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_real_policy {
  55         unsigned int            min;    /* in kHz */
  56         unsigned int            max;    /* in kHz */
  57         unsigned int            policy; /* see above */
  58         struct cpufreq_governor *governor; /* see below */
  59 };
  60
  61 struct cpufreq_policy {
  62         /* CPUs sharing clock, require sw coordination */
  63         cpumask_var_t           cpus;   /* Online CPUs only */
  64         cpumask_var_t           related_cpus; /* Online + Offline CPUs */
  65
  66         unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
  67                                                 should set cpufreq */
  68         unsigned int            cpu;    /* cpu nr of CPU managing this policy */
  69         unsigned int            last_cpu; /* cpu nr of previous CPU that managed
  70                                            * this policy */
  71         struct clk              *clk;
  72         struct cpufreq_cpuinfo  cpuinfo;/* see above */
  73
  74         unsigned int            min;    /* in kHz */
  75         unsigned int            max;    /* in kHz */
  76         unsigned int            cur;    /* in kHz, only needed if cpufreq
  77                                          * governors are used */
  78         unsigned int            suspend_freq; /* freq to set during suspend */
  79
  80         unsigned int            policy; /* see above */
  81         struct cpufreq_governor *governor; /* see below */
  82         void                    *governor_data;
  83         bool                    governor_enabled; /* governor start/stop flag */
  84
  85         struct work_struct      update; /* if update_policy() needs to be
  86                                          * called, but you're in IRQ context */
  87
  88         struct cpufreq_real_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          * Additional rules:
 104          * - Lock should not be held across
 105          *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
 106          */
 107         struct rw_semaphore     rwsem;
 108
 109         /* Synchronization for frequency transitions */
 110         bool                    transition_ongoing; /* Tracks transition status */
 111         spinlock_t              transition_lock;
 112         wait_queue_head_t       transition_wait;
 113         struct task_struct      *transition_task; /* Task which is doing the transition */
 114 };
 115
 116 /* Only for ACPI */
 117 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 118 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 119 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 120 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 121
 122 #ifdef CONFIG_CPU_FREQ
 123 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 124 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 125 #else
 126 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 127 {
 128         return NULL;
 129 }
 130 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 131 #endif
 132
 133 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 134 {
 135         return cpumask_weight(policy->cpus) > 1;
 136 }
 137
 138 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 139 extern struct kobject *cpufreq_global_kobject;
 140 int cpufreq_get_global_kobject(void);
 141 void cpufreq_put_global_kobject(void);
 142 int cpufreq_sysfs_create_file(const struct attribute *attr);
 143 void cpufreq_sysfs_remove_file(const struct attribute *attr);
 144
 145 #ifdef CONFIG_CPU_FREQ
 146 unsigned int cpufreq_get(unsigned int cpu);
 147 unsigned int cpufreq_quick_get(unsigned int cpu);
 148 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 149 void disable_cpufreq(void);
 150
 151 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 152 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 153 int cpufreq_update_policy(unsigned int cpu);
 154 bool have_governor_per_policy(void);
 155 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 156 #else
 157 static inline unsigned int cpufreq_get(unsigned int cpu)
 158 {
 159         return 0;
 160 }
 161 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 162 {
 163         return 0;
 164 }
 165 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 166 {
 167         return 0;
 168 }
 169 static inline void disable_cpufreq(void) { }
 170 #endif
 171
 172 /*********************************************************************
 173  *                      CPUFREQ DRIVER INTERFACE                     *
 174  *********************************************************************/
