2 * linux/drivers/cpufreq/cpufreq.c
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
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
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.
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
34 static LIST_HEAD(cpufreq_policy_list);
36 static inline bool policy_is_inactive(struct cpufreq_policy *policy)
38 return cpumask_empty(policy->cpus);
41 static bool suitable_policy(struct cpufreq_policy *policy, bool active)
43 return active == !policy_is_inactive(policy);
46 /* Finds Next Acive/Inactive policy */
47 static struct cpufreq_policy *next_policy(struct cpufreq_policy *policy,
51 policy = list_next_entry(policy, policy_list);
53 /* No more policies in the list */
54 if (&policy->policy_list == &cpufreq_policy_list)
56 } while (!suitable_policy(policy, active));
61 static struct cpufreq_policy *first_policy(bool active)
63 struct cpufreq_policy *policy;
65 /* No policies in the list */
66 if (list_empty(&cpufreq_policy_list))
69 policy = list_first_entry(&cpufreq_policy_list, typeof(*policy),
72 if (!suitable_policy(policy, active))
73 policy = next_policy(policy, active);
78 /* Macros to iterate over CPU policies */
79 #define for_each_suitable_policy(__policy, __active) \
80 for (__policy = first_policy(__active); \
82 __policy = next_policy(__policy, __active))
84 #define for_each_active_policy(__policy) \
85 for_each_suitable_policy(__policy, true)
86 #define for_each_inactive_policy(__policy) \
87 for_each_suitable_policy(__policy, false)
89 #define for_each_policy(__policy) \
90 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
92 /* Iterate over governors */
93 static LIST_HEAD(cpufreq_governor_list);
94 #define for_each_governor(__governor) \
95 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
98 * The "cpufreq driver" - the arch- or hardware-dependent low
99 * level driver of CPUFreq support, and its spinlock. This lock
100 * also protects the cpufreq_cpu_data array.
102 static struct cpufreq_driver *cpufreq_driver;
103 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
104 static DEFINE_RWLOCK(cpufreq_driver_lock);
105 DEFINE_MUTEX(cpufreq_governor_lock);
107 /* Flag to suspend/resume CPUFreq governors */
108 static bool cpufreq_suspended;
110 static inline bool has_target(void)
112 return cpufreq_driver->target_index || cpufreq_driver->target;
115 /* internal prototypes */
116 static int __cpufreq_governor(struct cpufreq_policy *policy,
118 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
119 static void handle_update(struct work_struct *work);
122 * Two notifier lists: the "policy" list is involved in the
123 * validation process for a new CPU frequency policy; the
124 * "transition" list for kernel code that needs to handle
125 * changes to devices when the CPU clock speed changes.
126 * The mutex locks both lists.
128 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
129 static struct srcu_notifier_head cpufreq_transition_notifier_list;
131 static bool init_cpufreq_transition_notifier_list_called;
132 static int __init init_cpufreq_transition_notifier_list(void)
134 srcu_init_notifier_head(&cpufreq_transition_notifier_list);
135 init_cpufreq_transition_notifier_list_called = true;
138 pure_initcall(init_cpufreq_transition_notifier_list);
140 static int off __read_mostly;
141 static int cpufreq_disabled(void)
145 void disable_cpufreq(void)
149 static DEFINE_MUTEX(cpufreq_governor_mutex);
151 bool have_governor_per_policy(void)
153 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
155 EXPORT_SYMBOL_GPL(have_governor_per_policy);
157 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
159 if (have_governor_per_policy())
160 return &policy->kobj;
162 return cpufreq_global_kobject;
164 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
166 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
168 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
170 return policy && !policy_is_inactive(policy) ?
171 policy->freq_table : NULL;
173 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
175 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
181 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
183 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
184 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
185 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
186 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
187 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
188 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
190 idle_time = cur_wall_time - busy_time;
192 *wall = cputime_to_usecs(cur_wall_time);
194 return cputime_to_usecs(idle_time);
197 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
199 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
201 if (idle_time == -1ULL)
202 return get_cpu_idle_time_jiffy(cpu, wall);
204 idle_time += get_cpu_iowait_time_us(cpu, wall);
208 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
211 * This is a generic cpufreq init() routine which can be used by cpufreq
212 * drivers of SMP systems. It will do following:
213 * - validate & show freq table passed
214 * - set policies transition latency
215 * - policy->cpus with all possible CPUs
217 int cpufreq_generic_init(struct cpufreq_policy *policy,
218 struct cpufreq_frequency_table *table,
219 unsigned int transition_latency)
223 ret = cpufreq_table_validate_and_show(policy, table);
225 pr_err("%s: invalid frequency table: %d\n", __func__, ret);
229 policy->cpuinfo.transition_latency = transition_latency;
232 * The driver only supports the SMP configuration where all processors
233 * share the clock and voltage and clock.
235 cpumask_setall(policy->cpus);
239 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
241 /* Only for cpufreq core internal use */
242 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
244 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
246 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
249 unsigned int cpufreq_generic_get(unsigned int cpu)
251 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
253 if (!policy || IS_ERR(policy->clk)) {
254 pr_err("%s: No %s associated to cpu: %d\n",
255 __func__, policy ? "clk" : "policy", cpu);
259 return clk_get_rate(policy->clk) / 1000;
261 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
264 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
266 * @cpu: cpu to find policy for.
268 * This returns policy for 'cpu', returns NULL if it doesn't exist.
269 * It also increments the kobject reference count to mark it busy and so would
270 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
271 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
272 * freed as that depends on the kobj count.
274 * Return: A valid policy on success, otherwise NULL on failure.
276 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
278 struct cpufreq_policy *policy = NULL;
281 if (WARN_ON(cpu >= nr_cpu_ids))
284 /* get the cpufreq driver */
285 read_lock_irqsave(&cpufreq_driver_lock, flags);
287 if (cpufreq_driver) {
289 policy = cpufreq_cpu_get_raw(cpu);
291 kobject_get(&policy->kobj);
294 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
298 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
301 * cpufreq_cpu_put: Decrements the usage count of a policy
303 * @policy: policy earlier returned by cpufreq_cpu_get().
305 * This decrements the kobject reference count incremented earlier by calling
308 void cpufreq_cpu_put(struct cpufreq_policy *policy)
310 kobject_put(&policy->kobj);
312 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
314 /*********************************************************************
315 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
316 *********************************************************************/
319 * adjust_jiffies - adjust the system "loops_per_jiffy"
321 * This function alters the system "loops_per_jiffy" for the clock
322 * speed change. Note that loops_per_jiffy cannot be updated on SMP
323 * systems as each CPU might be scaled differently. So, use the arch
324 * per-CPU loops_per_jiffy value wherever possible.
