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)
54 * The "cpufreq driver" - the arch- or hardware-dependent low
55 * level driver of CPUFreq support, and its spinlock. This lock
56 * also protects the cpufreq_cpu_data array.
58 static struct cpufreq_driver *cpufreq_driver;
59 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
60 static DEFINE_RWLOCK(cpufreq_driver_lock);
62 /* Flag to suspend/resume CPUFreq governors */
63 static bool cpufreq_suspended;
65 static inline bool has_target(void)
67 return cpufreq_driver->target_index || cpufreq_driver->target;
70 /* internal prototypes */
71 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
72 static int cpufreq_init_governor(struct cpufreq_policy *policy);
73 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
74 static int cpufreq_start_governor(struct cpufreq_policy *policy);
75 static void cpufreq_stop_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 * @target_freq: target frequency to resolve.
529 * The target to driver frequency mapping is cached in the policy.
531 * Return: Lowest driver-supported frequency greater than or equal to the
532 * given target_freq, subject to policy (min/max) and driver limitations.
534 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
535 unsigned int target_freq)
537 target_freq = clamp_val(target_freq, policy->min, policy->max);
538 policy->cached_target_freq = target_freq;
540 if (cpufreq_driver->target_index) {
543 idx = cpufreq_frequency_table_target(policy, target_freq,
545 policy->cached_resolved_idx = idx;
546 return policy->freq_table[idx].frequency;
549 if (cpufreq_driver->resolve_freq)
550 return cpufreq_driver->resolve_freq(policy, target_freq);
554 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
556 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
558 unsigned int latency;
560 if (policy->transition_delay_us)
561 return policy->transition_delay_us;
563 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
566 * For platforms that can change the frequency very fast (< 10
567 * us), the above formula gives a decent transition delay. But
568 * for platforms where transition_latency is in milliseconds, it
569 * ends up giving unrealistic values.
571 * Cap the default transition delay to 10 ms, which seems to be
572 * a reasonable amount of time after which we should reevaluate
575 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
578 return LATENCY_MULTIPLIER;
580 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
582 /*********************************************************************
584 *********************************************************************/
585 static ssize_t show_boost(struct kobject *kobj,
586 struct kobj_attribute *attr, char *buf)
588 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
591 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
592 const char *buf, size_t count)
596 ret = sscanf(buf, "%d", &enable);
597 if (ret != 1 || enable < 0 || enable > 1)
600 if (cpufreq_boost_trigger_state(enable)) {
601 pr_err("%s: Cannot %s BOOST!\n",
602 __func__, enable ? "enable" : "disable");
606 pr_debug("%s: cpufreq BOOST %s\n",
607 __func__, enable ? "enabled" : "disabled");
611 define_one_global_rw(boost);
613 static struct cpufreq_governor *find_governor(const char *str_governor)
615 struct cpufreq_governor *t;
618 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
624 static unsigned int cpufreq_parse_policy(char *str_governor)
626 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN))
627 return CPUFREQ_POLICY_PERFORMANCE;
629 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN))
630 return CPUFREQ_POLICY_POWERSAVE;
632 return CPUFREQ_POLICY_UNKNOWN;
636 * cpufreq_parse_governor - parse a governor string only for has_target()
637 * @str_governor: Governor name.
639 static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor)
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);
668 * cpufreq_per_cpu_attr_read() / show_##file_name() -
669 * print out cpufreq information
671 * Write out information from cpufreq_driver->policy[cpu]; object must be
675 #define show_one(file_name, object) \
676 static ssize_t show_##file_name \
677 (struct cpufreq_policy *policy, char *buf) \
679 return sprintf(buf, "%u\n", policy->object); \
682 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
683 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
684 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
685 show_one(scaling_min_freq, min);
686 show_one(scaling_max_freq, max);
688 __weak unsigned int arch_freq_get_on_cpu(int cpu)
693 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
698 freq = arch_freq_get_on_cpu(policy->cpu);
700 ret = sprintf(buf, "%u\n", freq);
701 else if (cpufreq_driver && cpufreq_driver->setpolicy &&
703 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
705 ret = sprintf(buf, "%u\n", policy->cur);
710 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
712 #define store_one(file_name, object) \
713 static ssize_t store_##file_name \
714 (struct cpufreq_policy *policy, const char *buf, size_t count) \
719 ret = sscanf(buf, "%lu", &val); \
723 ret = freq_qos_update_request(policy->object##_freq_req, val);\
724 return ret >= 0 ? count : ret; \
727 store_one(scaling_min_freq, min);
728 store_one(scaling_max_freq, max);
731 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
733 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
736 unsigned int cur_freq = __cpufreq_get(policy);
739 return sprintf(buf, "%u\n", cur_freq);
741 return sprintf(buf, "<unknown>\n");
745 * show_scaling_governor - show the current policy for the specified CPU
747 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
749 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
750 return sprintf(buf, "powersave\n");
751 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
752 return sprintf(buf, "performance\n");
753 else if (policy->governor)
754 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
755 policy->governor->name);
760 * store_scaling_governor - store policy for the specified CPU
762 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
763 const char *buf, size_t count)
765 char str_governor[16];
768 ret = sscanf(buf, "%15s", str_governor);
772 if (cpufreq_driver->setpolicy) {
773 unsigned int new_pol;
775 new_pol = cpufreq_parse_policy(str_governor);
779 ret = cpufreq_set_policy(policy, NULL, new_pol);
781 struct cpufreq_governor *new_gov;
783 new_gov = cpufreq_parse_governor(str_governor);
787 ret = cpufreq_set_policy(policy, new_gov,
788 CPUFREQ_POLICY_UNKNOWN);
790 module_put(new_gov->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);
944 down_read(&policy->rwsem);
945 ret = fattr->show(policy, buf);
946 up_read(&policy->rwsem);
951 static ssize_t store(struct kobject *kobj, struct attribute *attr,
952 const char *buf, size_t count)
954 struct cpufreq_policy *policy = to_policy(kobj);
955 struct freq_attr *fattr = to_attr(attr);
956 ssize_t ret = -EINVAL;
962 * cpus_read_trylock() is used here to work around a circular lock
963 * dependency problem with respect to the cpufreq_register_driver().
