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 /* Iterate over governors */
46 static LIST_HEAD(cpufreq_governor_list);
47 #define for_each_governor(__governor) \
48 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
50 static char default_governor[CPUFREQ_NAME_LEN];
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 static DEFINE_STATIC_KEY_FALSE(cpufreq_freq_invariance);
62 bool cpufreq_supports_freq_invariance(void)
64 return static_branch_likely(&cpufreq_freq_invariance);
67 /* Flag to suspend/resume CPUFreq governors */
68 static bool cpufreq_suspended;
70 static inline bool has_target(void)
72 return cpufreq_driver->target_index || cpufreq_driver->target;
75 /* internal prototypes */
76 static unsigned int __cpufreq_get(struct cpufreq_policy *policy);
77 static int cpufreq_init_governor(struct cpufreq_policy *policy);
78 static void cpufreq_exit_governor(struct cpufreq_policy *policy);
79 static void cpufreq_governor_limits(struct cpufreq_policy *policy);
80 static int cpufreq_set_policy(struct cpufreq_policy *policy,
81 struct cpufreq_governor *new_gov,
82 unsigned int new_pol);
85 * Two notifier lists: the "policy" list is involved in the
86 * validation process for a new CPU frequency policy; the
87 * "transition" list for kernel code that needs to handle
88 * changes to devices when the CPU clock speed changes.
89 * The mutex locks both lists.
91 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list);
92 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list);
94 static int off __read_mostly;
95 static int cpufreq_disabled(void)
99 void disable_cpufreq(void)
103 static DEFINE_MUTEX(cpufreq_governor_mutex);
105 bool have_governor_per_policy(void)
107 return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY);
109 EXPORT_SYMBOL_GPL(have_governor_per_policy);
111 static struct kobject *cpufreq_global_kobject;
113 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
115 if (have_governor_per_policy())
116 return &policy->kobj;
118 return cpufreq_global_kobject;
120 EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
122 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
124 struct kernel_cpustat kcpustat;
129 cur_wall_time = jiffies64_to_nsecs(get_jiffies_64());
131 kcpustat_cpu_fetch(&kcpustat, cpu);
133 busy_time = kcpustat.cpustat[CPUTIME_USER];
134 busy_time += kcpustat.cpustat[CPUTIME_SYSTEM];
135 busy_time += kcpustat.cpustat[CPUTIME_IRQ];
136 busy_time += kcpustat.cpustat[CPUTIME_SOFTIRQ];
137 busy_time += kcpustat.cpustat[CPUTIME_STEAL];
138 busy_time += kcpustat.cpustat[CPUTIME_NICE];
140 idle_time = cur_wall_time - busy_time;
142 *wall = div_u64(cur_wall_time, NSEC_PER_USEC);
144 return div_u64(idle_time, NSEC_PER_USEC);
147 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy)
149 u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL);
151 if (idle_time == -1ULL)
152 return get_cpu_idle_time_jiffy(cpu, wall);
154 idle_time += get_cpu_iowait_time_us(cpu, wall);
158 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
161 * This is a generic cpufreq init() routine which can be used by cpufreq
162 * drivers of SMP systems. It will do following:
163 * - validate & show freq table passed
164 * - set policies transition latency
165 * - policy->cpus with all possible CPUs
167 void cpufreq_generic_init(struct cpufreq_policy *policy,
168 struct cpufreq_frequency_table *table,
169 unsigned int transition_latency)
171 policy->freq_table = table;
172 policy->cpuinfo.transition_latency = transition_latency;
175 * The driver only supports the SMP configuration where all processors
176 * share the clock and voltage and clock.
178 cpumask_setall(policy->cpus);
180 EXPORT_SYMBOL_GPL(cpufreq_generic_init);
182 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
184 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
186 return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
188 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
190 unsigned int cpufreq_generic_get(unsigned int cpu)
192 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
194 if (!policy || IS_ERR(policy->clk)) {
195 pr_err("%s: No %s associated to cpu: %d\n",
196 __func__, policy ? "clk" : "policy", cpu);
200 return clk_get_rate(policy->clk) / 1000;
202 EXPORT_SYMBOL_GPL(cpufreq_generic_get);
205 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
206 * @cpu: CPU to find the policy for.
208 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
209 * the kobject reference counter of that policy. Return a valid policy on
210 * success or NULL on failure.
212 * The policy returned by this function has to be released with the help of
213 * cpufreq_cpu_put() to balance its kobject reference counter properly.
215 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
217 struct cpufreq_policy *policy = NULL;
220 if (WARN_ON(cpu >= nr_cpu_ids))
223 /* get the cpufreq driver */
224 read_lock_irqsave(&cpufreq_driver_lock, flags);
226 if (cpufreq_driver) {
228 policy = cpufreq_cpu_get_raw(cpu);
230 kobject_get(&policy->kobj);
233 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
237 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
240 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
241 * @policy: cpufreq policy returned by cpufreq_cpu_get().
243 void cpufreq_cpu_put(struct cpufreq_policy *policy)
245 kobject_put(&policy->kobj);
247 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
250 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
251 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
253 void cpufreq_cpu_release(struct cpufreq_policy *policy)
255 if (WARN_ON(!policy))
258 lockdep_assert_held(&policy->rwsem);
260 up_write(&policy->rwsem);
262 cpufreq_cpu_put(policy);
266 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
267 * @cpu: CPU to find the policy for.
269 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
270 * if the policy returned by it is not NULL, acquire its rwsem for writing.
271 * Return the policy if it is active or release it and return NULL otherwise.
273 * The policy returned by this function has to be released with the help of
274 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
277 struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
279 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
284 down_write(&policy->rwsem);
286 if (policy_is_inactive(policy)) {
287 cpufreq_cpu_release(policy);
294 /*********************************************************************
295 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
296 *********************************************************************/
299 * adjust_jiffies - Adjust the system "loops_per_jiffy".
300 * @val: CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
301 * @ci: Frequency change information.
303 * This function alters the system "loops_per_jiffy" for the clock
304 * speed change. Note that loops_per_jiffy cannot be updated on SMP
305 * systems as each CPU might be scaled differently. So, use the arch
306 * per-CPU loops_per_jiffy value wherever possible.
308 static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
311 static unsigned long l_p_j_ref;
312 static unsigned int l_p_j_ref_freq;
314 if (ci->flags & CPUFREQ_CONST_LOOPS)
317 if (!l_p_j_ref_freq) {
318 l_p_j_ref = loops_per_jiffy;
319 l_p_j_ref_freq = ci->old;
320 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
321 l_p_j_ref, l_p_j_ref_freq);
323 if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) {
324 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq,
326 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
327 loops_per_jiffy, ci->new);
333 * cpufreq_notify_transition - Notify frequency transition and adjust jiffies.
334 * @policy: cpufreq policy to enable fast frequency switching for.
335 * @freqs: contain details of the frequency update.
336 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
338 * This function calls the transition notifiers and adjust_jiffies().
340 * It is called twice on all CPU frequency changes that have external effects.
342 static void cpufreq_notify_transition(struct cpufreq_policy *policy,
343 struct cpufreq_freqs *freqs,
348 BUG_ON(irqs_disabled());
350 if (cpufreq_disabled())
353 freqs->policy = policy;
354 freqs->flags = cpufreq_driver->flags;
355 pr_debug("notification %u of frequency transition to %u kHz\n",
359 case CPUFREQ_PRECHANGE:
361 * Detect if the driver reported a value as "old frequency"
362 * which is not equal to what the cpufreq core thinks is
365 if (policy->cur && policy->cur != freqs->old) {
366 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
367 freqs->old, policy->cur);
368 freqs->old = policy->cur;
371 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
372 CPUFREQ_PRECHANGE, freqs);
374 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
377 case CPUFREQ_POSTCHANGE:
378 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
379 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs->new,
380 cpumask_pr_args(policy->cpus));
382 for_each_cpu(cpu, policy->cpus)
383 trace_cpu_frequency(freqs->new, cpu);
385 srcu_notifier_call_chain(&cpufreq_transition_notifier_list,
386 CPUFREQ_POSTCHANGE, freqs);
388 cpufreq_stats_record_transition(policy, freqs->new);
389 policy->cur = freqs->new;
393 /* Do post notifications when there are chances that transition has failed */
394 static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
395 struct cpufreq_freqs *freqs, int transition_failed)
397 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
398 if (!transition_failed)
401 swap(freqs->old, freqs->new);
402 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
403 cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE);
406 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
407 struct cpufreq_freqs *freqs)
411 * Catch double invocations of _begin() which lead to self-deadlock.
