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 <asm/cputime.h>
21 #include <linux/kernel.h>
22 #include <linux/kernel_stat.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/notifier.h>
26 #include <linux/cpufreq.h>
27 #include <linux/delay.h>
28 #include <linux/interrupt.h>
29 #include <linux/spinlock.h>
30 #include <linux/tick.h>
31 #include <linux/device.h>
32 #include <linux/slab.h>
33 #include <linux/cpu.h>
34 #include <linux/completion.h>
35 #include <linux/mutex.h>
36 #include <linux/syscore_ops.h>
38 #include <trace/events/power.h>
41 * The "cpufreq driver" - the arch- or hardware-dependent low
42 * level driver of CPUFreq support, and its spinlock. This lock
43 * also protects the cpufreq_cpu_data array.
45 static struct cpufreq_driver
*cpufreq_driver
;
46 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
47 static DEFINE_RWLOCK(cpufreq_driver_lock
);
48 static DEFINE_MUTEX(cpufreq_governor_lock
);
50 #ifdef CONFIG_HOTPLUG_CPU
51 /* This one keeps track of the previously set governor of a removed CPU */
52 static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN
], cpufreq_cpu_governor
);
56 * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure
57 * all cpufreq/hotplug/workqueue/etc related lock issues.
59 * The rules for this semaphore:
60 * - Any routine that wants to read from the policy structure will
61 * do a down_read on this semaphore.
62 * - Any routine that will write to the policy structure and/or may take away
63 * the policy altogether (eg. CPU hotplug), will hold this lock in write
64 * mode before doing so.
67 * - Governor routines that can be called in cpufreq hotplug path should not
68 * take this sem as top level hotplug notifier handler takes this.
69 * - Lock should not be held across
70 * __cpufreq_governor(data, CPUFREQ_GOV_STOP);
72 static DEFINE_PER_CPU(int, cpufreq_policy_cpu
);
73 static DEFINE_PER_CPU(struct rw_semaphore
, cpu_policy_rwsem
);
75 #define lock_policy_rwsem(mode, cpu) \
76 static int lock_policy_rwsem_##mode(int cpu) \
78 int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
79 BUG_ON(policy_cpu == -1); \
80 down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
85 lock_policy_rwsem(read
, cpu
);
86 lock_policy_rwsem(write
, cpu
);
88 #define unlock_policy_rwsem(mode, cpu) \
89 static void unlock_policy_rwsem_##mode(int cpu) \
91 int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \
92 BUG_ON(policy_cpu == -1); \
93 up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \
96 unlock_policy_rwsem(read
, cpu
);
97 unlock_policy_rwsem(write
, cpu
);
99 /* internal prototypes */
100 static int __cpufreq_governor(struct cpufreq_policy
*policy
,
102 static unsigned int __cpufreq_get(unsigned int cpu
);
103 static void handle_update(struct work_struct
*work
);
106 * Two notifier lists: the "policy" list is involved in the
107 * validation process for a new CPU frequency policy; the
108 * "transition" list for kernel code that needs to handle
109 * changes to devices when the CPU clock speed changes.
110 * The mutex locks both lists.
112 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list
);
113 static struct srcu_notifier_head cpufreq_transition_notifier_list
;
115 static bool init_cpufreq_transition_notifier_list_called
;
116 static int __init
init_cpufreq_transition_notifier_list(void)
118 srcu_init_notifier_head(&cpufreq_transition_notifier_list
);
119 init_cpufreq_transition_notifier_list_called
= true;
122 pure_initcall(init_cpufreq_transition_notifier_list
);
124 static int off __read_mostly
;
125 static int cpufreq_disabled(void)
129 void disable_cpufreq(void)
133 static LIST_HEAD(cpufreq_governor_list
);
134 static DEFINE_MUTEX(cpufreq_governor_mutex
);
136 bool have_governor_per_policy(void)
138 return cpufreq_driver
->have_governor_per_policy
;
140 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
142 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
144 if (have_governor_per_policy())
145 return &policy
->kobj
;
147 return cpufreq_global_kobject
;
149 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
151 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
157 cur_wall_time
= jiffies64_to_cputime64(get_jiffies_64());
159 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
160 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
161 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
162 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
163 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
164 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
166 idle_time
= cur_wall_time
- busy_time
;
168 *wall
= cputime_to_usecs(cur_wall_time
);
170 return cputime_to_usecs(idle_time
);
173 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
175 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
177 if (idle_time
== -1ULL)
178 return get_cpu_idle_time_jiffy(cpu
, wall
);
180 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
184 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
186 static struct cpufreq_policy
*__cpufreq_cpu_get(unsigned int cpu
, bool sysfs
)
188 struct cpufreq_policy
*data
;
191 if (cpu
>= nr_cpu_ids
)
194 /* get the cpufreq driver */
195 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
200 if (!try_module_get(cpufreq_driver
->owner
))
204 data
= per_cpu(cpufreq_cpu_data
, cpu
);
207 goto err_out_put_module
;
209 if (!sysfs
&& !kobject_get(&data
->kobj
))
210 goto err_out_put_module
;
212 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
216 module_put(cpufreq_driver
->owner
);
218 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
223 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
225 if (cpufreq_disabled())
228 return __cpufreq_cpu_get(cpu
, false);
230 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
232 static struct cpufreq_policy
*cpufreq_cpu_get_sysfs(unsigned int cpu
)
234 return __cpufreq_cpu_get(cpu
, true);
237 static void __cpufreq_cpu_put(struct cpufreq_policy
*data
, bool sysfs
)
240 kobject_put(&data
->kobj
);
241 module_put(cpufreq_driver
->owner
);
244 void cpufreq_cpu_put(struct cpufreq_policy
*data
)
246 if (cpufreq_disabled())
249 __cpufreq_cpu_put(data
, false);
251 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
253 static void cpufreq_cpu_put_sysfs(struct cpufreq_policy
*data
)
255 __cpufreq_cpu_put(data
, true);
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.
