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 (!strnicmp(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 (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
459 *policy = CPUFREQ_POLICY_PERFORMANCE;
461 } else if (!strnicmp(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 void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1081 if (WARN_ON(cpu == policy->cpu))
1084 down_write(&policy->rwsem);
1086 policy->last_cpu = policy->cpu;
1089 up_write(&policy->rwsem);
1091 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1092 CPUFREQ_UPDATE_POLICY_CPU, policy);
1095 static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1097 unsigned int j, cpu = dev->id;
1099 struct cpufreq_policy *policy;
1100 unsigned long flags;
1101 bool recover_policy = cpufreq_suspended;
1102 #ifdef CONFIG_HOTPLUG_CPU
1103 struct cpufreq_policy *tpolicy;
1106 if (cpu_is_offline(cpu))
1109 pr_debug("adding CPU %u\n", cpu);
1112 /* check whether a different CPU already registered this
1113 * CPU because it is in the same boat. */
1114 policy = cpufreq_cpu_get(cpu);
1115 if (unlikely(policy)) {
1116 cpufreq_cpu_put(policy);
1121 if (!down_read_trylock(&cpufreq_rwsem))
1124 #ifdef CONFIG_HOTPLUG_CPU
1125 /* Check if this cpu was hot-unplugged earlier and has siblings */
1126 read_lock_irqsave(&cpufreq_driver_lock, flags);
1127 list_for_each_entry(tpolicy, &cpufreq_policy_list, policy_list) {
1128 if (cpumask_test_cpu(cpu, tpolicy->related_cpus)) {
1129 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1130 ret = cpufreq_add_policy_cpu(tpolicy, cpu, dev);
1131 up_read(&cpufreq_rwsem);
1135 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1139 * Restore the saved policy when doing light-weight init and fall back
1140 * to the full init if that fails.
1142 policy = recover_policy ? cpufreq_policy_restore(cpu) : NULL;
1144 recover_policy = false;
1145 policy = cpufreq_policy_alloc();
1151 * In the resume path, since we restore a saved policy, the assignment
1152 * to policy->cpu is like an update of the existing policy, rather than
1153 * the creation of a brand new one. So we need to perform this update
1154 * by invoking update_policy_cpu().
1156 if (recover_policy && cpu != policy->cpu) {
1157 update_policy_cpu(policy, cpu);
1158 WARN_ON(kobject_move(&policy->kobj, &dev->kobj));
1163 cpumask_copy(policy->cpus, cpumask_of(cpu));
1165 init_completion(&policy->kobj_unregister);
1166 INIT_WORK(&policy->update, handle_update);
1168 /* call driver. From then on the cpufreq must be able
1169 * to accept all calls to ->verify and ->setpolicy for this CPU
1171 ret = cpufreq_driver->init(policy);
1173 pr_debug("initialization failed\n");
1174 goto err_set_policy_cpu;
1177 /* related cpus should atleast have policy->cpus */
1178 cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
1181 * affected cpus must always be the one, which are online. We aren't
1182 * managing offline cpus here.
1184 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1186 if (!recover_policy) {
1187 policy->user_policy.min = policy->min;
1188 policy->user_policy.max = policy->max;
1191 down_write(&policy->rwsem);
1192 write_lock_irqsave(&cpufreq_driver_lock, flags);
1193 for_each_cpu(j, policy->cpus)
1194 per_cpu(cpufreq_cpu_data, j) = policy;
1195 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1197 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1198 policy->cur = cpufreq_driver->get(policy->cpu);
1200 pr_err("%s: ->get() failed\n", __func__);
1206 * Sometimes boot loaders set CPU frequency to a value outside of
1207 * frequency table present with cpufreq core. In such cases CPU might be
1208 * unstable if it has to run on that frequency for long duration of time
1209 * and so its better to set it to a frequency which is specified in
1210 * freq-table. This also makes cpufreq stats inconsistent as
1211 * cpufreq-stats would fail to register because current frequency of CPU
1212 * isn't found in freq-table.
1214 * Because we don't want this change to effect boot process badly, we go
1215 * for the next freq which is >= policy->cur ('cur' must be set by now,
1216 * otherwise we will end up setting freq to lowest of the table as 'cur'
1217 * is initialized to zero).
1219 * We are passing target-freq as "policy->cur - 1" otherwise
1220 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1221 * equal to target-freq.
