linux/include/linux/cpufreq.h
<<
>>
Prefs
   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        cpumask_var_t           cpus;   /* CPUs requiring sw coordination */
  93        cpumask_var_t           related_cpus; /* CPUs with any coordination */
  94        unsigned int            shared_type; /* ANY or ALL affected CPUs
  95                                                should set cpufreq */
  96        unsigned int            cpu;    /* cpu nr of registered CPU */
  97        struct cpufreq_cpuinfo  cpuinfo;/* see above */
  98
  99        unsigned int            min;    /* in kHz */
 100        unsigned int            max;    /* in kHz */
 101        unsigned int            cur;    /* in kHz, only needed if cpufreq
 102                                         * governors are used */
 103        unsigned int            policy; /* see above */
 104        struct cpufreq_governor *governor; /* see below */
 105
 106        struct work_struct      update; /* if update_policy() needs to be
 107                                         * called, but you're in IRQ context */
 108
 109        struct cpufreq_real_policy      user_policy;
 110
 111        struct kobject          kobj;
 112        struct completion       kobj_unregister;
 113};
 114
 115#define CPUFREQ_ADJUST          (0)
 116#define CPUFREQ_INCOMPATIBLE    (1)
 117#define CPUFREQ_NOTIFY          (2)
 118#define CPUFREQ_START           (3)
 119
 120#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 121#define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 122#define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 123#define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 124
 125/******************** cpufreq transition notifiers *******************/
 126
 127#define CPUFREQ_PRECHANGE       (0)
 128#define CPUFREQ_POSTCHANGE      (1)
 129#define CPUFREQ_RESUMECHANGE    (8)
 130#define CPUFREQ_SUSPENDCHANGE   (9)
 131
 132struct cpufreq_freqs {
 133        unsigned int cpu;       /* cpu nr */
 134        unsigned int old;
 135        unsigned int new;
 136        u8 flags;               /* flags of cpufreq_driver, see below. */
 137};
 138
 139
 140/**
 141 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 142 * @old:   old value
 143 * @div:   divisor
 144 * @mult:  multiplier
 145 *
 146 *
 147 *    new = old * mult / div
 148 */
 149static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 150{
 151#if BITS_PER_LONG == 32
 152
 153        u64 result = ((u64) old) * ((u64) mult);
 154        do_div(result, div);
 155        return (unsigned long) result;
 156
 157#elif BITS_PER_LONG == 64
 158
 159        unsigned long result = old * ((u64) mult);
 160        result /= div;
 161        return result;
 162
 163#endif
 164};
 165
 166/*********************************************************************
 167 *                          CPUFREQ GOVERNORS                        *
 168 *********************************************************************/
 169
 170#define CPUFREQ_GOV_START  1
 171#define CPUFREQ_GOV_STOP   2
 172#define CPUFREQ_GOV_LIMITS 3
 173
 174struct cpufreq_governor {
 175        char    name[CPUFREQ_NAME_LEN];
 176        int     (*governor)     (struct cpufreq_policy *policy,
 177                                 unsigned int event);
 178        ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 179                                         char *buf);
 180        int     (*store_setspeed)       (struct cpufreq_policy *policy,
 181                                         unsigned int freq);
 182        unsigned int max_transition_latency; /* HW must be able to switch to
 183                        next freq faster than this value in nano secs or we
 184                        will fallback to performance governor */
 185        struct list_head        governor_list;
 186        struct module           *owner;
 187};
 188
 189/*
 190 * Pass a target to the cpufreq driver.
 191 */
 192extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 193                                 unsigned int target_freq,
 194                                 unsigned int relation);
 195extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 196                                   unsigned int target_freq,
 197                                   unsigned int relation);
 198
 199
 200extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 201                                   unsigned int cpu);
 202
 203int cpufreq_register_governor(struct cpufreq_governor *governor);
 204void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 205
 206
 207/*********************************************************************
 208 *                      CPUFREQ DRIVER INTERFACE                     *
 209 *********************************************************************/
 210
 211#define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 212#define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 213
 214struct freq_attr;
 215
 216struct cpufreq_driver {
 217        struct module           *owner;
 218        char                    name[CPUFREQ_NAME_LEN];
 219        u8                      flags;
 220
 221        /* needed by all drivers */
 222        int     (*init)         (struct cpufreq_policy *policy);
 223        int     (*verify)       (struct cpufreq_policy *policy);
 224
 225        /* define one out of two */
 226        int     (*setpolicy)    (struct cpufreq_policy *policy);
 227        int     (*target)       (struct cpufreq_policy *policy,
 228                                 unsigned int target_freq,
 229                                 unsigned int relation);
 230
 231        /* should be defined, if possible */
 232        unsigned int    (*get)  (unsigned int cpu);
 233
 234        /* optional */
 235        unsigned int (*getavg)  (struct cpufreq_policy *policy,
 236                                 unsigned int cpu);
 237        int     (*bios_limit)   (int cpu, unsigned int *limit);
 238
 239        int     (*exit)         (struct cpufreq_policy *policy);
 240        int     (*suspend)      (struct cpufreq_policy *policy);
 241        int     (*resume)       (struct cpufreq_policy *policy);
 242        struct freq_attr        **attr;
 243};
 244
 245/* flags */
 246
 247#define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 248                                         * all ->init() calls failed */
