1 /* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <[email protected]> 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 <linux/cpumask.h> 15 #include <linux/completion.h> 16 #include <linux/kobject.h> 17 #include <linux/notifier.h> 18 #include <linux/sysfs.h> 19 20 /********************************************************************* 21 * CPUFREQ INTERFACE * 22 *********************************************************************/ 23 /* 24 * Frequency values here are CPU kHz 25 * 26 * Maximum transition latency is in nanoseconds - if it's unknown, 27 * CPUFREQ_ETERNAL shall be used. 28 */ 29 30 #define CPUFREQ_ETERNAL (-1) 31 #define CPUFREQ_NAME_LEN 16 32 /* Print length for names. Extra 1 space for accomodating '\n' in prints */ 33 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1) 34 35 struct cpufreq_governor; 36 37 struct cpufreq_freqs { 38 unsigned int cpu; /* cpu nr */ 39 unsigned int old; 40 unsigned int new; 41 u8 flags; /* flags of cpufreq_driver, see below. */ 42 }; 43 44 struct cpufreq_cpuinfo { 45 unsigned int max_freq; 46 unsigned int min_freq; 47 48 /* in 10^(-9) s = nanoseconds */ 49 unsigned int transition_latency; 50 }; 51 52 struct cpufreq_real_policy { 53 unsigned int min; /* in kHz */ 54 unsigned int max; /* in kHz */ 55 unsigned int policy; /* see above */ 56 struct cpufreq_governor *governor; /* see below */ 57 }; 58 59 struct cpufreq_policy { 60 /* CPUs sharing clock, require sw coordination */ 61 cpumask_var_t cpus; /* Online CPUs only */ 62 cpumask_var_t related_cpus; /* Online + Offline CPUs */ 63 64 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs 65 should set cpufreq */ 66 unsigned int cpu; /* cpu nr of CPU managing this policy */ 67 unsigned int last_cpu; /* cpu nr of previous CPU that managed 68 * this policy */ 69 struct cpufreq_cpuinfo cpuinfo;/* see above */ 70 71 unsigned int min; /* in kHz */ 72 unsigned int max; /* in kHz */ 73 unsigned int cur; /* in kHz, only needed if cpufreq 74 * governors are used */ 75 unsigned int policy; /* see above */ 76 struct cpufreq_governor *governor; /* see below */ 77 void *governor_data; 78 bool governor_enabled; /* governor start/stop flag */ 79 80 struct work_struct update; /* if update_policy() needs to be 81 * called, but you're in IRQ context */ 82 83 struct cpufreq_real_policy user_policy; 84 85 struct list_head policy_list; 86 struct kobject kobj; 87 struct completion kobj_unregister; 88 89 /* 90 * The rules for this semaphore: 91 * - Any routine that wants to read from the policy structure will 92 * do a down_read on this semaphore. 93 * - Any routine that will write to the policy structure and/or may take away 94 * the policy altogether (eg. CPU hotplug), will hold this lock in write 95 * mode before doing so. 96 * 97 * Additional rules: 98 * - Lock should not be held across 99 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); 100 */ 101 struct rw_semaphore rwsem; 102 }; 103 104 /* Only for ACPI */ 105 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 106 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 107 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 108 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 109 110 #ifdef CONFIG_CPU_FREQ 111 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 112 void cpufreq_cpu_put(struct cpufreq_policy *policy); 113 #else 114 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) 115 { 116 return NULL; 117 } 118 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { } 119 #endif 120 121 static inline bool policy_is_shared(struct cpufreq_policy *policy) 122 { 123 return cpumask_weight(policy->cpus) > 1; 124 } 125 126 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ 127 extern struct kobject *cpufreq_global_kobject; 128 int cpufreq_get_global_kobject(void); 129 void cpufreq_put_global_kobject(void); 130 int cpufreq_sysfs_create_file(const struct attribute *attr); 131 void cpufreq_sysfs_remove_file(const struct attribute *attr); 132 133 #ifdef CONFIG_CPU_FREQ 134 unsigned int cpufreq_get(unsigned int cpu); 135 unsigned int cpufreq_quick_get(unsigned int cpu); 136 unsigned int cpufreq_quick_get_max(unsigned int cpu); 137 void disable_cpufreq(void); 138 139 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy); 140 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 141 int cpufreq_update_policy(unsigned int cpu); 142 bool have_governor_per_policy(void); 143 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy); 144 #else 145 static inline unsigned int cpufreq_get(unsigned int cpu) 146 { 147 return 0; 148 } 149 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 150 { 151 return 0; 152 } 153 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 154 { 155 return 0; 156 } 157 static inline void disable_cpufreq(void) { } 158 #endif 159 160 /********************************************************************* 161 * CPUFREQ DRIVER INTERFACE * 162 *********************************************************************/ 163 164 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 165 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 