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 <asm/cputime.h>
  15 #include <linux/mutex.h>
  16 #include <linux/notifier.h>
  17 #include <linux/threads.h>
  18 #include <linux/kobject.h>
  19 #include <linux/sysfs.h>
  20 #include <linux/completion.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/cpumask.h>
  23 #include <asm/div64.h>
  24 #include <asm/cputime.h>
  25
  26 #define CPUFREQ_NAME_LEN 16
  27 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
  28 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
  29
  30
  31 /*********************************************************************
  32  *                     CPUFREQ NOTIFIER INTERFACE                    *
  33  *********************************************************************/
  34
  35 #define CPUFREQ_TRANSITION_NOTIFIER     (0)
  36 #define CPUFREQ_POLICY_NOTIFIER         (1)
  37
  38 #ifdef CONFIG_CPU_FREQ
  39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
  40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
  41 extern void disable_cpufreq(void);
  42 #else           /* CONFIG_CPU_FREQ */
  43 static inline int cpufreq_register_notifier(struct notifier_block *nb,
  44                                                 unsigned int list)
  45 {
  46         return 0;
  47 }
  48 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
  49                                                 unsigned int list)
  50 {
  51         return 0;
  52 }
  53 static inline void disable_cpufreq(void) { }
  54 #endif          /* CONFIG_CPU_FREQ */
  55
  56 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
  57  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  58  * two generic policies are available:
  59  */
  60
  61 #define CPUFREQ_POLICY_POWERSAVE        (1)
  62 #define CPUFREQ_POLICY_PERFORMANCE      (2)
  63
  64 /* Frequency values here are CPU kHz so that hardware which doesn't run
  65  * with some frequencies can complain without having to guess what per
  66  * cent / per mille means.
  67  * Maximum transition latency is in nanoseconds - if it's unknown,
  68  * CPUFREQ_ETERNAL shall be used.
  69  */
  70
  71 struct cpufreq_governor;
  72
  73 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
  74 extern struct kobject *cpufreq_global_kobject;
  75
  76 #define CPUFREQ_ETERNAL                 (-1)
  77 struct cpufreq_cpuinfo {
  78         unsigned int            max_freq;
  79         unsigned int            min_freq;
  80
  81         /* in 10^(-9) s = nanoseconds */
  82         unsigned int            transition_latency;
  83 };
  84
  85 struct cpufreq_real_policy {
  86         unsigned int            min;    /* in kHz */
  87         unsigned int            max;    /* in kHz */
  88         unsigned int            policy; /* see above */
  89         struct cpufreq_governor *governor; /* see below */
  90 };
  91
  92 struct cpufreq_policy {
  93         /* CPUs sharing clock, require sw coordination */
  94         cpumask_var_t           cpus;   /* Online CPUs only */
  95         cpumask_var_t           related_cpus; /* Online + Offline CPUs */
  96
  97         unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
  98                                                 should set cpufreq */
  99         unsigned int            cpu;    /* cpu nr of CPU managing this policy */
 100         unsigned int            last_cpu; /* cpu nr of previous CPU that managed
 101                                            * this policy */
 102         struct cpufreq_cpuinfo  cpuinfo;/* see above */
 103
 104         unsigned int            min;    /* in kHz */
 105         unsigned int            max;    /* in kHz */
 106         unsigned int            cur;    /* in kHz, only needed if cpufreq
 107                                          * governors are used */
 108         unsigned int            policy; /* see above */
 109         struct cpufreq_governor *governor; /* see below */
 110         void                    *governor_data;
 111         bool                    governor_enabled; /* governor start/stop flag */
 112
 113         struct work_struct      update; /* if update_policy() needs to be
 114                                          * called, but you're in IRQ context */
 115
 116         struct cpufreq_real_policy      user_policy;
 117
 118         struct kobject          kobj;
 119         struct completion       kobj_unregister;
 120 };
 121
 122 #define CPUFREQ_ADJUST                  (0)
 123 #define CPUFREQ_INCOMPATIBLE            (1)
 124 #define CPUFREQ_NOTIFY                  (2)
 125 #define CPUFREQ_START                   (3)
 126 #define CPUFREQ_UPDATE_POLICY_CPU       (4)
 127
 128 /* Only for ACPI */
 129 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 130 #define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
 131 #define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
 132 #define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/
 133
 134 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 135 {
 136         return cpumask_weight(policy->cpus) > 1;
 137 }
 138
 139 /******************** cpufreq transition notifiers *******************/
 140
 141 #define CPUFREQ_PRECHANGE       (0)
 142 #define CPUFREQ_POSTCHANGE      (1)
 143 #define CPUFREQ_RESUMECHANGE    (8)
 144 #define CPUFREQ_SUSPENDCHANGE   (9)
 145
 146 struct cpufreq_freqs {
 147         unsigned int cpu;       /* cpu nr */
 148         unsigned int old;
 149         unsigned int new;
 150         u8 flags;               /* flags of cpufreq_driver, see below. */
 151 };
 152
 153
 154 /**
 155  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 156  * @old:   old value
 157  * @div:   divisor
 158  * @mult:  multiplier
 159  *
 160  *
 161  *    new = old * mult / div
 162  */
 163 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
 164 {
 165 #if BITS_PER_LONG == 32
 166
 167         u64 result = ((u64) old) * ((u64) mult);
