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) \
724 ret = sscanf(buf, "%lu", &val); \
728 ret = dev_pm_qos_update_request(policy->object##_freq_req, val);\
729 return ret >= 0 ? count : ret; \
732 store_one(scaling_min_freq, min);
733 store_one(scaling_max_freq, max);
736 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
738 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
741 unsigned int cur_freq = __cpufreq_get(policy);
744 return sprintf(buf, "%u\n", cur_freq);
746 return sprintf(buf, "<unknown>\n");
750 * show_scaling_governor - show the current policy for the specified CPU
752 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
754 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
755 return sprintf(buf, "powersave\n");
756 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
757 return sprintf(buf, "performance\n");
758 else if (policy->governor)
759 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
760 policy->governor->name);
765 * store_scaling_governor - store policy for the specified CPU
767 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
768 const char *buf, size_t count)
771 char str_governor[16];
772 struct cpufreq_policy new_policy;
774 memcpy(&new_policy, policy, sizeof(*policy));
776 ret = sscanf(buf, "%15s", str_governor);
780 if (cpufreq_driver->setpolicy) {
781 if (cpufreq_parse_policy(str_governor, &new_policy))
784 if (cpufreq_parse_governor(str_governor, &new_policy))
788 ret = cpufreq_set_policy(policy, &new_policy);
790 if (new_policy.governor)
791 module_put(new_policy.governor->owner);
793 return ret ? ret : count;
797 * show_scaling_driver - show the cpufreq driver currently loaded
799 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
801 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
805 * show_scaling_available_governors - show the available CPUfreq governors
807 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
811 struct cpufreq_governor *t;
814 i += sprintf(buf, "performance powersave");
818 for_each_governor(t) {
819 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
820 - (CPUFREQ_NAME_LEN + 2)))
822 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
825 i += sprintf(&buf[i], "\n");
829 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
834 for_each_cpu(cpu, mask) {
836 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
837 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
838 if (i >= (PAGE_SIZE - 5))
841 i += sprintf(&buf[i], "\n");
844 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
847 * show_related_cpus - show the CPUs affected by each transition even if
848 * hw coordination is in use
850 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
852 return cpufreq_show_cpus(policy->related_cpus, buf);
856 * show_affected_cpus - show the CPUs affected by each transition
858 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
860 return cpufreq_show_cpus(policy->cpus, buf);
863 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
864 const char *buf, size_t count)
866 unsigned int freq = 0;
869 if (!policy->governor || !policy->governor->store_setspeed)
872 ret = sscanf(buf, "%u", &freq);
876 policy->governor->store_setspeed(policy, freq);
881 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
883 if (!policy->governor || !policy->governor->show_setspeed)
884 return sprintf(buf, "<unsupported>\n");
886 return policy->governor->show_setspeed(policy, buf);
890 * show_bios_limit - show the current cpufreq HW/BIOS limitation
892 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
896 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
898 return sprintf(buf, "%u\n", limit);
899 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
902 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
903 cpufreq_freq_attr_ro(cpuinfo_min_freq);
904 cpufreq_freq_attr_ro(cpuinfo_max_freq);
905 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
906 cpufreq_freq_attr_ro(scaling_available_governors);
907 cpufreq_freq_attr_ro(scaling_driver);
908 cpufreq_freq_attr_ro(scaling_cur_freq);
909 cpufreq_freq_attr_ro(bios_limit);
910 cpufreq_freq_attr_ro(related_cpus);
911 cpufreq_freq_attr_ro(affected_cpus);
912 cpufreq_freq_attr_rw(scaling_min_freq);
913 cpufreq_freq_attr_rw(scaling_max_freq);
914 cpufreq_freq_attr_rw(scaling_governor);
915 cpufreq_freq_attr_rw(scaling_setspeed);
917 static struct attribute *default_attrs[] = {
918 &cpuinfo_min_freq.attr,
919 &cpuinfo_max_freq.attr,
920 &cpuinfo_transition_latency.attr,
921 &scaling_min_freq.attr,
922 &scaling_max_freq.attr,
925 &scaling_governor.attr,
926 &scaling_driver.attr,
927 &scaling_available_governors.attr,
928 &scaling_setspeed.attr,
932 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
933 #define to_attr(a) container_of(a, struct freq_attr, attr)
935 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
937 struct cpufreq_policy *policy = to_policy(kobj);
938 struct freq_attr *fattr = to_attr(attr);
941 down_read(&policy->rwsem);
942 ret = fattr->show(policy, buf);
943 up_read(&policy->rwsem);
948 static ssize_t store(struct kobject *kobj, struct attribute *attr,
949 const char *buf, size_t count)
951 struct cpufreq_policy *policy = to_policy(kobj);
952 struct freq_attr *fattr = to_attr(attr);
953 ssize_t ret = -EINVAL;
956 * cpus_read_trylock() is used here to work around a circular lock
957 * dependency problem with respect to the cpufreq_register_driver().
