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/delay.h>
23 #include <linux/device.h>
24 #include <linux/init.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/slab.h>
29 #include <linux/suspend.h>
30 #include <linux/syscore_ops.h>
31 #include <linux/tick.h>
32 #include <trace/events/power.h>
34 static LIST_HEAD(cpufreq_policy_list
);
36 static inline bool policy_is_inactive(struct cpufreq_policy
*policy
)
38 return cpumask_empty(policy
->cpus
);
41 /* Macros to iterate over CPU policies */
42 #define for_each_suitable_policy(__policy, __active) \
43 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
44 if ((__active) == !policy_is_inactive(__policy))
46 #define for_each_active_policy(__policy) \
47 for_each_suitable_policy(__policy, true)
48 #define for_each_inactive_policy(__policy) \
49 for_each_suitable_policy(__policy, false)
51 #define for_each_policy(__policy) \
52 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
54 /* Iterate over governors */
55 static LIST_HEAD(cpufreq_governor_list
);
56 #define for_each_governor(__governor) \
57 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
60 * The "cpufreq driver" - the arch- or hardware-dependent low
61 * level driver of CPUFreq support, and its spinlock. This lock
62 * also protects the cpufreq_cpu_data array.
64 static struct cpufreq_driver
*cpufreq_driver
;
65 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
66 static DEFINE_RWLOCK(cpufreq_driver_lock
);
68 /* Flag to suspend/resume CPUFreq governors */
69 static bool cpufreq_suspended
;
71 static inline bool has_target(void)
73 return cpufreq_driver
->target_index
|| cpufreq_driver
->target
;
76 /* internal prototypes */
77 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
);
78 static int cpufreq_init_governor(struct cpufreq_policy
*policy
);
79 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
);
80 static int cpufreq_start_governor(struct cpufreq_policy
*policy
);
81 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
);
82 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
);
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 static struct srcu_notifier_head cpufreq_transition_notifier_list
;
94 static bool init_cpufreq_transition_notifier_list_called
;
95 static int __init
init_cpufreq_transition_notifier_list(void)
97 srcu_init_notifier_head(&cpufreq_transition_notifier_list
);
98 init_cpufreq_transition_notifier_list_called
= true;
101 pure_initcall(init_cpufreq_transition_notifier_list
);
103 static int off __read_mostly
;
104 static int cpufreq_disabled(void)
108 void disable_cpufreq(void)
112 static DEFINE_MUTEX(cpufreq_governor_mutex
);
114 bool have_governor_per_policy(void)
116 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
118 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
120 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
122 if (have_governor_per_policy())
123 return &policy
->kobj
;
125 return cpufreq_global_kobject
;
127 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
129 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
135 cur_wall_time
= jiffies64_to_nsecs(get_jiffies_64());
137 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
138 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
139 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
140 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
141 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
142 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
144 idle_time
= cur_wall_time
- busy_time
;
146 *wall
= div_u64(cur_wall_time
, NSEC_PER_USEC
);
148 return div_u64(idle_time
, NSEC_PER_USEC
);
151 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
153 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
155 if (idle_time
== -1ULL)
156 return get_cpu_idle_time_jiffy(cpu
, wall
);
158 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
162 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
165 * This is a generic cpufreq init() routine which can be used by cpufreq
166 * drivers of SMP systems. It will do following:
167 * - validate & show freq table passed
168 * - set policies transition latency
169 * - policy->cpus with all possible CPUs
171 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
172 struct cpufreq_frequency_table
*table
,
173 unsigned int transition_latency
)
177 ret
= cpufreq_table_validate_and_show(policy
, table
);
179 pr_err("%s: invalid frequency table: %d\n", __func__
, ret
);
183 policy
->cpuinfo
.transition_latency
= transition_latency
;
186 * The driver only supports the SMP configuration where all processors
187 * share the clock and voltage and clock.
189 cpumask_setall(policy
->cpus
);
193 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
195 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
197 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
199 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
201 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
203 unsigned int cpufreq_generic_get(unsigned int cpu
)
205 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
207 if (!policy
|| IS_ERR(policy
->clk
)) {
208 pr_err("%s: No %s associated to cpu: %d\n",
209 __func__
, policy
? "clk" : "policy", cpu
);
213 return clk_get_rate(policy
->clk
) / 1000;
215 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
218 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
220 * @cpu: cpu to find policy for.
222 * This returns policy for 'cpu', returns NULL if it doesn't exist.
223 * It also increments the kobject reference count to mark it busy and so would
224 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
225 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
226 * freed as that depends on the kobj count.
228 * Return: A valid policy on success, otherwise NULL on failure.
230 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
232 struct cpufreq_policy
*policy
= NULL
;
235 if (WARN_ON(cpu
>= nr_cpu_ids
))
238 /* get the cpufreq driver */
239 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
241 if (cpufreq_driver
) {
243 policy
= cpufreq_cpu_get_raw(cpu
);
245 kobject_get(&policy
->kobj
);
248 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
252 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
255 * cpufreq_cpu_put: Decrements the usage count of a policy
257 * @policy: policy earlier returned by cpufreq_cpu_get().
259 * This decrements the kobject reference count incremented earlier by calling
262 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
264 kobject_put(&policy
->kobj
);
266 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
268 /*********************************************************************
269 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
270 *********************************************************************/
273 * adjust_jiffies - adjust the system "loops_per_jiffy"
275 * This function alters the system "loops_per_jiffy" for the clock
276 * speed change. Note that loops_per_jiffy cannot be updated on SMP
277 * systems as each CPU might be scaled differently. So, use the arch
278 * per-CPU loops_per_jiffy value wherever possible.
280 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
283 static unsigned long l_p_j_ref
;
284 static unsigned int l_p_j_ref_freq
;
286 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
289 if (!l_p_j_ref_freq
) {
290 l_p_j_ref
= loops_per_jiffy
;
291 l_p_j_ref_freq
= ci
->old
;
292 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
293 l_p_j_ref
, l_p_j_ref_freq
);
295 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
296 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
298 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
299 loops_per_jiffy
, ci
->new);
304 static void __cpufreq_notify_transition(struct cpufreq_policy
*policy
,
305 struct cpufreq_freqs
*freqs
, unsigned int state
)
307 BUG_ON(irqs_disabled());
309 if (cpufreq_disabled())
312 freqs
->flags
= cpufreq_driver
->flags
;
313 pr_debug("notification %u of frequency transition to %u kHz\n",
318 case CPUFREQ_PRECHANGE
:
319 /* detect if the driver reported a value as "old frequency"
320 * which is not equal to what the cpufreq core thinks is
323 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
324 if ((policy
) && (policy
->cpu
== freqs
->cpu
) &&
325 (policy
->cur
) && (policy
->cur
!= freqs
->old
)) {
326 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
327 freqs
->old
, policy
->cur
);
328 freqs
->old
= policy
->cur
;
331 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
332 CPUFREQ_PRECHANGE
, freqs
);
333 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
336 case CPUFREQ_POSTCHANGE
:
337 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
338 pr_debug("FREQ: %lu - CPU: %lu\n",
339 (unsigned long)freqs
->new, (unsigned long)freqs
->cpu
);
340 trace_cpu_frequency(freqs
->new, freqs
->cpu
);
341 cpufreq_stats_record_transition(policy
, freqs
->new);
342 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
343 CPUFREQ_POSTCHANGE
, freqs
);
344 if (likely(policy
) && likely(policy
->cpu
== freqs
->cpu
))
345 policy
->cur
= freqs
->new;
351 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
352 * on frequency transition.
