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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/*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
33
34#define CPUFREQ_TRANSITION_NOTIFIER (0)
35#define CPUFREQ_POLICY_NOTIFIER (1)
36
37#ifdef CONFIG_CPU_FREQ
38int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
39int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
40extern void disable_cpufreq(void);
41#else /* CONFIG_CPU_FREQ */
42static inline int cpufreq_register_notifier(struct notifier_block *nb,
43 unsigned int list)
44{
45 return 0;
46}
47static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
48 unsigned int list)
49{
50 return 0;
51}
52static inline void disable_cpufreq(void) { }
53#endif /* CONFIG_CPU_FREQ */
54
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:
58 */
59
60#define CPUFREQ_POLICY_POWERSAVE (1)
61#define CPUFREQ_POLICY_PERFORMANCE (2)
62
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.
68 */
69
70struct cpufreq_governor;
71
72/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
73extern struct kobject *cpufreq_global_kobject;
74
75#define CPUFREQ_ETERNAL (-1)
76struct cpufreq_cpuinfo {
77 unsigned int max_freq;
78 unsigned int min_freq;
79
80 /* in 10^(-9) s = nanoseconds */
81 unsigned int transition_latency;
82};
83
84struct cpufreq_real_policy {
85 unsigned int min; /* in kHz */
86 unsigned int max; /* in kHz */
87 unsigned int policy; /* see above */
88 struct cpufreq_governor *governor; /* see below */
89};
90
91struct cpufreq_policy {
92 /* CPUs sharing clock, require sw coordination */
93 cpumask_var_t cpus; /* Online CPUs only */
94 cpumask_var_t related_cpus; /* Online + Offline CPUs */
95
96 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
97 should set cpufreq */
98 unsigned int cpu; /* cpu nr of CPU managing this policy */
99 unsigned int last_cpu; /* cpu nr of previous CPU that managed
100 * this policy */
101 struct cpufreq_cpuinfo cpuinfo;/* see above */
102
103 unsigned int min; /* in kHz */
104 unsigned int max; /* in kHz */
105 unsigned int cur; /* in kHz, only needed if cpufreq
106 * governors are used */
107 unsigned int policy; /* see above */
108 struct cpufreq_governor *governor; /* see below */
109 void *governor_data;
110
111 struct work_struct update; /* if update_policy() needs to be
112 * called, but you're in IRQ context */
113
114 struct cpufreq_real_policy user_policy;
115
116 struct kobject kobj;
117 struct completion kobj_unregister;
118};
119
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)
125
126/* Only for ACPI */
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*/
131
132static inline bool policy_is_shared(struct cpufreq_policy *policy)
133{
134 return cpumask_weight(policy->cpus) > 1;
135}
136
137/******************** cpufreq transition notifiers *******************/
138
139#define CPUFREQ_PRECHANGE (0)
140#define CPUFREQ_POSTCHANGE (1)
141#define CPUFREQ_RESUMECHANGE (8)
142#define CPUFREQ_SUSPENDCHANGE (9)
143
144struct cpufreq_freqs {
145 unsigned int cpu; /* cpu nr */
146 unsigned int old;
147 unsigned int new;
148 u8 flags; /* flags of cpufreq_driver, see below. */
149};
150
151
152/**
153 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
154 * @old: old value
155 * @div: divisor
156 * @mult: multiplier
157 *
158 *
159 * new = old * mult / div
160 */
161static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
162{
163#if BITS_PER_LONG == 32
164
165 u64 result = ((u64) old) * ((u64) mult);
166 do_div(result, div);
167 return (unsigned long) result;
168
169#elif BITS_PER_LONG == 64
170
171 unsigned long result = old * ((u64) mult);
172 result /= div;
173 return result;
174
175#endif
176};
177
178/*********************************************************************
179 * CPUFREQ GOVERNORS *
180 *********************************************************************/
181
182#define CPUFREQ_GOV_START 1
183#define CPUFREQ_GOV_STOP 2
184#define CPUFREQ_GOV_LIMITS 3
185#define CPUFREQ_GOV_POLICY_INIT 4
186#define CPUFREQ_GOV_POLICY_EXIT 5
187
188struct cpufreq_governor {
189 char name[CPUFREQ_NAME_LEN];
190 int initialized;
191 int (*governor) (struct cpufreq_policy *policy,
192 unsigned int event);
193 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
194 char *buf);
195 int (*store_setspeed) (struct cpufreq_policy *policy,
196 unsigned int freq);
197 unsigned int max_transition_latency; /* HW must be able to switch to
198 next freq faster than this value in nano secs or we
199 will fallback to performance governor */
200 struct list_head governor_list;
201 struct module *owner;
202};
203
204/*
205 * Pass a target to the cpufreq driver.
206 */
207extern int cpufreq_driver_target(struct cpufreq_policy *policy,
208 unsigned int target_freq,
209 unsigned int relation);
210extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
211 unsigned int target_freq,
212 unsigned int relation);
213
214
215extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
216 unsigned int cpu);
217
218int cpufreq_register_governor(struct cpufreq_governor *governor);
219void cpufreq_unregister_governor(struct cpufreq_governor *governor);
220
221
222/*********************************************************************
223 * CPUFREQ DRIVER INTERFACE *
224 *********************************************************************/
225
226#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
227#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
228
229struct freq_attr;
230
231struct cpufreq_driver {
232 struct module *owner;
233 char name[CPUFREQ_NAME_LEN];
234 u8 flags;
235 /*
236 * This should be set by platforms having multiple clock-domains, i.e.
237 * supporting multiple policies. With this sysfs directories of governor
238 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
239 * use the same governor with different tunables for different clusters.
