1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/drivers/cpufreq/cpufreq.c
5 * Copyright (C) 2001 Russell King
6 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
9 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
10 * Added handling for CPU hotplug
11 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
12 * Fix handling for CPU hotplug -- affected CPUs
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/cpu.h>
18 #include <linux/cpufreq.h>
19 #include <linux/cpu_cooling.h>
20 #include <linux/delay.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/kernel_stat.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/pm_qos.h>
27 #include <linux/slab.h>
28 #include <linux/suspend.h>
29 #include <linux/syscore_ops.h>
30 #include <linux/tick.h>
31 #include <trace/events/power.h>
33 static LIST_HEAD(cpufreq_policy_list);
35 /* Macros to iterate over CPU policies */
36 #define for_each_suitable_policy(__policy, __active) \
37 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
38 if ((__active) == !policy_is_inactive(__policy))
40 #define for_each_active_policy(__policy) \
41 for_each_suitable_policy(__policy, true)
42 #define for_each_inactive_policy(__policy) \
43 for_each_suitable_policy(__policy, false)
45 #define for_each_policy(__policy) \
46 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
48 /* Iterate over governors */
49 static LIST_HEAD(cpufreq_governor_list);
50 #define for_each_governor(__governor) \
51 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
53 static char default_governor[CPUFREQ_NAME_LEN];
56 * The "cpufreq driver" - the arch- or hardware-dependent low
57 * level driver of CPUFreq support, and its spinlock. This lock
58 * also protects the cpufreq_cpu_data array.
60 static struct cpufreq_driver *cpufreq_driver;
61 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
62 static DEFINE_RWLOCK(cpufreq_driver_lock);
64 /* Flag to suspend/resume CPUFreq governors */
65 static bool cpufreq_suspended;
67 static inline bool has_target(void)
69 return cpufreq_driver->target_index || cpufreq_driver->target;
72 /* internal prototypes */
73 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
74 static int cpufreq_init_governor(struct cpufreq_policy *policy);
75 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
76 static void cpufreq_governor_limits(struct cpufreq_policy *policy);
77 static int cpufreq_set_policy(struct cpufreq_policy *policy,
78 struct cpufreq_governor *new_gov,
79 unsigned int new_pol);
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 static struct kobject *cpufreq_global_kobject;
110 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
112 if (have_governor_per_policy())
113 return &policy->kobj;
115 return cpufreq_global_kobject;
117 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
119 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
121 struct kernel_cpustat kcpustat;
126 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
128 kcpustat_cpu_fetch(&kcpustat, cpu);
130 busy_time = kcpustat.cpustat[CPUTIME_USER];
131 busy_time += kcpustat.cpustat[CPUTIME_SYSTEM];
132 busy_time += kcpustat.cpustat[CPUTIME_IRQ];
133 busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ];
134 busy_time += kcpustat.cpustat[CPUTIME_STEAL];
135 busy_time += kcpustat.cpustat[CPUTIME_NICE];
137 idle_time = cur_wall_time - busy_time;
139 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
141 return div_u64(idle_time, NSEC_PER_USEC);
144 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
146 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
148 if (idle_time == -1ULL)
149 return get_cpu_idle_time_jiffy(cpu, wall);
151 idle_time += get_cpu_iowait_time_us(cpu, wall);
155 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
157 __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
158 unsigned long max_freq)
161 EXPORT_SYMBOL_GPL(arch_set_freq_scale);
164 * This is a generic cpufreq init() routine which can be used by cpufreq
165 * drivers of SMP systems. It will do following:
166 * - validate & show freq table passed
167 * - set policies transition latency
168 * - policy->cpus with all possible CPUs
170 void cpufreq_generic_init(struct cpufreq_policy *policy,
171 struct cpufreq_frequency_table *table,
172 unsigned int transition_latency)
174 policy->freq_table = table;
175 policy->cpuinfo.transition_latency = transition_latency;
178 * The driver only supports the SMP configuration where all processors
179 * share the clock and voltage and clock.
181 cpumask_setall(policy->cpus);
183 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
185 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
187 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
189 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
191 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
193 unsigned int cpufreq_generic_get(unsigned int cpu)
195 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
197 if (!policy || IS_ERR(policy->clk)) {
198 pr_err("%s: No %s associated to cpu: %d\n",
199 __func__, policy ? "clk" : "policy", cpu);
203 return clk_get_rate(policy->clk) / 1000;
205 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
208 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
209 * @cpu: CPU to find the policy for.
211 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
212 * the kobject reference counter of that policy. Return a valid policy on
213 * success or NULL on failure.
215 * The policy returned by this function has to be released with the help of
216 * cpufreq_cpu_put() to balance its kobject reference counter properly.
218 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
220 struct cpufreq_policy *policy = NULL;
223 if (WARN_ON(cpu >= nr_cpu_ids))
226 /* get the cpufreq driver */
227 read_lock_irqsave(&cpufreq_driver_lock, flags);
229 if (cpufreq_driver) {
231 policy = cpufreq_cpu_get_raw(cpu);
233 kobject_get(&policy->kobj);
236 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
240 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
243 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
244 * @policy: cpufreq policy returned by cpufreq_cpu_get().
246 void cpufreq_cpu_put(struct cpufreq_policy *policy)
248 kobject_put(&policy->kobj);
250 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
253 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
254 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
256 void cpufreq_cpu_release(struct cpufreq_policy *policy)
258 if (WARN_ON(!policy))
261 lockdep_assert_held(&policy->rwsem);
263 up_write(&policy->rwsem);
265 cpufreq_cpu_put(policy);
269 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
270 * @cpu: CPU to find the policy for.
272 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
273 * if the policy returned by it is not NULL, acquire its rwsem for writing.
274 * Return the policy if it is active or release it and return NULL otherwise.
276 * The policy returned by this function has to be released with the help of
277 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
280 struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
282 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
287 down_write(&policy->rwsem);
289 if (policy_is_inactive(policy)) {
290 cpufreq_cpu_release(policy);
297 /*********************************************************************
298 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
299 *********************************************************************/
302 * adjust_jiffies - adjust the system "loops_per_jiffy"
304 * This function alters the system "loops_per_jiffy" for the clock
305 * speed change. Note that loops_per_jiffy cannot be updated on SMP
306 * systems as each CPU might be scaled differently. So, use the arch
307 * per-CPU loops_per_jiffy value wherever possible.
309 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
312 static unsigned long l_p_j_ref;
313 static unsigned int l_p_j_ref_freq;
315 if (ci->flags & CPUFREQ_CONST_LOOPS)
318 if (!l_p_j_ref_freq) {
319 l_p_j_ref = loops_per_jiffy;
320 l_p_j_ref_freq = ci->old;
321 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
322 l_p_j_ref, l_p_j_ref_freq);
324 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
325 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
327 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
328 loops_per_jiffy, ci->new);
334 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
335 * @policy: cpufreq policy to enable fast frequency switching for.
336 * @freqs: contain details of the frequency update.
