2 * linux/drivers/cpufreq/cpufreq.c
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org>
8 * Oct 2005 - Ashok Raj <ashok.raj@intel.com>
9 * Added handling for CPU hotplug
10 * Feb 2006 - Jacob Shin <jacob.shin@amd.com>
11 * Fix handling for CPU hotplug -- affected CPUs
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/cpu.h>
21 #include <linux/cpufreq.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/init.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/slab.h>
29 #include <linux/suspend.h>
30 #include <linux/syscore_ops.h>
31 #include <linux/tick.h>
32 #include <trace/events/power.h>
34 static LIST_HEAD(cpufreq_policy_list
);
36 static inline bool policy_is_inactive(struct cpufreq_policy
*policy
)
38 return cpumask_empty(policy
->cpus
);
41 /* Macros to iterate over CPU policies */
42 #define for_each_suitable_policy(__policy, __active) \
43 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
44 if ((__active) == !policy_is_inactive(__policy))
46 #define for_each_active_policy(__policy) \
47 for_each_suitable_policy(__policy, true)
48 #define for_each_inactive_policy(__policy) \
49 for_each_suitable_policy(__policy, false)
51 #define for_each_policy(__policy) \
52 list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
54 /* Iterate over governors */
55 static LIST_HEAD(cpufreq_governor_list
);
56 #define for_each_governor(__governor) \
57 list_for_each_entry(__governor, &cpufreq_governor_list, governor_list)
60 * The "cpufreq driver" - the arch- or hardware-dependent low
61 * level driver of CPUFreq support, and its spinlock. This lock
62 * also protects the cpufreq_cpu_data array.
64 static struct cpufreq_driver
*cpufreq_driver
;
65 static DEFINE_PER_CPU(struct cpufreq_policy
*, cpufreq_cpu_data
);
66 static DEFINE_RWLOCK(cpufreq_driver_lock
);
68 /* Flag to suspend/resume CPUFreq governors */
69 static bool cpufreq_suspended
;
71 static inline bool has_target(void)
73 return cpufreq_driver
->target_index
|| cpufreq_driver
->target
;
76 /* internal prototypes */
77 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
);
78 static int cpufreq_init_governor(struct cpufreq_policy
*policy
);
79 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
);
80 static int cpufreq_start_governor(struct cpufreq_policy
*policy
);
81 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
);
82 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
);
85 * Two notifier lists: the "policy" list is involved in the
86 * validation process for a new CPU frequency policy; the
87 * "transition" list for kernel code that needs to handle
88 * changes to devices when the CPU clock speed changes.
89 * The mutex locks both lists.
91 static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list
);
92 static struct srcu_notifier_head cpufreq_transition_notifier_list
;
94 static bool init_cpufreq_transition_notifier_list_called
;
95 static int __init
init_cpufreq_transition_notifier_list(void)
97 srcu_init_notifier_head(&cpufreq_transition_notifier_list
);
98 init_cpufreq_transition_notifier_list_called
= true;
101 pure_initcall(init_cpufreq_transition_notifier_list
);
103 static int off __read_mostly
;
104 static int cpufreq_disabled(void)
108 void disable_cpufreq(void)
112 static DEFINE_MUTEX(cpufreq_governor_mutex
);
114 bool have_governor_per_policy(void)
116 return !!(cpufreq_driver
->flags
& CPUFREQ_HAVE_GOVERNOR_PER_POLICY
);
118 EXPORT_SYMBOL_GPL(have_governor_per_policy
);
120 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
)
122 if (have_governor_per_policy())
123 return &policy
->kobj
;
125 return cpufreq_global_kobject
;
127 EXPORT_SYMBOL_GPL(get_governor_parent_kobj
);
129 static inline u64
get_cpu_idle_time_jiffy(unsigned int cpu
, u64
*wall
)
135 cur_wall_time
= jiffies64_to_cputime64(get_jiffies_64());
137 busy_time
= kcpustat_cpu(cpu
).cpustat
[CPUTIME_USER
];
138 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SYSTEM
];
139 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_IRQ
];
140 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_SOFTIRQ
];
141 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_STEAL
];
142 busy_time
+= kcpustat_cpu(cpu
).cpustat
[CPUTIME_NICE
];
144 idle_time
= cur_wall_time
- busy_time
;
146 *wall
= cputime_to_usecs(cur_wall_time
);
148 return cputime_to_usecs(idle_time
);
151 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
)
153 u64 idle_time
= get_cpu_idle_time_us(cpu
, io_busy
? wall
: NULL
);
155 if (idle_time
== -1ULL)
156 return get_cpu_idle_time_jiffy(cpu
, wall
);
158 idle_time
+= get_cpu_iowait_time_us(cpu
, wall
);
162 EXPORT_SYMBOL_GPL(get_cpu_idle_time
);
165 * This is a generic cpufreq init() routine which can be used by cpufreq
166 * drivers of SMP systems. It will do following:
167 * - validate & show freq table passed
168 * - set policies transition latency
169 * - policy->cpus with all possible CPUs
171 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
172 struct cpufreq_frequency_table
*table
,
173 unsigned int transition_latency
)
177 ret
= cpufreq_table_validate_and_show(policy
, table
);
179 pr_err("%s: invalid frequency table: %d\n", __func__
, ret
);
183 policy
->cpuinfo
.transition_latency
= transition_latency
;
186 * The driver only supports the SMP configuration where all processors
187 * share the clock and voltage and clock.
189 cpumask_setall(policy
->cpus
);
193 EXPORT_SYMBOL_GPL(cpufreq_generic_init
);
195 struct cpufreq_policy
*cpufreq_cpu_get_raw(unsigned int cpu
)
197 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
199 return policy
&& cpumask_test_cpu(cpu
, policy
->cpus
) ? policy
: NULL
;
201 EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw
);
203 unsigned int cpufreq_generic_get(unsigned int cpu
)
205 struct cpufreq_policy
*policy
= cpufreq_cpu_get_raw(cpu
);
207 if (!policy
|| IS_ERR(policy
->clk
)) {
208 pr_err("%s: No %s associated to cpu: %d\n",
209 __func__
, policy
? "clk" : "policy", cpu
);
213 return clk_get_rate(policy
->clk
) / 1000;
215 EXPORT_SYMBOL_GPL(cpufreq_generic_get
);
218 * cpufreq_cpu_get: returns policy for a cpu and marks it busy.
220 * @cpu: cpu to find policy for.
222 * This returns policy for 'cpu', returns NULL if it doesn't exist.
223 * It also increments the kobject reference count to mark it busy and so would
224 * require a corresponding call to cpufreq_cpu_put() to decrement it back.
225 * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be
226 * freed as that depends on the kobj count.
228 * Return: A valid policy on success, otherwise NULL on failure.
230 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
232 struct cpufreq_policy
*policy
= NULL
;
235 if (WARN_ON(cpu
>= nr_cpu_ids
))
238 /* get the cpufreq driver */
239 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
241 if (cpufreq_driver
) {
243 policy
= cpufreq_cpu_get_raw(cpu
);
245 kobject_get(&policy
->kobj
);
248 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
252 EXPORT_SYMBOL_GPL(cpufreq_cpu_get
);
255 * cpufreq_cpu_put: Decrements the usage count of a policy
257 * @policy: policy earlier returned by cpufreq_cpu_get().
259 * This decrements the kobject reference count incremented earlier by calling
262 void cpufreq_cpu_put(struct cpufreq_policy
*policy
)
264 kobject_put(&policy
->kobj
);
266 EXPORT_SYMBOL_GPL(cpufreq_cpu_put
);
268 /*********************************************************************
269 * EXTERNALLY AFFECTING FREQUENCY CHANGES *
270 *********************************************************************/
273 * adjust_jiffies - adjust the system "loops_per_jiffy"
275 * This function alters the system "loops_per_jiffy" for the clock
276 * speed change. Note that loops_per_jiffy cannot be updated on SMP
277 * systems as each CPU might be scaled differently. So, use the arch
278 * per-CPU loops_per_jiffy value wherever possible.
