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 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list
);
94 static int off __read_mostly
;
95 static int cpufreq_disabled(void)
99 void disable_cpufreq(void)
103 static DEFINE_MUTEX(cpufreq_governor_mutex
);
105 bool have_governor_per_policy(void)
107 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
109 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
111 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
113 if (have_governor_per_policy())
114 return &policy
->kobj
;
116 return cpufreq_global_kobject
;
118 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
120 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
126 cur_wall_time
= jiffies64_to_nsecs(get_jiffies_64());
128 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
129 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
130 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
131 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
132 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
133 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
135 idle_time
= cur_wall_time
- busy_time
;
137 *wall
= div_u64(cur_wall_time
, NSEC_PER_USEC
);
139 return div_u64(idle_time
, NSEC_PER_USEC
);
142 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
144 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
146 if (idle_time
== -1ULL)
147 return get_cpu_idle_time_jiffy(cpu
, wall
);
149 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
153 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
155 __weak
void arch_set_freq_scale(struct cpumask
*cpus
, unsigned long cur_freq
,
156 unsigned long max_freq
)
159 EXPORT_SYMBOL_GPL(arch_set_freq_scale
);
162 * This is a generic cpufreq init() routine which can be used by cpufreq
163 * drivers of SMP systems. It will do following:
164 * - validate & show freq table passed
165 * - set policies transition latency
166 * - policy->cpus with all possible CPUs
168 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
169 struct cpufreq_frequency_table
*table
,
170 unsigned int transition_latency
)
172 policy
->freq_table
= table
;
173 policy
->cpuinfo
.transition_latency
= transition_latency
;
176 * The driver only supports the SMP configuration where all processors
177 * share the clock and voltage and clock.
179 cpumask_setall(policy
->cpus
);
183 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
185 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
187 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
189 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
191 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
193 unsigned int cpufreq_generic_get(unsigned int cpu
)
195 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
197 if (!policy
|| IS_ERR(policy
->clk
)) {
198 pr_err("%s: No %s associated to cpu: %d\n",
199 __func__
, policy
? "clk" : "policy", cpu
);
203 return clk_get_rate(policy
->clk
) / 1000;
205 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
208 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
210 * @cpu: cpu to find policy for.
212 * This returns policy for 'cpu', returns NULL if it doesn't exist.
213 * It also increments the kobject reference count to mark it busy and so would
214 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
215 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
216 * freed as that depends on the kobj count.
218 * Return: A valid policy on success, otherwise NULL on failure.
220 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
222 struct cpufreq_policy
*policy
= NULL
;
225 if (WARN_ON(cpu
>= nr_cpu_ids
))
228 /* get the cpufreq driver */
229 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
231 if (cpufreq_driver
) {
233 policy
= cpufreq_cpu_get_raw(cpu
);
235 kobject_get(&policy
->kobj
);
238 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
242 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
245 * cpufreq_cpu_put: Decrements the usage count of a policy
247 * @policy: policy earlier returned by cpufreq_cpu_get().
249 * This decrements the kobject reference count incremented earlier by calling
252 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
254 kobject_put(&policy
->kobj
);
256 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
258 /*********************************************************************
259 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
260 *********************************************************************/
263 * adjust_jiffies - adjust the system "loops_per_jiffy"
265 * This function alters the system "loops_per_jiffy" for the clock
266 * speed change. Note that loops_per_jiffy cannot be updated on SMP
267 * systems as each CPU might be scaled differently. So, use the arch
268 * per-CPU loops_per_jiffy value wherever possible.
270 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
273 static unsigned long l_p_j_ref
;
274 static unsigned int l_p_j_ref_freq
;
276 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
279 if (!l_p_j_ref_freq
) {
280 l_p_j_ref
= loops_per_jiffy
;
281 l_p_j_ref_freq
= ci
->old
;
282 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
283 l_p_j_ref
, l_p_j_ref_freq
);
285 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
286 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
288 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
289 loops_per_jiffy
, ci
->new);
295 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
296 * @policy: cpufreq policy to enable fast frequency switching for.
297 * @freqs: contain details of the frequency update.
298 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
300 * This function calls the transition notifiers and the "adjust_jiffies"
301 * function. It is called twice on all CPU frequency changes that have
304 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
305 struct cpufreq_freqs
*freqs
,
308 BUG_ON(irqs_disabled());
310 if (cpufreq_disabled())
313 freqs
->flags
= cpufreq_driver
->flags
;
314 pr_debug("notification %u of frequency transition to %u kHz\n",
318 case CPUFREQ_PRECHANGE
:
320 * Detect if the driver reported a value as "old frequency"
321 * which is not equal to what the cpufreq core thinks is
324 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
325 if (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
;
332 for_each_cpu(freqs
->cpu
, policy
->cpus
) {
333 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
334 CPUFREQ_PRECHANGE
, freqs
);
337 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
340 case CPUFREQ_POSTCHANGE
:
341 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
342 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs
->new,
343 cpumask_pr_args(policy
->cpus
));
345 for_each_cpu(freqs
->cpu
, policy
->cpus
) {
346 trace_cpu_frequency(freqs
->new, freqs
->cpu
);
347 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
348 CPUFREQ_POSTCHANGE
, freqs
);
351 cpufreq_stats_record_transition(policy
, freqs
->new);
352 policy
->cur
= freqs
->new;
356 /* Do post notifications when there are chances that transition has failed */
357 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
358 struct cpufreq_freqs
*freqs
, int transition_failed
)
360 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
361 if (!transition_failed
)
364 swap(freqs
->old
, freqs
->new);
365 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
366 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
369 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
370 struct cpufreq_freqs
*freqs
)
374 * Catch double invocations of _begin() which lead to self-deadlock.
375 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
376 * doesn't invoke _begin() on their behalf, and hence the chances of
377 * double invocations are very low. Moreover, there are scenarios
378 * where these checks can emit false-positive warnings in these
379 * drivers; so we avoid that by skipping them altogether.
381 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
382 && current
== policy
->transition_task
);
385 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
387 spin_lock(&policy
->transition_lock
);
389 if (unlikely(policy
->transition_ongoing
)) {
390 spin_unlock(&policy
->transition_lock
);
394 policy
->transition_ongoing
= true;
395 policy
->transition_task
= current
;
397 spin_unlock(&policy
->transition_lock
);
399 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
401 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
403 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
404 struct cpufreq_freqs
*freqs
, int transition_failed
)
406 if (unlikely(WARN_ON(!policy
->transition_ongoing
)))
409 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
411 policy
->transition_ongoing
= false;
412 policy
->transition_task
= NULL
;
414 wake_up(&policy
->transition_wait
);
416 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
419 * Fast frequency switching status count. Positive means "enabled", negative
420 * means "disabled" and 0 means "not decided yet".
