2 * linux/drivers/cpufreq/cpufreq.c
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
8 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
9 * Added handling for CPU hotplug
10 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
11 * Fix handling for CPU hotplug -- affected CPUs
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/cpu.h>
21 #include <linux/cpufreq.h>
22 #include <linux/cpu_cooling.h>
23 #include <linux/delay.h>
24 #include <linux/device.h>
25 #include <linux/init.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/slab.h>
30 #include <linux/suspend.h>
31 #include <linux/syscore_ops.h>
32 #include <linux/tick.h>
33 #include <trace/events/power.h>
35 static LIST_HEAD(cpufreq_policy_list
);
37 /* Macros to iterate over CPU policies */
38 #define for_each_suitable_policy(__policy, __active) \
39 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
40 if ((__active) == !policy_is_inactive(__policy))
42 #define for_each_active_policy(__policy) \
43 for_each_suitable_policy(__policy, true)
44 #define for_each_inactive_policy(__policy) \
45 for_each_suitable_policy(__policy, false)
47 #define for_each_policy(__policy) \
48 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
50 /* Iterate over governors */
51 static LIST_HEAD(cpufreq_governor_list
);
52 #define for_each_governor(__governor) \
53 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
56 * The "cpufreq driver" - the arch- or hardware-dependent low
57 * level driver of CPUFreq support, and its spinlock. This lock
58 * also protects the cpufreq_cpu_data array.
60 static struct cpufreq_driver
*cpufreq_driver
;
61 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
62 static DEFINE_RWLOCK(cpufreq_driver_lock
);
64 /* Flag to suspend/resume CPUFreq governors */
65 static bool cpufreq_suspended
;
67 static inline bool has_target(void)
69 return cpufreq_driver
->target_index
|| cpufreq_driver
->target
;
72 /* internal prototypes */
73 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
);
74 static int cpufreq_init_governor(struct cpufreq_policy
*policy
);
75 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
);
76 static int cpufreq_start_governor(struct cpufreq_policy
*policy
);
77 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
);
78 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
);
81 * Two notifier lists: the "policy" list is involved in the
82 * validation process for a new CPU frequency policy; the
83 * "transition" list for kernel code that needs to handle
84 * changes to devices when the CPU clock speed changes.
85 * The mutex locks both lists.
87 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list
);
88 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list
);
90 static int off __read_mostly
;
91 static int cpufreq_disabled(void)
95 void disable_cpufreq(void)
99 static DEFINE_MUTEX(cpufreq_governor_mutex
);
101 bool have_governor_per_policy(void)
103 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
105 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
107 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
109 if (have_governor_per_policy())
110 return &policy
->kobj
;
112 return cpufreq_global_kobject
;
114 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
116 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
122 cur_wall_time
= jiffies64_to_nsecs(get_jiffies_64());
124 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
125 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
126 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
127 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
128 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
129 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
131 idle_time
= cur_wall_time
- busy_time
;
133 *wall
= div_u64(cur_wall_time
, NSEC_PER_USEC
);
135 return div_u64(idle_time
, NSEC_PER_USEC
);
138 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
140 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
142 if (idle_time
== -1ULL)
143 return get_cpu_idle_time_jiffy(cpu
, wall
);
145 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
149 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
151 __weak
void arch_set_freq_scale(struct cpumask
*cpus
, unsigned long cur_freq
,
152 unsigned long max_freq
)
155 EXPORT_SYMBOL_GPL(arch_set_freq_scale
);
158 * This is a generic cpufreq init() routine which can be used by cpufreq
159 * drivers of SMP systems. It will do following:
160 * - validate & show freq table passed
161 * - set policies transition latency
162 * - policy->cpus with all possible CPUs
164 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
165 struct cpufreq_frequency_table
*table
,
166 unsigned int transition_latency
)
168 policy
->freq_table
= table
;
169 policy
->cpuinfo
.transition_latency
= transition_latency
;
172 * The driver only supports the SMP configuration where all processors
173 * share the clock and voltage and clock.
175 cpumask_setall(policy
->cpus
);
179 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
181 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
183 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
185 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
187 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
189 unsigned int cpufreq_generic_get(unsigned int cpu
)
191 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
193 if (!policy
|| IS_ERR(policy
->clk
)) {
194 pr_err("%s: No %s associated to cpu: %d\n",
195 __func__
, policy
? "clk" : "policy", cpu
);
199 return clk_get_rate(policy
->clk
) / 1000;
201 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
204 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
205 * @cpu: CPU to find the policy for.
207 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
208 * the kobject reference counter of that policy. Return a valid policy on
209 * success or NULL on failure.
211 * The policy returned by this function has to be released with the help of
212 * cpufreq_cpu_put() to balance its kobject reference counter properly.
214 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
216 struct cpufreq_policy
*policy
= NULL
;
219 if (WARN_ON(cpu
>= nr_cpu_ids
))
222 /* get the cpufreq driver */
223 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
225 if (cpufreq_driver
) {
227 policy
= cpufreq_cpu_get_raw(cpu
);
229 kobject_get(&policy
->kobj
);
232 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
236 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
239 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
240 * @policy: cpufreq policy returned by cpufreq_cpu_get().
242 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
244 kobject_put(&policy
->kobj
);
246 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
249 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
250 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
252 void cpufreq_cpu_release(struct cpufreq_policy
*policy
)
254 if (WARN_ON(!policy
))
257 lockdep_assert_held(&policy
->rwsem
);
259 up_write(&policy
->rwsem
);
261 cpufreq_cpu_put(policy
);
265 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
266 * @cpu: CPU to find the policy for.
268 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
269 * if the policy returned by it is not NULL, acquire its rwsem for writing.
270 * Return the policy if it is active or release it and return NULL otherwise.
272 * The policy returned by this function has to be released with the help of
273 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
276 struct cpufreq_policy
*cpufreq_cpu_acquire(unsigned int cpu
)
278 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
283 down_write(&policy
->rwsem
);
285 if (policy_is_inactive(policy
)) {
286 cpufreq_cpu_release(policy
);
293 /*********************************************************************
294 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
295 *********************************************************************/
298 * adjust_jiffies - adjust the system "loops_per_jiffy"
300 * This function alters the system "loops_per_jiffy" for the clock
301 * speed change. Note that loops_per_jiffy cannot be updated on SMP
302 * systems as each CPU might be scaled differently. So, use the arch
303 * per-CPU loops_per_jiffy value wherever possible.
305 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
308 static unsigned long l_p_j_ref
;
309 static unsigned int l_p_j_ref_freq
;
311 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
314 if (!l_p_j_ref_freq
) {
315 l_p_j_ref
= loops_per_jiffy
;
316 l_p_j_ref_freq
= ci
->old
;
317 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
318 l_p_j_ref
, l_p_j_ref_freq
);
320 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
321 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
323 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
324 loops_per_jiffy
, ci
->new);
330 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
331 * @policy: cpufreq policy to enable fast frequency switching for.
332 * @freqs: contain details of the frequency update.
