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 static bool suitable_policy(struct cpufreq_policy
*policy
, bool active
)
43 return active
== !policy_is_inactive(policy
);
46 /* Finds Next Acive/Inactive policy */
47 static struct cpufreq_policy
*next_policy(struct cpufreq_policy
*policy
,
51 /* No more policies in the list */
52 if (list_is_last(&policy
->policy_list
, &cpufreq_policy_list
))
55 policy
= list_next_entry(policy
, policy_list
);
56 } while (!suitable_policy(policy
, active
));
61 static struct cpufreq_policy
*first_policy(bool active
)
63 struct cpufreq_policy
*policy
;
65 /* No policies in the list */
66 if (list_empty(&cpufreq_policy_list
))
69 policy
= list_first_entry(&cpufreq_policy_list
, typeof(*policy
),
72 if (!suitable_policy(policy
, active
))
73 policy
= next_policy(policy
, active
);
78 /* Macros to iterate over CPU policies */
79 #define for_each_suitable_policy(__policy, __active) \
80 for (__policy = first_policy(__active); \
82 __policy = next_policy(__policy, __active))
84 #define for_each_active_policy(__policy) \
85 for_each_suitable_policy(__policy, true)
86 #define for_each_inactive_policy(__policy) \
87 for_each_suitable_policy(__policy, false)
89 #define for_each_policy(__policy) \
90 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
92 /* Iterate over governors */
93 static LIST_HEAD(cpufreq_governor_list
);
94 #define for_each_governor(__governor) \
95 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
98 * The "cpufreq driver" - the arch- or hardware-dependent low
99 * level driver of CPUFreq support, and its spinlock. This lock
100 * also protects the cpufreq_cpu_data array.
102 static struct cpufreq_driver
*cpufreq_driver
;
103 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
104 static DEFINE_RWLOCK(cpufreq_driver_lock
);
106 static DEFINE_PER_CPU(struct update_util_data
*, cpufreq_update_util_data
);
109 * cpufreq_set_update_util_data - Populate the CPU's update_util_data pointer.
110 * @cpu: The CPU to set the pointer for.
111 * @data: New pointer value.
113 * Set and publish the update_util_data pointer for the given CPU. That pointer
114 * points to a struct update_util_data object containing a callback function
115 * to call from cpufreq_update_util(). That function will be called from an RCU
116 * read-side critical section, so it must not sleep.
118 * Callers must use RCU callbacks to free any memory that might be accessed
119 * via the old update_util_data pointer or invoke synchronize_rcu() right after
120 * this function to avoid use-after-free.
122 void cpufreq_set_update_util_data(int cpu
, struct update_util_data
*data
)
124 rcu_assign_pointer(per_cpu(cpufreq_update_util_data
, cpu
), data
);
126 EXPORT_SYMBOL_GPL(cpufreq_set_update_util_data
);
129 * cpufreq_update_util - Take a note about CPU utilization changes.
130 * @time: Current time.
131 * @util: Current utilization.
132 * @max: Utilization ceiling.
134 * This function is called by the scheduler on every invocation of
135 * update_load_avg() on the CPU whose utilization is being updated.
137 void cpufreq_update_util(u64 time
, unsigned long util
, unsigned long max
)
139 struct update_util_data
*data
;
143 data
= rcu_dereference(*this_cpu_ptr(&cpufreq_update_util_data
));
144 if (data
&& data
->func
)
145 data
->func(data
, time
, util
, max
);
150 DEFINE_MUTEX(cpufreq_governor_lock
);
152 /* Flag to suspend/resume CPUFreq governors */
153 static bool cpufreq_suspended
;
155 static inline bool has_target(void)
157 return cpufreq_driver
->target_index
|| cpufreq_driver
->target
;
160 /* internal prototypes */
161 static int __cpufreq_governor(struct cpufreq_policy
*policy
,
163 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
);
164 static void handle_update(struct work_struct
*work
);
167 * Two notifier lists: the "policy" list is involved in the
168 * validation process for a new CPU frequency policy; the
169 * "transition" list for kernel code that needs to handle
170 * changes to devices when the CPU clock speed changes.
171 * The mutex locks both lists.
173 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list
);
174 static struct srcu_notifier_head cpufreq_transition_notifier_list
;
176 static bool init_cpufreq_transition_notifier_list_called
;
177 static int __init
init_cpufreq_transition_notifier_list(void)
179 srcu_init_notifier_head(&cpufreq_transition_notifier_list
);
180 init_cpufreq_transition_notifier_list_called
= true;
183 pure_initcall(init_cpufreq_transition_notifier_list
);
185 static int off __read_mostly
;
186 static int cpufreq_disabled(void)
190 void disable_cpufreq(void)
194 static DEFINE_MUTEX(cpufreq_governor_mutex
);
196 bool have_governor_per_policy(void)
198 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
200 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
202 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
204 if (have_governor_per_policy())
205 return &policy
->kobj
;
207 return cpufreq_global_kobject
;
209 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
211 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
)
213 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
215 return policy
&& !policy_is_inactive(policy
) ?
216 policy
->freq_table
: NULL
;
218 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table
);
220 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
226 cur_wall_time
= jiffies64_to_cputime64(get_jiffies_64());
228 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
229 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
230 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
231 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
232 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
233 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
235 idle_time
= cur_wall_time
- busy_time
;
237 *wall
= cputime_to_usecs(cur_wall_time
);
239 return cputime_to_usecs(idle_time
);
242 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
244 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
246 if (idle_time
== -1ULL)
247 return get_cpu_idle_time_jiffy(cpu
, wall
);
249 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
253 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
256 * This is a generic cpufreq init() routine which can be used by cpufreq
257 * drivers of SMP systems. It will do following:
258 * - validate & show freq table passed
259 * - set policies transition latency
260 * - policy->cpus with all possible CPUs
262 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
263 struct cpufreq_frequency_table
*table
,
264 unsigned int transition_latency
)
268 ret
= cpufreq_table_validate_and_show(policy
, table
);
270 pr_err("%s: invalid frequency table: %d\n", __func__
, ret
);
274 policy
->cpuinfo
.transition_latency
= transition_latency
;
277 * The driver only supports the SMP configuration where all processors
278 * share the clock and voltage and clock.
280 cpumask_setall(policy
->cpus
);
284 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
286 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
288 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
290 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
292 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
294 unsigned int cpufreq_generic_get(unsigned int cpu
)
296 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
298 if (!policy
|| IS_ERR(policy
->clk
)) {
299 pr_err("%s: No %s associated to cpu: %d\n",
300 __func__
, policy
? "clk" : "policy", cpu
);
304 return clk_get_rate(policy
->clk
) / 1000;
306 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
309 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
311 * @cpu: cpu to find policy for.
313 * This returns policy for 'cpu', returns NULL if it doesn't exist.
314 * It also increments the kobject reference count to mark it busy and so would
315 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
316 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
317 * freed as that depends on the kobj count.
