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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/cpufreq/cpufreq.c
4 *
5 * Copyright (C) 2001 Russell King
6 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
8 *
9 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
10 * Added handling for CPU hotplug
11 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
12 * Fix handling for CPU hotplug -- affected CPUs
13 */
14
15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17#include <linux/cpu.h>
18#include <linux/cpufreq.h>
19#include <linux/cpu_cooling.h>
20#include <linux/delay.h>
21#include <linux/device.h>
22#include <linux/init.h>
23#include <linux/kernel_stat.h>
24#include <linux/module.h>
25#include <linux/mutex.h>
26#include <linux/pm_qos.h>
27#include <linux/slab.h>
28#include <linux/suspend.h>
29#include <linux/syscore_ops.h>
30#include <linux/tick.h>
31#include <linux/units.h>
32#include <trace/events/power.h>
33
34static LIST_HEAD(cpufreq_policy_list);
35
36/* Macros to iterate over CPU policies */
37#define for_each_suitable_policy(__policy, __active) \
38 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
39 if ((__active) == !policy_is_inactive(__policy))
40
41#define for_each_active_policy(__policy) \
42 for_each_suitable_policy(__policy, true)
43#define for_each_inactive_policy(__policy) \
44 for_each_suitable_policy(__policy, false)
45
46/* Iterate over governors */
47static LIST_HEAD(cpufreq_governor_list);
48#define for_each_governor(__governor) \
49 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
50
51static char default_governor[CPUFREQ_NAME_LEN];
52
53/*
54 * The "cpufreq driver" - the arch- or hardware-dependent low
55 * level driver of CPUFreq support, and its spinlock. This lock
56 * also protects the cpufreq_cpu_data array.
57 */
58static struct cpufreq_driver *cpufreq_driver;
59static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
60static DEFINE_RWLOCK(cpufreq_driver_lock);
61
62static DEFINE_STATIC_KEY_FALSE(cpufreq_freq_invariance);
63bool cpufreq_supports_freq_invariance(void)
64{
65 return static_branch_likely(&cpufreq_freq_invariance);
66}
67
68/* Flag to suspend/resume CPUFreq governors */
69static bool cpufreq_suspended;
70
71static inline bool has_target(void)
72{
73 return cpufreq_driver->target_index || cpufreq_driver->target;
74}
75
76bool has_target_index(void)
77{
78 return !!cpufreq_driver->target_index;
79}
80
81/* internal prototypes */
82static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
83static int cpufreq_init_governor(struct cpufreq_policy *policy);
84static void cpufreq_exit_governor(struct cpufreq_policy *policy);
85static void cpufreq_governor_limits(struct cpufreq_policy *policy);
86static int cpufreq_set_policy(struct cpufreq_policy *policy,
87 struct cpufreq_governor *new_gov,
88 unsigned int new_pol);
89static bool cpufreq_boost_supported(void);
90
91/*
92 * Two notifier lists: the "policy" list is involved in the
93 * validation process for a new CPU frequency policy; the
94 * "transition" list for kernel code that needs to handle
95 * changes to devices when the CPU clock speed changes.
96 * The mutex locks both lists.
97 */
98static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
99SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
100
101static int off __read_mostly;
102static int cpufreq_disabled(void)
103{
104 return off;
105}
106void disable_cpufreq(void)
107{
108 off = 1;
109}
110static DEFINE_MUTEX(cpufreq_governor_mutex);
111
112bool have_governor_per_policy(void)
113{
114 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
115}
116EXPORT_SYMBOL_GPL(have_governor_per_policy);
117
118static struct kobject *cpufreq_global_kobject;
119
120struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
121{
122 if (have_governor_per_policy())
123 return &policy->kobj;
124 else
125 return cpufreq_global_kobject;
126}
127EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
128
129static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
130{
131 struct kernel_cpustat kcpustat;
132 u64 cur_wall_time;
133 u64 idle_time;
134 u64 busy_time;
135
136 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
137
138 kcpustat_cpu_fetch(&kcpustat, cpu);
139
140 busy_time = kcpustat.cpustat[CPUTIME_USER];
141 busy_time += kcpustat.cpustat[CPUTIME_SYSTEM];
142 busy_time += kcpustat.cpustat[CPUTIME_IRQ];
143 busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ];
144 busy_time += kcpustat.cpustat[CPUTIME_STEAL];
145 busy_time += kcpustat.cpustat[CPUTIME_NICE];
146
147 idle_time = cur_wall_time - busy_time;
148 if (wall)
149 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
150
151 return div_u64(idle_time, NSEC_PER_USEC);
152}
153
154u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
155{
156 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
157
158 if (idle_time == -1ULL)
159 return get_cpu_idle_time_jiffy(cpu, wall);
160 else if (!io_busy)
161 idle_time += get_cpu_iowait_time_us(cpu, wall);
162
163 return idle_time;
164}
165EXPORT_SYMBOL_GPL(get_cpu_idle_time);
166
167/*
168 * This is a generic cpufreq init() routine which can be used by cpufreq
169 * drivers of SMP systems. It will do following:
170 * - validate & show freq table passed
171 * - set policies transition latency
172 * - policy->cpus with all possible CPUs
173 */
174void cpufreq_generic_init(struct cpufreq_policy *policy,
175 struct cpufreq_frequency_table *table,
176 unsigned int transition_latency)
177{
178 policy->freq_table = table;
179 policy->cpuinfo.transition_latency = transition_latency;
180
181 /*
182 * The driver only supports the SMP configuration where all processors
183 * share the clock and voltage and clock.
184 */
185 cpumask_setall(policy->cpus);
186}
187EXPORT_SYMBOL_GPL(cpufreq_generic_init);
188
189struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
190{
191 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
192
193 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
194}
195EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
196
197unsigned int cpufreq_generic_get(unsigned int cpu)
198{
199 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
200
201 if (!policy || IS_ERR(policy->clk)) {
202 pr_err("%s: No %s associated to cpu: %d\n",
203 __func__, policy ? "clk" : "policy", cpu);
204 return 0;
205 }
206
207 return clk_get_rate(policy->clk) / 1000;
208}
209EXPORT_SYMBOL_GPL(cpufreq_generic_get);
210
211/**
212 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
213 * @cpu: CPU to find the policy for.
214 *
215 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
216 * the kobject reference counter of that policy. Return a valid policy on
217 * success or NULL on failure.
218 *
219 * The policy returned by this function has to be released with the help of
220 * cpufreq_cpu_put() to balance its kobject reference counter properly.
221 */
222struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
223{
224 struct cpufreq_policy *policy = NULL;
225 unsigned long flags;
226
227 if (WARN_ON(cpu >= nr_cpu_ids))
228 return NULL;
229
230 /* get the cpufreq driver */
231 read_lock_irqsave(&cpufreq_driver_lock, flags);
232
233 if (cpufreq_driver) {
234 /* get the CPU */
235 policy = cpufreq_cpu_get_raw(cpu);
236 if (policy)
237 kobject_get(&policy->kobj);
238 }
239
240 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
241
242 return policy;
243}
244EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
245
246/**
247 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
248 * @policy: cpufreq policy returned by cpufreq_cpu_get().
249 */
250void cpufreq_cpu_put(struct cpufreq_policy *policy)
251{
252 kobject_put(&policy->kobj);
253}
254EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
255
256/**
257 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
258 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
259 */
260void cpufreq_cpu_release(struct cpufreq_policy *policy)
261{
262 if (WARN_ON(!policy))
263 return;
264
265 lockdep_assert_held(&policy->rwsem);
266
267 up_write(&policy->rwsem);
268
269 cpufreq_cpu_put(policy);
270}
271
272/**
273 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
274 * @cpu: CPU to find the policy for.
275 *
276 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
277 * if the policy returned by it is not NULL, acquire its rwsem for writing.
278 * Return the policy if it is active or release it and return NULL otherwise.
279 *
280 * The policy returned by this function has to be released with the help of
281 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
282 * counter properly.
283 */
284struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
285{
286 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
287
288 if (!policy)
289 return NULL;
290
291 down_write(&policy->rwsem);
292
293 if (policy_is_inactive(policy)) {
294 cpufreq_cpu_release(policy);
295 return NULL;
296 }
297
298 return policy;
299}
300
301/*********************************************************************
302 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
303 *********************************************************************/
304
305/**
306 * adjust_jiffies - Adjust the system "loops_per_jiffy".
307 * @val: CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
308 * @ci: Frequency change information.
309 *
310 * This function alters the system "loops_per_jiffy" for the clock
311 * speed change. Note that loops_per_jiffy cannot be updated on SMP
312 * systems as each CPU might be scaled differently. So, use the arch
313 * per-CPU loops_per_jiffy value wherever possible.
314 */
315static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
316{
317#ifndef CONFIG_SMP
318 static unsigned long l_p_j_ref;
319 static unsigned int l_p_j_ref_freq;
320
321 if (ci->flags & CPUFREQ_CONST_LOOPS)
322 return;
323
324 if (!l_p_j_ref_freq) {
325 l_p_j_ref = loops_per_jiffy;
326 l_p_j_ref_freq = ci->old;
327 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
328 l_p_j_ref, l_p_j_ref_freq);
329 }
330 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
331 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
332 ci->new);
333 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
334 loops_per_jiffy, ci->new);
335 }
336#endif
337}
338
339/**
340 * cpufreq_notify_transition - Notify frequency transition and adjust jiffies.
341 * @policy: cpufreq policy to enable fast frequency switching for.
342 * @freqs: contain details of the frequency update.
343 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
344 *
345 * This function calls the transition notifiers and adjust_jiffies().
346 *
347 * It is called twice on all CPU frequency changes that have external effects.
348 */
349static void cpufreq_notify_transition(struct cpufreq_policy *policy,
350 struct cpufreq_freqs *freqs,
351 unsigned int state)
352{
353 int cpu;
354
355 BUG_ON(irqs_disabled());
356
357 if (cpufreq_disabled())
358 return;
359
360 freqs->policy = policy;
361 freqs->flags = cpufreq_driver->flags;
362 pr_debug("notification %u of frequency transition to %u kHz\n",
363 state, freqs->new);
364
365 switch (state) {
366 case CPUFREQ_PRECHANGE:
367 /*
368 * Detect if the driver reported a value as "old frequency"
369 * which is not equal to what the cpufreq core thinks is
370 * "old frequency".
371 */
372 if (policy->cur && policy->cur != freqs->old) {
373 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
374 freqs->old, policy->cur);
375 freqs->old = policy->cur;
376 }
377
378 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
379 CPUFREQ_PRECHANGE, freqs);
380
381 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
382 break;
383
384 case CPUFREQ_POSTCHANGE:
385 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
386 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
387 cpumask_pr_args(policy->cpus));
388
389 for_each_cpu(cpu, policy->cpus)
390 trace_cpu_frequency(freqs->new, cpu);
391
392 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
393 CPUFREQ_POSTCHANGE, freqs);
394
395 cpufreq_stats_record_transition(policy, freqs->new);
396 policy->cur = freqs->new;
397 }
398}
399
400/* Do post notifications when there are chances that transition has failed */
401static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
402 struct cpufreq_freqs *freqs, int transition_failed)
403{
404 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
405 if (!transition_failed)
406 return;
407
408 swap(freqs->old, freqs->new);
409 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
410 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
411}
412
413void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
414 struct cpufreq_freqs *freqs)
415{
416
417 /*
418 * Catch double invocations of _begin() which lead to self-deadlock.
419 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
420 * doesn't invoke _begin() on their behalf, and hence the chances of
421 * double invocations are very low. Moreover, there are scenarios
422 * where these checks can emit false-positive warnings in these
423 * drivers; so we avoid that by skipping them altogether.
424 */
425 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
426 && current == policy->transition_task);
427
428wait:
429 wait_event(policy->transition_wait, !policy->transition_ongoing);
430
431 spin_lock(&policy->transition_lock);
432
433 if (unlikely(policy->transition_ongoing)) {
434 spin_unlock(&policy->transition_lock);
435 goto wait;
436 }
437
438 policy->transition_ongoing = true;
439 policy->transition_task = current;
440
441 spin_unlock(&policy->transition_lock);
442
443 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
444}
445EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
446
447void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
448 struct cpufreq_freqs *freqs, int transition_failed)
449{
450 if (WARN_ON(!policy->transition_ongoing))
451 return;
452
453 cpufreq_notify_post_transition(policy, freqs, transition_failed);
454
455 arch_set_freq_scale(policy->related_cpus,
456 policy->cur,
457 arch_scale_freq_ref(policy->cpu));
458
459 spin_lock(&policy->transition_lock);
460 policy->transition_ongoing = false;
461 policy->transition_task = NULL;
462 spin_unlock(&policy->transition_lock);
463
464 wake_up(&policy->transition_wait);
465}
466EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
467
468/*
469 * Fast frequency switching status count. Positive means "enabled", negative
470 * means "disabled" and 0 means "not decided yet".
471 */
472static int cpufreq_fast_switch_count;
473static DEFINE_MUTEX(cpufreq_fast_switch_lock);
474
475static void cpufreq_list_transition_notifiers(void)
476{
477 struct notifier_block *nb;
478
479 pr_info("Registered transition notifiers:\n");
480
481 mutex_lock(&cpufreq_transition_notifier_list.mutex);
482
483 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
484 pr_info("%pS\n", nb->notifier_call);
485
486 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
487}
488
489/**
490 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
491 * @policy: cpufreq policy to enable fast frequency switching for.
492 *
493 * Try to enable fast frequency switching for @policy.
494 *
495 * The attempt will fail if there is at least one transition notifier registered
496 * at this point, as fast frequency switching is quite fundamentally at odds
497 * with transition notifiers. Thus if successful, it will make registration of
498 * transition notifiers fail going forward.
499 */
500void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
501{
502 lockdep_assert_held(&policy->rwsem);
503
504 if (!policy->fast_switch_possible)
505 return;
506
507 mutex_lock(&cpufreq_fast_switch_lock);
508 if (cpufreq_fast_switch_count >= 0) {
509 cpufreq_fast_switch_count++;
510 policy->fast_switch_enabled = true;
511 } else {
512 pr_warn("CPU%u: Fast frequency switching not enabled\n",
513 policy->cpu);
514 cpufreq_list_transition_notifiers();
515 }
516 mutex_unlock(&cpufreq_fast_switch_lock);
517}
518EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
519
520/**
521 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
522 * @policy: cpufreq policy to disable fast frequency switching for.
523 */
524void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
525{
526 mutex_lock(&cpufreq_fast_switch_lock);
527 if (policy->fast_switch_enabled) {
528 policy->fast_switch_enabled = false;
529 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
530 cpufreq_fast_switch_count--;
531 }
532 mutex_unlock(&cpufreq_fast_switch_lock);
533}
534EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
535
536static unsigned int __resolve_freq(struct cpufreq_policy *policy,
537 unsigned int target_freq, unsigned int relation)
538{
539 unsigned int idx;
540
541 target_freq = clamp_val(target_freq, policy->min, policy->max);
542
543 if (!policy->freq_table)
544 return target_freq;
545
546 idx = cpufreq_frequency_table_target(policy, target_freq, relation);
547 policy->cached_resolved_idx = idx;
548 policy->cached_target_freq = target_freq;
549 return policy->freq_table[idx].frequency;
550}
551
552/**
553 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
554 * one.
555 * @policy: associated policy to interrogate
556 * @target_freq: target frequency to resolve.
557 *
558 * The target to driver frequency mapping is cached in the policy.
559 *
560 * Return: Lowest driver-supported frequency greater than or equal to the
561 * given target_freq, subject to policy (min/max) and driver limitations.
562 */
563unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
564 unsigned int target_freq)
565{
566 return __resolve_freq(policy, target_freq, CPUFREQ_RELATION_LE);
567}
568EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
569
570unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
571{
572 unsigned int latency;
573
574 if (policy->transition_delay_us)
575 return policy->transition_delay_us;
576
577 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
578 if (latency) {
579 /*
580 * For platforms that can change the frequency very fast (< 10
581 * us), the above formula gives a decent transition delay. But
582 * for platforms where transition_latency is in milliseconds, it
583 * ends up giving unrealistic values.
584 *
585 * Cap the default transition delay to 10 ms, which seems to be
586 * a reasonable amount of time after which we should reevaluate
587 * the frequency.
588 */
589 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
590 }
591
592 return LATENCY_MULTIPLIER;
593}
594EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
595
596/*********************************************************************
597 * SYSFS INTERFACE *
598 *********************************************************************/
599static ssize_t show_boost(struct kobject *kobj,
600 struct kobj_attribute *attr, char *buf)
601{
602 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
603}
604
605static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
606 const char *buf, size_t count)
607{
608 int ret, enable;
609
610 ret = sscanf(buf, "%d", &enable);
611 if (ret != 1 || enable < 0 || enable > 1)
612 return -EINVAL;
613
614 if (cpufreq_boost_trigger_state(enable)) {
615 pr_err("%s: Cannot %s BOOST!\n",
616 __func__, enable ? "enable" : "disable");
617 return -EINVAL;
618 }
619
620 pr_debug("%s: cpufreq BOOST %s\n",
621 __func__, enable ? "enabled" : "disabled");
622
623 return count;
624}
625define_one_global_rw(boost);
626
627static ssize_t show_local_boost(struct cpufreq_policy *policy, char *buf)
628{
629 return sysfs_emit(buf, "%d\n", policy->boost_enabled);
630}
631
632static ssize_t store_local_boost(struct cpufreq_policy *policy,
633 const char *buf, size_t count)
634{
635 int ret, enable;
636
637 ret = kstrtoint(buf, 10, &enable);
638 if (ret || enable < 0 || enable > 1)
639 return -EINVAL;
640
641 if (!cpufreq_driver->boost_enabled)
642 return -EINVAL;
643
644 if (policy->boost_enabled == enable)
645 return count;
646
647 cpus_read_lock();
648 ret = cpufreq_driver->set_boost(policy, enable);
649 cpus_read_unlock();
650
651 if (ret)
652 return ret;
653
654 policy->boost_enabled = enable;
655
656 return count;
657}
658
659static struct freq_attr local_boost = __ATTR(boost, 0644, show_local_boost, store_local_boost);
660
661static struct cpufreq_governor *find_governor(const char *str_governor)
662{
663 struct cpufreq_governor *t;
664
665 for_each_governor(t)
666 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
667 return t;
668
669 return NULL;
670}
671
672static struct cpufreq_governor *get_governor(const char *str_governor)
673{
674 struct cpufreq_governor *t;
675
676 mutex_lock(&cpufreq_governor_mutex);
677 t = find_governor(str_governor);
678 if (!t)
679 goto unlock;
680
681 if (!try_module_get(t->owner))
682 t = NULL;
683
684unlock:
685 mutex_unlock(&cpufreq_governor_mutex);
686
687 return t;
688}
689
690static unsigned int cpufreq_parse_policy(char *str_governor)
691{
692 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN))
693 return CPUFREQ_POLICY_PERFORMANCE;
694
695 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN))
696 return CPUFREQ_POLICY_POWERSAVE;
697
698 return CPUFREQ_POLICY_UNKNOWN;
699}
700
701/**
702 * cpufreq_parse_governor - parse a governor string only for has_target()
703 * @str_governor: Governor name.
704 */
705static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor)
706{
707 struct cpufreq_governor *t;
708
709 t = get_governor(str_governor);
710 if (t)
711 return t;
712
713 if (request_module("cpufreq_%s", str_governor))
714 return NULL;
715
716 return get_governor(str_governor);
717}
718
719/*
720 * cpufreq_per_cpu_attr_read() / show_##file_name() -
721 * print out cpufreq information
722 *
723 * Write out information from cpufreq_driver->policy[cpu]; object must be
724 * "unsigned int".