422 static int cpufreq_fast_switch_count
;
423 static DEFINE_MUTEX(cpufreq_fast_switch_lock
);
425 static void cpufreq_list_transition_notifiers(void)
427 struct notifier_block
*nb
;
429 pr_info("Registered transition notifiers:\n");
431 mutex_lock(&cpufreq_transition_notifier_list
.mutex
);
433 for (nb
= cpufreq_transition_notifier_list
.head
; nb
; nb
= nb
->next
)
434 pr_info("%pF\n", nb
->notifier_call
);
436 mutex_unlock(&cpufreq_transition_notifier_list
.mutex
);
440 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
441 * @policy: cpufreq policy to enable fast frequency switching for.
443 * Try to enable fast frequency switching for @policy.
445 * The attempt will fail if there is at least one transition notifier registered
446 * at this point, as fast frequency switching is quite fundamentally at odds
447 * with transition notifiers. Thus if successful, it will make registration of
448 * transition notifiers fail going forward.
450 void cpufreq_enable_fast_switch(struct cpufreq_policy
*policy
)
452 lockdep_assert_held(&policy
->rwsem
);
454 if (!policy
->fast_switch_possible
)
457 mutex_lock(&cpufreq_fast_switch_lock
);
458 if (cpufreq_fast_switch_count
>= 0) {
459 cpufreq_fast_switch_count
++;
460 policy
->fast_switch_enabled
= true;
462 pr_warn("CPU%u: Fast frequency switching not enabled\n",
464 cpufreq_list_transition_notifiers();
466 mutex_unlock(&cpufreq_fast_switch_lock
);
468 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch
);
471 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
472 * @policy: cpufreq policy to disable fast frequency switching for.
474 void cpufreq_disable_fast_switch(struct cpufreq_policy
*policy
)
476 mutex_lock(&cpufreq_fast_switch_lock
);
477 if (policy
->fast_switch_enabled
) {
478 policy
->fast_switch_enabled
= false;
479 if (!WARN_ON(cpufreq_fast_switch_count
<= 0))
480 cpufreq_fast_switch_count
--;
482 mutex_unlock(&cpufreq_fast_switch_lock
);
484 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch
);
487 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
489 * @target_freq: target frequency to resolve.
491 * The target to driver frequency mapping is cached in the policy.
493 * Return: Lowest driver-supported frequency greater than or equal to the
494 * given target_freq, subject to policy (min/max) and driver limitations.
496 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy
*policy
,
497 unsigned int target_freq
)
499 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
500 policy
->cached_target_freq
= target_freq
;
502 if (cpufreq_driver
->target_index
) {
505 idx
= cpufreq_frequency_table_target(policy
, target_freq
,
507 policy
->cached_resolved_idx
= idx
;
508 return policy
->freq_table
[idx
].frequency
;
511 if (cpufreq_driver
->resolve_freq
)
512 return cpufreq_driver
->resolve_freq(policy
, target_freq
);
516 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq
);
518 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy
*policy
)
520 unsigned int latency
;
522 if (policy
->transition_delay_us
)
523 return policy
->transition_delay_us
;
525 latency
= policy
->cpuinfo
.transition_latency
/ NSEC_PER_USEC
;
528 * For platforms that can change the frequency very fast (< 10
529 * us), the above formula gives a decent transition delay. But
530 * for platforms where transition_latency is in milliseconds, it
531 * ends up giving unrealistic values.
533 * Cap the default transition delay to 10 ms, which seems to be
534 * a reasonable amount of time after which we should reevaluate
537 return min(latency
* LATENCY_MULTIPLIER
, (unsigned int)10000);
540 return LATENCY_MULTIPLIER
;
542 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us
);
544 /*********************************************************************
546 *********************************************************************/
547 static ssize_t
show_boost(struct kobject
*kobj
,
548 struct kobj_attribute
*attr
, char *buf
)
550 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
553 static ssize_t
store_boost(struct kobject
*kobj
, struct kobj_attribute
*attr
,
554 const char *buf
, size_t count
)
558 ret
= sscanf(buf
, "%d", &enable
);
559 if (ret
!= 1 || enable
< 0 || enable
> 1)
562 if (cpufreq_boost_trigger_state(enable
)) {
563 pr_err("%s: Cannot %s BOOST!\n",
564 __func__
, enable
? "enable" : "disable");
568 pr_debug("%s: cpufreq BOOST %s\n",
569 __func__
, enable
? "enabled" : "disabled");
573 define_one_global_rw(boost
);
575 static struct cpufreq_governor
*find_governor(const char *str_governor
)
577 struct cpufreq_governor
*t
;
580 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
587 * cpufreq_parse_governor - parse a governor string
589 static int cpufreq_parse_governor(char *str_governor
,
590 struct cpufreq_policy
*policy
)
592 if (cpufreq_driver
->setpolicy
) {
593 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
594 policy
->policy
= CPUFREQ_POLICY_PERFORMANCE
;
598 if (!strncasecmp(str_governor
, "powersave", CPUFREQ_NAME_LEN
)) {
599 policy
->policy
= CPUFREQ_POLICY_POWERSAVE
;
603 struct cpufreq_governor
*t
;
605 mutex_lock(&cpufreq_governor_mutex
);
607 t
= find_governor(str_governor
);
611 mutex_unlock(&cpufreq_governor_mutex
);
613 ret
= request_module("cpufreq_%s", str_governor
);
617 mutex_lock(&cpufreq_governor_mutex
);
619 t
= find_governor(str_governor
);
621 if (t
&& !try_module_get(t
->owner
))
624 mutex_unlock(&cpufreq_governor_mutex
);
627 policy
->governor
= t
;
636 * cpufreq_per_cpu_attr_read() / show_##file_name() -
637 * print out cpufreq information
639 * Write out information from cpufreq_driver->policy[cpu]; object must be
643 #define show_one(file_name, object) \
644 static ssize_t show_##file_name \
645 (struct cpufreq_policy *policy, char *buf) \
647 return sprintf(buf, "%u\n", policy->object); \
650 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
651 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
652 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
653 show_one(scaling_min_freq
, min
);
654 show_one(scaling_max_freq
, max
);
656 __weak
unsigned int arch_freq_get_on_cpu(int cpu
)
661 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
666 freq
= arch_freq_get_on_cpu(policy
->cpu
);
668 ret
= sprintf(buf
, "%u\n", freq
);
669 else if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&&
671 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
673 ret
= sprintf(buf
, "%u\n", policy
->cur
);
677 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
678 struct cpufreq_policy
*new_policy
);
681 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
683 #define store_one(file_name, object) \
684 static ssize_t store_##file_name \
685 (struct cpufreq_policy *policy, const char *buf, size_t count) \
688 struct cpufreq_policy new_policy; \
690 memcpy(&new_policy, policy, sizeof(*policy)); \
691 new_policy.min = policy->user_policy.min; \
692 new_policy.max = policy->user_policy.max; \
694 ret = sscanf(buf, "%u", &new_policy.object); \
698 temp = new_policy.object; \
699 ret = cpufreq_set_policy(policy, &new_policy); \