333 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
335 * This function calls the transition notifiers and the "adjust_jiffies"
336 * function. It is called twice on all CPU frequency changes that have
339 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
340 struct cpufreq_freqs
*freqs
,
345 BUG_ON(irqs_disabled());
347 if (cpufreq_disabled())
350 freqs
->policy
= policy
;
351 freqs
->flags
= cpufreq_driver
->flags
;
352 pr_debug("notification %u of frequency transition to %u kHz\n",
356 case CPUFREQ_PRECHANGE
:
358 * Detect if the driver reported a value as "old frequency"
359 * which is not equal to what the cpufreq core thinks is
362 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
363 if (policy
->cur
&& (policy
->cur
!= freqs
->old
)) {
364 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
365 freqs
->old
, policy
->cur
);
366 freqs
->old
= policy
->cur
;
370 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
371 CPUFREQ_PRECHANGE
, freqs
);
373 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
376 case CPUFREQ_POSTCHANGE
:
377 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
378 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs
->new,
379 cpumask_pr_args(policy
->cpus
));
381 for_each_cpu(cpu
, policy
->cpus
)
382 trace_cpu_frequency(freqs
->new, cpu
);
384 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
385 CPUFREQ_POSTCHANGE
, freqs
);
387 cpufreq_stats_record_transition(policy
, freqs
->new);
388 policy
->cur
= freqs
->new;
392 /* Do post notifications when there are chances that transition has failed */
393 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
394 struct cpufreq_freqs
*freqs
, int transition_failed
)
396 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
397 if (!transition_failed
)
400 swap(freqs
->old
, freqs
->new);
401 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
402 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
405 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
406 struct cpufreq_freqs
*freqs
)
410 * Catch double invocations of _begin() which lead to self-deadlock.
411 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
412 * doesn't invoke _begin() on their behalf, and hence the chances of
413 * double invocations are very low. Moreover, there are scenarios
414 * where these checks can emit false-positive warnings in these
415 * drivers; so we avoid that by skipping them altogether.
417 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
418 && current
== policy
->transition_task
);
421 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
423 spin_lock(&policy
->transition_lock
);
425 if (unlikely(policy
->transition_ongoing
)) {
426 spin_unlock(&policy
->transition_lock
);
430 policy
->transition_ongoing
= true;
431 policy
->transition_task
= current
;
433 spin_unlock(&policy
->transition_lock
);
435 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
437 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
439 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
440 struct cpufreq_freqs
*freqs
, int transition_failed
)
442 if (WARN_ON(!policy
->transition_ongoing
))
445 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
447 policy
->transition_ongoing
= false;
448 policy
->transition_task
= NULL
;
450 wake_up(&policy
->transition_wait
);
452 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
455 * Fast frequency switching status count. Positive means "enabled", negative
456 * means "disabled" and 0 means "not decided yet".
458 static int cpufreq_fast_switch_count
;
459 static DEFINE_MUTEX(cpufreq_fast_switch_lock
);
461 static void cpufreq_list_transition_notifiers(void)
463 struct notifier_block
*nb
;
465 pr_info("Registered transition notifiers:\n");
467 mutex_lock(&cpufreq_transition_notifier_list
.mutex
);
469 for (nb
= cpufreq_transition_notifier_list
.head
; nb
; nb
= nb
->next
)
470 pr_info("%pS\n", nb
->notifier_call
);
472 mutex_unlock(&cpufreq_transition_notifier_list
.mutex
);
476 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
477 * @policy: cpufreq policy to enable fast frequency switching for.
479 * Try to enable fast frequency switching for @policy.
481 * The attempt will fail if there is at least one transition notifier registered
482 * at this point, as fast frequency switching is quite fundamentally at odds
483 * with transition notifiers. Thus if successful, it will make registration of
484 * transition notifiers fail going forward.
486 void cpufreq_enable_fast_switch(struct cpufreq_policy
*policy
)
488 lockdep_assert_held(&policy
->rwsem
);
490 if (!policy
->fast_switch_possible
)
493 mutex_lock(&cpufreq_fast_switch_lock
);
494 if (cpufreq_fast_switch_count
>= 0) {
495 cpufreq_fast_switch_count
++;
496 policy
->fast_switch_enabled
= true;
498 pr_warn("CPU%u: Fast frequency switching not enabled\n",
500 cpufreq_list_transition_notifiers();
502 mutex_unlock(&cpufreq_fast_switch_lock
);
504 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch
);
507 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
508 * @policy: cpufreq policy to disable fast frequency switching for.
510 void cpufreq_disable_fast_switch(struct cpufreq_policy
*policy
)
512 mutex_lock(&cpufreq_fast_switch_lock
);
513 if (policy
->fast_switch_enabled
) {
514 policy
->fast_switch_enabled
= false;
515 if (!WARN_ON(cpufreq_fast_switch_count
<= 0))
516 cpufreq_fast_switch_count
--;
518 mutex_unlock(&cpufreq_fast_switch_lock
);
520 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch
);
523 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
525 * @target_freq: target frequency to resolve.
527 * The target to driver frequency mapping is cached in the policy.
529 * Return: Lowest driver-supported frequency greater than or equal to the
530 * given target_freq, subject to policy (min/max) and driver limitations.
532 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy
*policy
,
533 unsigned int target_freq
)
535 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
536 policy
->cached_target_freq
= target_freq
;
538 if (cpufreq_driver
->target_index
) {
541 idx
= cpufreq_frequency_table_target(policy
, target_freq
,
543 policy
->cached_resolved_idx
= idx
;
544 return policy
->freq_table
[idx
].frequency
;
547 if (cpufreq_driver
->resolve_freq
)
548 return cpufreq_driver
->resolve_freq(policy
, target_freq
);
552 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq
);
554 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy
*policy
)
556 unsigned int latency
;
558 if (policy
->transition_delay_us
)
559 return policy
->transition_delay_us
;
561 latency
= policy
->cpuinfo
.transition_latency
/ NSEC_PER_USEC
;
564 * For platforms that can change the frequency very fast (< 10
565 * us), the above formula gives a decent transition delay. But
566 * for platforms where transition_latency is in milliseconds, it
567 * ends up giving unrealistic values.
