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/slab.h>
27 #include <linux/suspend.h>
28 #include <linux/syscore_ops.h>
29 #include <linux/tick.h>
30 #include <trace/events/power.h>
32 static LIST_HEAD(cpufreq_policy_list);
34 /* Macros to iterate over CPU policies */
35 #define for_each_suitable_policy(__policy, __active) \
36 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
37 if ((__active) == !policy_is_inactive(__policy))
39 #define for_each_active_policy(__policy) \
40 for_each_suitable_policy(__policy, true)
41 #define for_each_inactive_policy(__policy) \
42 for_each_suitable_policy(__policy, false)
44 #define for_each_policy(__policy) \
45 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
47 /* Iterate over governors */
48 static LIST_HEAD(cpufreq_governor_list);
49 #define for_each_governor(__governor) \
50 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
53 * The "cpufreq driver" - the arch- or hardware-dependent low
54 * level driver of CPUFreq support, and its spinlock. This lock
55 * also protects the cpufreq_cpu_data array.
57 static struct cpufreq_driver *cpufreq_driver;
58 static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data);
59 static DEFINE_RWLOCK(cpufreq_driver_lock);
61 /* Flag to suspend/resume CPUFreq governors */
62 static bool cpufreq_suspended;
64 static inline bool has_target(void)
66 return cpufreq_driver->target_index || cpufreq_driver->target;
69 /* internal prototypes */
70 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
71 static int cpufreq_init_governor(struct cpufreq_policy *policy);
72 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
73 static int cpufreq_start_governor(struct cpufreq_policy *policy);
74 static void cpufreq_stop_governor(struct cpufreq_policy *policy);
75 static void cpufreq_governor_limits(struct cpufreq_policy *policy);
78 * Two notifier lists: the "policy" list is involved in the
79 * validation process for a new CPU frequency policy; the
80 * "transition" list for kernel code that needs to handle
81 * changes to devices when the CPU clock speed changes.
82 * The mutex locks both lists.
84 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
85 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
87 static int off __read_mostly;
88 static int cpufreq_disabled(void)
92 void disable_cpufreq(void)
96 static DEFINE_MUTEX(cpufreq_governor_mutex);
98 bool have_governor_per_policy(void)
100 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
102 EXPORT_SYMBOL_GPL(have_governor_per_policy);
104 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
106 if (have_governor_per_policy())
107 return &policy->kobj;
109 return cpufreq_global_kobject;
111 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
113 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
119 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
121 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
122 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
123 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
124 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
125 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
126 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
128 idle_time = cur_wall_time - busy_time;
130 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
132 return div_u64(idle_time, NSEC_PER_USEC);
135 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
137 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
139 if (idle_time == -1ULL)
140 return get_cpu_idle_time_jiffy(cpu, wall);
142 idle_time += get_cpu_iowait_time_us(cpu, wall);
146 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
148 __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
149 unsigned long max_freq)
152 EXPORT_SYMBOL_GPL(arch_set_freq_scale);
155 * This is a generic cpufreq init() routine which can be used by cpufreq
156 * drivers of SMP systems. It will do following:
157 * - validate & show freq table passed
158 * - set policies transition latency
159 * - policy->cpus with all possible CPUs
161 int cpufreq_generic_init(struct cpufreq_policy *policy,
162 struct cpufreq_frequency_table *table,
163 unsigned int transition_latency)
165 policy->freq_table = table;
166 policy->cpuinfo.transition_latency = transition_latency;
169 * The driver only supports the SMP configuration where all processors
170 * share the clock and voltage and clock.
172 cpumask_setall(policy->cpus);
176 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
178 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
180 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
182 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
184 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
186 unsigned int cpufreq_generic_get(unsigned int cpu)
188 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
190 if (!policy || IS_ERR(policy->clk)) {
191 pr_err("%s: No %s associated to cpu: %d\n",
192 __func__, policy ? "clk" : "policy", cpu);
196 return clk_get_rate(policy->clk) / 1000;
198 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
201 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
202 * @cpu: CPU to find the policy for.
204 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
205 * the kobject reference counter of that policy. Return a valid policy on
206 * success or NULL on failure.
208 * The policy returned by this function has to be released with the help of
209 * cpufreq_cpu_put() to balance its kobject reference counter properly.
211 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
213 struct cpufreq_policy *policy = NULL;
216 if (WARN_ON(cpu >= nr_cpu_ids))
219 /* get the cpufreq driver */
220 read_lock_irqsave(&cpufreq_driver_lock, flags);
222 if (cpufreq_driver) {
224 policy = cpufreq_cpu_get_raw(cpu);
226 kobject_get(&policy->kobj);
229 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
233 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
236 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
237 * @policy: cpufreq policy returned by cpufreq_cpu_get().
239 void cpufreq_cpu_put(struct cpufreq_policy *policy)
241 kobject_put(&policy->kobj);
243 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
246 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
247 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
249 void cpufreq_cpu_release(struct cpufreq_policy *policy)
251 if (WARN_ON(!policy))
254 lockdep_assert_held(&policy->rwsem);
256 up_write(&policy->rwsem);
258 cpufreq_cpu_put(policy);
262 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
263 * @cpu: CPU to find the policy for.
265 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
266 * if the policy returned by it is not NULL, acquire its rwsem for writing.
267 * Return the policy if it is active or release it and return NULL otherwise.
269 * The policy returned by this function has to be released with the help of
270 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
273 struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
275 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
280 down_write(&policy->rwsem);
282 if (policy_is_inactive(policy)) {
283 cpufreq_cpu_release(policy);
290 /*********************************************************************
291 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
292 *********************************************************************/
295 * adjust_jiffies - adjust the system "loops_per_jiffy"
297 * This function alters the system "loops_per_jiffy" for the clock
298 * speed change. Note that loops_per_jiffy cannot be updated on SMP
299 * systems as each CPU might be scaled differently. So, use the arch
300 * per-CPU loops_per_jiffy value wherever possible.
302 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
305 static unsigned long l_p_j_ref;
306 static unsigned int l_p_j_ref_freq;
308 if (ci->flags & CPUFREQ_CONST_LOOPS)
311 if (!l_p_j_ref_freq) {
312 l_p_j_ref = loops_per_jiffy;
313 l_p_j_ref_freq = ci->old;
314 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
315 l_p_j_ref, l_p_j_ref_freq);
317 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
318 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
320 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
321 loops_per_jiffy, ci->new);
327 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
328 * @policy: cpufreq policy to enable fast frequency switching for.
329 * @freqs: contain details of the frequency update.
