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
;
91 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
92 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
93 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
94 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
96 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
97 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
99 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
101 return cpumask_weight(policy
->cpus
) > 1;
104 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
105 extern struct kobject
*cpufreq_global_kobject
;
106 int cpufreq_get_global_kobject(void);
107 void cpufreq_put_global_kobject(void);
108 int cpufreq_sysfs_create_file(const struct attribute
*attr
);
109 void cpufreq_sysfs_remove_file(const struct attribute
*attr
);
111 #ifdef CONFIG_CPU_FREQ
112 unsigned int cpufreq_get(unsigned int cpu
);
113 unsigned int cpufreq_quick_get(unsigned int cpu
);
114 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
115 void disable_cpufreq(void);
117 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
118 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
119 int cpufreq_update_policy(unsigned int cpu
);
120 bool have_governor_per_policy(void);
121 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
123 static inline unsigned int cpufreq_get(unsigned int cpu
)
127 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
131 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
135 static inline void disable_cpufreq(void) { }
138 /*********************************************************************
139 * CPUFREQ DRIVER INTERFACE *
140 *********************************************************************/
142 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
143 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
146 struct attribute attr
;
147 ssize_t (*show
)(struct cpufreq_policy
*, char *);
148 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
151 #define cpufreq_freq_attr_ro(_name) \
152 static struct freq_attr _name = \
153 __ATTR(_name, 0444, show_##_name, NULL)
155 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
156 static struct freq_attr _name = \
157 __ATTR(_name, _perm, show_##_name, NULL)
159 #define cpufreq_freq_attr_rw(_name) \
160 static struct freq_attr _name = \
161 __ATTR(_name, 0644, show_##_name, store_##_name)
164 struct attribute attr
;
165 ssize_t (*show
)(struct kobject
*kobj
,
166 struct attribute
*attr
, char *buf
);
167 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
168 const char *c
, size_t count
);
171 #define define_one_global_ro(_name) \
172 static struct global_attr _name = \
173 __ATTR(_name, 0444, show_##_name, NULL)
175 #define define_one_global_rw(_name) \
176 static struct global_attr _name = \
177 __ATTR(_name, 0644, show_##_name, store_##_name)
180 struct cpufreq_driver
{
181 char name
[CPUFREQ_NAME_LEN
];
184 * This should be set by platforms having multiple clock-domains, i.e.
185 * supporting multiple policies. With this sysfs directories of governor
186 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
187 * use the same governor with different tunables for different clusters.
189 bool have_governor_per_policy
;
191 /* needed by all drivers */
192 int (*init
) (struct cpufreq_policy
*policy
);
193 int (*verify
) (struct cpufreq_policy
*policy
);
195 /* define one out of two */
196 int (*setpolicy
) (struct cpufreq_policy
*policy
);
197 int (*target
) (struct cpufreq_policy
*policy
,
198 unsigned int target_freq
,
199 unsigned int relation
);
201 /* should be defined, if possible */
202 unsigned int (*get
) (unsigned int cpu
);
205 int (*bios_limit
) (int cpu
, unsigned int *limit
);
207 int (*exit
) (struct cpufreq_policy
*policy
);
208 int (*suspend
) (struct cpufreq_policy
*policy
);
209 int (*resume
) (struct cpufreq_policy
*policy
);
210 struct freq_attr
**attr
;
214 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
215 * all ->init() calls failed */
216 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
217 * "constants" aren't affected by
218 * frequency transitions */
219 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
222 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
223 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
225 const char *cpufreq_get_current_driver(void);
227 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
228 unsigned int min
, unsigned int max
)
230 if (policy
->min
< min
)
232 if (policy
->max
< min
)
234 if (policy
->min
> max
)
236 if (policy
->max
> max
)
238 if (policy
->min
> policy
->max
)
239 policy
->min
= policy
->max
;
243 /*********************************************************************
244 * CPUFREQ NOTIFIER INTERFACE *
245 *********************************************************************/
247 #define CPUFREQ_TRANSITION_NOTIFIER (0)
248 #define CPUFREQ_POLICY_NOTIFIER (1)
250 /* Transition notifiers */
251 #define CPUFREQ_PRECHANGE (0)
252 #define CPUFREQ_POSTCHANGE (1)