569 * Cap the default transition delay to 10 ms, which seems to be
570 * a reasonable amount of time after which we should reevaluate
573 return min(latency
* LATENCY_MULTIPLIER
, (unsigned int)10000);
576 return LATENCY_MULTIPLIER
;
578 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us
);
580 /*********************************************************************
582 *********************************************************************/
583 static ssize_t
show_boost(struct kobject
*kobj
,
584 struct kobj_attribute
*attr
, char *buf
)
586 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
589 static ssize_t
store_boost(struct kobject
*kobj
, struct kobj_attribute
*attr
,
590 const char *buf
, size_t count
)
594 ret
= sscanf(buf
, "%d", &enable
);
595 if (ret
!= 1 || enable
< 0 || enable
> 1)
598 if (cpufreq_boost_trigger_state(enable
)) {
599 pr_err("%s: Cannot %s BOOST!\n",
600 __func__
, enable
? "enable" : "disable");
604 pr_debug("%s: cpufreq BOOST %s\n",
605 __func__
, enable
? "enabled" : "disabled");
609 define_one_global_rw(boost
);
611 static struct cpufreq_governor
*find_governor(const char *str_governor
)
613 struct cpufreq_governor
*t
;
616 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
622 static int cpufreq_parse_policy(char *str_governor
,
623 struct cpufreq_policy
*policy
)
625 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
626 policy
->policy
= CPUFREQ_POLICY_PERFORMANCE
;
629 if (!strncasecmp(str_governor
, "powersave", CPUFREQ_NAME_LEN
)) {
630 policy
->policy
= CPUFREQ_POLICY_POWERSAVE
;
637 * cpufreq_parse_governor - parse a governor string only for !setpolicy
639 static int cpufreq_parse_governor(char *str_governor
,
640 struct cpufreq_policy
*policy
)
642 struct cpufreq_governor
*t
;
644 mutex_lock(&cpufreq_governor_mutex
);
646 t
= find_governor(str_governor
);
650 mutex_unlock(&cpufreq_governor_mutex
);
652 ret
= request_module("cpufreq_%s", str_governor
);
656 mutex_lock(&cpufreq_governor_mutex
);
658 t
= find_governor(str_governor
);
660 if (t
&& !try_module_get(t
->owner
))
663 mutex_unlock(&cpufreq_governor_mutex
);
666 policy
->governor
= t
;
674 * cpufreq_per_cpu_attr_read() / show_##file_name() -
675 * print out cpufreq information
677 * Write out information from cpufreq_driver->policy[cpu]; object must be
681 #define show_one(file_name, object) \
682 static ssize_t show_##file_name \
683 (struct cpufreq_policy *policy, char *buf) \
685 return sprintf(buf, "%u\n", policy->object); \
688 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
689 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
690 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
691 show_one(scaling_min_freq
, min
);
692 show_one(scaling_max_freq
, max
);
694 __weak
unsigned int arch_freq_get_on_cpu(int cpu
)
699 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
704 freq
= arch_freq_get_on_cpu(policy
->cpu
);
706 ret
= sprintf(buf
, "%u\n", freq
);
707 else if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&&
709 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
711 ret
= sprintf(buf
, "%u\n", policy
->cur
);
716 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
718 #define store_one(file_name, object) \
719 static ssize_t store_##file_name \
720 (struct cpufreq_policy *policy, const char *buf, size_t count) \
723 struct cpufreq_policy new_policy; \
725 memcpy(&new_policy, policy, sizeof(*policy)); \
726 new_policy.min = policy->user_policy.min; \
727 new_policy.max = policy->user_policy.max; \
729 ret = sscanf(buf, "%u", &new_policy.object); \
733 temp = new_policy.object; \
734 ret = cpufreq_set_policy(policy, &new_policy); \
736 policy->user_policy.object = temp; \
738 return ret ? ret : count; \
741 store_one(scaling_min_freq
, min
);
742 store_one(scaling_max_freq
, max
);
745 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
747 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
750 unsigned int cur_freq
= __cpufreq_get(policy
);
753 return sprintf(buf
, "%u\n", cur_freq
);
755 return sprintf(buf
, "<unknown>\n");
759 * show_scaling_governor - show the current policy for the specified CPU
761 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
763 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
764 return sprintf(buf
, "powersave\n");
765 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
766 return sprintf(buf
, "performance\n");
767 else if (policy
->governor
)
768 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
769 policy
->governor
->name
);
774 * store_scaling_governor - store policy for the specified CPU
776 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
777 const char *buf
, size_t count
)
780 char str_governor
[16];
781 struct cpufreq_policy new_policy
;
783 memcpy(&new_policy
, policy
, sizeof(*policy
));
785 ret
= sscanf(buf
, "%15s", str_governor
);
789 if (cpufreq_driver
->setpolicy
) {
790 if (cpufreq_parse_policy(str_governor
, &new_policy
))
793 if (cpufreq_parse_governor(str_governor
, &new_policy
))
797 ret
= cpufreq_set_policy(policy
, &new_policy
);
799 if (new_policy
.governor
)
800 module_put(new_policy
.governor
->owner
);
802 return ret
? ret
: count
;
806 * show_scaling_driver - show the cpufreq driver currently loaded
808 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
810 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
814 * show_scaling_available_governors - show the available CPUfreq governors
816 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
820 struct cpufreq_governor
*t
;
823 i
+= sprintf(buf
, "performance powersave");
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
);
834 i
+= sprintf(&buf
[i
], "\n");
838 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
843 for_each_cpu(cpu
, mask
) {
845 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
846 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
847 if (i
>= (PAGE_SIZE
- 5))
850 i
+= sprintf(&buf
[i
], "\n");
853 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
856 * show_related_cpus - show the CPUs affected by each transition even if
857 * hw coordination is in use
859 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
861 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
865 * show_affected_cpus - show the CPUs affected by each transition
867 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
869 return cpufreq_show_cpus(policy
->cpus
, buf
);
872 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
873 const char *buf
, size_t count
)
875 unsigned int freq
= 0;
878 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
881 ret
= sscanf(buf
, "%u", &freq
);
885 policy
->governor
->store_setspeed(policy
, freq
);
890 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
892 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
893 return sprintf(buf
, "<unsupported>\n");
895 return policy
->governor
->show_setspeed(policy
, buf
);
899 * show_bios_limit - show the current cpufreq HW/BIOS limitation
901 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
905 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
907 return sprintf(buf
, "%u\n", limit
);
908 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
911 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
912 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
913 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
914 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
915 cpufreq_freq_attr_ro(scaling_available_governors
);
916 cpufreq_freq_attr_ro(scaling_driver
);
917 cpufreq_freq_attr_ro(scaling_cur_freq
);
918 cpufreq_freq_attr_ro(bios_limit
);
919 cpufreq_freq_attr_ro(related_cpus
);
920 cpufreq_freq_attr_ro(affected_cpus
);
921 cpufreq_freq_attr_rw(scaling_min_freq
);
922 cpufreq_freq_attr_rw(scaling_max_freq
);
923 cpufreq_freq_attr_rw(scaling_governor
);
924 cpufreq_freq_attr_rw(scaling_setspeed
);
926 static struct attribute
*default_attrs
[] = {
927 &cpuinfo_min_freq
.attr
,
928 &cpuinfo_max_freq
.attr
,
929 &cpuinfo_transition_latency
.attr
,
930 &scaling_min_freq
.attr
,
931 &scaling_max_freq
.attr
,
934 &scaling_governor
.attr
,
935 &scaling_driver
.attr
,
936 &scaling_available_governors
.attr
,
937 &scaling_setspeed
.attr
,
941 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
942 #define to_attr(a) container_of(a, struct freq_attr, attr)
944 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
946 struct cpufreq_policy
*policy
= to_policy(kobj
);
947 struct freq_attr
*fattr
= to_attr(attr
);
950 down_read(&policy
->rwsem
);
951 ret
= fattr
->show(policy
, buf
);
952 up_read(&policy
->rwsem
);
957 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
958 const char *buf
, size_t count
)
960 struct cpufreq_policy
*policy
= to_policy(kobj
);
961 struct freq_attr
*fattr
= to_attr(attr
);
962 ssize_t ret
= -EINVAL
;
965 * cpus_read_trylock() is used here to work around a circular lock
966 * dependency problem with respect to the cpufreq_register_driver().
