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>
33 #include <linux/sched.h>
35 #include <trace/events/power.h>
37 static LIST_HEAD(cpufreq_policy_list);
39 static inline bool policy_is_inactive(struct cpufreq_policy *policy)
41 return cpumask_empty(policy->cpus);
44 static bool suitable_policy(struct cpufreq_policy *policy, bool active)
46 return active == !policy_is_inactive(policy);
49 /* Finds Next Acive/Inactive policy */
50 static struct cpufreq_policy *next_policy(struct cpufreq_policy *policy,
54 policy = list_next_entry(policy, policy_list);
56 /* No more policies in the list */
57 if (&policy->policy_list == &cpufreq_policy_list)
59 } while (!suitable_policy(policy, active));
64 static struct cpufreq_policy *first_policy(bool active)
66 struct cpufreq_policy *policy;
68 /* No policies in the list */
69 if (list_empty(&cpufreq_policy_list))
72 policy = list_first_entry(&cpufreq_policy_list, typeof(*policy),
75 if (!suitable_policy(policy, active))
76 policy = next_policy(policy, active);
81 /* Macros to iterate over CPU policies */
82 #define for_each_suitable_policy(__policy, __active) \
83 for (__policy = first_policy(__active); \
85 __policy = next_policy(__policy, __active))
87 #define for_each_active_policy(__policy) \
88 for_each_suitable_policy(__policy, true)
89 #define for_each_inactive_policy(__policy) \
90 for_each_suitable_policy(__policy, false)
92 #define for_each_policy(__policy) \
93 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
95 /* Iterate over governors */
96 static LIST_HEAD(cpufreq_governor_list);
97 #define for_each_governor(__governor) \
98 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
101 * The "cpufreq driver" - the arch- or hardware-dependent low
102 * level driver of CPUFreq support, and its spinlock. This lock
103 * also protects the cpufreq_cpu_data array.
105 static struct cpufreq_driver *cpufreq_driver;
106 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
107 static DEFINE_RWLOCK(cpufreq_driver_lock);
108 DEFINE_MUTEX(cpufreq_governor_lock);
110 /* Flag to suspend/resume CPUFreq governors */
111 static bool cpufreq_suspended;
113 static inline bool has_target(void)
115 return cpufreq_driver->target_index || cpufreq_driver->target;
118 /* internal prototypes */
119 static int __cpufreq_governor(struct cpufreq_policy *policy,
121 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
122 static void handle_update(struct work_struct *work);
125 * Two notifier lists: the "policy" list is involved in the
126 * validation process for a new CPU frequency policy; the
127 * "transition" list for kernel code that needs to handle
128 * changes to devices when the CPU clock speed changes.
129 * The mutex locks both lists.
131 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
132 static struct srcu_notifier_head cpufreq_transition_notifier_list;
134 static bool init_cpufreq_transition_notifier_list_called;
135 static int __init init_cpufreq_transition_notifier_list(void)
137 srcu_init_notifier_head(&cpufreq_transition_notifier_list);
138 init_cpufreq_transition_notifier_list_called = true;
141 pure_initcall(init_cpufreq_transition_notifier_list);
143 static int off __read_mostly;
144 static int cpufreq_disabled(void)
148 void disable_cpufreq(void)
152 static DEFINE_MUTEX(cpufreq_governor_mutex);
154 bool have_governor_per_policy(void)
156 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
158 EXPORT_SYMBOL_GPL(have_governor_per_policy);
160 bool cpufreq_driver_is_slow(void)
162 return !(cpufreq_driver->flags & CPUFREQ_DRIVER_FAST);
164 EXPORT_SYMBOL_GPL(cpufreq_driver_is_slow);
166 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
168 if (have_governor_per_policy())
169 return &policy->kobj;
171 return cpufreq_global_kobject;
173 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
175 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
177 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
179 return policy && !policy_is_inactive(policy) ?
180 policy->freq_table : NULL;
182 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
184 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
190 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
192 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
193 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
194 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
195 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
196 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
197 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
199 idle_time = cur_wall_time - busy_time;
201 *wall = cputime_to_usecs(cur_wall_time);
203 return cputime_to_usecs(idle_time);
206 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
208 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
210 if (idle_time == -1ULL)
211 return get_cpu_idle_time_jiffy(cpu, wall);
213 idle_time += get_cpu_iowait_time_us(cpu, wall);
217 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
220 * This is a generic cpufreq init() routine which can be used by cpufreq
221 * drivers of SMP systems. It will do following:
222 * - validate & show freq table passed
223 * - set policies transition latency
224 * - policy->cpus with all possible CPUs
226 int cpufreq_generic_init(struct cpufreq_policy *policy,
227 struct cpufreq_frequency_table *table,
228 unsigned int transition_latency)
232 ret = cpufreq_table_validate_and_show(policy, table);
234 pr_err("%s: invalid frequency table: %d\n", __func__, ret);
238 policy->cpuinfo.transition_latency = transition_latency;
241 * The driver only supports the SMP configuration where all processors
242 * share the clock and voltage and clock.
244 cpumask_setall(policy->cpus);
248 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
250 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
252 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
254 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
256 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
258 unsigned int cpufreq_generic_get(unsigned int cpu)
260 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
262 if (!policy || IS_ERR(policy->clk)) {
263 pr_err("%s: No %s associated to cpu: %d\n",
264 __func__, policy ? "clk" : "policy", cpu);
268 return clk_get_rate(policy->clk) / 1000;
270 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
273 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
275 * @cpu: cpu to find policy for.
277 * This returns policy for 'cpu', returns NULL if it doesn't exist.
278 * It also increments the kobject reference count to mark it busy and so would
279 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
280 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
281 * freed as that depends on the kobj count.
283 * Return: A valid policy on success, otherwise NULL on failure.
285 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
287 struct cpufreq_policy *policy = NULL;
290 if (WARN_ON(cpu >= nr_cpu_ids))
293 /* get the cpufreq driver */
294 read_lock_irqsave(&cpufreq_driver_lock, flags);
296 if (cpufreq_driver) {
298 policy = cpufreq_cpu_get_raw(cpu);
300 kobject_get(&policy->kobj);
303 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
307 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
310 * cpufreq_cpu_put: Decrements the usage count of a policy
312 * @policy: policy earlier returned by cpufreq_cpu_get().
314 * This decrements the kobject reference count incremented earlier by calling
317 void cpufreq_cpu_put(struct cpufreq_policy *policy)
319 kobject_put(&policy->kobj);
321 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
323 /*********************************************************************
324 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
325 *********************************************************************/
328 * adjust_jiffies - adjust the system "loops_per_jiffy"
330 * This function alters the system "loops_per_jiffy" for the clock
331 * speed change. Note that loops_per_jiffy cannot be updated on SMP
332 * systems as each CPU might be scaled differently. So, use the arch
333 * per-CPU loops_per_jiffy value wherever possible.