412 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
413 * doesn't invoke _begin() on their behalf, and hence the chances of
414 * double invocations are very low. Moreover, there are scenarios
415 * where these checks can emit false-positive warnings in these
416 * drivers; so we avoid that by skipping them altogether.
418 WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION)
419 && current == policy->transition_task);
422 wait_event(policy->transition_wait, !policy->transition_ongoing);
424 spin_lock(&policy->transition_lock);
426 if (unlikely(policy->transition_ongoing)) {
427 spin_unlock(&policy->transition_lock);
431 policy->transition_ongoing = true;
432 policy->transition_task = current;
434 spin_unlock(&policy->transition_lock);
436 cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
438 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
440 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
441 struct cpufreq_freqs *freqs, int transition_failed)
443 if (WARN_ON(!policy->transition_ongoing))
446 cpufreq_notify_post_transition(policy, freqs, transition_failed);
448 arch_set_freq_scale(policy->related_cpus,
450 policy->cpuinfo.max_freq);
452 policy->transition_ongoing = false;
453 policy->transition_task = NULL;
455 wake_up(&policy->transition_wait);
457 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end);
460 * Fast frequency switching status count. Positive means "enabled", negative
461 * means "disabled" and 0 means "not decided yet".
463 static int cpufreq_fast_switch_count;
464 static DEFINE_MUTEX(cpufreq_fast_switch_lock);
466 static void cpufreq_list_transition_notifiers(void)
468 struct notifier_block *nb;
470 pr_info("Registered transition notifiers:\n");
472 mutex_lock(&cpufreq_transition_notifier_list.mutex);
474 for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next)
475 pr_info("%pS\n", nb->notifier_call);
477 mutex_unlock(&cpufreq_transition_notifier_list.mutex);
481 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
482 * @policy: cpufreq policy to enable fast frequency switching for.
484 * Try to enable fast frequency switching for @policy.
486 * The attempt will fail if there is at least one transition notifier registered
487 * at this point, as fast frequency switching is quite fundamentally at odds
488 * with transition notifiers. Thus if successful, it will make registration of
489 * transition notifiers fail going forward.
491 void cpufreq_enable_fast_switch(struct cpufreq_policy *policy)
493 lockdep_assert_held(&policy->rwsem);
495 if (!policy->fast_switch_possible)
498 mutex_lock(&cpufreq_fast_switch_lock);
499 if (cpufreq_fast_switch_count >= 0) {
500 cpufreq_fast_switch_count++;
501 policy->fast_switch_enabled = true;
503 pr_warn("CPU%u: Fast frequency switching not enabled\n",
505 cpufreq_list_transition_notifiers();
507 mutex_unlock(&cpufreq_fast_switch_lock);
509 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch);
512 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
513 * @policy: cpufreq policy to disable fast frequency switching for.
515 void cpufreq_disable_fast_switch(struct cpufreq_policy *policy)
517 mutex_lock(&cpufreq_fast_switch_lock);
518 if (policy->fast_switch_enabled) {
519 policy->fast_switch_enabled = false;
520 if (!WARN_ON(cpufreq_fast_switch_count <= 0))
521 cpufreq_fast_switch_count--;
523 mutex_unlock(&cpufreq_fast_switch_lock);
525 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch);
527 static unsigned int __resolve_freq(struct cpufreq_policy *policy,
528 unsigned int target_freq, unsigned int relation)
532 target_freq = clamp_val(target_freq, policy->min, policy->max);
534 if (!cpufreq_driver->target_index)
537 idx = cpufreq_frequency_table_target(policy, target_freq, relation);
538 policy->cached_resolved_idx = idx;
539 policy->cached_target_freq = target_freq;
540 return policy->freq_table[idx].frequency;
544 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
546 * @policy: associated policy to interrogate
547 * @target_freq: target frequency to resolve.
549 * The target to driver frequency mapping is cached in the policy.
551 * Return: Lowest driver-supported frequency greater than or equal to the
552 * given target_freq, subject to policy (min/max) and driver limitations.
554 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy,
555 unsigned int target_freq)
557 return __resolve_freq(policy, target_freq, CPUFREQ_RELATION_LE);
559 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq);
561 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy *policy)
563 unsigned int latency;
565 if (policy->transition_delay_us)
566 return policy->transition_delay_us;
568 latency = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
571 * For platforms that can change the frequency very fast (< 10
572 * us), the above formula gives a decent transition delay. But
573 * for platforms where transition_latency is in milliseconds, it
574 * ends up giving unrealistic values.
576 * Cap the default transition delay to 10 ms, which seems to be
577 * a reasonable amount of time after which we should reevaluate
580 return min(latency * LATENCY_MULTIPLIER, (unsigned int)10000);
583 return LATENCY_MULTIPLIER;
585 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us);
587 /*********************************************************************
589 *********************************************************************/
590 static ssize_t show_boost(struct kobject *kobj,
591 struct kobj_attribute *attr, char *buf)
593 return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled);
596 static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr,
597 const char *buf, size_t count)
601 ret = sscanf(buf, "%d", &enable);
602 if (ret != 1 || enable < 0 || enable > 1)
605 if (cpufreq_boost_trigger_state(enable)) {
606 pr_err("%s: Cannot %s BOOST!\n",
607 __func__, enable ? "enable" : "disable");
611 pr_debug("%s: cpufreq BOOST %s\n",
612 __func__, enable ? "enabled" : "disabled");
616 define_one_global_rw(boost);
618 static struct cpufreq_governor *find_governor(const char *str_governor)
620 struct cpufreq_governor *t;
623 if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN))
629 static struct cpufreq_governor *get_governor(const char *str_governor)
631 struct cpufreq_governor *t;
633 mutex_lock(&cpufreq_governor_mutex);
634 t = find_governor(str_governor);
638 if (!try_module_get(t->owner))
642 mutex_unlock(&cpufreq_governor_mutex);
647 static unsigned int cpufreq_parse_policy(char *str_governor)
649 if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN))
650 return CPUFREQ_POLICY_PERFORMANCE;
652 if (!strncasecmp(str_governor, "powersave", CPUFREQ_NAME_LEN))
653 return CPUFREQ_POLICY_POWERSAVE;
655 return CPUFREQ_POLICY_UNKNOWN;
659 * cpufreq_parse_governor - parse a governor string only for has_target()
660 * @str_governor: Governor name.
