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);
79 * Two notifier lists: the "policy" list is involved in the
80 * validation process for a new CPU frequency policy; the
81 * "transition" list for kernel code that needs to handle
82 * changes to devices when the CPU clock speed changes.
83 * The mutex locks both lists.
85 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
86 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
88 static int off __read_mostly;
89 static int cpufreq_disabled(void)
93 void disable_cpufreq(void)
97 static DEFINE_MUTEX(cpufreq_governor_mutex);
99 bool have_governor_per_policy(void)
101 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
103 EXPORT_SYMBOL_GPL(have_governor_per_policy);
105 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
107 if (have_governor_per_policy())
108 return &policy->kobj;
110 return cpufreq_global_kobject;
112 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
114 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
120 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
122 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
123 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
124 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
125 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
126 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
127 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
129 idle_time = cur_wall_time - busy_time;
131 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
133 return div_u64(idle_time, NSEC_PER_USEC);
136 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
138 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
140 if (idle_time == -1ULL)
141 return get_cpu_idle_time_jiffy(cpu, wall);
143 idle_time += get_cpu_iowait_time_us(cpu, wall);
147 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
149 __weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
150 unsigned long max_freq)
153 EXPORT_SYMBOL_GPL(arch_set_freq_scale);
156 * This is a generic cpufreq init() routine which can be used by cpufreq
157 * drivers of SMP systems. It will do following:
158 * - validate & show freq table passed
159 * - set policies transition latency
160 * - policy->cpus with all possible CPUs
162 void cpufreq_generic_init(struct cpufreq_policy *policy,
163 struct cpufreq_frequency_table *table,
164 unsigned int transition_latency)
166 policy->freq_table = table;
167 policy->cpuinfo.transition_latency = transition_latency;
170 * The driver only supports the SMP configuration where all processors
171 * share the clock and voltage and clock.
173 cpumask_setall(policy->cpus);
175 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
177 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
179 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
181 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
183 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
185 unsigned int cpufreq_generic_get(unsigned int cpu)
187 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
189 if (!policy || IS_ERR(policy->clk)) {
190 pr_err("%s: No %s associated to cpu: %d\n",
191 __func__, policy ? "clk" : "policy", cpu);
195 return clk_get_rate(policy->clk) / 1000;
197 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
200 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
201 * @cpu: CPU to find the policy for.
203 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
204 * the kobject reference counter of that policy. Return a valid policy on
205 * success or NULL on failure.
207 * The policy returned by this function has to be released with the help of
208 * cpufreq_cpu_put() to balance its kobject reference counter properly.
210 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
212 struct cpufreq_policy *policy = NULL;
215 if (WARN_ON(cpu >= nr_cpu_ids))
218 /* get the cpufreq driver */
219 read_lock_irqsave(&cpufreq_driver_lock, flags);
221 if (cpufreq_driver) {
223 policy = cpufreq_cpu_get_raw(cpu);
225 kobject_get(&policy->kobj);
228 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
232 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
235 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
236 * @policy: cpufreq policy returned by cpufreq_cpu_get().
238 void cpufreq_cpu_put(struct cpufreq_policy *policy)
240 kobject_put(&policy->kobj);
242 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
245 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
246 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
248 void cpufreq_cpu_release(struct cpufreq_policy *policy)
250 if (WARN_ON(!policy))
253 lockdep_assert_held(&policy->rwsem);
255 up_write(&policy->rwsem);
257 cpufreq_cpu_put(policy);
261 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
262 * @cpu: CPU to find the policy for.
264 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
265 * if the policy returned by it is not NULL, acquire its rwsem for writing.
266 * Return the policy if it is active or release it and return NULL otherwise.
268 * The policy returned by this function has to be released with the help of
269 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
272 struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
274 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
279 down_write(&policy->rwsem);
281 if (policy_is_inactive(policy)) {
282 cpufreq_cpu_release(policy);
289 /*********************************************************************
290 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
291 *********************************************************************/
294 * adjust_jiffies - adjust the system "loops_per_jiffy"
296 * This function alters the system "loops_per_jiffy" for the clock
297 * speed change. Note that loops_per_jiffy cannot be updated on SMP
298 * systems as each CPU might be scaled differently. So, use the arch
299 * per-CPU loops_per_jiffy value wherever possible.
301 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
304 static unsigned long l_p_j_ref;
305 static unsigned int l_p_j_ref_freq;
307 if (ci->flags & CPUFREQ_CONST_LOOPS)
310 if (!l_p_j_ref_freq) {
311 l_p_j_ref = loops_per_jiffy;
312 l_p_j_ref_freq = ci->old;
313 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
314 l_p_j_ref, l_p_j_ref_freq);
316 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
317 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
319 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
320 loops_per_jiffy, ci->new);
326 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
327 * @policy: cpufreq policy to enable fast frequency switching for.
328 * @freqs: contain details of the frequency update.
329 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
331 * This function calls the transition notifiers and the "adjust_jiffies"
332 * function. It is called twice on all CPU frequency changes that have
335 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
336 struct cpufreq_freqs *freqs,
341 BUG_ON(irqs_disabled());
343 if (cpufreq_disabled())
346 freqs->policy = policy;
347 freqs->flags = cpufreq_driver->flags;
348 pr_debug("notification %u of frequency transition to %u kHz\n",
352 case CPUFREQ_PRECHANGE:
354 * Detect if the driver reported a value as "old frequency"
355 * which is not equal to what the cpufreq core thinks is
358 if (policy->cur && policy->cur != freqs->old) {
359 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
360 freqs->old, policy->cur);
361 freqs->old = policy->cur;
364 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
365 CPUFREQ_PRECHANGE, freqs);
367 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
370 case CPUFREQ_POSTCHANGE:
371 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
372 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
373 cpumask_pr_args(policy->cpus));
375 for_each_cpu(cpu, policy->cpus)
376 trace_cpu_frequency(freqs->new, cpu);
378 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
379 CPUFREQ_POSTCHANGE, freqs);
381 cpufreq_stats_record_transition(policy, freqs->new);
382 policy->cur = freqs->new;
386 /* Do post notifications when there are chances that transition has failed */
387 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
388 struct cpufreq_freqs *freqs, int transition_failed)
390 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
391 if (!transition_failed)
394 swap(freqs->old, freqs->new);
395 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
396 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
399 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
400 struct cpufreq_freqs *freqs)
404 * Catch double invocations of _begin() which lead to self-deadlock.
405 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
406 * doesn't invoke _begin() on their behalf, and hence the chances of
407 * double invocations are very low. Moreover, there are scenarios
408 * where these checks can emit false-positive warnings in these
409 * drivers; so we avoid that by skipping them altogether.
