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 <asm/cputime.h>
15 #include <linux/mutex.h>
16 #include <linux/notifier.h>
17 #include <linux/threads.h>
18 #include <linux/kobject.h>
19 #include <linux/sysfs.h>
20 #include <linux/completion.h>
21 #include <linux/workqueue.h>
22 #include <linux/cpumask.h>
23 #include <asm/div64.h>
25 #define CPUFREQ_NAME_LEN 16
26 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
27 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
30 /*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
34 #define CPUFREQ_TRANSITION_NOTIFIER (0)
35 #define CPUFREQ_POLICY_NOTIFIER (1)
37 #ifdef CONFIG_CPU_FREQ
38 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
39 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
40 extern void disable_cpufreq(void);
41 #else /* CONFIG_CPU_FREQ */
42 static inline int cpufreq_register_notifier(struct notifier_block *nb,
47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
52 static inline void disable_cpufreq(void) { }
53 #endif /* CONFIG_CPU_FREQ */
55 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
56 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
57 * two generic policies are available:
60 #define CPUFREQ_POLICY_POWERSAVE (1)
61 #define CPUFREQ_POLICY_PERFORMANCE (2)
63 /* Frequency values here are CPU kHz so that hardware which doesn't run
64 * with some frequencies can complain without having to guess what per
65 * cent / per mille means.
66 * Maximum transition latency is in nanoseconds - if it's unknown,
67 * CPUFREQ_ETERNAL shall be used.
70 struct cpufreq_governor;
72 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
73 extern struct kobject *cpufreq_global_kobject;
74 int cpufreq_get_global_kobject(void);
75 void cpufreq_put_global_kobject(void);
76 int cpufreq_sysfs_create_file(const struct attribute *attr);
77 void cpufreq_sysfs_remove_file(const struct attribute *attr);
79 #define CPUFREQ_ETERNAL (-1)
80 struct cpufreq_cpuinfo {
81 unsigned int max_freq;
82 unsigned int min_freq;
84 /* in 10^(-9) s = nanoseconds */
85 unsigned int transition_latency;
88 struct cpufreq_real_policy {
89 unsigned int min; /* in kHz */
90 unsigned int max; /* in kHz */
91 unsigned int policy; /* see above */
92 struct cpufreq_governor *governor; /* see below */
95 struct cpufreq_policy {
96 /* CPUs sharing clock, require sw coordination */
97 cpumask_var_t cpus; /* Online CPUs only */
98 cpumask_var_t related_cpus; /* Online + Offline CPUs */
100 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
101 should set cpufreq */
102 unsigned int cpu; /* cpu nr of CPU managing this policy */
103 unsigned int last_cpu; /* cpu nr of previous CPU that managed
105 struct cpufreq_cpuinfo cpuinfo;/* see above */
107 unsigned int min; /* in kHz */
108 unsigned int max; /* in kHz */
109 unsigned int cur; /* in kHz, only needed if cpufreq
110 * governors are used */
111 unsigned int policy; /* see above */
112 struct cpufreq_governor *governor; /* see below */
115 struct work_struct update; /* if update_policy() needs to be
116 * called, but you're in IRQ context */
118 struct cpufreq_real_policy user_policy;
121 struct completion kobj_unregister;
124 #define CPUFREQ_ADJUST (0)
125 #define CPUFREQ_INCOMPATIBLE (1)
126 #define CPUFREQ_NOTIFY (2)
127 #define CPUFREQ_START (3)
128 #define CPUFREQ_UPDATE_POLICY_CPU (4)
131 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
132 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
133 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
134 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
136 static inline bool policy_is_shared(struct cpufreq_policy *policy)
138 return cpumask_weight(policy->cpus) > 1;
141 /******************** cpufreq transition notifiers *******************/
143 #define CPUFREQ_PRECHANGE (0)
144 #define CPUFREQ_POSTCHANGE (1)
145 #define CPUFREQ_RESUMECHANGE (8)
146 #define CPUFREQ_SUSPENDCHANGE (9)
148 struct cpufreq_freqs {
149 unsigned int cpu; /* cpu nr */
152 u8 flags; /* flags of cpufreq_driver, see below. */
157 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
163 * new = old * mult / div
165 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
167 #if BITS_PER_LONG == 32
169 u64 result = ((u64) old) * ((u64) mult);
171 return (unsigned long) result;
173 #elif BITS_PER_LONG == 64
175 unsigned long result = old * ((u64) mult);
182 /*********************************************************************
183 * CPUFREQ GOVERNORS *
184 *********************************************************************/
186 #define CPUFREQ_GOV_START 1
187 #define CPUFREQ_GOV_STOP 2
188 #define CPUFREQ_GOV_LIMITS 3
189 #define CPUFREQ_GOV_POLICY_INIT 4
190 #define CPUFREQ_GOV_POLICY_EXIT 5
192 struct cpufreq_governor {
193 char name[CPUFREQ_NAME_LEN];
195 int (*governor) (struct cpufreq_policy *policy,
197 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
199 int (*store_setspeed) (struct cpufreq_policy *policy,
201 unsigned int max_transition_latency; /* HW must be able to switch to
202 next freq faster than this value in nano secs or we
203 will fallback to performance governor */
204 struct list_head governor_list;
205 struct module *owner;
209 * Pass a target to the cpufreq driver.