662 static struct cpufreq_governor *cpufreq_parse_governor(char *str_governor)
664 struct cpufreq_governor *t;
666 t = get_governor(str_governor);
670 if (request_module("cpufreq_%s", str_governor))
673 return get_governor(str_governor);
677 * cpufreq_per_cpu_attr_read() / show_##file_name() -
678 * print out cpufreq information
680 * Write out information from cpufreq_driver->policy[cpu]; object must be
684 #define show_one(file_name, object) \
685 static ssize_t show_##file_name \
686 (struct cpufreq_policy *policy, char *buf) \
688 return sprintf(buf, "%u\n", policy->object); \
691 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
692 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
693 show_one(cpuinfo_transition_latency, cpuinfo.transition_latency);
694 show_one(scaling_min_freq, min);
695 show_one(scaling_max_freq, max);
697 __weak unsigned int arch_freq_get_on_cpu(int cpu)
702 static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
707 freq = arch_freq_get_on_cpu(policy->cpu);
709 ret = sprintf(buf, "%u\n", freq);
710 else if (cpufreq_driver->setpolicy && cpufreq_driver->get)
711 ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu));
713 ret = sprintf(buf, "%u\n", policy->cur);
718 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
720 #define store_one(file_name, object) \
721 static ssize_t store_##file_name \
722 (struct cpufreq_policy *policy, const char *buf, size_t count) \
727 ret = sscanf(buf, "%lu", &val); \
731 ret = freq_qos_update_request(policy->object##_freq_req, val);\
732 return ret >= 0 ? count : ret; \
735 store_one(scaling_min_freq, min);
736 store_one(scaling_max_freq, max);
739 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
741 static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy,
744 unsigned int cur_freq = __cpufreq_get(policy);
747 return sprintf(buf, "%u\n", cur_freq);
749 return sprintf(buf, "<unknown>\n");
753 * show_scaling_governor - show the current policy for the specified CPU
755 static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
757 if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
758 return sprintf(buf, "powersave\n");
759 else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
760 return sprintf(buf, "performance\n");
761 else if (policy->governor)
762 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
763 policy->governor->name);
768 * store_scaling_governor - store policy for the specified CPU
770 static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
771 const char *buf, size_t count)
773 char str_governor[16];
776 ret = sscanf(buf, "%15s", str_governor);
780 if (cpufreq_driver->setpolicy) {
781 unsigned int new_pol;
783 new_pol = cpufreq_parse_policy(str_governor);
787 ret = cpufreq_set_policy(policy, NULL, new_pol);
789 struct cpufreq_governor *new_gov;
791 new_gov = cpufreq_parse_governor(str_governor);
795 ret = cpufreq_set_policy(policy, new_gov,
796 CPUFREQ_POLICY_UNKNOWN);
798 module_put(new_gov->owner);
801 return ret ? ret : count;
805 * show_scaling_driver - show the cpufreq driver currently loaded
807 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
809 return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
813 * show_scaling_available_governors - show the available CPUfreq governors
815 static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
819 struct cpufreq_governor *t;
822 i += sprintf(buf, "performance powersave");
826 mutex_lock(&cpufreq_governor_mutex);
827 for_each_governor(t) {
828 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
829 - (CPUFREQ_NAME_LEN + 2)))
831 i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
833 mutex_unlock(&cpufreq_governor_mutex);
835 i += sprintf(&buf[i], "\n");
839 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
844 for_each_cpu(cpu, mask) {
846 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
847 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
848 if (i >= (PAGE_SIZE - 5))
851 i += sprintf(&buf[i], "\n");
854 EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
857 * show_related_cpus - show the CPUs affected by each transition even if
858 * hw coordination is in use
860 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
862 return cpufreq_show_cpus(policy->related_cpus, buf);
866 * show_affected_cpus - show the CPUs affected by each transition
868 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
870 return cpufreq_show_cpus(policy->cpus, buf);
873 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
874 const char *buf, size_t count)
876 unsigned int freq = 0;
879 if (!policy->governor || !policy->governor->store_setspeed)
882 ret = sscanf(buf, "%u", &freq);
886 policy->governor->store_setspeed(policy, freq);
891 static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
893 if (!policy->governor || !policy->governor->show_setspeed)
894 return sprintf(buf, "<unsupported>\n");
896 return policy->governor->show_setspeed(policy, buf);
900 * show_bios_limit - show the current cpufreq HW/BIOS limitation
902 static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
906 ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
908 return sprintf(buf, "%u\n", limit);
909 return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
912 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400);
913 cpufreq_freq_attr_ro(cpuinfo_min_freq);
914 cpufreq_freq_attr_ro(cpuinfo_max_freq);
915 cpufreq_freq_attr_ro(cpuinfo_transition_latency);
916 cpufreq_freq_attr_ro(scaling_available_governors);
917 cpufreq_freq_attr_ro(scaling_driver);
918 cpufreq_freq_attr_ro(scaling_cur_freq);
919 cpufreq_freq_attr_ro(bios_limit);
920 cpufreq_freq_attr_ro(related_cpus);
921 cpufreq_freq_attr_ro(affected_cpus);
922 cpufreq_freq_attr_rw(scaling_min_freq);
923 cpufreq_freq_attr_rw(scaling_max_freq);
924 cpufreq_freq_attr_rw(scaling_governor);
925 cpufreq_freq_attr_rw(scaling_setspeed);
927 static struct attribute *cpufreq_attrs[] = {
928 &cpuinfo_min_freq.attr,
929 &cpuinfo_max_freq.attr,
930 &cpuinfo_transition_latency.attr,
931 &scaling_min_freq.attr,
932 &scaling_max_freq.attr,
935 &scaling_governor.attr,
936 &scaling_driver.attr,
937 &scaling_available_governors.attr,
938 &scaling_setspeed.attr,
941 ATTRIBUTE_GROUPS(cpufreq);
943 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
944 #define to_attr(a) container_of(a, struct freq_attr, attr)
946 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
948 struct cpufreq_policy *policy = to_policy(kobj);
949 struct freq_attr *fattr = to_attr(attr);
955 down_read(&policy->rwsem);
956 ret = fattr->show(policy, buf);
957 up_read(&policy->rwsem);
962 static ssize_t store(struct kobject *kobj, struct attribute *attr,
963 const char *buf, size_t count)
965 struct cpufreq_policy *policy = to_policy(kobj);
966 struct freq_attr *fattr = to_attr(attr);
967 ssize_t ret = -EINVAL;
973 * cpus_read_trylock() is used here to work around a circular lock
974 * dependency problem with respect to the cpufreq_register_driver().
976 if (!cpus_read_trylock())
979 if (cpu_online(policy->cpu)) {
980 down_write(&policy->rwsem);
981 ret = fattr->store(policy, buf, count);
982 up_write(&policy->rwsem);
990 static void cpufreq_sysfs_release(struct kobject *kobj)
992 struct cpufreq_policy *policy = to_policy(kobj);
993 pr_debug("last reference is dropped\n");
994 complete(&policy->kobj_unregister);
997 static const struct sysfs_ops sysfs_ops = {
1002 static struct kobj_type ktype_cpufreq = {
1003 .sysfs_ops = &sysfs_ops,
1004 .default_groups = cpufreq_groups,
1005 .release = cpufreq_sysfs_release,
1008 static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu,
1014 if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
1017 dev_dbg(dev, "%s: Adding symlink\n", __func__);
1018 if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq"))
1019 dev_err(dev, "cpufreq symlink creation failed\n");
1022 static void remove_cpu_dev_symlink(struct cpufreq_policy *policy,
1025 dev_dbg(dev, "%s: Removing symlink\n", __func__);
1026 sysfs_remove_link(&dev->kobj, "cpufreq");
1029 static int cpufreq_add_dev_interface(struct cpufreq_policy *policy)
1031 struct freq_attr **drv_attr;
1034 /* set up files for this cpu device */
1035 drv_attr = cpufreq_driver->attr;
1036 while (drv_attr && *drv_attr) {
1037 ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
1042 if (cpufreq_driver->get) {
1043 ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
1048 ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
1052 if (cpufreq_driver->bios_limit) {
1053 ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
1061 static int cpufreq_init_policy(struct cpufreq_policy *policy)
1063 struct cpufreq_governor *gov = NULL;
1064 unsigned int pol = CPUFREQ_POLICY_UNKNOWN;
1068 /* Update policy governor to the one used before hotplug. */
1069 gov = get_governor(policy->last_governor);
1071 pr_debug("Restoring governor %s for cpu %d\n",
1072 gov->name, policy->cpu);
1074 gov = get_governor(default_governor);
1078 gov = cpufreq_default_governor();
1079 __module_get(gov->owner);
1084 /* Use the default policy if there is no last_policy. */
1085 if (policy->last_policy) {
1086 pol = policy->last_policy;
1088 pol = cpufreq_parse_policy(default_governor);
1090 * In case the default governor is neither "performance"
1091 * nor "powersave", fall back to the initial policy
1092 * value set by the driver.
1094 if (pol == CPUFREQ_POLICY_UNKNOWN)
1095 pol = policy->policy;
1097 if (pol != CPUFREQ_POLICY_PERFORMANCE &&
1098 pol != CPUFREQ_POLICY_POWERSAVE)
1102 ret = cpufreq_set_policy(policy, gov, pol);
1104 module_put(gov->owner);
1109 static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
1113 /* Has this CPU been taken care of already? */
1114 if (cpumask_test_cpu(cpu, policy->cpus))
1117 down_write(&policy->rwsem);
1119 cpufreq_stop_governor(policy);
1121 cpumask_set_cpu(cpu, policy->cpus);
1124 ret = cpufreq_start_governor(policy);
1126 pr_err("%s: Failed to start governor\n", __func__);
1128 up_write(&policy->rwsem);
1132 void refresh_frequency_limits(struct cpufreq_policy *policy)
1134 if (!policy_is_inactive(policy)) {
1135 pr_debug("updating policy for CPU %u\n", policy->cpu);
1137 cpufreq_set_policy(policy, policy->governor, policy->policy);
1140 EXPORT_SYMBOL(refresh_frequency_limits);
1142 static void handle_update(struct work_struct *work)
1144 struct cpufreq_policy *policy =
1145 container_of(work, struct cpufreq_policy, update);
1147 pr_debug("handle_update for cpu %u called\n", policy->cpu);
1148 down_write(&policy->rwsem);
1149 refresh_frequency_limits(policy);
1150 up_write(&policy->rwsem);
1153 static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
1156 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
1158 schedule_work(&policy->update);
1162 static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
1165 struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
1167 schedule_work(&policy->update);
1171 static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
1173 struct kobject *kobj;
1174 struct completion *cmp;
1176 down_write(&policy->rwsem);
1177 cpufreq_stats_free_table(policy);
1178 kobj = &policy->kobj;
1179 cmp = &policy->kobj_unregister;
1180 up_write(&policy->rwsem);
1184 * We need to make sure that the underlying kobj is
1185 * actually not referenced anymore by anybody before we
1186 * proceed with unloading.
