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 #ifdef CONFIG_CPU_FREQ
97 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
98 void cpufreq_cpu_put(struct cpufreq_policy *policy);
100 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
104 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
107 static inline bool policy_is_shared(struct cpufreq_policy *policy)
109 return cpumask_weight(policy->cpus) > 1;
112 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
113 extern struct kobject *cpufreq_global_kobject;
114 int cpufreq_get_global_kobject(void);
115 void cpufreq_put_global_kobject(void);
116 int cpufreq_sysfs_create_file(const struct attribute *attr);
117 void cpufreq_sysfs_remove_file(const struct attribute *attr);
119 #ifdef CONFIG_CPU_FREQ
120 unsigned int cpufreq_get(unsigned int cpu);
121 unsigned int cpufreq_quick_get(unsigned int cpu);
122 unsigned int cpufreq_quick_get_max(unsigned int cpu);
123 void disable_cpufreq(void);
125 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
126 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
127 int cpufreq_update_policy(unsigned int cpu);
128 bool have_governor_per_policy(void);
129 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
131 static inline unsigned int cpufreq_get(unsigned int cpu)
135 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
139 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
143 static inline void disable_cpufreq(void) { }
146 /*********************************************************************
147 * CPUFREQ DRIVER INTERFACE *
148 *********************************************************************/
150 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
151 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
154 struct attribute attr;
155 ssize_t (*show)(struct cpufreq_policy *, char *);
156 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
159 #define cpufreq_freq_attr_ro(_name) \
160 static struct freq_attr _name = \
161 __ATTR(_name, 0444, show_##_name, NULL)
163 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
164 static struct freq_attr _name = \
165 __ATTR(_name, _perm, show_##_name, NULL)
167 #define cpufreq_freq_attr_rw(_name) \
168 static struct freq_attr _name = \
169 __ATTR(_name, 0644, show_##_name, store_##_name)
172 struct attribute attr;
173 ssize_t (*show)(struct kobject *kobj,
174 struct attribute *attr, char *buf);
175 ssize_t (*store)(struct kobject *a, struct attribute *b,
176 const char *c, size_t count);
179 #define define_one_global_ro(_name) \
180 static struct global_attr _name = \
181 __ATTR(_name, 0444, show_##_name, NULL)
183 #define define_one_global_rw(_name) \
184 static struct global_attr _name = \
185 __ATTR(_name, 0644, show_##_name, store_##_name)
188 struct cpufreq_driver {
189 char name[CPUFREQ_NAME_LEN];
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 (1 << 0) /* driver isn't removed even if
216 all ->init() calls failed */
217 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
218 kernel "constants" aren't
219 affected by frequency
221 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
225 * This should be set by platforms having multiple clock-domains, i.e.
226 * supporting multiple policies. With this sysfs directories of governor would
227 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
228 * governor with different tunables for different clusters.
230 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
232 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
233 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
235 const char *cpufreq_get_current_driver(void);
237 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
238 unsigned int min, unsigned int max)
240 if (policy->min < min)
242 if (policy->max < min)
244 if (policy->min > max)
246 if (policy->max > max)
248 if (policy->min > policy->max)
249 policy->min = policy->max;
254 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
256 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
257 policy->cpuinfo.max_freq);
260 /*********************************************************************
261 * CPUFREQ NOTIFIER INTERFACE *
262 *********************************************************************/
264 #define CPUFREQ_TRANSITION_NOTIFIER (0)
265 #define CPUFREQ_POLICY_NOTIFIER (1)
267 /* Transition notifiers */
268 #define CPUFREQ_PRECHANGE (0)
269 #define CPUFREQ_POSTCHANGE (1)
270 #define CPUFREQ_RESUMECHANGE (8)
271 #define CPUFREQ_SUSPENDCHANGE (9)
273 /* Policy Notifiers */
274 #define CPUFREQ_ADJUST (0)
275 #define CPUFREQ_INCOMPATIBLE (1)
276 #define CPUFREQ_NOTIFY (2)
277 #define CPUFREQ_START (3)
278 #define CPUFREQ_UPDATE_POLICY_CPU (4)
280 #ifdef CONFIG_CPU_FREQ
281 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
282 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
284 void cpufreq_notify_transition(struct cpufreq_policy *policy,
285 struct cpufreq_freqs *freqs, unsigned int state);