 175
 176 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 177 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 178
 179 struct freq_attr {
 180         struct attribute attr;
 181         ssize_t (*show)(struct cpufreq_policy *, char *);
 182         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 183 };
 184
 185 #define cpufreq_freq_attr_ro(_name)             \
 186 static struct freq_attr _name =                 \
 187 __ATTR(_name, 0444, show_##_name, NULL)
 188
 189 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 190 static struct freq_attr _name =                 \
 191 __ATTR(_name, _perm, show_##_name, NULL)
 192
 193 #define cpufreq_freq_attr_rw(_name)             \
 194 static struct freq_attr _name =                 \
 195 __ATTR(_name, 0644, show_##_name, store_##_name)
 196
 197 struct global_attr {
 198         struct attribute attr;
 199         ssize_t (*show)(struct kobject *kobj,
 200                         struct attribute *attr, char *buf);
 201         ssize_t (*store)(struct kobject *a, struct attribute *b,
 202                          const char *c, size_t count);
 203 };
 204
 205 #define define_one_global_ro(_name)             \
 206 static struct global_attr _name =               \
 207 __ATTR(_name, 0444, show_##_name, NULL)
 208
 209 #define define_one_global_rw(_name)             \
 210 static struct global_attr _name =               \
 211 __ATTR(_name, 0644, show_##_name, store_##_name)
 212
 213
 214 struct cpufreq_driver {
 215         char                    name[CPUFREQ_NAME_LEN];
 216         u8                      flags;
 217
 218         /* needed by all drivers */
 219         int     (*init)         (struct cpufreq_policy *policy);
 220         int     (*verify)       (struct cpufreq_policy *policy);
 221
 222         /* define one out of two */
 223         int     (*setpolicy)    (struct cpufreq_policy *policy);
 224         int     (*target)       (struct cpufreq_policy *policy, /* Deprecated */
 225                                  unsigned int target_freq,
 226                                  unsigned int relation);
 227         int     (*target_index) (struct cpufreq_policy *policy,
 228                                  unsigned int index);
 229
 230         /* should be defined, if possible */
 231         unsigned int    (*get)  (unsigned int cpu);
 232
 233         /* optional */
 234         int     (*bios_limit)   (int cpu, unsigned int *limit);
 235
 236         int     (*exit)         (struct cpufreq_policy *policy);
 237         void    (*stop_cpu)     (struct cpufreq_policy *policy);
 238         int     (*suspend)      (struct cpufreq_policy *policy);
 239         int     (*resume)       (struct cpufreq_policy *policy);
 240         struct freq_attr        **attr;
 241
 242         /* platform specific boost support code */
 243         bool                    boost_supported;
 244         bool                    boost_enabled;
 245         int     (*set_boost)    (int state);
 246 };
 247
 248 /* flags */
 249 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 250                                                    all ->init() calls failed */
 251 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 252                                                    kernel "constants" aren't
 253                                                    affected by frequency
 254                                                    transitions */
 255 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 256                                                    speed mismatches */
 257
 258 /*
 259  * This should be set by platforms having multiple clock-domains, i.e.
 260  * supporting multiple policies. With this sysfs directories of governor would
 261  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 262  * governor with different tunables for different clusters.
 263  */
 264 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 265
 266 /*
 267  * Driver will do POSTCHANGE notifications from outside of their ->target()
 268  * routine and so must set cpufreq_driver->flags with this flag, so that core
 269  * can handle them specially.
 270  */
 271 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 272
 273 /*
 274  * Set by drivers which want cpufreq core to check if CPU is running at a
 275  * frequency present in freq-table exposed by the driver. For these drivers if
 276  * CPU is found running at an out of table freq, we will try to set it to a freq
 277  * from the table. And if that fails, we will stop further boot process by
 278  * issuing a BUG_ON().