959 if (!cpus_read_trylock())
962 if (cpu_online(policy->cpu)) {
963 down_write(&policy->rwsem);
964 ret = fattr->store(policy, buf, count);
965 up_write(&policy->rwsem);
973 static void cpufreq_sysfs_release(struct kobject *kobj)
975 struct cpufreq_policy *policy = to_policy(kobj);
976 pr_debug("last reference is dropped\n");
977 complete(&policy->kobj_unregister);
980 static const struct sysfs_ops sysfs_ops = {
985 static struct kobj_type ktype_cpufreq = {
986 .sysfs_ops = &sysfs_ops,
987 .default_attrs = default_attrs,
988 .release = cpufreq_sysfs_release,
991 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
993 struct device *dev = get_cpu_device(cpu);
998 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1001 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1002 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1003 dev_err(dev, "cpufreq symlink creation failed\n");
1006 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1009 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1010 sysfs_remove_link(&dev->kobj, "cpufreq");
1013 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1015 struct freq_attr **drv_attr;
1018 /* set up files for this cpu device */
1019 drv_attr = cpufreq_driver->attr;
1020 while (drv_attr && *drv_attr) {
1021 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1026 if (cpufreq_driver->get) {
1027 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1032 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1036 if (cpufreq_driver->bios_limit) {
1037 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1045 __weak struct cpufreq_governor *cpufreq_default_governor(void)
1050 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1052 struct cpufreq_governor *gov = NULL, *def_gov = NULL;
1053 struct cpufreq_policy new_policy;
1055 memcpy(&new_policy, policy, sizeof(*policy));
1057 def_gov = cpufreq_default_governor();
1061 * Update governor of new_policy to the governor used before
1064 gov = find_governor(policy->last_governor);
1066 pr_debug("Restoring governor %s for cpu %d\n",
1067 policy->governor->name, policy->cpu);
1073 new_policy.governor = gov;
1075 /* Use the default policy if there is no last_policy. */
1076 if (policy->last_policy) {
1077 new_policy.policy = policy->last_policy;
1081 cpufreq_parse_policy(def_gov->name, &new_policy);
1085 return cpufreq_set_policy(policy, &new_policy);
1088 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1092 /* Has this CPU been taken care of already? */
1093 if (cpumask_test_cpu(cpu, policy->cpus))
1096 down_write(&policy->rwsem);
1098 cpufreq_stop_governor(policy);
1100 cpumask_set_cpu(cpu, policy->cpus);
1103 ret = cpufreq_start_governor(policy);
1105 pr_err("%s: Failed to start governor\n", __func__);
1107 up_write(&policy->rwsem);
1111 void refresh_frequency_limits(struct cpufreq_policy *policy)
1113 struct cpufreq_policy new_policy;
1115 if (!policy_is_inactive(policy)) {
1116 new_policy = *policy;
1117 pr_debug("updating policy for CPU %u\n", policy->cpu);
1119 cpufreq_set_policy(policy, &new_policy);
1122 EXPORT_SYMBOL(refresh_frequency_limits);
1124 static void handle_update(struct work_struct *work)
1126 struct cpufreq_policy *policy =
1127 container_of(work, struct cpufreq_policy, update);
1129 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1130 down_write(&policy->rwsem);
1131 refresh_frequency_limits(policy);
1132 up_write(&policy->rwsem);
1135 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1138 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1140 schedule_work(&policy->update);
1144 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1147 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1149 schedule_work(&policy->update);
1153 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1155 struct kobject *kobj;
1156 struct completion *cmp;
1158 down_write(&policy->rwsem);
1159 cpufreq_stats_free_table(policy);
1160 kobj = &policy->kobj;
1161 cmp = &policy->kobj_unregister;
1162 up_write(&policy->rwsem);
1166 * We need to make sure that the underlying kobj is
1167 * actually not referenced anymore by anybody before we
1168 * proceed with unloading.
1170 pr_debug("waiting for dropping of refcount\n");
1171 wait_for_completion(cmp);
1172 pr_debug("wait complete\n");
1175 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1177 struct cpufreq_policy *policy;
1178 struct device *dev = get_cpu_device(cpu);
1184 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1188 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1189 goto err_free_policy;
1191 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1192 goto err_free_cpumask;
1194 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1195 goto err_free_rcpumask;
1197 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1198 cpufreq_global_kobject, "policy%u", cpu);
1200 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1202 * The entire policy object will be freed below, but the extra
1203 * memory allocated for the kobject name needs to be freed by
1204 * releasing the kobject.
1206 kobject_put(&policy->kobj);
1207 goto err_free_real_cpus;
1210 policy->nb_min.notifier_call = cpufreq_notifier_min;
1211 policy->nb_max.notifier_call = cpufreq_notifier_max;
1213 ret = dev_pm_qos_add_notifier(dev, &policy->nb_min,
1214 DEV_PM_QOS_MIN_FREQUENCY);
1216 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1217 ret, cpumask_pr_args(policy->cpus));
1218 goto err_kobj_remove;
1221 ret = dev_pm_qos_add_notifier(dev, &policy->nb_max,
1222 DEV_PM_QOS_MAX_FREQUENCY);
1224 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1225 ret, cpumask_pr_args(policy->cpus));
1226 goto err_min_qos_notifier;
1229 INIT_LIST_HEAD(&policy->policy_list);
