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_real_policy
{
55 unsigned int min
; /* in kHz */
56 unsigned int max
; /* in kHz */
57 unsigned int policy
; /* see above */
58 struct cpufreq_governor
*governor
; /* see below */
61 struct cpufreq_policy
{
62 /* CPUs sharing clock, require sw coordination */
63 cpumask_var_t cpus
; /* Online CPUs only */
64 cpumask_var_t related_cpus
; /* Online + Offline CPUs */
66 unsigned int shared_type
; /* ACPI: ANY or ALL affected CPUs
68 unsigned int cpu
; /* cpu nr of CPU managing this policy */
69 unsigned int last_cpu
; /* cpu nr of previous CPU that managed
72 struct cpufreq_cpuinfo cpuinfo
;/* see above */
74 unsigned int min
; /* in kHz */
75 unsigned int max
; /* in kHz */
76 unsigned int cur
; /* in kHz, only needed if cpufreq
77 * governors are used */
78 unsigned int suspend_freq
; /* freq to set during suspend */
80 unsigned int policy
; /* see above */
81 struct cpufreq_governor
*governor
; /* see below */
83 bool governor_enabled
; /* governor start/stop flag */
85 struct work_struct update
; /* if update_policy() needs to be
86 * called, but you're in IRQ context */
88 struct cpufreq_real_policy user_policy
;
89 struct cpufreq_frequency_table
*freq_table
;
91 struct list_head policy_list
;
93 struct completion kobj_unregister
;
96 * The rules for this semaphore:
97 * - Any routine that wants to read from the policy structure will
98 * do a down_read on this semaphore.
99 * - Any routine that will write to the policy structure and/or may take away
100 * the policy altogether (eg. CPU hotplug), will hold this lock in write
101 * mode before doing so.
104 * - Lock should not be held across
105 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
107 struct rw_semaphore rwsem
;
109 /* Synchronization for frequency transitions */
110 bool transition_ongoing
; /* Tracks transition status */
111 spinlock_t transition_lock
;
112 wait_queue_head_t transition_wait
;
116 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
117 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
118 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
119 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
121 #ifdef CONFIG_CPU_FREQ
122 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
123 void cpufreq_cpu_put(struct cpufreq_policy
*policy
);
125 static inline struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
)
129 static inline void cpufreq_cpu_put(struct cpufreq_policy
*policy
) { }
132 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
134 return cpumask_weight(policy
->cpus
) > 1;
137 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
138 extern struct kobject
*cpufreq_global_kobject
;
139 int cpufreq_get_global_kobject(void);
140 void cpufreq_put_global_kobject(void);
141 int cpufreq_sysfs_create_file(const struct attribute
*attr
);
142 void cpufreq_sysfs_remove_file(const struct attribute
*attr
);
144 #ifdef CONFIG_CPU_FREQ
145 unsigned int cpufreq_get(unsigned int cpu
);
146 unsigned int cpufreq_quick_get(unsigned int cpu
);
147 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
148 void disable_cpufreq(void);
150 u64
get_cpu_idle_time(unsigned int cpu
, u64
*wall
, int io_busy
);
151 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
152 int cpufreq_update_policy(unsigned int cpu
);
153 bool have_governor_per_policy(void);
154 struct kobject
*get_governor_parent_kobj(struct cpufreq_policy
*policy
);
156 static inline unsigned int cpufreq_get(unsigned int cpu
)
160 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
164 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
168 static inline void disable_cpufreq(void) { }
171 /*********************************************************************
172 * CPUFREQ DRIVER INTERFACE *
173 *********************************************************************/
175 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
176 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
179 struct attribute attr
;
180 ssize_t (*show
)(struct cpufreq_policy
*, char *);
181 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
184 #define cpufreq_freq_attr_ro(_name) \
185 static struct freq_attr _name = \
186 __ATTR(_name, 0444, show_##_name, NULL)
188 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
189 static struct freq_attr _name = \
190 __ATTR(_name, _perm, show_##_name, NULL)
192 #define cpufreq_freq_attr_rw(_name) \
193 static struct freq_attr _name = \
194 __ATTR(_name, 0644, show_##_name, store_##_name)
197 struct attribute attr
;
198 ssize_t (*show
)(struct kobject
*kobj
,
199 struct attribute
*attr
, char *buf
);
200 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
201 const char *c
, size_t count
);
204 #define define_one_global_ro(_name) \
205 static struct global_attr _name = \
