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/tick.h>
31 #include <trace/events/power.h>
34 * The "cpufreq driver" - the arch- or hardware-dependent low
35 * level driver of CPUFreq support, and its spinlock. This lock
36 * also protects the cpufreq_cpu_data array.
38 static struct cpufreq_driver *cpufreq_driver;
39 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
40 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data_fallback);
41 static DEFINE_RWLOCK(cpufreq_driver_lock);
42 DEFINE_MUTEX(cpufreq_governor_lock);
43 static LIST_HEAD(cpufreq_policy_list);
45 /* This one keeps track of the previously set governor of a removed CPU */
46 static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
48 /* Flag to suspend/resume CPUFreq governors */
49 static bool cpufreq_suspended;
51 static inline bool has_target(void)
53 return cpufreq_driver->target_index || cpufreq_driver->target;
57 * rwsem to guarantee that cpufreq driver module doesn't unload during critical
60 static DECLARE_RWSEM(cpufreq_rwsem);
62 /* internal prototypes */
63 static int __cpufreq_governor(struct cpufreq_policy *policy,
65 static unsigned int __cpufreq_get(unsigned int cpu);
66 static void handle_update(struct work_struct *work);
69 * Two notifier lists: the "policy" list is involved in the
70 * validation process for a new CPU frequency policy; the
71 * "transition" list for kernel code that needs to handle
72 * changes to devices when the CPU clock speed changes.
73 * The mutex locks both lists.
75 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
76 static struct srcu_notifier_head cpufreq_transition_notifier_list;
78 static bool init_cpufreq_transition_notifier_list_called;
79 static int __init init_cpufreq_transition_notifier_list(void)
81 srcu_init_notifier_head(&cpufreq_transition_notifier_list);
82 init_cpufreq_transition_notifier_list_called = true;
85 pure_initcall(init_cpufreq_transition_notifier_list);
87 static int off __read_mostly;
88 static int cpufreq_disabled(void)
92 void disable_cpufreq(void)
96 static LIST_HEAD(cpufreq_governor_list);
97 static DEFINE_MUTEX(cpufreq_governor_mutex);
99 bool have_governor_per_policy(void)
101 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
103 EXPORT_SYMBOL_GPL(have_governor_per_policy);
105 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
107 if (have_governor_per_policy())
108 return &policy->kobj;
110 return cpufreq_global_kobject;
112 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
114 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
120 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
122 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
123 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
124 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
125 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
126 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
127 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
129 idle_time = cur_wall_time - busy_time;
131 *wall = cputime_to_usecs(cur_wall_time);
133 return cputime_to_usecs(idle_time);
136 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
138 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
140 if (idle_time == -1ULL)
141 return get_cpu_idle_time_jiffy(cpu, wall);
143 idle_time += get_cpu_iowait_time_us(cpu, wall);
147 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
150 * This is a generic cpufreq init() routine which can be used by cpufreq
151 * drivers of SMP systems. It will do following:
152 * - validate & show freq table passed
153 * - set policies transition latency
154 * - policy->cpus with all possible CPUs
156 int cpufreq_generic_init(struct cpufreq_policy *policy,
157 struct cpufreq_frequency_table *table,
158 unsigned int transition_latency)
162 ret = cpufreq_table_validate_and_show(policy, table);
164 pr_err("%s: invalid frequency table: %d\n", __func__, ret);
168 policy->cpuinfo.transition_latency = transition_latency;
171 * The driver only supports the SMP configuartion where all processors
172 * share the clock and voltage and clock.
174 cpumask_setall(policy->cpus);
178 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
180 unsigned int cpufreq_generic_get(unsigned int cpu)
182 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
184 if (!policy || IS_ERR(policy->clk)) {
185 pr_err("%s: No %s associated to cpu: %d\n",
186 __func__, policy ? "clk" : "policy", cpu);
190 return clk_get_rate(policy->clk) / 1000;
192 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
194 /* Only for cpufreq core internal use */
195 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
197 return per_cpu(cpufreq_cpu_data, cpu);
200 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
202 struct cpufreq_policy *policy = NULL;
205 if (cpufreq_disabled() || (cpu >= nr_cpu_ids))
208 if (!down_read_trylock(&cpufreq_rwsem))
211 /* get the cpufreq driver */
212 read_lock_irqsave(&cpufreq_driver_lock, flags);
214 if (cpufreq_driver) {
216 policy = per_cpu(cpufreq_cpu_data, cpu);
218 kobject_get(&policy->kobj);
221 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
224 up_read(&cpufreq_rwsem);
228 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
230 void cpufreq_cpu_put(struct cpufreq_policy *policy)
232 if (cpufreq_disabled())
235 kobject_put(&policy->kobj);
236 up_read(&cpufreq_rwsem);
238 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
240 /*********************************************************************
241 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
242 *********************************************************************/
245 * adjust_jiffies - adjust the system "loops_per_jiffy"
247 * This function alters the system "loops_per_jiffy" for the clock
248 * speed change. Note that loops_per_jiffy cannot be updated on SMP
249 * systems as each CPU might be scaled differently. So, use the arch
250 * per-CPU loops_per_jiffy value wherever possible.
253 static unsigned long l_p_j_ref;
254 static unsigned int l_p_j_ref_freq;
256 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
258 if (ci->flags & CPUFREQ_CONST_LOOPS)
261 if (!l_p_j_ref_freq) {
262 l_p_j_ref = loops_per_jiffy;
263 l_p_j_ref_freq = ci->old;
264 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
265 l_p_j_ref, l_p_j_ref_freq);
267 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
268 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
270 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
271 loops_per_jiffy, ci->new);
275 static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
281 static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
282 struct cpufreq_freqs *freqs, unsigned int state)
284 BUG_ON(irqs_disabled());
286 if (cpufreq_disabled())
289 freqs->flags = cpufreq_driver->flags;
290 pr_debug("notification %u of frequency transition to %u kHz\n",
295 case CPUFREQ_PRECHANGE:
296 /* detect if the driver reported a value as "old frequency"
297 * which is not equal to what the cpufreq core thinks is
300 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
301 if ((policy) && (policy->cpu == freqs->cpu) &&
302 (policy->cur) && (policy->cur != freqs->old)) {
303 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
304 freqs->old, policy->cur);
305 freqs->old = policy->cur;
308 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
309 CPUFREQ_PRECHANGE, freqs);
310 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
313 case CPUFREQ_POSTCHANGE:
314 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
315 pr_debug("FREQ: %lu - CPU: %lu\n",
316 (unsigned long)freqs->new, (unsigned long)freqs->cpu);
317 trace_cpu_frequency(freqs->new, freqs->cpu);
318 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
319 CPUFREQ_POSTCHANGE, freqs);
320 if (likely(policy) && likely(policy->cpu == freqs->cpu))
321 policy->cur = freqs->new;
327 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
328 * on frequency transition.