1223 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1225 /* Are we running at unknown frequency ? */
1226 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1227 if (ret == -EINVAL) {
1228 /* Warn user and fix it */
1229 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1230 __func__, policy->cpu, policy->cur);
1231 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1232 CPUFREQ_RELATION_L);
1235 * Reaching here after boot in a few seconds may not
1236 * mean that system will remain stable at "unknown"
1237 * frequency for longer duration. Hence, a BUG_ON().
1240 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1241 __func__, policy->cpu, policy->cur);
1245 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1246 CPUFREQ_START, policy);
1248 if (!recover_policy) {
1249 ret = cpufreq_add_dev_interface(policy, dev);
1251 goto err_out_unregister;
1252 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1253 CPUFREQ_CREATE_POLICY, policy);
1256 write_lock_irqsave(&cpufreq_driver_lock, flags);
1257 list_add(&policy->policy_list, &cpufreq_policy_list);
1258 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1260 cpufreq_init_policy(policy);
1262 if (!recover_policy) {
1263 policy->user_policy.policy = policy->policy;
1264 policy->user_policy.governor = policy->governor;
1266 up_write(&policy->rwsem);
1268 kobject_uevent(&policy->kobj, KOBJ_ADD);
1269 up_read(&cpufreq_rwsem);
1271 pr_debug("initialization complete\n");
1277 write_lock_irqsave(&cpufreq_driver_lock, flags);
1278 for_each_cpu(j, policy->cpus)
1279 per_cpu(cpufreq_cpu_data, j) = NULL;
1280 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1282 if (cpufreq_driver->exit)
1283 cpufreq_driver->exit(policy);
1285 if (recover_policy) {
1286 /* Do not leave stale fallback data behind. */
1287 per_cpu(cpufreq_cpu_data_fallback, cpu) = NULL;
1288 cpufreq_policy_put_kobj(policy);
1290 cpufreq_policy_free(policy);
1293 up_read(&cpufreq_rwsem);
1299 * cpufreq_add_dev - add a CPU device
1301 * Adds the cpufreq interface for a CPU device.
1303 * The Oracle says: try running cpufreq registration/unregistration concurrently
1304 * with with cpu hotplugging and all hell will break loose. Tried to clean this
1305 * mess up, but more thorough testing is needed. - Mathieu
1307 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1309 return __cpufreq_add_dev(dev, sif);
1312 static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
1313 unsigned int old_cpu)
1315 struct device *cpu_dev;
1318 /* first sibling now owns the new sysfs dir */
1319 cpu_dev = get_cpu_device(cpumask_any_but(policy->cpus, old_cpu));
1321 sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
1322 ret = kobject_move(&policy->kobj, &cpu_dev->kobj);
1324 pr_err("%s: Failed to move kobj: %d\n", __func__, ret);
1326 down_write(&policy->rwsem);
1327 cpumask_set_cpu(old_cpu, policy->cpus);
1328 up_write(&policy->rwsem);
1330 ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
1339 static int __cpufreq_remove_dev_prepare(struct device *dev,
1340 struct subsys_interface *sif)
1342 unsigned int cpu = dev->id, cpus;
1344 unsigned long flags;
1345 struct cpufreq_policy *policy;
1347 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1349 write_lock_irqsave(&cpufreq_driver_lock, flags);
1351 policy = per_cpu(cpufreq_cpu_data, cpu);
1353 /* Save the policy somewhere when doing a light-weight tear-down */
1354 if (cpufreq_suspended)
1355 per_cpu(cpufreq_cpu_data_fallback, cpu) = policy;
1357 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1360 pr_debug("%s: No cpu_data found\n", __func__);
1365 ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
1367 pr_err("%s: Failed to stop governor\n", __func__);
1372 if (!cpufreq_driver->setpolicy)
1373 strncpy(per_cpu(cpufreq_cpu_governor, cpu),
1374 policy->governor->name, CPUFREQ_NAME_LEN);
1376 down_read(&policy->rwsem);
1377 cpus = cpumask_weight(policy->cpus);
1378 up_read(&policy->rwsem);
1380 if (cpu != policy->cpu) {
1381 sysfs_remove_link(&dev->kobj, "cpufreq");
1382 } else if (cpus > 1) {
1383 new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu);
1385 update_policy_cpu(policy, new_cpu);
1387 if (!cpufreq_suspended)
1388 pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
1389 __func__, new_cpu, cpu);
1391 } else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) {
1392 cpufreq_driver->stop_cpu(policy);
1398 static int __cpufreq_remove_dev_finish(struct device *dev,
1399 struct subsys_interface *sif)
1401 unsigned int cpu = dev->id, cpus;
1403 unsigned long flags;
1404 struct cpufreq_policy *policy;
1406 read_lock_irqsave(&cpufreq_driver_lock, flags);
1407 policy = per_cpu(cpufreq_cpu_data, cpu);
1408 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1411 pr_debug("%s: No cpu_data found\n", __func__);
1415 down_write(&policy->rwsem);
1416 cpus = cpumask_weight(policy->cpus);
1419 cpumask_clear_cpu(cpu, policy->cpus);
1420 up_write(&policy->rwsem);
1422 /* If cpu is last user of policy, free policy */
1425 ret = __cpufreq_governor(policy,
1426 CPUFREQ_GOV_POLICY_EXIT);
1428 pr_err("%s: Failed to exit governor\n",
1434 if (!cpufreq_suspended)
1435 cpufreq_policy_put_kobj(policy);
1438 * Perform the ->exit() even during light-weight tear-down,
1439 * since this is a core component, and is essential for the
1440 * subsequent light-weight ->init() to succeed.
