2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
14 #include <linux/clk.h>
15 #include <linux/cpumask.h>
16 #include <linux/completion.h>
17 #include <linux/kobject.h>
18 #include <linux/notifier.h>
19 #include <linux/spinlock.h>
20 #include <linux/sysfs.h>
22 /*********************************************************************
24 *********************************************************************/
26 * Frequency values here are CPU kHz
28 * Maximum transition latency is in nanoseconds - if it's unknown,
29 * CPUFREQ_ETERNAL shall be used.
32 #define CPUFREQ_ETERNAL (-1)
33 #define CPUFREQ_NAME_LEN 16
34 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
35 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
37 struct cpufreq_governor;
39 struct cpufreq_freqs {
40 unsigned int cpu; /* cpu nr */
43 u8 flags; /* flags of cpufreq_driver, see below. */
46 struct cpufreq_cpuinfo {
47 unsigned int max_freq;
48 unsigned int min_freq;
50 /* in 10^(-9) s = nanoseconds */
51 unsigned int transition_latency;
54 struct cpufreq_user_policy {
55 unsigned int min; /* in kHz */
56 unsigned int max; /* in kHz */
59 struct cpufreq_policy {
60 /* CPUs sharing clock, require sw coordination */
61 cpumask_var_t cpus; /* Online CPUs only */
62 cpumask_var_t related_cpus; /* Online + Offline CPUs */
63 cpumask_var_t real_cpus; /* Related and present */
65 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
67 unsigned int cpu; /* cpu managing this policy, must be online */
70 struct cpufreq_cpuinfo cpuinfo;/* see above */
72 unsigned int min; /* in kHz */
73 unsigned int max; /* in kHz */
74 unsigned int cur; /* in kHz, only needed if cpufreq
75 * governors are used */
76 unsigned int restore_freq; /* = policy->cur before transition */
77 unsigned int suspend_freq; /* freq to set during suspend */
79 unsigned int policy; /* see above */
80 unsigned int last_policy; /* policy before unplug */
81 struct cpufreq_governor *governor; /* see below */
83 bool governor_enabled; /* governor start/stop flag */
84 char last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
86 struct work_struct update; /* if update_policy() needs to be
87 * called, but you're in IRQ context */
89 struct cpufreq_user_policy user_policy;
90 struct cpufreq_frequency_table *freq_table;
92 struct list_head policy_list;
94 struct completion kobj_unregister;
97 * The rules for this semaphore:
98 * - Any routine that wants to read from the policy structure will
99 * do a down_read on this semaphore.
100 * - Any routine that will write to the policy structure and/or may take away
101 * the policy altogether (eg. CPU hotplug), will hold this lock in write
102 * mode before doing so.
105 * - Lock should not be held across
106 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
108 struct rw_semaphore rwsem;
110 /* Synchronization for frequency transitions */
111 bool transition_ongoing; /* Tracks transition status */
112 spinlock_t transition_lock;
113 wait_queue_head_t transition_wait;
114 struct task_struct *transition_task; /* Task which is doing the transition */
117 struct cpufreq_stats *stats;
119 /* For cpufreq driver's internal use */
124 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
125 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
126 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
127 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
129 #ifdef CONFIG_CPU_FREQ
130 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
131 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
132 void cpufreq_cpu_put(struct cpufreq_policy *policy);
134 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
138 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
142 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
145 static inline bool policy_is_shared(struct cpufreq_policy *policy)
147 return cpumask_weight(policy->cpus) > 1;
150 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
151 extern struct kobject *cpufreq_global_kobject;
153 #ifdef CONFIG_CPU_FREQ
154 unsigned int cpufreq_get(unsigned int cpu);
155 unsigned int cpufreq_quick_get(unsigned int cpu);
156 unsigned int cpufreq_quick_get_max(unsigned int cpu);
157 void disable_cpufreq(void);
159 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
160 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
161 int cpufreq_update_policy(unsigned int cpu);
162 bool have_governor_per_policy(void);
163 bool cpufreq_driver_is_slow(void);
164 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
166 static inline unsigned int cpufreq_get(unsigned int cpu)