411 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
412 && current == policy->transition_task);
415 wait_event(policy->transition_wait, !policy->transition_ongoing);
417 spin_lock(&policy->transition_lock);
419 if (unlikely(policy->transition_ongoing)) {
420 spin_unlock(&policy->transition_lock);
424 policy->transition_ongoing = true;
425 policy->transition_task = current;
427 spin_unlock(&policy->transition_lock);
429 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
431 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
433 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
434 struct cpufreq_freqs *freqs, int transition_failed)
436 if (WARN_ON(!policy->transition_ongoing))
439 cpufreq_notify_post_transition(policy, freqs, transition_failed);
441 policy->transition_ongoing = false;
442 policy->transition_task = NULL;
444 wake_up(&policy->transition_wait);
446 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
449 * Fast frequency switching status count. Positive means "enabled", negative
450 * means "disabled" and 0 means "not decided yet".
452 static int cpufreq_fast_switch_count;
453 static DEFINE_MUTEX(cpufreq_fast_switch_lock);
455 static void cpufreq_list_transition_notifiers(void)
457 struct notifier_block *nb;
459 pr_info("Registered transition notifiers:\n");
461 mutex_lock(&cpufreq_transition_notifier_list.mutex);
463 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
464 pr_info("%pS\n", nb->notifier_call);
466 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
470 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
471 * @policy: cpufreq policy to enable fast frequency switching for.
473 * Try to enable fast frequency switching for @policy.
475 * The attempt will fail if there is at least one transition notifier registered
476 * at this point, as fast frequency switching is quite fundamentally at odds
477 * with transition notifiers. Thus if successful, it will make registration of
478 * transition notifiers fail going forward.
480 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
482 lockdep_assert_held(&policy->rwsem);
484 if (!policy->fast_switch_possible)
487 mutex_lock(&cpufreq_fast_switch_lock);
488 if (cpufreq_fast_switch_count >= 0) {
489 cpufreq_fast_switch_count++;
490 policy->fast_switch_enabled = true;
492 pr_warn("CPU%u: Fast frequency switching not enabled\n",
494 cpufreq_list_transition_notifiers();
496 mutex_unlock(&cpufreq_fast_switch_lock);
498 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
501 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
502 * @policy: cpufreq policy to disable fast frequency switching for.
504 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
506 mutex_lock(&cpufreq_fast_switch_lock);
507 if (policy->fast_switch_enabled) {
508 policy->fast_switch_enabled = false;
509 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
510 cpufreq_fast_switch_count--;
512 mutex_unlock(&cpufreq_fast_switch_lock);
514 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
517 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
519 * @target_freq: target frequency to resolve.
521 * The target to driver frequency mapping is cached in the policy.
523 * Return: Lowest driver-supported frequency greater than or equal to the
524 * given target_freq, subject to policy (min/max) and driver limitations.
526 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
527 unsigned int target_freq)
529 target_freq = clamp_val(target_freq, policy->min, policy->max);
530 policy->cached_target_freq = target_freq;
532 if (cpufreq_driver->target_index) {
535 idx = cpufreq_frequency_table_target(policy, target_freq,
537 policy->cached_resolved_idx = idx;
538 return policy->freq_table[idx].frequency;
541 if (cpufreq_driver->resolve_freq)
542 return cpufreq_driver->resolve_freq(policy, target_freq);
546 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
548 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
550 unsigned int latency;
552 if (policy->transition_delay_us)
553 return policy->transition_delay_us;
555 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
558 * For platforms that can change the frequency very fast (< 10
559 * us), the above formula gives a decent transition delay. But
560 * for platforms where transition_latency is in milliseconds, it
561 * ends up giving unrealistic values.
563 * Cap the default transition delay to 10 ms, which seems to be
564 * a reasonable amount of time after which we should reevaluate
567 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
570 return LATENCY_MULTIPLIER;
572 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
574 /*********************************************************************
576 *********************************************************************/
577 static ssize_t show_boost(struct kobject *kobj,
578 struct kobj_attribute *attr, char *buf)
580 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
583 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
584 const char *buf, size_t count)
588 ret = sscanf(buf, "%d", &enable);
589 if (ret != 1 || enable < 0 || enable > 1)
592 if (cpufreq_boost_trigger_state(enable)) {
593 pr_err("%s: Cannot %s BOOST!\n",
594 __func__, enable ? "enable" : "disable");
598 pr_debug("%s: cpufreq BOOST %s\n",
599 __func__, enable ? "enabled" : "disabled");
603 define_one_global_rw(boost);
605 static struct cpufreq_governor *find_governor(const char *str_governor)
607 struct cpufreq_governor *t;
610 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
616 static int cpufreq_parse_policy(char *str_governor,
617 struct cpufreq_policy *policy)
619 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
620 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
623 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
624 policy->policy = CPUFREQ_POLICY_POWERSAVE;
631 * cpufreq_parse_governor - parse a governor string only for has_target()
633 static int cpufreq_parse_governor(char *str_governor,
634 struct cpufreq_policy *policy)
636 struct cpufreq_governor *t;
638 mutex_lock(&cpufreq_governor_mutex);
640 t = find_governor(str_governor);
644 mutex_unlock(&cpufreq_governor_mutex);
646 ret = request_module("cpufreq_%s", str_governor);
650 mutex_lock(&cpufreq_governor_mutex);
652 t = find_governor(str_governor);
654 if (t && !try_module_get(t->owner))
657 mutex_unlock(&cpufreq_governor_mutex);
660 policy->governor = t;
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 = dev_pm_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)
766 char str_governor[16];
767 struct cpufreq_policy new_policy;
769 memcpy(&new_policy, policy, sizeof(*policy));
771 ret = sscanf(buf, "%15s", str_governor);
775 if (cpufreq_driver->setpolicy) {
776 if (cpufreq_parse_policy(str_governor, &new_policy))
779 if (cpufreq_parse_governor(str_governor, &new_policy))
783 ret = cpufreq_set_policy(policy, &new_policy);
785 if (new_policy.governor)
786 module_put(new_policy.governor->owner);
788 return ret ? ret : count;
792 * show_scaling_driver - show the cpufreq driver currently loaded
794 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
796 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
800 * show_scaling_available_governors - show the available CPUfreq governors
802 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
806 struct cpufreq_governor *t;
809 i += sprintf(buf, "performance powersave");
813 for_each_governor(t) {
814 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
815 - (CPUFREQ_NAME_LEN + 2)))
817 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
820 i += sprintf(&buf[i], "\n");
824 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
829 for_each_cpu(cpu, mask) {
831 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
832 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
833 if (i >= (PAGE_SIZE - 5))
836 i += sprintf(&buf[i], "\n");
839 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
842 * show_related_cpus - show the CPUs affected by each transition even if
843 * hw coordination is in use
845 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
847 return cpufreq_show_cpus(policy->related_cpus, buf);
851 * show_affected_cpus - show the CPUs affected by each transition
853 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
855 return cpufreq_show_cpus(policy->cpus, buf);
858 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
859 const char *buf, size_t count)
861 unsigned int freq = 0;
864 if (!policy->governor || !policy->governor->store_setspeed)
867 ret = sscanf(buf, "%u", &freq);
871 policy->governor->store_setspeed(policy, freq);
876 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
878 if (!policy->governor || !policy->governor->show_setspeed)
879 return sprintf(buf, "<unsupported>\n");
881 return policy->governor->show_setspeed(policy, buf);
885 * show_bios_limit - show the current cpufreq HW/BIOS limitation
887 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
891 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
893 return sprintf(buf, "%u\n", limit);
894 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
897 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
898 cpufreq_freq_attr_ro(cpuinfo_min_freq);
899 cpufreq_freq_attr_ro(cpuinfo_max_freq);
900 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
901 cpufreq_freq_attr_ro(scaling_available_governors);
902 cpufreq_freq_attr_ro(scaling_driver);
903 cpufreq_freq_attr_ro(scaling_cur_freq);
904 cpufreq_freq_attr_ro(bios_limit);
905 cpufreq_freq_attr_ro(related_cpus);
906 cpufreq_freq_attr_ro(affected_cpus);
907 cpufreq_freq_attr_rw(scaling_min_freq);
908 cpufreq_freq_attr_rw(scaling_max_freq);
909 cpufreq_freq_attr_rw(scaling_governor);
910 cpufreq_freq_attr_rw(scaling_setspeed);
912 static struct attribute *default_attrs[] = {
913 &cpuinfo_min_freq.attr,
914 &cpuinfo_max_freq.attr,
915 &cpuinfo_transition_latency.attr,
916 &scaling_min_freq.attr,
917 &scaling_max_freq.attr,
920 &scaling_governor.attr,
921 &scaling_driver.attr,
922 &scaling_available_governors.attr,
923 &scaling_setspeed.attr,
927 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
928 #define to_attr(a) container_of(a, struct freq_attr, attr)
930 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
932 struct cpufreq_policy *policy = to_policy(kobj);
933 struct freq_attr *fattr = to_attr(attr);
936 down_read(&policy->rwsem);
937 ret = fattr->show(policy, buf);
938 up_read(&policy->rwsem);
943 static ssize_t store(struct kobject *kobj, struct attribute *attr,
944 const char *buf, size_t count)
946 struct cpufreq_policy *policy = to_policy(kobj);
947 struct freq_attr *fattr = to_attr(attr);
948 ssize_t ret = -EINVAL;
951 * cpus_read_trylock() is used here to work around a circular lock
952 * dependency problem with respect to the cpufreq_register_driver().