271 static unsigned long l_p_j_ref
;
272 static unsigned int l_p_j_ref_freq
;
274 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
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; "
283 "freq is %u kHz\n", l_p_j_ref
, l_p_j_ref_freq
);
285 if ((val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) ||
286 (val
== CPUFREQ_RESUMECHANGE
|| val
== CPUFREQ_SUSPENDCHANGE
)) {
287 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
289 pr_debug("scaling loops_per_jiffy to %lu "
290 "for frequency %u kHz\n", loops_per_jiffy
, ci
->new);
294 static inline void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
300 void __cpufreq_notify_transition(struct cpufreq_policy
*policy
,
301 struct cpufreq_freqs
*freqs
, unsigned int state
)
303 BUG_ON(irqs_disabled());
305 if (cpufreq_disabled())
308 freqs
->flags
= cpufreq_driver
->flags
;
309 pr_debug("notification %u of frequency transition to %u kHz\n",
314 case CPUFREQ_PRECHANGE
:
315 /* detect if the driver reported a value as "old frequency"
316 * which is not equal to what the cpufreq core thinks is
319 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
320 if ((policy
) && (policy
->cpu
== freqs
->cpu
) &&
321 (policy
->cur
) && (policy
->cur
!= freqs
->old
)) {
322 pr_debug("Warning: CPU frequency is"
323 " %u, cpufreq assumed %u kHz.\n",
324 freqs
->old
, policy
->cur
);
325 freqs
->old
= policy
->cur
;
328 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
329 CPUFREQ_PRECHANGE
, freqs
);
330 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
333 case CPUFREQ_POSTCHANGE
:
334 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
335 pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs
->new,
336 (unsigned long)freqs
->cpu
);
337 trace_cpu_frequency(freqs
->new, freqs
->cpu
);
338 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
339 CPUFREQ_POSTCHANGE
, freqs
);
340 if (likely(policy
) && likely(policy
->cpu
== freqs
->cpu
))
341 policy
->cur
= freqs
->new;
347 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
348 * on frequency transition.
350 * This function calls the transition notifiers and the "adjust_jiffies"
351 * function. It is called twice on all CPU frequency changes that have
354 void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
355 struct cpufreq_freqs
*freqs
, unsigned int state
)
357 for_each_cpu(freqs
->cpu
, policy
->cpus
)
358 __cpufreq_notify_transition(policy
, freqs
, state
);
360 EXPORT_SYMBOL_GPL(cpufreq_notify_transition
);
363 /*********************************************************************
365 *********************************************************************/
367 static struct cpufreq_governor
*__find_governor(const char *str_governor
)
369 struct cpufreq_governor
*t
;
371 list_for_each_entry(t
, &cpufreq_governor_list
, governor_list
)
372 if (!strnicmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
379 * cpufreq_parse_governor - parse a governor string
381 static int cpufreq_parse_governor(char *str_governor
, unsigned int *policy
,
382 struct cpufreq_governor
**governor
)
389 if (cpufreq_driver
->setpolicy
) {
390 if (!strnicmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
391 *policy
= CPUFREQ_POLICY_PERFORMANCE
;
393 } else if (!strnicmp(str_governor
, "powersave",
395 *policy
= CPUFREQ_POLICY_POWERSAVE
;
398 } else if (cpufreq_driver
->target
) {
399 struct cpufreq_governor
*t
;
401 mutex_lock(&cpufreq_governor_mutex
);
403 t
= __find_governor(str_governor
);
408 mutex_unlock(&cpufreq_governor_mutex
);
409 ret
= request_module("cpufreq_%s", str_governor
);
410 mutex_lock(&cpufreq_governor_mutex
);
413 t
= __find_governor(str_governor
);
421 mutex_unlock(&cpufreq_governor_mutex
);
428 * cpufreq_per_cpu_attr_read() / show_##file_name() -
429 * print out cpufreq information
431 * Write out information from cpufreq_driver->policy[cpu]; object must be
435 #define show_one(file_name, object) \
436 static ssize_t show_##file_name \
437 (struct cpufreq_policy *policy, char *buf) \
439 return sprintf(buf, "%u\n", policy->object); \
442 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
443 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
444 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
445 show_one(scaling_min_freq
, min
);
446 show_one(scaling_max_freq
, max
);
447 show_one(scaling_cur_freq
, cur
);
449 static int __cpufreq_set_policy(struct cpufreq_policy
*data
,
450 struct cpufreq_policy
*policy
);
453 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
455 #define store_one(file_name, object) \
456 static ssize_t store_##file_name \
457 (struct cpufreq_policy *policy, const char *buf, size_t count) \
460 struct cpufreq_policy new_policy; \
462 ret = cpufreq_get_policy(&new_policy, policy->cpu); \
466 ret = sscanf(buf, "%u", &new_policy.object); \
470 ret = __cpufreq_set_policy(policy, &new_policy); \
471 policy->user_policy.object = policy->object; \
473 return ret ? ret : count; \
476 store_one(scaling_min_freq
, min
);
477 store_one(scaling_max_freq
, max
);
480 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
482 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
485 unsigned int cur_freq
= __cpufreq_get(policy
->cpu
);
487 return sprintf(buf
, "<unknown>");
488 return sprintf(buf
, "%u\n", cur_freq
);
492 * show_scaling_governor - show the current policy for the specified CPU
494 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
496 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
497 return sprintf(buf
, "powersave\n");
498 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
499 return sprintf(buf
, "performance\n");
500 else if (policy
->governor
)
501 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
502 policy
->governor
->name
);
507 * store_scaling_governor - store policy for the specified CPU
509 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
510 const char *buf
, size_t count
)
513 char str_governor
[16];
514 struct cpufreq_policy new_policy
;
516 ret
= cpufreq_get_policy(&new_policy
, policy
->cpu
);
520 ret
= sscanf(buf
, "%15s", str_governor
);
524 if (cpufreq_parse_governor(str_governor
, &new_policy
.policy
,
525 &new_policy
.governor
))
529 * Do not use cpufreq_set_policy here or the user_policy.max
530 * will be wrongly overridden
532 ret
= __cpufreq_set_policy(policy
, &new_policy
);
534 policy
->user_policy
.policy
= policy
->policy
;
535 policy