287 #else /* CONFIG_CPU_FREQ */
288 static inline int cpufreq_register_notifier(struct notifier_block *nb,
293 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
298 #endif /* !CONFIG_CPU_FREQ */
301 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
308 * new = old * mult / div
310 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
313 #if BITS_PER_LONG == 32
314 u64 result = ((u64) old) * ((u64) mult);
316 return (unsigned long) result;
318 #elif BITS_PER_LONG == 64
319 unsigned long result = old * ((u64) mult);
325 /*********************************************************************
326 * CPUFREQ GOVERNORS *
327 *********************************************************************/
330 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
331 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
332 * two generic policies are available:
334 #define CPUFREQ_POLICY_POWERSAVE (1)
335 #define CPUFREQ_POLICY_PERFORMANCE (2)
337 /* Governor Events */
338 #define CPUFREQ_GOV_START 1
339 #define CPUFREQ_GOV_STOP 2
340 #define CPUFREQ_GOV_LIMITS 3
341 #define CPUFREQ_GOV_POLICY_INIT 4
342 #define CPUFREQ_GOV_POLICY_EXIT 5
344 struct cpufreq_governor {
345 char name[CPUFREQ_NAME_LEN];
347 int (*governor) (struct cpufreq_policy *policy,
349 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
351 int (*store_setspeed) (struct cpufreq_policy *policy,
353 unsigned int max_transition_latency; /* HW must be able to switch to
354 next freq faster than this value in nano secs or we
355 will fallback to performance governor */
356 struct list_head governor_list;
357 struct module *owner;
360 /* Pass a target to the cpufreq driver */
361 int cpufreq_driver_target(struct cpufreq_policy *policy,
362 unsigned int target_freq,
363 unsigned int relation);
364 int __cpufreq_driver_target(struct cpufreq_policy *policy,
365 unsigned int target_freq,
366 unsigned int relation);
367 int cpufreq_register_governor(struct cpufreq_governor *governor);
368 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
370 /* CPUFREQ DEFAULT GOVERNOR */
372 * Performance governor is fallback governor if any other gov failed to auto
373 * load due latency restrictions
375 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
376 extern struct cpufreq_governor cpufreq_gov_performance;
378 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
379 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
380 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
381 extern struct cpufreq_governor cpufreq_gov_powersave;
382 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
383 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
384 extern struct cpufreq_governor cpufreq_gov_userspace;
385 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
386 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
387 extern struct cpufreq_governor cpufreq_gov_ondemand;
388 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
389 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
390 extern struct cpufreq_governor cpufreq_gov_conservative;
391 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
394 /*********************************************************************
395 * FREQUENCY TABLE HELPERS *
396 *********************************************************************/
398 #define CPUFREQ_ENTRY_INVALID ~0
399 #define CPUFREQ_TABLE_END ~1
401 struct cpufreq_frequency_table {
402 unsigned int driver_data; /* driver specific data, not used by core */
403 unsigned int frequency; /* kHz - doesn't need to be in ascending
407 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
408 struct cpufreq_frequency_table *table);
410 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
411 struct cpufreq_frequency_table *table);
412 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
414 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
415 struct cpufreq_frequency_table *table,
416 unsigned int target_freq,
417 unsigned int relation,
418 unsigned int *index);
420 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
421 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
423 /* the following funtion is for cpufreq core use only */
424 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
426 /* the following are really really optional */
427 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
428 extern struct freq_attr *cpufreq_generic_attr[];
429 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
431 void cpufreq_frequency_table_put_attr(unsigned int cpu);
432 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
433 struct cpufreq_frequency_table *table);
435 int cpufreq_generic_init(struct cpufreq_policy *policy,
436 struct cpufreq_frequency_table *table,
437 unsigned int transition_latency);
438 static inline int cpufreq_generic_exit(struct cpufreq_policy *policy)
440 cpufreq_frequency_table_put_attr(policy->cpu);
444 #endif /* _LINUX_CPUFREQ_H */