330 * This function calls the transition notifiers and the "adjust_jiffies"
331 * function. It is called twice on all CPU frequency changes that have
334 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
335 struct cpufreq_freqs *freqs, unsigned int state)
337 for_each_cpu(freqs->cpu, policy->cpus)
338 __cpufreq_notify_transition(policy, freqs, state);
341 /* Do post notifications when there are chances that transition has failed */
342 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
343 struct cpufreq_freqs *freqs, int transition_failed)
345 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
346 if (!transition_failed)
349 swap(freqs->old, freqs->new);
350 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
351 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
354 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
355 struct cpufreq_freqs *freqs)
359 * Catch double invocations of _begin() which lead to self-deadlock.
360 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
361 * doesn't invoke _begin() on their behalf, and hence the chances of
362 * double invocations are very low. Moreover, there are scenarios
363 * where these checks can emit false-positive warnings in these
364 * drivers; so we avoid that by skipping them altogether.
366 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
367 && current == policy->transition_task);
370 wait_event(policy->transition_wait, !policy->transition_ongoing);
372 spin_lock(&policy->transition_lock);
374 if (unlikely(policy->transition_ongoing)) {
375 spin_unlock(&policy->transition_lock);
379 policy->transition_ongoing = true;
380 policy->transition_task = current;
382 spin_unlock(&policy->transition_lock);
384 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
386 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
388 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
389 struct cpufreq_freqs *freqs, int transition_failed)
391 if (unlikely(WARN_ON(!policy->transition_ongoing)))
394 cpufreq_notify_post_transition(policy, freqs, transition_failed);
396 policy->transition_ongoing = false;
397 policy->transition_task = NULL;
399 wake_up(&policy->transition_wait);
401 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
404 /*********************************************************************
406 *********************************************************************/
407 static ssize_t show_boost(struct kobject *kobj,
408 struct attribute *attr, char *buf)
410 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
413 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
414 const char *buf, size_t count)
418 ret = sscanf(buf, "%d", &enable);
419 if (ret != 1 || enable < 0 || enable > 1)
422 if (cpufreq_boost_trigger_state(enable)) {
423 pr_err("%s: Cannot %s BOOST!\n",
424 __func__, enable ? "enable" : "disable");
428 pr_debug("%s: cpufreq BOOST %s\n",
429 __func__, enable ? "enabled" : "disabled");
433 define_one_global_rw(boost);
435 static struct cpufreq_governor *__find_governor(const char *str_governor)
437 struct cpufreq_governor *t;
439 list_for_each_entry(t, &cpufreq_governor_list, governor_list)
440 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
447 * cpufreq_parse_governor - parse a governor string
449 static int cpufreq_parse_governor(char *str_governor, unsigned int *policy,
450 struct cpufreq_governor **governor)
457 if (cpufreq_driver->setpolicy) {
458 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
459 *policy = CPUFREQ_POLICY_PERFORMANCE;
461 } else if (!strncasecmp(str_governor, "powersave",
463 *policy = CPUFREQ_POLICY_POWERSAVE;
466 } else if (has_target()) {
467 struct cpufreq_governor *t;
469 mutex_lock(&cpufreq_governor_mutex);
471 t = __find_governor(str_governor);
476 mutex_unlock(&cpufreq_governor_mutex);
477 ret = request_module("cpufreq_%s", str_governor);
478 mutex_lock(&cpufreq_governor_mutex);
481 t = __find_governor(str_governor);
489 mutex_unlock(&cpufreq_governor_mutex);
496 * cpufreq_per_cpu_attr_read() / show_##file_name() -
497 * print out cpufreq information
499 * Write out information from cpufreq_driver->policy[cpu]; object must be
503 #define show_one(file_name, object) \
504 static ssize_t show_##file_name \
505 (struct cpufreq_policy *policy, char *buf) \
507 return sprintf(buf, "%u\n", policy->object); \
510 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
511 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
512 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
513 show_one(scaling_min_freq, min);
514 show_one(scaling_max_freq, max);
515 show_one(scaling_cur_freq, cur);
517 static int cpufreq_set_policy(struct cpufreq_policy *policy,
518 struct cpufreq_policy *new_policy);
521 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
523 #define store_one(file_name, object) \
524 static ssize_t store_##file_name \
525 (struct cpufreq_policy *policy, const char *buf, size_t count) \
528 struct cpufreq_policy new_policy; \
530 ret = cpufreq_get_policy(&new_policy, policy->cpu); \
534 ret = sscanf(buf, "%u", &new_policy.object); \
538 ret = cpufreq_set_policy(policy, &new_policy); \
539 policy->user_policy.object = policy->object; \
541 return ret ? ret : count; \
544 store_one(scaling_min_freq, min);
545 store_one(scaling_max_freq, max);
548 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
550 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
553 unsigned int cur_freq = __cpufreq_get(policy->cpu);
555 return sprintf(buf, "<unknown>");
556 return sprintf(buf, "%u\n", cur_freq);
560 * show_scaling_governor - show the current policy for the specified CPU
562 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
564 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
565 return sprintf(buf, "powersave\n");
566 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
567 return sprintf(buf, "performance\n");
568 else if (policy->governor)
569 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
570 policy->governor->name);
575 * store_scaling_governor - store policy for the specified CPU
577 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
578 const char *buf, size_t count)
581 char str_governor[16];
582 struct cpufreq_policy new_policy;
584 ret = cpufreq_get_policy(&new_policy, policy->cpu);
588 ret = sscanf(buf, "%15s", str_governor);
592 if (cpufreq_parse_governor(str_governor, &new_policy.policy,
593 &new_policy.governor))
596 ret = cpufreq_set_policy(policy, &new_policy);
598 policy->user_policy.policy = policy->policy;
599 policy->user_policy.governor = policy->governor;
608 * show_scaling_driver - show the cpufreq driver currently loaded
610 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
612 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
616 * show_scaling_available_governors - show the available CPUfreq governors
618 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
622 struct cpufreq_governor *t;
625 i += sprintf(buf, "performance powersave");
629 list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
630 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
631 - (CPUFREQ_NAME_LEN + 2)))
633 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
636 i += sprintf(&buf[i], "\n");
640 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
645 for_each_cpu(cpu, mask) {
647 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
648 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
649 if (i >= (PAGE_SIZE - 5))
652 i += sprintf(&buf[i], "\n");
655 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
658 * show_related_cpus - show the CPUs affected by each transition even if
659 * hw coordination is in use
661 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
663 return cpufreq_show_cpus(policy->related_cpus, buf);
667 * show_affected_cpus - show the CPUs affected by each transition
669 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
671 return cpufreq_show_cpus(policy->cpus, buf);
674 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
675 const char *buf, size_t count)
677 unsigned int freq = 0;