1188 pr_debug("waiting for dropping of refcount\n");
1189 wait_for_completion(cmp);
1190 pr_debug("wait complete\n");
1193 static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
1195 struct cpufreq_policy *policy;
1196 struct device *dev = get_cpu_device(cpu);
1202 policy = kzalloc(sizeof(*policy), GFP_KERNEL);
1206 if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
1207 goto err_free_policy;
1209 if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
1210 goto err_free_cpumask;
1212 if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
1213 goto err_free_rcpumask;
1215 ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
1216 cpufreq_global_kobject, "policy%u", cpu);
1218 dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
1220 * The entire policy object will be freed below, but the extra
1221 * memory allocated for the kobject name needs to be freed by
1222 * releasing the kobject.
1224 kobject_put(&policy->kobj);
1225 goto err_free_real_cpus;
1228 freq_constraints_init(&policy->constraints);
1230 policy->nb_min.notifier_call = cpufreq_notifier_min;
1231 policy->nb_max.notifier_call = cpufreq_notifier_max;
1233 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MIN,
1236 dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1237 ret, cpumask_pr_args(policy->cpus));
1238 goto err_kobj_remove;
1241 ret = freq_qos_add_notifier(&policy->constraints, FREQ_QOS_MAX,
1244 dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1245 ret, cpumask_pr_args(policy->cpus));
1246 goto err_min_qos_notifier;
1249 INIT_LIST_HEAD(&policy->policy_list);
1250 init_rwsem(&policy->rwsem);
1251 spin_lock_init(&policy->transition_lock);
1252 init_waitqueue_head(&policy->transition_wait);
1253 init_completion(&policy->kobj_unregister);
1254 INIT_WORK(&policy->update, handle_update);
1259 err_min_qos_notifier:
1260 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1263 cpufreq_policy_put_kobj(policy);
1265 free_cpumask_var(policy->real_cpus);
1267 free_cpumask_var(policy->related_cpus);
1269 free_cpumask_var(policy->cpus);
1276 static void cpufreq_policy_free(struct cpufreq_policy *policy)
1278 unsigned long flags;
1281 /* Remove policy from list */
1282 write_lock_irqsave(&cpufreq_driver_lock, flags);
1283 list_del(&policy->policy_list);
1285 for_each_cpu(cpu, policy->related_cpus)
1286 per_cpu(cpufreq_cpu_data, cpu) = NULL;
1287 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1289 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MAX,
1291 freq_qos_remove_notifier(&policy->constraints, FREQ_QOS_MIN,
1294 /* Cancel any pending policy->update work before freeing the policy. */
1295 cancel_work_sync(&policy->update);
1297 if (policy->max_freq_req) {
1299 * Remove max_freq_req after sending CPUFREQ_REMOVE_POLICY
1300 * notification, since CPUFREQ_CREATE_POLICY notification was
1301 * sent after adding max_freq_req earlier.
1303 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1304 CPUFREQ_REMOVE_POLICY, policy);
1305 freq_qos_remove_request(policy->max_freq_req);
1308 freq_qos_remove_request(policy->min_freq_req);
1309 kfree(policy->min_freq_req);
1311 cpufreq_policy_put_kobj(policy);
1312 free_cpumask_var(policy->real_cpus);
1313 free_cpumask_var(policy->related_cpus);
1314 free_cpumask_var(policy->cpus);
1318 static int cpufreq_online(unsigned int cpu)
1320 struct cpufreq_policy *policy;
1322 unsigned long flags;
1326 pr_debug("%s: bringing CPU%u online\n", __func__, cpu);
1328 /* Check if this CPU already has a policy to manage it */
1329 policy = per_cpu(cpufreq_cpu_data, cpu);
1331 WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus));
1332 if (!policy_is_inactive(policy))
1333 return cpufreq_add_policy_cpu(policy, cpu);
1335 /* This is the only online CPU for the policy. Start over. */
1337 down_write(&policy->rwsem);
1339 policy->governor = NULL;
1340 up_write(&policy->rwsem);
1343 policy = cpufreq_policy_alloc(cpu);
1348 if (!new_policy && cpufreq_driver->online) {
1349 ret = cpufreq_driver->online(policy);
1351 pr_debug("%s: %d: initialization failed\n", __func__,
1353 goto out_exit_policy;
1356 /* Recover policy->cpus using related_cpus */
1357 cpumask_copy(policy->cpus, policy->related_cpus);
1359 cpumask_copy(policy->cpus, cpumask_of(cpu));
1362 * Call driver. From then on the cpufreq must be able
1363 * to accept all calls to ->verify and ->setpolicy for this CPU.
1365 ret = cpufreq_driver->init(policy);
1367 pr_debug("%s: %d: initialization failed\n", __func__,
1369 goto out_free_policy;
1373 * The initialization has succeeded and the policy is online.
1374 * If there is a problem with its frequency table, take it
1375 * offline and drop it.
1377 ret = cpufreq_table_validate_and_sort(policy);
1379 goto out_offline_policy;
1381 /* related_cpus should at least include policy->cpus. */
1382 cpumask_copy(policy->related_cpus, policy->cpus);
1385 down_write(&policy->rwsem);
1387 * affected cpus must always be the one, which are online. We aren't
1388 * managing offline cpus here.
1390 cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
1393 for_each_cpu(j, policy->related_cpus) {
1394 per_cpu(cpufreq_cpu_data, j) = policy;
1395 add_cpu_dev_symlink(policy, j, get_cpu_device(j));
1398 policy->min_freq_req = kzalloc(2 * sizeof(*policy->min_freq_req),
1400 if (!policy->min_freq_req) {
1402 goto out_destroy_policy;
1405 ret = freq_qos_add_request(&policy->constraints,
1406 policy->min_freq_req, FREQ_QOS_MIN,
1407 FREQ_QOS_MIN_DEFAULT_VALUE);
1410 * So we don't call freq_qos_remove_request() for an
1411 * uninitialized request.
1413 kfree(policy->min_freq_req);
1414 policy->min_freq_req = NULL;
1415 goto out_destroy_policy;
1419 * This must be initialized right here to avoid calling
1420 * freq_qos_remove_request() on uninitialized request in case
1423 policy->max_freq_req = policy->min_freq_req + 1;
1425 ret = freq_qos_add_request(&policy->constraints,
1426 policy->max_freq_req, FREQ_QOS_MAX,
1427 FREQ_QOS_MAX_DEFAULT_VALUE);
1429 policy->max_freq_req = NULL;
1430 goto out_destroy_policy;
1433 blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
1434 CPUFREQ_CREATE_POLICY, policy);
1437 if (cpufreq_driver->get && has_target()) {
1438 policy->cur = cpufreq_driver->get(policy->cpu);
1441 pr_err("%s: ->get() failed\n", __func__);
1442 goto out_destroy_policy;
1447 * Sometimes boot loaders set CPU frequency to a value outside of
1448 * frequency table present with cpufreq core. In such cases CPU might be
1449 * unstable if it has to run on that frequency for long duration of time
1450 * and so its better to set it to a frequency which is specified in
1451 * freq-table. This also makes cpufreq stats inconsistent as
1452 * cpufreq-stats would fail to register because current frequency of CPU
1453 * isn't found in freq-table.
1455 * Because we don't want this change to effect boot process badly, we go
1456 * for the next freq which is >= policy->cur ('cur' must be set by now,
1457 * otherwise we will end up setting freq to lowest of the table as 'cur'
1458 * is initialized to zero).
1460 * We are passing target-freq as "policy->cur - 1" otherwise
1461 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1462 * equal to target-freq.
1464 if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK)
1466 unsigned int old_freq = policy->cur;
1468 /* Are we running at unknown frequency ? */
1469 ret = cpufreq_frequency_table_get_index(policy, old_freq);
1470 if (ret == -EINVAL) {
1471 ret = __cpufreq_driver_target(policy, old_freq - 1,
1472 CPUFREQ_RELATION_L);
1475 * Reaching here after boot in a few seconds may not
1476 * mean that system will remain stable at "unknown"
1477 * frequency for longer duration. Hence, a BUG_ON().