954 if (!cpus_read_trylock())
957 if (cpu_online(policy->cpu)) {
958 down_write(&policy->rwsem);
959 ret = fattr->store(policy, buf, count);
960 up_write(&policy->rwsem);
968 static void cpufreq_sysfs_release(struct kobject *kobj)
970 struct cpufreq_policy *policy = to_policy(kobj);
971 pr_debug("last reference is dropped\n");
972 complete(&policy->kobj_unregister);
975 static const struct sysfs_ops sysfs_ops = {
980 static struct kobj_type ktype_cpufreq = {
981 .sysfs_ops = &sysfs_ops,
982 .default_attrs = default_attrs,
983 .release = cpufreq_sysfs_release,
986 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
988 struct device *dev = get_cpu_device(cpu);
993 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
996 dev_dbg(dev, "%s: Adding symlink\n", __func__);
997 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
998 dev_err(dev, "cpufreq symlink creation failed\n");
1001 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1004 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1005 sysfs_remove_link(&dev->kobj, "cpufreq");
1008 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1010 struct freq_attr **drv_attr;
1013 /* set up files for this cpu device */
1014 drv_attr = cpufreq_driver->attr;
1015 while (drv_attr && *drv_attr) {
1016 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1021 if (cpufreq_driver->get) {
1022 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1027 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1031 if (cpufreq_driver->bios_limit) {
1032 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1040 __weak struct cpufreq_governor *cpufreq_default_governor(void)
1045 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1047 struct cpufreq_governor *gov = NULL, *def_gov = NULL;
1048 struct cpufreq_policy new_policy;
1050 memcpy(&new_policy, policy, sizeof(*policy));
1052 def_gov = cpufreq_default_governor();
1056 * Update governor of new_policy to the governor used before
1059 gov = find_governor(policy->last_governor);
1061 pr_debug("Restoring governor %s for cpu %d\n",
1062 policy->governor->name, policy->cpu);
1068 new_policy.governor = gov;
1070 /* Use the default policy if there is no last_policy. */
1071 if (policy->last_policy) {
1072 new_policy.policy = policy->last_policy;
1076 cpufreq_parse_policy(def_gov->name, &new_policy);
1080 return cpufreq_set_policy(policy, &new_policy);
1083 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1087 /* Has this CPU been taken care of already? */
1088 if (cpumask_test_cpu(cpu, policy->cpus))
1091 down_write(&policy->rwsem);
1093 cpufreq_stop_governor(policy);
1095 cpumask_set_cpu(cpu, policy->cpus);
1098 ret = cpufreq_start_governor(policy);
1100 pr_err("%s: Failed to start governor\n", __func__);
1102 up_write(&policy->rwsem);
1106 void refresh_frequency_limits(struct cpufreq_policy *policy)
1108 struct cpufreq_policy new_policy;
1110 if (!policy_is_inactive(policy)) {
1111 new_policy = *policy;
1112 pr_debug("updating policy for CPU %u\n", policy->cpu);
1114 cpufreq_set_policy(policy, &new_policy);
1117 EXPORT_SYMBOL(refresh_frequency_limits);
1119 static void handle_update(struct work_struct *work)
1121 struct cpufreq_policy *policy =
1122 container_of(work, struct cpufreq_policy, update);
1124 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1125 down_write(&policy->rwsem);
1126 refresh_frequency_limits(policy);
1127 up_write(&policy->rwsem);
1130 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1133 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1135 schedule_work(&policy->update);
1139 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1142 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1144 schedule_work(&policy->update);
1148 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1150 struct kobject *kobj;
1151 struct completion *cmp;
1153 down_write(&policy->rwsem);
1154 cpufreq_stats_free_table(policy);
1155 kobj = &policy->kobj;
1156 cmp = &policy->kobj_unregister;
1157 up_write(&policy->rwsem);
1161 * We need to make sure that the underlying kobj is
1162 * actually not referenced anymore by anybody before we
1163 * proceed with unloading.
1165 pr_debug("waiting for dropping of refcount\n");
1166 wait_for_completion(cmp);
1167 pr_debug("wait complete\n");
1170 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1172 struct cpufreq_policy *policy;
1173 struct device *dev = get_cpu_device(cpu);
1179 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1183 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1184 goto err_free_policy;
1186 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1187 goto err_free_cpumask;
1189 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1190 goto err_free_rcpumask;
1192 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1193 cpufreq_global_kobject, "policy%u", cpu);
1195 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1197 * The entire policy object will be freed below, but the extra
1198 * memory allocated for the kobject name needs to be freed by
1199 * releasing the kobject.