206 __ATTR(_name, 0444, show_##_name, NULL)
208 #define define_one_global_rw(_name) \
209 static struct global_attr _name = \
210 __ATTR(_name, 0644, show_##_name, store_##_name)
213 struct cpufreq_driver
{
214 char name
[CPUFREQ_NAME_LEN
];
217 /* needed by all drivers */
218 int (*init
) (struct cpufreq_policy
*policy
);
219 int (*verify
) (struct cpufreq_policy
*policy
);
221 /* define one out of two */
222 int (*setpolicy
) (struct cpufreq_policy
*policy
);
223 int (*target
) (struct cpufreq_policy
*policy
, /* Deprecated */
224 unsigned int target_freq
,
225 unsigned int relation
);
226 int (*target_index
) (struct cpufreq_policy
*policy
,
229 /* should be defined, if possible */
230 unsigned int (*get
) (unsigned int cpu
);
233 int (*bios_limit
) (int cpu
, unsigned int *limit
);
235 int (*exit
) (struct cpufreq_policy
*policy
);
236 void (*stop_cpu
) (struct cpufreq_policy
*policy
);
237 int (*suspend
) (struct cpufreq_policy
*policy
);
238 int (*resume
) (struct cpufreq_policy
*policy
);
239 struct freq_attr
**attr
;
241 /* platform specific boost support code */
242 bool boost_supported
;
244 int (*set_boost
) (int state
);
248 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
249 all ->init() calls failed */
250 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
251 kernel "constants" aren't
252 affected by frequency
254 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
258 * This should be set by platforms having multiple clock-domains, i.e.
259 * supporting multiple policies. With this sysfs directories of governor would
260 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
261 * governor with different tunables for different clusters.
263 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
266 * Driver will do POSTCHANGE notifications from outside of their ->target()
267 * routine and so must set cpufreq_driver->flags with this flag, so that core
268 * can handle them specially.
270 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
273 * Set by drivers which want cpufreq core to check if CPU is running at a
274 * frequency present in freq-table exposed by the driver. For these drivers if
275 * CPU is found running at an out of table freq, we will try to set it to a freq
276 * from the table. And if that fails, we will stop further boot process by
277 * issuing a BUG_ON().
279 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
281 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
282 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
284 const char *cpufreq_get_current_driver(void);
286 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
,
287 unsigned int min
, unsigned int max
)
289 if (policy
->min
< min
)
291 if (policy
->max
< min
)
293 if (policy
->min
> max
)
295 if (policy
->max
> max
)
297 if (policy
->min
> policy
->max
)
298 policy
->min
= policy
->max
;
303 cpufreq_verify_within_cpu_limits(struct cpufreq_policy
*policy
)
305 cpufreq_verify_within_limits(policy
, policy
->cpuinfo
.min_freq
,
306 policy
->cpuinfo
.max_freq
);
309 #ifdef CONFIG_CPU_FREQ
310 void cpufreq_suspend(void);
311 void cpufreq_resume(void);
312 int cpufreq_generic_suspend(struct cpufreq_policy
*policy
);
314 static inline void cpufreq_suspend(void) {}
315 static inline void cpufreq_resume(void) {}
318 /*********************************************************************
319 * CPUFREQ NOTIFIER INTERFACE *
320 *********************************************************************/
322 #define CPUFREQ_TRANSITION_NOTIFIER (0)
323 #define CPUFREQ_POLICY_NOTIFIER (1)
325 /* Transition notifiers */
326 #define CPUFREQ_PRECHANGE (0)
327 #define CPUFREQ_POSTCHANGE (1)
329 /* Policy Notifiers */
330 #define CPUFREQ_ADJUST (0)
331 #define CPUFREQ_INCOMPATIBLE (1)
332 #define CPUFREQ_NOTIFY (2)
333 #define CPUFREQ_START (3)
334 #define CPUFREQ_UPDATE_POLICY_CPU (4)
335 #define CPUFREQ_CREATE_POLICY (5)
336 #define CPUFREQ_REMOVE_POLICY (6)
338 #ifdef CONFIG_CPU_FREQ
339 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
340 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
342 void cpufreq_freq_transition_begin(struct cpufreq_policy
*policy
,
343 struct cpufreq_freqs
*freqs
);
344 void cpufreq_freq_transition_end(struct cpufreq_policy
*policy
,
345 struct cpufreq_freqs
*freqs
, int transition_failed
);
347 #else /* CONFIG_CPU_FREQ */
348 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
353 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
358 #endif /* !CONFIG_CPU_FREQ */
361 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
368 * new = old * mult / div
370 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
,
373 #if BITS_PER_LONG == 32
374 u64 result
= ((u64
) old
) * ((u64
) mult
);
376 return (unsigned long) result
;
