1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/drivers/cpufreq/cpufreq.c
5 * Copyright (C) 2001 Russell King
6 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
9 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
10 * Added handling for CPU hotplug
11 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
12 * Fix handling for CPU hotplug -- affected CPUs
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/cpu.h>
18 #include <linux/cpufreq.h>
19 #include <linux/cpu_cooling.h>
20 #include <linux/delay.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/kernel_stat.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/pm_qos.h>
27 #include <linux/slab.h>
28 #include <linux/suspend.h>
29 #include <linux/syscore_ops.h>
30 #include <linux/tick.h>
31 #include <trace/events/power.h>
33 static LIST_HEAD(cpufreq_policy_list
);
35 /* Macros to iterate over CPU policies */
36 #define for_each_suitable_policy(__policy, __active) \
37 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
38 if ((__active) == !policy_is_inactive(__policy))
40 #define for_each_active_policy(__policy) \
41 for_each_suitable_policy(__policy, true)
42 #define for_each_inactive_policy(__policy) \
43 for_each_suitable_policy(__policy, false)
45 #define for_each_policy(__policy) \
46 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
48 /* Iterate over governors */
49 static LIST_HEAD(cpufreq_governor_list
);
50 #define for_each_governor(__governor) \
51 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
54 * The "cpufreq driver" - the arch- or hardware-dependent low
55 * level driver of CPUFreq support, and its spinlock. This lock
56 * also protects the cpufreq_cpu_data array.
58 static struct cpufreq_driver
*cpufreq_driver
;
59 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
60 static DEFINE_RWLOCK(cpufreq_driver_lock
);
62 /* Flag to suspend/resume CPUFreq governors */
63 static bool cpufreq_suspended
;
65 static inline bool has_target(void)
67 return cpufreq_driver
->target_index
|| cpufreq_driver
->target
;
70 /* internal prototypes */
71 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
);
72 static int cpufreq_init_governor(struct cpufreq_policy
*policy
);
73 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
);
74 static int cpufreq_start_governor(struct cpufreq_policy
*policy
);
75 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
);
76 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
);
79 * Two notifier lists: the "policy" list is involved in the
80 * validation process for a new CPU frequency policy; the
81 * "transition" list for kernel code that needs to handle
82 * changes to devices when the CPU clock speed changes.
83 * The mutex locks both lists.
85 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list
);
86 SRCU_NOTIFIER_HEAD_STATIC(cpufreq_transition_notifier_list
);
88 static int off __read_mostly
;
89 static int cpufreq_disabled(void)
93 void disable_cpufreq(void)
97 static DEFINE_MUTEX(cpufreq_governor_mutex
);
99 bool have_governor_per_policy(void)
101 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
103 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
105 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
107 if (have_governor_per_policy())
108 return &policy
->kobj
;
110 return cpufreq_global_kobject
;
112 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
114 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
120 cur_wall_time
= jiffies64_to_nsecs(get_jiffies_64());
122 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
123 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
124 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
125 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
126 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
127 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
129 idle_time
= cur_wall_time
- busy_time
;
131 *wall
= div_u64(cur_wall_time
, NSEC_PER_USEC
);
133 return div_u64(idle_time
, NSEC_PER_USEC
);
136 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
138 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
140 if (idle_time
== -1ULL)
141 return get_cpu_idle_time_jiffy(cpu
, wall
);
143 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
147 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
149 __weak
void arch_set_freq_scale(struct cpumask
*cpus
, unsigned long cur_freq
,
150 unsigned long max_freq
)
153 EXPORT_SYMBOL_GPL(arch_set_freq_scale
);
156 * This is a generic cpufreq init() routine which can be used by cpufreq
157 * drivers of SMP systems. It will do following:
158 * - validate & show freq table passed
159 * - set policies transition latency
160 * - policy->cpus with all possible CPUs
162 void cpufreq_generic_init(struct cpufreq_policy
*policy
,
163 struct cpufreq_frequency_table
*table
,
164 unsigned int transition_latency
)
166 policy
->freq_table
= table
;
167 policy
->cpuinfo
.transition_latency
= transition_latency
;
170 * The driver only supports the SMP configuration where all processors
171 * share the clock and voltage and clock.
173 cpumask_setall(policy
->cpus
);
175 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
177 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
179 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
181 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
183 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
185 unsigned int cpufreq_generic_get(unsigned int cpu
)
187 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
189 if (!policy
|| IS_ERR(policy
->clk
)) {
190 pr_err("%s: No %s associated to cpu: %d\n",
191 __func__
, policy
? "clk" : "policy", cpu
);
195 return clk_get_rate(policy
->clk
) / 1000;
197 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
200 * cpufreq_cpu_get - Return policy for a CPU and mark it as busy.
201 * @cpu: CPU to find the policy for.
203 * Call cpufreq_cpu_get_raw() to obtain a cpufreq policy for @cpu and increment
204 * the kobject reference counter of that policy. Return a valid policy on
205 * success or NULL on failure.
207 * The policy returned by this function has to be released with the help of
208 * cpufreq_cpu_put() to balance its kobject reference counter properly.
210 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
212 struct cpufreq_policy
*policy
= NULL
;
215 if (WARN_ON(cpu
>= nr_cpu_ids
))
218 /* get the cpufreq driver */
219 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
221 if (cpufreq_driver
) {
223 policy
= cpufreq_cpu_get_raw(cpu
);
225 kobject_get(&policy
->kobj
);
228 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
232 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
235 * cpufreq_cpu_put - Decrement kobject usage counter for cpufreq policy.
236 * @policy: cpufreq policy returned by cpufreq_cpu_get().
238 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
240 kobject_put(&policy
->kobj
);
242 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
245 * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
246 * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
248 void cpufreq_cpu_release(struct cpufreq_policy
*policy
)
250 if (WARN_ON(!policy
))
253 lockdep_assert_held(&policy
->rwsem
);
255 up_write(&policy
->rwsem
);
257 cpufreq_cpu_put(policy
);
261 * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
262 * @cpu: CPU to find the policy for.
264 * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
265 * if the policy returned by it is not NULL, acquire its rwsem for writing.
266 * Return the policy if it is active or release it and return NULL otherwise.
268 * The policy returned by this function has to be released with the help of
269 * cpufreq_cpu_release() in order to release its rwsem and balance its usage
272 struct cpufreq_policy
*cpufreq_cpu_acquire(unsigned int cpu
)
274 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
279 down_write(&policy
->rwsem
);
281 if (policy_is_inactive(policy
)) {
282 cpufreq_cpu_release(policy
);
289 /*********************************************************************
290 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
291 *********************************************************************/
294 * adjust_jiffies - adjust the system "loops_per_jiffy"
296 * This function alters the system "loops_per_jiffy" for the clock
297 * speed change. Note that loops_per_jiffy cannot be updated on SMP
298 * systems as each CPU might be scaled differently. So, use the arch
299 * per-CPU loops_per_jiffy value wherever possible.
301 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
304 static unsigned long l_p_j_ref
;
305 static unsigned int l_p_j_ref_freq
;
307 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
310 if (!l_p_j_ref_freq
) {
311 l_p_j_ref
= loops_per_jiffy
;
312 l_p_j_ref_freq
= ci
->old
;
313 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
314 l_p_j_ref
, l_p_j_ref_freq
);
316 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
317 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
319 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
320 loops_per_jiffy
, ci
->new);
326 * cpufreq_notify_transition - Notify frequency transition and adjust_jiffies.
327 * @policy: cpufreq policy to enable fast frequency switching for.
328 * @freqs: contain details of the frequency update.
329 * @state: set to CPUFREQ_PRECHANGE or CPUFREQ_POSTCHANGE.
