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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 <linux/cpumask.h>
15#include <linux/completion.h>
16#include <linux/kobject.h>
17#include <linux/notifier.h>
18#include <linux/sysfs.h>
19
20/*********************************************************************
21 * CPUFREQ INTERFACE *
22 *********************************************************************/
23/*
24 * Frequency values here are CPU kHz
25 *
26 * Maximum transition latency is in nanoseconds - if it's unknown,
27 * CPUFREQ_ETERNAL shall be used.
28 */
29
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)
34
35struct cpufreq_governor;
36
37struct cpufreq_freqs {
38 unsigned int cpu; /* cpu nr */
39 unsigned int old;
40 unsigned int new;
41 u8 flags; /* flags of cpufreq_driver, see below. */
42};
43
44struct cpufreq_cpuinfo {
45 unsigned int max_freq;
46 unsigned int min_freq;
47
48 /* in 10^(-9) s = nanoseconds */
49 unsigned int transition_latency;
50};
51
52struct 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 */
57};
58
59struct 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 */
63
64 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
65 should set cpufreq */
66 unsigned int cpu; /* cpu nr of CPU managing this policy */
67 unsigned int last_cpu; /* cpu nr of previous CPU that managed
68 * this policy */
69 struct cpufreq_cpuinfo cpuinfo;/* see above */
70
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 */
77 void *governor_data;
78 bool governor_enabled; /* governor start/stop flag */
79
80 struct work_struct update; /* if update_policy() needs to be
81 * called, but you're in IRQ context */
82
83 struct cpufreq_real_policy user_policy;
84
85 struct list_head policy_list;
86 struct kobject kobj;
87 struct completion kobj_unregister;
88};
89
90/* Only for ACPI */
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*/
95
96struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
97void cpufreq_cpu_put(struct cpufreq_policy *policy);
98
99static inline bool policy_is_shared(struct cpufreq_policy *policy)
100{
101 return cpumask_weight(policy->cpus) > 1;
102}
103
104/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
105extern struct kobject *cpufreq_global_kobject;
106int cpufreq_get_global_kobject(void);
107void cpufreq_put_global_kobject(void);
108int cpufreq_sysfs_create_file(const struct attribute *attr);
109void cpufreq_sysfs_remove_file(const struct attribute *attr);
110
111#ifdef CONFIG_CPU_FREQ
112unsigned int cpufreq_get(unsigned int cpu);
113unsigned int cpufreq_quick_get(unsigned int cpu);
114unsigned int cpufreq_quick_get_max(unsigned int cpu);
115void disable_cpufreq(void);
116
117u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
118int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
119int cpufreq_update_policy(unsigned int cpu);
120bool have_governor_per_policy(void);
121struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
122#else
123static inline unsigned int cpufreq_get(unsigned int cpu)
124{
125 return 0;
126}
127static inline unsigned int cpufreq_quick_get(unsigned int cpu)
128{
129 return 0;
130}
131static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
132{
133 return 0;
134}
135static inline void disable_cpufreq(void) { }
136#endif
137
138/*********************************************************************
139 * CPUFREQ DRIVER INTERFACE *
140 *********************************************************************/
141
142#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
143#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
144
145struct freq_attr {
146 struct attribute attr;
147 ssize_t (*show)(struct cpufreq_policy *, char *);
148 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
149};
150
151#define cpufreq_freq_attr_ro(_name) \
152static struct freq_attr _name = \
153__ATTR(_name, 0444, show_##_name, NULL)
154
155#define cpufreq_freq_attr_ro_perm(_name, _perm) \
156static struct freq_attr _name = \
157__ATTR(_name, _perm, show_##_name, NULL)
158
159#define cpufreq_freq_attr_rw(_name) \
160static struct freq_attr _name = \
161__ATTR(_name, 0644, show_##_name, store_##_name)
162
163struct global_attr {
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);
169};
170
171#define define_one_global_ro(_name) \
172static struct global_attr _name = \
173__ATTR(_name, 0444, show_##_name, NULL)
174
175#define define_one_global_rw(_name) \
176static struct global_attr _name = \
177__ATTR(_name, 0644, show_##_name, store_##_name)
178
179
180struct cpufreq_driver {
181 char name[CPUFREQ_NAME_LEN];
182 u8 flags;
183 /*
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.