337 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
339 * This function calls the transition notifiers and the "adjust_jiffies"
340 * function. It is called twice on all CPU frequency changes that have
343 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
344 struct cpufreq_freqs *freqs,
349 BUG_ON(irqs_disabled());
351 if (cpufreq_disabled())
354 freqs->policy = policy;
355 freqs->flags = cpufreq_driver->flags;
356 pr_debug("notification %u of frequency transition to %u kHz\n",
360 case CPUFREQ_PRECHANGE:
362 * Detect if the driver reported a value as "old frequency"
363 * which is not equal to what the cpufreq core thinks is
366 if (policy->cur && policy->cur != freqs->old) {
367 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
368 freqs->old, policy->cur);
369 freqs->old = policy->cur;
372 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
373 CPUFREQ_PRECHANGE, freqs);
375 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
378 case CPUFREQ_POSTCHANGE:
379 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
380 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
381 cpumask_pr_args(policy->cpus));
383 for_each_cpu(cpu, policy->cpus)
384 trace_cpu_frequency(freqs->new, cpu);
386 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
387 CPUFREQ_POSTCHANGE, freqs);
389 cpufreq_stats_record_transition(policy, freqs->new);
390 policy->cur = freqs->new;
394 /* Do post notifications when there are chances that transition has failed */
395 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
396 struct cpufreq_freqs *freqs, int transition_failed)
398 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
399 if (!transition_failed)
402 swap(freqs->old, freqs->new);
403 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
404 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
407 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
408 struct cpufreq_freqs *freqs)
412 * Catch double invocations of _begin() which lead to self-deadlock.
413 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
414 * doesn't invoke _begin() on their behalf, and hence the chances of
415 * double invocations are very low. Moreover, there are scenarios
416 * where these checks can emit false-positive warnings in these
417 * drivers; so we avoid that by skipping them altogether.
419 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
420 && current == policy->transition_task);
423 wait_event(policy->transition_wait, !policy->transition_ongoing);
425 spin_lock(&policy->transition_lock);
427 if (unlikely(policy->transition_ongoing)) {
428 spin_unlock(&policy->transition_lock);
432 policy->transition_ongoing = true;
433 policy->transition_task = current;
435 spin_unlock(&policy->transition_lock);
437 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
439 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
441 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
442 struct cpufreq_freqs *freqs, int transition_failed)
444 if (WARN_ON(!policy->transition_ongoing))
447 cpufreq_notify_post_transition(policy, freqs, transition_failed);
449 policy->transition_ongoing = false;
450 policy->transition_task = NULL;
452 wake_up(&policy->transition_wait);
454 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
457 * Fast frequency switching status count. Positive means "enabled", negative
458 * means "disabled" and 0 means "not decided yet".
460 static int cpufreq_fast_switch_count;
461 static DEFINE_MUTEX(cpufreq_fast_switch_lock);
463 static void cpufreq_list_transition_notifiers(void)
465 struct notifier_block *nb;
467 pr_info("Registered transition notifiers:\n");
469 mutex_lock(&cpufreq_transition_notifier_list.mutex);
471 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
472 pr_info("%pS\n", nb->notifier_call);
474 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
478 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
479 * @policy: cpufreq policy to enable fast frequency switching for.
481 * Try to enable fast frequency switching for @policy.
483 * The attempt will fail if there is at least one transition notifier registered
484 * at this point, as fast frequency switching is quite fundamentally at odds
485 * with transition notifiers. Thus if successful, it will make registration of
486 * transition notifiers fail going forward.
488 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
490 lockdep_assert_held(&policy->rwsem);
492 if (!policy->fast_switch_possible)
495 mutex_lock(&cpufreq_fast_switch_lock);
496 if (cpufreq_fast_switch_count >= 0) {
497 cpufreq_fast_switch_count++;
498 policy->fast_switch_enabled = true;
500 pr_warn("CPU%u: Fast frequency switching not enabled\n",
502 cpufreq_list_transition_notifiers();
504 mutex_unlock(&cpufreq_fast_switch_lock);
506 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
509 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
510 * @policy: cpufreq policy to disable fast frequency switching for.
512 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
514 mutex_lock(&cpufreq_fast_switch_lock);
515 if (policy->fast_switch_enabled) {
516 policy->fast_switch_enabled = false;
517 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
518 cpufreq_fast_switch_count--;
520 mutex_unlock(&cpufreq_fast_switch_lock);
522 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
525 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
527 * @policy: associated policy to interrogate
528 * @target_freq: target frequency to resolve.
530 * The target to driver frequency mapping is cached in the policy.
532 * Return: Lowest driver-supported frequency greater than or equal to the
533 * given target_freq, subject to policy (min/max) and driver limitations.
535 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
536 unsigned int target_freq)
538 target_freq = clamp_val(target_freq, policy->min, policy->max);
539 policy->cached_target_freq = target_freq;
541 if (cpufreq_driver->target_index) {
544 idx = cpufreq_frequency_table_target(policy, target_freq,
546 policy->cached_resolved_idx = idx;
547 return policy->freq_table[idx].frequency;
550 if (cpufreq_driver->resolve_freq)
551 return cpufreq_driver->resolve_freq(policy, target_freq);
555 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
557 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
559 unsigned int latency;
561 if (policy->transition_delay_us)
562 return policy->transition_delay_us;
564 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
567 * For platforms that can change the frequency very fast (< 10
568 * us), the above formula gives a decent transition delay. But
569 * for platforms where transition_latency is in milliseconds, it
570 * ends up giving unrealistic values.
572 * Cap the default transition delay to 10 ms, which seems to be
573 * a reasonable amount of time after which we should reevaluate
576 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
579 return LATENCY_MULTIPLIER;
581 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
583 /*********************************************************************
585 *********************************************************************/
586 static ssize_t show_boost(struct kobject *kobj,
587 struct kobj_attribute *attr, char *buf)
589 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
592 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
593 const char *buf, size_t count)
597 ret = sscanf(buf, "%d", &enable);
598 if (ret != 1 || enable < 0 || enable > 1)
601 if (cpufreq_boost_trigger_state(enable)) {
602 pr_err("%s: Cannot %s BOOST!\n",
603 __func__, enable ? "enable" : "disable");
607 pr_debug("%s: cpufreq BOOST %s\n",
608 __func__, enable ? "enabled" : "disabled");
612 define_one_global_rw(boost);
614 static struct cpufreq_governor *find_governor(const char *str_governor)
616 struct cpufreq_governor *t;
619 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
625 static struct cpufreq_governor *get_governor(const char *str_governor)
627 struct cpufreq_governor *t;
629 mutex_lock(&cpufreq_governor_mutex);
630 t = find_governor(str_governor);
634 if (!try_module_get(t->owner))
638 mutex_unlock(&cpufreq_governor_mutex);
643 static unsigned int cpufreq_parse_policy(char *str_governor)
645 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN))
646 return CPUFREQ_POLICY_PERFORMANCE;
648 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN))
649 return CPUFREQ_POLICY_POWERSAVE;
651 return CPUFREQ_POLICY_UNKNOWN;
655 * cpufreq_parse_governor - parse a governor string only for has_target()
656 * @str_governor: Governor name.