965 if (!cpus_read_trylock())
968 if (cpu_online(policy->cpu)) {
969 down_write(&policy->rwsem);
970 ret = fattr->store(policy, buf, count);
971 up_write(&policy->rwsem);
979 static void cpufreq_sysfs_release(struct kobject *kobj)
981 struct cpufreq_policy *policy = to_policy(kobj);
982 pr_debug("last reference is dropped\n");
983 complete(&policy->kobj_unregister);
986 static const struct sysfs_ops sysfs_ops = {
991 static struct kobj_type ktype_cpufreq = {
992 .sysfs_ops = &sysfs_ops,
993 .default_attrs = default_attrs,
994 .release = cpufreq_sysfs_release,
997 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
999 struct device *dev = get_cpu_device(cpu);
1004 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1007 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1008 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1009 dev_err(dev, "cpufreq symlink creation failed\n");
1012 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1015 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1016 sysfs_remove_link(&dev->kobj, "cpufreq");
1019 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1021 struct freq_attr **drv_attr;
1024 /* set up files for this cpu device */
1025 drv_attr = cpufreq_driver->attr;
1026 while (drv_attr && *drv_attr) {
1027 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1032 if (cpufreq_driver->get) {
1033 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1038 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1042 if (cpufreq_driver->bios_limit) {
1043 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1051 __weak struct cpufreq_governor *cpufreq_default_governor(void)
1056 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1058 struct cpufreq_governor *def_gov = cpufreq_default_governor();
1059 struct cpufreq_governor *gov = NULL;
1060 unsigned int pol = CPUFREQ_POLICY_UNKNOWN;
1063 /* Update policy governor to the one used before hotplug. */
1064 gov = find_governor(policy->last_governor);
1066 pr_debug("Restoring governor %s for cpu %d\n",
1067 policy->governor->name, policy->cpu);
1068 } else if (def_gov) {
1074 /* Use the default policy if there is no last_policy. */
1075 if (policy->last_policy) {
1076 pol = policy->last_policy;
1077 } else if (def_gov) {
1078 pol = cpufreq_parse_policy(def_gov->name);
1084 return cpufreq_set_policy(policy, gov, pol);
1087 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1091 /* Has this CPU been taken care of already? */
1092 if (cpumask_test_cpu(cpu, policy->cpus))
1095 down_write(&policy->rwsem);
1097 cpufreq_stop_governor(policy);
1099 cpumask_set_cpu(cpu, policy->cpus);
1102 ret = cpufreq_start_governor(policy);
1104 pr_err("%s: Failed to start governor\n", __func__);
1106 up_write(&policy->rwsem);
1110 void refresh_frequency_limits(struct cpufreq_policy *policy)
1112 if (!policy_is_inactive(policy)) {
1113 pr_debug("updating policy for CPU %u\n", policy->cpu);
1115 cpufreq_set_policy(policy, policy->governor, policy->policy);
1118 EXPORT_SYMBOL(refresh_frequency_limits);
1120 static void handle_update(struct work_struct *work)
1122 struct cpufreq_policy *policy =
1123 container_of(work, struct cpufreq_policy, update);
1125 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1126 down_write(&policy->rwsem);
1127 refresh_frequency_limits(policy);
1128 up_write(&policy->rwsem);
1131 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1134 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1136 schedule_work(&policy->update);
1140 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1143 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1145 schedule_work(&policy->update);
1149 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1151 struct kobject *kobj;
1152 struct completion *cmp;
1154 down_write(&policy->rwsem);
1155 cpufreq_stats_free_table(policy);
1156 kobj = &policy->kobj;
1157 cmp = &policy->kobj_unregister;
1158 up_write(&policy->rwsem);
1162 * We need to make sure that the underlying kobj is
1163 * actually not referenced anymore by anybody before we
1164 * proceed with unloading.
1166 pr_debug("waiting for dropping of refcount\n");
1167 wait_for_completion(cmp);
1168 pr_debug("wait complete\n");
1171 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1173 struct cpufreq_policy *policy;
1174 struct device *dev = get_cpu_device(cpu);
1180 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1184 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1185 goto err_free_policy;
1187 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1188 goto err_free_cpumask;
1190 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1191 goto err_free_rcpumask;
1193 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1194 cpufreq_global_kobject, "policy%u", cpu);
1196 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1198 * The entire policy object will be freed below, but the extra
1199 * memory allocated for the kobject name needs to be freed by
1200 * releasing the kobject.
