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/cpu_cooling.h>
23 #include <linux/delay.h>
24 #include <linux/device.h>
25 #include <linux/init.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/pm_qos.h>
30 #include <linux/slab.h>
31 #include <linux/suspend.h>
32 #include <linux/syscore_ops.h>
33 #include <linux/tick.h>
34 #include <trace/events/power.h>
36 static LIST_HEAD(cpufreq_policy_list);
38 /* Macros to iterate over CPU policies */
39 #define for_each_suitable_policy(__policy, __active) \
40 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
41 if ((__active) == !policy_is_inactive(__policy))
43 #define for_each_active_policy(__policy) \
44 for_each_suitable_policy(__policy, true)
45 #define for_each_inactive_policy(__policy) \
46 for_each_suitable_policy(__policy, false)
48 #define for_each_policy(__policy) \
49 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
51 /* Iterate over governors */
52 static LIST_HEAD(cpufreq_governor_list);
53 #define for_each_governor(__governor) \
54 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
57 * The "cpufreq driver" - the arch- or hardware-dependent low
58 * level driver of CPUFreq support, and its spinlock. This lock
59 * also protects the cpufreq_cpu_data array.
61 static struct cpufreq_driver *cpufreq_driver;
62 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
63 static DEFINE_RWLOCK(cpufreq_driver_lock);
65 /* Flag to suspend/resume CPUFreq governors */
66 static bool cpufreq_suspended;
68 static inline bool has_target(void)
70 return cpufreq_driver->target_index || cpufreq_driver->target;
73 /* internal prototypes */
74 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
75 static int cpufreq_init_governor(struct cpufreq_policy *policy);
76 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
77 static int cpufreq_start_governor(struct cpufreq_policy *policy);
78 static void cpufreq_stop_governor(struct cpufreq_policy *policy);
79 static void cpufreq_governor_limits(struct cpufreq_policy *policy);
82 * Two notifier lists: the "policy" list is involved in the
83 * validation process for a new CPU frequency policy; the
84 * "transition" list for kernel code that needs to handle
85 * changes to devices when the CPU clock speed changes.
86 * The mutex locks both lists.
88 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
89 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
91 static int off __read_mostly;
92 static int cpufreq_disabled(void)
96 void disable_cpufreq(void)
100 static DEFINE_MUTEX(cpufreq_governor_mutex);
102 bool have_governor_per_policy(void)
104 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
106 EXPORT_SYMBOL_GPL(have_governor_per_policy);
108 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
110 if (have_governor_per_policy())
111 return &policy->kobj;
113 return cpufreq_global_kobject;
115 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
117 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
123 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
125 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
126 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
127 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
128 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
129 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
130 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
132 idle_time = cur_wall_time - busy_time;
134 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
136 return div_u64(idle_time, NSEC_PER_USEC);
139 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
141 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
143 if (idle_time == -1ULL)
144 return get_cpu_idle_time_jiffy(cpu, wall);
146 idle_time += get_cpu_iowait_time_us(cpu, wall);
150 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
152 __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
153 unsigned long max_freq)
156 EXPORT_SYMBOL_GPL(arch_set_freq_scale);
159 * This is a generic cpufreq init() routine which can be used by cpufreq
160 * drivers of SMP systems. It will do following:
161 * - validate & show freq table passed
162 * - set policies transition latency
163 * - policy->cpus with all possible CPUs
165 int cpufreq_generic_init(struct cpufreq_policy *policy,
166 struct cpufreq_frequency_table *table,
167 unsigned int transition_latency)
169 policy->freq_table = table;
170 policy->cpuinfo.transition_latency = transition_latency;
173 * The driver only supports the SMP configuration where all processors
174 * share the clock and voltage and clock.
176 cpumask_setall(policy->cpus);
180 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
182 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
184 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
186 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
188 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
190 unsigned int cpufreq_generic_get(unsigned int cpu)
192 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
194 if (!policy || IS_ERR(policy->clk)) {
195 pr_err("%s: No %s associated to cpu: %d\n",
196 __func__, policy ? "clk" : "policy", cpu);
200 return clk_get_rate(policy->clk) / 1000;
202 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
205 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
206 * @cpu: CPU to find the policy for.
208 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
209 * the kobject reference counter of that policy. Return a valid policy on
210 * success or NULL on failure.
212 * The policy returned by this function has to be released with the help of
213 * cpufreq_cpu_put() to balance its kobject reference counter properly.
215 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
217 struct cpufreq_policy *policy = NULL;
220 if (WARN_ON(cpu >= nr_cpu_ids))
223 /* get the cpufreq driver */
224 read_lock_irqsave(&cpufreq_driver_lock, flags);
226 if (cpufreq_driver) {
228 policy = cpufreq_cpu_get_raw(cpu);
230 kobject_get(&policy->kobj);
233 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
237 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
240 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
241 * @policy: cpufreq policy returned by cpufreq_cpu_get().
243 void cpufreq_cpu_put(struct cpufreq_policy *policy)
245 kobject_put(&policy->kobj);
247 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
250 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
251 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
253 void cpufreq_cpu_release(struct cpufreq_policy *policy)
255 if (WARN_ON(!policy))
258 lockdep_assert_held(&policy->rwsem);
260 up_write(&policy->rwsem);
262 cpufreq_cpu_put(policy);
266 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
267 * @cpu: CPU to find the policy for.
269 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
270 * if the policy returned by it is not NULL, acquire its rwsem for writing.
271 * Return the policy if it is active or release it and return NULL otherwise.
273 * The policy returned by this function has to be released with the help of
274 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
277 struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
279 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
284 down_write(&policy->rwsem);
286 if (policy_is_inactive(policy)) {
287 cpufreq_cpu_release(policy);
294 /*********************************************************************
295 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
296 *********************************************************************/
299 * adjust_jiffies - adjust the system "loops_per_jiffy"
301 * This function alters the system "loops_per_jiffy" for the clock
302 * speed change. Note that loops_per_jiffy cannot be updated on SMP
303 * systems as each CPU might be scaled differently. So, use the arch
304 * per-CPU loops_per_jiffy value wherever possible.
306 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
309 static unsigned long l_p_j_ref;
310 static unsigned int l_p_j_ref_freq;
312 if (ci->flags & CPUFREQ_CONST_LOOPS)
315 if (!l_p_j_ref_freq) {
316 l_p_j_ref = loops_per_jiffy;
317 l_p_j_ref_freq = ci->old;
318 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
319 l_p_j_ref, l_p_j_ref_freq);
321 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
322 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
324 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
325 loops_per_jiffy, ci->new);
331 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
332 * @policy: cpufreq policy to enable fast frequency switching for.
333 * @freqs: contain details of the frequency update.