680 if (!policy->governor || !policy->governor->store_setspeed)
683 ret = sscanf(buf, "%u", &freq);
687 policy->governor->store_setspeed(policy, freq);
692 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
694 if (!policy->governor || !policy->governor->show_setspeed)
695 return sprintf(buf, "<unsupported>\n");
697 return policy->governor->show_setspeed(policy, buf);
701 * show_bios_limit - show the current cpufreq HW/BIOS limitation
703 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
707 if (cpufreq_driver->bios_limit) {
708 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
710 return sprintf(buf, "%u\n", limit);
712 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
715 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
716 cpufreq_freq_attr_ro(cpuinfo_min_freq);
717 cpufreq_freq_attr_ro(cpuinfo_max_freq);
718 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
719 cpufreq_freq_attr_ro(scaling_available_governors);
720 cpufreq_freq_attr_ro(scaling_driver);
721 cpufreq_freq_attr_ro(scaling_cur_freq);
722 cpufreq_freq_attr_ro(bios_limit);
723 cpufreq_freq_attr_ro(related_cpus);
724 cpufreq_freq_attr_ro(affected_cpus);
725 cpufreq_freq_attr_rw(scaling_min_freq);
726 cpufreq_freq_attr_rw(scaling_max_freq);
727 cpufreq_freq_attr_rw(scaling_governor);
728 cpufreq_freq_attr_rw(scaling_setspeed);
730 static struct attribute *default_attrs[] = {
731 &cpuinfo_min_freq.attr,
732 &cpuinfo_max_freq.attr,
733 &cpuinfo_transition_latency.attr,
734 &scaling_min_freq.attr,
735 &scaling_max_freq.attr,
738 &scaling_governor.attr,
739 &scaling_driver.attr,
740 &scaling_available_governors.attr,
741 &scaling_setspeed.attr,
745 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
746 #define to_attr(a) container_of(a, struct freq_attr, attr)
748 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
750 struct cpufreq_policy *policy = to_policy(kobj);
751 struct freq_attr *fattr = to_attr(attr);
754 if (!down_read_trylock(&cpufreq_rwsem))
757 down_read(&policy->rwsem);
760 ret = fattr->show(policy, buf);
764 up_read(&policy->rwsem);
765 up_read(&cpufreq_rwsem);
770 static ssize_t store(struct kobject *kobj, struct attribute *attr,
771 const char *buf, size_t count)
773 struct cpufreq_policy *policy = to_policy(kobj);
774 struct freq_attr *fattr = to_attr(attr);
775 ssize_t ret = -EINVAL;
779 if (!cpu_online(policy->cpu))
782 if (!down_read_trylock(&cpufreq_rwsem))
785 down_write(&policy->rwsem);
788 ret = fattr->store(policy, buf, count);
792 up_write(&policy->rwsem);
794 up_read(&cpufreq_rwsem);
801 static void cpufreq_sysfs_release(struct kobject *kobj)
803 struct cpufreq_policy *policy = to_policy(kobj);
804 pr_debug("last reference is dropped\n");
805 complete(&policy->kobj_unregister);
808 static const struct sysfs_ops sysfs_ops = {
813 static struct kobj_type ktype_cpufreq = {
814 .sysfs_ops = &sysfs_ops,
815 .default_attrs = default_attrs,
816 .release = cpufreq_sysfs_release,
819 struct kobject *cpufreq_global_kobject;
820 EXPORT_SYMBOL(cpufreq_global_kobject);
822 static int cpufreq_global_kobject_usage;
824 int cpufreq_get_global_kobject(void)
826 if (!cpufreq_global_kobject_usage++)
827 return kobject_add(cpufreq_global_kobject,
828 &cpu_subsys.dev_root->kobj, "%s", "cpufreq");
832 EXPORT_SYMBOL(cpufreq_get_global_kobject);
834 void cpufreq_put_global_kobject(void)
836 if (!--cpufreq_global_kobject_usage)
837 kobject_del(cpufreq_global_kobject);
839 EXPORT_SYMBOL(cpufreq_put_global_kobject);
841 int cpufreq_sysfs_create_file(const struct attribute *attr)
843 int ret = cpufreq_get_global_kobject();
846 ret = sysfs_create_file(cpufreq_global_kobject, attr);
848 cpufreq_put_global_kobject();
853 EXPORT_SYMBOL(cpufreq_sysfs_create_file);
855 void cpufreq_sysfs_remove_file(const struct attribute *attr)
857 sysfs_remove_file(cpufreq_global_kobject, attr);
858 cpufreq_put_global_kobject();
860 EXPORT_SYMBOL(cpufreq_sysfs_remove_file);
862 /* symlink affected CPUs */
863 static int cpufreq_add_dev_symlink(struct cpufreq_policy *policy)
868 for_each_cpu(j, policy->cpus) {
869 struct device *cpu_dev;
871 if (j == policy->cpu)
874 pr_debug("Adding link for CPU: %u\n", j);
875 cpu_dev = get_cpu_device(j);
876 ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
884 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
887 struct freq_attr **drv_attr;
890 /* prepare interface data */
891 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
892 &dev->kobj, "cpufreq");
896 /* set up files for this cpu device */
897 drv_attr = cpufreq_driver->attr;
898 while ((drv_attr) && (*drv_attr)) {
899 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
901 goto err_out_kobj_put;
904 if (cpufreq_driver->get) {
905 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
907 goto err_out_kobj_put;
910 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
912 goto err_out_kobj_put;
914 if (cpufreq_driver->bios_limit) {
915 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
917 goto err_out_kobj_put;
920 ret = cpufreq_add_dev_symlink(policy);
922 goto err_out_kobj_put;
927 kobject_put(&policy->kobj);
928 wait_for_completion(&policy->kobj_unregister);
932 static void cpufreq_init_policy(struct cpufreq_policy *policy)
934 struct cpufreq_governor *gov = NULL;
935 struct cpufreq_policy new_policy;
938 memcpy(&new_policy, policy, sizeof(*policy));
940 /* Update governor of new_policy to the governor used before hotplug */
941 gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));
943 pr_debug("Restoring governor %s for cpu %d\n",
944 policy->governor->name, policy->cpu);
946 gov = CPUFREQ_DEFAULT_GOVERNOR;
948 new_policy.governor = gov;
950 /* Use the default policy if its valid. */
951 if (cpufreq_driver->setpolicy)
952 cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
954 /* set default policy */
955 ret = cpufreq_set_policy(policy, &new_policy);
957 pr_debug("setting policy failed\n");
958 if (cpufreq_driver->exit)
959 cpufreq_driver->exit(policy);
963 #ifdef CONFIG_HOTPLUG_CPU
964 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
965 unsigned int cpu, struct device *dev)
971 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
973 pr_err("%s: Failed to stop governor\n", __func__);
978 down_write(&policy->rwsem);
980 write_lock_irqsave(&cpufreq_driver_lock, flags);
982 cpumask_set_cpu(cpu, policy->cpus);
983 per_cpu(cpufreq_cpu_data, cpu) = policy;
984 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
986 up_write(&policy->rwsem);
989 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
991 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
994 pr_err("%s: Failed to start governor\n", __func__);
999 return sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq");
1003 static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
1005 struct cpufreq_policy *policy;
1006 unsigned long flags;
1008 read_lock_irqsave(&cpufreq_driver_lock, flags);
1010 policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
1012 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1014 policy->governor = NULL;
1019 static struct cpufreq_policy *cpufreq_policy_alloc(void)
1021 struct cpufreq_policy *policy;
1023 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1027 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1028 goto err_free_policy;
1030 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1031 goto err_free_cpumask;
1033 INIT_LIST_HEAD(&policy->policy_list);
1034 init_rwsem(&policy->rwsem);
1035 spin_lock_init(&policy->transition_lock);
1036 init_waitqueue_head(&policy->transition_wait);
1041 free_cpumask_var(policy->cpus);
1048 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1050 struct kobject *kobj;
1051 struct completion *cmp;
1053 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1054 CPUFREQ_REMOVE_POLICY, policy);
1056 down_read(&policy->rwsem);
1057 kobj = &policy->kobj;
1058 cmp = &policy->kobj_unregister;
1059 up_read(&policy->rwsem);
1063 * We need to make sure that the underlying kobj is
1064 * actually not referenced anymore by anybody before we
1065 * proceed with unloading.