1202 kobject_put(&policy->kobj);
1203 goto err_free_real_cpus;
1206 freq_constraints_init(&policy->constraints);
1208 policy->nb_min.notifier_call = cpufreq_notifier_min;
1209 policy->nb_max.notifier_call = cpufreq_notifier_max;
1211 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN,
1214 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1215 ret, cpumask_pr_args(policy->cpus));
1216 goto err_kobj_remove;
1219 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX,
1222 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1223 ret, cpumask_pr_args(policy->cpus));
1224 goto err_min_qos_notifier;
1227 INIT_LIST_HEAD(&policy->policy_list);
1228 init_rwsem(&policy->rwsem);
1229 spin_lock_init(&policy->transition_lock);
1230 init_waitqueue_head(&policy->transition_wait);
1231 init_completion(&policy->kobj_unregister);
1232 INIT_WORK(&policy->update, handle_update);
1237 err_min_qos_notifier:
1238 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1241 cpufreq_policy_put_kobj(policy);
1243 free_cpumask_var(policy->real_cpus);
1245 free_cpumask_var(policy->related_cpus);
1247 free_cpumask_var(policy->cpus);
1254 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1256 unsigned long flags;
1259 /* Remove policy from list */
1260 write_lock_irqsave(&cpufreq_driver_lock, flags);
1261 list_del(&policy->policy_list);
1263 for_each_cpu(cpu, policy->related_cpus)
1264 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1265 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1267 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX,
1269 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1272 /* Cancel any pending policy->update work before freeing the policy. */
1273 cancel_work_sync(&policy->update);
1275 if (policy->max_freq_req) {
1277 * CPUFREQ_CREATE_POLICY notification is sent only after
1278 * successfully adding max_freq_req request.
1280 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1281 CPUFREQ_REMOVE_POLICY, policy);
1282 freq_qos_remove_request(policy->max_freq_req);
1285 freq_qos_remove_request(policy->min_freq_req);
1286 kfree(policy->min_freq_req);
1288 cpufreq_policy_put_kobj(policy);
1289 free_cpumask_var(policy->real_cpus);
1290 free_cpumask_var(policy->related_cpus);
1291 free_cpumask_var(policy->cpus);
1295 static int cpufreq_online(unsigned int cpu)
1297 struct cpufreq_policy *policy;
1299 unsigned long flags;
1303 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1305 /* Check if this CPU already has a policy to manage it */
1306 policy = per_cpu(cpufreq_cpu_data, cpu);
1308 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1309 if (!policy_is_inactive(policy))
1310 return cpufreq_add_policy_cpu(policy, cpu);
1312 /* This is the only online CPU for the policy. Start over. */
1314 down_write(&policy->rwsem);
1316 policy->governor = NULL;
1317 up_write(&policy->rwsem);
1320 policy = cpufreq_policy_alloc(cpu);
1325 if (!new_policy && cpufreq_driver->online) {
1326 ret = cpufreq_driver->online(policy);
1328 pr_debug("%s: %d: initialization failed\n", __func__,
1330 goto out_exit_policy;
1333 /* Recover policy->cpus using related_cpus */
1334 cpumask_copy(policy->cpus, policy->related_cpus);
1336 cpumask_copy(policy->cpus, cpumask_of(cpu));
1339 * Call driver. From then on the cpufreq must be able
1340 * to accept all calls to ->verify and ->setpolicy for this CPU.
1342 ret = cpufreq_driver->init(policy);
1344 pr_debug("%s: %d: initialization failed\n", __func__,
1346 goto out_free_policy;
1349 ret = cpufreq_table_validate_and_sort(policy);
1351 goto out_exit_policy;
1353 /* related_cpus should at least include policy->cpus. */
1354 cpumask_copy(policy->related_cpus, policy->cpus);
1357 down_write(&policy->rwsem);
1359 * affected cpus must always be the one, which are online. We aren't
1360 * managing offline cpus here.
1362 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1365 for_each_cpu(j, policy->related_cpus) {
1366 per_cpu(cpufreq_cpu_data, j) = policy;
1367 add_cpu_dev_symlink(policy, j);
1370 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1372 if (!policy->min_freq_req)
1373 goto out_destroy_policy;
1375 ret = freq_qos_add_request(&policy->constraints,
1376 policy->min_freq_req, FREQ_QOS_MIN,
1380 * So we don't call freq_qos_remove_request() for an
1381 * uninitialized request.
1383 kfree(policy->min_freq_req);
1384 policy->min_freq_req = NULL;
1385 goto out_destroy_policy;
1389 * This must be initialized right here to avoid calling
1390 * freq_qos_remove_request() on uninitialized request in case
1393 policy->max_freq_req = policy->min_freq_req + 1;
1395 ret = freq_qos_add_request(&policy->constraints,
1396 policy->max_freq_req, FREQ_QOS_MAX,
1399 policy->max_freq_req = NULL;
1400 goto out_destroy_policy;
1403 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1404 CPUFREQ_CREATE_POLICY, policy);
1407 if (cpufreq_driver->get && has_target()) {
1408 policy->cur = cpufreq_driver->get(policy->cpu);
1410 pr_err("%s: ->get() failed\n", __func__);
1411 goto out_destroy_policy;
1416 * Sometimes boot loaders set CPU frequency to a value outside of
1417 * frequency table present with cpufreq core. In such cases CPU might be
1418 * unstable if it has to run on that frequency for long duration of time
1419 * and so its better to set it to a frequency which is specified in
1420 * freq-table. This also makes cpufreq stats inconsistent as
1421 * cpufreq-stats would fail to register because current frequency of CPU
1422 * isn't found in freq-table.
1424 * Because we don't want this change to effect boot process badly, we go
1425 * for the next freq which is >= policy->cur ('cur' must be set by now,
1426 * otherwise we will end up setting freq to lowest of the table as 'cur'
1427 * is initialized to zero).
1429 * We are passing target-freq as "policy->cur - 1" otherwise
1430 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1431 * equal to target-freq.
1433 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1435 /* Are we running at unknown frequency ? */
1436 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1437 if (ret == -EINVAL) {
1438 /* Warn user and fix it */
1439 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1440 __func__, policy->cpu, policy->cur);
1441 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1442 CPUFREQ_RELATION_L);
1445 * Reaching here after boot in a few seconds may not
1446 * mean that system will remain stable at "unknown"
1447 * frequency for longer duration. Hence, a BUG_ON().
