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);
1080 * In case the default governor is neiter "performance"
1081 * nor "powersave", fall back to the initial policy
1082 * value set by the driver.
1084 if (pol == CPUFREQ_POLICY_UNKNOWN)
1085 pol = policy->policy;
1087 if (pol != CPUFREQ_POLICY_PERFORMANCE &&
1088 pol != CPUFREQ_POLICY_POWERSAVE)
1092 return cpufreq_set_policy(policy, gov, pol);
1095 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1099 /* Has this CPU been taken care of already? */
1100 if (cpumask_test_cpu(cpu, policy->cpus))
1103 down_write(&policy->rwsem);
1105 cpufreq_stop_governor(policy);
1107 cpumask_set_cpu(cpu, policy->cpus);
1110 ret = cpufreq_start_governor(policy);
1112 pr_err("%s: Failed to start governor\n", __func__);
1114 up_write(&policy->rwsem);
1118 void refresh_frequency_limits(struct cpufreq_policy *policy)
1120 if (!policy_is_inactive(policy)) {
1121 pr_debug("updating policy for CPU %u\n", policy->cpu);
1123 cpufreq_set_policy(policy, policy->governor, policy->policy);
1126 EXPORT_SYMBOL(refresh_frequency_limits);
1128 static void handle_update(struct work_struct *work)
1130 struct cpufreq_policy *policy =
1131 container_of(work, struct cpufreq_policy, update);
1133 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1134 down_write(&policy->rwsem);
1135 refresh_frequency_limits(policy);
1136 up_write(&policy->rwsem);
1139 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1142 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1144 schedule_work(&policy->update);
1148 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1151 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1153 schedule_work(&policy->update);
1157 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1159 struct kobject *kobj;
1160 struct completion *cmp;
1162 down_write(&policy->rwsem);
1163 cpufreq_stats_free_table(policy);
1164 kobj = &policy->kobj;
1165 cmp = &policy->kobj_unregister;
1166 up_write(&policy->rwsem);
1170 * We need to make sure that the underlying kobj is
1171 * actually not referenced anymore by anybody before we
1172 * proceed with unloading.
1174 pr_debug("waiting for dropping of refcount\n");
1175 wait_for_completion(cmp);
1176 pr_debug("wait complete\n");
1179 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1181 struct cpufreq_policy *policy;
1182 struct device *dev = get_cpu_device(cpu);
1188 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1192 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1193 goto err_free_policy;
1195 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1196 goto err_free_cpumask;
1198 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1199 goto err_free_rcpumask;
1201 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1202 cpufreq_global_kobject, "policy%u", cpu);
1204 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1206 * The entire policy object will be freed below, but the extra
1207 * memory allocated for the kobject name needs to be freed by
1208 * releasing the kobject.
1210 kobject_put(&policy->kobj);
1211 goto err_free_real_cpus;
1214 freq_constraints_init(&policy->constraints);
1216 policy->nb_min.notifier_call = cpufreq_notifier_min;
1217 policy->nb_max.notifier_call = cpufreq_notifier_max;
1219 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN,
1222 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1223 ret, cpumask_pr_args(policy->cpus));
1224 goto err_kobj_remove;
1227 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX,
1230 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1231 ret, cpumask_pr_args(policy->cpus));
1232 goto err_min_qos_notifier;
1235 INIT_LIST_HEAD(&policy->policy_list);
1236 init_rwsem(&policy->rwsem);
1237 spin_lock_init(&policy->transition_lock);
1238 init_waitqueue_head(&policy->transition_wait);
1239 init_completion(&policy->kobj_unregister);
1240 INIT_WORK(&policy->update, handle_update);
1245 err_min_qos_notifier:
1246 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1249 cpufreq_policy_put_kobj(policy);
1251 free_cpumask_var(policy->real_cpus);
1253 free_cpumask_var(policy->related_cpus);
1255 free_cpumask_var(policy->cpus);
1262 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1264 unsigned long flags;
1267 /* Remove policy from list */
1268 write_lock_irqsave(&cpufreq_driver_lock, flags);
1269 list_del(&policy->policy_list);
1271 for_each_cpu(cpu, policy->related_cpus)
1272 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1273 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1275 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX,
1277 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1280 /* Cancel any pending policy->update work before freeing the policy. */
1281 cancel_work_sync(&policy->update);
1283 if (policy->max_freq_req) {
1285 * CPUFREQ_CREATE_POLICY notification is sent only after
1286 * successfully adding max_freq_req request.