319 * Return: A valid policy on success, otherwise NULL on failure.
321 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
323 struct cpufreq_policy
*policy
= NULL
;
326 if (WARN_ON(cpu
>= nr_cpu_ids
))
329 /* get the cpufreq driver */
330 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
332 if (cpufreq_driver
) {
334 policy
= cpufreq_cpu_get_raw(cpu
);
336 kobject_get(&policy
->kobj
);
339 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
343 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
346 * cpufreq_cpu_put: Decrements the usage count of a policy
348 * @policy: policy earlier returned by cpufreq_cpu_get().
350 * This decrements the kobject reference count incremented earlier by calling
353 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
355 kobject_put(&policy
->kobj
);
357 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
359 /*********************************************************************
360 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
361 *********************************************************************/
364 * adjust_jiffies - adjust the system "loops_per_jiffy"
366 * This function alters the system "loops_per_jiffy" for the clock
367 * speed change. Note that loops_per_jiffy cannot be updated on SMP
368 * systems as each CPU might be scaled differently. So, use the arch
369 * per-CPU loops_per_jiffy value wherever possible.
371 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
374 static unsigned long l_p_j_ref
;
375 static unsigned int l_p_j_ref_freq
;
377 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
380 if (!l_p_j_ref_freq
) {
381 l_p_j_ref
= loops_per_jiffy
;
382 l_p_j_ref_freq
= ci
->old
;
383 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
384 l_p_j_ref
, l_p_j_ref_freq
);
386 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
387 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
389 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
390 loops_per_jiffy
, ci
->new);
395 static void __cpufreq_notify_transition(struct cpufreq_policy
*policy
,
396 struct cpufreq_freqs
*freqs
, unsigned int state
)
398 BUG_ON(irqs_disabled());
400 if (cpufreq_disabled())
403 freqs
->flags
= cpufreq_driver
->flags
;
404 pr_debug("notification %u of frequency transition to %u kHz\n",
409 case CPUFREQ_PRECHANGE
:
410 /* detect if the driver reported a value as "old frequency"
411 * which is not equal to what the cpufreq core thinks is
414 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
415 if ((policy
) && (policy
->cpu
== freqs
->cpu
) &&
416 (policy
->cur
) && (policy
->cur
!= freqs
->old
)) {
417 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
418 freqs
->old
, policy
->cur
);
419 freqs
->old
= policy
->cur
;
422 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
423 CPUFREQ_PRECHANGE
, freqs
);
424 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
427 case CPUFREQ_POSTCHANGE
:
428 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
429 pr_debug("FREQ: %lu - CPU: %lu\n",
430 (unsigned long)freqs
->new, (unsigned long)freqs
->cpu
);
431 trace_cpu_frequency(freqs
->new, freqs
->cpu
);
432 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
433 CPUFREQ_POSTCHANGE
, freqs
);
434 if (likely(policy
) && likely(policy
->cpu
== freqs
->cpu
))
435 policy
->cur
= freqs
->new;
441 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
442 * on frequency transition.
444 * This function calls the transition notifiers and the "adjust_jiffies"
445 * function. It is called twice on all CPU frequency changes that have
448 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
449 struct cpufreq_freqs
*freqs
, unsigned int state
)
451 for_each_cpu(freqs
->cpu
, policy
->cpus
)
452 __cpufreq_notify_transition(policy
, freqs
, state
);
455 /* Do post notifications when there are chances that transition has failed */
456 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
457 struct cpufreq_freqs
*freqs
, int transition_failed
)
459 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
460 if (!transition_failed
)
463 swap(freqs
->old
, freqs
->new);
464 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
465 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
468 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
469 struct cpufreq_freqs
*freqs
)
473 * Catch double invocations of _begin() which lead to self-deadlock.
474 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
475 * doesn't invoke _begin() on their behalf, and hence the chances of
476 * double invocations are very low. Moreover, there are scenarios
477 * where these checks can emit false-positive warnings in these
478 * drivers; so we avoid that by skipping them altogether.
480 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
481 && current
== policy
->transition_task
);
484 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
486 spin_lock(&policy
->transition_lock
);
488 if (unlikely(policy
->transition_ongoing
)) {
489 spin_unlock(&policy
->transition_lock
);
493 policy
->transition_ongoing
= true;
494 policy
->transition_task
= current
;
496 spin_unlock(&policy
->transition_lock
);
498 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
500 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
502 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
503 struct cpufreq_freqs
*freqs
, int transition_failed
)
505 if (unlikely(WARN_ON(!policy
->transition_ongoing
)))
508 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
510 policy
->transition_ongoing
= false;
511 policy
->transition_task
= NULL
;
513 wake_up(&policy
->transition_wait
);
515 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
518 /*********************************************************************
520 *********************************************************************/
521 static ssize_t
show_boost(struct kobject
*kobj
,
522 struct attribute
*attr
, char *buf
)
524 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
527 static ssize_t
store_boost(struct kobject
*kobj
, struct attribute
*attr
,
528 const char *buf
, size_t count
)
532 ret
= sscanf(buf
, "%d", &enable
);
533 if (ret
!= 1 || enable
< 0 || enable
> 1)
536 if (cpufreq_boost_trigger_state(enable
)) {
537 pr_err("%s: Cannot %s BOOST!\n",
538 __func__
, enable
? "enable" : "disable");
542 pr_debug("%s: cpufreq BOOST %s\n",
543 __func__
, enable
? "enabled" : "disabled");
547 define_one_global_rw(boost
);
549 static struct cpufreq_governor
*find_governor(const char *str_governor
)
551 struct cpufreq_governor
*t
;
554 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
561 * cpufreq_parse_governor - parse a governor string
563 static int cpufreq_parse_governor(char *str_governor
, unsigned int *policy
,
564 struct cpufreq_governor
**governor
)
568 if (cpufreq_driver
->setpolicy
) {
569 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
570 *policy
= CPUFREQ_POLICY_PERFORMANCE
;
572 } else if (!strncasecmp(str_governor
, "powersave",
574 *policy
= CPUFREQ_POLICY_POWERSAVE
;
578 struct cpufreq_governor
*t
;
580 mutex_lock(&cpufreq_governor_mutex
);
582 t
= find_governor(str_governor
);
587 mutex_unlock(&cpufreq_governor_mutex
);
588 ret
= request_module("cpufreq_%s", str_governor
);
589 mutex_lock(&cpufreq_governor_mutex
);
592 t
= find_governor(str_governor
);
600 mutex_unlock(&cpufreq_governor_mutex
);
606 * cpufreq_per_cpu_attr_read() / show_##file_name() -
607 * print out cpufreq information
609 * Write out information from cpufreq_driver->policy[cpu]; object must be
613 #define show_one(file_name, object) \
614 static ssize_t show_##file_name \
615 (struct cpufreq_policy *policy, char *buf) \
617 return sprintf(buf, "%u\n", policy->object); \
620 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