354 * This function calls the transition notifiers and the "adjust_jiffies"
355 * function. It is called twice on all CPU frequency changes that have
358 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
359 struct cpufreq_freqs
*freqs
, unsigned int state
)
361 for_each_cpu(freqs
->cpu
, policy
->cpus
)
362 __cpufreq_notify_transition(policy
, freqs
, state
);
365 /* Do post notifications when there are chances that transition has failed */
366 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
367 struct cpufreq_freqs
*freqs
, int transition_failed
)
369 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
370 if (!transition_failed
)
373 swap(freqs
->old
, freqs
->new);
374 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
375 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
378 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
379 struct cpufreq_freqs
*freqs
)
383 * Catch double invocations of _begin() which lead to self-deadlock.
384 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
385 * doesn't invoke _begin() on their behalf, and hence the chances of
386 * double invocations are very low. Moreover, there are scenarios
387 * where these checks can emit false-positive warnings in these
388 * drivers; so we avoid that by skipping them altogether.
390 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
391 && current
== policy
->transition_task
);
394 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
396 spin_lock(&policy
->transition_lock
);
398 if (unlikely(policy
->transition_ongoing
)) {
399 spin_unlock(&policy
->transition_lock
);
403 policy
->transition_ongoing
= true;
404 policy
->transition_task
= current
;
406 spin_unlock(&policy
->transition_lock
);
408 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
410 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
412 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
413 struct cpufreq_freqs
*freqs
, int transition_failed
)
415 if (unlikely(WARN_ON(!policy
->transition_ongoing
)))
418 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
420 policy
->transition_ongoing
= false;
421 policy
->transition_task
= NULL
;
423 wake_up(&policy
->transition_wait
);
425 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
428 * Fast frequency switching status count. Positive means "enabled", negative
429 * means "disabled" and 0 means "not decided yet".
431 static int cpufreq_fast_switch_count
;
432 static DEFINE_MUTEX(cpufreq_fast_switch_lock
);
434 static void cpufreq_list_transition_notifiers(void)
436 struct notifier_block
*nb
;
438 pr_info("Registered transition notifiers:\n");
440 mutex_lock(&cpufreq_transition_notifier_list
.mutex
);
442 for (nb
= cpufreq_transition_notifier_list
.head
; nb
; nb
= nb
->next
)
443 pr_info("%pF\n", nb
->notifier_call
);
445 mutex_unlock(&cpufreq_transition_notifier_list
.mutex
);
449 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
450 * @policy: cpufreq policy to enable fast frequency switching for.
452 * Try to enable fast frequency switching for @policy.
454 * The attempt will fail if there is at least one transition notifier registered
455 * at this point, as fast frequency switching is quite fundamentally at odds
456 * with transition notifiers. Thus if successful, it will make registration of
457 * transition notifiers fail going forward.
459 void cpufreq_enable_fast_switch(struct cpufreq_policy
*policy
)
461 lockdep_assert_held(&policy
->rwsem
);
463 if (!policy
->fast_switch_possible
)
466 mutex_lock(&cpufreq_fast_switch_lock
);
467 if (cpufreq_fast_switch_count
>= 0) {
468 cpufreq_fast_switch_count
++;
469 policy
->fast_switch_enabled
= true;
471 pr_warn("CPU%u: Fast frequency switching not enabled\n",
473 cpufreq_list_transition_notifiers();
475 mutex_unlock(&cpufreq_fast_switch_lock
);
477 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch
);
480 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
481 * @policy: cpufreq policy to disable fast frequency switching for.
483 void cpufreq_disable_fast_switch(struct cpufreq_policy
*policy
)
485 mutex_lock(&cpufreq_fast_switch_lock
);
486 if (policy
->fast_switch_enabled
) {
487 policy
->fast_switch_enabled
= false;
488 if (!WARN_ON(cpufreq_fast_switch_count
<= 0))
489 cpufreq_fast_switch_count
--;
491 mutex_unlock(&cpufreq_fast_switch_lock
);
493 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch
);
496 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
498 * @target_freq: target frequency to resolve.
500 * The target to driver frequency mapping is cached in the policy.
502 * Return: Lowest driver-supported frequency greater than or equal to the
503 * given target_freq, subject to policy (min/max) and driver limitations.
505 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy
*policy
,
506 unsigned int target_freq
)
508 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
509 policy
->cached_target_freq
= target_freq
;
511 if (cpufreq_driver
->target_index
) {
514 idx
= cpufreq_frequency_table_target(policy
, target_freq
,
516 policy
->cached_resolved_idx
= idx
;
517 return policy
->freq_table
[idx
].frequency
;
520 if (cpufreq_driver
->resolve_freq
)
521 return cpufreq_driver
->resolve_freq(policy
, target_freq
);
525 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq
);
527 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy
*policy
)
529 unsigned int latency
;
531 if (policy
->transition_delay_us
)
532 return policy
->transition_delay_us
;
534 latency
= policy
->cpuinfo
.transition_latency
/ NSEC_PER_USEC
;
537 * For platforms that can change the frequency very fast (< 10
538 * us), the above formula gives a decent transition delay. But
539 * for platforms where transition_latency is in milliseconds, it
540 * ends up giving unrealistic values.