335 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
338 static unsigned long l_p_j_ref;
339 static unsigned int l_p_j_ref_freq;
341 if (ci->flags & CPUFREQ_CONST_LOOPS)
344 if (!l_p_j_ref_freq) {
345 l_p_j_ref = loops_per_jiffy;
346 l_p_j_ref_freq = ci->old;
347 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
348 l_p_j_ref, l_p_j_ref_freq);
350 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
351 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
353 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
354 loops_per_jiffy, ci->new);
359 /*********************************************************************
360 * FREQUENCY INVARIANT CPU CAPACITY *
361 *********************************************************************/
363 static DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
364 static DEFINE_PER_CPU(unsigned long, max_freq_scale) = SCHED_CAPACITY_SCALE;
367 scale_freq_capacity(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs)
369 unsigned long cur = freqs ? freqs->new : policy->cur;
370 unsigned long scale = (cur << SCHED_CAPACITY_SHIFT) / policy->max;
371 struct cpufreq_cpuinfo *cpuinfo = &policy->cpuinfo;
374 pr_debug("cpus %*pbl cur/cur max freq %lu/%u kHz freq scale %lu\n",
375 cpumask_pr_args(policy->cpus), cur, policy->max, scale);
377 for_each_cpu(cpu, policy->cpus)
378 per_cpu(freq_scale, cpu) = scale;
383 scale = (policy->max << SCHED_CAPACITY_SHIFT) / cpuinfo->max_freq;
385 pr_debug("cpus %*pbl cur max/max freq %u/%u kHz max freq scale %lu\n",
386 cpumask_pr_args(policy->cpus), policy->max, cpuinfo->max_freq,
389 for_each_cpu(cpu, policy->cpus)
390 per_cpu(max_freq_scale, cpu) = scale;
393 unsigned long cpufreq_scale_freq_capacity(struct sched_domain *sd, int cpu)
395 return per_cpu(freq_scale, cpu);
398 unsigned long cpufreq_scale_max_freq_capacity(int cpu)
400 return per_cpu(max_freq_scale, cpu);
403 static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
404 struct cpufreq_freqs *freqs, unsigned int state)
406 BUG_ON(irqs_disabled());
408 if (cpufreq_disabled())
411 freqs->flags = cpufreq_driver->flags;
412 pr_debug("notification %u of frequency transition to %u kHz\n",
417 case CPUFREQ_PRECHANGE:
418 /* detect if the driver reported a value as "old frequency"
419 * which is not equal to what the cpufreq core thinks is
422 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
423 if ((policy) && (policy->cpu == freqs->cpu) &&
424 (policy->cur) && (policy->cur != freqs->old)) {
425 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
426 freqs->old, policy->cur);
427 freqs->old = policy->cur;
430 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
431 CPUFREQ_PRECHANGE, freqs);
432 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
435 case CPUFREQ_POSTCHANGE:
436 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
437 pr_debug("FREQ: %lu - CPU: %lu\n",
438 (unsigned long)freqs->new, (unsigned long)freqs->cpu);
439 trace_cpu_frequency(freqs->new, freqs->cpu);
440 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
441 CPUFREQ_POSTCHANGE, freqs);
442 if (likely(policy) && likely(policy->cpu == freqs->cpu))
443 policy->cur = freqs->new;
449 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
450 * on frequency transition.
452 * This function calls the transition notifiers and the "adjust_jiffies"
453 * function. It is called twice on all CPU frequency changes that have
456 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
457 struct cpufreq_freqs *freqs, unsigned int state)
459 for_each_cpu(freqs->cpu, policy->cpus)
460 __cpufreq_notify_transition(policy, freqs, state);
463 /* Do post notifications when there are chances that transition has failed */
464 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
465 struct cpufreq_freqs *freqs, int transition_failed)
467 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
468 if (!transition_failed)
471 swap(freqs->old, freqs->new);
472 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
473 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
476 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
477 struct cpufreq_freqs *freqs)
484 * Catch double invocations of _begin() which lead to self-deadlock.
485 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
486 * doesn't invoke _begin() on their behalf, and hence the chances of
487 * double invocations are very low. Moreover, there are scenarios
488 * where these checks can emit false-positive warnings in these
489 * drivers; so we avoid that by skipping them altogether.
491 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
492 && current == policy->transition_task);
495 wait_event(policy->transition_wait, !policy->transition_ongoing);
497 spin_lock(&policy->transition_lock);
499 if (unlikely(policy->transition_ongoing)) {
500 spin_unlock(&policy->transition_lock);
504 policy->transition_ongoing = true;
505 policy->transition_task = current;
507 spin_unlock(&policy->transition_lock);
509 scale_freq_capacity(policy, freqs);
511 for_each_cpu(cpu, policy->cpus)
512 trace_cpu_capacity(capacity_curr_of(cpu), cpu);
515 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
517 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
519 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
520 struct cpufreq_freqs *freqs, int transition_failed)
522 if (unlikely(WARN_ON(!policy->transition_ongoing)))
525 cpufreq_notify_post_transition(policy, freqs, transition_failed);
527 policy->transition_ongoing = false;
528 policy->transition_task = NULL;
530 wake_up(&policy->transition_wait);
532 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
535 /*********************************************************************
537 *********************************************************************/
538 static ssize_t show_boost(struct kobject *kobj,
539 struct attribute *attr, char *buf)
541 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
544 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
545 const char *buf, size_t count)
549 ret = sscanf(buf, "%d", &enable);
550 if (ret != 1 || enable < 0 || enable > 1)
553 if (cpufreq_boost_trigger_state(enable)) {
554 pr_err("%s: Cannot %s BOOST!\n",
555 __func__, enable ? "enable" : "disable");
559 pr_debug("%s: cpufreq BOOST %s\n",
560 __func__, enable ? "enabled" : "disabled");
564 define_one_global_rw(boost);
566 static struct cpufreq_governor *find_governor(const char *str_governor)
568 struct cpufreq_governor *t;
571 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
578 * cpufreq_parse_governor - parse a governor string
580 static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
581 struct cpufreq_governor **governor)
585 if (cpufreq_driver->setpolicy) {
586 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
587 *policy = CPUFREQ_POLICY_PERFORMANCE;
589 } else if (!strncasecmp(str_governor, "powersave",
591 *policy = CPUFREQ_POLICY_POWERSAVE;
595 struct cpufreq_governor *t;
597 mutex_lock(&cpufreq_governor_mutex);
599 t = find_governor(str_governor);
604 mutex_unlock(&cpufreq_governor_mutex);
605 ret = request_module("cpufreq_%s", str_governor);
606 mutex_lock(&cpufreq_governor_mutex);
609 t = find_governor(str_governor);
617 mutex_unlock(&cpufreq_governor_mutex);
623 * cpufreq_per_cpu_attr_read() / show_##file_name() -
624 * print out cpufreq information
626 * Write out information from cpufreq_driver->policy[cpu]; object must be
630 #define show_one(file_name, object) \
631 static ssize_t show_##file_name \