1288 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1289 CPUFREQ_REMOVE_POLICY, policy);
1290 freq_qos_remove_request(policy->max_freq_req);
1293 freq_qos_remove_request(policy->min_freq_req);
1294 kfree(policy->min_freq_req);
1296 cpufreq_policy_put_kobj(policy);
1297 free_cpumask_var(policy->real_cpus);
1298 free_cpumask_var(policy->related_cpus);
1299 free_cpumask_var(policy->cpus);
1303 static int cpufreq_online(unsigned int cpu)
1305 struct cpufreq_policy *policy;
1307 unsigned long flags;
1311 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1313 /* Check if this CPU already has a policy to manage it */
1314 policy = per_cpu(cpufreq_cpu_data, cpu);
1316 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1317 if (!policy_is_inactive(policy))
1318 return cpufreq_add_policy_cpu(policy, cpu);
1320 /* This is the only online CPU for the policy. Start over. */
1322 down_write(&policy->rwsem);
1324 policy->governor = NULL;
1325 up_write(&policy->rwsem);
1328 policy = cpufreq_policy_alloc(cpu);
1333 if (!new_policy && cpufreq_driver->online) {
1334 ret = cpufreq_driver->online(policy);
1336 pr_debug("%s: %d: initialization failed\n", __func__,
1338 goto out_exit_policy;
1341 /* Recover policy->cpus using related_cpus */
1342 cpumask_copy(policy->cpus, policy->related_cpus);
1344 cpumask_copy(policy->cpus, cpumask_of(cpu));
1347 * Call driver. From then on the cpufreq must be able
1348 * to accept all calls to ->verify and ->setpolicy for this CPU.
1350 ret = cpufreq_driver->init(policy);
1352 pr_debug("%s: %d: initialization failed\n", __func__,
1354 goto out_free_policy;
1357 ret = cpufreq_table_validate_and_sort(policy);
1359 goto out_exit_policy;
1361 /* related_cpus should at least include policy->cpus. */
1362 cpumask_copy(policy->related_cpus, policy->cpus);
1365 down_write(&policy->rwsem);
1367 * affected cpus must always be the one, which are online. We aren't
1368 * managing offline cpus here.
1370 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1373 for_each_cpu(j, policy->related_cpus) {
1374 per_cpu(cpufreq_cpu_data, j) = policy;
1375 add_cpu_dev_symlink(policy, j);
1378 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1380 if (!policy->min_freq_req)
1381 goto out_destroy_policy;
1383 ret = freq_qos_add_request(&policy->constraints,
1384 policy->min_freq_req, FREQ_QOS_MIN,
1388 * So we don't call freq_qos_remove_request() for an
1389 * uninitialized request.
1391 kfree(policy->min_freq_req);
1392 policy->min_freq_req = NULL;
1393 goto out_destroy_policy;
1397 * This must be initialized right here to avoid calling
1398 * freq_qos_remove_request() on uninitialized request in case
1401 policy->max_freq_req = policy->min_freq_req + 1;
1403 ret = freq_qos_add_request(&policy->constraints,
1404 policy->max_freq_req, FREQ_QOS_MAX,
1407 policy->max_freq_req = NULL;
1408 goto out_destroy_policy;
1411 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1412 CPUFREQ_CREATE_POLICY, policy);
1415 if (cpufreq_driver->get && has_target()) {
1416 policy->cur = cpufreq_driver->get(policy->cpu);
1418 pr_err("%s: ->get() failed\n", __func__);
1419 goto out_destroy_policy;
1424 * Sometimes boot loaders set CPU frequency to a value outside of
1425 * frequency table present with cpufreq core. In such cases CPU might be
1426 * unstable if it has to run on that frequency for long duration of time
1427 * and so its better to set it to a frequency which is specified in
1428 * freq-table. This also makes cpufreq stats inconsistent as
1429 * cpufreq-stats would fail to register because current frequency of CPU
1430 * isn't found in freq-table.
1432 * Because we don't want this change to effect boot process badly, we go
1433 * for the next freq which is >= policy->cur ('cur' must be set by now,
1434 * otherwise we will end up setting freq to lowest of the table as 'cur'
1435 * is initialized to zero).
1437 * We are passing target-freq as "policy->cur - 1" otherwise
1438 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1439 * equal to target-freq.
1441 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1443 /* Are we running at unknown frequency ? */
1444 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1445 if (ret == -EINVAL) {
1446 /* Warn user and fix it */
1447 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1448 __func__, policy->cpu, policy->cur);
1449 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1450 CPUFREQ_RELATION_L);
1453 * Reaching here after boot in a few seconds may not
1454 * mean that system will remain stable at "unknown"
1455 * frequency for longer duration. Hence, a BUG_ON().