1442 if (cpufreq_driver->exit)
1443 cpufreq_driver->exit(policy);
1445 /* Remove policy from list of active policies */
1446 write_lock_irqsave(&cpufreq_driver_lock, flags);
1447 list_del(&policy->policy_list);
1448 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1450 if (!cpufreq_suspended)
1451 cpufreq_policy_free(policy);
1452 } else if (has_target()) {
1453 ret = __cpufreq_governor(policy, CPUFREQ_GOV_START);
1455 ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
1458 pr_err("%s: Failed to start governor\n", __func__);
1463 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1468 * cpufreq_remove_dev - remove a CPU device
1470 * Removes the cpufreq interface for a CPU device.
1472 static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1474 unsigned int cpu = dev->id;
1477 if (cpu_is_offline(cpu))
1480 ret = __cpufreq_remove_dev_prepare(dev, sif);
1483 ret = __cpufreq_remove_dev_finish(dev, sif);
1488 static void handle_update(struct work_struct *work)
1490 struct cpufreq_policy *policy =
1491 container_of(work, struct cpufreq_policy, update);
1492 unsigned int cpu = policy->cpu;
1493 pr_debug("handle_update for cpu %u called\n", cpu);
1494 cpufreq_update_policy(cpu);
1498 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1501 * @old_freq: CPU frequency the kernel thinks the CPU runs at
1502 * @new_freq: CPU frequency the CPU actually runs at
1504 * We adjust to current frequency first, and need to clean up later.
1505 * So either call to cpufreq_update_policy() or schedule handle_update()).
1507 static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq,
1508 unsigned int new_freq)
1510 struct cpufreq_policy *policy;
1511 struct cpufreq_freqs freqs;
1512 unsigned long flags;
1514 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1515 old_freq, new_freq);
1517 freqs.old = old_freq;
1518 freqs.new = new_freq;
1520 read_lock_irqsave(&cpufreq_driver_lock, flags);
1521 policy = per_cpu(cpufreq_cpu_data, cpu);
1522 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1524 cpufreq_freq_transition_begin(policy, &freqs);
1525 cpufreq_freq_transition_end(policy, &freqs, 0);
1529 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1532 * This is the last known freq, without actually getting it from the driver.
1533 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1535 unsigned int cpufreq_quick_get(unsigned int cpu)
1537 struct cpufreq_policy *policy;
1538 unsigned int ret_freq = 0;
1540 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get)
1541 return cpufreq_driver->get(cpu);
1543 policy = cpufreq_cpu_get(cpu);
1545 ret_freq = policy->cur;
1546 cpufreq_cpu_put(policy);
1551 EXPORT_SYMBOL(cpufreq_quick_get);
1554 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1557 * Just return the max possible frequency for a given CPU.
