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         bool                    governor_enabled; /* governor start/stop flag */
  84         char                    last_governor[CPUFREQ_NAME_LEN]; /* last governor used */
  85
  86         struct work_struct      update; /* if update_policy() needs to be
  87                                          * called, but you're in IRQ context */
  88
  89         struct cpufreq_user_policy user_policy;
  90         struct cpufreq_frequency_table  *freq_table;
  91
  92         struct list_head        policy_list;
  93         struct kobject          kobj;
  94         struct completion       kobj_unregister;
  95
  96         /*
  97          * The rules for this semaphore:
  98          * - Any routine that wants to read from the policy structure will
  99          *   do a down_read on this semaphore.
 100          * - Any routine that will write to the policy structure and/or may take away
 101          *   the policy altogether (eg. CPU hotplug), will hold this lock in write
 102          *   mode before doing so.
 103          *
 104          * Additional rules:
 105          * - Lock should not be held across
 106          *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
 107          */
 108         struct rw_semaphore     rwsem;
 109
 110         /* Synchronization for frequency transitions */
 111         bool                    transition_ongoing; /* Tracks transition status */
 112         spinlock_t              transition_lock;
 113         wait_queue_head_t       transition_wait;
 114         struct task_struct      *transition_task; /* Task which is doing the transition */
 115
 116         /* cpufreq-stats */
 117         struct cpufreq_stats    *stats;
 118
 119         /* For cpufreq driver's internal use */
 120         void                    *driver_data;
 121 };
 122
 123 /* Only for ACPI */
 124 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 125 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 126 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 127 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 128
 129 #ifdef CONFIG_CPU_FREQ
 130 struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
 131 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 132 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 133 #else
 134 static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
 135 {
 136         return NULL;
 137 }
 138 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 139 {
 140         return NULL;
 141 }
 142 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 143 #endif
 144
 145 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 146 {
 147         return cpumask_weight(policy->cpus) > 1;
 148 }
 149
 150 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 151 extern struct kobject *cpufreq_global_kobject;
 152
 153 #ifdef CONFIG_CPU_FREQ
 154 unsigned int cpufreq_get(unsigned int cpu);
 155 unsigned int cpufreq_quick_get(unsigned int cpu);
 156 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 157 void disable_cpufreq(void);
 158
 159 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 160 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 161 int cpufreq_update_policy(unsigned int cpu);
 162 bool have_governor_per_policy(void);
 163 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 164 #else
 165 static inline unsigned int cpufreq_get(unsigned int cpu)
 166 {
 167         return 0;
 168 }
 169 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 170 {
 171         return 0;
 172 }
 173 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 174 {
 175         return 0;
 176 }
 177 static inline void disable_cpufreq(void) { }
 178 #endif
 179
 180 /*********************************************************************
 181  *                      CPUFREQ DRIVER INTERFACE                     *
 182  *********************************************************************/
 183
 184 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 185 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 186 #define CPUFREQ_RELATION_C 2  /* closest frequency to target */
 187
 188 struct freq_attr {
 189         struct attribute attr;
 190         ssize_t (*show)(struct cpufreq_policy *, char *);
 191         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 192 };
 193
 194 #define cpufreq_freq_attr_ro(_name)             \
 195 static struct freq_attr _name =                 \
 196 __ATTR(_name, 0444, show_##_name, NULL)
 197
 198 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 199 static struct freq_attr _name =                 \
 200 __ATTR(_name, _perm, show_##_name, NULL)
 201
 202 #define cpufreq_freq_attr_rw(_name)             \
 203 static struct freq_attr _name =                 \
 204 __ATTR(_name, 0644, show_##_name, store_##_name)
 205
 206 struct global_attr {
 207         struct attribute attr;
 208         ssize_t (*show)(struct kobject *kobj,
 209                         struct attribute *attr, char *buf);
 210         ssize_t (*store)(struct kobject *a, struct attribute *b,
 211                          const char *c, size_t count);
 212 };
 213
 214 #define define_one_global_ro(_name)             \
 215 static struct global_attr _name =               \
 216 __ATTR(_name, 0444, show_##_name, NULL)
 217
 218 #define define_one_global_rw(_name)             \
 219 static struct global_attr _name =               \
 220 __ATTR(_name, 0644, show_##_name, store_##_name)
 221
 222
 223 struct cpufreq_driver {
 224         char            name[CPUFREQ_NAME_LEN];
 225         u8              flags;
 226         void            *driver_data;
 227
 228         /* needed by all drivers */
 229         int             (*init)(struct cpufreq_policy *policy);
 230         int             (*verify)(struct cpufreq_policy *policy);
 231
 232         /* define one out of two */
 233         int             (*setpolicy)(struct cpufreq_policy *policy);
 234
 235         /*
 236          * On failure, should always restore frequency to policy->restore_freq
 237          * (i.e. old freq).
