .subsys = &cpu_subsys, | |
1412 | .add_dev = cpufreq_add_dev, | |
1413 | .remove_dev = cpufreq_remove_dev, | |
1414 | }; | |
1415 | ||
1416 | /** | |
1417 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. | |
1418 | * | |
1419 | * This function is only executed for the boot processor. The other CPUs | |
1420 | * have been put offline by means of CPU hotplug. | |
1421 | */ | |
1422 | static int cpufreq_bp_suspend(void) | |
1423 | { | |
1424 | int ret = 0; | |
1425 | ||
1426 | int cpu = smp_processor_id(); | |
1427 | struct cpufreq_policy *cpu_policy; | |
1428 | ||
1429 | pr_debug("suspending cpu %u\n", cpu); | |
1430 | ||
1431 | /* If there's no policy for the boot CPU, we have nothing to do. */ | |
1432 | cpu_policy = cpufreq_cpu_get(cpu); | |
1433 | if (!cpu_policy) | |
1434 | return 0; | |
1435 | ||
1436 | if (cpufreq_driver->suspend) { | |
1437 | ret = cpufreq_driver->suspend(cpu_policy); | |
1438 | if (ret) | |
1439 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " | |
1440 | "step on CPU %u\n", cpu_policy->cpu); | |
1441 | } | |
1442 | ||
1443 | cpufreq_cpu_put(cpu_policy); | |
1444 | return ret; | |
1445 | } | |
1446 | ||
1447 | /** | |
1448 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. | |
1449 | * | |
1450 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
1451 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are | |
1452 | * restored. It will verify that the current freq is in sync with | |
1453 | * what we believe it to be. This is a bit later than when it | |
1454 | * should be, but nonethteless it's better than calling | |
1455 | * cpufreq_driver->get() here which might re-enable interrupts... | |
1456 | * | |
1457 | * This function is only executed for the boot CPU. The other CPUs have not | |
1458 | * been turned on yet. | |
1459 | */ | |
1460 | static void cpufreq_bp_resume(void) | |
1461 | { | |
1462 | int ret = 0; | |
1463 | ||
1464 | int cpu = smp_processor_id(); | |
1465 | struct cpufreq_policy *cpu_policy; | |
1466 | ||
1467 | pr_debug("resuming cpu %u\n", cpu); | |
1468 | ||
1469 | /* If there's no policy for the boot CPU, we have nothing to do. */ | |
1470 | cpu_policy = cpufreq_cpu_get(cpu); | |
1471 | if (!cpu_policy) | |
1472 | return; | |
1473 | ||
1474 | if (cpufreq_driver->resume) { | |
1475 | ret = cpufreq_driver->resume(cpu_policy); | |
1476 | if (ret) { | |
1477 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1478 | "step on CPU %u\n", cpu_policy->cpu); | |
1479 | goto fail; | |
1480 | } | |
1481 | } | |
1482 | ||
1483 | schedule_work(&cpu_policy->update); | |
1484 | ||
1485 | fail: | |
1486 | cpufreq_cpu_put(cpu_policy); | |
1487 | } | |
1488 | ||
1489 | static struct syscore_ops cpufreq_syscore_ops = { | |
1490 | .suspend = cpufreq_bp_suspend, | |
1491 | .resume = cpufreq_bp_resume, | |
1492 | }; | |
1493 | ||
1494 | /** | |
1495 | * cpufreq_get_current_driver - return current driver's name | |
1496 | * | |
1497 | * Return the name string of the currently loaded cpufreq driver | |
1498 | * or NULL, if none. | |
1499 | */ | |
1500 | const char *cpufreq_get_current_driver(void) | |
1501 | { | |
1502 | if (cpufreq_driver) | |
1503 | return cpufreq_driver->name; | |
1504 | ||
1505 | return NULL; | |
1506 | } | |
1507 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1508 | ||
1509 | /********************************************************************* | |
1510 | * NOTIFIER LISTS INTERFACE * | |
1511 | *********************************************************************/ | |
1512 | ||
1513 | /** | |
1514 | * cpufreq_register_notifier - register a driver with cpufreq | |
1515 | * @nb: notifier function to register | |
1516 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1517 | * | |
1518 | * Add a driver to one of two lists: either a list of drivers that | |
1519 | * are notified about clock rate changes (once before and once after | |
1520 | * the transition), or a list of drivers that are notified about | |
1521 | * changes in cpufreq policy. | |
1522 | * | |
1523 | * This function may sleep, and has the same return conditions as | |
