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;
90 * The rules for this semaphore:
91 * - Any routine that wants to read from the policy structure will
92 * do a down_read on this semaphore.
93 * - Any routine that will write to the policy structure and/or may take away
94 * the policy altogether (eg. CPU hotplug), will hold this lock in write
95 * mode before doing so.
98 * - Lock should not be held across
99 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
101 struct rw_semaphore rwsem;
105 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
106 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
107 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
108 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
110 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
111 void cpufreq_cpu_put(struct cpufreq_policy *policy);
113 static inline bool policy_is_shared(struct cpufreq_policy *policy)
115 return cpumask_weight(policy->cpus) > 1;
118 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
119 extern struct kobject *cpufreq_global_kobject;
120 int cpufreq_get_global_kobject(void);
121 void cpufreq_put_global_kobject(void);
122 int cpufreq_sysfs_create_file(const struct attribute *attr);
123 void cpufreq_sysfs_remove_file(const struct attribute *attr);
125 #ifdef CONFIG_CPU_FREQ
126 unsigned int cpufreq_get(unsigned int cpu);
127 unsigned int cpufreq_quick_get(unsigned int cpu);
128 unsigned int cpufreq_quick_get_max(unsigned int cpu);
129 void disable_cpufreq(void);
131 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
132 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
133 int cpufreq_update_policy(unsigned int cpu);
134 bool have_governor_per_policy(void);
135 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
137 static inline unsigned int cpufreq_get(unsigned int cpu)
141 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
145 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
149 static inline void disable_cpufreq(void) { }
152 /*********************************************************************
153 * CPUFREQ DRIVER INTERFACE *
154 *********************************************************************/
156 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
157 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
160 struct attribute attr;
161 ssize_t (*show)(struct cpufreq_policy *, char *);
162 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
165 #define cpufreq_freq_attr_ro(_name) \
166 static struct freq_attr _name = \
167 __ATTR(_name, 0444, show_##_name, NULL)
169 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
170 static struct freq_attr _name = \
171 __ATTR(_name, _perm, show_##_name, NULL)
173 #define cpufreq_freq_attr_rw(_name) \
174 static struct freq_attr _name = \
175 __ATTR(_name, 0644, show_##_name, store_##_name)
178 struct attribute attr;
179 ssize_t (*show)(struct kobject *kobj,
180 struct attribute *attr, char *buf);
181 ssize_t (*store)(struct kobject *a, struct attribute *b,
182 const char *c, size_t count);
185 #define define_one_global_ro(_name) \
186 static struct global_attr _name = \
187 __ATTR(_name, 0444, show_##_name, NULL)
189 #define define_one_global_rw(_name) \
190 static struct global_attr _name = \
191 __ATTR(_name, 0644, show_##_name, store_##_name)
194 struct cpufreq_driver {
195 char name[CPUFREQ_NAME_LEN];
198 /* needed by all drivers */
199 int (*init) (struct cpufreq_policy *policy);
200 int (*verify) (struct cpufreq_policy *policy);
202 /* define one out of two */
203 int (*setpolicy) (struct cpufreq_policy *policy);
204 int (*target) (struct cpufreq_policy *policy, /* Deprecated */
205 unsigned int target_freq,
206 unsigned int relation);
207 int (*target_index) (struct cpufreq_policy *policy,
210 /* should be defined, if possible */
211 unsigned int (*get) (unsigned int cpu);
214 int (*bios_limit) (int cpu, unsigned int *limit);
216 int (*exit) (struct cpufreq_policy *policy);
217 int (*suspend) (struct cpufreq_policy *policy);
218 int (*resume) (struct cpufreq_policy *policy);
219 struct freq_attr **attr;
223 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
224 all ->init() calls failed */
225 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
226 kernel "constants" aren't
227 affected by frequency
229 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
233 * This should be set by platforms having multiple clock-domains, i.e.
234 * supporting multiple policies. With this sysfs directories of governor would
235 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
236 * governor with different tunables for different clusters.
238 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
241 * Driver will do POSTCHANGE notifications from outside of their ->target()
242 * routine and so must set cpufreq_driver->flags with this flag, so that core
243 * can handle them specially.