326 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
329 static unsigned long l_p_j_ref;
330 static unsigned int l_p_j_ref_freq;
332 if (ci->flags & CPUFREQ_CONST_LOOPS)
335 if (!l_p_j_ref_freq) {
336 l_p_j_ref = loops_per_jiffy;
337 l_p_j_ref_freq = ci->old;
338 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
339 l_p_j_ref, l_p_j_ref_freq);
341 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
342 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
344 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
345 loops_per_jiffy, ci->new);
350 static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
351 struct cpufreq_freqs *freqs, unsigned int state)
353 BUG_ON(irqs_disabled());
355 if (cpufreq_disabled())
358 freqs->flags = cpufreq_driver->flags;
359 pr_debug("notification %u of frequency transition to %u kHz\n",
364 case CPUFREQ_PRECHANGE:
365 /* detect if the driver reported a value as "old frequency"
366 * which is not equal to what the cpufreq core thinks is
369 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
370 if ((policy) && (policy->cpu == freqs->cpu) &&
371 (policy->cur) && (policy->cur != freqs->old)) {
372 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
373 freqs->old, policy->cur);
374 freqs->old = policy->cur;
377 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
378 CPUFREQ_PRECHANGE, freqs);
379 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
382 case CPUFREQ_POSTCHANGE:
383 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
384 pr_debug("FREQ: %lu - CPU: %lu\n",
385 (unsigned long)freqs->new, (unsigned long)freqs->cpu);
386 trace_cpu_frequency(freqs->new, freqs->cpu);
387 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
388 CPUFREQ_POSTCHANGE, freqs);
389 if (likely(policy) && likely(policy->cpu == freqs->cpu))
390 policy->cur = freqs->new;
396 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
397 * on frequency transition.
399 * This function calls the transition notifiers and the "adjust_jiffies"
400 * function. It is called twice on all CPU frequency changes that have
403 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
404 struct cpufreq_freqs *freqs, unsigned int state)
406 for_each_cpu(freqs->cpu, policy->cpus)
407 __cpufreq_notify_transition(policy, freqs, state);
410 /* Do post notifications when there are chances that transition has failed */
411 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
412 struct cpufreq_freqs *freqs, int transition_failed)
414 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
415 if (!transition_failed)
418 swap(freqs->old, freqs->new);
419 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
420 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
423 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
424 struct cpufreq_freqs *freqs)
428 * Catch double invocations of _begin() which lead to self-deadlock.
429 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
430 * doesn't invoke _begin() on their behalf, and hence the chances of
431 * double invocations are very low. Moreover, there are scenarios
432 * where these checks can emit false-positive warnings in these
433 * drivers; so we avoid that by skipping them altogether.
435 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
436 && current == policy->transition_task);
439 wait_event(policy->transition_wait, !policy->transition_ongoing);
441 spin_lock(&policy->transition_lock);
443 if (unlikely(policy->transition_ongoing)) {
444 spin_unlock(&policy->transition_lock);
448 policy->transition_ongoing = true;
449 policy->transition_task = current;
451 spin_unlock(&policy->transition_lock);
453 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
455 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
457 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
458 struct cpufreq_freqs *freqs, int transition_failed)
460 if (unlikely(WARN_ON(!policy->transition_ongoing)))
463 cpufreq_notify_post_transition(policy, freqs, transition_failed);
465 policy->transition_ongoing = false;
466 policy->transition_task = NULL;
468 wake_up(&policy->transition_wait);
470 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
473 /*********************************************************************
475 *********************************************************************/
476 static ssize_t show_boost(struct kobject *kobj,
477 struct attribute *attr, char *buf)
479 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
482 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
483 const char *buf, size_t count)
487 ret = sscanf(buf, "%d", &enable);
488 if (ret != 1 || enable < 0 || enable > 1)
491 if (cpufreq_boost_trigger_state(enable)) {
492 pr_err("%s: Cannot %s BOOST!\n",
493 __func__, enable ? "enable" : "disable");
497 pr_debug("%s: cpufreq BOOST %s\n",
498 __func__, enable ? "enabled" : "disabled");
502 define_one_global_rw(boost);
504 static struct cpufreq_governor *find_governor(const char *str_governor)
506 struct cpufreq_governor *t;
509 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
516 * cpufreq_parse_governor - parse a governor string
518 static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
519 struct cpufreq_governor **governor)
526 if (cpufreq_driver->setpolicy) {
527 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
528 *policy = CPUFREQ_POLICY_PERFORMANCE;
530 } else if (!strncasecmp(str_governor, "powersave",
532 *policy = CPUFREQ_POLICY_POWERSAVE;
536 struct cpufreq_governor *t;
538 mutex_lock(&cpufreq_governor_mutex);
540 t = find_governor(str_governor);
545 mutex_unlock(&cpufreq_governor_mutex);
546 ret = request_module("cpufreq_%s", str_governor);
547 mutex_lock(&cpufreq_governor_mutex);
550 t = find_governor(str_governor);
558 mutex_unlock(&cpufreq_governor_mutex);
565 * cpufreq_per_cpu_attr_read() / show_##file_name() -
566 * print out cpufreq information
568 * Write out information from cpufreq_driver->policy[cpu]; object must be
572 #define show_one(file_name, object) \
573 static ssize_t show_##file_name \
574 (struct cpufreq_policy *policy, char *buf) \
576 return sprintf(buf, "%u\n", policy->object); \
579 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
580 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
581 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
582 show_one(scaling_min_freq, min);
583 show_one(scaling_max_freq, max);
585 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
589 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
590 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
592 ret = sprintf(buf, "%u\n", policy->cur);
596 static int cpufreq_set_policy(struct cpufreq_policy *policy,
597 struct cpufreq_policy *new_policy);
600 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
602 #define store_one(file_name, object) \
603 static ssize_t store_##file_name \
604 (struct cpufreq_policy *policy, const char *buf, size_t count) \
607 struct cpufreq_policy new_policy; \
609 memcpy(&new_policy, policy, sizeof(*policy)); \
611 ret = sscanf(buf, "%u", &new_policy.object); \
615 temp = new_policy.object; \
616 ret = cpufreq_set_policy(policy, &new_policy); \
618 policy->user_policy.object = temp; \
620 return ret ? ret : count; \
623 store_one(scaling_min_freq, min);
624 store_one(scaling_max_freq, max);
627 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
629 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
632 unsigned int cur_freq = __cpufreq_get(policy);
634 return sprintf(buf, "<unknown>");
635 return sprintf(buf, "%u\n", cur_freq);
639 * show_scaling_governor - show the current policy for the specified CPU
641 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
643 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
644 return sprintf(buf, "powersave\n");
645 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
646 return sprintf(buf, "performance\n");
647 else if (policy->governor)
648 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
649 policy->governor->name);
654 * store_scaling_governor - store policy for the specified CPU