1458 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1459 __func__, policy->cpu, policy->cur);
1464 ret = cpufreq_add_dev_interface(policy);
1466 goto out_destroy_policy;
1468 cpufreq_stats_create_table(policy);
1470 write_lock_irqsave(&cpufreq_driver_lock, flags);
1471 list_add(&policy->policy_list, &cpufreq_policy_list);
1472 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1475 ret = cpufreq_init_policy(policy);
1477 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1478 __func__, cpu, ret);
1479 goto out_destroy_policy;
1482 up_write(&policy->rwsem);
1484 kobject_uevent(&policy->kobj, KOBJ_ADD);
1486 /* Callback for handling stuff after policy is ready */
1487 if (cpufreq_driver->ready)
1488 cpufreq_driver->ready(policy);
1490 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1491 policy->cdev = of_cpufreq_cooling_register(policy);
1493 pr_debug("initialization complete\n");
1498 for_each_cpu(j, policy->real_cpus)
1499 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1501 up_write(&policy->rwsem);
1504 if (cpufreq_driver->exit)
1505 cpufreq_driver->exit(policy);
1508 cpufreq_policy_free(policy);
1513 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1515 * @sif: Subsystem interface structure pointer (not used)
1517 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1519 struct cpufreq_policy *policy;
1520 unsigned cpu = dev->id;
1523 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1525 if (cpu_online(cpu)) {
1526 ret = cpufreq_online(cpu);
1531 /* Create sysfs link on CPU registration */
1532 policy = per_cpu(cpufreq_cpu_data, cpu);
1534 add_cpu_dev_symlink(policy, cpu);
1539 static int cpufreq_offline(unsigned int cpu)
1541 struct cpufreq_policy *policy;
1544 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1546 policy = cpufreq_cpu_get_raw(cpu);
1548 pr_debug("%s: No cpu_data found\n", __func__);
1552 down_write(&policy->rwsem);
1554 cpufreq_stop_governor(policy);
1556 cpumask_clear_cpu(cpu, policy->cpus);
1558 if (policy_is_inactive(policy)) {
1560 strncpy(policy->last_governor, policy->governor->name,
1563 policy->last_policy = policy->policy;
1564 } else if (cpu == policy->cpu) {
1565 /* Nominate new CPU */
1566 policy->cpu = cpumask_any(policy->cpus);
1569 /* Start governor again for active policy */
1570 if (!policy_is_inactive(policy)) {
1572 ret = cpufreq_start_governor(policy);
1574 pr_err("%s: Failed to start governor\n", __func__);
1580 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1581 cpufreq_cooling_unregister(policy->cdev);
1582 policy->cdev = NULL;
1585 if (cpufreq_driver->stop_cpu)
1586 cpufreq_driver->stop_cpu(policy);
1589 cpufreq_exit_governor(policy);
1592 * Perform the ->offline() during light-weight tear-down, as
1593 * that allows fast recovery when the CPU comes back.
1595 if (cpufreq_driver->offline) {
1596 cpufreq_driver->offline(policy);
1597 } else if (cpufreq_driver->exit) {
1598 cpufreq_driver->exit(policy);
1599 policy->freq_table = NULL;
1603 up_write(&policy->rwsem);
1608 * cpufreq_remove_dev - remove a CPU device
1610 * Removes the cpufreq interface for a CPU device.
1612 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1614 unsigned int cpu = dev->id;
1615 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1620 if (cpu_online(cpu))
1621 cpufreq_offline(cpu);
1623 cpumask_clear_cpu(cpu, policy->real_cpus);
1624 remove_cpu_dev_symlink(policy, dev);
1626 if (cpumask_empty(policy->real_cpus)) {
1627 /* We did light-weight exit earlier, do full tear down now */
1628 if (cpufreq_driver->offline)
1629 cpufreq_driver->exit(policy);
1631 cpufreq_policy_free(policy);
1636 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1638 * @policy: policy managing CPUs
1639 * @new_freq: CPU frequency the CPU actually runs at
1641 * We adjust to current frequency first, and need to clean up later.
1642 * So either call to cpufreq_update_policy() or schedule handle_update()).
1644 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1645 unsigned int new_freq)
1647 struct cpufreq_freqs freqs;
1649 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1650 policy->cur, new_freq);
1652 freqs.old = policy->cur;
1653 freqs.new = new_freq;
1655 cpufreq_freq_transition_begin(policy, &freqs);
1656 cpufreq_freq_transition_end(policy, &freqs, 0);
1659 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1661 unsigned int new_freq;
1663 new_freq = cpufreq_driver->get(policy->cpu);
1668 * If fast frequency switching is used with the given policy, the check
1669 * against policy->cur is pointless, so skip it in that case.