1480 pr_info("%s: CPU%d: Running at unlisted initial frequency: %u KHz, changing to: %u KHz\n",
1481 __func__, policy->cpu, old_freq, policy->cur);
1486 ret = cpufreq_add_dev_interface(policy);
1488 goto out_destroy_policy;
1490 cpufreq_stats_create_table(policy);
1492 write_lock_irqsave(&cpufreq_driver_lock, flags);
1493 list_add(&policy->policy_list, &cpufreq_policy_list);
1494 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
1497 * Register with the energy model before
1498 * sched_cpufreq_governor_change() is called, which will result
1499 * in rebuilding of the sched domains, which should only be done
1500 * once the energy model is properly initialized for the policy
1503 * Also, this should be called before the policy is registered
1504 * with cooling framework.
1506 if (cpufreq_driver->register_em)
1507 cpufreq_driver->register_em(policy);
1510 ret = cpufreq_init_policy(policy);
1512 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1513 __func__, cpu, ret);
1514 goto out_destroy_policy;
1517 up_write(&policy->rwsem);
1519 kobject_uevent(&policy->kobj, KOBJ_ADD);
1521 if (cpufreq_thermal_control_enabled(cpufreq_driver))
1522 policy->cdev = of_cpufreq_cooling_register(policy);
1524 pr_debug("initialization complete\n");
1529 for_each_cpu(j, policy->real_cpus)
1530 remove_cpu_dev_symlink(policy, get_cpu_device(j));
1532 up_write(&policy->rwsem);
1535 if (cpufreq_driver->offline)
1536 cpufreq_driver->offline(policy);
1539 if (cpufreq_driver->exit)
1540 cpufreq_driver->exit(policy);
1543 cpufreq_policy_free(policy);
1548 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1550 * @sif: Subsystem interface structure pointer (not used)
1552 static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
1554 struct cpufreq_policy *policy;
1555 unsigned cpu = dev->id;
1558 dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);
1560 if (cpu_online(cpu)) {
1561 ret = cpufreq_online(cpu);
1566 /* Create sysfs link on CPU registration */
1567 policy = per_cpu(cpufreq_cpu_data, cpu);
1569 add_cpu_dev_symlink(policy, cpu, dev);
1574 static int cpufreq_offline(unsigned int cpu)
1576 struct cpufreq_policy *policy;
1579 pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
1581 policy = cpufreq_cpu_get_raw(cpu);
1583 pr_debug("%s: No cpu_data found\n", __func__);
1587 down_write(&policy->rwsem);
1589 cpufreq_stop_governor(policy);
1591 cpumask_clear_cpu(cpu, policy->cpus);
1593 if (policy_is_inactive(policy)) {
1595 strncpy(policy->last_governor, policy->governor->name,
1598 policy->last_policy = policy->policy;
1599 } else if (cpu == policy->cpu) {
1600 /* Nominate new CPU */
1601 policy->cpu = cpumask_any(policy->cpus);
1604 /* Start governor again for active policy */
1605 if (!policy_is_inactive(policy)) {
1607 ret = cpufreq_start_governor(policy);
1609 pr_err("%s: Failed to start governor\n", __func__);
1615 if (cpufreq_thermal_control_enabled(cpufreq_driver)) {
1616 cpufreq_cooling_unregister(policy->cdev);
1617 policy->cdev = NULL;
1621 cpufreq_exit_governor(policy);
1624 * Perform the ->offline() during light-weight tear-down, as
1625 * that allows fast recovery when the CPU comes back.
1627 if (cpufreq_driver->offline) {
1628 cpufreq_driver->offline(policy);
1629 } else if (cpufreq_driver->exit) {
1630 cpufreq_driver->exit(policy);
1631 policy->freq_table = NULL;
1635 up_write(&policy->rwsem);
1640 * cpufreq_remove_dev - remove a CPU device
1642 * Removes the cpufreq interface for a CPU device.
1644 static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
1646 unsigned int cpu = dev->id;
1647 struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
1652 if (cpu_online(cpu))
1653 cpufreq_offline(cpu);
1655 cpumask_clear_cpu(cpu, policy->real_cpus);
1656 remove_cpu_dev_symlink(policy, dev);
1658 if (cpumask_empty(policy->real_cpus)) {
1659 /* We did light-weight exit earlier, do full tear down now */
1660 if (cpufreq_driver->offline)
1661 cpufreq_driver->exit(policy);
1663 cpufreq_policy_free(policy);
1668 * cpufreq_out_of_sync - Fix up actual and saved CPU frequency difference.
1669 * @policy: Policy managing CPUs.
1670 * @new_freq: New CPU frequency.
1672 * Adjust to the current frequency first and clean up later by either calling
1673 * cpufreq_update_policy(), or scheduling handle_update().
1675 static void cpufreq_out_of_sync(struct cpufreq_policy *policy,
1676 unsigned int new_freq)
1678 struct cpufreq_freqs freqs;
1680 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1681 policy->cur, new_freq);
1683 freqs.old = policy->cur;
1684 freqs.new = new_freq;
1686 cpufreq_freq_transition_begin(policy, &freqs);
1687 cpufreq_freq_transition_end(policy, &freqs, 0);
1690 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy *policy, bool update)
1692 unsigned int new_freq;
1694 new_freq = cpufreq_driver->get(policy->cpu);
1699 * If fast frequency switching is used with the given policy, the check
1700 * against policy->cur is pointless, so skip it in that case.
1702 if (policy->fast_switch_enabled || !has_target())
1705 if (policy->cur != new_freq) {
1706 cpufreq_out_of_sync(policy, new_freq);
1708 schedule_work(&policy->update);
1715 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1718 * This is the last known freq, without actually getting it from the driver.
1719 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1721 unsigned int cpufreq_quick_get(unsigned int cpu)
1723 struct cpufreq_policy *policy;
1724 unsigned int ret_freq = 0;
1725 unsigned long flags;
1727 read_lock_irqsave(&cpufreq_driver_lock, flags);
1729 if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) {
1730 ret_freq = cpufreq_driver->get(cpu);
1731 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1735 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
1737 policy = cpufreq_cpu_get(cpu);
1739 ret_freq = policy->cur;
1740 cpufreq_cpu_put(policy);
1745 EXPORT_SYMBOL(cpufreq_quick_get);
1748 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1751 * Just return the max possible frequency for a given CPU.
1753 unsigned int cpufreq_quick_get_max(unsigned int cpu)
1755 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1756 unsigned int ret_freq = 0;
1759 ret_freq = policy->max;
1760 cpufreq_cpu_put(policy);
1765 EXPORT_SYMBOL(cpufreq_quick_get_max);
1768 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU
1771 * The default return value is the max_freq field of cpuinfo.
1773 __weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
1775 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1776 unsigned int ret_freq = 0;
1779 ret_freq = policy->cpuinfo.max_freq;
1780 cpufreq_cpu_put(policy);
1785 EXPORT_SYMBOL(cpufreq_get_hw_max_freq);
1787 static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
1789 if (unlikely(policy_is_inactive(policy)))
1792 return cpufreq_verify_current_freq(policy, true);
1796 * cpufreq_get - get the current CPU frequency (in kHz)
1799 * Get the CPU current (static) CPU frequency
1801 unsigned int cpufreq_get(unsigned int cpu)
1803 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1804 unsigned int ret_freq = 0;
1807 down_read(&policy->rwsem);
1808 if (cpufreq_driver->get)
1809 ret_freq = __cpufreq_get(policy);
1810 up_read(&policy->rwsem);
1812 cpufreq_cpu_put(policy);
1817 EXPORT_SYMBOL(cpufreq_get);
1819 static struct subsys_interface cpufreq_interface = {
1821 .subsys = &cpu_subsys,
1822 .add_dev = cpufreq_add_dev,
1823 .remove_dev = cpufreq_remove_dev,
1827 * In case platform wants some specific frequency to be configured
1830 int cpufreq_generic_suspend(struct cpufreq_policy *policy)
1834 if (!policy->suspend_freq) {
1835 pr_debug("%s: suspend_freq not defined\n", __func__);
1839 pr_debug("%s: Setting suspend-freq: %u\n", __func__,
1840 policy->suspend_freq);
1842 ret = __cpufreq_driver_target(policy, policy->suspend_freq,
1843 CPUFREQ_RELATION_H);
1845 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1846 __func__, policy->suspend_freq, ret);
1850 EXPORT_SYMBOL(cpufreq_generic_suspend);
1853 * cpufreq_suspend() - Suspend CPUFreq governors.
1855 * Called during system wide Suspend/Hibernate cycles for suspending governors
1856 * as some platforms can't change frequency after this point in suspend cycle.
1857 * Because some of the devices (like: i2c, regulators, etc) they use for
1858 * changing frequency are suspended quickly after this point.