725 */
726
727#define show_one(file_name, object) \
728static ssize_t show_##file_name \
729(struct cpufreq_policy *policy, char *buf) \
730{ \
731 return sprintf(buf, "%u\n", policy->object); \
732}
733
734show_one(cpuinfo_min_freq, cpuinfo.min_freq);
735show_one(cpuinfo_max_freq, cpuinfo.max_freq);
736show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
737show_one(scaling_min_freq, min);
738show_one(scaling_max_freq, max);
739
740__weak unsigned int arch_freq_get_on_cpu(int cpu)
741{
742 return 0;
743}
744
745static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
746{
747 ssize_t ret;
748 unsigned int freq;
749
750 freq = arch_freq_get_on_cpu(policy->cpu);
751 if (freq)
752 ret = sprintf(buf, "%u\n", freq);
753 else if (cpufreq_driver->setpolicy && cpufreq_driver->get)
754 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
755 else
756 ret = sprintf(buf, "%u\n", policy->cur);
757 return ret;
758}
759
760/*
761 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
762 */
763#define store_one(file_name, object) \
764static ssize_t store_##file_name \
765(struct cpufreq_policy *policy, const char *buf, size_t count) \
766{ \
767 unsigned long val; \
768 int ret; \
769 \
770 ret = kstrtoul(buf, 0, &val); \
771 if (ret) \
772 return ret; \
773 \
774 ret = freq_qos_update_request(policy->object##_freq_req, val);\
775 return ret >= 0 ? count : ret; \
776}
777
778store_one(scaling_min_freq, min);
779store_one(scaling_max_freq, max);
780
781/*
782 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
783 */
784static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
785 char *buf)
786{
787 unsigned int cur_freq = __cpufreq_get(policy);
788
789 if (cur_freq)
790 return sprintf(buf, "%u\n", cur_freq);
791
792 return sprintf(buf, "<unknown>\n");
793}
794
795/*
796 * show_scaling_governor - show the current policy for the specified CPU
797 */
798static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
799{
800 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
801 return sprintf(buf, "powersave\n");
802 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
803 return sprintf(buf, "performance\n");
804 else if (policy->governor)
805 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
806 policy->governor->name);
807 return -EINVAL;
808}
809
810/*
811 * store_scaling_governor - store policy for the specified CPU
812 */
813static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
814 const char *buf, size_t count)
815{
816 char str_governor[16];
817 int ret;
818
819 ret = sscanf(buf, "%15s", str_governor);
820 if (ret != 1)
821 return -EINVAL;
822
823 if (cpufreq_driver->setpolicy) {
824 unsigned int new_pol;
825
826 new_pol = cpufreq_parse_policy(str_governor);
827 if (!new_pol)
828 return -EINVAL;
829
830 ret = cpufreq_set_policy(policy, NULL, new_pol);
831 } else {
832 struct cpufreq_governor *new_gov;
833
834 new_gov = cpufreq_parse_governor(str_governor);
835 if (!new_gov)
836 return -EINVAL;
837
838 ret = cpufreq_set_policy(policy, new_gov,
839 CPUFREQ_POLICY_UNKNOWN);
840
841 module_put(new_gov->owner);
842 }
843
844 return ret ? ret : count;
845}
846
847/*
848 * show_scaling_driver - show the cpufreq driver currently loaded
849 */
850static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
851{
852 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
853}
854
855/*
856 * show_scaling_available_governors - show the available CPUfreq governors
857 */
858static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
859 char *buf)
860{
861 ssize_t i = 0;
862 struct cpufreq_governor *t;
863
864 if (!has_target()) {
865 i += sprintf(buf, "performance powersave");
866 goto out;
867 }
868
869 mutex_lock(&cpufreq_governor_mutex);
870 for_each_governor(t) {
871 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
872 - (CPUFREQ_NAME_LEN + 2)))
873 break;
874 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
875 }
876 mutex_unlock(&cpufreq_governor_mutex);
877out:
878 i += sprintf(&buf[i], "\n");
879 return i;
880}
881
882ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
883{
884 ssize_t i = 0;
885 unsigned int cpu;
886
887 for_each_cpu(cpu, mask) {
888 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u ", cpu);
889 if (i >= (PAGE_SIZE - 5))
890 break;
891 }
892
893 /* Remove the extra space at the end */
894 i--;
895
896 i += sprintf(&buf[i], "\n");
897 return i;
898}
899EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
900
901/*
902 * show_related_cpus - show the CPUs affected by each transition even if
903 * hw coordination is in use
904 */
905static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
906{
907 return cpufreq_show_cpus(policy->related_cpus, buf);
908}
909
910/*
911 * show_affected_cpus - show the CPUs affected by each transition
912 */
913static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
914{
915 return cpufreq_show_cpus(policy->cpus, buf);
916}
917
918static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
919 const char *buf, size_t count)
920{
921 unsigned int freq = 0;
922 unsigned int ret;
923
924 if (!policy->governor || !policy->governor->store_setspeed)
925 return -EINVAL;
926
927 ret = sscanf(buf, "%u", &freq);
928 if (ret != 1)
929 return -EINVAL;
930
931 policy->governor->store_setspeed(policy, freq);
932
933 return count;
934}
935
936static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
937{
938 if (!policy->governor || !policy->governor->show_setspeed)
939 return sprintf(buf, "<unsupported>\n");
940
941 return policy->governor->show_setspeed(policy, buf);
942}
943
944/*
945 * show_bios_limit - show the current cpufreq HW/BIOS limitation
946 */
947static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
948{
949 unsigned int limit;
950 int ret;
951 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
952 if (!ret)
953 return sprintf(buf, "%u\n", limit);
954 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
955}
956
957cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
958cpufreq_freq_attr_ro(cpuinfo_min_freq);
959cpufreq_freq_attr_ro(cpuinfo_max_freq);
960cpufreq_freq_attr_ro(cpuinfo_transition_latency);
961cpufreq_freq_attr_ro(scaling_available_governors);
962cpufreq_freq_attr_ro(scaling_driver);
963cpufreq_freq_attr_ro(scaling_cur_freq);
964cpufreq_freq_attr_ro(bios_limit);
965cpufreq_freq_attr_ro(related_cpus);
966cpufreq_freq_attr_ro(affected_cpus);
967cpufreq_freq_attr_rw(scaling_min_freq);
968cpufreq_freq_attr_rw(scaling_max_freq);
969cpufreq_freq_attr_rw(scaling_governor);
970cpufreq_freq_attr_rw(scaling_setspeed);
971
972static struct attribute *cpufreq_attrs[] = {
973 &cpuinfo_min_freq.attr,
974 &cpuinfo_max_freq.attr,
975 &cpuinfo_transition_latency.attr,
976 &scaling_min_freq.attr,
977 &scaling_max_freq.attr,
978 &affected_cpus.attr,
979 &related_cpus.attr,
980 &scaling_governor.attr,
981 &scaling_driver.attr,
982 &scaling_available_governors.attr,
983 &scaling_setspeed.attr,
984 NULL
985};
986ATTRIBUTE_GROUPS(cpufreq);
987
988#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
989#define to_attr(a) container_of(a, struct freq_attr, attr)
990
991static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
992{
993 struct cpufreq_policy *policy = to_policy(kobj);
994 struct freq_attr *fattr = to_attr(attr);
995 ssize_t ret = -EBUSY;
996
997 if (!fattr->show)
998 return -EIO;
999
1000 down_read(&policy->rwsem);
1001 if (likely(!policy_is_inactive(policy)))
1002 ret = fattr->show(policy, buf);
1003 up_read(&policy->rwsem);
1004
1005 return ret;
1006}
1007
1008static ssize_t store(struct kobject *kobj, struct attribute *attr,
1009 const char *buf, size_t count)
1010{
1011 struct cpufreq_policy *policy = to_policy(kobj);
1012 struct freq_attr *fattr = to_attr(attr);
1013 ssize_t ret = -EBUSY;
1014
1015 if (!fattr->store)
1016 return -EIO;
1017
1018 down_write(&policy->rwsem);
1019 if (likely(!policy_is_inactive(policy)))
1020 ret = fattr->store(policy, buf, count);
1021 up_write(&policy->rwsem);
1022
1023 return ret;
1024}
1025
1026static void cpufreq_sysfs_release(struct kobject *kobj)
1027{
1028 struct cpufreq_policy *policy = to_policy(kobj);
1029 pr_debug("last reference is dropped\n");
1030 complete(&policy->kobj_unregister);
1031}
1032
1033static const struct sysfs_ops sysfs_ops = {
1034 .show = show,
1035 .store = store,
1036};
1037
1038static const struct kobj_type ktype_cpufreq = {
1039 .sysfs_ops = &sysfs_ops,
1040 .default_groups = cpufreq_groups,
1041 .release = cpufreq_sysfs_release,
1042};
1043
1044static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu,
1045 struct device *dev)
1046{
1047 if (unlikely(!dev))
1048 return;
1049
1050 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1051 return;
1052
1053 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1054 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1055 dev_err(dev, "cpufreq symlink creation failed\n");
1056}
1057
1058static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu,
1059 struct device *dev)
1060{
1061 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1062 sysfs_remove_link(&dev->kobj, "cpufreq");
1063 cpumask_clear_cpu(cpu, policy->real_cpus);
1064}
1065
1066static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1067{
1068 struct freq_attr **drv_attr;
1069 int ret = 0;
1070
1071 /* set up files for this cpu device */
1072 drv_attr = cpufreq_driver->attr;
1073 while (drv_attr && *drv_attr) {
1074 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1075 if (ret)
1076 return ret;
1077 drv_attr++;
1078 }
1079 if (cpufreq_driver->get) {
1080 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1081 if (ret)
1082 return ret;
1083 }
1084
1085 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1086 if (ret)
1087 return ret;
1088
1089 if (cpufreq_driver->bios_limit) {
1090 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1091 if (ret)
1092 return ret;
1093 }
1094
1095 if (cpufreq_boost_supported()) {
1096 ret = sysfs_create_file(&policy->kobj, &local_boost.attr);
1097 if (ret)
1098 return ret;
1099 }
1100
1101 return 0;
1102}
1103
1104static int cpufreq_init_policy(struct cpufreq_policy *policy)
1105{
1106 struct cpufreq_governor *gov = NULL;
1107 unsigned int pol = CPUFREQ_POLICY_UNKNOWN;
1108 int ret;
1109
1110 if (has_target()) {
1111 /* Update policy governor to the one used before hotplug. */
1112 gov = get_governor(policy->last_governor);
1113 if (gov) {
1114 pr_debug("Restoring governor %s for cpu %d\n",
1115 gov->name, policy->cpu);
1116 } else {
1117 gov = get_governor(default_governor);
1118 }
1119
1120 if (!gov) {
1121 gov = cpufreq_default_governor();
1122 __module_get(gov->owner);
1123 }
1124
1125 } else {
1126
1127 /* Use the default policy if there is no last_policy. */
1128 if (policy->last_policy) {
1129 pol = policy->last_policy;
1130 } else {
1131 pol = cpufreq_parse_policy(default_governor);
1132 /*
1133 * In case the default governor is neither "performance"
1134 * nor "powersave", fall back to the initial policy
1135 * value set by the driver.
1136 */
1137 if (pol == CPUFREQ_POLICY_UNKNOWN)
1138 pol = policy->policy;
1139 }
1140 if (pol != CPUFREQ_POLICY_PERFORMANCE &&
1141 pol != CPUFREQ_POLICY_POWERSAVE)
1142 return -ENODATA;
1143 }
1144
1145 ret = cpufreq_set_policy(policy, gov, pol);
1146 if (gov)
1147 module_put(gov->owner);
1148
1149 return ret;
1150}
1151
1152static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1153{
1154 int ret = 0;
1155
1156 /* Has this CPU been taken care of already? */
1157 if (cpumask_test_cpu(cpu, policy->cpus))
1158 return 0;
1159
1160 down_write(&policy->rwsem);
1161 if (has_target())
1162 cpufreq_stop_governor(policy);
1163
1164 cpumask_set_cpu(cpu, policy->cpus);
1165
1166 if (has_target()) {
1167 ret = cpufreq_start_governor(policy);
1168 if (ret)
1169 pr_err("%s: Failed to start governor\n", __func__);
1170 }
1171 up_write(&policy->rwsem);
1172 return ret;
1173}
1174
1175void refresh_frequency_limits(struct cpufreq_policy *policy)
1176{
1177 if (!policy_is_inactive(policy)) {
1178 pr_debug("updating policy for CPU %u\n", policy->cpu);
1179
1180 cpufreq_set_policy(policy, policy->governor, policy->policy);
1181 }
1182}
1183EXPORT_SYMBOL(refresh_frequency_limits);
1184
1185static void handle_update(struct work_struct *work)
1186{
1187 struct cpufreq_policy *policy =
1188 container_of(work, struct cpufreq_policy, update);
1189
1190 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1191 down_write(&policy->rwsem);
1192 refresh_frequency_limits(policy);
1193 up_write(&policy->rwsem);
1194}
1195
1196static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1197 void *data)
1198{
1199 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1200
1201 schedule_work(&policy->update);
1202 return 0;
1203}
1204
1205static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1206 void *data)
1207{
1208 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1209
1210 schedule_work(&policy->update);
1211 return 0;
1212}
1213
1214static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1215{
1216 struct kobject *kobj;
1217 struct completion *cmp;
1218
1219 down_write(&policy->rwsem);
1220 cpufreq_stats_free_table(policy);
1221 kobj = &policy->kobj;
1222 cmp = &policy->kobj_unregister;
1223 up_write(&policy->rwsem);
1224 kobject_put(kobj);
1225
1226 /*
1227 * We need to make sure that the underlying kobj is
1228 * actually not referenced anymore by anybody before we
1229 * proceed with unloading.
1230 */
1231 pr_debug("waiting for dropping of refcount\n");
1232 wait_for_completion(cmp);
1233 pr_debug("wait complete\n");
1234}
1235
1236static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1237{
1238 struct cpufreq_policy *policy;
1239 struct device *dev = get_cpu_device(cpu);
1240 int ret;
1241
1242 if (!dev)
1243 return NULL;
1244
1245 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1246 if (!policy)
1247 return NULL;
1248
1249 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1250 goto err_free_policy;
1251
1252 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1253 goto err_free_cpumask;
1254
1255 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1256 goto err_free_rcpumask;
1257
1258 init_completion(&policy->kobj_unregister);
1259 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1260 cpufreq_global_kobject, "policy%u", cpu);
1261 if (ret) {
1262 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1263 /*
1264 * The entire policy object will be freed below, but the extra
1265 * memory allocated for the kobject name needs to be freed by
1266 * releasing the kobject.
1267 */
1268 kobject_put(&policy->kobj);
1269 goto err_free_real_cpus;
1270 }
1271
1272 freq_constraints_init(&policy->constraints);
1273
1274 policy->nb_min.notifier_call = cpufreq_notifier_min;
1275 policy->nb_max.notifier_call = cpufreq_notifier_max;
1276
1277 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN,
1278 &policy->nb_min);
1279 if (ret) {
1280 dev_err(dev, "Failed to register MIN QoS notifier: %d (CPU%u)\n",
1281 ret, cpu);
1282 goto err_kobj_remove;
1283 }
1284
1285 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX,
1286 &policy->nb_max);
1287 if (ret) {
1288 dev_err(dev, "Failed to register MAX QoS notifier: %d (CPU%u)\n",
1289 ret, cpu);
1290 goto err_min_qos_notifier;
1291 }
1292
1293 INIT_LIST_HEAD(&policy->policy_list);
1294 init_rwsem(&policy->rwsem);
1295 spin_lock_init(&policy->transition_lock);
1296 init_waitqueue_head(&policy->transition_wait);
1297 INIT_WORK(&policy->update, handle_update);
1298
1299 policy->cpu = cpu;
1300 return policy;
1301
1302err_min_qos_notifier:
1303 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1304 &policy->nb_min);
1305err_kobj_remove:
1306 cpufreq_policy_put_kobj(policy);
1307err_free_real_cpus:
1308 free_cpumask_var(policy->real_cpus);
1309err_free_rcpumask:
1310 free_cpumask_var(policy->related_cpus);
1311err_free_cpumask:
1312 free_cpumask_var(policy->cpus);
1313err_free_policy:
1314 kfree(policy);
1315
1316 return NULL;
1317}
1318
1319static void cpufreq_policy_free(struct cpufreq_policy *policy)
1320{
1321 unsigned long flags;
1322 int cpu;
1323
1324 /*
1325 * The callers must ensure the policy is inactive by now, to avoid any
1326 * races with show()/store() callbacks.
1327 */
1328 if (unlikely(!policy_is_inactive(policy)))
1329 pr_warn("%s: Freeing active policy\n", __func__);
1330
1331 /* Remove policy from list */
1332 write_lock_irqsave(&cpufreq_driver_lock, flags);
1333 list_del(&policy->policy_list);
1334
1335 for_each_cpu(cpu, policy->related_cpus)
1336 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1337 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1338
1339 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX,
1340 &policy->nb_max);
1341 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1342 &policy->nb_min);
1343
1344 /* Cancel any pending policy->update work before freeing the policy. */
1345 cancel_work_sync(&policy->update);
1346
1347 if (policy->max_freq_req) {
1348 /*
1349 * Remove max_freq_req after sending CPUFREQ_REMOVE_POLICY
1350 * notification, since CPUFREQ_CREATE_POLICY notification was
1351 * sent after adding max_freq_req earlier.
1352 */
1353 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1354 CPUFREQ_REMOVE_POLICY, policy);
1355 freq_qos_remove_request(policy->max_freq_req);
1356 }
1357
1358 freq_qos_remove_request(policy->min_freq_req);
1359 kfree(policy->min_freq_req);
1360
1361 cpufreq_policy_put_kobj(policy);
1362 free_cpumask_var(policy->real_cpus);
1363 free_cpumask_var(policy->related_cpus);
1364 free_cpumask_var(policy->cpus);
1365 kfree(policy);
1366}
1367
1368static int cpufreq_online(unsigned int cpu)
1369{
1370 struct cpufreq_policy *policy;
1371 bool new_policy;
1372 unsigned long flags;
1373 unsigned int j;
1374 int ret;
1375
1376 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1377
1378 /* Check if this CPU already has a policy to manage it */
1379 policy = per_cpu(cpufreq_cpu_data, cpu);
1380 if (policy) {
1381 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1382 if (!policy_is_inactive(policy))
1383 return cpufreq_add_policy_cpu(policy, cpu);
1384
1385 /* This is the only online CPU for the policy. Start over. */
1386 new_policy = false;
1387 down_write(&policy->rwsem);
1388 policy->cpu = cpu;
1389 policy->governor = NULL;
1390 } else {
1391 new_policy = true;
1392 policy = cpufreq_policy_alloc(cpu);
1393 if (!policy)
1394 return -ENOMEM;
1395 down_write(&policy->rwsem);
1396 }
1397
1398 if (!new_policy && cpufreq_driver->online) {
1399 /* Recover policy->cpus using related_cpus */
1400 cpumask_copy(policy->cpus, policy->related_cpus);
1401
1402 ret = cpufreq_driver->online(policy);
1403 if (ret) {
1404 pr_debug("%s: %d: initialization failed\n", __func__,
1405 __LINE__);
1406 goto out_exit_policy;
1407 }
1408 } else {
1409 cpumask_copy(policy->cpus, cpumask_of(cpu));
1410
1411 /*
1412 * Call driver. From then on the cpufreq must be able
1413 * to accept all calls to ->verify and ->setpolicy for this CPU.
1414 */
1415 ret = cpufreq_driver->init(policy);
1416 if (ret) {
1417 pr_debug("%s: %d: initialization failed\n", __func__,
1418 __LINE__);
1419 goto out_free_policy;
1420 }
1421
1422 /*
1423 * The initialization has succeeded and the policy is online.
1424 * If there is a problem with its frequency table, take it
1425 * offline and drop it.