1524 | * blocking_notifier_chain_register. | |
1525 | */ | |
1526 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1527 | { | |
1528 | int ret; | |
1529 | ||
1530 | if (cpufreq_disabled()) | |
1531 | return -EINVAL; | |
1532 | ||
1533 | WARN_ON(!init_cpufreq_transition_notifier_list_called); | |
1534 | ||
1535 | switch (list) { | |
1536 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1537 | ret = srcu_notifier_chain_register( | |
1538 | &cpufreq_transition_notifier_list, nb); | |
1539 | break; | |
1540 | case CPUFREQ_POLICY_NOTIFIER: | |
1541 | ret = blocking_notifier_chain_register( | |
1542 | &cpufreq_policy_notifier_list, nb); | |
1543 | break; | |
1544 | default: | |
1545 | ret = -EINVAL; | |
1546 | } | |
1547 | ||
1548 | return ret; | |
1549 | } | |
1550 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1551 | ||
1552 | /** | |
1553 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1554 | * @nb: notifier block to be unregistered | |
1555 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1556 | * | |
1557 | * Remove a driver from the CPU frequency notifier list. | |
1558 | * | |
1559 | * This function may sleep, and has the same return conditions as | |
1560 | * blocking_notifier_chain_unregister. | |
1561 | */ | |
1562 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1563 | { | |
1564 | int ret; | |
1565 | ||
1566 | if (cpufreq_disabled()) | |
1567 | return -EINVAL; | |
1568 | ||
1569 | switch (list) { | |
1570 | case CPUFREQ_TRANSITION_NOTIFIER: | |
1571 | ret = srcu_notifier_chain_unregister( | |
1572 | &cpufreq_transition_notifier_list, nb); | |
1573 | break; | |
1574 | case CPUFREQ_POLICY_NOTIFIER: | |
1575 | ret = blocking_notifier_chain_unregister( | |
1576 | &cpufreq_policy_notifier_list, nb); | |
1577 | break; | |
1578 | default: | |
1579 | ret = -EINVAL; | |
1580 | } | |
1581 | ||
1582 | return ret; | |
1583 | } | |
1584 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1585 | ||
1586 | ||
1587 | /********************************************************************* | |
1588 | * GOVERNORS * | |
1589 | *********************************************************************/ | |
1590 | ||
1591 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1592 | unsigned int target_freq, | |
1593 | unsigned int relation) | |
1594 | { | |
1595 | int retval = -EINVAL; | |
1596 | unsigned int old_target_freq = target_freq; | |
1597 | ||
1598 | if (cpufreq_disabled()) | |
1599 | return -ENODEV; | |
1600 | if (policy->transition_ongoing) | |
1601 | return -EBUSY; | |
1602 | ||
1603 | /* Make sure that target_freq is within supported range */ | |
1604 | if (target_freq > policy->max) | |
1605 | target_freq = policy->max; | |
1606 | if (target_freq < policy->min) | |
1607 | target_freq = policy->min; | |
1608 | ||
1609 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1610 | policy->cpu, target_freq, relation, old_target_freq); | |
1611 | ||
1612 | if (target_freq == policy->cur) | |
1613 | return 0; | |
1614 | ||
1615 | if (cpufreq_driver->target) | |
1616 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
1617 | ||
1618 | return retval; | |
1619 | } | |
1620 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1621 | ||
1622 | int cpufreq_driver_target(struct cpufreq_policy *policy, | |
1623 | unsigned int target_freq, | |
1624 | unsigned int relation) | |
1625 | { | |
1626 | int ret = -EINVAL; | |
1627 | ||
1628 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) | |
1629 | goto fail; | |
1630 | ||
1631 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1632 | ||
1633 | unlock_policy_rwsem_write(policy->cpu); | |
1634 | ||
1635 | fail: | |
1636 | return ret; | |
1637 | } | |
1638 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1639 | ||
1640 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) | |
1641 | { | |
1642 | if (cpufreq_disabled()) | |
1643 | return 0; | |
1644 | ||
1645 | if (!cpufreq_driver->getavg) | |
1646 | return 0; | |
1647 | ||
1648 | return cpufreq_driver->getavg(policy, cpu); | |
1649 | } | |
1650 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); | |