621 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
622 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
623 show_one(scaling_min_freq
, min
);
624 show_one(scaling_max_freq
, max
);
626 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
630 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
)
631 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
633 ret
= sprintf(buf
, "%u\n", policy
->cur
);
637 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
638 struct cpufreq_policy
*new_policy
);
641 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
643 #define store_one(file_name, object) \
644 static ssize_t store_##file_name \
645 (struct cpufreq_policy *policy, const char *buf, size_t count) \
648 struct cpufreq_policy new_policy; \
650 memcpy(&new_policy, policy, sizeof(*policy)); \
652 ret = sscanf(buf, "%u", &new_policy.object); \
656 temp = new_policy.object; \
657 ret = cpufreq_set_policy(policy, &new_policy); \
659 policy->user_policy.object = temp; \
661 return ret ? ret : count; \
664 store_one(scaling_min_freq
, min
);
665 store_one(scaling_max_freq
, max
);
668 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
670 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
673 unsigned int cur_freq
= __cpufreq_get(policy
);
675 return sprintf(buf
, "<unknown>");
676 return sprintf(buf
, "%u\n", cur_freq
);
680 * show_scaling_governor - show the current policy for the specified CPU
682 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
684 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
685 return sprintf(buf
, "powersave\n");
686 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
687 return sprintf(buf
, "performance\n");
688 else if (policy
->governor
)
689 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
690 policy
->governor
->name
);
695 * store_scaling_governor - store policy for the specified CPU
697 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
698 const char *buf
, size_t count
)
701 char str_governor
[16];
702 struct cpufreq_policy new_policy
;
704 memcpy(&new_policy
, policy
, sizeof(*policy
));
706 ret
= sscanf(buf
, "%15s", str_governor
);
710 if (cpufreq_parse_governor(str_governor
, &new_policy
.policy
,
711 &new_policy
.governor
))
714 ret
= cpufreq_set_policy(policy
, &new_policy
);
715 return ret
? ret
: count
;
719 * show_scaling_driver - show the cpufreq driver currently loaded
721 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
723 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
727 * show_scaling_available_governors - show the available CPUfreq governors
729 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
733 struct cpufreq_governor
*t
;
736 i
+= sprintf(buf
, "performance powersave");
740 for_each_governor(t
) {
741 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
742 - (CPUFREQ_NAME_LEN
+ 2)))
744 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
747 i
+= sprintf(&buf
[i
], "\n");
751 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
756 for_each_cpu(cpu
, mask
) {
758 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
759 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
760 if (i
>= (PAGE_SIZE
- 5))
763 i
+= sprintf(&buf
[i
], "\n");
766 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
769 * show_related_cpus - show the CPUs affected by each transition even if
770 * hw coordination is in use
772 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
774 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
778 * show_affected_cpus - show the CPUs affected by each transition
780 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
782 return cpufreq_show_cpus(policy
->cpus
, buf
);
785 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
786 const char *buf
, size_t count
)
788 unsigned int freq
= 0;
791 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
794 ret
= sscanf(buf
, "%u", &freq
);
798 policy
->governor
->store_setspeed(policy
, freq
);
803 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
805 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
806 return sprintf(buf
, "<unsupported>\n");
808 return policy
->governor
->show_setspeed(policy
, buf
);
812 * show_bios_limit - show the current cpufreq HW/BIOS limitation
814 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
818 if (cpufreq_driver
->bios_limit
) {
819 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
821 return sprintf(buf
, "%u\n", limit
);
823 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
826 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
827 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
828 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
829 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
830 cpufreq_freq_attr_ro(scaling_available_governors
);
831 cpufreq_freq_attr_ro(scaling_driver
);
832 cpufreq_freq_attr_ro(scaling_cur_freq
);
833 cpufreq_freq_attr_ro(bios_limit
);
834 cpufreq_freq_attr_ro(related_cpus
);
835 cpufreq_freq_attr_ro(affected_cpus
);
836 cpufreq_freq_attr_rw(scaling_min_freq
);
837 cpufreq_freq_attr_rw(scaling_max_freq
);
838 cpufreq_freq_attr_rw(scaling_governor
);
839 cpufreq_freq_attr_rw(scaling_setspeed
);
841 static struct attribute
*default_attrs
[] = {
842 &cpuinfo_min_freq
.attr
,
843 &cpuinfo_max_freq
.attr
,
844 &cpuinfo_transition_latency
.attr
,
845 &scaling_min_freq
.attr
,
846 &scaling_max_freq
.attr
,
849 &scaling_governor
.attr
,
850 &scaling_driver
.attr
,
851 &scaling_available_governors
.attr
,
852 &scaling_setspeed
.attr
,
856 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
857 #define to_attr(a) container_of(a, struct freq_attr, attr)
859 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
861 struct cpufreq_policy
*policy
= to_policy(kobj
);
862 struct freq_attr
*fattr
= to_attr(attr
);
865 down_read(&policy
->rwsem
);
868 ret
= fattr
->show(policy
, buf
);
872 up_read(&policy
->rwsem
);
877 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
878 const char *buf
, size_t count
)
880 struct cpufreq_policy
*policy
= to_policy(kobj
);
881 struct freq_attr
*fattr
= to_attr(attr
);
882 ssize_t ret
= -EINVAL
;
886 if (!cpu_online(policy
->cpu
))
889 down_write(&policy
->rwsem
);
892 ret
= fattr
->store(policy
, buf
, count
);
896 up_write(&policy
->rwsem
);
903 static void cpufreq_sysfs_release(struct kobject
*kobj
)
905 struct cpufreq_policy
*policy
= to_policy(kobj
);
906 pr_debug("last reference is dropped\n");
907 complete(&policy
->kobj_unregister
);
910 static const struct sysfs_ops sysfs_ops
= {
915 static struct kobj_type ktype_cpufreq
= {
916 .sysfs_ops
= &sysfs_ops
,
917 .default_attrs
= default_attrs
,
918 .release
= cpufreq_sysfs_release
,
921 static int add_cpu_dev_symlink(struct cpufreq_policy
*policy
, int cpu
)
923 struct device
*cpu_dev
;
925 pr_debug("%s: Adding symlink for CPU: %u\n", __func__
, cpu
);
930 cpu_dev
= get_cpu_device(cpu
);
931 if (WARN_ON(!cpu_dev
))
934 return sysfs_create_link(&cpu_dev
->kobj
, &policy
->kobj
, "cpufreq");
937 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
, int cpu
)
939 struct device
*cpu_dev
;
941 pr_debug("%s: Removing symlink for CPU: %u\n", __func__
, cpu
);
943 cpu_dev
= get_cpu_device(cpu
);
944 if (WARN_ON(!cpu_dev
))
947 sysfs_remove_link(&cpu_dev
->kobj
, "cpufreq");
950 /* Add/remove symlinks for all related CPUs */
951 static int cpufreq_add_dev_symlink(struct cpufreq_policy
*policy
)
956 /* Some related CPUs might not be present (physically hotplugged) */
957 for_each_cpu(j
, policy
->real_cpus
) {
958 ret
= add_cpu_dev_symlink(policy
, j
);
966 static void cpufreq_remove_dev_symlink(struct cpufreq_policy
*policy
)
970 /* Some related CPUs might not be present (physically hotplugged) */
971 for_each_cpu(j
, policy
->real_cpus
)
972 remove_cpu_dev_symlink(policy
, j
);