1230 init_rwsem(&policy->rwsem);
1231 spin_lock_init(&policy->transition_lock);
1232 init_waitqueue_head(&policy->transition_wait);
1233 init_completion(&policy->kobj_unregister);
1234 INIT_WORK(&policy->update, handle_update);
1239 err_min_qos_notifier:
1240 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1241 DEV_PM_QOS_MIN_FREQUENCY);
1243 cpufreq_policy_put_kobj(policy);
1245 free_cpumask_var(policy->real_cpus);
1247 free_cpumask_var(policy->related_cpus);
1249 free_cpumask_var(policy->cpus);
1256 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1258 struct device *dev = get_cpu_device(policy->cpu);
1259 unsigned long flags;
1262 /* Remove policy from list */
1263 write_lock_irqsave(&cpufreq_driver_lock, flags);
1264 list_del(&policy->policy_list);
1266 for_each_cpu(cpu, policy->related_cpus)
1267 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1268 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1270 dev_pm_qos_remove_notifier(dev, &policy->nb_max,
1271 DEV_PM_QOS_MAX_FREQUENCY);
1272 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1273 DEV_PM_QOS_MIN_FREQUENCY);
1274 dev_pm_qos_remove_request(policy->max_freq_req);
1275 dev_pm_qos_remove_request(policy->min_freq_req);
1276 kfree(policy->min_freq_req);
1278 cpufreq_policy_put_kobj(policy);
1279 free_cpumask_var(policy->real_cpus);
1280 free_cpumask_var(policy->related_cpus);
1281 free_cpumask_var(policy->cpus);
1285 static int cpufreq_online(unsigned int cpu)
1287 struct cpufreq_policy *policy;
1289 unsigned long flags;
1293 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1295 /* Check if this CPU already has a policy to manage it */
1296 policy = per_cpu(cpufreq_cpu_data, cpu);
1298 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1299 if (!policy_is_inactive(policy))
1300 return cpufreq_add_policy_cpu(policy, cpu);
1302 /* This is the only online CPU for the policy. Start over. */
1304 down_write(&policy->rwsem);
1306 policy->governor = NULL;
1307 up_write(&policy->rwsem);
1310 policy = cpufreq_policy_alloc(cpu);
1315 if (!new_policy && cpufreq_driver->online) {
1316 ret = cpufreq_driver->online(policy);
1318 pr_debug("%s: %d: initialization failed\n", __func__,
1320 goto out_exit_policy;
1323 /* Recover policy->cpus using related_cpus */
1324 cpumask_copy(policy->cpus, policy->related_cpus);
1326 cpumask_copy(policy->cpus, cpumask_of(cpu));
1329 * Call driver. From then on the cpufreq must be able
1330 * to accept all calls to ->verify and ->setpolicy for this CPU.
1332 ret = cpufreq_driver->init(policy);
1334 pr_debug("%s: %d: initialization failed\n", __func__,
1336 goto out_free_policy;
1339 ret = cpufreq_table_validate_and_sort(policy);
1341 goto out_exit_policy;
1343 /* related_cpus should at least include policy->cpus. */
1344 cpumask_copy(policy->related_cpus, policy->cpus);
1347 down_write(&policy->rwsem);
1349 * affected cpus must always be the one, which are online. We aren't
1350 * managing offline cpus here.
1352 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1355 struct device *dev = get_cpu_device(cpu);
1357 for_each_cpu(j, policy->related_cpus) {
1358 per_cpu(cpufreq_cpu_data, j) = policy;
1359 add_cpu_dev_symlink(policy, j);
1362 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1364 if (!policy->min_freq_req)
1365 goto out_destroy_policy;
1367 ret = dev_pm_qos_add_request(dev, policy->min_freq_req,
1368 DEV_PM_QOS_MIN_FREQUENCY,
1372 * So we don't call dev_pm_qos_remove_request() for an
1373 * uninitialized request.
1375 kfree(policy->min_freq_req);
1376 policy->min_freq_req = NULL;
1378 dev_err(dev, "Failed to add min-freq constraint (%d)\n",
1380 goto out_destroy_policy;
1384 * This must be initialized right here to avoid calling
1385 * dev_pm_qos_remove_request() on uninitialized request in case
1388 policy->max_freq_req = policy->min_freq_req + 1;
1390 ret = dev_pm_qos_add_request(dev, policy->max_freq_req,
1391 DEV_PM_QOS_MAX_FREQUENCY,
1394 policy->max_freq_req = NULL;
1395 dev_err(dev, "Failed to add max-freq constraint (%d)\n",
1397 goto out_destroy_policy;
1401 if (cpufreq_driver->get && has_target()) {
1402 policy->cur = cpufreq_driver->get(policy->cpu);
1404 pr_err("%s: ->get() failed\n", __func__);
1405 goto out_destroy_policy;
1410 * Sometimes boot loaders set CPU frequency to a value outside of
1411 * frequency table present with cpufreq core. In such cases CPU might be
1412 * unstable if it has to run on that frequency for long duration of time
1413 * and so its better to set it to a frequency which is specified in
1414 * freq-table. This also makes cpufreq stats inconsistent as
1415 * cpufreq-stats would fail to register because current frequency of CPU
1416 * isn't found in freq-table.
1418 * Because we don't want this change to effect boot process badly, we go
1419 * for the next freq which is >= policy->cur ('cur' must be set by now,
1420 * otherwise we will end up setting freq to lowest of the table as 'cur'
1421 * is initialized to zero).
1423 * We are passing target-freq as "policy->cur - 1" otherwise
1424 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1425 * equal to target-freq.
1427 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1429 /* Are we running at unknown frequency ? */
1430 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1431 if (ret == -EINVAL) {
1432 /* Warn user and fix it */
1433 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1434 __func__, policy->cpu, policy->cur);
1435 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1436 CPUFREQ_RELATION_L);
1439 * Reaching here after boot in a few seconds may not
1440 * mean that system will remain stable at "unknown"
1441 * frequency for longer duration. Hence, a BUG_ON().