1651 | ||
1652 | /* | |
1653 | * when "event" is CPUFREQ_GOV_LIMITS | |
1654 | */ | |
1655 | ||
1656 | static int __cpufreq_governor(struct cpufreq_policy *policy, | |
1657 | unsigned int event) | |
1658 | { | |
1659 | int ret; | |
1660 | ||
1661 | /* Only must be defined when default governor is known to have latency | |
1662 | restrictions, like e.g. conservative or ondemand. | |
1663 | That this is the case is already ensured in Kconfig | |
1664 | */ | |
1665 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1666 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1667 | #else | |
1668 | struct cpufreq_governor *gov = NULL; | |
1669 | #endif | |
1670 | ||
1671 | if (policy->governor->max_transition_latency && | |
1672 | policy->cpuinfo.transition_latency > | |
1673 | policy->governor->max_transition_latency) { | |
1674 | if (!gov) | |
1675 | return -EINVAL; | |
1676 | else { | |
1677 | printk(KERN_WARNING "%s governor failed, too long" | |
1678 | " transition latency of HW, fallback" | |
1679 | " to %s governor\n", | |
1680 | policy->governor->name, | |
1681 | gov->name); | |
1682 | policy->governor = gov; | |
1683 | } | |
1684 | } | |
1685 | ||
1686 | if (!try_module_get(policy->governor->owner)) | |
1687 | return -EINVAL; | |
1688 | ||
1689 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", | |
1690 | policy->cpu, event); | |
1691 | ||
1692 | mutex_lock(&cpufreq_governor_lock); | |
1693 | if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) || | |
1694 | (policy->governor_enabled && (event == CPUFREQ_GOV_START))) { | |
1695 | mutex_unlock(&cpufreq_governor_lock); | |
1696 | return -EBUSY; | |
1697 | } | |
1698 | ||
1699 | if (event == CPUFREQ_GOV_STOP) | |
1700 | policy->governor_enabled = false; | |
1701 | else if (event == CPUFREQ_GOV_START) | |
1702 | policy->governor_enabled = true; | |
1703 | ||
1704 | mutex_unlock(&cpufreq_governor_lock); | |
1705 | ||
1706 | ret = policy->governor->governor(policy, event); | |
1707 | ||
1708 | if (!ret) { | |
1709 | if (event == CPUFREQ_GOV_POLICY_INIT) | |
1710 | policy->governor->initialized++; | |
1711 | else if (event == CPUFREQ_GOV_POLICY_EXIT) | |
1712 | policy->governor->initialized--; | |
1713 | } else { | |
1714 | /* Restore original values */ | |
1715 | mutex_lock(&cpufreq_governor_lock); | |
1716 | if (event == CPUFREQ_GOV_STOP) | |
1717 | policy->governor_enabled = true; | |
1718 | else if (event == CPUFREQ_GOV_START) | |
1719 | policy->governor_enabled = false; | |
1720 | mutex_unlock(&cpufreq_governor_lock); | |
1721 | } | |
1722 | ||
1723 | /* we keep one module reference alive for | |
1724 | each CPU governed by this CPU */ | |
1725 | if ((event != CPUFREQ_GOV_START) || ret) | |
1726 | module_put(policy->governor->owner); | |
1727 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1728 | module_put(policy->governor->owner); | |
1729 | ||
1730 | return ret; | |
1731 | } | |
1732 | ||
1733 | int cpufreq_register_governor(struct cpufreq_governor *governor) | |
1734 | { | |
1735 | int err; | |
1736 | ||
1737 | if (!governor) | |
1738 | return -EINVAL; | |
1739 | ||
1740 | if (cpufreq_disabled()) | |
1741 | return -ENODEV; | |
1742 | ||
1743 | mutex_lock(&cpufreq_governor_mutex); | |
1744 | ||
1745 | governor->initialized = 0; | |
1746 | err = -EBUSY; | |
1747 | if (__find_governor(governor->name) == NULL) { | |
1748 | err = 0; | |
1749 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1750 | } | |
1751 | ||
1752 | mutex_unlock(&cpufreq_governor_mutex); | |
1753 | return err; | |
1754 | } | |
1755 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1756 | ||
1757 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1758 | { | |
1759 | #ifdef CONFIG_HOTPLUG_CPU | |
1760 | int cpu; | |
1761 | #endif | |
1762 | ||
1763 | if (!governor) | |
1764 | return; | |
1765 | ||
1766 | if (cpufreq_disabled()) | |
1767 | return; | |
1768 | ||
1769 | #ifdef CONFIG_HOTPLUG_CPU | |
1770 | for_each_present_cpu(cpu) { | |
1771 | if (cpu_online(cpu)) | |
1772 | continue; | |
1773 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1774 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1775 | } | |