975 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
977 struct freq_attr
**drv_attr
;
980 /* set up files for this cpu device */
981 drv_attr
= cpufreq_driver
->attr
;
982 while (drv_attr
&& *drv_attr
) {
983 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
988 if (cpufreq_driver
->get
) {
989 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
994 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
998 if (cpufreq_driver
->bios_limit
) {
999 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
1004 return cpufreq_add_dev_symlink(policy
);
1007 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
1012 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
1014 struct cpufreq_governor
*gov
= NULL
;
1015 struct cpufreq_policy new_policy
;
1017 memcpy(&new_policy
, policy
, sizeof(*policy
));
1019 /* Update governor of new_policy to the governor used before hotplug */
1020 gov
= find_governor(policy
->last_governor
);
1022 pr_debug("Restoring governor %s for cpu %d\n",
1023 policy
->governor
->name
, policy
->cpu
);
1025 gov
= cpufreq_default_governor();
1030 new_policy
.governor
= gov
;
1032 /* Use the default policy if there is no last_policy. */
1033 if (cpufreq_driver
->setpolicy
) {
1034 if (policy
->last_policy
)
1035 new_policy
.policy
= policy
->last_policy
;
1037 cpufreq_parse_governor(gov
->name
, &new_policy
.policy
,
1040 /* set default policy */
1041 return cpufreq_set_policy(policy
, &new_policy
);
1044 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1048 /* Has this CPU been taken care of already? */
1049 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1053 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_STOP
);
1055 pr_err("%s: Failed to stop governor\n", __func__
);
1060 down_write(&policy
->rwsem
);
1061 cpumask_set_cpu(cpu
, policy
->cpus
);
1062 up_write(&policy
->rwsem
);
1065 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_START
);
1067 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
);
1070 pr_err("%s: Failed to start governor\n", __func__
);
1078 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1080 struct device
*dev
= get_cpu_device(cpu
);
1081 struct cpufreq_policy
*policy
;
1086 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1090 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1091 goto err_free_policy
;
1093 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1094 goto err_free_cpumask
;
1096 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1097 goto err_free_rcpumask
;
1099 kobject_init(&policy
->kobj
, &ktype_cpufreq
);
1100 INIT_LIST_HEAD(&policy
->policy_list
);
1101 init_rwsem(&policy
->rwsem
);
1102 spin_lock_init(&policy
->transition_lock
);
1103 init_waitqueue_head(&policy
->transition_wait
);
1104 init_completion(&policy
->kobj_unregister
);
1105 INIT_WORK(&policy
->update
, handle_update
);
1111 free_cpumask_var(policy
->related_cpus
);
1113 free_cpumask_var(policy
->cpus
);
1120 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
, bool notify
)
1122 struct kobject
*kobj
;
1123 struct completion
*cmp
;
1126 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1127 CPUFREQ_REMOVE_POLICY
, policy
);
1129 down_write(&policy
->rwsem
);
1130 cpufreq_remove_dev_symlink(policy
);
1131 kobj
= &policy
->kobj
;
1132 cmp
= &policy
->kobj_unregister
;
1133 up_write(&policy
->rwsem
);
1137 * We need to make sure that the underlying kobj is
1138 * actually not referenced anymore by anybody before we
1139 * proceed with unloading.
1141 pr_debug("waiting for dropping of refcount\n");
1142 wait_for_completion(cmp
);
1143 pr_debug("wait complete\n");
1146 static void cpufreq_policy_free(struct cpufreq_policy
*policy
, bool notify
)
1148 unsigned long flags
;
1151 /* Remove policy from list */
1152 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1153 list_del(&policy
->policy_list
);
1155 for_each_cpu(cpu
, policy
->related_cpus
)
1156 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1157 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1159 cpufreq_policy_put_kobj(policy
, notify
);
1160 free_cpumask_var(policy
->real_cpus
);
1161 free_cpumask_var(policy
->related_cpus
);
1162 free_cpumask_var(policy
->cpus
);
1166 static int cpufreq_online(unsigned int cpu
)
1168 struct cpufreq_policy
*policy
;
1170 unsigned long flags
;
1174 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1176 /* Check if this CPU already has a policy to manage it */
1177 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1179 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1180 if (!policy_is_inactive(policy
))
1181 return cpufreq_add_policy_cpu(policy
, cpu
);
1183 /* This is the only online CPU for the policy. Start over. */
1185 down_write(&policy
->rwsem
);
1187 policy
->governor
= NULL
;
1188 up_write(&policy
->rwsem
);
1191 policy
= cpufreq_policy_alloc(cpu
);
1196 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1198 /* call driver. From then on the cpufreq must be able
1199 * to accept all calls to ->verify and ->setpolicy for this CPU
1201 ret
= cpufreq_driver
->init(policy
);
1203 pr_debug("initialization failed\n");
1204 goto out_free_policy
;
1207 down_write(&policy
->rwsem
);
1210 /* related_cpus should at least include policy->cpus. */
1211 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1212 /* Remember CPUs present at the policy creation time. */
1213 cpumask_and(policy
->real_cpus
, policy
->cpus
, cpu_present_mask
);
1215 /* Name and add the kobject */
1216 ret
= kobject_add(&policy
->kobj
, cpufreq_global_kobject
,
1218 cpumask_first(policy
->related_cpus
));
1220 pr_err("%s: failed to add policy->kobj: %d\n", __func__
,
1222 goto out_exit_policy
;
1227 * affected cpus must always be the one, which are online. We aren't
1228 * managing offline cpus here.
1230 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1233 policy
->user_policy
.min
= policy
->min
;
1234 policy
->user_policy
.max
= policy
->max
;
1236 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1237 for_each_cpu(j
, policy
->related_cpus
)
1238 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1239 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
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
);
1290 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1291 CPUFREQ_START
, policy
);
1294 ret
= cpufreq_add_dev_interface(policy
);
1296 goto out_exit_policy
;
1297 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1298 CPUFREQ_CREATE_POLICY
, policy
);
1300 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1301 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1302 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1305 ret
= cpufreq_init_policy(policy
);
1307 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1308 __func__
, cpu
, ret
);
1309 /* cpufreq_policy_free() will notify based on this */
1311 goto out_exit_policy
;
1314 up_write(&policy
->rwsem
);
1316 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1318 /* Callback for handling stuff after policy is ready */
1319 if (cpufreq_driver
->ready
)
1320 cpufreq_driver
->ready(policy
);
1322 pr_debug("initialization complete\n");
1327 up_write(&policy
->rwsem
);
1329 if (cpufreq_driver
->exit
)
1330 cpufreq_driver
->exit(policy
);
1332 cpufreq_policy_free(policy
, !new_policy
);
1337 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1339 * @sif: Subsystem interface structure pointer (not used)
1341 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1343 unsigned cpu
= dev
->id
;
1346 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1348 if (cpu_online(cpu
)) {
1349 ret
= cpufreq_online(cpu
);
1352 * A hotplug notifier will follow and we will handle it as CPU
1353 * online then. For now, just create the sysfs link, unless
1354 * there is no policy or the link is already present.