280 static void adjust_jiffies(unsigned long val
, struct cpufreq_freqs
*ci
)
283 static unsigned long l_p_j_ref
;
284 static unsigned int l_p_j_ref_freq
;
286 if (ci
->flags
& CPUFREQ_CONST_LOOPS
)
289 if (!l_p_j_ref_freq
) {
290 l_p_j_ref
= loops_per_jiffy
;
291 l_p_j_ref_freq
= ci
->old
;
292 pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n",
293 l_p_j_ref
, l_p_j_ref_freq
);
295 if (val
== CPUFREQ_POSTCHANGE
&& ci
->old
!= ci
->new) {
296 loops_per_jiffy
= cpufreq_scale(l_p_j_ref
, l_p_j_ref_freq
,
298 pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n",
299 loops_per_jiffy
, ci
->new);
304 static void __cpufreq_notify_transition(struct cpufreq_policy
*policy
,
305 struct cpufreq_freqs
*freqs
, unsigned int state
)
307 BUG_ON(irqs_disabled());
309 if (cpufreq_disabled())
312 freqs
->flags
= cpufreq_driver
->flags
;
313 pr_debug("notification %u of frequency transition to %u kHz\n",
318 case CPUFREQ_PRECHANGE
:
319 /* detect if the driver reported a value as "old frequency"
320 * which is not equal to what the cpufreq core thinks is
323 if (!(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
324 if ((policy
) && (policy
->cpu
== freqs
->cpu
) &&
325 (policy
->cur
) && (policy
->cur
!= freqs
->old
)) {
326 pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n",
327 freqs
->old
, policy
->cur
);
328 freqs
->old
= policy
->cur
;
331 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
332 CPUFREQ_PRECHANGE
, freqs
);
333 adjust_jiffies(CPUFREQ_PRECHANGE
, freqs
);
336 case CPUFREQ_POSTCHANGE
:
337 adjust_jiffies(CPUFREQ_POSTCHANGE
, freqs
);
338 pr_debug("FREQ: %lu - CPU: %lu\n",
339 (unsigned long)freqs
->new, (unsigned long)freqs
->cpu
);
340 trace_cpu_frequency(freqs
->new, freqs
->cpu
);
341 cpufreq_stats_record_transition(policy
, freqs
->new);
342 srcu_notifier_call_chain(&cpufreq_transition_notifier_list
,
343 CPUFREQ_POSTCHANGE
, freqs
);
344 if (likely(policy
) && likely(policy
->cpu
== freqs
->cpu
))
345 policy
->cur
= freqs
->new;
351 * cpufreq_notify_transition - call notifier chain and adjust_jiffies
352 * on frequency transition.
354 * This function calls the transition notifiers and the "adjust_jiffies"
355 * function. It is called twice on all CPU frequency changes that have
358 static void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
359 struct cpufreq_freqs
*freqs
, unsigned int state
)
361 for_each_cpu(freqs
->cpu
, policy
->cpus
)
362 __cpufreq_notify_transition(policy
, freqs
, state
);
365 /* Do post notifications when there are chances that transition has failed */
366 static void cpufreq_notify_post_transition(struct cpufreq_policy
*policy
,
367 struct cpufreq_freqs
*freqs
, int transition_failed
)
369 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
370 if (!transition_failed
)
373 swap(freqs
->old
, freqs
->new);
374 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
375 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_POSTCHANGE
);
378 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
379 struct cpufreq_freqs
*freqs
)
383 * Catch double invocations of _begin() which lead to self-deadlock.
384 * ASYNC_NOTIFICATION drivers are left out because the cpufreq core
385 * doesn't invoke _begin() on their behalf, and hence the chances of
386 * double invocations are very low. Moreover, there are scenarios
387 * where these checks can emit false-positive warnings in these
388 * drivers; so we avoid that by skipping them altogether.
390 WARN_ON(!(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
)
391 && current
== policy
->transition_task
);
394 wait_event(policy
->transition_wait
, !policy
->transition_ongoing
);
396 spin_lock(&policy
->transition_lock
);
398 if (unlikely(policy
->transition_ongoing
)) {
399 spin_unlock(&policy
->transition_lock
);
403 policy
->transition_ongoing
= true;
404 policy
->transition_task
= current
;
406 spin_unlock(&policy
->transition_lock
);
408 cpufreq_notify_transition(policy
, freqs
, CPUFREQ_PRECHANGE
);
410 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin
);
412 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
413 struct cpufreq_freqs
*freqs
, int transition_failed
)
415 if (unlikely(WARN_ON(!policy
->transition_ongoing
)))
418 cpufreq_notify_post_transition(policy
, freqs
, transition_failed
);
420 policy
->transition_ongoing
= false;
421 policy
->transition_task
= NULL
;
423 wake_up(&policy
->transition_wait
);
425 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end
);
428 * Fast frequency switching status count. Positive means "enabled", negative
429 * means "disabled" and 0 means "not decided yet".
431 static int cpufreq_fast_switch_count
;
432 static DEFINE_MUTEX(cpufreq_fast_switch_lock
);
434 static void cpufreq_list_transition_notifiers(void)
436 struct notifier_block
*nb
;
438 pr_info("Registered transition notifiers:\n");
440 mutex_lock(&cpufreq_transition_notifier_list
.mutex
);
442 for (nb
= cpufreq_transition_notifier_list
.head
; nb
; nb
= nb
->next
)
443 pr_info("%pF\n", nb
->notifier_call
);
445 mutex_unlock(&cpufreq_transition_notifier_list
.mutex
);
449 * cpufreq_enable_fast_switch - Enable fast frequency switching for policy.
450 * @policy: cpufreq policy to enable fast frequency switching for.
452 * Try to enable fast frequency switching for @policy.
454 * The attempt will fail if there is at least one transition notifier registered
455 * at this point, as fast frequency switching is quite fundamentally at odds
456 * with transition notifiers. Thus if successful, it will make registration of
457 * transition notifiers fail going forward.
459 void cpufreq_enable_fast_switch(struct cpufreq_policy
*policy
)
461 lockdep_assert_held(&policy
->rwsem
);
463 if (!policy
->fast_switch_possible
)
466 mutex_lock(&cpufreq_fast_switch_lock
);
467 if (cpufreq_fast_switch_count
>= 0) {
468 cpufreq_fast_switch_count
++;
469 policy
->fast_switch_enabled
= true;
471 pr_warn("CPU%u: Fast frequency switching not enabled\n",
473 cpufreq_list_transition_notifiers();
475 mutex_unlock(&cpufreq_fast_switch_lock
);
477 EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch
);
480 * cpufreq_disable_fast_switch - Disable fast frequency switching for policy.
481 * @policy: cpufreq policy to disable fast frequency switching for.
483 void cpufreq_disable_fast_switch(struct cpufreq_policy
*policy
)
485 mutex_lock(&cpufreq_fast_switch_lock
);
486 if (policy
->fast_switch_enabled
) {
487 policy
->fast_switch_enabled
= false;
488 if (!WARN_ON(cpufreq_fast_switch_count
<= 0))
489 cpufreq_fast_switch_count
--;
491 mutex_unlock(&cpufreq_fast_switch_lock
);
493 EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch
);
496 * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported
498 * @target_freq: target frequency to resolve.
500 * The target to driver frequency mapping is cached in the policy.
502 * Return: Lowest driver-supported frequency greater than or equal to the
503 * given target_freq, subject to policy (min/max) and driver limitations.