1201 kobject_put(&policy->kobj);
1202 goto err_free_real_cpus;
1205 policy->nb_min.notifier_call = cpufreq_notifier_min;
1206 policy->nb_max.notifier_call = cpufreq_notifier_max;
1208 ret = dev_pm_qos_add_notifier(dev, &policy->nb_min,
1209 DEV_PM_QOS_MIN_FREQUENCY);
1211 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1212 ret, cpumask_pr_args(policy->cpus));
1213 goto err_kobj_remove;
1216 ret = dev_pm_qos_add_notifier(dev, &policy->nb_max,
1217 DEV_PM_QOS_MAX_FREQUENCY);
1219 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1220 ret, cpumask_pr_args(policy->cpus));
1221 goto err_min_qos_notifier;
1224 INIT_LIST_HEAD(&policy->policy_list);
1225 init_rwsem(&policy->rwsem);
1226 spin_lock_init(&policy->transition_lock);
1227 init_waitqueue_head(&policy->transition_wait);
1228 init_completion(&policy->kobj_unregister);
1229 INIT_WORK(&policy->update, handle_update);
1234 err_min_qos_notifier:
1235 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1236 DEV_PM_QOS_MIN_FREQUENCY);
1238 cpufreq_policy_put_kobj(policy);
1240 free_cpumask_var(policy->real_cpus);
1242 free_cpumask_var(policy->related_cpus);
1244 free_cpumask_var(policy->cpus);
1251 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1253 struct device *dev = get_cpu_device(policy->cpu);
1254 unsigned long flags;
1257 /* Remove policy from list */
1258 write_lock_irqsave(&cpufreq_driver_lock, flags);
1259 list_del(&policy->policy_list);
1261 for_each_cpu(cpu, policy->related_cpus)
1262 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1263 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1265 dev_pm_qos_remove_notifier(dev, &policy->nb_max,
1266 DEV_PM_QOS_MAX_FREQUENCY);
1267 dev_pm_qos_remove_notifier(dev, &policy->nb_min,
1268 DEV_PM_QOS_MIN_FREQUENCY);
1269 dev_pm_qos_remove_request(policy->max_freq_req);
1270 dev_pm_qos_remove_request(policy->min_freq_req);
1271 kfree(policy->min_freq_req);
1273 cpufreq_policy_put_kobj(policy);
1274 free_cpumask_var(policy->real_cpus);
1275 free_cpumask_var(policy->related_cpus);
1276 free_cpumask_var(policy->cpus);
1280 static int cpufreq_online(unsigned int cpu)
1282 struct cpufreq_policy *policy;
1284 unsigned long flags;
1288 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1290 /* Check if this CPU already has a policy to manage it */
1291 policy = per_cpu(cpufreq_cpu_data, cpu);
1293 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1294 if (!policy_is_inactive(policy))
1295 return cpufreq_add_policy_cpu(policy, cpu);
1297 /* This is the only online CPU for the policy. Start over. */
1299 down_write(&policy->rwsem);
1301 policy->governor = NULL;
1302 up_write(&policy->rwsem);
1305 policy = cpufreq_policy_alloc(cpu);
1310 if (!new_policy && cpufreq_driver->online) {
1311 ret = cpufreq_driver->online(policy);
1313 pr_debug("%s: %d: initialization failed\n", __func__,
1315 goto out_exit_policy;
1318 /* Recover policy->cpus using related_cpus */
1319 cpumask_copy(policy->cpus, policy->related_cpus);
1321 cpumask_copy(policy->cpus, cpumask_of(cpu));
1324 * Call driver. From then on the cpufreq must be able
1325 * to accept all calls to ->verify and ->setpolicy for this CPU.
1327 ret = cpufreq_driver->init(policy);
1329 pr_debug("%s: %d: initialization failed\n", __func__,
1331 goto out_free_policy;
1334 ret = cpufreq_table_validate_and_sort(policy);
1336 goto out_exit_policy;
1338 /* related_cpus should at least include policy->cpus. */
1339 cpumask_copy(policy->related_cpus, policy->cpus);
1342 down_write(&policy->rwsem);
1344 * affected cpus must always be the one, which are online. We aren't
1345 * managing offline cpus here.
1347 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1350 struct device *dev = get_cpu_device(cpu);
1352 for_each_cpu(j, policy->related_cpus) {
1353 per_cpu(cpufreq_cpu_data, j) = policy;
1354 add_cpu_dev_symlink(policy, j);
1357 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1359 if (!policy->min_freq_req)
1360 goto out_destroy_policy;
1362 ret = dev_pm_qos_add_request(dev, policy->min_freq_req,
1363 DEV_PM_QOS_MIN_FREQUENCY,
1367 * So we don't call dev_pm_qos_remove_request() for an
1368 * uninitialized request.
1370 kfree(policy->min_freq_req);
1371 policy->min_freq_req = NULL;
1373 dev_err(dev, "Failed to add min-freq constraint (%d)\n",
1375 goto out_destroy_policy;
1379 * This must be initialized right here to avoid calling
1380 * dev_pm_qos_remove_request() on uninitialized request in case
1383 policy->max_freq_req = policy->min_freq_req + 1;
1385 ret = dev_pm_qos_add_request(dev, policy->max_freq_req,
1386 DEV_PM_QOS_MAX_FREQUENCY,
1389 policy->max_freq_req = NULL;
1390 dev_err(dev, "Failed to add max-freq constraint (%d)\n",
1392 goto out_destroy_policy;
1396 if (cpufreq_driver->get && has_target()) {
1397 policy->cur = cpufreq_driver->get(policy->cpu);
1399 pr_err("%s: ->get() failed\n", __func__);
1400 goto out_destroy_policy;
1405 * Sometimes boot loaders set CPU frequency to a value outside of
1406 * frequency table present with cpufreq core. In such cases CPU might be
1407 * unstable if it has to run on that frequency for long duration of time
1408 * and so its better to set it to a frequency which is specified in
1409 * freq-table. This also makes cpufreq stats inconsistent as
1410 * cpufreq-stats would fail to register because current frequency of CPU
1411 * isn't found in freq-table.
1413 * Because we don't want this change to effect boot process badly, we go
1414 * for the next freq which is >= policy->cur ('cur' must be set by now,
1415 * otherwise we will end up setting freq to lowest of the table as 'cur'
1416 * is initialized to zero).
1418 * We are passing target-freq as "policy->cur - 1" otherwise
1419 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1420 * equal to target-freq.
1422 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1424 /* Are we running at unknown frequency ? */
1425 ret = cpufreq_frequency_table_get_index(policy, policy->cur);
1426 if (ret == -EINVAL) {
1427 /* Warn user and fix it */
1428 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1429 __func__, policy->cpu, policy->cur);
1430 ret = __cpufreq_driver_target(policy, policy->cur - 1,
1431 CPUFREQ_RELATION_L);
1434 * Reaching here after boot in a few seconds may not
1435 * mean that system will remain stable at "unknown"
1436 * frequency for longer duration. Hence, a BUG_ON().