1067 pr_debug("waiting for dropping of refcount\n");
1068 wait_for_completion(cmp);
1069 pr_debug("wait complete\n");
1072 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1074 free_cpumask_var(policy->related_cpus);
1075 free_cpumask_var(policy->cpus);
1079 static int update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu,
1080 struct device *cpu_dev)
1084 if (WARN_ON(cpu == policy->cpu))
1087 /* Move kobject to the new policy->cpu */
1088 ret = kobject_move(&policy->kobj, &cpu_dev->kobj);
1090 pr_err("%s: Failed to move kobj: %d\n", __func__, ret);
1094 down_write(&policy->rwsem);
1096 policy->last_cpu = policy->cpu;
1099 up_write(&policy->rwsem);
1101 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1102 CPUFREQ_UPDATE_POLICY_CPU, policy);
1107 static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1109 unsigned int j, cpu = dev->id;
1111 struct cpufreq_policy *policy;
1112 unsigned long flags;
1113 bool recover_policy = cpufreq_suspended;
1114 #ifdef CONFIG_HOTPLUG_CPU
1115 struct cpufreq_policy *tpolicy;
1118 if (cpu_is_offline(cpu))
1121 pr_debug("adding CPU %u\n", cpu);
1124 /* check whether a different CPU already registered this
1125 * CPU because it is in the same boat. */
1126 policy = cpufreq_cpu_get(cpu);
1127 if (unlikely(policy)) {
1128 cpufreq_cpu_put(policy);
1133 if (!down_read_trylock(&cpufreq_rwsem))
1136 #ifdef CONFIG_HOTPLUG_CPU
1137 /* Check if this cpu was hot-unplugged earlier and has siblings */
1138 read_lock_irqsave(&cpufreq_driver_lock, flags);
1139 list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) {
1140 if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) {
1141 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1142 ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev);
1143 up_read(&cpufreq_rwsem);
1147 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1151 * Restore the saved policy when doing light-weight init and fall back
1152 * to the full init if that fails.
1154 policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL;
1156 recover_policy = false;
1157 policy = cpufreq_policy_alloc();
1163 * In the resume path, since we restore a saved policy, the assignment
1164 * to policy->cpu is like an update of the existing policy, rather than
1165 * the creation of a brand new one. So we need to perform this update
1166 * by invoking update_policy_cpu().
1168 if (recover_policy && cpu != policy->cpu)
1169 WARN_ON(update_policy_cpu(policy, cpu, dev));
1173 cpumask_copy(policy->cpus, cpumask_of(cpu));
1175 init_completion(&policy->kobj_unregister);
1176 INIT_WORK(&policy->update, handle_update);
1178 /* call driver. From then on the cpufreq must be able
1179 * to accept all calls to ->verify and ->setpolicy for this CPU
1181 ret = cpufreq_driver->init(policy);
1183 pr_debug("initialization failed\n");
1184 goto err_set_policy_cpu;
1187 /* related cpus should atleast have policy->cpus */
1188 cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
1191 * affected cpus must always be the one, which are online. We aren't
1192 * managing offline cpus here.
1194 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1196 if (!recover_policy) {
1197 policy->user_policy.min = policy->min;
1198 policy->user_policy.max = policy->max;
1201 down_write(&policy->rwsem);
1202 write_lock_irqsave(&cpufreq_driver_lock, flags);
1203 for_each_cpu(j, policy->cpus)
1204 per_cpu(cpufreq_cpu_data, j) = policy;
1205 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1207 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1208 policy->cur = cpufreq_driver->get(policy->cpu);
1210 pr_err("%s: ->get() failed\n", __func__);
1216 * Sometimes boot loaders set CPU frequency to a value outside of
1217 * frequency table present with cpufreq core. In such cases CPU might be
1218 * unstable if it has to run on that frequency for long duration of time
1219 * and so its better to set it to a frequency which is specified in
1220 * freq-table. This also makes cpufreq stats inconsistent as
1221 * cpufreq-stats would fail to register because current frequency of CPU
1222 * isn't found in freq-table.
1224 * Because we don't want this change to effect boot process badly, we go
1225 * for the next freq which is >= policy->cur ('cur' must be set by now,
1226 * otherwise we will end up setting freq to lowest of the table as 'cur'
1227 * is initialized to zero).
1229 * We are passing target-freq as "policy->cur - 1" otherwise
1230 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1231 * equal to target-freq.
1233 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1235 /* Are we running at unknown frequency ? */
1236 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1237 if (ret == -EINVAL) {
1238 /* Warn user and fix it */
1239 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1240 __func__, policy->cpu, policy->cur);
1241 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1242 CPUFREQ_RELATION_L);
1245 * Reaching here after boot in a few seconds may not
1246 * mean that system will remain stable at "unknown"
1247 * frequency for longer duration. Hence, a BUG_ON().
1250 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1251 __func__, policy->cpu, policy->cur);
1255 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1256 CPUFREQ_START, policy);
1258 if (!recover_policy) {
1259 ret = cpufreq_add_dev_interface(policy, dev);
1261 goto err_out_unregister;
1262 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1263 CPUFREQ_CREATE_POLICY, policy);
1266 write_lock_irqsave(&cpufreq_driver_lock, flags);
1267 list_add(&policy->policy_list, &cpufreq_policy_list);
1268 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1270 cpufreq_init_policy(policy);
1272 if (!recover_policy) {
1273 policy->user_policy.policy = policy->policy;
1274 policy->user_policy.governor = policy->governor;
1276 up_write(&policy->rwsem);
1278 kobject_uevent(&policy->kobj, KOBJ_ADD);
1279 up_read(&cpufreq_rwsem);
1281 pr_debug("initialization complete\n");
1287 write_lock_irqsave(&cpufreq_driver_lock, flags);
1288 for_each_cpu(j, policy->cpus)
1289 per_cpu(cpufreq_cpu_data, j) = NULL;
1290 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1292 up_write(&policy->rwsem);
1294 if (cpufreq_driver->exit)
1295 cpufreq_driver->exit(policy);
1297 if (recover_policy) {
1298 /* Do not leave stale fallback data behind. */
1299 per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL;
1300 cpufreq_policy_put_kobj(policy);
1302 cpufreq_policy_free(policy);
1305 up_read(&cpufreq_rwsem);
1311 * cpufreq_add_dev - add a CPU device
1313 * Adds the cpufreq interface for a CPU device.