1444 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1445 __func__, policy->cpu, policy->cur);
1450 ret = cpufreq_add_dev_interface(policy);
1452 goto out_destroy_policy;
1454 cpufreq_stats_create_table(policy);
1456 write_lock_irqsave(&cpufreq_driver_lock, flags);
1457 list_add(&policy->policy_list, &cpufreq_policy_list);
1458 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1461 ret = cpufreq_init_policy(policy);
1463 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1464 __func__, cpu, ret);
1465 goto out_destroy_policy;
1468 up_write(&policy->rwsem);
1470 kobject_uevent(&policy->kobj, KOBJ_ADD);
1472 /* Callback for handling stuff after policy is ready */
1473 if (cpufreq_driver->ready)
1474 cpufreq_driver->ready(policy);
1476 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1477 policy->cdev = of_cpufreq_cooling_register(policy);
1479 pr_debug("initialization complete\n");
1484 for_each_cpu(j, policy->real_cpus)
1485 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1487 up_write(&policy->rwsem);
1490 if (cpufreq_driver->exit)
1491 cpufreq_driver->exit(policy);
1494 cpufreq_policy_free(policy);
1499 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1501 * @sif: Subsystem interface structure pointer (not used)
1503 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1505 struct cpufreq_policy *policy;
1506 unsigned cpu = dev->id;
1509 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1511 if (cpu_online(cpu)) {
1512 ret = cpufreq_online(cpu);
1517 /* Create sysfs link on CPU registration */
1518 policy = per_cpu(cpufreq_cpu_data, cpu);
1520 add_cpu_dev_symlink(policy, cpu);
1525 static int cpufreq_offline(unsigned int cpu)
1527 struct cpufreq_policy *policy;
1530 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1532 policy = cpufreq_cpu_get_raw(cpu);
1534 pr_debug("%s: No cpu_data found\n", __func__);
1538 down_write(&policy->rwsem);
1540 cpufreq_stop_governor(policy);
1542 cpumask_clear_cpu(cpu, policy->cpus);
1544 if (policy_is_inactive(policy)) {
1546 strncpy(policy->last_governor, policy->governor->name,
1549 policy->last_policy = policy->policy;
1550 } else if (cpu == policy->cpu) {
1551 /* Nominate new CPU */
1552 policy->cpu = cpumask_any(policy->cpus);
1555 /* Start governor again for active policy */
1556 if (!policy_is_inactive(policy)) {
1558 ret = cpufreq_start_governor(policy);
1560 pr_err("%s: Failed to start governor\n", __func__);
1566 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1567 cpufreq_cooling_unregister(policy->cdev);
1568 policy->cdev = NULL;
1571 if (cpufreq_driver->stop_cpu)
1572 cpufreq_driver->stop_cpu(policy);
1575 cpufreq_exit_governor(policy);
1578 * Perform the ->offline() during light-weight tear-down, as
1579 * that allows fast recovery when the CPU comes back.
1581 if (cpufreq_driver->offline) {
1582 cpufreq_driver->offline(policy);
1583 } else if (cpufreq_driver->exit) {
1584 cpufreq_driver->exit(policy);
1585 policy->freq_table = NULL;
1589 up_write(&policy->rwsem);
1594 * cpufreq_remove_dev - remove a CPU device
1596 * Removes the cpufreq interface for a CPU device.
1598 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1600 unsigned int cpu = dev->id;
1601 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1606 if (cpu_online(cpu))
1607 cpufreq_offline(cpu);
1609 cpumask_clear_cpu(cpu, policy->real_cpus);
1610 remove_cpu_dev_symlink(policy, dev);
1612 if (cpumask_empty(policy->real_cpus)) {
1613 /* We did light-weight exit earlier, do full tear down now */
1614 if (cpufreq_driver->offline)
1615 cpufreq_driver->exit(policy);
1617 cpufreq_policy_free(policy);
1622 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1624 * @policy: policy managing CPUs
1625 * @new_freq: CPU frequency the CPU actually runs at
1627 * We adjust to current frequency first, and need to clean up later.
1628 * So either call to cpufreq_update_policy() or schedule handle_update()).
1630 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1631 unsigned int new_freq)
1633 struct cpufreq_freqs freqs;
1635 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1636 policy->cur, new_freq);
1638 freqs.old = policy->cur;
1639 freqs.new = new_freq;
1641 cpufreq_freq_transition_begin(policy, &freqs);
1642 cpufreq_freq_transition_end(policy, &freqs, 0);
1645 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1647 unsigned int new_freq;
1649 new_freq = cpufreq_driver->get(policy->cpu);
1654 * If fast frequency switching is used with the given policy, the check
1655 * against policy->cur is pointless, so skip it in that case.
1657 if (policy->fast_switch_enabled || !has_target())
1660 if (policy->cur != new_freq) {
1661 cpufreq_out_of_sync(policy, new_freq);
1663 schedule_work(&policy->update);
1670 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1673 * This is the last known freq, without actually getting it from the driver.
1674 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1676 unsigned int cpufreq_quick_get(unsigned int cpu)
1678 struct cpufreq_policy *policy;
1679 unsigned int ret_freq = 0;
1680 unsigned long flags;
1682 read_lock_irqsave(&cpufreq_driver_lock, flags);
1684 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1685 ret_freq = cpufreq_driver->get(cpu);
1686 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1690 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1692 policy = cpufreq_cpu_get(cpu);
1694 ret_freq = policy->cur;
1695 cpufreq_cpu_put(policy);
1700 EXPORT_SYMBOL(cpufreq_quick_get);
1703 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1706 * Just return the max possible frequency for a given CPU.