656 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
657 const char *buf, size_t count)
660 char str_governor[16];
661 struct cpufreq_policy new_policy;
663 memcpy(&new_policy, policy, sizeof(*policy));
665 ret = sscanf(buf, "%15s", str_governor);
669 if (cpufreq_parse_governor(str_governor, &new_policy.policy,
670 &new_policy.governor))
673 ret = cpufreq_set_policy(policy, &new_policy);
677 policy->user_policy.policy = policy->policy;
682 * show_scaling_driver - show the cpufreq driver currently loaded
684 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
686 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
690 * show_scaling_available_governors - show the available CPUfreq governors
692 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
696 struct cpufreq_governor *t;
699 i += sprintf(buf, "performance powersave");
703 for_each_governor(t) {
704 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
705 - (CPUFREQ_NAME_LEN + 2)))
707 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
710 i += sprintf(&buf[i], "\n");
714 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
719 for_each_cpu(cpu, mask) {
721 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
722 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
723 if (i >= (PAGE_SIZE - 5))
726 i += sprintf(&buf[i], "\n");
729 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
732 * show_related_cpus - show the CPUs affected by each transition even if
733 * hw coordination is in use
735 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
737 return cpufreq_show_cpus(policy->related_cpus, buf);
741 * show_affected_cpus - show the CPUs affected by each transition
743 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
745 return cpufreq_show_cpus(policy->cpus, buf);
748 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
749 const char *buf, size_t count)
751 unsigned int freq = 0;
754 if (!policy->governor || !policy->governor->store_setspeed)
757 ret = sscanf(buf, "%u", &freq);
761 policy->governor->store_setspeed(policy, freq);
766 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
768 if (!policy->governor || !policy->governor->show_setspeed)
769 return sprintf(buf, "<unsupported>\n");
771 return policy->governor->show_setspeed(policy, buf);
775 * show_bios_limit - show the current cpufreq HW/BIOS limitation
777 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
781 if (cpufreq_driver->bios_limit) {
782 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
784 return sprintf(buf, "%u\n", limit);
786 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
789 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
790 cpufreq_freq_attr_ro(cpuinfo_min_freq);
791 cpufreq_freq_attr_ro(cpuinfo_max_freq);
792 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
793 cpufreq_freq_attr_ro(scaling_available_governors);
794 cpufreq_freq_attr_ro(scaling_driver);
795 cpufreq_freq_attr_ro(scaling_cur_freq);
796 cpufreq_freq_attr_ro(bios_limit);
797 cpufreq_freq_attr_ro(related_cpus);
798 cpufreq_freq_attr_ro(affected_cpus);
799 cpufreq_freq_attr_rw(scaling_min_freq);
800 cpufreq_freq_attr_rw(scaling_max_freq);
801 cpufreq_freq_attr_rw(scaling_governor);
802 cpufreq_freq_attr_rw(scaling_setspeed);
804 static struct attribute *default_attrs[] = {
805 &cpuinfo_min_freq.attr,
806 &cpuinfo_max_freq.attr,
807 &cpuinfo_transition_latency.attr,
808 &scaling_min_freq.attr,
809 &scaling_max_freq.attr,
812 &scaling_governor.attr,
813 &scaling_driver.attr,
814 &scaling_available_governors.attr,
815 &scaling_setspeed.attr,
819 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
820 #define to_attr(a) container_of(a, struct freq_attr, attr)
822 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
824 struct cpufreq_policy *policy = to_policy(kobj);
825 struct freq_attr *fattr = to_attr(attr);
828 down_read(&policy->rwsem);
831 ret = fattr->show(policy, buf);
835 up_read(&policy->rwsem);
840 static ssize_t store(struct kobject *kobj, struct attribute *attr,
841 const char *buf, size_t count)
843 struct cpufreq_policy *policy = to_policy(kobj);
844 struct freq_attr *fattr = to_attr(attr);
845 ssize_t ret = -EINVAL;
849 if (!cpu_online(policy->cpu))
852 down_write(&policy->rwsem);
854 /* Updating inactive policies is invalid, so avoid doing that. */
855 if (unlikely(policy_is_inactive(policy))) {
857 goto unlock_policy_rwsem;
861 ret = fattr->store(policy, buf, count);
866 up_write(&policy->rwsem);
873 static void cpufreq_sysfs_release(struct kobject *kobj)
875 struct cpufreq_policy *policy = to_policy(kobj);
876 pr_debug("last reference is dropped\n");
877 complete(&policy->kobj_unregister);
880 static const struct sysfs_ops sysfs_ops = {
885 static struct kobj_type ktype_cpufreq = {
886 .sysfs_ops = &sysfs_ops,
887 .default_attrs = default_attrs,
888 .release = cpufreq_sysfs_release,
891 struct kobject *cpufreq_global_kobject;
892 EXPORT_SYMBOL(cpufreq_global_kobject);
894 static int cpufreq_global_kobject_usage;
896 int cpufreq_get_global_kobject(void)
898 if (!cpufreq_global_kobject_usage++)
899 return kobject_add(cpufreq_global_kobject,
900 &cpu_subsys.dev_root->kobj, "%s", "cpufreq");
904 EXPORT_SYMBOL(cpufreq_get_global_kobject);
906 void cpufreq_put_global_kobject(void)
908 if (!--cpufreq_global_kobject_usage)
909 kobject_del(cpufreq_global_kobject);
911 EXPORT_SYMBOL(cpufreq_put_global_kobject);
913 int cpufreq_sysfs_create_file(const struct attribute *attr)
915 int ret = cpufreq_get_global_kobject();
918 ret = sysfs_create_file(cpufreq_global_kobject, attr);
920 cpufreq_put_global_kobject();
925 EXPORT_SYMBOL(cpufreq_sysfs_create_file);
927 void cpufreq_sysfs_remove_file(const struct attribute *attr)
929 sysfs_remove_file(cpufreq_global_kobject, attr);
930 cpufreq_put_global_kobject();
932 EXPORT_SYMBOL(cpufreq_sysfs_remove_file);
934 static int add_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
936 struct device *cpu_dev;
938 pr_debug("%s: Adding symlink for CPU: %u\n", __func__, cpu);
943 cpu_dev = get_cpu_device(cpu);
944 if (WARN_ON(!cpu_dev))
947 return sysfs_create_link(&cpu_dev->kobj, &policy->kobj, "cpufreq");
950 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
952 struct device *cpu_dev;
954 pr_debug("%s: Removing symlink for CPU: %u\n", __func__, cpu);
956 cpu_dev = get_cpu_device(cpu);
957 if (WARN_ON(!cpu_dev))
960 sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
963 /* Add/remove symlinks for all related CPUs */
964 static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
969 /* Some related CPUs might not be present (physically hotplugged) */
970 for_each_cpu(j, policy->real_cpus) {
971 if (j == policy->kobj_cpu)
974 ret = add_cpu_dev_symlink(policy, j);
982 static void cpufreq_remove_dev_symlink(struct cpufreq_policy *policy)
986 /* Some related CPUs might not be present (physically hotplugged) */
987 for_each_cpu(j, policy->real_cpus) {
988 if (j == policy->kobj_cpu)
991 remove_cpu_dev_symlink(policy, j);
995 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
997 struct freq_attr **drv_attr;
1000 /* set up files for this cpu device */
1001 drv_attr = cpufreq_driver->attr;
1002 while (drv_attr && *drv_attr) {
1003 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1008 if (cpufreq_driver->get) {
1009 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1014 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1018 if (cpufreq_driver->bios_limit) {
1019 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1024 return cpufreq_add_dev_symlink(policy);
1027 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1029 struct cpufreq_governor *gov = NULL;
1030 struct cpufreq_policy new_policy;
1032 memcpy(&new_policy, policy, sizeof(*policy));
1034 /* Update governor of new_policy to the governor used before hotplug */
1035 gov = find_governor(policy->last_governor);
1037 pr_debug("Restoring governor %s for cpu %d\n",
1038 policy->governor->name, policy->cpu);
1040 gov = CPUFREQ_DEFAULT_GOVERNOR;
1042 new_policy.governor = gov;
1044 /* Use the default policy if its valid. */