701 policy->user_policy.object = temp; \
703 return ret ? ret : count; \
706 store_one(scaling_min_freq
, min
);
707 store_one(scaling_max_freq
, max
);
710 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
712 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
715 unsigned int cur_freq
= __cpufreq_get(policy
);
718 return sprintf(buf
, "%u\n", cur_freq
);
720 return sprintf(buf
, "<unknown>\n");
724 * show_scaling_governor - show the current policy for the specified CPU
726 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
728 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
729 return sprintf(buf
, "powersave\n");
730 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
731 return sprintf(buf
, "performance\n");
732 else if (policy
->governor
)
733 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
734 policy
->governor
->name
);
739 * store_scaling_governor - store policy for the specified CPU
741 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
742 const char *buf
, size_t count
)
745 char str_governor
[16];
746 struct cpufreq_policy new_policy
;
748 memcpy(&new_policy
, policy
, sizeof(*policy
));
750 ret
= sscanf(buf
, "%15s", str_governor
);
754 if (cpufreq_parse_governor(str_governor
, &new_policy
))
757 ret
= cpufreq_set_policy(policy
, &new_policy
);
759 if (new_policy
.governor
)
760 module_put(new_policy
.governor
->owner
);
762 return ret
? ret
: count
;
766 * show_scaling_driver - show the cpufreq driver currently loaded
768 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
770 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
774 * show_scaling_available_governors - show the available CPUfreq governors
776 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
780 struct cpufreq_governor
*t
;
783 i
+= sprintf(buf
, "performance powersave");
787 for_each_governor(t
) {
788 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
789 - (CPUFREQ_NAME_LEN
+ 2)))
791 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
794 i
+= sprintf(&buf
[i
], "\n");
798 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
803 for_each_cpu(cpu
, mask
) {
805 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
806 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
807 if (i
>= (PAGE_SIZE
- 5))
810 i
+= sprintf(&buf
[i
], "\n");
813 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
816 * show_related_cpus - show the CPUs affected by each transition even if
817 * hw coordination is in use
819 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
821 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
825 * show_affected_cpus - show the CPUs affected by each transition
827 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
829 return cpufreq_show_cpus(policy
->cpus
, buf
);
832 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
833 const char *buf
, size_t count
)
835 unsigned int freq
= 0;
838 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
841 ret
= sscanf(buf
, "%u", &freq
);
845 policy
->governor
->store_setspeed(policy
, freq
);
850 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
852 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
853 return sprintf(buf
, "<unsupported>\n");
855 return policy
->governor
->show_setspeed(policy
, buf
);
859 * show_bios_limit - show the current cpufreq HW/BIOS limitation
861 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
865 if (cpufreq_driver
->bios_limit
) {
866 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
868 return sprintf(buf
, "%u\n", limit
);
870 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
873 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
874 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
875 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
876 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
877 cpufreq_freq_attr_ro(scaling_available_governors
);
878 cpufreq_freq_attr_ro(scaling_driver
);
879 cpufreq_freq_attr_ro(scaling_cur_freq
);
880 cpufreq_freq_attr_ro(bios_limit
);
881 cpufreq_freq_attr_ro(related_cpus
);
882 cpufreq_freq_attr_ro(affected_cpus
);
883 cpufreq_freq_attr_rw(scaling_min_freq
);
884 cpufreq_freq_attr_rw(scaling_max_freq
);
885 cpufreq_freq_attr_rw(scaling_governor
);
886 cpufreq_freq_attr_rw(scaling_setspeed
);
888 static struct attribute
*default_attrs
[] = {
889 &cpuinfo_min_freq
.attr
,
890 &cpuinfo_max_freq
.attr
,
891 &cpuinfo_transition_latency
.attr
,
892 &scaling_min_freq
.attr
,
893 &scaling_max_freq
.attr
,
896 &scaling_governor
.attr
,
897 &scaling_driver
.attr
,
898 &scaling_available_governors
.attr
,
899 &scaling_setspeed
.attr
,
903 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
904 #define to_attr(a) container_of(a, struct freq_attr, attr)
906 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
908 struct cpufreq_policy
*policy
= to_policy(kobj
);
909 struct freq_attr
*fattr
= to_attr(attr
);
915 down_read(&policy
->rwsem
);
916 ret
= fattr
->show(policy
, buf
);
917 up_read(&policy
->rwsem
);
922 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
923 const char *buf
, size_t count
)
925 struct cpufreq_policy
*policy
= to_policy(kobj
);
926 struct freq_attr
*fattr
= to_attr(attr
);
927 ssize_t ret
= -EINVAL
;
933 * cpus_read_trylock() is used here to work around a circular lock
934 * dependency problem with respect to the cpufreq_register_driver().
936 if (!cpus_read_trylock())
939 if (cpu_online(policy
->cpu
)) {
940 down_write(&policy
->rwsem
);
941 ret
= fattr
->store(policy
, buf
, count
);
942 up_write(&policy
->rwsem
);
950 static void cpufreq_sysfs_release(struct kobject
*kobj
)
952 struct cpufreq_policy
*policy
= to_policy(kobj
);
953 pr_debug("last reference is dropped\n");
954 complete(&policy
->kobj_unregister
);
957 static const struct sysfs_ops sysfs_ops
= {
962 static struct kobj_type ktype_cpufreq
= {
963 .sysfs_ops
= &sysfs_ops
,
964 .default_attrs
= default_attrs
,
965 .release
= cpufreq_sysfs_release
,
968 static void add_cpu_dev_symlink(struct cpufreq_policy
*policy
, unsigned int cpu
)
970 struct device
*dev
= get_cpu_device(cpu
);
975 if (cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
))
978 dev_dbg(dev
, "%s: Adding symlink\n", __func__
);
979 if (sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq"))
980 dev_err(dev
, "cpufreq symlink creation failed\n");
983 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
,
986 dev_dbg(dev
, "%s: Removing symlink\n", __func__
);
987 sysfs_remove_link(&dev
->kobj
, "cpufreq");
990 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
992 struct freq_attr
**drv_attr
;
995 /* set up files for this cpu device */
996 drv_attr
= cpufreq_driver
->attr
;
997 while (drv_attr
&& *drv_attr
) {
998 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
1003 if (cpufreq_driver
->get
) {
1004 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
1009 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
1013 if (cpufreq_driver
->bios_limit
) {
1014 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
1022 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
1027 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