632 (struct cpufreq_policy *policy, char *buf) \
634 return sprintf(buf, "%u\n", policy->object); \
637 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
638 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
639 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
640 show_one(scaling_min_freq, min);
641 show_one(scaling_max_freq, max);
643 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
647 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
648 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
650 ret = sprintf(buf, "%u\n", policy->cur);
654 static int cpufreq_set_policy(struct cpufreq_policy *policy,
655 struct cpufreq_policy *new_policy);
658 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
660 #define store_one(file_name, object) \
661 static ssize_t store_##file_name \
662 (struct cpufreq_policy *policy, const char *buf, size_t count) \
665 struct cpufreq_policy new_policy; \
667 memcpy(&new_policy, policy, sizeof(*policy)); \
669 ret = sscanf(buf, "%u", &new_policy.object); \
673 temp = new_policy.object; \
674 ret = cpufreq_set_policy(policy, &new_policy); \
676 policy->user_policy.object = temp; \
678 return ret ? ret : count; \
681 store_one(scaling_min_freq, min);
682 store_one(scaling_max_freq, max);
685 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
687 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
690 unsigned int cur_freq = __cpufreq_get(policy);
692 return sprintf(buf, "<unknown>");
693 return sprintf(buf, "%u\n", cur_freq);
697 * show_scaling_governor - show the current policy for the specified CPU
699 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
701 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
702 return sprintf(buf, "powersave\n");
703 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
704 return sprintf(buf, "performance\n");
705 else if (policy->governor)
706 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
707 policy->governor->name);
712 * store_scaling_governor - store policy for the specified CPU
714 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
715 const char *buf, size_t count)
718 char str_governor[16];
719 struct cpufreq_policy new_policy;
721 memcpy(&new_policy, policy, sizeof(*policy));
723 ret = sscanf(buf, "%15s", str_governor);
727 if (cpufreq_parse_governor(str_governor, &new_policy.policy,
728 &new_policy.governor))
731 ret = cpufreq_set_policy(policy, &new_policy);
732 return ret ? ret : count;
736 * show_scaling_driver - show the cpufreq driver currently loaded
738 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
740 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
744 * show_scaling_available_governors - show the available CPUfreq governors
746 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
750 struct cpufreq_governor *t;
753 i += sprintf(buf, "performance powersave");
757 for_each_governor(t) {
758 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
759 - (CPUFREQ_NAME_LEN + 2)))
761 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
764 i += sprintf(&buf[i], "\n");
768 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
773 for_each_cpu(cpu, mask) {
775 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
776 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
777 if (i >= (PAGE_SIZE - 5))
780 i += sprintf(&buf[i], "\n");
783 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
786 * show_related_cpus - show the CPUs affected by each transition even if
787 * hw coordination is in use
789 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
791 return cpufreq_show_cpus(policy->related_cpus, buf);
795 * show_affected_cpus - show the CPUs affected by each transition
797 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
799 return cpufreq_show_cpus(policy->cpus, buf);
802 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
803 const char *buf, size_t count)
805 unsigned int freq = 0;
808 if (!policy->governor || !policy->governor->store_setspeed)
811 ret = sscanf(buf, "%u", &freq);
815 policy->governor->store_setspeed(policy, freq);
820 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
822 if (!policy->governor || !policy->governor->show_setspeed)
823 return sprintf(buf, "<unsupported>\n");
825 return policy->governor->show_setspeed(policy, buf);
829 * show_bios_limit - show the current cpufreq HW/BIOS limitation
831 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
835 if (cpufreq_driver->bios_limit) {
836 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
838 return sprintf(buf, "%u\n", limit);
840 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
843 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
844 cpufreq_freq_attr_ro(cpuinfo_min_freq);
845 cpufreq_freq_attr_ro(cpuinfo_max_freq);
846 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
847 cpufreq_freq_attr_ro(scaling_available_governors);
848 cpufreq_freq_attr_ro(scaling_driver);
849 cpufreq_freq_attr_ro(scaling_cur_freq);
850 cpufreq_freq_attr_ro(bios_limit);
851 cpufreq_freq_attr_ro(related_cpus);
852 cpufreq_freq_attr_ro(affected_cpus);
853 cpufreq_freq_attr_rw(scaling_min_freq);
854 cpufreq_freq_attr_rw(scaling_max_freq);
855 cpufreq_freq_attr_rw(scaling_governor);
856 cpufreq_freq_attr_rw(scaling_setspeed);
858 static struct attribute *default_attrs[] = {
859 &cpuinfo_min_freq.attr,
860 &cpuinfo_max_freq.attr,
861 &cpuinfo_transition_latency.attr,
862 &scaling_min_freq.attr,
863 &scaling_max_freq.attr,
866 &scaling_governor.attr,
867 &scaling_driver.attr,
868 &scaling_available_governors.attr,
869 &scaling_setspeed.attr,
873 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
874 #define to_attr(a) container_of(a, struct freq_attr, attr)
876 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
878 struct cpufreq_policy *policy = to_policy(kobj);
879 struct freq_attr *fattr = to_attr(attr);
882 down_read(&policy->rwsem);
885 ret = fattr->show(policy, buf);
889 up_read(&policy->rwsem);
894 static ssize_t store(struct kobject *kobj, struct attribute *attr,
895 const char *buf, size_t count)
897 struct cpufreq_policy *policy = to_policy(kobj);
898 struct freq_attr *fattr = to_attr(attr);
899 ssize_t ret = -EINVAL;
903 if (!cpu_online(policy->cpu))
906 down_write(&policy->rwsem);
909 ret = fattr->store(policy, buf, count);
913 up_write(&policy->rwsem);
920 static void cpufreq_sysfs_release(struct kobject *kobj)
922 struct cpufreq_policy *policy = to_policy(kobj);
923 pr_debug("last reference is dropped\n");
924 complete(&policy->kobj_unregister);
927 static const struct sysfs_ops sysfs_ops = {
932 static struct kobj_type ktype_cpufreq = {
933 .sysfs_ops = &sysfs_ops,
934 .default_attrs = default_attrs,
935 .release = cpufreq_sysfs_release,
938 static int add_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
940 struct device *cpu_dev;
942 pr_debug("%s: Adding symlink for CPU: %u\n", __func__, cpu);
947 cpu_dev = get_cpu_device(cpu);
948 if (WARN_ON(!cpu_dev))
951 return sysfs_create_link(&cpu_dev->kobj, &policy->kobj, "cpufreq");
954 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, int cpu)
956 struct device *cpu_dev;
958 pr_debug("%s: Removing symlink for CPU: %u\n", __func__, cpu);
960 cpu_dev = get_cpu_device(cpu);
961 if (WARN_ON(!cpu_dev))
964 sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
967 /* Add/remove symlinks for all related CPUs */
968 static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
973 /* Some related CPUs might not be present (physically hotplugged) */
974 for_each_cpu(j, policy->real_cpus) {