1045 if (cpufreq_driver->setpolicy)
1046 cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
1048 /* set default policy */
1049 return cpufreq_set_policy(policy, &new_policy);
1052 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1056 /* Has this CPU been taken care of already? */
1057 if (cpumask_test_cpu(cpu, policy->cpus))
1061 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1063 pr_err("%s: Failed to stop governor\n", __func__);
1068 down_write(&policy->rwsem);
1069 cpumask_set_cpu(cpu, policy->cpus);
1070 up_write(&policy->rwsem);
1073 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1075 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1078 pr_err("%s: Failed to start governor\n", __func__);
1086 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1088 struct device *dev = get_cpu_device(cpu);
1089 struct cpufreq_policy *policy;
1095 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1099 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1100 goto err_free_policy;
1102 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1103 goto err_free_cpumask;
1105 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1106 goto err_free_rcpumask;
1108 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &dev->kobj,
1111 pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
1112 goto err_free_real_cpus;
1115 INIT_LIST_HEAD(&policy->policy_list);
1116 init_rwsem(&policy->rwsem);
1117 spin_lock_init(&policy->transition_lock);
1118 init_waitqueue_head(&policy->transition_wait);
1119 init_completion(&policy->kobj_unregister);
1120 INIT_WORK(&policy->update, handle_update);
1124 /* Set this once on allocation */
1125 policy->kobj_cpu = cpu;
1130 free_cpumask_var(policy->real_cpus);
1132 free_cpumask_var(policy->related_cpus);
1134 free_cpumask_var(policy->cpus);
1141 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy, bool notify)
1143 struct kobject *kobj;
1144 struct completion *cmp;
1147 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1148 CPUFREQ_REMOVE_POLICY, policy);
1150 down_write(&policy->rwsem);
1151 cpufreq_remove_dev_symlink(policy);
1152 kobj = &policy->kobj;
1153 cmp = &policy->kobj_unregister;
1154 up_write(&policy->rwsem);
1158 * We need to make sure that the underlying kobj is
1159 * actually not referenced anymore by anybody before we
1160 * proceed with unloading.
1162 pr_debug("waiting for dropping of refcount\n");
1163 wait_for_completion(cmp);
1164 pr_debug("wait complete\n");
1167 static void cpufreq_policy_free(struct cpufreq_policy *policy, bool notify)
1169 unsigned long flags;
1172 /* Remove policy from list */
1173 write_lock_irqsave(&cpufreq_driver_lock, flags);
1174 list_del(&policy->policy_list);
1176 for_each_cpu(cpu, policy->related_cpus)
1177 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1178 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1180 cpufreq_policy_put_kobj(policy, notify);
1181 free_cpumask_var(policy->real_cpus);
1182 free_cpumask_var(policy->related_cpus);
1183 free_cpumask_var(policy->cpus);
1187 static int cpufreq_online(unsigned int cpu)
1189 struct cpufreq_policy *policy;
1191 unsigned long flags;
1195 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1197 /* Check if this CPU already has a policy to manage it */
1198 policy = per_cpu(cpufreq_cpu_data, cpu);
1200 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1201 if (!policy_is_inactive(policy))
1202 return cpufreq_add_policy_cpu(policy, cpu);
1204 /* This is the only online CPU for the policy. Start over. */
1206 down_write(&policy->rwsem);
1208 policy->governor = NULL;
1209 up_write(&policy->rwsem);
1212 policy = cpufreq_policy_alloc(cpu);
1217 cpumask_copy(policy->cpus, cpumask_of(cpu));
1219 /* call driver. From then on the cpufreq must be able
1220 * to accept all calls to ->verify and ->setpolicy for this CPU
1222 ret = cpufreq_driver->init(policy);
1224 pr_debug("initialization failed\n");
1225 goto out_free_policy;
1228 down_write(&policy->rwsem);
1231 /* related_cpus should at least include policy->cpus. */
1232 cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
1233 /* Remember CPUs present at the policy creation time. */
1234 cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);
1238 * affected cpus must always be the one, which are online. We aren't
1239 * managing offline cpus here.
1241 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1244 policy->user_policy.min = policy->min;
1245 policy->user_policy.max = policy->max;
1247 write_lock_irqsave(&cpufreq_driver_lock, flags);
1248 for_each_cpu(j, policy->related_cpus)
1249 per_cpu(cpufreq_cpu_data, j) = policy;
1250 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1253 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1254 policy->cur = cpufreq_driver->get(policy->cpu);
1256 pr_err("%s: ->get() failed\n", __func__);
1257 goto out_exit_policy;
1262 * Sometimes boot loaders set CPU frequency to a value outside of
1263 * frequency table present with cpufreq core. In such cases CPU might be
1264 * unstable if it has to run on that frequency for long duration of time
1265 * and so its better to set it to a frequency which is specified in
1266 * freq-table. This also makes cpufreq stats inconsistent as
1267 * cpufreq-stats would fail to register because current frequency of CPU
1268 * isn't found in freq-table.
1270 * Because we don't want this change to effect boot process badly, we go
1271 * for the next freq which is >= policy->cur ('cur' must be set by now,
1272 * otherwise we will end up setting freq to lowest of the table as 'cur'
1273 * is initialized to zero).
1275 * We are passing target-freq as "policy->cur - 1" otherwise
1276 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1277 * equal to target-freq.
1279 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1281 /* Are we running at unknown frequency ? */
1282 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1283 if (ret == -EINVAL) {
1284 /* Warn user and fix it */
1285 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1286 __func__, policy->cpu, policy->cur);
1287 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1288 CPUFREQ_RELATION_L);
1291 * Reaching here after boot in a few seconds may not
1292 * mean that system will remain stable at "unknown"
1293 * frequency for longer duration. Hence, a BUG_ON().
1296 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1297 __func__, policy->cpu, policy->cur);
1301 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1302 CPUFREQ_START, policy);
1305 ret = cpufreq_add_dev_interface(policy);
1307 goto out_exit_policy;
1308 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1309 CPUFREQ_CREATE_POLICY, policy);
1311 write_lock_irqsave(&cpufreq_driver_lock, flags);
1312 list_add(&policy->policy_list, &cpufreq_policy_list);
1313 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1316 ret = cpufreq_init_policy(policy);
1318 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1319 __func__, cpu, ret);
1320 /* cpufreq_policy_free() will notify based on this */
1322 goto out_exit_policy;
1326 policy->user_policy.policy = policy->policy;
1328 up_write(&policy->rwsem);
1330 kobject_uevent(&policy->kobj, KOBJ_ADD);
1332 /* Callback for handling stuff after policy is ready */
1333 if (cpufreq_driver->ready)
1334 cpufreq_driver->ready(policy);
1336 pr_debug("initialization complete\n");
1341 up_write(&policy->rwsem);
1343 if (cpufreq_driver->exit)
1344 cpufreq_driver->exit(policy);
1346 cpufreq_policy_free(policy, !new_policy);
1351 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1353 * @sif: Subsystem interface structure pointer (not used)
1355 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1357 unsigned cpu = dev->id;
1360 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1362 if (cpu_online(cpu)) {
1363 ret = cpufreq_online(cpu);
1366 * A hotplug notifier will follow and we will handle it as CPU
1367 * online then. For now, just create the sysfs link, unless
1368 * there is no policy or the link is already present.