170 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
174 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
178 static inline void disable_cpufreq(void) { }
181 /*********************************************************************
182 * CPUFREQ DRIVER INTERFACE *
183 *********************************************************************/
185 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
186 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
187 #define CPUFREQ_RELATION_C 2 /* closest frequency to target */
190 struct attribute attr;
191 ssize_t (*show)(struct cpufreq_policy *, char *);
192 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
195 #define cpufreq_freq_attr_ro(_name) \
196 static struct freq_attr _name = \
197 __ATTR(_name, 0444, show_##_name, NULL)
199 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
200 static struct freq_attr _name = \
201 __ATTR(_name, _perm, show_##_name, NULL)
203 #define cpufreq_freq_attr_rw(_name) \
204 static struct freq_attr _name = \
205 __ATTR(_name, 0644, show_##_name, store_##_name)
208 struct attribute attr;
209 ssize_t (*show)(struct kobject *kobj,
210 struct attribute *attr, char *buf);
211 ssize_t (*store)(struct kobject *a, struct attribute *b,
212 const char *c, size_t count);
215 #define define_one_global_ro(_name) \
216 static struct global_attr _name = \
217 __ATTR(_name, 0444, show_##_name, NULL)
219 #define define_one_global_rw(_name) \
220 static struct global_attr _name = \
221 __ATTR(_name, 0644, show_##_name, store_##_name)
224 struct cpufreq_driver {
225 char name[CPUFREQ_NAME_LEN];
229 /* needed by all drivers */
230 int (*init)(struct cpufreq_policy *policy);
231 int (*verify)(struct cpufreq_policy *policy);
233 /* define one out of two */
234 int (*setpolicy)(struct cpufreq_policy *policy);
237 * On failure, should always restore frequency to policy->restore_freq
240 int (*target)(struct cpufreq_policy *policy,
241 unsigned int target_freq,
242 unsigned int relation); /* Deprecated */
243 int (*target_index)(struct cpufreq_policy *policy,
246 * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
249 * get_intermediate should return a stable intermediate frequency
250 * platform wants to switch to and target_intermediate() should set CPU
251 * to to that frequency, before jumping to the frequency corresponding
252 * to 'index'. Core will take care of sending notifications and driver
253 * doesn't have to handle them in target_intermediate() or
256 * Drivers can return '0' from get_intermediate() in case they don't
257 * wish to switch to intermediate frequency for some target frequency.
258 * In that case core will directly call ->target_index().
260 unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
262 int (*target_intermediate)(struct cpufreq_policy *policy,
265 /* should be defined, if possible */
266 unsigned int (*get)(unsigned int cpu);
269 int (*bios_limit)(int cpu, unsigned int *limit);
271 int (*exit)(struct cpufreq_policy *policy);
272 void (*stop_cpu)(struct cpufreq_policy *policy);
273 int (*suspend)(struct cpufreq_policy *policy);
274 int (*resume)(struct cpufreq_policy *policy);
276 /* Will be called after the driver is fully initialized */
277 void (*ready)(struct cpufreq_policy *policy);
279 struct freq_attr **attr;
281 /* platform specific boost support code */
282 bool boost_supported;
284 int (*set_boost)(int state);
288 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
289 all ->init() calls failed */
290 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
291 kernel "constants" aren't
292 affected by frequency
294 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
298 * This should be set by platforms having multiple clock-domains, i.e.
299 * supporting multiple policies. With this sysfs directories of governor would
300 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
301 * governor with different tunables for different clusters.
303 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
306 * Driver will do POSTCHANGE notifications from outside of their ->target()
307 * routine and so must set cpufreq_driver->flags with this flag, so that core
308 * can handle them specially.
310 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
313 * Set by drivers which want cpufreq core to check if CPU is running at a
314 * frequency present in freq-table exposed by the driver. For these drivers if
315 * CPU is found running at an out of table freq, we will try to set it to a freq
316 * from the table. And if that fails, we will stop further boot process by
317 * issuing a BUG_ON().