968 if (!cpus_read_trylock())
971 if (cpu_online(policy
->cpu
)) {
972 down_write(&policy
->rwsem
);
973 ret
= fattr
->store(policy
, buf
, count
);
974 up_write(&policy
->rwsem
);
982 static void cpufreq_sysfs_release(struct kobject
*kobj
)
984 struct cpufreq_policy
*policy
= to_policy(kobj
);
985 pr_debug("last reference is dropped\n");
986 complete(&policy
->kobj_unregister
);
989 static const struct sysfs_ops sysfs_ops
= {
994 static struct kobj_type ktype_cpufreq
= {
995 .sysfs_ops
= &sysfs_ops
,
996 .default_attrs
= default_attrs
,
997 .release
= cpufreq_sysfs_release
,
1000 static void add_cpu_dev_symlink(struct cpufreq_policy
*policy
, unsigned int cpu
)
1002 struct device
*dev
= get_cpu_device(cpu
);
1007 if (cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
))
1010 dev_dbg(dev
, "%s: Adding symlink\n", __func__
);
1011 if (sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq"))
1012 dev_err(dev
, "cpufreq symlink creation failed\n");
1015 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
,
1018 dev_dbg(dev
, "%s: Removing symlink\n", __func__
);
1019 sysfs_remove_link(&dev
->kobj
, "cpufreq");
1022 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
1024 struct freq_attr
**drv_attr
;
1027 /* set up files for this cpu device */
1028 drv_attr
= cpufreq_driver
->attr
;
1029 while (drv_attr
&& *drv_attr
) {
1030 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
1035 if (cpufreq_driver
->get
) {
1036 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
1041 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
1045 if (cpufreq_driver
->bios_limit
) {
1046 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
1054 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
1059 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
1061 struct cpufreq_governor
*gov
= NULL
, *def_gov
= NULL
;
1062 struct cpufreq_policy new_policy
;
1064 memcpy(&new_policy
, policy
, sizeof(*policy
));
1066 def_gov
= cpufreq_default_governor();
1070 * Update governor of new_policy to the governor used before
1073 gov
= find_governor(policy
->last_governor
);
1075 pr_debug("Restoring governor %s for cpu %d\n",
1076 policy
->governor
->name
, policy
->cpu
);
1082 new_policy
.governor
= gov
;
1084 /* Use the default policy if there is no last_policy. */
1085 if (policy
->last_policy
) {
1086 new_policy
.policy
= policy
->last_policy
;
1090 cpufreq_parse_policy(def_gov
->name
, &new_policy
);
1094 return cpufreq_set_policy(policy
, &new_policy
);
1097 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1101 /* Has this CPU been taken care of already? */
1102 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1105 down_write(&policy
->rwsem
);
1107 cpufreq_stop_governor(policy
);
1109 cpumask_set_cpu(cpu
, policy
->cpus
);
1112 ret
= cpufreq_start_governor(policy
);
1114 pr_err("%s: Failed to start governor\n", __func__
);
1116 up_write(&policy
->rwsem
);
1120 static void handle_update(struct work_struct
*work
)
1122 struct cpufreq_policy
*policy
=
1123 container_of(work
, struct cpufreq_policy
, update
);
1124 unsigned int cpu
= policy
->cpu
;
1125 pr_debug("handle_update for cpu %u called\n", cpu
);
1126 cpufreq_update_policy(cpu
);
1129 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1131 struct cpufreq_policy
*policy
;
1134 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1138 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1139 goto err_free_policy
;
1141 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1142 goto err_free_cpumask
;
1144 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1145 goto err_free_rcpumask
;
1147 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
1148 cpufreq_global_kobject
, "policy%u", cpu
);
1150 pr_err("%s: failed to init policy->kobj: %d\n", __func__
, ret
);
1152 * The entire policy object will be freed below, but the extra
1153 * memory allocated for the kobject name needs to be freed by
1154 * releasing the kobject.
1156 kobject_put(&policy
->kobj
);
1157 goto err_free_real_cpus
;
1160 INIT_LIST_HEAD(&policy
->policy_list
);
1161 init_rwsem(&policy
->rwsem
);
1162 spin_lock_init(&policy
->transition_lock
);
1163 init_waitqueue_head(&policy
->transition_wait
);
1164 init_completion(&policy
->kobj_unregister
);
1165 INIT_WORK(&policy
->update
, handle_update
);
1171 free_cpumask_var(policy
->real_cpus
);
1173 free_cpumask_var(policy
->related_cpus
);
1175 free_cpumask_var(policy
->cpus
);
1182 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
)
1184 struct kobject
*kobj
;
1185 struct completion
*cmp
;
1187 down_write(&policy
->rwsem
);
1188 cpufreq_stats_free_table(policy
);
1189 kobj
= &policy
->kobj
;
1190 cmp
= &policy
->kobj_unregister
;
1191 up_write(&policy
->rwsem
);
1195 * We need to make sure that the underlying kobj is
1196 * actually not referenced anymore by anybody before we
1197 * proceed with unloading.
1199 pr_debug("waiting for dropping of refcount\n");
1200 wait_for_completion(cmp
);
1201 pr_debug("wait complete\n");
1204 static void cpufreq_policy_free(struct cpufreq_policy
*policy
)
1206 unsigned long flags
;
1209 /* Remove policy from list */
1210 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1211 list_del(&policy
->policy_list
);
1213 for_each_cpu(cpu
, policy
->related_cpus
)
1214 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1215 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1217 cpufreq_policy_put_kobj(policy
);
1218 free_cpumask_var(policy
->real_cpus
);
1219 free_cpumask_var(policy
->related_cpus
);
1220 free_cpumask_var(policy
->cpus
);
1224 static int cpufreq_online(unsigned int cpu
)
1226 struct cpufreq_policy
*policy
;
1228 unsigned long flags
;
1232 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1234 /* Check if this CPU already has a policy to manage it */
1235 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1237 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1238 if (!policy_is_inactive(policy
))
1239 return cpufreq_add_policy_cpu(policy
, cpu
);
1241 /* This is the only online CPU for the policy. Start over. */
1243 down_write(&policy
->rwsem
);
1245 policy
->governor
= NULL
;
1246 up_write(&policy
->rwsem
);
1249 policy
= cpufreq_policy_alloc(cpu
);
1254 if (!new_policy
&& cpufreq_driver
->online
) {
1255 ret
= cpufreq_driver
->online(policy
);
1257 pr_debug("%s: %d: initialization failed\n", __func__
,
1259 goto out_exit_policy
;
1262 /* Recover policy->cpus using related_cpus */
1263 cpumask_copy(policy
->cpus
, policy
->related_cpus
);
1265 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1268 * Call driver. From then on the cpufreq must be able
1269 * to accept all calls to ->verify and ->setpolicy for this CPU.
1271 ret
= cpufreq_driver
->init(policy
);
1273 pr_debug("%s: %d: initialization failed\n", __func__
,
1275 goto out_free_policy
;
1278 ret
= cpufreq_table_validate_and_sort(policy
);
1280 goto out_exit_policy
;
1282 /* related_cpus should at least include policy->cpus. */
1283 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1286 down_write(&policy
->rwsem
);
1288 * affected cpus must always be the one, which are online. We aren't
1289 * managing offline cpus here.
1291 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1294 policy
->user_policy
.min
= policy
->min
;
1295 policy
->user_policy
.max
= policy
->max
;
1297 for_each_cpu(j
, policy
->related_cpus
) {
1298 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1299 add_cpu_dev_symlink(policy
, j
);
1302 policy
->min
= policy
->user_policy
.min
;
1303 policy
->max
= policy
->user_policy
.max
;
1306 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
1307 policy
->cur
= cpufreq_driver
->get(policy
->cpu
);
1309 pr_err("%s: ->get() failed\n", __func__
);
1310 goto out_destroy_policy
;
1315 * Sometimes boot loaders set CPU frequency to a value outside of
1316 * frequency table present with cpufreq core. In such cases CPU might be
1317 * unstable if it has to run on that frequency for long duration of time
1318 * and so its better to set it to a frequency which is specified in
1319 * freq-table. This also makes cpufreq stats inconsistent as
1320 * cpufreq-stats would fail to register because current frequency of CPU
1321 * isn't found in freq-table.
1323 * Because we don't want this change to effect boot process badly, we go
1324 * for the next freq which is >= policy->cur ('cur' must be set by now,
1325 * otherwise we will end up setting freq to lowest of the table as 'cur'
1326 * is initialized to zero).
1328 * We are passing target-freq as "policy->cur - 1" otherwise
1329 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1330 * equal to target-freq.
1332 if ((cpufreq_driver
->flags
& CPUFREQ_NEED_INITIAL_FREQ_CHECK
)
1334 /* Are we running at unknown frequency ? */
1335 ret
= cpufreq_frequency_table_get_index(policy
, policy
->cur
);
1336 if (ret
== -EINVAL
) {
1337 /* Warn user and fix it */
1338 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1339 __func__
, policy
->cpu
, policy
->cur
);
1340 ret
= __cpufreq_driver_target(policy
, policy
->cur
- 1,
1341 CPUFREQ_RELATION_L
);
1344 * Reaching here after boot in a few seconds may not
1345 * mean that system will remain stable at "unknown"
1346 * frequency for longer duration. Hence, a BUG_ON().