1029 struct cpufreq_governor
*gov
= NULL
;
1030 struct cpufreq_policy new_policy
;
1032 memcpy(&new_policy
, policy
, sizeof(*policy
));
1034 /* Update governor of new_policy to the governor used before hotplug */
1035 gov
= find_governor(policy
->last_governor
);
1037 pr_debug("Restoring governor %s for cpu %d\n",
1038 policy
->governor
->name
, policy
->cpu
);
1040 gov
= cpufreq_default_governor();
1045 new_policy
.governor
= gov
;
1047 /* Use the default policy if there is no last_policy. */
1048 if (cpufreq_driver
->setpolicy
) {
1049 if (policy
->last_policy
)
1050 new_policy
.policy
= policy
->last_policy
;
1052 cpufreq_parse_governor(gov
->name
, &new_policy
);
1054 /* set default policy */
1055 return cpufreq_set_policy(policy
, &new_policy
);
1058 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1062 /* Has this CPU been taken care of already? */
1063 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1066 down_write(&policy
->rwsem
);
1068 cpufreq_stop_governor(policy
);
1070 cpumask_set_cpu(cpu
, policy
->cpus
);
1073 ret
= cpufreq_start_governor(policy
);
1075 pr_err("%s: Failed to start governor\n", __func__
);
1077 up_write(&policy
->rwsem
);
1081 static void handle_update(struct work_struct
*work
)
1083 struct cpufreq_policy
*policy
=
1084 container_of(work
, struct cpufreq_policy
, update
);
1085 unsigned int cpu
= policy
->cpu
;
1086 pr_debug("handle_update for cpu %u called\n", cpu
);
1087 cpufreq_update_policy(cpu
);
1090 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1092 struct cpufreq_policy
*policy
;
1095 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1099 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1100 goto err_free_policy
;
1102 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1103 goto err_free_cpumask
;
1105 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1106 goto err_free_rcpumask
;
1108 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
1109 cpufreq_global_kobject
, "policy%u", cpu
);
1111 pr_err("%s: failed to init policy->kobj: %d\n", __func__
, ret
);
1112 kobject_put(&policy
->kobj
);
1113 goto err_free_real_cpus
;
1116 INIT_LIST_HEAD(&policy
->policy_list
);
1117 init_rwsem(&policy
->rwsem
);
1118 spin_lock_init(&policy
->transition_lock
);
1119 init_waitqueue_head(&policy
->transition_wait
);
1120 init_completion(&policy
->kobj_unregister
);
1121 INIT_WORK(&policy
->update
, handle_update
);
1127 free_cpumask_var(policy
->real_cpus
);
1129 free_cpumask_var(policy
->related_cpus
);
1131 free_cpumask_var(policy
->cpus
);
1138 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
)
1140 struct kobject
*kobj
;
1141 struct completion
*cmp
;
1143 down_write(&policy
->rwsem
);
1144 cpufreq_stats_free_table(policy
);
1145 kobj
= &policy
->kobj
;
1146 cmp
= &policy
->kobj_unregister
;
1147 up_write(&policy
->rwsem
);
1151 * We need to make sure that the underlying kobj is
1152 * actually not referenced anymore by anybody before we
1153 * proceed with unloading.
1155 pr_debug("waiting for dropping of refcount\n");
1156 wait_for_completion(cmp
);
1157 pr_debug("wait complete\n");
1160 static void cpufreq_policy_free(struct cpufreq_policy
*policy
)
1162 unsigned long flags
;
1165 /* Remove policy from list */
1166 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1167 list_del(&policy
->policy_list
);
1169 for_each_cpu(cpu
, policy
->related_cpus
)
1170 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1171 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1173 cpufreq_policy_put_kobj(policy
);
1174 free_cpumask_var(policy
->real_cpus
);
1175 free_cpumask_var(policy
->related_cpus
);
1176 free_cpumask_var(policy
->cpus
);
1180 static int cpufreq_online(unsigned int cpu
)
1182 struct cpufreq_policy
*policy
;
1184 unsigned long flags
;
1188 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1190 /* Check if this CPU already has a policy to manage it */
1191 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1193 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1194 if (!policy_is_inactive(policy
))
1195 return cpufreq_add_policy_cpu(policy
, cpu
);
1197 /* This is the only online CPU for the policy. Start over. */
1199 down_write(&policy
->rwsem
);
1201 policy
->governor
= NULL
;
1202 up_write(&policy
->rwsem
);
1205 policy
= cpufreq_policy_alloc(cpu
);
1210 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1212 /* call driver. From then on the cpufreq must be able
1213 * to accept all calls to ->verify and ->setpolicy for this CPU
1215 ret
= cpufreq_driver
->init(policy
);
1217 pr_debug("initialization failed\n");
1218 goto out_free_policy
;
1221 ret
= cpufreq_table_validate_and_sort(policy
);
1223 goto out_exit_policy
;
1225 down_write(&policy
->rwsem
);
1228 /* related_cpus should at least include policy->cpus. */
1229 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1233 * affected cpus must always be the one, which are online. We aren't
1234 * managing offline cpus here.
1236 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1239 policy
->user_policy
.min
= policy
->min
;
1240 policy
->user_policy
.max
= policy
->max
;
1242 for_each_cpu(j
, policy
->related_cpus
) {
1243 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1244 add_cpu_dev_symlink(policy
, j
);
1247 policy
->min
= policy
->user_policy
.min
;
1248 policy
->max
= policy
->user_policy
.max
;
1251 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
1252 policy
->cur
= cpufreq_driver
->get(policy
->cpu
);
1254 pr_err("%s: ->get() failed\n", __func__
);
1255 goto out_destroy_policy
;
1260 * Sometimes boot loaders set CPU frequency to a value outside of
1261 * frequency table present with cpufreq core. In such cases CPU might be
1262 * unstable if it has to run on that frequency for long duration of time
1263 * and so its better to set it to a frequency which is specified in
1264 * freq-table. This also makes cpufreq stats inconsistent as
1265 * cpufreq-stats would fail to register because current frequency of CPU
1266 * isn't found in freq-table.
1268 * Because we don't want this change to effect boot process badly, we go
1269 * for the next freq which is >= policy->cur ('cur' must be set by now,
1270 * otherwise we will end up setting freq to lowest of the table as 'cur'
1271 * is initialized to zero).
1273 * We are passing target-freq as "policy->cur - 1" otherwise
1274 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1275 * equal to target-freq.
1277 if ((cpufreq_driver
->flags
& CPUFREQ_NEED_INITIAL_FREQ_CHECK
)
1279 /* Are we running at unknown frequency ? */
1280 ret
= cpufreq_frequency_table_get_index(policy
, policy
->cur
);
1281 if (ret
== -EINVAL
) {
1282 /* Warn user and fix it */
1283 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1284 __func__
, policy
->cpu
, policy
->cur
);
1285 ret
= __cpufreq_driver_target(policy
, policy
->cur
- 1,
1286 CPUFREQ_RELATION_L
);
1289 * Reaching here after boot in a few seconds may not
1290 * mean that system will remain stable at "unknown"
1291 * frequency for longer duration. Hence, a BUG_ON().