1426 */
1427 ret = cpufreq_table_validate_and_sort(policy);
1428 if (ret)
1429 goto out_offline_policy;
1430
1431 /* related_cpus should at least include policy->cpus. */
1432 cpumask_copy(policy->related_cpus, policy->cpus);
1433 }
1434
1435 /*
1436 * affected cpus must always be the one, which are online. We aren't
1437 * managing offline cpus here.
1438 */
1439 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1440
1441 if (new_policy) {
1442 for_each_cpu(j, policy->related_cpus) {
1443 per_cpu(cpufreq_cpu_data, j) = policy;
1444 add_cpu_dev_symlink(policy, j, get_cpu_device(j));
1445 }
1446
1447 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1448 GFP_KERNEL);
1449 if (!policy->min_freq_req) {
1450 ret = -ENOMEM;
1451 goto out_destroy_policy;
1452 }
1453
1454 ret = freq_qos_add_request(&policy->constraints,
1455 policy->min_freq_req, FREQ_QOS_MIN,
1456 FREQ_QOS_MIN_DEFAULT_VALUE);
1457 if (ret < 0) {
1458 /*
1459 * So we don't call freq_qos_remove_request() for an
1460 * uninitialized request.
1461 */
1462 kfree(policy->min_freq_req);
1463 policy->min_freq_req = NULL;
1464 goto out_destroy_policy;
1465 }
1466
1467 /*
1468 * This must be initialized right here to avoid calling
1469 * freq_qos_remove_request() on uninitialized request in case
1470 * of errors.
1471 */
1472 policy->max_freq_req = policy->min_freq_req + 1;
1473
1474 ret = freq_qos_add_request(&policy->constraints,
1475 policy->max_freq_req, FREQ_QOS_MAX,
1476 FREQ_QOS_MAX_DEFAULT_VALUE);
1477 if (ret < 0) {
1478 policy->max_freq_req = NULL;
1479 goto out_destroy_policy;
1480 }
1481
1482 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1483 CPUFREQ_CREATE_POLICY, policy);
1484 }
1485
1486 if (cpufreq_driver->get && has_target()) {
1487 policy->cur = cpufreq_driver->get(policy->cpu);
1488 if (!policy->cur) {
1489 ret = -EIO;
1490 pr_err("%s: ->get() failed\n", __func__);
1491 goto out_destroy_policy;
1492 }
1493 }
1494
1495 /*
1496 * Sometimes boot loaders set CPU frequency to a value outside of
1497 * frequency table present with cpufreq core. In such cases CPU might be
1498 * unstable if it has to run on that frequency for long duration of time
1499 * and so its better to set it to a frequency which is specified in
1500 * freq-table. This also makes cpufreq stats inconsistent as
1501 * cpufreq-stats would fail to register because current frequency of CPU
1502 * isn't found in freq-table.
1503 *
1504 * Because we don't want this change to effect boot process badly, we go
1505 * for the next freq which is >= policy->cur ('cur' must be set by now,
1506 * otherwise we will end up setting freq to lowest of the table as 'cur'
1507 * is initialized to zero).
1508 *
1509 * We are passing target-freq as "policy->cur - 1" otherwise
1510 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1511 * equal to target-freq.
1512 */
1513 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1514 && has_target()) {
1515 unsigned int old_freq = policy->cur;
1516
1517 /* Are we running at unknown frequency ? */
1518 ret = cpufreq_frequency_table_get_index(policy, old_freq);
1519 if (ret == -EINVAL) {
1520 ret = __cpufreq_driver_target(policy, old_freq - 1,
1521 CPUFREQ_RELATION_L);
1522
1523 /*
1524 * Reaching here after boot in a few seconds may not
1525 * mean that system will remain stable at "unknown"
1526 * frequency for longer duration. Hence, a BUG_ON().
1527 */
1528 BUG_ON(ret);
1529 pr_info("%s: CPU%d: Running at unlisted initial frequency: %u KHz, changing to: %u KHz\n",
1530 __func__, policy->cpu, old_freq, policy->cur);
1531 }
1532 }
1533
1534 if (new_policy) {
1535 ret = cpufreq_add_dev_interface(policy);
1536 if (ret)
1537 goto out_destroy_policy;
1538
1539 cpufreq_stats_create_table(policy);
1540
1541 write_lock_irqsave(&cpufreq_driver_lock, flags);
1542 list_add(&policy->policy_list, &cpufreq_policy_list);
1543 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1544
1545 /*
1546 * Register with the energy model before
1547 * sugov_eas_rebuild_sd() is called, which will result
1548 * in rebuilding of the sched domains, which should only be done
1549 * once the energy model is properly initialized for the policy
1550 * first.
1551 *
1552 * Also, this should be called before the policy is registered
1553 * with cooling framework.
1554 */
1555 if (cpufreq_driver->register_em)
1556 cpufreq_driver->register_em(policy);
1557 }
1558
1559 ret = cpufreq_init_policy(policy);
1560 if (ret) {
1561 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1562 __func__, cpu, ret);
1563 goto out_destroy_policy;
1564 }
1565
1566 up_write(&policy->rwsem);
1567
1568 kobject_uevent(&policy->kobj, KOBJ_ADD);
1569
1570 /* Callback for handling stuff after policy is ready */
1571 if (cpufreq_driver->ready)
1572 cpufreq_driver->ready(policy);
1573
1574 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1575 policy->cdev = of_cpufreq_cooling_register(policy);
1576
1577 pr_debug("initialization complete\n");
1578
1579 return 0;
1580
1581out_destroy_policy:
1582 for_each_cpu(j, policy->real_cpus)
1583 remove_cpu_dev_symlink(policy, j, get_cpu_device(j));
1584
1585out_offline_policy:
1586 if (cpufreq_driver->offline)
1587 cpufreq_driver->offline(policy);
1588
1589out_exit_policy:
1590 if (cpufreq_driver->exit)
1591 cpufreq_driver->exit(policy);
1592
1593out_free_policy:
1594 cpumask_clear(policy->cpus);
1595 up_write(&policy->rwsem);
1596
1597 cpufreq_policy_free(policy);
1598 return ret;
1599}
1600
1601/**
1602 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1603 * @dev: CPU device.
1604 * @sif: Subsystem interface structure pointer (not used)
1605 */
1606static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1607{
1608 struct cpufreq_policy *policy;
1609 unsigned cpu = dev->id;
1610 int ret;
1611
1612 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1613
1614 if (cpu_online(cpu)) {
1615 ret = cpufreq_online(cpu);
1616 if (ret)
1617 return ret;
1618 }
1619
1620 /* Create sysfs link on CPU registration */
1621 policy = per_cpu(cpufreq_cpu_data, cpu);
1622 if (policy)
1623 add_cpu_dev_symlink(policy, cpu, dev);
1624
1625 return 0;
1626}
1627
1628static void __cpufreq_offline(unsigned int cpu, struct cpufreq_policy *policy)
1629{
1630 int ret;
1631
1632 if (has_target())
1633 cpufreq_stop_governor(policy);
1634
1635 cpumask_clear_cpu(cpu, policy->cpus);
1636
1637 if (!policy_is_inactive(policy)) {
1638 /* Nominate a new CPU if necessary. */
1639 if (cpu == policy->cpu)
1640 policy->cpu = cpumask_any(policy->cpus);
1641
1642 /* Start the governor again for the active policy. */
1643 if (has_target()) {
1644 ret = cpufreq_start_governor(policy);
1645 if (ret)
1646 pr_err("%s: Failed to start governor\n", __func__);
1647 }
1648
1649 return;
1650 }
1651
1652 if (has_target())
1653 strscpy(policy->last_governor, policy->governor->name,
1654 CPUFREQ_NAME_LEN);
1655 else
1656 policy->last_policy = policy->policy;
1657
1658 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1659 cpufreq_cooling_unregister(policy->cdev);
1660 policy->cdev = NULL;
1661 }
1662
1663 if (has_target())
1664 cpufreq_exit_governor(policy);
1665
1666 /*
1667 * Perform the ->offline() during light-weight tear-down, as
1668 * that allows fast recovery when the CPU comes back.
1669 */
1670 if (cpufreq_driver->offline) {
1671 cpufreq_driver->offline(policy);
1672 } else if (cpufreq_driver->exit) {
1673 cpufreq_driver->exit(policy);
1674 policy->freq_table = NULL;
1675 }
1676}
1677
1678static int cpufreq_offline(unsigned int cpu)
1679{
1680 struct cpufreq_policy *policy;
1681
1682 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1683
1684 policy = cpufreq_cpu_get_raw(cpu);
1685 if (!policy) {
1686 pr_debug("%s: No cpu_data found\n", __func__);
1687 return 0;
1688 }
1689
1690 down_write(&policy->rwsem);
1691
1692 __cpufreq_offline(cpu, policy);
1693
1694 up_write(&policy->rwsem);
1695 return 0;
1696}
1697
1698/*
1699 * cpufreq_remove_dev - remove a CPU device
1700 *
1701 * Removes the cpufreq interface for a CPU device.
1702 */
1703static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1704{
1705 unsigned int cpu = dev->id;
1706 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1707
1708 if (!policy)
1709 return;
1710
1711 down_write(&policy->rwsem);
1712
1713 if (cpu_online(cpu))
1714 __cpufreq_offline(cpu, policy);
1715
1716 remove_cpu_dev_symlink(policy, cpu, dev);
1717
1718 if (!cpumask_empty(policy->real_cpus)) {
1719 up_write(&policy->rwsem);
1720 return;
1721 }
1722
1723 /* We did light-weight exit earlier, do full tear down now */
1724 if (cpufreq_driver->offline)
1725 cpufreq_driver->exit(policy);
1726
1727 up_write(&policy->rwsem);
1728
1729 cpufreq_policy_free(policy);
1730}
1731
1732/**
1733 * cpufreq_out_of_sync - Fix up actual and saved CPU frequency difference.
1734 * @policy: Policy managing CPUs.
1735 * @new_freq: New CPU frequency.
1736 *
1737 * Adjust to the current frequency first and clean up later by either calling
1738 * cpufreq_update_policy(), or scheduling handle_update().
1739 */
1740static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1741 unsigned int new_freq)
1742{
1743 struct cpufreq_freqs freqs;
1744
1745 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1746 policy->cur, new_freq);
1747
1748 freqs.old = policy->cur;
1749 freqs.new = new_freq;
1750
1751 cpufreq_freq_transition_begin(policy, &freqs);
1752 cpufreq_freq_transition_end(policy, &freqs, 0);
1753}
1754
1755static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1756{
1757 unsigned int new_freq;
1758
1759 new_freq = cpufreq_driver->get(policy->cpu);
1760 if (!new_freq)
1761 return 0;
1762
1763 /*
1764 * If fast frequency switching is used with the given policy, the check
1765 * against policy->cur is pointless, so skip it in that case.
1766 */
1767 if (policy->fast_switch_enabled || !has_target())
1768 return new_freq;
1769
1770 if (policy->cur != new_freq) {
1771 /*
1772 * For some platforms, the frequency returned by hardware may be
1773 * slightly different from what is provided in the frequency
1774 * table, for example hardware may return 499 MHz instead of 500
1775 * MHz. In such cases it is better to avoid getting into
1776 * unnecessary frequency updates.
1777 */
1778 if (abs(policy->cur - new_freq) < KHZ_PER_MHZ)
1779 return policy->cur;
1780
1781 cpufreq_out_of_sync(policy, new_freq);
1782 if (update)
1783 schedule_work(&policy->update);
1784 }
1785
1786 return new_freq;
1787}
1788
1789/**
1790 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1791 * @cpu: CPU number
1792 *
1793 * This is the last known freq, without actually getting it from the driver.
1794 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1795 */
1796unsigned int cpufreq_quick_get(unsigned int cpu)
1797{
1798 struct cpufreq_policy *policy;
1799 unsigned int ret_freq = 0;
1800 unsigned long flags;
1801
1802 read_lock_irqsave(&cpufreq_driver_lock, flags);
1803
1804 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1805 ret_freq = cpufreq_driver->get(cpu);
1806 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1807 return ret_freq;
1808 }
1809
1810 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1811
1812 policy = cpufreq_cpu_get(cpu);
1813 if (policy) {
1814 ret_freq = policy->cur;
1815 cpufreq_cpu_put(policy);
1816 }
1817
1818 return ret_freq;
1819}
1820EXPORT_SYMBOL(cpufreq_quick_get);
1821
1822/**
1823 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1824 * @cpu: CPU number
1825 *
1826 * Just return the max possible frequency for a given CPU.
1827 */
1828unsigned int cpufreq_quick_get_max(unsigned int cpu)
1829{
1830 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1831 unsigned int ret_freq = 0;
1832
1833 if (policy) {
1834 ret_freq = policy->max;
1835 cpufreq_cpu_put(policy);
1836 }
1837
1838 return ret_freq;
1839}
1840EXPORT_SYMBOL(cpufreq_quick_get_max);
1841
1842/**
1843 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU
1844 * @cpu: CPU number
1845 *
1846 * The default return value is the max_freq field of cpuinfo.
1847 */
1848__weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
1849{
1850 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1851 unsigned int ret_freq = 0;
1852
1853 if (policy) {
1854 ret_freq = policy->cpuinfo.max_freq;
1855 cpufreq_cpu_put(policy);
1856 }
1857
1858 return ret_freq;
1859}
1860EXPORT_SYMBOL(cpufreq_get_hw_max_freq);
1861
1862static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1863{
1864 if (unlikely(policy_is_inactive(policy)))
1865 return 0;
1866
1867 return cpufreq_verify_current_freq(policy, true);
1868}
1869
1870/**
1871 * cpufreq_get - get the current CPU frequency (in kHz)
1872 * @cpu: CPU number
1873 *
1874 * Get the CPU current (static) CPU frequency
1875 */
1876unsigned int cpufreq_get(unsigned int cpu)
1877{
1878 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1879 unsigned int ret_freq = 0;
1880
1881 if (policy) {
1882 down_read(&policy->rwsem);
1883 if (cpufreq_driver->get)
1884 ret_freq = __cpufreq_get(policy);
1885 up_read(&policy->rwsem);
1886
1887 cpufreq_cpu_put(policy);
1888 }
1889
1890 return ret_freq;
1891}
1892EXPORT_SYMBOL(cpufreq_get);
1893
1894static struct subsys_interface cpufreq_interface = {
1895 .name = "cpufreq",
1896 .subsys = &cpu_subsys,
1897 .add_dev = cpufreq_add_dev,
1898 .remove_dev = cpufreq_remove_dev,
1899};
1900
1901/*
1902 * In case platform wants some specific frequency to be configured
1903 * during suspend..
1904 */
1905int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1906{
1907 int ret;
1908
1909 if (!policy->suspend_freq) {
1910 pr_debug("%s: suspend_freq not defined\n", __func__);
1911 return 0;
1912 }
1913
1914 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1915 policy->suspend_freq);
1916
1917 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1918 CPUFREQ_RELATION_H);
1919 if (ret)
1920 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1921 __func__, policy->suspend_freq, ret);
1922
1923 return ret;
1924}
1925EXPORT_SYMBOL(cpufreq_generic_suspend);
1926
1927/**
1928 * cpufreq_suspend() - Suspend CPUFreq governors.
1929 *
1930 * Called during system wide Suspend/Hibernate cycles for suspending governors
1931 * as some platforms can't change frequency after this point in suspend cycle.
1932 * Because some of the devices (like: i2c, regulators, etc) they use for
1933 * changing frequency are suspended quickly after this point.
1934 */
1935void cpufreq_suspend(void)
1936{
1937 struct cpufreq_policy *policy;
1938
1939 if (!cpufreq_driver)
1940 return;
1941
1942 if (!has_target() && !cpufreq_driver->suspend)
1943 goto suspend;
1944
1945 pr_debug("%s: Suspending Governors\n", __func__);
1946
1947 for_each_active_policy(policy) {
1948 if (has_target()) {
1949 down_write(&policy->rwsem);
1950 cpufreq_stop_governor(policy);
1951 up_write(&policy->rwsem);
1952 }
1953
1954 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1955 pr_err("%s: Failed to suspend driver: %s\n", __func__,
1956 cpufreq_driver->name);
1957 }
1958
1959suspend:
1960 cpufreq_suspended = true;
1961}
1962
1963/**
1964 * cpufreq_resume() - Resume CPUFreq governors.
1965 *
1966 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1967 * are suspended with cpufreq_suspend().
1968 */
1969void cpufreq_resume(void)
1970{
1971 struct cpufreq_policy *policy;
1972 int ret;
1973
1974 if (!cpufreq_driver)
1975 return;
1976
1977 if (unlikely(!cpufreq_suspended))
1978 return;
1979
1980 cpufreq_suspended = false;
1981
1982 if (!has_target() && !cpufreq_driver->resume)
1983 return;
1984
1985 pr_debug("%s: Resuming Governors\n", __func__);
1986
1987 for_each_active_policy(policy) {
1988 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1989 pr_err("%s: Failed to resume driver: %s\n", __func__,
1990 cpufreq_driver->name);
1991 } else if (has_target()) {
1992 down_write(&policy->rwsem);
1993 ret = cpufreq_start_governor(policy);
1994 up_write(&policy->rwsem);
1995
1996 if (ret)
1997 pr_err("%s: Failed to start governor for CPU%u's policy\n",
1998 __func__, policy->cpu);
1999 }
2000 }
2001}
2002
2003/**
2004 * cpufreq_driver_test_flags - Test cpufreq driver's flags against given ones.
2005 * @flags: Flags to test against the current cpufreq driver's flags.
2006 *
2007 * Assumes that the driver is there, so callers must ensure that this is the
2008 * case.
2009 */
2010bool cpufreq_driver_test_flags(u16 flags)
2011{
2012 return !!(cpufreq_driver->flags & flags);
2013}
2014
2015/**
2016 * cpufreq_get_current_driver - Return the current driver's name.
2017 *
2018 * Return the name string of the currently registered cpufreq driver or NULL if
2019 * none.
2020 */
2021const char *cpufreq_get_current_driver(void)
2022{
2023 if (cpufreq_driver)
2024 return cpufreq_driver->name;
2025
2026 return NULL;
2027}
2028EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
2029
2030/**
2031 * cpufreq_get_driver_data - Return current driver data.
2032 *
2033 * Return the private data of the currently registered cpufreq driver, or NULL
2034 * if no cpufreq driver has been registered.
2035 */
2036void *cpufreq_get_driver_data(void)
2037{
2038 if (cpufreq_driver)
2039 return cpufreq_driver->driver_data;
2040
2041 return NULL;
2042}
2043EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
2044
2045/*********************************************************************
2046 * NOTIFIER LISTS INTERFACE *
2047 *********************************************************************/
2048
2049/**
2050 * cpufreq_register_notifier - Register a notifier with cpufreq.
2051 * @nb: notifier function to register.
2052 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER.
2053 *
2054 * Add a notifier to one of two lists: either a list of notifiers that run on
2055 * clock rate changes (once before and once after every transition), or a list
2056 * of notifiers that ron on cpufreq policy changes.
2057 *
2058 * This function may sleep and it has the same return values as
2059 * blocking_notifier_chain_register().
2060 */
2061int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
2062{
2063 int ret;
2064
2065 if (cpufreq_disabled())
2066 return -EINVAL;
2067
2068 switch (list) {
2069 case CPUFREQ_TRANSITION_NOTIFIER:
2070 mutex_lock(&cpufreq_fast_switch_lock);
2071
2072 if (cpufreq_fast_switch_count > 0) {
2073 mutex_unlock(&cpufreq_fast_switch_lock);
2074 return -EBUSY;
2075 }
2076 ret = srcu_notifier_chain_register(
2077 &cpufreq_transition_notifier_list, nb);
2078 if (!ret)
2079 cpufreq_fast_switch_count--;
2080
2081 mutex_unlock(&cpufreq_fast_switch_lock);
2082 break;
2083 case CPUFREQ_POLICY_NOTIFIER:
2084 ret = blocking_notifier_chain_register(
2085 &cpufreq_policy_notifier_list, nb);
2086 break;
2087 default:
2088 ret = -EINVAL;
2089 }
2090
2091 return ret;
2092}
2093EXPORT_SYMBOL(cpufreq_register_notifier);
2094
2095/**
2096 * cpufreq_unregister_notifier - Unregister a notifier from cpufreq.