1315 * The Oracle says: try running cpufreq registration/unregistration concurrently
1316 * with with cpu hotplugging and all hell will break loose. Tried to clean this
1317 * mess up, but more thorough testing is needed. - Mathieu
1319 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1321 return __cpufreq_add_dev(dev, sif);
1324 static int __cpufreq_remove_dev_prepare(struct device *dev,
1325 struct subsys_interface *sif)
1327 unsigned int cpu = dev->id, cpus;
1329 unsigned long flags;
1330 struct cpufreq_policy *policy;
1332 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1334 write_lock_irqsave(&cpufreq_driver_lock, flags);
1336 policy = per_cpu(cpufreq_cpu_data, cpu);
1338 /* Save the policy somewhere when doing a light-weight tear-down */
1339 if (cpufreq_suspended)
1340 per_cpu(cpufreq_cpu_data_fallback, cpu) = policy;
1342 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1345 pr_debug("%s: No cpu_data found\n", __func__);
1350 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1352 pr_err("%s: Failed to stop governor\n", __func__);
1357 if (!cpufreq_driver->setpolicy)
1358 strncpy(per_cpu(cpufreq_cpu_governor, cpu),
1359 policy->governor->name, CPUFREQ_NAME_LEN);
1361 down_read(&policy->rwsem);
1362 cpus = cpumask_weight(policy->cpus);
1363 up_read(&policy->rwsem);
1365 if (cpu != policy->cpu) {
1366 sysfs_remove_link(&dev->kobj, "cpufreq");
1367 } else if (cpus > 1) {
1368 /* Nominate new CPU */
1369 int new_cpu = cpumask_any_but(policy->cpus, cpu);
1370 struct device *cpu_dev = get_cpu_device(new_cpu);
1372 sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
1373 ret = update_policy_cpu(policy, new_cpu, cpu_dev);
1375 if (sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
1377 pr_err("%s: Failed to restore kobj link to cpu:%d\n",
1378 __func__, cpu_dev->id);
1382 if (!cpufreq_suspended)
1383 pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
1384 __func__, new_cpu, cpu);
1385 } else if (cpufreq_driver->stop_cpu) {
1386 cpufreq_driver->stop_cpu(policy);
1392 static int __cpufreq_remove_dev_finish(struct device *dev,
1393 struct subsys_interface *sif)
1395 unsigned int cpu = dev->id, cpus;
1397 unsigned long flags;
1398 struct cpufreq_policy *policy;
1400 read_lock_irqsave(&cpufreq_driver_lock, flags);
1401 policy = per_cpu(cpufreq_cpu_data, cpu);
1402 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1405 pr_debug("%s: No cpu_data found\n", __func__);
1409 down_write(&policy->rwsem);
1410 cpus = cpumask_weight(policy->cpus);
1413 cpumask_clear_cpu(cpu, policy->cpus);
1414 up_write(&policy->rwsem);
1416 /* If cpu is last user of policy, free policy */
1419 ret = __cpufreq_governor(policy,
1420 CPUFREQ_GOV_POLICY_EXIT);
1422 pr_err("%s: Failed to exit governor\n",
1428 if (!cpufreq_suspended)
1429 cpufreq_policy_put_kobj(policy);
1432 * Perform the ->exit() even during light-weight tear-down,
1433 * since this is a core component, and is essential for the
1434 * subsequent light-weight ->init() to succeed.
1436 if (cpufreq_driver->exit)
1437 cpufreq_driver->exit(policy);
1439 /* Remove policy from list of active policies */
1440 write_lock_irqsave(&cpufreq_driver_lock, flags);
1441 list_del(&policy->policy_list);
1442 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1444 if (!cpufreq_suspended)
1445 cpufreq_policy_free(policy);
1446 } else if (has_target()) {
1447 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1449 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1452 pr_err("%s: Failed to start governor\n", __func__);
1457 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1462 * cpufreq_remove_dev - remove a CPU device
1464 * Removes the cpufreq interface for a CPU device.
1466 static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1468 unsigned int cpu = dev->id;
1471 if (cpu_is_offline(cpu))
1474 ret = __cpufreq_remove_dev_prepare(dev, sif);
1477 ret = __cpufreq_remove_dev_finish(dev, sif);
1482 static void handle_update(struct work_struct *work)
1484 struct cpufreq_policy *policy =
1485 container_of(work, struct cpufreq_policy, update);
1486 unsigned int cpu = policy->cpu;
1487 pr_debug("handle_update for cpu %u called\n", cpu);
1488 cpufreq_update_policy(cpu);
1492 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1495 * @old_freq: CPU frequency the kernel thinks the CPU runs at
1496 * @new_freq: CPU frequency the CPU actually runs at
1498 * We adjust to current frequency first, and need to clean up later.
1499 * So either call to cpufreq_update_policy() or schedule handle_update()).
1501 static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
1502 unsigned int new_freq)
1504 struct cpufreq_policy *policy;
1505 struct cpufreq_freqs freqs;
1506 unsigned long flags;
1508 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1509 old_freq, new_freq);
1511 freqs.old = old_freq;
1512 freqs.new = new_freq;
1514 read_lock_irqsave(&cpufreq_driver_lock, flags);
1515 policy = per_cpu(cpufreq_cpu_data, cpu);
1516 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1518 cpufreq_freq_transition_begin(policy, &freqs);
1519 cpufreq_freq_transition_end(policy, &freqs, 0);
1523 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1526 * This is the last known freq, without actually getting it from the driver.
1527 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1529 unsigned int cpufreq_quick_get(unsigned int cpu)
1531 struct cpufreq_policy *policy;
1532 unsigned int ret_freq = 0;
1534 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
1535 return cpufreq_driver->get(cpu);
1537 policy = cpufreq_cpu_get(cpu);
1539 ret_freq = policy->cur;
1540 cpufreq_cpu_put(policy);
1545 EXPORT_SYMBOL(cpufreq_quick_get);
1548 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1551 * Just return the max possible frequency for a given CPU.
