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 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
97 void cpufreq_cpu_put(struct cpufreq_policy *policy);
99 static inline bool policy_is_shared(struct cpufreq_policy *policy)
101 return cpumask_weight(policy->cpus) > 1;
104 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
105 extern struct kobject *cpufreq_global_kobject;
106 int cpufreq_get_global_kobject(void);
107 void cpufreq_put_global_kobject(void);
108 int cpufreq_sysfs_create_file(const struct attribute *attr);
109 void cpufreq_sysfs_remove_file(const struct attribute *attr);
111 #ifdef CONFIG_CPU_FREQ
112 unsigned int cpufreq_get(unsigned int cpu);
113 unsigned int cpufreq_quick_get(unsigned int cpu);
114 unsigned int cpufreq_quick_get_max(unsigned int cpu);
115 void disable_cpufreq(void);
117 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
118 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
119 int cpufreq_update_policy(unsigned int cpu);
120 bool have_governor_per_policy(void);
121 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
123 static inline unsigned int cpufreq_get(unsigned int cpu)
127 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
131 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
135 static inline void disable_cpufreq(void) { }
138 /*********************************************************************
139 * CPUFREQ DRIVER INTERFACE *
140 *********************************************************************/
142 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
143 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
146 struct attribute attr;
147 ssize_t (*show)(struct cpufreq_policy *, char *);
148 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
151 #define cpufreq_freq_attr_ro(_name) \
152 static struct freq_attr _name = \
153 __ATTR(_name, 0444, show_##_name, NULL)
155 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
156 static struct freq_attr _name = \
157 __ATTR(_name, _perm, show_##_name, NULL)
159 #define cpufreq_freq_attr_rw(_name) \
160 static struct freq_attr _name = \
161 __ATTR(_name, 0644, show_##_name, store_##_name)
164 struct attribute attr;
165 ssize_t (*show)(struct kobject *kobj,
166 struct attribute *attr, char *buf);
167 ssize_t (*store)(struct kobject *a, struct attribute *b,
168 const char *c, size_t count);
171 #define define_one_global_ro(_name) \
172 static struct global_attr _name = \
173 __ATTR(_name, 0444, show_##_name, NULL)
175 #define define_one_global_rw(_name) \
176 static struct global_attr _name = \
177 __ATTR(_name, 0644, show_##_name, store_##_name)
180 struct cpufreq_driver {
181 char name[CPUFREQ_NAME_LEN];
184 * This should be set by platforms having multiple clock-domains, i.e.
185 * supporting multiple policies. With this sysfs directories of governor
186 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
187 * use the same governor with different tunables for different clusters.
189 bool have_governor_per_policy;
191 /* needed by all drivers */
192 int (*init) (struct cpufreq_policy *policy);
193 int (*verify) (struct cpufreq_policy *policy);
195 /* define one out of two */
196 int (*setpolicy) (struct cpufreq_policy *policy);
197 int (*target) (struct cpufreq_policy *policy,
198 unsigned int target_freq,
199 unsigned int relation);
201 /* should be defined, if possible */
202 unsigned int (*get) (unsigned int cpu);
205 int (*bios_limit) (int cpu, unsigned int *limit);
207 int (*exit) (struct cpufreq_policy *policy);
208 int (*suspend) (struct cpufreq_policy *policy);
209 int (*resume) (struct cpufreq_policy *policy);
210 struct freq_attr **attr;
214 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
215 * all ->init() calls failed */
216 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
217 * "constants" aren't affected by
218 * frequency transitions */
219 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
222 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
223 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
225 const char *cpufreq_get_current_driver(void);
227 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
228 unsigned int min, unsigned int max)
230 if (policy->min < min)
232 if (policy->max < min)
234 if (policy->min > max)
236 if (policy->max > max)
238 if (policy->min > policy->max)
239 policy->min = policy->max;
243 /*********************************************************************
244 * CPUFREQ NOTIFIER INTERFACE *
245 *********************************************************************/
247 #define CPUFREQ_TRANSITION_NOTIFIER (0)
248 #define CPUFREQ_POLICY_NOTIFIER (1)
250 /* Transition notifiers */
251 #define CPUFREQ_PRECHANGE (0)
252 #define CPUFREQ_POSTCHANGE (1)
253 #define CPUFREQ_RESUMECHANGE (8)
254 #define CPUFREQ_SUSPENDCHANGE (9)
256 /* Policy Notifiers */
