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