975 ret = add_cpu_dev_symlink(policy, j);
983 static void cpufreq_remove_dev_symlink(struct cpufreq_policy *policy)
987 /* Some related CPUs might not be present (physically hotplugged) */
988 for_each_cpu(j, policy->real_cpus)
989 remove_cpu_dev_symlink(policy, j);
992 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
994 struct freq_attr **drv_attr;
997 /* set up files for this cpu device */
998 drv_attr = cpufreq_driver->attr;
999 while (drv_attr && *drv_attr) {
1000 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1005 if (cpufreq_driver->get) {
1006 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1011 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1015 if (cpufreq_driver->bios_limit) {
1016 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1021 return cpufreq_add_dev_symlink(policy);
1024 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1026 struct cpufreq_governor *gov = NULL;
1027 struct cpufreq_policy new_policy;
1029 memcpy(&new_policy, policy, sizeof(*policy));
1031 /* Update governor of new_policy to the governor used before hotplug */
1032 gov = find_governor(policy->last_governor);
1034 pr_debug("Restoring governor %s for cpu %d\n",
1035 policy->governor->name, policy->cpu);
1037 gov = CPUFREQ_DEFAULT_GOVERNOR;
1039 new_policy.governor = gov;
1041 /* Use the default policy if there is no last_policy. */
1042 if (cpufreq_driver->setpolicy) {
1043 if (policy->last_policy)
1044 new_policy.policy = policy->last_policy;
1046 cpufreq_parse_governor(gov->name, &new_policy.policy,
1049 /* set default policy */
1050 return cpufreq_set_policy(policy, &new_policy);
1053 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1057 /* Has this CPU been taken care of already? */
1058 if (cpumask_test_cpu(cpu, policy->cpus))
1062 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1064 pr_err("%s: Failed to stop governor\n", __func__);
1069 down_write(&policy->rwsem);
1070 cpumask_set_cpu(cpu, policy->cpus);
1071 up_write(&policy->rwsem);
1074 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1076 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1079 pr_err("%s: Failed to start governor\n", __func__);
1087 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1089 struct device *dev = get_cpu_device(cpu);
1090 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 kobject_init(&policy->kobj, &ktype_cpufreq);
1109 INIT_LIST_HEAD(&policy->policy_list);
1110 init_rwsem(&policy->rwsem);
1111 spin_lock_init(&policy->transition_lock);
1112 init_waitqueue_head(&policy->transition_wait);
1113 init_completion(&policy->kobj_unregister);
1114 INIT_WORK(&policy->update, handle_update);
1120 free_cpumask_var(policy->related_cpus);
1122 free_cpumask_var(policy->cpus);
1129 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy, bool notify)
1131 struct kobject *kobj;
1132 struct completion *cmp;
1135 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1136 CPUFREQ_REMOVE_POLICY, policy);
1138 down_write(&policy->rwsem);
1139 cpufreq_remove_dev_symlink(policy);
1140 kobj = &policy->kobj;
1141 cmp = &policy->kobj_unregister;
1142 up_write(&policy->rwsem);
1146 * We need to make sure that the underlying kobj is
1147 * actually not referenced anymore by anybody before we
1148 * proceed with unloading.
1150 pr_debug("waiting for dropping of refcount\n");
1151 wait_for_completion(cmp);
1152 pr_debug("wait complete\n");
1155 static void cpufreq_policy_free(struct cpufreq_policy *policy, bool notify)
1157 unsigned long flags;
1160 /* Remove policy from list */
1161 write_lock_irqsave(&cpufreq_driver_lock, flags);
1162 list_del(&policy->policy_list);
1164 for_each_cpu(cpu, policy->related_cpus)
1165 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1166 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1168 cpufreq_policy_put_kobj(policy, notify);
1169 free_cpumask_var(policy->real_cpus);
1170 free_cpumask_var(policy->related_cpus);
1171 free_cpumask_var(policy->cpus);
1175 static int cpufreq_online(unsigned int cpu)
1177 struct cpufreq_policy *policy;
1179 unsigned long flags;
1183 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1185 /* Check if this CPU already has a policy to manage it */
1186 policy = per_cpu(cpufreq_cpu_data, cpu);
1188 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1189 if (!policy_is_inactive(policy))
1190 return cpufreq_add_policy_cpu(policy, cpu);
1192 /* This is the only online CPU for the policy. Start over. */
1194 down_write(&policy->rwsem);
1196 policy->governor = NULL;
1197 up_write(&policy->rwsem);
1200 policy = cpufreq_policy_alloc(cpu);
1205 cpumask_copy(policy->cpus, cpumask_of(cpu));
1207 /* call driver. From then on the cpufreq must be able
1208 * to accept all calls to ->verify and ->setpolicy for this CPU
1210 ret = cpufreq_driver->init(policy);
1212 pr_debug("initialization failed\n");
1213 goto out_free_policy;
1216 down_write(&policy->rwsem);
1219 /* related_cpus should at least include policy->cpus. */
1220 cpumask_copy(policy->related_cpus, policy->cpus);
1221 /* Remember CPUs present at the policy creation time. */
1222 cpumask_and(policy->real_cpus, policy->cpus, cpu_present_mask);
1224 /* Name and add the kobject */
1225 ret = kobject_add(&policy->kobj, cpufreq_global_kobject,
1227 cpumask_first(policy->related_cpus));
1229 pr_err("%s: failed to add policy->kobj: %d\n", __func__,
1231 goto out_exit_policy;
1236 * affected cpus must always be the one, which are online. We aren't
1237 * managing offline cpus here.
1239 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1242 policy->user_policy.min = policy->min;
1243 policy->user_policy.max = policy->max;
1245 write_lock_irqsave(&cpufreq_driver_lock, flags);
1246 for_each_cpu(j, policy->related_cpus)
1247 per_cpu(cpufreq_cpu_data, j) = policy;
1248 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1251 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1252 policy->cur = cpufreq_driver->get(policy->cpu);
1254 pr_err("%s: ->get() failed\n", __func__);
1255 goto out_exit_policy;
1260 * Sometimes boot loaders set CPU frequency to a value outside of
1261 * frequency table present with cpufreq core. In such cases CPU might be
1262 * unstable if it has to run on that frequency for long duration of time
1263 * and so its better to set it to a frequency which is specified in
1264 * freq-table. This also makes cpufreq stats inconsistent as
1265 * cpufreq-stats would fail to register because current frequency of CPU
1266 * isn't found in freq-table.
1268 * Because we don't want this change to effect boot process badly, we go
1269 * for the next freq which is >= policy->cur ('cur' must be set by now,
1270 * otherwise we will end up setting freq to lowest of the table as 'cur'
1271 * is initialized to zero).
1273 * We are passing target-freq as "policy->cur - 1" otherwise
1274 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1275 * equal to target-freq.
1277 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1279 /* Are we running at unknown frequency ? */
1280 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1281 if (ret == -EINVAL) {
1282 /* Warn user and fix it */
1283 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1284 __func__, policy->cpu, policy->cur);
1285 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1286 CPUFREQ_RELATION_L);
1289 * Reaching here after boot in a few seconds may not
1290 * mean that system will remain stable at "unknown"
1291 * frequency for longer duration. Hence, a BUG_ON().
