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 #define CPUFREQ_NAME_LEN 16
21 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
22 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
24 /*********************************************************************
25 * CPUFREQ NOTIFIER INTERFACE *
26 *********************************************************************/
28 #define CPUFREQ_TRANSITION_NOTIFIER (0)
29 #define CPUFREQ_POLICY_NOTIFIER (1)
31 #ifdef CONFIG_CPU_FREQ
32 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
33 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
34 extern void disable_cpufreq(void);
35 #else /* CONFIG_CPU_FREQ */
36 static inline int cpufreq_register_notifier(struct notifier_block *nb,
41 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
46 static inline void disable_cpufreq(void) { }
47 #endif /* CONFIG_CPU_FREQ */
49 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
50 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
51 * two generic policies are available:
54 #define CPUFREQ_POLICY_POWERSAVE (1)
55 #define CPUFREQ_POLICY_PERFORMANCE (2)
57 /* Frequency values here are CPU kHz so that hardware which doesn't run
58 * with some frequencies can complain without having to guess what per
59 * cent / per mille means.
60 * Maximum transition latency is in nanoseconds - if it's unknown,
61 * CPUFREQ_ETERNAL shall be used.
64 struct cpufreq_governor;
66 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
67 extern struct kobject *cpufreq_global_kobject;
68 int cpufreq_get_global_kobject(void);
69 void cpufreq_put_global_kobject(void);
70 int cpufreq_sysfs_create_file(const struct attribute *attr);
71 void cpufreq_sysfs_remove_file(const struct attribute *attr);
73 #define CPUFREQ_ETERNAL (-1)
74 struct cpufreq_cpuinfo {
75 unsigned int max_freq;
76 unsigned int min_freq;
78 /* in 10^(-9) s = nanoseconds */
79 unsigned int transition_latency;
82 struct cpufreq_real_policy {
83 unsigned int min; /* in kHz */
84 unsigned int max; /* in kHz */
85 unsigned int policy; /* see above */
86 struct cpufreq_governor *governor; /* see below */
89 struct cpufreq_policy {
90 /* CPUs sharing clock, require sw coordination */
91 cpumask_var_t cpus; /* Online CPUs only */
92 cpumask_var_t related_cpus; /* Online + Offline CPUs */
94 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
96 unsigned int cpu; /* cpu nr of CPU managing this policy */
97 unsigned int last_cpu; /* cpu nr of previous CPU that managed
99 struct cpufreq_cpuinfo cpuinfo;/* see above */
101 unsigned int min; /* in kHz */
102 unsigned int max; /* in kHz */
103 unsigned int cur; /* in kHz, only needed if cpufreq
104 * governors are used */
105 unsigned int policy; /* see above */
106 struct cpufreq_governor *governor; /* see below */
108 bool governor_enabled; /* governor start/stop flag */
110 struct work_struct update; /* if update_policy() needs to be
111 * called, but you're in IRQ context */
113 struct cpufreq_real_policy user_policy;
116 struct completion kobj_unregister;
117 int transition_ongoing; /* Tracks transition status */
120 #define CPUFREQ_ADJUST (0)
121 #define CPUFREQ_INCOMPATIBLE (1)
122 #define CPUFREQ_NOTIFY (2)
123 #define CPUFREQ_START (3)
124 #define CPUFREQ_UPDATE_POLICY_CPU (4)
127 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
128 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
129 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
130 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
132 static inline bool policy_is_shared(struct cpufreq_policy *policy)
134 return cpumask_weight(policy->cpus) > 1;
137 /******************** cpufreq transition notifiers *******************/
139 #define CPUFREQ_PRECHANGE (0)
140 #define CPUFREQ_POSTCHANGE (1)
141 #define CPUFREQ_RESUMECHANGE (8)
142 #define CPUFREQ_SUSPENDCHANGE (9)
144 struct cpufreq_freqs {
145 unsigned int cpu; /* cpu nr */
148 u8 flags; /* flags of cpufreq_driver, see below. */
152 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
159 * new = old * mult / div
161 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
164 #if BITS_PER_LONG == 32
166 u64 result = ((u64) old) * ((u64) mult);
168 return (unsigned long) result;
170 #elif BITS_PER_LONG == 64
172 unsigned long result = old * ((u64) mult);
179 /*********************************************************************
180 * CPUFREQ GOVERNORS *
181 *********************************************************************/
183 #define CPUFREQ_GOV_START 1
184 #define CPUFREQ_GOV_STOP 2
185 #define CPUFREQ_GOV_LIMITS 3
186 #define CPUFREQ_GOV_POLICY_INIT 4
187 #define CPUFREQ_GOV_POLICY_EXIT 5
189 struct cpufreq_governor {
190 char name[CPUFREQ_NAME_LEN];
192 int (*governor) (struct cpufreq_policy *policy,
194 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
196 int (*store_setspeed) (struct cpufreq_policy *policy,
198 unsigned int max_transition_latency; /* HW must be able to switch to
199 next freq faster than this value in nano secs or we
200 will fallback to performance governor */
201 struct list_head governor_list;
202 struct module *owner;
206 * Pass a target to the cpufreq driver.