1450 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1451 __func__, policy->cpu, policy->cur);
1456 ret = cpufreq_add_dev_interface(policy);
1458 goto out_destroy_policy;
1460 cpufreq_stats_create_table(policy);
1462 write_lock_irqsave(&cpufreq_driver_lock, flags);
1463 list_add(&policy->policy_list, &cpufreq_policy_list);
1464 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1467 ret = cpufreq_init_policy(policy);
1469 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1470 __func__, cpu, ret);
1471 goto out_destroy_policy;
1474 up_write(&policy->rwsem);
1476 kobject_uevent(&policy->kobj, KOBJ_ADD);
1478 /* Callback for handling stuff after policy is ready */
1479 if (cpufreq_driver->ready)
1480 cpufreq_driver->ready(policy);
1482 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1483 policy->cdev = of_cpufreq_cooling_register(policy);
1485 pr_debug("initialization complete\n");
1490 for_each_cpu(j, policy->real_cpus)
1491 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1493 up_write(&policy->rwsem);
1496 if (cpufreq_driver->exit)
1497 cpufreq_driver->exit(policy);
1500 cpufreq_policy_free(policy);
1505 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1507 * @sif: Subsystem interface structure pointer (not used)
1509 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1511 struct cpufreq_policy *policy;
1512 unsigned cpu = dev->id;
1515 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1517 if (cpu_online(cpu)) {
1518 ret = cpufreq_online(cpu);
1523 /* Create sysfs link on CPU registration */
1524 policy = per_cpu(cpufreq_cpu_data, cpu);
1526 add_cpu_dev_symlink(policy, cpu);
1531 static int cpufreq_offline(unsigned int cpu)
1533 struct cpufreq_policy *policy;
1536 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1538 policy = cpufreq_cpu_get_raw(cpu);
1540 pr_debug("%s: No cpu_data found\n", __func__);
1544 down_write(&policy->rwsem);
1546 cpufreq_stop_governor(policy);
1548 cpumask_clear_cpu(cpu, policy->cpus);
1550 if (policy_is_inactive(policy)) {
1552 strncpy(policy->last_governor, policy->governor->name,
1555 policy->last_policy = policy->policy;
1556 } else if (cpu == policy->cpu) {
1557 /* Nominate new CPU */
1558 policy->cpu = cpumask_any(policy->cpus);
1561 /* Start governor again for active policy */
1562 if (!policy_is_inactive(policy)) {
1564 ret = cpufreq_start_governor(policy);
1566 pr_err("%s: Failed to start governor\n", __func__);
1572 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1573 cpufreq_cooling_unregister(policy->cdev);
1574 policy->cdev = NULL;
1577 if (cpufreq_driver->stop_cpu)
1578 cpufreq_driver->stop_cpu(policy);
1581 cpufreq_exit_governor(policy);
1584 * Perform the ->offline() during light-weight tear-down, as
1585 * that allows fast recovery when the CPU comes back.
1587 if (cpufreq_driver->offline) {
1588 cpufreq_driver->offline(policy);
1589 } else if (cpufreq_driver->exit) {
1590 cpufreq_driver->exit(policy);
1591 policy->freq_table = NULL;
1595 up_write(&policy->rwsem);
1600 * cpufreq_remove_dev - remove a CPU device
1602 * Removes the cpufreq interface for a CPU device.
1604 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1606 unsigned int cpu = dev->id;
1607 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1612 if (cpu_online(cpu))
1613 cpufreq_offline(cpu);
1615 cpumask_clear_cpu(cpu, policy->real_cpus);
1616 remove_cpu_dev_symlink(policy, dev);
1618 if (cpumask_empty(policy->real_cpus)) {
1619 /* We did light-weight exit earlier, do full tear down now */
1620 if (cpufreq_driver->offline)
1621 cpufreq_driver->exit(policy);
1623 cpufreq_policy_free(policy);
1628 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1630 * @policy: policy managing CPUs
1631 * @new_freq: CPU frequency the CPU actually runs at
1633 * We adjust to current frequency first, and need to clean up later.
1634 * So either call to cpufreq_update_policy() or schedule handle_update()).
1636 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1637 unsigned int new_freq)
1639 struct cpufreq_freqs freqs;
1641 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1642 policy->cur, new_freq);
1644 freqs.old = policy->cur;
1645 freqs.new = new_freq;
1647 cpufreq_freq_transition_begin(policy, &freqs);
1648 cpufreq_freq_transition_end(policy, &freqs, 0);
1651 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1653 unsigned int new_freq;
1655 new_freq = cpufreq_driver->get(policy->cpu);
1660 * If fast frequency switching is used with the given policy, the check
1661 * against policy->cur is pointless, so skip it in that case.
1663 if (policy->fast_switch_enabled || !has_target())
1666 if (policy->cur != new_freq) {
1667 cpufreq_out_of_sync(policy, new_freq);
1669 schedule_work(&policy->update);
1676 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1679 * This is the last known freq, without actually getting it from the driver.
1680 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1682 unsigned int cpufreq_quick_get(unsigned int cpu)
1684 struct cpufreq_policy *policy;
1685 unsigned int ret_freq = 0;
1686 unsigned long flags;
1688 read_lock_irqsave(&cpufreq_driver_lock, flags);
1690 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1691 ret_freq = cpufreq_driver->get(cpu);
1692 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1696 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1698 policy = cpufreq_cpu_get(cpu);
1700 ret_freq = policy->cur;
1701 cpufreq_cpu_put(policy);
1706 EXPORT_SYMBOL(cpufreq_quick_get);
1709 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1712 * Just return the max possible frequency for a given CPU.