1860 void cpufreq_suspend(void)
1862 struct cpufreq_policy *policy;
1864 if (!cpufreq_driver)
1867 if (!has_target() && !cpufreq_driver->suspend)
1870 pr_debug("%s: Suspending Governors\n", __func__);
1872 for_each_active_policy(policy) {
1874 down_write(&policy->rwsem);
1875 cpufreq_stop_governor(policy);
1876 up_write(&policy->rwsem);
1879 if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
1880 pr_err("%s: Failed to suspend driver: %s\n", __func__,
1881 cpufreq_driver->name);
1885 cpufreq_suspended = true;
1889 * cpufreq_resume() - Resume CPUFreq governors.
1891 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1892 * are suspended with cpufreq_suspend().
1894 void cpufreq_resume(void)
1896 struct cpufreq_policy *policy;
1899 if (!cpufreq_driver)
1902 if (unlikely(!cpufreq_suspended))
1905 cpufreq_suspended = false;
1907 if (!has_target() && !cpufreq_driver->resume)
1910 pr_debug("%s: Resuming Governors\n", __func__);
1912 for_each_active_policy(policy) {
1913 if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) {
1914 pr_err("%s: Failed to resume driver: %p\n", __func__,
1916 } else if (has_target()) {
1917 down_write(&policy->rwsem);
1918 ret = cpufreq_start_governor(policy);
1919 up_write(&policy->rwsem);
1922 pr_err("%s: Failed to start governor for policy: %p\n",
1929 * cpufreq_driver_test_flags - Test cpufreq driver's flags against given ones.
1930 * @flags: Flags to test against the current cpufreq driver's flags.
1932 * Assumes that the driver is there, so callers must ensure that this is the
1935 bool cpufreq_driver_test_flags(u16 flags)
1937 return !!(cpufreq_driver->flags & flags);
1941 * cpufreq_get_current_driver - Return the current driver's name.
1943 * Return the name string of the currently registered cpufreq driver or NULL if
1946 const char *cpufreq_get_current_driver(void)
1949 return cpufreq_driver->name;
1953 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver);
1956 * cpufreq_get_driver_data - Return current driver data.
1958 * Return the private data of the currently registered cpufreq driver, or NULL
1959 * if no cpufreq driver has been registered.
1961 void *cpufreq_get_driver_data(void)
1964 return cpufreq_driver->driver_data;
1968 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data);
1970 /*********************************************************************
1971 * NOTIFIER LISTS INTERFACE *
1972 *********************************************************************/
1975 * cpufreq_register_notifier - Register a notifier with cpufreq.
1976 * @nb: notifier function to register.
1977 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER.
1979 * Add a notifier to one of two lists: either a list of notifiers that run on
1980 * clock rate changes (once before and once after every transition), or a list
1981 * of notifiers that ron on cpufreq policy changes.
1983 * This function may sleep and it has the same return values as
1984 * blocking_notifier_chain_register().
1986 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1990 if (cpufreq_disabled())
1994 case CPUFREQ_TRANSITION_NOTIFIER:
1995 mutex_lock(&cpufreq_fast_switch_lock);
1997 if (cpufreq_fast_switch_count > 0) {
1998 mutex_unlock(&cpufreq_fast_switch_lock);
2001 ret = srcu_notifier_chain_register(
2002 &cpufreq_transition_notifier_list, nb);
2004 cpufreq_fast_switch_count--;
2006 mutex_unlock(&cpufreq_fast_switch_lock);
2008 case CPUFREQ_POLICY_NOTIFIER:
2009 ret = blocking_notifier_chain_register(
2010 &cpufreq_policy_notifier_list, nb);
2018 EXPORT_SYMBOL(cpufreq_register_notifier);
2021 * cpufreq_unregister_notifier - Unregister a notifier from cpufreq.
2022 * @nb: notifier block to be unregistered.
2023 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER.
2025 * Remove a notifier from one of the cpufreq notifier lists.
2027 * This function may sleep and it has the same return values as
2028 * blocking_notifier_chain_unregister().
2030 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
2034 if (cpufreq_disabled())
2038 case CPUFREQ_TRANSITION_NOTIFIER:
2039 mutex_lock(&cpufreq_fast_switch_lock);
2041 ret = srcu_notifier_chain_unregister(
2042 &cpufreq_transition_notifier_list, nb);
2043 if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0))
2044 cpufreq_fast_switch_count++;
2046 mutex_unlock(&cpufreq_fast_switch_lock);
2048 case CPUFREQ_POLICY_NOTIFIER:
2049 ret = blocking_notifier_chain_unregister(
2050 &cpufreq_policy_notifier_list, nb);
2058 EXPORT_SYMBOL(cpufreq_unregister_notifier);
2061 /*********************************************************************
2063 *********************************************************************/
2066 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
2067 * @policy: cpufreq policy to switch the frequency for.
2068 * @target_freq: New frequency to set (may be approximate).
2070 * Carry out a fast frequency switch without sleeping.
2072 * The driver's ->fast_switch() callback invoked by this function must be
2073 * suitable for being called from within RCU-sched read-side critical sections
2074 * and it is expected to select the minimum available frequency greater than or
2075 * equal to @target_freq (CPUFREQ_RELATION_L).
2077 * This function must not be called if policy->fast_switch_enabled is unset.
2079 * Governors calling this function must guarantee that it will never be invoked
2080 * twice in parallel for the same policy and that it will never be called in
2081 * parallel with either ->target() or ->target_index() for the same policy.
2083 * Returns the actual frequency set for the CPU.
2085 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2086 * error condition, the hardware configuration must be preserved.
2088 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy,
2089 unsigned int target_freq)
2094 target_freq = clamp_val(target_freq, policy->min, policy->max);
2095 freq = cpufreq_driver->fast_switch(policy, target_freq);
2101 arch_set_freq_scale(policy->related_cpus, freq,
2102 policy->cpuinfo.max_freq);
2103 cpufreq_stats_record_transition(policy, freq);
2105 if (trace_cpu_frequency_enabled()) {
2106 for_each_cpu(cpu, policy->cpus)
2107 trace_cpu_frequency(freq, cpu);
2112 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch);
2115 * cpufreq_driver_adjust_perf - Adjust CPU performance level in one go.
2117 * @min_perf: Minimum (required) performance level (units of @capacity).
2118 * @target_perf: Target (desired) performance level (units of @capacity).
2119 * @capacity: Capacity of the target CPU.
2121 * Carry out a fast performance level switch of @cpu without sleeping.
2123 * The driver's ->adjust_perf() callback invoked by this function must be
2124 * suitable for being called from within RCU-sched read-side critical sections
2125 * and it is expected to select a suitable performance level equal to or above
2126 * @min_perf and preferably equal to or below @target_perf.
2128 * This function must not be called if policy->fast_switch_enabled is unset.
2130 * Governors calling this function must guarantee that it will never be invoked
2131 * twice in parallel for the same CPU and that it will never be called in
2132 * parallel with either ->target() or ->target_index() or ->fast_switch() for
2135 void cpufreq_driver_adjust_perf(unsigned int cpu,
2136 unsigned long min_perf,
2137 unsigned long target_perf,
2138 unsigned long capacity)
2140 cpufreq_driver->adjust_perf(cpu, min_perf, target_perf, capacity);
2144 * cpufreq_driver_has_adjust_perf - Check "direct fast switch" callback.
2146 * Return 'true' if the ->adjust_perf callback is present for the
2147 * current driver or 'false' otherwise.
2149 bool cpufreq_driver_has_adjust_perf(void)
2151 return !!cpufreq_driver->adjust_perf;
2154 /* Must set freqs->new to intermediate frequency */
2155 static int __target_intermediate(struct cpufreq_policy *policy,
2156 struct cpufreq_freqs *freqs, int index)
2160 freqs->new = cpufreq_driver->get_intermediate(policy, index);
2162 /* We don't need to switch to intermediate freq */
2166 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2167 __func__, policy->cpu, freqs->old, freqs->new);
2169 cpufreq_freq_transition_begin(policy, freqs);
2170 ret = cpufreq_driver->target_intermediate(policy, index);
2171 cpufreq_freq_transition_end(policy, freqs, ret);
2174 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2180 static int __target_index(struct cpufreq_policy *policy, int index)
2182 struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0};
2183 unsigned int restore_freq, intermediate_freq = 0;
2184 unsigned int newfreq = policy->freq_table[index].frequency;
2185 int retval = -EINVAL;
2188 if (newfreq == policy->cur)
2191 /* Save last value to restore later on errors */
2192 restore_freq = policy->cur;
2194 notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
2196 /* Handle switching to intermediate frequency */
2197 if (cpufreq_driver->get_intermediate) {
2198 retval = __target_intermediate(policy, &freqs, index);
2202 intermediate_freq = freqs.new;
2203 /* Set old freq to intermediate */
2204 if (intermediate_freq)
2205 freqs.old = freqs.new;
2208 freqs.new = newfreq;
2209 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2210 __func__, policy->cpu, freqs.old, freqs.new);
2212 cpufreq_freq_transition_begin(policy, &freqs);
2215 retval = cpufreq_driver->target_index(policy, index);
2217 pr_err("%s: Failed to change cpu frequency: %d\n", __func__,
2221 cpufreq_freq_transition_end(policy, &freqs, retval);
2224 * Failed after setting to intermediate freq? Driver should have
2225 * reverted back to initial frequency and so should we. Check
2226 * here for intermediate_freq instead of get_intermediate, in
2227 * case we haven't switched to intermediate freq at all.