1708 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1710 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1711 unsigned int ret_freq = 0;
1714 ret_freq = policy->max;
1715 cpufreq_cpu_put(policy);
1720 EXPORT_SYMBOL(cpufreq_quick_get_max);
1722 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1724 if (unlikely(policy_is_inactive(policy)))
1727 return cpufreq_verify_current_freq(policy, true);
1731 * cpufreq_get - get the current CPU frequency (in kHz)
1734 * Get the CPU current (static) CPU frequency
1736 unsigned int cpufreq_get(unsigned int cpu)
1738 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1739 unsigned int ret_freq = 0;
1742 down_read(&policy->rwsem);
1743 if (cpufreq_driver->get)
1744 ret_freq = __cpufreq_get(policy);
1745 up_read(&policy->rwsem);
1747 cpufreq_cpu_put(policy);
1752 EXPORT_SYMBOL(cpufreq_get);
1754 static struct subsys_interface cpufreq_interface = {
1756 .subsys = &cpu_subsys,
1757 .add_dev = cpufreq_add_dev,
1758 .remove_dev = cpufreq_remove_dev,
1762 * In case platform wants some specific frequency to be configured
1765 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1769 if (!policy->suspend_freq) {
1770 pr_debug("%s: suspend_freq not defined\n", __func__);
1774 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1775 policy->suspend_freq);
1777 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1778 CPUFREQ_RELATION_H);
1780 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1781 __func__, policy->suspend_freq, ret);
1785 EXPORT_SYMBOL(cpufreq_generic_suspend);
1788 * cpufreq_suspend() - Suspend CPUFreq governors
1790 * Called during system wide Suspend/Hibernate cycles for suspending governors
1791 * as some platforms can't change frequency after this point in suspend cycle.
1792 * Because some of the devices (like: i2c, regulators, etc) they use for
1793 * changing frequency are suspended quickly after this point.
1795 void cpufreq_suspend(void)
1797 struct cpufreq_policy *policy;
1799 if (!cpufreq_driver)
1802 if (!has_target() && !cpufreq_driver->suspend)
1805 pr_debug("%s: Suspending Governors\n", __func__);
1807 for_each_active_policy(policy) {
1809 down_write(&policy->rwsem);
1810 cpufreq_stop_governor(policy);
1811 up_write(&policy->rwsem);
1814 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1815 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1820 cpufreq_suspended = true;
1824 * cpufreq_resume() - Resume CPUFreq governors
1826 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1827 * are suspended with cpufreq_suspend().
1829 void cpufreq_resume(void)
1831 struct cpufreq_policy *policy;
1834 if (!cpufreq_driver)
1837 if (unlikely(!cpufreq_suspended))
1840 cpufreq_suspended = false;
1842 if (!has_target() && !cpufreq_driver->resume)
1845 pr_debug("%s: Resuming Governors\n", __func__);
1847 for_each_active_policy(policy) {
1848 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1849 pr_err("%s: Failed to resume driver: %p\n", __func__,
1851 } else if (has_target()) {
1852 down_write(&policy->rwsem);
1853 ret = cpufreq_start_governor(policy);
1854 up_write(&policy->rwsem);
1857 pr_err("%s: Failed to start governor for policy: %p\n",
1864 * cpufreq_get_current_driver - return current driver's name
1866 * Return the name string of the currently loaded cpufreq driver
1869 const char *cpufreq_get_current_driver(void)
1872 return cpufreq_driver->name;
1876 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1879 * cpufreq_get_driver_data - return current driver data
1881 * Return the private data of the currently loaded cpufreq
1882 * driver, or NULL if no cpufreq driver is loaded.
1884 void *cpufreq_get_driver_data(void)
1887 return cpufreq_driver->driver_data;
1891 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1893 /*********************************************************************
1894 * NOTIFIER LISTS INTERFACE *
1895 *********************************************************************/
1898 * cpufreq_register_notifier - register a driver with cpufreq
1899 * @nb: notifier function to register
1900 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1902 * Add a driver to one of two lists: either a list of drivers that
1903 * are notified about clock rate changes (once before and once after
1904 * the transition), or a list of drivers that are notified about
1905 * changes in cpufreq policy.
1907 * This function may sleep, and has the same return conditions as
1908 * blocking_notifier_chain_register.
1910 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1914 if (cpufreq_disabled())
1918 case CPUFREQ_TRANSITION_NOTIFIER:
1919 mutex_lock(&cpufreq_fast_switch_lock);
1921 if (cpufreq_fast_switch_count > 0) {
1922 mutex_unlock(&cpufreq_fast_switch_lock);
1925 ret = srcu_notifier_chain_register(
1926 &cpufreq_transition_notifier_list, nb);
1928 cpufreq_fast_switch_count--;
1930 mutex_unlock(&cpufreq_fast_switch_lock);
1932 case CPUFREQ_POLICY_NOTIFIER:
1933 ret = blocking_notifier_chain_register(
1934 &cpufreq_policy_notifier_list, nb);
1942 EXPORT_SYMBOL(cpufreq_register_notifier);
1945 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1946 * @nb: notifier block to be unregistered
1947 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1949 * Remove a driver from the CPU frequency notifier list.
1951 * This function may sleep, and has the same return conditions as
1952 * blocking_notifier_chain_unregister.
1954 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1958 if (cpufreq_disabled())
1962 case CPUFREQ_TRANSITION_NOTIFIER:
1963 mutex_lock(&cpufreq_fast_switch_lock);
1965 ret = srcu_notifier_chain_unregister(
1966 &cpufreq_transition_notifier_list, nb);
1967 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1968 cpufreq_fast_switch_count++;
1970 mutex_unlock(&cpufreq_fast_switch_lock);
1972 case CPUFREQ_POLICY_NOTIFIER:
1973 ret = blocking_notifier_chain_unregister(
1974 &cpufreq_policy_notifier_list, nb);
1982 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1985 /*********************************************************************
1987 *********************************************************************/
1990 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1991 * @policy: cpufreq policy to switch the frequency for.
1992 * @target_freq: New frequency to set (may be approximate).
1994 * Carry out a fast frequency switch without sleeping.