542 * Cap the default transition delay to 10 ms, which seems to be
543 * a reasonable amount of time after which we should reevaluate
546 return min(latency
* LATENCY_MULTIPLIER
, (unsigned int)10000);
549 return LATENCY_MULTIPLIER
;
551 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us
);
553 /*********************************************************************
555 *********************************************************************/
556 static ssize_t
show_boost(struct kobject
*kobj
,
557 struct attribute
*attr
, char *buf
)
559 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
562 static ssize_t
store_boost(struct kobject
*kobj
, struct attribute
*attr
,
563 const char *buf
, size_t count
)
567 ret
= sscanf(buf
, "%d", &enable
);
568 if (ret
!= 1 || enable
< 0 || enable
> 1)
571 if (cpufreq_boost_trigger_state(enable
)) {
572 pr_err("%s: Cannot %s BOOST!\n",
573 __func__
, enable
? "enable" : "disable");
577 pr_debug("%s: cpufreq BOOST %s\n",
578 __func__
, enable
? "enabled" : "disabled");
582 define_one_global_rw(boost
);
584 static struct cpufreq_governor
*find_governor(const char *str_governor
)
586 struct cpufreq_governor
*t
;
589 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
596 * cpufreq_parse_governor - parse a governor string
598 static int cpufreq_parse_governor(char *str_governor
, unsigned int *policy
,
599 struct cpufreq_governor
**governor
)
603 if (cpufreq_driver
->setpolicy
) {
604 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
605 *policy
= CPUFREQ_POLICY_PERFORMANCE
;
607 } else if (!strncasecmp(str_governor
, "powersave",
609 *policy
= CPUFREQ_POLICY_POWERSAVE
;
613 struct cpufreq_governor
*t
;
615 mutex_lock(&cpufreq_governor_mutex
);
617 t
= find_governor(str_governor
);
622 mutex_unlock(&cpufreq_governor_mutex
);
623 ret
= request_module("cpufreq_%s", str_governor
);
624 mutex_lock(&cpufreq_governor_mutex
);
627 t
= find_governor(str_governor
);
634 if (t
&& !try_module_get(t
->owner
))
637 mutex_unlock(&cpufreq_governor_mutex
);
643 * cpufreq_per_cpu_attr_read() / show_##file_name() -
644 * print out cpufreq information
646 * Write out information from cpufreq_driver->policy[cpu]; object must be
650 #define show_one(file_name, object) \
651 static ssize_t show_##file_name \
652 (struct cpufreq_policy *policy, char *buf) \
654 return sprintf(buf, "%u\n", policy->object); \
657 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
658 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
659 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
660 show_one(scaling_min_freq
, min
);
661 show_one(scaling_max_freq
, max
);
663 __weak
unsigned int arch_freq_get_on_cpu(int cpu
)
668 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
673 freq
= arch_freq_get_on_cpu(policy
->cpu
);
675 ret
= sprintf(buf
, "%u\n", freq
);
676 else if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&&
678 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
680 ret
= sprintf(buf
, "%u\n", policy
->cur
);
684 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
685 struct cpufreq_policy
*new_policy
);
688 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
690 #define store_one(file_name, object) \
691 static ssize_t store_##file_name \
692 (struct cpufreq_policy *policy, const char *buf, size_t count) \
695 struct cpufreq_policy new_policy; \
697 memcpy(&new_policy, policy, sizeof(*policy)); \
699 ret = sscanf(buf, "%u", &new_policy.object); \
703 temp = new_policy.object; \
704 ret = cpufreq_set_policy(policy, &new_policy); \
706 policy->user_policy.object = temp; \
708 return ret ? ret : count; \
711 store_one(scaling_min_freq
, min
);
712 store_one(scaling_max_freq
, max
);
715 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
717 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
720 unsigned int cur_freq
= __cpufreq_get(policy
);
723 return sprintf(buf
, "%u\n", cur_freq
);
725 return sprintf(buf
, "<unknown>\n");
729 * show_scaling_governor - show the current policy for the specified CPU
731 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
733 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
734 return sprintf(buf
, "powersave\n");
735 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
736 return sprintf(buf
, "performance\n");
737 else if (policy
->governor
)
738 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
739 policy
->governor
->name
);
744 * store_scaling_governor - store policy for the specified CPU
746 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
747 const char *buf
, size_t count
)
750 char str_governor
[16];
751 struct cpufreq_policy new_policy
;
753 memcpy(&new_policy
, policy
, sizeof(*policy
));
755 ret
= sscanf(buf
, "%15s", str_governor
);
759 if (cpufreq_parse_governor(str_governor
, &new_policy
.policy
,
760 &new_policy
.governor
))
763 ret
= cpufreq_set_policy(policy
, &new_policy
);
765 if (new_policy
.governor
)
766 module_put(new_policy
.governor
->owner
);
768 return ret
? ret
: count
;
772 * show_scaling_driver - show the cpufreq driver currently loaded
774 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
776 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
780 * show_scaling_available_governors - show the available CPUfreq governors
782 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
786 struct cpufreq_governor
*t
;
789 i
+= sprintf(buf
, "performance powersave");
793 for_each_governor(t
) {
794 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
795 - (CPUFREQ_NAME_LEN
+ 2)))
797 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
800 i
+= sprintf(&buf
[i
], "\n");
804 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
809 for_each_cpu(cpu
, mask
) {
811 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
812 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
813 if (i
>= (PAGE_SIZE
- 5))
816 i
+= sprintf(&buf
[i
], "\n");
819 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
822 * show_related_cpus - show the CPUs affected by each transition even if
823 * hw coordination is in use
825 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
827 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
831 * show_affected_cpus - show the CPUs affected by each transition
833 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
835 return cpufreq_show_cpus(policy
->cpus
, buf
);
838 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
839 const char *buf
, size_t count
)
841 unsigned int freq
= 0;
844 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
847 ret
= sscanf(buf
, "%u", &freq
);
851 policy
->governor
->store_setspeed(policy
, freq
);
856 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
858 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
859 return sprintf(buf
, "<unsupported>\n");
861 return policy
->governor
->show_setspeed(policy
, buf
);
865 * show_bios_limit - show the current cpufreq HW/BIOS limitation
867 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
871 if (cpufreq_driver
->bios_limit
) {
872 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
874 return sprintf(buf
, "%u\n", limit
);
876 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
879 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
880 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
881 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
882 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
883 cpufreq_freq_attr_ro(scaling_available_governors
);
884 cpufreq_freq_attr_ro(scaling_driver
);
885 cpufreq_freq_attr_ro(scaling_cur_freq
);
886 cpufreq_freq_attr_ro(bios_limit
);
887 cpufreq_freq_attr_ro(related_cpus
);
888 cpufreq_freq_attr_ro(affected_cpus
);
889 cpufreq_freq_attr_rw(scaling_min_freq
);
890 cpufreq_freq_attr_rw(scaling_max_freq
);
891 cpufreq_freq_attr_rw(scaling_governor
);
892 cpufreq_freq_attr_rw(scaling_setspeed
);
894 static struct attribute
*default_attrs
[] = {
895 &cpuinfo_min_freq
.attr
,
896 &cpuinfo_max_freq
.attr
,
897 &cpuinfo_transition_latency
.attr
,
898 &scaling_min_freq
.attr
,
899 &scaling_max_freq
.attr
,
902 &scaling_governor
.attr
,
903 &scaling_driver
.attr
,
904 &scaling_available_governors
.attr
,
905 &scaling_setspeed
.attr
,
909 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
910 #define to_attr(a) container_of(a, struct freq_attr, attr)
912 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
914 struct cpufreq_policy
*policy
= to_policy(kobj
);
915 struct freq_attr