1553 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1555 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1556 unsigned int ret_freq = 0;
1559 ret_freq = policy->max;
1560 cpufreq_cpu_put(policy);
1565 EXPORT_SYMBOL(cpufreq_quick_get_max);
1567 static unsigned int __cpufreq_get(unsigned int cpu)
1569 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1570 unsigned int ret_freq = 0;
1572 if (!cpufreq_driver->get)
1575 ret_freq = cpufreq_driver->get(cpu);
1577 if (ret_freq && policy->cur &&
1578 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1579 /* verify no discrepancy between actual and
1580 saved value exists */
1581 if (unlikely(ret_freq != policy->cur)) {
1582 cpufreq_out_of_sync(cpu, policy->cur, ret_freq);
1583 schedule_work(&policy->update);
1591 * cpufreq_get - get the current CPU frequency (in kHz)
1594 * Get the CPU current (static) CPU frequency
1596 unsigned int cpufreq_get(unsigned int cpu)
1598 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1599 unsigned int ret_freq = 0;
1602 down_read(&policy->rwsem);
1603 ret_freq = __cpufreq_get(cpu);
1604 up_read(&policy->rwsem);
1606 cpufreq_cpu_put(policy);
1611 EXPORT_SYMBOL(cpufreq_get);
1613 static struct subsys_interface cpufreq_interface = {
1615 .subsys = &cpu_subsys,
1616 .add_dev = cpufreq_add_dev,
1617 .remove_dev = cpufreq_remove_dev,
1621 * In case platform wants some specific frequency to be configured
1624 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1628 if (!policy->suspend_freq) {
1629 pr_err("%s: suspend_freq can't be zero\n", __func__);
1633 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1634 policy->suspend_freq);
1636 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1637 CPUFREQ_RELATION_H);
1639 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1640 __func__, policy->suspend_freq, ret);
1644 EXPORT_SYMBOL(cpufreq_generic_suspend);
1647 * cpufreq_suspend() - Suspend CPUFreq governors
1649 * Called during system wide Suspend/Hibernate cycles for suspending governors
1650 * as some platforms can't change frequency after this point in suspend cycle.
1651 * Because some of the devices (like: i2c, regulators, etc) they use for
1652 * changing frequency are suspended quickly after this point.
1654 void cpufreq_suspend(void)
1656 struct cpufreq_policy *policy;
1658 if (!cpufreq_driver)
1664 pr_debug("%s: Suspending Governors\n", __func__);
1666 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
1667 if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
1668 pr_err("%s: Failed to stop governor for policy: %p\n",
1670 else if (cpufreq_driver->suspend
1671 && cpufreq_driver->suspend(policy))
1672 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1677 cpufreq_suspended = true;
1681 * cpufreq_resume() - Resume CPUFreq governors
1683 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1684 * are suspended with cpufreq_suspend().
1686 void cpufreq_resume(void)
1688 struct cpufreq_policy *policy;
1690 if (!cpufreq_driver)
1693 cpufreq_suspended = false;
1698 pr_debug("%s: Resuming Governors\n", __func__);
1700 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
1701 if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
1702 pr_err("%s: Failed to resume driver: %p\n", __func__,
1704 else if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
1705 || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
1706 pr_err("%s: Failed to start governor for policy: %p\n",
1710 * schedule call cpufreq_update_policy() for boot CPU, i.e. last
1711 * policy in list. It will verify that the current freq is in
1712 * sync with what we believe it to be.
1714 if (list_is_last(&policy->policy_list, &cpufreq_policy_list))
1715 schedule_work(&policy->update);
1720 * cpufreq_get_current_driver - return current driver's name
1722 * Return the name string of the currently loaded cpufreq driver
1725 const char *cpufreq_get_current_driver(void)
1728 return cpufreq_driver->name;
1732 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1734 /*********************************************************************
1735 * NOTIFIER LISTS INTERFACE *
1736 *********************************************************************/
1739 * cpufreq_register_notifier - register a driver with cpufreq
1740 * @nb: notifier function to register
1741 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1743 * Add a driver to one of two lists: either a list of drivers that
1744 * are notified about clock rate changes (once before and once after
1745 * the transition), or a list of drivers that are notified about
1746 * changes in cpufreq policy.
1748 * This function may sleep, and has the same return conditions as
1749 * blocking_notifier_chain_register.
1751 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1755 if (cpufreq_disabled())
1758 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1761 case CPUFREQ_TRANSITION_NOTIFIER:
1762 ret = srcu_notifier_chain_register(
1763 &cpufreq_transition_notifier_list, nb);
1765 case CPUFREQ_POLICY_NOTIFIER:
1766 ret = blocking_notifier_chain_register(
1767 &cpufreq_policy_notifier_list, nb);
1775 EXPORT_SYMBOL(cpufreq_register_notifier);
1778 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1779 * @nb: notifier block to be unregistered
1780 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1782 * Remove a driver from the CPU frequency notifier list.
1784 * This function may sleep, and has the same return conditions as
1785 * blocking_notifier_chain_unregister.
1787 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1791 if (cpufreq_disabled())
1795 case CPUFREQ_TRANSITION_NOTIFIER:
1796 ret = srcu_notifier_chain_unregister(
1797 &cpufreq_transition_notifier_list, nb);
1799 case CPUFREQ_POLICY_NOTIFIER:
1800 ret = blocking_notifier_chain_unregister(
1801 &cpufreq_policy_notifier_list, nb);
1809 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1812 /*********************************************************************
1814 *********************************************************************/
1816 /* Must set freqs->new to intermediate frequency */
1817 static int __target_intermediate(struct cpufreq_policy *policy,
1818 struct cpufreq_freqs *freqs, int index)
1822 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1824 /* We don't need to switch to intermediate freq */
1828 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1829 __func__, policy->cpu, freqs->old, freqs->new);
1831 cpufreq_freq_transition_begin(policy, freqs);
1832 ret = cpufreq_driver->target_intermediate(policy, index);
1833 cpufreq_freq_transition_end(policy, freqs, ret);
1836 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1842 static int __target_index(struct cpufreq_policy *policy,
1843 struct cpufreq_frequency_table *freq_table, int index)
1845 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1846 unsigned int intermediate_freq = 0;
1847 int retval = -EINVAL;
1850 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1852 /* Handle switching to intermediate frequency */
1853 if (cpufreq_driver->get_intermediate) {
1854 retval = __target_intermediate(policy, &freqs, index);
1858 intermediate_freq = freqs.new;
1859 /* Set old freq to intermediate */
1860 if (intermediate_freq)
1861 freqs.old = freqs.new;
1864 freqs.new = freq_table[index].frequency;
1865 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1866 __func__, policy->cpu, freqs.old, freqs.new);
1868 cpufreq_freq_transition_begin(policy, &freqs);
1871 retval = cpufreq_driver->target_index(policy, index);
1873 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
1877 cpufreq_freq_transition_end(policy, &freqs, retval);
1880 * Failed after setting to intermediate freq? Driver should have
1881 * reverted back to initial frequency and so should we. Check
1882 * here for intermediate_freq instead of get_intermediate, in
1883 * case we have't switched to intermediate freq at all.