331 * This function calls the transition notifiers and the "adjust_jiffies"
332 * function. It is called twice on all CPU frequency changes that have
335 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
336 struct cpufreq_freqs
*freqs
,
341 BUG_ON(irqs_disabled());
343 if (cpufreq_disabled())
346 freqs
->policy
= policy
;
347 freqs
->flags
= cpufreq_driver
->flags
;
348 pr_debug("notification %u of frequency transition to %u kHz\n",
352 case CPUFREQ_PRECHANGE
:
354 * Detect if the driver reported a value as "old frequency"
355 * which is not equal to what the cpufreq core thinks is
358 if (policy
->cur
&& policy
->cur
!= freqs
->old
) {
359 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
360 freqs
->old
, policy
->cur
);
361 freqs
->old
= policy
->cur
;
364 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
365 CPUFREQ_PRECHANGE
, freqs
);
367 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
370 case CPUFREQ_POSTCHANGE
:
371 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
372 pr_debug("FREQ: %u - CPUs: %*pbl\n", freqs
->new,
373 cpumask_pr_args(policy
->cpus
));
375 for_each_cpu(cpu
, policy
->cpus
)
376 trace_cpu_frequency(freqs
->new, cpu
);
378 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
379 CPUFREQ_POSTCHANGE
, freqs
);
381 cpufreq_stats_record_transition(policy
, freqs
->new);
382 policy
->cur
= freqs
->new;
386 /* Do post notifications when there are chances that transition has failed */
387 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
388 struct cpufreq_freqs
*freqs
, int transition_failed
)
390 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
391 if (!transition_failed
)
394 swap(freqs
->old
, freqs
->new);
395 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
396 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
399 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
400 struct cpufreq_freqs
*freqs
)
404 * Catch double invocations of _begin() which lead to self-deadlock.
405 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
406 * doesn't invoke _begin() on their behalf, and hence the chances of
407 * double invocations are very low. Moreover, there are scenarios
408 * where these checks can emit false-positive warnings in these
409 * drivers; so we avoid that by skipping them altogether.
411 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
412 && current
== policy
->transition_task
);
415 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
417 spin_lock(&policy
->transition_lock
);
419 if (unlikely(policy
->transition_ongoing
)) {
420 spin_unlock(&policy
->transition_lock
);
424 policy
->transition_ongoing
= true;
425 policy
->transition_task
= current
;
427 spin_unlock(&policy
->transition_lock
);
429 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
431 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
433 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
434 struct cpufreq_freqs
*freqs
, int transition_failed
)
436 if (WARN_ON(!policy
->transition_ongoing
))
439 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
441 policy
->transition_ongoing
= false;
442 policy
->transition_task
= NULL
;
444 wake_up(&policy
->transition_wait
);
446 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
449 * Fast frequency switching status count. Positive means "enabled", negative
450 * means "disabled" and 0 means "not decided yet".
452 static int cpufreq_fast_switch_count
;
453 static DEFINE_MUTEX(cpufreq_fast_switch_lock
);
455 static void cpufreq_list_transition_notifiers(void)
457 struct notifier_block
*nb
;
459 pr_info("Registered transition notifiers:\n");
461 mutex_lock(&cpufreq_transition_notifier_list
.mutex
);
463 for (nb
= cpufreq_transition_notifier_list
.head
; nb
; nb
= nb
->next
)
464 pr_info("%pS\n", nb
->notifier_call
);
466 mutex_unlock(&cpufreq_transition_notifier_list
.mutex
);
470 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
471 * @policy: cpufreq policy to enable fast frequency switching for.
473 * Try to enable fast frequency switching for @policy.
475 * The attempt will fail if there is at least one transition notifier registered
476 * at this point, as fast frequency switching is quite fundamentally at odds
477 * with transition notifiers. Thus if successful, it will make registration of
478 * transition notifiers fail going forward.
480 void cpufreq_enable_fast_switch(struct cpufreq_policy
*policy
)
482 lockdep_assert_held(&policy
->rwsem
);
484 if (!policy
->fast_switch_possible
)
487 mutex_lock(&cpufreq_fast_switch_lock
);
488 if (cpufreq_fast_switch_count
>= 0) {
489 cpufreq_fast_switch_count
++;
490 policy
->fast_switch_enabled
= true;
492 pr_warn("CPU%u: Fast frequency switching not enabled\n",
494 cpufreq_list_transition_notifiers();
496 mutex_unlock(&cpufreq_fast_switch_lock
);
498 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch
);
501 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
502 * @policy: cpufreq policy to disable fast frequency switching for.
504 void cpufreq_disable_fast_switch(struct cpufreq_policy
*policy
)
506 mutex_lock(&cpufreq_fast_switch_lock
);
507 if (policy
->fast_switch_enabled
) {
508 policy
->fast_switch_enabled
= false;
509 if (!WARN_ON(cpufreq_fast_switch_count
<= 0))
510 cpufreq_fast_switch_count
--;
512 mutex_unlock(&cpufreq_fast_switch_lock
);
514 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch
);
517 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
519 * @target_freq: target frequency to resolve.
521 * The target to driver frequency mapping is cached in the policy.
523 * Return: Lowest driver-supported frequency greater than or equal to the
524 * given target_freq, subject to policy (min/max) and driver limitations.
526 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy
*policy
,
527 unsigned int target_freq
)
529 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
530 policy
->cached_target_freq
= target_freq
;
532 if (cpufreq_driver
->target_index
) {
535 idx
= cpufreq_frequency_table_target(policy
, target_freq
,
537 policy
->cached_resolved_idx
= idx
;
538 return policy
->freq_table
[idx
].frequency
;
541 if (cpufreq_driver
->resolve_freq
)
542 return cpufreq_driver
->resolve_freq(policy
, target_freq
);
546 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq
);
548 unsigned int cpufreq_policy_transition_delay_us(struct cpufreq_policy
*policy
)
550 unsigned int latency
;
552 if (policy
->transition_delay_us
)
553 return policy
->transition_delay_us
;
555 latency
= policy
->cpuinfo
.transition_latency
/ NSEC_PER_USEC
;
558 * For platforms that can change the frequency very fast (< 10
559 * us), the above formula gives a decent transition delay. But
560 * for platforms where transition_latency is in milliseconds, it
561 * ends up giving unrealistic values.