 279  */
 280 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 281
 282 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 283 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 284
 285 const char *cpufreq_get_current_driver(void);
 286
 287 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 288                 unsigned int min, unsigned int max)
 289 {
 290         if (policy->min < min)
 291                 policy->min = min;
 292         if (policy->max < min)
 293                 policy->max = min;
 294         if (policy->min > max)
 295                 policy->min = max;
 296         if (policy->max > max)
 297                 policy->max = max;
 298         if (policy->min > policy->max)
 299                 policy->min = policy->max;
 300         return;
 301 }
 302
 303 static inline void
 304 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 305 {
 306         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 307                         policy->cpuinfo.max_freq);
 308 }
 309
 310 #ifdef CONFIG_CPU_FREQ
 311 void cpufreq_suspend(void);
 312 void cpufreq_resume(void);
 313 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 314 #else
 315 static inline void cpufreq_suspend(void) {}
 316 static inline void cpufreq_resume(void) {}
 317 #endif
 318
 319 /*********************************************************************
 320  *                     CPUFREQ NOTIFIER INTERFACE                    *
 321  *********************************************************************/
 322
 323 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 324 #define CPUFREQ_POLICY_NOTIFIER         (1)
 325
 326 /* Transition notifiers */
 327 #define CPUFREQ_PRECHANGE               (0)
 328 #define CPUFREQ_POSTCHANGE              (1)
 329
 330 /* Policy Notifiers  */
 331 #define CPUFREQ_ADJUST                  (0)
 332 #define CPUFREQ_INCOMPATIBLE            (1)
 333 #define CPUFREQ_NOTIFY                  (2)
 334 #define CPUFREQ_START                   (3)
 335 #define CPUFREQ_UPDATE_POLICY_CPU       (4)
 336 #define CPUFREQ_CREATE_POLICY           (5)
 337 #define CPUFREQ_REMOVE_POLICY           (6)
 338
 339 #ifdef CONFIG_CPU_FREQ
 340 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 341 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 342
 343 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 344                 struct cpufreq_freqs *freqs);
 345 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 346                 struct cpufreq_freqs *freqs, int transition_failed);
 347
 348 #else /* CONFIG_CPU_FREQ */
 349 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 350                                                 unsigned int list)
 351 {
 352         return 0;
 353 }
 354 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 355                                                 unsigned int list)
 356 {
 357         return 0;
 358 }
 359 #endif /* !CONFIG_CPU_FREQ */
 360
 361 /**
 362  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 363  * safe)
 364  * @old:   old value
 365  * @div:   divisor
 366  * @mult:  multiplier
 367  *
 368  *
 369  * new = old * mult / div
 370  */
 371 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 372                 u_int mult)
 373 {
 374 #if BITS_PER_LONG == 32
 375         u64 result = ((u64) old) * ((u64) mult);
 376         do_div(result, div);
 377         return (unsigned long) result;
 378
 379 #elif BITS_PER_LONG == 64
 380         unsigned long result = old * ((u64) mult);
 381         result /= div;
 382         return result;
 383 #endif
 384 }
 385
 386 /*********************************************************************
 387  *                          CPUFREQ GOVERNORS                        *
 388  *********************************************************************/
 389
 390 /*
 391  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 392  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 393  * two generic policies are available:
 394  */
 395 #define CPUFREQ_POLICY_POWERSAVE        (1)
 396 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 397
 398 /* Governor Events */
 399 #define CPUFREQ_GOV_START       1
 400 #define CPUFREQ_GOV_STOP        2
 401 #define CPUFREQ_GOV_LIMITS      3
 402 #define CPUFREQ_GOV_POLICY_INIT 4
 403 #define CPUFREQ_GOV_POLICY_EXIT 5
 404
 405 struct cpufreq_governor {
 406         char    name[CPUFREQ_NAME_LEN];
 407         int     initialized;
 408         int     (*governor)     (struct cpufreq_policy *policy,
 409                                  unsigned int event);
 410         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 411                                          char *buf);
 412         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 413                                          unsigned int freq);
 414         unsigned int max_transition_latency; /* HW must be able to switch to
 415                         next freq faster than this value in nano secs or we
 416                         will fallback to performance governor */
 417         struct list_head        governor_list;
 418         struct module           *owner;
 419 };
 420
 421 /* Pass a target to the cpufreq driver */
 422 int cpufreq_driver_target(struct cpufreq_policy *policy,
 423                                  unsigned int target_freq,
 424                                  unsigned int relation);