1370 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1372 ret = policy && !cpumask_test_and_set_cpu(cpu, policy->real_cpus)
1373 ? add_cpu_dev_symlink(policy, cpu) : 0;
1379 static void cpufreq_offline_prepare(unsigned int cpu)
1381 struct cpufreq_policy *policy;
1383 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1385 policy = cpufreq_cpu_get_raw(cpu);
1387 pr_debug("%s: No cpu_data found\n", __func__);
1392 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1394 pr_err("%s: Failed to stop governor\n", __func__);
1397 down_write(&policy->rwsem);
1398 cpumask_clear_cpu(cpu, policy->cpus);
1400 if (policy_is_inactive(policy)) {
1402 strncpy(policy->last_governor, policy->governor->name,
1404 } else if (cpu == policy->cpu) {
1405 /* Nominate new CPU */
1406 policy->cpu = cpumask_any(policy->cpus);
1408 up_write(&policy->rwsem);
1410 /* Start governor again for active policy */
1411 if (!policy_is_inactive(policy)) {
1413 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1415 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1418 pr_err("%s: Failed to start governor\n", __func__);
1420 } else if (cpufreq_driver->stop_cpu) {
1421 cpufreq_driver->stop_cpu(policy);
1425 static void cpufreq_offline_finish(unsigned int cpu)
1427 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1430 pr_debug("%s: No cpu_data found\n", __func__);
1434 /* Only proceed for inactive policies */
1435 if (!policy_is_inactive(policy))
1438 /* If cpu is last user of policy, free policy */
1440 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
1442 pr_err("%s: Failed to exit governor\n", __func__);
1446 * Perform the ->exit() even during light-weight tear-down,
1447 * since this is a core component, and is essential for the
1448 * subsequent light-weight ->init() to succeed.
1450 if (cpufreq_driver->exit)
1451 cpufreq_driver->exit(policy);
1455 * cpufreq_remove_dev - remove a CPU device
1457 * Removes the cpufreq interface for a CPU device.
1459 static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1461 unsigned int cpu = dev->id;
1462 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1467 if (cpu_online(cpu)) {
1468 cpufreq_offline_prepare(cpu);
1469 cpufreq_offline_finish(cpu);
1472 cpumask_clear_cpu(cpu, policy->real_cpus);
1474 if (cpumask_empty(policy->real_cpus)) {
1475 cpufreq_policy_free(policy, true);
1479 if (cpu != policy->kobj_cpu) {
1480 remove_cpu_dev_symlink(policy, cpu);
1483 * The CPU owning the policy object is going away. Move it to
1484 * another suitable CPU.
1486 unsigned int new_cpu = cpumask_first(policy->real_cpus);
1487 struct device *new_dev = get_cpu_device(new_cpu);
1489 dev_dbg(dev, "%s: Moving policy object to CPU%u\n", __func__, new_cpu);
1491 sysfs_remove_link(&new_dev->kobj, "cpufreq");
1492 policy->kobj_cpu = new_cpu;
1493 WARN_ON(kobject_move(&policy->kobj, &new_dev->kobj));
1499 static void handle_update(struct work_struct *work)
1501 struct cpufreq_policy *policy =
1502 container_of(work, struct cpufreq_policy, update);
1503 unsigned int cpu = policy->cpu;
1504 pr_debug("handle_update for cpu %u called\n", cpu);
1505 cpufreq_update_policy(cpu);
1509 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1511 * @policy: policy managing CPUs
1512 * @new_freq: CPU frequency the CPU actually runs at
1514 * We adjust to current frequency first, and need to clean up later.
1515 * So either call to cpufreq_update_policy() or schedule handle_update()).
1517 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1518 unsigned int new_freq)
1520 struct cpufreq_freqs freqs;
1522 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1523 policy->cur, new_freq);
1525 freqs.old = policy->cur;
1526 freqs.new = new_freq;
1528 cpufreq_freq_transition_begin(policy, &freqs);
1529 cpufreq_freq_transition_end(policy, &freqs, 0);
1533 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1536 * This is the last known freq, without actually getting it from the driver.
1537 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1539 unsigned int cpufreq_quick_get(unsigned int cpu)
1541 struct cpufreq_policy *policy;
1542 unsigned int ret_freq = 0;
1544 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
1545 return cpufreq_driver->get(cpu);
1547 policy = cpufreq_cpu_get(cpu);
1549 ret_freq = policy->cur;
1550 cpufreq_cpu_put(policy);
1555 EXPORT_SYMBOL(cpufreq_quick_get);
1558 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1561 * Just return the max possible frequency for a given CPU.
1563 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1565 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1566 unsigned int ret_freq = 0;
1569 ret_freq = policy->max;
1570 cpufreq_cpu_put(policy);
1575 EXPORT_SYMBOL(cpufreq_quick_get_max);
1577 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1579 unsigned int ret_freq = 0;
1581 if (!cpufreq_driver->get)
1584 ret_freq = cpufreq_driver->get(policy->cpu);
1586 /* Updating inactive policies is invalid, so avoid doing that. */
1587 if (unlikely(policy_is_inactive(policy)))
1590 if (ret_freq && policy->cur &&
1591 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1592 /* verify no discrepancy between actual and
1593 saved value exists */
1594 if (unlikely(ret_freq != policy->cur)) {
1595 cpufreq_out_of_sync(policy, ret_freq);
1596 schedule_work(&policy->update);
1604 * cpufreq_get - get the current CPU frequency (in kHz)
1607 * Get the CPU current (static) CPU frequency
1609 unsigned int cpufreq_get(unsigned int cpu)
1611 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1612 unsigned int ret_freq = 0;
1615 down_read(&policy->rwsem);
1616 ret_freq = __cpufreq_get(policy);
1617 up_read(&policy->rwsem);
1619 cpufreq_cpu_put(policy);
1624 EXPORT_SYMBOL(cpufreq_get);
1626 static struct subsys_interface cpufreq_interface = {
1628 .subsys = &cpu_subsys,
1629 .add_dev = cpufreq_add_dev,
1630 .remove_dev = cpufreq_remove_dev,
1634 * In case platform wants some specific frequency to be configured
1637 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1641 if (!policy->suspend_freq) {
1642 pr_err("%s: suspend_freq can't be zero\n", __func__);
1646 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1647 policy->suspend_freq);
1649 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1650 CPUFREQ_RELATION_H);
1652 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1653 __func__, policy->suspend_freq, ret);
1657 EXPORT_SYMBOL(cpufreq_generic_suspend);
1660 * cpufreq_suspend() - Suspend CPUFreq governors
1662 * Called during system wide Suspend/Hibernate cycles for suspending governors
1663 * as some platforms can't change frequency after this point in suspend cycle.