*fattr
= to_attr(attr
);
918 down_read(&policy
->rwsem
);
919 ret
= fattr
->show(policy
, buf
);
920 up_read(&policy
->rwsem
);
925 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
926 const char *buf
, size_t count
)
928 struct cpufreq_policy
*policy
= to_policy(kobj
);
929 struct freq_attr
*fattr
= to_attr(attr
);
930 ssize_t ret
= -EINVAL
;
934 if (cpu_online(policy
->cpu
)) {
935 down_write(&policy
->rwsem
);
936 ret
= fattr
->store(policy
, buf
, count
);
937 up_write(&policy
->rwsem
);
945 static void cpufreq_sysfs_release(struct kobject
*kobj
)
947 struct cpufreq_policy
*policy
= to_policy(kobj
);
948 pr_debug("last reference is dropped\n");
949 complete(&policy
->kobj_unregister
);
952 static const struct sysfs_ops sysfs_ops
= {
957 static struct kobj_type ktype_cpufreq
= {
958 .sysfs_ops
= &sysfs_ops
,
959 .default_attrs
= default_attrs
,
960 .release
= cpufreq_sysfs_release
,
963 static void add_cpu_dev_symlink(struct cpufreq_policy
*policy
, unsigned int cpu
)
965 struct device
*dev
= get_cpu_device(cpu
);
970 if (cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
))
973 dev_dbg(dev
, "%s: Adding symlink\n", __func__
);
974 if (sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq"))
975 dev_err(dev
, "cpufreq symlink creation failed\n");
978 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
,
981 dev_dbg(dev
, "%s: Removing symlink\n", __func__
);
982 sysfs_remove_link(&dev
->kobj
, "cpufreq");
985 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
987 struct freq_attr
**drv_attr
;
990 /* set up files for this cpu device */
991 drv_attr
= cpufreq_driver
->attr
;
992 while (drv_attr
&& *drv_attr
) {
993 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
998 if (cpufreq_driver
->get
) {
999 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
1004 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
1008 if (cpufreq_driver
->bios_limit
) {
1009 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
1017 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
1022 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
1024 struct cpufreq_governor
*gov
= NULL
;
1025 struct cpufreq_policy new_policy
;
1027 memcpy(&new_policy
, policy
, sizeof(*policy
));
1029 /* Update governor of new_policy to the governor used before hotplug */
1030 gov
= find_governor(policy
->last_governor
);
1032 pr_debug("Restoring governor %s for cpu %d\n",
1033 policy
->governor
->name
, policy
->cpu
);
1035 gov
= cpufreq_default_governor();
1040 new_policy
.governor
= gov
;
1042 /* Use the default policy if there is no last_policy. */
1043 if (cpufreq_driver
->setpolicy
) {
1044 if (policy
->last_policy
)
1045 new_policy
.policy
= policy
->last_policy
;
1047 cpufreq_parse_governor(gov
->name
, &new_policy
.policy
,
1050 /* set default policy */
1051 return cpufreq_set_policy(policy
, &new_policy
);
1054 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1058 /* Has this CPU been taken care of already? */
1059 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1062 down_write(&policy
->rwsem
);
1064 cpufreq_stop_governor(policy
);
1066 cpumask_set_cpu(cpu
, policy
->cpus
);
1069 ret
= cpufreq_start_governor(policy
);
1071 pr_err("%s: Failed to start governor\n", __func__
);
1073 up_write(&policy
->rwsem
);
1077 static void handle_update(struct work_struct
*work
)
1079 struct cpufreq_policy
*policy
=
1080 container_of(work
, struct cpufreq_policy
, update
);
1081 unsigned int cpu
= policy
->cpu
;
1082 pr_debug("handle_update for cpu %u called\n", cpu
);
1083 cpufreq_update_policy(cpu
);
1086 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1088 struct cpufreq_policy
*policy
;
1091 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1095 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1096 goto err_free_policy
;
1098 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1099 goto err_free_cpumask
;
1101 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1102 goto err_free_rcpumask
;
1104 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
1105 cpufreq_global_kobject
, "policy%u", cpu
);
1107 pr_err("%s: failed to init policy->kobj: %d\n", __func__
, ret
);
1108 goto err_free_real_cpus
;
1111 INIT_LIST_HEAD(&policy
->policy_list
);
1112 init_rwsem(&policy
->rwsem
);
1113 spin_lock_init(&policy
->transition_lock
);
1114 init_waitqueue_head(&policy
->transition_wait
);
1115 init_completion(&policy
->kobj_unregister
);
1116 INIT_WORK(&policy
->update
, handle_update
);
1122 free_cpumask_var(policy
->real_cpus
);
1124 free_cpumask_var(policy
->related_cpus
);
1126 free_cpumask_var(policy
->cpus
);
1133 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
)
1135 struct kobject
*kobj
;
1136 struct completion
*cmp
;
1138 down_write(&policy
->rwsem
);
1139 cpufreq_stats_free_table(policy
);
1140 kobj
= &policy
->kobj
;
1141 cmp
= &policy
->kobj_unregister
;
1142 up_write(&policy
->rwsem
);
1146 * We need to make sure that the underlying kobj is
1147 * actually not referenced anymore by anybody before we
1148 * proceed with unloading.
1150 pr_debug("waiting for dropping of refcount\n");
1151 wait_for_completion(cmp
);
1152 pr_debug("wait complete\n");
1155 static void cpufreq_policy_free(struct cpufreq_policy
*policy
)
1157 unsigned long flags
;
1160 /* Remove policy from list */
1161 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1162 list_del(&policy
->policy_list
);
1164 for_each_cpu(cpu
, policy
->related_cpus
)
1165 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1166 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1168 cpufreq_policy_put_kobj(policy
);
1169 free_cpumask_var(policy
->real_cpus
);
1170 free_cpumask_var(policy
->related_cpus
);
1171 free_cpumask_var(policy
->cpus
);
1175 static int cpufreq_online(unsigned int cpu
)
1177 struct cpufreq_policy
*policy
;
1179 unsigned long flags
;
1183 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1185 /* Check if this CPU already has a policy to manage it */
1186 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1188 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1189 if (!policy_is_inactive(policy
))
1190 return cpufreq_add_policy_cpu(policy
, cpu
);
1192 /* This is the only online CPU for the policy. Start over. */
1194 down_write(&policy
->rwsem
);
1196 policy
->governor
= NULL
;
1197 up_write(&policy
->rwsem
);
1200 policy
= cpufreq_policy_alloc(cpu
);
1205 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1207 /* call driver. From then on the cpufreq must be able
1208 * to accept all calls to ->verify and ->setpolicy for this CPU
1210 ret
= cpufreq_driver
->init(policy
);
1212 pr_debug("initialization failed\n");
1213 goto out_free_policy
;
1216 down_write(&policy
->rwsem
);
1219 /* related_cpus should at least include policy->cpus. */
1220 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1224 * affected cpus must always be the one, which are online. We aren't
1225 * managing offline cpus here.
1227 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1230 policy
->user_policy
.min
= policy
->min
;
1231 policy
->user_policy
.max
= policy
->max
;
1233 for_each_cpu(j
, policy
->related_cpus
) {
1234 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1235 add_cpu_dev_symlink(policy
, j
);
1238 policy
->min
= policy
->user_policy
.min
;
1239 policy
->max
= policy
->user_policy
.max
;
1242 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
1243 policy
->cur
= cpufreq_driver
->get(policy
->cpu
);
1245 pr_err("%s: ->get() failed\n", __func__
);
1246 goto out_exit_policy
;
1251 * Sometimes boot loaders set CPU frequency to a value outside of
1252 * frequency table present with cpufreq core. In such cases CPU might be
1253 * unstable if it has to run on that frequency for long duration of time
1254 * and so its better to set it to a frequency which is specified in
1255 * freq-table. This also makes cpufreq stats inconsistent as
1256 * cpufreq-stats would fail to register because current frequency of CPU
1257 * isn't found in freq-table.
1259 * Because we don't want this change to effect boot process badly, we go
1260 * for the next freq which is >= policy->cur ('cur' must be set by now,
1261 * otherwise we will end up setting freq to lowest of the table as 'cur'
1262 * is initialized to zero).
1264 * We are passing target-freq as "policy->cur - 1" otherwise
1265 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1266 * equal to target-freq.