245 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
247 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
248 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
250 const char *cpufreq_get_current_driver(void);
252 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
253 unsigned int min, unsigned int max)
255 if (policy->min < min)
257 if (policy->max < min)
259 if (policy->min > max)
261 if (policy->max > max)
263 if (policy->min > policy->max)
264 policy->min = policy->max;
269 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
271 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
272 policy->cpuinfo.max_freq);
275 /*********************************************************************
276 * CPUFREQ NOTIFIER INTERFACE *
277 *********************************************************************/
279 #define CPUFREQ_TRANSITION_NOTIFIER (0)
280 #define CPUFREQ_POLICY_NOTIFIER (1)
282 /* Transition notifiers */
283 #define CPUFREQ_PRECHANGE (0)
284 #define CPUFREQ_POSTCHANGE (1)
285 #define CPUFREQ_RESUMECHANGE (8)
286 #define CPUFREQ_SUSPENDCHANGE (9)
288 /* Policy Notifiers */
289 #define CPUFREQ_ADJUST (0)
290 #define CPUFREQ_INCOMPATIBLE (1)
291 #define CPUFREQ_NOTIFY (2)
292 #define CPUFREQ_START (3)
293 #define CPUFREQ_UPDATE_POLICY_CPU (4)
295 #ifdef CONFIG_CPU_FREQ
296 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
297 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
299 void cpufreq_notify_transition(struct cpufreq_policy *policy,
300 struct cpufreq_freqs *freqs, unsigned int state);
302 #else /* CONFIG_CPU_FREQ */
303 static inline int cpufreq_register_notifier(struct notifier_block *nb,
308 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
313 #endif /* !CONFIG_CPU_FREQ */
316 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
323 * new = old * mult / div
325 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
328 #if BITS_PER_LONG == 32
329 u64 result = ((u64) old) * ((u64) mult);
331 return (unsigned long) result;
333 #elif BITS_PER_LONG == 64
334 unsigned long result = old * ((u64) mult);
340 /*********************************************************************
341 * CPUFREQ GOVERNORS *
342 *********************************************************************/
345 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
346 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
347 * two generic policies are available:
349 #define CPUFREQ_POLICY_POWERSAVE (1)
350 #define CPUFREQ_POLICY_PERFORMANCE (2)
352 /* Governor Events */
353 #define CPUFREQ_GOV_START 1
354 #define CPUFREQ_GOV_STOP 2
355 #define CPUFREQ_GOV_LIMITS 3
356 #define CPUFREQ_GOV_POLICY_INIT 4
357 #define CPUFREQ_GOV_POLICY_EXIT 5
359 struct cpufreq_governor {
360 char name[CPUFREQ_NAME_LEN];
362 int (*governor) (struct cpufreq_policy *policy,
364 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
366 int (*store_setspeed) (struct cpufreq_policy *policy,
368 unsigned int max_transition_latency; /* HW must be able to switch to
369 next freq faster than this value in nano secs or we
370 will fallback to performance governor */
371 struct list_head governor_list;
372 struct module *owner;
375 /* Pass a target to the cpufreq driver */
376 int cpufreq_driver_target(struct cpufreq_policy *policy,
377 unsigned int target_freq,
378 unsigned int relation);
379 int __cpufreq_driver_target(struct cpufreq_policy *policy,
380 unsigned int target_freq,
381 unsigned int relation);
382 int cpufreq_register_governor(struct cpufreq_governor *governor);
383 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
385 /* CPUFREQ DEFAULT GOVERNOR */
387 * Performance governor is fallback governor if any other gov failed to auto
388 * load due latency restrictions
390 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
391 extern struct cpufreq_governor cpufreq_gov_performance;
393 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
394 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
395 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
396 extern struct cpufreq_governor cpufreq_gov_powersave;
397 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
398 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
399 extern struct cpufreq_governor cpufreq_gov_userspace;
400 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
401 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
402 extern struct cpufreq_governor cpufreq_gov_ondemand;
403 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
404 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
405 extern struct cpufreq_governor cpufreq_gov_conservative;
406 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
409 /*********************************************************************
410 * FREQUENCY TABLE HELPERS *
411 *********************************************************************/
413 #define CPUFREQ_ENTRY_INVALID ~0
414 #define CPUFREQ_TABLE_END ~1
416 struct cpufreq_frequency_table {
417 unsigned int driver_data; /* driver specific data, not used by core */
418 unsigned int frequency; /* kHz - doesn't need to be in ascending
422 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
423 struct cpufreq_frequency_table *table);
425 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
426 struct cpufreq_frequency_table *table);
427 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
429 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
430 struct cpufreq_frequency_table *table,
431 unsigned int target_freq,
432 unsigned int relation,
433 unsigned int *index);
435 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
436 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
438 /* the following funtion is for cpufreq core use only */
439 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
441 /* the following are really really optional */
442 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
443 extern struct freq_attr *cpufreq_generic_attr[];
444 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
446 void cpufreq_frequency_table_put_attr(unsigned int cpu);
447 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
448 struct cpufreq_frequency_table *table);
450 int cpufreq_generic_init(struct cpufreq_policy *policy,
451 struct cpufreq_frequency_table *table,
452 unsigned int transition_latency);
453 static inline int cpufreq_generic_exit(struct cpufreq_policy *policy)
455 cpufreq_frequency_table_put_attr(policy->cpu);
459 #endif /* _LINUX_CPUFREQ_H */