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1/*
2 * linux/include/linux/cpufreq.h
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 *
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.
10 */
11#ifndef _LINUX_CPUFREQ_H
12#define _LINUX_CPUFREQ_H
13
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>
24
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)
28
29/*********************************************************************
30 * CPUFREQ NOTIFIER INTERFACE *
31 *********************************************************************/
32
33#define CPUFREQ_TRANSITION_NOTIFIER (0)
34#define CPUFREQ_POLICY_NOTIFIER (1)
35
36#ifdef CONFIG_CPU_FREQ
37int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
38int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
39extern void disable_cpufreq(void);
40#else /* CONFIG_CPU_FREQ */
41static inline int cpufreq_register_notifier(struct notifier_block *nb,
42 unsigned int list)
43{
44 return 0;
45}
46static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
47 unsigned int list)
48{
49 return 0;
50}
51static inline void disable_cpufreq(void) { }
52#endif /* CONFIG_CPU_FREQ */
53
54/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
56 * two generic policies are available:
57 */
58
59#define CPUFREQ_POLICY_POWERSAVE (1)
60#define CPUFREQ_POLICY_PERFORMANCE (2)
61
62/* Frequency values here are CPU kHz so that hardware which doesn't run
63 * with some frequencies can complain without having to guess what per
64 * cent / per mille means.
65 * Maximum transition latency is in nanoseconds - if it's unknown,
66 * CPUFREQ_ETERNAL shall be used.
67 */
68
69struct cpufreq_governor;
70
71/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
72extern struct kobject *cpufreq_global_kobject;
73int cpufreq_get_global_kobject(void);
74void cpufreq_put_global_kobject(void);
75int cpufreq_sysfs_create_file(const struct attribute *attr);
76void cpufreq_sysfs_remove_file(const struct attribute *attr);
77
78#define CPUFREQ_ETERNAL (-1)
79struct cpufreq_cpuinfo {
80 unsigned int max_freq;
81 unsigned int min_freq;
82
83 /* in 10^(-9) s = nanoseconds */
84 unsigned int transition_latency;
85};
86
87struct cpufreq_real_policy {
88 unsigned int min; /* in kHz */
89 unsigned int max; /* in kHz */
90 unsigned int policy; /* see above */
91 struct cpufreq_governor *governor; /* see below */
92};
93
94struct cpufreq_policy {
95 /* CPUs sharing clock, require sw coordination */
96 cpumask_var_t cpus; /* Online CPUs only */
97 cpumask_var_t related_cpus; /* Online + Offline CPUs */
98
99 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
100 should set cpufreq */
101 unsigned int cpu; /* cpu nr of CPU managing this policy */
102 unsigned int last_cpu; /* cpu nr of previous CPU that managed
103 * this policy */
104 struct cpufreq_cpuinfo cpuinfo;/* see above */
105
106 unsigned int min; /* in kHz */
107 unsigned int max; /* in kHz */
108 unsigned int cur; /* in kHz, only needed if cpufreq
109 * governors are used */
110 unsigned int policy; /* see above */
111 struct cpufreq_governor *governor; /* see below */
112 void *governor_data;
113 bool governor_enabled; /* governor start/stop flag */
114
115 struct work_struct update; /* if update_policy() needs to be
116 * called, but you're in IRQ context */
117
118 struct cpufreq_real_policy user_policy;
119
120 struct kobject kobj;
121 struct completion kobj_unregister;
122 int transition_ongoing; /* Tracks transition status */