->user_policy
.governor
= policy
->governor
;
544 * show_scaling_driver - show the cpufreq driver currently loaded
546 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
548 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
552 * show_scaling_available_governors - show the available CPUfreq governors
554 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
558 struct cpufreq_governor
*t
;
560 if (!cpufreq_driver
->target
) {
561 i
+= sprintf(buf
, "performance powersave");
565 list_for_each_entry(t
, &cpufreq_governor_list
, governor_list
) {
566 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
567 - (CPUFREQ_NAME_LEN
+ 2)))
569 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
572 i
+= sprintf(&buf
[i
], "\n");
576 static ssize_t
show_cpus(const struct cpumask
*mask
, char *buf
)
581 for_each_cpu(cpu
, mask
) {
583 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
584 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
585 if (i
>= (PAGE_SIZE
- 5))
588 i
+= sprintf(&buf
[i
], "\n");
593 * show_related_cpus - show the CPUs affected by each transition even if
594 * hw coordination is in use
596 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
598 return show_cpus(policy
->related_cpus
, buf
);
602 * show_affected_cpus - show the CPUs affected by each transition
604 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
606 return show_cpus(policy
->cpus
, buf
);
609 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
610 const char *buf
, size_t count
)
612 unsigned int freq
= 0;
615 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
618 ret
= sscanf(buf
, "%u", &freq
);
622 policy
->governor
->store_setspeed(policy
, freq
);
627 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
629 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
630 return sprintf(buf
, "<unsupported>\n");
632 return policy
->governor
->show_setspeed(policy
, buf
);
636 * show_bios_limit - show the current cpufreq HW/BIOS limitation
638 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
642 if (cpufreq_driver
->bios_limit
) {
643 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
645 return sprintf(buf
, "%u\n", limit
);
647 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
650 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
651 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
652 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
653 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
654 cpufreq_freq_attr_ro(scaling_available_governors
);
655 cpufreq_freq_attr_ro(scaling_driver
);
656 cpufreq_freq_attr_ro(scaling_cur_freq
);
657 cpufreq_freq_attr_ro(bios_limit
);
658 cpufreq_freq_attr_ro(related_cpus
);
659 cpufreq_freq_attr_ro(affected_cpus
);
660 cpufreq_freq_attr_rw(scaling_min_freq
);
661 cpufreq_freq_attr_rw(scaling_max_freq
);
662 cpufreq_freq_attr_rw(scaling_governor
);
663 cpufreq_freq_attr_rw(scaling_setspeed
);
665 static struct attribute
*default_attrs
[] = {
666 &cpuinfo_min_freq
.attr
,
667 &cpuinfo_max_freq
.attr
,
668 &cpuinfo_transition_latency
.attr
,
669 &scaling_min_freq
.attr
,
670 &scaling_max_freq
.attr
,
673 &scaling_governor
.attr
,
674 &scaling_driver
.attr
,
675 &scaling_available_governors
.attr
,
676 &scaling_setspeed
.attr
,
680 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
681 #define to_attr(a) container_of(a, struct freq_attr, attr)
683 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
685 struct cpufreq_policy
*policy
= to_policy(kobj
);
686 struct freq_attr
*fattr
= to_attr(attr
);
687 ssize_t ret
= -EINVAL
;
688 policy
= cpufreq_cpu_get_sysfs(policy
->cpu
);
692 if (lock_policy_rwsem_read(policy
->cpu
) < 0)
696 ret
= fattr
->show(policy
, buf
);
700 unlock_policy_rwsem_read(policy
->cpu
);
702 cpufreq_cpu_put_sysfs(policy
);
707 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
708 const char *buf
, size_t count
)
710 struct cpufreq_policy
*policy
= to_policy(kobj
);
711 struct freq_attr
*fattr
= to_attr(attr
);
712 ssize_t ret
= -EINVAL
;
713 policy
= cpufreq_cpu_get_sysfs(policy
->cpu
);
717 if (lock_policy_rwsem_write(policy
->cpu
) < 0)
721 ret
= fattr
->store(policy
, buf
, count
);
725 unlock_policy_rwsem_write(policy
->cpu
);
727 cpufreq_cpu_put_sysfs(policy
);
732 static void cpufreq_sysfs_release(struct kobject
*kobj
)
734 struct cpufreq_policy
*policy
= to_policy(kobj
);
735 pr_debug("last reference is dropped\n");
736 complete(&policy
->kobj_unregister
);
739 static const struct sysfs_ops sysfs_ops
= {
744 static struct kobj_type ktype_cpufreq
= {
745 .sysfs_ops
= &sysfs_ops
,
746 .default_attrs
= default_attrs
,
747 .release
= cpufreq_sysfs_release
,
750 struct kobject
*cpufreq_global_kobject
;
751 EXPORT_SYMBOL(cpufreq_global_kobject
);
753 static int cpufreq_global_kobject_usage
;
755 int cpufreq_get_global_kobject(void)
757 if (!cpufreq_global_kobject_usage
++)
758 return kobject_add(cpufreq_global_kobject
,
759 &cpu_subsys
.dev_root
->kobj
, "%s", "cpufreq");
763 EXPORT_SYMBOL(cpufreq_get_global_kobject
);
765 void cpufreq_put_global_kobject(void)
767 if (!--cpufreq_global_kobject_usage
)
768 kobject_del(cpufreq_global_kobject
);
770 EXPORT_SYMBOL(cpufreq_put_global_kobject
);
772 int cpufreq_sysfs_create_file(const struct attribute
*attr
)
774 int ret
= cpufreq_get_global_kobject();
777 ret
= sysfs_create_file(cpufreq_global_kobject
, attr
);
779 cpufreq_put_global_kobject();
784 EXPORT_SYMBOL(cpufreq_sysfs_create_file
);
786 void cpufreq_sysfs_remove_file(const struct attribute
*attr
)
788 sysfs_remove_file(cpufreq_global_kobject
, attr
);
789 cpufreq_put_global_kobject();
791 EXPORT_SYMBOL(cpufreq_sysfs_remove_file
);
793 /* symlink affected CPUs */
794 static int cpufreq_add_dev_symlink(unsigned int cpu
,
795 struct cpufreq_policy
*policy
)
800 for_each_cpu(j
, policy
->cpus
) {
801 struct cpufreq_policy
*managed_policy
;
802 struct device
*cpu_dev
;
807 pr_debug("CPU %u already managed, adding link\n", j
);
808 managed_policy
= cpufreq_cpu_get(cpu
);
809 cpu_dev
= get_cpu_device(j
);
810 ret
= sysfs_create_link(&cpu_dev
->kobj
, &policy
->kobj
,
813 cpufreq_cpu_put(managed_policy
);
820 static int cpufreq_add_dev_interface(unsigned int cpu
,
821 struct cpufreq_policy
*policy
,
824 struct cpufreq_policy new_policy
;
825 struct freq_attr
**drv_attr
;
830 /* prepare interface data */
831 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
832 &dev