1294 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1295 __func__, policy->cpu, policy->cur);
1300 ret = cpufreq_add_dev_interface(policy);
1302 goto out_exit_policy;
1303 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1304 CPUFREQ_CREATE_POLICY, policy);
1306 write_lock_irqsave(&cpufreq_driver_lock, flags);
1307 list_add(&policy->policy_list, &cpufreq_policy_list);
1308 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1311 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1312 CPUFREQ_START, policy);
1314 ret = cpufreq_init_policy(policy);
1316 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1317 __func__, cpu, ret);
1318 /* cpufreq_policy_free() will notify based on this */
1320 goto out_exit_policy;
1323 up_write(&policy->rwsem);
1325 kobject_uevent(&policy->kobj, KOBJ_ADD);
1327 /* Callback for handling stuff after policy is ready */
1328 if (cpufreq_driver->ready)
1329 cpufreq_driver->ready(policy);
1331 pr_debug("initialization complete\n");
1336 up_write(&policy->rwsem);
1338 if (cpufreq_driver->exit)
1339 cpufreq_driver->exit(policy);
1341 cpufreq_policy_free(policy, !new_policy);
1346 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1348 * @sif: Subsystem interface structure pointer (not used)
1350 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1352 unsigned cpu = dev->id;
1355 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1357 if (cpu_online(cpu)) {
1358 ret = cpufreq_online(cpu);
1361 * A hotplug notifier will follow and we will handle it as CPU
1362 * online then. For now, just create the sysfs link, unless
1363 * there is no policy or the link is already present.
1365 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1367 ret = policy && !cpumask_test_and_set_cpu(cpu, policy->real_cpus)
1368 ? add_cpu_dev_symlink(policy, cpu) : 0;
1374 static void cpufreq_offline_prepare(unsigned int cpu)
1376 struct cpufreq_policy *policy;
1378 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1380 policy = cpufreq_cpu_get_raw(cpu);
1382 pr_debug("%s: No cpu_data found\n", __func__);
1387 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1389 pr_err("%s: Failed to stop governor\n", __func__);
1392 down_write(&policy->rwsem);
1393 cpumask_clear_cpu(cpu, policy->cpus);
1395 if (policy_is_inactive(policy)) {
1397 strncpy(policy->last_governor, policy->governor->name,
1400 policy->last_policy = policy->policy;
1401 } else if (cpu == policy->cpu) {
1402 /* Nominate new CPU */
1403 policy->cpu = cpumask_any(policy->cpus);
1405 up_write(&policy->rwsem);
1407 /* Start governor again for active policy */
1408 if (!policy_is_inactive(policy)) {
1410 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1412 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1415 pr_err("%s: Failed to start governor\n", __func__);
1417 } else if (cpufreq_driver->stop_cpu) {
1418 cpufreq_driver->stop_cpu(policy);
1422 static void cpufreq_offline_finish(unsigned int cpu)
1424 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1427 pr_debug("%s: No cpu_data found\n", __func__);
1431 /* Only proceed for inactive policies */
1432 if (!policy_is_inactive(policy))
1435 /* If cpu is last user of policy, free policy */
1437 int ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
1439 pr_err("%s: Failed to exit governor\n", __func__);
1443 * Perform the ->exit() even during light-weight tear-down,
1444 * since this is a core component, and is essential for the
1445 * subsequent light-weight ->init() to succeed.
1447 if (cpufreq_driver->exit) {
1448 cpufreq_driver->exit(policy);
1449 policy->freq_table = NULL;
1454 * cpufreq_remove_dev - remove a CPU device
1456 * Removes the cpufreq interface for a CPU device.
1458 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1460 unsigned int cpu = dev->id;
1461 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1466 if (cpu_online(cpu)) {
1467 cpufreq_offline_prepare(cpu);
1468 cpufreq_offline_finish(cpu);
1471 cpumask_clear_cpu(cpu, policy->real_cpus);
1472 remove_cpu_dev_symlink(policy, cpu);
1474 if (cpumask_empty(policy->real_cpus))
1475 cpufreq_policy_free(policy, true);
1478 static void handle_update(struct work_struct *work)
1480 struct cpufreq_policy *policy =
1481 container_of(work, struct cpufreq_policy, update);
1482 unsigned int cpu = policy->cpu;
1483 pr_debug("handle_update for cpu %u called\n", cpu);
1484 cpufreq_update_policy(cpu);
1488 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1490 * @policy: policy managing CPUs
1491 * @new_freq: CPU frequency the CPU actually runs at
1493 * We adjust to current frequency first, and need to clean up later.
1494 * So either call to cpufreq_update_policy() or schedule handle_update()).
1496 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1497 unsigned int new_freq)
1499 struct cpufreq_freqs freqs;
1501 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1502 policy->cur, new_freq);
1504 freqs.old = policy->cur;
1505 freqs.new = new_freq;
1507 cpufreq_freq_transition_begin(policy, &freqs);
1508 cpufreq_freq_transition_end(policy, &freqs, 0);
1512 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1515 * This is the last known freq, without actually getting it from the driver.
1516 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1518 unsigned int cpufreq_quick_get(unsigned int cpu)
1520 struct cpufreq_policy *policy;
1521 unsigned int ret_freq = 0;
1523 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
1524 return cpufreq_driver->get(cpu);
1526 policy = cpufreq_cpu_get(cpu);
1528 ret_freq = policy->cur;
1529 cpufreq_cpu_put(policy);
1534 EXPORT_SYMBOL(cpufreq_quick_get);
1537 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1540 * Just return the max possible frequency for a given CPU.
1542 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1544 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1545 unsigned int ret_freq = 0;
1548 ret_freq = policy->max;
1549 cpufreq_cpu_put(policy);
1554 EXPORT_SYMBOL(cpufreq_quick_get_max);
1556 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1558 unsigned int ret_freq = 0;
1560 if (!cpufreq_driver->get)
1563 ret_freq = cpufreq_driver->get(policy->cpu);
1565 /* Updating inactive policies is invalid, so avoid doing that. */
1566 if (unlikely(policy_is_inactive(policy)))
1569 if (ret_freq && policy->cur &&
1570 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1571 /* verify no discrepancy between actual and
1572 saved value exists */
1573 if (unlikely(ret_freq != policy->cur)) {
1574 cpufreq_out_of_sync(policy, ret_freq);
1575 schedule_work(&policy->update);
1583 * cpufreq_get - get the current CPU frequency (in kHz)
1586 * Get the CPU current (static) CPU frequency
1588 unsigned int cpufreq_get(unsigned int cpu)
1590 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1591 unsigned int ret_freq = 0;
1594 down_read(&policy->rwsem);
1595 ret_freq = __cpufreq_get(policy);
1596 up_read(&policy->rwsem);
1598 cpufreq_cpu_put(policy);
1603 EXPORT_SYMBOL(cpufreq_get);
1605 static struct subsys_interface cpufreq_interface = {
1607 .subsys = &cpu_subsys,
1608 .add_dev = cpufreq_add_dev,
1609 .remove_dev = cpufreq_remove_dev,
1613 * In case platform wants some specific frequency to be configured
1616 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1620 if (!policy->suspend_freq) {
1621 pr_debug("%s: suspend_freq not defined\n", __func__);
1625 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1626 policy->suspend_freq);
1628 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1629 CPUFREQ_RELATION_H);
1631 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1632 __func__, policy->suspend_freq, ret);
1636 EXPORT_SYMBOL(cpufreq_generic_suspend);
1639 * cpufreq_suspend() - Suspend CPUFreq governors
1641 * Called during system wide Suspend/Hibernate cycles for suspending governors
1642 * as some platforms can't change frequency after this point in suspend cycle.
