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/clk.h> 15 #include <linux/cpumask.h> 16 #include <linux/completion.h> 17 #include <linux/kobject.h> 18 #include <linux/notifier.h> 19 #include <linux/spinlock.h> 20 #include <linux/sysfs.h> 21 22 /********************************************************************* 23 * CPUFREQ INTERFACE * 24 *********************************************************************/ 25 /* 26 * Frequency values here are CPU kHz 27 * 28 * Maximum transition latency is in nanoseconds - if it's unknown, 29 * CPUFREQ_ETERNAL shall be used. 30 */ 31 32 #define CPUFREQ_ETERNAL (-1) 33 #define CPUFREQ_NAME_LEN 16 34 /* Print length for names. Extra 1 space for accomodating '\n' in prints */ 35 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1) 36 37 struct cpufreq_governor; 38 39 struct cpufreq_freqs { 40 unsigned int cpu; /* cpu nr */ 41 unsigned int old; 42 unsigned int new; 43 u8 flags; /* flags of cpufreq_driver, see below. */ 44 }; 45 46 struct cpufreq_cpuinfo { 47 unsigned int max_freq; 48 unsigned int min_freq; 49 50 /* in 10^(-9) s = nanoseconds */ 51 unsigned int transition_latency; 52 }; 53 54 struct cpufreq_real_policy { 55 unsigned int min; /* in kHz */ 56 unsigned int max; /* in kHz */ 57 unsigned int policy; /* see above */ 58 struct cpufreq_governor *governor; /* see below */ 59 }; 60 61 struct cpufreq_policy { 62 /* CPUs sharing clock, require sw coordination */ 63 cpumask_var_t cpus; /* Online CPUs only */ 64 cpumask_var_t related_cpus; /* Online + Offline CPUs */ 65 66 unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs 67 should set cpufreq */ 68 unsigned int cpu; /* cpu nr of CPU managing this policy */ 69 unsigned int last_cpu; /* cpu nr of previous CPU that managed 70 * this policy */ 71 struct clk *clk; 72 struct cpufreq_cpuinfo cpuinfo;/* see above */ 73 74 unsigned int min; /* in kHz */ 75 unsigned int max; /* in kHz */ 76 unsigned int cur; /* in kHz, only needed if cpufreq 77 * governors are used */ 78 unsigned int suspend_freq; /* freq to set during suspend */ 79 80 unsigned int policy; /* see above */ 81 struct cpufreq_governor *governor; /* see below */ 82 void *governor_data; 83 bool governor_enabled; /* governor start/stop flag */ 84 85 struct work_struct update; /* if update_policy() needs to be 86 * called, but you're in IRQ context */ 87 88 struct cpufreq_real_policy user_policy; 89 struct cpufreq_frequency_table *freq_table; 90 91 struct list_head policy_list; 92 struct kobject kobj; 93 struct completion kobj_unregister; 94 95 /* 96 * The rules for this semaphore: 97 * - Any routine that wants to read from the policy structure will 98 * do a down_read on this semaphore. 99 * - Any routine that will write to the policy structure and/or may take away 100 * the policy altogether (eg. CPU hotplug), will hold this lock in write 101 * mode before doing so. 102 * 103 * Additional rules: 104 * - Lock should not be held across 105 * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); 106 */ 107 struct rw_semaphore rwsem; 108 109 /* Synchronization for frequency transitions */ 110 bool transition_ongoing; /* Tracks transition status */ 111 spinlock_t transition_lock; 112 wait_queue_head_t transition_wait; 113 }; 114 115 /* Only for ACPI */ 116 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 117 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 118 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 119 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 120 121 #ifdef CONFIG_CPU_FREQ 122 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 123 void cpufreq_cpu_put(struct cpufreq_policy *policy); 124 #else 125 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) 126 { 127 return NULL; 128 } 129 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { } 130 #endif 131 132 static inline bool policy_is_shared(struct cpufreq_policy *policy) 133 { 134 return cpumask_weight(policy->cpus) > 1; 135 } 136 137 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ 138 extern struct kobject *cpufreq_global_kobject; 139 int cpufreq_get_global_kobject(void); 140 void cpufreq_put_global_kobject(void); 141 int cpufreq_sysfs_create_file(const struct attribute *attr); 142 void cpufreq_sysfs_remove_file(const