211 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
212 unsigned int target_freq,
213 unsigned int relation);
214 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
215 unsigned int target_freq,
216 unsigned int relation);
219 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
222 int cpufreq_register_governor(struct cpufreq_governor *governor);
223 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
226 /*********************************************************************
227 * CPUFREQ DRIVER INTERFACE *
228 *********************************************************************/
230 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
231 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
235 struct cpufreq_driver {
236 struct module *owner;
237 char name[CPUFREQ_NAME_LEN];
240 * This should be set by platforms having multiple clock-domains, i.e.
241 * supporting multiple policies. With this sysfs directories of governor
242 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
243 * use the same governor with different tunables for different clusters.
245 bool have_governor_per_policy;
247 /* needed by all drivers */
248 int (*init) (struct cpufreq_policy *policy);
249 int (*verify) (struct cpufreq_policy *policy);
251 /* define one out of two */
252 int (*setpolicy) (struct cpufreq_policy *policy);
253 int (*target) (struct cpufreq_policy *policy,
254 unsigned int target_freq,
255 unsigned int relation);
257 /* should be defined, if possible */
258 unsigned int (*get) (unsigned int cpu);
261 unsigned int (*getavg) (struct cpufreq_policy *policy,
263 int (*bios_limit) (int cpu, unsigned int *limit);
265 int (*exit) (struct cpufreq_policy *policy);
266 int (*suspend) (struct cpufreq_policy *policy);
267 int (*resume) (struct cpufreq_policy *policy);
268 struct freq_attr **attr;
273 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
274 * all ->init() calls failed */
275 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
276 * "constants" aren't affected by
277 * frequency transitions */
278 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
281 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
282 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
285 void cpufreq_notify_transition(struct cpufreq_policy *policy,
286 struct cpufreq_freqs *freqs, unsigned int state);
288 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
290 if (policy->min < min)
292 if (policy->max < min)
294 if (policy->min > max)
296 if (policy->max > max)
298 if (policy->min > policy->max)
299 policy->min = policy->max;
304 struct attribute attr;
305 ssize_t (*show)(struct cpufreq_policy *, char *);
306 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
309 #define cpufreq_freq_attr_ro(_name) \
310 static struct freq_attr _name = \
311 __ATTR(_name, 0444, show_##_name, NULL)
313 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
314 static struct freq_attr _name = \
315 __ATTR(_name, _perm, show_##_name, NULL)
317 #define cpufreq_freq_attr_rw(_name) \
318 static struct freq_attr _name = \
319 __ATTR(_name, 0644, show_##_name, store_##_name)
322 struct attribute attr;
323 ssize_t (*show)(struct kobject *kobj,
324 struct attribute *attr, char *buf);
325 ssize_t (*store)(struct kobject *a, struct attribute *b,
326 const char *c, size_t count);
329 #define define_one_global_ro(_name) \
330 static struct global_attr _name = \
331 __ATTR(_name, 0444, show_##_name, NULL)
333 #define define_one_global_rw(_name) \
334 static struct global_attr _name = \
335 __ATTR(_name, 0644, show_##_name, store_##_name)
337 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
338 void cpufreq_cpu_put(struct cpufreq_policy *data);
339 const char *cpufreq_get_current_driver(void);
341 /*********************************************************************
342 * CPUFREQ 2.6. INTERFACE *
343 *********************************************************************/
344 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
345 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
346 int cpufreq_update_policy(unsigned int cpu);
347 bool have_governor_per_policy(void);
348 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
350 #ifdef CONFIG_CPU_FREQ
351 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
352 unsigned int cpufreq_get(unsigned int cpu);
354 static inline unsigned int cpufreq_get(unsigned int cpu)
360 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
361 #ifdef CONFIG_CPU_FREQ
362 unsigned int cpufreq_quick_get(unsigned int cpu);
363 unsigned int cpufreq_quick_get_max(unsigned int cpu);
365 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
369 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
376 /*********************************************************************
377 * CPUFREQ DEFAULT GOVERNOR *
378 *********************************************************************/
382 Performance governor is fallback governor if any other gov failed to
383 auto load due latency restrictions
385 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
386 extern struct cpufreq_governor cpufreq_gov_performance;
388 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
389 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
390 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
391 extern struct cpufreq_governor cpufreq_gov_powersave;
392 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
393 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
394 extern struct cpufreq_governor cpufreq_gov_userspace;
395 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
396 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
397 extern struct cpufreq_governor cpufreq_gov_ondemand;
398 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
399 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
400 extern struct cpufreq_governor cpufreq_gov_conservative;
401 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
405 /*********************************************************************
406 * FREQUENCY TABLE HELPERS *
407 *********************************************************************/
409 #define CPUFREQ_ENTRY_INVALID ~0
410 #define CPUFREQ_TABLE_END ~1
412 struct cpufreq_frequency_table {
413 unsigned int driver_data; /* driver specific data, not used by core */
414 unsigned int frequency; /* kHz - doesn't need to be in ascending
418 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
419 struct cpufreq_frequency_table *table);
421 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
422 struct cpufreq_frequency_table *table);
424 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
425 struct cpufreq_frequency_table *table,
426 unsigned int target_freq,
427 unsigned int relation,
428 unsigned int *index);
430 /* the following 3 funtions are for cpufreq core use only */
431 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
433 /* the following are really really optional */
434 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
436 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
438 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
440 void cpufreq_frequency_table_put_attr(unsigned int cpu);
441 #endif /* _LINUX_CPUFREQ_H */