1294 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1295 __func__
, policy
->cpu
, policy
->cur
);
1300 ret
= cpufreq_add_dev_interface(policy
);
1302 goto out_destroy_policy
;
1304 cpufreq_stats_create_table(policy
);
1306 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1307 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1308 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1311 ret
= cpufreq_init_policy(policy
);
1313 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1314 __func__
, cpu
, ret
);
1315 /* cpufreq_policy_free() will notify based on this */
1317 goto out_destroy_policy
;
1320 up_write(&policy
->rwsem
);
1322 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1324 /* Callback for handling stuff after policy is ready */
1325 if (cpufreq_driver
->ready
)
1326 cpufreq_driver
->ready(policy
);
1328 pr_debug("initialization complete\n");
1333 for_each_cpu(j
, policy
->real_cpus
)
1334 remove_cpu_dev_symlink(policy
, get_cpu_device(j
));
1336 up_write(&policy
->rwsem
);
1339 if (cpufreq_driver
->exit
)
1340 cpufreq_driver
->exit(policy
);
1343 cpufreq_policy_free(policy
);
1348 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1350 * @sif: Subsystem interface structure pointer (not used)
1352 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1354 struct cpufreq_policy
*policy
;
1355 unsigned cpu
= dev
->id
;
1358 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1360 if (cpu_online(cpu
)) {
1361 ret
= cpufreq_online(cpu
);
1366 /* Create sysfs link on CPU registration */
1367 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1369 add_cpu_dev_symlink(policy
, cpu
);
1374 static int cpufreq_offline(unsigned int cpu
)
1376 struct cpufreq_policy
*policy
;
1379 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1381 policy
= cpufreq_cpu_get_raw(cpu
);
1383 pr_debug("%s: No cpu_data found\n", __func__
);
1387 down_write(&policy
->rwsem
);
1389 cpufreq_stop_governor(policy
);
1391 cpumask_clear_cpu(cpu
, policy
->cpus
);
1393 if (policy_is_inactive(policy
)) {
1395 strncpy(policy
->last_governor
, policy
->governor
->name
,
1398 policy
->last_policy
= policy
->policy
;
1399 } else if (cpu
== policy
->cpu
) {
1400 /* Nominate new CPU */
1401 policy
->cpu
= cpumask_any(policy
->cpus
);
1404 /* Start governor again for active policy */
1405 if (!policy_is_inactive(policy
)) {
1407 ret
= cpufreq_start_governor(policy
);
1409 pr_err("%s: Failed to start governor\n", __func__
);
1415 if (cpufreq_driver
->stop_cpu
)
1416 cpufreq_driver
->stop_cpu(policy
);
1419 cpufreq_exit_governor(policy
);
1422 * Perform the ->exit() even during light-weight tear-down,
1423 * since this is a core component, and is essential for the
1424 * subsequent light-weight ->init() to succeed.
1426 if (cpufreq_driver
->exit
) {
1427 cpufreq_driver
->exit(policy
);
1428 policy
->freq_table
= NULL
;
1432 up_write(&policy
->rwsem
);
1437 * cpufreq_remove_dev - remove a CPU device
1439 * Removes the cpufreq interface for a CPU device.
1441 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1443 unsigned int cpu
= dev
->id
;
1444 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1449 if (cpu_online(cpu
))
1450 cpufreq_offline(cpu
);
1452 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1453 remove_cpu_dev_symlink(policy
, dev
);
1455 if (cpumask_empty(policy
->real_cpus
))
1456 cpufreq_policy_free(policy
);
1460 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1462 * @policy: policy managing CPUs
1463 * @new_freq: CPU frequency the CPU actually runs at
1465 * We adjust to current frequency first, and need to clean up later.
1466 * So either call to cpufreq_update_policy() or schedule handle_update()).
1468 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1469 unsigned int new_freq
)
1471 struct cpufreq_freqs freqs
;
1473 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1474 policy
->cur
, new_freq
);
1476 freqs
.old
= policy
->cur
;
1477 freqs
.new = new_freq
;
1479 cpufreq_freq_transition_begin(policy
, &freqs
);
1480 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1484 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1487 * This is the last known freq, without actually getting it from the driver.
1488 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1490 unsigned int cpufreq_quick_get(unsigned int cpu
)
1492 struct cpufreq_policy
*policy
;
1493 unsigned int ret_freq
= 0;
1494 unsigned long flags
;
1496 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1498 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
) {
1499 ret_freq
= cpufreq_driver
->get(cpu
);
1500 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1504 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1506 policy
= cpufreq_cpu_get(cpu
);
1508 ret_freq
= policy
->cur
;
1509 cpufreq_cpu_put(policy
);
1514 EXPORT_SYMBOL(cpufreq_quick_get
);
1517 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1520 * Just return the max possible frequency for a given CPU.
1522 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1524 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1525 unsigned int ret_freq
= 0;
1528 ret_freq
= policy
->max
;
1529 cpufreq_cpu_put(policy
);
1534 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1536 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1538 unsigned int ret_freq
= 0;
1540 if (unlikely(policy_is_inactive(policy
)) || !cpufreq_driver
->get
)
1543 ret_freq
= cpufreq_driver
->get(policy
->cpu
);
1546 * If fast frequency switching is used with the given policy, the check
1547 * against policy->cur is pointless, so skip it in that case too.
1549 if (policy
->fast_switch_enabled
)
1552 if (ret_freq
&& policy
->cur
&&
1553 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1554 /* verify no discrepancy between actual and
1555 saved value exists */
1556 if (unlikely(ret_freq
!= policy
->cur
)) {
1557 cpufreq_out_of_sync(policy
, ret_freq
);
1558 schedule_work(&policy
->update
);
1566 * cpufreq_get - get the current CPU frequency (in kHz)
1569 * Get the CPU current (static) CPU frequency
1571 unsigned int cpufreq_get(unsigned int cpu
)
1573 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1574 unsigned int ret_freq
= 0;
1577 down_read(&policy
->rwsem
);
1578 ret_freq
= __cpufreq_get(policy
);
1579 up_read(&policy
->rwsem
);
1581 cpufreq_cpu_put(policy
);
1586 EXPORT_SYMBOL(cpufreq_get
);
1588 static unsigned int cpufreq_update_current_freq(struct cpufreq_policy
*policy
)
1590 unsigned int new_freq
;
1592 new_freq
= cpufreq_driver
->get(policy
->cpu
);
1597 pr_debug("cpufreq: Driver did not initialize current freq\n");
1598 policy
->cur
= new_freq
;
1599 } else if (policy
->cur
!= new_freq
&& has_target()) {
1600 cpufreq_out_of_sync(policy
, new_freq
);
1606 static struct subsys_interface cpufreq_interface
= {
1608 .subsys
= &cpu_subsys
,
1609 .add_dev
= cpufreq_add_dev
,
1610 .remove_dev
= cpufreq_remove_dev
,
1614 * In case platform wants some specific frequency to be configured
1617 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1621 if (!policy
->suspend_freq
) {
1622 pr_debug("%s: suspend_freq not defined\n", __func__
);
1626 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1627 policy
->suspend_freq
);
1629 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1630 CPUFREQ_RELATION_H
);
1632 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1633 __func__
, policy
->suspend_freq
, ret
);
1637 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1640 * cpufreq_suspend() - Suspend CPUFreq governors
1642 * Called during system wide Suspend/Hibernate cycles for suspending governors
1643 * as some platforms can't change frequency after this point in suspend cycle.