658 static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor)
660 struct cpufreq_governor *t;
662 t = get_governor(str_governor);
666 if (request_module("cpufreq_%s", str_governor))
669 return get_governor(str_governor);
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->setpolicy && cpufreq_driver->get)
707 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
709 ret = sprintf(buf, "%u\n", policy->cur);
714 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
716 #define store_one(file_name, object) \
717 static ssize_t store_##file_name \
718 (struct cpufreq_policy *policy, const char *buf, size_t count) \
723 ret = sscanf(buf, "%lu", &val); \
727 ret = freq_qos_update_request(policy->object##_freq_req, val);\
728 return ret >= 0 ? count : ret; \
731 store_one(scaling_min_freq, min);
732 store_one(scaling_max_freq, max);
735 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
737 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
740 unsigned int cur_freq = __cpufreq_get(policy);
743 return sprintf(buf, "%u\n", cur_freq);
745 return sprintf(buf, "<unknown>\n");
749 * show_scaling_governor - show the current policy for the specified CPU
751 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
753 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
754 return sprintf(buf, "powersave\n");
755 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
756 return sprintf(buf, "performance\n");
757 else if (policy->governor)
758 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
759 policy->governor->name);
764 * store_scaling_governor - store policy for the specified CPU
766 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
767 const char *buf, size_t count)
769 char str_governor[16];
772 ret = sscanf(buf, "%15s", str_governor);
776 if (cpufreq_driver->setpolicy) {
777 unsigned int new_pol;
779 new_pol = cpufreq_parse_policy(str_governor);
783 ret = cpufreq_set_policy(policy, NULL, new_pol);
785 struct cpufreq_governor *new_gov;
787 new_gov = cpufreq_parse_governor(str_governor);
791 ret = cpufreq_set_policy(policy, new_gov,
792 CPUFREQ_POLICY_UNKNOWN);
794 module_put(new_gov->owner);
797 return ret ? ret : count;
801 * show_scaling_driver - show the cpufreq driver currently loaded
803 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
805 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
809 * show_scaling_available_governors - show the available CPUfreq governors
811 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
815 struct cpufreq_governor *t;
818 i += sprintf(buf, "performance powersave");
822 mutex_lock(&cpufreq_governor_mutex);
823 for_each_governor(t) {
824 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
825 - (CPUFREQ_NAME_LEN + 2)))
827 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
829 mutex_unlock(&cpufreq_governor_mutex);
831 i += sprintf(&buf[i], "\n");
835 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
840 for_each_cpu(cpu, mask) {
842 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
843 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
844 if (i >= (PAGE_SIZE - 5))
847 i += sprintf(&buf[i], "\n");
850 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
853 * show_related_cpus - show the CPUs affected by each transition even if
854 * hw coordination is in use
856 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
858 return cpufreq_show_cpus(policy->related_cpus, buf);
862 * show_affected_cpus - show the CPUs affected by each transition
864 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
866 return cpufreq_show_cpus(policy->cpus, buf);
869 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
870 const char *buf, size_t count)
872 unsigned int freq = 0;
875 if (!policy->governor || !policy->governor->store_setspeed)
878 ret = sscanf(buf, "%u", &freq);
882 policy->governor->store_setspeed(policy, freq);
887 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
889 if (!policy->governor || !policy->governor->show_setspeed)
890 return sprintf(buf, "<unsupported>\n");
892 return policy->governor->show_setspeed(policy, buf);
896 * show_bios_limit - show the current cpufreq HW/BIOS limitation
898 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
902 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
904 return sprintf(buf, "%u\n", limit);
905 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
908 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
909 cpufreq_freq_attr_ro(cpuinfo_min_freq);
910 cpufreq_freq_attr_ro(cpuinfo_max_freq);
911 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
912 cpufreq_freq_attr_ro(scaling_available_governors);
913 cpufreq_freq_attr_ro(scaling_driver);
914 cpufreq_freq_attr_ro(scaling_cur_freq);
915 cpufreq_freq_attr_ro(bios_limit);
916 cpufreq_freq_attr_ro(related_cpus);
917 cpufreq_freq_attr_ro(affected_cpus);
918 cpufreq_freq_attr_rw(scaling_min_freq);
919 cpufreq_freq_attr_rw(scaling_max_freq);
920 cpufreq_freq_attr_rw(scaling_governor);
921 cpufreq_freq_attr_rw(scaling_setspeed);
923 static struct attribute *default_attrs[] = {
924 &cpuinfo_min_freq.attr,
925 &cpuinfo_max_freq.attr,
926 &cpuinfo_transition_latency.attr,
927 &scaling_min_freq.attr,
928 &scaling_max_freq.attr,
931 &scaling_governor.attr,
932 &scaling_driver.attr,
933 &scaling_available_governors.attr,
934 &scaling_setspeed.attr,
938 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
939 #define to_attr(a) container_of(a, struct freq_attr, attr)
941 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
943 struct cpufreq_policy *policy = to_policy(kobj);
944 struct freq_attr *fattr = to_attr(attr);
950 down_read(&policy->rwsem);
951 ret = fattr->show(policy, buf);
952 up_read(&policy->rwsem);
957 static ssize_t store(struct kobject *kobj, struct attribute *attr,
958 const char *buf, size_t count)
960 struct cpufreq_policy *policy = to_policy(kobj);
961 struct freq_attr *fattr = to_attr(attr);
962 ssize_t ret = -EINVAL;
968 * cpus_read_trylock() is used here to work around a circular lock
969 * dependency problem with respect to the cpufreq_register_driver().
971 if (!cpus_read_trylock())
974 if (cpu_online(policy->cpu)) {
975 down_write(&policy->rwsem);
976 ret = fattr->store(policy, buf, count);
977 up_write(&policy->rwsem);
985 static void cpufreq_sysfs_release(struct kobject *kobj)
987 struct cpufreq_policy *policy = to_policy(kobj);
988 pr_debug("last reference is dropped\n");
989 complete(&policy->kobj_unregister);
992 static const struct sysfs_ops sysfs_ops = {
997 static struct kobj_type ktype_cpufreq = {
998 .sysfs_ops = &sysfs_ops,
999 .default_attrs = default_attrs,
1000 .release = cpufreq_sysfs_release,
1003 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
1005 struct device *dev = get_cpu_device(cpu);
1010 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1013 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1014 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1015 dev_err(dev, "cpufreq symlink creation failed\n");
1018 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1021 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1022 sysfs_remove_link(&dev->kobj, "cpufreq");
1025 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1027 struct freq_attr **drv_attr;
1030 /* set up files for this cpu device */
1031 drv_attr = cpufreq_driver->attr;
1032 while (drv_attr && *drv_attr) {
1033 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1038 if (cpufreq_driver->get) {
1039 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1044 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1048 if (cpufreq_driver->bios_limit) {
1049 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1057 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1059 struct cpufreq_governor *gov = NULL;
1060 unsigned int pol = CPUFREQ_POLICY_UNKNOWN;
1064 /* Update policy governor to the one used before hotplug. */
1065 gov = get_governor(policy->last_governor);
1067 pr_debug("Restoring governor %s for cpu %d\n",
1068 gov->name, policy->cpu);
1070 gov = get_governor(default_governor);
1074 gov = cpufreq_default_governor();
1075 __module_get(gov->owner);
1080 /* Use the default policy if there is no last_policy. */
1081 if (policy->last_policy) {
1082 pol = policy->last_policy;
1084 pol = cpufreq_parse_policy(default_governor);
1086 * In case the default governor is neither "performance"
1087 * nor "powersave", fall back to the initial policy
1088 * value set by the driver.
