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/*********************************************************************
  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 */
 436