->kobj
, "cpufreq");
836 /* set up files for this cpu device */
837 drv_attr
= cpufreq_driver
->attr
;
838 while ((drv_attr
) && (*drv_attr
)) {
839 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
841 goto err_out_kobj_put
;
844 if (cpufreq_driver
->get
) {
845 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
847 goto err_out_kobj_put
;
849 if (cpufreq_driver
->target
) {
850 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
852 goto err_out_kobj_put
;
854 if (cpufreq_driver
->bios_limit
) {
855 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
857 goto err_out_kobj_put
;
860 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
861 for_each_cpu(j
, policy
->cpus
) {
862 per_cpu(cpufreq_cpu_data
, j
) = policy
;
863 per_cpu(cpufreq_policy_cpu
, j
) = policy
->cpu
;
865 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
867 ret
= cpufreq_add_dev_symlink(cpu
, policy
);
869 goto err_out_kobj_put
;
871 memcpy(&new_policy
, policy
, sizeof(struct cpufreq_policy
));
872 /* assure that the starting sequence is run in __cpufreq_set_policy */
873 policy
->governor
= NULL
;
875 /* set default policy */
876 ret
= __cpufreq_set_policy(policy
, &new_policy
);
877 policy
->user_policy
.policy
= policy
->policy
;
878 policy
->user_policy
.governor
= policy
->governor
;
881 pr_debug("setting policy failed\n");
882 if (cpufreq_driver
->exit
)
883 cpufreq_driver
->exit(policy
);
888 kobject_put(&policy
->kobj
);
889 wait_for_completion(&policy
->kobj_unregister
);
893 #ifdef CONFIG_HOTPLUG_CPU
894 static int cpufreq_add_policy_cpu(unsigned int cpu
, unsigned int sibling
,
897 struct cpufreq_policy
*policy
;
898 int ret
= 0, has_target
= !!cpufreq_driver
->target
;
901 policy
= cpufreq_cpu_get(sibling
);
905 __cpufreq_governor(policy
, CPUFREQ_GOV_STOP
);
907 lock_policy_rwsem_write(sibling
);
909 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
911 cpumask_set_cpu(cpu
, policy
->cpus
);
912 per_cpu(cpufreq_policy_cpu
, cpu
) = policy
->cpu
;
913 per_cpu(cpufreq_cpu_data
, cpu
) = policy
;
914 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
916 unlock_policy_rwsem_write(sibling
);
919 __cpufreq_governor(policy
, CPUFREQ_GOV_START
);
920 __cpufreq_governor(policy
, CPUFREQ_GOV_LIMITS
);
923 ret
= sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq");
925 cpufreq_cpu_put(policy
);
934 * cpufreq_add_dev - add a CPU device
936 * Adds the cpufreq interface for a CPU device.
938 * The Oracle says: try running cpufreq registration/unregistration concurrently
939 * with with cpu hotplugging and all hell will break loose. Tried to clean this
940 * mess up, but more thorough testing is needed. - Mathieu
942 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
944 unsigned int j
, cpu
= dev
->id
;
946 struct cpufreq_policy
*policy
;
948 #ifdef CONFIG_HOTPLUG_CPU
949 struct cpufreq_governor
*gov
;
953 if (cpu_is_offline(cpu
))
956 pr_debug("adding CPU %u\n", cpu
);
959 /* check whether a different CPU already registered this
960 * CPU because it is in the same boat. */
961 policy
= cpufreq_cpu_get(cpu
);
962 if (unlikely(policy
)) {
963 cpufreq_cpu_put(policy
);
967 #ifdef CONFIG_HOTPLUG_CPU
968 /* Check if this cpu was hot-unplugged earlier and has siblings */
969 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
970 for_each_online_cpu(sibling
) {
971 struct cpufreq_policy
*cp
= per_cpu(cpufreq_cpu_data
, sibling
);
972 if (cp
&& cpumask_test_cpu(cpu
, cp
->related_cpus
)) {
973 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
974 return cpufreq_add_policy_cpu(cpu
, sibling
, dev
);
977 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
981 if (!try_module_get(cpufreq_driver
->owner
)) {
986 policy
= kzalloc(sizeof(struct cpufreq_policy
), GFP_KERNEL
);
990 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
991 goto err_free_policy
;
993 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
994 goto err_free_cpumask
;
997 policy
->governor
= CPUFREQ_DEFAULT_GOVERNOR
;
998 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1000 /* Initially set CPU itself as the policy_cpu */
1001 per_cpu(cpufreq_policy_cpu
, cpu
) = cpu
;
1003 init_completion(&policy
->kobj_unregister
);
1004 INIT_WORK(&policy
->update
, handle_update
);
1006 /* call driver. From then on the cpufreq must be able
1007 * to accept all calls to ->verify and ->setpolicy for this CPU
1009 ret
= cpufreq_driver
->init(policy
);
1011 pr_debug("initialization failed\n");
1012 goto err_set_policy_cpu
;
1015 /* related cpus should atleast have policy->cpus */
1016 cpumask_or(policy
->related_cpus
, policy
->related_cpus
, policy
->cpus
);
1019 * affected cpus must always be the one, which are online. We aren't
1020 * managing offline cpus here.
1022 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1024 policy
->user_policy
.min
= policy
->min
;
1025 policy
->user_policy
.max
= policy
->max
;
1027 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1028 CPUFREQ_START
, policy
);
1030 #ifdef CONFIG_HOTPLUG_CPU
1031 gov
= __find_governor(per_cpu(cpufreq_cpu_governor
, cpu
));
1033 policy
->governor
= gov
;
1034 pr_debug("Restoring governor %s for cpu %d\n",
1035 policy
->governor
->name
, cpu
);
1039 ret
= cpufreq_add_dev_interface(cpu
, policy
, dev
);
1041 goto err_out_unregister
;
1043 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1044 module_put(cpufreq_driver
->owner
);
1045 pr_debug("initialization complete\n");
1050 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1051 for_each_cpu(j
, policy
->cpus
)
1052 per_cpu(cpufreq_cpu_data
, j
) = NULL
;
1053 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1055 kobject_put(&policy
->kobj
);
1056 wait_for_completion(&policy
->kobj_unregister
);
1059 per_cpu(cpufreq_policy_cpu
, cpu
) = -1;
1060 free_cpumask_var(policy
->related_cpus
);
1062 free_cpumask_var(policy
->cpus
);
1066 module_put(cpufreq_driver
->owner
);
1071 static void update_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1075 policy
->last_cpu
= policy
->cpu
;
1078 for_each_cpu(j
, policy
->cpus
)
1079 per_cpu(cpufreq_policy_cpu
, j
) = cpu
;
1081 #ifdef CONFIG_CPU_FREQ_TABLE
1082 cpufreq_frequency_table_update_policy_cpu(policy
);
1084 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1085 CPUFREQ_UPDATE_POLICY_CPU
, policy
);
1089 * __cpufreq_remove_dev - remove a CPU device
1091 * Removes the cpufreq interface for a CPU device.