1885 if (unlikely(retval && intermediate_freq)) {
1886 freqs.old = intermediate_freq;
1887 freqs.new = policy->restore_freq;
1888 cpufreq_freq_transition_begin(policy, &freqs);
1889 cpufreq_freq_transition_end(policy, &freqs, 0);
1896 int __cpufreq_driver_target(struct cpufreq_policy *policy,
1897 unsigned int target_freq,
1898 unsigned int relation)
1900 unsigned int old_target_freq = target_freq;
1901 int retval = -EINVAL;
1903 if (cpufreq_disabled())
1906 /* Make sure that target_freq is within supported range */
1907 if (target_freq > policy->max)
1908 target_freq = policy->max;
1909 if (target_freq < policy->min)
1910 target_freq = policy->min;
1912 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1913 policy->cpu, target_freq, relation, old_target_freq);
1916 * This might look like a redundant call as we are checking it again
1917 * after finding index. But it is left intentionally for cases where
1918 * exactly same freq is called again and so we can save on few function
1921 if (target_freq == policy->cur)
1924 /* Save last value to restore later on errors */
1925 policy->restore_freq = policy->cur;
1927 if (cpufreq_driver->target)
1928 retval = cpufreq_driver->target(policy, target_freq, relation);
1929 else if (cpufreq_driver->target_index) {
1930 struct cpufreq_frequency_table *freq_table;
1933 freq_table = cpufreq_frequency_get_table(policy->cpu);
1934 if (unlikely(!freq_table)) {
1935 pr_err("%s: Unable to find freq_table\n", __func__);
1939 retval = cpufreq_frequency_table_target(policy, freq_table,
1940 target_freq, relation, &index);
1941 if (unlikely(retval)) {
1942 pr_err("%s: Unable to find matching freq\n", __func__);
1946 if (freq_table[index].frequency == policy->cur) {
1951 retval = __target_index(policy, freq_table, index);
1957 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1959 int cpufreq_driver_target(struct cpufreq_policy *policy,
1960 unsigned int target_freq,
1961 unsigned int relation)
1965 down_write(&policy->rwsem);
1967 ret = __cpufreq_driver_target(policy, target_freq, relation);
1969 up_write(&policy->rwsem);
1973 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1976 * when "event" is CPUFREQ_GOV_LIMITS
1979 static int __cpufreq_governor(struct cpufreq_policy *policy,
1984 /* Only must be defined when default governor is known to have latency
1985 restrictions, like e.g. conservative or ondemand.
1986 That this is the case is already ensured in Kconfig
1988 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1989 struct cpufreq_governor *gov = &cpufreq_gov_performance;
1991 struct cpufreq_governor *gov = NULL;
1994 /* Don't start any governor operations if we are entering suspend */
1995 if (cpufreq_suspended)
1998 if (policy->governor->max_transition_latency &&
1999 policy->cpuinfo.transition_latency >
2000 policy->governor->max_transition_latency) {
2004 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
2005 policy->governor->name, gov->name);
2006 policy->governor = gov;
2010 if (event == CPUFREQ_GOV_POLICY_INIT)
2011 if (!try_module_get(policy->governor->owner))
2014 pr_debug("__cpufreq_governor for CPU %u, event %u\n",
2015 policy->cpu, event);
2017 mutex_lock(&cpufreq_governor_lock);
2018 if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
2019 || (!policy->governor_enabled
2020 && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
2021 mutex_unlock(&cpufreq_governor_lock);
2025 if (event == CPUFREQ_GOV_STOP)
2026 policy->governor_enabled = false;
2027 else if (event == CPUFREQ_GOV_START)
2028 policy->governor_enabled = true;
2030 mutex_unlock(&cpufreq_governor_lock);
2032 ret = policy->governor->governor(policy, event);
2035 if (event == CPUFREQ_GOV_POLICY_INIT)
2036 policy->governor->initialized++;
2037 else if (event == CPUFREQ_GOV_POLICY_EXIT)
2038 policy->governor->initialized--;
2040 /* Restore original values */
2041 mutex_lock(&cpufreq_governor_lock);
2042 if (event == CPUFREQ_GOV_STOP)
2043 policy->governor_enabled = true;
2044 else if (event == CPUFREQ_GOV_START)
2045 policy->governor_enabled = false;
2046 mutex_unlock(&cpufreq_governor_lock);
2049 if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
2050 ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
2051 module_put(policy->governor->owner);
2056 int cpufreq_register_governor(struct cpufreq_governor *governor)
2063 if (cpufreq_disabled())
2066 mutex_lock(&cpufreq_governor_mutex);
2068 governor->initialized = 0;
2070 if (__find_governor(governor->name) == NULL) {
2072 list_add(&governor->governor_list, &cpufreq_governor_list);
2075 mutex_unlock(&cpufreq_governor_mutex);
2078 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2080 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2087 if (cpufreq_disabled())
2090 for_each_present_cpu(cpu) {
2091 if (cpu_online(cpu))
2093 if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
2094 strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
2097 mutex_lock(&cpufreq_governor_mutex);
2098 list_del(&governor->governor_list);
2099 mutex_unlock(&cpufreq_governor_mutex);
2102 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2105 /*********************************************************************
2106 * POLICY INTERFACE *
2107 *********************************************************************/
2110 * cpufreq_get_policy - get the current cpufreq_policy
2111 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2114 * Reads the current cpufreq policy.
2116 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2118 struct cpufreq_policy *cpu_policy;
2122 cpu_policy = cpufreq_cpu_get(cpu);
2126 memcpy(policy, cpu_policy, sizeof(*policy));
2128 cpufreq_cpu_put(cpu_policy);
2131 EXPORT_SYMBOL(cpufreq_get_policy);
2134 * policy : current policy.
2135 * new_policy: policy to be set.
2137 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2138 struct cpufreq_policy *new_policy)
2140 struct cpufreq_governor *old_gov;
2143 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2144 new_policy->cpu, new_policy->min, new_policy->max);
2146 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2148 if (new_policy->min > policy->max || new_policy->max < policy->min)
2151 /* verify the cpu speed can be set within this limit */
2152 ret = cpufreq_driver->verify(new_policy);
2156 /* adjust if necessary - all reasons */
2157 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2158 CPUFREQ_ADJUST, new_policy);
2160 /* adjust if necessary - hardware incompatibility*/
2161 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2162 CPUFREQ_INCOMPATIBLE, new_policy);
2165 * verify the cpu speed can be set within this limit, which might be
2166 * different to the first one
2168 ret = cpufreq_driver->verify(new_policy);
2172 /* notification of the new policy */
2173 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2174 CPUFREQ_NOTIFY, new_policy);
2176 policy->min = new_policy->min;
2177 policy->max = new_policy->max;
2179 pr_debug("new min and max freqs are %u - %u kHz\n",
2180 policy->min, policy->max);
2182 if (cpufreq_driver->setpolicy) {
2183 policy->policy = new_policy->policy;
2184 pr_debug("setting range\n");
2185 return cpufreq_driver->setpolicy(new_policy);
2188 if (new_policy->governor == policy->governor)
2191 pr_debug("governor switch\n");
2193 /* save old, working values */
2194 old_gov = policy->governor;
2195 /* end old governor */
2197 __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
2198 up_write(&policy->rwsem);
2199 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2200 down_write(&policy->rwsem);
2203 /* start new governor */
2204 policy->governor = new_policy->governor;
2205 if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {
2206 if (!__cpufreq_governor(policy, CPUFREQ_GOV_START))
2209 up_write(&policy->rwsem);
2210 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2211 down_write(&policy->rwsem);
2214 /* new governor failed, so re-start old one */
2215 pr_debug("starting governor %s failed\n", policy->governor->name);
2217 policy->governor = old_gov;
2218 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);
2219 __cpufreq_governor(policy, CPUFREQ_GOV_START);
2225 pr_debug("governor: change or update limits\n");
2226 return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2230 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2231 * @cpu: CPU which shall be re-evaluated
2233 * Useful for policy notifiers which have different necessities
2234 * at different times.