1714 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1716 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1717 unsigned int ret_freq = 0;
1720 ret_freq = policy->max;
1721 cpufreq_cpu_put(policy);
1726 EXPORT_SYMBOL(cpufreq_quick_get_max);
1728 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1730 if (unlikely(policy_is_inactive(policy)))
1733 return cpufreq_verify_current_freq(policy, true);
1737 * cpufreq_get - get the current CPU frequency (in kHz)
1740 * Get the CPU current (static) CPU frequency
1742 unsigned int cpufreq_get(unsigned int cpu)
1744 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1745 unsigned int ret_freq = 0;
1748 down_read(&policy->rwsem);
1749 if (cpufreq_driver->get)
1750 ret_freq = __cpufreq_get(policy);
1751 up_read(&policy->rwsem);
1753 cpufreq_cpu_put(policy);
1758 EXPORT_SYMBOL(cpufreq_get);
1760 static struct subsys_interface cpufreq_interface = {
1762 .subsys = &cpu_subsys,
1763 .add_dev = cpufreq_add_dev,
1764 .remove_dev = cpufreq_remove_dev,
1768 * In case platform wants some specific frequency to be configured
1771 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1775 if (!policy->suspend_freq) {
1776 pr_debug("%s: suspend_freq not defined\n", __func__);
1780 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1781 policy->suspend_freq);
1783 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1784 CPUFREQ_RELATION_H);
1786 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1787 __func__, policy->suspend_freq, ret);
1791 EXPORT_SYMBOL(cpufreq_generic_suspend);
1794 * cpufreq_suspend() - Suspend CPUFreq governors
1796 * Called during system wide Suspend/Hibernate cycles for suspending governors
1797 * as some platforms can't change frequency after this point in suspend cycle.
1798 * Because some of the devices (like: i2c, regulators, etc) they use for
1799 * changing frequency are suspended quickly after this point.
1801 void cpufreq_suspend(void)
1803 struct cpufreq_policy *policy;
1805 if (!cpufreq_driver)
1808 if (!has_target() && !cpufreq_driver->suspend)
1811 pr_debug("%s: Suspending Governors\n", __func__);
1813 for_each_active_policy(policy) {
1815 down_write(&policy->rwsem);
1816 cpufreq_stop_governor(policy);
1817 up_write(&policy->rwsem);
1820 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1821 pr_err("%s: Failed to suspend driver: %s\n", __func__,
1822 cpufreq_driver->name);
1826 cpufreq_suspended = true;
1830 * cpufreq_resume() - Resume CPUFreq governors
1832 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1833 * are suspended with cpufreq_suspend().
1835 void cpufreq_resume(void)
1837 struct cpufreq_policy *policy;
1840 if (!cpufreq_driver)
1843 if (unlikely(!cpufreq_suspended))
1846 cpufreq_suspended = false;
1848 if (!has_target() && !cpufreq_driver->resume)
1851 pr_debug("%s: Resuming Governors\n", __func__);
1853 for_each_active_policy(policy) {
1854 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1855 pr_err("%s: Failed to resume driver: %p\n", __func__,
1857 } else if (has_target()) {
1858 down_write(&policy->rwsem);
1859 ret = cpufreq_start_governor(policy);
1860 up_write(&policy->rwsem);
1863 pr_err("%s: Failed to start governor for policy: %p\n",
1870 * cpufreq_get_current_driver - return current driver's name
1872 * Return the name string of the currently loaded cpufreq driver
1875 const char *cpufreq_get_current_driver(void)
1878 return cpufreq_driver->name;
1882 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1885 * cpufreq_get_driver_data - return current driver data
1887 * Return the private data of the currently loaded cpufreq
1888 * driver, or NULL if no cpufreq driver is loaded.
1890 void *cpufreq_get_driver_data(void)
1893 return cpufreq_driver->driver_data;
1897 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1899 /*********************************************************************
1900 * NOTIFIER LISTS INTERFACE *
1901 *********************************************************************/
1904 * cpufreq_register_notifier - register a driver with cpufreq
1905 * @nb: notifier function to register
1906 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1908 * Add a driver to one of two lists: either a list of drivers that
1909 * are notified about clock rate changes (once before and once after
1910 * the transition), or a list of drivers that are notified about
1911 * changes in cpufreq policy.
1913 * This function may sleep, and has the same return conditions as
1914 * blocking_notifier_chain_register.
1916 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1920 if (cpufreq_disabled())
1924 case CPUFREQ_TRANSITION_NOTIFIER:
1925 mutex_lock(&cpufreq_fast_switch_lock);
1927 if (cpufreq_fast_switch_count > 0) {
1928 mutex_unlock(&cpufreq_fast_switch_lock);
1931 ret = srcu_notifier_chain_register(
1932 &cpufreq_transition_notifier_list, nb);
1934 cpufreq_fast_switch_count--;
1936 mutex_unlock(&cpufreq_fast_switch_lock);
1938 case CPUFREQ_POLICY_NOTIFIER:
1939 ret = blocking_notifier_chain_register(
1940 &cpufreq_policy_notifier_list, nb);
1948 EXPORT_SYMBOL(cpufreq_register_notifier);
1951 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1952 * @nb: notifier block to be unregistered
1953 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1955 * Remove a driver from the CPU frequency notifier list.
1957 * This function may sleep, and has the same return conditions as
1958 * blocking_notifier_chain_unregister.