1090 if (pol == CPUFREQ_POLICY_UNKNOWN)
1091 pol = policy->policy;
1093 if (pol != CPUFREQ_POLICY_PERFORMANCE &&
1094 pol != CPUFREQ_POLICY_POWERSAVE)
1098 ret = cpufreq_set_policy(policy, gov, pol);
1100 module_put(gov->owner);
1105 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1109 /* Has this CPU been taken care of already? */
1110 if (cpumask_test_cpu(cpu, policy->cpus))
1113 down_write(&policy->rwsem);
1115 cpufreq_stop_governor(policy);
1117 cpumask_set_cpu(cpu, policy->cpus);
1120 ret = cpufreq_start_governor(policy);
1122 pr_err("%s: Failed to start governor\n", __func__);
1124 up_write(&policy->rwsem);
1128 void refresh_frequency_limits(struct cpufreq_policy *policy)
1130 if (!policy_is_inactive(policy)) {
1131 pr_debug("updating policy for CPU %u\n", policy->cpu);
1133 cpufreq_set_policy(policy, policy->governor, policy->policy);
1136 EXPORT_SYMBOL(refresh_frequency_limits);
1138 static void handle_update(struct work_struct *work)
1140 struct cpufreq_policy *policy =
1141 container_of(work, struct cpufreq_policy, update);
1143 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1144 down_write(&policy->rwsem);
1145 refresh_frequency_limits(policy);
1146 up_write(&policy->rwsem);
1149 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1152 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1154 schedule_work(&policy->update);
1158 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1161 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1163 schedule_work(&policy->update);
1167 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1169 struct kobject *kobj;
1170 struct completion *cmp;
1172 down_write(&policy->rwsem);
1173 cpufreq_stats_free_table(policy);
1174 kobj = &policy->kobj;
1175 cmp = &policy->kobj_unregister;
1176 up_write(&policy->rwsem);
1180 * We need to make sure that the underlying kobj is
1181 * actually not referenced anymore by anybody before we
1182 * proceed with unloading.
1184 pr_debug("waiting for dropping of refcount\n");
1185 wait_for_completion(cmp);
1186 pr_debug("wait complete\n");
1189 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1191 struct cpufreq_policy *policy;
1192 struct device *dev = get_cpu_device(cpu);
1198 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1202 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1203 goto err_free_policy;
1205 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1206 goto err_free_cpumask;
1208 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1209 goto err_free_rcpumask;
1211 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1212 cpufreq_global_kobject, "policy%u", cpu);
1214 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1216 * The entire policy object will be freed below, but the extra
1217 * memory allocated for the kobject name needs to be freed by
1218 * releasing the kobject.
1220 kobject_put(&policy->kobj);
1221 goto err_free_real_cpus;
1224 freq_constraints_init(&policy->constraints);
1226 policy->nb_min.notifier_call = cpufreq_notifier_min;
1227 policy->nb_max.notifier_call = cpufreq_notifier_max;
1229 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN,
1232 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1233 ret, cpumask_pr_args(policy->cpus));
1234 goto err_kobj_remove;
1237 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX,
1240 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1241 ret, cpumask_pr_args(policy->cpus));
1242 goto err_min_qos_notifier;
1245 INIT_LIST_HEAD(&policy->policy_list);
1246 init_rwsem(&policy->rwsem);
1247 spin_lock_init(&policy->transition_lock);
1248 init_waitqueue_head(&policy->transition_wait);
1249 init_completion(&policy->kobj_unregister);
1250 INIT_WORK(&policy->update, handle_update);
1255 err_min_qos_notifier:
1256 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1259 cpufreq_policy_put_kobj(policy);
1261 free_cpumask_var(policy->real_cpus);
1263 free_cpumask_var(policy->related_cpus);
1265 free_cpumask_var(policy->cpus);
1272 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1274 unsigned long flags;
1277 /* Remove policy from list */
1278 write_lock_irqsave(&cpufreq_driver_lock, flags);
1279 list_del(&policy->policy_list);
1281 for_each_cpu(cpu, policy->related_cpus)
1282 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1283 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1285 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX,
1287 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1290 /* Cancel any pending policy->update work before freeing the policy. */
1291 cancel_work_sync(&policy->update);
1293 if (policy->max_freq_req) {
1295 * CPUFREQ_CREATE_POLICY notification is sent only after
1296 * successfully adding max_freq_req request.
1298 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1299 CPUFREQ_REMOVE_POLICY, policy);
1300 freq_qos_remove_request(policy->max_freq_req);
1303 freq_qos_remove_request(policy->min_freq_req);
1304 kfree(policy->min_freq_req);
1306 cpufreq_policy_put_kobj(policy);
1307 free_cpumask_var(policy->real_cpus);
1308 free_cpumask_var(policy->related_cpus);
1309 free_cpumask_var(policy->cpus);
1313 static int cpufreq_online(unsigned int cpu)
1315 struct cpufreq_policy *policy;
1317 unsigned long flags;
1321 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1323 /* Check if this CPU already has a policy to manage it */
1324 policy = per_cpu(cpufreq_cpu_data, cpu);
1326 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1327 if (!policy_is_inactive(policy))
1328 return cpufreq_add_policy_cpu(policy, cpu);
1330 /* This is the only online CPU for the policy. Start over. */
1332 down_write(&policy->rwsem);
1334 policy->governor = NULL;
1335 up_write(&policy->rwsem);
1338 policy = cpufreq_policy_alloc(cpu);
1343 if (!new_policy && cpufreq_driver->online) {
1344 ret = cpufreq_driver->online(policy);
1346 pr_debug("%s: %d: initialization failed\n", __func__,
1348 goto out_exit_policy;
1351 /* Recover policy->cpus using related_cpus */
1352 cpumask_copy(policy->cpus, policy->related_cpus);
1354 cpumask_copy(policy->cpus, cpumask_of(cpu));
1357 * Call driver. From then on the cpufreq must be able
1358 * to accept all calls to ->verify and ->setpolicy for this CPU.
1360 ret = cpufreq_driver->init(policy);
1362 pr_debug("%s: %d: initialization failed\n", __func__,
1364 goto out_free_policy;
1367 ret = cpufreq_table_validate_and_sort(policy);
1369 goto out_exit_policy;
1371 /* related_cpus should at least include policy->cpus. */
1372 cpumask_copy(policy->related_cpus, policy->cpus);
1375 down_write(&policy->rwsem);
1377 * affected cpus must always be the one, which are online. We aren't
1378 * managing offline cpus here.
1380 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1383 for_each_cpu(j, policy->related_cpus) {
1384 per_cpu(cpufreq_cpu_data, j) = policy;
1385 add_cpu_dev_symlink(policy, j);
1388 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1390 if (!policy->min_freq_req)
1391 goto out_destroy_policy;
1393 ret = freq_qos_add_request(&policy->constraints,
1394 policy->min_freq_req, FREQ_QOS_MIN,
1398 * So we don't call freq_qos_remove_request() for an
1399 * uninitialized request.
1401 kfree(policy->min_freq_req);
1402 policy->min_freq_req = NULL;
1403 goto out_destroy_policy;
1407 * This must be initialized right here to avoid calling
1408 * freq_qos_remove_request() on uninitialized request in case
1411 policy->max_freq_req = policy->min_freq_req + 1;
1413 ret = freq_qos_add_request(&policy->constraints,
1414 policy->max_freq_req, FREQ_QOS_MAX,
1417 policy->max_freq_req = NULL;
1418 goto out_destroy_policy;
1421 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1422 CPUFREQ_CREATE_POLICY, policy);
1425 if (cpufreq_driver->get && has_target()) {
1426 policy->cur = cpufreq_driver->get(policy->cpu);
1428 pr_err("%s: ->get() failed\n", __func__);
1429 goto out_destroy_policy;
1434 * Sometimes boot loaders set CPU frequency to a value outside of
1435 * frequency table present with cpufreq core. In such cases CPU might be
1436 * unstable if it has to run on that frequency for long duration of time
1437 * and so its better to set it to a frequency which is specified in
1438 * freq-table. This also makes cpufreq stats inconsistent as
1439 * cpufreq-stats would fail to register because current frequency of CPU
1440 * isn't found in freq-table.