1644 * Because some of the devices (like: i2c, regulators, etc) they use for
1645 * changing frequency are suspended quickly after this point.
1647 void cpufreq_suspend(void)
1649 struct cpufreq_policy
*policy
;
1651 if (!cpufreq_driver
)
1654 if (!has_target() && !cpufreq_driver
->suspend
)
1657 pr_debug("%s: Suspending Governors\n", __func__
);
1659 for_each_active_policy(policy
) {
1661 down_write(&policy
->rwsem
);
1662 cpufreq_stop_governor(policy
);
1663 up_write(&policy
->rwsem
);
1666 if (cpufreq_driver
->suspend
&& cpufreq_driver
->suspend(policy
))
1667 pr_err("%s: Failed to suspend driver: %p\n", __func__
,
1672 cpufreq_suspended
= true;
1676 * cpufreq_resume() - Resume CPUFreq governors
1678 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1679 * are suspended with cpufreq_suspend().
1681 void cpufreq_resume(void)
1683 struct cpufreq_policy
*policy
;
1686 if (!cpufreq_driver
)
1689 if (unlikely(!cpufreq_suspended
))
1692 cpufreq_suspended
= false;
1694 if (!has_target() && !cpufreq_driver
->resume
)
1697 pr_debug("%s: Resuming Governors\n", __func__
);
1699 for_each_active_policy(policy
) {
1700 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
)) {
1701 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1703 } else if (has_target()) {
1704 down_write(&policy
->rwsem
);
1705 ret
= cpufreq_start_governor(policy
);
1706 up_write(&policy
->rwsem
);
1709 pr_err("%s: Failed to start governor for policy: %p\n",
1716 * cpufreq_get_current_driver - return current driver's name
1718 * Return the name string of the currently loaded cpufreq driver
1721 const char *cpufreq_get_current_driver(void)
1724 return cpufreq_driver
->name
;
1728 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1731 * cpufreq_get_driver_data - return current driver data
1733 * Return the private data of the currently loaded cpufreq
1734 * driver, or NULL if no cpufreq driver is loaded.
1736 void *cpufreq_get_driver_data(void)
1739 return cpufreq_driver
->driver_data
;
1743 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1745 /*********************************************************************
1746 * NOTIFIER LISTS INTERFACE *
1747 *********************************************************************/
1750 * cpufreq_register_notifier - register a driver with cpufreq
1751 * @nb: notifier function to register
1752 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1754 * Add a driver to one of two lists: either a list of drivers that
1755 * are notified about clock rate changes (once before and once after
1756 * the transition), or a list of drivers that are notified about
1757 * changes in cpufreq policy.
1759 * This function may sleep, and has the same return conditions as
1760 * blocking_notifier_chain_register.
1762 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1766 if (cpufreq_disabled())
1770 case CPUFREQ_TRANSITION_NOTIFIER
:
1771 mutex_lock(&cpufreq_fast_switch_lock
);
1773 if (cpufreq_fast_switch_count
> 0) {
1774 mutex_unlock(&cpufreq_fast_switch_lock
);
1777 ret
= srcu_notifier_chain_register(
1778 &cpufreq_transition_notifier_list
, nb
);
1780 cpufreq_fast_switch_count
--;
1782 mutex_unlock(&cpufreq_fast_switch_lock
);
1784 case CPUFREQ_POLICY_NOTIFIER
:
1785 ret
= blocking_notifier_chain_register(
1786 &cpufreq_policy_notifier_list
, nb
);
1794 EXPORT_SYMBOL(cpufreq_register_notifier
);
1797 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1798 * @nb: notifier block to be unregistered
1799 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1801 * Remove a driver from the CPU frequency notifier list.
1803 * This function may sleep, and has the same return conditions as
1804 * blocking_notifier_chain_unregister.
1806 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1810 if (cpufreq_disabled())
1814 case CPUFREQ_TRANSITION_NOTIFIER
:
1815 mutex_lock(&cpufreq_fast_switch_lock
);
1817 ret
= srcu_notifier_chain_unregister(
1818 &cpufreq_transition_notifier_list
, nb
);
1819 if (!ret
&& !WARN_ON(cpufreq_fast_switch_count
>= 0))
1820 cpufreq_fast_switch_count
++;
1822 mutex_unlock(&cpufreq_fast_switch_lock
);
1824 case CPUFREQ_POLICY_NOTIFIER
:
1825 ret
= blocking_notifier_chain_unregister(
1826 &cpufreq_policy_notifier_list
, nb
);
1834 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1837 /*********************************************************************
1839 *********************************************************************/
1842 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1843 * @policy: cpufreq policy to switch the frequency for.
1844 * @target_freq: New frequency to set (may be approximate).
1846 * Carry out a fast frequency switch without sleeping.
1848 * The driver's ->fast_switch() callback invoked by this function must be
1849 * suitable for being called from within RCU-sched read-side critical sections
1850 * and it is expected to select the minimum available frequency greater than or
1851 * equal to @target_freq (CPUFREQ_RELATION_L).
1853 * This function must not be called if policy->fast_switch_enabled is unset.
1855 * Governors calling this function must guarantee that it will never be invoked
1856 * twice in parallel for the same policy and that it will never be called in
1857 * parallel with either ->target() or ->target_index() for the same policy.
1859 * Returns the actual frequency set for the CPU.
1861 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
1862 * error condition, the hardware configuration must be preserved.
1864 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy
*policy
,
1865 unsigned int target_freq
)
1867 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1869 return cpufreq_driver
->fast_switch(policy
, target_freq
);
1871 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch
);
1873 /* Must set freqs->new to intermediate frequency */
1874 static int __target_intermediate(struct cpufreq_policy
*policy
,
1875 struct cpufreq_freqs
*freqs
, int index
)
1879 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
1881 /* We don't need to switch to intermediate freq */
1885 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1886 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
1888 cpufreq_freq_transition_begin(policy
, freqs
);
1889 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
1890 cpufreq_freq_transition_end(policy
, freqs
, ret
);
1893 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1899 static int __target_index(struct cpufreq_policy
*policy
, int index
)
1901 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
1902 unsigned int intermediate_freq
= 0;
1903 unsigned int newfreq
= policy
->freq_table
[index
].frequency
;
1904 int retval
= -EINVAL
;
1907 if (newfreq
== policy
->cur
)
1910 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
1912 /* Handle switching to intermediate frequency */
1913 if (cpufreq_driver
->get_intermediate
) {
1914 retval
= __target_intermediate(policy
, &freqs
, index
);
1918 intermediate_freq
= freqs
.new;
1919 /* Set old freq to intermediate */
1920 if (intermediate_freq
)
1921 freqs
.old
= freqs
.new;
1924 freqs
.new = newfreq
;
1925 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1926 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
1928 cpufreq_freq_transition_begin(policy
, &freqs
);
1931 retval
= cpufreq_driver
->target_index(policy
, index
);
1933 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
1937 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
1940 * Failed after setting to intermediate freq? Driver should have
1941 * reverted back to initial frequency and so should we. Check
1942 * here for intermediate_freq instead of get_intermediate, in
1943 * case we haven't switched to intermediate freq at all.