1439 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1440 __func__, policy->cpu, policy->cur);
1445 ret = cpufreq_add_dev_interface(policy);
1447 goto out_destroy_policy;
1449 cpufreq_stats_create_table(policy);
1451 write_lock_irqsave(&cpufreq_driver_lock, flags);
1452 list_add(&policy->policy_list, &cpufreq_policy_list);
1453 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1456 ret = cpufreq_init_policy(policy);
1458 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1459 __func__, cpu, ret);
1460 goto out_destroy_policy;
1463 up_write(&policy->rwsem);
1465 kobject_uevent(&policy->kobj, KOBJ_ADD);
1467 /* Callback for handling stuff after policy is ready */
1468 if (cpufreq_driver->ready)
1469 cpufreq_driver->ready(policy);
1471 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1472 policy->cdev = of_cpufreq_cooling_register(policy);
1474 pr_debug("initialization complete\n");
1479 for_each_cpu(j, policy->real_cpus)
1480 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1482 up_write(&policy->rwsem);
1485 if (cpufreq_driver->exit)
1486 cpufreq_driver->exit(policy);
1489 cpufreq_policy_free(policy);
1494 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1496 * @sif: Subsystem interface structure pointer (not used)
1498 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1500 struct cpufreq_policy *policy;
1501 unsigned cpu = dev->id;
1504 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1506 if (cpu_online(cpu)) {
1507 ret = cpufreq_online(cpu);
1512 /* Create sysfs link on CPU registration */
1513 policy = per_cpu(cpufreq_cpu_data, cpu);
1515 add_cpu_dev_symlink(policy, cpu);
1520 static int cpufreq_offline(unsigned int cpu)
1522 struct cpufreq_policy *policy;
1525 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1527 policy = cpufreq_cpu_get_raw(cpu);
1529 pr_debug("%s: No cpu_data found\n", __func__);
1533 down_write(&policy->rwsem);
1535 cpufreq_stop_governor(policy);
1537 cpumask_clear_cpu(cpu, policy->cpus);
1539 if (policy_is_inactive(policy)) {
1541 strncpy(policy->last_governor, policy->governor->name,
1544 policy->last_policy = policy->policy;
1545 } else if (cpu == policy->cpu) {
1546 /* Nominate new CPU */
1547 policy->cpu = cpumask_any(policy->cpus);
1550 /* Start governor again for active policy */
1551 if (!policy_is_inactive(policy)) {
1553 ret = cpufreq_start_governor(policy);
1555 pr_err("%s: Failed to start governor\n", __func__);
1561 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1562 cpufreq_cooling_unregister(policy->cdev);
1563 policy->cdev = NULL;
1566 if (cpufreq_driver->stop_cpu)
1567 cpufreq_driver->stop_cpu(policy);
1570 cpufreq_exit_governor(policy);
1573 * Perform the ->offline() during light-weight tear-down, as
1574 * that allows fast recovery when the CPU comes back.
1576 if (cpufreq_driver->offline) {
1577 cpufreq_driver->offline(policy);
1578 } else if (cpufreq_driver->exit) {
1579 cpufreq_driver->exit(policy);
1580 policy->freq_table = NULL;
1584 up_write(&policy->rwsem);
1589 * cpufreq_remove_dev - remove a CPU device
1591 * Removes the cpufreq interface for a CPU device.
1593 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1595 unsigned int cpu = dev->id;
1596 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1601 if (cpu_online(cpu))
1602 cpufreq_offline(cpu);
1604 cpumask_clear_cpu(cpu, policy->real_cpus);
1605 remove_cpu_dev_symlink(policy, dev);
1607 if (cpumask_empty(policy->real_cpus)) {
1608 /* We did light-weight exit earlier, do full tear down now */
1609 if (cpufreq_driver->offline)
1610 cpufreq_driver->exit(policy);
1612 cpufreq_policy_free(policy);
1617 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1619 * @policy: policy managing CPUs
1620 * @new_freq: CPU frequency the CPU actually runs at
1622 * We adjust to current frequency first, and need to clean up later.
1623 * So either call to cpufreq_update_policy() or schedule handle_update()).
1625 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1626 unsigned int new_freq)
1628 struct cpufreq_freqs freqs;
1630 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1631 policy->cur, new_freq);
1633 freqs.old = policy->cur;
1634 freqs.new = new_freq;
1636 cpufreq_freq_transition_begin(policy, &freqs);
1637 cpufreq_freq_transition_end(policy, &freqs, 0);
1640 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1642 unsigned int new_freq;
1644 new_freq = cpufreq_driver->get(policy->cpu);
1649 * If fast frequency switching is used with the given policy, the check
1650 * against policy->cur is pointless, so skip it in that case.
1652 if (policy->fast_switch_enabled || !has_target())
1655 if (policy->cur != new_freq) {
1656 cpufreq_out_of_sync(policy, new_freq);
1658 schedule_work(&policy->update);
1665 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1668 * This is the last known freq, without actually getting it from the driver.
1669 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1671 unsigned int cpufreq_quick_get(unsigned int cpu)
1673 struct cpufreq_policy *policy;
1674 unsigned int ret_freq = 0;
1675 unsigned long flags;
1677 read_lock_irqsave(&cpufreq_driver_lock, flags);
1679 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1680 ret_freq = cpufreq_driver->get(cpu);
1681 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1685 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1687 policy = cpufreq_cpu_get(cpu);
1689 ret_freq = policy->cur;
1690 cpufreq_cpu_put(policy);
1695 EXPORT_SYMBOL(cpufreq_quick_get);
1698 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1701 * Just return the max possible frequency for a given CPU.
1703 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1705 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1706 unsigned int ret_freq = 0;
1709 ret_freq = policy->max;
1710 cpufreq_cpu_put(policy);
1715 EXPORT_SYMBOL(cpufreq_quick_get_max);
1717 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1719 if (unlikely(policy_is_inactive(policy)))
1722 return cpufreq_verify_current_freq(policy, true);
1726 * cpufreq_get - get the current CPU frequency (in kHz)
1729 * Get the CPU current (static) CPU frequency
1731 unsigned int cpufreq_get(unsigned int cpu)
1733 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1734 unsigned int ret_freq = 0;
1737 down_read(&policy->rwsem);
1738 if (cpufreq_driver->get)
1739 ret_freq = __cpufreq_get(policy);
1740 up_read(&policy->rwsem);
1742 cpufreq_cpu_put(policy);
1747 EXPORT_SYMBOL(cpufreq_get);
1749 static struct subsys_interface cpufreq_interface = {
1751 .subsys = &cpu_subsys,
1752 .add_dev = cpufreq_add_dev,
1753 .remove_dev = cpufreq_remove_dev,
1757 * In case platform wants some specific frequency to be configured
1760 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1764 if (!policy->suspend_freq) {
1765 pr_debug("%s: suspend_freq not defined\n", __func__);
1769 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1770 policy->suspend_freq);
1772 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1773 CPUFREQ_RELATION_H);
1775 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1776 __func__, policy->suspend_freq, ret);
1780 EXPORT_SYMBOL(cpufreq_generic_suspend);
1783 * cpufreq_suspend() - Suspend CPUFreq governors
1785 * Called during system wide Suspend/Hibernate cycles for suspending governors
1786 * as some platforms can't change frequency after this point in suspend cycle.
1787 * Because some of the devices (like: i2c, regulators, etc) they use for
1788 * changing frequency are suspended quickly after this point.
