intel_pstate: Add trace point to report internal state.
[linux-block.git] / include / linux / cpufreq.h
CommitLineData
1da177e4 1/*
bb176f7d 2 * linux/include/linux/cpufreq.h
1da177e4 3 *
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4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
335dc333 6 *
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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
652ed95d 14#include <linux/clk.h>
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15#include <linux/cpumask.h>
16#include <linux/completion.h>
1da177e4 17#include <linux/kobject.h>
5ff0a268 18#include <linux/notifier.h>
1da177e4 19#include <linux/sysfs.h>
1da177e4 20
1da177e4 21/*********************************************************************
74aca95d 22 * CPUFREQ INTERFACE *
1da177e4 23 *********************************************************************/
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24/*
25 * Frequency values here are CPU kHz
26 *
b53cc6ea 27 * Maximum transition latency is in nanoseconds - if it's unknown,
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28 * CPUFREQ_ETERNAL shall be used.
29 */
30
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31#define CPUFREQ_ETERNAL (-1)
32#define CPUFREQ_NAME_LEN 16
33/* Print length for names. Extra 1 space for accomodating '\n' in prints */
34#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
35
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36struct cpufreq_governor;
37
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38struct cpufreq_freqs {
39 unsigned int cpu; /* cpu nr */
40 unsigned int old;
41 unsigned int new;
42 u8 flags; /* flags of cpufreq_driver, see below. */
43};
8aa84ad8 44
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45struct cpufreq_cpuinfo {
46 unsigned int max_freq;
47 unsigned int min_freq;
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48
49 /* in 10^(-9) s = nanoseconds */
50 unsigned int transition_latency;
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51};
52
53struct cpufreq_real_policy {
54 unsigned int min; /* in kHz */
55 unsigned int max; /* in kHz */
335dc333 56 unsigned int policy; /* see above */
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57 struct cpufreq_governor *governor; /* see below */
58};
59
60struct cpufreq_policy {
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61 /* CPUs sharing clock, require sw coordination */
62 cpumask_var_t cpus; /* Online CPUs only */
63 cpumask_var_t related_cpus; /* Online + Offline CPUs */
64
62b36cc1 65 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
3b2d9942 66 should set cpufreq */
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67 unsigned int cpu; /* cpu nr of CPU managing this policy */
68 unsigned int last_cpu; /* cpu nr of previous CPU that managed
69 * this policy */
652ed95d 70 struct clk *clk;
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71 struct cpufreq_cpuinfo cpuinfo;/* see above */
72
73 unsigned int min; /* in kHz */
74 unsigned int max; /* in kHz */
75 unsigned int cur; /* in kHz, only needed if cpufreq
76 * governors are used */
335dc333 77 unsigned int policy; /* see above */
1da177e4 78 struct cpufreq_governor *governor; /* see below */
7bd353a9 79 void *governor_data;
95731ebb 80 bool governor_enabled; /* governor start/stop flag */
1da177e4 81
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82 struct work_struct update; /* if update_policy() needs to be
83 * called, but you're in IRQ context */
84
85 struct cpufreq_real_policy user_policy;
86
c88a1f8b 87 struct list_head policy_list;
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88 struct kobject kobj;
89 struct completion kobj_unregister;
ad7722da 90
91 /*
92 * The rules for this semaphore:
93 * - Any routine that wants to read from the policy structure will
94 * do a down_read on this semaphore.
95 * - Any routine that will write to the policy structure and/or may take away
96 * the policy altogether (eg. CPU hotplug), will hold this lock in write
97 * mode before doing so.