2097 * @nb: notifier block to be unregistered.
2098 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER.
2099 *
2100 * Remove a notifier from one of the cpufreq notifier lists.
2101 *
2102 * This function may sleep and it has the same return values as
2103 * blocking_notifier_chain_unregister().
2104 */
2105int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
2106{
2107 int ret;
2108
2109 if (cpufreq_disabled())
2110 return -EINVAL;
2111
2112 switch (list) {
2113 case CPUFREQ_TRANSITION_NOTIFIER:
2114 mutex_lock(&cpufreq_fast_switch_lock);
2115
2116 ret = srcu_notifier_chain_unregister(
2117 &cpufreq_transition_notifier_list, nb);
2118 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
2119 cpufreq_fast_switch_count++;
2120
2121 mutex_unlock(&cpufreq_fast_switch_lock);
2122 break;
2123 case CPUFREQ_POLICY_NOTIFIER:
2124 ret = blocking_notifier_chain_unregister(
2125 &cpufreq_policy_notifier_list, nb);
2126 break;
2127 default:
2128 ret = -EINVAL;
2129 }
2130
2131 return ret;
2132}
2133EXPORT_SYMBOL(cpufreq_unregister_notifier);
2134
2135
2136/*********************************************************************
2137 * GOVERNORS *
2138 *********************************************************************/
2139
2140/**
2141 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
2142 * @policy: cpufreq policy to switch the frequency for.
2143 * @target_freq: New frequency to set (may be approximate).
2144 *
2145 * Carry out a fast frequency switch without sleeping.
2146 *
2147 * The driver's ->fast_switch() callback invoked by this function must be
2148 * suitable for being called from within RCU-sched read-side critical sections
2149 * and it is expected to select the minimum available frequency greater than or
2150 * equal to @target_freq (CPUFREQ_RELATION_L).
2151 *
2152 * This function must not be called if policy->fast_switch_enabled is unset.
2153 *
2154 * Governors calling this function must guarantee that it will never be invoked
2155 * twice in parallel for the same policy and that it will never be called in
2156 * parallel with either ->target() or ->target_index() for the same policy.
2157 *
2158 * Returns the actual frequency set for the CPU.
2159 *
2160 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2161 * error condition, the hardware configuration must be preserved.
2162 */
2163unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2164 unsigned int target_freq)
2165{
2166 unsigned int freq;
2167 int cpu;
2168
2169 target_freq = clamp_val(target_freq, policy->min, policy->max);
2170 freq = cpufreq_driver->fast_switch(policy, target_freq);
2171
2172 if (!freq)
2173 return 0;
2174
2175 policy->cur = freq;
2176 arch_set_freq_scale(policy->related_cpus, freq,
2177 arch_scale_freq_ref(policy->cpu));
2178 cpufreq_stats_record_transition(policy, freq);
2179
2180 if (trace_cpu_frequency_enabled()) {
2181 for_each_cpu(cpu, policy->cpus)
2182 trace_cpu_frequency(freq, cpu);
2183 }
2184
2185 return freq;
2186}
2187EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2188
2189/**
2190 * cpufreq_driver_adjust_perf - Adjust CPU performance level in one go.
2191 * @cpu: Target CPU.
2192 * @min_perf: Minimum (required) performance level (units of @capacity).
2193 * @target_perf: Target (desired) performance level (units of @capacity).
2194 * @capacity: Capacity of the target CPU.
2195 *
2196 * Carry out a fast performance level switch of @cpu without sleeping.
2197 *
2198 * The driver's ->adjust_perf() callback invoked by this function must be
2199 * suitable for being called from within RCU-sched read-side critical sections
2200 * and it is expected to select a suitable performance level equal to or above
2201 * @min_perf and preferably equal to or below @target_perf.
2202 *
2203 * This function must not be called if policy->fast_switch_enabled is unset.
2204 *
2205 * Governors calling this function must guarantee that it will never be invoked
2206 * twice in parallel for the same CPU and that it will never be called in
2207 * parallel with either ->target() or ->target_index() or ->fast_switch() for
2208 * the same CPU.
2209 */
2210void cpufreq_driver_adjust_perf(unsigned int cpu,
2211 unsigned long min_perf,
2212 unsigned long target_perf,
2213 unsigned long capacity)
2214{
2215 cpufreq_driver->adjust_perf(cpu, min_perf, target_perf, capacity);
2216}
2217
2218/**
2219 * cpufreq_driver_has_adjust_perf - Check "direct fast switch" callback.
2220 *
2221 * Return 'true' if the ->adjust_perf callback is present for the
2222 * current driver or 'false' otherwise.
2223 */
2224bool cpufreq_driver_has_adjust_perf(void)
2225{
2226 return !!cpufreq_driver->adjust_perf;
2227}
2228
2229/* Must set freqs->new to intermediate frequency */
2230static int __target_intermediate(struct cpufreq_policy *policy,
2231 struct cpufreq_freqs *freqs, int index)
2232{
2233 int ret;
2234
2235 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2236
2237 /* We don't need to switch to intermediate freq */
2238 if (!freqs->new)
2239 return 0;
2240
2241 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2242 __func__, policy->cpu, freqs->old, freqs->new);
2243
2244 cpufreq_freq_transition_begin(policy, freqs);
2245 ret = cpufreq_driver->target_intermediate(policy, index);
2246 cpufreq_freq_transition_end(policy, freqs, ret);
2247
2248 if (ret)
2249 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2250 __func__, ret);
2251
2252 return ret;
2253}
2254
2255static int __target_index(struct cpufreq_policy *policy, int index)
2256{
2257 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2258 unsigned int restore_freq, intermediate_freq = 0;
2259 unsigned int newfreq = policy->freq_table[index].frequency;
2260 int retval = -EINVAL;
2261 bool notify;
2262
2263 if (newfreq == policy->cur)
2264 return 0;
2265
2266 /* Save last value to restore later on errors */
2267 restore_freq = policy->cur;
2268
2269 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2270 if (notify) {
2271 /* Handle switching to intermediate frequency */
2272 if (cpufreq_driver->get_intermediate) {
2273 retval = __target_intermediate(policy, &freqs, index);
2274 if (retval)
2275 return retval;
2276
2277 intermediate_freq = freqs.new;
2278 /* Set old freq to intermediate */
2279 if (intermediate_freq)
2280 freqs.old = freqs.new;
2281 }
2282
2283 freqs.new = newfreq;
2284 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2285 __func__, policy->cpu, freqs.old, freqs.new);
2286
2287 cpufreq_freq_transition_begin(policy, &freqs);
2288 }
2289
2290 retval = cpufreq_driver->target_index(policy, index);
2291 if (retval)
2292 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2293 retval);
2294
2295 if (notify) {
2296 cpufreq_freq_transition_end(policy, &freqs, retval);
2297
2298 /*
2299 * Failed after setting to intermediate freq? Driver should have
2300 * reverted back to initial frequency and so should we. Check
2301 * here for intermediate_freq instead of get_intermediate, in
2302 * case we haven't switched to intermediate freq at all.
2303 */
2304 if (unlikely(retval && intermediate_freq)) {
2305 freqs.old = intermediate_freq;
2306 freqs.new = restore_freq;
2307 cpufreq_freq_transition_begin(policy, &freqs);
2308 cpufreq_freq_transition_end(policy, &freqs, 0);
2309 }
2310 }
2311
2312 return retval;
2313}
2314
2315int __cpufreq_driver_target(struct cpufreq_policy *policy,
2316 unsigned int target_freq,
2317 unsigned int relation)
2318{
2319 unsigned int old_target_freq = target_freq;
2320
2321 if (cpufreq_disabled())
2322 return -ENODEV;
2323
2324 target_freq = __resolve_freq(policy, target_freq, relation);
2325
2326 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2327 policy->cpu, target_freq, relation, old_target_freq);
2328
2329 /*
2330 * This might look like a redundant call as we are checking it again
2331 * after finding index. But it is left intentionally for cases where
2332 * exactly same freq is called again and so we can save on few function
2333 * calls.
2334 */
2335 if (target_freq == policy->cur &&
2336 !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS))
2337 return 0;
2338
2339 if (cpufreq_driver->target) {
2340 /*
2341 * If the driver hasn't setup a single inefficient frequency,
2342 * it's unlikely it knows how to decode CPUFREQ_RELATION_E.
2343 */
2344 if (!policy->efficiencies_available)
2345 relation &= ~CPUFREQ_RELATION_E;
2346
2347 return cpufreq_driver->target(policy, target_freq, relation);
2348 }
2349
2350 if (!cpufreq_driver->target_index)
2351 return -EINVAL;
2352
2353 return __target_index(policy, policy->cached_resolved_idx);
2354}
2355EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2356
2357int cpufreq_driver_target(struct cpufreq_policy *policy,
2358 unsigned int target_freq,
2359 unsigned int relation)
2360{
2361 int ret;
2362
2363 down_write(&policy->rwsem);
2364
2365 ret = __cpufreq_driver_target(policy, target_freq, relation);
2366
2367 up_write(&policy->rwsem);
2368
2369 return ret;
2370}
2371EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2372
2373__weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2374{
2375 return NULL;
2376}
2377
2378static int cpufreq_init_governor(struct cpufreq_policy *policy)
2379{
2380 int ret;
2381
2382 /* Don't start any governor operations if we are entering suspend */
2383 if (cpufreq_suspended)
2384 return 0;
2385 /*
2386 * Governor might not be initiated here if ACPI _PPC changed
2387 * notification happened, so check it.
2388 */
2389 if (!policy->governor)
2390 return -EINVAL;
2391
2392 /* Platform doesn't want dynamic frequency switching ? */
2393 if (policy->governor->flags & CPUFREQ_GOV_DYNAMIC_SWITCHING &&
2394 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2395 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2396
2397 if (gov) {
2398 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2399 policy->governor->name, gov->name);
2400 policy->governor = gov;
2401 } else {
2402 return -EINVAL;
2403 }
2404 }
2405
2406 if (!try_module_get(policy->governor->owner))
2407 return -EINVAL;
2408
2409 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2410
2411 if (policy->governor->init) {
2412 ret = policy->governor->init(policy);
2413 if (ret) {
2414 module_put(policy->governor->owner);
2415 return ret;
2416 }
2417 }
2418
2419 policy->strict_target = !!(policy->governor->flags & CPUFREQ_GOV_STRICT_TARGET);
2420
2421 return 0;
2422}
2423
2424static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2425{
2426 if (cpufreq_suspended || !policy->governor)
2427 return;
2428
2429 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2430
2431 if (policy->governor->exit)
2432 policy->governor->exit(policy);
2433
2434 module_put(policy->governor->owner);
2435}
2436
2437int cpufreq_start_governor(struct cpufreq_policy *policy)
2438{
2439 int ret;
2440
2441 if (cpufreq_suspended)
2442 return 0;
2443
2444 if (!policy->governor)
2445 return -EINVAL;
2446
2447 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2448
2449 if (cpufreq_driver->get)
2450 cpufreq_verify_current_freq(policy, false);
2451
2452 if (policy->governor->start) {
2453 ret = policy->governor->start(policy);
2454 if (ret)
2455 return ret;
2456 }
2457
2458 if (policy->governor->limits)
2459 policy->governor->limits(policy);
2460
2461 return 0;
2462}
2463
2464void cpufreq_stop_governor(struct cpufreq_policy *policy)
2465{
2466 if (cpufreq_suspended || !policy->governor)
2467 return;
2468
2469 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2470
2471 if (policy->governor->stop)
2472 policy->governor->stop(policy);
2473}
2474
2475static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2476{
2477 if (cpufreq_suspended || !policy->governor)
2478 return;
2479
2480 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2481
2482 if (policy->governor->limits)
2483 policy->governor->limits(policy);
2484}
2485
2486int cpufreq_register_governor(struct cpufreq_governor *governor)
2487{
2488 int err;
2489
2490 if (!governor)
2491 return -EINVAL;
2492
2493 if (cpufreq_disabled())
2494 return -ENODEV;
2495
2496 mutex_lock(&cpufreq_governor_mutex);
2497
2498 err = -EBUSY;
2499 if (!find_governor(governor->name)) {
2500 err = 0;
2501 list_add(&governor->governor_list, &cpufreq_governor_list);
2502 }
2503
2504 mutex_unlock(&cpufreq_governor_mutex);
2505 return err;
2506}
2507EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2508
2509void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2510{
2511 struct cpufreq_policy *policy;
2512 unsigned long flags;
2513
2514 if (!governor)
2515 return;
2516
2517 if (cpufreq_disabled())
2518 return;
2519
2520 /* clear last_governor for all inactive policies */
2521 read_lock_irqsave(&cpufreq_driver_lock, flags);
2522 for_each_inactive_policy(policy) {
2523 if (!strcmp(policy->last_governor, governor->name)) {
2524 policy->governor = NULL;
2525 strcpy(policy->last_governor, "\0");
2526 }
2527 }
2528 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2529
2530 mutex_lock(&cpufreq_governor_mutex);
2531 list_del(&governor->governor_list);
2532 mutex_unlock(&cpufreq_governor_mutex);
2533}
2534EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2535
2536
2537/*********************************************************************
2538 * POLICY INTERFACE *
2539 *********************************************************************/
2540
2541/**
2542 * cpufreq_get_policy - get the current cpufreq_policy
2543 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2544 * is written
2545 * @cpu: CPU to find the policy for
2546 *
2547 * Reads the current cpufreq policy.
2548 */
2549int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2550{
2551 struct cpufreq_policy *cpu_policy;
2552 if (!policy)
2553 return -EINVAL;
2554
2555 cpu_policy = cpufreq_cpu_get(cpu);
2556 if (!cpu_policy)
2557 return -EINVAL;
2558
2559 memcpy(policy, cpu_policy, sizeof(*policy));
2560
2561 cpufreq_cpu_put(cpu_policy);
2562 return 0;
2563}
2564EXPORT_SYMBOL(cpufreq_get_policy);
2565
2566/**
2567 * cpufreq_set_policy - Modify cpufreq policy parameters.
2568 * @policy: Policy object to modify.
2569 * @new_gov: Policy governor pointer.
2570 * @new_pol: Policy value (for drivers with built-in governors).
2571 *
2572 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
2573 * limits to be set for the policy, update @policy with the verified limits
2574 * values and either invoke the driver's ->setpolicy() callback (if present) or
2575 * carry out a governor update for @policy. That is, run the current governor's
2576 * ->limits() callback (if @new_gov points to the same object as the one in
2577 * @policy) or replace the governor for @policy with @new_gov.
2578 *
2579 * The cpuinfo part of @policy is not updated by this function.
2580 */
2581static int cpufreq_set_policy(struct cpufreq_policy *policy,
2582 struct cpufreq_governor *new_gov,
2583 unsigned int new_pol)
2584{
2585 struct cpufreq_policy_data new_data;
2586 struct cpufreq_governor *old_gov;
2587 int ret;
2588
2589 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2590 new_data.freq_table = policy->freq_table;
2591 new_data.cpu = policy->cpu;
2592 /*
2593 * PM QoS framework collects all the requests from users and provide us
2594 * the final aggregated value here.
2595 */
2596 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN);
2597 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX);
2598
2599 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2600 new_data.cpu, new_data.min, new_data.max);
2601
2602 /*
2603 * Verify that the CPU speed can be set within these limits and make sure
2604 * that min <= max.
2605 */
2606 ret = cpufreq_driver->verify(&new_data);
2607 if (ret)
2608 return ret;
2609
2610 /*
2611 * Resolve policy min/max to available frequencies. It ensures
2612 * no frequency resolution will neither overshoot the requested maximum
2613 * nor undershoot the requested minimum.
2614 */
2615 policy->min = new_data.min;
2616 policy->max = new_data.max;
2617 policy->min = __resolve_freq(policy, policy->min, CPUFREQ_RELATION_L);
2618 policy->max = __resolve_freq(policy, policy->max, CPUFREQ_RELATION_H);
2619 trace_cpu_frequency_limits(policy);
2620
2621 policy->cached_target_freq = UINT_MAX;
2622
2623 pr_debug("new min and max freqs are %u - %u kHz\n",
2624 policy->min, policy->max);
2625
2626 if (cpufreq_driver->setpolicy) {
2627 policy->policy = new_pol;
2628 pr_debug("setting range\n");
2629 return cpufreq_driver->setpolicy(policy);
2630 }
2631
2632 if (new_gov == policy->governor) {
2633 pr_debug("governor limits update\n");
2634 cpufreq_governor_limits(policy);
2635 return 0;
2636 }
2637
2638 pr_debug("governor switch\n");
2639
2640 /* save old, working values */
2641 old_gov = policy->governor;
2642 /* end old governor */
2643 if (old_gov) {
2644 cpufreq_stop_governor(policy);
2645 cpufreq_exit_governor(policy);
2646 }
2647
2648 /* start new governor */
2649 policy->governor = new_gov;
2650 ret = cpufreq_init_governor(policy);
2651 if (!ret) {
2652 ret = cpufreq_start_governor(policy);
2653 if (!ret) {
2654 pr_debug("governor change\n");
2655 return 0;
2656 }
2657 cpufreq_exit_governor(policy);
2658 }
2659
2660 /* new governor failed, so re-start old one */
2661 pr_debug("starting governor %s failed\n", policy->governor->name);
2662 if (old_gov) {
2663 policy->governor = old_gov;
2664 if (cpufreq_init_governor(policy))
2665 policy->governor = NULL;
2666 else
2667 cpufreq_start_governor(policy);
2668 }
2669
2670 return ret;
2671}
2672
2673/**
2674 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2675 * @cpu: CPU to re-evaluate the policy for.
2676 *
2677 * Update the current frequency for the cpufreq policy of @cpu and use
2678 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2679 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2680 * for the policy in question, among other things.
2681 */
2682void cpufreq_update_policy(unsigned int cpu)
2683{
2684 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2685
2686 if (!policy)
2687 return;
2688
2689 /*
2690 * BIOS might change freq behind our back
2691 * -> ask driver for current freq and notify governors about a change
2692 */
2693 if (cpufreq_driver->get && has_target() &&
2694 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2695 goto unlock;
2696
2697 refresh_frequency_limits(policy);
2698
2699unlock:
2700 cpufreq_cpu_release(policy);
2701}
2702EXPORT_SYMBOL(cpufreq_update_policy);
2703
2704/**
2705 * cpufreq_update_limits - Update policy limits for a given CPU.
2706 * @cpu: CPU to update the policy limits for.
2707 *
2708 * Invoke the driver's ->update_limits callback if present or call
2709 * cpufreq_update_policy() for @cpu.