 238          */
 239         int             (*target)(struct cpufreq_policy *policy,
 240                                   unsigned int target_freq,
 241                                   unsigned int relation);       /* Deprecated */
 242         int             (*target_index)(struct cpufreq_policy *policy,
 243                                         unsigned int index);
 244         /*
 245          * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
 246          * unset.
 247          *
 248          * get_intermediate should return a stable intermediate frequency
 249          * platform wants to switch to and target_intermediate() should set CPU
 250          * to to that frequency, before jumping to the frequency corresponding
 251          * to 'index'. Core will take care of sending notifications and driver
 252          * doesn't have to handle them in target_intermediate() or
 253          * target_index().
 254          *
 255          * Drivers can return '0' from get_intermediate() in case they don't
 256          * wish to switch to intermediate frequency for some target frequency.
 257          * In that case core will directly call ->target_index().
 258          */
 259         unsigned int    (*get_intermediate)(struct cpufreq_policy *policy,
 260                                             unsigned int index);
 261         int             (*target_intermediate)(struct cpufreq_policy *policy,
 262                                                unsigned int index);
 263
 264         /* should be defined, if possible */
 265         unsigned int    (*get)(unsigned int cpu);
 266
 267         /* optional */
 268         int             (*bios_limit)(int cpu, unsigned int *limit);
 269
 270         int             (*exit)(struct cpufreq_policy *policy);
 271         void            (*stop_cpu)(struct cpufreq_policy *policy);
 272         int             (*suspend)(struct cpufreq_policy *policy);
 273         int             (*resume)(struct cpufreq_policy *policy);
 274
 275         /* Will be called after the driver is fully initialized */
 276         void            (*ready)(struct cpufreq_policy *policy);
 277
 278         struct freq_attr **attr;
 279
 280         /* platform specific boost support code */
 281         bool            boost_enabled;
 282         int             (*set_boost)(int state);
 283 };
 284
 285 /* flags */
 286 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 287                                                    all ->init() calls failed */
 288 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 289                                                    kernel "constants" aren't
 290                                                    affected by frequency
 291                                                    transitions */
 292 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 293                                                    speed mismatches */
 294
 295 /*
 296  * This should be set by platforms having multiple clock-domains, i.e.
 297  * supporting multiple policies. With this sysfs directories of governor would
 298  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 299  * governor with different tunables for different clusters.
 300  */
 301 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 302
 303 /*
 304  * Driver will do POSTCHANGE notifications from outside of their ->target()
 305  * routine and so must set cpufreq_driver->flags with this flag, so that core
 306  * can handle them specially.
 307  */
 308 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 309
 310 /*
 311  * Set by drivers which want cpufreq core to check if CPU is running at a
 312  * frequency present in freq-table exposed by the driver. For these drivers if
 313  * CPU is found running at an out of table freq, we will try to set it to a freq
 314  * from the table. And if that fails, we will stop further boot process by
 315  * issuing a BUG_ON().