1559 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1561 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1562 unsigned int ret_freq = 0;
1565 ret_freq = policy->max;
1566 cpufreq_cpu_put(policy);
1571 EXPORT_SYMBOL(cpufreq_quick_get_max);
1573 static unsigned int __cpufreq_get(unsigned int cpu)
1575 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1576 unsigned int ret_freq = 0;
1578 if (!cpufreq_driver->get)
1581 ret_freq = cpufreq_driver->get(cpu);
1583 if (ret_freq && policy->cur &&
1584 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1585 /* verify no discrepancy between actual and
1586 saved value exists */
1587 if (unlikely(ret_freq != policy->cur)) {
1588 cpufreq_out_of_sync(cpu, policy->cur, ret_freq);
1589 schedule_work(&policy->update);
1597 * cpufreq_get - get the current CPU frequency (in kHz)
1600 * Get the CPU current (static) CPU frequency
1602 unsigned int cpufreq_get(unsigned int cpu)
1604 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1605 unsigned int ret_freq = 0;
1608 down_read(&policy->rwsem);
1609 ret_freq = __cpufreq_get(cpu);
1610 up_read(&policy->rwsem);
1612 cpufreq_cpu_put(policy);
1617 EXPORT_SYMBOL(cpufreq_get);
1619 static struct subsys_interface cpufreq_interface = {
1621 .subsys = &cpu_subsys,
1622 .add_dev = cpufreq_add_dev,
1623 .remove_dev = cpufreq_remove_dev,
1627 * In case platform wants some specific frequency to be configured
1630 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1634 if (!policy->suspend_freq) {
1635 pr_err("%s: suspend_freq can't be zero\n", __func__);
1639 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1640 policy->suspend_freq);
1642 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1643 CPUFREQ_RELATION_H);
1645 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1646 __func__, policy->suspend_freq, ret);
1650 EXPORT_SYMBOL(cpufreq_generic_suspend);
1653 * cpufreq_suspend() - Suspend CPUFreq governors
1655 * Called during system wide Suspend/Hibernate cycles for suspending governors
1656 * as some platforms can't change frequency after this point in suspend cycle.
1657 * Because some of the devices (like: i2c, regulators, etc) they use for
1658 * changing frequency are suspended quickly after this point.
1660 void cpufreq_suspend(void)
1662 struct cpufreq_policy *policy;
1664 if (!cpufreq_driver)
1670 pr_debug("%s: Suspending Governors\n", __func__);
1672 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
1673 if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP))
1674 pr_err("%s: Failed to stop governor for policy: %p\n",
1676 else if (cpufreq_driver->suspend
1677 && cpufreq_driver->suspend(policy))
1678 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1682 cpufreq_suspended = true;
1686 * cpufreq_resume() - Resume CPUFreq governors
1688 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1689 * are suspended with cpufreq_suspend().
1691 void cpufreq_resume(void)
1693 struct cpufreq_policy *policy;
1695 if (!cpufreq_driver)
1701 pr_debug("%s: Resuming Governors\n", __func__);
1703 cpufreq_suspended = false;
1705 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
1706 if (cpufreq_driver->resume && cpufreq_driver->resume(policy))
1707 pr_err("%s: Failed to resume driver: %p\n", __func__,
1709 else if (__cpufreq_governor(policy, CPUFREQ_GOV_START)
1710 || __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))
1711 pr_err("%s: Failed to start governor for policy: %p\n",
1715 * schedule call cpufreq_update_policy() for boot CPU, i.e. last
1716 * policy in list. It will verify that the current freq is in
1717 * sync with what we believe it to be.
1719 if (list_is_last(&policy->policy_list, &cpufreq_policy_list))
1720 schedule_work(&policy->update);
1725 * cpufreq_get_current_driver - return current driver's name
1727 * Return the name string of the currently loaded cpufreq driver
1730 const char *cpufreq_get_current_driver(void)
1733 return cpufreq_driver->name;
1737 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1739 /*********************************************************************
1740 * NOTIFIER LISTS INTERFACE *
1741 *********************************************************************/
1744 * cpufreq_register_notifier - register a driver with cpufreq
1745 * @nb: notifier function to register
1746 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1748 * Add a driver to one of two lists: either a list of drivers that
1749 * are notified about clock rate changes (once before and once after
1750 * the transition), or a list of drivers that are notified about
1751 * changes in cpufreq policy.
1753 * This function may sleep, and has the same return conditions as
1754 * blocking_notifier_chain_register.
1756 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1760 if (cpufreq_disabled())
1763 WARN_ON(!init_cpufreq_transition_notifier_list_called);
1766 case CPUFREQ_TRANSITION_NOTIFIER:
1767 ret = srcu_notifier_chain_register(
1768 &cpufreq_transition_notifier_list, nb);
1770 case CPUFREQ_POLICY_NOTIFIER:
1771 ret = blocking_notifier_chain_register(
1772 &cpufreq_policy_notifier_list, nb);
1780 EXPORT_SYMBOL(cpufreq_register_notifier);
1783 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1784 * @nb: notifier block to be unregistered
1785 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1787 * Remove a driver from the CPU frequency notifier list.