1960 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1964 if (cpufreq_disabled())
1968 case CPUFREQ_TRANSITION_NOTIFIER:
1969 mutex_lock(&cpufreq_fast_switch_lock);
1971 ret = srcu_notifier_chain_unregister(
1972 &cpufreq_transition_notifier_list, nb);
1973 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1974 cpufreq_fast_switch_count++;
1976 mutex_unlock(&cpufreq_fast_switch_lock);
1978 case CPUFREQ_POLICY_NOTIFIER:
1979 ret = blocking_notifier_chain_unregister(
1980 &cpufreq_policy_notifier_list, nb);
1988 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1991 /*********************************************************************
1993 *********************************************************************/
1996 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1997 * @policy: cpufreq policy to switch the frequency for.
1998 * @target_freq: New frequency to set (may be approximate).
2000 * Carry out a fast frequency switch without sleeping.
2002 * The driver's ->fast_switch() callback invoked by this function must be
2003 * suitable for being called from within RCU-sched read-side critical sections
2004 * and it is expected to select the minimum available frequency greater than or
2005 * equal to @target_freq (CPUFREQ_RELATION_L).
2007 * This function must not be called if policy->fast_switch_enabled is unset.
2009 * Governors calling this function must guarantee that it will never be invoked
2010 * twice in parallel for the same policy and that it will never be called in
2011 * parallel with either ->target() or ->target_index() for the same policy.
2013 * Returns the actual frequency set for the CPU.
2015 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2016 * error condition, the hardware configuration must be preserved.
2018 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2019 unsigned int target_freq)
2021 target_freq = clamp_val(target_freq, policy->min, policy->max);
2023 return cpufreq_driver->fast_switch(policy, target_freq);
2025 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2027 /* Must set freqs->new to intermediate frequency */
2028 static int __target_intermediate(struct cpufreq_policy *policy,
2029 struct cpufreq_freqs *freqs, int index)
2033 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2035 /* We don't need to switch to intermediate freq */
2039 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2040 __func__, policy->cpu, freqs->old, freqs->new);
2042 cpufreq_freq_transition_begin(policy, freqs);
2043 ret = cpufreq_driver->target_intermediate(policy, index);
2044 cpufreq_freq_transition_end(policy, freqs, ret);
2047 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2053 static int __target_index(struct cpufreq_policy *policy, int index)
2055 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2056 unsigned int intermediate_freq = 0;
2057 unsigned int newfreq = policy->freq_table[index].frequency;
2058 int retval = -EINVAL;
2061 if (newfreq == policy->cur)
2064 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2066 /* Handle switching to intermediate frequency */
2067 if (cpufreq_driver->get_intermediate) {
2068 retval = __target_intermediate(policy, &freqs, index);
2072 intermediate_freq = freqs.new;
2073 /* Set old freq to intermediate */
2074 if (intermediate_freq)
2075 freqs.old = freqs.new;
2078 freqs.new = newfreq;
2079 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2080 __func__, policy->cpu, freqs.old, freqs.new);
2082 cpufreq_freq_transition_begin(policy, &freqs);
2085 retval = cpufreq_driver->target_index(policy, index);
2087 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2091 cpufreq_freq_transition_end(policy, &freqs, retval);
2094 * Failed after setting to intermediate freq? Driver should have
2095 * reverted back to initial frequency and so should we. Check
2096 * here for intermediate_freq instead of get_intermediate, in
2097 * case we haven't switched to intermediate freq at all.
2099 if (unlikely(retval && intermediate_freq)) {
2100 freqs.old = intermediate_freq;
2101 freqs.new = policy->restore_freq;
2102 cpufreq_freq_transition_begin(policy, &freqs);
2103 cpufreq_freq_transition_end(policy, &freqs, 0);
2110 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2111 unsigned int target_freq,
2112 unsigned int relation)
2114 unsigned int old_target_freq = target_freq;
2117 if (cpufreq_disabled())
2120 /* Make sure that target_freq is within supported range */
2121 target_freq = clamp_val(target_freq, policy->min, policy->max);
2123 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2124 policy->cpu, target_freq, relation, old_target_freq);
2127 * This might look like a redundant call as we are checking it again
2128 * after finding index. But it is left intentionally for cases where
2129 * exactly same freq is called again and so we can save on few function
2132 if (target_freq == policy->cur)
2135 /* Save last value to restore later on errors */
2136 policy->restore_freq = policy->cur;
2138 if (cpufreq_driver->target)
2139 return cpufreq_driver->target(policy, target_freq, relation);
2141 if (!cpufreq_driver->target_index)
2144 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2146 return __target_index(policy, index);
2148 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2150 int cpufreq_driver_target(struct cpufreq_policy *policy,
2151 unsigned int target_freq,
2152 unsigned int relation)
2156 down_write(&policy->rwsem);
2158 ret = __cpufreq_driver_target(policy, target_freq, relation);
2160 up_write(&policy->rwsem);
2164 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2166 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2171 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2175 /* Don't start any governor operations if we are entering suspend */
2176 if (cpufreq_suspended)
2179 * Governor might not be initiated here if ACPI _PPC changed
2180 * notification happened, so check it.