1790 void cpufreq_suspend(void)
1792 struct cpufreq_policy *policy;
1794 if (!cpufreq_driver)
1797 if (!has_target() && !cpufreq_driver->suspend)
1800 pr_debug("%s: Suspending Governors\n", __func__);
1802 for_each_active_policy(policy) {
1804 down_write(&policy->rwsem);
1805 cpufreq_stop_governor(policy);
1806 up_write(&policy->rwsem);
1809 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1810 pr_err("%s: Failed to suspend driver: %p\n", __func__,
1815 cpufreq_suspended = true;
1819 * cpufreq_resume() - Resume CPUFreq governors
1821 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1822 * are suspended with cpufreq_suspend().
1824 void cpufreq_resume(void)
1826 struct cpufreq_policy *policy;
1829 if (!cpufreq_driver)
1832 if (unlikely(!cpufreq_suspended))
1835 cpufreq_suspended = false;
1837 if (!has_target() && !cpufreq_driver->resume)
1840 pr_debug("%s: Resuming Governors\n", __func__);
1842 for_each_active_policy(policy) {
1843 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1844 pr_err("%s: Failed to resume driver: %p\n", __func__,
1846 } else if (has_target()) {
1847 down_write(&policy->rwsem);
1848 ret = cpufreq_start_governor(policy);
1849 up_write(&policy->rwsem);
1852 pr_err("%s: Failed to start governor for policy: %p\n",
1859 * cpufreq_get_current_driver - return current driver's name
1861 * Return the name string of the currently loaded cpufreq driver
1864 const char *cpufreq_get_current_driver(void)
1867 return cpufreq_driver->name;
1871 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1874 * cpufreq_get_driver_data - return current driver data
1876 * Return the private data of the currently loaded cpufreq
1877 * driver, or NULL if no cpufreq driver is loaded.
1879 void *cpufreq_get_driver_data(void)
1882 return cpufreq_driver->driver_data;
1886 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1888 /*********************************************************************
1889 * NOTIFIER LISTS INTERFACE *
1890 *********************************************************************/
1893 * cpufreq_register_notifier - register a driver with cpufreq
1894 * @nb: notifier function to register
1895 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1897 * Add a driver to one of two lists: either a list of drivers that
1898 * are notified about clock rate changes (once before and once after
1899 * the transition), or a list of drivers that are notified about
1900 * changes in cpufreq policy.
1902 * This function may sleep, and has the same return conditions as
1903 * blocking_notifier_chain_register.
1905 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1909 if (cpufreq_disabled())
1913 case CPUFREQ_TRANSITION_NOTIFIER:
1914 mutex_lock(&cpufreq_fast_switch_lock);
1916 if (cpufreq_fast_switch_count > 0) {
1917 mutex_unlock(&cpufreq_fast_switch_lock);
1920 ret = srcu_notifier_chain_register(
1921 &cpufreq_transition_notifier_list, nb);
1923 cpufreq_fast_switch_count--;
1925 mutex_unlock(&cpufreq_fast_switch_lock);
1927 case CPUFREQ_POLICY_NOTIFIER:
1928 ret = blocking_notifier_chain_register(
1929 &cpufreq_policy_notifier_list, nb);
1937 EXPORT_SYMBOL(cpufreq_register_notifier);
1940 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1941 * @nb: notifier block to be unregistered
1942 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1944 * Remove a driver from the CPU frequency notifier list.
1946 * This function may sleep, and has the same return conditions as
1947 * blocking_notifier_chain_unregister.
1949 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1953 if (cpufreq_disabled())
1957 case CPUFREQ_TRANSITION_NOTIFIER:
1958 mutex_lock(&cpufreq_fast_switch_lock);
1960 ret = srcu_notifier_chain_unregister(
1961 &cpufreq_transition_notifier_list, nb);
1962 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
1963 cpufreq_fast_switch_count++;
1965 mutex_unlock(&cpufreq_fast_switch_lock);
1967 case CPUFREQ_POLICY_NOTIFIER:
1968 ret = blocking_notifier_chain_unregister(
1969 &cpufreq_policy_notifier_list, nb);
1977 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1980 /*********************************************************************
1982 *********************************************************************/
1985 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1986 * @policy: cpufreq policy to switch the frequency for.
1987 * @target_freq: New frequency to set (may be approximate).
1989 * Carry out a fast frequency switch without sleeping.
1991 * The driver's ->fast_switch() callback invoked by this function must be
1992 * suitable for being called from within RCU-sched read-side critical sections
1993 * and it is expected to select the minimum available frequency greater than or
1994 * equal to @target_freq (CPUFREQ_RELATION_L).
1996 * This function must not be called if policy->fast_switch_enabled is unset.
1998 * Governors calling this function must guarantee that it will never be invoked
1999 * twice in parallel for the same policy and that it will never be called in
2000 * parallel with either ->target() or ->target_index() for the same policy.
2002 * Returns the actual frequency set for the CPU.
2004 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2005 * error condition, the hardware configuration must be preserved.
2007 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2008 unsigned int target_freq)
2010 target_freq = clamp_val(target_freq, policy->min, policy->max);
2012 return cpufreq_driver->fast_switch(policy, target_freq);
2014 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2016 /* Must set freqs->new to intermediate frequency */
2017 static int __target_intermediate(struct cpufreq_policy *policy,
2018 struct cpufreq_freqs *freqs, int index)
2022 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2024 /* We don't need to switch to intermediate freq */
2028 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2029 __func__, policy->cpu, freqs->old, freqs->new);
2031 cpufreq_freq_transition_begin(policy, freqs);
2032 ret = cpufreq_driver->target_intermediate(policy, index);
2033 cpufreq_freq_transition_end(policy, freqs, ret);
2036 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2042 static int __target_index(struct cpufreq_policy *policy, int index)
2044 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2045 unsigned int intermediate_freq = 0;
2046 unsigned int newfreq = policy->freq_table[index].frequency;
2047 int retval = -EINVAL;
2050 if (newfreq == policy->cur)
2053 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2055 /* Handle switching to intermediate frequency */
2056 if (cpufreq_driver->get_intermediate) {
2057 retval = __target_intermediate(policy, &freqs, index);
2061 intermediate_freq = freqs.new;
2062 /* Set old freq to intermediate */
2063 if (intermediate_freq)
2064 freqs.old = freqs.new;
2067 freqs.new = newfreq;
2068 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2069 __func__, policy->cpu, freqs.old, freqs.new);
2071 cpufreq_freq_transition_begin(policy, &freqs);
2074 retval = cpufreq_driver->target_index(policy, index);
2076 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2080 cpufreq_freq_transition_end(policy, &freqs, retval);
2083 * Failed after setting to intermediate freq? Driver should have
2084 * reverted back to initial frequency and so should we. Check
2085 * here for intermediate_freq instead of get_intermediate, in
2086 * case we haven't switched to intermediate freq at all.