334 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
336 * This function calls the transition notifiers and the "adjust_jiffies"
337 * function. It is called twice on all CPU frequency changes that have
340 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
341 struct cpufreq_freqs *freqs,
346 BUG_ON(irqs_disabled());
348 if (cpufreq_disabled())
351 freqs->policy = policy;
352 freqs->flags = cpufreq_driver->flags;
353 pr_debug("notification %u of frequency transition to %u kHz\n",
357 case CPUFREQ_PRECHANGE:
359 * Detect if the driver reported a value as "old frequency"
360 * which is not equal to what the cpufreq core thinks is
363 if (policy->cur && policy->cur != freqs->old) {
364 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
365 freqs->old, policy->cur);
366 freqs->old = policy->cur;
369 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
370 CPUFREQ_PRECHANGE, freqs);
372 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
375 case CPUFREQ_POSTCHANGE:
376 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
377 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
378 cpumask_pr_args(policy->cpus));
380 for_each_cpu(cpu, policy->cpus)
381 trace_cpu_frequency(freqs->new, cpu);
383 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
384 CPUFREQ_POSTCHANGE, freqs);
386 cpufreq_stats_record_transition(policy, freqs->new);
387 policy->cur = freqs->new;
391 /* Do post notifications when there are chances that transition has failed */
392 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
393 struct cpufreq_freqs *freqs, int transition_failed)
395 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
396 if (!transition_failed)
399 swap(freqs->old, freqs->new);
400 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
401 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
404 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
405 struct cpufreq_freqs *freqs)
409 * Catch double invocations of _begin() which lead to self-deadlock.
410 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
411 * doesn't invoke _begin() on their behalf, and hence the chances of
412 * double invocations are very low. Moreover, there are scenarios
413 * where these checks can emit false-positive warnings in these
414 * drivers; so we avoid that by skipping them altogether.
416 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
417 && current == policy->transition_task);
420 wait_event(policy->transition_wait, !policy->transition_ongoing);
422 spin_lock(&policy->transition_lock);
424 if (unlikely(policy->transition_ongoing)) {
425 spin_unlock(&policy->transition_lock);
429 policy->transition_ongoing = true;
430 policy->transition_task = current;
432 spin_unlock(&policy->transition_lock);
434 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
436 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
438 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
439 struct cpufreq_freqs *freqs, int transition_failed)
441 if (WARN_ON(!policy->transition_ongoing))
444 cpufreq_notify_post_transition(policy, freqs, transition_failed);
446 policy->transition_ongoing = false;
447 policy->transition_task = NULL;
449 wake_up(&policy->transition_wait);
451 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
454 * Fast frequency switching status count. Positive means "enabled", negative
455 * means "disabled" and 0 means "not decided yet".
457 static int cpufreq_fast_switch_count;
458 static DEFINE_MUTEX(cpufreq_fast_switch_lock);
460 static void cpufreq_list_transition_notifiers(void)
462 struct notifier_block *nb;
464 pr_info("Registered transition notifiers:\n");
466 mutex_lock(&cpufreq_transition_notifier_list.mutex);
468 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
469 pr_info("%pS\n", nb->notifier_call);
471 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
475 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
476 * @policy: cpufreq policy to enable fast frequency switching for.
478 * Try to enable fast frequency switching for @policy.
480 * The attempt will fail if there is at least one transition notifier registered
481 * at this point, as fast frequency switching is quite fundamentally at odds
482 * with transition notifiers. Thus if successful, it will make registration of
483 * transition notifiers fail going forward.
485 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
487 lockdep_assert_held(&policy->rwsem);
489 if (!policy->fast_switch_possible)
492 mutex_lock(&cpufreq_fast_switch_lock);
493 if (cpufreq_fast_switch_count >= 0) {
494 cpufreq_fast_switch_count++;
495 policy->fast_switch_enabled = true;
497 pr_warn("CPU%u: Fast frequency switching not enabled\n",
499 cpufreq_list_transition_notifiers();
501 mutex_unlock(&cpufreq_fast_switch_lock);
503 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
506 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
507 * @policy: cpufreq policy to disable fast frequency switching for.
509 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
511 mutex_lock(&cpufreq_fast_switch_lock);
512 if (policy->fast_switch_enabled) {
513 policy->fast_switch_enabled = false;
514 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
515 cpufreq_fast_switch_count--;
517 mutex_unlock(&cpufreq_fast_switch_lock);
519 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
522 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
524 * @target_freq: target frequency to resolve.
526 * The target to driver frequency mapping is cached in the policy.
528 * Return: Lowest driver-supported frequency greater than or equal to the
529 * given target_freq, subject to policy (min/max) and driver limitations.
531 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
532 unsigned int target_freq)
534 target_freq = clamp_val(target_freq, policy->min, policy->max);
535 policy->cached_target_freq = target_freq;
537 if (cpufreq_driver->target_index) {
540 idx = cpufreq_frequency_table_target(policy, target_freq,
542 policy->cached_resolved_idx = idx;
543 return policy->freq_table[idx].frequency;
546 if (cpufreq_driver->resolve_freq)
547 return cpufreq_driver->resolve_freq(policy, target_freq);
551 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
553 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
555 unsigned int latency;
557 if (policy->transition_delay_us)
558 return policy->transition_delay_us;
560 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
563 * For platforms that can change the frequency very fast (< 10
564 * us), the above formula gives a decent transition delay. But
565 * for platforms where transition_latency is in milliseconds, it
566 * ends up giving unrealistic values.
568 * Cap the default transition delay to 10 ms, which seems to be
569 * a reasonable amount of time after which we should reevaluate
572 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
575 return LATENCY_MULTIPLIER;
577 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
579 /*********************************************************************
581 *********************************************************************/
582 static ssize_t show_boost(struct kobject *kobj,
583 struct kobj_attribute *attr, char *buf)
585 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
588 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
589 const char *buf, size_t count)
593 ret = sscanf(buf, "%d", &enable);
594 if (ret != 1 || enable < 0 || enable > 1)
597 if (cpufreq_boost_trigger_state(enable)) {
598 pr_err("%s: Cannot %s BOOST!\n",
599 __func__, enable ? "enable" : "disable");
603 pr_debug("%s: cpufreq BOOST %s\n",
604 __func__, enable ? "enabled" : "disabled");
608 define_one_global_rw(boost);
610 static struct cpufreq_governor *find_governor(const char *str_governor)
612 struct cpufreq_governor *t;
615 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
621 static int cpufreq_parse_policy(char *str_governor,
622 struct cpufreq_policy *policy)
624 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
625 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
628 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
629 policy->policy = CPUFREQ_POLICY_POWERSAVE;
636 * cpufreq_parse_governor - parse a governor string only for has_target()
638 static int cpufreq_parse_governor(char *str_governor,
639 struct cpufreq_policy *policy)
641 struct cpufreq_governor *t;
643 mutex_lock(&cpufreq_governor_mutex);
645 t = find_governor(str_governor);
649 mutex_unlock(&cpufreq_governor_mutex);
651 ret = request_module("cpufreq_%s", str_governor);
655 mutex_lock(&cpufreq_governor_mutex);
657 t = find_governor(str_governor);
659 if (t && !try_module_get(t->owner))
662 mutex_unlock(&cpufreq_governor_mutex);
665 policy->governor = t;
673 * cpufreq_per_cpu_attr_read() / show_##file_name() -
674 * print out cpufreq information
676 * Write out information from cpufreq_driver->policy[cpu]; object must be
680 #define show_one(file_name, object) \
681 static ssize_t show_##file_name \
682 (struct cpufreq_policy *policy, char *buf) \
684 return sprintf(buf, "%u\n", policy->object); \
687 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
688 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
689 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
690 show_one(scaling_min_freq, min);
691 show_one(scaling_max_freq, max);
693 __weak unsigned int arch_freq_get_on_cpu(int cpu)
698 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
703 freq = arch_freq_get_on_cpu(policy->cpu);
705 ret = sprintf(buf, "%u\n", freq);
706 else if (cpufreq_driver && cpufreq_driver->setpolicy &&
708 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
710 ret = sprintf(buf, "%u\n", policy->cur);
715 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
717 #define store_one(file_name, object) \
718 static ssize_t store_##file_name \
719 (struct cpufreq_policy *policy, const char *buf, size_t count) \
