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