1789 * This function may sleep, and has the same return conditions as
1790 * blocking_notifier_chain_unregister.
1792 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1796 if (cpufreq_disabled())
1800 case CPUFREQ_TRANSITION_NOTIFIER:
1801 ret = srcu_notifier_chain_unregister(
1802 &cpufreq_transition_notifier_list, nb);
1804 case CPUFREQ_POLICY_NOTIFIER:
1805 ret = blocking_notifier_chain_unregister(
1806 &cpufreq_policy_notifier_list, nb);
1814 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1817 /*********************************************************************
1819 *********************************************************************/
1821 /* Must set freqs->new to intermediate frequency */
1822 static int __target_intermediate(struct cpufreq_policy *policy,
1823 struct cpufreq_freqs *freqs, int index)
1827 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1829 /* We don't need to switch to intermediate freq */
1833 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1834 __func__, policy->cpu, freqs->old, freqs->new);
1836 cpufreq_freq_transition_begin(policy, freqs);
1837 ret = cpufreq_driver->target_intermediate(policy, index);
1838 cpufreq_freq_transition_end(policy, freqs, ret);
1841 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1847 static int __target_index(struct cpufreq_policy *policy,
1848 struct cpufreq_frequency_table *freq_table, int index)
1850 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1851 unsigned int intermediate_freq = 0;
1852 int retval = -EINVAL;
1855 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1857 /* Handle switching to intermediate frequency */
1858 if (cpufreq_driver->get_intermediate) {
1859 retval = __target_intermediate(policy, &freqs, index);
1863 intermediate_freq = freqs.new;
1864 /* Set old freq to intermediate */
1865 if (intermediate_freq)
1866 freqs.old = freqs.new;
1869 freqs.new = freq_table[index].frequency;
1870 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1871 __func__, policy->cpu, freqs.old, freqs.new);
1873 cpufreq_freq_transition_begin(policy, &freqs);
1876 retval = cpufreq_driver->target_index(policy, index);
1878 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
1882 cpufreq_freq_transition_end(policy, &freqs, retval);
1885 * Failed after setting to intermediate freq? Driver should have
1886 * reverted back to initial frequency and so should we. Check
1887 * here for intermediate_freq instead of get_intermediate, in
1888 * case we have't switched to intermediate freq at all.
1890 if (unlikely(retval && intermediate_freq)) {
1891 freqs.old = intermediate_freq;
1892 freqs.new = policy->restore_freq;
1893 cpufreq_freq_transition_begin(policy, &freqs);
1894 cpufreq_freq_transition_end(policy, &freqs, 0);
1901 int __cpufreq_driver_target(struct cpufreq_policy *policy,
1902 unsigned int target_freq,
1903 unsigned int relation)
1905 unsigned int old_target_freq = target_freq;
1906 int retval = -EINVAL;
1908 if (cpufreq_disabled())
1911 /* Make sure that target_freq is within supported range */
1912 if (target_freq > policy->max)
1913 target_freq = policy->max;
1914 if (target_freq < policy->min)
1915 target_freq = policy->min;
1917 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1918 policy->cpu, target_freq, relation, old_target_freq);
1921 * This might look like a redundant call as we are checking it again
1922 * after finding index. But it is left intentionally for cases where
1923 * exactly same freq is called again and so we can save on few function
1926 if (target_freq == policy->cur)
1929 /* Save last value to restore later on errors */
1930 policy->restore_freq = policy->cur;
1932 if (cpufreq_driver->target)
1933 retval = cpufreq_driver->target(policy, target_freq, relation);
1934 else if (cpufreq_driver->target_index) {
1935 struct cpufreq_frequency_table *freq_table;
1938 freq_table = cpufreq_frequency_get_table(policy->cpu);
1939 if (unlikely(!freq_table)) {
1940 pr_err("%s: Unable to find freq_table\n", __func__);
1944 retval = cpufreq_frequency_table_target(policy, freq_table,
1945 target_freq, relation, &index);
1946 if (unlikely(retval)) {
1947 pr_err("%s: Unable to find matching freq\n", __func__);
1951 if (freq_table[index].frequency == policy->cur) {
1956 retval = __target_index(policy, freq_table, index);
1962 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1964 int cpufreq_driver_target(struct cpufreq_policy *policy,
1965 unsigned int target_freq,
1966 unsigned int relation)
1970 down_write(&policy->rwsem);
1972 ret = __cpufreq_driver_target(policy, target_freq, relation);
1974 up_write(&policy->rwsem);
1978 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1981 * when "event" is CPUFREQ_GOV_LIMITS
1984 static int __cpufreq_governor(struct cpufreq_policy *policy,
1989 /* Only must be defined when default governor is known to have latency
1990 restrictions, like e.g. conservative or ondemand.