2229 if (unlikely(retval && intermediate_freq)) {
2230 freqs.old = intermediate_freq;
2231 freqs.new = restore_freq;
2232 cpufreq_freq_transition_begin(policy, &freqs);
2233 cpufreq_freq_transition_end(policy, &freqs, 0);
2240 int __cpufreq_driver_target(struct cpufreq_policy *policy,
2241 unsigned int target_freq,
2242 unsigned int relation)
2244 unsigned int old_target_freq = target_freq;
2246 if (cpufreq_disabled())
2249 target_freq = __resolve_freq(policy, target_freq, relation);
2251 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2252 policy->cpu, target_freq, relation, old_target_freq);
2255 * This might look like a redundant call as we are checking it again
2256 * after finding index. But it is left intentionally for cases where
2257 * exactly same freq is called again and so we can save on few function
2260 if (target_freq == policy->cur &&
2261 !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS))
2264 if (cpufreq_driver->target) {
2266 * If the driver hasn't setup a single inefficient frequency,
2267 * it's unlikely it knows how to decode CPUFREQ_RELATION_E.
2269 if (!policy->efficiencies_available)
2270 relation &= ~CPUFREQ_RELATION_E;
2272 return cpufreq_driver->target(policy, target_freq, relation);
2275 if (!cpufreq_driver->target_index)
2278 return __target_index(policy, policy->cached_resolved_idx);
2280 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
2282 int cpufreq_driver_target(struct cpufreq_policy *policy,
2283 unsigned int target_freq,
2284 unsigned int relation)
2288 down_write(&policy->rwsem);
2290 ret = __cpufreq_driver_target(policy, target_freq, relation);
2292 up_write(&policy->rwsem);
2296 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
2298 __weak struct cpufreq_governor *cpufreq_fallback_governor(void)
2303 static int cpufreq_init_governor(struct cpufreq_policy *policy)
2307 /* Don't start any governor operations if we are entering suspend */
2308 if (cpufreq_suspended)
2311 * Governor might not be initiated here if ACPI _PPC changed
2312 * notification happened, so check it.
2314 if (!policy->governor)
2317 /* Platform doesn't want dynamic frequency switching ? */
2318 if (policy->governor->flags & CPUFREQ_GOV_DYNAMIC_SWITCHING &&
2319 cpufreq_driver->flags & CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING) {
2320 struct cpufreq_governor *gov = cpufreq_fallback_governor();
2323 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2324 policy->governor->name, gov->name);
2325 policy->governor = gov;
2331 if (!try_module_get(policy->governor->owner))
2334 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2336 if (policy->governor->init) {
2337 ret = policy->governor->init(policy);
2339 module_put(policy->governor->owner);
2344 policy->strict_target = !!(policy->governor->flags & CPUFREQ_GOV_STRICT_TARGET);
2349 static void cpufreq_exit_governor(struct cpufreq_policy *policy)
2351 if (cpufreq_suspended || !policy->governor)
2354 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2356 if (policy->governor->exit)
2357 policy->governor->exit(policy);
2359 module_put(policy->governor->owner);
2362 int cpufreq_start_governor(struct cpufreq_policy *policy)
2366 if (cpufreq_suspended)
2369 if (!policy->governor)
2372 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2374 if (cpufreq_driver->get)
2375 cpufreq_verify_current_freq(policy, false);
2377 if (policy->governor->start) {
2378 ret = policy->governor->start(policy);
2383 if (policy->governor->limits)
2384 policy->governor->limits(policy);
2389 void cpufreq_stop_governor(struct cpufreq_policy *policy)
2391 if (cpufreq_suspended || !policy->governor)
2394 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2396 if (policy->governor->stop)
2397 policy->governor->stop(policy);
2400 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
2402 if (cpufreq_suspended || !policy->governor)
2405 pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
2407 if (policy->governor->limits)
2408 policy->governor->limits(policy);
2411 int cpufreq_register_governor(struct cpufreq_governor *governor)
2418 if (cpufreq_disabled())
2421 mutex_lock(&cpufreq_governor_mutex);
2424 if (!find_governor(governor->name)) {
2426 list_add(&governor->governor_list, &cpufreq_governor_list);
2429 mutex_unlock(&cpufreq_governor_mutex);
2432 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
2434 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
2436 struct cpufreq_policy *policy;
2437 unsigned long flags;
2442 if (cpufreq_disabled())
2445 /* clear last_governor for all inactive policies */
2446 read_lock_irqsave(&cpufreq_driver_lock, flags);
2447 for_each_inactive_policy(policy) {
2448 if (!strcmp(policy->last_governor, governor->name)) {
2449 policy->governor = NULL;
2450 strcpy(policy->last_governor, "\0");
2453 read_unlock_irqrestore(&cpufreq_driver_lock, flags);
2455 mutex_lock(&cpufreq_governor_mutex);
2456 list_del(&governor->governor_list);
2457 mutex_unlock(&cpufreq_governor_mutex);
2459 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
2462 /*********************************************************************
2463 * POLICY INTERFACE *
2464 *********************************************************************/
2467 * cpufreq_get_policy - get the current cpufreq_policy
2468 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2470 * @cpu: CPU to find the policy for
2472 * Reads the current cpufreq policy.
2474 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
2476 struct cpufreq_policy *cpu_policy;
2480 cpu_policy = cpufreq_cpu_get(cpu);
2484 memcpy(policy, cpu_policy, sizeof(*policy));
2486 cpufreq_cpu_put(cpu_policy);
2489 EXPORT_SYMBOL(cpufreq_get_policy);
2492 * cpufreq_set_policy - Modify cpufreq policy parameters.
2493 * @policy: Policy object to modify.
2494 * @new_gov: Policy governor pointer.
2495 * @new_pol: Policy value (for drivers with built-in governors).
2497 * Invoke the cpufreq driver's ->verify() callback to sanity-check the frequency
2498 * limits to be set for the policy, update @policy with the verified limits
2499 * values and either invoke the driver's ->setpolicy() callback (if present) or
2500 * carry out a governor update for @policy. That is, run the current governor's
2501 * ->limits() callback (if @new_gov points to the same object as the one in
2502 * @policy) or replace the governor for @policy with @new_gov.
2504 * The cpuinfo part of @policy is not updated by this function.
2506 static int cpufreq_set_policy(struct cpufreq_policy *policy,
2507 struct cpufreq_governor *new_gov,
2508 unsigned int new_pol)
2510 struct cpufreq_policy_data new_data;
2511 struct cpufreq_governor *old_gov;
2514 memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo));
2515 new_data.freq_table = policy->freq_table;
2516 new_data.cpu = policy->cpu;
2518 * PM QoS framework collects all the requests from users and provide us
2519 * the final aggregated value here.
2521 new_data.min = freq_qos_read_value(&policy->constraints, FREQ_QOS_MIN);
2522 new_data.max = freq_qos_read_value(&policy->constraints, FREQ_QOS_MAX);
2524 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2525 new_data.cpu, new_data.min, new_data.max);
2528 * Verify that the CPU speed can be set within these limits and make sure
2531 ret = cpufreq_driver->verify(&new_data);
2536 * Resolve policy min/max to available frequencies. It ensures
2537 * no frequency resolution will neither overshoot the requested maximum
2538 * nor undershoot the requested minimum.