1671 if (policy->fast_switch_enabled || !has_target())
1674 if (policy->cur != new_freq) {
1675 cpufreq_out_of_sync(policy, new_freq);
1677 schedule_work(&policy->update);
1684 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1687 * This is the last known freq, without actually getting it from the driver.
1688 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1690 unsigned int cpufreq_quick_get(unsigned int cpu)
1692 struct cpufreq_policy *policy;
1693 unsigned int ret_freq = 0;
1694 unsigned long flags;
1696 read_lock_irqsave(&cpufreq_driver_lock, flags);
1698 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1699 ret_freq = cpufreq_driver->get(cpu);
1700 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1704 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1706 policy = cpufreq_cpu_get(cpu);
1708 ret_freq = policy->cur;
1709 cpufreq_cpu_put(policy);
1714 EXPORT_SYMBOL(cpufreq_quick_get);
1717 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1720 * Just return the max possible frequency for a given CPU.
1722 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1724 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1725 unsigned int ret_freq = 0;
1728 ret_freq = policy->max;
1729 cpufreq_cpu_put(policy);
1734 EXPORT_SYMBOL(cpufreq_quick_get_max);
1736 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1738 if (unlikely(policy_is_inactive(policy)))
1741 return cpufreq_verify_current_freq(policy, true);
1745 * cpufreq_get - get the current CPU frequency (in kHz)
1748 * Get the CPU current (static) CPU frequency
1750 unsigned int cpufreq_get(unsigned int cpu)
1752 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1753 unsigned int ret_freq = 0;
1756 down_read(&policy->rwsem);
1757 if (cpufreq_driver->get)
1758 ret_freq = __cpufreq_get(policy);
1759 up_read(&policy->rwsem);
1761 cpufreq_cpu_put(policy);
1766 EXPORT_SYMBOL(cpufreq_get);
1768 static struct subsys_interface cpufreq_interface = {
1770 .subsys = &cpu_subsys,
1771 .add_dev = cpufreq_add_dev,
1772 .remove_dev = cpufreq_remove_dev,
1776 * In case platform wants some specific frequency to be configured
1779 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1783 if (!policy->suspend_freq) {
1784 pr_debug("%s: suspend_freq not defined\n", __func__);
1788 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1789 policy->suspend_freq);
1791 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1792 CPUFREQ_RELATION_H);
1794 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1795 __func__, policy->suspend_freq, ret);
1799 EXPORT_SYMBOL(cpufreq_generic_suspend);
1802 * cpufreq_suspend() - Suspend CPUFreq governors
1804 * Called during system wide Suspend/Hibernate cycles for suspending governors
1805 * as some platforms can't change frequency after this point in suspend cycle.
1806 * Because some of the devices (like: i2c, regulators, etc) they use for
1807 * changing frequency are suspended quickly after this point.
1809 void cpufreq_suspend(void)
1811 struct cpufreq_policy *policy;
1813 if (!cpufreq_driver)
1816 if (!has_target() && !cpufreq_driver->suspend)
1819 pr_debug("%s: Suspending Governors\n", __func__);
1821 for_each_active_policy(policy) {
1823 down_write(&policy->rwsem);
1824 cpufreq_stop_governor(policy);
1825 up_write(&policy->rwsem);
1828 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1829 pr_err("%s: Failed to suspend driver: %s\n", __func__,
1830 cpufreq_driver->name);
1834 cpufreq_suspended = true;
1838 * cpufreq_resume() - Resume CPUFreq governors
1840 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1841 * are suspended with cpufreq_suspend().
1843 void cpufreq_resume(void)
1845 struct cpufreq_policy *policy;
1848 if (!cpufreq_driver)
1851 if (unlikely(!cpufreq_suspended))
1854 cpufreq_suspended = false;
1856 if (!has_target() && !cpufreq_driver->resume)
1859 pr_debug("%s: Resuming Governors\n", __func__);
1861 for_each_active_policy(policy) {
1862 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1863 pr_err("%s: Failed to resume driver: %p\n", __func__,
1865 } else if (has_target()) {
1866 down_write(&policy->rwsem);
1867 ret = cpufreq_start_governor(policy);
1868 up_write(&policy->rwsem);
1871 pr_err("%s: Failed to start governor for policy: %p\n",
1878 * cpufreq_get_current_driver - return current driver's name
1880 * Return the name string of the currently loaded cpufreq driver
1883 const char *cpufreq_get_current_driver(void)
1886 return cpufreq_driver->name;
1890 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1893 * cpufreq_get_driver_data - return current driver data
1895 * Return the private data of the currently loaded cpufreq
1896 * driver, or NULL if no cpufreq driver is loaded.