123};
124
125#define CPUFREQ_ADJUST (0)
126#define CPUFREQ_INCOMPATIBLE (1)
127#define CPUFREQ_NOTIFY (2)
128#define CPUFREQ_START (3)
129#define CPUFREQ_UPDATE_POLICY_CPU (4)
130
131/* Only for ACPI */
132#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
133#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
134#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
135#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
136
137static inline bool policy_is_shared(struct cpufreq_policy *policy)
138{
139 return cpumask_weight(policy->cpus) > 1;
140}
141
142/******************** cpufreq transition notifiers *******************/
143
144#define CPUFREQ_PRECHANGE (0)
145#define CPUFREQ_POSTCHANGE (1)
146#define CPUFREQ_RESUMECHANGE (8)
147#define CPUFREQ_SUSPENDCHANGE (9)
148
149struct cpufreq_freqs {
150 unsigned int cpu; /* cpu nr */
151 unsigned int old;
152 unsigned int new;
153 u8 flags; /* flags of cpufreq_driver, see below. */
154};
155
156/**
157 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
158 * safe)
159 * @old: old value
160 * @div: divisor
161 * @mult: multiplier
162 *
163 *
164 * new = old * mult / div
165 */
166static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
167 u_int mult)
168{
169#if BITS_PER_LONG == 32
170
171 u64 result = ((u64) old) * ((u64) mult);
172 do_div(result, div);
173 return (unsigned long) result;
174
175#elif BITS_PER_LONG == 64
176
177 unsigned long result = old * ((u64) mult);
178 result /= div;
179 return result;
180
181#endif
182};
183
184/*********************************************************************
185 * CPUFREQ GOVERNORS *
186 *********************************************************************/
187
188#define CPUFREQ_GOV_START 1
189#define CPUFREQ_GOV_STOP 2
190#define CPUFREQ_GOV_LIMITS 3
191#define CPUFREQ_GOV_POLICY_INIT 4
192#define CPUFREQ_GOV_POLICY_EXIT 5
193
194struct cpufreq_governor {
195 char name[CPUFREQ_NAME_LEN];
196 int initialized;
197 int (*governor) (struct cpufreq_policy *policy,
198 unsigned int event);
199 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
200 char *buf);
201 int (*store_setspeed) (struct cpufreq_policy *policy,
202 unsigned int freq);
203 unsigned int max_transition_latency; /* HW must be able to switch to
204 next freq faster than this value in nano secs or we
205 will fallback to performance governor */
206 struct list_head governor_list;
207 struct module *owner;
208};
209
210/*
211 * Pass a target to the cpufreq driver.
212 */
213extern int cpufreq_driver_target(struct cpufreq_policy *policy,
214 unsigned int target_freq,
215 unsigned int relation);
216extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
217 unsigned int target_freq,
218 unsigned int relation);
219
220extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
221 unsigned int cpu);
222
223int cpufreq_register_governor(struct cpufreq_governor *governor);
224void cpufreq_unregister_governor(struct cpufreq_governor *governor);
225
226/*********************************************************************
227 * CPUFREQ DRIVER INTERFACE *
228 *********************************************************************/
229
230#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
231#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
232
233struct freq_attr;
234
235struct cpufreq_driver {
236 struct module *owner;
237 char name[CPUFREQ_NAME_LEN];
238 u8 flags;
239 /*
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.