722 struct cpufreq_policy new_policy; \
724 memcpy(&new_policy, policy, sizeof(*policy)); \
725 new_policy.min = policy->user_policy.min; \
726 new_policy.max = policy->user_policy.max; \
728 ret = sscanf(buf, "%u", &new_policy.object); \
732 temp = new_policy.object; \
733 ret = cpufreq_set_policy(policy, &new_policy); \
735 policy->user_policy.object = temp; \
737 return ret ? ret : count; \
740 store_one(scaling_min_freq, min);
741 store_one(scaling_max_freq, max);
744 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
746 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
749 unsigned int cur_freq = __cpufreq_get(policy);
752 return sprintf(buf, "%u\n", cur_freq);
754 return sprintf(buf, "<unknown>\n");
758 * show_scaling_governor - show the current policy for the specified CPU
760 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
762 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
763 return sprintf(buf, "powersave\n");
764 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
765 return sprintf(buf, "performance\n");
766 else if (policy->governor)
767 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
768 policy->governor->name);
773 * store_scaling_governor - store policy for the specified CPU
775 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
776 const char *buf, size_t count)
779 char str_governor[16];
780 struct cpufreq_policy new_policy;
782 memcpy(&new_policy, policy, sizeof(*policy));
784 ret = sscanf(buf, "%15s", str_governor);
788 if (cpufreq_driver->setpolicy) {
789 if (cpufreq_parse_policy(str_governor, &new_policy))
792 if (cpufreq_parse_governor(str_governor, &new_policy))
796 ret = cpufreq_set_policy(policy, &new_policy);
798 if (new_policy.governor)
799 module_put(new_policy.governor->owner);
801 return ret ? ret : count;
805 * show_scaling_driver - show the cpufreq driver currently loaded
807 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
809 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
813 * show_scaling_available_governors - show the available CPUfreq governors
815 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
819 struct cpufreq_governor *t;
822 i += sprintf(buf, "performance powersave");
826 for_each_governor(t) {
827 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
828 - (CPUFREQ_NAME_LEN + 2)))
830 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
833 i += sprintf(&buf[i], "\n");
837 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
842 for_each_cpu(cpu, mask) {
844 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
845 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
846 if (i >= (PAGE_SIZE - 5))
849 i += sprintf(&buf[i], "\n");
852 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
855 * show_related_cpus - show the CPUs affected by each transition even if
856 * hw coordination is in use
858 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
860 return cpufreq_show_cpus(policy->related_cpus, buf);
864 * show_affected_cpus - show the CPUs affected by each transition
866 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
868 return cpufreq_show_cpus(policy->cpus, buf);
871 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
872 const char *buf, size_t count)
874 unsigned int freq = 0;
877 if (!policy->governor || !policy->governor->store_setspeed)
880 ret = sscanf(buf, "%u", &freq);
884 policy->governor->store_setspeed(policy, freq);
889 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
891 if (!policy->governor || !policy->governor->show_setspeed)
892 return sprintf(buf, "<unsupported>\n");
894 return policy->governor->show_setspeed(policy, buf);
898 * show_bios_limit - show the current cpufreq HW/BIOS limitation
900 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
904 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
906 return sprintf(buf, "%u\n", limit);
907 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
910 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
911 cpufreq_freq_attr_ro(cpuinfo_min_freq);
912 cpufreq_freq_attr_ro(cpuinfo_max_freq);
913 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
914 cpufreq_freq_attr_ro(scaling_available_governors);
915 cpufreq_freq_attr_ro(scaling_driver);
916 cpufreq_freq_attr_ro(scaling_cur_freq);
917 cpufreq_freq_attr_ro(bios_limit);
918 cpufreq_freq_attr_ro(related_cpus);
919 cpufreq_freq_attr_ro(affected_cpus);
920 cpufreq_freq_attr_rw(scaling_min_freq);
921 cpufreq_freq_attr_rw(scaling_max_freq);
922 cpufreq_freq_attr_rw(scaling_governor);
923 cpufreq_freq_attr_rw(scaling_setspeed);
925 static struct attribute *default_attrs[] = {
926 &cpuinfo_min_freq.attr,
927 &cpuinfo_max_freq.attr,
928 &cpuinfo_transition_latency.attr,
929 &scaling_min_freq.attr,
930 &scaling_max_freq.attr,
933 &scaling_governor.attr,
934 &scaling_driver.attr,
935 &scaling_available_governors.attr,
936 &scaling_setspeed.attr,
940 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
941 #define to_attr(a) container_of(a, struct freq_attr, attr)
943 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
945 struct cpufreq_policy *policy = to_policy(kobj);
946 struct freq_attr *fattr = to_attr(attr);
949 down_read(&policy->rwsem);
950 ret = fattr->show(policy, buf);
951 up_read(&policy->rwsem);
956 static ssize_t store(struct kobject *kobj, struct attribute *attr,
957 const char *buf, size_t count)
959 struct cpufreq_policy *policy = to_policy(kobj);
960 struct freq_attr *fattr = to_attr(attr);
961 ssize_t ret = -EINVAL;
964 * cpus_read_trylock() is used here to work around a circular lock
965 * dependency problem with respect to the cpufreq_register_driver().
967 if (!cpus_read_trylock())
970 if (cpu_online(policy->cpu)) {
971 down_write(&policy->rwsem);
972 ret = fattr->store(policy, buf, count);
973 up_write(&policy->rwsem);
981 static void cpufreq_sysfs_release(struct kobject *kobj)
983 struct cpufreq_policy *policy = to_policy(kobj);
984 pr_debug("last reference is dropped\n");
985 complete(&policy->kobj_unregister);
988 static const struct sysfs_ops sysfs_ops = {
993 static struct kobj_type ktype_cpufreq = {
994 .sysfs_ops = &sysfs_ops,
995 .default_attrs = default_attrs,
996 .release = cpufreq_sysfs_release,
999 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
1001 struct device *dev = get_cpu_device(cpu);
1006 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1009 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1010 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1011 dev_err(dev, "cpufreq symlink creation failed\n");
1014 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1017 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1018 sysfs_remove_link(&dev->kobj, "cpufreq");
1021 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1023 struct freq_attr **drv_attr;
1026 /* set up files for this cpu device */
1027 drv_attr = cpufreq_driver->attr;
1028 while (drv_attr && *drv_attr) {
1029 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1034 if (cpufreq_driver->get) {
1035 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1040 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1044 if (cpufreq_driver->bios_limit) {
1045 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1053 __weak struct cpufreq_governor *cpufreq_default_governor(void)
1058 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1060 struct cpufreq_governor *gov = NULL, *def_gov = NULL;
1061 struct cpufreq_policy new_policy;
1063 memcpy(&new_policy, policy, sizeof(*policy));
1065 def_gov = cpufreq_default_governor();
1069 * Update governor of new_policy to the governor used before
1072 gov = find_governor(policy->last_governor);
1074 pr_debug("Restoring governor %s for cpu %d\n",
1075 policy->governor->name, policy->cpu);
1081 new_policy.governor = gov;
1083 /* Use the default policy if there is no last_policy. */
1084 if (policy->last_policy) {
1085 new_policy.policy = policy->last_policy;
1089 cpufreq_parse_policy(def_gov->name, &new_policy);
1093 return cpufreq_set_policy(policy, &new_policy);
1096 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1100 /* Has this CPU been taken care of already? */
1101 if (cpumask_test_cpu(cpu, policy->cpus))
1104 down_write(&policy->rwsem);
1106 cpufreq_stop_governor(policy);
1108 cpumask_set_cpu(cpu, policy->cpus);
1111 ret = cpufreq_start_governor(policy);
1113 pr_err("%s: Failed to start governor\n", __func__);
1115 up_write(&policy->rwsem);
1119 void refresh_frequency_limits(struct cpufreq_policy *policy)
1121 struct cpufreq_policy new_policy;
1123 if (!policy_is_inactive(policy)) {
1124 new_policy = *policy;
1125 pr_debug("updating policy for CPU %u\n", policy->cpu);
1127 new_policy.min = policy->user_policy.min;
1128 new_policy.max = policy->user_policy.max;
1129 cpufreq_set_policy(policy, &new_policy);
1132 EXPORT_SYMBOL(refresh_frequency_limits);
1134 static void handle_update(struct work_struct *work)
1136 struct cpufreq_policy *policy =
1137 container_of(work, struct cpufreq_policy, update);
1139 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1140 down_write(&policy->rwsem);
1141 refresh_frequency_limits(policy);
1142 up_write(&policy->rwsem);
1145 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1148 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1150 schedule_work(&policy->update);
1154 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1157 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1159 schedule_work(&policy->update);
1163 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1165 struct kobject *kobj;
1166 struct completion *cmp;
1168 down_write(&policy->rwsem);
1169 cpufreq_stats_free_table(policy);
1170 kobj = &policy->kobj;
1171 cmp = &policy->kobj_unregister;
1172 up_write(&policy->rwsem);
1176 * We need to make sure that the underlying kobj is
1177 * actually not referenced anymore by anybody before we
1178 * proceed with unloading.