1664 * Because some of the devices (like: i2c, regulators, etc) they use for
1665 * changing frequency are suspended quickly after this point.
1667 void cpufreq_suspend(void)
1669 struct cpufreq_policy *policy;
1671 if (!cpufreq_driver)
1677 pr_debug("%s: Suspending Governors\n", __func__);
1679 for_each_active_policy(policy) {
1680 if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
1681 pr_err("%s: Failed to stop governor for policy: %p\n",
1683 else if (cpufreq_driver->suspend
1684 && cpufreq_driver->suspend(policy))
1685 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1690 cpufreq_suspended = true;
1694 * cpufreq_resume() - Resume CPUFreq governors
1696 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1697 * are suspended with cpufreq_suspend().
1699 void cpufreq_resume(void)
1701 struct cpufreq_policy *policy;
1703 if (!cpufreq_driver)
1706 cpufreq_suspended = false;
1711 pr_debug("%s: Resuming Governors\n", __func__);
1713 for_each_active_policy(policy) {
1714 if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
1715 pr_err("%s: Failed to resume driver: %p\n", __func__,
1717 else if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
1718 || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
1719 pr_err("%s: Failed to start governor for policy: %p\n",
1724 * schedule call cpufreq_update_policy() for first-online CPU, as that
1725 * wouldn't be hotplugged-out on suspend. It will verify that the
1726 * current freq is in sync with what we believe it to be.
1728 policy = cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask));
1729 if (WARN_ON(!policy))
1732 schedule_work(&policy->update);
1736 * cpufreq_get_current_driver - return current driver's name
1738 * Return the name string of the currently loaded cpufreq driver
1741 const char *cpufreq_get_current_driver(void)
1744 return cpufreq_driver->name;
1748 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1751 * cpufreq_get_driver_data - return current driver data
1753 * Return the private data of the currently loaded cpufreq
1754 * driver, or NULL if no cpufreq driver is loaded.
1756 void *cpufreq_get_driver_data(void)
1759 return cpufreq_driver->driver_data;
1763 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1765 /*********************************************************************
1766 * NOTIFIER LISTS INTERFACE *
1767 *********************************************************************/
1770 * cpufreq_register_notifier - register a driver with cpufreq
1771 * @nb: notifier function to register
1772 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1774 * Add a driver to one of two lists: either a list of drivers that
1775 * are notified about clock rate changes (once before and once after
1776 * the transition), or a list of drivers that are notified about
1777 * changes in cpufreq policy.
1779 * This function may sleep, and has the same return conditions as
1780 * blocking_notifier_chain_register.
1782 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1786 if (cpufreq_disabled())
1789 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1792 case CPUFREQ_TRANSITION_NOTIFIER:
1793 ret = srcu_notifier_chain_register(
1794 &cpufreq_transition_notifier_list, nb);
1796 case CPUFREQ_POLICY_NOTIFIER:
1797 ret = blocking_notifier_chain_register(
1798 &cpufreq_policy_notifier_list, nb);
1806 EXPORT_SYMBOL(cpufreq_register_notifier);
1809 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1810 * @nb: notifier block to be unregistered
1811 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1813 * Remove a driver from the CPU frequency notifier list.
1815 * This function may sleep, and has the same return conditions as
1816 * blocking_notifier_chain_unregister.
1818 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1822 if (cpufreq_disabled())
1826 case CPUFREQ_TRANSITION_NOTIFIER:
1827 ret = srcu_notifier_chain_unregister(
1828 &cpufreq_transition_notifier_list, nb);
1830 case CPUFREQ_POLICY_NOTIFIER:
1831 ret = blocking_notifier_chain_unregister(
1832 &cpufreq_policy_notifier_list, nb);
1840 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1843 /*********************************************************************
1845 *********************************************************************/
1847 /* Must set freqs->new to intermediate frequency */
1848 static int __target_intermediate(struct cpufreq_policy *policy,
1849 struct cpufreq_freqs *freqs, int index)
1853 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1855 /* We don't need to switch to intermediate freq */
1859 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1860 __func__, policy->cpu, freqs->old, freqs->new);
1862 cpufreq_freq_transition_begin(policy, freqs);
1863 ret = cpufreq_driver->target_intermediate(policy, index);
1864 cpufreq_freq_transition_end(policy, freqs, ret);
1867 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1873 static int __target_index(struct cpufreq_policy *policy,
1874 struct cpufreq_frequency_table *freq_table, int index)
1876 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1877 unsigned int intermediate_freq = 0;
1878 int retval = -EINVAL;
1881 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1883 /* Handle switching to intermediate frequency */
1884 if (cpufreq_driver->get_intermediate) {
1885 retval = __target_intermediate(policy, &freqs, index);
1889 intermediate_freq = freqs.new;
1890 /* Set old freq to intermediate */
1891 if (intermediate_freq)
1892 freqs.old = freqs.new;
1895 freqs.new = freq_table[index].frequency;
1896 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1897 __func__, policy->cpu, freqs.old, freqs.new);
1899 cpufreq_freq_transition_begin(policy, &freqs);
1902 retval = cpufreq_driver->target_index(policy, index);
1904 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
1908 cpufreq_freq_transition_end(policy, &freqs, retval);
1911 * Failed after setting to intermediate freq? Driver should have
1912 * reverted back to initial frequency and so should we. Check
1913 * here for intermediate_freq instead of get_intermediate, in
1914 * case we haven't switched to intermediate freq at all.
1916 if (unlikely(retval && intermediate_freq)) {
1917 freqs.old = intermediate_freq;
1918 freqs.new = policy->restore_freq;
1919 cpufreq_freq_transition_begin(policy, &freqs);
1920 cpufreq_freq_transition_end(policy, &freqs, 0);
1927 int __cpufreq_driver_target(struct cpufreq_policy *policy,
1928 unsigned int target_freq,
1929 unsigned int relation)
1931 unsigned int old_target_freq = target_freq;
1932 int retval = -EINVAL;
1934 if (cpufreq_disabled())
1937 /* Make sure that target_freq is within supported range */
1938 if (target_freq > policy->max)
1939 target_freq = policy->max;
1940 if (target_freq < policy->min)
1941 target_freq = policy->min;
1943 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1944 policy->cpu, target_freq, relation, old_target_freq);
1947 * This might look like a redundant call as we are checking it again
1948 * after finding index. But it is left intentionally for cases where
1949 * exactly same freq is called again and so we can save on few function
1952 if (target_freq == policy->cur)
1955 /* Save last value to restore later on errors */
1956 policy->restore_freq = policy->cur;
1958 if (cpufreq_driver->target)
1959 retval = cpufreq_driver->target(policy, target_freq, relation);
1960 else if (cpufreq_driver->target_index) {
1961 struct cpufreq_frequency_table *freq_table;
1964 freq_table = cpufreq_frequency_get_table(policy->cpu);
1965 if (unlikely(!freq_table)) {
1966 pr_err("%s: Unable to find freq_table\n", __func__);
1970 retval = cpufreq_frequency_table_target(policy, freq_table,
1971 target_freq, relation, &index);
1972 if (unlikely(retval)) {
1973 pr_err("%s: Unable to find matching freq\n", __func__);
1977 if (freq_table[index].frequency == policy->cur) {
1982 retval = __target_index(policy, freq_table, index);
1988 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1990 int cpufreq_driver_target(struct cpufreq_policy *policy,
1991 unsigned int target_freq,
1992 unsigned int relation)
1996 down_write(&policy->rwsem);
1998 ret = __cpufreq_driver_target(policy, target_freq, relation);
2000 up_write(&policy->rwsem);
2004 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2006 static int __cpufreq_governor(struct cpufreq_policy *policy,
2011 /* Only must be defined when default governor is known to have latency
2012 restrictions, like e.g. conservative or ondemand.
