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 };
 114
 115 /* Only for ACPI */
 116 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 117 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 118 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 119 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 120
 121 #ifdef CONFIG_CPU_FREQ
 122 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 123 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 124 #else
 125 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 126 {
 127         return NULL;
 128 }
 129 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 130 #endif
 131
 132 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 133 {
 134         return cpumask_weight(policy->cpus) > 1;
 135 }
 136
 137 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 138 extern struct kobject *cpufreq_global_kobject;
 139 int cpufreq_get_global_kobject(void);
 140 void cpufreq_put_global_kobject(void);
 141 int cpufreq_sysfs_create_file(const struct attribute *attr);
 142 void cpufreq_sysfs_remove_file(const struct attribute *attr);
 143
 144 #ifdef CONFIG_CPU_FREQ
 145 unsigned int cpufreq_get(unsigned int cpu);
 146 unsigned int cpufreq_quick_get(unsigned int cpu);
 147 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 148 void disable_cpufreq(void);
 149
 150 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 151 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 152 int cpufreq_update_policy(unsigned int cpu);
 153 bool have_governor_per_policy(void);
 154 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 155 #else
 156 static inline unsigned int cpufreq_get(unsigned int cpu)
 157 {
 158         return 0;
 159 }
 160 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 161 {
 162         return 0;
 163 }
 164 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 165 {
 166         return 0;
 167 }
 168 static inline void disable_cpufreq(void) { }
 169 #endif
 170
 171 /*********************************************************************
 172  *                      CPUFREQ DRIVER INTERFACE                     *
 173  *********************************************************************/
 174
 175 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 176 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 177
 178 struct freq_attr {
 179         struct attribute attr;
 180         ssize_t (*show)(struct cpufreq_policy *, char *);
 181         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 182 };
 183
 184 #define cpufreq_freq_attr_ro(_name)             \
 185 static struct freq_attr _name =                 \
 186 __ATTR(_name, 0444, show_##_name, NULL)
 187
 188 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 189 static struct freq_attr _name =                 \
 190 __ATTR(_name, _perm, show_##_name, NULL)
 191
 192 #define cpufreq_freq_attr_rw(_name)             \
 193 static struct freq_attr _name =                 \
 194 __ATTR(_name, 0644, show_##_name, store_##_name)
 195
 196 struct global_attr {
 197         struct attribute attr;
 198         ssize_t (*show)(struct kobject *kobj,
 199                         struct attribute *attr, char *buf);
 200         ssize_t (*store)(struct kobject *a, struct attribute *b,
 201                          const char *c, size_t count);
 202 };
 203
 204 #define define_one_global_ro(_name)             \
 205 static struct global_attr _name =               \
 206 __ATTR(_name, 0444, show_##_name, NULL)
 207
 208 #define define_one_global_rw(_name)             \
 209 static struct global_attr _name =               \
 210 __ATTR(_name, 0644, show_##_name, store_##_name)
 211
 212
 213 struct cpufreq_driver {
 214         char                    name[CPUFREQ_NAME_LEN];
 215         u8                      flags;
 216
 217         /* needed by all drivers */
 218         int     (*init)         (struct cpufreq_policy *policy);
 219         int     (*verify)       (struct cpufreq_policy *policy);
 220
 221         /* define one out of two */
 222         int     (*setpolicy)    (struct cpufreq_policy *policy);
 223         int     (*target)       (struct cpufreq_policy *policy, /* Deprecated */
 224                                  unsigned int target_freq,
 225                                  unsigned int relation);
 226         int     (*target_index) (struct cpufreq_policy *policy,
 227                                  unsigned int index);
 228
 229         /* should be defined, if possible */
 230         unsigned int    (*get)  (unsigned int cpu);
 231
 232         /* optional */
 233         int     (*bios_limit)   (int cpu, unsigned int *limit);
 234
 235         int     (*exit)         (struct cpufreq_policy *policy);
 236         void    (*stop_cpu)     (struct cpufreq_policy *policy);
 237         int     (*suspend)      (struct cpufreq_policy *policy);
 238         int     (*resume)       (struct cpufreq_policy *policy);
 239         struct freq_attr        **attr;
 240
 241         /* platform specific boost support code */
 242         bool                    boost_supported;
 243         bool                    boost_enabled;
 244         int     (*set_boost)    (int state);
 245 };
 246
 247 /* flags */
 248 #define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
 249                                                    all ->init() calls failed */
 250 #define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
 251                                                    kernel "constants" aren't
 252                                                    affected by frequency
 253                                                    transitions */
 254 #define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
 255                                                    speed mismatches */
 256
 257 /*
 258  * This should be set by platforms having multiple clock-domains, i.e.