1180 pr_debug("waiting for dropping of refcount\n");
1181 wait_for_completion(cmp);
1182 pr_debug("wait complete\n");
1185 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1187 struct cpufreq_policy *policy;
1188 struct device *dev = get_cpu_device(cpu);
1194 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1198 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1199 goto err_free_policy;
1201 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1202 goto err_free_cpumask;
1204 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1205 goto err_free_rcpumask;
1207 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1208 cpufreq_global_kobject, "policy%u", cpu);
1210 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1212 * The entire policy object will be freed below, but the extra
1213 * memory allocated for the kobject name needs to be freed by
1214 * releasing the kobject.
1216 kobject_put(&policy->kobj);
1217 goto err_free_real_cpus;
1220 policy->nb_min.notifier_call = cpufreq_notifier_min;
1221 policy->nb_max.notifier_call = cpufreq_notifier_max;
1223 ret = dev_pm_qos_add_notifier(dev, &policy->nb_min,
1224 DEV_PM_QOS_MIN_FREQUENCY);
1226 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1227 ret, cpumask_pr_args(policy->cpus));
1228 goto err_kobj_remove;
1231 ret = dev_pm_qos_add_notifier(dev, &policy->nb_max,
1232 DEV_PM_QOS_MAX_FREQUENCY);
1234 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1235 ret, cpumask_pr_args(policy->cpus));
1236 goto err_min_qos_notifier;
1239 INIT_LIST_HEAD(&policy->policy_list);
1240 init_rwsem(&policy->rwsem);
1241 spin_lock_init(&policy->transition_lock);
1242 init_waitqueue_head(&policy->transition_wait);
1243 init_completion(&policy->kobj_unregister);
1244 INIT_WORK(&policy->update, handle_update);
1249 err_min_qos_notifier:
1250 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1251 DEV_PM_QOS_MIN_FREQUENCY);
1253 cpufreq_policy_put_kobj(policy);
1255 free_cpumask_var(policy->real_cpus);
1257 free_cpumask_var(policy->related_cpus);
1259 free_cpumask_var(policy->cpus);
1266 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1268 struct device *dev = get_cpu_device(policy->cpu);
1269 unsigned long flags;
1272 /* Remove policy from list */
1273 write_lock_irqsave(&cpufreq_driver_lock, flags);
1274 list_del(&policy->policy_list);
1276 for_each_cpu(cpu, policy->related_cpus)
1277 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1278 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1280 dev_pm_qos_remove_notifier(dev, &policy->nb_max,
1281 DEV_PM_QOS_MAX_FREQUENCY);
1282 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1283 DEV_PM_QOS_MIN_FREQUENCY);
1285 cpufreq_policy_put_kobj(policy);
1286 free_cpumask_var(policy->real_cpus);
1287 free_cpumask_var(policy->related_cpus);
1288 free_cpumask_var(policy->cpus);
1292 static int cpufreq_online(unsigned int cpu)
1294 struct cpufreq_policy *policy;
1296 unsigned long flags;
1300 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1302 /* Check if this CPU already has a policy to manage it */
1303 policy = per_cpu(cpufreq_cpu_data, cpu);
1305 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1306 if (!policy_is_inactive(policy))
1307 return cpufreq_add_policy_cpu(policy, cpu);
1309 /* This is the only online CPU for the policy. Start over. */
1311 down_write(&policy->rwsem);
1313 policy->governor = NULL;
1314 up_write(&policy->rwsem);
1317 policy = cpufreq_policy_alloc(cpu);
1322 if (!new_policy && cpufreq_driver->online) {
1323 ret = cpufreq_driver->online(policy);
1325 pr_debug("%s: %d: initialization failed\n", __func__,
1327 goto out_exit_policy;
1330 /* Recover policy->cpus using related_cpus */
1331 cpumask_copy(policy->cpus, policy->related_cpus);
1333 cpumask_copy(policy->cpus, cpumask_of(cpu));
1336 * Call driver. From then on the cpufreq must be able
1337 * to accept all calls to ->verify and ->setpolicy for this CPU.
1339 ret = cpufreq_driver->init(policy);
1341 pr_debug("%s: %d: initialization failed\n", __func__,
1343 goto out_free_policy;
1346 ret = cpufreq_table_validate_and_sort(policy);
1348 goto out_exit_policy;
1350 /* related_cpus should at least include policy->cpus. */
1351 cpumask_copy(policy->related_cpus, policy->cpus);
1354 down_write(&policy->rwsem);
1356 * affected cpus must always be the one, which are online. We aren't
1357 * managing offline cpus here.
1359 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1362 policy->user_policy.min = policy->min;
1363 policy->user_policy.max = policy->max;
1365 for_each_cpu(j, policy->related_cpus) {
1366 per_cpu(cpufreq_cpu_data, j) = policy;
1367 add_cpu_dev_symlink(policy, j);
1370 policy->min = policy->user_policy.min;
1371 policy->max = policy->user_policy.max;
1374 if (cpufreq_driver->get && has_target()) {
1375 policy->cur = cpufreq_driver->get(policy->cpu);
1377 pr_err("%s: ->get() failed\n", __func__);
1378 goto out_destroy_policy;
1383 * Sometimes boot loaders set CPU frequency to a value outside of
1384 * frequency table present with cpufreq core. In such cases CPU might be
1385 * unstable if it has to run on that frequency for long duration of time
1386 * and so its better to set it to a frequency which is specified in
1387 * freq-table. This also makes cpufreq stats inconsistent as
1388 * cpufreq-stats would fail to register because current frequency of CPU
1389 * isn't found in freq-table.