378 #elif BITS_PER_LONG == 64
379 unsigned long result
= old
* ((u64
) mult
);
385 /*********************************************************************
386 * CPUFREQ GOVERNORS *
387 *********************************************************************/
390 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
391 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
392 * two generic policies are available:
394 #define CPUFREQ_POLICY_POWERSAVE (1)
395 #define CPUFREQ_POLICY_PERFORMANCE (2)
397 /* Governor Events */
398 #define CPUFREQ_GOV_START 1
399 #define CPUFREQ_GOV_STOP 2
400 #define CPUFREQ_GOV_LIMITS 3
401 #define CPUFREQ_GOV_POLICY_INIT 4
402 #define CPUFREQ_GOV_POLICY_EXIT 5
404 struct cpufreq_governor
{
405 char name
[CPUFREQ_NAME_LEN
];
407 int (*governor
) (struct cpufreq_policy
*policy
,
409 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
411 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
413 unsigned int max_transition_latency
; /* HW must be able to switch to
414 next freq faster than this value in nano secs or we
415 will fallback to performance governor */
416 struct list_head governor_list
;
417 struct module
*owner
;
420 /* Pass a target to the cpufreq driver */
421 int cpufreq_driver_target(struct cpufreq_policy
*policy
,
422 unsigned int target_freq
,
423 unsigned int relation
);
424 int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
425 unsigned int target_freq
,
426 unsigned int relation
);
427 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
428 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
430 /* CPUFREQ DEFAULT GOVERNOR */
432 * Performance governor is fallback governor if any other gov failed to auto
433 * load due latency restrictions
435 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
436 extern struct cpufreq_governor cpufreq_gov_performance
;
438 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
439 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
440 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
441 extern struct cpufreq_governor cpufreq_gov_powersave
;
442 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
443 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
444 extern struct cpufreq_governor cpufreq_gov_userspace
;
445 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
446 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
447 extern struct cpufreq_governor cpufreq_gov_ondemand
;
448 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
449 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
450 extern struct cpufreq_governor cpufreq_gov_conservative
;
451 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
454 /*********************************************************************
455 * FREQUENCY TABLE HELPERS *
456 *********************************************************************/
458 /* Special Values of .frequency field */
459 #define CPUFREQ_ENTRY_INVALID ~0
460 #define CPUFREQ_TABLE_END ~1
461 /* Special Values of .flags field */
462 #define CPUFREQ_BOOST_FREQ (1 << 0)
464 struct cpufreq_frequency_table
{
466 unsigned int driver_data
; /* driver specific data, not used by core */
467 unsigned int frequency
; /* kHz - doesn't need to be in ascending
471 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
472 struct cpufreq_frequency_table
*table
);
474 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
475 struct cpufreq_frequency_table
*table
);
476 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy
*policy
);
478 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
479 struct cpufreq_frequency_table
*table
,
480 unsigned int target_freq
,
481 unsigned int relation
,
482 unsigned int *index
);
483 int cpufreq_frequency_table_get_index(struct cpufreq_policy
*policy
,
486 ssize_t
cpufreq_show_cpus(const struct cpumask
*mask
, char *buf
);
488 #ifdef CONFIG_CPU_FREQ
489 int cpufreq_boost_trigger_state(int state
);
490 int cpufreq_boost_supported(void);
491 int cpufreq_boost_enabled(void);
493 static inline int cpufreq_boost_trigger_state(int state
)
497 static inline int cpufreq_boost_supported(void)
501 static inline int cpufreq_boost_enabled(void)
506 /* the following funtion is for cpufreq core use only */
507 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
509 /* the following are really really optional */
510 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
511 extern struct freq_attr
*cpufreq_generic_attr
[];
512 int cpufreq_table_validate_and_show(struct cpufreq_policy
*policy
,
513 struct cpufreq_frequency_table
*table
);
515 unsigned int cpufreq_generic_get(unsigned int cpu
);
516 int cpufreq_generic_init(struct cpufreq_policy
*policy
,
517 struct cpufreq_frequency_table
*table
,
518 unsigned int transition_latency
);
519 #endif /* _LINUX_CPUFREQ_H */