1643 * Because some of the devices (like: i2c, regulators, etc) they use for
1644 * changing frequency are suspended quickly after this point.
1646 void cpufreq_suspend(void)
1648 struct cpufreq_policy *policy;
1650 if (!cpufreq_driver)
1656 pr_debug("%s: Suspending Governors\n", __func__);
1658 for_each_active_policy(policy) {
1659 if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
1660 pr_err("%s: Failed to stop governor for policy: %p\n",
1662 else if (cpufreq_driver->suspend
1663 && cpufreq_driver->suspend(policy))
1664 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1669 cpufreq_suspended = true;
1673 * cpufreq_resume() - Resume CPUFreq governors
1675 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1676 * are suspended with cpufreq_suspend().
1678 void cpufreq_resume(void)
1680 struct cpufreq_policy *policy;
1682 if (!cpufreq_driver)
1685 cpufreq_suspended = false;
1690 pr_debug("%s: Resuming Governors\n", __func__);
1692 for_each_active_policy(policy) {
1693 if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
1694 pr_err("%s: Failed to resume driver: %p\n", __func__,
1696 else if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
1697 || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
1698 pr_err("%s: Failed to start governor for policy: %p\n",
1703 * schedule call cpufreq_update_policy() for first-online CPU, as that
1704 * wouldn't be hotplugged-out on suspend. It will verify that the
1705 * current freq is in sync with what we believe it to be.
1707 policy = cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask));
1708 if (WARN_ON(!policy))
1711 schedule_work(&policy->update);
1715 * cpufreq_get_current_driver - return current driver's name
1717 * Return the name string of the currently loaded cpufreq driver
1720 const char *cpufreq_get_current_driver(void)
1723 return cpufreq_driver->name;
1727 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1730 * cpufreq_get_driver_data - return current driver data
1732 * Return the private data of the currently loaded cpufreq
1733 * driver, or NULL if no cpufreq driver is loaded.
1735 void *cpufreq_get_driver_data(void)
1738 return cpufreq_driver->driver_data;
1742 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1744 /*********************************************************************
1745 * NOTIFIER LISTS INTERFACE *
1746 *********************************************************************/
1749 * cpufreq_register_notifier - register a driver with cpufreq
1750 * @nb: notifier function to register
1751 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1753 * Add a driver to one of two lists: either a list of drivers that
1754 * are notified about clock rate changes (once before and once after
1755 * the transition), or a list of drivers that are notified about
1756 * changes in cpufreq policy.
1758 * This function may sleep, and has the same return conditions as
1759 * blocking_notifier_chain_register.
1761 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1765 if (cpufreq_disabled())
1768 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1771 case CPUFREQ_TRANSITION_NOTIFIER:
1772 ret = srcu_notifier_chain_register(
1773 &cpufreq_transition_notifier_list, nb);
1775 case CPUFREQ_POLICY_NOTIFIER:
1776 ret = blocking_notifier_chain_register(
1777 &cpufreq_policy_notifier_list, nb);
1785 EXPORT_SYMBOL(cpufreq_register_notifier);
1788 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1789 * @nb: notifier block to be unregistered
1790 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1792 * Remove a driver from the CPU frequency notifier list.
1794 * This function may sleep, and has the same return conditions as
1795 * blocking_notifier_chain_unregister.
1797 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1801 if (cpufreq_disabled())
1805 case CPUFREQ_TRANSITION_NOTIFIER:
1806 ret = srcu_notifier_chain_unregister(
1807 &cpufreq_transition_notifier_list, nb);
1809 case CPUFREQ_POLICY_NOTIFIER:
1810 ret = blocking_notifier_chain_unregister(
1811 &cpufreq_policy_notifier_list, nb);
1819 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1822 /*********************************************************************
1824 *********************************************************************/
1826 /* Must set freqs->new to intermediate frequency */
1827 static int __target_intermediate(struct cpufreq_policy *policy,
1828 struct cpufreq_freqs *freqs, int index)
1832 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1834 /* We don't need to switch to intermediate freq */
1838 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1839 __func__, policy->cpu, freqs->old, freqs->new);
1841 cpufreq_freq_transition_begin(policy, freqs);
1842 ret = cpufreq_driver->target_intermediate(policy, index);
1843 cpufreq_freq_transition_end(policy, freqs, ret);
1846 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1852 static int __target_index(struct cpufreq_policy *policy,
1853 struct cpufreq_frequency_table *freq_table, int index)
1855 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1856 unsigned int intermediate_freq = 0;
1857 int retval = -EINVAL;
1860 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1862 /* Handle switching to intermediate frequency */
1863 if (cpufreq_driver->get_intermediate) {
1864 retval = __target_intermediate(policy, &freqs, index);
1868 intermediate_freq = freqs.new;
1869 /* Set old freq to intermediate */
1870 if (intermediate_freq)
1871 freqs.old = freqs.new;
1874 freqs.new = freq_table[index].frequency;
1875 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1876 __func__, policy->cpu, freqs.old, freqs.new);
1878 cpufreq_freq_transition_begin(policy, &freqs);
1881 retval = cpufreq_driver->target_index(policy, index);
1883 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
1887 cpufreq_freq_transition_end(policy, &freqs, retval);
1890 * Failed after setting to intermediate freq? Driver should have
1891 * reverted back to initial frequency and so should we. Check
1892 * here for intermediate_freq instead of get_intermediate, in
1893 * case we haven't switched to intermediate freq at all.
1895 if (unlikely(retval && intermediate_freq)) {
1896 freqs.old = intermediate_freq;
1897 freqs.new = policy->restore_freq;
1898 cpufreq_freq_transition_begin(policy, &freqs);
1899 cpufreq_freq_transition_end(policy, &freqs, 0);
1906 int __cpufreq_driver_target(struct cpufreq_policy *policy,
1907 unsigned int target_freq,
1908 unsigned int relation)
1910 unsigned int old_target_freq = target_freq;
1911 int retval = -EINVAL;
1913 if (cpufreq_disabled())
1916 /* Make sure that target_freq is within supported range */
1917 if (target_freq > policy->max)
1918 target_freq = policy->max;
1919 if (target_freq < policy->min)
1920 target_freq = policy->min;
1922 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1923 policy->cpu, target_freq, relation, old_target_freq);
1926 * This might look like a redundant call as we are checking it again
1927 * after finding index. But it is left intentionally for cases where
1928 * exactly same freq is called again and so we can save on few function
1931 if (target_freq == policy->cur)
1934 /* Save last value to restore later on errors */
1935 policy->restore_freq = policy->cur;
1937 if (cpufreq_driver->target)
1938 retval = cpufreq_driver->target(policy, target_freq, relation);
1939 else if (cpufreq_driver->target_index) {
1940 struct cpufreq_frequency_table *freq_table;
1943 freq_table = cpufreq_frequency_get_table(policy->cpu);
1944 if (unlikely(!freq_table)) {
1945 pr_err("%s: Unable to find freq_table\n", __func__);
1949 retval = cpufreq_frequency_table_target(policy, freq_table,
1950 target_freq, relation, &index);
1951 if (unlikely(retval)) {
1952 pr_err("%s: Unable to find matching freq\n", __func__);
1956 if (freq_table[index].frequency == policy->cur) {
1961 retval = __target_index(policy, freq_table, index);
1967 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1969 int cpufreq_driver_target(struct cpufreq_policy *policy,
1970 unsigned int target_freq,
1971 unsigned int relation)
1975 down_write(&policy->rwsem);
1977 ret = __cpufreq_driver_target(policy, target_freq, relation);
1979 up_write(&policy->rwsem);
1983 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1985 static int __cpufreq_governor(struct cpufreq_policy *policy,
1990 /* Only must be defined when default governor is known to have latency
1991 restrictions, like e.g. conservative or ondemand.