2710 */
2711void cpufreq_update_limits(unsigned int cpu)
2712{
2713 if (cpufreq_driver->update_limits)
2714 cpufreq_driver->update_limits(cpu);
2715 else
2716 cpufreq_update_policy(cpu);
2717}
2718EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2719
2720/*********************************************************************
2721 * BOOST *
2722 *********************************************************************/
2723static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state)
2724{
2725 int ret;
2726
2727 if (!policy->freq_table)
2728 return -ENXIO;
2729
2730 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
2731 if (ret) {
2732 pr_err("%s: Policy frequency update failed\n", __func__);
2733 return ret;
2734 }
2735
2736 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
2737 if (ret < 0)
2738 return ret;
2739
2740 return 0;
2741}
2742
2743int cpufreq_boost_trigger_state(int state)
2744{
2745 struct cpufreq_policy *policy;
2746 unsigned long flags;
2747 int ret = 0;
2748
2749 if (cpufreq_driver->boost_enabled == state)
2750 return 0;
2751
2752 write_lock_irqsave(&cpufreq_driver_lock, flags);
2753 cpufreq_driver->boost_enabled = state;
2754 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2755
2756 cpus_read_lock();
2757 for_each_active_policy(policy) {
2758 ret = cpufreq_driver->set_boost(policy, state);
2759 if (ret)
2760 goto err_reset_state;
2761
2762 policy->boost_enabled = state;
2763 }
2764 cpus_read_unlock();
2765
2766 return 0;
2767
2768err_reset_state:
2769 cpus_read_unlock();
2770
2771 write_lock_irqsave(&cpufreq_driver_lock, flags);
2772 cpufreq_driver->boost_enabled = !state;
2773 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2774
2775 pr_err("%s: Cannot %s BOOST\n",
2776 __func__, state ? "enable" : "disable");
2777
2778 return ret;
2779}
2780
2781static bool cpufreq_boost_supported(void)
2782{
2783 return cpufreq_driver->set_boost;
2784}
2785
2786static int create_boost_sysfs_file(void)
2787{
2788 int ret;
2789
2790 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2791 if (ret)
2792 pr_err("%s: cannot register global BOOST sysfs file\n",
2793 __func__);
2794
2795 return ret;
2796}
2797
2798static void remove_boost_sysfs_file(void)
2799{
2800 if (cpufreq_boost_supported())
2801 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2802}
2803
2804int cpufreq_enable_boost_support(void)
2805{
2806 if (!cpufreq_driver)
2807 return -EINVAL;
2808
2809 if (cpufreq_boost_supported())
2810 return 0;
2811
2812 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2813
2814 /* This will get removed on driver unregister */
2815 return create_boost_sysfs_file();
2816}
2817EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2818
2819int cpufreq_boost_enabled(void)
2820{
2821 return cpufreq_driver->boost_enabled;
2822}
2823EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2824
2825/*********************************************************************
2826 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2827 *********************************************************************/
2828static enum cpuhp_state hp_online;
2829
2830static int cpuhp_cpufreq_online(unsigned int cpu)
2831{
2832 cpufreq_online(cpu);
2833
2834 return 0;
2835}
2836
2837static int cpuhp_cpufreq_offline(unsigned int cpu)
2838{
2839 cpufreq_offline(cpu);
2840
2841 return 0;
2842}
2843
2844/**
2845 * cpufreq_register_driver - register a CPU Frequency driver
2846 * @driver_data: A struct cpufreq_driver containing the values#
2847 * submitted by the CPU Frequency driver.
2848 *
2849 * Registers a CPU Frequency driver to this core code. This code
2850 * returns zero on success, -EEXIST when another driver got here first
2851 * (and isn't unregistered in the meantime).
2852 *
2853 */
2854int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2855{
2856 unsigned long flags;
2857 int ret;
2858
2859 if (cpufreq_disabled())
2860 return -ENODEV;
2861
2862 /*
2863 * The cpufreq core depends heavily on the availability of device
2864 * structure, make sure they are available before proceeding further.
2865 */
2866 if (!get_cpu_device(0))
2867 return -EPROBE_DEFER;
2868
2869 if (!driver_data || !driver_data->verify || !driver_data->init ||
2870 !(driver_data->setpolicy || driver_data->target_index ||
2871 driver_data->target) ||
2872 (driver_data->setpolicy && (driver_data->target_index ||
2873 driver_data->target)) ||
2874 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2875 (!driver_data->online != !driver_data->offline) ||
2876 (driver_data->adjust_perf && !driver_data->fast_switch))
2877 return -EINVAL;
2878
2879 pr_debug("trying to register driver %s\n", driver_data->name);
2880
2881 /* Protect against concurrent CPU online/offline. */
2882 cpus_read_lock();
2883
2884 write_lock_irqsave(&cpufreq_driver_lock, flags);
2885 if (cpufreq_driver) {
2886 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2887 ret = -EEXIST;
2888 goto out;
2889 }
2890 cpufreq_driver = driver_data;
2891 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2892
2893 /*
2894 * Mark support for the scheduler's frequency invariance engine for
2895 * drivers that implement target(), target_index() or fast_switch().
2896 */
2897 if (!cpufreq_driver->setpolicy) {
2898 static_branch_enable_cpuslocked(&cpufreq_freq_invariance);
2899 pr_debug("supports frequency invariance");
2900 }
2901
2902 if (driver_data->setpolicy)
2903 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2904
2905 if (cpufreq_boost_supported()) {
2906 ret = create_boost_sysfs_file();
2907 if (ret)
2908 goto err_null_driver;
2909 }
2910
2911 ret = subsys_interface_register(&cpufreq_interface);
2912 if (ret)
2913 goto err_boost_unreg;
2914
2915 if (unlikely(list_empty(&cpufreq_policy_list))) {
2916 /* if all ->init() calls failed, unregister */
2917 ret = -ENODEV;
2918 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2919 driver_data->name);
2920 goto err_if_unreg;
2921 }
2922
2923 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2924 "cpufreq:online",
2925 cpuhp_cpufreq_online,
2926 cpuhp_cpufreq_offline);
2927 if (ret < 0)
2928 goto err_if_unreg;
2929 hp_online = ret;
2930 ret = 0;
2931
2932 pr_debug("driver %s up and running\n", driver_data->name);
2933 goto out;
2934
2935err_if_unreg:
2936 subsys_interface_unregister(&cpufreq_interface);
2937err_boost_unreg:
2938 remove_boost_sysfs_file();
2939err_null_driver:
2940 write_lock_irqsave(&cpufreq_driver_lock, flags);
2941 cpufreq_driver = NULL;
2942 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2943out:
2944 cpus_read_unlock();
2945 return ret;
2946}
2947EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2948
2949/*
2950 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2951 *
2952 * Unregister the current CPUFreq driver. Only call this if you have
2953 * the right to do so, i.e. if you have succeeded in initialising before!
2954 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2955 * currently not initialised.
2956 */
2957void cpufreq_unregister_driver(struct cpufreq_driver *driver)
2958{
2959 unsigned long flags;
2960
2961 if (WARN_ON(!cpufreq_driver || (driver != cpufreq_driver)))
2962 return;
2963
2964 pr_debug("unregistering driver %s\n", driver->name);
2965
2966 /* Protect against concurrent cpu hotplug */
2967 cpus_read_lock();
2968 subsys_interface_unregister(&cpufreq_interface);
2969 remove_boost_sysfs_file();
2970 static_branch_disable_cpuslocked(&cpufreq_freq_invariance);
2971 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2972
2973 write_lock_irqsave(&cpufreq_driver_lock, flags);
2974
2975 cpufreq_driver = NULL;
2976
2977 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2978 cpus_read_unlock();
2979}
2980EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2981
2982static int __init cpufreq_core_init(void)
2983{
2984 struct cpufreq_governor *gov = cpufreq_default_governor();
2985 struct device *dev_root;
2986
2987 if (cpufreq_disabled())
2988 return -ENODEV;
2989
2990 dev_root = bus_get_dev_root(&cpu_subsys);
2991 if (dev_root) {
2992 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &dev_root->kobj);
2993 put_device(dev_root);
2994 }
2995 BUG_ON(!cpufreq_global_kobject);
2996
2997 if (!strlen(default_governor))
2998 strscpy(default_governor, gov->name, CPUFREQ_NAME_LEN);
2999
3000 return 0;
3001}
3002module_param(off, int, 0444);
3003module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444);
3004core_initcall(cpufreq_core_init);
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 <linux/cpu.h>
21#include <linux/cpufreq.h>
22#include <linux/delay.h>
23#include <linux/device.h>
24#include <linux/init.h>
25#include <linux/kernel_stat.h>
26#include <linux/module.h>
27#include <linux/mutex.h>
28#include <linux/slab.h>
29#include <linux/suspend.h>
30#include <linux/syscore_ops.h>
31#include <linux/tick.h>
32#include <trace/events/power.h>
33
34static LIST_HEAD(cpufreq_policy_list);
35
36static inline bool policy_is_inactive(struct cpufreq_policy *policy)
37{
38 return cpumask_empty(policy->cpus);
39}
40
41/* Macros to iterate over CPU policies */
42#define for_each_suitable_policy(__policy, __active) \
43 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
44 if ((__active) == !policy_is_inactive(__policy))
45
46#define for_each_active_policy(__policy) \
47 for_each_suitable_policy(__policy, true)
48#define for_each_inactive_policy(__policy) \
49 for_each_suitable_policy(__policy, false)
50
51#define for_each_policy(__policy) \
52 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
53
54/* Iterate over governors */
55static LIST_HEAD(cpufreq_governor_list);
56#define for_each_governor(__governor) \
57 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
58
59/**
60 * The "cpufreq driver" - the arch- or hardware-dependent low
61 * level driver of CPUFreq support, and its spinlock. This lock
62 * also protects the cpufreq_cpu_data array.
63 */
64static struct cpufreq_driver *cpufreq_driver;
65static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
66static DEFINE_RWLOCK(cpufreq_driver_lock);
67
68/* Flag to suspend/resume CPUFreq governors */
69static bool cpufreq_suspended;
70
71static inline bool has_target(void)
72{
73 return cpufreq_driver->target_index || cpufreq_driver->target;
74}
75
76/* internal prototypes */
77static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
78static int cpufreq_init_governor(struct cpufreq_policy *policy);
79static void cpufreq_exit_governor(struct cpufreq_policy *policy);
80static int cpufreq_start_governor(struct cpufreq_policy *policy);
81static void cpufreq_stop_governor(struct cpufreq_policy *policy);
82static void cpufreq_governor_limits(struct cpufreq_policy *policy);
83
84/**
85 * Two notifier lists: the "policy" list is involved in the
86 * validation process for a new CPU frequency policy; the
87 * "transition" list for kernel code that needs to handle
88 * changes to devices when the CPU clock speed changes.
89 * The mutex locks both lists.
90 */
91static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
92static struct srcu_notifier_head cpufreq_transition_notifier_list;
93
94static bool init_cpufreq_transition_notifier_list_called;
95static int __init init_cpufreq_transition_notifier_list(void)
96{
97 srcu_init_notifier_head(&cpufreq_transition_notifier_list);
98 init_cpufreq_transition_notifier_list_called = true;
99 return 0;
100}
101pure_initcall(init_cpufreq_transition_notifier_list);
102
103static int off __read_mostly;
104static int cpufreq_disabled(void)
105{
106 return off;
107}
108void disable_cpufreq(void)
109{
110 off = 1;
111}
112static DEFINE_MUTEX(cpufreq_governor_mutex);
113
114bool have_governor_per_policy(void)
115{
116 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
117}
118EXPORT_SYMBOL_GPL(have_governor_per_policy);
119
120struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
121{
122 if (have_governor_per_policy())
123 return &policy->kobj;
124 else
125 return cpufreq_global_kobject;
126}
127EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
128
129static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
130{
131 u64 idle_time;
132 u64 cur_wall_time;
133 u64 busy_time;
134
135 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
136
137 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
138 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
139 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
140 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
141 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
142 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
143
144 idle_time = cur_wall_time - busy_time;
145 if (wall)
146 *wall = cputime_to_usecs(cur_wall_time);
147
148 return cputime_to_usecs(idle_time);
149}
150
151u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
152{
153 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
154
155 if (idle_time == -1ULL)
156 return get_cpu_idle_time_jiffy(cpu, wall);
157 else if (!io_busy)
158 idle_time += get_cpu_iowait_time_us(cpu, wall);
159
160 return idle_time;
161}
162EXPORT_SYMBOL_GPL(get_cpu_idle_time);
163
164/*
165 * This is a generic cpufreq init() routine which can be used by cpufreq
166 * drivers of SMP systems. It will do following:
167 * - validate & show freq table passed
168 * - set policies transition latency
169 * - policy->cpus with all possible CPUs
170 */
171int cpufreq_generic_init(struct cpufreq_policy *policy,
172 struct cpufreq_frequency_table *table,
173 unsigned int transition_latency)
174{
175 int ret;
176
177 ret = cpufreq_table_validate_and_show(policy, table);
178 if (ret) {
179 pr_err("%s: invalid frequency table: %d\n", __func__, ret);
180 return ret;
181 }
182
183 policy->cpuinfo.transition_latency = transition_latency;
184
185 /*
186 * The driver only supports the SMP configuration where all processors
187 * share the clock and voltage and clock.
188 */
189 cpumask_setall(policy->cpus);
190
191 return 0;
192}
193EXPORT_SYMBOL_GPL(cpufreq_generic_init);
194
195struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
196{
197 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
198
199 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
200}
201EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
202
203unsigned int cpufreq_generic_get(unsigned int cpu)
204{
205 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
206
207 if (!policy || IS_ERR(policy->clk)) {
208 pr_err("%s: No %s associated to cpu: %d\n",
209 __func__, policy ? "clk" : "policy", cpu);
210 return 0;
211 }
212
213 return clk_get_rate(policy->clk) / 1000;
214}
215EXPORT_SYMBOL_GPL(cpufreq_generic_get);
216
217/**
218 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
219 *
220 * @cpu: cpu to find policy for.
221 *
222 * This returns policy for 'cpu', returns NULL if it doesn't exist.
223 * It also increments the kobject reference count to mark it busy and so would
224 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
225 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
226 * freed as that depends on the kobj count.
227 *
228 * Return: A valid policy on success, otherwise NULL on failure.
229 */
230struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
231{
232 struct cpufreq_policy *policy = NULL;
233 unsigned long flags;
234
235 if (WARN_ON(cpu >= nr_cpu_ids))
236 return NULL;
237
238 /* get the cpufreq driver */
239 read_lock_irqsave(&cpufreq_driver_lock, flags);
240
241 if (cpufreq_driver) {
242 /* get the CPU */
243 policy = cpufreq_cpu_get_raw(cpu);
244 if (policy)
245 kobject_get(&policy->kobj);
246 }
247
248 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
249
250 return policy;
251}
252EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
253
254/**
255 * cpufreq_cpu_put: Decrements the usage count of a policy
256 *
257 * @policy: policy earlier returned by cpufreq_cpu_get().
258 *
259 * This decrements the kobject reference count incremented earlier by calling
260 * cpufreq_cpu_get().
261 */
262void cpufreq_cpu_put(struct cpufreq_policy *policy)
263{
264 kobject_put(&policy->kobj);
265}
266EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
267
268/*********************************************************************
269 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
270 *********************************************************************/
271
272/**
273 * adjust_jiffies - adjust the system "loops_per_jiffy"
274 *
275 * This function alters the system "loops_per_jiffy" for the clock
276 * speed change. Note that loops_per_jiffy cannot be updated on SMP
277 * systems as each CPU might be scaled differently. So, use the arch
278 * per-CPU loops_per_jiffy value wherever possible.
279 */
280static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
281{
282#ifndef CONFIG_SMP
283 static unsigned long l_p_j_ref;
284 static unsigned int l_p_j_ref_freq;
285
286 if (ci->flags & CPUFREQ_CONST_LOOPS)
287 return;
288
289 if (!l_p_j_ref_freq) {
290 l_p_j_ref = loops_per_jiffy;
291 l_p_j_ref_freq = ci->old;
292 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
293 l_p_j_ref, l_p_j_ref_freq);
294 }
295 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
296 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
297 ci->new);
298 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
299 loops_per_jiffy, ci->new);
300 }
301#endif
302}
303
304static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
305 struct cpufreq_freqs *freqs, unsigned int state)
306{
307 BUG_ON(irqs_disabled());
308
309 if (cpufreq_disabled())
310 return;
311
312 freqs->flags = cpufreq_driver->flags;
313 pr_debug("notification %u of frequency transition to %u kHz\n",
314 state, freqs->new);
315
316 switch (state) {
317
318 case CPUFREQ_PRECHANGE:
319 /* detect if the driver reported a value as "old frequency"
320 * which is not equal to what the cpufreq core thinks is
321 * "old frequency".
322 */
323 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
324 if ((policy) && (policy->cpu == freqs->cpu) &&
325 (policy->cur) && (policy->cur != freqs->old)) {
326 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
327 freqs->old, policy->cur);
328 freqs->old = policy->cur;
329 }
330 }
331 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
332 CPUFREQ_PRECHANGE, freqs);
333 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
334 break;
335
336 case CPUFREQ_POSTCHANGE:
337 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
338 pr_debug("FREQ: %lu - CPU: %lu\n",
339 (unsigned long)freqs->new, (unsigned long)freqs->cpu);
340 trace_cpu_frequency(freqs->new, freqs->cpu);
341 cpufreq_stats_record_transition(policy, freqs->new);
342 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
343 CPUFREQ_POSTCHANGE, freqs);
344 if (likely(policy) && likely(policy->cpu == freqs->cpu))
345 policy->cur = freqs->new;
346 break;
347 }
348}
349
350/**
351 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
352 * on frequency transition.
353 *
354 * This function calls the transition notifiers and the "adjust_jiffies"
355 * function. It is called twice on all CPU frequency changes that have
356 * external effects.
357 */
358static void cpufreq_notify_transition(struct cpufreq_policy *policy,
359 struct cpufreq_freqs *freqs, unsigned int state)
360{
361 for_each_cpu(freqs->cpu, policy->cpus)
362 __cpufreq_notify_transition(policy, freqs, state);
363}
364
365/* Do post notifications when there are chances that transition has failed */
366static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
367 struct cpufreq_freqs *freqs, int transition_failed)
368{
369 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
370 if (!transition_failed)
371 return;
372
373 swap(freqs->old, freqs->new);
374 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
375 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
376}
377
378void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
379 struct cpufreq_freqs *freqs)
380{
381
382 /*
383 * Catch double invocations of _begin() which lead to self-deadlock.
384 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
385 * doesn't invoke _begin() on their behalf, and hence the chances of
386 * double invocations are very low. Moreover, there are scenarios
387 * where these checks can emit false-positive warnings in these
388 * drivers; so we avoid that by skipping them altogether.
389 */
390 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
391 && current == policy->transition_task);
392
393wait:
394 wait_event(policy->transition_wait, !policy->transition_ongoing);
395
396 spin_lock(&policy->transition_lock);
397
398 if (unlikely(policy->transition_ongoing)) {
399 spin_unlock(&policy->transition_lock);
400 goto wait;
401 }
402
403 policy->transition_ongoing = true;
404 policy->transition_task = current;
405
406 spin_unlock(&policy->transition_lock);
407
408 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
409}
410EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
411
412void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
413 struct cpufreq_freqs *freqs, int transition_failed)
414{
415 if (unlikely(WARN_ON(!policy->transition_ongoing)))
416 return;
417
418 cpufreq_notify_post_transition(policy, freqs, transition_failed);
419
420 policy->transition_ongoing = false;
421 policy->transition_task = NULL;
422
423 wake_up(&policy->transition_wait);
424}
425EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
426
427/*
428 * Fast frequency switching status count. Positive means "enabled", negative
429 * means "disabled" and 0 means "not decided yet".
430 */
431static int cpufreq_fast_switch_count;
432static DEFINE_MUTEX(cpufreq_fast_switch_lock);
433
434static void cpufreq_list_transition_notifiers(void)
435{
436 struct notifier_block *nb;
437
438 pr_info("Registered transition notifiers:\n");
439
440 mutex_lock(&cpufreq_transition_notifier_list.mutex);
441
442 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
443 pr_info("%pF\n", nb->notifier_call);
444
445 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
446}
447
448/**
449 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
450 * @policy: cpufreq policy to enable fast frequency switching for.
451 *
452 * Try to enable fast frequency switching for @policy.