1442 * Because we don't want this change to effect boot process badly, we go
1443 * for the next freq which is >= policy->cur ('cur' must be set by now,
1444 * otherwise we will end up setting freq to lowest of the table as 'cur'
1445 * is initialized to zero).
1447 * We are passing target-freq as "policy->cur - 1" otherwise
1448 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1449 * equal to target-freq.
1451 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1453 /* Are we running at unknown frequency ? */
1454 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1455 if (ret == -EINVAL) {
1456 /* Warn user and fix it */
1457 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1458 __func__, policy->cpu, policy->cur);
1459 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1460 CPUFREQ_RELATION_L);
1463 * Reaching here after boot in a few seconds may not
1464 * mean that system will remain stable at "unknown"
1465 * frequency for longer duration. Hence, a BUG_ON().
1468 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1469 __func__, policy->cpu, policy->cur);
1474 ret = cpufreq_add_dev_interface(policy);
1476 goto out_destroy_policy;
1478 cpufreq_stats_create_table(policy);
1480 write_lock_irqsave(&cpufreq_driver_lock, flags);
1481 list_add(&policy->policy_list, &cpufreq_policy_list);
1482 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1485 ret = cpufreq_init_policy(policy);
1487 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1488 __func__, cpu, ret);
1489 goto out_destroy_policy;
1492 up_write(&policy->rwsem);
1494 kobject_uevent(&policy->kobj, KOBJ_ADD);
1496 /* Callback for handling stuff after policy is ready */
1497 if (cpufreq_driver->ready)
1498 cpufreq_driver->ready(policy);
1500 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1501 policy->cdev = of_cpufreq_cooling_register(policy);
1503 pr_debug("initialization complete\n");
1508 for_each_cpu(j, policy->real_cpus)
1509 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1511 up_write(&policy->rwsem);
1514 if (cpufreq_driver->exit)
1515 cpufreq_driver->exit(policy);
1518 cpufreq_policy_free(policy);
1523 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1525 * @sif: Subsystem interface structure pointer (not used)
1527 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1529 struct cpufreq_policy *policy;
1530 unsigned cpu = dev->id;
1533 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1535 if (cpu_online(cpu)) {
1536 ret = cpufreq_online(cpu);
1541 /* Create sysfs link on CPU registration */
1542 policy = per_cpu(cpufreq_cpu_data, cpu);
1544 add_cpu_dev_symlink(policy, cpu);
1549 static int cpufreq_offline(unsigned int cpu)
1551 struct cpufreq_policy *policy;
1554 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1556 policy = cpufreq_cpu_get_raw(cpu);
1558 pr_debug("%s: No cpu_data found\n", __func__);
1562 down_write(&policy->rwsem);
1564 cpufreq_stop_governor(policy);
1566 cpumask_clear_cpu(cpu, policy->cpus);
1568 if (policy_is_inactive(policy)) {
1570 strncpy(policy->last_governor, policy->governor->name,
1573 policy->last_policy = policy->policy;
1574 } else if (cpu == policy->cpu) {
1575 /* Nominate new CPU */
1576 policy->cpu = cpumask_any(policy->cpus);
1579 /* Start governor again for active policy */
1580 if (!policy_is_inactive(policy)) {
1582 ret = cpufreq_start_governor(policy);
1584 pr_err("%s: Failed to start governor\n", __func__);
1590 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1591 cpufreq_cooling_unregister(policy->cdev);
1592 policy->cdev = NULL;
1595 if (cpufreq_driver->stop_cpu)
1596 cpufreq_driver->stop_cpu(policy);
1599 cpufreq_exit_governor(policy);
1602 * Perform the ->offline() during light-weight tear-down, as
1603 * that allows fast recovery when the CPU comes back.
1605 if (cpufreq_driver->offline) {
1606 cpufreq_driver->offline(policy);
1607 } else if (cpufreq_driver->exit) {
1608 cpufreq_driver->exit(policy);
1609 policy->freq_table = NULL;
1613 up_write(&policy->rwsem);
1618 * cpufreq_remove_dev - remove a CPU device
1620 * Removes the cpufreq interface for a CPU device.
1622 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1624 unsigned int cpu = dev->id;
1625 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1630 if (cpu_online(cpu))
1631 cpufreq_offline(cpu);
1633 cpumask_clear_cpu(cpu, policy->real_cpus);
1634 remove_cpu_dev_symlink(policy, dev);
1636 if (cpumask_empty(policy->real_cpus)) {
1637 /* We did light-weight exit earlier, do full tear down now */
1638 if (cpufreq_driver->offline)
1639 cpufreq_driver->exit(policy);
1641 cpufreq_policy_free(policy);
1646 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1648 * @policy: policy managing CPUs
1649 * @new_freq: CPU frequency the CPU actually runs at
1651 * We adjust to current frequency first, and need to clean up later.
1652 * So either call to cpufreq_update_policy() or schedule handle_update()).
1654 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1655 unsigned int new_freq)
1657 struct cpufreq_freqs freqs;
1659 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1660 policy->cur, new_freq);
1662 freqs.old = policy->cur;
1663 freqs.new = new_freq;
1665 cpufreq_freq_transition_begin(policy, &freqs);
1666 cpufreq_freq_transition_end(policy, &freqs, 0);
1669 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1671 unsigned int new_freq;
1673 new_freq = cpufreq_driver->get(policy->cpu);
1678 * If fast frequency switching is used with the given policy, the check
1679 * against policy->cur is pointless, so skip it in that case.
1681 if (policy->fast_switch_enabled || !has_target())
1684 if (policy->cur != new_freq) {
1685 cpufreq_out_of_sync(policy, new_freq);
1687 schedule_work(&policy->update);
1694 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1697 * This is the last known freq, without actually getting it from the driver.
1698 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1700 unsigned int cpufreq_quick_get(unsigned int cpu)
1702 struct cpufreq_policy *policy;
1703 unsigned int ret_freq = 0;
1704 unsigned long flags;
1706 read_lock_irqsave(&cpufreq_driver_lock, flags);
1708 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1709 ret_freq = cpufreq_driver->get(cpu);
1710 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1714 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1716 policy = cpufreq_cpu_get(cpu);
1718 ret_freq = policy->cur;
1719 cpufreq_cpu_put(policy);
1724 EXPORT_SYMBOL(cpufreq_quick_get);
1727 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1730 * Just return the max possible frequency for a given CPU.
1732 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1734 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1735 unsigned int ret_freq = 0;
1738 ret_freq = policy->max;
1739 cpufreq_cpu_put(policy);
1744 EXPORT_SYMBOL(cpufreq_quick_get_max);
1747 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU
1750 * The default return value is the max_freq field of cpuinfo.