struct attribute *attr); 143 144 #ifdef CONFIG_CPU_FREQ 145 unsigned int cpufreq_get(unsigned int cpu); 146 unsigned int cpufreq_quick_get(unsigned int cpu); 147 unsigned int cpufreq_quick_get_max(unsigned int cpu); 148 void disable_cpufreq(void); 149 150 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy); 151 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 152 int cpufreq_update_policy(unsigned int cpu); 153 bool have_governor_per_policy(void); 154 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy); 155 #else 156 static inline unsigned int cpufreq_get(unsigned int cpu) 157 { 158 return 0; 159 } 160 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 161 { 162 return 0; 163 } 164 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 165 { 166 return 0; 167 } 168 static inline void disable_cpufreq(void) { } 169 #endif 170 171 /********************************************************************* 172 * CPUFREQ DRIVER INTERFACE * 173 *********************************************************************/ 174 175 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 176 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 177 178 struct freq_attr { 179 struct attribute attr; 180 ssize_t (*show)(struct cpufreq_policy *, char *); 181 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 182 }; 183 184 #define cpufreq_freq_attr_ro(_name) \ 185 static struct freq_attr _name = \ 186 __ATTR(_name, 0444, show_##_name, NULL) 187 188 #define cpufreq_freq_attr_ro_perm(_name, _perm) \ 189 static struct freq_attr _name = \ 190 __ATTR(_name, _perm, show_##_name, NULL) 191 192 #define cpufreq_freq_attr_rw(_name) \ 193 static struct freq_attr _name = \ 194 __ATTR(_name, 0644, show_##_name, store_##_name) 195 196 struct global_attr { 197 struct attribute attr; 198 ssize_t (*show)(struct kobject *kobj, 199 struct attribute *attr, char *buf); 200 ssize_t (*store)(struct kobject *a, struct attribute *b, 201 const char *c, size_t count); 202 }; 203 204 #define define_one_global_ro(_name) \ 205 static struct global_attr _name = \ 206 __ATTR(_name, 0444, show_##_name, NULL) 207 208 #define define_one_global_rw(_name) \ 209 static struct global_attr _name = \ 210 __ATTR(_name, 0644, show_##_name, store_##_name) 211 212 213 struct cpufreq_driver { 214 char name[CPUFREQ_NAME_LEN]; 215 u8 flags; 216 217 /* needed by all drivers */ 218 int (*init) (struct cpufreq_policy *policy); 219 int (*verify) (struct cpufreq_policy *policy); 220 221 /* define one out of two */ 222 int (*setpolicy) (struct cpufreq_policy *policy); 223 int (*target) (struct cpufreq_policy *policy, /* Deprecated */ 224 unsigned int target_freq, 225 unsigned int relation); 226 int (*target_index) (struct cpufreq_policy *policy, 227 unsigned int index); 228 229 /* should be defined, if possible */ 230 unsigned int (*get) (unsigned int cpu); 231 232 /* optional */ 233 int (*bios_limit) (int cpu, unsigned int *limit); 234 235 int (*exit) (struct cpufreq_policy *policy); 236 void (*stop_cpu) (struct cpufreq_policy *policy); 237 int (*suspend) (struct cpufreq_policy *policy); 238 int (*resume) (struct cpufreq_policy *policy); 239 struct freq_attr **attr; 240 241 /* platform specific boost support code */ 242 bool boost_supported; 243 bool boost_enabled; 244 int (*set_boost) (int state); 245 }; 246 247 /* flags */ 248 #define CPUFREQ_STICKY (1 << 0) /* driver isn't removed even if 249 all ->init() calls failed */ 250 #define CPUFREQ_CONST_LOOPS (1 << 1) /* loops_per_jiffy or other 251 kernel "constants" aren't 252 affected by frequency 253 transitions */ 254 #define CPUFREQ_PM_NO_WARN (1 << 2) /* don't warn on suspend/resume 255 speed mismatches */ 256 257 /* 258 * This should be set by platforms having multiple clock-domains, i.e. 259 * supporting multiple policies. With this sysfs directories of governor would 260 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same 261 * governor with different tunables for different clusters. 262 */ 263 #define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3) 264 265 /* 266 * Driver will do POSTCHANGE notifications from outside of their ->target() 267 * routine and so must set cpufreq_driver->flags with this flag, so that core 268 * can handle them specially. 