188 */
189 bool have_governor_per_policy;
190
191 /* needed by all drivers */
192 int (*init) (struct cpufreq_policy *policy);
193 int (*verify) (struct cpufreq_policy *policy);
194
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);
200
201 /* should be defined, if possible */
202 unsigned int (*get) (unsigned int cpu);
203
204 /* optional */
205 int (*bios_limit) (int cpu, unsigned int *limit);
206
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;
211};
212
213/* flags */
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
220 * mismatches */
221
222int cpufreq_register_driver(struct cpufreq_driver *driver_data);
223int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
224
225const char *cpufreq_get_current_driver(void);
226
227static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
228 unsigned int min, unsigned int max)
229{
230 if (policy->min < min)
231 policy->min = min;
232 if (policy->max < min)
233 policy->max = min;
234 if (policy->min > max)
235 policy->min = max;
236 if (policy->max > max)
237 policy->max = max;
238 if (policy->min > policy->max)
239 policy->min = policy->max;
240 return;
241}
242
243/*********************************************************************
244 * CPUFREQ NOTIFIER INTERFACE *
245 *********************************************************************/
246
247#define CPUFREQ_TRANSITION_NOTIFIER (0)
248#define CPUFREQ_POLICY_NOTIFIER (1)
249
250/* Transition notifiers */
251#define CPUFREQ_PRECHANGE (0)
252#define CPUFREQ_POSTCHANGE (1)
253#define CPUFREQ_RESUMECHANGE (8)
254#define CPUFREQ_SUSPENDCHANGE (9)
255
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)
262
263#ifdef CONFIG_CPU_FREQ
264int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
265int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
266
267void cpufreq_notify_transition(struct cpufreq_policy *policy,
268 struct cpufreq_freqs *freqs, unsigned int state);
269
270#else /* CONFIG_CPU_FREQ */
271static inline int cpufreq_register_notifier(struct notifier_block *nb,
272 unsigned int list)
273{
274 return 0;
275}
276static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
277 unsigned int list)
278{
279 return 0;
280}
281#endif /* !CONFIG_CPU_FREQ */
282
283/**
284 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
285 * safe)
286 * @old: old value
287 * @div: divisor
288 * @mult: multiplier
289 *
290 *
291 * new = old * mult / div
292 */
293static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
294 u_int mult)
295{
296#if BITS_PER_LONG == 32
297 u64 result = ((u64) old) * ((u64) mult);
298 do_div(result, div);
299 return (unsigned long) result;
300
301#elif BITS_PER_LONG == 64
302 unsigned long result = old * ((u64) mult);
303 result /= div;
304 return result;
305#endif
306}
307
308/*********************************************************************
309 * CPUFREQ GOVERNORS *
310 *********************************************************************/
311
312/*
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:
316 */
317#define CPUFREQ_POLICY_POWERSAVE (1)
318#define CPUFREQ_POLICY_PERFORMANCE (2)
319
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
326
327struct cpufreq_governor {
328 char name[CPUFREQ_NAME_LEN];
329 int initialized;
330 int (*governor) (struct cpufreq_policy *policy,
331 unsigned int event);
332 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
333 char *buf);
334 int (*store_setspeed) (struct cpufreq_policy *policy,
335 unsigned int freq);
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;
341};
342
343/* Pass a target to the cpufreq driver */
344int cpufreq_driver_target(struct cpufreq_policy *policy,
345 unsigned int target_freq,
346 unsigned int relation);
347int __cpufreq_driver_target(struct cpufreq_policy *policy,
348 unsigned int target_freq,
349 unsigned int relation);
350int cpufreq_register_governor(struct cpufreq_governor *governor);
351void cpufreq_unregister_governor(struct cpufreq_governor *governor);
352
353/* CPUFREQ DEFAULT GOVERNOR */
354/*
355 * Performance governor is fallback governor if any other gov failed to auto
356 * load due latency restrictions
357 */
358#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
359extern struct cpufreq_governor cpufreq_gov_performance;
360#endif
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)
364extern struct cpufreq_governor cpufreq_gov_powersave;
365#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
366#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
367extern struct cpufreq_governor cpufreq_gov_userspace;
368#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
369#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
370extern struct cpufreq_governor cpufreq_gov_ondemand;
371#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
372#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
373extern struct cpufreq_governor cpufreq_gov_conservative;
374#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
375#endif
376
377/*********************************************************************
378 * FREQUENCY TABLE HELPERS *
379 *********************************************************************/
380
381#define CPUFREQ_ENTRY_INVALID ~0
382#define CPUFREQ_TABLE_END ~1
383
384struct 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
387 * order */
388};
389
390int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
391 struct cpufreq_frequency_table *table);
392
393int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
394 struct cpufreq_frequency_table *table);
395
396int 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);
401
402void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
403ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
404
405/* the following funtion is for cpufreq core use only */
406struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
407
408/* the following are really really optional */
409extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
410void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
411 unsigned int cpu);
412void cpufreq_frequency_table_put_attr(unsigned int cpu);
413
414#endif /* _LINUX_CPUFREQ_H */