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/cpumask.h>
15 #include <linux/completion.h>
16 #include <linux/kobject.h>
17 #include <linux/notifier.h>
18 #include <linux/sysfs.h>
20 /*********************************************************************
22 *********************************************************************/
24 * Frequency values here are CPU kHz
26 * Maximum transition latency is in nanoseconds - if it's unknown,
27 * CPUFREQ_ETERNAL shall be used.
30 #define CPUFREQ_ETERNAL (-1)
31 #define CPUFREQ_NAME_LEN 16
32 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
33 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
35 struct cpufreq_governor
;
37 struct cpufreq_freqs
{
38 unsigned int cpu
; /* cpu nr */
41 u8 flags
; /* flags of cpufreq_driver, see below. */
44 struct cpufreq_cpuinfo
{
45 unsigned int max_freq
;
46 unsigned int min_freq
;
48 /* in 10^(-9) s = nanoseconds */
49 unsigned int transition_latency
;
52 struct cpufreq_real_policy
{
53 unsigned int min
; /* in kHz */
54 unsigned int max
; /* in kHz */
55 unsigned int policy
; /* see above */
56 struct cpufreq_governor
*governor
; /* see below */
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 */
64 unsigned int shared_type
; /* ACPI: ANY or ALL affected CPUs
66 unsigned int cpu
; /* cpu nr of CPU managing this policy */
67 unsigned int last_cpu
; /* cpu nr of previous CPU that managed
69 struct cpufreq_cpuinfo cpuinfo
;/* see above */
71 unsigned int min
; /* in kHz */
72 unsigned int max
; /* in kHz */
73 unsigned int cur
; /* in kHz, only needed if cpufreq
74 * governors are used */
75 unsigned int policy
; /* see above */
76 struct cpufreq_governor
*governor
; /* see below */
78 bool governor_enabled
; /* governor start/stop flag */
80 struct work_struct update
; /* if update_policy() needs to be
81 * called, but you're in IRQ context */
83 struct cpufreq_real_policy user_policy
;
85 struct list_head policy_list
;
87 struct completion kobj_unregister
;
90 * The rules for this semaphore:
91 * - Any routine that wants to read from the policy structure will
92 * do a down_read on this semaphore.
93 * - Any routine that will write to the policy structure and/or may take away
94 * the policy altogether (eg. CPU hotplug), will hold this lock in write
95 * mode before doing so.
98 * - Lock should not be held across
99 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
101 struct rw_semaphore rwsem
;
105 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
106 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
107 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
108 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
110 #ifdef CONFIG_CPU_FREQ
111 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
112 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
114 static inline struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
118 static inline void cpufreq_cpu_put(struct cpufreq_policy
*policy
) { }
121 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
123 return cpumask_weight(policy
->cpus
) > 1;
126 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
127 extern struct kobject
*cpufreq_global_kobject
;
128 int cpufreq_get_global_kobject(void);
129 void cpufreq_put_global_kobject(void);
130 int cpufreq_sysfs_create_file(const struct attribute
*attr
);
131 void cpufreq_sysfs_remove_file(const struct attribute
*attr
);
133 #ifdef CONFIG_CPU_FREQ
134 unsigned int cpufreq_get(unsigned int cpu
);
135 unsigned int cpufreq_quick_get(unsigned int cpu
);
136 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
137 void disable_cpufreq(void);
139 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
140 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
141 int cpufreq_update_policy(unsigned int cpu
);
142 bool have_governor_per_policy(void);
143 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
145 static inline unsigned int cpufreq_get(unsigned int cpu
)
149 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
153 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
157 static inline void disable_cpufreq(void) { }
160 /*********************************************************************
161 * CPUFREQ DRIVER INTERFACE *
162 *********************************************************************/
164 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
165 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
168 struct attribute attr
;
169 ssize_t (*show
)(struct cpufreq_policy
*, char *);