 168         do_div(result, div);
 169         return (unsigned long) result;
 170
 171 #elif BITS_PER_LONG == 64
 172
 173         unsigned long result = old * ((u64) mult);
 174         result /= div;
 175         return result;
 176
 177 #endif
 178 };
 179
 180 /*********************************************************************
 181  *                          CPUFREQ GOVERNORS                        *
 182  *********************************************************************/
 183
 184 #define CPUFREQ_GOV_START       1
 185 #define CPUFREQ_GOV_STOP        2
 186 #define CPUFREQ_GOV_LIMITS      3
 187 #define CPUFREQ_GOV_POLICY_INIT 4
 188 #define CPUFREQ_GOV_POLICY_EXIT 5
 189
 190 struct cpufreq_governor {
 191         char    name[CPUFREQ_NAME_LEN];
 192         int     initialized;
 193         int     (*governor)     (struct cpufreq_policy *policy,
 194                                  unsigned int event);
 195         ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
 196                                          char *buf);
 197         int     (*store_setspeed)       (struct cpufreq_policy *policy,
 198                                          unsigned int freq);
 199         unsigned int max_transition_latency; /* HW must be able to switch to
 200                         next freq faster than this value in nano secs or we
 201                         will fallback to performance governor */
 202         struct list_head        governor_list;
 203         struct module           *owner;
 204 };
 205
 206 /*
 207  * Pass a target to the cpufreq driver.
 208  */
 209 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
 210                                  unsigned int target_freq,
 211                                  unsigned int relation);
 212 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
 213                                    unsigned int target_freq,
 214                                    unsigned int relation);
 215
 216
 217 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
 218                                    unsigned int cpu);
 219
 220 int cpufreq_register_governor(struct cpufreq_governor *governor);
 221 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
 222
 223
 224 /*********************************************************************
 225  *                      CPUFREQ DRIVER INTERFACE                     *
 226  *********************************************************************/
 227
 228 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 229 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
 230
 231 struct freq_attr;
 232
 233 struct cpufreq_driver {
 234         struct module           *owner;
 235         char                    name[CPUFREQ_NAME_LEN];
 236         u8                      flags;
 237         /*
 238          * This should be set by platforms having multiple clock-domains, i.e.
 239          * supporting multiple policies. With this sysfs directories of governor
 240          * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
 241          * use the same governor with different tunables for different clusters.
 242          */
 243         bool                    have_governor_per_policy;
 244
 245         /* needed by all drivers */
 246         int     (*init)         (struct cpufreq_policy *policy);
 247         int     (*verify)       (struct cpufreq_policy *policy);
 248
 249         /* define one out of two */
 250         int     (*setpolicy)    (struct cpufreq_policy *policy);
 251         int     (*target)       (struct cpufreq_policy *policy,
 252                                  unsigned int target_freq,
 253                                  unsigned int relation);
 254
 255         /* should be defined, if possible */
 256         unsigned int    (*get)  (unsigned int cpu);
 257
 258         /* optional */
 259         unsigned int (*getavg)  (struct cpufreq_policy *policy,
 260                                  unsigned int cpu);
 261         int     (*bios_limit)   (int cpu, unsigned int *limit);
 262
 263         int     (*exit)         (struct cpufreq_policy *policy);
 264         int     (*suspend)      (struct cpufreq_policy *policy);
 265         int     (*resume)       (struct cpufreq_policy *policy);
 266         struct freq_attr        **attr;
 267 };
 268
 269 /* flags */
 270
 271 #define CPUFREQ_STICKY          0x01    /* the driver isn't removed even if
 272                                          * all ->init() calls failed */
 273 #define CPUFREQ_CONST_LOOPS     0x02    /* loops_per_jiffy or other kernel
 274                                          * "constants" aren't affected by
 275                                          * frequency transitions */
 276 #define CPUFREQ_PM_NO_WARN      0x04    /* don't warn on suspend/resume speed
 277                                          * mismatches */
 278
 279 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 280 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
 281
 282
 283 void cpufreq_notify_transition(struct cpufreq_policy *policy,
 284                 struct cpufreq_freqs *freqs, unsigned int state);
 285
 286 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
 287 {
 288         if (policy->min < min)
 289                 policy->min = min;
 290         if (policy->max < min)
 291                 policy->max = min;
 292         if (policy->min > max)
 293                 policy->min = max;
 294         if (policy->max > max)
 295                 policy->max = max;
 296         if (policy->min > policy->max)
 297                 policy->min = policy->max;
 298         return;
 299 }
 300
 301 struct freq_attr {
 302         struct attribute attr;
 303         ssize_t (*show)(struct cpufreq_policy *, char *);
 304         ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 305 };
 306
 307 #define cpufreq_freq_attr_ro(_name)             \
 308 static struct freq_attr _name =                 \