453 *
454 * The attempt will fail if there is at least one transition notifier registered
455 * at this point, as fast frequency switching is quite fundamentally at odds
456 * with transition notifiers. Thus if successful, it will make registration of
457 * transition notifiers fail going forward.
458 */
459void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
460{
461 lockdep_assert_held(&policy->rwsem);
462
463 if (!policy->fast_switch_possible)
464 return;
465
466 mutex_lock(&cpufreq_fast_switch_lock);
467 if (cpufreq_fast_switch_count >= 0) {
468 cpufreq_fast_switch_count++;
469 policy->fast_switch_enabled = true;
470 } else {
471 pr_warn("CPU%u: Fast frequency switching not enabled\n",
472 policy->cpu);
473 cpufreq_list_transition_notifiers();
474 }
475 mutex_unlock(&cpufreq_fast_switch_lock);
476}
477EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
478
479/**
480 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
481 * @policy: cpufreq policy to disable fast frequency switching for.
482 */
483void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
484{
485 mutex_lock(&cpufreq_fast_switch_lock);
486 if (policy->fast_switch_enabled) {
487 policy->fast_switch_enabled = false;
488 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
489 cpufreq_fast_switch_count--;
490 }
491 mutex_unlock(&cpufreq_fast_switch_lock);
492}
493EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
494
495/**
496 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
497 * one.
498 * @target_freq: target frequency to resolve.
499 *
500 * The target to driver frequency mapping is cached in the policy.
501 *
502 * Return: Lowest driver-supported frequency greater than or equal to the
503 * given target_freq, subject to policy (min/max) and driver limitations.
504 */
505unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
506 unsigned int target_freq)
507{
508 target_freq = clamp_val(target_freq, policy->min, policy->max);
509 policy->cached_target_freq = target_freq;
510
511 if (cpufreq_driver->target_index) {
512 int idx;
513
514 idx = cpufreq_frequency_table_target(policy, target_freq,
515 CPUFREQ_RELATION_L);
516 policy->cached_resolved_idx = idx;
517 return policy->freq_table[idx].frequency;
518 }
519
520 if (cpufreq_driver->resolve_freq)
521 return cpufreq_driver->resolve_freq(policy, target_freq);
522
523 return target_freq;
524}
525EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
526
527/*********************************************************************
528 * SYSFS INTERFACE *
529 *********************************************************************/
530static ssize_t show_boost(struct kobject *kobj,
531 struct attribute *attr, char *buf)
532{
533 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
534}
535
536static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
537 const char *buf, size_t count)
538{
539 int ret, enable;
540
541 ret = sscanf(buf, "%d", &enable);
542 if (ret != 1 || enable < 0 || enable > 1)
543 return -EINVAL;
544
545 if (cpufreq_boost_trigger_state(enable)) {
546 pr_err("%s: Cannot %s BOOST!\n",
547 __func__, enable ? "enable" : "disable");
548 return -EINVAL;
549 }
550
551 pr_debug("%s: cpufreq BOOST %s\n",
552 __func__, enable ? "enabled" : "disabled");
553
554 return count;
555}
556define_one_global_rw(boost);
557
558static struct cpufreq_governor *find_governor(const char *str_governor)
559{
560 struct cpufreq_governor *t;
561
562 for_each_governor(t)
563 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
564 return t;
565
566 return NULL;
567}
568
569/**
570 * cpufreq_parse_governor - parse a governor string
571 */
572static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
573 struct cpufreq_governor **governor)
574{
575 int err = -EINVAL;
576
577 if (cpufreq_driver->setpolicy) {
578 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
579 *policy = CPUFREQ_POLICY_PERFORMANCE;
580 err = 0;
581 } else if (!strncasecmp(str_governor, "powersave",
582 CPUFREQ_NAME_LEN)) {
583 *policy = CPUFREQ_POLICY_POWERSAVE;
584 err = 0;
585 }
586 } else {
587 struct cpufreq_governor *t;
588
589 mutex_lock(&cpufreq_governor_mutex);
590
591 t = find_governor(str_governor);
592
593 if (t == NULL) {
594 int ret;
595
596 mutex_unlock(&cpufreq_governor_mutex);
597 ret = request_module("cpufreq_%s", str_governor);
598 mutex_lock(&cpufreq_governor_mutex);
599
600 if (ret == 0)
601 t = find_governor(str_governor);
602 }
603
604 if (t != NULL) {
605 *governor = t;
606 err = 0;
607 }
608
609 mutex_unlock(&cpufreq_governor_mutex);
610 }
611 return err;
612}
613
614/**
615 * cpufreq_per_cpu_attr_read() / show_##file_name() -
616 * print out cpufreq information
617 *
618 * Write out information from cpufreq_driver->policy[cpu]; object must be
619 * "unsigned int".
620 */
621
622#define show_one(file_name, object) \
623static ssize_t show_##file_name \
624(struct cpufreq_policy *policy, char *buf) \
625{ \
626 return sprintf(buf, "%u\n", policy->object); \
627}
628
629show_one(cpuinfo_min_freq, cpuinfo.min_freq);
630show_one(cpuinfo_max_freq, cpuinfo.max_freq);
631show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
632show_one(scaling_min_freq, min);
633show_one(scaling_max_freq, max);
634
635static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
636{
637 ssize_t ret;
638
639 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
640 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
641 else
642 ret = sprintf(buf, "%u\n", policy->cur);
643 return ret;
644}
645
646static int cpufreq_set_policy(struct cpufreq_policy *policy,
647 struct cpufreq_policy *new_policy);
648
649/**
650 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
651 */
652#define store_one(file_name, object) \
653static ssize_t store_##file_name \
654(struct cpufreq_policy *policy, const char *buf, size_t count) \
655{ \
656 int ret, temp; \
657 struct cpufreq_policy new_policy; \
658 \
659 memcpy(&new_policy, policy, sizeof(*policy)); \
660 \
661 ret = sscanf(buf, "%u", &new_policy.object); \
662 if (ret != 1) \
663 return -EINVAL; \
664 \
665 temp = new_policy.object; \
666 ret = cpufreq_set_policy(policy, &new_policy); \
667 if (!ret) \
668 policy->user_policy.object = temp; \
669 \
670 return ret ? ret : count; \
671}
672
673store_one(scaling_min_freq, min);
674store_one(scaling_max_freq, max);
675
676/**
677 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
678 */
679static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
680 char *buf)
681{
682 unsigned int cur_freq = __cpufreq_get(policy);
683
684 if (cur_freq)
685 return sprintf(buf, "%u\n", cur_freq);
686
687 return sprintf(buf, "<unknown>\n");
688}
689
690/**
691 * show_scaling_governor - show the current policy for the specified CPU
692 */
693static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
694{
695 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
696 return sprintf(buf, "powersave\n");
697 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
698 return sprintf(buf, "performance\n");
699 else if (policy->governor)
700 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
701 policy->governor->name);
702 return -EINVAL;
703}
704
705/**
706 * store_scaling_governor - store policy for the specified CPU
707 */
708static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
709 const char *buf, size_t count)
710{
711 int ret;
712 char str_governor[16];
713 struct cpufreq_policy new_policy;
714
715 memcpy(&new_policy, policy, sizeof(*policy));
716
717 ret = sscanf(buf, "%15s", str_governor);
718 if (ret != 1)
719 return -EINVAL;
720
721 if (cpufreq_parse_governor(str_governor, &new_policy.policy,
722 &new_policy.governor))
723 return -EINVAL;
724
725 ret = cpufreq_set_policy(policy, &new_policy);
726 return ret ? ret : count;
727}
728
729/**
730 * show_scaling_driver - show the cpufreq driver currently loaded
731 */
732static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
733{
734 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
735}
736
737/**
738 * show_scaling_available_governors - show the available CPUfreq governors
739 */
740static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
741 char *buf)
742{
743 ssize_t i = 0;
744 struct cpufreq_governor *t;
745
746 if (!has_target()) {
747 i += sprintf(buf, "performance powersave");
748 goto out;
749 }
750
751 for_each_governor(t) {
752 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
753 - (CPUFREQ_NAME_LEN + 2)))
754 goto out;
755 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
756 }
757out:
758 i += sprintf(&buf[i], "\n");
759 return i;
760}
761
762ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
763{
764 ssize_t i = 0;
765 unsigned int cpu;
766
767 for_each_cpu(cpu, mask) {
768 if (i)
769 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
770 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
771 if (i >= (PAGE_SIZE - 5))
772 break;
773 }
774 i += sprintf(&buf[i], "\n");
775 return i;
776}
777EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
778
779/**
780 * show_related_cpus - show the CPUs affected by each transition even if
781 * hw coordination is in use
782 */
783static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
784{
785 return cpufreq_show_cpus(policy->related_cpus, buf);
786}
787
788/**
789 * show_affected_cpus - show the CPUs affected by each transition
790 */
791static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
792{
793 return cpufreq_show_cpus(policy->cpus, buf);
794}
795
796static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
797 const char *buf, size_t count)
798{
799 unsigned int freq = 0;
800 unsigned int ret;
801
802 if (!policy->governor || !policy->governor->store_setspeed)
803 return -EINVAL;
804
805 ret = sscanf(buf, "%u", &freq);
806 if (ret != 1)
807 return -EINVAL;
808
809 policy->governor->store_setspeed(policy, freq);
810
811 return count;
812}
813
814static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
815{
816 if (!policy->governor || !policy->governor->show_setspeed)
817 return sprintf(buf, "<unsupported>\n");
818
819 return policy->governor->show_setspeed(policy, buf);
820}
821
822/**
823 * show_bios_limit - show the current cpufreq HW/BIOS limitation
824 */
825static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
826{
827 unsigned int limit;
828 int ret;
829 if (cpufreq_driver->bios_limit) {
830 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
831 if (!ret)
832 return sprintf(buf, "%u\n", limit);
833 }
834 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
835}
836
837cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
838cpufreq_freq_attr_ro(cpuinfo_min_freq);
839cpufreq_freq_attr_ro(cpuinfo_max_freq);
840cpufreq_freq_attr_ro(cpuinfo_transition_latency);
841cpufreq_freq_attr_ro(scaling_available_governors);
842cpufreq_freq_attr_ro(scaling_driver);
843cpufreq_freq_attr_ro(scaling_cur_freq);
844cpufreq_freq_attr_ro(bios_limit);
845cpufreq_freq_attr_ro(related_cpus);
846cpufreq_freq_attr_ro(affected_cpus);
847cpufreq_freq_attr_rw(scaling_min_freq);
848cpufreq_freq_attr_rw(scaling_max_freq);
849cpufreq_freq_attr_rw(scaling_governor);
850cpufreq_freq_attr_rw(scaling_setspeed);
851
852static struct attribute *default_attrs[] = {
853 &cpuinfo_min_freq.attr,
854 &cpuinfo_max_freq.attr,
855 &cpuinfo_transition_latency.attr,
856 &scaling_min_freq.attr,
857 &scaling_max_freq.attr,
858 &affected_cpus.attr,
859 &related_cpus.attr,
860 &scaling_governor.attr,
861 &scaling_driver.attr,
862 &scaling_available_governors.attr,
863 &scaling_setspeed.attr,
864 NULL
865};
866
867#define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
868#define to_attr(a) container_of(a, struct freq_attr, attr)
869
870static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
871{
872 struct cpufreq_policy *policy = to_policy(kobj);
873 struct freq_attr *fattr = to_attr(attr);
874 ssize_t ret;
875
876 down_read(&policy->rwsem);
877 ret = fattr->show(policy, buf);
878 up_read(&policy->rwsem);
879
880 return ret;
881}
882
883static ssize_t store(struct kobject *kobj, struct attribute *attr,
884 const char *buf, size_t count)
885{
886 struct cpufreq_policy *policy = to_policy(kobj);
887 struct freq_attr *fattr = to_attr(attr);
888 ssize_t ret = -EINVAL;
889
890 get_online_cpus();
891
892 if (cpu_online(policy->cpu)) {
893 down_write(&policy->rwsem);
894 ret = fattr->store(policy, buf, count);
895 up_write(&policy->rwsem);
896 }
897
898 put_online_cpus();
899
900 return ret;
901}
902
903static void cpufreq_sysfs_release(struct kobject *kobj)
904{
905 struct cpufreq_policy *policy = to_policy(kobj);
906 pr_debug("last reference is dropped\n");
907 complete(&policy->kobj_unregister);
908}
909
910static const struct sysfs_ops sysfs_ops = {
911 .show = show,
912 .store = store,
913};
914
915static struct kobj_type ktype_cpufreq = {
916 .sysfs_ops = &sysfs_ops,
917 .default_attrs = default_attrs,
918 .release = cpufreq_sysfs_release,
919};
920
921static int add_cpu_dev_symlink(struct cpufreq_policy *policy,
922 struct device *dev)
923{
924 dev_dbg(dev, "%s: Adding symlink\n", __func__);
925 return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
926}
927
928static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
929 struct device *dev)
930{
931 dev_dbg(dev, "%s: Removing symlink\n", __func__);
932 sysfs_remove_link(&dev->kobj, "cpufreq");
933}
934
935static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
936{
937 struct freq_attr **drv_attr;
938 int ret = 0;
939
940 /* set up files for this cpu device */
941 drv_attr = cpufreq_driver->attr;
942 while (drv_attr && *drv_attr) {
943 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
944 if (ret)
945 return ret;
946 drv_attr++;
947 }
948 if (cpufreq_driver->get) {
949 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
950 if (ret)
951 return ret;
952 }
953
954 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
955 if (ret)
956 return ret;
957
958 if (cpufreq_driver->bios_limit) {
959 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
960 if (ret)
961 return ret;
962 }
963
964 return 0;
965}
966
967__weak struct cpufreq_governor *cpufreq_default_governor(void)
968{
969 return NULL;
970}
971
972static int cpufreq_init_policy(struct cpufreq_policy *policy)
973{
974 struct cpufreq_governor *gov = NULL;
975 struct cpufreq_policy new_policy;
976
977 memcpy(&new_policy, policy, sizeof(*policy));
978
979 /* Update governor of new_policy to the governor used before hotplug */
980 gov = find_governor(policy->last_governor);
981 if (gov) {
982 pr_debug("Restoring governor %s for cpu %d\n",
983 policy->governor->name, policy->cpu);
984 } else {
985 gov = cpufreq_default_governor();
986 if (!gov)
987 return -ENODATA;
988 }
989
990 new_policy.governor = gov;
991
992 /* Use the default policy if there is no last_policy. */
993 if (cpufreq_driver->setpolicy) {
994 if (policy->last_policy)
995 new_policy.policy = policy->last_policy;
996 else
997 cpufreq_parse_governor(gov->name, &new_policy.policy,
998 NULL);
999 }
1000 /* set default policy */
1001 return cpufreq_set_policy(policy, &new_policy);
1002}
1003
1004static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1005{
1006 int ret = 0;
1007
1008 /* Has this CPU been taken care of already? */
1009 if (cpumask_test_cpu(cpu, policy->cpus))
1010 return 0;
1011
1012 down_write(&policy->rwsem);
1013 if (has_target())
1014 cpufreq_stop_governor(policy);
1015
1016 cpumask_set_cpu(cpu, policy->cpus);
1017
1018 if (has_target()) {
1019 ret = cpufreq_start_governor(policy);
1020 if (ret)
1021 pr_err("%s: Failed to start governor\n", __func__);
1022 }
1023 up_write(&policy->rwsem);
1024 return ret;
1025}
1026
1027static void handle_update(struct work_struct *work)
1028{
1029 struct cpufreq_policy *policy =
1030 container_of(work, struct cpufreq_policy, update);
1031 unsigned int cpu = policy->cpu;
1032 pr_debug("handle_update for cpu %u called\n", cpu);
1033 cpufreq_update_policy(cpu);
1034}
1035
1036static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1037{
1038 struct cpufreq_policy *policy;
1039 int ret;
1040
1041 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1042 if (!policy)
1043 return NULL;
1044
1045 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1046 goto err_free_policy;
1047
1048 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1049 goto err_free_cpumask;
1050
1051 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1052 goto err_free_rcpumask;
1053
1054 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1055 cpufreq_global_kobject, "policy%u", cpu);
1056 if (ret) {
1057 pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
1058 goto err_free_real_cpus;
1059 }
1060
1061 INIT_LIST_HEAD(&policy->policy_list);
1062 init_rwsem(&policy->rwsem);
1063 spin_lock_init(&policy->transition_lock);
1064 init_waitqueue_head(&policy->transition_wait);
1065 init_completion(&policy->kobj_unregister);
1066 INIT_WORK(&policy->update, handle_update);
1067
1068 policy->cpu = cpu;
1069 return policy;
1070
1071err_free_real_cpus:
1072 free_cpumask_var(policy->real_cpus);
1073err_free_rcpumask:
1074 free_cpumask_var(policy->related_cpus);
1075err_free_cpumask:
1076 free_cpumask_var(policy->cpus);
1077err_free_policy:
1078 kfree(policy);
1079
1080 return NULL;
1081}
1082
1083static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy, bool notify)
1084{
1085 struct kobject *kobj;
1086 struct completion *cmp;
1087
1088 if (notify)
1089 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1090 CPUFREQ_REMOVE_POLICY, policy);
1091
1092 down_write(&policy->rwsem);
1093 cpufreq_stats_free_table(policy);
1094 kobj = &policy->kobj;
1095 cmp = &policy->kobj_unregister;
1096 up_write(&policy->rwsem);
1097 kobject_put(kobj);
1098
1099 /*
1100 * We need to make sure that the underlying kobj is
1101 * actually not referenced anymore by anybody before we
1102 * proceed with unloading.
1103 */
1104 pr_debug("waiting for dropping of refcount\n");
1105 wait_for_completion(cmp);
1106 pr_debug("wait complete\n");
1107}
1108
1109static void cpufreq_policy_free(struct cpufreq_policy *policy, bool notify)
1110{
1111 unsigned long flags;
1112 int cpu;
1113
1114 /* Remove policy from list */
1115 write_lock_irqsave(&cpufreq_driver_lock, flags);
1116 list_del(&policy->policy_list);
1117
1118 for_each_cpu(cpu, policy->related_cpus)
1119 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1120 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1121
1122 cpufreq_policy_put_kobj(policy, notify);
1123 free_cpumask_var(policy->real_cpus);
1124 free_cpumask_var(policy->related_cpus);
1125 free_cpumask_var(policy->cpus);
1126 kfree(policy);
1127}
1128
1129static int cpufreq_online(unsigned int cpu)
1130{
1131 struct cpufreq_policy *policy;
1132 bool new_policy;
1133 unsigned long flags;
1134 unsigned int j;
1135 int ret;
1136
1137 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1138
1139 /* Check if this CPU already has a policy to manage it */
1140 policy = per_cpu(cpufreq_cpu_data, cpu);
1141 if (policy) {
1142 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1143 if (!policy_is_inactive(policy))
1144 return cpufreq_add_policy_cpu(policy, cpu);
1145
1146 /* This is the only online CPU for the policy. Start over. */
1147 new_policy = false;
1148 down_write(&policy->rwsem);
1149 policy->cpu = cpu;
1150 policy->governor = NULL;
1151 up_write(&policy->rwsem);
1152 } else {
1153 new_policy = true;
1154 policy = cpufreq_policy_alloc(cpu);
1155 if (!policy)
1156 return -ENOMEM;
1157 }
1158
1159 cpumask_copy(policy->cpus, cpumask_of(cpu));
1160
1161 /* call driver. From then on the cpufreq must be able
1162 * to accept all calls to ->verify and ->setpolicy for this CPU
1163 */
1164 ret = cpufreq_driver->init(policy);
1165 if (ret) {
1166 pr_debug("initialization failed\n");
1167 goto out_free_policy;
1168 }
1169
1170 down_write(&policy->rwsem);
1171
1172 if (new_policy) {
1173 /* related_cpus should at least include policy->cpus. */
1174 cpumask_copy(policy->related_cpus, policy->cpus);
1175 /* Clear mask of registered CPUs */
1176 cpumask_clear(policy->real_cpus);
1177 }
1178
1179 /*
1180 * affected cpus must always be the one, which are online. We aren't
1181 * managing offline cpus here.