1996 * The driver's ->fast_switch() callback invoked by this function must be
1997 * suitable for being called from within RCU-sched read-side critical sections
1998 * and it is expected to select the minimum available frequency greater than or
1999 * equal to @target_freq (CPUFREQ_RELATION_L).
2001 * This function must not be called if policy->fast_switch_enabled is unset.
2003 * Governors calling this function must guarantee that it will never be invoked
2004 * twice in parallel for the same policy and that it will never be called in
2005 * parallel with either ->target() or ->target_index() for the same policy.
2007 * Returns the actual frequency set for the CPU.
2009 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2010 * error condition, the hardware configuration must be preserved.
2012 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2013 unsigned int target_freq)
2015 target_freq = clamp_val(target_freq, policy->min, policy->max);
2017 return cpufreq_driver->fast_switch(policy, target_freq);
2019 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2021 /* Must set freqs->new to intermediate frequency */
2022 static int __target_intermediate(struct cpufreq_policy *policy,
2023 struct cpufreq_freqs *freqs, int index)
2027 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2029 /* We don't need to switch to intermediate freq */
2033 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2034 __func__, policy->cpu, freqs->old, freqs->new);
2036 cpufreq_freq_transition_begin(policy, freqs);
2037 ret = cpufreq_driver->target_intermediate(policy, index);
2038 cpufreq_freq_transition_end(policy, freqs, ret);
2041 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2047 static int __target_index(struct cpufreq_policy *policy, int index)
2049 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2050 unsigned int intermediate_freq = 0;
2051 unsigned int newfreq = policy->freq_table[index].frequency;
2052 int retval = -EINVAL;
2055 if (newfreq == policy->cur)
2058 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2060 /* Handle switching to intermediate frequency */
2061 if (cpufreq_driver->get_intermediate) {
2062 retval = __target_intermediate(policy, &freqs, index);
2066 intermediate_freq = freqs.new;
2067 /* Set old freq to intermediate */
2068 if (intermediate_freq)
2069 freqs.old = freqs.new;
2072 freqs.new = newfreq;
2073 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2074 __func__, policy->cpu, freqs.old, freqs.new);
2076 cpufreq_freq_transition_begin(policy, &freqs);
2079 retval = cpufreq_driver->target_index(policy, index);
2081 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2085 cpufreq_freq_transition_end(policy, &freqs, retval);
2088 * Failed after setting to intermediate freq? Driver should have
2089 * reverted back to initial frequency and so should we. Check
2090 * here for intermediate_freq instead of get_intermediate, in
2091 * case we haven't switched to intermediate freq at all.
2093 if (unlikely(retval && intermediate_freq)) {
2094 freqs.old = intermediate_freq;
2095 freqs.new = policy->restore_freq;
2096 cpufreq_freq_transition_begin(policy, &freqs);
2097 cpufreq_freq_transition_end(policy, &freqs, 0);
2104 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2105 unsigned int target_freq,
2106 unsigned int relation)
2108 unsigned int old_target_freq = target_freq;
2111 if (cpufreq_disabled())
2114 /* Make sure that target_freq is within supported range */
2115 target_freq = clamp_val(target_freq, policy->min, policy->max);
2117 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2118 policy->cpu, target_freq, relation, old_target_freq);
2121 * This might look like a redundant call as we are checking it again
2122 * after finding index. But it is left intentionally for cases where
2123 * exactly same freq is called again and so we can save on few function
2126 if (target_freq == policy->cur)
2129 /* Save last value to restore later on errors */
2130 policy->restore_freq = policy->cur;
2132 if (cpufreq_driver->target)
2133 return cpufreq_driver->target(policy, target_freq, relation);
2135 if (!cpufreq_driver->target_index)
2138 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2140 return __target_index(policy, index);
2142 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2144 int cpufreq_driver_target(struct cpufreq_policy *policy,
2145 unsigned int target_freq,
2146 unsigned int relation)
2150 down_write(&policy->rwsem);
2152 ret = __cpufreq_driver_target(policy, target_freq, relation);
2154 up_write(&policy->rwsem);
2158 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2160 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2165 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2169 /* Don't start any governor operations if we are entering suspend */
2170 if (cpufreq_suspended)
2173 * Governor might not be initiated here if ACPI _PPC changed
2174 * notification happened, so check it.
2176 if (!policy->governor)
2179 /* Platform doesn't want dynamic frequency switching ? */
2180 if (policy->governor->dynamic_switching &&
2181 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2182 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2185 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2186 policy->governor->name, gov->name);
2187 policy->governor = gov;
2193 if (!try_module_get(policy->governor->owner))
2196 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2198 if (policy->governor->init) {
2199 ret = policy->governor->init(policy);
2201 module_put(policy->governor->owner);
2209 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2211 if (cpufreq_suspended || !policy->governor)
2214 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2216 if (policy->governor->exit)
2217 policy->governor->exit(policy);
2219 module_put(policy->governor->owner);
2222 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2226 if (cpufreq_suspended)
2229 if (!policy->governor)
2232 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2234 if (cpufreq_driver->get)
2235 cpufreq_verify_current_freq(policy, false);
2237 if (policy->governor->start) {
2238 ret = policy->governor->start(policy);
2243 if (policy->governor->limits)
2244 policy->governor->limits(policy);
2249 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2251 if (cpufreq_suspended || !policy->governor)
2254 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2256 if (policy->governor->stop)
2257 policy->governor->stop(policy);
2260 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2262 if (cpufreq_suspended || !policy->governor)
2265 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2267 if (policy->governor->limits)
2268 policy->governor->limits(policy);
2271 int cpufreq_register_governor(struct cpufreq_governor *governor)
2278 if (cpufreq_disabled())
2281 mutex_lock(&cpufreq_governor_mutex);
2284 if (!find_governor(governor->name)) {
2286 list_add(&governor->governor_list, &cpufreq_governor_list);
2289 mutex_unlock(&cpufreq_governor_mutex);
2292 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2294 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2296 struct cpufreq_policy *policy;
2297 unsigned long flags;
2302 if (cpufreq_disabled())
2305 /* clear last_governor for all inactive policies */
2306 read_lock_irqsave(&cpufreq_driver_lock, flags);
2307 for_each_inactive_policy(policy) {
2308 if (!strcmp(policy->last_governor, governor->name)) {
2309 policy->governor = NULL;
2310 strcpy(policy->last_governor, "\0");
2313 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2315 mutex_lock(&cpufreq_governor_mutex);
2316 list_del(&governor->governor_list);
2317 mutex_unlock(&cpufreq_governor_mutex);
2319 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2322 /*********************************************************************
2323 * POLICY INTERFACE *
2324 *********************************************************************/
2327 * cpufreq_get_policy - get the current cpufreq_policy
2328 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2331 * Reads the current cpufreq policy.