1945 if (unlikely(retval
&& intermediate_freq
)) {
1946 freqs
.old
= intermediate_freq
;
1947 freqs
.new = policy
->restore_freq
;
1948 cpufreq_freq_transition_begin(policy
, &freqs
);
1949 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1956 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
1957 unsigned int target_freq
,
1958 unsigned int relation
)
1960 unsigned int old_target_freq
= target_freq
;
1963 if (cpufreq_disabled())
1966 /* Make sure that target_freq is within supported range */
1967 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1969 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1970 policy
->cpu
, target_freq
, relation
, old_target_freq
);
1973 * This might look like a redundant call as we are checking it again
1974 * after finding index. But it is left intentionally for cases where
1975 * exactly same freq is called again and so we can save on few function
1978 if (target_freq
== policy
->cur
)
1981 /* Save last value to restore later on errors */
1982 policy
->restore_freq
= policy
->cur
;
1984 if (cpufreq_driver
->target
)
1985 return cpufreq_driver
->target(policy
, target_freq
, relation
);
1987 if (!cpufreq_driver
->target_index
)
1990 index
= cpufreq_frequency_table_target(policy
, target_freq
, relation
);
1992 return __target_index(policy
, index
);
1994 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
1996 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
1997 unsigned int target_freq
,
1998 unsigned int relation
)
2002 down_write(&policy
->rwsem
);
2004 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
2006 up_write(&policy
->rwsem
);
2010 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
2012 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
2017 static int cpufreq_init_governor(struct cpufreq_policy
*policy
)
2021 /* Don't start any governor operations if we are entering suspend */
2022 if (cpufreq_suspended
)
2025 * Governor might not be initiated here if ACPI _PPC changed
2026 * notification happened, so check it.
2028 if (!policy
->governor
)
2031 /* Platform doesn't want dynamic frequency switching ? */
2032 if (policy
->governor
->dynamic_switching
&&
2033 cpufreq_driver
->flags
& CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
) {
2034 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
2037 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2038 policy
->governor
->name
, gov
->name
);
2039 policy
->governor
= gov
;
2045 if (!try_module_get(policy
->governor
->owner
))
2048 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2050 if (policy
->governor
->init
) {
2051 ret
= policy
->governor
->init(policy
);
2053 module_put(policy
->governor
->owner
);
2061 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
)
2063 if (cpufreq_suspended
|| !policy
->governor
)
2066 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2068 if (policy
->governor
->exit
)
2069 policy
->governor
->exit(policy
);
2071 module_put(policy
->governor
->owner
);
2074 static int cpufreq_start_governor(struct cpufreq_policy
*policy
)
2078 if (cpufreq_suspended
)
2081 if (!policy
->governor
)
2084 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2086 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
)
2087 cpufreq_update_current_freq(policy
);
2089 if (policy
->governor
->start
) {
2090 ret
= policy
->governor
->start(policy
);
2095 if (policy
->governor
->limits
)
2096 policy
->governor
->limits(policy
);
2101 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
)
2103 if (cpufreq_suspended
|| !policy
->governor
)
2106 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2108 if (policy
->governor
->stop
)
2109 policy
->governor
->stop(policy
);
2112 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
)
2114 if (cpufreq_suspended
|| !policy
->governor
)
2117 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2119 if (policy
->governor
->limits
)
2120 policy
->governor
->limits(policy
);
2123 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2130 if (cpufreq_disabled())
2133 mutex_lock(&cpufreq_governor_mutex
);
2136 if (!find_governor(governor
->name
)) {
2138 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2141 mutex_unlock(&cpufreq_governor_mutex
);
2144 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2146 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2148 struct cpufreq_policy
*policy
;
2149 unsigned long flags
;
2154 if (cpufreq_disabled())
2157 /* clear last_governor for all inactive policies */
2158 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2159 for_each_inactive_policy(policy
) {
2160 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2161 policy
->governor
= NULL
;
2162 strcpy(policy
->last_governor
, "\0");
2165 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2167 mutex_lock(&cpufreq_governor_mutex
);
2168 list_del(&governor
->governor_list
);
2169 mutex_unlock(&cpufreq_governor_mutex
);
2171 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2174 /*********************************************************************
2175 * POLICY INTERFACE *
2176 *********************************************************************/
2179 * cpufreq_get_policy - get the current cpufreq_policy
2180 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2183 * Reads the current cpufreq policy.
2185 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2187 struct cpufreq_policy
*cpu_policy
;
2191 cpu_policy
= cpufreq_cpu_get(cpu
);
2195 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2197 cpufreq_cpu_put(cpu_policy
);
2200 EXPORT_SYMBOL(cpufreq_get_policy
);
2203 * policy : current policy.
2204 * new_policy: policy to be set.
2206 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2207 struct cpufreq_policy
*new_policy
)
2209 struct cpufreq_governor
*old_gov
;
2212 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2213 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2215 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2218 * This check works well when we store new min/max freq attributes,
2219 * because new_policy is a copy of policy with one field updated.
2221 if (new_policy
->min
> new_policy
->max
)
2224 /* verify the cpu speed can be set within this limit */
2225 ret
= cpufreq_driver
->verify(new_policy
);
2229 /* adjust if necessary - all reasons */
2230 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2231 CPUFREQ_ADJUST
, new_policy
);
2234 * verify the cpu speed can be set within this limit, which might be
2235 * different to the first one
2237 ret
= cpufreq_driver
->verify(new_policy
);
2241 /* notification of the new policy */
2242 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2243 CPUFREQ_NOTIFY
, new_policy
);
2245 policy
->min
= new_policy
->min
;
2246 policy
->max
= new_policy
->max
;
2247 trace_cpu_frequency_limits(policy
);
2249 policy
->cached_target_freq
= UINT_MAX
;
2251 pr_debug("new min and max freqs are %u - %u kHz\n",
2252 policy
->min
, policy
->max
);
2254 if (cpufreq_driver
->setpolicy
) {
2255 policy
->policy
= new_policy
->policy
;
2256 pr_debug("setting range\n");
2257 return cpufreq_driver
->setpolicy(new_policy
);
2260 if (new_policy
->governor
== policy
->governor
) {
2261 pr_debug("cpufreq: governor limits update\n");
2262 cpufreq_governor_limits(policy
);
2266 pr_debug("governor switch\n");
2268 /* save old, working values */
2269 old_gov
= policy
->governor
;
2270 /* end old governor */
2272 cpufreq_stop_governor(policy
);
2273 cpufreq_exit_governor(policy
);
2276 /* start new governor */
2277 policy
->governor
= new_policy
->governor
;
2278 ret
= cpufreq_init_governor(policy
);
2280 ret
= cpufreq_start_governor(policy
);
2282 pr_debug("cpufreq: governor change\n");
2285 cpufreq_exit_governor(policy
);
2288 /* new governor failed, so re-start old one */
2289 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2291 policy
->governor
= old_gov
;
2292 if (cpufreq_init_governor(policy
))
2293 policy
->governor
= NULL
;
2295 cpufreq_start_governor(policy
);
2302 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2303 * @cpu: CPU which shall be re-evaluated
2305 * Useful for policy notifiers which have different necessities
2306 * at different times.