1776 | #endif | |
1777 | ||
1778 | mutex_lock(&cpufreq_governor_mutex); | |
1779 | list_del(&governor->governor_list); | |
1780 | mutex_unlock(&cpufreq_governor_mutex); | |
1781 | return; | |
1782 | } | |
1783 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1784 | ||
1785 | ||
1786 | /********************************************************************* | |
1787 | * POLICY INTERFACE * | |
1788 | *********************************************************************/ | |
1789 | ||
1790 | /** | |
1791 | * cpufreq_get_policy - get the current cpufreq_policy | |
1792 | * @policy: struct cpufreq_policy into which the current cpufreq_policy | |
1793 | * is written | |
1794 | * | |
1795 | * Reads the current cpufreq policy. | |
1796 | */ | |
1797 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1798 | { | |
1799 | struct cpufreq_policy *cpu_policy; | |
1800 | if (!policy) | |
1801 | return -EINVAL; | |
1802 | ||
1803 | cpu_policy = cpufreq_cpu_get(cpu); | |
1804 | if (!cpu_policy) | |
1805 | return -EINVAL; | |
1806 | ||
1807 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); | |
1808 | ||
1809 | cpufreq_cpu_put(cpu_policy); | |
1810 | return 0; | |
1811 | } | |
1812 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1813 | ||
1814 | /* | |
1815 | * data : current policy. | |
1816 | * policy : policy to be set. | |
1817 | */ | |
1818 | static int __cpufreq_set_policy(struct cpufreq_policy *data, | |
1819 | struct cpufreq_policy *policy) | |
1820 | { | |
1821 | int ret = 0, failed = 1; | |
1822 | ||
1823 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, | |
1824 | policy->min, policy->max); | |
1825 | ||
1826 | memcpy(&policy->cpuinfo, &data->cpuinfo, | |
1827 | sizeof(struct cpufreq_cpuinfo)); | |
1828 | ||
1829 | if (policy->min > data->max || policy->max < data->min) { | |
1830 | ret = -EINVAL; | |
1831 | goto error_out; | |
1832 | } | |
1833 | ||
1834 | /* verify the cpu speed can be set within this limit */ | |
1835 | ret = cpufreq_driver->verify(policy); | |
1836 | if (ret) | |
1837 | goto error_out; | |
1838 | ||
1839 | /* adjust if necessary - all reasons */ | |
1840 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1841 | CPUFREQ_ADJUST, policy); | |
1842 | ||
1843 | /* adjust if necessary - hardware incompatibility*/ | |
1844 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1845 | CPUFREQ_INCOMPATIBLE, policy); | |
1846 | ||
1847 | /* | |
1848 | * verify the cpu speed can be set within this limit, which might be | |
1849 | * different to the first one | |
1850 | */ | |
1851 | ret = cpufreq_driver->verify(policy); | |
1852 | if (ret) | |
1853 | goto error_out; | |
1854 | ||
1855 | /* notification of the new policy */ | |
1856 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1857 | CPUFREQ_NOTIFY, policy); | |
1858 | ||
1859 | data->min = policy->min; | |
1860 | data->max = policy->max; | |
1861 | ||
1862 | pr_debug("new min and max freqs are %u - %u kHz\n", | |
1863 | data->min, data->max); | |
1864 | ||
1865 | if (cpufreq_driver->setpolicy) { | |
1866 | data->policy = policy->policy; | |
1867 | pr_debug("setting range\n"); | |
1868 | ret = cpufreq_driver->setpolicy(policy); | |
1869 | } else { | |
1870 | if (policy->governor != data->governor) { | |
1871 | /* save old, working values */ | |
1872 | struct cpufreq_governor *old_gov = data->governor; | |
1873 | ||
1874 | pr_debug("governor switch\n"); | |
1875 | ||
1876 | /* end old governor */ | |
1877 | if (data->governor) { | |
1878 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
1879 | unlock_policy_rwsem_write(policy->cpu); | |
1880 | __cpufreq_governor(data, | |
1881 | CPUFREQ_GOV_POLICY_EXIT); | |
1882 | lock_policy_rwsem_write(policy->cpu); | |
1883 | } | |
1884 | ||
1885 | /* start new governor */ | |
1886 | data->governor = policy->governor; | |
1887 | if (!__cpufreq_governor(data, CPUFREQ_GOV_POLICY_INIT)) { | |
1888 | if (!__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1889 | failed = 0; | |
1890 | } else { | |
1891 | unlock_policy_rwsem_write(policy->cpu); | |