1752 __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
1754 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1755 unsigned int ret_freq = 0;
1758 ret_freq = policy->cpuinfo.max_freq;
1759 cpufreq_cpu_put(policy);
1764 EXPORT_SYMBOL(cpufreq_get_hw_max_freq);
1766 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1768 if (unlikely(policy_is_inactive(policy)))
1771 return cpufreq_verify_current_freq(policy, true);
1775 * cpufreq_get - get the current CPU frequency (in kHz)
1778 * Get the CPU current (static) CPU frequency
1780 unsigned int cpufreq_get(unsigned int cpu)
1782 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1783 unsigned int ret_freq = 0;
1786 down_read(&policy->rwsem);
1787 if (cpufreq_driver->get)
1788 ret_freq = __cpufreq_get(policy);
1789 up_read(&policy->rwsem);
1791 cpufreq_cpu_put(policy);
1796 EXPORT_SYMBOL(cpufreq_get);
1798 static struct subsys_interface cpufreq_interface = {
1800 .subsys = &cpu_subsys,
1801 .add_dev = cpufreq_add_dev,
1802 .remove_dev = cpufreq_remove_dev,
1806 * In case platform wants some specific frequency to be configured
1809 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1813 if (!policy->suspend_freq) {
1814 pr_debug("%s: suspend_freq not defined\n", __func__);
1818 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1819 policy->suspend_freq);
1821 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1822 CPUFREQ_RELATION_H);
1824 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1825 __func__, policy->suspend_freq, ret);
1829 EXPORT_SYMBOL(cpufreq_generic_suspend);
1832 * cpufreq_suspend() - Suspend CPUFreq governors
1834 * Called during system wide Suspend/Hibernate cycles for suspending governors
1835 * as some platforms can't change frequency after this point in suspend cycle.
1836 * Because some of the devices (like: i2c, regulators, etc) they use for
1837 * changing frequency are suspended quickly after this point.
1839 void cpufreq_suspend(void)
1841 struct cpufreq_policy *policy;
1843 if (!cpufreq_driver)
1846 if (!has_target() && !cpufreq_driver->suspend)
1849 pr_debug("%s: Suspending Governors\n", __func__);
1851 for_each_active_policy(policy) {
1853 down_write(&policy->rwsem);
1854 cpufreq_stop_governor(policy);
1855 up_write(&policy->rwsem);
1858 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1859 pr_err("%s: Failed to suspend driver: %s\n", __func__,
1860 cpufreq_driver->name);
1864 cpufreq_suspended = true;
1868 * cpufreq_resume() - Resume CPUFreq governors
1870 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1871 * are suspended with cpufreq_suspend().
1873 void cpufreq_resume(void)
1875 struct cpufreq_policy *policy;
1878 if (!cpufreq_driver)
1881 if (unlikely(!cpufreq_suspended))
1884 cpufreq_suspended = false;
1886 if (!has_target() && !cpufreq_driver->resume)
1889 pr_debug("%s: Resuming Governors\n", __func__);
1891 for_each_active_policy(policy) {
1892 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1893 pr_err("%s: Failed to resume driver: %p\n", __func__,
1895 } else if (has_target()) {
1896 down_write(&policy->rwsem);
1897 ret = cpufreq_start_governor(policy);
1898 up_write(&policy->rwsem);
1901 pr_err("%s: Failed to start governor for policy: %p\n",
1908 * cpufreq_get_current_driver - return current driver's name
1910 * Return the name string of the currently loaded cpufreq driver
1913 const char *cpufreq_get_current_driver(void)
1916 return cpufreq_driver->name;
1920 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1923 * cpufreq_get_driver_data - return current driver data
1925 * Return the private data of the currently loaded cpufreq
1926 * driver, or NULL if no cpufreq driver is loaded.
1928 void *cpufreq_get_driver_data(void)
1931 return cpufreq_driver->driver_data;
1935 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1937 /*********************************************************************
1938 * NOTIFIER LISTS INTERFACE *
1939 *********************************************************************/
1942 * cpufreq_register_notifier - register a driver with cpufreq
1943 * @nb: notifier function to register
1944 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1946 * Add a driver to one of two lists: either a list of drivers that
1947 * are notified about clock rate changes (once before and once after
1948 * the transition), or a list of drivers that are notified about
1949 * changes in cpufreq policy.
1951 * This function may sleep, and has the same return conditions as
1952 * blocking_notifier_chain_register.
1954 int cpufreq_register_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 if (cpufreq_fast_switch_count > 0) {
1966 mutex_unlock(&cpufreq_fast_switch_lock);
1969 ret = srcu_notifier_chain_register(
1970 &cpufreq_transition_notifier_list, nb);
1972 cpufreq_fast_switch_count--;
1974 mutex_unlock(&cpufreq_fast_switch_lock);
1976 case CPUFREQ_POLICY_NOTIFIER:
1977 ret = blocking_notifier_chain_register(
1978 &cpufreq_policy_notifier_list, nb);
1986 EXPORT_SYMBOL(cpufreq_register_notifier);
1989 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1990 * @nb: notifier block to be unregistered
1991 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1993 * Remove a driver from the CPU frequency notifier list.
1995 * This function may sleep, and has the same return conditions as
1996 * blocking_notifier_chain_unregister.
1998 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
2002 if (cpufreq_disabled())
2006 case CPUFREQ_TRANSITION_NOTIFIER:
2007 mutex_lock(&cpufreq_fast_switch_lock);
2009 ret = srcu_notifier_chain_unregister(
2010 &cpufreq_transition_notifier_list, nb);
2011 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
2012 cpufreq_fast_switch_count++;
2014 mutex_unlock(&cpufreq_fast_switch_lock);
2016 case CPUFREQ_POLICY_NOTIFIER:
2017 ret = blocking_notifier_chain_unregister(
2018 &cpufreq_policy_notifier_list, nb);
2026 EXPORT_SYMBOL(cpufreq_unregister_notifier);
2029 /*********************************************************************
2031 *********************************************************************/
2034 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
2035 * @policy: cpufreq policy to switch the frequency for.
2036 * @target_freq: New frequency to set (may be approximate).
2038 * Carry out a fast frequency switch without sleeping.
2040 * The driver's ->fast_switch() callback invoked by this function must be
2041 * suitable for being called from within RCU-sched read-side critical sections
2042 * and it is expected to select the minimum available frequency greater than or
2043 * equal to @target_freq (CPUFREQ_RELATION_L).
2045 * This function must not be called if policy->fast_switch_enabled is unset.
2047 * Governors calling this function must guarantee that it will never be invoked
2048 * twice in parallel for the same policy and that it will never be called in
2049 * parallel with either ->target() or ->target_index() for the same policy.
2051 * Returns the actual frequency set for the CPU.
2053 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2054 * error condition, the hardware configuration must be preserved.