1898 void *cpufreq_get_driver_data(void)
1901 return cpufreq_driver->driver_data;
1905 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1907 /*********************************************************************
1908 * NOTIFIER LISTS INTERFACE *
1909 *********************************************************************/
1912 * cpufreq_register_notifier - register a driver with cpufreq
1913 * @nb: notifier function to register
1914 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1916 * Add a driver to one of two lists: either a list of drivers that
1917 * are notified about clock rate changes (once before and once after
1918 * the transition), or a list of drivers that are notified about
1919 * changes in cpufreq policy.
1921 * This function may sleep, and has the same return conditions as
1922 * blocking_notifier_chain_register.
1924 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1928 if (cpufreq_disabled())
1932 case CPUFREQ_TRANSITION_NOTIFIER:
1933 mutex_lock(&cpufreq_fast_switch_lock);
1935 if (cpufreq_fast_switch_count > 0) {
1936 mutex_unlock(&cpufreq_fast_switch_lock);
1939 ret = srcu_notifier_chain_register(
1940 &cpufreq_transition_notifier_list, nb);
1942 cpufreq_fast_switch_count--;
1944 mutex_unlock(&cpufreq_fast_switch_lock);
1946 case CPUFREQ_POLICY_NOTIFIER:
1947 ret = blocking_notifier_chain_register(
1948 &cpufreq_policy_notifier_list, nb);
1956 EXPORT_SYMBOL(cpufreq_register_notifier);
1959 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1960 * @nb: notifier block to be unregistered
1961 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1963 * Remove a driver from the CPU frequency notifier list.
1965 * This function may sleep, and has the same return conditions as
1966 * blocking_notifier_chain_unregister.
1968 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1972 if (cpufreq_disabled())
1976 case CPUFREQ_TRANSITION_NOTIFIER:
1977 mutex_lock(&cpufreq_fast_switch_lock);
1979 ret = srcu_notifier_chain_unregister(
1980 &cpufreq_transition_notifier_list, nb);
1981 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1982 cpufreq_fast_switch_count++;
1984 mutex_unlock(&cpufreq_fast_switch_lock);
1986 case CPUFREQ_POLICY_NOTIFIER:
1987 ret = blocking_notifier_chain_unregister(
1988 &cpufreq_policy_notifier_list, nb);
1996 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1999 /*********************************************************************
2001 *********************************************************************/
2004 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
2005 * @policy: cpufreq policy to switch the frequency for.
2006 * @target_freq: New frequency to set (may be approximate).
2008 * Carry out a fast frequency switch without sleeping.
2010 * The driver's ->fast_switch() callback invoked by this function must be
2011 * suitable for being called from within RCU-sched read-side critical sections
2012 * and it is expected to select the minimum available frequency greater than or
2013 * equal to @target_freq (CPUFREQ_RELATION_L).
2015 * This function must not be called if policy->fast_switch_enabled is unset.
2017 * Governors calling this function must guarantee that it will never be invoked
2018 * twice in parallel for the same policy and that it will never be called in
2019 * parallel with either ->target() or ->target_index() for the same policy.
2021 * Returns the actual frequency set for the CPU.
2023 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2024 * error condition, the hardware configuration must be preserved.
2026 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2027 unsigned int target_freq)
2029 target_freq = clamp_val(target_freq, policy->min, policy->max);
2031 return cpufreq_driver->fast_switch(policy, target_freq);
2033 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2035 /* Must set freqs->new to intermediate frequency */
2036 static int __target_intermediate(struct cpufreq_policy *policy,
2037 struct cpufreq_freqs *freqs, int index)
2041 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2043 /* We don't need to switch to intermediate freq */
2047 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2048 __func__, policy->cpu, freqs->old, freqs->new);
2050 cpufreq_freq_transition_begin(policy, freqs);
2051 ret = cpufreq_driver->target_intermediate(policy, index);
2052 cpufreq_freq_transition_end(policy, freqs, ret);
2055 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2061 static int __target_index(struct cpufreq_policy *policy, int index)
2063 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2064 unsigned int intermediate_freq = 0;
2065 unsigned int newfreq = policy->freq_table[index].frequency;
2066 int retval = -EINVAL;
2069 if (newfreq == policy->cur)
2072 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2074 /* Handle switching to intermediate frequency */
2075 if (cpufreq_driver->get_intermediate) {
2076 retval = __target_intermediate(policy, &freqs, index);
2080 intermediate_freq = freqs.new;
2081 /* Set old freq to intermediate */
2082 if (intermediate_freq)
2083 freqs.old = freqs.new;
2086 freqs.new = newfreq;
2087 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2088 __func__, policy->cpu, freqs.old, freqs.new);
2090 cpufreq_freq_transition_begin(policy, &freqs);
2093 retval = cpufreq_driver->target_index(policy, index);
2095 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2099 cpufreq_freq_transition_end(policy, &freqs, retval);
2102 * Failed after setting to intermediate freq? Driver should have
2103 * reverted back to initial frequency and so should we. Check
2104 * here for intermediate_freq instead of get_intermediate, in
2105 * case we haven't switched to intermediate freq at all.