1992 That this is the case is already ensured in Kconfig
1994 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1995 struct cpufreq_governor *gov = &cpufreq_gov_performance;
1997 struct cpufreq_governor *gov = NULL;
2000 /* Don't start any governor operations if we are entering suspend */
2001 if (cpufreq_suspended)
2004 * Governor might not be initiated here if ACPI _PPC changed
2005 * notification happened, so check it.
2007 if (!policy->governor)
2010 if (policy->governor->max_transition_latency &&
2011 policy->cpuinfo.transition_latency >
2012 policy->governor->max_transition_latency) {
2016 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
2017 policy->governor->name, gov->name);
2018 policy->governor = gov;
2022 if (event == CPUFREQ_GOV_POLICY_INIT)
2023 if (!try_module_get(policy->governor->owner))
2026 pr_debug("%s: for CPU %u, event %u\n", __func__, policy->cpu, event);
2028 mutex_lock(&cpufreq_governor_lock);
2029 if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
2030 || (!policy->governor_enabled
2031 && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
2032 mutex_unlock(&cpufreq_governor_lock);
2036 if (event == CPUFREQ_GOV_STOP)
2037 policy->governor_enabled = false;
2038 else if (event == CPUFREQ_GOV_START)
2039 policy->governor_enabled = true;
2041 mutex_unlock(&cpufreq_governor_lock);
2043 ret = policy->governor->governor(policy, event);
2046 if (event == CPUFREQ_GOV_POLICY_INIT)
2047 policy->governor->initialized++;
2048 else if (event == CPUFREQ_GOV_POLICY_EXIT)
2049 policy->governor->initialized--;
2051 /* Restore original values */
2052 mutex_lock(&cpufreq_governor_lock);
2053 if (event == CPUFREQ_GOV_STOP)
2054 policy->governor_enabled = true;
2055 else if (event == CPUFREQ_GOV_START)
2056 policy->governor_enabled = false;
2057 mutex_unlock(&cpufreq_governor_lock);
2060 if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
2061 ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
2062 module_put(policy->governor->owner);
2067 int cpufreq_register_governor(struct cpufreq_governor *governor)
2074 if (cpufreq_disabled())
2077 mutex_lock(&cpufreq_governor_mutex);
2079 governor->initialized = 0;
2081 if (!find_governor(governor->name)) {
2083 list_add(&governor->governor_list, &cpufreq_governor_list);
2086 mutex_unlock(&cpufreq_governor_mutex);
2089 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2091 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2093 struct cpufreq_policy *policy;
2094 unsigned long flags;
2099 if (cpufreq_disabled())
2102 /* clear last_governor for all inactive policies */
2103 read_lock_irqsave(&cpufreq_driver_lock, flags);
2104 for_each_inactive_policy(policy) {
2105 if (!strcmp(policy->last_governor, governor->name)) {
2106 policy->governor = NULL;
2107 strcpy(policy->last_governor, "\0");
2110 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2112 mutex_lock(&cpufreq_governor_mutex);
2113 list_del(&governor->governor_list);
2114 mutex_unlock(&cpufreq_governor_mutex);
2117 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2120 /*********************************************************************
2121 * POLICY INTERFACE *
2122 *********************************************************************/
2125 * cpufreq_get_policy - get the current cpufreq_policy
2126 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2129 * Reads the current cpufreq policy.
2131 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2133 struct cpufreq_policy *cpu_policy;
2137 cpu_policy = cpufreq_cpu_get(cpu);
2141 memcpy(policy, cpu_policy, sizeof(*policy));
2143 cpufreq_cpu_put(cpu_policy);
2146 EXPORT_SYMBOL(cpufreq_get_policy);
2149 * policy : current policy.
2150 * new_policy: policy to be set.
2152 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2153 struct cpufreq_policy *new_policy)
2155 struct cpufreq_governor *old_gov;
2158 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2159 new_policy->cpu, new_policy->min, new_policy->max);
2161 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2164 * This check works well when we store new min/max freq attributes,
2165 * because new_policy is a copy of policy with one field updated.
2167 if (new_policy->min > new_policy->max)
2170 /* verify the cpu speed can be set within this limit */
2171 ret = cpufreq_driver->verify(new_policy);
2175 /* adjust if necessary - all reasons */
2176 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2177 CPUFREQ_ADJUST, new_policy);
2180 * verify the cpu speed can be set within this limit, which might be
2181 * different to the first one
2183 ret = cpufreq_driver->verify(new_policy);
2187 /* notification of the new policy */
2188 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2189 CPUFREQ_NOTIFY, new_policy);
2191 scale_freq_capacity(new_policy, NULL);
2193 policy->min = new_policy->min;
2194 policy->max = new_policy->max;
2195 trace_cpu_frequency_limits(policy->max, policy->min, policy->cpu);
2197 pr_debug("new min and max freqs are %u - %u kHz\n",
2198 policy->min, policy->max);
2200 if (cpufreq_driver->setpolicy) {
2201 policy->policy = new_policy->policy;
2202 pr_debug("setting range\n");
2203 return cpufreq_driver->setpolicy(new_policy);
2206 if (new_policy->governor == policy->governor)
2209 pr_debug("governor switch\n");
2211 /* save old, working values */
2212 old_gov = policy->governor;
2213 /* end old governor */
2215 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
2217 /* This can happen due to race with other operations */
2218 pr_debug("%s: Failed to Stop Governor: %s (%d)\n",
2219 __func__, old_gov->name, ret);
2223 up_write(&policy->rwsem);
2224 ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2225 down_write(&policy->rwsem);
2228 pr_err("%s: Failed to Exit Governor: %s (%d)\n",
2229 __func__, old_gov->name, ret);
2234 /* start new governor */
2235 policy->governor = new_policy->governor;
2236 ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);
2238 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
2242 up_write(&policy->rwsem);
2243 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2244 down_write(&policy->rwsem);
2247 /* new governor failed, so re-start old one */
2248 pr_debug("starting governor %s failed\n", policy->governor->name);
2250 policy->governor = old_gov;
2251 if (__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT))
2252 policy->governor = NULL;
2254 __cpufreq_governor(policy, CPUFREQ_GOV_START);
2260 pr_debug("governor: change or update limits\n");
2261 return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2265 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2266 * @cpu: CPU which shall be re-evaluated
2268 * Useful for policy notifiers which have different necessities
2269 * at different times.