505 unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy
*policy
,
506 unsigned int target_freq
)
508 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
509 policy
->cached_target_freq
= target_freq
;
511 if (cpufreq_driver
->target_index
) {
514 idx
= cpufreq_frequency_table_target(policy
, target_freq
,
516 policy
->cached_resolved_idx
= idx
;
517 return policy
->freq_table
[idx
].frequency
;
520 if (cpufreq_driver
->resolve_freq
)
521 return cpufreq_driver
->resolve_freq(policy
, target_freq
);
525 EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq
);
527 /*********************************************************************
529 *********************************************************************/
530 static ssize_t
show_boost(struct kobject
*kobj
,
531 struct attribute
*attr
, char *buf
)
533 return sprintf(buf
, "%d\n", cpufreq_driver
->boost_enabled
);
536 static ssize_t
store_boost(struct kobject
*kobj
, struct attribute
*attr
,
537 const char *buf
, size_t count
)
541 ret
= sscanf(buf
, "%d", &enable
);
542 if (ret
!= 1 || enable
< 0 || enable
> 1)
545 if (cpufreq_boost_trigger_state(enable
)) {
546 pr_err("%s: Cannot %s BOOST!\n",
547 __func__
, enable
? "enable" : "disable");
551 pr_debug("%s: cpufreq BOOST %s\n",
552 __func__
, enable
? "enabled" : "disabled");
556 define_one_global_rw(boost
);
558 static struct cpufreq_governor
*find_governor(const char *str_governor
)
560 struct cpufreq_governor
*t
;
563 if (!strncasecmp(str_governor
, t
->name
, CPUFREQ_NAME_LEN
))
570 * cpufreq_parse_governor - parse a governor string
572 static int cpufreq_parse_governor(char *str_governor
, unsigned int *policy
,
573 struct cpufreq_governor
**governor
)
577 if (cpufreq_driver
->setpolicy
) {
578 if (!strncasecmp(str_governor
, "performance", CPUFREQ_NAME_LEN
)) {
579 *policy
= CPUFREQ_POLICY_PERFORMANCE
;
581 } else if (!strncasecmp(str_governor
, "powersave",
583 *policy
= CPUFREQ_POLICY_POWERSAVE
;
587 struct cpufreq_governor
*t
;
589 mutex_lock(&cpufreq_governor_mutex
);
591 t
= find_governor(str_governor
);
596 mutex_unlock(&cpufreq_governor_mutex
);
597 ret
= request_module("cpufreq_%s", str_governor
);
598 mutex_lock(&cpufreq_governor_mutex
);
601 t
= find_governor(str_governor
);
609 mutex_unlock(&cpufreq_governor_mutex
);
615 * cpufreq_per_cpu_attr_read() / show_##file_name() -
616 * print out cpufreq information
618 * Write out information from cpufreq_driver->policy[cpu]; object must be
622 #define show_one(file_name, object) \
623 static ssize_t show_##file_name \
624 (struct cpufreq_policy *policy, char *buf) \
626 return sprintf(buf, "%u\n", policy->object); \
629 show_one(cpuinfo_min_freq
, cpuinfo
.min_freq
);
630 show_one(cpuinfo_max_freq
, cpuinfo
.max_freq
);
631 show_one(cpuinfo_transition_latency
, cpuinfo
.transition_latency
);
632 show_one(scaling_min_freq
, min
);
633 show_one(scaling_max_freq
, max
);
635 static ssize_t
show_scaling_cur_freq(struct cpufreq_policy
*policy
, char *buf
)
639 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
)
640 ret
= sprintf(buf
, "%u\n", cpufreq_driver
->get(policy
->cpu
));
642 ret
= sprintf(buf
, "%u\n", policy
->cur
);
646 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
647 struct cpufreq_policy
*new_policy
);
650 * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
652 #define store_one(file_name, object) \
653 static ssize_t store_##file_name \
654 (struct cpufreq_policy *policy, const char *buf, size_t count) \
657 struct cpufreq_policy new_policy; \
659 memcpy(&new_policy, policy, sizeof(*policy)); \
661 ret = sscanf(buf, "%u", &new_policy.object); \
665 temp = new_policy.object; \
666 ret = cpufreq_set_policy(policy, &new_policy); \
668 policy->user_policy.object = temp; \
670 return ret ? ret : count; \
673 store_one(scaling_min_freq
, min
);
674 store_one(scaling_max_freq
, max
);
677 * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
679 static ssize_t
show_cpuinfo_cur_freq(struct cpufreq_policy
*policy
,
682 unsigned int cur_freq
= __cpufreq_get(policy
);
685 return sprintf(buf
, "%u\n", cur_freq
);
687 return sprintf(buf
, "<unknown>\n");
691 * show_scaling_governor - show the current policy for the specified CPU
693 static ssize_t
show_scaling_governor(struct cpufreq_policy
*policy
, char *buf
)
695 if (policy
->policy
== CPUFREQ_POLICY_POWERSAVE
)
696 return sprintf(buf
, "powersave\n");
697 else if (policy
->policy
== CPUFREQ_POLICY_PERFORMANCE
)
698 return sprintf(buf
, "performance\n");
699 else if (policy
->governor
)
700 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n",
701 policy
->governor
->name
);
706 * store_scaling_governor - store policy for the specified CPU
708 static ssize_t
store_scaling_governor(struct cpufreq_policy
*policy
,
709 const char *buf
, size_t count
)
712 char str_governor
[16];
713 struct cpufreq_policy new_policy
;
715 memcpy(&new_policy
, policy
, sizeof(*policy
));
717 ret
= sscanf(buf
, "%15s", str_governor
);
721 if (cpufreq_parse_governor(str_governor
, &new_policy
.policy
,
722 &new_policy
.governor
))
725 ret
= cpufreq_set_policy(policy
, &new_policy
);
726 return ret
? ret
: count
;
730 * show_scaling_driver - show the cpufreq driver currently loaded
732 static ssize_t
show_scaling_driver(struct cpufreq_policy
*policy
, char *buf
)
734 return scnprintf(buf
, CPUFREQ_NAME_PLEN
, "%s\n", cpufreq_driver
->name
);
738 * show_scaling_available_governors - show the available CPUfreq governors
740 static ssize_t
show_scaling_available_governors(struct cpufreq_policy
*policy
,
744 struct cpufreq_governor
*t
;
747 i
+= sprintf(buf
, "performance powersave");
751 for_each_governor(t
) {
752 if (i
>= (ssize_t
) ((PAGE_SIZE
/ sizeof(char))
753 - (CPUFREQ_NAME_LEN
+ 2)))
755 i
+= scnprintf(&buf
[i
], CPUFREQ_NAME_PLEN
, "%s ", t
->name
);
758 i
+= sprintf(&buf
[i
], "\n");
762 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
)
767 for_each_cpu(cpu
, mask
) {
769 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), " ");
770 i
+= scnprintf(&buf
[i
], (PAGE_SIZE
- i
- 2), "%u", cpu
);
771 if (i
>= (PAGE_SIZE
- 5))
774 i
+= sprintf(&buf
[i
], "\n");
777 EXPORT_SYMBOL_GPL(cpufreq_show_cpus
);
780 * show_related_cpus - show the CPUs affected by each transition even if
781 * hw coordination is in use
783 static ssize_t
show_related_cpus(struct cpufreq_policy
*policy
, char *buf
)
785 return cpufreq_show_cpus(policy
->related_cpus
, buf
);
789 * show_affected_cpus - show the CPUs affected by each transition
791 static ssize_t
show_affected_cpus(struct cpufreq_policy
*policy
, char *buf
)
793 return cpufreq_show_cpus(policy
->cpus
, buf
);
796 static ssize_t
store_scaling_setspeed(struct cpufreq_policy
*policy
,
797 const char *buf
, size_t count
)
799 unsigned int freq
= 0;
802 if (!policy
->governor
|| !policy
->governor
->store_setspeed
)
805 ret
= sscanf(buf
, "%u", &freq
);
809 policy
->governor
->store_setspeed(policy
, freq
);
814 static ssize_t
show_scaling_setspeed(struct cpufreq_policy
*policy
, char *buf
)
816 if (!policy
->governor
|| !policy
->governor
->show_setspeed
)
817 return sprintf(buf
, "<unsupported>\n");
819 return policy
->governor
->show_setspeed(policy
, buf
);
823 * show_bios_limit - show the current cpufreq HW/BIOS limitation
825 static ssize_t
show_bios_limit(struct cpufreq_policy
*policy
, char *buf
)
829 if (cpufreq_driver
->bios_limit
) {
830 ret
= cpufreq_driver
->bios_limit(policy
->cpu
, &limit
);
832 return sprintf(buf
, "%u\n", limit
);
834 return sprintf(buf
, "%u\n", policy
->cpuinfo
.max_freq
);
837 cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq
, 0400);
838 cpufreq_freq_attr_ro(cpuinfo_min_freq
);
839 cpufreq_freq_attr_ro(cpuinfo_max_freq
);
840 cpufreq_freq_attr_ro(cpuinfo_transition_latency
);
841 cpufreq_freq_attr_ro(scaling_available_governors
);
842 cpufreq_freq_attr_ro(scaling_driver
);
843 cpufreq_freq_attr_ro(scaling_cur_freq
);
844 cpufreq_freq_attr_ro(bios_limit
);
845 cpufreq_freq_attr_ro(related_cpus
);
846 cpufreq_freq_attr_ro(affected_cpus
);
847 cpufreq_freq_attr_rw(scaling_min_freq
);
848 cpufreq_freq_attr_rw(scaling_max_freq
);
849 cpufreq_freq_attr_rw(scaling_governor
);
850 cpufreq_freq_attr_rw(scaling_setspeed
);
852 static struct attribute
*default_attrs
[] = {
853 &cpuinfo_min_freq
.attr
,
854 &cpuinfo_max_freq
.attr
,
855 &cpuinfo_transition_latency
.attr
,
856 &scaling_min_freq
.attr
,
857 &scaling_max_freq
.attr
,
860 &scaling_governor
.attr
,
861 &scaling_driver
.attr
,
862 &scaling_available_governors
.attr