1268 if ((cpufreq_driver
->flags
& CPUFREQ_NEED_INITIAL_FREQ_CHECK
)
1270 /* Are we running at unknown frequency ? */
1271 ret
= cpufreq_frequency_table_get_index(policy
, policy
->cur
);
1272 if (ret
== -EINVAL
) {
1273 /* Warn user and fix it */
1274 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1275 __func__
, policy
->cpu
, policy
->cur
);
1276 ret
= __cpufreq_driver_target(policy
, policy
->cur
- 1,
1277 CPUFREQ_RELATION_L
);
1280 * Reaching here after boot in a few seconds may not
1281 * mean that system will remain stable at "unknown"
1282 * frequency for longer duration. Hence, a BUG_ON().
1285 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1286 __func__
, policy
->cpu
, policy
->cur
);
1291 ret
= cpufreq_add_dev_interface(policy
);
1293 goto out_exit_policy
;
1295 cpufreq_stats_create_table(policy
);
1297 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1298 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1299 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1302 ret
= cpufreq_init_policy(policy
);
1304 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1305 __func__
, cpu
, ret
);
1306 /* cpufreq_policy_free() will notify based on this */
1308 goto out_exit_policy
;
1311 up_write(&policy
->rwsem
);
1313 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1315 /* Callback for handling stuff after policy is ready */
1316 if (cpufreq_driver
->ready
)
1317 cpufreq_driver
->ready(policy
);
1319 pr_debug("initialization complete\n");
1324 up_write(&policy
->rwsem
);
1326 if (cpufreq_driver
->exit
)
1327 cpufreq_driver
->exit(policy
);
1329 for_each_cpu(j
, policy
->real_cpus
)
1330 remove_cpu_dev_symlink(policy
, get_cpu_device(j
));
1333 cpufreq_policy_free(policy
);
1338 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1340 * @sif: Subsystem interface structure pointer (not used)
1342 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1344 struct cpufreq_policy
*policy
;
1345 unsigned cpu
= dev
->id
;
1348 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1350 if (cpu_online(cpu
)) {
1351 ret
= cpufreq_online(cpu
);
1356 /* Create sysfs link on CPU registration */
1357 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1359 add_cpu_dev_symlink(policy
, cpu
);
1364 static int cpufreq_offline(unsigned int cpu
)
1366 struct cpufreq_policy
*policy
;
1369 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1371 policy
= cpufreq_cpu_get_raw(cpu
);
1373 pr_debug("%s: No cpu_data found\n", __func__
);
1377 down_write(&policy
->rwsem
);
1379 cpufreq_stop_governor(policy
);
1381 cpumask_clear_cpu(cpu
, policy
->cpus
);
1383 if (policy_is_inactive(policy
)) {
1385 strncpy(policy
->last_governor
, policy
->governor
->name
,
1388 policy
->last_policy
= policy
->policy
;
1389 } else if (cpu
== policy
->cpu
) {
1390 /* Nominate new CPU */
1391 policy
->cpu
= cpumask_any(policy
->cpus
);
1394 /* Start governor again for active policy */
1395 if (!policy_is_inactive(policy
)) {
1397 ret
= cpufreq_start_governor(policy
);
1399 pr_err("%s: Failed to start governor\n", __func__
);
1405 if (cpufreq_driver
->stop_cpu
)
1406 cpufreq_driver
->stop_cpu(policy
);
1409 cpufreq_exit_governor(policy
);
1412 * Perform the ->exit() even during light-weight tear-down,
1413 * since this is a core component, and is essential for the
1414 * subsequent light-weight ->init() to succeed.
1416 if (cpufreq_driver
->exit
) {
1417 cpufreq_driver
->exit(policy
);
1418 policy
->freq_table
= NULL
;
1422 up_write(&policy
->rwsem
);
1427 * cpufreq_remove_dev - remove a CPU device
1429 * Removes the cpufreq interface for a CPU device.
1431 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1433 unsigned int cpu
= dev
->id
;
1434 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1439 if (cpu_online(cpu
))
1440 cpufreq_offline(cpu
);
1442 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1443 remove_cpu_dev_symlink(policy
, dev
);
1445 if (cpumask_empty(policy
->real_cpus
))
1446 cpufreq_policy_free(policy
);
1450 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1452 * @policy: policy managing CPUs
1453 * @new_freq: CPU frequency the CPU actually runs at
1455 * We adjust to current frequency first, and need to clean up later.
1456 * So either call to cpufreq_update_policy() or schedule handle_update()).
1458 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1459 unsigned int new_freq
)
1461 struct cpufreq_freqs freqs
;
1463 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1464 policy
->cur
, new_freq
);
1466 freqs
.old
= policy
->cur
;
1467 freqs
.new = new_freq
;
1469 cpufreq_freq_transition_begin(policy
, &freqs
);
1470 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1474 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1477 * This is the last known freq, without actually getting it from the driver.
1478 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1480 unsigned int cpufreq_quick_get(unsigned int cpu
)
1482 struct cpufreq_policy
*policy
;
1483 unsigned int ret_freq
= 0;
1484 unsigned long flags
;
1486 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1488 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
) {
1489 ret_freq
= cpufreq_driver
->get(cpu
);
1490 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1494 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1496 policy
= cpufreq_cpu_get(cpu
);
1498 ret_freq
= policy
->cur
;
1499 cpufreq_cpu_put(policy
);
1504 EXPORT_SYMBOL(cpufreq_quick_get
);
1507 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1510 * Just return the max possible frequency for a given CPU.
1512 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1514 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1515 unsigned int ret_freq
= 0;
1518 ret_freq
= policy
->max
;
1519 cpufreq_cpu_put(policy
);
1524 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1526 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1528 unsigned int ret_freq
= 0;
1530 if (!cpufreq_driver
->get
)
1533 ret_freq
= cpufreq_driver
->get(policy
->cpu
);
1536 * Updating inactive policies is invalid, so avoid doing that. Also
1537 * if fast frequency switching is used with the given policy, the check
1538 * against policy->cur is pointless, so skip it in that case too.
1540 if (unlikely(policy_is_inactive(policy
)) || policy
->fast_switch_enabled
)
1543 if (ret_freq
&& policy
->cur
&&
1544 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1545 /* verify no discrepancy between actual and
1546 saved value exists */
1547 if (unlikely(ret_freq
!= policy
->cur
)) {
1548 cpufreq_out_of_sync(policy
, ret_freq
);
1549 schedule_work(&policy
->update
);
1557 * cpufreq_get - get the current CPU frequency (in kHz)
1560 * Get the CPU current (static) CPU frequency
1562 unsigned int cpufreq_get(unsigned int cpu
)
1564 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1565 unsigned int ret_freq
= 0;
1568 down_read(&policy
->rwsem
);
1570 if (!policy_is_inactive(policy
))
1571 ret_freq
= __cpufreq_get(policy
);
1573 up_read(&policy
->rwsem
);
1575 cpufreq_cpu_put(policy
);
1580 EXPORT_SYMBOL(cpufreq_get
);
1582 static unsigned int cpufreq_update_current_freq(struct cpufreq_policy
*policy
)
1584 unsigned int new_freq
;
1586 new_freq
= cpufreq_driver
->get(policy
->cpu
);
1591 pr_debug("cpufreq: Driver did not initialize current freq\n");
1592 policy
->cur
= new_freq
;
1593 } else if (policy
->cur
!= new_freq
&& has_target()) {
1594 cpufreq_out_of_sync(policy
, new_freq
);
1600 static struct subsys_interface cpufreq_interface
= {
1602 .subsys
= &cpu_subsys
,
1603 .add_dev
= cpufreq_add_dev
,
1604 .remove_dev
= cpufreq_remove_dev
,
1608 * In case platform wants some specific frequency to be configured
1611 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1615 if (!policy
->suspend_freq
) {
1616 pr_debug("%s: suspend_freq not defined\n", __func__
);
1620 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1621 policy
->suspend_freq
);
1623 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1624 CPUFREQ_RELATION_H
);
1626 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1627 __func__
, policy
->suspend_freq
, ret
);
1631 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1634 * cpufreq_suspend() - Suspend CPUFreq governors
1636 * Called during system wide Suspend/Hibernate cycles for suspending governors
1637 * as some platforms can't change frequency after this point in suspend cycle.