1356 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1358 ret
= policy
&& !cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
)
1359 ? add_cpu_dev_symlink(policy
, cpu
) : 0;
1365 static void cpufreq_offline(unsigned int cpu
)
1367 struct cpufreq_policy
*policy
;
1370 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1372 policy
= cpufreq_cpu_get_raw(cpu
);
1374 pr_debug("%s: No cpu_data found\n", __func__
);
1379 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_STOP
);
1381 pr_err("%s: Failed to stop governor\n", __func__
);
1384 down_write(&policy
->rwsem
);
1385 cpumask_clear_cpu(cpu
, policy
->cpus
);
1387 if (policy_is_inactive(policy
)) {
1389 strncpy(policy
->last_governor
, policy
->governor
->name
,
1392 policy
->last_policy
= policy
->policy
;
1393 } else if (cpu
== policy
->cpu
) {
1394 /* Nominate new CPU */
1395 policy
->cpu
= cpumask_any(policy
->cpus
);
1397 up_write(&policy
->rwsem
);
1399 /* Start governor again for active policy */
1400 if (!policy_is_inactive(policy
)) {
1402 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_START
);
1404 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
);
1407 pr_err("%s: Failed to start governor\n", __func__
);
1413 if (cpufreq_driver
->stop_cpu
)
1414 cpufreq_driver
->stop_cpu(policy
);
1416 /* If cpu is last user of policy, free policy */
1418 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_POLICY_EXIT
);
1420 pr_err("%s: Failed to exit governor\n", __func__
);
1424 * Perform the ->exit() even during light-weight tear-down,
1425 * since this is a core component, and is essential for the
1426 * subsequent light-weight ->init() to succeed.
1428 if (cpufreq_driver
->exit
) {
1429 cpufreq_driver
->exit(policy
);
1430 policy
->freq_table
= NULL
;
1435 * cpufreq_remove_dev - remove a CPU device
1437 * Removes the cpufreq interface for a CPU device.
1439 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1441 unsigned int cpu
= dev
->id
;
1442 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1447 if (cpu_online(cpu
))
1448 cpufreq_offline(cpu
);
1450 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1451 remove_cpu_dev_symlink(policy
, cpu
);
1453 if (cpumask_empty(policy
->real_cpus
))
1454 cpufreq_policy_free(policy
, true);
1457 static void handle_update(struct work_struct
*work
)
1459 struct cpufreq_policy
*policy
=
1460 container_of(work
, struct cpufreq_policy
, update
);
1461 unsigned int cpu
= policy
->cpu
;
1462 pr_debug("handle_update for cpu %u called\n", cpu
);
1463 cpufreq_update_policy(cpu
);
1467 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1469 * @policy: policy managing CPUs
1470 * @new_freq: CPU frequency the CPU actually runs at
1472 * We adjust to current frequency first, and need to clean up later.
1473 * So either call to cpufreq_update_policy() or schedule handle_update()).
1475 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1476 unsigned int new_freq
)
1478 struct cpufreq_freqs freqs
;
1480 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1481 policy
->cur
, new_freq
);
1483 freqs
.old
= policy
->cur
;
1484 freqs
.new = new_freq
;
1486 cpufreq_freq_transition_begin(policy
, &freqs
);
1487 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1491 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1494 * This is the last known freq, without actually getting it from the driver.
1495 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1497 unsigned int cpufreq_quick_get(unsigned int cpu
)
1499 struct cpufreq_policy
*policy
;
1500 unsigned int ret_freq
= 0;
1502 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
)
1503 return cpufreq_driver
->get(cpu
);
1505 policy
= cpufreq_cpu_get(cpu
);
1507 ret_freq
= policy
->cur
;
1508 cpufreq_cpu_put(policy
);
1513 EXPORT_SYMBOL(cpufreq_quick_get
);
1516 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1519 * Just return the max possible frequency for a given CPU.
1521 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1523 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1524 unsigned int ret_freq
= 0;
1527 ret_freq
= policy
->max
;
1528 cpufreq_cpu_put(policy
);
1533 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1535 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1537 unsigned int ret_freq
= 0;
1539 if (!cpufreq_driver
->get
)
1542 ret_freq
= cpufreq_driver
->get(policy
->cpu
);
1544 /* Updating inactive policies is invalid, so avoid doing that. */
1545 if (unlikely(policy_is_inactive(policy
)))
1548 if (ret_freq
&& policy
->cur
&&
1549 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1550 /* verify no discrepancy between actual and
1551 saved value exists */
1552 if (unlikely(ret_freq
!= policy
->cur
)) {
1553 cpufreq_out_of_sync(policy
, ret_freq
);
1554 schedule_work(&policy
->update
);
1562 * cpufreq_get - get the current CPU frequency (in kHz)
1565 * Get the CPU current (static) CPU frequency
1567 unsigned int cpufreq_get(unsigned int cpu
)
1569 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1570 unsigned int ret_freq
= 0;
1573 down_read(&policy
->rwsem
);
1574 ret_freq
= __cpufreq_get(policy
);
1575 up_read(&policy
->rwsem
);
1577 cpufreq_cpu_put(policy
);
1582 EXPORT_SYMBOL(cpufreq_get
);
1584 static struct subsys_interface cpufreq_interface
= {
1586 .subsys
= &cpu_subsys
,
1587 .add_dev
= cpufreq_add_dev
,
1588 .remove_dev
= cpufreq_remove_dev
,
1592 * In case platform wants some specific frequency to be configured
1595 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1599 if (!policy
->suspend_freq
) {
1600 pr_debug("%s: suspend_freq not defined\n", __func__
);
1604 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1605 policy
->suspend_freq
);
1607 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1608 CPUFREQ_RELATION_H
);
1610 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1611 __func__
, policy
->suspend_freq
, ret
);
1615 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1618 * cpufreq_suspend() - Suspend CPUFreq governors
1620 * Called during system wide Suspend/Hibernate cycles for suspending governors
1621 * as some platforms can't change frequency after this point in suspend cycle.
1622 * Because some of the devices (like: i2c, regulators, etc) they use for
1623 * changing frequency are suspended quickly after this point.