1892 | __cpufreq_governor(data, | |
1893 | CPUFREQ_GOV_POLICY_EXIT); | |
1894 | lock_policy_rwsem_write(policy->cpu); | |
1895 | } | |
1896 | } | |
1897 | ||
1898 | if (failed) { | |
1899 | /* new governor failed, so re-start old one */ | |
1900 | pr_debug("starting governor %s failed\n", | |
1901 | data->governor->name); | |
1902 | if (old_gov) { | |
1903 | data->governor = old_gov; | |
1904 | __cpufreq_governor(data, | |
1905 | CPUFREQ_GOV_POLICY_INIT); | |
1906 | __cpufreq_governor(data, | |
1907 | CPUFREQ_GOV_START); | |
1908 | } | |
1909 | ret = -EINVAL; | |
1910 | goto error_out; | |
1911 | } | |
1912 | /* might be a policy change, too, so fall through */ | |
1913 | } | |
1914 | pr_debug("governor: change or update limits\n"); | |
1915 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1916 | } | |
1917 | ||
1918 | error_out: | |
1919 | return ret; | |
1920 | } | |
1921 | ||
1922 | /** | |
1923 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1924 | * @cpu: CPU which shall be re-evaluated | |
1925 | * | |
1926 | * Useful for policy notifiers which have different necessities | |
1927 | * at different times. | |
1928 | */ | |
1929 | int cpufreq_update_policy(unsigned int cpu) | |
1930 | { | |
1931 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1932 | struct cpufreq_policy policy; | |
1933 | int ret; | |
1934 | ||
1935 | if (!data) { | |
1936 | ret = -ENODEV; | |
1937 | goto no_policy; | |
1938 | } | |
1939 | ||
1940 | if (unlikely(lock_policy_rwsem_write(cpu))) { | |
1941 | ret = -EINVAL; | |
1942 | goto fail; | |
1943 | } | |
1944 | ||
1945 | pr_debug("updating policy for CPU %u\n", cpu); | |
1946 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); | |
1947 | policy.min = data->user_policy.min; | |
1948 | policy.max = data->user_policy.max; | |
1949 | policy.policy = data->user_policy.policy; | |
1950 | policy.governor = data->user_policy.governor; | |
1951 | ||
1952 | /* | |
1953 | * BIOS might change freq behind our back | |
1954 | * -> ask driver for current freq and notify governors about a change | |
1955 | */ | |
1956 | if (cpufreq_driver->get) { | |
1957 | policy.cur = cpufreq_driver->get(cpu); | |
1958 | if (!data->cur) { | |
1959 | pr_debug("Driver did not initialize current freq"); | |
1960 | data->cur = policy.cur; | |
1961 | } else { | |
1962 | if (data->cur != policy.cur && cpufreq_driver->target) | |
1963 | cpufreq_out_of_sync(cpu, data->cur, | |
1964 | policy.cur); | |
1965 | } | |
1966 | } | |
1967 | ||
1968 | ret = __cpufreq_set_policy(data, &policy); | |
1969 | ||
1970 | unlock_policy_rwsem_write(cpu); | |
1971 | ||
1972 | fail: | |
1973 | cpufreq_cpu_put(data); | |
1974 | no_policy: | |
1975 | return ret; | |
1976 | } | |
1977 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1978 | ||
1979 | static int cpufreq_cpu_callback(struct notifier_block *nfb, | |
1980 | unsigned long action, void *hcpu) | |
1981 | { | |
1982 | unsigned int cpu = (unsigned long)hcpu; | |
1983 | struct device *dev; | |
1984 | ||
1985 | dev = get_cpu_device(cpu); | |
1986 | if (dev) { | |
1987 | switch (action) { | |
1988 | case CPU_ONLINE: | |
1989 | case CPU_ONLINE_FROZEN: | |
1990 | cpufreq_add_dev(dev, NULL); | |
1991 | cpufreq_update_policy(cpu); | |
1992 | break; | |
1993 | case CPU_DOWN_PREPARE: | |
1994 | case CPU_DOWN_PREPARE_FROZEN: | |
1995 | __cpufreq_remove_dev(dev, NULL); | |
1996 | break; | |
1997 | case CPU_DOWN_FAILED: | |
1998 | case CPU_DOWN_FAILED_FROZEN: | |
1999 | cpufreq_add_dev(dev, NULL); | |
2000 | break; | |
2001 | } | |
2002 | } | |
2003 | return NOTIFY_OK; | |
2004 | } | |
2005 | ||
2006 | static struct notifier_block __refdata cpufreq_cpu_notifier = { | |
2007 | .notifier_call = cpufreq_cpu_callback, | |
2008 | }; | |
2009 | ||
2010 | /********************************************************************* | |
2011 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2012 | *********************************************************************/ | |
2013 | ||
2014 | /** | |
2015 | * cpufreq_register_driver - register a CPU Frequency driver | |