1349 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1350 __func__
, policy
->cpu
, policy
->cur
);
1355 ret
= cpufreq_add_dev_interface(policy
);
1357 goto out_destroy_policy
;
1359 cpufreq_stats_create_table(policy
);
1361 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1362 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1363 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1366 ret
= cpufreq_init_policy(policy
);
1368 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1369 __func__
, cpu
, ret
);
1370 goto out_destroy_policy
;
1373 up_write(&policy
->rwsem
);
1375 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1377 /* Callback for handling stuff after policy is ready */
1378 if (cpufreq_driver
->ready
)
1379 cpufreq_driver
->ready(policy
);
1381 if (IS_ENABLED(CONFIG_CPU_THERMAL
) &&
1382 cpufreq_driver
->flags
& CPUFREQ_IS_COOLING_DEV
)
1383 policy
->cdev
= of_cpufreq_cooling_register(policy
);
1385 pr_debug("initialization complete\n");
1390 for_each_cpu(j
, policy
->real_cpus
)
1391 remove_cpu_dev_symlink(policy
, get_cpu_device(j
));
1393 up_write(&policy
->rwsem
);
1396 if (cpufreq_driver
->exit
)
1397 cpufreq_driver
->exit(policy
);
1400 cpufreq_policy_free(policy
);
1405 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1407 * @sif: Subsystem interface structure pointer (not used)
1409 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1411 struct cpufreq_policy
*policy
;
1412 unsigned cpu
= dev
->id
;
1415 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1417 if (cpu_online(cpu
)) {
1418 ret
= cpufreq_online(cpu
);
1423 /* Create sysfs link on CPU registration */
1424 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1426 add_cpu_dev_symlink(policy
, cpu
);
1431 static int cpufreq_offline(unsigned int cpu
)
1433 struct cpufreq_policy
*policy
;
1436 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1438 policy
= cpufreq_cpu_get_raw(cpu
);
1440 pr_debug("%s: No cpu_data found\n", __func__
);
1444 down_write(&policy
->rwsem
);
1446 cpufreq_stop_governor(policy
);
1448 cpumask_clear_cpu(cpu
, policy
->cpus
);
1450 if (policy_is_inactive(policy
)) {
1452 strncpy(policy
->last_governor
, policy
->governor
->name
,
1455 policy
->last_policy
= policy
->policy
;
1456 } else if (cpu
== policy
->cpu
) {
1457 /* Nominate new CPU */
1458 policy
->cpu
= cpumask_any(policy
->cpus
);
1461 /* Start governor again for active policy */
1462 if (!policy_is_inactive(policy
)) {
1464 ret
= cpufreq_start_governor(policy
);
1466 pr_err("%s: Failed to start governor\n", __func__
);
1472 if (IS_ENABLED(CONFIG_CPU_THERMAL
) &&
1473 cpufreq_driver
->flags
& CPUFREQ_IS_COOLING_DEV
) {
1474 cpufreq_cooling_unregister(policy
->cdev
);
1475 policy
->cdev
= NULL
;
1478 if (cpufreq_driver
->stop_cpu
)
1479 cpufreq_driver
->stop_cpu(policy
);
1482 cpufreq_exit_governor(policy
);
1485 * Perform the ->offline() during light-weight tear-down, as
1486 * that allows fast recovery when the CPU comes back.
1488 if (cpufreq_driver
->offline
) {
1489 cpufreq_driver
->offline(policy
);
1490 } else if (cpufreq_driver
->exit
) {
1491 cpufreq_driver
->exit(policy
);
1492 policy
->freq_table
= NULL
;
1496 up_write(&policy
->rwsem
);
1501 * cpufreq_remove_dev - remove a CPU device
1503 * Removes the cpufreq interface for a CPU device.
1505 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1507 unsigned int cpu
= dev
->id
;
1508 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1513 if (cpu_online(cpu
))
1514 cpufreq_offline(cpu
);
1516 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1517 remove_cpu_dev_symlink(policy
, dev
);
1519 if (cpumask_empty(policy
->real_cpus
)) {
1520 /* We did light-weight exit earlier, do full tear down now */
1521 if (cpufreq_driver
->offline
)
1522 cpufreq_driver
->exit(policy
);
1524 cpufreq_policy_free(policy
);
1529 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1531 * @policy: policy managing CPUs
1532 * @new_freq: CPU frequency the CPU actually runs at
1534 * We adjust to current frequency first, and need to clean up later.
1535 * So either call to cpufreq_update_policy() or schedule handle_update()).
1537 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1538 unsigned int new_freq
)
1540 struct cpufreq_freqs freqs
;
1542 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1543 policy
->cur
, new_freq
);
1545 freqs
.old
= policy
->cur
;
1546 freqs
.new = new_freq
;
1548 cpufreq_freq_transition_begin(policy
, &freqs
);
1549 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1553 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1556 * This is the last known freq, without actually getting it from the driver.
1557 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1559 unsigned int cpufreq_quick_get(unsigned int cpu
)
1561 struct cpufreq_policy
*policy
;
1562 unsigned int ret_freq
= 0;
1563 unsigned long flags
;
1565 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1567 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
) {
1568 ret_freq
= cpufreq_driver
->get(cpu
);
1569 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1573 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1575 policy
= cpufreq_cpu_get(cpu
);
1577 ret_freq
= policy
->cur
;
1578 cpufreq_cpu_put(policy
);
1583 EXPORT_SYMBOL(cpufreq_quick_get
);
1586 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1589 * Just return the max possible frequency for a given CPU.
1591 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1593 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1594 unsigned int ret_freq
= 0;
1597 ret_freq
= policy
->max
;
1598 cpufreq_cpu_put(policy
);
1603 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1605 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1607 unsigned int ret_freq
= 0;
1609 if (unlikely(policy_is_inactive(policy
)))
1612 ret_freq
= cpufreq_driver
->get(policy
->cpu
);
1615 * If fast frequency switching is used with the given policy, the check
1616 * against policy->cur is pointless, so skip it in that case too.
1618 if (policy
->fast_switch_enabled
)
1621 if (ret_freq
&& policy
->cur
&&
1622 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1623 /* verify no discrepancy between actual and
1624 saved value exists */
1625 if (unlikely(ret_freq
!= policy
->cur
)) {
1626 cpufreq_out_of_sync(policy
, ret_freq
);
1627 schedule_work(&policy
->update
);
1635 * cpufreq_get - get the current CPU frequency (in kHz)
1638 * Get the CPU current (static) CPU frequency
1640 unsigned int cpufreq_get(unsigned int cpu
)
1642 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1643 unsigned int ret_freq
= 0;
1646 down_read(&policy
->rwsem
);
1647 if (cpufreq_driver
->get
)
1648 ret_freq
= __cpufreq_get(policy
);
1649 up_read(&policy
->rwsem
);
1651 cpufreq_cpu_put(policy
);
1656 EXPORT_SYMBOL(cpufreq_get
);
1658 static unsigned int cpufreq_update_current_freq(struct cpufreq_policy
*policy
)
1660 unsigned int new_freq
;
1662 new_freq
= cpufreq_driver
->get(policy
->cpu
);
1667 pr_debug("cpufreq: Driver did not initialize current freq\n");
1668 policy
->cur
= new_freq
;
1669 } else if (policy
->cur
!= new_freq
&& has_target()) {
1670 cpufreq_out_of_sync(policy
, new_freq
);
1676 static struct subsys_interface cpufreq_interface
= {
1678 .subsys
= &cpu_subsys
,
1679 .add_dev
= cpufreq_add_dev
,
1680 .remove_dev
= cpufreq_remove_dev
,
1684 * In case platform wants some specific frequency to be configured
1687 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1691 if (!policy
->suspend_freq
) {
1692 pr_debug("%s: suspend_freq not defined\n", __func__
);
1696 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1697 policy
->suspend_freq
);
1699 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1700 CPUFREQ_RELATION_H
);
1702 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1703 __func__
, policy
->suspend_freq
, ret
);
1707 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1710 * cpufreq_suspend() - Suspend CPUFreq governors
1712 * Called during system wide Suspend/Hibernate cycles for suspending governors
1713 * as some platforms can't change frequency after this point in suspend cycle.