330 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
332 * This function calls the transition notifiers and the "adjust_jiffies"
333 * function. It is called twice on all CPU frequency changes that have
336 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
337 struct cpufreq_freqs *freqs,
342 BUG_ON(irqs_disabled());
344 if (cpufreq_disabled())
347 freqs->policy = policy;
348 freqs->flags = cpufreq_driver->flags;
349 pr_debug("notification %u of frequency transition to %u kHz\n",
353 case CPUFREQ_PRECHANGE:
355 * Detect if the driver reported a value as "old frequency"
356 * which is not equal to what the cpufreq core thinks is
359 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
360 if (policy->cur && (policy->cur != freqs->old)) {
361 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
362 freqs->old, policy->cur);
363 freqs->old = policy->cur;
367 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
368 CPUFREQ_PRECHANGE, freqs);
370 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
373 case CPUFREQ_POSTCHANGE:
374 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
375 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
376 cpumask_pr_args(policy->cpus));
378 for_each_cpu(cpu, policy->cpus)
379 trace_cpu_frequency(freqs->new, cpu);
381 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
382 CPUFREQ_POSTCHANGE, freqs);
384 cpufreq_stats_record_transition(policy, freqs->new);
385 policy->cur = freqs->new;
389 /* Do post notifications when there are chances that transition has failed */
390 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
391 struct cpufreq_freqs *freqs, int transition_failed)
393 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
394 if (!transition_failed)
397 swap(freqs->old, freqs->new);
398 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
399 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
402 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
403 struct cpufreq_freqs *freqs)
407 * Catch double invocations of _begin() which lead to self-deadlock.
408 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
409 * doesn't invoke _begin() on their behalf, and hence the chances of
410 * double invocations are very low. Moreover, there are scenarios
411 * where these checks can emit false-positive warnings in these
412 * drivers; so we avoid that by skipping them altogether.
414 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
415 && current == policy->transition_task);
418 wait_event(policy->transition_wait, !policy->transition_ongoing);
420 spin_lock(&policy->transition_lock);
422 if (unlikely(policy->transition_ongoing)) {
423 spin_unlock(&policy->transition_lock);
427 policy->transition_ongoing = true;
428 policy->transition_task = current;
430 spin_unlock(&policy->transition_lock);
432 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
434 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
436 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
437 struct cpufreq_freqs *freqs, int transition_failed)
439 if (WARN_ON(!policy->transition_ongoing))
442 cpufreq_notify_post_transition(policy, freqs, transition_failed);
444 policy->transition_ongoing = false;
445 policy->transition_task = NULL;
447 wake_up(&policy->transition_wait);
449 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
452 * Fast frequency switching status count. Positive means "enabled", negative
453 * means "disabled" and 0 means "not decided yet".
455 static int cpufreq_fast_switch_count;
456 static DEFINE_MUTEX(cpufreq_fast_switch_lock);
458 static void cpufreq_list_transition_notifiers(void)
460 struct notifier_block *nb;
462 pr_info("Registered transition notifiers:\n");
464 mutex_lock(&cpufreq_transition_notifier_list.mutex);
466 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
467 pr_info("%pS\n", nb->notifier_call);
469 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
473 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
474 * @policy: cpufreq policy to enable fast frequency switching for.
476 * Try to enable fast frequency switching for @policy.
478 * The attempt will fail if there is at least one transition notifier registered
479 * at this point, as fast frequency switching is quite fundamentally at odds
480 * with transition notifiers. Thus if successful, it will make registration of
481 * transition notifiers fail going forward.
483 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
485 lockdep_assert_held(&policy->rwsem);
487 if (!policy->fast_switch_possible)
490 mutex_lock(&cpufreq_fast_switch_lock);
491 if (cpufreq_fast_switch_count >= 0) {
492 cpufreq_fast_switch_count++;
493 policy->fast_switch_enabled = true;
495 pr_warn("CPU%u: Fast frequency switching not enabled\n",
497 cpufreq_list_transition_notifiers();
499 mutex_unlock(&cpufreq_fast_switch_lock);
501 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
504 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
505 * @policy: cpufreq policy to disable fast frequency switching for.
507 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
509 mutex_lock(&cpufreq_fast_switch_lock);
510 if (policy->fast_switch_enabled) {
511 policy->fast_switch_enabled = false;
512 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
513 cpufreq_fast_switch_count--;
515 mutex_unlock(&cpufreq_fast_switch_lock);
517 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
520 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
522 * @target_freq: target frequency to resolve.
524 * The target to driver frequency mapping is cached in the policy.
526 * Return: Lowest driver-supported frequency greater than or equal to the
527 * given target_freq, subject to policy (min/max) and driver limitations.
529 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
530 unsigned int target_freq)
532 target_freq = clamp_val(target_freq, policy->min, policy->max);
533 policy->cached_target_freq = target_freq;
535 if (cpufreq_driver->target_index) {
538 idx = cpufreq_frequency_table_target(policy, target_freq,
540 policy->cached_resolved_idx = idx;
541 return policy->freq_table[idx].frequency;
544 if (cpufreq_driver->resolve_freq)
545 return cpufreq_driver->resolve_freq(policy, target_freq);
549 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
551 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
553 unsigned int latency;
555 if (policy->transition_delay_us)
556 return policy->transition_delay_us;
558 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
561 * For platforms that can change the frequency very fast (< 10
562 * us), the above formula gives a decent transition delay. But
563 * for platforms where transition_latency is in milliseconds, it
564 * ends up giving unrealistic values.
566 * Cap the default transition delay to 10 ms, which seems to be
567 * a reasonable amount of time after which we should reevaluate
570 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
573 return LATENCY_MULTIPLIER;
575 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
577 /*********************************************************************
579 *********************************************************************/
580 static ssize_t show_boost(struct kobject *kobj,
581 struct kobj_attribute *attr, char *buf)
583 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
586 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
587 const char *buf, size_t count)
591 ret = sscanf(buf, "%d", &enable);
592 if (ret != 1 || enable < 0 || enable > 1)
595 if (cpufreq_boost_trigger_state(enable)) {
596 pr_err("%s: Cannot %s BOOST!\n",
597 __func__, enable ? "enable" : "disable");
601 pr_debug("%s: cpufreq BOOST %s\n",
602 __func__, enable ? "enabled" : "disabled");
606 define_one_global_rw(boost);
608 static struct cpufreq_governor *find_governor(const char *str_governor)
610 struct cpufreq_governor *t;
613 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
619 static int cpufreq_parse_policy(char *str_governor,
620 struct cpufreq_policy *policy)
622 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
623 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
626 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
627 policy->policy = CPUFREQ_POLICY_POWERSAVE;
634 * cpufreq_parse_governor - parse a governor string only for !setpolicy
636 static int cpufreq_parse_governor(char *str_governor,
637 struct cpufreq_policy *policy)
639 struct cpufreq_governor *t;
641 mutex_lock(&cpufreq_governor_mutex);
643 t = find_governor(str_governor);
647 mutex_unlock(&cpufreq_governor_mutex);
649 ret = request_module("cpufreq_%s", str_governor);
653 mutex_lock(&cpufreq_governor_mutex);
655 t = find_governor(str_governor);
657 if (t && !try_module_get(t->owner))
660 mutex_unlock(&cpufreq_governor_mutex);