1638 * Because some of the devices (like: i2c, regulators, etc) they use for
1639 * changing frequency are suspended quickly after this point.
1641 void cpufreq_suspend(void)
1643 struct cpufreq_policy
*policy
;
1645 if (!cpufreq_driver
)
1648 if (!has_target() && !cpufreq_driver
->suspend
)
1651 pr_debug("%s: Suspending Governors\n", __func__
);
1653 for_each_active_policy(policy
) {
1655 down_write(&policy
->rwsem
);
1656 cpufreq_stop_governor(policy
);
1657 up_write(&policy
->rwsem
);
1660 if (cpufreq_driver
->suspend
&& cpufreq_driver
->suspend(policy
))
1661 pr_err("%s: Failed to suspend driver: %p\n", __func__
,
1666 cpufreq_suspended
= true;
1670 * cpufreq_resume() - Resume CPUFreq governors
1672 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1673 * are suspended with cpufreq_suspend().
1675 void cpufreq_resume(void)
1677 struct cpufreq_policy
*policy
;
1680 if (!cpufreq_driver
)
1683 cpufreq_suspended
= false;
1685 if (!has_target() && !cpufreq_driver
->resume
)
1688 pr_debug("%s: Resuming Governors\n", __func__
);
1690 for_each_active_policy(policy
) {
1691 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
)) {
1692 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1694 } else if (has_target()) {
1695 down_write(&policy
->rwsem
);
1696 ret
= cpufreq_start_governor(policy
);
1697 up_write(&policy
->rwsem
);
1700 pr_err("%s: Failed to start governor for policy: %p\n",
1707 * cpufreq_get_current_driver - return current driver's name
1709 * Return the name string of the currently loaded cpufreq driver
1712 const char *cpufreq_get_current_driver(void)
1715 return cpufreq_driver
->name
;
1719 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1722 * cpufreq_get_driver_data - return current driver data
1724 * Return the private data of the currently loaded cpufreq
1725 * driver, or NULL if no cpufreq driver is loaded.
1727 void *cpufreq_get_driver_data(void)
1730 return cpufreq_driver
->driver_data
;
1734 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1736 /*********************************************************************
1737 * NOTIFIER LISTS INTERFACE *
1738 *********************************************************************/
1741 * cpufreq_register_notifier - register a driver with cpufreq
1742 * @nb: notifier function to register
1743 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1745 * Add a driver to one of two lists: either a list of drivers that
1746 * are notified about clock rate changes (once before and once after
1747 * the transition), or a list of drivers that are notified about
1748 * changes in cpufreq policy.
1750 * This function may sleep, and has the same return conditions as
1751 * blocking_notifier_chain_register.
1753 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1757 if (cpufreq_disabled())
1760 WARN_ON(!init_cpufreq_transition_notifier_list_called
);
1763 case CPUFREQ_TRANSITION_NOTIFIER
:
1764 mutex_lock(&cpufreq_fast_switch_lock
);
1766 if (cpufreq_fast_switch_count
> 0) {
1767 mutex_unlock(&cpufreq_fast_switch_lock
);
1770 ret
= srcu_notifier_chain_register(
1771 &cpufreq_transition_notifier_list
, nb
);
1773 cpufreq_fast_switch_count
--;
1775 mutex_unlock(&cpufreq_fast_switch_lock
);
1777 case CPUFREQ_POLICY_NOTIFIER
:
1778 ret
= blocking_notifier_chain_register(
1779 &cpufreq_policy_notifier_list
, nb
);
1787 EXPORT_SYMBOL(cpufreq_register_notifier
);
1790 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1791 * @nb: notifier block to be unregistered
1792 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1794 * Remove a driver from the CPU frequency notifier list.
1796 * This function may sleep, and has the same return conditions as
1797 * blocking_notifier_chain_unregister.
1799 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1803 if (cpufreq_disabled())
1807 case CPUFREQ_TRANSITION_NOTIFIER
:
1808 mutex_lock(&cpufreq_fast_switch_lock
);
1810 ret
= srcu_notifier_chain_unregister(
1811 &cpufreq_transition_notifier_list
, nb
);
1812 if (!ret
&& !WARN_ON(cpufreq_fast_switch_count
>= 0))
1813 cpufreq_fast_switch_count
++;
1815 mutex_unlock(&cpufreq_fast_switch_lock
);
1817 case CPUFREQ_POLICY_NOTIFIER
:
1818 ret
= blocking_notifier_chain_unregister(
1819 &cpufreq_policy_notifier_list
, nb
);
1827 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1830 /*********************************************************************
1832 *********************************************************************/
1835 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1836 * @policy: cpufreq policy to switch the frequency for.
1837 * @target_freq: New frequency to set (may be approximate).
1839 * Carry out a fast frequency switch without sleeping.
1841 * The driver's ->fast_switch() callback invoked by this function must be
1842 * suitable for being called from within RCU-sched read-side critical sections
1843 * and it is expected to select the minimum available frequency greater than or
1844 * equal to @target_freq (CPUFREQ_RELATION_L).
1846 * This function must not be called if policy->fast_switch_enabled is unset.
1848 * Governors calling this function must guarantee that it will never be invoked
1849 * twice in parallel for the same policy and that it will never be called in
1850 * parallel with either ->target() or ->target_index() for the same policy.
1852 * Returns the actual frequency set for the CPU.
1854 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
1855 * error condition, the hardware configuration must be preserved.
1857 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy
*policy
,
1858 unsigned int target_freq
)
1860 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1862 return cpufreq_driver
->fast_switch(policy
, target_freq
);
1864 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch
);
1866 /* Must set freqs->new to intermediate frequency */
1867 static int __target_intermediate(struct cpufreq_policy
*policy
,
1868 struct cpufreq_freqs
*freqs
, int index
)
1872 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
1874 /* We don't need to switch to intermediate freq */
1878 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1879 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
1881 cpufreq_freq_transition_begin(policy
, freqs
);
1882 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
1883 cpufreq_freq_transition_end(policy
, freqs
, ret
);
1886 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1892 static int __target_index(struct cpufreq_policy
*policy
, int index
)
1894 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
1895 unsigned int intermediate_freq
= 0;
1896 unsigned int newfreq
= policy
->freq_table
[index
].frequency
;
1897 int retval
= -EINVAL
;
1900 if (newfreq
== policy
->cur
)
1903 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
1905 /* Handle switching to intermediate frequency */
1906 if (cpufreq_driver
->get_intermediate
) {
1907 retval
= __target_intermediate(policy
, &freqs
, index
);
1911 intermediate_freq
= freqs
.new;
1912 /* Set old freq to intermediate */
1913 if (intermediate_freq
)
1914 freqs
.old
= freqs
.new;
1917 freqs
.new = newfreq
;
1918 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1919 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
1921 cpufreq_freq_transition_begin(policy
, &freqs
);
1924 retval
= cpufreq_driver
->target_index(policy
, index
);
1926 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
1930 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
1933 * Failed after setting to intermediate freq? Driver should have
1934 * reverted back to initial frequency and so should we. Check
1935 * here for intermediate_freq instead of get_intermediate, in
1936 * case we haven't switched to intermediate freq at all.