2236 int cpufreq_update_policy(unsigned int cpu)
2238 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2239 struct cpufreq_policy new_policy;
2245 down_write(&policy->rwsem);
2247 pr_debug("updating policy for CPU %u\n", cpu);
2248 memcpy(&new_policy, policy, sizeof(*policy));
2249 new_policy.min = policy->user_policy.min;
2250 new_policy.max = policy->user_policy.max;
2251 new_policy.policy = policy->user_policy.policy;
2252 new_policy.governor = policy->user_policy.governor;
2255 * BIOS might change freq behind our back
2256 * -> ask driver for current freq and notify governors about a change
2258 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
2259 new_policy.cur = cpufreq_driver->get(cpu);
2260 if (WARN_ON(!new_policy.cur)) {
2266 pr_debug("Driver did not initialize current freq\n");
2267 policy->cur = new_policy.cur;
2269 if (policy->cur != new_policy.cur && has_target())
2270 cpufreq_out_of_sync(cpu, policy->cur,
2275 ret = cpufreq_set_policy(policy, &new_policy);
2278 up_write(&policy->rwsem);
2280 cpufreq_cpu_put(policy);
2283 EXPORT_SYMBOL(cpufreq_update_policy);
2285 static int cpufreq_cpu_callback(struct notifier_block *nfb,
2286 unsigned long action, void *hcpu)
2288 unsigned int cpu = (unsigned long)hcpu;
2291 dev = get_cpu_device(cpu);
2293 switch (action & ~CPU_TASKS_FROZEN) {
2295 __cpufreq_add_dev(dev, NULL);
2298 case CPU_DOWN_PREPARE:
2299 __cpufreq_remove_dev_prepare(dev, NULL);
2303 __cpufreq_remove_dev_finish(dev, NULL);
2306 case CPU_DOWN_FAILED:
2307 __cpufreq_add_dev(dev, NULL);
2314 static struct notifier_block __refdata cpufreq_cpu_notifier = {
2315 .notifier_call = cpufreq_cpu_callback,
2318 /*********************************************************************
2320 *********************************************************************/
2321 static int cpufreq_boost_set_sw(int state)
2323 struct cpufreq_frequency_table *freq_table;
2324 struct cpufreq_policy *policy;
2327 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
2328 freq_table = cpufreq_frequency_get_table(policy->cpu);
2330 ret = cpufreq_frequency_table_cpuinfo(policy,
2333 pr_err("%s: Policy frequency update failed\n",
2337 policy->user_policy.max = policy->max;
2338 __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2345 int cpufreq_boost_trigger_state(int state)
2347 unsigned long flags;
2350 if (cpufreq_driver->boost_enabled == state)
2353 write_lock_irqsave(&cpufreq_driver_lock, flags);
2354 cpufreq_driver->boost_enabled = state;
2355 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2357 ret = cpufreq_driver->set_boost(state);
2359 write_lock_irqsave(&cpufreq_driver_lock, flags);
2360 cpufreq_driver->boost_enabled = !state;
2361 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2363 pr_err("%s: Cannot %s BOOST\n",
2364 __func__, state ? "enable" : "disable");
2370 int cpufreq_boost_supported(void)
2372 if (likely(cpufreq_driver))
2373 return cpufreq_driver->boost_supported;
2377 EXPORT_SYMBOL_GPL(cpufreq_boost_supported);
2379 int cpufreq_boost_enabled(void)
2381 return cpufreq_driver->boost_enabled;
2383 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2385 /*********************************************************************
2386 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2387 *********************************************************************/
2390 * cpufreq_register_driver - register a CPU Frequency driver
2391 * @driver_data: A struct cpufreq_driver containing the values#
2392 * submitted by the CPU Frequency driver.
2394 * Registers a CPU Frequency driver to this core code. This code
2395 * returns zero on success, -EBUSY when another driver got here first
2396 * (and isn't unregistered in the meantime).
2399 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2401 unsigned long flags;
2404 if (cpufreq_disabled())
2407 if (!driver_data || !driver_data->verify || !driver_data->init ||
2408 !(driver_data->setpolicy || driver_data->target_index ||
2409 driver_data->target) ||
2410 (driver_data->setpolicy && (driver_data->target_index ||
2411 driver_data->target)) ||
2412 (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
2415 pr_debug("trying to register driver %s\n", driver_data->name);
2417 if (driver_data->setpolicy)
2418 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2420 write_lock_irqsave(&cpufreq_driver_lock, flags);
2421 if (cpufreq_driver) {
2422 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2425 cpufreq_driver = driver_data;
2426 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2428 if (cpufreq_boost_supported()) {
2430 * Check if driver provides function to enable boost -
2431 * if not, use cpufreq_boost_set_sw as default
2433 if (!cpufreq_driver->set_boost)
2434 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2436 ret = cpufreq_sysfs_create_file(&boost.attr);
2438 pr_err("%s: cannot register global BOOST sysfs file\n",
2440 goto err_null_driver;
2444 ret = subsys_interface_register(&cpufreq_interface);
2446 goto err_boost_unreg;
2448 if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
2452 /* check for at least one working CPU */
2453 for (i = 0; i < nr_cpu_ids; i++)
2454 if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
2459 /* if all ->init() calls failed, unregister */
2461 pr_debug("no CPU initialized for driver %s\n",
2467 register_hotcpu_notifier(&cpufreq_cpu_notifier);
2468 pr_debug("driver %s up and running\n", driver_data->name);
2472 subsys_interface_unregister(&cpufreq_interface);
2474 if (cpufreq_boost_supported())
2475 cpufreq_sysfs_remove_file(&boost.attr);
2477 write_lock_irqsave(&cpufreq_driver_lock, flags);
2478 cpufreq_driver = NULL;
2479 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2482 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2485 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2487 * Unregister the current CPUFreq driver. Only call this if you have
2488 * the right to do so, i.e. if you have succeeded in initialising before!
2489 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2490 * currently not initialised.
2492 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2494 unsigned long flags;
2496 if (!cpufreq_driver || (driver != cpufreq_driver))
2499 pr_debug("unregistering driver %s\n", driver->name);
2501 subsys_interface_unregister(&cpufreq_interface);
2502 if (cpufreq_boost_supported())
2503 cpufreq_sysfs_remove_file(&boost.attr);
2505 unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
2507 down_write(&cpufreq_rwsem);
2508 write_lock_irqsave(&cpufreq_driver_lock, flags);
2510 cpufreq_driver = NULL;
2512 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2513 up_write(&cpufreq_rwsem);
2517 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2519 static int __init cpufreq_core_init(void)
2521 if (cpufreq_disabled())
2524 cpufreq_global_kobject = kobject_create();
2525 BUG_ON(!cpufreq_global_kobject);
2529 core_initcall(cpufreq_core_init);