170 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
173 #define cpufreq_freq_attr_ro(_name) \
174 static struct freq_attr _name = \
175 __ATTR(_name, 0444, show_##_name, NULL)
177 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
178 static struct freq_attr _name = \
179 __ATTR(_name, _perm, show_##_name, NULL)
181 #define cpufreq_freq_attr_rw(_name) \
182 static struct freq_attr _name = \
183 __ATTR(_name, 0644, show_##_name, store_##_name)
186 struct attribute attr
;
187 ssize_t (*show
)(struct kobject
*kobj
,
188 struct attribute
*attr
, char *buf
);
189 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
190 const char *c
, size_t count
);
193 #define define_one_global_ro(_name) \
194 static struct global_attr _name = \
195 __ATTR(_name, 0444, show_##_name, NULL)
197 #define define_one_global_rw(_name) \
198 static struct global_attr _name = \
199 __ATTR(_name, 0644, show_##_name, store_##_name)
202 struct cpufreq_driver
{
203 char name
[CPUFREQ_NAME_LEN
];
206 /* needed by all drivers */
207 int (*init
) (struct cpufreq_policy
*policy
);
208 int (*verify
) (struct cpufreq_policy
*policy
);
210 /* define one out of two */
211 int (*setpolicy
) (struct cpufreq_policy
*policy
);
212 int (*target
) (struct cpufreq_policy
*policy
, /* Deprecated */
213 unsigned int target_freq
,
214 unsigned int relation
);
215 int (*target_index
) (struct cpufreq_policy
*policy
,
218 /* should be defined, if possible */
219 unsigned int (*get
) (unsigned int cpu
);
222 int (*bios_limit
) (int cpu
, unsigned int *limit
);
224 int (*exit
) (struct cpufreq_policy
*policy
);
225 int (*suspend
) (struct cpufreq_policy
*policy
);
226 int (*resume
) (struct cpufreq_policy
*policy
);
227 struct freq_attr
**attr
;
231 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
232 all ->init() calls failed */
233 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
234 kernel "constants" aren't
235 affected by frequency
237 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
241 * This should be set by platforms having multiple clock-domains, i.e.
242 * supporting multiple policies. With this sysfs directories of governor would
243 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
244 * governor with different tunables for different clusters.
246 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
249 * Driver will do POSTCHANGE notifications from outside of their ->target()
250 * routine and so must set cpufreq_driver->flags with this flag, so that core
251 * can handle them specially.
253 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
255 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
256 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
258 const char *cpufreq_get_current_driver(void);
260 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
261 unsigned int min
, unsigned int max
)
263 if (policy
->min
< min
)
265 if (policy
->max
< min
)
267 if (policy
->min
> max
)
269 if (policy
->max
> max
)
271 if (policy
->min
> policy
->max
)
272 policy
->min
= policy
->max
;
277 cpufreq_verify_within_cpu_limits(struct cpufreq_policy
*policy
)
279 cpufreq_verify_within_limits(policy
, policy
->cpuinfo
.min_freq
,
280 policy
->cpuinfo
.max_freq
);
283 /*********************************************************************
284 * CPUFREQ NOTIFIER INTERFACE *
285 *********************************************************************/
287 #define CPUFREQ_TRANSITION_NOTIFIER (0)
288 #define CPUFREQ_POLICY_NOTIFIER (1)
290 /* Transition notifiers */
291 #define CPUFREQ_PRECHANGE (0)
292 #define CPUFREQ_POSTCHANGE (1)
293 #define CPUFREQ_RESUMECHANGE (8)
294 #define CPUFREQ_SUSPENDCHANGE (9)
296 /* Policy Notifiers */
297 #define CPUFREQ_ADJUST (0)
298 #define CPUFREQ_INCOMPATIBLE (1)
299 #define CPUFREQ_NOTIFY (2)
300 #define CPUFREQ_START (3)
301 #define CPUFREQ_UPDATE_POLICY_CPU (4)
303 #ifdef CONFIG_CPU_FREQ
304 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
305 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
307 void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
308 struct cpufreq_freqs
*freqs
, unsigned int state
);
310 #else /* CONFIG_CPU_FREQ */
311 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
316 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
321 #endif /* !CONFIG_CPU_FREQ */
324 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
331 * new = old * mult / div
333 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
336 #if BITS_PER_LONG == 32
337 u64 result
= ((u64
) old
) * ((u64
) mult
);