2056 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2057 unsigned int target_freq)
2059 target_freq = clamp_val(target_freq, policy->min, policy->max);
2061 return cpufreq_driver->fast_switch(policy, target_freq);
2063 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2065 /* Must set freqs->new to intermediate frequency */
2066 static int __target_intermediate(struct cpufreq_policy *policy,
2067 struct cpufreq_freqs *freqs, int index)
2071 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2073 /* We don't need to switch to intermediate freq */
2077 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2078 __func__, policy->cpu, freqs->old, freqs->new);
2080 cpufreq_freq_transition_begin(policy, freqs);
2081 ret = cpufreq_driver->target_intermediate(policy, index);
2082 cpufreq_freq_transition_end(policy, freqs, ret);
2085 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2091 static int __target_index(struct cpufreq_policy *policy, int index)
2093 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2094 unsigned int intermediate_freq = 0;
2095 unsigned int newfreq = policy->freq_table[index].frequency;
2096 int retval = -EINVAL;
2099 if (newfreq == policy->cur)
2102 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2104 /* Handle switching to intermediate frequency */
2105 if (cpufreq_driver->get_intermediate) {
2106 retval = __target_intermediate(policy, &freqs, index);
2110 intermediate_freq = freqs.new;
2111 /* Set old freq to intermediate */
2112 if (intermediate_freq)
2113 freqs.old = freqs.new;
2116 freqs.new = newfreq;
2117 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2118 __func__, policy->cpu, freqs.old, freqs.new);
2120 cpufreq_freq_transition_begin(policy, &freqs);
2123 retval = cpufreq_driver->target_index(policy, index);
2125 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2129 cpufreq_freq_transition_end(policy, &freqs, retval);
2132 * Failed after setting to intermediate freq? Driver should have
2133 * reverted back to initial frequency and so should we. Check
2134 * here for intermediate_freq instead of get_intermediate, in
2135 * case we haven't switched to intermediate freq at all.
2137 if (unlikely(retval && intermediate_freq)) {
2138 freqs.old = intermediate_freq;
2139 freqs.new = policy->restore_freq;
2140 cpufreq_freq_transition_begin(policy, &freqs);
2141 cpufreq_freq_transition_end(policy, &freqs, 0);
2148 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2149 unsigned int target_freq,
2150 unsigned int relation)
2152 unsigned int old_target_freq = target_freq;
2155 if (cpufreq_disabled())
2158 /* Make sure that target_freq is within supported range */
2159 target_freq = clamp_val(target_freq, policy->min, policy->max);
2161 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2162 policy->cpu, target_freq, relation, old_target_freq);
2165 * This might look like a redundant call as we are checking it again
2166 * after finding index. But it is left intentionally for cases where
2167 * exactly same freq is called again and so we can save on few function
2170 if (target_freq == policy->cur)
2173 /* Save last value to restore later on errors */
2174 policy->restore_freq = policy->cur;
2176 if (cpufreq_driver->target)
2177 return cpufreq_driver->target(policy, target_freq, relation);
2179 if (!cpufreq_driver->target_index)
2182 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2184 return __target_index(policy, index);
2186 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2188 int cpufreq_driver_target(struct cpufreq_policy *policy,
2189 unsigned int target_freq,
2190 unsigned int relation)
2194 down_write(&policy->rwsem);
2196 ret = __cpufreq_driver_target(policy, target_freq, relation);
2198 up_write(&policy->rwsem);
2202 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2204 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2209 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2213 /* Don't start any governor operations if we are entering suspend */
2214 if (cpufreq_suspended)
2217 * Governor might not be initiated here if ACPI _PPC changed
2218 * notification happened, so check it.
2220 if (!policy->governor)
2223 /* Platform doesn't want dynamic frequency switching ? */
2224 if (policy->governor->dynamic_switching &&
2225 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2226 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2229 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2230 policy->governor->name, gov->name);
2231 policy->governor = gov;
2237 if (!try_module_get(policy->governor->owner))
2240 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2242 if (policy->governor->init) {
2243 ret = policy->governor->init(policy);
2245 module_put(policy->governor->owner);
2253 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2255 if (cpufreq_suspended || !policy->governor)
2258 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2260 if (policy->governor->exit)
2261 policy->governor->exit(policy);
2263 module_put(policy->governor->owner);
2266 int cpufreq_start_governor(struct cpufreq_policy *policy)
2270 if (cpufreq_suspended)
2273 if (!policy->governor)
2276 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2278 if (cpufreq_driver->get)
2279 cpufreq_verify_current_freq(policy, false);
2281 if (policy->governor->start) {
2282 ret = policy->governor->start(policy);
2287 if (policy->governor->limits)
2288 policy->governor->limits(policy);
2293 void cpufreq_stop_governor(struct cpufreq_policy *policy)
2295 if (cpufreq_suspended || !policy->governor)
2298 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2300 if (policy->governor->stop)
2301 policy->governor->stop(policy);
2304 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2306 if (cpufreq_suspended || !policy->governor)
2309 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2311 if (policy->governor->limits)
2312 policy->governor->limits(policy);
2315 int cpufreq_register_governor(struct cpufreq_governor *governor)
2322 if (cpufreq_disabled())
2325 mutex_lock(&cpufreq_governor_mutex);
2328 if (!find_governor(governor->name)) {
2330 list_add(&governor->governor_list, &cpufreq_governor_list);
2333 mutex_unlock(&cpufreq_governor_mutex);
2336 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2338 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2340 struct cpufreq_policy *policy;
2341 unsigned long flags;
2346 if (cpufreq_disabled())
2349 /* clear last_governor for all inactive policies */
2350 read_lock_irqsave(&cpufreq_driver_lock, flags);
2351 for_each_inactive_policy(policy) {
2352 if (!strcmp(policy->last_governor, governor->name)) {
2353 policy->governor = NULL;
2354 strcpy(policy->last_governor, "\0");
2357 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2359 mutex_lock(&cpufreq_governor_mutex);
2360 list_del(&governor->governor_list);
2361 mutex_unlock(&cpufreq_governor_mutex);
2363 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2366 /*********************************************************************
2367 * POLICY INTERFACE *
2368 *********************************************************************/
2371 * cpufreq_get_policy - get the current cpufreq_policy
2372 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2374 * @cpu: CPU to find the policy for
2376 * Reads the current cpufreq policy.
2378 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2380 struct cpufreq_policy *cpu_policy;
2384 cpu_policy = cpufreq_cpu_get(cpu);
2388 memcpy(policy, cpu_policy, sizeof(*policy));
2390 cpufreq_cpu_put(cpu_policy);
2393 EXPORT_SYMBOL(cpufreq_get_policy);
2396 * cpufreq_set_policy - Modify cpufreq policy parameters.
2397 * @policy: Policy object to modify.
2398 * @new_gov: Policy governor pointer.
2399 * @new_pol: Policy value (for drivers with built-in governors).
2401 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
2402 * limits to be set for the policy, update @policy with the verified limits
2403 * values and either invoke the driver's ->setpolicy() callback (if present) or
2404 * carry out a governor update for @policy. That is, run the current governor's
2405 * ->limits() callback (if @new_gov points to the same object as the one in
2406 * @policy) or replace the governor for @policy with @new_gov.
2408 * The cpuinfo part of @policy is not updated by this function.
2410 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2411 struct cpufreq_governor *new_gov,
2412 unsigned int new_pol)
2414 struct cpufreq_policy_data new_data;
2415 struct cpufreq_governor *old_gov;
2418 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2419 new_data.freq_table = policy->freq_table;
2420 new_data.cpu = policy->cpu;
2422 * PM QoS framework collects all the requests from users and provide us
2423 * the final aggregated value here.