1092 * Caller should already have policy_rwsem in write mode for this CPU.
1093 * This routine frees the rwsem before returning.
1095 static int __cpufreq_remove_dev(struct device
*dev
,
1096 struct subsys_interface
*sif
)
1098 unsigned int cpu
= dev
->id
, ret
, cpus
;
1099 unsigned long flags
;
1100 struct cpufreq_policy
*data
;
1101 struct kobject
*kobj
;
1102 struct completion
*cmp
;
1103 struct device
*cpu_dev
;
1105 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1107 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1109 data
= per_cpu(cpufreq_cpu_data
, cpu
);
1110 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1112 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1115 pr_debug("%s: No cpu_data found\n", __func__
);
1119 if (cpufreq_driver
->target
)
1120 __cpufreq_governor(data
, CPUFREQ_GOV_STOP
);
1122 #ifdef CONFIG_HOTPLUG_CPU
1123 if (!cpufreq_driver
->setpolicy
)
1124 strncpy(per_cpu(cpufreq_cpu_governor
, cpu
),
1125 data
->governor
->name
, CPUFREQ_NAME_LEN
);
1128 WARN_ON(lock_policy_rwsem_write(cpu
));
1129 cpus
= cpumask_weight(data
->cpus
);
1132 cpumask_clear_cpu(cpu
, data
->cpus
);
1133 unlock_policy_rwsem_write(cpu
);
1135 if (cpu
!= data
->cpu
) {
1136 sysfs_remove_link(&dev
->kobj
, "cpufreq");
1137 } else if (cpus
> 1) {
1138 /* first sibling now owns the new sysfs dir */
1139 cpu_dev
= get_cpu_device(cpumask_first(data
->cpus
));
1140 sysfs_remove_link(&cpu_dev
->kobj
, "cpufreq");
1141 ret
= kobject_move(&data
->kobj
, &cpu_dev
->kobj
);
1143 pr_err("%s: Failed to move kobj: %d", __func__
, ret
);
1145 WARN_ON(lock_policy_rwsem_write(cpu
));
1146 cpumask_set_cpu(cpu
, data
->cpus
);
1148 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1149 per_cpu(cpufreq_cpu_data
, cpu
) = data
;
1150 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1152 unlock_policy_rwsem_write(cpu
);
1154 ret
= sysfs_create_link(&cpu_dev
->kobj
, &data
->kobj
,
1159 WARN_ON(lock_policy_rwsem_write(cpu
));
1160 update_policy_cpu(data
, cpu_dev
->id
);
1161 unlock_policy_rwsem_write(cpu
);
1162 pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
1163 __func__
, cpu_dev
->id
, cpu
);
1166 if ((cpus
== 1) && (cpufreq_driver
->target
))
1167 __cpufreq_governor(data
, CPUFREQ_GOV_POLICY_EXIT
);
1169 pr_debug("%s: removing link, cpu: %d\n", __func__
, cpu
);
1170 cpufreq_cpu_put(data
);
1172 /* If cpu is last user of policy, free policy */
1174 lock_policy_rwsem_read(cpu
);
1176 cmp
= &data
->kobj_unregister
;
1177 unlock_policy_rwsem_read(cpu
);
1180 /* we need to make sure that the underlying kobj is actually
1181 * not referenced anymore by anybody before we proceed with
1184 pr_debug("waiting for dropping of refcount\n");
1185 wait_for_completion(cmp
);
1186 pr_debug("wait complete\n");
1188 if (cpufreq_driver
->exit
)
1189 cpufreq_driver
->exit(data
);
1191 free_cpumask_var(data
->related_cpus
);
1192 free_cpumask_var(data
->cpus
);
1194 } else if (cpufreq_driver
->target
) {
1195 __cpufreq_governor(data
, CPUFREQ_GOV_START
);
1196 __cpufreq_governor(data
, CPUFREQ_GOV_LIMITS
);
1199 per_cpu(cpufreq_policy_cpu
, cpu
) = -1;
1203 static int cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1205 unsigned int cpu
= dev
->id
;
1208 if (cpu_is_offline(cpu
))
1211 retval
= __cpufreq_remove_dev(dev
, sif
);
1215 static void handle_update(struct work_struct
*work
)
1217 struct cpufreq_policy
*policy
=
1218 container_of(work
, struct cpufreq_policy
, update
);
1219 unsigned int cpu
= policy
->cpu
;
1220 pr_debug("handle_update for cpu %u called\n", cpu
);
1221 cpufreq_update_policy(cpu
);
1225 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1228 * @old_freq: CPU frequency the kernel thinks the CPU runs at
1229 * @new_freq: CPU frequency the CPU actually runs at
1231 * We adjust to current frequency first, and need to clean up later.
1232 * So either call to cpufreq_update_policy() or schedule handle_update()).
1234 static void cpufreq_out_of_sync(unsigned int cpu
, unsigned int old_freq
,
1235 unsigned int new_freq
)
1237 struct cpufreq_policy
*policy
;
1238 struct cpufreq_freqs freqs
;
1239 unsigned long flags
;
1241 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing "
1242 "core thinks of %u, is %u kHz.\n", old_freq
, new_freq
);
1244 freqs
.old
= old_freq
;
1245 freqs
.new = new_freq
;
1247 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1248 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1249 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1251 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_PRECHANGE
);
1252 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_POSTCHANGE
);
1256 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1259 * This is the last known freq, without actually getting it from the driver.
1260 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1262 unsigned int cpufreq_quick_get(unsigned int cpu
)
1264 struct cpufreq_policy
*policy
;
1265 unsigned int ret_freq
= 0;
1267 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
)
1268 return cpufreq_driver
->get(cpu
);
1270 policy
= cpufreq_cpu_get(cpu
);
1272 ret_freq
= policy
->cur
;
1273 cpufreq_cpu_put(policy
);
1278 EXPORT_SYMBOL(cpufreq_quick_get
);
1281 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1284 * Just return the max possible frequency for a given CPU.