2107 if (unlikely(retval && intermediate_freq)) {
2108 freqs.old = intermediate_freq;
2109 freqs.new = policy->restore_freq;
2110 cpufreq_freq_transition_begin(policy, &freqs);
2111 cpufreq_freq_transition_end(policy, &freqs, 0);
2118 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2119 unsigned int target_freq,
2120 unsigned int relation)
2122 unsigned int old_target_freq = target_freq;
2125 if (cpufreq_disabled())
2128 /* Make sure that target_freq is within supported range */
2129 target_freq = clamp_val(target_freq, policy->min, policy->max);
2131 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2132 policy->cpu, target_freq, relation, old_target_freq);
2135 * This might look like a redundant call as we are checking it again
2136 * after finding index. But it is left intentionally for cases where
2137 * exactly same freq is called again and so we can save on few function
2140 if (target_freq == policy->cur)
2143 /* Save last value to restore later on errors */
2144 policy->restore_freq = policy->cur;
2146 if (cpufreq_driver->target)
2147 return cpufreq_driver->target(policy, target_freq, relation);
2149 if (!cpufreq_driver->target_index)
2152 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2154 return __target_index(policy, index);
2156 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2158 int cpufreq_driver_target(struct cpufreq_policy *policy,
2159 unsigned int target_freq,
2160 unsigned int relation)
2164 down_write(&policy->rwsem);
2166 ret = __cpufreq_driver_target(policy, target_freq, relation);
2168 up_write(&policy->rwsem);
2172 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2174 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2179 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2183 /* Don't start any governor operations if we are entering suspend */
2184 if (cpufreq_suspended)
2187 * Governor might not be initiated here if ACPI _PPC changed
2188 * notification happened, so check it.
2190 if (!policy->governor)
2193 /* Platform doesn't want dynamic frequency switching ? */
2194 if (policy->governor->dynamic_switching &&
2195 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2196 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2199 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2200 policy->governor->name, gov->name);
2201 policy->governor = gov;
2207 if (!try_module_get(policy->governor->owner))
2210 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2212 if (policy->governor->init) {
2213 ret = policy->governor->init(policy);
2215 module_put(policy->governor->owner);
2223 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2225 if (cpufreq_suspended || !policy->governor)
2228 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2230 if (policy->governor->exit)
2231 policy->governor->exit(policy);
2233 module_put(policy->governor->owner);
2236 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2240 if (cpufreq_suspended)
2243 if (!policy->governor)
2246 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2248 if (cpufreq_driver->get)
2249 cpufreq_verify_current_freq(policy, false);
2251 if (policy->governor->start) {
2252 ret = policy->governor->start(policy);
2257 if (policy->governor->limits)
2258 policy->governor->limits(policy);
2263 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2265 if (cpufreq_suspended || !policy->governor)
2268 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2270 if (policy->governor->stop)
2271 policy->governor->stop(policy);
2274 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2276 if (cpufreq_suspended || !policy->governor)
2279 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2281 if (policy->governor->limits)
2282 policy->governor->limits(policy);
2285 int cpufreq_register_governor(struct cpufreq_governor *governor)
2292 if (cpufreq_disabled())
2295 mutex_lock(&cpufreq_governor_mutex);
2298 if (!find_governor(governor->name)) {
2300 list_add(&governor->governor_list, &cpufreq_governor_list);
2303 mutex_unlock(&cpufreq_governor_mutex);
2306 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2308 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2310 struct cpufreq_policy *policy;
2311 unsigned long flags;
2316 if (cpufreq_disabled())
2319 /* clear last_governor for all inactive policies */
2320 read_lock_irqsave(&cpufreq_driver_lock, flags);
2321 for_each_inactive_policy(policy) {
2322 if (!strcmp(policy->last_governor, governor->name)) {
2323 policy->governor = NULL;
2324 strcpy(policy->last_governor, "\0");
2327 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2329 mutex_lock(&cpufreq_governor_mutex);
2330 list_del(&governor->governor_list);
2331 mutex_unlock(&cpufreq_governor_mutex);
2333 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2336 /*********************************************************************
2337 * POLICY INTERFACE *
2338 *********************************************************************/
2341 * cpufreq_get_policy - get the current cpufreq_policy
2342 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2345 * Reads the current cpufreq policy.