2013 That this is the case is already ensured in Kconfig
2015 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
2016 struct cpufreq_governor *gov = &cpufreq_gov_performance;
2018 struct cpufreq_governor *gov = NULL;
2021 /* Don't start any governor operations if we are entering suspend */
2022 if (cpufreq_suspended)
2025 * Governor might not be initiated here if ACPI _PPC changed
2026 * notification happened, so check it.
2028 if (!policy->governor)
2031 if (policy->governor->max_transition_latency &&
2032 policy->cpuinfo.transition_latency >
2033 policy->governor->max_transition_latency) {
2037 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
2038 policy->governor->name, gov->name);
2039 policy->governor = gov;
2043 if (event == CPUFREQ_GOV_POLICY_INIT)
2044 if (!try_module_get(policy->governor->owner))
2047 pr_debug("__cpufreq_governor for CPU %u, event %u\n",
2048 policy->cpu, event);
2050 mutex_lock(&cpufreq_governor_lock);
2051 if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
2052 || (!policy->governor_enabled
2053 && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
2054 mutex_unlock(&cpufreq_governor_lock);
2058 if (event == CPUFREQ_GOV_STOP)
2059 policy->governor_enabled = false;
2060 else if (event == CPUFREQ_GOV_START)
2061 policy->governor_enabled = true;
2063 mutex_unlock(&cpufreq_governor_lock);
2065 ret = policy->governor->governor(policy, event);
2068 if (event == CPUFREQ_GOV_POLICY_INIT)
2069 policy->governor->initialized++;
2070 else if (event == CPUFREQ_GOV_POLICY_EXIT)
2071 policy->governor->initialized--;
2073 /* Restore original values */
2074 mutex_lock(&cpufreq_governor_lock);
2075 if (event == CPUFREQ_GOV_STOP)
2076 policy->governor_enabled = true;
2077 else if (event == CPUFREQ_GOV_START)
2078 policy->governor_enabled = false;
2079 mutex_unlock(&cpufreq_governor_lock);
2082 if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
2083 ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
2084 module_put(policy->governor->owner);
2089 int cpufreq_register_governor(struct cpufreq_governor *governor)
2096 if (cpufreq_disabled())
2099 mutex_lock(&cpufreq_governor_mutex);
2101 governor->initialized = 0;
2103 if (!find_governor(governor->name)) {
2105 list_add(&governor->governor_list, &cpufreq_governor_list);
2108 mutex_unlock(&cpufreq_governor_mutex);
2111 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2113 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2115 struct cpufreq_policy *policy;
2116 unsigned long flags;
2121 if (cpufreq_disabled())
2124 /* clear last_governor for all inactive policies */
2125 read_lock_irqsave(&cpufreq_driver_lock, flags);
2126 for_each_inactive_policy(policy) {
2127 if (!strcmp(policy->last_governor, governor->name)) {
2128 policy->governor = NULL;
2129 strcpy(policy->last_governor, "\0");
2132 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2134 mutex_lock(&cpufreq_governor_mutex);
2135 list_del(&governor->governor_list);
2136 mutex_unlock(&cpufreq_governor_mutex);
2139 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2142 /*********************************************************************
2143 * POLICY INTERFACE *
2144 *********************************************************************/
2147 * cpufreq_get_policy - get the current cpufreq_policy
2148 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2151 * Reads the current cpufreq policy.
2153 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2155 struct cpufreq_policy *cpu_policy;
2159 cpu_policy = cpufreq_cpu_get(cpu);
2163 memcpy(policy, cpu_policy, sizeof(*policy));
2165 cpufreq_cpu_put(cpu_policy);
2168 EXPORT_SYMBOL(cpufreq_get_policy);
2171 * policy : current policy.
2172 * new_policy: policy to be set.
2174 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2175 struct cpufreq_policy *new_policy)
2177 struct cpufreq_governor *old_gov;
2180 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2181 new_policy->cpu, new_policy->min, new_policy->max);
2183 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2186 * This check works well when we store new min/max freq attributes,
2187 * because new_policy is a copy of policy with one field updated.
2189 if (new_policy->min > new_policy->max)
2192 /* verify the cpu speed can be set within this limit */
2193 ret = cpufreq_driver->verify(new_policy);
2197 /* adjust if necessary - all reasons */
2198 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2199 CPUFREQ_ADJUST, new_policy);
2202 * verify the cpu speed can be set within this limit, which might be
2203 * different to the first one
2205 ret = cpufreq_driver->verify(new_policy);
2209 /* notification of the new policy */
2210 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2211 CPUFREQ_NOTIFY, new_policy);
2213 policy->min = new_policy->min;
2214 policy->max = new_policy->max;
2216 pr_debug("new min and max freqs are %u - %u kHz\n",
2217 policy->min, policy->max);
2219 if (cpufreq_driver->setpolicy) {
2220 policy->policy = new_policy->policy;
2221 pr_debug("setting range\n");
2222 return cpufreq_driver->setpolicy(new_policy);
2225 if (new_policy->governor == policy->governor)
2228 pr_debug("governor switch\n");
2230 /* save old, working values */
2231 old_gov = policy->governor;
2232 /* end old governor */
2234 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
2236 /* This can happen due to race with other operations */
2237 pr_debug("%s: Failed to Stop Governor: %s (%d)\n",
2238 __func__, old_gov->name, ret);
2242 up_write(&policy->rwsem);
2243 ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2244 down_write(&policy->rwsem);
2247 pr_err("%s: Failed to Exit Governor: %s (%d)\n",
2248 __func__, old_gov->name, ret);
2253 /* start new governor */
2254 policy->governor = new_policy->governor;
2255 ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);
2257 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
2261 up_write(&policy->rwsem);
2262 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2263 down_write(&policy->rwsem);
2266 /* new governor failed, so re-start old one */
2267 pr_debug("starting governor %s failed\n", policy->governor->name);
2269 policy->governor = old_gov;
2270 if (__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT))
2271 policy->governor = NULL;
2273 __cpufreq_governor(policy, CPUFREQ_GOV_START);
2279 pr_debug("governor: change or update limits\n");
2280 return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2284 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2285 * @cpu: CPU which shall be re-evaluated
2287 * Useful for policy notifiers which have different necessities
2288 * at different times.