2333 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2335 struct cpufreq_policy *cpu_policy;
2339 cpu_policy = cpufreq_cpu_get(cpu);
2343 memcpy(policy, cpu_policy, sizeof(*policy));
2345 cpufreq_cpu_put(cpu_policy);
2348 EXPORT_SYMBOL(cpufreq_get_policy);
2351 * cpufreq_set_policy - Modify cpufreq policy parameters.
2352 * @policy: Policy object to modify.
2353 * @new_policy: New policy data.
2355 * Pass @new_policy to the cpufreq driver's ->verify() callback, run the
2356 * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to
2357 * the driver's ->verify() callback again and run the notifiers for it again
2358 * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters
2359 * of @new_policy to @policy and either invoke the driver's ->setpolicy()
2360 * callback (if present) or carry out a governor update for @policy. That is,
2361 * run the current governor's ->limits() callback (if the governor field in
2362 * @new_policy points to the same object as the one in @policy) or replace the
2363 * governor for @policy with the new one stored in @new_policy.
2365 * The cpuinfo part of @policy is not updated by this function.
2367 int cpufreq_set_policy(struct cpufreq_policy *policy,
2368 struct cpufreq_policy *new_policy)
2370 struct cpufreq_governor *old_gov;
2371 struct device *cpu_dev = get_cpu_device(policy->cpu);
2374 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2375 new_policy->cpu, new_policy->min, new_policy->max);
2377 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2380 * PM QoS framework collects all the requests from users and provide us
2381 * the final aggregated value here.
2383 new_policy->min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
2384 new_policy->max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
2386 /* verify the cpu speed can be set within this limit */
2387 ret = cpufreq_driver->verify(new_policy);
2392 * The notifier-chain shall be removed once all the users of
2393 * CPUFREQ_ADJUST are moved to use the QoS framework.
2395 /* adjust if necessary - all reasons */
2396 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2397 CPUFREQ_ADJUST, new_policy);
2400 * verify the cpu speed can be set within this limit, which might be
2401 * different to the first one
2403 ret = cpufreq_driver->verify(new_policy);
2407 /* notification of the new policy */
2408 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2409 CPUFREQ_NOTIFY, new_policy);
2411 policy->min = new_policy->min;
2412 policy->max = new_policy->max;
2413 trace_cpu_frequency_limits(policy);
2415 policy->cached_target_freq = UINT_MAX;
2417 pr_debug("new min and max freqs are %u - %u kHz\n",
2418 policy->min, policy->max);
2420 if (cpufreq_driver->setpolicy) {
2421 policy->policy = new_policy->policy;
2422 pr_debug("setting range\n");
2423 return cpufreq_driver->setpolicy(policy);
2426 if (new_policy->governor == policy->governor) {
2427 pr_debug("governor limits update\n");
2428 cpufreq_governor_limits(policy);
2432 pr_debug("governor switch\n");
2434 /* save old, working values */
2435 old_gov = policy->governor;
2436 /* end old governor */
2438 cpufreq_stop_governor(policy);
2439 cpufreq_exit_governor(policy);
2442 /* start new governor */
2443 policy->governor = new_policy->governor;
2444 ret = cpufreq_init_governor(policy);
2446 ret = cpufreq_start_governor(policy);
2448 pr_debug("governor change\n");
2449 sched_cpufreq_governor_change(policy, old_gov);
2452 cpufreq_exit_governor(policy);
2455 /* new governor failed, so re-start old one */
2456 pr_debug("starting governor %s failed\n", policy->governor->name);
2458 policy->governor = old_gov;
2459 if (cpufreq_init_governor(policy))
2460 policy->governor = NULL;
2462 cpufreq_start_governor(policy);
2469 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2470 * @cpu: CPU to re-evaluate the policy for.
2472 * Update the current frequency for the cpufreq policy of @cpu and use
2473 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2474 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2475 * for the policy in question, among other things.
2477 void cpufreq_update_policy(unsigned int cpu)
2479 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2485 * BIOS might change freq behind our back
2486 * -> ask driver for current freq and notify governors about a change
2488 if (cpufreq_driver->get && has_target() &&
2489 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2492 refresh_frequency_limits(policy);
2495 cpufreq_cpu_release(policy);
2497 EXPORT_SYMBOL(cpufreq_update_policy);
2500 * cpufreq_update_limits - Update policy limits for a given CPU.
2501 * @cpu: CPU to update the policy limits for.
2503 * Invoke the driver's ->update_limits callback if present or call
2504 * cpufreq_update_policy() for @cpu.