1714 * Because some of the devices (like: i2c, regulators, etc) they use for
1715 * changing frequency are suspended quickly after this point.
1717 void cpufreq_suspend(void)
1719 struct cpufreq_policy
*policy
;
1721 if (!cpufreq_driver
)
1724 if (!has_target() && !cpufreq_driver
->suspend
)
1727 pr_debug("%s: Suspending Governors\n", __func__
);
1729 for_each_active_policy(policy
) {
1731 down_write(&policy
->rwsem
);
1732 cpufreq_stop_governor(policy
);
1733 up_write(&policy
->rwsem
);
1736 if (cpufreq_driver
->suspend
&& cpufreq_driver
->suspend(policy
))
1737 pr_err("%s: Failed to suspend driver: %p\n", __func__
,
1742 cpufreq_suspended
= true;
1746 * cpufreq_resume() - Resume CPUFreq governors
1748 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1749 * are suspended with cpufreq_suspend().
1751 void cpufreq_resume(void)
1753 struct cpufreq_policy
*policy
;
1756 if (!cpufreq_driver
)
1759 if (unlikely(!cpufreq_suspended
))
1762 cpufreq_suspended
= false;
1764 if (!has_target() && !cpufreq_driver
->resume
)
1767 pr_debug("%s: Resuming Governors\n", __func__
);
1769 for_each_active_policy(policy
) {
1770 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
)) {
1771 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1773 } else if (has_target()) {
1774 down_write(&policy
->rwsem
);
1775 ret
= cpufreq_start_governor(policy
);
1776 up_write(&policy
->rwsem
);
1779 pr_err("%s: Failed to start governor for policy: %p\n",
1786 * cpufreq_get_current_driver - return current driver's name
1788 * Return the name string of the currently loaded cpufreq driver
1791 const char *cpufreq_get_current_driver(void)
1794 return cpufreq_driver
->name
;
1798 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1801 * cpufreq_get_driver_data - return current driver data
1803 * Return the private data of the currently loaded cpufreq
1804 * driver, or NULL if no cpufreq driver is loaded.
1806 void *cpufreq_get_driver_data(void)
1809 return cpufreq_driver
->driver_data
;
1813 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1815 /*********************************************************************
1816 * NOTIFIER LISTS INTERFACE *
1817 *********************************************************************/
1820 * cpufreq_register_notifier - register a driver with cpufreq
1821 * @nb: notifier function to register
1822 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1824 * Add a driver to one of two lists: either a list of drivers that
1825 * are notified about clock rate changes (once before and once after
1826 * the transition), or a list of drivers that are notified about
1827 * changes in cpufreq policy.
1829 * This function may sleep, and has the same return conditions as
1830 * blocking_notifier_chain_register.
1832 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1836 if (cpufreq_disabled())
1840 case CPUFREQ_TRANSITION_NOTIFIER
:
1841 mutex_lock(&cpufreq_fast_switch_lock
);
1843 if (cpufreq_fast_switch_count
> 0) {
1844 mutex_unlock(&cpufreq_fast_switch_lock
);
1847 ret
= srcu_notifier_chain_register(
1848 &cpufreq_transition_notifier_list
, nb
);
1850 cpufreq_fast_switch_count
--;
1852 mutex_unlock(&cpufreq_fast_switch_lock
);
1854 case CPUFREQ_POLICY_NOTIFIER
:
1855 ret
= blocking_notifier_chain_register(
1856 &cpufreq_policy_notifier_list
, nb
);
1864 EXPORT_SYMBOL(cpufreq_register_notifier
);
1867 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1868 * @nb: notifier block to be unregistered
1869 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1871 * Remove a driver from the CPU frequency notifier list.
1873 * This function may sleep, and has the same return conditions as
1874 * blocking_notifier_chain_unregister.
1876 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1880 if (cpufreq_disabled())
1884 case CPUFREQ_TRANSITION_NOTIFIER
:
1885 mutex_lock(&cpufreq_fast_switch_lock
);
1887 ret
= srcu_notifier_chain_unregister(
1888 &cpufreq_transition_notifier_list
, nb
);
1889 if (!ret
&& !WARN_ON(cpufreq_fast_switch_count
>= 0))
1890 cpufreq_fast_switch_count
++;
1892 mutex_unlock(&cpufreq_fast_switch_lock
);
1894 case CPUFREQ_POLICY_NOTIFIER
:
1895 ret
= blocking_notifier_chain_unregister(
1896 &cpufreq_policy_notifier_list
, nb
);
1904 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1907 /*********************************************************************
1909 *********************************************************************/
1912 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1913 * @policy: cpufreq policy to switch the frequency for.
1914 * @target_freq: New frequency to set (may be approximate).
1916 * Carry out a fast frequency switch without sleeping.
1918 * The driver's ->fast_switch() callback invoked by this function must be
1919 * suitable for being called from within RCU-sched read-side critical sections
1920 * and it is expected to select the minimum available frequency greater than or
1921 * equal to @target_freq (CPUFREQ_RELATION_L).
1923 * This function must not be called if policy->fast_switch_enabled is unset.
1925 * Governors calling this function must guarantee that it will never be invoked
1926 * twice in parallel for the same policy and that it will never be called in
1927 * parallel with either ->target() or ->target_index() for the same policy.
1929 * Returns the actual frequency set for the CPU.
1931 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
1932 * error condition, the hardware configuration must be preserved.
1934 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy
*policy
,
1935 unsigned int target_freq
)
1937 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1939 return cpufreq_driver
->fast_switch(policy
, target_freq
);
1941 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch
);
1943 /* Must set freqs->new to intermediate frequency */
1944 static int __target_intermediate(struct cpufreq_policy
*policy
,
1945 struct cpufreq_freqs
*freqs
, int index
)
1949 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
1951 /* We don't need to switch to intermediate freq */
1955 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1956 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
1958 cpufreq_freq_transition_begin(policy
, freqs
);
1959 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
1960 cpufreq_freq_transition_end(policy
, freqs
, ret
);
1963 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1969 static int __target_index(struct cpufreq_policy
*policy
, int index
)
1971 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
1972 unsigned int intermediate_freq
= 0;
1973 unsigned int newfreq
= policy
->freq_table
[index
].frequency
;
1974 int retval
= -EINVAL
;
1977 if (newfreq
== policy
->cur
)
1980 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
1982 /* Handle switching to intermediate frequency */
1983 if (cpufreq_driver
->get_intermediate
) {
1984 retval
= __target_intermediate(policy
, &freqs
, index
);
1988 intermediate_freq
= freqs
.new;
1989 /* Set old freq to intermediate */
1990 if (intermediate_freq
)
1991 freqs
.old
= freqs
.new;
1994 freqs
.new = newfreq
;
1995 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1996 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
1998 cpufreq_freq_transition_begin(policy
, &freqs
);
2001 retval
= cpufreq_driver
->target_index(policy
, index
);
2003 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
2007 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
2010 * Failed after setting to intermediate freq? Driver should have
2011 * reverted back to initial frequency and so should we. Check
2012 * here for intermediate_freq instead of get_intermediate, in
2013 * case we haven't switched to intermediate freq at all.