663 policy->governor = t;
671 * cpufreq_per_cpu_attr_read() / show_##file_name() -
672 * print out cpufreq information
674 * Write out information from cpufreq_driver->policy[cpu]; object must be
678 #define show_one(file_name, object) \
679 static ssize_t show_##file_name \
680 (struct cpufreq_policy *policy, char *buf) \
682 return sprintf(buf, "%u\n", policy->object); \
685 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
686 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
687 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
688 show_one(scaling_min_freq, min);
689 show_one(scaling_max_freq, max);
691 __weak unsigned int arch_freq_get_on_cpu(int cpu)
696 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
701 freq = arch_freq_get_on_cpu(policy->cpu);
703 ret = sprintf(buf, "%u\n", freq);
704 else if (cpufreq_driver && cpufreq_driver->setpolicy &&
706 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
708 ret = sprintf(buf, "%u\n", policy->cur);
713 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
715 #define store_one(file_name, object) \
716 static ssize_t store_##file_name \
717 (struct cpufreq_policy *policy, const char *buf, size_t count) \
720 struct cpufreq_policy new_policy; \
722 memcpy(&new_policy, policy, sizeof(*policy)); \
723 new_policy.min = policy->user_policy.min; \
724 new_policy.max = policy->user_policy.max; \
726 ret = sscanf(buf, "%u", &new_policy.object); \
730 temp = new_policy.object; \
731 ret = cpufreq_set_policy(policy, &new_policy); \
733 policy->user_policy.object = temp; \
735 return ret ? ret : count; \
738 store_one(scaling_min_freq, min);
739 store_one(scaling_max_freq, max);
742 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
744 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
747 unsigned int cur_freq = __cpufreq_get(policy);
750 return sprintf(buf, "%u\n", cur_freq);
752 return sprintf(buf, "<unknown>\n");
756 * show_scaling_governor - show the current policy for the specified CPU
758 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
760 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
761 return sprintf(buf, "powersave\n");
762 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
763 return sprintf(buf, "performance\n");
764 else if (policy->governor)
765 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
766 policy->governor->name);
771 * store_scaling_governor - store policy for the specified CPU
773 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
774 const char *buf, size_t count)
777 char str_governor[16];
778 struct cpufreq_policy new_policy;
780 memcpy(&new_policy, policy, sizeof(*policy));
782 ret = sscanf(buf, "%15s", str_governor);
786 if (cpufreq_driver->setpolicy) {
787 if (cpufreq_parse_policy(str_governor, &new_policy))
790 if (cpufreq_parse_governor(str_governor, &new_policy))
794 ret = cpufreq_set_policy(policy, &new_policy);
796 if (new_policy.governor)
797 module_put(new_policy.governor->owner);
799 return ret ? ret : count;
803 * show_scaling_driver - show the cpufreq driver currently loaded
805 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
807 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
811 * show_scaling_available_governors - show the available CPUfreq governors
813 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
817 struct cpufreq_governor *t;
820 i += sprintf(buf, "performance powersave");
824 for_each_governor(t) {
825 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
826 - (CPUFREQ_NAME_LEN + 2)))
828 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
831 i += sprintf(&buf[i], "\n");
835 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
840 for_each_cpu(cpu, mask) {
842 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
843 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
844 if (i >= (PAGE_SIZE - 5))
847 i += sprintf(&buf[i], "\n");
850 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
853 * show_related_cpus - show the CPUs affected by each transition even if
854 * hw coordination is in use
856 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
858 return cpufreq_show_cpus(policy->related_cpus, buf);
862 * show_affected_cpus - show the CPUs affected by each transition
864 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
866 return cpufreq_show_cpus(policy->cpus, buf);
869 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
870 const char *buf, size_t count)
872 unsigned int freq = 0;
875 if (!policy->governor || !policy->governor->store_setspeed)
878 ret = sscanf(buf, "%u", &freq);
882 policy->governor->store_setspeed(policy, freq);
887 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
889 if (!policy->governor || !policy->governor->show_setspeed)
890 return sprintf(buf, "<unsupported>\n");
892 return policy->governor->show_setspeed(policy, buf);
896 * show_bios_limit - show the current cpufreq HW/BIOS limitation
898 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
902 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
904 return sprintf(buf, "%u\n", limit);
905 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
908 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
909 cpufreq_freq_attr_ro(cpuinfo_min_freq);
910 cpufreq_freq_attr_ro(cpuinfo_max_freq);
911 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
912 cpufreq_freq_attr_ro(scaling_available_governors);
913 cpufreq_freq_attr_ro(scaling_driver);
914 cpufreq_freq_attr_ro(scaling_cur_freq);
915 cpufreq_freq_attr_ro(bios_limit);
916 cpufreq_freq_attr_ro(related_cpus);
917 cpufreq_freq_attr_ro(affected_cpus);
918 cpufreq_freq_attr_rw(scaling_min_freq);
919 cpufreq_freq_attr_rw(scaling_max_freq);
920 cpufreq_freq_attr_rw(scaling_governor);
921 cpufreq_freq_attr_rw(scaling_setspeed);
923 static struct attribute *default_attrs[] = {
924 &cpuinfo_min_freq.attr,
925 &cpuinfo_max_freq.attr,
926 &cpuinfo_transition_latency.attr,
927 &scaling_min_freq.attr,
928 &scaling_max_freq.attr,
931 &scaling_governor.attr,
932 &scaling_driver.attr,
933 &scaling_available_governors.attr,
934 &scaling_setspeed.attr,
938 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
939 #define to_attr(a) container_of(a, struct freq_attr, attr)
941 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
943 struct cpufreq_policy *policy = to_policy(kobj);
944 struct freq_attr *fattr = to_attr(attr);
947 down_read(&policy->rwsem);
948 ret = fattr->show(policy, buf);
949 up_read(&policy->rwsem);
954 static ssize_t store(struct kobject *kobj, struct attribute *attr,
955 const char *buf, size_t count)
957 struct cpufreq_policy *policy = to_policy(kobj);
958 struct freq_attr *fattr = to_attr(attr);
959 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 *gov = NULL, *def_gov = NULL;
1059 struct cpufreq_policy new_policy;
1061 memcpy(&new_policy, policy, sizeof(*policy));
1063 def_gov = cpufreq_default_governor();
1067 * Update governor of new_policy to the governor used before
1070 gov = find_governor(policy->last_governor);
1072 pr_debug("Restoring governor %s for cpu %d\n",
1073 policy->governor->name, policy->cpu);
1079 new_policy.governor = gov;
1081 /* Use the default policy if there is no last_policy. */
1082 if (policy->last_policy) {
1083 new_policy.policy = policy->last_policy;
1087 cpufreq_parse_policy(def_gov->name, &new_policy);
1091 return cpufreq_set_policy(policy, &new_policy);
1094 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1098 /* Has this CPU been taken care of already? */
1099 if (cpumask_test_cpu(cpu, policy->cpus))
1102 down_write(&policy->rwsem);
1104 cpufreq_stop_governor(policy);
1106 cpumask_set_cpu(cpu, policy->cpus);
1109 ret = cpufreq_start_governor(policy);
1111 pr_err("%s: Failed to start governor\n", __func__);
1113 up_write(&policy->rwsem);
1117 static void handle_update(struct work_struct *work)
1119 struct cpufreq_policy *policy =
1120 container_of(work, struct cpufreq_policy, update);
1121 unsigned int cpu = policy->cpu;
1122 pr_debug("handle_update for cpu %u called\n", cpu);
1123 cpufreq_update_policy(cpu);
1126 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1128 struct cpufreq_policy *policy;
1131 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1135 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1136 goto err_free_policy;
1138 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1139 goto err_free_cpumask;
1141 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1142 goto err_free_rcpumask;
1144 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1145 cpufreq_global_kobject, "policy%u", cpu);
1147 pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
1149 * The entire policy object will be freed below, but the extra
1150 * memory allocated for the kobject name needs to be freed by
1151 * releasing the kobject.