2088 if (unlikely(retval && intermediate_freq)) {
2089 freqs.old = intermediate_freq;
2090 freqs.new = policy->restore_freq;
2091 cpufreq_freq_transition_begin(policy, &freqs);
2092 cpufreq_freq_transition_end(policy, &freqs, 0);
2099 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2100 unsigned int target_freq,
2101 unsigned int relation)
2103 unsigned int old_target_freq = target_freq;
2106 if (cpufreq_disabled())
2109 /* Make sure that target_freq is within supported range */
2110 target_freq = clamp_val(target_freq, policy->min, policy->max);
2112 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2113 policy->cpu, target_freq, relation, old_target_freq);
2116 * This might look like a redundant call as we are checking it again
2117 * after finding index. But it is left intentionally for cases where
2118 * exactly same freq is called again and so we can save on few function
2121 if (target_freq == policy->cur)
2124 /* Save last value to restore later on errors */
2125 policy->restore_freq = policy->cur;
2127 if (cpufreq_driver->target)
2128 return cpufreq_driver->target(policy, target_freq, relation);
2130 if (!cpufreq_driver->target_index)
2133 index = cpufreq_frequency_table_target(policy, target_freq, relation);
2135 return __target_index(policy, index);
2137 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2139 int cpufreq_driver_target(struct cpufreq_policy *policy,
2140 unsigned int target_freq,
2141 unsigned int relation)
2145 down_write(&policy->rwsem);
2147 ret = __cpufreq_driver_target(policy, target_freq, relation);
2149 up_write(&policy->rwsem);
2153 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2155 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2160 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2164 /* Don't start any governor operations if we are entering suspend */
2165 if (cpufreq_suspended)
2168 * Governor might not be initiated here if ACPI _PPC changed
2169 * notification happened, so check it.
2171 if (!policy->governor)
2174 /* Platform doesn't want dynamic frequency switching ? */
2175 if (policy->governor->dynamic_switching &&
2176 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2177 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2180 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2181 policy->governor->name, gov->name);
2182 policy->governor = gov;
2188 if (!try_module_get(policy->governor->owner))
2191 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2193 if (policy->governor->init) {
2194 ret = policy->governor->init(policy);
2196 module_put(policy->governor->owner);
2204 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2206 if (cpufreq_suspended || !policy->governor)
2209 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2211 if (policy->governor->exit)
2212 policy->governor->exit(policy);
2214 module_put(policy->governor->owner);
2217 static int cpufreq_start_governor(struct cpufreq_policy *policy)
2221 if (cpufreq_suspended)
2224 if (!policy->governor)
2227 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2229 if (cpufreq_driver->get)
2230 cpufreq_verify_current_freq(policy, false);
2232 if (policy->governor->start) {
2233 ret = policy->governor->start(policy);
2238 if (policy->governor->limits)
2239 policy->governor->limits(policy);
2244 static void cpufreq_stop_governor(struct cpufreq_policy *policy)
2246 if (cpufreq_suspended || !policy->governor)
2249 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2251 if (policy->governor->stop)
2252 policy->governor->stop(policy);
2255 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2257 if (cpufreq_suspended || !policy->governor)
2260 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2262 if (policy->governor->limits)
2263 policy->governor->limits(policy);
2266 int cpufreq_register_governor(struct cpufreq_governor *governor)
2273 if (cpufreq_disabled())
2276 mutex_lock(&cpufreq_governor_mutex);
2279 if (!find_governor(governor->name)) {
2281 list_add(&governor->governor_list, &cpufreq_governor_list);
2284 mutex_unlock(&cpufreq_governor_mutex);
2287 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2289 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2291 struct cpufreq_policy *policy;
2292 unsigned long flags;
2297 if (cpufreq_disabled())
2300 /* clear last_governor for all inactive policies */
2301 read_lock_irqsave(&cpufreq_driver_lock, flags);
2302 for_each_inactive_policy(policy) {
2303 if (!strcmp(policy->last_governor, governor->name)) {
2304 policy->governor = NULL;
2305 strcpy(policy->last_governor, "\0");
2308 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2310 mutex_lock(&cpufreq_governor_mutex);
2311 list_del(&governor->governor_list);
2312 mutex_unlock(&cpufreq_governor_mutex);
2314 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2317 /*********************************************************************
2318 * POLICY INTERFACE *
2319 *********************************************************************/
2322 * cpufreq_get_policy - get the current cpufreq_policy
2323 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2326 * Reads the current cpufreq policy.
2328 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2330 struct cpufreq_policy *cpu_policy;
2334 cpu_policy = cpufreq_cpu_get(cpu);
2338 memcpy(policy, cpu_policy, sizeof(*policy));
2340 cpufreq_cpu_put(cpu_policy);
2343 EXPORT_SYMBOL(cpufreq_get_policy);
2346 * cpufreq_set_policy - Modify cpufreq policy parameters.
2347 * @policy: Policy object to modify.
2348 * @new_policy: New policy data.
2350 * Pass @new_policy to the cpufreq driver's ->verify() callback, run the
2351 * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to
2352 * the driver's ->verify() callback again and run the notifiers for it again
2353 * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters
2354 * of @new_policy to @policy and either invoke the driver's ->setpolicy()
2355 * callback (if present) or carry out a governor update for @policy. That is,
2356 * run the current governor's ->limits() callback (if the governor field in
2357 * @new_policy points to the same object as the one in @policy) or replace the
2358 * governor for @policy with the new one stored in @new_policy.
2360 * The cpuinfo part of @policy is not updated by this function.
2362 int cpufreq_set_policy(struct cpufreq_policy *policy,
2363 struct cpufreq_policy *new_policy)
2365 struct cpufreq_governor *old_gov;
2366 struct device *cpu_dev = get_cpu_device(policy->cpu);
2369 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2370 new_policy->cpu, new_policy->min, new_policy->max);
2372 memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2375 * PM QoS framework collects all the requests from users and provide us
2376 * the final aggregated value here.
2378 new_policy->min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
2379 new_policy->max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
2381 /* verify the cpu speed can be set within this limit */
2382 ret = cpufreq_driver->verify(new_policy);
2387 * The notifier-chain shall be removed once all the users of
2388 * CPUFREQ_ADJUST are moved to use the QoS framework.
2390 /* adjust if necessary - all reasons */
2391 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2392 CPUFREQ_ADJUST, new_policy);
2395 * verify the cpu speed can be set within this limit, which might be
2396 * different to the first one
2398 ret = cpufreq_driver->verify(new_policy);
2402 /* notification of the new policy */
2403 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
2404 CPUFREQ_NOTIFY, new_policy);
2406 policy->min = new_policy->min;
2407 policy->max = new_policy->max;
2408 trace_cpu_frequency_limits(policy);
2410 policy->cached_target_freq = UINT_MAX;
2412 pr_debug("new min and max freqs are %u - %u kHz\n",
2413 policy->min, policy->max);
2415 if (cpufreq_driver->setpolicy) {
2416 policy->policy = new_policy->policy;
2417 pr_debug("setting range\n");
2418 return cpufreq_driver->setpolicy(policy);
2421 if (new_policy->governor == policy->governor) {
2422 pr_debug("governor limits update\n");
2423 cpufreq_governor_limits(policy);
2427 pr_debug("governor switch\n");
2429 /* save old, working values */
2430 old_gov = policy->governor;
2431 /* end old governor */
2433 cpufreq_stop_governor(policy);
2434 cpufreq_exit_governor(policy);
2437 /* start new governor */
2438 policy->governor = new_policy->governor;
2439 ret = cpufreq_init_governor(policy);
2441 ret = cpufreq_start_governor(policy);
2443 pr_debug("governor change\n");
2444 sched_cpufreq_governor_change(policy, old_gov);
2447 cpufreq_exit_governor(policy);
2450 /* new governor failed, so re-start old one */
2451 pr_debug("starting governor %s failed\n", policy->governor->name);
2453 policy->governor = old_gov;
2454 if (cpufreq_init_governor(policy))
2455 policy->governor = NULL;
2457 cpufreq_start_governor(policy);
2464 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2465 * @cpu: CPU to re-evaluate the policy for.