98 *
99 * Additional rules:
100 * - Lock should not be held across
101 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
102 */
103 struct rw_semaphore rwsem;
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104};
105
62b36cc1 106/* Only for ACPI */
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107#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
108#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
109#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
110#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
1da177e4 111
c75b505d 112#ifdef CONFIG_CPU_FREQ
74aca95d 113struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
3a3e9e06 114void cpufreq_cpu_put(struct cpufreq_policy *policy);
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115#else
116static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
117{
118 return NULL;
119}
120static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
121#endif
74aca95d 122
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123static inline bool policy_is_shared(struct cpufreq_policy *policy)
124{
125 return cpumask_weight(policy->cpus) > 1;
126}
127
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128/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
129extern struct kobject *cpufreq_global_kobject;
130int cpufreq_get_global_kobject(void);
131void cpufreq_put_global_kobject(void);
132int cpufreq_sysfs_create_file(const struct attribute *attr);
133void cpufreq_sysfs_remove_file(const struct attribute *attr);
1da177e4 134
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135#ifdef CONFIG_CPU_FREQ
136unsigned int cpufreq_get(unsigned int cpu);
137unsigned int cpufreq_quick_get(unsigned int cpu);
138unsigned int cpufreq_quick_get_max(unsigned int cpu);
139void disable_cpufreq(void);
1da177e4 140
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141u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
142int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
143int cpufreq_update_policy(unsigned int cpu);
144bool have_governor_per_policy(void);
145struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
146#else
147static inline unsigned int cpufreq_get(unsigned int cpu)
1da177e4 148{
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149 return 0;
150}
151static inline unsigned int cpufreq_quick_get(unsigned int cpu)
152{
153 return 0;
154}
155static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
156{
157 return 0;
158}
159static inline void disable_cpufreq(void) { }
1da177e4 160#endif
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161
162/*********************************************************************
74aca95d 163 * CPUFREQ DRIVER INTERFACE *
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164 *********************************************************************/
165
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166#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
167#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
1da177e4 168
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169struct freq_attr {
170 struct attribute attr;
171 ssize_t (*show)(struct cpufreq_policy *, char *);
172 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
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173};
174
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175#define cpufreq_freq_attr_ro(_name) \
176static struct freq_attr _name = \
177__ATTR(_name, 0444, show_##_name, NULL)
1da177e4 178
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179#define cpufreq_freq_attr_ro_perm(_name, _perm) \
180static struct freq_attr _name = \
181__ATTR(_name, _perm, show_##_name, NULL)
1da177e4 182
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183#define cpufreq_freq_attr_rw(_name) \
184static struct freq_attr _name = \
185__ATTR(_name, 0644, show_##_name, store_##_name)
186
187struct global_attr {
188 struct attribute attr;
189 ssize_t (*show)(struct kobject *kobj,
190 struct attribute *attr, char *buf);
191 ssize_t (*store)(struct kobject *a, struct attribute *b,
192 const char *c, size_t count);
193};
194
195#define define_one_global_ro(_name) \
196static struct global_attr _name = \
197__ATTR(_name, 0444, show_##_name, NULL)
198
199#define define_one_global_rw(_name) \
200static struct global_attr _name = \
201__ATTR(_name, 0644, show_##_name, store_##_name)
1da177e4 202
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203
204struct cpufreq_driver {
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205 char name[CPUFREQ_NAME_LEN];
206 u8 flags;
207
208 /* needed by all drivers */
209 int (*init) (struct cpufreq_policy *policy);
210 int (*verify) (struct cpufreq_policy *policy);
211
212 /* define one out of two */
213 int (*setpolicy) (struct cpufreq_policy *policy);
9c0ebcf7 214 int (*target) (struct cpufreq_policy *policy, /* Deprecated */
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215 unsigned int target_freq,
216 unsigned int relation);
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217 int (*target_index) (struct cpufreq_policy *policy,
218 unsigned int index);
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219
220 /* should be defined, if possible */
221 unsigned int (*get) (unsigned int cpu);
222
223 /* optional */
e2f74f35 224 int (*bios_limit) (int cpu, unsigned int *limit);
bf0b90e3 225
1da177e4 226 int (*exit) (struct cpufreq_policy *policy);
7ca64e2d 227 int (*suspend) (struct cpufreq_policy *policy);
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228 int (*resume) (struct cpufreq_policy *policy);
229 struct freq_attr **attr;
230};
231
232/* flags */
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233#define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if
234 all ->init() calls failed */
235#define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other
236 kernel "constants" aren't
237 affected by frequency
238 transitions */
239#define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume
240 speed mismatches */
1da177e4 241
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242/*
243 * This should be set by platforms having multiple clock-domains, i.e.