563 * Cap the default transition delay to 10 ms, which seems to be
564 * a reasonable amount of time after which we should reevaluate
567 return min(latency
* LATENCY_MULTIPLIER
, (unsigned int)10000);
570 return LATENCY_MULTIPLIER
;
572 EXPORT_SYMBOL_GPL(cpufreq_policy_transition_delay_us
);
574 /*********************************************************************
576 *********************************************************************/
577 static ssize_t
show_boost(struct kobject
*kobj
,
578 struct kobj_attribute
*attr
, char *buf
)
580 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
583 static ssize_t
store_boost(struct kobject
*kobj
, struct kobj_attribute
*attr
,
584 const char *buf
, size_t count
)
588 ret
= sscanf(buf
, "%d", &enable
);
589 if (ret
!= 1 || enable
< 0 || enable
> 1)
592 if (cpufreq_boost_trigger_state(enable
)) {
593 pr_err("%s: Cannot %s BOOST!\n",
594 __func__
, enable
? "enable" : "disable");
598 pr_debug("%s: cpufreq BOOST %s\n",
599 __func__
, enable
? "enabled" : "disabled");
603 define_one_global_rw(boost
);
605 static struct cpufreq_governor
*find_governor(const char *str_governor
)
607 struct cpufreq_governor
*t
;
610 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
616 static int cpufreq_parse_policy(char *str_governor
,
617 struct cpufreq_policy
*policy
)
619 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
620 policy
->policy
= CPUFREQ_POLICY_PERFORMANCE
;
623 if (!strncasecmp(str_governor
, "powersave", CPUFREQ_NAME_LEN
)) {
624 policy
->policy
= CPUFREQ_POLICY_POWERSAVE
;
631 * cpufreq_parse_governor - parse a governor string only for has_target()
633 static int cpufreq_parse_governor(char *str_governor
,
634 struct cpufreq_policy
*policy
)
636 struct cpufreq_governor
*t
;
638 mutex_lock(&cpufreq_governor_mutex
);
640 t
= find_governor(str_governor
);
644 mutex_unlock(&cpufreq_governor_mutex
);
646 ret
= request_module("cpufreq_%s", str_governor
);
650 mutex_lock(&cpufreq_governor_mutex
);
652 t
= find_governor(str_governor
);
654 if (t
&& !try_module_get(t
->owner
))
657 mutex_unlock(&cpufreq_governor_mutex
);
660 policy
->governor
= t
;
668 * cpufreq_per_cpu_attr_read() / show_##file_name() -
669 * print out cpufreq information
671 * Write out information from cpufreq_driver->policy[cpu]; object must be
675 #define show_one(file_name, object) \
676 static ssize_t show_##file_name \
677 (struct cpufreq_policy *policy, char *buf) \
679 return sprintf(buf, "%u\n", policy->object); \
682 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
683 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
684 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
685 show_one(scaling_min_freq
, min
);
686 show_one(scaling_max_freq
, max
);
688 __weak
unsigned int arch_freq_get_on_cpu(int cpu
)
693 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
698 freq
= arch_freq_get_on_cpu(policy
->cpu
);
700 ret
= sprintf(buf
, "%u\n", freq
);
701 else if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&&
703 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
705 ret
= sprintf(buf
, "%u\n", policy
->cur
);
710 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
712 #define store_one(file_name, object) \
713 static ssize_t store_##file_name \
714 (struct cpufreq_policy *policy, const char *buf, size_t count) \
719 ret = sscanf(buf, "%lu", &val); \
723 ret = dev_pm_qos_update_request(policy->object##_freq_req, val);\
724 return ret >= 0 ? count : ret; \
727 store_one(scaling_min_freq
, min
);
728 store_one(scaling_max_freq
, max
);
731 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
733 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
736 unsigned int cur_freq
= __cpufreq_get(policy
);
739 return sprintf(buf
, "%u\n", cur_freq
);
741 return sprintf(buf
, "<unknown>\n");
745 * show_scaling_governor - show the current policy for the specified CPU
747 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
749 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
750 return sprintf(buf
, "powersave\n");
751 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
752 return sprintf(buf
, "performance\n");
753 else if (policy
->governor
)
754 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
755 policy
->governor
->name
);
760 * store_scaling_governor - store policy for the specified CPU
762 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
763 const char *buf
, size_t count
)
766 char str_governor
[16];
767 struct cpufreq_policy new_policy
;
769 memcpy(&new_policy
, policy
, sizeof(*policy
));
771 ret
= sscanf(buf
, "%15s", str_governor
);
775 if (cpufreq_driver
->setpolicy
) {
776 if (cpufreq_parse_policy(str_governor
, &new_policy
))
779 if (cpufreq_parse_governor(str_governor
, &new_policy
))
783 ret
= cpufreq_set_policy(policy
, &new_policy
);
785 if (new_policy
.governor
)
786 module_put(new_policy
.governor
->owner
);
788 return ret
? ret
: count
;
792 * show_scaling_driver - show the cpufreq driver currently loaded
794 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
796 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
800 * show_scaling_available_governors - show the available CPUfreq governors
802 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
806 struct cpufreq_governor
*t
;
809 i
+= sprintf(buf
, "performance powersave");
813 for_each_governor(t
) {
814 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
815 - (CPUFREQ_NAME_LEN
+ 2)))
817 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
820 i
+= sprintf(&buf
[i
], "\n");
824 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
829 for_each_cpu(cpu
, mask
) {
831 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
832 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
833 if (i
>= (PAGE_SIZE
- 5))
836 i
+= sprintf(&buf
[i
], "\n");
839 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
842 * show_related_cpus - show the CPUs affected by each transition even if
843 * hw coordination is in use
845 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
847 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
851 * show_affected_cpus - show the CPUs affected by each transition
853 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
855 return cpufreq_show_cpus(policy
->cpus
, buf
);
858 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
859 const char *buf
, size_t count
)
861 unsigned int freq
= 0;
864 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
867 ret
= sscanf(buf
, "%u", &freq
);
871 policy
->governor
->store_setspeed(policy
, freq
);
876 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
878 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
879 return sprintf(buf
, "<unsupported>\n");
881 return policy
->governor
->show_setspeed(policy
, buf
);
885 * show_bios_limit - show the current cpufreq HW/BIOS limitation
887 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
891 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
893 return sprintf(buf
, "%u\n", limit
);
894 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
897 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
898 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
899 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
900 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
901 cpufreq_freq_attr_ro(scaling_available_governors
);
902 cpufreq_freq_attr_ro(scaling_driver
);
903 cpufreq_freq_attr_ro(scaling_cur_freq
);
904 cpufreq_freq_attr_ro(bios_limit
);
905 cpufreq_freq_attr_ro(related_cpus
);
906 cpufreq_freq_attr_ro(affected_cpus
);
907 cpufreq_freq_attr_rw(scaling_min_freq
);
908 cpufreq_freq_attr_rw(scaling_max_freq
);
909 cpufreq_freq_attr_rw(scaling_governor
);
910 cpufreq_freq_attr_rw(scaling_setspeed
);
912 static struct attribute
*default_attrs
[] = {
913 &cpuinfo_min_freq
.attr
,
914 &cpuinfo_max_freq
.attr
,
915 &cpuinfo_transition_latency
.attr
,
916 &scaling_min_freq
.attr
,
917 &scaling_max_freq
.attr
,
920 &scaling_governor
.attr
,
921 &scaling_driver
.attr
,
922 &scaling_available_governors
.attr
,
923 &scaling_setspeed
.attr
,
927 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
928 #define to_attr(a) container_of(a, struct freq_attr, attr)
930 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
932 struct cpufreq_policy
*policy
= to_policy(kobj
);
933 struct freq_attr
*fattr
= to_attr(attr
);
936 down_read(&policy
->rwsem
);
937 ret
= fattr
->show(policy
, buf
);
938 up_read(&policy
->rwsem
);
943 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
944 const char *buf
, size_t count
)
946 struct cpufreq_policy
*policy
= to_policy(kobj
);
947 struct freq_attr
*fattr
= to_attr(attr
);
948 ssize_t ret
= -EINVAL
;
951 * cpus_read_trylock() is used here to work around a circular lock
952 * dependency problem with respect to the cpufreq_register_driver().