240 */
241 bool have_governor_per_policy;
242
243 /* needed by all drivers */
244 int (*init) (struct cpufreq_policy *policy);
245 int (*verify) (struct cpufreq_policy *policy);
246
247 /* define one out of two */
248 int (*setpolicy) (struct cpufreq_policy *policy);
249 int (*target) (struct cpufreq_policy *policy,
250 unsigned int target_freq,
251 unsigned int relation);
252
253 /* should be defined, if possible */
254 unsigned int (*get) (unsigned int cpu);
255
256 /* optional */
257 unsigned int (*getavg) (struct cpufreq_policy *policy,
258 unsigned int cpu);
259 int (*bios_limit) (int cpu, unsigned int *limit);
260
261 int (*exit) (struct cpufreq_policy *policy);
262 int (*suspend) (struct cpufreq_policy *policy);
263 int (*resume) (struct cpufreq_policy *policy);
264 struct freq_attr **attr;
265};
266
267/* flags */
268
269#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
270 * all ->init() calls failed */
271#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
272 * "constants" aren't affected by
273 * frequency transitions */
274#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
275 * mismatches */
276
277int cpufreq_register_driver(struct cpufreq_driver *driver_data);
278int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
279
280
281void cpufreq_notify_transition(struct cpufreq_policy *policy,
282 struct cpufreq_freqs *freqs, unsigned int state);
283
284static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
285{
286 if (policy->min < min)
287 policy->min = min;
288 if (policy->max < min)
289 policy->max = min;
290 if (policy->min > max)
291 policy->min = max;
292 if (policy->max > max)
293 policy->max = max;
294 if (policy->min > policy->max)
295 policy->min = policy->max;
296 return;
297}
298
299struct freq_attr {
300 struct attribute attr;
301 ssize_t (*show)(struct cpufreq_policy *, char *);
302 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
303};
304
305#define cpufreq_freq_attr_ro(_name) \
306static struct freq_attr _name = \
307__ATTR(_name, 0444, show_##_name, NULL)
308
309#define cpufreq_freq_attr_ro_perm(_name, _perm) \
310static struct freq_attr _name = \
311__ATTR(_name, _perm, show_##_name, NULL)
312
313#define cpufreq_freq_attr_rw(_name) \
314static struct freq_attr _name = \
315__ATTR(_name, 0644, show_##_name, store_##_name)
316
317struct global_attr {
318 struct attribute attr;
319 ssize_t (*show)(struct kobject *kobj,
320 struct attribute *attr, char *buf);
321 ssize_t (*store)(struct kobject *a, struct attribute *b,
322 const char *c, size_t count);
323};
324
325#define define_one_global_ro(_name) \
326static struct global_attr _name = \
327__ATTR(_name, 0444, show_##_name, NULL)
328
329#define define_one_global_rw(_name) \
330static struct global_attr _name = \
331__ATTR(_name, 0644, show_##_name, store_##_name)
332
333struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
334void cpufreq_cpu_put(struct cpufreq_policy *data);
335const char *cpufreq_get_current_driver(void);
336
337/*********************************************************************
338 * CPUFREQ 2.6. INTERFACE *
339 *********************************************************************/
340int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
341int cpufreq_update_policy(unsigned int cpu);
342bool have_governor_per_policy(void);
343
344#ifdef CONFIG_CPU_FREQ
345/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
346unsigned int cpufreq_get(unsigned int cpu);
347#else
348static inline unsigned int cpufreq_get(unsigned int cpu)
349{
350 return 0;
351}
352#endif
353
354/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
355#ifdef CONFIG_CPU_FREQ
356unsigned int cpufreq_quick_get(unsigned int cpu);
357unsigned int cpufreq_quick_get_max(unsigned int cpu);
358#else
359static inline unsigned int cpufreq_quick_get(unsigned int cpu)
360{
361 return 0;
362}
363static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
364{
365 return 0;
366}
367#endif
368
369
370/*********************************************************************
371 * CPUFREQ DEFAULT GOVERNOR *
372 *********************************************************************/
373
374
375/*
376 Performance governor is fallback governor if any other gov failed to
377 auto load due latency restrictions
378*/
379#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
380extern struct cpufreq_governor cpufreq_gov_performance;
381#endif
382#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
383#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
384#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
385extern struct cpufreq_governor cpufreq_gov_powersave;
386#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
387#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
388extern struct cpufreq_governor cpufreq_gov_userspace;
389#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
390#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
391extern struct cpufreq_governor cpufreq_gov_ondemand;
392#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
393#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
394extern struct cpufreq_governor cpufreq_gov_conservative;
395#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
396#endif
397
398
399/*********************************************************************
400 * FREQUENCY TABLE HELPERS *
401 *********************************************************************/
402
403#define CPUFREQ_ENTRY_INVALID ~0
404#define CPUFREQ_TABLE_END ~1
405
406struct cpufreq_frequency_table {
407 unsigned int index; /* any */
408 unsigned int frequency; /* kHz - doesn't need to be in ascending
409 * order */
410};
411
412int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
413 struct cpufreq_frequency_table *table);
414
415int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
416 struct cpufreq_frequency_table *table);
417
418int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
419 struct cpufreq_frequency_table *table,
420 unsigned int target_freq,
421 unsigned int relation,
422 unsigned int *index);
423
424/* the following 3 funtions are for cpufreq core use only */
425struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
426
427/* the following are really really optional */
428extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
429
430void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
431 unsigned int cpu);
432void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
433
434void cpufreq_frequency_table_put_attr(unsigned int cpu);
435#endif /* _LINUX_CPUFREQ_H */