,
863 &scaling_setspeed
.attr
,
867 #define to_policy(k) container_of(k, struct cpufreq_policy, kobj)
868 #define to_attr(a) container_of(a, struct freq_attr, attr)
870 static ssize_t
show(struct kobject
*kobj
, struct attribute
*attr
, char *buf
)
872 struct cpufreq_policy
*policy
= to_policy(kobj
);
873 struct freq_attr
*fattr
= to_attr(attr
);
876 down_read(&policy
->rwsem
);
877 ret
= fattr
->show(policy
, buf
);
878 up_read(&policy
->rwsem
);
883 static ssize_t
store(struct kobject
*kobj
, struct attribute
*attr
,
884 const char *buf
, size_t count
)
886 struct cpufreq_policy
*policy
= to_policy(kobj
);
887 struct freq_attr
*fattr
= to_attr(attr
);
888 ssize_t ret
= -EINVAL
;
892 if (cpu_online(policy
->cpu
)) {
893 down_write(&policy
->rwsem
);
894 ret
= fattr
->store(policy
, buf
, count
);
895 up_write(&policy
->rwsem
);
903 static void cpufreq_sysfs_release(struct kobject
*kobj
)
905 struct cpufreq_policy
*policy
= to_policy(kobj
);
906 pr_debug("last reference is dropped\n");
907 complete(&policy
->kobj_unregister
);
910 static const struct sysfs_ops sysfs_ops
= {
915 static struct kobj_type ktype_cpufreq
= {
916 .sysfs_ops
= &sysfs_ops
,
917 .default_attrs
= default_attrs
,
918 .release
= cpufreq_sysfs_release
,
921 static int add_cpu_dev_symlink(struct cpufreq_policy
*policy
,
924 dev_dbg(dev
, "%s: Adding symlink\n", __func__
);
925 return sysfs_create_link(&dev
->kobj
, &policy
->kobj
, "cpufreq");
928 static void remove_cpu_dev_symlink(struct cpufreq_policy
*policy
,
931 dev_dbg(dev
, "%s: Removing symlink\n", __func__
);
932 sysfs_remove_link(&dev
->kobj
, "cpufreq");
935 static int cpufreq_add_dev_interface(struct cpufreq_policy
*policy
)
937 struct freq_attr
**drv_attr
;
940 /* set up files for this cpu device */
941 drv_attr
= cpufreq_driver
->attr
;
942 while (drv_attr
&& *drv_attr
) {
943 ret
= sysfs_create_file(&policy
->kobj
, &((*drv_attr
)->attr
));
948 if (cpufreq_driver
->get
) {
949 ret
= sysfs_create_file(&policy
->kobj
, &cpuinfo_cur_freq
.attr
);
954 ret
= sysfs_create_file(&policy
->kobj
, &scaling_cur_freq
.attr
);
958 if (cpufreq_driver
->bios_limit
) {
959 ret
= sysfs_create_file(&policy
->kobj
, &bios_limit
.attr
);
967 __weak
struct cpufreq_governor
*cpufreq_default_governor(void)
972 static int cpufreq_init_policy(struct cpufreq_policy
*policy
)
974 struct cpufreq_governor
*gov
= NULL
;
975 struct cpufreq_policy new_policy
;
977 memcpy(&new_policy
, policy
, sizeof(*policy
));
979 /* Update governor of new_policy to the governor used before hotplug */
980 gov
= find_governor(policy
->last_governor
);
982 pr_debug("Restoring governor %s for cpu %d\n",
983 policy
->governor
->name
, policy
->cpu
);
985 gov
= cpufreq_default_governor();
990 new_policy
.governor
= gov
;
992 /* Use the default policy if there is no last_policy. */
993 if (cpufreq_driver
->setpolicy
) {
994 if (policy
->last_policy
)
995 new_policy
.policy
= policy
->last_policy
;
997 cpufreq_parse_governor(gov
->name
, &new_policy
.policy
,
1000 /* set default policy */
1001 return cpufreq_set_policy(policy
, &new_policy
);
1004 static int cpufreq_add_policy_cpu(struct cpufreq_policy
*policy
, unsigned int cpu
)
1008 /* Has this CPU been taken care of already? */
1009 if (cpumask_test_cpu(cpu
, policy
->cpus
))
1012 down_write(&policy
->rwsem
);
1014 cpufreq_stop_governor(policy
);
1016 cpumask_set_cpu(cpu
, policy
->cpus
);
1019 ret
= cpufreq_start_governor(policy
);
1021 pr_err("%s: Failed to start governor\n", __func__
);
1023 up_write(&policy
->rwsem
);
1027 static void handle_update(struct work_struct
*work
)
1029 struct cpufreq_policy
*policy
=
1030 container_of(work
, struct cpufreq_policy
, update
);
1031 unsigned int cpu
= policy
->cpu
;
1032 pr_debug("handle_update for cpu %u called\n", cpu
);
1033 cpufreq_update_policy(cpu
);
1036 static struct cpufreq_policy
*cpufreq_policy_alloc(unsigned int cpu
)
1038 struct cpufreq_policy
*policy
;
1041 policy
= kzalloc(sizeof(*policy
), GFP_KERNEL
);
1045 if (!alloc_cpumask_var(&policy
->cpus
, GFP_KERNEL
))
1046 goto err_free_policy
;
1048 if (!zalloc_cpumask_var(&policy
->related_cpus
, GFP_KERNEL
))
1049 goto err_free_cpumask
;
1051 if (!zalloc_cpumask_var(&policy
->real_cpus
, GFP_KERNEL
))
1052 goto err_free_rcpumask
;
1054 ret
= kobject_init_and_add(&policy
->kobj
, &ktype_cpufreq
,
1055 cpufreq_global_kobject
, "policy%u", cpu
);
1057 pr_err("%s: failed to init policy->kobj: %d\n", __func__
, ret
);
1058 goto err_free_real_cpus
;
1061 INIT_LIST_HEAD(&policy
->policy_list
);
1062 init_rwsem(&policy
->rwsem
);
1063 spin_lock_init(&policy
->transition_lock
);
1064 init_waitqueue_head(&policy
->transition_wait
);
1065 init_completion(&policy
->kobj_unregister
);
1066 INIT_WORK(&policy
->update
, handle_update
);
1072 free_cpumask_var(policy
->real_cpus
);
1074 free_cpumask_var(policy
->related_cpus
);
1076 free_cpumask_var(policy
->cpus
);
1083 static void cpufreq_policy_put_kobj(struct cpufreq_policy
*policy
, bool notify
)
1085 struct kobject
*kobj
;
1086 struct completion
*cmp
;
1089 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1090 CPUFREQ_REMOVE_POLICY
, policy
);
1092 down_write(&policy
->rwsem
);
1093 cpufreq_stats_free_table(policy
);
1094 kobj
= &policy
->kobj
;
1095 cmp
= &policy
->kobj_unregister
;
1096 up_write(&policy
->rwsem
);
1100 * We need to make sure that the underlying kobj is
1101 * actually not referenced anymore by anybody before we
1102 * proceed with unloading.
1104 pr_debug("waiting for dropping of refcount\n");
1105 wait_for_completion(cmp
);
1106 pr_debug("wait complete\n");
1109 static void cpufreq_policy_free(struct cpufreq_policy
*policy
, bool notify
)
1111 unsigned long flags
;
1114 /* Remove policy from list */
1115 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1116 list_del(&policy
->policy_list
);
1118 for_each_cpu(cpu
, policy
->related_cpus
)
1119 per_cpu(cpufreq_cpu_data
, cpu
) = NULL
;
1120 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1122 cpufreq_policy_put_kobj(policy
, notify
);
1123 free_cpumask_var(policy
->real_cpus
);
1124 free_cpumask_var(policy
->related_cpus
);
1125 free_cpumask_var(policy
->cpus
);
1129 static int cpufreq_online(unsigned int cpu
)
1131 struct cpufreq_policy
*policy
;
1133 unsigned long flags
;
1137 pr_debug("%s: bringing CPU%u online\n", __func__
, cpu
);
1139 /* Check if this CPU already has a policy to manage it */
1140 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1142 WARN_ON(!cpumask_test_cpu(cpu
, policy
->related_cpus
));
1143 if (!policy_is_inactive(policy
))
1144 return cpufreq_add_policy_cpu(policy
, cpu
);
1146 /* This is the only online CPU for the policy. Start over. */
1148 down_write(&policy
->rwsem
);
1150 policy
->governor
= NULL
;
1151 up_write(&policy
->rwsem
);
1154 policy
= cpufreq_policy_alloc(cpu
);
1159 cpumask_copy(policy
->cpus
, cpumask_of(cpu
));
1161 /* call driver. From then on the cpufreq must be able
1162 * to accept all calls to ->verify and ->setpolicy for this CPU
1164 ret
= cpufreq_driver
->init(policy
);
1166 pr_debug("initialization failed\n");
1167 goto out_free_policy
;
1170 down_write(&policy
->rwsem
);
1173 /* related_cpus should at least include policy->cpus. */
1174 cpumask_copy(policy
->related_cpus
, policy
->cpus
);
1175 /* Clear mask of registered CPUs */
1176 cpumask_clear(policy
->real_cpus
);
1180 * affected cpus must always be the one, which are online. We aren't
1181 * managing offline cpus here.
1183 cpumask_and(policy
->cpus
, policy
->cpus
, cpu_online_mask
);
1186 policy
->user_policy
.min
= policy
->min
;
1187 policy
->user_policy
.max
= policy
->max
;
1189 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1190 for_each_cpu(j
, policy
->related_cpus
)
1191 per_cpu(cpufreq_cpu_data
, j
) = policy
;
1192 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1195 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
1196 policy
->cur
= cpufreq_driver
->get(policy
->cpu
);
1198 pr_err("%s: ->get() failed\n", __func__
);
1199 goto out_exit_policy
;
1204 * Sometimes boot loaders set CPU frequency to a value outside of
1205 * frequency table present with cpufreq core. In such cases CPU might be
1206 * unstable if it has to run on that frequency for long duration of time
1207 * and so its better to set it to a frequency which is specified in
1208 * freq-table. This also makes cpufreq stats inconsistent as
1209 * cpufreq-stats would fail to register because current frequency of CPU
1210 * isn't found in freq-table.