954 if (!cpus_read_trylock())
957 if (cpu_online(policy
->cpu
)) {
958 down_write(&policy
->rwsem
);
959 ret
= fattr
->store(policy
, buf
, count
);
960 up_write(&policy
->rwsem
);
968 static void cpufreq_sysfs_release(struct kobject
*kobj
)
970 struct cpufreq_policy
*policy
= to_policy(kobj
);
971 pr_debug("last reference is dropped\n");
972 complete(&policy
->kobj_unregister
);
975 static const struct sysfs_ops sysfs_ops
= {
980 static struct kobj_type ktype_cpufreq
= {
981 .sysfs_ops
= &sysfs_ops
,
982 .default_attrs
= default_attrs
,
983 .release
= cpufreq_sysfs_release
,
986 static void add_cpu_dev_symlink(struct cpufreq_policy
*policy
, unsigned int cpu
)
988 struct device
*dev
= get_cpu_device(cpu
);
993 if (cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
))
996 dev_dbg(dev
, "%s: Adding symlink\n", __func__
);
997 if (sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq"))
998 dev_err(dev
, "cpufreq symlink creation failed\n");
1001 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
,
1004 dev_dbg(dev
, "%s: Removing symlink\n", __func__
);
1005 sysfs_remove_link(&dev
->kobj
, "cpufreq");
1008 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
1010 struct freq_attr
**drv_attr
;
1013 /* set up files for this cpu device */
1014 drv_attr
= cpufreq_driver
->attr
;
1015 while (drv_attr
&& *drv_attr
) {
1016 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
1021 if (cpufreq_driver
->get
) {
1022 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
1027 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
1031 if (cpufreq_driver
->bios_limit
) {
1032 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
1040 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
1045 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
1047 struct cpufreq_governor
*gov
= NULL
, *def_gov
= NULL
;
1048 struct cpufreq_policy new_policy
;
1050 memcpy(&new_policy
, policy
, sizeof(*policy
));
1052 def_gov
= cpufreq_default_governor();
1056 * Update governor of new_policy to the governor used before
1059 gov
= find_governor(policy
->last_governor
);
1061 pr_debug("Restoring governor %s for cpu %d\n",
1062 policy
->governor
->name
, policy
->cpu
);
1068 new_policy
.governor
= gov
;
1070 /* Use the default policy if there is no last_policy. */
1071 if (policy
->last_policy
) {
1072 new_policy
.policy
= policy
->last_policy
;
1076 cpufreq_parse_policy(def_gov
->name
, &new_policy
);
1080 return cpufreq_set_policy(policy
, &new_policy
);
1083 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1087 /* Has this CPU been taken care of already? */
1088 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1091 down_write(&policy
->rwsem
);
1093 cpufreq_stop_governor(policy
);
1095 cpumask_set_cpu(cpu
, policy
->cpus
);
1098 ret
= cpufreq_start_governor(policy
);
1100 pr_err("%s: Failed to start governor\n", __func__
);
1102 up_write(&policy
->rwsem
);
1106 void refresh_frequency_limits(struct cpufreq_policy
*policy
)
1108 struct cpufreq_policy new_policy
;
1110 if (!policy_is_inactive(policy
)) {
1111 new_policy
= *policy
;
1112 pr_debug("updating policy for CPU %u\n", policy
->cpu
);
1114 cpufreq_set_policy(policy
, &new_policy
);
1117 EXPORT_SYMBOL(refresh_frequency_limits
);
1119 static void handle_update(struct work_struct
*work
)
1121 struct cpufreq_policy
*policy
=
1122 container_of(work
, struct cpufreq_policy
, update
);
1124 pr_debug("handle_update for cpu %u called\n", policy
->cpu
);
1125 down_write(&policy
->rwsem
);
1126 refresh_frequency_limits(policy
);
1127 up_write(&policy
->rwsem
);
1130 static int cpufreq_notifier_min(struct notifier_block
*nb
, unsigned long freq
,
1133 struct cpufreq_policy
*policy
= container_of(nb
, struct cpufreq_policy
, nb_min
);
1135 schedule_work(&policy
->update
);
1139 static int cpufreq_notifier_max(struct notifier_block
*nb
, unsigned long freq
,
1142 struct cpufreq_policy
*policy
= container_of(nb
, struct cpufreq_policy
, nb_max
);
1144 schedule_work(&policy
->update
);
1148 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
)
1150 struct kobject
*kobj
;
1151 struct completion
*cmp
;
1153 down_write(&policy
->rwsem
);
1154 cpufreq_stats_free_table(policy
);
1155 kobj
= &policy
->kobj
;
1156 cmp
= &policy
->kobj_unregister
;
1157 up_write(&policy
->rwsem
);
1161 * We need to make sure that the underlying kobj is
1162 * actually not referenced anymore by anybody before we
1163 * proceed with unloading.
1165 pr_debug("waiting for dropping of refcount\n");
1166 wait_for_completion(cmp
);
1167 pr_debug("wait complete\n");
1170 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1172 struct cpufreq_policy
*policy
;
1173 struct device
*dev
= get_cpu_device(cpu
);
1179 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1183 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1184 goto err_free_policy
;
1186 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1187 goto err_free_cpumask
;
1189 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1190 goto err_free_rcpumask
;
1192 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
1193 cpufreq_global_kobject
, "policy%u", cpu
);
1195 dev_err(dev
, "%s: failed to init policy->kobj: %d\n", __func__
, ret
);
1197 * The entire policy object will be freed below, but the extra
1198 * memory allocated for the kobject name needs to be freed by
1199 * releasing the kobject.
1201 kobject_put(&policy
->kobj
);
1202 goto err_free_real_cpus
;
1205 policy
->nb_min
.notifier_call
= cpufreq_notifier_min
;
1206 policy
->nb_max
.notifier_call
= cpufreq_notifier_max
;
1208 ret
= dev_pm_qos_add_notifier(dev
, &policy
->nb_min
,
1209 DEV_PM_QOS_MIN_FREQUENCY
);
1211 dev_err(dev
, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
1212 ret
, cpumask_pr_args(policy
->cpus
));
1213 goto err_kobj_remove
;
1216 ret
= dev_pm_qos_add_notifier(dev
, &policy
->nb_max
,
1217 DEV_PM_QOS_MAX_FREQUENCY
);
1219 dev_err(dev
, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
1220 ret
, cpumask_pr_args(policy
->cpus
));
1221 goto err_min_qos_notifier
;
1224 INIT_LIST_HEAD(&policy
->policy_list
);
1225 init_rwsem(&policy
->rwsem
);
1226 spin_lock_init(&policy
->transition_lock
);
1227 init_waitqueue_head(&policy
->transition_wait
);
1228 init_completion(&policy
->kobj_unregister
);
1229 INIT_WORK(&policy
->update
, handle_update
);
1234 err_min_qos_notifier
:
1235 dev_pm_qos_remove_notifier(dev
, &policy
->nb_min
,
1236 DEV_PM_QOS_MIN_FREQUENCY
);
1238 cpufreq_policy_put_kobj(policy
);
1240 free_cpumask_var(policy
->real_cpus
);
1242 free_cpumask_var(policy
->related_cpus
);
1244 free_cpumask_var(policy
->cpus
);
1251 static void cpufreq_policy_free(struct cpufreq_policy
*policy
)
1253 struct device
*dev
= get_cpu_device(policy
->cpu
);
1254 unsigned long flags
;
1257 /* Remove policy from list */
1258 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1259 list_del(&policy
->policy_list
);
1261 for_each_cpu(cpu
, policy
->related_cpus
)
1262 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1263 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1265 dev_pm_qos_remove_notifier(dev
, &policy
->nb_max
,
1266 DEV_PM_QOS_MAX_FREQUENCY
);
1267 dev_pm_qos_remove_notifier(dev
, &policy
->nb_min
,
1268 DEV_PM_QOS_MIN_FREQUENCY
);
1270 if (policy
->max_freq_req
) {
1272 * CPUFREQ_CREATE_POLICY notification is sent only after
1273 * successfully adding max_freq_req request.
1275 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1276 CPUFREQ_REMOVE_POLICY
, policy
);
1277 dev_pm_qos_remove_request(policy
->max_freq_req
);
1280 dev_pm_qos_remove_request(policy
->min_freq_req
);
1281 kfree(policy
->min_freq_req
);
1283 cpufreq_policy_put_kobj(policy
);
1284 free_cpumask_var(policy
->real_cpus
);
1285 free_cpumask_var(policy
->related_cpus
);
1286 free_cpumask_var(policy
->cpus
);
1290 static int cpufreq_online(unsigned int cpu
)
1292 struct cpufreq_policy
*policy
;
1294 unsigned long flags
;
1298 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1300 /* Check if this CPU already has a policy to manage it */
1301 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1303 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1304 if (!policy_is_inactive(policy
))
1305 return cpufreq_add_policy_cpu(policy
, cpu
);
1307 /* This is the only online CPU for the policy. Start over. */
1309 down_write(&policy
->rwsem
);
1311 policy
->governor
= NULL
;
1312 up_write(&policy
->rwsem
);
1315 policy
= cpufreq_policy_alloc(cpu
);
1320 if (!new_policy
&& cpufreq_driver
->online
) {
1321 ret
= cpufreq_driver
->online(policy
);
1323 pr_debug("%s: %d: initialization failed\n", __func__
,
1325 goto out_exit_policy
;
1328 /* Recover policy->cpus using related_cpus */
1329 cpumask_copy(policy
->cpus
, policy
->related_cpus
);
1331 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1334 * Call driver. From then on the cpufreq must be able
1335 * to accept all calls to ->verify and ->setpolicy for this CPU.
1337 ret
= cpufreq_driver
->init(policy
);
1339 pr_debug("%s: %d: initialization failed\n", __func__
,
1341 goto out_free_policy
;
1344 ret
= cpufreq_table_validate_and_sort(policy
);
1346 goto out_exit_policy
;
1348 /* related_cpus should at least include policy->cpus. */
1349 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1352 down_write(&policy
->rwsem
);
1354 * affected cpus must always be the one, which are online. We aren't
1355 * managing offline cpus here.