1991 That this is the case is already ensured in Kconfig
1993 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1994 struct cpufreq_governor *gov = &cpufreq_gov_performance;
1996 struct cpufreq_governor *gov = NULL;
1999 /* Don't start any governor operations if we are entering suspend */
2000 if (cpufreq_suspended)
2003 if (policy->governor->max_transition_latency &&
2004 policy->cpuinfo.transition_latency >
2005 policy->governor->max_transition_latency) {
2009 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
2010 policy->governor->name, gov->name);
2011 policy->governor = gov;
2015 if (event == CPUFREQ_GOV_POLICY_INIT)
2016 if (!try_module_get(policy->governor->owner))
2019 pr_debug("__cpufreq_governor for CPU %u, event %u\n",
2020 policy->cpu, event);
2022 mutex_lock(&cpufreq_governor_lock);
2023 if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
2024 || (!policy->governor_enabled
2025 && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
2026 mutex_unlock(&cpufreq_governor_lock);
2030 if (event == CPUFREQ_GOV_STOP)
2031 policy->governor_enabled = false;
2032 else if (event == CPUFREQ_GOV_START)
2033 policy->governor_enabled = true;
2035 mutex_unlock(&cpufreq_governor_lock);
2037 ret = policy->governor->governor(policy, event);
2040 if (event == CPUFREQ_GOV_POLICY_INIT)
2041 policy->governor->initialized++;
2042 else if (event == CPUFREQ_GOV_POLICY_EXIT)
2043 policy->governor->initialized--;
2045 /* Restore original values */
2046 mutex_lock(&cpufreq_governor_lock);
2047 if (event == CPUFREQ_GOV_STOP)
2048 policy->governor_enabled = true;
2049 else if (event == CPUFREQ_GOV_START)
2050 policy->governor_enabled = false;
2051 mutex_unlock(&cpufreq_governor_lock);
2054 if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||
2055 ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
2056 module_put(policy->governor->owner);
2061 int cpufreq_register_governor(struct cpufreq_governor *governor)
2068 if (cpufreq_disabled())
2071 mutex_lock(&cpufreq_governor_mutex);
2073 governor->initialized = 0;
2075 if (__find_governor(governor->name) == NULL) {
2077 list_add(&governor->governor_list, &cpufreq_governor_list);
2080 mutex_unlock(&cpufreq_governor_mutex);
2083 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2085 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2092 if (cpufreq_disabled())
2095 for_each_present_cpu(cpu) {
2096 if (cpu_online(cpu))
2098 if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
2099 strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
2102 mutex_lock(&cpufreq_governor_mutex);
2103 list_del(&governor->governor_list);
2104 mutex_unlock(&cpufreq_governor_mutex);
2107 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2110 /*********************************************************************
2111 * POLICY INTERFACE *
2112 *********************************************************************/
2115 * cpufreq_get_policy - get the current cpufreq_policy
2116 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2119 * Reads the current cpufreq policy.
2121 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2123 struct cpufreq_policy *cpu_policy;
2127 cpu_policy = cpufreq_cpu_get(cpu);
2131 memcpy(policy, cpu_policy, sizeof(*policy));
2133 cpufreq_cpu_put(cpu_policy);
2136 EXPORT_SYMBOL(cpufreq_get_policy);
2139 * policy : current policy.
2140 * new_policy: policy to be set.