1153 kobject_put(&policy->kobj);
1154 goto err_free_real_cpus;
1157 INIT_LIST_HEAD(&policy->policy_list);
1158 init_rwsem(&policy->rwsem);
1159 spin_lock_init(&policy->transition_lock);
1160 init_waitqueue_head(&policy->transition_wait);
1161 init_completion(&policy->kobj_unregister);
1162 INIT_WORK(&policy->update, handle_update);
1168 free_cpumask_var(policy->real_cpus);
1170 free_cpumask_var(policy->related_cpus);
1172 free_cpumask_var(policy->cpus);
1179 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1181 struct kobject *kobj;
1182 struct completion *cmp;
1184 down_write(&policy->rwsem);
1185 cpufreq_stats_free_table(policy);
1186 kobj = &policy->kobj;
1187 cmp = &policy->kobj_unregister;
1188 up_write(&policy->rwsem);
1192 * We need to make sure that the underlying kobj is
1193 * actually not referenced anymore by anybody before we
1194 * proceed with unloading.
1196 pr_debug("waiting for dropping of refcount\n");
1197 wait_for_completion(cmp);
1198 pr_debug("wait complete\n");
1201 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1203 unsigned long flags;
1206 /* Remove policy from list */
1207 write_lock_irqsave(&cpufreq_driver_lock, flags);
1208 list_del(&policy->policy_list);
1210 for_each_cpu(cpu, policy->related_cpus)
1211 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1212 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1214 cpufreq_policy_put_kobj(policy);
1215 free_cpumask_var(policy->real_cpus);
1216 free_cpumask_var(policy->related_cpus);
1217 free_cpumask_var(policy->cpus);
1221 static int cpufreq_online(unsigned int cpu)
1223 struct cpufreq_policy *policy;
1225 unsigned long flags;
1229 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1231 /* Check if this CPU already has a policy to manage it */
1232 policy = per_cpu(cpufreq_cpu_data, cpu);
1234 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1235 if (!policy_is_inactive(policy))
1236 return cpufreq_add_policy_cpu(policy, cpu);
1238 /* This is the only online CPU for the policy. Start over. */
1240 down_write(&policy->rwsem);
1242 policy->governor = NULL;
1243 up_write(&policy->rwsem);
1246 policy = cpufreq_policy_alloc(cpu);
1251 if (!new_policy && cpufreq_driver->online) {
1252 ret = cpufreq_driver->online(policy);
1254 pr_debug("%s: %d: initialization failed\n", __func__,
1256 goto out_exit_policy;
1259 /* Recover policy->cpus using related_cpus */
1260 cpumask_copy(policy->cpus, policy->related_cpus);
1262 cpumask_copy(policy->cpus, cpumask_of(cpu));
1265 * Call driver. From then on the cpufreq must be able
1266 * to accept all calls to ->verify and ->setpolicy for this CPU.
1268 ret = cpufreq_driver->init(policy);
1270 pr_debug("%s: %d: initialization failed\n", __func__,
1272 goto out_free_policy;
1275 ret = cpufreq_table_validate_and_sort(policy);
1277 goto out_exit_policy;
1279 /* related_cpus should at least include policy->cpus. */
1280 cpumask_copy(policy->related_cpus, policy->cpus);
1283 down_write(&policy->rwsem);
1285 * affected cpus must always be the one, which are online. We aren't
1286 * managing offline cpus here.
1288 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1291 policy->user_policy.min = policy->min;
1292 policy->user_policy.max = policy->max;
1294 for_each_cpu(j, policy->related_cpus) {
1295 per_cpu(cpufreq_cpu_data, j) = policy;
1296 add_cpu_dev_symlink(policy, j);
1299 policy->min = policy->user_policy.min;
1300 policy->max = policy->user_policy.max;
1303 if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
1304 policy->cur = cpufreq_driver->get(policy->cpu);
1306 pr_err("%s: ->get() failed\n", __func__);
1307 goto out_destroy_policy;
1312 * Sometimes boot loaders set CPU frequency to a value outside of
1313 * frequency table present with cpufreq core. In such cases CPU might be
1314 * unstable if it has to run on that frequency for long duration of time
1315 * and so its better to set it to a frequency which is specified in
1316 * freq-table. This also makes cpufreq stats inconsistent as
1317 * cpufreq-stats would fail to register because current frequency of CPU
1318 * isn't found in freq-table.
1320 * Because we don't want this change to effect boot process badly, we go
1321 * for the next freq which is >= policy->cur ('cur' must be set by now,
1322 * otherwise we will end up setting freq to lowest of the table as 'cur'
1323 * is initialized to zero).
1325 * We are passing target-freq as "policy->cur - 1" otherwise
1326 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1327 * equal to target-freq.
1329 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1331 /* Are we running at unknown frequency ? */
1332 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1333 if (ret == -EINVAL) {
1334 /* Warn user and fix it */
1335 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1336 __func__, policy->cpu, policy->cur);
1337 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1338 CPUFREQ_RELATION_L);
1341 * Reaching here after boot in a few seconds may not
1342 * mean that system will remain stable at "unknown"
1343 * frequency for longer duration. Hence, a BUG_ON().