 316  */
 317 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 318
 319 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 320 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 321
 322 const char *cpufreq_get_current_driver(void);
 323 void *cpufreq_get_driver_data(void);
 324
 325 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 326                 unsigned int min, unsigned int max)
 327 {
 328         if (policy->min < min)
 329                 policy->min = min;
 330         if (policy->max < min)
 331                 policy->max = min;
 332         if (policy->min > max)
 333                 policy->min = max;
 334         if (policy->max > max)
 335                 policy->max = max;
 336         if (policy->min > policy->max)
 337                 policy->min = policy->max;
 338         return;
 339 }
 340
 341 static inline void
 342 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 343 {
 344         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 345                         policy->cpuinfo.max_freq);
 346 }
 347
 348 #ifdef CONFIG_CPU_FREQ
 349 void cpufreq_suspend(void);
 350 void cpufreq_resume(void);
 351 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 352 #else
 353 static inline void cpufreq_suspend(void) {}
 354 static inline void cpufreq_resume(void) {}
 355 #endif
 356
 357 /*********************************************************************
 358  *                     CPUFREQ NOTIFIER INTERFACE                    *
 359  *********************************************************************/
 360
 361 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 362 #define CPUFREQ_POLICY_NOTIFIER         (1)
 363
 364 /* Transition notifiers */
 365 #define CPUFREQ_PRECHANGE               (0)
 366 #define CPUFREQ_POSTCHANGE              (1)
 367
 368 /* Policy Notifiers  */
 369 #define CPUFREQ_ADJUST                  (0)
 370 #define CPUFREQ_NOTIFY                  (1)
 371 #define CPUFREQ_START                   (2)
 372 #define CPUFREQ_CREATE_POLICY           (3)
 373 #define CPUFREQ_REMOVE_POLICY           (4)
 374
 375 #ifdef CONFIG_CPU_FREQ
 376 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 377 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 378
 379 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 380                 struct cpufreq_freqs *freqs);
 381 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 382                 struct cpufreq_freqs *freqs, int transition_failed);
 383
 384 #else /* CONFIG_CPU_FREQ */
 385 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 386                                                 unsigned int list)
 387 {
 388         return 0;
 389 }
 390 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 391                                                 unsigned int list)
 392 {
 393         return 0;
 394 }
 395 #endif /* !CONFIG_CPU_FREQ */
 396
 397 /**
 398  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 399  * safe)
 400  * @old:   old value
 401  * @div:   divisor
 402  * @mult:  multiplier
 403  *
 404  *
 405  * new = old * mult / div
 406  */
 407 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 408                 u_int mult)
 409 {
 410 #if BITS_PER_LONG == 32
 411         u64 result = ((u64) old) * ((u64) mult);
 412         do_div(result, div);
 413         return (unsigned long) result;
 414
 415 #elif BITS_PER_LONG == 64
 416         unsigned long result = old * ((u64) mult);
 417         result /= div;
 418         return result;
 419 #endif
 420 }
 421
 422 /*********************************************************************
 423  *                          CPUFREQ GOVERNORS                        *
 424  *********************************************************************/
 425
 426 /*
 427  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 428  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 429  * two generic policies are available:
 430  */
 431 #define CPUFREQ_POLICY_POWERSAVE        (1)
 432 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 433
 434 /* Governor Events */
 435 #define CPUFREQ_GOV_START       1
 436 #define CPUFREQ_GOV_STOP        2
 437 #define CPUFREQ_GOV_LIMITS      3
 438 #define CPUFREQ_GOV_POLICY_INIT 4
 439 #define CPUFREQ_GOV_POLICY_EXIT 5
 440
 441 struct cpufreq_governor {
 442         char    name[CPUFREQ_NAME_LEN];
 443         int     initialized;
 444         int     (*governor)     (struct cpufreq_policy *policy,
 445                                  unsigned int event);
 446         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 447                                          char *buf);
 448         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 449                                          unsigned int freq);
 450         unsigned int max_transition_latency; /* HW must be able to switch to
 451                         next freq faster than this value in nano secs or we
 452                         will fallback to performance governor */
 453         struct list_head        governor_list;
 454         struct module           *owner;
 455 };
 456
 457 /* Pass a target to the cpufreq driver */
 458 int cpufreq_driver_target(struct cpufreq_policy *policy,
 459                                  unsigned int target_freq,
 460                                  unsigned int relation);