1391 * Because we don't want this change to effect boot process badly, we go
1392 * for the next freq which is >= policy->cur ('cur' must be set by now,
1393 * otherwise we will end up setting freq to lowest of the table as 'cur'
1394 * is initialized to zero).
1396 * We are passing target-freq as "policy->cur - 1" otherwise
1397 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1398 * equal to target-freq.
1400 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1402 /* Are we running at unknown frequency ? */
1403 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1404 if (ret == -EINVAL) {
1405 /* Warn user and fix it */
1406 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1407 __func__, policy->cpu, policy->cur);
1408 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1409 CPUFREQ_RELATION_L);
1412 * Reaching here after boot in a few seconds may not
1413 * mean that system will remain stable at "unknown"
1414 * frequency for longer duration. Hence, a BUG_ON().
1417 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1418 __func__, policy->cpu, policy->cur);
1423 ret = cpufreq_add_dev_interface(policy);
1425 goto out_destroy_policy;
1427 cpufreq_stats_create_table(policy);
1429 write_lock_irqsave(&cpufreq_driver_lock, flags);
1430 list_add(&policy->policy_list, &cpufreq_policy_list);
1431 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1434 ret = cpufreq_init_policy(policy);
1436 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1437 __func__, cpu, ret);
1438 goto out_destroy_policy;
1441 up_write(&policy->rwsem);
1443 kobject_uevent(&policy->kobj, KOBJ_ADD);
1445 /* Callback for handling stuff after policy is ready */
1446 if (cpufreq_driver->ready)
1447 cpufreq_driver->ready(policy);
1449 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1450 policy->cdev = of_cpufreq_cooling_register(policy);
1452 pr_debug("initialization complete\n");
1457 for_each_cpu(j, policy->real_cpus)
1458 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1460 up_write(&policy->rwsem);
1463 if (cpufreq_driver->exit)
1464 cpufreq_driver->exit(policy);
1467 cpufreq_policy_free(policy);
1472 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1474 * @sif: Subsystem interface structure pointer (not used)
1476 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1478 struct cpufreq_policy *policy;
1479 unsigned cpu = dev->id;
1482 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1484 if (cpu_online(cpu)) {
1485 ret = cpufreq_online(cpu);
1490 /* Create sysfs link on CPU registration */
1491 policy = per_cpu(cpufreq_cpu_data, cpu);
1493 add_cpu_dev_symlink(policy, cpu);
1498 static int cpufreq_offline(unsigned int cpu)
1500 struct cpufreq_policy *policy;
1503 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1505 policy = cpufreq_cpu_get_raw(cpu);
1507 pr_debug("%s: No cpu_data found\n", __func__);
1511 down_write(&policy->rwsem);
1513 cpufreq_stop_governor(policy);
1515 cpumask_clear_cpu(cpu, policy->cpus);
1517 if (policy_is_inactive(policy)) {
1519 strncpy(policy->last_governor, policy->governor->name,
1522 policy->last_policy = policy->policy;
1523 } else if (cpu == policy->cpu) {
1524 /* Nominate new CPU */
1525 policy->cpu = cpumask_any(policy->cpus);
1528 /* Start governor again for active policy */
1529 if (!policy_is_inactive(policy)) {
1531 ret = cpufreq_start_governor(policy);
1533 pr_err("%s: Failed to start governor\n", __func__);
1539 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1540 cpufreq_cooling_unregister(policy->cdev);
1541 policy->cdev = NULL;
1544 if (cpufreq_driver->stop_cpu)
1545 cpufreq_driver->stop_cpu(policy);
1548 cpufreq_exit_governor(policy);
1551 * Perform the ->offline() during light-weight tear-down, as
1552 * that allows fast recovery when the CPU comes back.
1554 if (cpufreq_driver->offline) {
1555 cpufreq_driver->offline(policy);
1556 } else if (cpufreq_driver->exit) {
1557 cpufreq_driver->exit(policy);
1558 policy->freq_table = NULL;
1562 up_write(&policy->rwsem);
1567 * cpufreq_remove_dev - remove a CPU device
1569 * Removes the cpufreq interface for a CPU device.
1571 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1573 unsigned int cpu = dev->id;
1574 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1579 if (cpu_online(cpu))
1580 cpufreq_offline(cpu);
1582 cpumask_clear_cpu(cpu, policy->real_cpus);
1583 remove_cpu_dev_symlink(policy, dev);
1585 if (cpumask_empty(policy->real_cpus)) {
1586 /* We did light-weight exit earlier, do full tear down now */
1587 if (cpufreq_driver->offline)
1588 cpufreq_driver->exit(policy);
1590 cpufreq_policy_free(policy);
1595 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1597 * @policy: policy managing CPUs
1598 * @new_freq: CPU frequency the CPU actually runs at
1600 * We adjust to current frequency first, and need to clean up later.
1601 * So either call to cpufreq_update_policy() or schedule handle_update()).
1603 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1604 unsigned int new_freq)
1606 struct cpufreq_freqs freqs;
1608 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1609 policy->cur, new_freq);
1611 freqs.old = policy->cur;
1612 freqs.new = new_freq;
1614 cpufreq_freq_transition_begin(policy, &freqs);
1615 cpufreq_freq_transition_end(policy, &freqs, 0);
1618 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1620 unsigned int new_freq;
1622 new_freq = cpufreq_driver->get(policy->cpu);
1627 * If fast frequency switching is used with the given policy, the check
1628 * against policy->cur is pointless, so skip it in that case.
1630 if (policy->fast_switch_enabled || !has_target())
1633 if (policy->cur != new_freq) {
1634 cpufreq_out_of_sync(policy, new_freq);
1636 schedule_work(&policy->update);
1643 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1646 * This is the last known freq, without actually getting it from the driver.
1647 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1649 unsigned int cpufreq_quick_get(unsigned int cpu)
1651 struct cpufreq_policy *policy;
1652 unsigned int ret_freq = 0;
1653 unsigned long flags;
1655 read_lock_irqsave(&cpufreq_driver_lock, flags);
1657 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1658 ret_freq = cpufreq_driver->get(cpu);
1659 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1663 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1665 policy = cpufreq_cpu_get(cpu);
1667 ret_freq = policy->cur;
1668 cpufreq_cpu_put(policy);
1673 EXPORT_SYMBOL(cpufreq_quick_get);
1676 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1679 * Just return the max possible frequency for a given CPU.
1681 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1683 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1684 unsigned int ret_freq = 0;
1687 ret_freq = policy->max;
1688 cpufreq_cpu_put(policy);
1693 EXPORT_SYMBOL(cpufreq_quick_get_max);
1695 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1697 if (unlikely(policy_is_inactive(policy)))
1700 return cpufreq_verify_current_freq(policy, true);
1704 * cpufreq_get - get the current CPU frequency (in kHz)
1707 * Get the CPU current (static) CPU frequency
1709 unsigned int cpufreq_get(unsigned int cpu)
1711 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1712 unsigned int ret_freq = 0;
1715 down_read(&policy->rwsem);
1716 if (cpufreq_driver->get)
1717 ret_freq = __cpufreq_get(policy);
1718 up_read(&policy->rwsem);
1720 cpufreq_cpu_put(policy);
1725 EXPORT_SYMBOL(cpufreq_get);
1727 static struct subsys_interface cpufreq_interface = {
1729 .subsys = &cpu_subsys,
1730 .add_dev = cpufreq_add_dev,
1731 .remove_dev = cpufreq_remove_dev,
1735 * In case platform wants some specific frequency to be configured
1738 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1742 if (!policy->suspend_freq) {
1743 pr_debug("%s: suspend_freq not defined\n", __func__);
1747 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1748 policy->suspend_freq);
1750 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1751 CPUFREQ_RELATION_H);
1753 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1754 __func__, policy->suspend_freq, ret);
1758 EXPORT_SYMBOL(cpufreq_generic_suspend);
1761 * cpufreq_suspend() - Suspend CPUFreq governors
1763 * Called during system wide Suspend/Hibernate cycles for suspending governors
1764 * as some platforms can't change frequency after this point in suspend cycle.