2290 int cpufreq_update_policy(unsigned int cpu)
2292 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2293 struct cpufreq_policy new_policy;
2299 down_write(&policy->rwsem);
2301 pr_debug("updating policy for CPU %u\n", cpu);
2302 memcpy(&new_policy, policy, sizeof(*policy));
2303 new_policy.min = policy->user_policy.min;
2304 new_policy.max = policy->user_policy.max;
2305 new_policy.policy = policy->user_policy.policy;
2308 * BIOS might change freq behind our back
2309 * -> ask driver for current freq and notify governors about a change
2311 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
2312 new_policy.cur = cpufreq_driver->get(cpu);
2313 if (WARN_ON(!new_policy.cur)) {
2319 pr_debug("Driver did not initialize current freq\n");
2320 policy->cur = new_policy.cur;
2322 if (policy->cur != new_policy.cur && has_target())
2323 cpufreq_out_of_sync(policy, new_policy.cur);
2327 ret = cpufreq_set_policy(policy, &new_policy);
2330 up_write(&policy->rwsem);
2332 cpufreq_cpu_put(policy);
2335 EXPORT_SYMBOL(cpufreq_update_policy);
2337 static int cpufreq_cpu_callback(struct notifier_block *nfb,
2338 unsigned long action, void *hcpu)
2340 unsigned int cpu = (unsigned long)hcpu;
2342 switch (action & ~CPU_TASKS_FROZEN) {
2344 cpufreq_online(cpu);
2347 case CPU_DOWN_PREPARE:
2348 cpufreq_offline_prepare(cpu);
2352 cpufreq_offline_finish(cpu);
2355 case CPU_DOWN_FAILED:
2356 cpufreq_online(cpu);
2362 static struct notifier_block __refdata cpufreq_cpu_notifier = {
2363 .notifier_call = cpufreq_cpu_callback,
2366 /*********************************************************************
2368 *********************************************************************/
2369 static int cpufreq_boost_set_sw(int state)
2371 struct cpufreq_frequency_table *freq_table;
2372 struct cpufreq_policy *policy;
2375 for_each_active_policy(policy) {
2376 freq_table = cpufreq_frequency_get_table(policy->cpu);
2378 ret = cpufreq_frequency_table_cpuinfo(policy,
2381 pr_err("%s: Policy frequency update failed\n",
2385 policy->user_policy.max = policy->max;
2386 __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2393 int cpufreq_boost_trigger_state(int state)
2395 unsigned long flags;
2398 if (cpufreq_driver->boost_enabled == state)
2401 write_lock_irqsave(&cpufreq_driver_lock, flags);
2402 cpufreq_driver->boost_enabled = state;
2403 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2405 ret = cpufreq_driver->set_boost(state);
2407 write_lock_irqsave(&cpufreq_driver_lock, flags);
2408 cpufreq_driver->boost_enabled = !state;
2409 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2411 pr_err("%s: Cannot %s BOOST\n",
2412 __func__, state ? "enable" : "disable");
2418 int cpufreq_boost_supported(void)
2420 if (likely(cpufreq_driver))
2421 return cpufreq_driver->boost_supported;
2425 EXPORT_SYMBOL_GPL(cpufreq_boost_supported);
2427 int cpufreq_boost_enabled(void)
2429 return cpufreq_driver->boost_enabled;
2431 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2433 /*********************************************************************
2434 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2435 *********************************************************************/
2438 * cpufreq_register_driver - register a CPU Frequency driver
2439 * @driver_data: A struct cpufreq_driver containing the values#
2440 * submitted by the CPU Frequency driver.
2442 * Registers a CPU Frequency driver to this core code. This code
2443 * returns zero on success, -EBUSY when another driver got here first
2444 * (and isn't unregistered in the meantime).
2447 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2449 unsigned long flags;
2452 if (cpufreq_disabled())
2455 if (!driver_data || !driver_data->verify || !driver_data->init ||
2456 !(driver_data->setpolicy || driver_data->target_index ||
2457 driver_data->target) ||
2458 (driver_data->setpolicy && (driver_data->target_index ||
2459 driver_data->target)) ||
2460 (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
2463 pr_debug("trying to register driver %s\n", driver_data->name);
2465 /* Protect against concurrent CPU online/offline. */
2468 write_lock_irqsave(&cpufreq_driver_lock, flags);
2469 if (cpufreq_driver) {
2470 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2474 cpufreq_driver = driver_data;
2475 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2477 if (driver_data->setpolicy)
2478 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2480 if (cpufreq_boost_supported()) {
2482 * Check if driver provides function to enable boost -
2483 * if not, use cpufreq_boost_set_sw as default
2485 if (!cpufreq_driver->set_boost)
2486 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2488 ret = cpufreq_sysfs_create_file(&boost.attr);
2490 pr_err("%s: cannot register global BOOST sysfs file\n",
2492 goto err_null_driver;
2496 ret = subsys_interface_register(&cpufreq_interface);
2498 goto err_boost_unreg;
2500 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2501 list_empty(&cpufreq_policy_list)) {
2502 /* if all ->init() calls failed, unregister */
2503 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2508 register_hotcpu_notifier(&cpufreq_cpu_notifier);
2509 pr_debug("driver %s up and running\n", driver_data->name);
2516 subsys_interface_unregister(&cpufreq_interface);
2518 if (cpufreq_boost_supported())
2519 cpufreq_sysfs_remove_file(&boost.attr);
2521 write_lock_irqsave(&cpufreq_driver_lock, flags);
2522 cpufreq_driver = NULL;
2523 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2526 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2529 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2531 * Unregister the current CPUFreq driver. Only call this if you have
2532 * the right to do so, i.e. if you have succeeded in initialising before!
2533 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2534 * currently not initialised.
2536 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2538 unsigned long flags;
2540 if (!cpufreq_driver || (driver != cpufreq_driver))
2543 pr_debug("unregistering driver %s\n", driver->name);
2545 /* Protect against concurrent cpu hotplug */
2547 subsys_interface_unregister(&cpufreq_interface);
2548 if (cpufreq_boost_supported())
2549 cpufreq_sysfs_remove_file(&boost.attr);
2551 unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
2553 write_lock_irqsave(&cpufreq_driver_lock, flags);
2555 cpufreq_driver = NULL;
2557 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2562 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2565 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2566 * or mutexes when secondary CPUs are halted.
2568 static struct syscore_ops cpufreq_syscore_ops = {
2569 .shutdown = cpufreq_suspend,
2572 static int __init cpufreq_core_init(void)
2574 if (cpufreq_disabled())
2577 cpufreq_global_kobject = kobject_create();
2578 BUG_ON(!cpufreq_global_kobject);
2580 register_syscore_ops(&cpufreq_syscore_ops);
2584 core_initcall(cpufreq_core_init);