 425 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 426                                    unsigned int target_freq,
 427                                    unsigned int relation);
 428 int cpufreq_register_governor(struct cpufreq_governor *governor);
 429 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 430
 431 /* CPUFREQ DEFAULT GOVERNOR */
 432 /*
 433  * Performance governor is fallback governor if any other gov failed to auto
 434  * load due latency restrictions
 435  */
 436 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 437 extern struct cpufreq_governor cpufreq_gov_performance;
 438 #endif
 439 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 440 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 441 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 442 extern struct cpufreq_governor cpufreq_gov_powersave;
 443 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 444 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 445 extern struct cpufreq_governor cpufreq_gov_userspace;
 446 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 447 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 448 extern struct cpufreq_governor cpufreq_gov_ondemand;
 449 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 450 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 451 extern struct cpufreq_governor cpufreq_gov_conservative;
 452 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 453 #endif
 454
 455 /*********************************************************************
 456  *                     FREQUENCY TABLE HELPERS                       *
 457  *********************************************************************/
 458
 459 /* Special Values of .frequency field */
 460 #define CPUFREQ_ENTRY_INVALID   ~0
 461 #define CPUFREQ_TABLE_END       ~1
 462 /* Special Values of .flags field */
 463 #define CPUFREQ_BOOST_FREQ      (1 << 0)
 464
 465 struct cpufreq_frequency_table {
 466         unsigned int    flags;
 467         unsigned int    driver_data; /* driver specific data, not used by core */
 468         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 469                                     * order */
 470 };
 471
 472 #if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
 473 int dev_pm_opp_init_cpufreq_table(struct device *dev,
 474                                   struct cpufreq_frequency_table **table);
 475 void dev_pm_opp_free_cpufreq_table(struct device *dev,
 476                                    struct cpufreq_frequency_table **table);
 477 #else
 478 static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
 479                                                 struct cpufreq_frequency_table
 480                                                 **table)
 481 {
 482         return -EINVAL;
 483 }
 484
 485 static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
 486                                                  struct cpufreq_frequency_table
 487                                                  **table)
 488 {
 489 }
 490 #endif
 491
 492 static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
 493 {
 494         while ((*pos)->frequency != CPUFREQ_TABLE_END)
 495                 if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
 496                         return true;
 497                 else
 498                         (*pos)++;
 499         return false;
 500 }
 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; cpufreq_next_valid(&pos); pos++)
 520
 521 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 522                                     struct cpufreq_frequency_table *table);
 523
 524 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 525                                    struct cpufreq_frequency_table *table);
 526 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 527
 528 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 529                                    struct cpufreq_frequency_table *table,
 530                                    unsigned int target_freq,
 531                                    unsigned int relation,
 532                                    unsigned int *index);
 533 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 534                 unsigned int freq);
 535
 536 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 537
 538 #ifdef CONFIG_CPU_FREQ
 539 int cpufreq_boost_trigger_state(int state);
 540 int cpufreq_boost_supported(void);
 541 int cpufreq_boost_enabled(void);
 542 #else
 543 static inline int cpufreq_boost_trigger_state(int state)
 544 {
 545         return 0;
 546 }
 547 static inline int cpufreq_boost_supported(void)
 548 {
 549         return 0;
 550 }
 551 static inline int cpufreq_boost_enabled(void)
 552 {
 553         return 0;
 554 }
 555 #endif
 556 /* the following funtion is for cpufreq core use only */
 557 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 558
 559 /* the following are really really optional */
 560 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 561 extern struct freq_attr *cpufreq_generic_attr[];
 562 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 563                                       struct cpufreq_frequency_table *table);
 564
 565 unsigned int cpufreq_generic_get(unsigned int cpu);
 566 int cpufreq_generic_init(struct cpufreq_policy *policy,
 567                 struct cpufreq_frequency_table *table,
 568                 unsigned int transition_latency);
 569 #endif /* _LINUX_CPUFREQ_H */