1182 */
1183 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1184
1185 if (new_policy) {
1186 policy->user_policy.min = policy->min;
1187 policy->user_policy.max = policy->max;
1188
1189 write_lock_irqsave(&cpufreq_driver_lock, flags);
1190 for_each_cpu(j, policy->related_cpus)
1191 per_cpu(cpufreq_cpu_data, j) = policy;
1192 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1193 } else {
1194 policy->min = policy->user_policy.min;
1195 policy->max = policy->user_policy.max;
1196 }
1197
1198 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1199 policy->cur = cpufreq_driver->get(policy->cpu);
1200 if (!policy->cur) {
1201 pr_err("%s: ->get() failed\n", __func__);
1202 goto out_exit_policy;
1203 }
1204 }
1205
1206 /*
1207 * Sometimes boot loaders set CPU frequency to a value outside of
1208 * frequency table present with cpufreq core. In such cases CPU might be
1209 * unstable if it has to run on that frequency for long duration of time
1210 * and so its better to set it to a frequency which is specified in
1211 * freq-table. This also makes cpufreq stats inconsistent as
1212 * cpufreq-stats would fail to register because current frequency of CPU
1213 * isn't found in freq-table.
1214 *
1215 * Because we don't want this change to effect boot process badly, we go
1216 * for the next freq which is >= policy->cur ('cur' must be set by now,
1217 * otherwise we will end up setting freq to lowest of the table as 'cur'
1218 * is initialized to zero).
1219 *
1220 * We are passing target-freq as "policy->cur - 1" otherwise
1221 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1222 * equal to target-freq.
1223 */
1224 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1225 && has_target()) {
1226 /* Are we running at unknown frequency ? */
1227 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1228 if (ret == -EINVAL) {
1229 /* Warn user and fix it */
1230 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1231 __func__, policy->cpu, policy->cur);
1232 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1233 CPUFREQ_RELATION_L);
1234
1235 /*
1236 * Reaching here after boot in a few seconds may not
1237 * mean that system will remain stable at "unknown"
1238 * frequency for longer duration. Hence, a BUG_ON().
1239 */
1240 BUG_ON(ret);
1241 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1242 __func__, policy->cpu, policy->cur);
1243 }
1244 }
1245
1246 if (new_policy) {
1247 ret = cpufreq_add_dev_interface(policy);
1248 if (ret)
1249 goto out_exit_policy;
1250
1251 cpufreq_stats_create_table(policy);
1252 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1253 CPUFREQ_CREATE_POLICY, policy);
1254
1255 write_lock_irqsave(&cpufreq_driver_lock, flags);
1256 list_add(&policy->policy_list, &cpufreq_policy_list);
1257 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1258 }
1259
1260 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1261 CPUFREQ_START, policy);
1262
1263 ret = cpufreq_init_policy(policy);
1264 if (ret) {
1265 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1266 __func__, cpu, ret);
1267 /* cpufreq_policy_free() will notify based on this */
1268 new_policy = false;
1269 goto out_exit_policy;
1270 }
1271
1272 up_write(&policy->rwsem);
1273
1274 kobject_uevent(&policy->kobj, KOBJ_ADD);
1275
1276 /* Callback for handling stuff after policy is ready */
1277 if (cpufreq_driver->ready)
1278 cpufreq_driver->ready(policy);
1279
1280 pr_debug("initialization complete\n");
1281
1282 return 0;
1283
1284out_exit_policy:
1285 up_write(&policy->rwsem);
1286
1287 if (cpufreq_driver->exit)
1288 cpufreq_driver->exit(policy);
1289out_free_policy:
1290 cpufreq_policy_free(policy, !new_policy);
1291 return ret;
1292}
1293
1294static int cpufreq_offline(unsigned int cpu);
1295
1296/**
1297 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1298 * @dev: CPU device.
1299 * @sif: Subsystem interface structure pointer (not used)
1300 */
1301static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1302{
1303 struct cpufreq_policy *policy;
1304 unsigned cpu = dev->id;
1305 int ret;
1306
1307 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1308
1309 if (cpu_online(cpu)) {
1310 ret = cpufreq_online(cpu);
1311 if (ret)
1312 return ret;
1313 }
1314
1315 /* Create sysfs link on CPU registration */
1316 policy = per_cpu(cpufreq_cpu_data, cpu);
1317 if (!policy || cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1318 return 0;
1319
1320 ret = add_cpu_dev_symlink(policy, dev);
1321 if (ret) {
1322 cpumask_clear_cpu(cpu, policy->real_cpus);
1323 cpufreq_offline(cpu);
1324 }
1325
1326 return ret;
1327}
1328
1329static int cpufreq_offline(unsigned int cpu)
1330{
1331 struct cpufreq_policy *policy;
1332 int ret;
1333
1334 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1335
1336 policy = cpufreq_cpu_get_raw(cpu);
1337 if (!policy) {
1338 pr_debug("%s: No cpu_data found\n", __func__);
1339 return 0;
1340 }
1341
1342 down_write(&policy->rwsem);
1343 if (has_target())
1344 cpufreq_stop_governor(policy);
1345
1346 cpumask_clear_cpu(cpu, policy->cpus);
1347
1348 if (policy_is_inactive(policy)) {
1349 if (has_target())
1350 strncpy(policy->last_governor, policy->governor->name,
1351 CPUFREQ_NAME_LEN);
1352 else
1353 policy->last_policy = policy->policy;
1354 } else if (cpu == policy->cpu) {
1355 /* Nominate new CPU */
1356 policy->cpu = cpumask_any(policy->cpus);
1357 }
1358
1359 /* Start governor again for active policy */
1360 if (!policy_is_inactive(policy)) {
1361 if (has_target()) {
1362 ret = cpufreq_start_governor(policy);
1363 if (ret)
1364 pr_err("%s: Failed to start governor\n", __func__);
1365 }
1366
1367 goto unlock;
1368 }
1369
1370 if (cpufreq_driver->stop_cpu)
1371 cpufreq_driver->stop_cpu(policy);
1372
1373 if (has_target())
1374 cpufreq_exit_governor(policy);
1375
1376 /*
1377 * Perform the ->exit() even during light-weight tear-down,
1378 * since this is a core component, and is essential for the
1379 * subsequent light-weight ->init() to succeed.
1380 */
1381 if (cpufreq_driver->exit) {
1382 cpufreq_driver->exit(policy);
1383 policy->freq_table = NULL;
1384 }
1385
1386unlock:
1387 up_write(&policy->rwsem);
1388 return 0;
1389}
1390
1391/**
1392 * cpufreq_remove_dev - remove a CPU device
1393 *
1394 * Removes the cpufreq interface for a CPU device.
1395 */
1396static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1397{
1398 unsigned int cpu = dev->id;
1399 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1400
1401 if (!policy)
1402 return;
1403
1404 if (cpu_online(cpu))
1405 cpufreq_offline(cpu);
1406
1407 cpumask_clear_cpu(cpu, policy->real_cpus);
1408 remove_cpu_dev_symlink(policy, dev);
1409
1410 if (cpumask_empty(policy->real_cpus))
1411 cpufreq_policy_free(policy, true);
1412}
1413
1414/**
1415 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1416 * in deep trouble.
1417 * @policy: policy managing CPUs
1418 * @new_freq: CPU frequency the CPU actually runs at
1419 *
1420 * We adjust to current frequency first, and need to clean up later.
1421 * So either call to cpufreq_update_policy() or schedule handle_update()).
1422 */
1423static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1424 unsigned int new_freq)
1425{
1426 struct cpufreq_freqs freqs;
1427
1428 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1429 policy->cur, new_freq);
1430
1431 freqs.old = policy->cur;
1432 freqs.new = new_freq;
1433
1434 cpufreq_freq_transition_begin(policy, &freqs);
1435 cpufreq_freq_transition_end(policy, &freqs, 0);
1436}
1437
1438/**
1439 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1440 * @cpu: CPU number
1441 *
1442 * This is the last known freq, without actually getting it from the driver.
1443 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1444 */
1445unsigned int cpufreq_quick_get(unsigned int cpu)
1446{
1447 struct cpufreq_policy *policy;
1448 unsigned int ret_freq = 0;
1449 unsigned long flags;
1450
1451 read_lock_irqsave(&cpufreq_driver_lock, flags);
1452
1453 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1454 ret_freq = cpufreq_driver->get(cpu);
1455 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1456 return ret_freq;
1457 }
1458
1459 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1460
1461 policy = cpufreq_cpu_get(cpu);
1462 if (policy) {
1463 ret_freq = policy->cur;
1464 cpufreq_cpu_put(policy);
1465 }
1466
1467 return ret_freq;
1468}
1469EXPORT_SYMBOL(cpufreq_quick_get);
1470
1471/**
1472 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1473 * @cpu: CPU number
1474 *
1475 * Just return the max possible frequency for a given CPU.
1476 */
1477unsigned int cpufreq_quick_get_max(unsigned int cpu)
1478{
1479 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1480 unsigned int ret_freq = 0;
1481
1482 if (policy) {
1483 ret_freq = policy->max;
1484 cpufreq_cpu_put(policy);
1485 }
1486
1487 return ret_freq;
1488}
1489EXPORT_SYMBOL(cpufreq_quick_get_max);
1490
1491static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1492{
1493 unsigned int ret_freq = 0;
1494
1495 if (!cpufreq_driver->get)
1496 return ret_freq;
1497
1498 ret_freq = cpufreq_driver->get(policy->cpu);
1499
1500 /*
1501 * Updating inactive policies is invalid, so avoid doing that. Also
1502 * if fast frequency switching is used with the given policy, the check
1503 * against policy->cur is pointless, so skip it in that case too.
1504 */
1505 if (unlikely(policy_is_inactive(policy)) || policy->fast_switch_enabled)
1506 return ret_freq;
1507
1508 if (ret_freq && policy->cur &&
1509 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1510 /* verify no discrepancy between actual and
1511 saved value exists */
1512 if (unlikely(ret_freq != policy->cur)) {
1513 cpufreq_out_of_sync(policy, ret_freq);
1514 schedule_work(&policy->update);
1515 }
1516 }
1517
1518 return ret_freq;
1519}
1520
1521/**
1522 * cpufreq_get - get the current CPU frequency (in kHz)
1523 * @cpu: CPU number
1524 *
1525 * Get the CPU current (static) CPU frequency
1526 */
1527unsigned int cpufreq_get(unsigned int cpu)
1528{
1529 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1530 unsigned int ret_freq = 0;
1531
1532 if (policy) {
1533 down_read(&policy->rwsem);
1534
1535 if (!policy_is_inactive(policy))
1536 ret_freq = __cpufreq_get(policy);
1537
1538 up_read(&policy->rwsem);
1539
1540 cpufreq_cpu_put(policy);
1541 }
1542
1543 return ret_freq;
1544}
1545EXPORT_SYMBOL(cpufreq_get);
1546
1547static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy)
1548{
1549 unsigned int new_freq;
1550
1551 new_freq = cpufreq_driver->get(policy->cpu);
1552 if (!new_freq)
1553 return 0;
1554
1555 if (!policy->cur) {
1556 pr_debug("cpufreq: Driver did not initialize current freq\n");
1557 policy->cur = new_freq;
1558 } else if (policy->cur != new_freq && has_target()) {
1559 cpufreq_out_of_sync(policy, new_freq);
1560 }
1561
1562 return new_freq;
1563}
1564
1565static struct subsys_interface cpufreq_interface = {
1566 .name = "cpufreq",
1567 .subsys = &cpu_subsys,
1568 .add_dev = cpufreq_add_dev,
1569 .remove_dev = cpufreq_remove_dev,
1570};
1571
1572/*
1573 * In case platform wants some specific frequency to be configured
1574 * during suspend..
1575 */
1576int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1577{
1578 int ret;
1579
1580 if (!policy->suspend_freq) {
1581 pr_debug("%s: suspend_freq not defined\n", __func__);
1582 return 0;
1583 }
1584
1585 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1586 policy->suspend_freq);
1587
1588 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1589 CPUFREQ_RELATION_H);
1590 if (ret)
1591 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1592 __func__, policy->suspend_freq, ret);
1593
1594 return ret;
1595}
1596EXPORT_SYMBOL(cpufreq_generic_suspend);
1597
1598/**
1599 * cpufreq_suspend() - Suspend CPUFreq governors
1600 *
1601 * Called during system wide Suspend/Hibernate cycles for suspending governors
1602 * as some platforms can't change frequency after this point in suspend cycle.
1603 * Because some of the devices (like: i2c, regulators, etc) they use for
1604 * changing frequency are suspended quickly after this point.
1605 */
1606void cpufreq_suspend(void)
1607{
1608 struct cpufreq_policy *policy;
1609
1610 if (!cpufreq_driver)
1611 return;
1612
1613 if (!has_target() && !cpufreq_driver->suspend)
1614 goto suspend;
1615
1616 pr_debug("%s: Suspending Governors\n", __func__);
1617
1618 for_each_active_policy(policy) {
1619 if (has_target()) {
1620 down_write(&policy->rwsem);
1621 cpufreq_stop_governor(policy);
1622 up_write(&policy->rwsem);
1623 }
1624
1625 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1626 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1627 policy);
1628 }
1629
1630suspend:
1631 cpufreq_suspended = true;
1632}
1633
1634/**
1635 * cpufreq_resume() - Resume CPUFreq governors
1636 *
1637 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1638 * are suspended with cpufreq_suspend().
1639 */
1640void cpufreq_resume(void)
1641{
1642 struct cpufreq_policy *policy;
1643 int ret;
1644
1645 if (!cpufreq_driver)
1646 return;
1647
1648 cpufreq_suspended = false;
1649
1650 if (!has_target() && !cpufreq_driver->resume)
1651 return;
1652
1653 pr_debug("%s: Resuming Governors\n", __func__);
1654
1655 for_each_active_policy(policy) {
1656 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1657 pr_err("%s: Failed to resume driver: %p\n", __func__,
1658 policy);
1659 } else if (has_target()) {
1660 down_write(&policy->rwsem);
1661 ret = cpufreq_start_governor(policy);
1662 up_write(&policy->rwsem);
1663
1664 if (ret)
1665 pr_err("%s: Failed to start governor for policy: %p\n",
1666 __func__, policy);
1667 }
1668 }
1669}
1670
1671/**
1672 * cpufreq_get_current_driver - return current driver's name
1673 *
1674 * Return the name string of the currently loaded cpufreq driver
1675 * or NULL, if none.
1676 */
1677const char *cpufreq_get_current_driver(void)
1678{
1679 if (cpufreq_driver)
1680 return cpufreq_driver->name;
1681
1682 return NULL;
1683}
1684EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1685
1686/**
1687 * cpufreq_get_driver_data - return current driver data
1688 *
1689 * Return the private data of the currently loaded cpufreq
1690 * driver, or NULL if no cpufreq driver is loaded.
1691 */
1692void *cpufreq_get_driver_data(void)
1693{
1694 if (cpufreq_driver)
1695 return cpufreq_driver->driver_data;
1696
1697 return NULL;
1698}
1699EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1700
1701/*********************************************************************
1702 * NOTIFIER LISTS INTERFACE *
1703 *********************************************************************/
1704
1705/**
1706 * cpufreq_register_notifier - register a driver with cpufreq
1707 * @nb: notifier function to register
1708 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1709 *
1710 * Add a driver to one of two lists: either a list of drivers that
1711 * are notified about clock rate changes (once before and once after
1712 * the transition), or a list of drivers that are notified about
1713 * changes in cpufreq policy.
1714 *
1715 * This function may sleep, and has the same return conditions as
1716 * blocking_notifier_chain_register.
1717 */
1718int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1719{
1720 int ret;
1721
1722 if (cpufreq_disabled())
1723 return -EINVAL;
1724
1725 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1726
1727 switch (list) {
1728 case CPUFREQ_TRANSITION_NOTIFIER:
1729 mutex_lock(&cpufreq_fast_switch_lock);
1730
1731 if (cpufreq_fast_switch_count > 0) {
1732 mutex_unlock(&cpufreq_fast_switch_lock);
1733 return -EBUSY;
1734 }
1735 ret = srcu_notifier_chain_register(
1736 &cpufreq_transition_notifier_list, nb);
1737 if (!ret)
1738 cpufreq_fast_switch_count--;
1739
1740 mutex_unlock(&cpufreq_fast_switch_lock);
1741 break;
1742 case CPUFREQ_POLICY_NOTIFIER:
1743 ret = blocking_notifier_chain_register(
1744 &cpufreq_policy_notifier_list, nb);
1745 break;
1746 default:
1747 ret = -EINVAL;
1748 }
1749
1750 return ret;
1751}
1752EXPORT_SYMBOL(cpufreq_register_notifier);
1753
1754/**
1755 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1756 * @nb: notifier block to be unregistered
1757 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1758 *
1759 * Remove a driver from the CPU frequency notifier list.
1760 *
1761 * This function may sleep, and has the same return conditions as
1762 * blocking_notifier_chain_unregister.
1763 */
1764int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1765{
1766 int ret;
1767
1768 if (cpufreq_disabled())
1769 return -EINVAL;
1770
1771 switch (list) {
1772 case CPUFREQ_TRANSITION_NOTIFIER:
1773 mutex_lock(&cpufreq_fast_switch_lock);
1774
1775 ret = srcu_notifier_chain_unregister(
1776 &cpufreq_transition_notifier_list, nb);
1777 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1778 cpufreq_fast_switch_count++;
1779
1780 mutex_unlock(&cpufreq_fast_switch_lock);
1781 break;
1782 case CPUFREQ_POLICY_NOTIFIER:
1783 ret = blocking_notifier_chain_unregister(
1784 &cpufreq_policy_notifier_list, nb);
1785 break;
1786 default:
1787 ret = -EINVAL;
1788 }
1789
1790 return ret;
1791}
1792EXPORT_SYMBOL(cpufreq_unregister_notifier);
1793
1794
1795/*********************************************************************
1796 * GOVERNORS *
1797 *********************************************************************/
1798
1799/**
1800 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1801 * @policy: cpufreq policy to switch the frequency for.
1802 * @target_freq: New frequency to set (may be approximate).
1803 *
1804 * Carry out a fast frequency switch without sleeping.
1805 *
1806 * The driver's ->fast_switch() callback invoked by this function must be
1807 * suitable for being called from within RCU-sched read-side critical sections
1808 * and it is expected to select the minimum available frequency greater than or
1809 * equal to @target_freq (CPUFREQ_RELATION_L).
1810 *
1811 * This function must not be called if policy->fast_switch_enabled is unset.
1812 *
1813 * Governors calling this function must guarantee that it will never be invoked
1814 * twice in parallel for the same policy and that it will never be called in
1815 * parallel with either ->target() or ->target_index() for the same policy.
1816 *
1817 * If CPUFREQ_ENTRY_INVALID is returned by the driver's ->fast_switch()
1818 * callback to indicate an error condition, the hardware configuration must be
1819 * preserved.