339 return (unsigned long) result
;
341 #elif BITS_PER_LONG == 64
342 unsigned long result
= old
* ((u64
) mult
);
348 /*********************************************************************
349 * CPUFREQ GOVERNORS *
350 *********************************************************************/
353 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
354 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
355 * two generic policies are available:
357 #define CPUFREQ_POLICY_POWERSAVE (1)
358 #define CPUFREQ_POLICY_PERFORMANCE (2)
360 /* Governor Events */
361 #define CPUFREQ_GOV_START 1
362 #define CPUFREQ_GOV_STOP 2
363 #define CPUFREQ_GOV_LIMITS 3
364 #define CPUFREQ_GOV_POLICY_INIT 4
365 #define CPUFREQ_GOV_POLICY_EXIT 5
367 struct cpufreq_governor
{
368 char name
[CPUFREQ_NAME_LEN
];
370 int (*governor
) (struct cpufreq_policy
*policy
,
372 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
374 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
376 unsigned int max_transition_latency
; /* HW must be able to switch to
377 next freq faster than this value in nano secs or we
378 will fallback to performance governor */
379 struct list_head governor_list
;
380 struct module
*owner
;
383 /* Pass a target to the cpufreq driver */
384 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
385 unsigned int target_freq
,
386 unsigned int relation
);
387 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
388 unsigned int target_freq
,
389 unsigned int relation
);
390 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
391 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
393 /* CPUFREQ DEFAULT GOVERNOR */
395 * Performance governor is fallback governor if any other gov failed to auto
396 * load due latency restrictions
398 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
399 extern struct cpufreq_governor cpufreq_gov_performance
;
401 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
402 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
403 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
404 extern struct cpufreq_governor cpufreq_gov_powersave
;
405 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
406 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
407 extern struct cpufreq_governor cpufreq_gov_userspace
;
408 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
409 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
410 extern struct cpufreq_governor cpufreq_gov_ondemand
;
411 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
412 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
413 extern struct cpufreq_governor cpufreq_gov_conservative
;
414 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
417 /*********************************************************************
418 * FREQUENCY TABLE HELPERS *
419 *********************************************************************/
421 #define CPUFREQ_ENTRY_INVALID ~0
422 #define CPUFREQ_TABLE_END ~1
424 struct cpufreq_frequency_table
{
425 unsigned int driver_data
; /* driver specific data, not used by core */
426 unsigned int frequency
; /* kHz - doesn't need to be in ascending
430 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
431 struct cpufreq_frequency_table
*table
);
433 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
434 struct cpufreq_frequency_table
*table
);
435 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy
*policy
);
437 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
438 struct cpufreq_frequency_table
*table
,
439 unsigned int target_freq
,
440 unsigned int relation
,
441 unsigned int *index
);
443 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy
*policy
);
444 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
446 /* the following funtion is for cpufreq core use only */
447 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
449 /* the following are really really optional */
450 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
451 extern struct freq_attr
*cpufreq_generic_attr
[];
452 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
454 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
455 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
456 struct cpufreq_frequency_table
*table
);
458 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
459 struct cpufreq_frequency_table
*table
,
460 unsigned int transition_latency
);
461 static inline int cpufreq_generic_exit(struct cpufreq_policy
*policy
)
463 cpufreq_frequency_table_put_attr(policy
->cpu
);
467 #endif /* _LINUX_CPUFREQ_H */