1346 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1347 __func__, policy->cpu, policy->cur);
1352 ret = cpufreq_add_dev_interface(policy);
1354 goto out_destroy_policy;
1356 cpufreq_stats_create_table(policy);
1358 write_lock_irqsave(&cpufreq_driver_lock, flags);
1359 list_add(&policy->policy_list, &cpufreq_policy_list);
1360 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1363 ret = cpufreq_init_policy(policy);
1365 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1366 __func__, cpu, ret);
1367 goto out_destroy_policy;
1370 up_write(&policy->rwsem);
1372 kobject_uevent(&policy->kobj, KOBJ_ADD);
1374 /* Callback for handling stuff after policy is ready */
1375 if (cpufreq_driver->ready)
1376 cpufreq_driver->ready(policy);
1378 if (IS_ENABLED(CONFIG_CPU_THERMAL) &&
1379 cpufreq_driver->flags & CPUFREQ_IS_COOLING_DEV)
1380 policy->cdev = of_cpufreq_cooling_register(policy);
1382 pr_debug("initialization complete\n");
1387 for_each_cpu(j, policy->real_cpus)
1388 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1390 up_write(&policy->rwsem);
1393 if (cpufreq_driver->exit)
1394 cpufreq_driver->exit(policy);
1397 cpufreq_policy_free(policy);
1402 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1404 * @sif: Subsystem interface structure pointer (not used)
1406 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1408 struct cpufreq_policy *policy;
1409 unsigned cpu = dev->id;
1412 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1414 if (cpu_online(cpu)) {
1415 ret = cpufreq_online(cpu);
1420 /* Create sysfs link on CPU registration */
1421 policy = per_cpu(cpufreq_cpu_data, cpu);
1423 add_cpu_dev_symlink(policy, cpu);
1428 static int cpufreq_offline(unsigned int cpu)
1430 struct cpufreq_policy *policy;
1433 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1435 policy = cpufreq_cpu_get_raw(cpu);
1437 pr_debug("%s: No cpu_data found\n", __func__);
1441 down_write(&policy->rwsem);
1443 cpufreq_stop_governor(policy);
1445 cpumask_clear_cpu(cpu, policy->cpus);
1447 if (policy_is_inactive(policy)) {
1449 strncpy(policy->last_governor, policy->governor->name,
1452 policy->last_policy = policy->policy;
1453 } else if (cpu == policy->cpu) {
1454 /* Nominate new CPU */
1455 policy->cpu = cpumask_any(policy->cpus);
1458 /* Start governor again for active policy */
1459 if (!policy_is_inactive(policy)) {
1461 ret = cpufreq_start_governor(policy);
1463 pr_err("%s: Failed to start governor\n", __func__);
1469 if (IS_ENABLED(CONFIG_CPU_THERMAL) &&
1470 cpufreq_driver->flags & CPUFREQ_IS_COOLING_DEV) {
1471 cpufreq_cooling_unregister(policy->cdev);
1472 policy->cdev = NULL;
1475 if (cpufreq_driver->stop_cpu)
1476 cpufreq_driver->stop_cpu(policy);
1479 cpufreq_exit_governor(policy);
1482 * Perform the ->offline() during light-weight tear-down, as
1483 * that allows fast recovery when the CPU comes back.
1485 if (cpufreq_driver->offline) {
1486 cpufreq_driver->offline(policy);
1487 } else if (cpufreq_driver->exit) {
1488 cpufreq_driver->exit(policy);
1489 policy->freq_table = NULL;
1493 up_write(&policy->rwsem);
1498 * cpufreq_remove_dev - remove a CPU device
1500 * Removes the cpufreq interface for a CPU device.
1502 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1504 unsigned int cpu = dev->id;
1505 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1510 if (cpu_online(cpu))
1511 cpufreq_offline(cpu);
1513 cpumask_clear_cpu(cpu, policy->real_cpus);
1514 remove_cpu_dev_symlink(policy, dev);
1516 if (cpumask_empty(policy->real_cpus)) {
1517 /* We did light-weight exit earlier, do full tear down now */
1518 if (cpufreq_driver->offline)
1519 cpufreq_driver->exit(policy);
1521 cpufreq_policy_free(policy);
1526 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1528 * @policy: policy managing CPUs
1529 * @new_freq: CPU frequency the CPU actually runs at
1531 * We adjust to current frequency first, and need to clean up later.
1532 * So either call to cpufreq_update_policy() or schedule handle_update()).
1534 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1535 unsigned int new_freq)
1537 struct cpufreq_freqs freqs;
1539 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1540 policy->cur, new_freq);
1542 freqs.old = policy->cur;
1543 freqs.new = new_freq;
1545 cpufreq_freq_transition_begin(policy, &freqs);
1546 cpufreq_freq_transition_end(policy, &freqs, 0);
1550 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1553 * This is the last known freq, without actually getting it from the driver.
1554 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1556 unsigned int cpufreq_quick_get(unsigned int cpu)
1558 struct cpufreq_policy *policy;
1559 unsigned int ret_freq = 0;
1560 unsigned long flags;
1562 read_lock_irqsave(&cpufreq_driver_lock, flags);
1564 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1565 ret_freq = cpufreq_driver->get(cpu);
1566 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1570 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1572 policy = cpufreq_cpu_get(cpu);
1574 ret_freq = policy->cur;
1575 cpufreq_cpu_put(policy);
1580 EXPORT_SYMBOL(cpufreq_quick_get);
1583 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1586 * Just return the max possible frequency for a given CPU.
1588 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1590 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1591 unsigned int ret_freq = 0;
1594 ret_freq = policy->max;
1595 cpufreq_cpu_put(policy);
1600 EXPORT_SYMBOL(cpufreq_quick_get_max);
1602 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1604 unsigned int ret_freq = 0;
1606 if (unlikely(policy_is_inactive(policy)))
1609 ret_freq = cpufreq_driver->get(policy->cpu);
1612 * If fast frequency switching is used with the given policy, the check
1613 * against policy->cur is pointless, so skip it in that case too.
1615 if (policy->fast_switch_enabled)
1618 if (ret_freq && policy->cur &&
1619 !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
1620 /* verify no discrepancy between actual and
1621 saved value exists */
1622 if (unlikely(ret_freq != policy->cur)) {
1623 cpufreq_out_of_sync(policy, ret_freq);
1624 schedule_work(&policy->update);
1632 * cpufreq_get - get the current CPU frequency (in kHz)
1635 * Get the CPU current (static) CPU frequency
1637 unsigned int cpufreq_get(unsigned int cpu)
1639 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1640 unsigned int ret_freq = 0;
1643 down_read(&policy->rwsem);
1644 if (cpufreq_driver->get)
1645 ret_freq = __cpufreq_get(policy);
1646 up_read(&policy->rwsem);
1648 cpufreq_cpu_put(policy);
1653 EXPORT_SYMBOL(cpufreq_get);
1655 static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy)
1657 unsigned int new_freq;
1659 new_freq = cpufreq_driver->get(policy->cpu);
1664 pr_debug("cpufreq: Driver did not initialize current freq\n");
1665 policy->cur = new_freq;
1666 } else if (policy->cur != new_freq && has_target()) {
1667 cpufreq_out_of_sync(policy, new_freq);
1673 static struct subsys_interface cpufreq_interface = {
1675 .subsys = &cpu_subsys,
1676 .add_dev = cpufreq_add_dev,
1677 .remove_dev = cpufreq_remove_dev,
1681 * In case platform wants some specific frequency to be configured
1684 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1688 if (!policy->suspend_freq) {
1689 pr_debug("%s: suspend_freq not defined\n", __func__);
1693 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1694 policy->suspend_freq);
1696 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1697 CPUFREQ_RELATION_H);
1699 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1700 __func__, policy->suspend_freq, ret);
1704 EXPORT_SYMBOL(cpufreq_generic_suspend);
1707 * cpufreq_suspend() - Suspend CPUFreq governors
1709 * Called during system wide Suspend/Hibernate cycles for suspending governors
1710 * as some platforms can't change frequency after this point in suspend cycle.
1711 * Because some of the devices (like: i2c, regulators, etc) they use for
1712 * changing frequency are suspended quickly after this point.
1714 void cpufreq_suspend(void)
1716 struct cpufreq_policy *policy;
1718 if (!cpufreq_driver)
1721 if (!has_target() && !cpufreq_driver->suspend)
1724 pr_debug("%s: Suspending Governors\n", __func__);
1726 for_each_active_policy(policy) {
1728 down_write(&policy->rwsem);
1729 cpufreq_stop_governor(policy);
1730 up_write(&policy->rwsem);
1733 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1734 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1739 cpufreq_suspended = true;
1743 * cpufreq_resume() - Resume CPUFreq governors
1745 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1746 * are suspended with cpufreq_suspend().
