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
;
88 int transition_ongoing
; /* Tracks transition status */
92 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
93 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
94 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
95 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
97 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
98 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
100 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
102 return cpumask_weight(policy
->cpus
) > 1;
105 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
106 extern struct kobject
*cpufreq_global_kobject
;
107 int cpufreq_get_global_kobject(void);
108 void cpufreq_put_global_kobject(void);
109 int cpufreq_sysfs_create_file(const struct attribute
*attr
);
110 void cpufreq_sysfs_remove_file(const struct attribute
*attr
);
112 #ifdef CONFIG_CPU_FREQ
113 unsigned int cpufreq_get(unsigned int cpu
);
114 unsigned int cpufreq_quick_get(unsigned int cpu
);
115 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
116 void disable_cpufreq(void);
118 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
119 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
120 int cpufreq_update_policy(unsigned int cpu
);
121 bool have_governor_per_policy(void);
122 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
124 static inline unsigned int cpufreq_get(unsigned int cpu
)
128 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
132 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
136 static inline void disable_cpufreq(void) { }
139 /*********************************************************************
140 * CPUFREQ DRIVER INTERFACE *
141 *********************************************************************/
143 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
144 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
147 struct attribute attr
;
148 ssize_t (*show
)(struct cpufreq_policy
*, char *);
149 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
152 #define cpufreq_freq_attr_ro(_name) \
153 static struct freq_attr _name = \
154 __ATTR(_name, 0444, show_##_name, NULL)
156 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
157 static struct freq_attr _name = \
158 __ATTR(_name, _perm, show_##_name, NULL)
160 #define cpufreq_freq_attr_rw(_name) \
161 static struct freq_attr _name = \
162 __ATTR(_name, 0644, show_##_name, store_##_name)
165 struct attribute attr
;
166 ssize_t (*show
)(struct kobject
*kobj
,
167 struct attribute
*attr
, char *buf
);
168 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
169 const char *c
, size_t count
);
172 #define define_one_global_ro(_name) \
173 static struct global_attr _name = \
174 __ATTR(_name, 0444, show_##_name, NULL)
176 #define define_one_global_rw(_name) \
177 static struct global_attr _name = \
178 __ATTR(_name, 0644, show_##_name, store_##_name)
181 struct cpufreq_driver
{
182 char name
[CPUFREQ_NAME_LEN
];
185 * This should be set by platforms having multiple clock-domains, i.e.
186 * supporting multiple policies. With this sysfs directories of governor
187 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
188 * use the same governor with different tunables for different clusters.
190 bool have_governor_per_policy
;
192 /* needed by all drivers */
193 int (*init
) (struct cpufreq_policy
*policy
);
194 int (*verify
) (struct cpufreq_policy
*policy
);
196 /* define one out of two */
197 int (*setpolicy
) (struct cpufreq_policy
*policy
);
198 int (*target
) (struct cpufreq_policy
*policy
,
199 unsigned int target_freq
,
200 unsigned int relation
);
202 /* should be defined, if possible */
203 unsigned int (*get
) (unsigned int cpu
);
206 int (*bios_limit
) (int cpu
, unsigned int *limit
);
208 int (*exit
) (struct cpufreq_policy
*policy
);
209 int (*suspend
) (struct cpufreq_policy
*policy
);
210 int (*resume
) (struct cpufreq_policy
*policy
);
211 struct freq_attr
**attr
;
215 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
216 * all ->init() calls failed */
217 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
218 * "constants" aren't affected by
219 * frequency transitions */
220 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
223 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
224 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
226 const char *cpufreq_get_current_driver(void);
228 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
229 unsigned int min
, unsigned int max
)
231 if (policy
->min
< min
)
233 if (policy
->max
< min
)
235 if (policy
->min
> max
)
237 if (policy
->max
> max
)
239 if (policy
->min
> policy
->max
)
240 policy
->min
= policy
->max
;
244 /*********************************************************************
245 * CPUFREQ NOTIFIER INTERFACE *
246 *********************************************************************/
248 #define CPUFREQ_TRANSITION_NOTIFIER (0)
249 #define CPUFREQ_POLICY_NOTIFIER (1)
251 /* Transition notifiers */