2142 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2143 struct cpufreq_policy *new_policy)
2145 struct cpufreq_governor *old_gov;
2148 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2149 new_policy->cpu, new_policy->min, new_policy->max);
2151 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2153 if (new_policy->min > policy->max || new_policy->max < policy->min)
2156 /* verify the cpu speed can be set within this limit */
2157 ret = cpufreq_driver->verify(new_policy);
2161 /* adjust if necessary - all reasons */
2162 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2163 CPUFREQ_ADJUST, new_policy);
2165 /* adjust if necessary - hardware incompatibility*/
2166 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2167 CPUFREQ_INCOMPATIBLE, new_policy);
2170 * verify the cpu speed can be set within this limit, which might be
2171 * different to the first one
2173 ret = cpufreq_driver->verify(new_policy);
2177 /* notification of the new policy */
2178 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2179 CPUFREQ_NOTIFY, new_policy);
2181 policy->min = new_policy->min;
2182 policy->max = new_policy->max;
2184 pr_debug("new min and max freqs are %u - %u kHz\n",
2185 policy->min, policy->max);
2187 if (cpufreq_driver->setpolicy) {
2188 policy->policy = new_policy->policy;
2189 pr_debug("setting range\n");
2190 return cpufreq_driver->setpolicy(new_policy);
2193 if (new_policy->governor == policy->governor)
2196 pr_debug("governor switch\n");
2198 /* save old, working values */
2199 old_gov = policy->governor;
2200 /* end old governor */
2202 __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
2203 up_write(&policy->rwsem);
2204 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2205 down_write(&policy->rwsem);
2208 /* start new governor */
2209 policy->governor = new_policy->governor;
2210 if (!__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT)) {
2211 if (!__cpufreq_governor(policy, CPUFREQ_GOV_START))
2214 up_write(&policy->rwsem);
2215 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
2216 down_write(&policy->rwsem);
2219 /* new governor failed, so re-start old one */
2220 pr_debug("starting governor %s failed\n", policy->governor->name);
2222 policy->governor = old_gov;
2223 __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_INIT);
2224 __cpufreq_governor(policy, CPUFREQ_GOV_START);
2230 pr_debug("governor: change or update limits\n");
2231 return __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2235 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2236 * @cpu: CPU which shall be re-evaluated
2238 * Useful for policy notifiers which have different necessities
2239 * at different times.
2241 int cpufreq_update_policy(unsigned int cpu)
2243 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
2244 struct cpufreq_policy new_policy;
2250 down_write(&policy->rwsem);
2252 pr_debug("updating policy for CPU %u\n", cpu);
2253 memcpy(&new_policy, policy, sizeof(*policy));
2254 new_policy.min = policy->user_policy.min;
2255 new_policy.max = policy->user_policy.max;
2256 new_policy.policy = policy->user_policy.policy;
2257 new_policy.governor = policy->user_policy.governor;
2260 * BIOS might change freq behind our back
2261 * -> ask driver for current freq and notify governors about a change
2263 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
2264 new_policy.cur = cpufreq_driver->get(cpu);
2265 if (WARN_ON(!new_policy.cur)) {
2271 pr_debug("Driver did not initialize current freq\n");
2272 policy->cur = new_policy.cur;
2274 if (policy->cur != new_policy.cur && has_target())
2275 cpufreq_out_of_sync(cpu, policy->cur,
2280 ret = cpufreq_set_policy(policy, &new_policy);
2283 up_write(&policy->rwsem);
2285 cpufreq_cpu_put(policy);
2288 EXPORT_SYMBOL(cpufreq_update_policy);
2290 static int cpufreq_cpu_callback(struct notifier_block *nfb,
2291 unsigned long action, void *hcpu)
2293 unsigned int cpu = (unsigned long)hcpu;
2296 dev = get_cpu_device(cpu);
2298 switch (action & ~CPU_TASKS_FROZEN) {
2300 __cpufreq_add_dev(dev, NULL);
2303 case CPU_DOWN_PREPARE:
2304 __cpufreq_remove_dev_prepare(dev, NULL);
2308 __cpufreq_remove_dev_finish(dev, NULL);
2311 case CPU_DOWN_FAILED:
2312 __cpufreq_add_dev(dev, NULL);
2319 static struct notifier_block __refdata cpufreq_cpu_notifier = {
2320 .notifier_call = cpufreq_cpu_callback,
2323 /*********************************************************************
2325 *********************************************************************/
2326 static int cpufreq_boost_set_sw(int state)
2328 struct cpufreq_frequency_table *freq_table;
2329 struct cpufreq_policy *policy;
2332 list_for_each_entry(policy, &cpufreq_policy_list, policy_list) {
2333 freq_table = cpufreq_frequency_get_table(policy->cpu);
2335 ret = cpufreq_frequency_table_cpuinfo(policy,
2338 pr_err("%s: Policy frequency update failed\n",
2342 policy->user_policy.max = policy->max;
2343 __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
2350 int cpufreq_boost_trigger_state(int state)
2352 unsigned long flags;
2355 if (cpufreq_driver->boost_enabled == state)
2358 write_lock_irqsave(&cpufreq_driver_lock, flags);
2359 cpufreq_driver->boost_enabled = state;
2360 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2362 ret = cpufreq_driver->set_boost(state);
2364 write_lock_irqsave(&cpufreq_driver_lock, flags);
2365 cpufreq_driver->boost_enabled = !state;
2366 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2368 pr_err("%s: Cannot %s BOOST\n",
2369 __func__, state ? "enable" : "disable");
2375 int cpufreq_boost_supported(void)
2377 if (likely(cpufreq_driver))
2378 return cpufreq_driver->boost_supported;
2382 EXPORT_SYMBOL_GPL(cpufreq_boost_supported);
2384 int cpufreq_boost_enabled(void)
2386 return cpufreq_driver->boost_enabled;
2388 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2390 /*********************************************************************
2391 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2392 *********************************************************************/
2395 * cpufreq_register_driver - register a CPU Frequency driver
2396 * @driver_data: A struct cpufreq_driver containing the values#
2397 * submitted by the CPU Frequency driver.