319 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
322 * Indicates that it is safe to call cpufreq_driver_target from
323 * non-interruptable context in scheduler hot paths. Drivers must
324 * opt-in to this flag, as the safe default is that they might sleep
325 * or be too slow for hot path use.
327 #define CPUFREQ_DRIVER_FAST (1 << 6)
329 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
330 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
332 const char *cpufreq_get_current_driver(void);
333 void *cpufreq_get_driver_data(void);
335 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
336 unsigned int min, unsigned int max)
338 if (policy->min < min)
340 if (policy->max < min)
342 if (policy->min > max)
344 if (policy->max > max)
346 if (policy->min > policy->max)
347 policy->min = policy->max;
352 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
354 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
355 policy->cpuinfo.max_freq);
358 #ifdef CONFIG_CPU_FREQ
359 void cpufreq_suspend(void);
360 void cpufreq_resume(void);
361 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
363 static inline void cpufreq_suspend(void) {}
364 static inline void cpufreq_resume(void) {}
367 /*********************************************************************
368 * CPUFREQ NOTIFIER INTERFACE *
369 *********************************************************************/
371 #define CPUFREQ_TRANSITION_NOTIFIER (0)
372 #define CPUFREQ_POLICY_NOTIFIER (1)
374 /* Transition notifiers */
375 #define CPUFREQ_PRECHANGE (0)
376 #define CPUFREQ_POSTCHANGE (1)
378 /* Policy Notifiers */
379 #define CPUFREQ_ADJUST (0)
380 #define CPUFREQ_NOTIFY (1)
381 #define CPUFREQ_START (2)
382 #define CPUFREQ_CREATE_POLICY (3)
383 #define CPUFREQ_REMOVE_POLICY (4)
385 #ifdef CONFIG_CPU_FREQ
386 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
387 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
389 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
390 struct cpufreq_freqs *freqs);
391 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
392 struct cpufreq_freqs *freqs, int transition_failed);
394 #else /* CONFIG_CPU_FREQ */
395 static inline int cpufreq_register_notifier(struct notifier_block *nb,
400 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
405 #endif /* !CONFIG_CPU_FREQ */
408 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
415 * new = old * mult / div
417 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
420 #if BITS_PER_LONG == 32
421 u64 result = ((u64) old) * ((u64) mult);
423 return (unsigned long) result;
425 #elif BITS_PER_LONG == 64
426 unsigned long result = old * ((u64) mult);
432 /*********************************************************************
433 * CPUFREQ GOVERNORS *
434 *********************************************************************/
437 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
438 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
439 * two generic policies are available:
441 #define CPUFREQ_POLICY_POWERSAVE (1)
442 #define CPUFREQ_POLICY_PERFORMANCE (2)
444 /* Governor Events */
445 #define CPUFREQ_GOV_START 1
446 #define CPUFREQ_GOV_STOP 2
447 #define CPUFREQ_GOV_LIMITS 3
448 #define CPUFREQ_GOV_POLICY_INIT 4
449 #define CPUFREQ_GOV_POLICY_EXIT 5
451 struct cpufreq_governor {
452 char name[CPUFREQ_NAME_LEN];
454 int (*governor) (struct cpufreq_policy *policy,
456 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
458 int (*store_setspeed) (struct cpufreq_policy *policy,
460 unsigned int max_transition_latency; /* HW must be able to switch to
461 next freq faster than this value in nano secs or we
462 will fallback to performance governor */
463 struct list_head governor_list;
464 struct module *owner;
467 /* Pass a target to the cpufreq driver */
468 int cpufreq_driver_target(struct cpufreq_policy *policy,
469 unsigned int target_freq,
470 unsigned int relation);
471 int __cpufreq_driver_target(struct cpufreq_policy *policy,
472 unsigned int target_freq,
473 unsigned int relation);
474 int cpufreq_register_governor(struct cpufreq_governor *governor);
475 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
477 /* CPUFREQ DEFAULT GOVERNOR */
479 * Performance governor is fallback governor if any other gov failed to auto
480 * load due latency restrictions
482 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
483 extern struct cpufreq_governor cpufreq_gov_performance;
485 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
486 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
487 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
488 extern struct cpufreq_governor cpufreq_gov_powersave;