1625 void cpufreq_suspend(void)
1627 struct cpufreq_policy
*policy
;
1629 if (!cpufreq_driver
)
1635 pr_debug("%s: Suspending Governors\n", __func__
);
1637 for_each_active_policy(policy
) {
1638 if (__cpufreq_governor(policy
, CPUFREQ_GOV_STOP
))
1639 pr_err("%s: Failed to stop governor for policy: %p\n",
1641 else if (cpufreq_driver
->suspend
1642 && cpufreq_driver
->suspend(policy
))
1643 pr_err("%s: Failed to suspend driver: %p\n", __func__
,
1648 cpufreq_suspended
= true;
1652 * cpufreq_resume() - Resume CPUFreq governors
1654 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1655 * are suspended with cpufreq_suspend().
1657 void cpufreq_resume(void)
1659 struct cpufreq_policy
*policy
;
1661 if (!cpufreq_driver
)
1664 cpufreq_suspended
= false;
1669 pr_debug("%s: Resuming Governors\n", __func__
);
1671 for_each_active_policy(policy
) {
1672 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
))
1673 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1675 else if (__cpufreq_governor(policy
, CPUFREQ_GOV_START
)
1676 || __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
))
1677 pr_err("%s: Failed to start governor for policy: %p\n",
1682 * schedule call cpufreq_update_policy() for first-online CPU, as that
1683 * wouldn't be hotplugged-out on suspend. It will verify that the
1684 * current freq is in sync with what we believe it to be.
1686 policy
= cpufreq_cpu_get_raw(cpumask_first(cpu_online_mask
));
1687 if (WARN_ON(!policy
))
1690 schedule_work(&policy
->update
);
1694 * cpufreq_get_current_driver - return current driver's name
1696 * Return the name string of the currently loaded cpufreq driver
1699 const char *cpufreq_get_current_driver(void)
1702 return cpufreq_driver
->name
;
1706 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1709 * cpufreq_get_driver_data - return current driver data
1711 * Return the private data of the currently loaded cpufreq
1712 * driver, or NULL if no cpufreq driver is loaded.
1714 void *cpufreq_get_driver_data(void)
1717 return cpufreq_driver
->driver_data
;
1721 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1723 /*********************************************************************
1724 * NOTIFIER LISTS INTERFACE *
1725 *********************************************************************/
1728 * cpufreq_register_notifier - register a driver with cpufreq
1729 * @nb: notifier function to register
1730 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1732 * Add a driver to one of two lists: either a list of drivers that
1733 * are notified about clock rate changes (once before and once after
1734 * the transition), or a list of drivers that are notified about
1735 * changes in cpufreq policy.
1737 * This function may sleep, and has the same return conditions as
1738 * blocking_notifier_chain_register.
1740 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1744 if (cpufreq_disabled())
1747 WARN_ON(!init_cpufreq_transition_notifier_list_called
);
1750 case CPUFREQ_TRANSITION_NOTIFIER
:
1751 ret
= srcu_notifier_chain_register(
1752 &cpufreq_transition_notifier_list
, nb
);
1754 case CPUFREQ_POLICY_NOTIFIER
:
1755 ret
= blocking_notifier_chain_register(
1756 &cpufreq_policy_notifier_list
, nb
);
1764 EXPORT_SYMBOL(cpufreq_register_notifier
);
1767 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1768 * @nb: notifier block to be unregistered
1769 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1771 * Remove a driver from the CPU frequency notifier list.
1773 * This function may sleep, and has the same return conditions as
1774 * blocking_notifier_chain_unregister.
1776 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1780 if (cpufreq_disabled())
1784 case CPUFREQ_TRANSITION_NOTIFIER
:
1785 ret
= srcu_notifier_chain_unregister(
1786 &cpufreq_transition_notifier_list
, nb
);
1788 case CPUFREQ_POLICY_NOTIFIER
:
1789 ret
= blocking_notifier_chain_unregister(
1790 &cpufreq_policy_notifier_list
, nb
);
1798 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1801 /*********************************************************************
1803 *********************************************************************/
1805 /* Must set freqs->new to intermediate frequency */
1806 static int __target_intermediate(struct cpufreq_policy
*policy
,
1807 struct cpufreq_freqs
*freqs
, int index
)
1811 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
1813 /* We don't need to switch to intermediate freq */
1817 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1818 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
1820 cpufreq_freq_transition_begin(policy
, freqs
);
1821 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
1822 cpufreq_freq_transition_end(policy
, freqs
, ret
);
1825 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1831 static int __target_index(struct cpufreq_policy
*policy
,
1832 struct cpufreq_frequency_table
*freq_table
, int index
)
1834 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
1835 unsigned int intermediate_freq
= 0;
1836 int retval
= -EINVAL
;
1839 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
1841 /* Handle switching to intermediate frequency */
1842 if (cpufreq_driver
->get_intermediate
) {
1843 retval
= __target_intermediate(policy
, &freqs
, index
);
1847 intermediate_freq
= freqs
.new;
1848 /* Set old freq to intermediate */
1849 if (intermediate_freq
)
1850 freqs
.old
= freqs
.new;
1853 freqs
.new = freq_table
[index
].frequency
;
1854 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1855 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
1857 cpufreq_freq_transition_begin(policy
, &freqs
);
1860 retval
= cpufreq_driver
->target_index(policy
, index
);
1862 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
1866 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
1869 * Failed after setting to intermediate freq? Driver should have
1870 * reverted back to initial frequency and so should we. Check
1871 * here for intermediate_freq instead of get_intermediate, in
1872 * case we haven't switched to intermediate freq at all.
1874 if (unlikely(retval
&& intermediate_freq
)) {
1875 freqs
.old
= intermediate_freq
;
1876 freqs
.new = policy
->restore_freq
;
1877 cpufreq_freq_transition_begin(policy
, &freqs
);
1878 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1885 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
1886 unsigned int target_freq
,
1887 unsigned int relation
)
1889 unsigned int old_target_freq
= target_freq
;
1890 int retval
= -EINVAL
;
1892 if (cpufreq_disabled())
1895 /* Make sure that target_freq is within supported range */
1896 if (target_freq
> policy
->max
)
1897 target_freq
= policy
->max
;
1898 if (target_freq
< policy
->min
)
1899 target_freq
= policy
->min
;
1901 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1902 policy
->cpu
, target_freq
, relation
, old_target_freq
);
1905 * This might look like a redundant call as we are checking it again
1906 * after finding index. But it is left intentionally for cases where
1907 * exactly same freq is called again and so we can save on few function
1910 if (target_freq
== policy
->cur
)
1913 /* Save last value to restore later on errors */
1914 policy
->restore_freq
= policy
->cur
;
1916 if (cpufreq_driver
->target
)
1917 retval
= cpufreq_driver
->target(policy
, target_freq
, relation
);
1918 else if (cpufreq_driver
->target_index
) {
1919 struct cpufreq_frequency_table
*freq_table
;
1922 freq_table
= cpufreq_frequency_get_table(policy
->cpu
);
1923 if (unlikely(!freq_table
)) {
1924 pr_err("%s: Unable to find freq_table\n", __func__
);
1928 retval
= cpufreq_frequency_table_target(policy
, freq_table
,
1929 target_freq
, relation
, &index
);
1930 if (unlikely(retval
)) {
1931 pr_err("%s: Unable to find matching freq\n", __func__
);
1935 if (freq_table
[index
].frequency
== policy
->cur
) {
1940 retval
= __target_index(policy
, freq_table
, index
);
1946 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
1948 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
1949 unsigned int target_freq
,
1950 unsigned int relation
)
1954 down_write(&policy
->rwsem
);
1956 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
1958 up_write(&policy
->rwsem
);
1962 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
1964 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
1969 static int __cpufreq_governor(struct cpufreq_policy
*policy
,
1974 /* Don't start any governor operations if we are entering suspend */
1975 if (cpufreq_suspended
)
1978 * Governor might not be initiated here if ACPI _PPC changed
1979 * notification happened, so check it.