244 * supporting multiple policies. With this sysfs directories of governor would
245 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
246 * governor with different tunables for different clusters.
247 */
248#define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
249
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250/*
251 * Driver will do POSTCHANGE notifications from outside of their ->target()
252 * routine and so must set cpufreq_driver->flags with this flag, so that core
253 * can handle them specially.
254 */
255#define CPUFREQ_ASYNC_NOTIFICATION (1 << 4)
256
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257/*
258 * Set by drivers which want cpufreq core to check if CPU is running at a
259 * frequency present in freq-table exposed by the driver. For these drivers if
260 * CPU is found running at an out of table freq, we will try to set it to a freq
261 * from the table. And if that fails, we will stop further boot process by
262 * issuing a BUG_ON().
263 */
264#define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
265
221dee28
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266int cpufreq_register_driver(struct cpufreq_driver *driver_data);
267int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
1da177e4 268
74aca95d 269const char *cpufreq_get_current_driver(void);
1da177e4 270
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271static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
272 unsigned int min, unsigned int max)
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273{
274 if (policy->min < min)
275 policy->min = min;
276 if (policy->max < min)
277 policy->max = min;
278 if (policy->min > max)
279 policy->min = max;
280 if (policy->max > max)
281 policy->max = max;
282 if (policy->min > policy->max)
283 policy->min = policy->max;
284 return;
285}
286
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287static inline void
288cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
289{
290 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
291 policy->cpuinfo.max_freq);
292}
293
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294/*********************************************************************
295 * CPUFREQ NOTIFIER INTERFACE *
296 *********************************************************************/
6dad2a29 297
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298#define CPUFREQ_TRANSITION_NOTIFIER (0)
299#define CPUFREQ_POLICY_NOTIFIER (1)
1da177e4 300
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301/* Transition notifiers */
302#define CPUFREQ_PRECHANGE (0)
303#define CPUFREQ_POSTCHANGE (1)
304#define CPUFREQ_RESUMECHANGE (8)
305#define CPUFREQ_SUSPENDCHANGE (9)
6dad2a29 306
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307/* Policy Notifiers */
308#define CPUFREQ_ADJUST (0)
309#define CPUFREQ_INCOMPATIBLE (1)
310#define CPUFREQ_NOTIFY (2)
311#define CPUFREQ_START (3)
312#define CPUFREQ_UPDATE_POLICY_CPU (4)
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313#define CPUFREQ_CREATE_POLICY (5)
314#define CPUFREQ_REMOVE_POLICY (6)
6dad2a29 315
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316#ifdef CONFIG_CPU_FREQ
317int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
318int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
6dad2a29 319
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320void cpufreq_notify_transition(struct cpufreq_policy *policy,
321 struct cpufreq_freqs *freqs, unsigned int state);
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322void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
323 struct cpufreq_freqs *freqs, int transition_failed);
1da177e4 324
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325#else /* CONFIG_CPU_FREQ */
326static inline int cpufreq_register_notifier(struct notifier_block *nb,
327 unsigned int list)
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328{
329 return 0;
330}
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331static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
332 unsigned int list)
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333{
334 return 0;
335}
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336#endif /* !CONFIG_CPU_FREQ */
337
338/**
339 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
340 * safe)
341 * @old: old value
342 * @div: divisor
343 * @mult: multiplier
344 *
345 *
346 * new = old * mult / div
347 */
348static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
349 u_int mult)
3d737108 350{
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351#if BITS_PER_LONG == 32
352 u64 result = ((u64) old) * ((u64) mult);
353 do_div(result, div);
354 return (unsigned long) result;
355
356#elif BITS_PER_LONG == 64
357 unsigned long result = old * ((u64) mult);
358 result /= div;
359 return result;
95235ca2 360#endif
74aca95d 361}
95235ca2 362
1da177e4 363/*********************************************************************
74aca95d 364 * CPUFREQ GOVERNORS *
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365 *********************************************************************/
366
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367/*
368 * If (cpufreq_driver->target) exists, the ->governor decides what frequency
369 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
370 * two generic policies are available:
371 */