 259  * supporting multiple policies. With this sysfs directories of governor would
 260  * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 261  * governor with different tunables for different clusters.
 262  */
 263 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)
 264
 265 /*
 266  * Driver will do POSTCHANGE notifications from outside of their ->target()
 267  * routine and so must set cpufreq_driver->flags with this flag, so that core
 268  * can handle them specially.
 269  */
 270 #define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)
 271
 272 /*
 273  * Set by drivers which want cpufreq core to check if CPU is running at a
 274  * frequency present in freq-table exposed by the driver. For these drivers if
 275  * CPU is found running at an out of table freq, we will try to set it to a freq
 276  * from the table. And if that fails, we will stop further boot process by
 277  * issuing a BUG_ON().
 278  */
 279 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)
 280
 281 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 282 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 283
 284 const char *cpufreq_get_current_driver(void);
 285
 286 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 287                 unsigned int min, unsigned int max)
 288 {
 289         if (policy->min < min)
 290                 policy->min = min;
 291         if (policy->max < min)
 292                 policy->max = min;
 293         if (policy->min > max)
 294                 policy->min = max;
 295         if (policy->max > max)
 296                 policy->max = max;
 297         if (policy->min > policy->max)
 298                 policy->min = policy->max;
 299         return;
 300 }
 301
 302 static inline void
 303 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
 304 {
 305         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
 306                         policy->cpuinfo.max_freq);
 307 }
 308
 309 #ifdef CONFIG_CPU_FREQ
 310 void cpufreq_suspend(void);
 311 void cpufreq_resume(void);
 312 int cpufreq_generic_suspend(struct cpufreq_policy *policy);
 313 #else
 314 static inline void cpufreq_suspend(void) {}
 315 static inline void cpufreq_resume(void) {}
 316 #endif
 317
 318 /*********************************************************************
 319  *                     CPUFREQ NOTIFIER INTERFACE                    *
 320  *********************************************************************/
 321
 322 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
 323 #define CPUFREQ_POLICY_NOTIFIER         (1)
 324
 325 /* Transition notifiers */
 326 #define CPUFREQ_PRECHANGE               (0)
 327 #define CPUFREQ_POSTCHANGE              (1)
 328
 329 /* Policy Notifiers  */
 330 #define CPUFREQ_ADJUST                  (0)
 331 #define CPUFREQ_INCOMPATIBLE            (1)
 332 #define CPUFREQ_NOTIFY                  (2)
 333 #define CPUFREQ_START                   (3)
 334 #define CPUFREQ_UPDATE_POLICY_CPU       (4)
 335 #define CPUFREQ_CREATE_POLICY           (5)
 336 #define CPUFREQ_REMOVE_POLICY           (6)
 337
 338 #ifdef CONFIG_CPU_FREQ
 339 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 340 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
 341
 342 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 343                 struct cpufreq_freqs *freqs);
 344 void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
 345                 struct cpufreq_freqs *freqs, int transition_failed);
 346
 347 #else /* CONFIG_CPU_FREQ */
 348 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 349                                                 unsigned int list)
 350 {
 351         return 0;
 352 }
 353 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 354                                                 unsigned int list)
 355 {
 356         return 0;
 357 }
 358 #endif /* !CONFIG_CPU_FREQ */
 359
 360 /**
 361  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 362  * safe)
 363  * @old:   old value
 364  * @div:   divisor
 365  * @mult:  multiplier
 366  *
 367  *
 368  * new = old * mult / div
 369  */
 370 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 371                 u_int mult)
 372 {
 373 #if BITS_PER_LONG == 32
 374         u64 result = ((u64) old) * ((u64) mult);
 375         do_div(result, div);
 376         return (unsigned long) result;
 377
 378 #elif BITS_PER_LONG == 64
 379         unsigned long result = old * ((u64) mult);
 380         result /= div;
 381         return result;
 382 #endif
 383 }
 384
 385 /*********************************************************************
 386  *                          CPUFREQ GOVERNORS                        *
 387  *********************************************************************/
 388
 389 /*
 390  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
 391  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 392  * two generic policies are available:
 393  */
 394 #define CPUFREQ_POLICY_POWERSAVE        (1)
 395 #define CPUFREQ_POLICY_PERFORMANCE      (2)
 396
 397 /* Governor Events */
 398 #define CPUFREQ_GOV_START       1
 399 #define CPUFREQ_GOV_STOP        2
 400 #define CPUFREQ_GOV_LIMITS      3