1286 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1288 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1289 unsigned int ret_freq
= 0;
1292 ret_freq
= policy
->max
;
1293 cpufreq_cpu_put(policy
);
1298 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1300 static unsigned int __cpufreq_get(unsigned int cpu
)
1302 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1303 unsigned int ret_freq
= 0;
1305 if (!cpufreq_driver
->get
)
1308 ret_freq
= cpufreq_driver
->get(cpu
);
1310 if (ret_freq
&& policy
->cur
&&
1311 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1312 /* verify no discrepancy between actual and
1313 saved value exists */
1314 if (unlikely(ret_freq
!= policy
->cur
)) {
1315 cpufreq_out_of_sync(cpu
, policy
->cur
, ret_freq
);
1316 schedule_work(&policy
->update
);
1324 * cpufreq_get - get the current CPU frequency (in kHz)
1327 * Get the CPU current (static) CPU frequency
1329 unsigned int cpufreq_get(unsigned int cpu
)
1331 unsigned int ret_freq
= 0;
1332 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1337 if (unlikely(lock_policy_rwsem_read(cpu
)))
1340 ret_freq
= __cpufreq_get(cpu
);
1342 unlock_policy_rwsem_read(cpu
);
1345 cpufreq_cpu_put(policy
);
1349 EXPORT_SYMBOL(cpufreq_get
);
1351 static struct subsys_interface cpufreq_interface
= {
1353 .subsys
= &cpu_subsys
,
1354 .add_dev
= cpufreq_add_dev
,
1355 .remove_dev
= cpufreq_remove_dev
,
1359 * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
1361 * This function is only executed for the boot processor. The other CPUs
1362 * have been put offline by means of CPU hotplug.
1364 static int cpufreq_bp_suspend(void)
1368 int cpu
= smp_processor_id();
1369 struct cpufreq_policy
*cpu_policy
;
1371 pr_debug("suspending cpu %u\n", cpu
);
1373 /* If there's no policy for the boot CPU, we have nothing to do. */
1374 cpu_policy
= cpufreq_cpu_get(cpu
);
1378 if (cpufreq_driver
->suspend
) {
1379 ret
= cpufreq_driver
->suspend(cpu_policy
);
1381 printk(KERN_ERR
"cpufreq: suspend failed in ->suspend "
1382 "step on CPU %u\n", cpu_policy
->cpu
);
1385 cpufreq_cpu_put(cpu_policy
);
1390 * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
1392 * 1.) resume CPUfreq hardware support (cpufreq_driver->resume())
1393 * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are
1394 * restored. It will verify that the current freq is in sync with
1395 * what we believe it to be. This is a bit later than when it
1396 * should be, but nonethteless it's better than calling
1397 * cpufreq_driver->get() here which might re-enable interrupts...
1399 * This function is only executed for the boot CPU. The other CPUs have not
1400 * been turned on yet.
1402 static void cpufreq_bp_resume(void)
1406 int cpu
= smp_processor_id();
1407 struct cpufreq_policy
*cpu_policy
;
1409 pr_debug("resuming cpu %u\n", cpu
);
1411 /* If there's no policy for the boot CPU, we have nothing to do. */
1412 cpu_policy
= cpufreq_cpu_get(cpu
);
1416 if (cpufreq_driver
->resume
) {
1417 ret
= cpufreq_driver
->resume(cpu_policy
);
1419 printk(KERN_ERR
"cpufreq: resume failed in ->resume "
1420 "step on CPU %u\n", cpu_policy
->cpu
);
1425 schedule_work(&cpu_policy
->update
);
1428 cpufreq_cpu_put(cpu_policy
);
1431 static struct syscore_ops cpufreq_syscore_ops
= {
1432 .suspend
= cpufreq_bp_suspend
,
1433 .resume
= cpufreq_bp_resume
,
1437 * cpufreq_get_current_driver - return current driver's name
1439 * Return the name string of the currently loaded cpufreq driver
1442 const char *cpufreq_get_current_driver(void)
1445 return cpufreq_driver
->name
;
1449 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1451 /*********************************************************************
1452 * NOTIFIER LISTS INTERFACE *
1453 *********************************************************************/
1456 * cpufreq_register_notifier - register a driver with cpufreq
1457 * @nb: notifier function to register
1458 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1460 * Add a driver to one of two lists: either a list of drivers that
1461 * are notified about clock rate changes (once before and once after
1462 * the transition), or a list of drivers that are notified about
1463 * changes in cpufreq policy.
1465 * This function may sleep, and has the same return conditions as
1466 * blocking_notifier_chain_register.
1468 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1472 if (cpufreq_disabled())
1475 WARN_ON(!init_cpufreq_transition_notifier_list_called
);
1478 case CPUFREQ_TRANSITION_NOTIFIER
:
1479 ret
= srcu_notifier_chain_register(
1480 &cpufreq_transition_notifier_list
, nb
);
1482 case CPUFREQ_POLICY_NOTIFIER
:
1483 ret
= blocking_notifier_chain_register(
1484 &cpufreq_policy_notifier_list
, nb
);
1492 EXPORT_SYMBOL(cpufreq_register_notifier
);
1495 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1496 * @nb: notifier block to be unregistered
1497 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1499 * Remove a driver from the CPU frequency notifier list.
1501 * This function may sleep, and has the same return conditions as
1502 * blocking_notifier_chain_unregister.
1504 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1508 if (cpufreq_disabled())
1512 case CPUFREQ_TRANSITION_NOTIFIER
:
1513 ret
= srcu_notifier_chain_unregister(
1514 &cpufreq_transition_notifier_list
, nb
);
1516 case CPUFREQ_POLICY_NOTIFIER
:
1517 ret
= blocking_notifier_chain_unregister(
1518 &cpufreq_policy_notifier_list
, nb
);
1526 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1529 /*********************************************************************
1531 *********************************************************************/
1533 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
1534 unsigned int target_freq
,
1535 unsigned int relation
)
1537 int retval
= -EINVAL
;
1538 unsigned int old_target_freq
= target_freq
;
1540 if (cpufreq_disabled())
1543 /* Make sure that target_freq is within supported range */
1544 if (target_freq
> policy
->max
)
1545 target_freq
= policy
->max
;
1546 if (target_freq
< policy
->min
)
1547 target_freq
= policy
->min
;
1549 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1550 policy
->cpu
, target_freq
, relation
, old_target_freq
);
1552 if (target_freq
== policy
->cur
)
1555 if (cpufreq_driver
->target
)
1556 retval
= cpufreq_driver
->target(policy
, target_freq
, relation
);
1560 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
1562 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
1563 unsigned int target_freq
,
1564 unsigned int relation
)
1568 if (unlikely(lock_policy_rwsem_write(policy
->cpu
)))
1571 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
1573 unlock_policy_rwsem_write(policy
->cpu
);
1578 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
1580 int __cpufreq_driver_getavg(struct cpufreq_policy
*policy
, unsigned int cpu
)
1582 if (cpufreq_disabled())
1585 if (!cpufreq_driver
->getavg
)
1588 return cpufreq_driver
->getavg(policy
, cpu
);
1590 EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg
);
1593 * when "event" is CPUFREQ_GOV_LIMITS
1596 static int __cpufreq_governor(struct cpufreq_policy
*policy
,
1601 /* Only must be defined when default governor is known to have latency
1602 restrictions, like e.g. conservative or ondemand.