1748 void cpufreq_resume(void)
1750 struct cpufreq_policy *policy;
1753 if (!cpufreq_driver)
1756 if (unlikely(!cpufreq_suspended))
1759 cpufreq_suspended = false;
1761 if (!has_target() && !cpufreq_driver->resume)
1764 pr_debug("%s: Resuming Governors\n", __func__);
1766 for_each_active_policy(policy) {
1767 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1768 pr_err("%s: Failed to resume driver: %p\n", __func__,
1770 } else if (has_target()) {
1771 down_write(&policy->rwsem);
1772 ret = cpufreq_start_governor(policy);
1773 up_write(&policy->rwsem);
1776 pr_err("%s: Failed to start governor for policy: %p\n",
1783 * cpufreq_get_current_driver - return current driver's name
1785 * Return the name string of the currently loaded cpufreq driver
1788 const char *cpufreq_get_current_driver(void)
1791 return cpufreq_driver->name;
1795 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1798 * cpufreq_get_driver_data - return current driver data
1800 * Return the private data of the currently loaded cpufreq
1801 * driver, or NULL if no cpufreq driver is loaded.
1803 void *cpufreq_get_driver_data(void)
1806 return cpufreq_driver->driver_data;
1810 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1812 /*********************************************************************
1813 * NOTIFIER LISTS INTERFACE *
1814 *********************************************************************/
1817 * cpufreq_register_notifier - register a driver with cpufreq
1818 * @nb: notifier function to register
1819 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1821 * Add a driver to one of two lists: either a list of drivers that
1822 * are notified about clock rate changes (once before and once after
1823 * the transition), or a list of drivers that are notified about
1824 * changes in cpufreq policy.
1826 * This function may sleep, and has the same return conditions as
1827 * blocking_notifier_chain_register.
1829 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1833 if (cpufreq_disabled())
1837 case CPUFREQ_TRANSITION_NOTIFIER:
1838 mutex_lock(&cpufreq_fast_switch_lock);
1840 if (cpufreq_fast_switch_count > 0) {
1841 mutex_unlock(&cpufreq_fast_switch_lock);
1844 ret = srcu_notifier_chain_register(
1845 &cpufreq_transition_notifier_list, nb);
1847 cpufreq_fast_switch_count--;
1849 mutex_unlock(&cpufreq_fast_switch_lock);
1851 case CPUFREQ_POLICY_NOTIFIER:
1852 ret = blocking_notifier_chain_register(
1853 &cpufreq_policy_notifier_list, nb);
1861 EXPORT_SYMBOL(cpufreq_register_notifier);
1864 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1865 * @nb: notifier block to be unregistered
1866 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1868 * Remove a driver from the CPU frequency notifier list.
1870 * This function may sleep, and has the same return conditions as
1871 * blocking_notifier_chain_unregister.
1873 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1877 if (cpufreq_disabled())
1881 case CPUFREQ_TRANSITION_NOTIFIER:
1882 mutex_lock(&cpufreq_fast_switch_lock);
1884 ret = srcu_notifier_chain_unregister(
1885 &cpufreq_transition_notifier_list, nb);
1886 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1887 cpufreq_fast_switch_count++;
1889 mutex_unlock(&cpufreq_fast_switch_lock);
1891 case CPUFREQ_POLICY_NOTIFIER:
1892 ret = blocking_notifier_chain_unregister(
1893 &cpufreq_policy_notifier_list, nb);
1901 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1904 /*********************************************************************
1906 *********************************************************************/
1909 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1910 * @policy: cpufreq policy to switch the frequency for.
1911 * @target_freq: New frequency to set (may be approximate).
1913 * Carry out a fast frequency switch without sleeping.
1915 * The driver's ->fast_switch() callback invoked by this function must be
1916 * suitable for being called from within RCU-sched read-side critical sections
1917 * and it is expected to select the minimum available frequency greater than or
1918 * equal to @target_freq (CPUFREQ_RELATION_L).
1920 * This function must not be called if policy->fast_switch_enabled is unset.
1922 * Governors calling this function must guarantee that it will never be invoked
1923 * twice in parallel for the same policy and that it will never be called in
1924 * parallel with either ->target() or ->target_index() for the same policy.
1926 * Returns the actual frequency set for the CPU.
1928 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
1929 * error condition, the hardware configuration must be preserved.
1931 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
1932 unsigned int target_freq)
1934 target_freq = clamp_val(target_freq, policy->min, policy->max);
1936 return cpufreq_driver->fast_switch(policy, target_freq);
1938 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
1940 /* Must set freqs->new to intermediate frequency */
1941 static int __target_intermediate(struct cpufreq_policy *policy,
1942 struct cpufreq_freqs *freqs, int index)
1946 freqs->new = cpufreq_driver->get_intermediate(policy, index);
1948 /* We don't need to switch to intermediate freq */
1952 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1953 __func__, policy->cpu, freqs->old, freqs->new);
1955 cpufreq_freq_transition_begin(policy, freqs);
1956 ret = cpufreq_driver->target_intermediate(policy, index);
1957 cpufreq_freq_transition_end(policy, freqs, ret);
1960 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1966 static int __target_index(struct cpufreq_policy *policy, int index)
1968 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
1969 unsigned int intermediate_freq = 0;
1970 unsigned int newfreq = policy->freq_table[index].frequency;
1971 int retval = -EINVAL;
1974 if (newfreq == policy->cur)
1977 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
1979 /* Handle switching to intermediate frequency */
1980 if (cpufreq_driver->get_intermediate) {
1981 retval = __target_intermediate(policy, &freqs, index);
1985 intermediate_freq = freqs.new;
1986 /* Set old freq to intermediate */
1987 if (intermediate_freq)
1988 freqs.old = freqs.new;
1991 freqs.new = newfreq;
1992 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1993 __func__, policy->cpu, freqs.old, freqs.new);
1995 cpufreq_freq_transition_begin(policy, &freqs);
1998 retval = cpufreq_driver->target_index(policy, index);
2000 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2004 cpufreq_freq_transition_end(policy, &freqs, retval);
2007 * Failed after setting to intermediate freq? Driver should have
2008 * reverted back to initial frequency and so should we. Check
2009 * here for intermediate_freq instead of get_intermediate, in
2010 * case we haven't switched to intermediate freq at all.