2271 int cpufreq_update_policy(unsigned int cpu)
2273 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2274 struct cpufreq_policy new_policy;
2280 down_write(&policy->rwsem);
2282 pr_debug("updating policy for CPU %u\n", cpu);
2283 memcpy(&new_policy, policy, sizeof(*policy));
2284 new_policy.min = policy->user_policy.min;
2285 new_policy.max = policy->user_policy.max;
2288 * BIOS might change freq behind our back
2289 * -> ask driver for current freq and notify governors about a change
2291 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
2292 new_policy.cur = cpufreq_driver->get(cpu);
2293 if (WARN_ON(!new_policy.cur)) {
2299 pr_debug("Driver did not initialize current freq\n");
2300 policy->cur = new_policy.cur;
2302 if (policy->cur != new_policy.cur && has_target())
2303 cpufreq_out_of_sync(policy, new_policy.cur);
2307 ret = cpufreq_set_policy(policy, &new_policy);
2310 up_write(&policy->rwsem);
2312 cpufreq_cpu_put(policy);
2315 EXPORT_SYMBOL(cpufreq_update_policy);
2317 static int cpufreq_cpu_callback(struct notifier_block *nfb,
2318 unsigned long action, void *hcpu)
2320 unsigned int cpu = (unsigned long)hcpu;
2322 switch (action & ~CPU_TASKS_FROZEN) {
2324 cpufreq_online(cpu);
2327 case CPU_DOWN_PREPARE:
2328 cpufreq_offline_prepare(cpu);
2332 cpufreq_offline_finish(cpu);
2335 case CPU_DOWN_FAILED:
2336 cpufreq_online(cpu);
2342 static struct notifier_block __refdata cpufreq_cpu_notifier = {
2343 .notifier_call = cpufreq_cpu_callback,
2346 /*********************************************************************
2348 *********************************************************************/
2349 static int cpufreq_boost_set_sw(int state)
2351 struct cpufreq_frequency_table *freq_table;
2352 struct cpufreq_policy *policy;
2355 for_each_active_policy(policy) {
2356 freq_table = cpufreq_frequency_get_table(policy->cpu);
2358 ret = cpufreq_frequency_table_cpuinfo(policy,
2361 pr_err("%s: Policy frequency update failed\n",
2365 policy->user_policy.max = policy->max;
2366 __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2373 int cpufreq_boost_trigger_state(int state)
2375 unsigned long flags;
2378 if (cpufreq_driver->boost_enabled == state)
2381 write_lock_irqsave(&cpufreq_driver_lock, flags);
2382 cpufreq_driver->boost_enabled = state;
2383 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2385 ret = cpufreq_driver->set_boost(state);
2387 write_lock_irqsave(&cpufreq_driver_lock, flags);
2388 cpufreq_driver->boost_enabled = !state;
2389 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2391 pr_err("%s: Cannot %s BOOST\n",
2392 __func__, state ? "enable" : "disable");
2398 int cpufreq_boost_supported(void)
2400 if (likely(cpufreq_driver))
2401 return cpufreq_driver->boost_supported;
2405 EXPORT_SYMBOL_GPL(cpufreq_boost_supported);
2407 static int create_boost_sysfs_file(void)
2411 if (!cpufreq_boost_supported())
2415 * Check if driver provides function to enable boost -
2416 * if not, use cpufreq_boost_set_sw as default
2418 if (!cpufreq_driver->set_boost)
2419 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2421 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2423 pr_err("%s: cannot register global BOOST sysfs file\n",
2429 static void remove_boost_sysfs_file(void)
2431 if (cpufreq_boost_supported())
2432 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2435 int cpufreq_enable_boost_support(void)
2437 if (!cpufreq_driver)
2440 if (cpufreq_boost_supported())
2443 cpufreq_driver->boost_supported = true;
2445 /* This will get removed on driver unregister */
2446 return create_boost_sysfs_file();
2448 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2450 int cpufreq_boost_enabled(void)
2452 return cpufreq_driver->boost_enabled;
2454 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2456 /*********************************************************************
2457 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2458 *********************************************************************/
2461 * cpufreq_register_driver - register a CPU Frequency driver
2462 * @driver_data: A struct cpufreq_driver containing the values#
2463 * submitted by the CPU Frequency driver.
2465 * Registers a CPU Frequency driver to this core code. This code
2466 * returns zero on success, -EBUSY when another driver got here first
2467 * (and isn't unregistered in the meantime).
2470 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2472 unsigned long flags;
2475 if (cpufreq_disabled())
2478 if (!driver_data || !driver_data->verify || !driver_data->init ||
2479 !(driver_data->setpolicy || driver_data->target_index ||
2480 driver_data->target) ||
2481 (driver_data->setpolicy && (driver_data->target_index ||
2482 driver_data->target)) ||
2483 (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
2486 pr_debug("trying to register driver %s\n", driver_data->name);
2488 /* Protect against concurrent CPU online/offline. */
2491 write_lock_irqsave(&cpufreq_driver_lock, flags);
2492 if (cpufreq_driver) {
2493 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2497 cpufreq_driver = driver_data;
2498 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2500 if (driver_data->setpolicy)
2501 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2503 ret = create_boost_sysfs_file();
2505 goto err_null_driver;
2507 ret = subsys_interface_register(&cpufreq_interface);
2509 goto err_boost_unreg;
2511 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2512 list_empty(&cpufreq_policy_list)) {
2513 /* if all ->init() calls failed, unregister */
2514 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2519 register_hotcpu_notifier(&cpufreq_cpu_notifier);
2520 pr_debug("driver %s up and running\n", driver_data->name);
2527 subsys_interface_unregister(&cpufreq_interface);
2529 remove_boost_sysfs_file();
2531 write_lock_irqsave(&cpufreq_driver_lock, flags);
2532 cpufreq_driver = NULL;
2533 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2536 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2539 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2541 * Unregister the current CPUFreq driver. Only call this if you have
2542 * the right to do so, i.e. if you have succeeded in initialising before!
2543 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2544 * currently not initialised.
2546 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2548 unsigned long flags;
2550 if (!cpufreq_driver || (driver != cpufreq_driver))
2553 pr_debug("unregistering driver %s\n", driver->name);
2555 /* Protect against concurrent cpu hotplug */
2557 subsys_interface_unregister(&cpufreq_interface);
2558 remove_boost_sysfs_file();
2559 unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
2561 write_lock_irqsave(&cpufreq_driver_lock, flags);
2563 cpufreq_driver = NULL;
2565 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2570 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2573 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2574 * or mutexes when secondary CPUs are halted.
2576 static struct syscore_ops cpufreq_syscore_ops = {
2577 .shutdown = cpufreq_suspend,
2580 struct kobject *cpufreq_global_kobject;
2581 EXPORT_SYMBOL(cpufreq_global_kobject);
2583 static int __init cpufreq_core_init(void)
2585 if (cpufreq_disabled())
2588 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2589 BUG_ON(!cpufreq_global_kobject);
2591 register_syscore_ops(&cpufreq_syscore_ops);
2595 core_initcall(cpufreq_core_init);