1603 That this is the case is already ensured in Kconfig
1605 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1606 struct cpufreq_governor
*gov
= &cpufreq_gov_performance
;
1608 struct cpufreq_governor
*gov
= NULL
;
1611 if (policy
->governor
->max_transition_latency
&&
1612 policy
->cpuinfo
.transition_latency
>
1613 policy
->governor
->max_transition_latency
) {
1617 printk(KERN_WARNING
"%s governor failed, too long"
1618 " transition latency of HW, fallback"
1619 " to %s governor\n",
1620 policy
->governor
->name
,
1622 policy
->governor
= gov
;
1626 if (!try_module_get(policy
->governor
->owner
))
1629 pr_debug("__cpufreq_governor for CPU %u, event %u\n",
1630 policy
->cpu
, event
);
1632 mutex_lock(&cpufreq_governor_lock
);
1633 if ((!policy
->governor_enabled
&& (event
== CPUFREQ_GOV_STOP
)) ||
1634 (policy
->governor_enabled
&& (event
== CPUFREQ_GOV_START
))) {
1635 mutex_unlock(&cpufreq_governor_lock
);
1639 if (event
== CPUFREQ_GOV_STOP
)
1640 policy
->governor_enabled
= false;
1641 else if (event
== CPUFREQ_GOV_START
)
1642 policy
->governor_enabled
= true;
1644 mutex_unlock(&cpufreq_governor_lock
);
1646 ret
= policy
->governor
->governor(policy
, event
);
1649 if (event
== CPUFREQ_GOV_POLICY_INIT
)
1650 policy
->governor
->initialized
++;
1651 else if (event
== CPUFREQ_GOV_POLICY_EXIT
)
1652 policy
->governor
->initialized
--;
1654 /* Restore original values */
1655 mutex_lock(&cpufreq_governor_lock
);
1656 if (event
== CPUFREQ_GOV_STOP
)
1657 policy
->governor_enabled
= true;
1658 else if (event
== CPUFREQ_GOV_START
)
1659 policy
->governor_enabled
= false;
1660 mutex_unlock(&cpufreq_governor_lock
);
1663 /* we keep one module reference alive for
1664 each CPU governed by this CPU */
1665 if ((event
!= CPUFREQ_GOV_START
) || ret
)
1666 module_put(policy
->governor
->owner
);
1667 if ((event
== CPUFREQ_GOV_STOP
) && !ret
)
1668 module_put(policy
->governor
->owner
);
1673 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
1680 if (cpufreq_disabled())
1683 mutex_lock(&cpufreq_governor_mutex
);
1685 governor
->initialized
= 0;
1687 if (__find_governor(governor
->name
) == NULL
) {
1689 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
1692 mutex_unlock(&cpufreq_governor_mutex
);
1695 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
1697 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
1699 #ifdef CONFIG_HOTPLUG_CPU
1706 if (cpufreq_disabled())
1709 #ifdef CONFIG_HOTPLUG_CPU
1710 for_each_present_cpu(cpu
) {
1711 if (cpu_online(cpu
))
1713 if (!strcmp(per_cpu(cpufreq_cpu_governor
, cpu
), governor
->name
))
1714 strcpy(per_cpu(cpufreq_cpu_governor
, cpu
), "\0");
1718 mutex_lock(&cpufreq_governor_mutex
);
1719 list_del(&governor
->governor_list
);
1720 mutex_unlock(&cpufreq_governor_mutex
);
1723 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
1726 /*********************************************************************
1727 * POLICY INTERFACE *
1728 *********************************************************************/
1731 * cpufreq_get_policy - get the current cpufreq_policy
1732 * @policy: struct cpufreq_policy into which the current cpufreq_policy
1735 * Reads the current cpufreq policy.
1737 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
1739 struct cpufreq_policy
*cpu_policy
;
1743 cpu_policy
= cpufreq_cpu_get(cpu
);
1747 memcpy(policy
, cpu_policy
, sizeof(struct cpufreq_policy
));
1749 cpufreq_cpu_put(cpu_policy
);
1752 EXPORT_SYMBOL(cpufreq_get_policy
);
1755 * data : current policy.
1756 * policy : policy to be set.
1758 static int __cpufreq_set_policy(struct cpufreq_policy
*data
,
1759 struct cpufreq_policy
*policy
)
1761 int ret
= 0, failed
= 1;
1763 pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy
->cpu
,
1764 policy
->min
, policy
->max
);
1766 memcpy(&policy
->cpuinfo
, &data
->cpuinfo
,
1767 sizeof(struct cpufreq_cpuinfo
));
1769 if (policy
->min
> data
->max
|| policy
->max
< data
->min
) {
1774 /* verify the cpu speed can be set within this limit */
1775 ret
= cpufreq_driver
->verify(policy
);
1779 /* adjust if necessary - all reasons */
1780 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1781 CPUFREQ_ADJUST
, policy
);
1783 /* adjust if necessary - hardware incompatibility*/
1784 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1785 CPUFREQ_INCOMPATIBLE
, policy
);
1788 * verify the cpu speed can be set within this limit, which might be
1789 * different to the first one
1791 ret
= cpufreq_driver
->verify(policy
);
1795 /* notification of the new policy */
1796 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1797 CPUFREQ_NOTIFY
, policy
);
1799 data
->min
= policy
->min
;
1800 data
->max
= policy
->max
;
1802 pr_debug("new min and max freqs are %u - %u kHz\n",
1803 data
->min
, data
->max
);
1805 if (cpufreq_driver
->setpolicy
) {
1806 data
->policy
= policy
->policy
;
1807 pr_debug("setting range\n");
1808 ret
= cpufreq_driver
->setpolicy(policy
);
1810 if (policy
->governor
!= data
->governor
) {
1811 /* save old, working values */
1812 struct cpufreq_governor
*old_gov
= data
->governor
;
1814 pr_debug("governor switch\n");
1816 /* end old governor */
1817 if (data
->governor
) {
1818 __cpufreq_governor(data
, CPUFREQ_GOV_STOP
);
1819 unlock_policy_rwsem_write(policy
->cpu
);
1820 __cpufreq_governor(data
,
1821 CPUFREQ_GOV_POLICY_EXIT
);
1822 lock_policy_rwsem_write(policy
->cpu
);
1825 /* start new governor */
1826 data
->governor
= policy
->governor
;
1827 if (!__cpufreq_governor(data
, CPUFREQ_GOV_POLICY_INIT
)) {
1828 if (!__cpufreq_governor(data
, CPUFREQ_GOV_START
)) {
1831 unlock_policy_rwsem_write(policy
->cpu
);
1832 __cpufreq_governor(data
,
1833 CPUFREQ_GOV_POLICY_EXIT
);
1834 lock_policy_rwsem_write(policy
->cpu
);
1839 /* new governor failed, so re-start old one */
1840 pr_debug("starting governor %s failed\n",
1841 data
->governor
->name
);
1843 data
->governor
= old_gov
;
1844 __cpufreq_governor(data
,
1845 CPUFREQ_GOV_POLICY_INIT
);
1846 __cpufreq_governor(data
,
1852 /* might be a policy change, too, so fall through */
1854 pr_debug("governor: change or update limits\n");
1855 __cpufreq_governor(data
, CPUFREQ_GOV_LIMITS
);
1863 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
1864 * @cpu: CPU which shall be re-evaluated
1866 * Useful for policy notifiers which have different necessities
1867 * at different times.