1938 if (unlikely(retval
&& intermediate_freq
)) {
1939 freqs
.old
= intermediate_freq
;
1940 freqs
.new = policy
->restore_freq
;
1941 cpufreq_freq_transition_begin(policy
, &freqs
);
1942 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1949 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
1950 unsigned int target_freq
,
1951 unsigned int relation
)
1953 unsigned int old_target_freq
= target_freq
;
1956 if (cpufreq_disabled())
1959 /* Make sure that target_freq is within supported range */
1960 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1962 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1963 policy
->cpu
, target_freq
, relation
, old_target_freq
);
1966 * This might look like a redundant call as we are checking it again
1967 * after finding index. But it is left intentionally for cases where
1968 * exactly same freq is called again and so we can save on few function
1971 if (target_freq
== policy
->cur
)
1974 /* Save last value to restore later on errors */
1975 policy
->restore_freq
= policy
->cur
;
1977 if (cpufreq_driver
->target
)
1978 return cpufreq_driver
->target(policy
, target_freq
, relation
);
1980 if (!cpufreq_driver
->target_index
)
1983 index
= cpufreq_frequency_table_target(policy
, target_freq
, relation
);
1985 return __target_index(policy
, index
);
1987 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
1989 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
1990 unsigned int target_freq
,
1991 unsigned int relation
)
1995 down_write(&policy
->rwsem
);
1997 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
1999 up_write(&policy
->rwsem
);
2003 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
2005 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
2010 static int cpufreq_init_governor(struct cpufreq_policy
*policy
)
2014 /* Don't start any governor operations if we are entering suspend */
2015 if (cpufreq_suspended
)
2018 * Governor might not be initiated here if ACPI _PPC changed
2019 * notification happened, so check it.
2021 if (!policy
->governor
)
2024 /* Platform doesn't want dynamic frequency switching ? */
2025 if (policy
->governor
->dynamic_switching
&&
2026 cpufreq_driver
->flags
& CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
) {
2027 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
2030 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2031 policy
->governor
->name
, gov
->name
);
2032 policy
->governor
= gov
;
2038 if (!try_module_get(policy
->governor
->owner
))
2041 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2043 if (policy
->governor
->init
) {
2044 ret
= policy
->governor
->init(policy
);
2046 module_put(policy
->governor
->owner
);
2054 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
)
2056 if (cpufreq_suspended
|| !policy
->governor
)
2059 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2061 if (policy
->governor
->exit
)
2062 policy
->governor
->exit(policy
);
2064 module_put(policy
->governor
->owner
);
2067 static int cpufreq_start_governor(struct cpufreq_policy
*policy
)
2071 if (cpufreq_suspended
)
2074 if (!policy
->governor
)
2077 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2079 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
)
2080 cpufreq_update_current_freq(policy
);
2082 if (policy
->governor
->start
) {
2083 ret
= policy
->governor
->start(policy
);
2088 if (policy
->governor
->limits
)
2089 policy
->governor
->limits(policy
);
2094 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
)
2096 if (cpufreq_suspended
|| !policy
->governor
)
2099 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2101 if (policy
->governor
->stop
)
2102 policy
->governor
->stop(policy
);
2105 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
)
2107 if (cpufreq_suspended
|| !policy
->governor
)
2110 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2112 if (policy
->governor
->limits
)
2113 policy
->governor
->limits(policy
);
2116 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2123 if (cpufreq_disabled())
2126 mutex_lock(&cpufreq_governor_mutex
);
2129 if (!find_governor(governor
->name
)) {
2131 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2134 mutex_unlock(&cpufreq_governor_mutex
);
2137 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2139 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2141 struct cpufreq_policy
*policy
;
2142 unsigned long flags
;
2147 if (cpufreq_disabled())
2150 /* clear last_governor for all inactive policies */
2151 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2152 for_each_inactive_policy(policy
) {
2153 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2154 policy
->governor
= NULL
;
2155 strcpy(policy
->last_governor
, "\0");
2158 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2160 mutex_lock(&cpufreq_governor_mutex
);
2161 list_del(&governor
->governor_list
);
2162 mutex_unlock(&cpufreq_governor_mutex
);
2165 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2168 /*********************************************************************
2169 * POLICY INTERFACE *
2170 *********************************************************************/
2173 * cpufreq_get_policy - get the current cpufreq_policy
2174 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2177 * Reads the current cpufreq policy.
2179 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2181 struct cpufreq_policy
*cpu_policy
;
2185 cpu_policy
= cpufreq_cpu_get(cpu
);
2189 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2191 cpufreq_cpu_put(cpu_policy
);
2194 EXPORT_SYMBOL(cpufreq_get_policy
);
2197 * policy : current policy.
2198 * new_policy: policy to be set.
2200 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2201 struct cpufreq_policy
*new_policy
)
2203 struct cpufreq_governor
*old_gov
;
2206 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2207 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2209 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2212 * This check works well when we store new min/max freq attributes,
2213 * because new_policy is a copy of policy with one field updated.
2215 if (new_policy
->min
> new_policy
->max
)
2218 /* verify the cpu speed can be set within this limit */
2219 ret
= cpufreq_driver
->verify(new_policy
);
2223 /* adjust if necessary - all reasons */
2224 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2225 CPUFREQ_ADJUST
, new_policy
);
2228 * verify the cpu speed can be set within this limit, which might be
2229 * different to the first one
2231 ret
= cpufreq_driver
->verify(new_policy
);
2235 /* notification of the new policy */
2236 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2237 CPUFREQ_NOTIFY
, new_policy
);
2239 policy
->min
= new_policy
->min
;
2240 policy
->max
= new_policy
->max
;
2241 trace_cpu_frequency_limits(policy
->max
, policy
->min
, policy
->cpu
);
2243 policy
->cached_target_freq
= UINT_MAX
;
2245 pr_debug("new min and max freqs are %u - %u kHz\n",
2246 policy
->min
, policy
->max
);
2248 if (cpufreq_driver
->setpolicy
) {
2249 policy
->policy
= new_policy
->policy
;
2250 pr_debug("setting range\n");
2251 return cpufreq_driver
->setpolicy(new_policy
);
2254 if (new_policy
->governor
== policy
->governor
) {
2255 pr_debug("cpufreq: governor limits update\n");
2256 cpufreq_governor_limits(policy
);
2260 pr_debug("governor switch\n");
2262 /* save old, working values */
2263 old_gov
= policy
->governor
;
2264 /* end old governor */
2266 cpufreq_stop_governor(policy
);
2267 cpufreq_exit_governor(policy
);
2270 /* start new governor */
2271 policy
->governor
= new_policy
->governor
;
2272 ret
= cpufreq_init_governor(policy
);
2274 ret
= cpufreq_start_governor(policy
);
2276 pr_debug("cpufreq: governor change\n");
2279 cpufreq_exit_governor(policy
);
2282 /* new governor failed, so re-start old one */
2283 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2285 policy
->governor
= old_gov
;
2286 if (cpufreq_init_governor(policy
))
2287 policy
->governor
= NULL
;
2289 cpufreq_start_governor(policy
);
2296 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2297 * @cpu: CPU which shall be re-evaluated
2299 * Useful for policy notifiers which have different necessities
2300 * at different times.