1212 * Because we don't want this change to effect boot process badly, we go
1213 * for the next freq which is >= policy->cur ('cur' must be set by now,
1214 * otherwise we will end up setting freq to lowest of the table as 'cur'
1215 * is initialized to zero).
1217 * We are passing target-freq as "policy->cur - 1" otherwise
1218 * __cpufreq_driver_target() would simply fail, as policy->cur will be
1219 * equal to target-freq.
1221 if ((cpufreq_driver
->flags
& CPUFREQ_NEED_INITIAL_FREQ_CHECK
)
1223 /* Are we running at unknown frequency ? */
1224 ret
= cpufreq_frequency_table_get_index(policy
, policy
->cur
);
1225 if (ret
== -EINVAL
) {
1226 /* Warn user and fix it */
1227 pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n",
1228 __func__
, policy
->cpu
, policy
->cur
);
1229 ret
= __cpufreq_driver_target(policy
, policy
->cur
- 1,
1230 CPUFREQ_RELATION_L
);
1233 * Reaching here after boot in a few seconds may not
1234 * mean that system will remain stable at "unknown"
1235 * frequency for longer duration. Hence, a BUG_ON().
1238 pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n",
1239 __func__
, policy
->cpu
, policy
->cur
);
1244 ret
= cpufreq_add_dev_interface(policy
);
1246 goto out_exit_policy
;
1248 cpufreq_stats_create_table(policy
);
1249 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1250 CPUFREQ_CREATE_POLICY
, policy
);
1252 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
1253 list_add(&policy
->policy_list
, &cpufreq_policy_list
);
1254 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1257 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
1258 CPUFREQ_START
, policy
);
1260 ret
= cpufreq_init_policy(policy
);
1262 pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
1263 __func__
, cpu
, ret
);
1264 /* cpufreq_policy_free() will notify based on this */
1266 goto out_exit_policy
;
1269 up_write(&policy
->rwsem
);
1271 kobject_uevent(&policy
->kobj
, KOBJ_ADD
);
1273 /* Callback for handling stuff after policy is ready */
1274 if (cpufreq_driver
->ready
)
1275 cpufreq_driver
->ready(policy
);
1277 pr_debug("initialization complete\n");
1282 up_write(&policy
->rwsem
);
1284 if (cpufreq_driver
->exit
)
1285 cpufreq_driver
->exit(policy
);
1287 cpufreq_policy_free(policy
, !new_policy
);
1291 static int cpufreq_offline(unsigned int cpu
);
1294 * cpufreq_add_dev - the cpufreq interface for a CPU device.
1296 * @sif: Subsystem interface structure pointer (not used)
1298 static int cpufreq_add_dev(struct device
*dev
, struct subsys_interface
*sif
)
1300 struct cpufreq_policy
*policy
;
1301 unsigned cpu
= dev
->id
;
1304 dev_dbg(dev
, "%s: adding CPU%u\n", __func__
, cpu
);
1306 if (cpu_online(cpu
)) {
1307 ret
= cpufreq_online(cpu
);
1312 /* Create sysfs link on CPU registration */
1313 policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1314 if (!policy
|| cpumask_test_and_set_cpu(cpu
, policy
->real_cpus
))
1317 ret
= add_cpu_dev_symlink(policy
, dev
);
1319 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1320 cpufreq_offline(cpu
);
1326 static int cpufreq_offline(unsigned int cpu
)
1328 struct cpufreq_policy
*policy
;
1331 pr_debug("%s: unregistering CPU %u\n", __func__
, cpu
);
1333 policy
= cpufreq_cpu_get_raw(cpu
);
1335 pr_debug("%s: No cpu_data found\n", __func__
);
1339 down_write(&policy
->rwsem
);
1341 cpufreq_stop_governor(policy
);
1343 cpumask_clear_cpu(cpu
, policy
->cpus
);
1345 if (policy_is_inactive(policy
)) {
1347 strncpy(policy
->last_governor
, policy
->governor
->name
,
1350 policy
->last_policy
= policy
->policy
;
1351 } else if (cpu
== policy
->cpu
) {
1352 /* Nominate new CPU */
1353 policy
->cpu
= cpumask_any(policy
->cpus
);
1356 /* Start governor again for active policy */
1357 if (!policy_is_inactive(policy
)) {
1359 ret
= cpufreq_start_governor(policy
);
1361 pr_err("%s: Failed to start governor\n", __func__
);
1367 if (cpufreq_driver
->stop_cpu
)
1368 cpufreq_driver
->stop_cpu(policy
);
1371 cpufreq_exit_governor(policy
);
1374 * Perform the ->exit() even during light-weight tear-down,
1375 * since this is a core component, and is essential for the
1376 * subsequent light-weight ->init() to succeed.
1378 if (cpufreq_driver
->exit
) {
1379 cpufreq_driver
->exit(policy
);
1380 policy
->freq_table
= NULL
;
1384 up_write(&policy
->rwsem
);
1389 * cpufreq_remove_dev - remove a CPU device
1391 * Removes the cpufreq interface for a CPU device.
1393 static void cpufreq_remove_dev(struct device
*dev
, struct subsys_interface
*sif
)
1395 unsigned int cpu
= dev
->id
;
1396 struct cpufreq_policy
*policy
= per_cpu(cpufreq_cpu_data
, cpu
);
1401 if (cpu_online(cpu
))
1402 cpufreq_offline(cpu
);
1404 cpumask_clear_cpu(cpu
, policy
->real_cpus
);
1405 remove_cpu_dev_symlink(policy
, dev
);
1407 if (cpumask_empty(policy
->real_cpus
))
1408 cpufreq_policy_free(policy
, true);
1412 * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're
1414 * @policy: policy managing CPUs
1415 * @new_freq: CPU frequency the CPU actually runs at
1417 * We adjust to current frequency first, and need to clean up later.
1418 * So either call to cpufreq_update_policy() or schedule handle_update()).
1420 static void cpufreq_out_of_sync(struct cpufreq_policy
*policy
,
1421 unsigned int new_freq
)
1423 struct cpufreq_freqs freqs
;
1425 pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n",
1426 policy
->cur
, new_freq
);
1428 freqs
.old
= policy
->cur
;
1429 freqs
.new = new_freq
;
1431 cpufreq_freq_transition_begin(policy
, &freqs
);
1432 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1436 * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur
1439 * This is the last known freq, without actually getting it from the driver.
1440 * Return value will be same as what is shown in scaling_cur_freq in sysfs.
1442 unsigned int cpufreq_quick_get(unsigned int cpu
)
1444 struct cpufreq_policy
*policy
;
1445 unsigned int ret_freq
= 0;
1446 unsigned long flags
;
1448 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
1450 if (cpufreq_driver
&& cpufreq_driver
->setpolicy
&& cpufreq_driver
->get
) {
1451 ret_freq
= cpufreq_driver
->get(cpu
);
1452 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1456 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
1458 policy
= cpufreq_cpu_get(cpu
);
1460 ret_freq
= policy
->cur
;
1461 cpufreq_cpu_put(policy
);
1466 EXPORT_SYMBOL(cpufreq_quick_get
);
1469 * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU
1472 * Just return the max possible frequency for a given CPU.
1474 unsigned int cpufreq_quick_get_max(unsigned int cpu
)
1476 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1477 unsigned int ret_freq
= 0;
1480 ret_freq
= policy
->max
;
1481 cpufreq_cpu_put(policy
);
1486 EXPORT_SYMBOL(cpufreq_quick_get_max
);
1488 static unsigned int __cpufreq_get(struct cpufreq_policy
*policy
)
1490 unsigned int ret_freq
= 0;
1492 if (!cpufreq_driver
->get
)
1495 ret_freq
= cpufreq_driver
->get(policy
->cpu
);
1498 * Updating inactive policies is invalid, so avoid doing that. Also
1499 * if fast frequency switching is used with the given policy, the check
1500 * against policy->cur is pointless, so skip it in that case too.
