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
  35 struct cpufreq_governor;
  36
  37 struct 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
  44 struct 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
  52 struct 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
  59 struct 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
  96 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
  97 void cpufreq_cpu_put(struct cpufreq_policy *policy);
  98
  99 static 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 */
 105 extern struct kobject *cpufreq_global_kobject;
 106 int cpufreq_get_global_kobject(void);
 107 void cpufreq_put_global_kobject(void);
 108 int cpufreq_sysfs_create_file(const struct attribute *attr);
 109 void cpufreq_sysfs_remove_file(const struct attribute *attr);
 110
 111 #ifdef CONFIG_CPU_FREQ
 112 unsigned int cpufreq_get(unsigned int cpu);
 113 unsigned int cpufreq_quick_get(unsigned int cpu);
 114 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 115 void disable_cpufreq(void);
 116
 117 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 118 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 119 int cpufreq_update_policy(unsigned int cpu);
 120 bool have_governor_per_policy(void);
 121 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 122 #else
 123 static inline unsigned int cpufreq_get(unsigned int cpu)
 124 {
 125         return 0;
 126 }
 127 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 128 {
 129         return 0;
 130 }
 131 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 132 {
 133         return 0;
 134 }
 135 static 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
 145 struct 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)             \
 152 static struct freq_attr _name =                 \
 153 __ATTR(_name, 0444, show_##_name, NULL)
 154
 155 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 156 static struct freq_attr _name =                 \
 157 __ATTR(_name, _perm, show_##_name, NULL)
 158
 159 #define cpufreq_freq_attr_rw(_name)             \
 160 static struct freq_attr _name =                 \
 161 __ATTR(_name, 0644, show_##_name, store_##_name)
 162
 163 struct 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)             \
 172 static struct global_attr _name =               \
 173 __ATTR(_name, 0444, show_##_name, NULL)
 174
 175 #define define_one_global_rw(_name)             \
 176 static struct global_attr _name =               \
 177 __ATTR(_name, 0644, show_##_name, store_##_name)
 178
 179
 180 struct cpufreq_driver {
 181         char                    name[CPUFREQ_NAME_LEN];
 182         u8                      flags;
 183
 184         /* needed by all drivers */
 185         int     (*init)         (struct cpufreq_policy *policy);
 186         int     (*verify)       (struct cpufreq_policy *policy);
 187
 188         /* define one out of two */
 189         int     (*setpolicy)    (struct cpufreq_policy *policy);
 190         int     (*target)       (struct cpufreq_policy *policy,
 191                                  unsigned int target_freq,
 192                                  unsigned int relation);
 193
 194         /* should be defined, if possible */
 195         unsigned int    (*get)  (unsigned int cpu);
 196
 197         /* optional */
 198         int     (*bios_limit)   (int cpu, unsigned int *limit);
 199
 200         int     (*exit)         (struct cpufreq_policy *policy);
 201         int     (*suspend)      (struct cpufreq_policy *policy);
 202         int     (*resume)       (struct cpufreq_policy *policy);
 203         struct freq_attr        **attr;
 204 };
 205
 206 /* flags */
 207 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 208                                                    all ->init() calls failed */
 209 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 210                                                    kernel "constants" aren't
 211                                                    affected by frequency
 212                                                    transitions */
 213 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 214                                                    speed mismatches */
 215
 216 /*
 217  * This should be set by platforms having multiple clock-domains, i.e.
 218  * supporting multiple policies. With this sysfs directories of governor would
 219  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 220  * governor with different tunables for different clusters.
 221  */
 222 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 223
 224 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 225 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 226
 227 const char *cpufreq_get_current_driver(void);
 228
 229 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 230                 unsigned int min, unsigned int max)
 231 {
 232         if (policy->min < min)
 233                 policy->min = min;
 234         if (policy->max < min)
 235                 policy->max = min;
 236         if (policy->min > max)
 237                 policy->min = max;
 238         if (policy->max > max)
 239                 policy->max = max;
 240         if (policy->min > policy->max)
 241                 policy->min = policy->max;
 242         return;
 243 }
 244
 245 static inline void
 246 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 247 {
 248         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 249                         policy->cpuinfo.max_freq);
 250 }
 251
 252 /*********************************************************************
 253  *                     CPUFREQ NOTIFIER INTERFACE                    *
 254  *********************************************************************/
 255
 256 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 257 #define CPUFREQ_POLICY_NOTIFIER         (1)
 258
 259 /* Transition notifiers */
 260 #define CPUFREQ_PRECHANGE               (0)
 261 #define CPUFREQ_POSTCHANGE              (1)
 262 #define CPUFREQ_RESUMECHANGE            (8)
 263 #define CPUFREQ_SUSPENDCHANGE           (9)
 264
 265 /* Policy Notifiers  */
 266 #define CPUFREQ_ADJUST                  (0)
 267 #define CPUFREQ_INCOMPATIBLE            (1)
 268 #define CPUFREQ_NOTIFY                  (2)
 269 #define CPUFREQ_START                   (3)
 270 #define CPUFREQ_UPDATE_POLICY_CPU       (4)
 271
 272 #ifdef CONFIG_CPU_FREQ
 273 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 274 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 275
 276 void cpufreq_notify_transition(struct cpufreq_policy *policy,
 277                 struct cpufreq_freqs *freqs, unsigned int state);