2015 if (unlikely(retval
&& intermediate_freq
)) {
2016 freqs
.old
= intermediate_freq
;
2017 freqs
.new = policy
->restore_freq
;
2018 cpufreq_freq_transition_begin(policy
, &freqs
);
2019 cpufreq_freq_transition_end(policy
, &freqs
, 0);
2026 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
2027 unsigned int target_freq
,
2028 unsigned int relation
)
2030 unsigned int old_target_freq
= target_freq
;
2033 if (cpufreq_disabled())
2036 /* Make sure that target_freq is within supported range */
2037 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
2039 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2040 policy
->cpu
, target_freq
, relation
, old_target_freq
);
2043 * This might look like a redundant call as we are checking it again
2044 * after finding index. But it is left intentionally for cases where
2045 * exactly same freq is called again and so we can save on few function
2048 if (target_freq
== policy
->cur
)
2051 /* Save last value to restore later on errors */
2052 policy
->restore_freq
= policy
->cur
;
2054 if (cpufreq_driver
->target
)
2055 return cpufreq_driver
->target(policy
, target_freq
, relation
);
2057 if (!cpufreq_driver
->target_index
)
2060 index
= cpufreq_frequency_table_target(policy
, target_freq
, relation
);
2062 return __target_index(policy
, index
);
2064 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
2066 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
2067 unsigned int target_freq
,
2068 unsigned int relation
)
2072 down_write(&policy
->rwsem
);
2074 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
2076 up_write(&policy
->rwsem
);
2080 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
2082 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
2087 static int cpufreq_init_governor(struct cpufreq_policy
*policy
)
2091 /* Don't start any governor operations if we are entering suspend */
2092 if (cpufreq_suspended
)
2095 * Governor might not be initiated here if ACPI _PPC changed
2096 * notification happened, so check it.
2098 if (!policy
->governor
)
2101 /* Platform doesn't want dynamic frequency switching ? */
2102 if (policy
->governor
->dynamic_switching
&&
2103 cpufreq_driver
->flags
& CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
) {
2104 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
2107 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2108 policy
->governor
->name
, gov
->name
);
2109 policy
->governor
= gov
;
2115 if (!try_module_get(policy
->governor
->owner
))
2118 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2120 if (policy
->governor
->init
) {
2121 ret
= policy
->governor
->init(policy
);
2123 module_put(policy
->governor
->owner
);
2131 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
)
2133 if (cpufreq_suspended
|| !policy
->governor
)
2136 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2138 if (policy
->governor
->exit
)
2139 policy
->governor
->exit(policy
);
2141 module_put(policy
->governor
->owner
);
2144 static int cpufreq_start_governor(struct cpufreq_policy
*policy
)
2148 if (cpufreq_suspended
)
2151 if (!policy
->governor
)
2154 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2156 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
)
2157 cpufreq_update_current_freq(policy
);
2159 if (policy
->governor
->start
) {
2160 ret
= policy
->governor
->start(policy
);
2165 if (policy
->governor
->limits
)
2166 policy
->governor
->limits(policy
);
2171 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
)
2173 if (cpufreq_suspended
|| !policy
->governor
)
2176 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2178 if (policy
->governor
->stop
)
2179 policy
->governor
->stop(policy
);
2182 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
)
2184 if (cpufreq_suspended
|| !policy
->governor
)
2187 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2189 if (policy
->governor
->limits
)
2190 policy
->governor
->limits(policy
);
2193 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2200 if (cpufreq_disabled())
2203 mutex_lock(&cpufreq_governor_mutex
);
2206 if (!find_governor(governor
->name
)) {
2208 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2211 mutex_unlock(&cpufreq_governor_mutex
);
2214 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2216 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2218 struct cpufreq_policy
*policy
;
2219 unsigned long flags
;
2224 if (cpufreq_disabled())
2227 /* clear last_governor for all inactive policies */
2228 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2229 for_each_inactive_policy(policy
) {
2230 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2231 policy
->governor
= NULL
;
2232 strcpy(policy
->last_governor
, "\0");
2235 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2237 mutex_lock(&cpufreq_governor_mutex
);
2238 list_del(&governor
->governor_list
);
2239 mutex_unlock(&cpufreq_governor_mutex
);
2241 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2244 /*********************************************************************
2245 * POLICY INTERFACE *
2246 *********************************************************************/
2249 * cpufreq_get_policy - get the current cpufreq_policy
2250 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2253 * Reads the current cpufreq policy.
2255 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2257 struct cpufreq_policy
*cpu_policy
;
2261 cpu_policy
= cpufreq_cpu_get(cpu
);
2265 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2267 cpufreq_cpu_put(cpu_policy
);
2270 EXPORT_SYMBOL(cpufreq_get_policy
);
2273 * cpufreq_set_policy - Modify cpufreq policy parameters.
2274 * @policy: Policy object to modify.
2275 * @new_policy: New policy data.
2277 * Pass @new_policy to the cpufreq driver's ->verify() callback, run the
2278 * installed policy notifiers for it with the CPUFREQ_ADJUST value, pass it to
2279 * the driver's ->verify() callback again and run the notifiers for it again
2280 * with the CPUFREQ_NOTIFY value. Next, copy the min and max parameters
2281 * of @new_policy to @policy and either invoke the driver's ->setpolicy()
2282 * callback (if present) or carry out a governor update for @policy. That is,
2283 * run the current governor's ->limits() callback (if the governor field in
2284 * @new_policy points to the same object as the one in @policy) or replace the
2285 * governor for @policy with the new one stored in @new_policy.
2287 * The cpuinfo part of @policy is not updated by this function.
2289 int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2290 struct cpufreq_policy
*new_policy
)
2292 struct cpufreq_governor
*old_gov
;
2295 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2296 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2298 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2301 * This check works well when we store new min/max freq attributes,
2302 * because new_policy is a copy of policy with one field updated.
2304 if (new_policy
->min
> new_policy
->max
)
2307 /* verify the cpu speed can be set within this limit */
2308 ret
= cpufreq_driver
->verify(new_policy
);
2312 /* adjust if necessary - all reasons */
2313 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2314 CPUFREQ_ADJUST
, new_policy
);
2317 * verify the cpu speed can be set within this limit, which might be
2318 * different to the first one
2320 ret
= cpufreq_driver
->verify(new_policy
);
2324 /* notification of the new policy */
2325 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2326 CPUFREQ_NOTIFY
, new_policy
);
2328 policy
->min
= new_policy
->min
;
2329 policy
->max
= new_policy
->max
;
2330 trace_cpu_frequency_limits(policy
);
2332 policy
->cached_target_freq
= UINT_MAX
;
2334 pr_debug("new min and max freqs are %u - %u kHz\n",
2335 policy
->min
, policy
->max
);
2337 if (cpufreq_driver
->setpolicy
) {
2338 policy
->policy
= new_policy
->policy
;
2339 pr_debug("setting range\n");
2340 return cpufreq_driver
->setpolicy(policy
);
2343 if (new_policy
->governor
== policy
->governor
) {
2344 pr_debug("governor limits update\n");
2345 cpufreq_governor_limits(policy
);
2349 pr_debug("governor switch\n");
2351 /* save old, working values */
2352 old_gov
= policy
->governor
;
2353 /* end old governor */
2355 cpufreq_stop_governor(policy
);
2356 cpufreq_exit_governor(policy
);
2359 /* start new governor */
2360 policy
->governor
= new_policy
->governor
;
2361 ret
= cpufreq_init_governor(policy
);
2363 ret
= cpufreq_start_governor(policy
);
2365 pr_debug("governor change\n");
2366 sched_cpufreq_governor_change(policy
, old_gov
);
2369 cpufreq_exit_governor(policy
);
2372 /* new governor failed, so re-start old one */
2373 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2375 policy
->governor
= old_gov
;
2376 if (cpufreq_init_governor(policy
))
2377 policy
->governor
= NULL
;
2379 cpufreq_start_governor(policy
);
2386 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2387 * @cpu: CPU to re-evaluate the policy for.