372#define CPUFREQ_POLICY_POWERSAVE (1)
373#define CPUFREQ_POLICY_PERFORMANCE (2)
374
375/* Governor Events */
376#define CPUFREQ_GOV_START 1
377#define CPUFREQ_GOV_STOP 2
378#define CPUFREQ_GOV_LIMITS 3
379#define CPUFREQ_GOV_POLICY_INIT 4
380#define CPUFREQ_GOV_POLICY_EXIT 5
381
382struct cpufreq_governor {
383 char name[CPUFREQ_NAME_LEN];
384 int initialized;
385 int (*governor) (struct cpufreq_policy *policy,
386 unsigned int event);
387 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
388 char *buf);
389 int (*store_setspeed) (struct cpufreq_policy *policy,
390 unsigned int freq);
391 unsigned int max_transition_latency; /* HW must be able to switch to
392 next freq faster than this value in nano secs or we
393 will fallback to performance governor */
394 struct list_head governor_list;
395 struct module *owner;
396};
397
398/* Pass a target to the cpufreq driver */
399int cpufreq_driver_target(struct cpufreq_policy *policy,
400 unsigned int target_freq,
401 unsigned int relation);
402int __cpufreq_driver_target(struct cpufreq_policy *policy,
403 unsigned int target_freq,
404 unsigned int relation);
405int cpufreq_register_governor(struct cpufreq_governor *governor);
406void cpufreq_unregister_governor(struct cpufreq_governor *governor);
407
408/* CPUFREQ DEFAULT GOVERNOR */
1c256245 409/*
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410 * Performance governor is fallback governor if any other gov failed to auto
411 * load due latency restrictions
412 */
6afde10c 413#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
1da177e4 414extern struct cpufreq_governor cpufreq_gov_performance;
6afde10c 415#endif
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416#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
417#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
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418#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
419extern struct cpufreq_governor cpufreq_gov_powersave;
420#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
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421#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
422extern struct cpufreq_governor cpufreq_gov_userspace;
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423#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
424#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
425extern struct cpufreq_governor cpufreq_gov_ondemand;
426#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
427#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
428extern struct cpufreq_governor cpufreq_gov_conservative;
429#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
1da177e4
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430#endif
431
1da177e4
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432/*********************************************************************
433 * FREQUENCY TABLE HELPERS *
434 *********************************************************************/
435
436#define CPUFREQ_ENTRY_INVALID ~0
437#define CPUFREQ_TABLE_END ~1
438
439struct cpufreq_frequency_table {
50701588 440 unsigned int driver_data; /* driver specific data, not used by core */
1da177e4
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441 unsigned int frequency; /* kHz - doesn't need to be in ascending
442 * order */
443};
444
445int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
446 struct cpufreq_frequency_table *table);
447
448int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
449 struct cpufreq_frequency_table *table);
18434512 450int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
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451
452int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
453 struct cpufreq_frequency_table *table,
454 unsigned int target_freq,
455 unsigned int relation,
456 unsigned int *index);
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457int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
458 unsigned int freq);
1da177e4 459
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460void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
461ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
462
463/* the following funtion is for cpufreq core use only */
1da177e4 464struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
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465
466/* the following are really really optional */
467extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
18434512 468extern struct freq_attr *cpufreq_generic_attr[];
335dc333 469void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
1da177e4 470 unsigned int cpu);
1da177e4 471void cpufreq_frequency_table_put_attr(unsigned int cpu);
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472int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
473 struct cpufreq_frequency_table *table);
f4fd3797 474
652ed95d 475unsigned int cpufreq_generic_get(unsigned int cpu);
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476int cpufreq_generic_init(struct cpufreq_policy *policy,
477 struct cpufreq_frequency_table *table,
478 unsigned int transition_latency);
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479static inline int cpufreq_generic_exit(struct cpufreq_policy *policy)
480{
481 cpufreq_frequency_table_put_attr(policy->cpu);
482 return 0;
483}
484
1da177e4 485#endif /* _LINUX_CPUFREQ_H */