1357 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1360 struct device
*dev
= get_cpu_device(cpu
);
1362 for_each_cpu(j
, policy
->related_cpus
) {
1363 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1364 add_cpu_dev_symlink(policy
, j
);
1367 policy
->min_freq_req
= kzalloc(2 * sizeof(*policy
->min_freq_req
),
1369 if (!policy
->min_freq_req
)
1370 goto out_destroy_policy
;
1372 ret
= dev_pm_qos_add_request(dev
, policy
->min_freq_req
,
1373 DEV_PM_QOS_MIN_FREQUENCY
,
1377 * So we don't call dev_pm_qos_remove_request() for an
1378 * uninitialized request.
1380 kfree(policy
->min_freq_req
);
1381 policy
->min_freq_req
= NULL
;
1383 dev_err(dev
, "Failed to add min-freq constraint (%d)\n",
1385 goto out_destroy_policy
;
1389 * This must be initialized right here to avoid calling
1390 * dev_pm_qos_remove_request() on uninitialized request in case
1393 policy
->max_freq_req
= policy
->min_freq_req
+ 1;
1395 ret
= dev_pm_qos_add_request(dev
, policy
->max_freq_req
,
1396 DEV_PM_QOS_MAX_FREQUENCY
,
1399 policy
->max_freq_req
= NULL
;
1400 dev_err(dev
, "Failed to add max-freq constraint (%d)\n",
1402 goto out_destroy_policy
;
1405 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1406 CPUFREQ_CREATE_POLICY
, policy
);
1409 if (cpufreq_driver
->get
&& has_target()) {
1410 policy
->cur
= cpufreq_driver
->get(policy
->cpu
);
1412 pr_err("%s: ->get() failed\n", __func__
);
1413 goto out_destroy_policy
;
1418 * Sometimes boot loaders set CPU frequency to a value outside of
1419 * frequency table present with cpufreq core. In such cases CPU might be
1420 * unstable if it has to run on that frequency for long duration of time
1421 * and so its better to set it to a frequency which is specified in
1422 * freq-table. This also makes cpufreq stats inconsistent as
1423 * cpufreq-stats would fail to register because current frequency of CPU
1424 * isn't found in freq-table.
1426 * Because we don't want this change to effect boot process badly, we go
1427 * for the next freq which is >= policy->cur ('cur' must be set by now,
1428 * otherwise we will end up setting freq to lowest of the table as 'cur'
1429 * is initialized to zero).
1431 * We are passing target-freq as "policy->cur - 1" otherwise
1432 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1433 * equal to target-freq.
1435 if ((cpufreq_driver
->flags
& CPUFREQ_NEED_INITIAL_FREQ_CHECK
)
1437 /* Are we running at unknown frequency ? */
1438 ret
= cpufreq_frequency_table_get_index(policy
, policy
->cur
);
1439 if (ret
== -EINVAL
) {
1440 /* Warn user and fix it */
1441 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1442 __func__
, policy
->cpu
, policy
->cur
);
1443 ret
= __cpufreq_driver_target(policy
, policy
->cur
- 1,
1444 CPUFREQ_RELATION_L
);
1447 * Reaching here after boot in a few seconds may not
1448 * mean that system will remain stable at "unknown"
1449 * frequency for longer duration. Hence, a BUG_ON().
1452 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1453 __func__
, policy
->cpu
, policy
->cur
);
1458 ret
= cpufreq_add_dev_interface(policy
);
1460 goto out_destroy_policy
;
1462 cpufreq_stats_create_table(policy
);
1464 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1465 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1466 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1469 ret
= cpufreq_init_policy(policy
);
1471 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1472 __func__
, cpu
, ret
);
1473 goto out_destroy_policy
;
1476 up_write(&policy
->rwsem
);
1478 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1480 /* Callback for handling stuff after policy is ready */
1481 if (cpufreq_driver
->ready
)
1482 cpufreq_driver
->ready(policy
);
1484 if (cpufreq_thermal_control_enabled(cpufreq_driver
))
1485 policy
->cdev
= of_cpufreq_cooling_register(policy
);
1487 pr_debug("initialization complete\n");
1492 for_each_cpu(j
, policy
->real_cpus
)
1493 remove_cpu_dev_symlink(policy
, get_cpu_device(j
));
1495 up_write(&policy
->rwsem
);
1498 if (cpufreq_driver
->exit
)
1499 cpufreq_driver
->exit(policy
);
1502 cpufreq_policy_free(policy
);
1507 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1509 * @sif: Subsystem interface structure pointer (not used)
1511 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1513 struct cpufreq_policy
*policy
;
1514 unsigned cpu
= dev
->id
;
1517 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1519 if (cpu_online(cpu
)) {
1520 ret
= cpufreq_online(cpu
);
1525 /* Create sysfs link on CPU registration */
1526 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1528 add_cpu_dev_symlink(policy
, cpu
);
1533 static int cpufreq_offline(unsigned int cpu
)
1535 struct cpufreq_policy
*policy
;
1538 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1540 policy
= cpufreq_cpu_get_raw(cpu
);
1542 pr_debug("%s: No cpu_data found\n", __func__
);
1546 down_write(&policy
->rwsem
);
1548 cpufreq_stop_governor(policy
);
1550 cpumask_clear_cpu(cpu
, policy
->cpus
);
1552 if (policy_is_inactive(policy
)) {
1554 strncpy(policy
->last_governor
, policy
->governor
->name
,
1557 policy
->last_policy
= policy
->policy
;
1558 } else if (cpu
== policy
->cpu
) {
1559 /* Nominate new CPU */
1560 policy
->cpu
= cpumask_any(policy
->cpus
);
1563 /* Start governor again for active policy */
1564 if (!policy_is_inactive(policy
)) {
1566 ret
= cpufreq_start_governor(policy
);
1568 pr_err("%s: Failed to start governor\n", __func__
);
1574 if (cpufreq_thermal_control_enabled(cpufreq_driver
)) {
1575 cpufreq_cooling_unregister(policy
->cdev
);
1576 policy
->cdev
= NULL
;
1579 if (cpufreq_driver
->stop_cpu
)
1580 cpufreq_driver
->stop_cpu(policy
);
1583 cpufreq_exit_governor(policy
);
1586 * Perform the ->offline() during light-weight tear-down, as
1587 * that allows fast recovery when the CPU comes back.
1589 if (cpufreq_driver
->offline
) {
1590 cpufreq_driver
->offline(policy
);
1591 } else if (cpufreq_driver
->exit
) {
1592 cpufreq_driver
->exit(policy
);
1593 policy
->freq_table
= NULL
;
1597 up_write(&policy
->rwsem
);
1602 * cpufreq_remove_dev - remove a CPU device
1604 * Removes the cpufreq interface for a CPU device.
1606 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1608 unsigned int cpu
= dev
->id
;
1609 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1614 if (cpu_online(cpu
))
1615 cpufreq_offline(cpu
);
1617 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1618 remove_cpu_dev_symlink(policy
, dev
);
1620 if (cpumask_empty(policy
->real_cpus
)) {
1621 /* We did light-weight exit earlier, do full tear down now */
1622 if (cpufreq_driver
->offline
)
1623 cpufreq_driver
->exit(policy
);
1625 cpufreq_policy_free(policy
);
1630 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1632 * @policy: policy managing CPUs
1633 * @new_freq: CPU frequency the CPU actually runs at
1635 * We adjust to current frequency first, and need to clean up later.
1636 * So either call to cpufreq_update_policy() or schedule handle_update()).
1638 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1639 unsigned int new_freq
)
1641 struct cpufreq_freqs freqs
;
1643 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1644 policy
->cur
, new_freq
);
1646 freqs
.old
= policy
->cur
;
1647 freqs
.new = new_freq
;
1649 cpufreq_freq_transition_begin(policy
, &freqs
);
1650 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1653 static unsigned int cpufreq_verify_current_freq(struct cpufreq_policy
*policy
, bool update
)
1655 unsigned int new_freq
;
1657 new_freq
= cpufreq_driver
->get(policy
->cpu
);
1662 * If fast frequency switching is used with the given policy, the check
1663 * against policy->cur is pointless, so skip it in that case.