252 #define CPUFREQ_PRECHANGE (0)
253 #define CPUFREQ_POSTCHANGE (1)
254 #define CPUFREQ_RESUMECHANGE (8)
255 #define CPUFREQ_SUSPENDCHANGE (9)
257 /* Policy Notifiers */
258 #define CPUFREQ_ADJUST (0)
259 #define CPUFREQ_INCOMPATIBLE (1)
260 #define CPUFREQ_NOTIFY (2)
261 #define CPUFREQ_START (3)
262 #define CPUFREQ_UPDATE_POLICY_CPU (4)
264 #ifdef CONFIG_CPU_FREQ
265 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
266 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
268 void cpufreq_notify_transition(struct cpufreq_policy
*policy
,
269 struct cpufreq_freqs
*freqs
, unsigned int state
);
271 #else /* CONFIG_CPU_FREQ */
272 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
277 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
282 #endif /* !CONFIG_CPU_FREQ */
285 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
292 * new = old * mult / div
294 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
297 #if BITS_PER_LONG == 32
298 u64 result
= ((u64
) old
) * ((u64
) mult
);
300 return (unsigned long) result
;
302 #elif BITS_PER_LONG == 64
303 unsigned long result
= old
* ((u64
) mult
);
309 /*********************************************************************
310 * CPUFREQ GOVERNORS *
311 *********************************************************************/
314 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
315 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
316 * two generic policies are available:
318 #define CPUFREQ_POLICY_POWERSAVE (1)
319 #define CPUFREQ_POLICY_PERFORMANCE (2)
321 /* Governor Events */
322 #define CPUFREQ_GOV_START 1
323 #define CPUFREQ_GOV_STOP 2
324 #define CPUFREQ_GOV_LIMITS 3
325 #define CPUFREQ_GOV_POLICY_INIT 4
326 #define CPUFREQ_GOV_POLICY_EXIT 5
328 struct cpufreq_governor
{
329 char name
[CPUFREQ_NAME_LEN
];
331 int (*governor
) (struct cpufreq_policy
*policy
,
333 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
335 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
337 unsigned int max_transition_latency
; /* HW must be able to switch to
338 next freq faster than this value in nano secs or we
339 will fallback to performance governor */
340 struct list_head governor_list
;
341 struct module
*owner
;
344 /* Pass a target to the cpufreq driver */
345 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
346 unsigned int target_freq
,
347 unsigned int relation
);
348 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
349 unsigned int target_freq
,
350 unsigned int relation
);
351 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
352 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
354 /* CPUFREQ DEFAULT GOVERNOR */
356 * Performance governor is fallback governor if any other gov failed to auto
357 * load due latency restrictions
359 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
360 extern struct cpufreq_governor cpufreq_gov_performance
;
362 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
363 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
365 extern struct cpufreq_governor cpufreq_gov_powersave
;
366 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
367 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
368 extern struct cpufreq_governor cpufreq_gov_userspace
;
369 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
370 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
371 extern struct cpufreq_governor cpufreq_gov_ondemand
;
372 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
373 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
374 extern struct cpufreq_governor cpufreq_gov_conservative
;
375 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
378 /*********************************************************************
379 * FREQUENCY TABLE HELPERS *
380 *********************************************************************/
382 #define CPUFREQ_ENTRY_INVALID ~0
383 #define CPUFREQ_TABLE_END ~1
385 struct cpufreq_frequency_table
{
386 unsigned int driver_data
; /* driver specific data, not used by core */
387 unsigned int frequency
; /* kHz - doesn't need to be in ascending
391 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
392 struct cpufreq_frequency_table
*table
);
394 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
395 struct cpufreq_frequency_table
*table
);
397 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
398 struct cpufreq_frequency_table
*table
,
399 unsigned int target_freq
,
400 unsigned int relation
,
401 unsigned int *index
);
403 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy
*policy
);
404 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
406 /* the following funtion is for cpufreq core use only */
407 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
409 /* the following are really really optional */
410 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
411 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
413 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
415 #endif /* _LINUX_CPUFREQ_H */