 309 __ATTR(_name, 0444, show_##_name, NULL)
 310
 311 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
 312 static struct freq_attr _name =                 \
 313 __ATTR(_name, _perm, show_##_name, NULL)
 314
 315 #define cpufreq_freq_attr_rw(_name)             \
 316 static struct freq_attr _name =                 \
 317 __ATTR(_name, 0644, show_##_name, store_##_name)
 318
 319 struct global_attr {
 320         struct attribute attr;
 321         ssize_t (*show)(struct kobject *kobj,
 322                         struct attribute *attr, char *buf);
 323         ssize_t (*store)(struct kobject *a, struct attribute *b,
 324                          const char *c, size_t count);
 325 };
 326
 327 #define define_one_global_ro(_name)             \
 328 static struct global_attr _name =               \
 329 __ATTR(_name, 0444, show_##_name, NULL)
 330
 331 #define define_one_global_rw(_name)             \
 332 static struct global_attr _name =               \
 333 __ATTR(_name, 0644, show_##_name, store_##_name)
 334
 335 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 336 void cpufreq_cpu_put(struct cpufreq_policy *data);
 337 const char *cpufreq_get_current_driver(void);
 338
 339 /*********************************************************************
 340  *                        CPUFREQ 2.6. INTERFACE                     *
 341  *********************************************************************/
 342 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 343 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 344 int cpufreq_update_policy(unsigned int cpu);
 345 bool have_governor_per_policy(void);
 346 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 347
 348 #ifdef CONFIG_CPU_FREQ
 349 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
 350 unsigned int cpufreq_get(unsigned int cpu);
 351 #else
 352 static inline unsigned int cpufreq_get(unsigned int cpu)
 353 {
 354         return 0;
 355 }
 356 #endif
 357
 358 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
 359 #ifdef CONFIG_CPU_FREQ
 360 unsigned int cpufreq_quick_get(unsigned int cpu);
 361 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 362 #else
 363 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 364 {
 365         return 0;
 366 }
 367 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 368 {
 369         return 0;
 370 }
 371 #endif
 372
 373
 374 /*********************************************************************
 375  *                       CPUFREQ DEFAULT GOVERNOR                    *
 376  *********************************************************************/
 377
 378
 379 /*
 380   Performance governor is fallback governor if any other gov failed to
 381   auto load due latency restrictions
 382 */
 383 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 384 extern struct cpufreq_governor cpufreq_gov_performance;
 385 #endif
 386 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 387 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
 388 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 389 extern struct cpufreq_governor cpufreq_gov_powersave;
 390 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
 391 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 392 extern struct cpufreq_governor cpufreq_gov_userspace;
 393 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
 394 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 395 extern struct cpufreq_governor cpufreq_gov_ondemand;
 396 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
 397 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 398 extern struct cpufreq_governor cpufreq_gov_conservative;
 399 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
 400 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE)
 401 extern struct cpufreq_governor cpufreq_gov_interactive;
 402 #define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_interactive)
 403 #endif
 404
 405
 406 /*********************************************************************
 407  *                     FREQUENCY TABLE HELPERS                       *
 408  *********************************************************************/
 409
 410 #define CPUFREQ_ENTRY_INVALID ~0
 411 #define CPUFREQ_TABLE_END     ~1
 412
 413 struct cpufreq_frequency_table {
 414         unsigned int    index;     /* any */
 415         unsigned int    frequency; /* kHz - doesn't need to be in ascending
 416                                     * order */
 417 };
 418
 419 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 420                                     struct cpufreq_frequency_table *table);
 421
 422 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 423                                    struct cpufreq_frequency_table *table);
 424
 425 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 426                                    struct cpufreq_frequency_table *table,
 427                                    unsigned int target_freq,
 428                                    unsigned int relation,
 429                                    unsigned int *index);
 430
 431 /* the following 3 funtions are for cpufreq core use only */
 432 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
 433
 434 /* the following are really really optional */
 435 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 436
 437 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 438                                       unsigned int cpu);
 439 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
 440
 441 void cpufreq_frequency_table_put_attr(unsigned int cpu);
 442
 443 /*********************************************************************
 444  *                         CPUFREQ STATS                             *
 445  *********************************************************************/
 446
 447 void acct_update_power(struct task_struct *p, cputime_t cputime);
 448
 449 #endif /* _LINUX_CPUFREQ_H */