2506 void cpufreq_update_limits(unsigned int cpu)
2508 if (cpufreq_driver->update_limits)
2509 cpufreq_driver->update_limits(cpu);
2511 cpufreq_update_policy(cpu);
2513 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2515 /*********************************************************************
2517 *********************************************************************/
2518 static int cpufreq_boost_set_sw(int state)
2520 struct cpufreq_policy *policy;
2523 for_each_active_policy(policy) {
2524 if (!policy->freq_table)
2527 ret = cpufreq_frequency_table_cpuinfo(policy,
2528 policy->freq_table);
2530 pr_err("%s: Policy frequency update failed\n",
2535 ret = dev_pm_qos_update_request(policy->max_freq_req, policy->max);
2543 int cpufreq_boost_trigger_state(int state)
2545 unsigned long flags;
2548 if (cpufreq_driver->boost_enabled == state)
2551 write_lock_irqsave(&cpufreq_driver_lock, flags);
2552 cpufreq_driver->boost_enabled = state;
2553 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2555 ret = cpufreq_driver->set_boost(state);
2557 write_lock_irqsave(&cpufreq_driver_lock, flags);
2558 cpufreq_driver->boost_enabled = !state;
2559 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2561 pr_err("%s: Cannot %s BOOST\n",
2562 __func__, state ? "enable" : "disable");
2568 static bool cpufreq_boost_supported(void)
2570 return cpufreq_driver->set_boost;
2573 static int create_boost_sysfs_file(void)
2577 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2579 pr_err("%s: cannot register global BOOST sysfs file\n",
2585 static void remove_boost_sysfs_file(void)
2587 if (cpufreq_boost_supported())
2588 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2591 int cpufreq_enable_boost_support(void)
2593 if (!cpufreq_driver)
2596 if (cpufreq_boost_supported())
2599 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2601 /* This will get removed on driver unregister */
2602 return create_boost_sysfs_file();
2604 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2606 int cpufreq_boost_enabled(void)
2608 return cpufreq_driver->boost_enabled;
2610 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2612 /*********************************************************************
2613 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2614 *********************************************************************/
2615 static enum cpuhp_state hp_online;
2617 static int cpuhp_cpufreq_online(unsigned int cpu)
2619 cpufreq_online(cpu);
2624 static int cpuhp_cpufreq_offline(unsigned int cpu)
2626 cpufreq_offline(cpu);
2632 * cpufreq_register_driver - register a CPU Frequency driver
2633 * @driver_data: A struct cpufreq_driver containing the values#
2634 * submitted by the CPU Frequency driver.
2636 * Registers a CPU Frequency driver to this core code. This code
2637 * returns zero on success, -EEXIST when another driver got here first
2638 * (and isn't unregistered in the meantime).
2641 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2643 unsigned long flags;
2646 if (cpufreq_disabled())
2649 if (!driver_data || !driver_data->verify || !driver_data->init ||
2650 !(driver_data->setpolicy || driver_data->target_index ||
2651 driver_data->target) ||
2652 (driver_data->setpolicy && (driver_data->target_index ||
2653 driver_data->target)) ||
2654 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2655 (!driver_data->online != !driver_data->offline))
2658 pr_debug("trying to register driver %s\n", driver_data->name);
2660 /* Protect against concurrent CPU online/offline. */
2663 write_lock_irqsave(&cpufreq_driver_lock, flags);
2664 if (cpufreq_driver) {
2665 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2669 cpufreq_driver = driver_data;
2670 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2672 if (driver_data->setpolicy)
2673 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2675 if (cpufreq_boost_supported()) {
2676 ret = create_boost_sysfs_file();
2678 goto err_null_driver;
2681 ret = subsys_interface_register(&cpufreq_interface);
2683 goto err_boost_unreg;
2685 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2686 list_empty(&cpufreq_policy_list)) {
2687 /* if all ->init() calls failed, unregister */
2689 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2694 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2696 cpuhp_cpufreq_online,
2697 cpuhp_cpufreq_offline);
2703 pr_debug("driver %s up and running\n", driver_data->name);
2707 subsys_interface_unregister(&cpufreq_interface);
2709 remove_boost_sysfs_file();
2711 write_lock_irqsave(&cpufreq_driver_lock, flags);
2712 cpufreq_driver = NULL;
2713 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2718 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2721 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2723 * Unregister the current CPUFreq driver. Only call this if you have
2724 * the right to do so, i.e. if you have succeeded in initialising before!
2725 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2726 * currently not initialised.
2728 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2730 unsigned long flags;
2732 if (!cpufreq_driver || (driver != cpufreq_driver))
2735 pr_debug("unregistering driver %s\n", driver->name);
2737 /* Protect against concurrent cpu hotplug */
2739 subsys_interface_unregister(&cpufreq_interface);
2740 remove_boost_sysfs_file();
2741 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2743 write_lock_irqsave(&cpufreq_driver_lock, flags);
2745 cpufreq_driver = NULL;
2747 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2752 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2755 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2756 * or mutexes when secondary CPUs are halted.
2758 static struct syscore_ops cpufreq_syscore_ops = {
2759 .shutdown = cpufreq_suspend,
2762 struct kobject *cpufreq_global_kobject;
2763 EXPORT_SYMBOL(cpufreq_global_kobject);
2765 static int __init cpufreq_core_init(void)
2767 if (cpufreq_disabled())
2770 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2771 BUG_ON(!cpufreq_global_kobject);
2773 register_syscore_ops(&cpufreq_syscore_ops);
2777 module_param(off, int, 0444);
2778 core_initcall(cpufreq_core_init);