2182 if (!policy->governor)
2185 /* Platform doesn't want dynamic frequency switching ? */
2186 if (policy->governor->dynamic_switching &&
2187 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2188 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2191 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2192 policy->governor->name, gov->name);
2193 policy->governor = gov;
2199 if (!try_module_get(policy->governor->owner))
2202 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2204 if (policy->governor->init) {
2205 ret = policy->governor->init(policy);
2207 module_put(policy->governor->owner);
2215 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2217 if (cpufreq_suspended || !policy->governor)
2220 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2222 if (policy->governor->exit)
2223 policy->governor->exit(policy);
2225 module_put(policy->governor->owner);
2228 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2232 if (cpufreq_suspended)
2235 if (!policy->governor)
2238 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2240 if (cpufreq_driver->get)
2241 cpufreq_verify_current_freq(policy, false);
2243 if (policy->governor->start) {
2244 ret = policy->governor->start(policy);
2249 if (policy->governor->limits)
2250 policy->governor->limits(policy);
2255 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2257 if (cpufreq_suspended || !policy->governor)
2260 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2262 if (policy->governor->stop)
2263 policy->governor->stop(policy);
2266 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2268 if (cpufreq_suspended || !policy->governor)
2271 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2273 if (policy->governor->limits)
2274 policy->governor->limits(policy);
2277 int cpufreq_register_governor(struct cpufreq_governor *governor)
2284 if (cpufreq_disabled())
2287 mutex_lock(&cpufreq_governor_mutex);
2290 if (!find_governor(governor->name)) {
2292 list_add(&governor->governor_list, &cpufreq_governor_list);
2295 mutex_unlock(&cpufreq_governor_mutex);
2298 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2300 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2302 struct cpufreq_policy *policy;
2303 unsigned long flags;
2308 if (cpufreq_disabled())
2311 /* clear last_governor for all inactive policies */
2312 read_lock_irqsave(&cpufreq_driver_lock, flags);
2313 for_each_inactive_policy(policy) {
2314 if (!strcmp(policy->last_governor, governor->name)) {
2315 policy->governor = NULL;
2316 strcpy(policy->last_governor, "\0");
2319 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2321 mutex_lock(&cpufreq_governor_mutex);
2322 list_del(&governor->governor_list);
2323 mutex_unlock(&cpufreq_governor_mutex);
2325 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2328 /*********************************************************************
2329 * POLICY INTERFACE *
2330 *********************************************************************/
2333 * cpufreq_get_policy - get the current cpufreq_policy
2334 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2337 * Reads the current cpufreq policy.
2339 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2341 struct cpufreq_policy *cpu_policy;
2345 cpu_policy = cpufreq_cpu_get(cpu);
2349 memcpy(policy, cpu_policy, sizeof(*policy));
2351 cpufreq_cpu_put(cpu_policy);
2354 EXPORT_SYMBOL(cpufreq_get_policy);
2357 * cpufreq_set_policy - Modify cpufreq policy parameters.
2358 * @policy: Policy object to modify.
2359 * @new_gov: Policy governor pointer.
2360 * @new_pol: Policy value (for drivers with built-in governors).
2362 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
2363 * limits to be set for the policy, update @policy with the verified limits
2364 * values and either invoke the driver's ->setpolicy() callback (if present) or
2365 * carry out a governor update for @policy. That is, run the current governor's
2366 * ->limits() callback (if @new_gov points to the same object as the one in
2367 * @policy) or replace the governor for @policy with @new_gov.
2369 * The cpuinfo part of @policy is not updated by this function.
2371 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2372 struct cpufreq_governor *new_gov,
2373 unsigned int new_pol)
2375 struct cpufreq_policy_data new_data;
2376 struct cpufreq_governor *old_gov;
2379 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2380 new_data.freq_table = policy->freq_table;
2381 new_data.cpu = policy->cpu;
2383 * PM QoS framework collects all the requests from users and provide us
2384 * the final aggregated value here.
2386 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN);
2387 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX);
2389 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2390 new_data.cpu, new_data.min, new_data.max);
2393 * Verify that the CPU speed can be set within these limits and make sure
2396 ret = cpufreq_driver->verify(&new_data);
2400 policy->min = new_data.min;
2401 policy->max = new_data.max;
2402 trace_cpu_frequency_limits(policy);
2404 policy->cached_target_freq = UINT_MAX;
2406 pr_debug("new min and max freqs are %u - %u kHz\n",
2407 policy->min, policy->max);
2409 if (cpufreq_driver->setpolicy) {
2410 policy->policy = new_pol;
2411 pr_debug("setting range\n");
2412 return cpufreq_driver->setpolicy(policy);
2415 if (new_gov == policy->governor) {
2416 pr_debug("governor limits update\n");
2417 cpufreq_governor_limits(policy);
2421 pr_debug("governor switch\n");
2423 /* save old, working values */
2424 old_gov = policy->governor;
2425 /* end old governor */
2427 cpufreq_stop_governor(policy);
2428 cpufreq_exit_governor(policy);
2431 /* start new governor */
2432 policy->governor = new_gov;
2433 ret = cpufreq_init_governor(policy);
2435 ret = cpufreq_start_governor(policy);
2437 pr_debug("governor change\n");
2438 sched_cpufreq_governor_change(policy, old_gov);
2441 cpufreq_exit_governor(policy);
2444 /* new governor failed, so re-start old one */
2445 pr_debug("starting governor %s failed\n", policy->governor->name);
2447 policy->governor = old_gov;
2448 if (cpufreq_init_governor(policy))
2449 policy->governor = NULL;
2451 cpufreq_start_governor(policy);
2458 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2459 * @cpu: CPU to re-evaluate the policy for.
2461 * Update the current frequency for the cpufreq policy of @cpu and use
2462 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2463 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2464 * for the policy in question, among other things.
2466 void cpufreq_update_policy(unsigned int cpu)
2468 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2474 * BIOS might change freq behind our back
2475 * -> ask driver for current freq and notify governors about a change
2477 if (cpufreq_driver->get && has_target() &&
2478 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2481 refresh_frequency_limits(policy);
2484 cpufreq_cpu_release(policy);
2486 EXPORT_SYMBOL(cpufreq_update_policy);
2489 * cpufreq_update_limits - Update policy limits for a given CPU.