2425 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN);
2426 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX);
2428 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2429 new_data.cpu, new_data.min, new_data.max);
2432 * Verify that the CPU speed can be set within these limits and make sure
2435 ret = cpufreq_driver->verify(&new_data);
2439 policy->min = new_data.min;
2440 policy->max = new_data.max;
2441 trace_cpu_frequency_limits(policy);
2443 policy->cached_target_freq = UINT_MAX;
2445 pr_debug("new min and max freqs are %u - %u kHz\n",
2446 policy->min, policy->max);
2448 if (cpufreq_driver->setpolicy) {
2449 policy->policy = new_pol;
2450 pr_debug("setting range\n");
2451 return cpufreq_driver->setpolicy(policy);
2454 if (new_gov == policy->governor) {
2455 pr_debug("governor limits update\n");
2456 cpufreq_governor_limits(policy);
2460 pr_debug("governor switch\n");
2462 /* save old, working values */
2463 old_gov = policy->governor;
2464 /* end old governor */
2466 cpufreq_stop_governor(policy);
2467 cpufreq_exit_governor(policy);
2470 /* start new governor */
2471 policy->governor = new_gov;
2472 ret = cpufreq_init_governor(policy);
2474 ret = cpufreq_start_governor(policy);
2476 pr_debug("governor change\n");
2477 sched_cpufreq_governor_change(policy, old_gov);
2480 cpufreq_exit_governor(policy);
2483 /* new governor failed, so re-start old one */
2484 pr_debug("starting governor %s failed\n", policy->governor->name);
2486 policy->governor = old_gov;
2487 if (cpufreq_init_governor(policy))
2488 policy->governor = NULL;
2490 cpufreq_start_governor(policy);
2497 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2498 * @cpu: CPU to re-evaluate the policy for.
2500 * Update the current frequency for the cpufreq policy of @cpu and use
2501 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2502 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2503 * for the policy in question, among other things.
2505 void cpufreq_update_policy(unsigned int cpu)
2507 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2513 * BIOS might change freq behind our back
2514 * -> ask driver for current freq and notify governors about a change
2516 if (cpufreq_driver->get && has_target() &&
2517 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2520 refresh_frequency_limits(policy);
2523 cpufreq_cpu_release(policy);
2525 EXPORT_SYMBOL(cpufreq_update_policy);
2528 * cpufreq_update_limits - Update policy limits for a given CPU.
2529 * @cpu: CPU to update the policy limits for.
2531 * Invoke the driver's ->update_limits callback if present or call
2532 * cpufreq_update_policy() for @cpu.
2534 void cpufreq_update_limits(unsigned int cpu)
2536 if (cpufreq_driver->update_limits)
2537 cpufreq_driver->update_limits(cpu);
2539 cpufreq_update_policy(cpu);
2541 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2543 /*********************************************************************
2545 *********************************************************************/
2546 static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state)
2550 if (!policy->freq_table)
2553 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
2555 pr_err("%s: Policy frequency update failed\n", __func__);
2559 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
2566 int cpufreq_boost_trigger_state(int state)
2568 struct cpufreq_policy *policy;
2569 unsigned long flags;
2572 if (cpufreq_driver->boost_enabled == state)
2575 write_lock_irqsave(&cpufreq_driver_lock, flags);
2576 cpufreq_driver->boost_enabled = state;
2577 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2580 for_each_active_policy(policy) {
2581 ret = cpufreq_driver->set_boost(policy, state);
2583 goto err_reset_state;
2592 write_lock_irqsave(&cpufreq_driver_lock, flags);
2593 cpufreq_driver->boost_enabled = !state;
2594 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2596 pr_err("%s: Cannot %s BOOST\n",
2597 __func__, state ? "enable" : "disable");
2602 static bool cpufreq_boost_supported(void)
2604 return cpufreq_driver->set_boost;
2607 static int create_boost_sysfs_file(void)
2611 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2613 pr_err("%s: cannot register global BOOST sysfs file\n",
2619 static void remove_boost_sysfs_file(void)
2621 if (cpufreq_boost_supported())
2622 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2625 int cpufreq_enable_boost_support(void)
2627 if (!cpufreq_driver)
2630 if (cpufreq_boost_supported())
2633 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2635 /* This will get removed on driver unregister */
2636 return create_boost_sysfs_file();
2638 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2640 int cpufreq_boost_enabled(void)
2642 return cpufreq_driver->boost_enabled;
2644 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2646 /*********************************************************************
2647 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2648 *********************************************************************/
2649 static enum cpuhp_state hp_online;
2651 static int cpuhp_cpufreq_online(unsigned int cpu)
2653 cpufreq_online(cpu);
2658 static int cpuhp_cpufreq_offline(unsigned int cpu)
2660 cpufreq_offline(cpu);
2666 * cpufreq_register_driver - register a CPU Frequency driver
2667 * @driver_data: A struct cpufreq_driver containing the values#
2668 * submitted by the CPU Frequency driver.
2670 * Registers a CPU Frequency driver to this core code. This code
2671 * returns zero on success, -EEXIST when another driver got here first
2672 * (and isn't unregistered in the meantime).
2675 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2677 unsigned long flags;
2680 if (cpufreq_disabled())
2684 * The cpufreq core depends heavily on the availability of device
2685 * structure, make sure they are available before proceeding further.
2687 if (!get_cpu_device(0))
2688 return -EPROBE_DEFER;
2690 if (!driver_data || !driver_data->verify || !driver_data->init ||
2691 !(driver_data->setpolicy || driver_data->target_index ||
2692 driver_data->target) ||
2693 (driver_data->setpolicy && (driver_data->target_index ||
2694 driver_data->target)) ||
2695 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2696 (!driver_data->online != !driver_data->offline))
2699 pr_debug("trying to register driver %s\n", driver_data->name);
2701 /* Protect against concurrent CPU online/offline. */
2704 write_lock_irqsave(&cpufreq_driver_lock, flags);
2705 if (cpufreq_driver) {
2706 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2710 cpufreq_driver = driver_data;
2711 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2713 if (driver_data->setpolicy)
2714 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2716 if (cpufreq_boost_supported()) {
2717 ret = create_boost_sysfs_file();
2719 goto err_null_driver;
2722 ret = subsys_interface_register(&cpufreq_interface);
2724 goto err_boost_unreg;
2726 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2727 list_empty(&cpufreq_policy_list)) {
2728 /* if all ->init() calls failed, unregister */
2730 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2735 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2737 cpuhp_cpufreq_online,
2738 cpuhp_cpufreq_offline);
2744 pr_debug("driver %s up and running\n", driver_data->name);
2748 subsys_interface_unregister(&cpufreq_interface);
2750 remove_boost_sysfs_file();
2752 write_lock_irqsave(&cpufreq_driver_lock, flags);
2753 cpufreq_driver = NULL;
2754 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2759 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2762 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2764 * Unregister the current CPUFreq driver. Only call this if you have
2765 * the right to do so, i.e. if you have succeeded in initialising before!
2766 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2767 * currently not initialised.
2769 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2771 unsigned long flags;
2773 if (!cpufreq_driver || (driver != cpufreq_driver))
2776 pr_debug("unregistering driver %s\n", driver->name);
2778 /* Protect against concurrent cpu hotplug */
2780 subsys_interface_unregister(&cpufreq_interface);
2781 remove_boost_sysfs_file();
2782 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2784 write_lock_irqsave(&cpufreq_driver_lock, flags);
2786 cpufreq_driver = NULL;
2788 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2793 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2795 static int __init cpufreq_core_init(void)
2797 struct cpufreq_governor *gov = cpufreq_default_governor();
2799 if (cpufreq_disabled())
2802 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2803 BUG_ON(!cpufreq_global_kobject);
2805 if (!strlen(default_governor))
2806 strncpy(default_governor, gov->name, CPUFREQ_NAME_LEN);
2810 module_param(off, int, 0444);
2811 module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444);
2812 core_initcall(cpufreq_core_init);