1665 if (policy
->fast_switch_enabled
|| !has_target())
1668 if (policy
->cur
!= new_freq
) {
1669 cpufreq_out_of_sync(policy
, new_freq
);
1671 schedule_work(&policy
->update
);
1678 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1681 * This is the last known freq, without actually getting it from the driver.
1682 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1684 unsigned int cpufreq_quick_get(unsigned int cpu
)
1686 struct cpufreq_policy
*policy
;
1687 unsigned int ret_freq
= 0;
1688 unsigned long flags
;
1690 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1692 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
) {
1693 ret_freq
= cpufreq_driver
->get(cpu
);
1694 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1698 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1700 policy
= cpufreq_cpu_get(cpu
);
1702 ret_freq
= policy
->cur
;
1703 cpufreq_cpu_put(policy
);
1708 EXPORT_SYMBOL(cpufreq_quick_get
);
1711 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1714 * Just return the max possible frequency for a given CPU.
1716 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1718 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1719 unsigned int ret_freq
= 0;
1722 ret_freq
= policy
->max
;
1723 cpufreq_cpu_put(policy
);
1728 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1730 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1732 if (unlikely(policy_is_inactive(policy
)))
1735 return cpufreq_verify_current_freq(policy
, true);
1739 * cpufreq_get - get the current CPU frequency (in kHz)
1742 * Get the CPU current (static) CPU frequency
1744 unsigned int cpufreq_get(unsigned int cpu
)
1746 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1747 unsigned int ret_freq
= 0;
1750 down_read(&policy
->rwsem
);
1751 if (cpufreq_driver
->get
)
1752 ret_freq
= __cpufreq_get(policy
);
1753 up_read(&policy
->rwsem
);
1755 cpufreq_cpu_put(policy
);
1760 EXPORT_SYMBOL(cpufreq_get
);
1762 static struct subsys_interface cpufreq_interface
= {
1764 .subsys
= &cpu_subsys
,
1765 .add_dev
= cpufreq_add_dev
,
1766 .remove_dev
= cpufreq_remove_dev
,
1770 * In case platform wants some specific frequency to be configured
1773 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1777 if (!policy
->suspend_freq
) {
1778 pr_debug("%s: suspend_freq not defined\n", __func__
);
1782 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1783 policy
->suspend_freq
);
1785 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1786 CPUFREQ_RELATION_H
);
1788 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1789 __func__
, policy
->suspend_freq
, ret
);
1793 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1796 * cpufreq_suspend() - Suspend CPUFreq governors
1798 * Called during system wide Suspend/Hibernate cycles for suspending governors
1799 * as some platforms can't change frequency after this point in suspend cycle.
1800 * Because some of the devices (like: i2c, regulators, etc) they use for
1801 * changing frequency are suspended quickly after this point.
1803 void cpufreq_suspend(void)
1805 struct cpufreq_policy
*policy
;
1807 if (!cpufreq_driver
)
1810 if (!has_target() && !cpufreq_driver
->suspend
)
1813 pr_debug("%s: Suspending Governors\n", __func__
);
1815 for_each_active_policy(policy
) {
1817 down_write(&policy
->rwsem
);
1818 cpufreq_stop_governor(policy
);
1819 up_write(&policy
->rwsem
);
1822 if (cpufreq_driver
->suspend
&& cpufreq_driver
->suspend(policy
))
1823 pr_err("%s: Failed to suspend driver: %s\n", __func__
,
1824 cpufreq_driver
->name
);
1828 cpufreq_suspended
= true;
1832 * cpufreq_resume() - Resume CPUFreq governors
1834 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1835 * are suspended with cpufreq_suspend().
1837 void cpufreq_resume(void)
1839 struct cpufreq_policy
*policy
;
1842 if (!cpufreq_driver
)
1845 if (unlikely(!cpufreq_suspended
))
1848 cpufreq_suspended
= false;
1850 if (!has_target() && !cpufreq_driver
->resume
)
1853 pr_debug("%s: Resuming Governors\n", __func__
);
1855 for_each_active_policy(policy
) {
1856 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
)) {
1857 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1859 } else if (has_target()) {
1860 down_write(&policy
->rwsem
);
1861 ret
= cpufreq_start_governor(policy
);
1862 up_write(&policy
->rwsem
);
1865 pr_err("%s: Failed to start governor for policy: %p\n",
1872 * cpufreq_get_current_driver - return current driver's name
1874 * Return the name string of the currently loaded cpufreq driver
1877 const char *cpufreq_get_current_driver(void)
1880 return cpufreq_driver
->name
;
1884 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1887 * cpufreq_get_driver_data - return current driver data
1889 * Return the private data of the currently loaded cpufreq
1890 * driver, or NULL if no cpufreq driver is loaded.
1892 void *cpufreq_get_driver_data(void)
1895 return cpufreq_driver
->driver_data
;
1899 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1901 /*********************************************************************
1902 * NOTIFIER LISTS INTERFACE *
1903 *********************************************************************/
1906 * cpufreq_register_notifier - register a driver with cpufreq
1907 * @nb: notifier function to register
1908 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1910 * Add a driver to one of two lists: either a list of drivers that
1911 * are notified about clock rate changes (once before and once after
1912 * the transition), or a list of drivers that are notified about
1913 * changes in cpufreq policy.
1915 * This function may sleep, and has the same return conditions as
1916 * blocking_notifier_chain_register.
1918 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1922 if (cpufreq_disabled())
1926 case CPUFREQ_TRANSITION_NOTIFIER
:
1927 mutex_lock(&cpufreq_fast_switch_lock
);
1929 if (cpufreq_fast_switch_count
> 0) {
1930 mutex_unlock(&cpufreq_fast_switch_lock
);
1933 ret
= srcu_notifier_chain_register(
1934 &cpufreq_transition_notifier_list
, nb
);
1936 cpufreq_fast_switch_count
--;
1938 mutex_unlock(&cpufreq_fast_switch_lock
);
1940 case CPUFREQ_POLICY_NOTIFIER
:
1941 ret
= blocking_notifier_chain_register(
1942 &cpufreq_policy_notifier_list
, nb
);
1950 EXPORT_SYMBOL(cpufreq_register_notifier
);
1953 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1954 * @nb: notifier block to be unregistered
1955 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1957 * Remove a driver from the CPU frequency notifier list.
1959 * This function may sleep, and has the same return conditions as
1960 * blocking_notifier_chain_unregister.
1962 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1966 if (cpufreq_disabled())
1970 case CPUFREQ_TRANSITION_NOTIFIER
:
1971 mutex_lock(&cpufreq_fast_switch_lock
);
1973 ret
= srcu_notifier_chain_unregister(
1974 &cpufreq_transition_notifier_list
, nb
);
1975 if (!ret
&& !WARN_ON(cpufreq_fast_switch_count
>= 0))
1976 cpufreq_fast_switch_count
++;
1978 mutex_unlock(&cpufreq_fast_switch_lock
);
1980 case CPUFREQ_POLICY_NOTIFIER
:
1981 ret
= blocking_notifier_chain_unregister(
1982 &cpufreq_policy_notifier_list
, nb
);
1990 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1993 /*********************************************************************
1995 *********************************************************************/
1998 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1999 * @policy: cpufreq policy to switch the frequency for.
2000 * @target_freq: New frequency to set (may be approximate).
2002 * Carry out a fast frequency switch without sleeping.
2004 * The driver's ->fast_switch() callback invoked by this function must be
2005 * suitable for being called from within RCU-sched read-side critical sections
2006 * and it is expected to select the minimum available frequency greater than or
2007 * equal to @target_freq (CPUFREQ_RELATION_L).
2009 * This function must not be called if policy->fast_switch_enabled is unset.
2011 * Governors calling this function must guarantee that it will never be invoked
2012 * twice in parallel for the same policy and that it will never be called in
2013 * parallel with either ->target() or ->target_index() for the same policy.
2015 * Returns the actual frequency set for the CPU.
2017 * If 0 is returned by the driver's ->fast_switch() callback to indicate an
2018 * error condition, the hardware configuration must be preserved.