1765 * Because some of the devices (like: i2c, regulators, etc) they use for
1766 * changing frequency are suspended quickly after this point.
1768 void cpufreq_suspend(void)
1770 struct cpufreq_policy *policy;
1772 if (!cpufreq_driver)
1775 if (!has_target() && !cpufreq_driver->suspend)
1778 pr_debug("%s: Suspending Governors\n", __func__);
1780 for_each_active_policy(policy) {
1782 down_write(&policy->rwsem);
1783 cpufreq_stop_governor(policy);
1784 up_write(&policy->rwsem);
1787 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1788 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1793 cpufreq_suspended = true;
1797 * cpufreq_resume() - Resume CPUFreq governors
1799 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1800 * are suspended with cpufreq_suspend().
1802 void cpufreq_resume(void)
1804 struct cpufreq_policy *policy;
1807 if (!cpufreq_driver)
1810 if (unlikely(!cpufreq_suspended))
1813 cpufreq_suspended = false;
1815 if (!has_target() && !cpufreq_driver->resume)
1818 pr_debug("%s: Resuming Governors\n", __func__);
1820 for_each_active_policy(policy) {
1821 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1822 pr_err("%s: Failed to resume driver: %p\n", __func__,
1824 } else if (has_target()) {
1825 down_write(&policy->rwsem);
1826 ret = cpufreq_start_governor(policy);
1827 up_write(&policy->rwsem);
1830 pr_err("%s: Failed to start governor for policy: %p\n",
1837 * cpufreq_get_current_driver - return current driver's name
1839 * Return the name string of the currently loaded cpufreq driver
1842 const char *cpufreq_get_current_driver(void)
1845 return cpufreq_driver->name;
1849 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1852 * cpufreq_get_driver_data - return current driver data
1854 * Return the private data of the currently loaded cpufreq
1855 * driver, or NULL if no cpufreq driver is loaded.
1857 void *cpufreq_get_driver_data(void)
1860 return cpufreq_driver->driver_data;
1864 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1866 /*********************************************************************
1867 * NOTIFIER LISTS INTERFACE *
1868 *********************************************************************/
1871 * cpufreq_register_notifier - register a driver with cpufreq
1872 * @nb: notifier function to register
1873 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1875 * Add a driver to one of two lists: either a list of drivers that
1876 * are notified about clock rate changes (once before and once after
1877 * the transition), or a list of drivers that are notified about
1878 * changes in cpufreq policy.
1880 * This function may sleep, and has the same return conditions as
1881 * blocking_notifier_chain_register.
1883 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1887 if (cpufreq_disabled())
1891 case CPUFREQ_TRANSITION_NOTIFIER:
1892 mutex_lock(&cpufreq_fast_switch_lock);
1894 if (cpufreq_fast_switch_count > 0) {
1895 mutex_unlock(&cpufreq_fast_switch_lock);
1898 ret = srcu_notifier_chain_register(
1899 &cpufreq_transition_notifier_list, nb);
1901 cpufreq_fast_switch_count--;
1903 mutex_unlock(&cpufreq_fast_switch_lock);
1905 case CPUFREQ_POLICY_NOTIFIER:
1906 ret = blocking_notifier_chain_register(
1907 &cpufreq_policy_notifier_list, nb);
1915 EXPORT_SYMBOL(cpufreq_register_notifier);
1918 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1919 * @nb: notifier block to be unregistered
1920 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1922 * Remove a driver from the CPU frequency notifier list.
1924 * This function may sleep, and has the same return conditions as
1925 * blocking_notifier_chain_unregister.
1927 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1931 if (cpufreq_disabled())
1935 case CPUFREQ_TRANSITION_NOTIFIER:
1936 mutex_lock(&cpufreq_fast_switch_lock);
1938 ret = srcu_notifier_chain_unregister(
1939 &cpufreq_transition_notifier_list, nb);
1940 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1941 cpufreq_fast_switch_count++;
1943 mutex_unlock(&cpufreq_fast_switch_lock);
1945 case CPUFREQ_POLICY_NOTIFIER:
1946 ret = blocking_notifier_chain_unregister(
1947 &cpufreq_policy_notifier_list, nb);
1955 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1958 /*********************************************************************
1960 *********************************************************************/
1963 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1964 * @policy: cpufreq policy to switch the frequency for.
1965 * @target_freq: New frequency to set (may be approximate).
1967 * Carry out a fast frequency switch without sleeping.
1969 * The driver's ->fast_switch() callback invoked by this function must be
1970 * suitable for being called from within RCU-sched read-side critical sections
1971 * and it is expected to select the minimum available frequency greater than or
1972 * equal to @target_freq (CPUFREQ_RELATION_L).
1974 * This function must not be called if policy->fast_switch_enabled is unset.
1976 * Governors calling this function must guarantee that it will never be invoked
1977 * twice in parallel for the same policy and that it will never be called in
1978 * parallel with either ->target() or ->target_index() for the same policy.
1980 * Returns the actual frequency set for the CPU.
1982 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
1983 * error condition, the hardware configuration must be preserved.
1985 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
1986 unsigned int target_freq)
1988 target_freq = clamp_val(target_freq, policy->min, policy->max);
1990 return cpufreq_driver->fast_switch(policy, target_freq);
1992 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
1994 /* Must set freqs->new to intermediate frequency */
1995 static int __target_intermediate(struct cpufreq_policy *policy,
1996 struct cpufreq_freqs *freqs, int index)
2000 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2002 /* We don't need to switch to intermediate freq */
2006 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2007 __func__, policy->cpu, freqs->old, freqs->new);
2009 cpufreq_freq_transition_begin(policy, freqs);
2010 ret = cpufreq_driver->target_intermediate(policy, index);
2011 cpufreq_freq_transition_end(policy, freqs, ret);
2014 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2020 static int __target_index(struct cpufreq_policy *policy, int index)
2022 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2023 unsigned int intermediate_freq = 0;
2024 unsigned int newfreq = policy->freq_table[index].frequency;
2025 int retval = -EINVAL;
2028 if (newfreq == policy->cur)
2031 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2033 /* Handle switching to intermediate frequency */
2034 if (cpufreq_driver->get_intermediate) {
2035 retval = __target_intermediate(policy, &freqs, index);
2039 intermediate_freq = freqs.new;
2040 /* Set old freq to intermediate */
2041 if (intermediate_freq)
2042 freqs.old = freqs.new;
2045 freqs.new = newfreq;
2046 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2047 __func__, policy->cpu, freqs.old, freqs.new);
2049 cpufreq_freq_transition_begin(policy, &freqs);
2052 retval = cpufreq_driver->target_index(policy, index);
2054 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2058 cpufreq_freq_transition_end(policy, &freqs, retval);
2061 * Failed after setting to intermediate freq? Driver should have
2062 * reverted back to initial frequency and so should we. Check
2063 * here for intermediate_freq instead of get_intermediate, in
2064 * case we haven't switched to intermediate freq at all.