244 */
245 bool have_governor_per_policy;
246
247 /* needed by all drivers */
248 int (*init) (struct cpufreq_policy *policy);
249 int (*verify) (struct cpufreq_policy *policy);
250
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);
256
257 /* should be defined, if possible */
258 unsigned int (*get) (unsigned int cpu);
259
260 /* optional */
261 unsigned int (*getavg) (struct cpufreq_policy *policy,
262 unsigned int cpu);
263 int (*bios_limit) (int cpu, unsigned int *limit);
264
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;
269};
270
271/* flags */
272
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
279 * mismatches */
280
281int cpufreq_register_driver(struct cpufreq_driver *driver_data);
282int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
283
284void cpufreq_notify_transition(struct cpufreq_policy *policy,
285 struct cpufreq_freqs *freqs, unsigned int state);
286
287static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
288 unsigned int min, unsigned int max)
289{
290 if (policy->min < min)
291 policy->min = min;
292 if (policy->max < min)
293 policy->max = min;
294 if (policy->min > max)
295 policy->min = max;
296 if (policy->max > max)
297 policy->max = max;
298 if (policy->min > policy->max)
299 policy->min = policy->max;
300 return;
301}
302
303struct freq_attr {
304 struct attribute attr;
305 ssize_t (*show)(struct cpufreq_policy *, char *);
306 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
307};
308
309#define cpufreq_freq_attr_ro(_name) \
310static struct freq_attr _name = \
311__ATTR(_name, 0444, show_##_name, NULL)
312
313#define cpufreq_freq_attr_ro_perm(_name, _perm) \
314static struct freq_attr _name = \
315__ATTR(_name, _perm, show_##_name, NULL)
316
317#define cpufreq_freq_attr_rw(_name) \
318static struct freq_attr _name = \
319__ATTR(_name, 0644, show_##_name, store_##_name)
320
321struct global_attr {
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);
327};
328
329#define define_one_global_ro(_name) \
330static struct global_attr _name = \
331__ATTR(_name, 0444, show_##_name, NULL)
332
333#define define_one_global_rw(_name) \
334static struct global_attr _name = \
335__ATTR(_name, 0644, show_##_name, store_##_name)
336
337struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
338void cpufreq_cpu_put(struct cpufreq_policy *data);
339const char *cpufreq_get_current_driver(void);
340
341/*********************************************************************
342 * CPUFREQ 2.6. INTERFACE *
343 *********************************************************************/
344u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
345int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
346int cpufreq_update_policy(unsigned int cpu);
347bool have_governor_per_policy(void);
348struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
349
350#ifdef CONFIG_CPU_FREQ
351/*
352 * query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it
353 */
354unsigned int cpufreq_get(unsigned int cpu);
355#else
356static inline unsigned int cpufreq_get(unsigned int cpu)
357{
358 return 0;
359}
360#endif
361
362/*
363 * query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it
364 */
365#ifdef CONFIG_CPU_FREQ
366unsigned int cpufreq_quick_get(unsigned int cpu);
367unsigned int cpufreq_quick_get_max(unsigned int cpu);
368#else
369static inline unsigned int cpufreq_quick_get(unsigned int cpu)
370{
371 return 0;
372}
373static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
374{
375 return 0;
376}
377#endif
378
379/*********************************************************************
380 * CPUFREQ DEFAULT GOVERNOR *
381 *********************************************************************/
382
383/*
384 * Performance governor is fallback governor if any other gov failed to auto
385 * load due latency restrictions
386 */
387#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
388extern struct cpufreq_governor cpufreq_gov_performance;
389#endif
390#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
391#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
392#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
393extern struct cpufreq_governor cpufreq_gov_powersave;
394#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
395#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
396extern struct cpufreq_governor cpufreq_gov_userspace;
397#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
398#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
399extern struct cpufreq_governor cpufreq_gov_ondemand;
400#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
401#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
402extern struct cpufreq_governor cpufreq_gov_conservative;
403#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
404#endif
405
406/*********************************************************************
407 * FREQUENCY TABLE HELPERS *
408 *********************************************************************/
409
410#define CPUFREQ_ENTRY_INVALID ~0
411#define CPUFREQ_TABLE_END ~1
412
413struct cpufreq_frequency_table {
414 unsigned int driver_data; /* driver specific data, not used by core */
415 unsigned int frequency; /* kHz - doesn't need to be in ascending
416 * order */
417};
418
419int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
420 struct cpufreq_frequency_table *table);
421
422int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
423 struct cpufreq_frequency_table *table);
424
425int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
426 struct cpufreq_frequency_table *table,
427 unsigned int target_freq,
428 unsigned int relation,
429 unsigned int *index);
430
431/* the following 3 funtions are for cpufreq core use only */
432struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
433
434/* the following are really really optional */
435extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
436
437void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
438 unsigned int cpu);
439void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
440
441void cpufreq_frequency_table_put_attr(unsigned int cpu);
442
443ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
444
445#endif /* _LINUX_CPUFREQ_H */