1502 if (unlikely(policy_is_inactive(policy
)) || policy
->fast_switch_enabled
)
1505 if (ret_freq
&& policy
->cur
&&
1506 !(cpufreq_driver
->flags
& CPUFREQ_CONST_LOOPS
)) {
1507 /* verify no discrepancy between actual and
1508 saved value exists */
1509 if (unlikely(ret_freq
!= policy
->cur
)) {
1510 cpufreq_out_of_sync(policy
, ret_freq
);
1511 schedule_work(&policy
->update
);
1519 * cpufreq_get - get the current CPU frequency (in kHz)
1522 * Get the CPU current (static) CPU frequency
1524 unsigned int cpufreq_get(unsigned int cpu
)
1526 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
1527 unsigned int ret_freq
= 0;
1530 down_read(&policy
->rwsem
);
1532 if (!policy_is_inactive(policy
))
1533 ret_freq
= __cpufreq_get(policy
);
1535 up_read(&policy
->rwsem
);
1537 cpufreq_cpu_put(policy
);
1542 EXPORT_SYMBOL(cpufreq_get
);
1544 static unsigned int cpufreq_update_current_freq(struct cpufreq_policy
*policy
)
1546 unsigned int new_freq
;
1548 new_freq
= cpufreq_driver
->get(policy
->cpu
);
1553 pr_debug("cpufreq: Driver did not initialize current freq\n");
1554 policy
->cur
= new_freq
;
1555 } else if (policy
->cur
!= new_freq
&& has_target()) {
1556 cpufreq_out_of_sync(policy
, new_freq
);
1562 static struct subsys_interface cpufreq_interface
= {
1564 .subsys
= &cpu_subsys
,
1565 .add_dev
= cpufreq_add_dev
,
1566 .remove_dev
= cpufreq_remove_dev
,
1570 * In case platform wants some specific frequency to be configured
1573 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
)
1577 if (!policy
->suspend_freq
) {
1578 pr_debug("%s: suspend_freq not defined\n", __func__
);
1582 pr_debug("%s: Setting suspend-freq: %u\n", __func__
,
1583 policy
->suspend_freq
);
1585 ret
= __cpufreq_driver_target(policy
, policy
->suspend_freq
,
1586 CPUFREQ_RELATION_H
);
1588 pr_err("%s: unable to set suspend-freq: %u. err: %d\n",
1589 __func__
, policy
->suspend_freq
, ret
);
1593 EXPORT_SYMBOL(cpufreq_generic_suspend
);
1596 * cpufreq_suspend() - Suspend CPUFreq governors
1598 * Called during system wide Suspend/Hibernate cycles for suspending governors
1599 * as some platforms can't change frequency after this point in suspend cycle.
1600 * Because some of the devices (like: i2c, regulators, etc) they use for
1601 * changing frequency are suspended quickly after this point.
1603 void cpufreq_suspend(void)
1605 struct cpufreq_policy
*policy
;
1607 if (!cpufreq_driver
)
1610 if (!has_target() && !cpufreq_driver
->suspend
)
1613 pr_debug("%s: Suspending Governors\n", __func__
);
1615 for_each_active_policy(policy
) {
1617 down_write(&policy
->rwsem
);
1618 cpufreq_stop_governor(policy
);
1619 up_write(&policy
->rwsem
);
1622 if (cpufreq_driver
->suspend
&& cpufreq_driver
->suspend(policy
))
1623 pr_err("%s: Failed to suspend driver: %p\n", __func__
,
1628 cpufreq_suspended
= true;
1632 * cpufreq_resume() - Resume CPUFreq governors
1634 * Called during system wide Suspend/Hibernate cycle for resuming governors that
1635 * are suspended with cpufreq_suspend().
1637 void cpufreq_resume(void)
1639 struct cpufreq_policy
*policy
;
1642 if (!cpufreq_driver
)
1645 cpufreq_suspended
= false;
1647 if (!has_target() && !cpufreq_driver
->resume
)
1650 pr_debug("%s: Resuming Governors\n", __func__
);
1652 for_each_active_policy(policy
) {
1653 if (cpufreq_driver
->resume
&& cpufreq_driver
->resume(policy
)) {
1654 pr_err("%s: Failed to resume driver: %p\n", __func__
,
1656 } else if (has_target()) {
1657 down_write(&policy
->rwsem
);
1658 ret
= cpufreq_start_governor(policy
);
1659 up_write(&policy
->rwsem
);
1662 pr_err("%s: Failed to start governor for policy: %p\n",
1669 * cpufreq_get_current_driver - return current driver's name
1671 * Return the name string of the currently loaded cpufreq driver
1674 const char *cpufreq_get_current_driver(void)
1677 return cpufreq_driver
->name
;
1681 EXPORT_SYMBOL_GPL(cpufreq_get_current_driver
);
1684 * cpufreq_get_driver_data - return current driver data
1686 * Return the private data of the currently loaded cpufreq
1687 * driver, or NULL if no cpufreq driver is loaded.
1689 void *cpufreq_get_driver_data(void)
1692 return cpufreq_driver
->driver_data
;
1696 EXPORT_SYMBOL_GPL(cpufreq_get_driver_data
);
1698 /*********************************************************************
1699 * NOTIFIER LISTS INTERFACE *
1700 *********************************************************************/
1703 * cpufreq_register_notifier - register a driver with cpufreq
1704 * @nb: notifier function to register
1705 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1707 * Add a driver to one of two lists: either a list of drivers that
1708 * are notified about clock rate changes (once before and once after
1709 * the transition), or a list of drivers that are notified about
1710 * changes in cpufreq policy.
1712 * This function may sleep, and has the same return conditions as
1713 * blocking_notifier_chain_register.
1715 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
)
1719 if (cpufreq_disabled())
1722 WARN_ON(!init_cpufreq_transition_notifier_list_called
);
1725 case CPUFREQ_TRANSITION_NOTIFIER
:
1726 mutex_lock(&cpufreq_fast_switch_lock
);
1728 if (cpufreq_fast_switch_count
> 0) {
1729 mutex_unlock(&cpufreq_fast_switch_lock
);
1732 ret
= srcu_notifier_chain_register(
1733 &cpufreq_transition_notifier_list
, nb
);
1735 cpufreq_fast_switch_count
--;
1737 mutex_unlock(&cpufreq_fast_switch_lock
);
1739 case CPUFREQ_POLICY_NOTIFIER
:
1740 ret
= blocking_notifier_chain_register(
1741 &cpufreq_policy_notifier_list
, nb
);
1749 EXPORT_SYMBOL(cpufreq_register_notifier
);
1752 * cpufreq_unregister_notifier - unregister a driver with cpufreq
1753 * @nb: notifier block to be unregistered
1754 * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1756 * Remove a driver from the CPU frequency notifier list.
1758 * This function may sleep, and has the same return conditions as
1759 * blocking_notifier_chain_unregister.
1761 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
)
1765 if (cpufreq_disabled())
1769 case CPUFREQ_TRANSITION_NOTIFIER
:
1770 mutex_lock(&cpufreq_fast_switch_lock
);
1772 ret
= srcu_notifier_chain_unregister(
1773 &cpufreq_transition_notifier_list
, nb
);
1774 if (!ret
&& !WARN_ON(cpufreq_fast_switch_count
>= 0))
1775 cpufreq_fast_switch_count
++;
1777 mutex_unlock(&cpufreq_fast_switch_lock
);
1779 case CPUFREQ_POLICY_NOTIFIER
:
1780 ret
= blocking_notifier_chain_unregister(
1781 &cpufreq_policy_notifier_list
, nb
);
1789 EXPORT_SYMBOL(cpufreq_unregister_notifier
);
1792 /*********************************************************************
1794 *********************************************************************/
1797 * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch.
1798 * @policy: cpufreq policy to switch the frequency for.
1799 * @target_freq: New frequency to set (may be approximate).
1801 * Carry out a fast frequency switch without sleeping.
1803 * The driver's ->fast_switch() callback invoked by this function must be
1804 * suitable for being called from within RCU-sched read-side critical sections
1805 * and it is expected to select the minimum available frequency greater than or
1806 * equal to @target_freq (CPUFREQ_RELATION_L).
1808 * This function must not be called if policy->fast_switch_enabled is unset.
1810 * Governors calling this function must guarantee that it will never be invoked
1811 * twice in parallel for the same policy and that it will never be called in
1812 * parallel with either ->target() or ->target_index() for the same policy.
1814 * If CPUFREQ_ENTRY_INVALID is returned by the driver's ->fast_switch()
1815 * callback to indicate an error condition, the hardware configuration must be
1818 unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy
*policy
,
1819 unsigned int target_freq
)
1821 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1823 return cpufreq_driver
->fast_switch(policy
, target_freq
);
1825 EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch
);
1827 /* Must set freqs->new to intermediate frequency */
1828 static int __target_intermediate(struct cpufreq_policy
*policy
,
1829 struct cpufreq_freqs
*freqs
, int index
)
1833 freqs
->new = cpufreq_driver
->get_intermediate(policy
, index
);
1835 /* We don't need to switch to intermediate freq */
1839 pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n",
1840 __func__
, policy
->cpu
, freqs
->old
, freqs
->new);
1842 cpufreq_freq_transition_begin(policy
, freqs
);
1843 ret
= cpufreq_driver
->target_intermediate(policy
, index
);
1844 cpufreq_freq_transition_end(policy
, freqs
, ret
);
1847 pr_err("%s: Failed to change to intermediate frequency: %d\n",
1853 static int __target_index(struct cpufreq_policy
*policy
, int index
)
1855 struct cpufreq_freqs freqs
= {.old
= policy
->cur
, .flags
= 0};
1856 unsigned int intermediate_freq
= 0;
1857 unsigned int newfreq
= policy
->freq_table
[index
].frequency
;
1858 int retval
= -EINVAL
;
1861 if (newfreq
== policy
->cur
)
1864 notify
= !(cpufreq_driver
->flags
& CPUFREQ_ASYNC_NOTIFICATION
);
1866 /* Handle switching to intermediate frequency */
1867 if (cpufreq_driver
->get_intermediate
) {
1868 retval
= __target_intermediate(policy
, &freqs
, index
);
1872 intermediate_freq
= freqs
.new;
1873 /* Set old freq to intermediate */
1874 if (intermediate_freq
)
1875 freqs
.old
= freqs
.new;
1878 freqs
.new = newfreq
;
1879 pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
1880 __func__
, policy
->cpu
, freqs
.old
, freqs
.new);
1882 cpufreq_freq_transition_begin(policy
, &freqs
);
1885 retval
= cpufreq_driver
->target_index(policy
, index
);
1887 pr_err("%s: Failed to change cpu frequency: %d\n", __func__
,
1891 cpufreq_freq_transition_end(policy
, &freqs
, retval
);
1894 * Failed after setting to intermediate freq? Driver should have
1895 * reverted back to initial frequency and so should we. Check
1896 * here for intermediate_freq instead of get_intermediate, in
1897 * case we haven't switched to intermediate freq at all.