2347 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2349 struct cpufreq_policy *cpu_policy;
2353 cpu_policy = cpufreq_cpu_get(cpu);
2357 memcpy(policy, cpu_policy, sizeof(*policy));
2359 cpufreq_cpu_put(cpu_policy);
2362 EXPORT_SYMBOL(cpufreq_get_policy);
2365 * cpufreq_set_policy - Modify cpufreq policy parameters.
2366 * @policy: Policy object to modify.
2367 * @new_gov: Policy governor pointer.
2368 * @new_pol: Policy value (for drivers with built-in governors).
2370 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
2371 * limits to be set for the policy, update @policy with the verified limits
2372 * values and either invoke the driver's ->setpolicy() callback (if present) or
2373 * carry out a governor update for @policy. That is, run the current governor's
2374 * ->limits() callback (if @new_gov points to the same object as the one in
2375 * @policy) or replace the governor for @policy with @new_gov.
2377 * The cpuinfo part of @policy is not updated by this function.
2379 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2380 struct cpufreq_governor *new_gov,
2381 unsigned int new_pol)
2383 struct cpufreq_policy_data new_data;
2384 struct cpufreq_governor *old_gov;
2387 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2388 new_data.freq_table = policy->freq_table;
2389 new_data.cpu = policy->cpu;
2391 * PM QoS framework collects all the requests from users and provide us
2392 * the final aggregated value here.
2394 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN);
2395 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX);
2397 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2398 new_data.cpu, new_data.min, new_data.max);
2401 * Verify that the CPU speed can be set within these limits and make sure
2404 ret = cpufreq_driver->verify(&new_data);
2408 policy->min = new_data.min;
2409 policy->max = new_data.max;
2410 trace_cpu_frequency_limits(policy);
2412 policy->cached_target_freq = UINT_MAX;
2414 pr_debug("new min and max freqs are %u - %u kHz\n",
2415 policy->min, policy->max);
2417 if (cpufreq_driver->setpolicy) {
2418 policy->policy = new_pol;
2419 pr_debug("setting range\n");
2420 return cpufreq_driver->setpolicy(policy);
2423 if (new_gov == policy->governor) {
2424 pr_debug("governor limits update\n");
2425 cpufreq_governor_limits(policy);
2429 pr_debug("governor switch\n");
2431 /* save old, working values */
2432 old_gov = policy->governor;
2433 /* end old governor */
2435 cpufreq_stop_governor(policy);
2436 cpufreq_exit_governor(policy);
2439 /* start new governor */
2440 policy->governor = new_gov;
2441 ret = cpufreq_init_governor(policy);
2443 ret = cpufreq_start_governor(policy);
2445 pr_debug("governor change\n");
2446 sched_cpufreq_governor_change(policy, old_gov);
2449 cpufreq_exit_governor(policy);
2452 /* new governor failed, so re-start old one */
2453 pr_debug("starting governor %s failed\n", policy->governor->name);
2455 policy->governor = old_gov;
2456 if (cpufreq_init_governor(policy))
2457 policy->governor = NULL;
2459 cpufreq_start_governor(policy);
2466 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2467 * @cpu: CPU to re-evaluate the policy for.
2469 * Update the current frequency for the cpufreq policy of @cpu and use
2470 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2471 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2472 * for the policy in question, among other things.
2474 void cpufreq_update_policy(unsigned int cpu)
2476 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2482 * BIOS might change freq behind our back
2483 * -> ask driver for current freq and notify governors about a change
2485 if (cpufreq_driver->get && has_target() &&
2486 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2489 refresh_frequency_limits(policy);
2492 cpufreq_cpu_release(policy);
2494 EXPORT_SYMBOL(cpufreq_update_policy);
2497 * cpufreq_update_limits - Update policy limits for a given CPU.
2498 * @cpu: CPU to update the policy limits for.
2500 * Invoke the driver's ->update_limits callback if present or call
2501 * cpufreq_update_policy() for @cpu.