2389 * Update the current frequency for the cpufreq policy of @cpu and use
2390 * cpufreq_set_policy() to re-apply the min and max limits saved in the
2391 * user_policy sub-structure of that policy, which triggers the evaluation
2392 * of policy notifiers and the cpufreq driver's ->verify() callback for the
2393 * policy in question, among other things.
2395 void cpufreq_update_policy(unsigned int cpu
)
2397 struct cpufreq_policy
*policy
= cpufreq_cpu_acquire(cpu
);
2398 struct cpufreq_policy new_policy
;
2404 * BIOS might change freq behind our back
2405 * -> ask driver for current freq and notify governors about a change
2407 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
&&
2408 (cpufreq_suspended
|| WARN_ON(!cpufreq_update_current_freq(policy
))))
2411 pr_debug("updating policy for CPU %u\n", cpu
);
2412 memcpy(&new_policy
, policy
, sizeof(*policy
));
2413 new_policy
.min
= policy
->user_policy
.min
;
2414 new_policy
.max
= policy
->user_policy
.max
;
2416 cpufreq_set_policy(policy
, &new_policy
);
2419 cpufreq_cpu_release(policy
);
2421 EXPORT_SYMBOL(cpufreq_update_policy
);
2424 * cpufreq_update_limits - Update policy limits for a given CPU.
2425 * @cpu: CPU to update the policy limits for.
2427 * Invoke the driver's ->update_limits callback if present or call
2428 * cpufreq_update_policy() for @cpu.
2430 void cpufreq_update_limits(unsigned int cpu
)
2432 if (cpufreq_driver
->update_limits
)
2433 cpufreq_driver
->update_limits(cpu
);
2435 cpufreq_update_policy(cpu
);
2437 EXPORT_SYMBOL_GPL(cpufreq_update_limits
);
2439 /*********************************************************************
2441 *********************************************************************/
2442 static int cpufreq_boost_set_sw(int state
)
2444 struct cpufreq_policy
*policy
;
2447 for_each_active_policy(policy
) {
2448 if (!policy
->freq_table
)
2451 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2452 policy
->freq_table
);
2454 pr_err("%s: Policy frequency update failed\n",
2459 down_write(&policy
->rwsem
);
2460 policy
->user_policy
.max
= policy
->max
;
2461 cpufreq_governor_limits(policy
);
2462 up_write(&policy
->rwsem
);
2468 int cpufreq_boost_trigger_state(int state
)
2470 unsigned long flags
;
2473 if (cpufreq_driver
->boost_enabled
== state
)
2476 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2477 cpufreq_driver
->boost_enabled
= state
;
2478 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2480 ret
= cpufreq_driver
->set_boost(state
);
2482 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2483 cpufreq_driver
->boost_enabled
= !state
;
2484 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2486 pr_err("%s: Cannot %s BOOST\n",
2487 __func__
, state
? "enable" : "disable");
2493 static bool cpufreq_boost_supported(void)
2495 return cpufreq_driver
->set_boost
;
2498 static int create_boost_sysfs_file(void)
2502 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2504 pr_err("%s: cannot register global BOOST sysfs file\n",
2510 static void remove_boost_sysfs_file(void)
2512 if (cpufreq_boost_supported())
2513 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2516 int cpufreq_enable_boost_support(void)
2518 if (!cpufreq_driver
)
2521 if (cpufreq_boost_supported())
2524 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2526 /* This will get removed on driver unregister */
2527 return create_boost_sysfs_file();
2529 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2531 int cpufreq_boost_enabled(void)
2533 return cpufreq_driver
->boost_enabled
;
2535 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2537 /*********************************************************************
2538 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2539 *********************************************************************/
2540 static enum cpuhp_state hp_online
;
2542 static int cpuhp_cpufreq_online(unsigned int cpu
)
2544 cpufreq_online(cpu
);
2549 static int cpuhp_cpufreq_offline(unsigned int cpu
)
2551 cpufreq_offline(cpu
);
2557 * cpufreq_register_driver - register a CPU Frequency driver
2558 * @driver_data: A struct cpufreq_driver containing the values#
2559 * submitted by the CPU Frequency driver.
2561 * Registers a CPU Frequency driver to this core code. This code
2562 * returns zero on success, -EEXIST when another driver got here first
2563 * (and isn't unregistered in the meantime).
2566 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2568 unsigned long flags
;
2571 if (cpufreq_disabled())
2574 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2575 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2576 driver_data
->target
) ||
2577 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2578 driver_data
->target
)) ||
2579 (!driver_data
->get_intermediate
!= !driver_data
->target_intermediate
) ||
2580 (!driver_data
->online
!= !driver_data
->offline
))
2583 pr_debug("trying to register driver %s\n", driver_data
->name
);
2585 /* Protect against concurrent CPU online/offline. */
2588 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2589 if (cpufreq_driver
) {
2590 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2594 cpufreq_driver
= driver_data
;
2595 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2597 if (driver_data
->setpolicy
)
2598 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2600 if (cpufreq_boost_supported()) {
2601 ret
= create_boost_sysfs_file();
2603 goto err_null_driver
;
2606 ret
= subsys_interface_register(&cpufreq_interface
);
2608 goto err_boost_unreg
;
2610 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2611 list_empty(&cpufreq_policy_list
)) {
2612 /* if all ->init() calls failed, unregister */
2614 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2619 ret
= cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN
,
2621 cpuhp_cpufreq_online
,
2622 cpuhp_cpufreq_offline
);
2628 pr_debug("driver %s up and running\n", driver_data
->name
);
2632 subsys_interface_unregister(&cpufreq_interface
);
2634 remove_boost_sysfs_file();
2636 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2637 cpufreq_driver
= NULL
;
2638 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2643 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2646 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2648 * Unregister the current CPUFreq driver. Only call this if you have
2649 * the right to do so, i.e. if you have succeeded in initialising before!
2650 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2651 * currently not initialised.
2653 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2655 unsigned long flags
;
2657 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2660 pr_debug("unregistering driver %s\n", driver
->name
);
2662 /* Protect against concurrent cpu hotplug */
2664 subsys_interface_unregister(&cpufreq_interface
);
2665 remove_boost_sysfs_file();
2666 cpuhp_remove_state_nocalls_cpuslocked(hp_online
);
2668 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2670 cpufreq_driver
= NULL
;
2672 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2677 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2680 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2681 * or mutexes when secondary CPUs are halted.
2683 static struct syscore_ops cpufreq_syscore_ops
= {
2684 .shutdown
= cpufreq_suspend
,
2687 struct kobject
*cpufreq_global_kobject
;
2688 EXPORT_SYMBOL(cpufreq_global_kobject
);
2690 static int __init
cpufreq_core_init(void)
2692 if (cpufreq_disabled())
2695 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2696 BUG_ON(!cpufreq_global_kobject
);
2698 register_syscore_ops(&cpufreq_syscore_ops
);
2702 module_param(off
, int, 0444);
2703 core_initcall(cpufreq_core_init
);