1899 if (unlikely(retval
&& intermediate_freq
)) {
1900 freqs
.old
= intermediate_freq
;
1901 freqs
.new = policy
->restore_freq
;
1902 cpufreq_freq_transition_begin(policy
, &freqs
);
1903 cpufreq_freq_transition_end(policy
, &freqs
, 0);
1910 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
1911 unsigned int target_freq
,
1912 unsigned int relation
)
1914 unsigned int old_target_freq
= target_freq
;
1917 if (cpufreq_disabled())
1920 /* Make sure that target_freq is within supported range */
1921 target_freq
= clamp_val(target_freq
, policy
->min
, policy
->max
);
1923 pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n",
1924 policy
->cpu
, target_freq
, relation
, old_target_freq
);
1927 * This might look like a redundant call as we are checking it again
1928 * after finding index. But it is left intentionally for cases where
1929 * exactly same freq is called again and so we can save on few function
1932 if (target_freq
== policy
->cur
)
1935 /* Save last value to restore later on errors */
1936 policy
->restore_freq
= policy
->cur
;
1938 if (cpufreq_driver
->target
)
1939 return cpufreq_driver
->target(policy
, target_freq
, relation
);
1941 if (!cpufreq_driver
->target_index
)
1944 index
= cpufreq_frequency_table_target(policy
, target_freq
, relation
);
1946 return __target_index(policy
, index
);
1948 EXPORT_SYMBOL_GPL(__cpufreq_driver_target
);
1950 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
1951 unsigned int target_freq
,
1952 unsigned int relation
)
1956 down_write(&policy
->rwsem
);
1958 ret
= __cpufreq_driver_target(policy
, target_freq
, relation
);
1960 up_write(&policy
->rwsem
);
1964 EXPORT_SYMBOL_GPL(cpufreq_driver_target
);
1966 __weak
struct cpufreq_governor
*cpufreq_fallback_governor(void)
1971 static int cpufreq_init_governor(struct cpufreq_policy
*policy
)
1975 /* Don't start any governor operations if we are entering suspend */
1976 if (cpufreq_suspended
)
1979 * Governor might not be initiated here if ACPI _PPC changed
1980 * notification happened, so check it.
1982 if (!policy
->governor
)
1985 if (policy
->governor
->max_transition_latency
&&
1986 policy
->cpuinfo
.transition_latency
>
1987 policy
->governor
->max_transition_latency
) {
1988 struct cpufreq_governor
*gov
= cpufreq_fallback_governor();
1991 pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n",
1992 policy
->governor
->name
, gov
->name
);
1993 policy
->governor
= gov
;
1999 if (!try_module_get(policy
->governor
->owner
))
2002 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2004 if (policy
->governor
->init
) {
2005 ret
= policy
->governor
->init(policy
);
2007 module_put(policy
->governor
->owner
);
2015 static void cpufreq_exit_governor(struct cpufreq_policy
*policy
)
2017 if (cpufreq_suspended
|| !policy
->governor
)
2020 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2022 if (policy
->governor
->exit
)
2023 policy
->governor
->exit(policy
);
2025 module_put(policy
->governor
->owner
);
2028 static int cpufreq_start_governor(struct cpufreq_policy
*policy
)
2032 if (cpufreq_suspended
)
2035 if (!policy
->governor
)
2038 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2040 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
)
2041 cpufreq_update_current_freq(policy
);
2043 if (policy
->governor
->start
) {
2044 ret
= policy
->governor
->start(policy
);
2049 if (policy
->governor
->limits
)
2050 policy
->governor
->limits(policy
);
2055 static void cpufreq_stop_governor(struct cpufreq_policy
*policy
)
2057 if (cpufreq_suspended
|| !policy
->governor
)
2060 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2062 if (policy
->governor
->stop
)
2063 policy
->governor
->stop(policy
);
2066 static void cpufreq_governor_limits(struct cpufreq_policy
*policy
)
2068 if (cpufreq_suspended
|| !policy
->governor
)
2071 pr_debug("%s: for CPU %u\n", __func__
, policy
->cpu
);
2073 if (policy
->governor
->limits
)
2074 policy
->governor
->limits(policy
);
2077 int cpufreq_register_governor(struct cpufreq_governor
*governor
)
2084 if (cpufreq_disabled())
2087 mutex_lock(&cpufreq_governor_mutex
);
2090 if (!find_governor(governor
->name
)) {
2092 list_add(&governor
->governor_list
, &cpufreq_governor_list
);
2095 mutex_unlock(&cpufreq_governor_mutex
);
2098 EXPORT_SYMBOL_GPL(cpufreq_register_governor
);
2100 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
)
2102 struct cpufreq_policy
*policy
;
2103 unsigned long flags
;
2108 if (cpufreq_disabled())
2111 /* clear last_governor for all inactive policies */
2112 read_lock_irqsave(&cpufreq_driver_lock
, flags
);
2113 for_each_inactive_policy(policy
) {
2114 if (!strcmp(policy
->last_governor
, governor
->name
)) {
2115 policy
->governor
= NULL
;
2116 strcpy(policy
->last_governor
, "\0");
2119 read_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2121 mutex_lock(&cpufreq_governor_mutex
);
2122 list_del(&governor
->governor_list
);
2123 mutex_unlock(&cpufreq_governor_mutex
);
2126 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor
);
2129 /*********************************************************************
2130 * POLICY INTERFACE *
2131 *********************************************************************/
2134 * cpufreq_get_policy - get the current cpufreq_policy
2135 * @policy: struct cpufreq_policy into which the current cpufreq_policy
2138 * Reads the current cpufreq policy.
2140 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
)
2142 struct cpufreq_policy
*cpu_policy
;
2146 cpu_policy
= cpufreq_cpu_get(cpu
);
2150 memcpy(policy
, cpu_policy
, sizeof(*policy
));
2152 cpufreq_cpu_put(cpu_policy
);
2155 EXPORT_SYMBOL(cpufreq_get_policy
);
2158 * policy : current policy.
2159 * new_policy: policy to be set.
2161 static int cpufreq_set_policy(struct cpufreq_policy
*policy
,
2162 struct cpufreq_policy
*new_policy
)
2164 struct cpufreq_governor
*old_gov
;
2167 pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
2168 new_policy
->cpu
, new_policy
->min
, new_policy
->max
);
2170 memcpy(&new_policy
->cpuinfo
, &policy
->cpuinfo
, sizeof(policy
->cpuinfo
));
2173 * This check works well when we store new min/max freq attributes,
2174 * because new_policy is a copy of policy with one field updated.
2176 if (new_policy
->min
> new_policy
->max
)
2179 /* verify the cpu speed can be set within this limit */
2180 ret
= cpufreq_driver
->verify(new_policy
);
2184 /* adjust if necessary - all reasons */
2185 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2186 CPUFREQ_ADJUST
, new_policy
);
2189 * verify the cpu speed can be set within this limit, which might be
2190 * different to the first one
2192 ret
= cpufreq_driver
->verify(new_policy
);
2196 /* notification of the new policy */
2197 blocking_notifier_call_chain(&cpufreq_policy_notifier_list
,
2198 CPUFREQ_NOTIFY
, new_policy
);
2200 policy
->min
= new_policy
->min
;
2201 policy
->max
= new_policy
->max
;
2203 policy
->cached_target_freq
= UINT_MAX
;
2205 pr_debug("new min and max freqs are %u - %u kHz\n",
2206 policy
->min
, policy
->max
);
2208 if (cpufreq_driver
->setpolicy
) {
2209 policy
->policy
= new_policy
->policy
;
2210 pr_debug("setting range\n");
2211 return cpufreq_driver
->setpolicy(new_policy
);
2214 if (new_policy
->governor
== policy
->governor
) {
2215 pr_debug("cpufreq: governor limits update\n");
2216 cpufreq_governor_limits(policy
);
2220 pr_debug("governor switch\n");
2222 /* save old, working values */
2223 old_gov
= policy
->governor
;
2224 /* end old governor */
2226 cpufreq_stop_governor(policy
);
2227 cpufreq_exit_governor(policy
);
2230 /* start new governor */
2231 policy
->governor
= new_policy
->governor
;
2232 ret
= cpufreq_init_governor(policy
);
2234 ret
= cpufreq_start_governor(policy
);
2236 pr_debug("cpufreq: governor change\n");
2239 cpufreq_exit_governor(policy
);
2242 /* new governor failed, so re-start old one */
2243 pr_debug("starting governor %s failed\n", policy
->governor
->name
);
2245 policy
->governor
= old_gov
;
2246 if (cpufreq_init_governor(policy
))
2247 policy
->governor
= NULL
;
2249 cpufreq_start_governor(policy
);
2256 * cpufreq_update_policy - re-evaluate an existing cpufreq policy
2257 * @cpu: CPU which shall be re-evaluated
2259 * Useful for policy notifiers which have different necessities
2260 * at different times.