2399 * Registers a CPU Frequency driver to this core code. This code
2400 * returns zero on success, -EBUSY when another driver got here first
2401 * (and isn't unregistered in the meantime).
2404 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2406 unsigned long flags;
2409 if (cpufreq_disabled())
2412 if (!driver_data || !driver_data->verify || !driver_data->init ||
2413 !(driver_data->setpolicy || driver_data->target_index ||
2414 driver_data->target) ||
2415 (driver_data->setpolicy && (driver_data->target_index ||
2416 driver_data->target)) ||
2417 (!!driver_data->get_intermediate != !!driver_data->target_intermediate))
2420 pr_debug("trying to register driver %s\n", driver_data->name);
2422 if (driver_data->setpolicy)
2423 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2425 write_lock_irqsave(&cpufreq_driver_lock, flags);
2426 if (cpufreq_driver) {
2427 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2430 cpufreq_driver = driver_data;
2431 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2433 if (cpufreq_boost_supported()) {
2435 * Check if driver provides function to enable boost -
2436 * if not, use cpufreq_boost_set_sw as default
2438 if (!cpufreq_driver->set_boost)
2439 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2441 ret = cpufreq_sysfs_create_file(&boost.attr);
2443 pr_err("%s: cannot register global BOOST sysfs file\n",
2445 goto err_null_driver;
2449 ret = subsys_interface_register(&cpufreq_interface);
2451 goto err_boost_unreg;
2453 if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) {
2457 /* check for at least one working CPU */
2458 for (i = 0; i < nr_cpu_ids; i++)
2459 if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) {
2464 /* if all ->init() calls failed, unregister */
2466 pr_debug("no CPU initialized for driver %s\n",
2472 register_hotcpu_notifier(&cpufreq_cpu_notifier);
2473 pr_debug("driver %s up and running\n", driver_data->name);
2477 subsys_interface_unregister(&cpufreq_interface);
2479 if (cpufreq_boost_supported())
2480 cpufreq_sysfs_remove_file(&boost.attr);
2482 write_lock_irqsave(&cpufreq_driver_lock, flags);
2483 cpufreq_driver = NULL;
2484 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2487 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2490 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2492 * Unregister the current CPUFreq driver. Only call this if you have
2493 * the right to do so, i.e. if you have succeeded in initialising before!
2494 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2495 * currently not initialised.
2497 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2499 unsigned long flags;
2501 if (!cpufreq_driver || (driver != cpufreq_driver))
2504 pr_debug("unregistering driver %s\n", driver->name);
2506 subsys_interface_unregister(&cpufreq_interface);
2507 if (cpufreq_boost_supported())
2508 cpufreq_sysfs_remove_file(&boost.attr);
2510 unregister_hotcpu_notifier(&cpufreq_cpu_notifier);
2512 down_write(&cpufreq_rwsem);
2513 write_lock_irqsave(&cpufreq_driver_lock, flags);
2515 cpufreq_driver = NULL;
2517 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2518 up_write(&cpufreq_rwsem);
2522 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2524 static int __init cpufreq_core_init(void)
2526 if (cpufreq_disabled())
2529 cpufreq_global_kobject = kobject_create();
2530 BUG_ON(!cpufreq_global_kobject);
2534 core_initcall(cpufreq_core_init);