269 */ 270 #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4) 271 272 /* 273 * Set by drivers which want cpufreq core to check if CPU is running at a 274 * frequency present in freq-table exposed by the driver. For these drivers if 275 * CPU is found running at an out of table freq, we will try to set it to a freq 276 * from the table. And if that fails, we will stop further boot process by 277 * issuing a BUG_ON(). 278 */ 279 #define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5) 280 281 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 282 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 283 284 const char *cpufreq_get_current_driver(void); 285 286 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, 287 unsigned int min, unsigned int max) 288 { 289 if (policy->min < min) 290 policy->min = min; 291 if (policy->max < min) 292 policy->max = min; 293 if (policy->min > max) 294 policy->min = max; 295 if (policy->max > max) 296 policy->max = max; 297 if (policy->min > policy->max) 298 policy->min = policy->max; 299 return; 300 } 301 302 static inline void 303 cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy) 304 { 305 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, 306 policy->cpuinfo.max_freq); 307 } 308 309 #ifdef CONFIG_CPU_FREQ 310 void cpufreq_suspend(void); 311 void cpufreq_resume(void); 312 int cpufreq_generic_suspend(struct cpufreq_policy *policy); 313 #else 314 static inline void cpufreq_suspend(void) {} 315 static inline void cpufreq_resume(void) {} 316 #endif 317 318 /********************************************************************* 319 * CPUFREQ NOTIFIER INTERFACE * 320 *********************************************************************/ 321 322 #define CPUFREQ_TRANSITION_NOTIFIER (0) 323 #define CPUFREQ_POLICY_NOTIFIER (1) 324 325 /* Transition notifiers */ 326 #define CPUFREQ_PRECHANGE (0) 327 #define CPUFREQ_POSTCHANGE (1) 328 329 /* Policy Notifiers */ 330 #define CPUFREQ_ADJUST (0) 331 #define CPUFREQ_INCOMPATIBLE (1) 332 #define CPUFREQ_NOTIFY (2) 333 #define CPUFREQ_START (3) 334 #define CPUFREQ_UPDATE_POLICY_CPU (4) 335 #define CPUFREQ_CREATE_POLICY (5) 336 #define CPUFREQ_REMOVE_POLICY (6) 337 338 #ifdef CONFIG_CPU_FREQ 339 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 340 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 341 342 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, 343 struct cpufreq_freqs *freqs); 344 void cpufreq_freq_transition_end(struct cpufreq_policy *policy, 345 struct cpufreq_freqs *freqs, int transition_failed); 346 347 #else /* CONFIG_CPU_FREQ */ 348 static inline int cpufreq_register_notifier(struct notifier_block *nb, 349 unsigned int list) 350 { 351 return 0; 352 } 353 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 354 unsigned int list) 355 { 356 return 0; 357 } 358 #endif /* !CONFIG_CPU_FREQ */ 359 360 /** 361 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch 362 * safe) 363 * @old: old value 364 * @div: divisor 365 * @mult: multiplier 366 * 367 * 368 * new = old * mult / div 369 */ 370 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, 371 u_int mult) 372 { 373 #if BITS_PER_LONG == 32 374 u64 result = ((u64) old) * ((u64) mult); 375 do_div(result, div); 376 return (unsigned long) result; 377 378 #elif BITS_PER_LONG == 64 379 unsigned long result = old * ((u64) mult); 380 result /= div; 381 return result; 382 #endif 383 } 384 385 /********************************************************************* 386 * CPUFREQ GOVERNORS * 387 *********************************************************************/ 388 389 /* 390 * If (cpufreq_driver->target) exists, the ->governor decides what frequency 391 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 392 * two generic policies are available: 393 */ 394 #define CPUFREQ_POLICY_POWERSAVE (1) 395 #define CPUFREQ_POLICY_PERFORMANCE (2) 396 397 /* Governor Events */ 398 #define CPUFREQ_GOV_START 1 399 #define CPUFREQ_GOV_STOP 2 400 #define CPUFREQ_GOV_LIMITS 3 401 #define CPUFREQ_GOV_POLICY_INIT 4 402 #define CPUFREQ_GOV_POLICY_EXIT 5 403 404 struct cpufreq_governor { 405 char name[CPUFREQ_NAME_LEN]; 406 int initialized; 407 int (*governor) (struct cpufreq_policy *policy, 408 unsigned int