1981 if (!policy
->governor
)
1984 if (policy
->governor
->max_transition_latency
&&
1985 policy
->cpuinfo
.transition_latency
>
1986 policy
->governor
->max_transition_latency
) {
1987 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
1990 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
1991 policy
->governor
->name
, gov
->name
);
1992 policy
->governor
= gov
;
1998 if (event
== CPUFREQ_GOV_POLICY_INIT
)
1999 if (!try_module_get(policy
->governor
->owner
))
2002 pr_debug("%s: for CPU %u, event %u\n", __func__
, policy
->cpu
, event
);
2004 mutex_lock(&cpufreq_governor_lock
);
2005 if ((policy
->governor_enabled
&& event
== CPUFREQ_GOV_START
)
2006 || (!policy
->governor_enabled
2007 && (event
== CPUFREQ_GOV_LIMITS
|| event
== CPUFREQ_GOV_STOP
))) {
2008 mutex_unlock(&cpufreq_governor_lock
);
2012 if (event
== CPUFREQ_GOV_STOP
)
2013 policy
->governor_enabled
= false;
2014 else if (event
== CPUFREQ_GOV_START
)
2015 policy
->governor_enabled
= true;
2017 mutex_unlock(&cpufreq_governor_lock
);
2019 ret
= policy
->governor
->governor(policy
, event
);
2022 if (event
== CPUFREQ_GOV_POLICY_INIT
)
2023 policy
->governor
->initialized
++;
2024 else if (event
== CPUFREQ_GOV_POLICY_EXIT
)
2025 policy
->governor
->initialized
--;
2027 /* Restore original values */
2028 mutex_lock(&cpufreq_governor_lock
);
2029 if (event
== CPUFREQ_GOV_STOP
)
2030 policy
->governor_enabled
= true;
2031 else if (event
== CPUFREQ_GOV_START
)
2032 policy
->governor_enabled
= false;
2033 mutex_unlock(&cpufreq_governor_lock
);
2036 if (((event
== CPUFREQ_GOV_POLICY_INIT
) && ret
) ||
2037 ((event
== CPUFREQ_GOV_POLICY_EXIT
) && !ret
))
2038 module_put(policy
->governor
->owner
);
2043 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2050 if (cpufreq_disabled())
2053 mutex_lock(&cpufreq_governor_mutex
);
2055 governor
->initialized
= 0;
2057 if (!find_governor(governor
->name
)) {
2059 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2062 mutex_unlock(&cpufreq_governor_mutex
);
2065 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2067 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2069 struct cpufreq_policy
*policy
;
2070 unsigned long flags
;
2075 if (cpufreq_disabled())
2078 /* clear last_governor for all inactive policies */
2079 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2080 for_each_inactive_policy(policy
) {
2081 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2082 policy
->governor
= NULL
;
2083 strcpy(policy
->last_governor
, "\0");
2086 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2088 mutex_lock(&cpufreq_governor_mutex
);
2089 list_del(&governor
->governor_list
);
2090 mutex_unlock(&cpufreq_governor_mutex
);
2093 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2096 /*********************************************************************
2097 * POLICY INTERFACE *
2098 *********************************************************************/
2101 * cpufreq_get_policy - get the current cpufreq_policy
2102 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2105 * Reads the current cpufreq policy.
2107 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2109 struct cpufreq_policy
*cpu_policy
;
2113 cpu_policy
= cpufreq_cpu_get(cpu
);
2117 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2119 cpufreq_cpu_put(cpu_policy
);
2122 EXPORT_SYMBOL(cpufreq_get_policy
);
2125 * policy : current policy.
2126 * new_policy: policy to be set.
2128 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2129 struct cpufreq_policy
*new_policy
)
2131 struct cpufreq_governor
*old_gov
;
2134 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2135 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2137 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2140 * This check works well when we store new min/max freq attributes,
2141 * because new_policy is a copy of policy with one field updated.
2143 if (new_policy
->min
> new_policy
->max
)
2146 /* verify the cpu speed can be set within this limit */
2147 ret
= cpufreq_driver
->verify(new_policy
);
2151 /* adjust if necessary - all reasons */
2152 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2153 CPUFREQ_ADJUST
, new_policy
);
2156 * verify the cpu speed can be set within this limit, which might be
2157 * different to the first one
2159 ret
= cpufreq_driver
->verify(new_policy
);
2163 /* notification of the new policy */
2164 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2165 CPUFREQ_NOTIFY
, new_policy
);
2167 policy
->min
= new_policy
->min
;
2168 policy
->max
= new_policy
->max
;
2170 pr_debug("new min and max freqs are %u - %u kHz\n",
2171 policy
->min
, policy
->max
);
2173 if (cpufreq_driver
->setpolicy
) {
2174 policy
->policy
= new_policy
->policy
;
2175 pr_debug("setting range\n");
2176 return cpufreq_driver
->setpolicy(new_policy
);
2179 if (new_policy
->governor
== policy
->governor
)
2182 pr_debug("governor switch\n");
2184 /* save old, working values */
2185 old_gov
= policy
->governor
;
2186 /* end old governor */
2188 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_STOP
);
2190 /* This can happen due to race with other operations */
2191 pr_debug("%s: Failed to Stop Governor: %s (%d)\n",
2192 __func__
, old_gov
->name
, ret
);
2196 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_POLICY_EXIT
);
2198 pr_err("%s: Failed to Exit Governor: %s (%d)\n",
2199 __func__
, old_gov
->name
, ret
);
2204 /* start new governor */
2205 policy
->governor
= new_policy
->governor
;
2206 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_POLICY_INIT
);
2208 ret
= __cpufreq_governor(policy
, CPUFREQ_GOV_START
);
2212 __cpufreq_governor(policy
, CPUFREQ_GOV_POLICY_EXIT
);
2215 /* new governor failed, so re-start old one */
2216 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2218 policy
->governor
= old_gov
;
2219 if (__cpufreq_governor(policy
, CPUFREQ_GOV_POLICY_INIT
))
2220 policy
->governor
= NULL
;
2222 __cpufreq_governor(policy
, CPUFREQ_GOV_START
);
2228 pr_debug("governor: change or update limits\n");
2229 return __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
);
2233 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2234 * @cpu: CPU which shall be re-evaluated
2236 * Useful for policy notifiers which have different necessities
2237 * at different times.