2066 if (unlikely(retval && intermediate_freq)) {
2067 freqs.old = intermediate_freq;
2068 freqs.new = policy->restore_freq;
2069 cpufreq_freq_transition_begin(policy, &freqs);
2070 cpufreq_freq_transition_end(policy, &freqs, 0);
2077 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2078 unsigned int target_freq,
2079 unsigned int relation)
2081 unsigned int old_target_freq = target_freq;
2084 if (cpufreq_disabled())
2087 /* Make sure that target_freq is within supported range */
2088 target_freq = clamp_val(target_freq, policy->min, policy->max);
2090 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2091 policy->cpu, target_freq, relation, old_target_freq);
2094 * This might look like a redundant call as we are checking it again
2095 * after finding index. But it is left intentionally for cases where
2096 * exactly same freq is called again and so we can save on few function
2099 if (target_freq == policy->cur)
2102 /* Save last value to restore later on errors */
2103 policy->restore_freq = policy->cur;
2105 if (cpufreq_driver->target)
2106 return cpufreq_driver->target(policy, target_freq, relation);
2108 if (!cpufreq_driver->target_index)
2111 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2113 return __target_index(policy, index);
2115 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2117 int cpufreq_driver_target(struct cpufreq_policy *policy,
2118 unsigned int target_freq,
2119 unsigned int relation)
2123 down_write(&policy->rwsem);
2125 ret = __cpufreq_driver_target(policy, target_freq, relation);
2127 up_write(&policy->rwsem);
2131 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2133 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2138 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2142 /* Don't start any governor operations if we are entering suspend */
2143 if (cpufreq_suspended)
2146 * Governor might not be initiated here if ACPI _PPC changed
2147 * notification happened, so check it.
2149 if (!policy->governor)
2152 /* Platform doesn't want dynamic frequency switching ? */
2153 if (policy->governor->dynamic_switching &&
2154 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2155 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2158 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2159 policy->governor->name, gov->name);
2160 policy->governor = gov;
2166 if (!try_module_get(policy->governor->owner))
2169 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2171 if (policy->governor->init) {
2172 ret = policy->governor->init(policy);
2174 module_put(policy->governor->owner);
2182 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2184 if (cpufreq_suspended || !policy->governor)
2187 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2189 if (policy->governor->exit)
2190 policy->governor->exit(policy);
2192 module_put(policy->governor->owner);
2195 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2199 if (cpufreq_suspended)
2202 if (!policy->governor)
2205 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2207 if (cpufreq_driver->get)
2208 cpufreq_verify_current_freq(policy, false);
2210 if (policy->governor->start) {
2211 ret = policy->governor->start(policy);
2216 if (policy->governor->limits)
2217 policy->governor->limits(policy);
2222 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2224 if (cpufreq_suspended || !policy->governor)
2227 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2229 if (policy->governor->stop)
2230 policy->governor->stop(policy);
2233 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2235 if (cpufreq_suspended || !policy->governor)
2238 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2240 if (policy->governor->limits)
2241 policy->governor->limits(policy);
2244 int cpufreq_register_governor(struct cpufreq_governor *governor)
2251 if (cpufreq_disabled())
2254 mutex_lock(&cpufreq_governor_mutex);
2257 if (!find_governor(governor->name)) {
2259 list_add(&governor->governor_list, &cpufreq_governor_list);
2262 mutex_unlock(&cpufreq_governor_mutex);
2265 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2267 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2269 struct cpufreq_policy *policy;
2270 unsigned long flags;
2275 if (cpufreq_disabled())
2278 /* clear last_governor for all inactive policies */
2279 read_lock_irqsave(&cpufreq_driver_lock, flags);
2280 for_each_inactive_policy(policy) {
2281 if (!strcmp(policy->last_governor, governor->name)) {
2282 policy->governor = NULL;
2283 strcpy(policy->last_governor, "\0");
2286 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2288 mutex_lock(&cpufreq_governor_mutex);
2289 list_del(&governor->governor_list);
2290 mutex_unlock(&cpufreq_governor_mutex);
2292 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2295 /*********************************************************************
2296 * POLICY INTERFACE *
2297 *********************************************************************/
2300 * cpufreq_get_policy - get the current cpufreq_policy
2301 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2304 * Reads the current cpufreq policy.
2306 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2308 struct cpufreq_policy *cpu_policy;
2312 cpu_policy = cpufreq_cpu_get(cpu);
2316 memcpy(policy, cpu_policy, sizeof(*policy));
2318 cpufreq_cpu_put(cpu_policy);
2321 EXPORT_SYMBOL(cpufreq_get_policy);
2324 * cpufreq_set_policy - Modify cpufreq policy parameters.
2325 * @policy: Policy object to modify.
2326 * @new_policy: New policy data.
2328 * Pass @new_policy to the cpufreq driver's ->verify() callback, run the
2329 * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to
2330 * the driver's ->verify() callback again and run the notifiers for it again
2331 * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters
2332 * of @new_policy to @policy and either invoke the driver's ->setpolicy()
2333 * callback (if present) or carry out a governor update for @policy. That is,
2334 * run the current governor's ->limits() callback (if the governor field in
2335 * @new_policy points to the same object as the one in @policy) or replace the
2336 * governor for @policy with the new one stored in @new_policy.
2338 * The cpuinfo part of @policy is not updated by this function.
2340 int cpufreq_set_policy(struct cpufreq_policy *policy,
2341 struct cpufreq_policy *new_policy)
2343 struct cpufreq_governor *old_gov;
2344 struct device *cpu_dev = get_cpu_device(policy->cpu);
2345 unsigned long min, max;
2348 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2349 new_policy->cpu, new_policy->min, new_policy->max);
2351 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2354 * This check works well when we store new min/max freq attributes,
2355 * because new_policy is a copy of policy with one field updated.
2357 if (new_policy->min > new_policy->max)
2361 * PM QoS framework collects all the requests from users and provide us
2362 * the final aggregated value here.
2364 min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
2365 max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
2367 if (min > new_policy->min)
2368 new_policy->min = min;
2369 if (max < new_policy->max)
2370 new_policy->max = max;
2372 /* verify the cpu speed can be set within this limit */
2373 ret = cpufreq_driver->verify(new_policy);
2378 * The notifier-chain shall be removed once all the users of
2379 * CPUFREQ_ADJUST are moved to use the QoS framework.
2381 /* adjust if necessary - all reasons */
2382 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2383 CPUFREQ_ADJUST, new_policy);
2386 * verify the cpu speed can be set within this limit, which might be
2387 * different to the first one
2389 ret = cpufreq_driver->verify(new_policy);
2393 /* notification of the new policy */
2394 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2395 CPUFREQ_NOTIFY, new_policy);
2397 policy->min = new_policy->min;
2398 policy->max = new_policy->max;
2399 trace_cpu_frequency_limits(policy);
2401 policy->cached_target_freq = UINT_MAX;
2403 pr_debug("new min and max freqs are %u - %u kHz\n",
2404 policy->min, policy->max);
2406 if (cpufreq_driver->setpolicy) {
2407 policy->policy = new_policy->policy;
2408 pr_debug("setting range\n");
2409 return cpufreq_driver->setpolicy(policy);
2412 if (new_policy->governor == policy->governor) {
2413 pr_debug("governor limits update\n");
2414 cpufreq_governor_limits(policy);
2418 pr_debug("governor switch\n");
2420 /* save old, working values */
2421 old_gov = policy->governor;
2422 /* end old governor */
2424 cpufreq_stop_governor(policy);
2425 cpufreq_exit_governor(policy);
2428 /* start new governor */
2429 policy->governor = new_policy->governor;
2430 ret = cpufreq_init_governor(policy);
2432 ret = cpufreq_start_governor(policy);
2434 pr_debug("governor change\n");
2435 sched_cpufreq_governor_change(policy, old_gov);
2438 cpufreq_exit_governor(policy);
2441 /* new governor failed, so re-start old one */
2442 pr_debug("starting governor %s failed\n", policy->governor->name);
2444 policy->governor = old_gov;
2445 if (cpufreq_init_governor(policy))
2446 policy->governor = NULL;
2448 cpufreq_start_governor(policy);
2455 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2456 * @cpu: CPU to re-evaluate the policy for.