253 #define CPUFREQ_RESUMECHANGE (8)
254 #define CPUFREQ_SUSPENDCHANGE (9)
256 /* Policy Notifiers */
257 #define CPUFREQ_ADJUST (0)
258 #define CPUFREQ_INCOMPATIBLE (1)
259 #define CPUFREQ_NOTIFY (2)
260 #define CPUFREQ_START (3)
261 #define CPUFREQ_UPDATE_POLICY_CPU (4)
263 #ifdef CONFIG_CPU_FREQ
264 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
265 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
267 void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
268 struct cpufreq_freqs
*freqs
, unsigned int state
);
270 #else /* CONFIG_CPU_FREQ */
271 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
276 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
281 #endif /* !CONFIG_CPU_FREQ */
284 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
291 * new = old * mult / div
293 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
296 #if BITS_PER_LONG == 32
297 u64 result
= ((u64
) old
) * ((u64
) mult
);
299 return (unsigned long) result
;
301 #elif BITS_PER_LONG == 64
302 unsigned long result
= old
* ((u64
) mult
);
308 /*********************************************************************
309 * CPUFREQ GOVERNORS *
310 *********************************************************************/
313 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
314 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
315 * two generic policies are available:
317 #define CPUFREQ_POLICY_POWERSAVE (1)
318 #define CPUFREQ_POLICY_PERFORMANCE (2)
320 /* Governor Events */
321 #define CPUFREQ_GOV_START 1
322 #define CPUFREQ_GOV_STOP 2
323 #define CPUFREQ_GOV_LIMITS 3
324 #define CPUFREQ_GOV_POLICY_INIT 4
325 #define CPUFREQ_GOV_POLICY_EXIT 5
327 struct cpufreq_governor
{
328 char name
[CPUFREQ_NAME_LEN
];
330 int (*governor
) (struct cpufreq_policy
*policy
,
332 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
334 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
336 unsigned int max_transition_latency
; /* HW must be able to switch to
337 next freq faster than this value in nano secs or we
338 will fallback to performance governor */
339 struct list_head governor_list
;
340 struct module
*owner
;
343 /* Pass a target to the cpufreq driver */
344 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
345 unsigned int target_freq
,
346 unsigned int relation
);
347 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
348 unsigned int target_freq
,
349 unsigned int relation
);
350 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
351 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
353 /* CPUFREQ DEFAULT GOVERNOR */
355 * Performance governor is fallback governor if any other gov failed to auto
356 * load due latency restrictions
358 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
359 extern struct cpufreq_governor cpufreq_gov_performance
;
361 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
362 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
364 extern struct cpufreq_governor cpufreq_gov_powersave
;
365 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
366 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
367 extern struct cpufreq_governor cpufreq_gov_userspace
;
368 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
369 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
370 extern struct cpufreq_governor cpufreq_gov_ondemand
;
371 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
372 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
373 extern struct cpufreq_governor cpufreq_gov_conservative
;
374 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
377 /*********************************************************************
378 * FREQUENCY TABLE HELPERS *
379 *********************************************************************/
381 #define CPUFREQ_ENTRY_INVALID ~0
382 #define CPUFREQ_TABLE_END ~1
384 struct cpufreq_frequency_table
{
385 unsigned int driver_data
; /* driver specific data, not used by core */
386 unsigned int frequency
; /* kHz - doesn't need to be in ascending
390 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
391 struct cpufreq_frequency_table
*table
);
393 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
394 struct cpufreq_frequency_table
*table
);
396 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
397 struct cpufreq_frequency_table
*table
,
398 unsigned int target_freq
,
399 unsigned int relation
,
400 unsigned int *index
);
402 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy
*policy
);
403 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
405 /* the following funtion is for cpufreq core use only */
406 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
408 /* the following are really really optional */
409 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
410 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
412 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
413 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
414 struct cpufreq_frequency_table
*table
);
416 #endif /* _LINUX_CPUFREQ_H */