2016 | * @driver_data: A struct cpufreq_driver containing the values# | |
2017 | * submitted by the CPU Frequency driver. | |
2018 | * | |
2019 | * Registers a CPU Frequency driver to this core code. This code | |
2020 | * returns zero on success, -EBUSY when another driver got here first | |
2021 | * (and isn't unregistered in the meantime). | |
2022 | * | |
2023 | */ | |
2024 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) | |
2025 | { | |
2026 | unsigned long flags; | |
2027 | int ret; | |
2028 | ||
2029 | if (cpufreq_disabled()) | |
2030 | return -ENODEV; | |
2031 | ||
2032 | if (!driver_data || !driver_data->verify || !driver_data->init || | |
2033 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
2034 | return -EINVAL; | |
2035 | ||
2036 | pr_debug("trying to register driver %s\n", driver_data->name); | |
2037 | ||
2038 | if (driver_data->setpolicy) | |
2039 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2040 | ||
2041 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2042 | if (cpufreq_driver) { | |
2043 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2044 | return -EBUSY; | |
2045 | } | |
2046 | cpufreq_driver = driver_data; | |
2047 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2048 | ||
2049 | ret = subsys_interface_register(&cpufreq_interface); | |
2050 | if (ret) | |
2051 | goto err_null_driver; | |
2052 | ||
2053 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { | |
2054 | int i; | |
2055 | ret = -ENODEV; | |
2056 | ||
2057 | /* check for at least one working CPU */ | |
2058 | for (i = 0; i < nr_cpu_ids; i++) | |
2059 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
2060 | ret = 0; | |
2061 | break; | |
2062 | } | |
2063 | ||
2064 | /* if all ->init() calls failed, unregister */ | |
2065 | if (ret) { | |
2066 | pr_debug("no CPU initialized for driver %s\n", | |
2067 | driver_data->name); | |
2068 | goto err_if_unreg; | |
2069 | } | |
2070 | } | |
2071 | ||
2072 | register_hotcpu_notifier(&cpufreq_cpu_notifier); | |
2073 | pr_debug("driver %s up and running\n", driver_data->name); | |
2074 | ||
2075 | return 0; | |
2076 | err_if_unreg: | |
2077 | subsys_interface_unregister(&cpufreq_interface); | |
2078 | err_null_driver: | |
2079 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2080 | cpufreq_driver = NULL; | |
2081 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2082 | return ret; | |
2083 | } | |
2084 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2085 | ||
2086 | /** | |
2087 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2088 | * | |
2089 | * Unregister the current CPUFreq driver. Only call this if you have | |
2090 | * the right to do so, i.e. if you have succeeded in initialising before! | |
2091 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2092 | * currently not initialised. | |
2093 | */ | |
2094 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) | |
2095 | { | |
2096 | unsigned long flags; | |
2097 | ||
2098 | if (!cpufreq_driver || (driver != cpufreq_driver)) | |
2099 | return -EINVAL; | |
2100 | ||
2101 | pr_debug("unregistering driver %s\n", driver->name); | |
2102 | ||
2103 | subsys_interface_unregister(&cpufreq_interface); | |
2104 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); | |
2105 | ||
2106 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2107 | cpufreq_driver = NULL; | |
2108 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2109 | ||
2110 | return 0; | |
2111 | } | |
2112 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
2113 | ||
2114 | static int __init cpufreq_core_init(void) | |
2115 | { | |
2116 | int cpu; | |
2117 | ||
2118 | if (cpufreq_disabled()) | |
2119 | return -ENODEV; | |
2120 | ||
2121 | for_each_possible_cpu(cpu) { | |
2122 | per_cpu(cpufreq_policy_cpu, cpu) = -1; | |
2123 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); | |
2124 | } | |
2125 | ||
2126 | cpufreq_global_kobject = kobject_create(); | |
2127 | BUG_ON(!cpufreq_global_kobject); | |
2128 | register_syscore_ops(&cpufreq_syscore_ops); | |
2129 | ||
2130 | return 0; | |
2131 | } | |
2132 | core_initcall(cpufreq_core_init); |