 461 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 462                                    unsigned int target_freq,
 463                                    unsigned int relation);
 464 int cpufreq_register_governor(struct cpufreq_governor *governor);
 465 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 466
 467 struct cpufreq_governor *cpufreq_default_governor(void);
 468 struct cpufreq_governor *cpufreq_fallback_governor(void);
 469
 470 /*********************************************************************
 471  *                     FREQUENCY TABLE HELPERS                       *
 472  *********************************************************************/
 473
 474 /* Special Values of .frequency field */
 475 #define CPUFREQ_ENTRY_INVALID   ~0u
 476 #define CPUFREQ_TABLE_END       ~1u
 477 /* Special Values of .flags field */
 478 #define CPUFREQ_BOOST_FREQ      (1 << 0)
 479
 480 struct cpufreq_frequency_table {
 481         unsigned int    flags;
 482         unsigned int    driver_data; /* driver specific data, not used by core */
 483         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 484                                     * order */
 485 };
 486
 487 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
 488 int dev_pm_opp_init_cpufreq_table(struct device *dev,
 489                                   struct cpufreq_frequency_table **table);
 490 void dev_pm_opp_free_cpufreq_table(struct device *dev,
 491                                    struct cpufreq_frequency_table **table);
 492 #else
 493 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
 494                                                 struct cpufreq_frequency_table
 495                                                 **table)
 496 {
 497         return -EINVAL;
 498 }
 499
 500 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 501                                                  struct cpufreq_frequency_table
 502                                                  **table)
 503 {
 504 }
 505 #endif
 506
 507 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
 508 {
 509         while ((*pos)->frequency != CPUFREQ_TABLE_END)
 510                 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
 511                         return true;
 512                 else
 513                         (*pos)++;
 514         return false;
 515 }
 516
 517 /*
 518  * cpufreq_for_each_entry -     iterate over a cpufreq_frequency_table
 519  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 520  * @table:      the cpufreq_frequency_table * to iterate over.
 521  */
 522
 523 #define cpufreq_for_each_entry(pos, table)      \
 524         for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)
 525
 526 /*
 527  * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
 528  *      excluding CPUFREQ_ENTRY_INVALID frequencies.
 529  * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 530  * @table:      the cpufreq_frequency_table * to iterate over.
 531  */
 532
 533 #define cpufreq_for_each_valid_entry(pos, table)        \
 534         for (pos = table; cpufreq_next_valid(&pos); pos++)
 535
 536 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 537                                     struct cpufreq_frequency_table *table);
 538
 539 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 540                                    struct cpufreq_frequency_table *table);
 541 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 542
 543 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 544                                    struct cpufreq_frequency_table *table,
 545                                    unsigned int target_freq,
 546                                    unsigned int relation,
 547                                    unsigned int *index);
 548 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 549                 unsigned int freq);
 550
 551 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 552
 553 #ifdef CONFIG_CPU_FREQ
 554 int cpufreq_boost_trigger_state(int state);
 555 int cpufreq_boost_enabled(void);
 556 int cpufreq_enable_boost_support(void);
 557 bool policy_has_boost_freq(struct cpufreq_policy *policy);
 558 #else
 559 static inline int cpufreq_boost_trigger_state(int state)
 560 {
 561         return 0;
 562 }
 563 static inline int cpufreq_boost_enabled(void)
 564 {
 565         return 0;
 566 }
 567
 568 static inline int cpufreq_enable_boost_support(void)
 569 {
 570         return -EINVAL;
 571 }
 572
 573 static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
 574 {
 575         return false;
 576 }
 577 #endif
 578 /* the following funtion is for cpufreq core use only */
 579 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 580
 581 /* the following are really really optional */
 582 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 583 extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs;
 584 extern struct freq_attr *cpufreq_generic_attr[];
 585 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 586                                       struct cpufreq_frequency_table *table);
 587
 588 unsigned int cpufreq_generic_get(unsigned int cpu);
 589 int cpufreq_generic_init(struct cpufreq_policy *policy,
 590                 struct cpufreq_frequency_table *table,
 591                 unsigned int transition_latency);
 592 #endif /* _LINUX_CPUFREQ_H */