event); 409 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 410 char *buf); 411 int (*store_setspeed) (struct cpufreq_policy *policy, 412 unsigned int freq); 413 unsigned int max_transition_latency; /* HW must be able to switch to 414 next freq faster than this value in nano secs or we 415 will fallback to performance governor */ 416 struct list_head governor_list; 417 struct module *owner; 418 }; 419 420 /* Pass a target to the cpufreq driver */ 421 int cpufreq_driver_target(struct cpufreq_policy *policy, 422 unsigned int target_freq, 423 unsigned int relation); 424 int __cpufreq_driver_target(struct cpufreq_policy *policy, 425 unsigned int target_freq, 426 unsigned int relation); 427 int cpufreq_register_governor(struct cpufreq_governor *governor); 428 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 429 430 /* CPUFREQ DEFAULT GOVERNOR */ 431 /* 432 * Performance governor is fallback governor if any other gov failed to auto 433 * load due latency restrictions 434 */ 435 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 436 extern struct cpufreq_governor cpufreq_gov_performance; 437 #endif 438 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 439 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 440 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 441 extern struct cpufreq_governor cpufreq_gov_powersave; 442 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 443 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 444 extern struct cpufreq_governor cpufreq_gov_userspace; 445 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 446 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 447 extern struct cpufreq_governor cpufreq_gov_ondemand; 448 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 449 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 450 extern struct cpufreq_governor cpufreq_gov_conservative; 451 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 452 #endif 453 454 /********************************************************************* 455 * FREQUENCY TABLE HELPERS * 456 *********************************************************************/ 457 458 /* Special Values of .frequency field */ 459 #define CPUFREQ_ENTRY_INVALID ~0 460 #define CPUFREQ_TABLE_END ~1 461 /* Special Values of .flags field */ 462 #define CPUFREQ_BOOST_FREQ (1 << 0) 463 464 struct cpufreq_frequency_table { 465 unsigned int flags; 466 unsigned int driver_data; /* driver specific data, not used by core */ 467 unsigned int frequency; /* kHz - doesn't need to be in ascending 468 * order */ 469 }; 470 471 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 472 struct cpufreq_frequency_table *table); 473 474 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 475 struct cpufreq_frequency_table *table); 476 int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy); 477 478 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 479 struct cpufreq_frequency_table *table, 480 unsigned int target_freq, 481 unsigned int relation, 482 unsigned int *index); 483 int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy, 484 unsigned int freq); 485 486 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf); 487 488 #ifdef CONFIG_CPU_FREQ 489 int cpufreq_boost_trigger_state(int state); 490 int cpufreq_boost_supported(void); 491 int cpufreq_boost_enabled(void); 492 #else 493 static inline int cpufreq_boost_trigger_state(int state) 494 { 495 return 0; 496 } 497 static inline int cpufreq_boost_supported(void) 498 { 499 return 0; 500 } 501 static inline int cpufreq_boost_enabled(void) 502 { 503 return 0; 504 } 505 #endif 506 /* the following funtion is for cpufreq core use only */ 507 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 508 509 /* the following are really really optional */ 510 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 511 extern struct freq_attr *cpufreq_generic_attr[]; 512 int cpufreq_table_validate_and_show(struct cpufreq_policy *policy, 513 struct cpufreq_frequency_table *table); 514 515 unsigned int cpufreq_generic_get(unsigned int cpu); 516 int cpufreq_generic_init(struct cpufreq_policy *policy, 517 struct cpufreq_frequency_table *table, 518 unsigned int transition_latency); 519 #endif /* _LINUX_CPUFREQ_H */ 520