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/clk.h>
  15 #include <linux/cpumask.h>
  16 #include <linux/completion.h>
  17 #include <linux/kobject.h>
  18 #include <linux/notifier.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/sysfs.h>
  21
  22 /*********************************************************************
  23  *                        CPUFREQ INTERFACE                          *
  24  *********************************************************************/
  25 /*
  26  * Frequency values here are CPU kHz
  27  *
  28  * Maximum transition latency is in nanoseconds - if it's unknown,
  29  * CPUFREQ_ETERNAL shall be used.
  30  */
  31
  32 #define CPUFREQ_ETERNAL                 (-1)
  33 #define CPUFREQ_NAME_LEN                16
  34 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
  35 #define CPUFREQ_NAME_PLEN               (CPUFREQ_NAME_LEN + 1)
  36
  37 struct cpufreq_governor;
  38
  39 struct cpufreq_freqs {
  40         unsigned int cpu;       /* cpu nr */
  41         unsigned int old;
  42         unsigned int new;
  43         u8 flags;               /* flags of cpufreq_driver, see below. */
  44 };
  45
  46 struct cpufreq_cpuinfo {
  47         unsigned int            max_freq;
  48         unsigned int            min_freq;
  49
  50         /* in 10^(-9) s = nanoseconds */
  51         unsigned int            transition_latency;
  52 };
  53
  54 struct cpufreq_user_policy {
  55         unsigned int            min;    /* in kHz */
  56         unsigned int            max;    /* in kHz */
  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         cpumask_var_t           real_cpus; /* Related and present */
  64
  65         unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
  66                                                 should set cpufreq */
  67         unsigned int            cpu;    /* cpu managing this policy, must be online */
  68
  69         struct clk              *clk;
  70         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  71
  72         unsigned int            min;    /* in kHz */
  73         unsigned int            max;    /* in kHz */
  74         unsigned int            cur;    /* in kHz, only needed if cpufreq
  75                                          * governors are used */
  76         unsigned int            restore_freq; /* = policy->cur before transition */
  77         unsigned int            suspend_freq; /* freq to set during suspend */
  78
  79         unsigned int            policy; /* see above */
  80         unsigned int            last_policy; /* policy before unplug */
  81         struct cpufreq_governor *governor; /* see below */
  82         void                    *governor_data;
  83         char                    last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
  84
  85         struct work_struct      update; /* if update_policy() needs to be
  86                                          * called, but you're in IRQ context */
  87
  88         struct cpufreq_user_policy user_policy;
  89         struct cpufreq_frequency_table  *freq_table;
  90
  91         struct list_head        policy_list;
  92         struct kobject          kobj;
  93         struct completion       kobj_unregister;
  94
  95         /*
  96          * The rules for this semaphore:
  97          * - Any routine that wants to read from the policy structure will
  98          *   do a down_read on this semaphore.
  99          * - Any routine that will write to the policy structure and/or may take away
 100          *   the policy altogether (eg. CPU hotplug), will hold this lock in write
 101          *   mode before doing so.
 102          */
 103         struct rw_semaphore     rwsem;
 104
 105         /* Synchronization for frequency transitions */
 106         bool                    transition_ongoing; /* Tracks transition status */
 107         spinlock_t              transition_lock;
 108         wait_queue_head_t       transition_wait;
 109         struct task_struct      *transition_task; /* Task which is doing the transition */
 110
 111         /* cpufreq-stats */
 112         struct cpufreq_stats    *stats;
 113
 114         /* For cpufreq driver's internal use */
 115         void                    *driver_data;
 116 };
 117
 118 /* Only for ACPI */
 119 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 120 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 121 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 122 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 123
 124 #ifdef CONFIG_CPU_FREQ
 125 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
 126 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 127 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 128 #else
 129 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
 130 {
 131         return NULL;
 132 }
 133 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 134 {
 135         return NULL;
 136 }
 137 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 138 #endif
 139
 140 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 141 {
 142         return cpumask_weight(policy->cpus) > 1;
 143 }
 144
 145 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 146 extern struct kobject *cpufreq_global_kobject;
 147
 148 #ifdef CONFIG_CPU_FREQ
 149 unsigned int cpufreq_get(unsigned int cpu);
 150 unsigned int cpufreq_quick_get(unsigned int cpu);
 151 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 152 void disable_cpufreq(void);
 153
 154 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 155 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 156 int cpufreq_update_policy(unsigned int cpu);
 157 bool have_governor_per_policy(void);
 158 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 159 #else