166 167 struct freq_attr { 168 struct attribute attr; 169 ssize_t (*show)(struct cpufreq_policy *, char *); 170 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 171 }; 172 173 #define cpufreq_freq_attr_ro(_name) \ 174 static struct freq_attr _name = \ 175 __ATTR(_name, 0444, show_##_name, NULL) 176 177 #define cpufreq_freq_attr_ro_perm(_name, _perm) \ 178 static struct freq_attr _name = \ 179 __ATTR(_name, _perm, show_##_name, NULL) 180 181 #define cpufreq_freq_attr_rw(_name) \ 182 static struct freq_attr _name = \ 183 __ATTR(_name, 0644, show_##_name, store_##_name) 184 185 struct global_attr { 186 struct attribute attr; 187 ssize_t (*show)(struct kobject *kobj, 188 struct attribute *attr, char *buf); 189 ssize_t (*store)(struct kobject *a, struct attribute *b, 190 const char *c, size_t count); 191 }; 192 193 #define define_one_global_ro(_name) \ 194 static struct global_attr _name = \ 195 __ATTR(_name, 0444, show_##_name, NULL) 196 197 #define define_one_global_rw(_name) \ 198 static struct global_attr _name = \ 199 __ATTR(_name, 0644, show_##_name, store_##_name) 200 201 202 struct cpufreq_driver { 203 char name[CPUFREQ_NAME_LEN]; 204 u8 flags; 205 206 /* needed by all drivers */ 207 int (*init) (struct cpufreq_policy *policy); 208 int (*verify) (struct cpufreq_policy *policy); 209 210 /* define one out of two */ 211 int (*setpolicy) (struct cpufreq_policy *policy); 212 int (*target) (struct cpufreq_policy *policy, /* Deprecated */ 213 unsigned int target_freq, 214 unsigned int relation); 215 int (*target_index) (struct cpufreq_policy *policy, 216 unsigned int index); 217 218 /* should be defined, if possible */ 219 unsigned int (*get) (unsigned int cpu); 220 221 /* optional */ 222 int (*bios_limit) (int cpu, unsigned int *limit); 223 224 int (*exit) (struct cpufreq_policy *policy); 225 int (*suspend) (struct cpufreq_policy *policy); 226 int (*resume) (struct cpufreq_policy *policy); 227 struct freq_attr **attr; 228 }; 229 230 /* flags */ 231 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if 232 all ->init() calls failed */ 233 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other 234 kernel "constants" aren't 235 affected by frequency 236 transitions */ 237 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume 238 speed mismatches */ 239 240 /* 241 * This should be set by platforms having multiple clock-domains, i.e. 242 * supporting multiple policies. With this sysfs directories of governor would 243 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same 244 * governor with different tunables for different clusters. 245 */ 246 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3) 247 248 /* 249 * Driver will do POSTCHANGE notifications from outside of their ->target() 250 * routine and so must set cpufreq_driver->flags with this flag, so that core 251 * can handle them specially. 252 */ 253 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4) 254 255 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 256 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 257 258 const char *cpufreq_get_current_driver(void); 259 260 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, 261 unsigned int min, unsigned int max) 262 { 263 if (policy->min < min) 264 policy->min = min; 265 if (policy->max < min) 266 policy->max = min; 267 if (policy->min > max) 268 policy->min = max; 269 if (policy->max > max) 270 policy->max = max; 271 if (policy->min > policy->max) 272 policy->min = policy->max; 273 return; 274 } 275 276 static inline void 277 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy) 278 { 279 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 280 policy->cpuinfo.max_freq); 281 } 282 283 /********************************************************************* 284 * CPUFREQ NOTIFIER INTERFACE * 285 *********************************************************************/ 286 287 #define CPUFREQ_TRANSITION_NOTIFIER (0) 288 #define CPUFREQ_POLICY_NOTIFIER (1) 289 290 /* Transition notifiers */ 291 #define CPUFREQ_PRECHANGE (0) 292 #define CPUFREQ_POSTCHANGE (1) 293 #define CPUFREQ_RESUMECHANGE (8) 294 #define CPUFREQ_SUSPENDCHANGE (9) 295 296 /* Policy Notifiers */ 297 #define CPUFREQ_ADJUST (0) 298 #define CPUFREQ_INCOMPATIBLE (1) 299 #define CPUFREQ_NOTIFY (2) 300 #define CPUFREQ_START (3) 301 #define CPUFREQ_UPDATE_POLICY_CPU (4) 302 303 #ifdef CONFIG_CPU_FREQ 304 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 305 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 306 307 void cpufreq_notify_transition(struct cpufreq_policy *policy, 308 struct cpufreq_freqs *freqs, unsigned int state); 309 310 #else /* CONFIG_CPU_FREQ */ 311 static inline int cpufreq_register_notifier(struct notifier_block *nb, 312 unsigned int list) 313 { 314 return 0; 315 } 316 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 317 unsigned int list) 318 { 319 return 0; 320 } 321 #endif /* !CONFIG_CPU_FREQ */ 322 323 /** 324 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch 325 * safe) 326 * @old: old value 327 * @div: divisor 328 * @mult: multiplier 329 * 330 * 331 * new = old * mult / div 332 */ 333 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, 334 u_int mult) 335 { 336 #if BITS_PER_LONG == 32 337 u64 result = ((u64) old) * ((u64) mult); 338 do_div(result, div); 339 return (unsigned long) result; 340 341 #elif BITS_PER_LONG == 64 342 unsigned long result = old * ((u64) mult); 343 result /= div; 344 return result; 345 #endif 346 } 347 348 /********************************************************************* 349 * CPUFREQ GOVERNORS * 350 *********************************************************************/ 351 352 /* 353 * If (cpufreq_driver->target) exists, the ->governor decides what frequency 354 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 355 * two generic policies are available: 356 */ 357 #define CPUFREQ_POLICY_POWERSAVE (1) 358 #define CPUFREQ_POLICY_PERFORMANCE (2) 359 360 /* Governor Events */ 361 #define CPUFREQ_GOV_START 1 362 #define CPUFREQ_GOV_STOP 2 363 #define CPUFREQ_GOV_LIMITS 3 364 #define CPUFREQ_GOV_POLICY_INIT 4 365 #define CPUFREQ_GOV_POLICY_EXIT 5 366 367 struct cpufreq_governor { 368 char name[CPUFREQ_NAME_LEN]; 369 int initialized; 370 int (*governor) (struct cpufreq_policy *policy, 371 unsigned int event); 372 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 373 char *buf); 374 int (*store_setspeed) (struct cpufreq_policy *policy, 375 unsigned int freq); 376 unsigned int max_transition_latency; /* HW must be able to switch to 377 next freq faster than this value in nano secs or we 378 will fallback to performance governor */ 379 struct list_head governor_list; 380 struct module *owner; 381 }; 382 383 /* Pass a target to the cpufreq driver */ 384 int cpufreq_driver_target(struct cpufreq_policy *policy, 385 unsigned int target_freq, 386 unsigned int relation); 387 int __cpufreq_driver_target(struct cpufreq_policy *policy, 388 unsigned int target_freq, 389 unsigned int relation); 390 int cpufreq_register_governor(struct cpufreq_governor *governor); 391 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 392 393 /* CPUFREQ DEFAULT GOVERNOR */ 394 /* 395 * Performance governor is fallback governor if any other gov failed to auto 396 * load due latency restrictions 397 */ 398 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 399 extern struct cpufreq_governor cpufreq_gov_performance; 400 #endif 401 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 402 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 403 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 404 extern struct cpufreq_governor cpufreq_gov_powersave; 405 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 406 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 407 extern struct cpufreq_governor cpufreq_gov_userspace; 408 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 409 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 410 extern struct cpufreq_governor cpufreq_gov_ondemand; 411 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 412 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 413 extern struct cpufreq_governor cpufreq_gov_conservative; 414 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 415 #endif 416 417 /********************************************************************* 418 * FREQUENCY TABLE HELPERS * 419 *********************************************************************/ 420 421 #define CPUFREQ_ENTRY_INVALID ~0 422 #define CPUFREQ_TABLE_END ~1 423 424 struct cpufreq_frequency_table { 425 unsigned int driver_data; /* driver specific data, not used by core */ 426 unsigned int frequency; /* kHz - doesn't need to be in ascending 427 * order */ 428 }; 429 430 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 431 struct cpufreq_frequency_table *table); 432 433 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 434 struct cpufreq_frequency_table *table); 435 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy); 436 437 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 438 struct cpufreq_frequency_table *table, 439 unsigned int target_freq, 440 unsigned int relation, 441 unsigned int *index); 442 443 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy); 444 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf); 445 446 /* the following funtion is for cpufreq core use only */ 447 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 448 449 /* the following are really really optional */ 450 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 451 extern struct freq_attr *cpufreq_generic_attr[]; 452 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 453 unsigned int cpu); 454 void cpufreq_frequency_table_put_attr(unsigned int cpu); 455 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy, 456 struct cpufreq_frequency_table *table); 457 458 int cpufreq_generic_init(struct cpufreq_policy *policy, 459 struct cpufreq_frequency_table *table, 460 unsigned int transition_latency); 461 static inline int cpufreq_generic_exit(struct cpufreq_policy *policy) 462 { 463 cpufreq_frequency_table_put_attr(policy->cpu); 464 return 0; 465 } 466 467 #endif /* _LINUX_CPUFREQ_H */ 468