2020 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy
*policy
,
2021 unsigned int target_freq
)
2023 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
2025 return cpufreq_driver
->fast_switch(policy
, target_freq
);
2027 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch
);
2029 /* Must set freqs->new to intermediate frequency */
2030 static int __target_intermediate(struct cpufreq_policy
*policy
,
2031 struct cpufreq_freqs
*freqs
, int index
)
2035 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
2037 /* We don't need to switch to intermediate freq */
2041 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
2042 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
2044 cpufreq_freq_transition_begin(policy
, freqs
);
2045 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
2046 cpufreq_freq_transition_end(policy
, freqs
, ret
);
2049 pr_err("%s: Failed to change to intermediate frequency: %d\n",
2055 static int __target_index(struct cpufreq_policy
*policy
, int index
)
2057 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
2058 unsigned int intermediate_freq
= 0;
2059 unsigned int newfreq
= policy
->freq_table
[index
].frequency
;
2060 int retval
= -EINVAL
;
2063 if (newfreq
== policy
->cur
)
2066 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
2068 /* Handle switching to intermediate frequency */
2069 if (cpufreq_driver
->get_intermediate
) {
2070 retval
= __target_intermediate(policy
, &freqs
, index
);
2074 intermediate_freq
= freqs
.new;
2075 /* Set old freq to intermediate */
2076 if (intermediate_freq
)
2077 freqs
.old
= freqs
.new;
2080 freqs
.new = newfreq
;
2081 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
2082 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
2084 cpufreq_freq_transition_begin(policy
, &freqs
);
2087 retval
= cpufreq_driver
->target_index(policy
, index
);
2089 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
2093 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
2096 * Failed after setting to intermediate freq? Driver should have
2097 * reverted back to initial frequency and so should we. Check
2098 * here for intermediate_freq instead of get_intermediate, in
2099 * case we haven't switched to intermediate freq at all.
2101 if (unlikely(retval
&& intermediate_freq
)) {
2102 freqs
.old
= intermediate_freq
;
2103 freqs
.new = policy
->restore_freq
;
2104 cpufreq_freq_transition_begin(policy
, &freqs
);
2105 cpufreq_freq_transition_end(policy
, &freqs
, 0);
2112 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
2113 unsigned int target_freq
,
2114 unsigned int relation
)
2116 unsigned int old_target_freq
= target_freq
;
2119 if (cpufreq_disabled())
2122 /* Make sure that target_freq is within supported range */
2123 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
2125 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
2126 policy
->cpu
, target_freq
, relation
, old_target_freq
);
2129 * This might look like a redundant call as we are checking it again
2130 * after finding index. But it is left intentionally for cases where
2131 * exactly same freq is called again and so we can save on few function
2134 if (target_freq
== policy
->cur
)
2137 /* Save last value to restore later on errors */
2138 policy
->restore_freq
= policy
->cur
;
2140 if (cpufreq_driver
->target
)
2141 return cpufreq_driver
->target(policy
, target_freq
, relation
);
2143 if (!cpufreq_driver
->target_index
)
2146 index
= cpufreq_frequency_table_target(policy
, target_freq
, relation
);
2148 return __target_index(policy
, index
);
2150 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
2152 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
2153 unsigned int target_freq
,
2154 unsigned int relation
)
2158 down_write(&policy
->rwsem
);
2160 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
2162 up_write(&policy
->rwsem
);
2166 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
2168 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
2173 static int cpufreq_init_governor(struct cpufreq_policy
*policy
)
2177 /* Don't start any governor operations if we are entering suspend */
2178 if (cpufreq_suspended
)
2181 * Governor might not be initiated here if ACPI _PPC changed
2182 * notification happened, so check it.
2184 if (!policy
->governor
)
2187 /* Platform doesn't want dynamic frequency switching ? */
2188 if (policy
->governor
->dynamic_switching
&&
2189 cpufreq_driver
->flags
& CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING
) {
2190 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
2193 pr_warn("Can't use %s governor as dynamic switching is disallowed. Fallback to %s governor\n",
2194 policy
->governor
->name
, gov
->name
);
2195 policy
->governor
= gov
;
2201 if (!try_module_get(policy
->governor
->owner
))
2204 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2206 if (policy
->governor
->init
) {
2207 ret
= policy
->governor
->init(policy
);
2209 module_put(policy
->governor
->owner
);
2217 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
)
2219 if (cpufreq_suspended
|| !policy
->governor
)
2222 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2224 if (policy
->governor
->exit
)
2225 policy
->governor
->exit(policy
);
2227 module_put(policy
->governor
->owner
);
2230 static int cpufreq_start_governor(struct cpufreq_policy
*policy
)
2234 if (cpufreq_suspended
)
2237 if (!policy
->governor
)
2240 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2242 if (cpufreq_driver
->get
)
2243 cpufreq_verify_current_freq(policy
, false);
2245 if (policy
->governor
->start
) {
2246 ret
= policy
->governor
->start(policy
);
2251 if (policy
->governor
->limits
)
2252 policy
->governor
->limits(policy
);
2257 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
)
2259 if (cpufreq_suspended
|| !policy
->governor
)
2262 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2264 if (policy
->governor
->stop
)
2265 policy
->governor
->stop(policy
);
2268 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
)
2270 if (cpufreq_suspended
|| !policy
->governor
)
2273 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2275 if (policy
->governor
->limits
)
2276 policy
->governor
->limits(policy
);
2279 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2286 if (cpufreq_disabled())
2289 mutex_lock(&cpufreq_governor_mutex
);
2292 if (!find_governor(governor
->name
)) {
2294 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2297 mutex_unlock(&cpufreq_governor_mutex
);
2300 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2302 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2304 struct cpufreq_policy
*policy
;
2305 unsigned long flags
;
2310 if (cpufreq_disabled())
2313 /* clear last_governor for all inactive policies */
2314 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2315 for_each_inactive_policy(policy
) {
2316 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2317 policy
->governor
= NULL
;
2318 strcpy(policy
->last_governor
, "\0");
2321 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2323 mutex_lock(&cpufreq_governor_mutex
);
2324 list_del(&governor
->governor_list
);
2325 mutex_unlock(&cpufreq_governor_mutex
);
2327 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2330 /*********************************************************************
2331 * POLICY INTERFACE *
2332 *********************************************************************/
2335 * cpufreq_get_policy - get the current cpufreq_policy
2336 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2339 * Reads the current cpufreq policy.
2341 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2343 struct cpufreq_policy
*cpu_policy
;
2347 cpu_policy
= cpufreq_cpu_get(cpu
);
2351 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2353 cpufreq_cpu_put(cpu_policy
);
2356 EXPORT_SYMBOL(cpufreq_get_policy
);
2359 * cpufreq_set_policy - Modify cpufreq policy parameters.
2360 * @policy: Policy object to modify.
2361 * @new_policy: New policy data.
2363 * Pass @new_policy to the cpufreq driver's ->verify() callback. Next, copy the
2364 * min and max parameters of @new_policy to @policy and either invoke the
2365 * driver's ->setpolicy() callback (if present) or carry out a governor update
2366 * for @policy. That is, run the current governor's ->limits() callback (if the
2367 * governor field in @new_policy points to the same object as the one in
2368 * @policy) or replace the governor for @policy with the new one stored in
2371 * The cpuinfo part of @policy is not updated by this function.
2373 int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2374 struct cpufreq_policy
*new_policy
)
2376 struct cpufreq_governor
*old_gov
;
2377 struct device
*cpu_dev
= get_cpu_device(policy
->cpu
);
2380 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2381 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2383 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2386 * PM QoS framework collects all the requests from users and provide us
2387 * the final aggregated value here.