257 #define CPUFREQ_ADJUST (0)
258 #define CPUFREQ_INCOMPATIBLE (1)
259 #define CPUFREQ_NOTIFY (2)
260 #define CPUFREQ_START (3)
261 #define CPUFREQ_UPDATE_POLICY_CPU (4)
263 #ifdef CONFIG_CPU_FREQ
264 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
265 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
267 void cpufreq_notify_transition(struct cpufreq_policy *policy,
268 struct cpufreq_freqs *freqs, unsigned int state);
270 #else /* CONFIG_CPU_FREQ */
271 static inline int cpufreq_register_notifier(struct notifier_block *nb,
276 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
281 #endif /* !CONFIG_CPU_FREQ */
284 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
291 * new = old * mult / div
293 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
296 #if BITS_PER_LONG == 32
297 u64 result = ((u64) old) * ((u64) mult);
299 return (unsigned long) result;
301 #elif BITS_PER_LONG == 64
302 unsigned long result = old * ((u64) mult);
308 /*********************************************************************
309 * CPUFREQ GOVERNORS *
310 *********************************************************************/
313 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
314 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
315 * two generic policies are available:
317 #define CPUFREQ_POLICY_POWERSAVE (1)
318 #define CPUFREQ_POLICY_PERFORMANCE (2)
320 /* Governor Events */
321 #define CPUFREQ_GOV_START 1
322 #define CPUFREQ_GOV_STOP 2
323 #define CPUFREQ_GOV_LIMITS 3
324 #define CPUFREQ_GOV_POLICY_INIT 4
325 #define CPUFREQ_GOV_POLICY_EXIT 5
327 struct cpufreq_governor {
328 char name[CPUFREQ_NAME_LEN];
330 int (*governor) (struct cpufreq_policy *policy,
332 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
334 int (*store_setspeed) (struct cpufreq_policy *policy,
336 unsigned int max_transition_latency; /* HW must be able to switch to
337 next freq faster than this value in nano secs or we
338 will fallback to performance governor */
339 struct list_head governor_list;
340 struct module *owner;
343 /* Pass a target to the cpufreq driver */
344 int cpufreq_driver_target(struct cpufreq_policy *policy,
345 unsigned int target_freq,
346 unsigned int relation);
347 int __cpufreq_driver_target(struct cpufreq_policy *policy,
348 unsigned int target_freq,
349 unsigned int relation);
350 int cpufreq_register_governor(struct cpufreq_governor *governor);
351 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
353 /* CPUFREQ DEFAULT GOVERNOR */
355 * Performance governor is fallback governor if any other gov failed to auto
356 * load due latency restrictions
358 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
359 extern struct cpufreq_governor cpufreq_gov_performance;
361 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
362 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
364 extern struct cpufreq_governor cpufreq_gov_powersave;
365 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
366 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
367 extern struct cpufreq_governor cpufreq_gov_userspace;
368 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
369 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
370 extern struct cpufreq_governor cpufreq_gov_ondemand;
371 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
372 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
373 extern struct cpufreq_governor cpufreq_gov_conservative;
374 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
377 /*********************************************************************
378 * FREQUENCY TABLE HELPERS *
379 *********************************************************************/
381 #define CPUFREQ_ENTRY_INVALID ~0
382 #define CPUFREQ_TABLE_END ~1
384 struct cpufreq_frequency_table {
385 unsigned int driver_data; /* driver specific data, not used by core */
386 unsigned int frequency; /* kHz - doesn't need to be in ascending
390 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
391 struct cpufreq_frequency_table *table);
393 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
394 struct cpufreq_frequency_table *table);
396 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
397 struct cpufreq_frequency_table *table,
398 unsigned int target_freq,
399 unsigned int relation,
400 unsigned int *index);
402 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
403 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
405 /* the following funtion is for cpufreq core use only */
406 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
408 /* the following are really really optional */
409 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
410 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
412 void cpufreq_frequency_table_put_attr(unsigned int cpu);
414 #endif /* _LINUX_CPUFREQ_H */