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