2490 * @cpu: CPU to update the policy limits for.
2492 * Invoke the driver's ->update_limits callback if present or call
2493 * cpufreq_update_policy() for @cpu.
2495 void cpufreq_update_limits(unsigned int cpu)
2497 if (cpufreq_driver->update_limits)
2498 cpufreq_driver->update_limits(cpu);
2500 cpufreq_update_policy(cpu);
2502 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2504 /*********************************************************************
2506 *********************************************************************/
2507 static int cpufreq_boost_set_sw(int state)
2509 struct cpufreq_policy *policy;
2512 for_each_active_policy(policy) {
2513 if (!policy->freq_table)
2516 ret = cpufreq_frequency_table_cpuinfo(policy,
2517 policy->freq_table);
2519 pr_err("%s: Policy frequency update failed\n",
2524 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
2532 int cpufreq_boost_trigger_state(int state)
2534 unsigned long flags;
2537 if (cpufreq_driver->boost_enabled == state)
2540 write_lock_irqsave(&cpufreq_driver_lock, flags);
2541 cpufreq_driver->boost_enabled = state;
2542 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2544 ret = cpufreq_driver->set_boost(state);
2546 write_lock_irqsave(&cpufreq_driver_lock, flags);
2547 cpufreq_driver->boost_enabled = !state;
2548 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2550 pr_err("%s: Cannot %s BOOST\n",
2551 __func__, state ? "enable" : "disable");
2557 static bool cpufreq_boost_supported(void)
2559 return cpufreq_driver->set_boost;
2562 static int create_boost_sysfs_file(void)
2566 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2568 pr_err("%s: cannot register global BOOST sysfs file\n",
2574 static void remove_boost_sysfs_file(void)
2576 if (cpufreq_boost_supported())
2577 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2580 int cpufreq_enable_boost_support(void)
2582 if (!cpufreq_driver)
2585 if (cpufreq_boost_supported())
2588 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2590 /* This will get removed on driver unregister */
2591 return create_boost_sysfs_file();
2593 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2595 int cpufreq_boost_enabled(void)
2597 return cpufreq_driver->boost_enabled;
2599 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2601 /*********************************************************************
2602 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2603 *********************************************************************/
2604 static enum cpuhp_state hp_online;
2606 static int cpuhp_cpufreq_online(unsigned int cpu)
2608 cpufreq_online(cpu);
2613 static int cpuhp_cpufreq_offline(unsigned int cpu)
2615 cpufreq_offline(cpu);
2621 * cpufreq_register_driver - register a CPU Frequency driver
2622 * @driver_data: A struct cpufreq_driver containing the values#
2623 * submitted by the CPU Frequency driver.
2625 * Registers a CPU Frequency driver to this core code. This code
2626 * returns zero on success, -EEXIST when another driver got here first
2627 * (and isn't unregistered in the meantime).
2630 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2632 unsigned long flags;
2635 if (cpufreq_disabled())
2639 * The cpufreq core depends heavily on the availability of device
2640 * structure, make sure they are available before proceeding further.
2642 if (!get_cpu_device(0))
2643 return -EPROBE_DEFER;
2645 if (!driver_data || !driver_data->verify || !driver_data->init ||
2646 !(driver_data->setpolicy || driver_data->target_index ||
2647 driver_data->target) ||
2648 (driver_data->setpolicy && (driver_data->target_index ||
2649 driver_data->target)) ||
2650 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2651 (!driver_data->online != !driver_data->offline))
2654 pr_debug("trying to register driver %s\n", driver_data->name);
2656 /* Protect against concurrent CPU online/offline. */
2659 write_lock_irqsave(&cpufreq_driver_lock, flags);
2660 if (cpufreq_driver) {
2661 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2665 cpufreq_driver = driver_data;
2666 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2668 if (driver_data->setpolicy)
2669 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2671 if (cpufreq_boost_supported()) {
2672 ret = create_boost_sysfs_file();
2674 goto err_null_driver;
2677 ret = subsys_interface_register(&cpufreq_interface);
2679 goto err_boost_unreg;
2681 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2682 list_empty(&cpufreq_policy_list)) {
2683 /* if all ->init() calls failed, unregister */
2685 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2690 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2692 cpuhp_cpufreq_online,
2693 cpuhp_cpufreq_offline);
2699 pr_debug("driver %s up and running\n", driver_data->name);
2703 subsys_interface_unregister(&cpufreq_interface);
2705 remove_boost_sysfs_file();
2707 write_lock_irqsave(&cpufreq_driver_lock, flags);
2708 cpufreq_driver = NULL;
2709 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2714 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2717 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2719 * Unregister the current CPUFreq driver. Only call this if you have
2720 * the right to do so, i.e. if you have succeeded in initialising before!
2721 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2722 * currently not initialised.
2724 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2726 unsigned long flags;
2728 if (!cpufreq_driver || (driver != cpufreq_driver))
2731 pr_debug("unregistering driver %s\n", driver->name);
2733 /* Protect against concurrent cpu hotplug */
2735 subsys_interface_unregister(&cpufreq_interface);
2736 remove_boost_sysfs_file();
2737 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2739 write_lock_irqsave(&cpufreq_driver_lock, flags);
2741 cpufreq_driver = NULL;
2743 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2748 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2750 static int __init cpufreq_core_init(void)
2752 if (cpufreq_disabled())
2755 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2756 BUG_ON(!cpufreq_global_kobject);
2760 module_param(off, int, 0444);
2761 core_initcall(cpufreq_core_init);