2467 * Update the current frequency for the cpufreq policy of @cpu and use
2468 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2469 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2470 * for the policy in question, among other things.
2472 void cpufreq_update_policy(unsigned int cpu)
2474 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2480 * BIOS might change freq behind our back
2481 * -> ask driver for current freq and notify governors about a change
2483 if (cpufreq_driver->get && has_target() &&
2484 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2487 refresh_frequency_limits(policy);
2490 cpufreq_cpu_release(policy);
2492 EXPORT_SYMBOL(cpufreq_update_policy);
2495 * cpufreq_update_limits - Update policy limits for a given CPU.
2496 * @cpu: CPU to update the policy limits for.
2498 * Invoke the driver's ->update_limits callback if present or call
2499 * cpufreq_update_policy() for @cpu.
2501 void cpufreq_update_limits(unsigned int cpu)
2503 if (cpufreq_driver->update_limits)
2504 cpufreq_driver->update_limits(cpu);
2506 cpufreq_update_policy(cpu);
2508 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2510 /*********************************************************************
2512 *********************************************************************/
2513 static int cpufreq_boost_set_sw(int state)
2515 struct cpufreq_policy *policy;
2518 for_each_active_policy(policy) {
2519 if (!policy->freq_table)
2522 ret = cpufreq_frequency_table_cpuinfo(policy,
2523 policy->freq_table);
2525 pr_err("%s: Policy frequency update failed\n",
2530 ret = dev_pm_qos_update_request(policy->max_freq_req, policy->max);
2538 int cpufreq_boost_trigger_state(int state)
2540 unsigned long flags;
2543 if (cpufreq_driver->boost_enabled == state)
2546 write_lock_irqsave(&cpufreq_driver_lock, flags);
2547 cpufreq_driver->boost_enabled = state;
2548 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2550 ret = cpufreq_driver->set_boost(state);
2552 write_lock_irqsave(&cpufreq_driver_lock, flags);
2553 cpufreq_driver->boost_enabled = !state;
2554 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2556 pr_err("%s: Cannot %s BOOST\n",
2557 __func__, state ? "enable" : "disable");
2563 static bool cpufreq_boost_supported(void)
2565 return cpufreq_driver->set_boost;
2568 static int create_boost_sysfs_file(void)
2572 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2574 pr_err("%s: cannot register global BOOST sysfs file\n",
2580 static void remove_boost_sysfs_file(void)
2582 if (cpufreq_boost_supported())
2583 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2586 int cpufreq_enable_boost_support(void)
2588 if (!cpufreq_driver)
2591 if (cpufreq_boost_supported())
2594 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2596 /* This will get removed on driver unregister */
2597 return create_boost_sysfs_file();
2599 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2601 int cpufreq_boost_enabled(void)
2603 return cpufreq_driver->boost_enabled;
2605 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2607 /*********************************************************************
2608 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2609 *********************************************************************/
2610 static enum cpuhp_state hp_online;
2612 static int cpuhp_cpufreq_online(unsigned int cpu)
2614 cpufreq_online(cpu);
2619 static int cpuhp_cpufreq_offline(unsigned int cpu)
2621 cpufreq_offline(cpu);
2627 * cpufreq_register_driver - register a CPU Frequency driver
2628 * @driver_data: A struct cpufreq_driver containing the values#
2629 * submitted by the CPU Frequency driver.
2631 * Registers a CPU Frequency driver to this core code. This code
2632 * returns zero on success, -EEXIST when another driver got here first
2633 * (and isn't unregistered in the meantime).
2636 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2638 unsigned long flags;
2641 if (cpufreq_disabled())
2644 if (!driver_data || !driver_data->verify || !driver_data->init ||
2645 !(driver_data->setpolicy || driver_data->target_index ||
2646 driver_data->target) ||
2647 (driver_data->setpolicy && (driver_data->target_index ||
2648 driver_data->target)) ||
2649 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2650 (!driver_data->online != !driver_data->offline))
2653 pr_debug("trying to register driver %s\n", driver_data->name);
2655 /* Protect against concurrent CPU online/offline. */
2658 write_lock_irqsave(&cpufreq_driver_lock, flags);
2659 if (cpufreq_driver) {
2660 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2664 cpufreq_driver = driver_data;
2665 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2667 if (driver_data->setpolicy)
2668 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2670 if (cpufreq_boost_supported()) {
2671 ret = create_boost_sysfs_file();
2673 goto err_null_driver;
2676 ret = subsys_interface_register(&cpufreq_interface);
2678 goto err_boost_unreg;
2680 if (!(cpufreq_driver->flags & CPUFREQ_STICKY) &&
2681 list_empty(&cpufreq_policy_list)) {
2682 /* if all ->init() calls failed, unregister */
2684 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2689 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2691 cpuhp_cpufreq_online,
2692 cpuhp_cpufreq_offline);
2698 pr_debug("driver %s up and running\n", driver_data->name);
2702 subsys_interface_unregister(&cpufreq_interface);
2704 remove_boost_sysfs_file();
2706 write_lock_irqsave(&cpufreq_driver_lock, flags);
2707 cpufreq_driver = NULL;
2708 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2713 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2716 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2718 * Unregister the current CPUFreq driver. Only call this if you have
2719 * the right to do so, i.e. if you have succeeded in initialising before!
2720 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2721 * currently not initialised.
2723 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2725 unsigned long flags;
2727 if (!cpufreq_driver || (driver != cpufreq_driver))
2730 pr_debug("unregistering driver %s\n", driver->name);
2732 /* Protect against concurrent cpu hotplug */
2734 subsys_interface_unregister(&cpufreq_interface);
2735 remove_boost_sysfs_file();
2736 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2738 write_lock_irqsave(&cpufreq_driver_lock, flags);
2740 cpufreq_driver = NULL;
2742 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2747 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2750 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2751 * or mutexes when secondary CPUs are halted.
2753 static struct syscore_ops cpufreq_syscore_ops = {
2754 .shutdown = cpufreq_suspend,
2757 struct kobject *cpufreq_global_kobject;
2758 EXPORT_SYMBOL(cpufreq_global_kobject);
2760 static int __init cpufreq_core_init(void)
2762 if (cpufreq_disabled())
2765 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2766 BUG_ON(!cpufreq_global_kobject);
2768 register_syscore_ops(&cpufreq_syscore_ops);
2772 module_param(off, int, 0444);
2773 core_initcall(cpufreq_core_init);