 160 static inline unsigned int cpufreq_get(unsigned int cpu)
 161 {
 162         return 0;
 163 }
 164 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 165 {
 166         return 0;
 167 }
 168 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 169 {
 170         return 0;
 171 }
 172 static inline void disable_cpufreq(void) { }
 173 #endif
 174
 175 /*********************************************************************
 176  *                      CPUFREQ DRIVER INTERFACE                     *
 177  *********************************************************************/
 178
 179 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 180 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 181 #define CPUFREQ_RELATION_C 2  /* closest frequency to target */
 182
 183 struct freq_attr {
 184         struct attribute attr;
 185         ssize_t (*show)(struct cpufreq_policy *, char *);
 186         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 187 };
 188
 189 #define cpufreq_freq_attr_ro(_name)             \
 190 static struct freq_attr _name =                 \
 191 __ATTR(_name, 0444, show_##_name, NULL)
 192
 193 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 194 static struct freq_attr _name =                 \
 195 __ATTR(_name, _perm, show_##_name, NULL)
 196
 197 #define cpufreq_freq_attr_rw(_name)             \
 198 static struct freq_attr _name =                 \
 199 __ATTR(_name, 0644, show_##_name, store_##_name)
 200
 201 struct global_attr {
 202         struct attribute attr;
 203         ssize_t (*show)(struct kobject *kobj,
 204                         struct attribute *attr, char *buf);
 205         ssize_t (*store)(struct kobject *a, struct attribute *b,
 206                          const char *c, size_t count);
 207 };
 208
 209 #define define_one_global_ro(_name)             \
 210 static struct global_attr _name =               \
 211 __ATTR(_name, 0444, show_##_name, NULL)
 212
 213 #define define_one_global_rw(_name)             \
 214 static struct global_attr _name =               \
 215 __ATTR(_name, 0644, show_##_name, store_##_name)
 216
 217
 218 struct cpufreq_driver {
 219         char            name[CPUFREQ_NAME_LEN];
 220         u8              flags;
 221         void            *driver_data;
 222
 223         /* needed by all drivers */
 224         int             (*init)(struct cpufreq_policy *policy);
 225         int             (*verify)(struct cpufreq_policy *policy);
 226
 227         /* define one out of two */
 228         int             (*setpolicy)(struct cpufreq_policy *policy);
 229
 230         /*
 231          * On failure, should always restore frequency to policy->restore_freq
 232          * (i.e. old freq).
 233          */
 234         int             (*target)(struct cpufreq_policy *policy,
 235                                   unsigned int target_freq,
 236                                   unsigned int relation);       /* Deprecated */
 237         int             (*target_index)(struct cpufreq_policy *policy,
 238                                         unsigned int index);
 239         /*
 240          * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
 241          * unset.
 242          *
 243          * get_intermediate should return a stable intermediate frequency
 244          * platform wants to switch to and target_intermediate() should set CPU
 245          * to to that frequency, before jumping to the frequency corresponding
 246          * to 'index'. Core will take care of sending notifications and driver
 247          * doesn't have to handle them in target_intermediate() or
 248          * target_index().
 249          *
 250          * Drivers can return '0' from get_intermediate() in case they don't
 251          * wish to switch to intermediate frequency for some target frequency.
 252          * In that case core will directly call ->target_index().
 253          */
 254         unsigned int    (*get_intermediate)(struct cpufreq_policy *policy,
 255                                             unsigned int index);
 256         int             (*target_intermediate)(struct cpufreq_policy *policy,
 257                                                unsigned int index);
 258
 259         /* should be defined, if possible */
 260         unsigned int    (*get)(unsigned int cpu);
 261
 262         /* optional */
 263         int             (*bios_limit)(int cpu, unsigned int *limit);
 264
 265         int             (*exit)(struct cpufreq_policy *policy);
 266         void            (*stop_cpu)(struct cpufreq_policy *policy);
 267         int             (*suspend)(struct cpufreq_policy *policy);
 268         int             (*resume)(struct cpufreq_policy *policy);
 269
 270         /* Will be called after the driver is fully initialized */
 271         void            (*ready)(struct cpufreq_policy *policy);
 272
 273         struct freq_attr **attr;
 274
 275         /* platform specific boost support code */
 276         bool            boost_enabled;
 277         int             (*set_boost)(int state);
 278 };
 279
 280 /* flags */
 281 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 282                                                    all ->init() calls failed */
 283 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 284                                                    kernel "constants" aren't
 285                                                    affected by frequency
 286                                                    transitions */
 287 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 288                                                    speed mismatches */
 289
 290 /*
 291  * This should be set by platforms having multiple clock-domains, i.e.