1820 */
1821unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
1822 unsigned int target_freq)
1823{
1824 target_freq = clamp_val(target_freq, policy->min, policy->max);
1825
1826 return cpufreq_driver->fast_switch(policy, target_freq);
1827}
1828EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
1829
1830/* Must set freqs->new to intermediate frequency */
1831static int __target_intermediate(struct cpufreq_policy *policy,
1832 struct cpufreq_freqs *freqs, int index)
1833{
1834 int ret;
1835
1836 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1837
1838 /* We don't need to switch to intermediate freq */
1839 if (!freqs->new)
1840 return 0;
1841
1842 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1843 __func__, policy->cpu, freqs->old, freqs->new);
1844
1845 cpufreq_freq_transition_begin(policy, freqs);
1846 ret = cpufreq_driver->target_intermediate(policy, index);
1847 cpufreq_freq_transition_end(policy, freqs, ret);
1848
1849 if (ret)
1850 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1851 __func__, ret);
1852
1853 return ret;
1854}
1855
1856static int __target_index(struct cpufreq_policy *policy, int index)
1857{
1858 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1859 unsigned int intermediate_freq = 0;
1860 unsigned int newfreq = policy->freq_table[index].frequency;
1861 int retval = -EINVAL;
1862 bool notify;
1863
1864 if (newfreq == policy->cur)
1865 return 0;
1866
1867 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1868 if (notify) {
1869 /* Handle switching to intermediate frequency */
1870 if (cpufreq_driver->get_intermediate) {
1871 retval = __target_intermediate(policy, &freqs, index);
1872 if (retval)
1873 return retval;
1874
1875 intermediate_freq = freqs.new;
1876 /* Set old freq to intermediate */
1877 if (intermediate_freq)
1878 freqs.old = freqs.new;
1879 }
1880
1881 freqs.new = newfreq;
1882 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1883 __func__, policy->cpu, freqs.old, freqs.new);
1884
1885 cpufreq_freq_transition_begin(policy, &freqs);
1886 }
1887
1888 retval = cpufreq_driver->target_index(policy, index);
1889 if (retval)
1890 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
1891 retval);
1892
1893 if (notify) {
1894 cpufreq_freq_transition_end(policy, &freqs, retval);
1895
1896 /*
1897 * Failed after setting to intermediate freq? Driver should have
1898 * reverted back to initial frequency and so should we. Check
1899 * here for intermediate_freq instead of get_intermediate, in
1900 * case we haven't switched to intermediate freq at all.
1901 */
1902 if (unlikely(retval && intermediate_freq)) {
1903 freqs.old = intermediate_freq;
1904 freqs.new = policy->restore_freq;
1905 cpufreq_freq_transition_begin(policy, &freqs);
1906 cpufreq_freq_transition_end(policy, &freqs, 0);
1907 }
1908 }
1909
1910 return retval;
1911}
1912
1913int __cpufreq_driver_target(struct cpufreq_policy *policy,
1914 unsigned int target_freq,
1915 unsigned int relation)
1916{
1917 unsigned int old_target_freq = target_freq;
1918 int index;
1919
1920 if (cpufreq_disabled())
1921 return -ENODEV;
1922
1923 /* Make sure that target_freq is within supported range */
1924 target_freq = clamp_val(target_freq, policy->min, policy->max);
1925
1926 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1927 policy->cpu, target_freq, relation, old_target_freq);
1928
1929 /*
1930 * This might look like a redundant call as we are checking it again
1931 * after finding index. But it is left intentionally for cases where
1932 * exactly same freq is called again and so we can save on few function
1933 * calls.
1934 */
1935 if (target_freq == policy->cur)
1936 return 0;
1937
1938 /* Save last value to restore later on errors */
1939 policy->restore_freq = policy->cur;
1940
1941 if (cpufreq_driver->target)
1942 return cpufreq_driver->target(policy, target_freq, relation);
1943
1944 if (!cpufreq_driver->target_index)
1945 return -EINVAL;
1946
1947 index = cpufreq_frequency_table_target(policy, target_freq, relation);
1948
1949 return __target_index(policy, index);
1950}
1951EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1952
1953int cpufreq_driver_target(struct cpufreq_policy *policy,
1954 unsigned int target_freq,
1955 unsigned int relation)
1956{
1957 int ret = -EINVAL;
1958
1959 down_write(&policy->rwsem);
1960
1961 ret = __cpufreq_driver_target(policy, target_freq, relation);
1962
1963 up_write(&policy->rwsem);
1964
1965 return ret;
1966}
1967EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1968
1969__weak struct cpufreq_governor *cpufreq_fallback_governor(void)
1970{
1971 return NULL;
1972}
1973
1974static int cpufreq_init_governor(struct cpufreq_policy *policy)
1975{
1976 int ret;
1977
1978 /* Don't start any governor operations if we are entering suspend */
1979 if (cpufreq_suspended)
1980 return 0;
1981 /*
1982 * Governor might not be initiated here if ACPI _PPC changed
1983 * notification happened, so check it.
1984 */
1985 if (!policy->governor)
1986 return -EINVAL;
1987
1988 if (policy->governor->max_transition_latency &&
1989 policy->cpuinfo.transition_latency >
1990 policy->governor->max_transition_latency) {
1991 struct cpufreq_governor *gov = cpufreq_fallback_governor();
1992
1993 if (gov) {
1994 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
1995 policy->governor->name, gov->name);
1996 policy->governor = gov;
1997 } else {
1998 return -EINVAL;
1999 }
2000 }
2001
2002 if (!try_module_get(policy->governor->owner))
2003 return -EINVAL;
2004
2005 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2006
2007 if (policy->governor->init) {
2008 ret = policy->governor->init(policy);
2009 if (ret) {
2010 module_put(policy->governor->owner);
2011 return ret;
2012 }
2013 }
2014
2015 return 0;
2016}
2017
2018static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2019{
2020 if (cpufreq_suspended || !policy->governor)
2021 return;
2022
2023 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2024
2025 if (policy->governor->exit)
2026 policy->governor->exit(policy);
2027
2028 module_put(policy->governor->owner);
2029}
2030
2031static int cpufreq_start_governor(struct cpufreq_policy *policy)
2032{
2033 int ret;
2034
2035 if (cpufreq_suspended)
2036 return 0;
2037
2038 if (!policy->governor)
2039 return -EINVAL;
2040
2041 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2042
2043 if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
2044 cpufreq_update_current_freq(policy);
2045
2046 if (policy->governor->start) {
2047 ret = policy->governor->start(policy);
2048 if (ret)
2049 return ret;
2050 }
2051
2052 if (policy->governor->limits)
2053 policy->governor->limits(policy);
2054
2055 return 0;
2056}
2057
2058static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2059{
2060 if (cpufreq_suspended || !policy->governor)
2061 return;
2062
2063 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2064
2065 if (policy->governor->stop)
2066 policy->governor->stop(policy);
2067}
2068
2069static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2070{
2071 if (cpufreq_suspended || !policy->governor)
2072 return;
2073
2074 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2075
2076 if (policy->governor->limits)
2077 policy->governor->limits(policy);
2078}
2079
2080int cpufreq_register_governor(struct cpufreq_governor *governor)
2081{
2082 int err;
2083
2084 if (!governor)
2085 return -EINVAL;
2086
2087 if (cpufreq_disabled())
2088 return -ENODEV;
2089
2090 mutex_lock(&cpufreq_governor_mutex);
2091
2092 err = -EBUSY;
2093 if (!find_governor(governor->name)) {
2094 err = 0;
2095 list_add(&governor->governor_list, &cpufreq_governor_list);
2096 }
2097
2098 mutex_unlock(&cpufreq_governor_mutex);
2099 return err;
2100}
2101EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2102
2103void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2104{
2105 struct cpufreq_policy *policy;
2106 unsigned long flags;
2107
2108 if (!governor)
2109 return;
2110
2111 if (cpufreq_disabled())
2112 return;
2113
2114 /* clear last_governor for all inactive policies */
2115 read_lock_irqsave(&cpufreq_driver_lock, flags);
2116 for_each_inactive_policy(policy) {
2117 if (!strcmp(policy->last_governor, governor->name)) {
2118 policy->governor = NULL;
2119 strcpy(policy->last_governor, "\0");
2120 }
2121 }
2122 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2123
2124 mutex_lock(&cpufreq_governor_mutex);
2125 list_del(&governor->governor_list);
2126 mutex_unlock(&cpufreq_governor_mutex);
2127 return;
2128}
2129EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2130
2131
2132/*********************************************************************
2133 * POLICY INTERFACE *
2134 *********************************************************************/
2135
2136/**
2137 * cpufreq_get_policy - get the current cpufreq_policy
2138 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2139 * is written
2140 *
2141 * Reads the current cpufreq policy.
2142 */
2143int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2144{
2145 struct cpufreq_policy *cpu_policy;
2146 if (!policy)
2147 return -EINVAL;
2148
2149 cpu_policy = cpufreq_cpu_get(cpu);
2150 if (!cpu_policy)
2151 return -EINVAL;
2152
2153 memcpy(policy, cpu_policy, sizeof(*policy));
2154
2155 cpufreq_cpu_put(cpu_policy);
2156 return 0;
2157}
2158EXPORT_SYMBOL(cpufreq_get_policy);
2159
2160/*
2161 * policy : current policy.
2162 * new_policy: policy to be set.
2163 */
2164static int cpufreq_set_policy(struct cpufreq_policy *policy,
2165 struct cpufreq_policy *new_policy)
2166{
2167 struct cpufreq_governor *old_gov;
2168 int ret;
2169
2170 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2171 new_policy->cpu, new_policy->min, new_policy->max);
2172
2173 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2174
2175 /*
2176 * This check works well when we store new min/max freq attributes,
2177 * because new_policy is a copy of policy with one field updated.
2178 */
2179 if (new_policy->min > new_policy->max)
2180 return -EINVAL;
2181
2182 /* verify the cpu speed can be set within this limit */
2183 ret = cpufreq_driver->verify(new_policy);
2184 if (ret)
2185 return ret;
2186
2187 /* adjust if necessary - all reasons */
2188 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2189 CPUFREQ_ADJUST, new_policy);
2190
2191 /*
2192 * verify the cpu speed can be set within this limit, which might be
2193 * different to the first one
2194 */
2195 ret = cpufreq_driver->verify(new_policy);
2196 if (ret)
2197 return ret;
2198
2199 /* notification of the new policy */
2200 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2201 CPUFREQ_NOTIFY, new_policy);
2202
2203 policy->min = new_policy->min;
2204 policy->max = new_policy->max;
2205
2206 policy->cached_target_freq = UINT_MAX;
2207
2208 pr_debug("new min and max freqs are %u - %u kHz\n",
2209 policy->min, policy->max);
2210
2211 if (cpufreq_driver->setpolicy) {
2212 policy->policy = new_policy->policy;
2213 pr_debug("setting range\n");
2214 return cpufreq_driver->setpolicy(new_policy);
2215 }
2216
2217 if (new_policy->governor == policy->governor) {
2218 pr_debug("cpufreq: governor limits update\n");
2219 cpufreq_governor_limits(policy);
2220 return 0;
2221 }
2222
2223 pr_debug("governor switch\n");
2224
2225 /* save old, working values */
2226 old_gov = policy->governor;
2227 /* end old governor */
2228 if (old_gov) {
2229 cpufreq_stop_governor(policy);
2230 cpufreq_exit_governor(policy);
2231 }
2232
2233 /* start new governor */
2234 policy->governor = new_policy->governor;
2235 ret = cpufreq_init_governor(policy);
2236 if (!ret) {
2237 ret = cpufreq_start_governor(policy);
2238 if (!ret) {
2239 pr_debug("cpufreq: governor change\n");
2240 return 0;
2241 }
2242 cpufreq_exit_governor(policy);
2243 }
2244
2245 /* new governor failed, so re-start old one */
2246 pr_debug("starting governor %s failed\n", policy->governor->name);
2247 if (old_gov) {
2248 policy->governor = old_gov;
2249 if (cpufreq_init_governor(policy))
2250 policy->governor = NULL;
2251 else
2252 cpufreq_start_governor(policy);
2253 }
2254
2255 return ret;
2256}
2257
2258/**
2259 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2260 * @cpu: CPU which shall be re-evaluated
2261 *
2262 * Useful for policy notifiers which have different necessities
2263 * at different times.
2264 */
2265void cpufreq_update_policy(unsigned int cpu)
2266{
2267 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2268 struct cpufreq_policy new_policy;
2269
2270 if (!policy)
2271 return;
2272
2273 down_write(&policy->rwsem);
2274
2275 if (policy_is_inactive(policy))
2276 goto unlock;
2277
2278 pr_debug("updating policy for CPU %u\n", cpu);
2279 memcpy(&new_policy, policy, sizeof(*policy));
2280 new_policy.min = policy->user_policy.min;
2281 new_policy.max = policy->user_policy.max;
2282
2283 /*
2284 * BIOS might change freq behind our back
2285 * -> ask driver for current freq and notify governors about a change
2286 */
2287 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
2288 if (cpufreq_suspended)
2289 goto unlock;
2290
2291 new_policy.cur = cpufreq_update_current_freq(policy);
2292 if (WARN_ON(!new_policy.cur))
2293 goto unlock;
2294 }
2295
2296 cpufreq_set_policy(policy, &new_policy);
2297
2298unlock:
2299 up_write(&policy->rwsem);
2300
2301 cpufreq_cpu_put(policy);
2302}
2303EXPORT_SYMBOL(cpufreq_update_policy);
2304
2305/*********************************************************************
2306 * BOOST *
2307 *********************************************************************/
2308static int cpufreq_boost_set_sw(int state)
2309{
2310 struct cpufreq_policy *policy;
2311 int ret = -EINVAL;
2312
2313 for_each_active_policy(policy) {
2314 if (!policy->freq_table)
2315 continue;
2316
2317 ret = cpufreq_frequency_table_cpuinfo(policy,
2318 policy->freq_table);
2319 if (ret) {
2320 pr_err("%s: Policy frequency update failed\n",
2321 __func__);
2322 break;
2323 }
2324
2325 down_write(&policy->rwsem);
2326 policy->user_policy.max = policy->max;
2327 cpufreq_governor_limits(policy);
2328 up_write(&policy->rwsem);
2329 }
2330
2331 return ret;
2332}
2333
2334int cpufreq_boost_trigger_state(int state)
2335{
2336 unsigned long flags;
2337 int ret = 0;
2338
2339 if (cpufreq_driver->boost_enabled == state)
2340 return 0;
2341
2342 write_lock_irqsave(&cpufreq_driver_lock, flags);
2343 cpufreq_driver->boost_enabled = state;
2344 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2345
2346 ret = cpufreq_driver->set_boost(state);
2347 if (ret) {
2348 write_lock_irqsave(&cpufreq_driver_lock, flags);
2349 cpufreq_driver->boost_enabled = !state;
2350 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2351
2352 pr_err("%s: Cannot %s BOOST\n",
2353 __func__, state ? "enable" : "disable");
2354 }
2355
2356 return ret;
2357}
2358
2359static bool cpufreq_boost_supported(void)
2360{
2361 return likely(cpufreq_driver) && cpufreq_driver->set_boost;
2362}
2363
2364static int create_boost_sysfs_file(void)
2365{
2366 int ret;
2367
2368 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2369 if (ret)
2370 pr_err("%s: cannot register global BOOST sysfs file\n",
2371 __func__);
2372
2373 return ret;
2374}
2375
2376static void remove_boost_sysfs_file(void)
2377{
2378 if (cpufreq_boost_supported())
2379 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2380}
2381
2382int cpufreq_enable_boost_support(void)
2383{
2384 if (!cpufreq_driver)
2385 return -EINVAL;
2386
2387 if (cpufreq_boost_supported())
2388 return 0;
2389
2390 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2391
2392 /* This will get removed on driver unregister */
2393 return create_boost_sysfs_file();
2394}
2395EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2396
2397int cpufreq_boost_enabled(void)
2398{
2399 return cpufreq_driver->boost_enabled;
2400}
2401EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2402
2403/*********************************************************************
2404 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2405 *********************************************************************/
2406static enum cpuhp_state hp_online;
2407
2408/**
2409 * cpufreq_register_driver - register a CPU Frequency driver
2410 * @driver_data: A struct cpufreq_driver containing the values#
2411 * submitted by the CPU Frequency driver.
2412 *
2413 * Registers a CPU Frequency driver to this core code. This code
2414 * returns zero on success, -EEXIST when another driver got here first
2415 * (and isn't unregistered in the meantime).
2416 *
2417 */
2418int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2419{
2420 unsigned long flags;
2421 int ret;
2422
2423 if (cpufreq_disabled())
2424 return -ENODEV;
2425
2426 if (!driver_data || !driver_data->verify || !driver_data->init ||
2427 !(driver_data->setpolicy || driver_data->target_index ||
2428 driver_data->target) ||
2429 (driver_data->setpolicy && (driver_data->target_index ||
2430 driver_data->target)) ||
2431 (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
2432 return -EINVAL;
2433
2434 pr_debug("trying to register driver %s\n", driver_data->name);
2435
2436 /* Protect against concurrent CPU online/offline. */
2437 get_online_cpus();
2438
2439 write_lock_irqsave(&cpufreq_driver_lock, flags);
2440 if (cpufreq_driver) {
2441 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2442 ret = -EEXIST;
2443 goto out;
2444 }
2445 cpufreq_driver = driver_data;
2446 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2447
2448 if (driver_data->setpolicy)
2449 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2450
2451 if (cpufreq_boost_supported()) {
2452 ret = create_boost_sysfs_file();
2453 if (ret)
2454 goto err_null_driver;
2455 }
2456
2457 ret = subsys_interface_register(&cpufreq_interface);
2458 if (ret)
2459 goto err_boost_unreg;
2460
2461 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2462 list_empty(&cpufreq_policy_list)) {
2463 /* if all ->init() calls failed, unregister */
2464 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2465 driver_data->name);
2466 goto err_if_unreg;
2467 }
2468
2469 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online",
2470 cpufreq_online,
2471 cpufreq_offline);
2472 if (ret < 0)
2473 goto err_if_unreg;
2474 hp_online = ret;
2475 ret = 0;
2476
2477 pr_debug("driver %s up and running\n", driver_data->name);
2478 goto out;
2479
2480err_if_unreg:
2481 subsys_interface_unregister(&cpufreq_interface);
2482err_boost_unreg:
2483 remove_boost_sysfs_file();
2484err_null_driver:
2485 write_lock_irqsave(&cpufreq_driver_lock, flags);
2486 cpufreq_driver = NULL;
2487 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2488out:
2489 put_online_cpus();
2490 return ret;
2491}
2492EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2493
2494/**
2495 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2496 *
2497 * Unregister the current CPUFreq driver. Only call this if you have
2498 * the right to do so, i.e. if you have succeeded in initialising before!
2499 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2500 * currently not initialised.
2501 */
2502int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2503{
2504 unsigned long flags;
2505
2506 if (!cpufreq_driver || (driver != cpufreq_driver))
2507 return -EINVAL;
2508
2509 pr_debug("unregistering driver %s\n", driver->name);
2510
2511 /* Protect against concurrent cpu hotplug */
2512 get_online_cpus();
2513 subsys_interface_unregister(&cpufreq_interface);
2514 remove_boost_sysfs_file();
2515 cpuhp_remove_state_nocalls(hp_online);
2516
2517 write_lock_irqsave(&cpufreq_driver_lock, flags);
2518
2519 cpufreq_driver = NULL;
2520
2521 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2522 put_online_cpus();
2523
2524 return 0;
2525}
2526EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2527
2528/*
2529 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2530 * or mutexes when secondary CPUs are halted.
2531 */
2532static struct syscore_ops cpufreq_syscore_ops = {
2533 .shutdown = cpufreq_suspend,
2534};
2535
2536struct kobject *cpufreq_global_kobject;
2537EXPORT_SYMBOL(cpufreq_global_kobject);
2538
2539static int __init cpufreq_core_init(void)
2540{
2541 if (cpufreq_disabled())
2542 return -ENODEV;
2543
2544 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2545 BUG_ON(!cpufreq_global_kobject);
2546
2547 register_syscore_ops(&cpufreq_syscore_ops);
2548
2549 return 0;
2550}
2551core_initcall(cpufreq_core_init);