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 <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 */
 415