 292  * supporting multiple policies. With this sysfs directories of governor would
 293  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 294  * governor with different tunables for different clusters.
 295  */
 296 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 297
 298 /*
 299  * Driver will do POSTCHANGE notifications from outside of their ->target()
 300  * routine and so must set cpufreq_driver->flags with this flag, so that core
 301  * can handle them specially.
 302  */
 303 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 304
 305 /*
 306  * Set by drivers which want cpufreq core to check if CPU is running at a
 307  * frequency present in freq-table exposed by the driver. For these drivers if
 308  * CPU is found running at an out of table freq, we will try to set it to a freq
 309  * from the table. And if that fails, we will stop further boot process by
 310  * issuing a BUG_ON().
 311  */
 312 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 313
 314 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 315 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 316
 317 const char *cpufreq_get_current_driver(void);
 318 void *cpufreq_get_driver_data(void);
 319
 320 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 321                 unsigned int min, unsigned int max)
 322 {
 323         if (policy->min < min)
 324                 policy->min = min;
 325         if (policy->max < min)
 326                 policy->max = min;
 327         if (policy->min > max)
 328                 policy->min = max;
 329         if (policy->max > max)
 330                 policy->max = max;
 331         if (policy->min > policy->max)
 332                 policy->min = policy->max;
 333         return;
 334 }
 335
 336 static inline void
 337 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 338 {
 339         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 340                         policy->cpuinfo.max_freq);
 341 }
 342
 343 #ifdef CONFIG_CPU_FREQ
 344 void cpufreq_suspend(void);
 345 void cpufreq_resume(void);
 346 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 347 #else
 348 static inline void cpufreq_suspend(void) {}
 349 static inline void cpufreq_resume(void) {}
 350 #endif
 351
 352 /*********************************************************************
 353  *                     CPUFREQ NOTIFIER INTERFACE                    *
 354  *********************************************************************/
 355
 356 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 357 #define CPUFREQ_POLICY_NOTIFIER         (1)
 358
 359 /* Transition notifiers */
 360 #define CPUFREQ_PRECHANGE               (0)
 361 #define CPUFREQ_POSTCHANGE              (1)
 362
 363 /* Policy Notifiers  */
 364 #define CPUFREQ_ADJUST                  (0)
 365 #define CPUFREQ_NOTIFY                  (1)
 366 #define CPUFREQ_START                   (2)
 367 #define CPUFREQ_CREATE_POLICY           (3)
 368 #define CPUFREQ_REMOVE_POLICY           (4)
 369
 370 #ifdef CONFIG_CPU_FREQ
 371 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 372 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 373
 374 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 375                 struct cpufreq_freqs *freqs);
 376 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 377                 struct cpufreq_freqs *freqs, int transition_failed);
 378
 379 #else /* CONFIG_CPU_FREQ */
 380 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 381                                                 unsigned int list)
 382 {
 383         return 0;
 384 }
 385 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 386                                                 unsigned int list)
 387 {
 388         return 0;
 389 }
 390 #endif /* !CONFIG_CPU_FREQ */
 391
 392 /**
 393  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 394  * safe)
 395  * @old:   old value
 396  * @div:   divisor
 397  * @mult:  multiplier
 398  *
 399  *
 400  * new = old * mult / div
 401  */
 402 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 403                 u_int mult)
 404 {
 405 #if BITS_PER_LONG == 32
 406         u64 result = ((u64) old) * ((u64) mult);
 407         do_div(result, div);
 408         return (unsigned long) result;
 409
 410 #elif BITS_PER_LONG == 64
 411         unsigned long result = old * ((u64) mult);
 412         result /= div;
 413         return result;
 414 #endif
 415 }
 416
 417 /*********************************************************************
 418  *                          CPUFREQ GOVERNORS                        *
 419  *********************************************************************/
 420
 421 /*
 422  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 423  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 424  * two generic policies are available:
 425  */
 426 #define CPUFREQ_POLICY_POWERSAVE        (1)
 427 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 428
 429 /* Governor Events */
 430 #define CPUFREQ_GOV_START       1
 431 #define CPUFREQ_GOV_STOP        2
 432 #define CPUFREQ_GOV_LIMITS      3
 433 #define CPUFREQ_GOV_POLICY_INIT 4
 434 #define CPUFREQ_GOV_POLICY_EXIT 5
 435
 436 struct cpufreq_governor {
 437         char    name[CPUFREQ_NAME_LEN];
 438         int     initialized;
 439         int     (*governor)     (struct cpufreq_policy *policy,
 440                                  unsigned int event);
 441         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 442                                          char *buf);
 443         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 444                                          unsigned int freq);
 445         unsigned int max_transition_latency; /* HW must be able to switch to