489 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
490 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
491 extern struct cpufreq_governor cpufreq_gov_userspace;
492 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
493 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
494 extern struct cpufreq_governor cpufreq_gov_ondemand;
495 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
496 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
497 extern struct cpufreq_governor cpufreq_gov_conservative;
498 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
499 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE)
500 extern struct cpufreq_governor cpufreq_gov_interactive;
501 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_interactive)
502 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_SCHED)
503 extern struct cpufreq_governor cpufreq_gov_sched;
504 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_sched)
507 /*********************************************************************
508 * FREQUENCY TABLE HELPERS *
509 *********************************************************************/
511 /* Special Values of .frequency field */
512 #define CPUFREQ_ENTRY_INVALID ~0u
513 #define CPUFREQ_TABLE_END ~1u
514 /* Special Values of .flags field */
515 #define CPUFREQ_BOOST_FREQ (1 << 0)
517 struct cpufreq_frequency_table {
519 unsigned int driver_data; /* driver specific data, not used by core */
520 unsigned int frequency; /* kHz - doesn't need to be in ascending
524 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
525 int dev_pm_opp_init_cpufreq_table(struct device *dev,
526 struct cpufreq_frequency_table **table);
527 void dev_pm_opp_free_cpufreq_table(struct device *dev,
528 struct cpufreq_frequency_table **table);
530 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
531 struct cpufreq_frequency_table
537 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
538 struct cpufreq_frequency_table
544 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
546 while ((*pos)->frequency != CPUFREQ_TABLE_END)
547 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
555 * cpufreq_for_each_entry - iterate over a cpufreq_frequency_table
556 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
557 * @table: the cpufreq_frequency_table * to iterate over.
560 #define cpufreq_for_each_entry(pos, table) \
561 for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
564 * cpufreq_for_each_valid_entry - iterate over a cpufreq_frequency_table
565 * excluding CPUFREQ_ENTRY_INVALID frequencies.
566 * @pos: the cpufreq_frequency_table * to use as a loop cursor.
567 * @table: the cpufreq_frequency_table * to iterate over.
570 #define cpufreq_for_each_valid_entry(pos, table) \
571 for (pos = table; cpufreq_next_valid(&pos); pos++)
573 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
574 struct cpufreq_frequency_table *table);
576 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
577 struct cpufreq_frequency_table *table);
578 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
580 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
581 struct cpufreq_frequency_table *table,
582 unsigned int target_freq,
583 unsigned int relation,
584 unsigned int *index);
585 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
588 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
590 #ifdef CONFIG_CPU_FREQ
591 int cpufreq_boost_trigger_state(int state);
592 int cpufreq_boost_supported(void);
593 int cpufreq_boost_enabled(void);
594 int cpufreq_enable_boost_support(void);
595 bool policy_has_boost_freq(struct cpufreq_policy *policy);
597 static inline int cpufreq_boost_trigger_state(int state)
601 static inline int cpufreq_boost_supported(void)
605 static inline int cpufreq_boost_enabled(void)
610 static inline int cpufreq_enable_boost_support(void)
615 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
620 /* the following funtion is for cpufreq core use only */
621 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
623 /* the following are really really optional */
624 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
625 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
626 extern struct freq_attr *cpufreq_generic_attr[];
627 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
628 struct cpufreq_frequency_table *table);
630 unsigned int cpufreq_generic_get(unsigned int cpu);
631 int cpufreq_generic_init(struct cpufreq_policy *policy,
632 struct cpufreq_frequency_table *table,
633 unsigned int transition_latency);
636 unsigned long cpufreq_scale_freq_capacity(struct sched_domain *sd, int cpu);
637 unsigned long cpufreq_scale_max_freq_capacity(int cpu);
638 #endif /* _LINUX_CPUFREQ_H */