208 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
209 unsigned int target_freq,
210 unsigned int relation);
211 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
212 unsigned int target_freq,
213 unsigned int relation);
214 int cpufreq_register_governor(struct cpufreq_governor *governor);
215 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
217 /*********************************************************************
218 * CPUFREQ DRIVER INTERFACE *
219 *********************************************************************/
221 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
222 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
226 struct cpufreq_driver {
227 struct module *owner;
228 char name[CPUFREQ_NAME_LEN];
231 * This should be set by platforms having multiple clock-domains, i.e.
232 * supporting multiple policies. With this sysfs directories of governor
233 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
234 * use the same governor with different tunables for different clusters.
236 bool have_governor_per_policy;
238 /* needed by all drivers */
239 int (*init) (struct cpufreq_policy *policy);
240 int (*verify) (struct cpufreq_policy *policy);
242 /* define one out of two */
243 int (*setpolicy) (struct cpufreq_policy *policy);
244 int (*target) (struct cpufreq_policy *policy,
245 unsigned int target_freq,
246 unsigned int relation);
248 /* should be defined, if possible */
249 unsigned int (*get) (unsigned int cpu);
252 int (*bios_limit) (int cpu, unsigned int *limit);
254 int (*exit) (struct cpufreq_policy *policy);
255 int (*suspend) (struct cpufreq_policy *policy);
256 int (*resume) (struct cpufreq_policy *policy);
257 struct freq_attr **attr;
262 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
263 * all ->init() calls failed */
264 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
265 * "constants" aren't affected by
266 * frequency transitions */
267 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
270 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
271 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
273 void cpufreq_notify_transition(struct cpufreq_policy *policy,
274 struct cpufreq_freqs *freqs, unsigned int state);
276 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
277 unsigned int min, unsigned int max)
279 if (policy->min < min)
281 if (policy->max < min)
283 if (policy->min > max)
285 if (policy->max > max)
287 if (policy->min > policy->max)
288 policy->min = policy->max;
293 struct attribute attr;
294 ssize_t (*show)(struct cpufreq_policy *, char *);
295 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
298 #define cpufreq_freq_attr_ro(_name) \
299 static struct freq_attr _name = \
300 __ATTR(_name, 0444, show_##_name, NULL)
302 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
303 static struct freq_attr _name = \
304 __ATTR(_name, _perm, show_##_name, NULL)
306 #define cpufreq_freq_attr_rw(_name) \
307 static struct freq_attr _name = \
308 __ATTR(_name, 0644, show_##_name, store_##_name)
311 struct attribute attr;
312 ssize_t (*show)(struct kobject *kobj,
313 struct attribute *attr, char *buf);
314 ssize_t (*store)(struct kobject *a, struct attribute *b,
315 const char *c, size_t count);
318 #define define_one_global_ro(_name) \
319 static struct global_attr _name = \
320 __ATTR(_name, 0444, show_##_name, NULL)
322 #define define_one_global_rw(_name) \
323 static struct global_attr _name = \
324 __ATTR(_name, 0644, show_##_name, store_##_name)
326 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
327 void cpufreq_cpu_put(struct cpufreq_policy *data);
328 const char *cpufreq_get_current_driver(void);
330 /*********************************************************************
331 * CPUFREQ 2.6. INTERFACE *
332 *********************************************************************/
333 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
334 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
335 int cpufreq_update_policy(unsigned int cpu);
336 bool have_governor_per_policy(void);
337 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
339 #ifdef CONFIG_CPU_FREQ
341 * query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it
343 unsigned int cpufreq_get(unsigned int cpu);
345 static inline unsigned int cpufreq_get(unsigned int cpu)
352 * query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it
354 #ifdef CONFIG_CPU_FREQ
355 unsigned int cpufreq_quick_get(unsigned int cpu);
356 unsigned int cpufreq_quick_get_max(unsigned int cpu);
358 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
362 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
368 /*********************************************************************
369 * CPUFREQ DEFAULT GOVERNOR *
370 *********************************************************************/
373 * Performance governor is fallback governor if any other gov failed to auto
374 * load due latency restrictions
376 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
377 extern struct cpufreq_governor cpufreq_gov_performance;
379 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
380 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
381 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
382 extern struct cpufreq_governor cpufreq_gov_powersave;
383 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
384 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
385 extern struct cpufreq_governor cpufreq_gov_userspace;
386 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
387 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
388 extern struct cpufreq_governor cpufreq_gov_ondemand;
389 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
390 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
391 extern struct cpufreq_governor cpufreq_gov_conservative;
392 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
395 /*********************************************************************
396 * FREQUENCY TABLE HELPERS *
397 *********************************************************************/
399 #define CPUFREQ_ENTRY_INVALID ~0
400 #define CPUFREQ_TABLE_END ~1
402 struct cpufreq_frequency_table {
403 unsigned int driver_data; /* driver specific data, not used by core */
404 unsigned int frequency; /* kHz - doesn't need to be in ascending
408 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
409 struct cpufreq_frequency_table *table);
411 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
412 struct cpufreq_frequency_table *table);
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 /* the following 3 funtions are for cpufreq core use only */
421 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
423 /* the following are really really optional */
424 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
426 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
428 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
430 void cpufreq_frequency_table_put_attr(unsigned int cpu);
432 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
434 #endif /* _LINUX_CPUFREQ_H */