 401 #define CPUFREQ_GOV_POLICY_INIT 4
 402 #define CPUFREQ_GOV_POLICY_EXIT 5
 403
 404 struct cpufreq_governor {
 405         char    name[CPUFREQ_NAME_LEN];
 406         int     initialized;
 407         int     (*governor)     (struct cpufreq_policy *policy,
 408                                  unsigned int event);
 409         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 410                                          char *buf);
 411         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 412                                          unsigned int freq);
 413         unsigned int max_transition_latency; /* HW must be able to switch to
 414                         next freq faster than this value in nano secs or we
 415                         will fallback to performance governor */
 416         struct list_head        governor_list;
 417         struct module           *owner;
 418 };
 419
 420 /* Pass a target to the cpufreq driver */
 421 int cpufreq_driver_target(struct cpufreq_policy *policy,
 422                                  unsigned int target_freq,
 423                                  unsigned int relation);
 424 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 425                                    unsigned int target_freq,
 426                                    unsigned int relation);
 427 int cpufreq_register_governor(struct cpufreq_governor *governor);
 428 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 429
 430 /* CPUFREQ DEFAULT GOVERNOR */
 431 /*
 432  * Performance governor is fallback governor if any other gov failed to auto
 433  * load due latency restrictions
 434  */
 435 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 436 extern struct cpufreq_governor cpufreq_gov_performance;
 437 #endif
 438 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 439 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 440 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 441 extern struct cpufreq_governor cpufreq_gov_powersave;
 442 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 443 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 444 extern struct cpufreq_governor cpufreq_gov_userspace;
 445 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 446 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 447 extern struct cpufreq_governor cpufreq_gov_ondemand;
 448 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 449 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 450 extern struct cpufreq_governor cpufreq_gov_conservative;
 451 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 452 #endif
 453
 454 /*********************************************************************
 455  *                     FREQUENCY TABLE HELPERS                       *
 456  *********************************************************************/
 457
 458 #define CPUFREQ_ENTRY_INVALID ~0
 459 #define CPUFREQ_TABLE_END     ~1
 460 #define CPUFREQ_BOOST_FREQ    ~2
 461
 462 struct cpufreq_frequency_table {
 463         unsigned int    driver_data; /* driver specific data, not used by core */
 464         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 465                                     * order */
 466 };
 467
 468 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 469                                     struct cpufreq_frequency_table *table);
 470
 471 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 472                                    struct cpufreq_frequency_table *table);
 473 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy);
 474
 475 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 476                                    struct cpufreq_frequency_table *table,
 477                                    unsigned int target_freq,
 478                                    unsigned int relation,
 479                                    unsigned int *index);
 480 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
 481                 unsigned int freq);
 482
 483 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
 484
 485 #ifdef CONFIG_CPU_FREQ
 486 int cpufreq_boost_trigger_state(int state);
 487 int cpufreq_boost_supported(void);
 488 int cpufreq_boost_enabled(void);
 489 #else
 490 static inline int cpufreq_boost_trigger_state(int state)
 491 {
 492         return 0;
 493 }
 494 static inline int cpufreq_boost_supported(void)
 495 {
 496         return 0;
 497 }
 498 static inline int cpufreq_boost_enabled(void)
 499 {
 500         return 0;
 501 }
 502 #endif
 503 /* the following funtion is for cpufreq core use only */
 504 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 505
 506 /* the following are really really optional */
 507 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 508 extern struct freq_attr *cpufreq_generic_attr[];
 509 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
 510                                       struct cpufreq_frequency_table *table);
 511
 512 unsigned int cpufreq_generic_get(unsigned int cpu);
 513 int cpufreq_generic_init(struct cpufreq_policy *policy,
 514                 struct cpufreq_frequency_table *table,
 515                 unsigned int transition_latency);
 516 #endif /* _LINUX_CPUFREQ_H */