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