 249#define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 250                                         * "constants" aren't affected by
 251                                         * frequency transitions */
 252#define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 253                                         * mismatches */
 254
 255int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 256int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 257
 258
 259void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
 260
 261
 262static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 263{
 264        if (policy->min < min)
 265                policy->min = min;
 266        if (policy->max < min)
 267                policy->max = min;
 268        if (policy->min > max)
 269                policy->min = max;
 270        if (policy->max > max)
 271                policy->max = max;
 272        if (policy->min > policy->max)
 273                policy->min = policy->max;
 274        return;
 275}
 276
 277struct freq_attr {
 278        struct attribute attr;
 279        ssize_t (*show)(struct cpufreq_policy *, char *);
 280        ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 281};
 282
 283#define cpufreq_freq_attr_ro(_name)             \
 284static struct freq_attr _name =                 \
 285__ATTR(_name, 0444, show_##_name, NULL)
 286
 287#define cpufreq_freq_attr_ro_perm(_name, _perm) \
 288static struct freq_attr _name =                 \
 289__ATTR(_name, _perm, show_##_name, NULL)
 290
 291#define cpufreq_freq_attr_rw(_name)             \
 292static struct freq_attr _name =                 \
 293__ATTR(_name, 0644, show_##_name, store_##_name)
 294
 295struct global_attr {
 296        struct attribute attr;
 297        ssize_t (*show)(struct kobject *kobj,
 298                        struct attribute *attr, char *buf);
 299        ssize_t (*store)(struct kobject *a, struct attribute *b,
 300                         const char *c, size_t count);
 301};
 302
 303#define define_one_global_ro(_name)             \
 304static struct global_attr _name =               \
 305__ATTR(_name, 0444, show_##_name, NULL)
 306
 307#define define_one_global_rw(_name)             \
 308static struct global_attr _name =               \
 309__ATTR(_name, 0644, show_##_name, store_##_name)
 310
 311
 312/*********************************************************************
 313 *                        CPUFREQ 2.6. INTERFACE                     *
 314 *********************************************************************/
 315int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 316int cpufreq_update_policy(unsigned int cpu);
 317
 318#ifdef CONFIG_CPU_FREQ
 319/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 320unsigned int cpufreq_get(unsigned int cpu);
 321#else
 322static inline unsigned int cpufreq_get(unsigned int cpu)
 323{
 324        return 0;
 325}
 326#endif
 327
 328/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 329#ifdef CONFIG_CPU_FREQ
 330unsigned int cpufreq_quick_get(unsigned int cpu);
 331unsigned int cpufreq_quick_get_max(unsigned int cpu);
 332#else
 333static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 334{
 335        return 0;
 336}
 337static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 338{
 339        return 0;
 340}
 341#endif
 342
 343
 344/*********************************************************************
 345 *                       CPUFREQ DEFAULT GOVERNOR                    *
 346 *********************************************************************/
 347
 348
 349/*
 350  Performance governor is fallback governor if any other gov failed to
 351  auto load due latency restrictions
 352*/
 353#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 354extern struct cpufreq_governor cpufreq_gov_performance;
 355#endif
 356#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 357#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 358#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 359extern struct cpufreq_governor cpufreq_gov_powersave;
 360#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 361#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 362extern struct cpufreq_governor cpufreq_gov_userspace;
 363#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 364#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 365extern struct cpufreq_governor cpufreq_gov_ondemand;
 366#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 367#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 368extern struct cpufreq_governor cpufreq_gov_conservative;
 369#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 370#endif
 371
 372
 373/*********************************************************************
 374 *                     FREQUENCY TABLE HELPERS                       *
 375 *********************************************************************/
 376
 377#define CPUFREQ_ENTRY_INVALID ~0
 378#define CPUFREQ_TABLE_END     ~1
 379
 380struct cpufreq_frequency_table {
 381        unsigned int    index;     /* any */
 382        unsigned int    frequency; /* kHz - doesn't need to be in ascending
 383                                    * order */
 384};
 385
 386int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 387                                    struct cpufreq_frequency_table *table);
 388
 389int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 390                                   struct cpufreq_frequency_table *table);
 391
 392int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 393                                   struct cpufreq_frequency_table *table,
 394                                   unsigned int target_freq,
 395                                   unsigned int relation,
 396                                   unsigned int *index);
 397
 398/* the following 3 funtions are for cpufreq core use only */
 399struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 400struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 401void   cpufreq_cpu_put(struct cpufreq_policy *data);
 402
 403/* the following are really really optional */
 404extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 405
 406void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 407                                      unsigned int cpu);
 408
 409void cpufreq_frequency_table_put_attr(unsigned int cpu);
 410#endif /* _LINUX_CPUFREQ_H */
 411
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.