 278
 279 #else /* CONFIG_CPU_FREQ */
 280 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 281                                                 unsigned int list)
 282 {
 283         return 0;
 284 }
 285 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 286                                                 unsigned int list)
 287 {
 288         return 0;
 289 }
 290 #endif /* !CONFIG_CPU_FREQ */
 291
 292 /**
 293  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 294  * safe)
 295  * @old:   old value
 296  * @div:   divisor
 297  * @mult:  multiplier
 298  *
 299  *
 300  * new = old * mult / div
 301  */
 302 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 303                 u_int mult)
 304 {
 305 #if BITS_PER_LONG == 32
 306         u64 result = ((u64) old) * ((u64) mult);
 307         do_div(result, div);
 308         return (unsigned long) result;
 309
 310 #elif BITS_PER_LONG == 64
 311         unsigned long result = old * ((u64) mult);
 312         result /= div;
 313         return result;
 314 #endif
 315 }
 316
 317 /*********************************************************************
 318  *                          CPUFREQ GOVERNORS                        *
 319  *********************************************************************/
 320
 321 /*
 322  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 323  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 324  * two generic policies are available:
 325  */
 326 #define CPUFREQ_POLICY_POWERSAVE        (1)
 327 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 328
 329 /* Governor Events */
 330 #define CPUFREQ_GOV_START       1
 331 #define CPUFREQ_GOV_STOP        2
 332 #define CPUFREQ_GOV_LIMITS      3
 333 #define CPUFREQ_GOV_POLICY_INIT 4
 334 #define CPUFREQ_GOV_POLICY_EXIT 5
 335
 336 struct cpufreq_governor {
 337         char    name[CPUFREQ_NAME_LEN];
 338         int     initialized;
 339         int     (*governor)     (struct cpufreq_policy *policy,
 340                                  unsigned int event);
 341         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 342                                          char *buf);
 343         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 344                                          unsigned int freq);
 345         unsigned int max_transition_latency; /* HW must be able to switch to
 346                         next freq faster than this value in nano secs or we
 347                         will fallback to performance governor */
 348         struct list_head        governor_list;
 349         struct module           *owner;
 350 };
 351
 352 /* Pass a target to the cpufreq driver */
 353 int cpufreq_driver_target(struct cpufreq_policy *policy,
 354                                  unsigned int target_freq,
 355                                  unsigned int relation);
 356 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 357                                    unsigned int target_freq,
 358                                    unsigned int relation);
 359 int cpufreq_register_governor(struct cpufreq_governor *governor);
 360 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 361
 362 /* CPUFREQ DEFAULT GOVERNOR */
 363 /*
 364  * Performance governor is fallback governor if any other gov failed to auto
 365  * load due latency restrictions
 366  */
 367 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 368 extern struct cpufreq_governor cpufreq_gov_performance;
 369 #endif
 370 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 371 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 372 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 373 extern struct cpufreq_governor cpufreq_gov_powersave;
 374 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 375 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 376 extern struct cpufreq_governor cpufreq_gov_userspace;
 377 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 378 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 379 extern struct cpufreq_governor cpufreq_gov_ondemand;
 380 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 381 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 382 extern struct cpufreq_governor cpufreq_gov_conservative;
 383 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 384 #endif
 385
 386 /*********************************************************************
 387  *                     FREQUENCY TABLE HELPERS                       *
 388  *********************************************************************/
 389
 390 #define CPUFREQ_ENTRY_INVALID ~0
 391 #define CPUFREQ_TABLE_END     ~1
 392
 393 struct cpufreq_frequency_table {
 394         unsigned int    driver_data; /* driver specific data, not used by core */
 395         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 396                                     * order */
 397 };
 398
 399 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 400                                     struct cpufreq_frequency_table *table);
 401
 402 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 403                                    struct cpufreq_frequency_table *table);
 404 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 405
 406 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 407                                    struct cpufreq_frequency_table *table,
 408                                    unsigned int target_freq,
 409                                    unsigned int relation,
 410                                    unsigned int *index);
 411
 412 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
 413 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 414
 415 /* the following funtion is for cpufreq core use only */
 416 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 417
 418 /* the following are really really optional */
 419 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 420 extern struct freq_attr *cpufreq_generic_attr[];
 421 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 422                                       unsigned int cpu);
 423 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 424 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 425                                       struct cpufreq_frequency_table *table);
 426
 427 int cpufreq_generic_init(struct cpufreq_policy *policy,
 428                 struct cpufreq_frequency_table *table,
 429                 unsigned int transition_latency);
 430 static inline int cpufreq_generic_exit(struct cpufreq_policy *policy)
 431 {
 432         cpufreq_frequency_table_put_attr(policy->cpu);
 433         return 0;
 434 }
 435
 436 #endif /* _LINUX_CPUFREQ_H */