2308 void cpufreq_update_policy(unsigned int cpu
)
2310 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
2311 struct cpufreq_policy new_policy
;
2316 down_write(&policy
->rwsem
);
2318 if (policy_is_inactive(policy
))
2321 pr_debug("updating policy for CPU %u\n", cpu
);
2322 memcpy(&new_policy
, policy
, sizeof(*policy
));
2323 new_policy
.min
= policy
->user_policy
.min
;
2324 new_policy
.max
= policy
->user_policy
.max
;
2327 * BIOS might change freq behind our back
2328 * -> ask driver for current freq and notify governors about a change
2330 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
2331 if (cpufreq_suspended
)
2334 new_policy
.cur
= cpufreq_update_current_freq(policy
);
2335 if (WARN_ON(!new_policy
.cur
))
2339 cpufreq_set_policy(policy
, &new_policy
);
2342 up_write(&policy
->rwsem
);
2344 cpufreq_cpu_put(policy
);
2346 EXPORT_SYMBOL(cpufreq_update_policy
);
2348 /*********************************************************************
2350 *********************************************************************/
2351 static int cpufreq_boost_set_sw(int state
)
2353 struct cpufreq_policy
*policy
;
2356 for_each_active_policy(policy
) {
2357 if (!policy
->freq_table
)
2360 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2361 policy
->freq_table
);
2363 pr_err("%s: Policy frequency update failed\n",
2368 down_write(&policy
->rwsem
);
2369 policy
->user_policy
.max
= policy
->max
;
2370 cpufreq_governor_limits(policy
);
2371 up_write(&policy
->rwsem
);
2377 int cpufreq_boost_trigger_state(int state
)
2379 unsigned long flags
;
2382 if (cpufreq_driver
->boost_enabled
== state
)
2385 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2386 cpufreq_driver
->boost_enabled
= state
;
2387 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2389 ret
= cpufreq_driver
->set_boost(state
);
2391 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2392 cpufreq_driver
->boost_enabled
= !state
;
2393 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2395 pr_err("%s: Cannot %s BOOST\n",
2396 __func__
, state
? "enable" : "disable");
2402 static bool cpufreq_boost_supported(void)
2404 return likely(cpufreq_driver
) && cpufreq_driver
->set_boost
;
2407 static int create_boost_sysfs_file(void)
2411 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2413 pr_err("%s: cannot register global BOOST sysfs file\n",
2419 static void remove_boost_sysfs_file(void)
2421 if (cpufreq_boost_supported())
2422 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2425 int cpufreq_enable_boost_support(void)
2427 if (!cpufreq_driver
)
2430 if (cpufreq_boost_supported())
2433 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2435 /* This will get removed on driver unregister */
2436 return create_boost_sysfs_file();
2438 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2440 int cpufreq_boost_enabled(void)
2442 return cpufreq_driver
->boost_enabled
;
2444 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2446 /*********************************************************************
2447 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2448 *********************************************************************/
2449 static enum cpuhp_state hp_online
;
2451 static int cpuhp_cpufreq_online(unsigned int cpu
)
2453 cpufreq_online(cpu
);
2458 static int cpuhp_cpufreq_offline(unsigned int cpu
)
2460 cpufreq_offline(cpu
);
2466 * cpufreq_register_driver - register a CPU Frequency driver
2467 * @driver_data: A struct cpufreq_driver containing the values#
2468 * submitted by the CPU Frequency driver.
2470 * Registers a CPU Frequency driver to this core code. This code
2471 * returns zero on success, -EEXIST when another driver got here first
2472 * (and isn't unregistered in the meantime).
2475 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2477 unsigned long flags
;
2480 if (cpufreq_disabled())
2484 * The cpufreq core depends heavily on the availability of device
2485 * structure, make sure they are available before proceeding further.
2487 if (!get_cpu_device(0))
2488 return -EPROBE_DEFER
;
2490 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2491 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2492 driver_data
->target
) ||
2493 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2494 driver_data
->target
)) ||
2495 (!!driver_data
->get_intermediate
!= !!driver_data
->target_intermediate
))
2498 pr_debug("trying to register driver %s\n", driver_data
->name
);
2500 /* Protect against concurrent CPU online/offline. */
2503 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2504 if (cpufreq_driver
) {
2505 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2509 cpufreq_driver
= driver_data
;
2510 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2512 if (driver_data
->setpolicy
)
2513 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2515 if (cpufreq_boost_supported()) {
2516 ret
= create_boost_sysfs_file();
2518 goto err_null_driver
;
2521 ret
= subsys_interface_register(&cpufreq_interface
);
2523 goto err_boost_unreg
;
2525 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2526 list_empty(&cpufreq_policy_list
)) {
2527 /* if all ->init() calls failed, unregister */
2529 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2534 ret
= cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN
,
2536 cpuhp_cpufreq_online
,
2537 cpuhp_cpufreq_offline
);
2543 pr_debug("driver %s up and running\n", driver_data
->name
);
2547 subsys_interface_unregister(&cpufreq_interface
);
2549 remove_boost_sysfs_file();
2551 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2552 cpufreq_driver
= NULL
;
2553 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2558 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2561 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2563 * Unregister the current CPUFreq driver. Only call this if you have
2564 * the right to do so, i.e. if you have succeeded in initialising before!
2565 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2566 * currently not initialised.
2568 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2570 unsigned long flags
;
2572 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2575 pr_debug("unregistering driver %s\n", driver
->name
);
2577 /* Protect against concurrent cpu hotplug */
2579 subsys_interface_unregister(&cpufreq_interface
);
2580 remove_boost_sysfs_file();
2581 cpuhp_remove_state_nocalls_cpuslocked(hp_online
);
2583 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2585 cpufreq_driver
= NULL
;
2587 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2592 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2594 struct kobject
*cpufreq_global_kobject
;
2595 EXPORT_SYMBOL(cpufreq_global_kobject
);
2597 static int __init
cpufreq_core_init(void)
2599 if (cpufreq_disabled())
2602 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2603 BUG_ON(!cpufreq_global_kobject
);
2607 module_param(off
, int, 0444);
2608 core_initcall(cpufreq_core_init
);