2262 void cpufreq_update_policy(unsigned int cpu
)
2264 struct cpufreq_policy
*policy
= cpufreq_cpu_get(cpu
);
2265 struct cpufreq_policy new_policy
;
2270 down_write(&policy
->rwsem
);
2272 if (policy_is_inactive(policy
))
2275 pr_debug("updating policy for CPU %u\n", cpu
);
2276 memcpy(&new_policy
, policy
, sizeof(*policy
));
2277 new_policy
.min
= policy
->user_policy
.min
;
2278 new_policy
.max
= policy
->user_policy
.max
;
2281 * BIOS might change freq behind our back
2282 * -> ask driver for current freq and notify governors about a change
2284 if (cpufreq_driver
->get
&& !cpufreq_driver
->setpolicy
) {
2285 if (cpufreq_suspended
)
2288 new_policy
.cur
= cpufreq_update_current_freq(policy
);
2289 if (WARN_ON(!new_policy
.cur
))
2293 cpufreq_set_policy(policy
, &new_policy
);
2296 up_write(&policy
->rwsem
);
2298 cpufreq_cpu_put(policy
);
2300 EXPORT_SYMBOL(cpufreq_update_policy
);
2302 /*********************************************************************
2304 *********************************************************************/
2305 static int cpufreq_boost_set_sw(int state
)
2307 struct cpufreq_policy
*policy
;
2310 for_each_active_policy(policy
) {
2311 if (!policy
->freq_table
)
2314 ret
= cpufreq_frequency_table_cpuinfo(policy
,
2315 policy
->freq_table
);
2317 pr_err("%s: Policy frequency update failed\n",
2322 down_write(&policy
->rwsem
);
2323 policy
->user_policy
.max
= policy
->max
;
2324 cpufreq_governor_limits(policy
);
2325 up_write(&policy
->rwsem
);
2331 int cpufreq_boost_trigger_state(int state
)
2333 unsigned long flags
;
2336 if (cpufreq_driver
->boost_enabled
== state
)
2339 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2340 cpufreq_driver
->boost_enabled
= state
;
2341 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2343 ret
= cpufreq_driver
->set_boost(state
);
2345 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2346 cpufreq_driver
->boost_enabled
= !state
;
2347 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2349 pr_err("%s: Cannot %s BOOST\n",
2350 __func__
, state
? "enable" : "disable");
2356 static bool cpufreq_boost_supported(void)
2358 return likely(cpufreq_driver
) && cpufreq_driver
->set_boost
;
2361 static int create_boost_sysfs_file(void)
2365 ret
= sysfs_create_file(cpufreq_global_kobject
, &boost
.attr
);
2367 pr_err("%s: cannot register global BOOST sysfs file\n",
2373 static void remove_boost_sysfs_file(void)
2375 if (cpufreq_boost_supported())
2376 sysfs_remove_file(cpufreq_global_kobject
, &boost
.attr
);
2379 int cpufreq_enable_boost_support(void)
2381 if (!cpufreq_driver
)
2384 if (cpufreq_boost_supported())
2387 cpufreq_driver
->set_boost
= cpufreq_boost_set_sw
;
2389 /* This will get removed on driver unregister */
2390 return create_boost_sysfs_file();
2392 EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support
);
2394 int cpufreq_boost_enabled(void)
2396 return cpufreq_driver
->boost_enabled
;
2398 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled
);
2400 /*********************************************************************
2401 * REGISTER / UNREGISTER CPUFREQ DRIVER *
2402 *********************************************************************/
2403 static enum cpuhp_state hp_online
;
2405 static char cpufreq_driver_name
[CPUFREQ_NAME_LEN
];
2407 static int __init
cpufreq_driver_setup(char *str
)
2409 strlcpy(cpufreq_driver_name
, str
, CPUFREQ_NAME_LEN
);
2414 * Set this name to only allow one specific cpu freq driver, e.g.,
2415 * cpufreq_driver=powernow-k8
2417 __setup("cpufreq_driver=", cpufreq_driver_setup
);
2420 * cpufreq_register_driver - register a CPU Frequency driver
2421 * @driver_data: A struct cpufreq_driver containing the values#
2422 * submitted by the CPU Frequency driver.
2424 * Registers a CPU Frequency driver to this core code. This code
2425 * returns zero on success, -EEXIST when another driver got here first
2426 * (and isn't unregistered in the meantime).
2429 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
)
2431 unsigned long flags
;
2434 if (cpufreq_disabled())
2437 if (!driver_data
|| !driver_data
->verify
|| !driver_data
->init
||
2438 !(driver_data
->setpolicy
|| driver_data
->target_index
||
2439 driver_data
->target
) ||
2440 (driver_data
->setpolicy
&& (driver_data
->target_index
||
2441 driver_data
->target
)) ||
2442 (!!driver_data
->get_intermediate
!= !!driver_data
->target_intermediate
))
2445 pr_debug("trying to register driver %s, cpufreq_driver=%s\n",
2446 driver_data
->name
, cpufreq_driver_name
);
2448 if (cpufreq_driver_name
[0])
2449 if (!driver_data
->name
||
2450 strcmp(cpufreq_driver_name
, driver_data
->name
))
2453 /* Protect against concurrent CPU online/offline. */
2456 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2457 if (cpufreq_driver
) {
2458 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2462 cpufreq_driver
= driver_data
;
2463 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2465 if (driver_data
->setpolicy
)
2466 driver_data
->flags
|= CPUFREQ_CONST_LOOPS
;
2468 if (cpufreq_boost_supported()) {
2469 ret
= create_boost_sysfs_file();
2471 goto err_null_driver
;
2474 ret
= subsys_interface_register(&cpufreq_interface
);
2476 goto err_boost_unreg
;
2478 if (!(cpufreq_driver
->flags
& CPUFREQ_STICKY
) &&
2479 list_empty(&cpufreq_policy_list
)) {
2480 /* if all ->init() calls failed, unregister */
2481 pr_debug("%s: No CPU initialized for driver %s\n", __func__
,
2486 ret
= cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN
, "cpufreq:online",
2494 pr_debug("driver %s up and running\n", driver_data
->name
);
2498 subsys_interface_unregister(&cpufreq_interface
);
2500 remove_boost_sysfs_file();
2502 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2503 cpufreq_driver
= NULL
;
2504 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2509 EXPORT_SYMBOL_GPL(cpufreq_register_driver
);
2512 * cpufreq_unregister_driver - unregister the current CPUFreq driver
2514 * Unregister the current CPUFreq driver. Only call this if you have
2515 * the right to do so, i.e. if you have succeeded in initialising before!
2516 * Returns zero if successful, and -EINVAL if the cpufreq_driver is
2517 * currently not initialised.
2519 int cpufreq_unregister_driver(struct cpufreq_driver
*driver
)
2521 unsigned long flags
;
2523 if (!cpufreq_driver
|| (driver
!= cpufreq_driver
))
2526 pr_debug("unregistering driver %s\n", driver
->name
);
2528 /* Protect against concurrent cpu hotplug */
2530 subsys_interface_unregister(&cpufreq_interface
);
2531 remove_boost_sysfs_file();
2532 cpuhp_remove_state_nocalls(hp_online
);
2534 write_lock_irqsave(&cpufreq_driver_lock
, flags
);
2536 cpufreq_driver
= NULL
;
2538 write_unlock_irqrestore(&cpufreq_driver_lock
, flags
);
2543 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver
);
2546 * Stop cpufreq at shutdown to make sure it isn't holding any locks
2547 * or mutexes when secondary CPUs are halted.
2549 static struct syscore_ops cpufreq_syscore_ops
= {
2550 .shutdown
= cpufreq_suspend
,
2553 struct kobject
*cpufreq_global_kobject
;
2554 EXPORT_SYMBOL(cpufreq_global_kobject
);
2556 static int __init
cpufreq_core_init(void)
2558 if (cpufreq_disabled())
2561 cpufreq_global_kobject
= kobject_create_and_add("cpufreq", &cpu_subsys
.dev_root
->kobj
);
2562 BUG_ON(!cpufreq_global_kobject
);
2564 register_syscore_ops(&cpufreq_syscore_ops
);
2568 core_initcall(cpufreq_core_init
);