2302 void cpufreq_update_policy(unsigned int cpu
)
2304 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
2305 struct cpufreq_policy new_policy
;
2310 down_write(&policy
->rwsem
);
2312 if (policy_is_inactive(policy
))
2315 pr_debug("updating policy for CPU %u\n", cpu
);
2316 memcpy(&new_policy
, policy
, sizeof(*policy
));
2317 new_policy
.min
= policy
->user_policy
.min
;
2318 new_policy
.max
= policy
->user_policy
.max
;
2321 * BIOS might change freq behind our back
2322 * -> ask driver for current freq and notify governors about a change
2324 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
2325 if (cpufreq_suspended
)
2328 new_policy
.cur
= cpufreq_update_current_freq(policy
);
2329 if (WARN_ON(!new_policy
.cur
))
2333 cpufreq_set_policy(policy
, &new_policy
);
2336 up_write(&policy
->rwsem
);
2338 cpufreq_cpu_put(policy
);
2340 EXPORT_SYMBOL(cpufreq_update_policy
);
2342 /*********************************************************************
2344 *********************************************************************/
2345 static int cpufreq_boost_set_sw(int state
)
2347 struct cpufreq_policy
*policy
;
2350 for_each_active_policy(policy
) {
2351 if (!policy
->freq_table
)
2354 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2355 policy
->freq_table
);
2357 pr_err("%s: Policy frequency update failed\n",
2362 down_write(&policy
->rwsem
);
2363 policy
->user_policy
.max
= policy
->max
;
2364 cpufreq_governor_limits(policy
);
2365 up_write(&policy
->rwsem
);
2371 int cpufreq_boost_trigger_state(int state
)
2373 unsigned long flags
;
2376 if (cpufreq_driver
->boost_enabled
== state
)
2379 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2380 cpufreq_driver
->boost_enabled
= state
;
2381 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2383 ret
= cpufreq_driver
->set_boost(state
);
2385 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2386 cpufreq_driver
->boost_enabled
= !state
;
2387 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2389 pr_err("%s: Cannot %s BOOST\n",
2390 __func__
, state
? "enable" : "disable");
2396 static bool cpufreq_boost_supported(void)
2398 return likely(cpufreq_driver
) && cpufreq_driver
->set_boost
;
2401 static int create_boost_sysfs_file(void)
2405 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2407 pr_err("%s: cannot register global BOOST sysfs file\n",
2413 static void remove_boost_sysfs_file(void)
2415 if (cpufreq_boost_supported())
2416 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2419 int cpufreq_enable_boost_support(void)
2421 if (!cpufreq_driver
)
2424 if (cpufreq_boost_supported())
2427 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2429 /* This will get removed on driver unregister */
2430 return create_boost_sysfs_file();
2432 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2434 int cpufreq_boost_enabled(void)
2436 return cpufreq_driver
->boost_enabled
;
2438 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2440 /*********************************************************************
2441 * FREQUENCY INVARIANT ACCOUNTING SUPPORT *
2442 *********************************************************************/
2444 __weak
void arch_set_freq_scale(struct cpumask
*cpus
,
2445 unsigned long cur_freq
,
2446 unsigned long max_freq
)
2449 EXPORT_SYMBOL_GPL(arch_set_freq_scale
);
2451 /*********************************************************************
2452 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2453 *********************************************************************/
2454 static enum cpuhp_state hp_online
;
2456 static int cpuhp_cpufreq_online(unsigned int cpu
)
2458 cpufreq_online(cpu
);
2463 static int cpuhp_cpufreq_offline(unsigned int cpu
)
2465 cpufreq_offline(cpu
);
2471 * cpufreq_register_driver - register a CPU Frequency driver
2472 * @driver_data: A struct cpufreq_driver containing the values#
2473 * submitted by the CPU Frequency driver.
2475 * Registers a CPU Frequency driver to this core code. This code
2476 * returns zero on success, -EEXIST when another driver got here first
2477 * (and isn't unregistered in the meantime).
2480 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2482 unsigned long flags
;
2485 if (cpufreq_disabled())
2488 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2489 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2490 driver_data
->target
) ||
2491 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2492 driver_data
->target
)) ||
2493 (!!driver_data
->get_intermediate
!= !!driver_data
->target_intermediate
))
2496 pr_debug("trying to register driver %s\n", driver_data
->name
);
2498 /* Protect against concurrent CPU online/offline. */
2501 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2502 if (cpufreq_driver
) {
2503 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2507 cpufreq_driver
= driver_data
;
2508 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2510 if (driver_data
->setpolicy
)
2511 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2513 if (cpufreq_boost_supported()) {
2514 ret
= create_boost_sysfs_file();
2516 goto err_null_driver
;
2519 ret
= subsys_interface_register(&cpufreq_interface
);
2521 goto err_boost_unreg
;
2523 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2524 list_empty(&cpufreq_policy_list
)) {
2525 /* if all ->init() calls failed, unregister */
2527 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2532 ret
= cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN
,
2534 cpuhp_cpufreq_online
,
2535 cpuhp_cpufreq_offline
);
2541 pr_debug("driver %s up and running\n", driver_data
->name
);
2545 subsys_interface_unregister(&cpufreq_interface
);
2547 remove_boost_sysfs_file();
2549 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2550 cpufreq_driver
= NULL
;
2551 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2556 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2559 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2561 * Unregister the current CPUFreq driver. Only call this if you have
2562 * the right to do so, i.e. if you have succeeded in initialising before!
2563 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2564 * currently not initialised.
2566 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2568 unsigned long flags
;
2570 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2573 pr_debug("unregistering driver %s\n", driver
->name
);
2575 /* Protect against concurrent cpu hotplug */
2577 subsys_interface_unregister(&cpufreq_interface
);
2578 remove_boost_sysfs_file();
2579 cpuhp_remove_state_nocalls_cpuslocked(hp_online
);
2581 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2583 cpufreq_driver
= NULL
;
2585 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2590 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2593 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2594 * or mutexes when secondary CPUs are halted.
2596 static struct syscore_ops cpufreq_syscore_ops
= {
2597 .shutdown
= cpufreq_suspend
,
2600 struct kobject
*cpufreq_global_kobject
;
2601 EXPORT_SYMBOL(cpufreq_global_kobject
);
2603 static int __init
cpufreq_core_init(void)
2605 if (cpufreq_disabled())
2608 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2609 BUG_ON(!cpufreq_global_kobject
);
2611 register_syscore_ops(&cpufreq_syscore_ops
);
2615 module_param(off
, int, 0444);
2616 core_initcall(cpufreq_core_init
);