2389 new_policy
->min
= dev_pm_qos_read_value(cpu_dev
, DEV_PM_QOS_MIN_FREQUENCY
);
2390 new_policy
->max
= dev_pm_qos_read_value(cpu_dev
, DEV_PM_QOS_MAX_FREQUENCY
);
2392 /* verify the cpu speed can be set within this limit */
2393 ret
= cpufreq_driver
->verify(new_policy
);
2397 policy
->min
= new_policy
->min
;
2398 policy
->max
= new_policy
->max
;
2399 trace_cpu_frequency_limits(policy
);
2401 policy
->cached_target_freq
= UINT_MAX
;
2403 pr_debug("new min and max freqs are %u - %u kHz\n",
2404 policy
->min
, policy
->max
);
2406 if (cpufreq_driver
->setpolicy
) {
2407 policy
->policy
= new_policy
->policy
;
2408 pr_debug("setting range\n");
2409 return cpufreq_driver
->setpolicy(policy
);
2412 if (new_policy
->governor
== policy
->governor
) {
2413 pr_debug("governor limits update\n");
2414 cpufreq_governor_limits(policy
);
2418 pr_debug("governor switch\n");
2420 /* save old, working values */
2421 old_gov
= policy
->governor
;
2422 /* end old governor */
2424 cpufreq_stop_governor(policy
);
2425 cpufreq_exit_governor(policy
);
2428 /* start new governor */
2429 policy
->governor
= new_policy
->governor
;
2430 ret
= cpufreq_init_governor(policy
);
2432 ret
= cpufreq_start_governor(policy
);
2434 pr_debug("governor change\n");
2435 sched_cpufreq_governor_change(policy
, old_gov
);
2438 cpufreq_exit_governor(policy
);
2441 /* new governor failed, so re-start old one */
2442 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2444 policy
->governor
= old_gov
;
2445 if (cpufreq_init_governor(policy
))
2446 policy
->governor
= NULL
;
2448 cpufreq_start_governor(policy
);
2455 * cpufreq_update_policy - Re-evaluate an existing cpufreq policy.
2456 * @cpu: CPU to re-evaluate the policy for.
2458 * Update the current frequency for the cpufreq policy of @cpu and use
2459 * cpufreq_set_policy() to re-apply the min and max limits, which triggers the
2460 * evaluation of policy notifiers and the cpufreq driver's ->verify() callback
2461 * for the policy in question, among other things.
2463 void cpufreq_update_policy(unsigned int cpu
)
2465 struct cpufreq_policy
*policy
= cpufreq_cpu_acquire(cpu
);
2471 * BIOS might change freq behind our back
2472 * -> ask driver for current freq and notify governors about a change
2474 if (cpufreq_driver
->get
&& has_target() &&
2475 (cpufreq_suspended
|| WARN_ON(!cpufreq_verify_current_freq(policy
, false))))
2478 refresh_frequency_limits(policy
);
2481 cpufreq_cpu_release(policy
);
2483 EXPORT_SYMBOL(cpufreq_update_policy
);
2486 * cpufreq_update_limits - Update policy limits for a given CPU.
2487 * @cpu: CPU to update the policy limits for.
2489 * Invoke the driver's ->update_limits callback if present or call
2490 * cpufreq_update_policy() for @cpu.
2492 void cpufreq_update_limits(unsigned int cpu
)
2494 if (cpufreq_driver
->update_limits
)
2495 cpufreq_driver
->update_limits(cpu
);
2497 cpufreq_update_policy(cpu
);
2499 EXPORT_SYMBOL_GPL(cpufreq_update_limits
);
2501 /*********************************************************************
2503 *********************************************************************/
2504 static int cpufreq_boost_set_sw(int state
)
2506 struct cpufreq_policy
*policy
;
2509 for_each_active_policy(policy
) {
2510 if (!policy
->freq_table
)
2513 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2514 policy
->freq_table
);
2516 pr_err("%s: Policy frequency update failed\n",
2521 ret
= dev_pm_qos_update_request(policy
->max_freq_req
, policy
->max
);
2529 int cpufreq_boost_trigger_state(int state
)
2531 unsigned long flags
;
2534 if (cpufreq_driver
->boost_enabled
== state
)
2537 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2538 cpufreq_driver
->boost_enabled
= state
;
2539 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2541 ret
= cpufreq_driver
->set_boost(state
);
2543 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2544 cpufreq_driver
->boost_enabled
= !state
;
2545 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2547 pr_err("%s: Cannot %s BOOST\n",
2548 __func__
, state
? "enable" : "disable");
2554 static bool cpufreq_boost_supported(void)
2556 return cpufreq_driver
->set_boost
;
2559 static int create_boost_sysfs_file(void)
2563 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2565 pr_err("%s: cannot register global BOOST sysfs file\n",
2571 static void remove_boost_sysfs_file(void)
2573 if (cpufreq_boost_supported())
2574 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2577 int cpufreq_enable_boost_support(void)
2579 if (!cpufreq_driver
)
2582 if (cpufreq_boost_supported())
2585 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2587 /* This will get removed on driver unregister */
2588 return create_boost_sysfs_file();
2590 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2592 int cpufreq_boost_enabled(void)
2594 return cpufreq_driver
->boost_enabled
;
2596 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2598 /*********************************************************************
2599 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2600 *********************************************************************/
2601 static enum cpuhp_state hp_online
;
2603 static int cpuhp_cpufreq_online(unsigned int cpu
)
2605 cpufreq_online(cpu
);
2610 static int cpuhp_cpufreq_offline(unsigned int cpu
)
2612 cpufreq_offline(cpu
);
2618 * cpufreq_register_driver - register a CPU Frequency driver
2619 * @driver_data: A struct cpufreq_driver containing the values#
2620 * submitted by the CPU Frequency driver.
2622 * Registers a CPU Frequency driver to this core code. This code
2623 * returns zero on success, -EEXIST when another driver got here first
2624 * (and isn't unregistered in the meantime).
2627 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2629 unsigned long flags
;
2632 if (cpufreq_disabled())
2635 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2636 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2637 driver_data
->target
) ||
2638 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2639 driver_data
->target
)) ||
2640 (!driver_data
->get_intermediate
!= !driver_data
->target_intermediate
) ||
2641 (!driver_data
->online
!= !driver_data
->offline
))
2644 pr_debug("trying to register driver %s\n", driver_data
->name
);
2646 /* Protect against concurrent CPU online/offline. */
2649 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2650 if (cpufreq_driver
) {
2651 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2655 cpufreq_driver
= driver_data
;
2656 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2658 if (driver_data
->setpolicy
)
2659 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2661 if (cpufreq_boost_supported()) {
2662 ret
= create_boost_sysfs_file();
2664 goto err_null_driver
;
2667 ret
= subsys_interface_register(&cpufreq_interface
);
2669 goto err_boost_unreg
;
2671 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2672 list_empty(&cpufreq_policy_list
)) {
2673 /* if all ->init() calls failed, unregister */
2675 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2680 ret
= cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN
,
2682 cpuhp_cpufreq_online
,
2683 cpuhp_cpufreq_offline
);
2689 pr_debug("driver %s up and running\n", driver_data
->name
);
2693 subsys_interface_unregister(&cpufreq_interface
);
2695 remove_boost_sysfs_file();
2697 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2698 cpufreq_driver
= NULL
;
2699 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2704 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2707 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2709 * Unregister the current CPUFreq driver. Only call this if you have
2710 * the right to do so, i.e. if you have succeeded in initialising before!
2711 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2712 * currently not initialised.
2714 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2716 unsigned long flags
;
2718 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2721 pr_debug("unregistering driver %s\n", driver
->name
);
2723 /* Protect against concurrent cpu hotplug */
2725 subsys_interface_unregister(&cpufreq_interface
);
2726 remove_boost_sysfs_file();
2727 cpuhp_remove_state_nocalls_cpuslocked(hp_online
);
2729 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2731 cpufreq_driver
= NULL
;
2733 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2738 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2741 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2742 * or mutexes when secondary CPUs are halted.
2744 static struct syscore_ops cpufreq_syscore_ops
= {
2745 .shutdown
= cpufreq_suspend
,
2748 struct kobject
*cpufreq_global_kobject
;
2749 EXPORT_SYMBOL(cpufreq_global_kobject
);
2751 static int __init
cpufreq_core_init(void)
2753 if (cpufreq_disabled())
2756 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2757 BUG_ON(!cpufreq_global_kobject
);
2759 register_syscore_ops(&cpufreq_syscore_ops
);
2763 module_param(off
, int, 0444);
2764 core_initcall(cpufreq_core_init
);