2239 int cpufreq_update_policy(unsigned int cpu
)
2241 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
2242 struct cpufreq_policy new_policy
;
2248 down_write(&policy
->rwsem
);
2250 pr_debug("updating policy for CPU %u\n", cpu
);
2251 memcpy(&new_policy
, policy
, sizeof(*policy
));
2252 new_policy
.min
= policy
->user_policy
.min
;
2253 new_policy
.max
= policy
->user_policy
.max
;
2256 * BIOS might change freq behind our back
2257 * -> ask driver for current freq and notify governors about a change
2259 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
2260 new_policy
.cur
= cpufreq_driver
->get(cpu
);
2261 if (WARN_ON(!new_policy
.cur
)) {
2267 pr_debug("Driver did not initialize current freq\n");
2268 policy
->cur
= new_policy
.cur
;
2270 if (policy
->cur
!= new_policy
.cur
&& has_target())
2271 cpufreq_out_of_sync(policy
, new_policy
.cur
);
2275 ret
= cpufreq_set_policy(policy
, &new_policy
);
2278 up_write(&policy
->rwsem
);
2280 cpufreq_cpu_put(policy
);
2283 EXPORT_SYMBOL(cpufreq_update_policy
);
2285 static int cpufreq_cpu_callback(struct notifier_block
*nfb
,
2286 unsigned long action
, void *hcpu
)
2288 unsigned int cpu
= (unsigned long)hcpu
;
2290 switch (action
& ~CPU_TASKS_FROZEN
) {
2292 cpufreq_online(cpu
);
2295 case CPU_DOWN_PREPARE
:
2296 cpufreq_offline(cpu
);
2299 case CPU_DOWN_FAILED
:
2300 cpufreq_online(cpu
);
2306 static struct notifier_block __refdata cpufreq_cpu_notifier
= {
2307 .notifier_call
= cpufreq_cpu_callback
,
2310 /*********************************************************************
2312 *********************************************************************/
2313 static int cpufreq_boost_set_sw(int state
)
2315 struct cpufreq_frequency_table
*freq_table
;
2316 struct cpufreq_policy
*policy
;
2319 for_each_active_policy(policy
) {
2320 freq_table
= cpufreq_frequency_get_table(policy
->cpu
);
2322 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2325 pr_err("%s: Policy frequency update failed\n",
2329 policy
->user_policy
.max
= policy
->max
;
2330 __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
);
2337 int cpufreq_boost_trigger_state(int state
)
2339 unsigned long flags
;
2342 if (cpufreq_driver
->boost_enabled
== state
)
2345 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2346 cpufreq_driver
->boost_enabled
= state
;
2347 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2349 ret
= cpufreq_driver
->set_boost(state
);
2351 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2352 cpufreq_driver
->boost_enabled
= !state
;
2353 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2355 pr_err("%s: Cannot %s BOOST\n",
2356 __func__
, state
? "enable" : "disable");
2362 static bool cpufreq_boost_supported(void)
2364 return likely(cpufreq_driver
) && cpufreq_driver
->set_boost
;
2367 static int create_boost_sysfs_file(void)
2371 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2373 pr_err("%s: cannot register global BOOST sysfs file\n",
2379 static void remove_boost_sysfs_file(void)
2381 if (cpufreq_boost_supported())
2382 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2385 int cpufreq_enable_boost_support(void)
2387 if (!cpufreq_driver
)
2390 if (cpufreq_boost_supported())
2393 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2395 /* This will get removed on driver unregister */
2396 return create_boost_sysfs_file();
2398 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2400 int cpufreq_boost_enabled(void)
2402 return cpufreq_driver
->boost_enabled
;
2404 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2406 /*********************************************************************
2407 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2408 *********************************************************************/
2411 * cpufreq_register_driver - register a CPU Frequency driver
2412 * @driver_data: A struct cpufreq_driver containing the values#
2413 * submitted by the CPU Frequency driver.
2415 * Registers a CPU Frequency driver to this core code. This code
2416 * returns zero on success, -EBUSY when another driver got here first
2417 * (and isn't unregistered in the meantime).
2420 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2422 unsigned long flags
;
2425 if (cpufreq_disabled())
2428 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2429 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2430 driver_data
->target
) ||
2431 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2432 driver_data
->target
)) ||
2433 (!!driver_data
->get_intermediate
!= !!driver_data
->target_intermediate
))
2436 pr_debug("trying to register driver %s\n", driver_data
->name
);
2438 /* Protect against concurrent CPU online/offline. */
2441 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2442 if (cpufreq_driver
) {
2443 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2447 cpufreq_driver
= driver_data
;
2448 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2450 if (driver_data
->setpolicy
)
2451 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2453 if (cpufreq_boost_supported()) {
2454 ret
= create_boost_sysfs_file();
2456 goto err_null_driver
;
2459 ret
= subsys_interface_register(&cpufreq_interface
);
2461 goto err_boost_unreg
;
2463 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2464 list_empty(&cpufreq_policy_list
)) {
2465 /* if all ->init() calls failed, unregister */
2466 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2471 register_hotcpu_notifier(&cpufreq_cpu_notifier
);
2472 pr_debug("driver %s up and running\n", driver_data
->name
);
2479 subsys_interface_unregister(&cpufreq_interface
);
2481 remove_boost_sysfs_file();
2483 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2484 cpufreq_driver
= NULL
;
2485 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2488 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2491 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2493 * Unregister the current CPUFreq driver. Only call this if you have
2494 * the right to do so, i.e. if you have succeeded in initialising before!
2495 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2496 * currently not initialised.
2498 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2500 unsigned long flags
;
2502 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2505 pr_debug("unregistering driver %s\n", driver
->name
);
2507 /* Protect against concurrent cpu hotplug */
2509 subsys_interface_unregister(&cpufreq_interface
);
2510 remove_boost_sysfs_file();
2511 unregister_hotcpu_notifier(&cpufreq_cpu_notifier
);
2513 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2515 cpufreq_driver
= NULL
;
2517 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2522 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2525 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2526 * or mutexes when secondary CPUs are halted.
2528 static struct syscore_ops cpufreq_syscore_ops
= {
2529 .shutdown
= cpufreq_suspend
,
2532 struct kobject
*cpufreq_global_kobject
;
2533 EXPORT_SYMBOL(cpufreq_global_kobject
);
2535 static int __init
cpufreq_core_init(void)
2537 if (cpufreq_disabled())
2540 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2541 BUG_ON(!cpufreq_global_kobject
);
2543 register_syscore_ops(&cpufreq_syscore_ops
);
2547 core_initcall(cpufreq_core_init
);