LXR linux/include/linux/cpufreq.h

   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 */
 446