2012 if (unlikely(retval && intermediate_freq)) {
2013 freqs.old = intermediate_freq;
2014 freqs.new = policy->restore_freq;
2015 cpufreq_freq_transition_begin(policy, &freqs);
2016 cpufreq_freq_transition_end(policy, &freqs, 0);
2023 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2024 unsigned int target_freq,
2025 unsigned int relation)
2027 unsigned int old_target_freq = target_freq;
2030 if (cpufreq_disabled())
2033 /* Make sure that target_freq is within supported range */
2034 target_freq = clamp_val(target_freq, policy->min, policy->max);
2036 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2037 policy->cpu, target_freq, relation, old_target_freq);
2040 * This might look like a redundant call as we are checking it again
2041 * after finding index. But it is left intentionally for cases where
2042 * exactly same freq is called again and so we can save on few function
2045 if (target_freq == policy->cur)
2048 /* Save last value to restore later on errors */
2049 policy->restore_freq = policy->cur;
2051 if (cpufreq_driver->target)
2052 return cpufreq_driver->target(policy, target_freq, relation);
2054 if (!cpufreq_driver->target_index)
2057 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2059 return __target_index(policy, index);
2061 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2063 int cpufreq_driver_target(struct cpufreq_policy *policy,
2064 unsigned int target_freq,
2065 unsigned int relation)
2069 down_write(&policy->rwsem);
2071 ret = __cpufreq_driver_target(policy, target_freq, relation);
2073 up_write(&policy->rwsem);
2077 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2079 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2084 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2088 /* Don't start any governor operations if we are entering suspend */
2089 if (cpufreq_suspended)
2092 * Governor might not be initiated here if ACPI _PPC changed
2093 * notification happened, so check it.
2095 if (!policy->governor)
2098 /* Platform doesn't want dynamic frequency switching ? */
2099 if (policy->governor->dynamic_switching &&
2100 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2101 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2104 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2105 policy->governor->name, gov->name);
2106 policy->governor = gov;
2112 if (!try_module_get(policy->governor->owner))
2115 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2117 if (policy->governor->init) {
2118 ret = policy->governor->init(policy);
2120 module_put(policy->governor->owner);
2128 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2130 if (cpufreq_suspended || !policy->governor)
2133 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2135 if (policy->governor->exit)
2136 policy->governor->exit(policy);
2138 module_put(policy->governor->owner);
2141 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2145 if (cpufreq_suspended)
2148 if (!policy->governor)
2151 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2153 if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
2154 cpufreq_update_current_freq(policy);
2156 if (policy->governor->start) {
2157 ret = policy->governor->start(policy);
2162 if (policy->governor->limits)
2163 policy->governor->limits(policy);
2168 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2170 if (cpufreq_suspended || !policy->governor)
2173 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2175 if (policy->governor->stop)
2176 policy->governor->stop(policy);
2179 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2181 if (cpufreq_suspended || !policy->governor)
2184 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2186 if (policy->governor->limits)
2187 policy->governor->limits(policy);
2190 int cpufreq_register_governor(struct cpufreq_governor *governor)
2197 if (cpufreq_disabled())
2200 mutex_lock(&cpufreq_governor_mutex);
2203 if (!find_governor(governor->name)) {
2205 list_add(&governor->governor_list, &cpufreq_governor_list);
2208 mutex_unlock(&cpufreq_governor_mutex);
2211 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2213 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2215 struct cpufreq_policy *policy;
2216 unsigned long flags;
2221 if (cpufreq_disabled())
2224 /* clear last_governor for all inactive policies */
2225 read_lock_irqsave(&cpufreq_driver_lock, flags);
2226 for_each_inactive_policy(policy) {
2227 if (!strcmp(policy->last_governor, governor->name)) {
2228 policy->governor = NULL;
2229 strcpy(policy->last_governor, "\0");
2232 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2234 mutex_lock(&cpufreq_governor_mutex);
2235 list_del(&governor->governor_list);
2236 mutex_unlock(&cpufreq_governor_mutex);
2238 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2241 /*********************************************************************
2242 * POLICY INTERFACE *
2243 *********************************************************************/
2246 * cpufreq_get_policy - get the current cpufreq_policy
2247 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2250 * Reads the current cpufreq policy.
2252 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2254 struct cpufreq_policy *cpu_policy;
2258 cpu_policy = cpufreq_cpu_get(cpu);
2262 memcpy(policy, cpu_policy, sizeof(*policy));
2264 cpufreq_cpu_put(cpu_policy);
2267 EXPORT_SYMBOL(cpufreq_get_policy);
2270 * cpufreq_set_policy - Modify cpufreq policy parameters.
2271 * @policy: Policy object to modify.
2272 * @new_policy: New policy data.
2274 * Pass @new_policy to the cpufreq driver's ->verify() callback, run the
2275 * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to
2276 * the driver's ->verify() callback again and run the notifiers for it again
2277 * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters
2278 * of @new_policy to @policy and either invoke the driver's ->setpolicy()
2279 * callback (if present) or carry out a governor update for @policy. That is,
2280 * run the current governor's ->limits() callback (if the governor field in
2281 * @new_policy points to the same object as the one in @policy) or replace the
2282 * governor for @policy with the new one stored in @new_policy.
2284 * The cpuinfo part of @policy is not updated by this function.
2286 int cpufreq_set_policy(struct cpufreq_policy *policy,
2287 struct cpufreq_policy *new_policy)
2289 struct cpufreq_governor *old_gov;
2292 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2293 new_policy->cpu, new_policy->min, new_policy->max);
2295 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2298 * This check works well when we store new min/max freq attributes,
2299 * because new_policy is a copy of policy with one field updated.
2301 if (new_policy->min > new_policy->max)
2304 /* verify the cpu speed can be set within this limit */
2305 ret = cpufreq_driver->verify(new_policy);
2309 /* adjust if necessary - all reasons */
2310 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2311 CPUFREQ_ADJUST, new_policy);
2314 * verify the cpu speed can be set within this limit, which might be
2315 * different to the first one
2317 ret = cpufreq_driver->verify(new_policy);
2321 /* notification of the new policy */
2322 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2323 CPUFREQ_NOTIFY, new_policy);
2325 policy->min = new_policy->min;
2326 policy->max = new_policy->max;
2327 trace_cpu_frequency_limits(policy);
2329 policy->cached_target_freq = UINT_MAX;
2331 pr_debug("new min and max freqs are %u - %u kHz\n",
2332 policy->min, policy->max);
2334 if (cpufreq_driver->setpolicy) {
2335 policy->policy = new_policy->policy;
2336 pr_debug("setting range\n");
2337 return cpufreq_driver->setpolicy(policy);
2340 if (new_policy->governor == policy->governor) {
2341 pr_debug("governor limits update\n");
2342 cpufreq_governor_limits(policy);
2346 pr_debug("governor switch\n");
2348 /* save old, working values */
2349 old_gov = policy->governor;
2350 /* end old governor */
2352 cpufreq_stop_governor(policy);
2353 cpufreq_exit_governor(policy);
2356 /* start new governor */
2357 policy->governor = new_policy->governor;
2358 ret = cpufreq_init_governor(policy);
2360 ret = cpufreq_start_governor(policy);
2362 pr_debug("governor change\n");
2363 sched_cpufreq_governor_change(policy, old_gov);
2366 cpufreq_exit_governor(policy);
2369 /* new governor failed, so re-start old one */
2370 pr_debug("starting governor %s failed\n", policy->governor->name);
2372 policy->governor = old_gov;
2373 if (cpufreq_init_governor(policy))
2374 policy->governor = NULL;
2376 cpufreq_start_governor(policy);
2383 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2384 * @cpu: CPU to re-evaluate the policy for.