 446                         next freq faster than this value in nano secs or we
 447                         will fallback to performance governor */
 448         struct list_head        governor_list;
 449         struct module           *owner;
 450 };
 451
 452 /* Pass a target to the cpufreq driver */
 453 int cpufreq_driver_target(struct cpufreq_policy *policy,
 454                                  unsigned int target_freq,
 455                                  unsigned int relation);
 456 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 457                                    unsigned int target_freq,
 458                                    unsigned int relation);
 459 int cpufreq_register_governor(struct cpufreq_governor *governor);
 460 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 461
 462 struct cpufreq_governor *cpufreq_default_governor(void);
 463 struct cpufreq_governor *cpufreq_fallback_governor(void);
 464
 465 /*********************************************************************
 466  *                     FREQUENCY TABLE HELPERS                       *
 467  *********************************************************************/
 468
 469 /* Special Values of .frequency field */
 470 #define CPUFREQ_ENTRY_INVALID   ~0u
 471 #define CPUFREQ_TABLE_END       ~1u
 472 /* Special Values of .flags field */
 473 #define CPUFREQ_BOOST_FREQ      (1 << 0)
 474
 475 struct cpufreq_frequency_table {
 476         unsigned int    flags;
 477         unsigned int    driver_data; /* driver specific data, not used by core */
 478         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 479                                     * order */
 480 };
 481
 482 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
 483 int dev_pm_opp_init_cpufreq_table(struct device *dev,
 484                                   struct cpufreq_frequency_table **table);
 485 void dev_pm_opp_free_cpufreq_table(struct device *dev,
 486                                    struct cpufreq_frequency_table **table);
 487 #else
 488 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
 489                                                 struct cpufreq_frequency_table
 490                                                 **table)
 491 {
 492         return -EINVAL;
 493 }
 494
 495 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 496                                                  struct cpufreq_frequency_table
 497                                                  **table)
 498 {
 499 }
 500 #endif
 501
 502 /*
 503  * cpufreq_for_each_entry -     iterate over a cpufreq_frequency_table
 504  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 505  * @table:      the cpufreq_frequency_table * to iterate over.
 506  */
 507
 508 #define cpufreq_for_each_entry(pos, table)      \
 509         for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
 510
 511 /*
 512  * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
 513  *      excluding CPUFREQ_ENTRY_INVALID frequencies.
 514  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 515  * @table:      the cpufreq_frequency_table * to iterate over.
 516  */
 517
 518 #define cpufreq_for_each_valid_entry(pos, table)                        \
 519         for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)   \
 520                 if (pos->frequency == CPUFREQ_ENTRY_INVALID)            \
 521                         continue;                                       \
 522                 else
 523
 524 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 525                                     struct cpufreq_frequency_table *table);
 526
 527 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 528                                    struct cpufreq_frequency_table *table);
 529 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 530
 531 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 532                                    struct cpufreq_frequency_table *table,
 533                                    unsigned int target_freq,
 534                                    unsigned int relation,
 535                                    unsigned int *index);
 536 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 537                 unsigned int freq);
 538
 539 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 540
 541 #ifdef CONFIG_CPU_FREQ
 542 int cpufreq_boost_trigger_state(int state);
 543 int cpufreq_boost_enabled(void);
 544 int cpufreq_enable_boost_support(void);
 545 bool policy_has_boost_freq(struct cpufreq_policy *policy);
 546 #else
 547 static inline int cpufreq_boost_trigger_state(int state)
 548 {
 549         return 0;
 550 }
 551 static inline int cpufreq_boost_enabled(void)
 552 {
 553         return 0;
 554 }
 555
 556 static inline int cpufreq_enable_boost_support(void)
 557 {
 558         return -EINVAL;
 559 }
 560
 561 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
 562 {
 563         return false;
 564 }
 565 #endif
 566 /* the following funtion is for cpufreq core use only */
 567 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 568
 569 /* the following are really really optional */
 570 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 571 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
 572 extern struct freq_attr *cpufreq_generic_attr[];
 573 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 574                                       struct cpufreq_frequency_table *table);
 575
 576 unsigned int cpufreq_generic_get(unsigned int cpu);
 577 int cpufreq_generic_init(struct cpufreq_policy *policy,
 578                 struct cpufreq_frequency_table *table,
 579                 unsigned int transition_latency);
 580 #endif /* _LINUX_CPUFREQ_H */