2458 * Update the current frequency for the cpufreq policy of @cpu and use
2459 * cpufreq_set_policy() to re-apply the min and max limits saved in the
2460 * user_policy sub-structure of that policy, which triggers the evaluation
2461 * of policy notifiers and the cpufreq driver's ->verify() callback for the
2462 * policy in question, among other things.
2464 void cpufreq_update_policy(unsigned int cpu)
2466 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2472 * BIOS might change freq behind our back
2473 * -> ask driver for current freq and notify governors about a change
2475 if (cpufreq_driver->get && has_target() &&
2476 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2479 refresh_frequency_limits(policy);
2482 cpufreq_cpu_release(policy);
2484 EXPORT_SYMBOL(cpufreq_update_policy);
2487 * cpufreq_update_limits - Update policy limits for a given CPU.
2488 * @cpu: CPU to update the policy limits for.
2490 * Invoke the driver's ->update_limits callback if present or call
2491 * cpufreq_update_policy() for @cpu.
2493 void cpufreq_update_limits(unsigned int cpu)
2495 if (cpufreq_driver->update_limits)
2496 cpufreq_driver->update_limits(cpu);
2498 cpufreq_update_policy(cpu);
2500 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2502 /*********************************************************************
2504 *********************************************************************/
2505 static int cpufreq_boost_set_sw(int state)
2507 struct cpufreq_policy *policy;
2510 for_each_active_policy(policy) {
2511 if (!policy->freq_table)
2514 ret = cpufreq_frequency_table_cpuinfo(policy,
2515 policy->freq_table);
2517 pr_err("%s: Policy frequency update failed\n",
2522 down_write(&policy->rwsem);
2523 policy->user_policy.max = policy->max;
2524 cpufreq_governor_limits(policy);
2525 up_write(&policy->rwsem);
2531 int cpufreq_boost_trigger_state(int state)
2533 unsigned long flags;
2536 if (cpufreq_driver->boost_enabled == state)
2539 write_lock_irqsave(&cpufreq_driver_lock, flags);
2540 cpufreq_driver->boost_enabled = state;
2541 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2543 ret = cpufreq_driver->set_boost(state);
2545 write_lock_irqsave(&cpufreq_driver_lock, flags);
2546 cpufreq_driver->boost_enabled = !state;
2547 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2549 pr_err("%s: Cannot %s BOOST\n",
2550 __func__, state ? "enable" : "disable");
2556 static bool cpufreq_boost_supported(void)
2558 return cpufreq_driver->set_boost;
2561 static int create_boost_sysfs_file(void)
2565 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2567 pr_err("%s: cannot register global BOOST sysfs file\n",
2573 static void remove_boost_sysfs_file(void)
2575 if (cpufreq_boost_supported())
2576 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2579 int cpufreq_enable_boost_support(void)
2581 if (!cpufreq_driver)
2584 if (cpufreq_boost_supported())
2587 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2589 /* This will get removed on driver unregister */
2590 return create_boost_sysfs_file();
2592 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2594 int cpufreq_boost_enabled(void)
2596 return cpufreq_driver->boost_enabled;
2598 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2600 /*********************************************************************
2601 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2602 *********************************************************************/
2603 static enum cpuhp_state hp_online;
2605 static int cpuhp_cpufreq_online(unsigned int cpu)
2607 cpufreq_online(cpu);
2612 static int cpuhp_cpufreq_offline(unsigned int cpu)
2614 cpufreq_offline(cpu);
2620 * cpufreq_register_driver - register a CPU Frequency driver
2621 * @driver_data: A struct cpufreq_driver containing the values#
2622 * submitted by the CPU Frequency driver.
2624 * Registers a CPU Frequency driver to this core code. This code
2625 * returns zero on success, -EEXIST when another driver got here first
2626 * (and isn't unregistered in the meantime).
2629 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2631 unsigned long flags;
2634 if (cpufreq_disabled())
2637 if (!driver_data || !driver_data->verify || !driver_data->init ||
2638 !(driver_data->setpolicy || driver_data->target_index ||
2639 driver_data->target) ||
2640 (driver_data->setpolicy && (driver_data->target_index ||
2641 driver_data->target)) ||
2642 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2643 (!driver_data->online != !driver_data->offline))
2646 pr_debug("trying to register driver %s\n", driver_data->name);
2648 /* Protect against concurrent CPU online/offline. */
2651 write_lock_irqsave(&cpufreq_driver_lock, flags);
2652 if (cpufreq_driver) {
2653 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2657 cpufreq_driver = driver_data;
2658 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2660 if (driver_data->setpolicy)
2661 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2663 if (cpufreq_boost_supported()) {
2664 ret = create_boost_sysfs_file();
2666 goto err_null_driver;
2669 ret = subsys_interface_register(&cpufreq_interface);
2671 goto err_boost_unreg;
2673 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2674 list_empty(&cpufreq_policy_list)) {
2675 /* if all ->init() calls failed, unregister */
2677 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2682 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2684 cpuhp_cpufreq_online,
2685 cpuhp_cpufreq_offline);
2691 pr_debug("driver %s up and running\n", driver_data->name);
2695 subsys_interface_unregister(&cpufreq_interface);
2697 remove_boost_sysfs_file();
2699 write_lock_irqsave(&cpufreq_driver_lock, flags);
2700 cpufreq_driver = NULL;
2701 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2706 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2709 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2711 * Unregister the current CPUFreq driver. Only call this if you have
2712 * the right to do so, i.e. if you have succeeded in initialising before!
2713 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2714 * currently not initialised.
2716 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2718 unsigned long flags;
2720 if (!cpufreq_driver || (driver != cpufreq_driver))
2723 pr_debug("unregistering driver %s\n", driver->name);
2725 /* Protect against concurrent cpu hotplug */
2727 subsys_interface_unregister(&cpufreq_interface);
2728 remove_boost_sysfs_file();
2729 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2731 write_lock_irqsave(&cpufreq_driver_lock, flags);
2733 cpufreq_driver = NULL;
2735 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2740 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2743 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2744 * or mutexes when secondary CPUs are halted.
2746 static struct syscore_ops cpufreq_syscore_ops = {
2747 .shutdown = cpufreq_suspend,
2750 struct kobject *cpufreq_global_kobject;
2751 EXPORT_SYMBOL(cpufreq_global_kobject);
2753 static int __init cpufreq_core_init(void)
2755 if (cpufreq_disabled())
2758 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2759 BUG_ON(!cpufreq_global_kobject);
2761 register_syscore_ops(&cpufreq_syscore_ops);
2765 module_param(off, int, 0444);
2766 core_initcall(cpufreq_core_init);