2386 * Update the current frequency for the cpufreq policy of @cpu and use
2387 * cpufreq_set_policy() to re-apply the min and max limits saved in the
2388 * user_policy sub-structure of that policy, which triggers the evaluation
2389 * of policy notifiers and the cpufreq driver's ->verify() callback for the
2390 * policy in question, among other things.
2392 void cpufreq_update_policy(unsigned int cpu)
2394 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2395 struct cpufreq_policy new_policy;
2401 * BIOS might change freq behind our back
2402 * -> ask driver for current freq and notify governors about a change
2404 if (cpufreq_driver->get && !cpufreq_driver->setpolicy &&
2405 (cpufreq_suspended || WARN_ON(!cpufreq_update_current_freq(policy))))
2408 pr_debug("updating policy for CPU %u\n", cpu);
2409 memcpy(&new_policy, policy, sizeof(*policy));
2410 new_policy.min = policy->user_policy.min;
2411 new_policy.max = policy->user_policy.max;
2413 cpufreq_set_policy(policy, &new_policy);
2416 cpufreq_cpu_release(policy);
2418 EXPORT_SYMBOL(cpufreq_update_policy);
2421 * cpufreq_update_limits - Update policy limits for a given CPU.
2422 * @cpu: CPU to update the policy limits for.
2424 * Invoke the driver's ->update_limits callback if present or call
2425 * cpufreq_update_policy() for @cpu.
2427 void cpufreq_update_limits(unsigned int cpu)
2429 if (cpufreq_driver->update_limits)
2430 cpufreq_driver->update_limits(cpu);
2432 cpufreq_update_policy(cpu);
2434 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2436 /*********************************************************************
2438 *********************************************************************/
2439 static int cpufreq_boost_set_sw(int state)
2441 struct cpufreq_policy *policy;
2444 for_each_active_policy(policy) {
2445 if (!policy->freq_table)
2448 ret = cpufreq_frequency_table_cpuinfo(policy,
2449 policy->freq_table);
2451 pr_err("%s: Policy frequency update failed\n",
2456 down_write(&policy->rwsem);
2457 policy->user_policy.max = policy->max;
2458 cpufreq_governor_limits(policy);
2459 up_write(&policy->rwsem);
2465 int cpufreq_boost_trigger_state(int state)
2467 unsigned long flags;
2470 if (cpufreq_driver->boost_enabled == state)
2473 write_lock_irqsave(&cpufreq_driver_lock, flags);
2474 cpufreq_driver->boost_enabled = state;
2475 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2477 ret = cpufreq_driver->set_boost(state);
2479 write_lock_irqsave(&cpufreq_driver_lock, flags);
2480 cpufreq_driver->boost_enabled = !state;
2481 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2483 pr_err("%s: Cannot %s BOOST\n",
2484 __func__, state ? "enable" : "disable");
2490 static bool cpufreq_boost_supported(void)
2492 return cpufreq_driver->set_boost;
2495 static int create_boost_sysfs_file(void)
2499 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2501 pr_err("%s: cannot register global BOOST sysfs file\n",
2507 static void remove_boost_sysfs_file(void)
2509 if (cpufreq_boost_supported())
2510 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2513 int cpufreq_enable_boost_support(void)
2515 if (!cpufreq_driver)
2518 if (cpufreq_boost_supported())
2521 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2523 /* This will get removed on driver unregister */
2524 return create_boost_sysfs_file();
2526 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2528 int cpufreq_boost_enabled(void)
2530 return cpufreq_driver->boost_enabled;
2532 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2534 /*********************************************************************
2535 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2536 *********************************************************************/
2537 static enum cpuhp_state hp_online;
2539 static int cpuhp_cpufreq_online(unsigned int cpu)
2541 cpufreq_online(cpu);
2546 static int cpuhp_cpufreq_offline(unsigned int cpu)
2548 cpufreq_offline(cpu);
2554 * cpufreq_register_driver - register a CPU Frequency driver
2555 * @driver_data: A struct cpufreq_driver containing the values#
2556 * submitted by the CPU Frequency driver.
2558 * Registers a CPU Frequency driver to this core code. This code
2559 * returns zero on success, -EEXIST when another driver got here first
2560 * (and isn't unregistered in the meantime).
2563 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2565 unsigned long flags;
2568 if (cpufreq_disabled())
2571 if (!driver_data || !driver_data->verify || !driver_data->init ||
2572 !(driver_data->setpolicy || driver_data->target_index ||
2573 driver_data->target) ||
2574 (driver_data->setpolicy && (driver_data->target_index ||
2575 driver_data->target)) ||
2576 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2577 (!driver_data->online != !driver_data->offline))
2580 pr_debug("trying to register driver %s\n", driver_data->name);
2582 /* Protect against concurrent CPU online/offline. */
2585 write_lock_irqsave(&cpufreq_driver_lock, flags);
2586 if (cpufreq_driver) {
2587 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2591 cpufreq_driver = driver_data;
2592 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2594 if (driver_data->setpolicy)
2595 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2597 if (cpufreq_boost_supported()) {
2598 ret = create_boost_sysfs_file();
2600 goto err_null_driver;
2603 ret = subsys_interface_register(&cpufreq_interface);
2605 goto err_boost_unreg;
2607 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2608 list_empty(&cpufreq_policy_list)) {
2609 /* if all ->init() calls failed, unregister */
2611 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2616 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2618 cpuhp_cpufreq_online,
2619 cpuhp_cpufreq_offline);
2625 pr_debug("driver %s up and running\n", driver_data->name);
2629 subsys_interface_unregister(&cpufreq_interface);
2631 remove_boost_sysfs_file();
2633 write_lock_irqsave(&cpufreq_driver_lock, flags);
2634 cpufreq_driver = NULL;
2635 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2640 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2643 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2645 * Unregister the current CPUFreq driver. Only call this if you have
2646 * the right to do so, i.e. if you have succeeded in initialising before!
2647 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2648 * currently not initialised.
2650 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2652 unsigned long flags;
2654 if (!cpufreq_driver || (driver != cpufreq_driver))
2657 pr_debug("unregistering driver %s\n", driver->name);
2659 /* Protect against concurrent cpu hotplug */
2661 subsys_interface_unregister(&cpufreq_interface);
2662 remove_boost_sysfs_file();
2663 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2665 write_lock_irqsave(&cpufreq_driver_lock, flags);
2667 cpufreq_driver = NULL;
2669 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2674 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2677 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2678 * or mutexes when secondary CPUs are halted.
2680 static struct syscore_ops cpufreq_syscore_ops = {
2681 .shutdown = cpufreq_suspend,
2684 struct kobject *cpufreq_global_kobject;
2685 EXPORT_SYMBOL(cpufreq_global_kobject);
2687 static int __init cpufreq_core_init(void)
2689 if (cpufreq_disabled())
2692 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2693 BUG_ON(!cpufreq_global_kobject);
2695 register_syscore_ops(&cpufreq_syscore_ops);
2699 module_param(off, int, 0444);
2700 core_initcall(cpufreq_core_init);