2503 void cpufreq_update_limits(unsigned int cpu)
2505 if (cpufreq_driver->update_limits)
2506 cpufreq_driver->update_limits(cpu);
2508 cpufreq_update_policy(cpu);
2510 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2512 /*********************************************************************
2514 *********************************************************************/
2515 static int cpufreq_boost_set_sw(int state)
2517 struct cpufreq_policy *policy;
2520 for_each_active_policy(policy) {
2521 if (!policy->freq_table)
2524 ret = cpufreq_frequency_table_cpuinfo(policy,
2525 policy->freq_table);
2527 pr_err("%s: Policy frequency update failed\n",
2532 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
2540 int cpufreq_boost_trigger_state(int state)
2542 unsigned long flags;
2545 if (cpufreq_driver->boost_enabled == state)
2548 write_lock_irqsave(&cpufreq_driver_lock, flags);
2549 cpufreq_driver->boost_enabled = state;
2550 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2552 ret = cpufreq_driver->set_boost(state);
2554 write_lock_irqsave(&cpufreq_driver_lock, flags);
2555 cpufreq_driver->boost_enabled = !state;
2556 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2558 pr_err("%s: Cannot %s BOOST\n",
2559 __func__, state ? "enable" : "disable");
2565 static bool cpufreq_boost_supported(void)
2567 return cpufreq_driver->set_boost;
2570 static int create_boost_sysfs_file(void)
2574 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2576 pr_err("%s: cannot register global BOOST sysfs file\n",
2582 static void remove_boost_sysfs_file(void)
2584 if (cpufreq_boost_supported())
2585 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2588 int cpufreq_enable_boost_support(void)
2590 if (!cpufreq_driver)
2593 if (cpufreq_boost_supported())
2596 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2598 /* This will get removed on driver unregister */
2599 return create_boost_sysfs_file();
2601 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2603 int cpufreq_boost_enabled(void)
2605 return cpufreq_driver->boost_enabled;
2607 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2609 /*********************************************************************
2610 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2611 *********************************************************************/
2612 static enum cpuhp_state hp_online;
2614 static int cpuhp_cpufreq_online(unsigned int cpu)
2616 cpufreq_online(cpu);
2621 static int cpuhp_cpufreq_offline(unsigned int cpu)
2623 cpufreq_offline(cpu);
2629 * cpufreq_register_driver - register a CPU Frequency driver
2630 * @driver_data: A struct cpufreq_driver containing the values#
2631 * submitted by the CPU Frequency driver.
2633 * Registers a CPU Frequency driver to this core code. This code
2634 * returns zero on success, -EEXIST when another driver got here first
2635 * (and isn't unregistered in the meantime).
2638 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2640 unsigned long flags;
2643 if (cpufreq_disabled())
2647 * The cpufreq core depends heavily on the availability of device
2648 * structure, make sure they are available before proceeding further.
2650 if (!get_cpu_device(0))
2651 return -EPROBE_DEFER;
2653 if (!driver_data || !driver_data->verify || !driver_data->init ||
2654 !(driver_data->setpolicy || driver_data->target_index ||
2655 driver_data->target) ||
2656 (driver_data->setpolicy && (driver_data->target_index ||
2657 driver_data->target)) ||
2658 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2659 (!driver_data->online != !driver_data->offline))
2662 pr_debug("trying to register driver %s\n", driver_data->name);
2664 /* Protect against concurrent CPU online/offline. */
2667 write_lock_irqsave(&cpufreq_driver_lock, flags);
2668 if (cpufreq_driver) {
2669 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2673 cpufreq_driver = driver_data;
2674 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2676 if (driver_data->setpolicy)
2677 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2679 if (cpufreq_boost_supported()) {
2680 ret = create_boost_sysfs_file();
2682 goto err_null_driver;
2685 ret = subsys_interface_register(&cpufreq_interface);
2687 goto err_boost_unreg;
2689 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2690 list_empty(&cpufreq_policy_list)) {
2691 /* if all ->init() calls failed, unregister */
2693 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2698 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2700 cpuhp_cpufreq_online,
2701 cpuhp_cpufreq_offline);
2707 pr_debug("driver %s up and running\n", driver_data->name);
2711 subsys_interface_unregister(&cpufreq_interface);
2713 remove_boost_sysfs_file();
2715 write_lock_irqsave(&cpufreq_driver_lock, flags);
2716 cpufreq_driver = NULL;
2717 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2722 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2725 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2727 * Unregister the current CPUFreq driver. Only call this if you have
2728 * the right to do so, i.e. if you have succeeded in initialising before!
2729 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2730 * currently not initialised.
2732 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2734 unsigned long flags;
2736 if (!cpufreq_driver || (driver != cpufreq_driver))
2739 pr_debug("unregistering driver %s\n", driver->name);
2741 /* Protect against concurrent cpu hotplug */
2743 subsys_interface_unregister(&cpufreq_interface);
2744 remove_boost_sysfs_file();
2745 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2747 write_lock_irqsave(&cpufreq_driver_lock, flags);
2749 cpufreq_driver = NULL;
2751 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2756 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2758 static int __init cpufreq_core_init(void)
2760 if (cpufreq_disabled())
2763 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2764 BUG_ON(!cpufreq_global_kobject);
2768 module_param(off, int, 0444);
2769 core_initcall(cpufreq_core_init);