2540 policy->min = new_data.min;
2541 policy->max = new_data.max;
2542 policy->min = __resolve_freq(policy, policy->min, CPUFREQ_RELATION_L);
2543 policy->max = __resolve_freq(policy, policy->max, CPUFREQ_RELATION_H);
2544 trace_cpu_frequency_limits(policy);
2546 policy->cached_target_freq = UINT_MAX;
2548 pr_debug("new min and max freqs are %u - %u kHz\n",
2549 policy->min, policy->max);
2551 if (cpufreq_driver->setpolicy) {
2552 policy->policy = new_pol;
2553 pr_debug("setting range\n");
2554 return cpufreq_driver->setpolicy(policy);
2557 if (new_gov == policy->governor) {
2558 pr_debug("governor limits update\n");
2559 cpufreq_governor_limits(policy);
2563 pr_debug("governor switch\n");
2565 /* save old, working values */
2566 old_gov = policy->governor;
2567 /* end old governor */
2569 cpufreq_stop_governor(policy);
2570 cpufreq_exit_governor(policy);
2573 /* start new governor */
2574 policy->governor = new_gov;
2575 ret = cpufreq_init_governor(policy);
2577 ret = cpufreq_start_governor(policy);
2579 pr_debug("governor change\n");
2580 sched_cpufreq_governor_change(policy, old_gov);
2583 cpufreq_exit_governor(policy);
2586 /* new governor failed, so re-start old one */
2587 pr_debug("starting governor %s failed\n", policy->governor->name);
2589 policy->governor = old_gov;
2590 if (cpufreq_init_governor(policy))
2591 policy->governor = NULL;
2593 cpufreq_start_governor(policy);
2600 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2601 * @cpu: CPU to re-evaluate the policy for.
2603 * Update the current frequency for the cpufreq policy of @cpu and use
2604 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2605 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2606 * for the policy in question, among other things.
2608 void cpufreq_update_policy(unsigned int cpu)
2610 struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
2616 * BIOS might change freq behind our back
2617 * -> ask driver for current freq and notify governors about a change
2619 if (cpufreq_driver->get && has_target() &&
2620 (cpufreq_suspended || WARN_ON(!cpufreq_verify_current_freq(policy, false))))
2623 refresh_frequency_limits(policy);
2626 cpufreq_cpu_release(policy);
2628 EXPORT_SYMBOL(cpufreq_update_policy);
2631 * cpufreq_update_limits - Update policy limits for a given CPU.
2632 * @cpu: CPU to update the policy limits for.
2634 * Invoke the driver's ->update_limits callback if present or call
2635 * cpufreq_update_policy() for @cpu.
2637 void cpufreq_update_limits(unsigned int cpu)
2639 if (cpufreq_driver->update_limits)
2640 cpufreq_driver->update_limits(cpu);
2642 cpufreq_update_policy(cpu);
2644 EXPORT_SYMBOL_GPL(cpufreq_update_limits);
2646 /*********************************************************************
2648 *********************************************************************/
2649 static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state)
2653 if (!policy->freq_table)
2656 ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
2658 pr_err("%s: Policy frequency update failed\n", __func__);
2662 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
2669 int cpufreq_boost_trigger_state(int state)
2671 struct cpufreq_policy *policy;
2672 unsigned long flags;
2675 if (cpufreq_driver->boost_enabled == state)
2678 write_lock_irqsave(&cpufreq_driver_lock, flags);
2679 cpufreq_driver->boost_enabled = state;
2680 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2683 for_each_active_policy(policy) {
2684 ret = cpufreq_driver->set_boost(policy, state);
2686 goto err_reset_state;
2695 write_lock_irqsave(&cpufreq_driver_lock, flags);
2696 cpufreq_driver->boost_enabled = !state;
2697 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2699 pr_err("%s: Cannot %s BOOST\n",
2700 __func__, state ? "enable" : "disable");
2705 static bool cpufreq_boost_supported(void)
2707 return cpufreq_driver->set_boost;
2710 static int create_boost_sysfs_file(void)
2714 ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr);
2716 pr_err("%s: cannot register global BOOST sysfs file\n",
2722 static void remove_boost_sysfs_file(void)
2724 if (cpufreq_boost_supported())
2725 sysfs_remove_file(cpufreq_global_kobject, &boost.attr);
2728 int cpufreq_enable_boost_support(void)
2730 if (!cpufreq_driver)
2733 if (cpufreq_boost_supported())
2736 cpufreq_driver->set_boost = cpufreq_boost_set_sw;
2738 /* This will get removed on driver unregister */
2739 return create_boost_sysfs_file();
2741 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support);
2743 int cpufreq_boost_enabled(void)
2745 return cpufreq_driver->boost_enabled;
2747 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
2749 /*********************************************************************
2750 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2751 *********************************************************************/
2752 static enum cpuhp_state hp_online;
2754 static int cpuhp_cpufreq_online(unsigned int cpu)
2756 cpufreq_online(cpu);
2761 static int cpuhp_cpufreq_offline(unsigned int cpu)
2763 cpufreq_offline(cpu);
2769 * cpufreq_register_driver - register a CPU Frequency driver
2770 * @driver_data: A struct cpufreq_driver containing the values#
2771 * submitted by the CPU Frequency driver.
2773 * Registers a CPU Frequency driver to this core code. This code
2774 * returns zero on success, -EEXIST when another driver got here first
2775 * (and isn't unregistered in the meantime).
2778 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
2780 unsigned long flags;
2783 if (cpufreq_disabled())
2787 * The cpufreq core depends heavily on the availability of device
2788 * structure, make sure they are available before proceeding further.
2790 if (!get_cpu_device(0))
2791 return -EPROBE_DEFER;
2793 if (!driver_data || !driver_data->verify || !driver_data->init ||
2794 !(driver_data->setpolicy || driver_data->target_index ||
2795 driver_data->target) ||
2796 (driver_data->setpolicy && (driver_data->target_index ||
2797 driver_data->target)) ||
2798 (!driver_data->get_intermediate != !driver_data->target_intermediate) ||
2799 (!driver_data->online != !driver_data->offline))
2802 pr_debug("trying to register driver %s\n", driver_data->name);
2804 /* Protect against concurrent CPU online/offline. */
2807 write_lock_irqsave(&cpufreq_driver_lock, flags);
2808 if (cpufreq_driver) {
2809 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2813 cpufreq_driver = driver_data;
2814 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2817 * Mark support for the scheduler's frequency invariance engine for
2818 * drivers that implement target(), target_index() or fast_switch().
2820 if (!cpufreq_driver->setpolicy) {
2821 static_branch_enable_cpuslocked(&cpufreq_freq_invariance);
2822 pr_debug("supports frequency invariance");
2825 if (driver_data->setpolicy)
2826 driver_data->flags |= CPUFREQ_CONST_LOOPS;
2828 if (cpufreq_boost_supported()) {
2829 ret = create_boost_sysfs_file();
2831 goto err_null_driver;
2834 ret = subsys_interface_register(&cpufreq_interface);
2836 goto err_boost_unreg;
2838 if (unlikely(list_empty(&cpufreq_policy_list))) {
2839 /* if all ->init() calls failed, unregister */
2841 pr_debug("%s: No CPU initialized for driver %s\n", __func__,
2846 ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN,
2848 cpuhp_cpufreq_online,
2849 cpuhp_cpufreq_offline);
2855 pr_debug("driver %s up and running\n", driver_data->name);
2859 subsys_interface_unregister(&cpufreq_interface);
2861 remove_boost_sysfs_file();
2863 write_lock_irqsave(&cpufreq_driver_lock, flags);
2864 cpufreq_driver = NULL;
2865 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2870 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
2873 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2875 * Unregister the current CPUFreq driver. Only call this if you have
2876 * the right to do so, i.e. if you have succeeded in initialising before!
2877 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2878 * currently not initialised.
2880 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
2882 unsigned long flags;
2884 if (!cpufreq_driver || (driver != cpufreq_driver))
2887 pr_debug("unregistering driver %s\n", driver->name);
2889 /* Protect against concurrent cpu hotplug */
2891 subsys_interface_unregister(&cpufreq_interface);
2892 remove_boost_sysfs_file();
2893 static_branch_disable_cpuslocked(&cpufreq_freq_invariance);
2894 cpuhp_remove_state_nocalls_cpuslocked(hp_online);
2896 write_lock_irqsave(&cpufreq_driver_lock, flags);
2898 cpufreq_driver = NULL;
2900 write_unlock_irqrestore(&cpufreq_driver_lock, flags);
2905 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);
2907 static int __init cpufreq_core_init(void)
2909 struct cpufreq_governor *gov = cpufreq_default_governor();
2911 if (cpufreq_disabled())
2914 cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj);
2915 BUG_ON(!cpufreq_global_kobject);
2917 if (!strlen(default_governor))
2918 strncpy(default_governor, gov->name, CPUFREQ_NAME_LEN);
2922 module_param(off, int, 0444);
2923 module_param_string(default_governor, default_governor, CPUFREQ_NAME_LEN, 0444);
2924 core_initcall(cpufreq_core_init);