1869 int cpufreq_update_policy(unsigned int cpu
)
1871 struct cpufreq_policy
*data
= cpufreq_cpu_get(cpu
);
1872 struct cpufreq_policy policy
;
1880 if (unlikely(lock_policy_rwsem_write(cpu
))) {
1885 pr_debug("updating policy for CPU %u\n", cpu
);
1886 memcpy(&policy
, data
, sizeof(struct cpufreq_policy
));
1887 policy
.min
= data
->user_policy
.min
;
1888 policy
.max
= data
->user_policy
.max
;
1889 policy
.policy
= data
->user_policy
.policy
;
1890 policy
.governor
= data
->user_policy
.governor
;
1893 * BIOS might change freq behind our back
1894 * -> ask driver for current freq and notify governors about a change
1896 if (cpufreq_driver
->get
) {
1897 policy
.cur
= cpufreq_driver
->get(cpu
);
1899 pr_debug("Driver did not initialize current freq");
1900 data
->cur
= policy
.cur
;
1902 if (data
->cur
!= policy
.cur
&& cpufreq_driver
->target
)
1903 cpufreq_out_of_sync(cpu
, data
->cur
,
1908 ret
= __cpufreq_set_policy(data
, &policy
);
1910 unlock_policy_rwsem_write(cpu
);
1913 cpufreq_cpu_put(data
);
1917 EXPORT_SYMBOL(cpufreq_update_policy
);
1919 static int __cpuinit
cpufreq_cpu_callback(struct notifier_block
*nfb
,
1920 unsigned long action
, void *hcpu
)
1922 unsigned int cpu
= (unsigned long)hcpu
;
1925 dev
= get_cpu_device(cpu
);
1929 cpufreq_add_dev(dev
, NULL
);
1931 case CPU_DOWN_PREPARE
:
1932 case CPU_UP_CANCELED_FROZEN
:
1933 __cpufreq_remove_dev(dev
, NULL
);
1935 case CPU_DOWN_FAILED
:
1936 cpufreq_add_dev(dev
, NULL
);
1943 static struct notifier_block __refdata cpufreq_cpu_notifier
= {
1944 .notifier_call
= cpufreq_cpu_callback
,
1947 /*********************************************************************
1948 * REGISTER / UNREGISTER CPUFREQ DRIVER *
1949 *********************************************************************/
1952 * cpufreq_register_driver - register a CPU Frequency driver
1953 * @driver_data: A struct cpufreq_driver containing the values#
1954 * submitted by the CPU Frequency driver.
1956 * Registers a CPU Frequency driver to this core code. This code
1957 * returns zero on success, -EBUSY when another driver got here first
1958 * (and isn't unregistered in the meantime).
1961 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
1963 unsigned long flags
;
1966 if (cpufreq_disabled())
1969 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
1970 ((!driver_data
->setpolicy
) && (!driver_data
->target
)))
1973 pr_debug("trying to register driver %s\n", driver_data
->name
);
1975 if (driver_data
->setpolicy
)
1976 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
1978 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1979 if (cpufreq_driver
) {
1980 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1983 cpufreq_driver
= driver_data
;
1984 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1986 ret
= subsys_interface_register(&cpufreq_interface
);
1988 goto err_null_driver
;
1990 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
)) {
1994 /* check for at least one working CPU */
1995 for (i
= 0; i
< nr_cpu_ids
; i
++)
1996 if (cpu_possible(i
) && per_cpu(cpufreq_cpu_data
, i
)) {
2001 /* if all ->init() calls failed, unregister */
2003 pr_debug("no CPU initialized for driver %s\n",
2009 register_hotcpu_notifier(&cpufreq_cpu_notifier
);
2010 pr_debug("driver %s up and running\n", driver_data
->name
);
2014 subsys_interface_unregister(&cpufreq_interface
);
2016 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2017 cpufreq_driver
= NULL
;
2018 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2021 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2024 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2026 * Unregister the current CPUFreq driver. Only call this if you have
2027 * the right to do so, i.e. if you have succeeded in initialising before!
2028 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2029 * currently not initialised.
2031 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2033 unsigned long flags
;
2035 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2038 pr_debug("unregistering driver %s\n", driver
->name
);
2040 subsys_interface_unregister(&cpufreq_interface
);
2041 unregister_hotcpu_notifier(&cpufreq_cpu_notifier
);
2043 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2044 cpufreq_driver
= NULL
;
2045 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2049 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2051 static int __init
cpufreq_core_init(void)
2055 if (cpufreq_disabled())
2058 for_each_possible_cpu(cpu
) {
2059 per_cpu(cpufreq_policy_cpu
, cpu
) = -1;
2060 init_rwsem(&per_cpu(cpu_policy_rwsem
, cpu
));
2063 cpufreq_global_kobject
= kobject_create();
2064 BUG_ON(!cpufreq_global_kobject
);
2065 register_syscore_ops(&cpufreq_syscore_ops
);
2069 core_initcall(cpufreq_core_init
);