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 int transition_ongoing; /* Tracks transition status */ 89 }; 90 91 /* Only for ACPI */ 92 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 93 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 94 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 95 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 96 97 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 98 void cpufreq_cpu_put(struct cpufreq_policy *policy); 99 100 static inline bool policy_is_shared(struct cpufreq_policy *policy) 101 { 102 return cpumask_weight(policy->cpus) > 1; 103 } 104 105 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */ 106 extern struct kobject *cpufreq_global_kobject; 107 int cpufreq_get_global_kobject(void); 108 void cpufreq_put_global_kobject(void); 109 int cpufreq_sysfs_create_file(const struct attribute *attr); 110 void cpufreq_sysfs_remove_file(const struct attribute *attr); 111 112 #ifdef CONFIG_CPU_FREQ 113 unsigned int cpufreq_get(unsigned int cpu); 114 unsigned int cpufreq_quick_get(unsigned int cpu); 115 unsigned int cpufreq_quick_get_max(unsigned int cpu); 116 void disable_cpufreq(void); 117 118 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy); 119 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 120 int cpufreq_update_policy(unsigned int cpu); 121 bool have_governor_per_policy(void); 122 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy); 123 #else 124 static inline unsigned int cpufreq_get(unsigned int cpu) 125 { 126 return 0; 127 } 128 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 129 { 130 return 0; 131 } 132 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 133 { 134 return 0; 135 } 136 static inline void disable_cpufreq(void) { } 137 #endif 138 139 /********************************************************************* 140 * CPUFREQ DRIVER INTERFACE * 141 *********************************************************************/ 142 143 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 144 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 145 146 struct freq_attr { 147 struct attribute attr; 148 ssize_t (*show)(struct cpufreq_policy *, char *); 149 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 150 }; 151 152 #define cpufreq_freq_attr_ro(_name) \ 153 static struct freq_attr _name = \ 154 __ATTR(_name, 0444, show_##_name, NULL) 155 156 #define cpufreq_freq_attr_ro_perm(_name, _perm) \ 157 static struct freq_attr _name = \ 158 __ATTR(_name, _perm, show_##_name, NULL) 159 160 #define cpufreq_freq_attr_rw(_name) \ 161 static struct freq_attr _name = \ 162 __ATTR(_name, 0644, show_##_name, store_##_name) 163 164 struct global_attr { 165 struct attribute attr; 166 ssize_t (*show)(struct kobject *kobj, 167 struct attribute *attr, char *buf); 168 ssize_t (*store)(struct kobject *a, struct attribute *b, 169 const char *c, size_t count); 170 }; 171 172 #define define_one_global_ro(_name) \ 173 static struct global_attr _name = \ 174 __ATTR(_name, 0444, show_##_name, NULL) 175 176 #define define_one_global_rw(_name) \ 177 static struct global_attr _name = \ 178 __ATTR(_name, 0644, show_##_name, store_##_name) 179 180 181 struct cpufreq_driver { 182 char name[CPUFREQ_NAME_LEN]; 183 u8 flags; 184 /* 185 * This should be set by platforms having multiple clock-domains, i.e. 186 * supporting multiple policies. With this sysfs directories of governor 187 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can 188 * use the same governor with different tunables for different clusters. 189 */ 190 bool have_governor_per_policy; 191 192 /* needed by all drivers */ 193 int (*init) (struct cpufreq_policy *policy); 194 int (*verify) (struct cpufreq_policy *policy); 195 196 /* define one out of two */ 197 int (*setpolicy) (struct cpufreq_policy *policy); 198 int (*target) (struct cpufreq_policy *policy, 199 unsigned int target_freq, 200 unsigned int relation); 201 202 /* should be defined, if possible */ 203 unsigned int (*get) (unsigned int cpu); 204 205 /* optional */ 206 int (*bios_limit) (int cpu, unsigned int *limit); 207 208 int (*exit) (struct cpufreq_policy *policy); 209 int (*suspend) (struct cpufreq_policy *policy); 210 int (*resume) (struct cpufreq_policy *policy); 211 struct freq_attr **attr; 212 }; 213 214 /* flags */ 215 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 216 * all ->init() calls failed */ 217 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 218 * "constants" aren't affected by 219 * frequency transitions */ 220 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 221 * mismatches */ 222 223 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 224 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 225 226 const char *cpufreq_get_current_driver(void); 227 228 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, 229 unsigned int min, unsigned int max) 230 { 231 if (policy->min < min) 232 policy->min = min; 233 if (policy->max < min) 234 policy->max = min; 235 if (policy->min > max) 236 policy->min = max; 237 if (policy->max > max) 238 policy->max = max; 239 if (policy->min > policy->max) 240 policy->min = policy->max; 241 return; 242 } 243 244 /********************************************************************* 245 * CPUFREQ NOTIFIER INTERFACE * 246 *********************************************************************/ 247 248 #define CPUFREQ_TRANSITION_NOTIFIER (0) 249 #define CPUFREQ_POLICY_NOTIFIER (1) 250 251 /* Transition notifiers */ 252 #define CPUFREQ_PRECHANGE (0) 253 #define CPUFREQ_POSTCHANGE (1) 254 #define CPUFREQ_RESUMECHANGE (8) 255 #define CPUFREQ_SUSPENDCHANGE (9) 256 257 /* Policy Notifiers */ 258 #define CPUFREQ_ADJUST (0) 259 #define CPUFREQ_INCOMPATIBLE (1) 260 #define CPUFREQ_NOTIFY (2) 261 #define CPUFREQ_START (3) 262 #define CPUFREQ_UPDATE_POLICY_CPU (4) 263 264 #ifdef CONFIG_CPU_FREQ 265 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 266 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 267 268 void cpufreq_notify_transition(struct cpufreq_policy *policy, 269 struct cpufreq_freqs *freqs, unsigned int state); 270 271 #else /* CONFIG_CPU_FREQ */ 272 static inline int cpufreq_register_notifier(struct notifier_block *nb, 273 unsigned int list) 274 { 275 return 0; 276 } 277 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 278 unsigned int list) 279 { 280 return 0; 281 } 282 #endif /* !CONFIG_CPU_FREQ */ 283 284 /** 285 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch 286 * safe) 287 * @old: old value 288 * @div: divisor 289 * @mult: multiplier 290 * 291 * 292 * new = old * mult / div 293 */ 294 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, 295 u_int mult) 296 { 297 #if BITS_PER_LONG == 32 298 u64 result = ((u64) old) * ((u64) mult); 299 do_div(result, div); 300 return (unsigned long) result; 301 302 #elif BITS_PER_LONG == 64 303 unsigned long result = old * ((u64) mult); 304 result /= div; 305 return result; 306 #endif 307 } 308 309 /********************************************************************* 310 * CPUFREQ GOVERNORS * 311 *********************************************************************/ 312 313 /* 314 * If (cpufreq_driver->target) exists, the ->governor decides what frequency 315 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 316 * two generic policies are available: 317 */ 318 #define CPUFREQ_POLICY_POWERSAVE (1) 319 #define CPUFREQ_POLICY_PERFORMANCE (2) 320 321 /* Governor Events */ 322 #define CPUFREQ_GOV_START 1 323 #define CPUFREQ_GOV_STOP 2 324 #define CPUFREQ_GOV_LIMITS 3 325 #define CPUFREQ_GOV_POLICY_INIT 4 326 #define CPUFREQ_GOV_POLICY_EXIT 5 327 328 struct cpufreq_governor { 329 char name[CPUFREQ_NAME_LEN]; 330 int initialized; 331 int (*governor) (struct cpufreq_policy *policy, 332 unsigned int event); 333 ssize_t (*show_setspeed) (struct cpufreq_policy *policy, 334 char *buf); 335 int (*store_setspeed) (struct cpufreq_policy *policy, 336 unsigned int freq); 337 unsigned int max_transition_latency; /* HW must be able to switch to 338 next freq faster than this value in nano secs or we 339 will fallback to performance governor */ 340 struct list_head governor_list; 341 struct module *owner; 342 }; 343 344 /* Pass a target to the cpufreq driver */ 345 int cpufreq_driver_target(struct cpufreq_policy *policy, 346 unsigned int target_freq, 347 unsigned int relation); 348 int __cpufreq_driver_target(struct cpufreq_policy *policy, 349 unsigned int target_freq, 350 unsigned int relation); 351 int cpufreq_register_governor(struct cpufreq_governor *governor); 352 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 353 354 /* CPUFREQ DEFAULT GOVERNOR */ 355 /* 356 * Performance governor is fallback governor if any other gov failed to auto 357 * load due latency restrictions 358 */ 359 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 360 extern struct cpufreq_governor cpufreq_gov_performance; 361 #endif 362 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 363 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE) 365 extern struct cpufreq_governor cpufreq_gov_powersave; 366 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave) 367 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 368 extern struct cpufreq_governor cpufreq_gov_userspace; 369 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 370 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 371 extern struct cpufreq_governor cpufreq_gov_ondemand; 372 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 373 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 374 extern struct cpufreq_governor cpufreq_gov_conservative; 375 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 376 #endif 377 378 /********************************************************************* 379 * FREQUENCY TABLE HELPERS * 380 *********************************************************************/ 381 382 #define CPUFREQ_ENTRY_INVALID ~0 383 #define CPUFREQ_TABLE_END ~1 384 385 struct cpufreq_frequency_table { 386 unsigned int driver_data; /* driver specific data, not used by core */ 387 unsigned int frequency; /* kHz - doesn't need to be in ascending 388 * order */ 389 }; 390 391 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 392 struct cpufreq_frequency_table *table); 393 394 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 395 struct cpufreq_frequency_table *table); 396 397 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 398 struct cpufreq_frequency_table *table, 399 unsigned int target_freq, 400 unsigned int relation, 401 unsigned int *index); 402 403 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy); 404 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf); 405 406 /* the following funtion is for cpufreq core use only */ 407 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 408 409 /* the following are really really optional */ 410 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 411 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 412 unsigned int cpu); 413 void cpufreq_frequency_table_put_attr(unsigned int cpu); 414 415 #endif /* _LINUX_CPUFREQ_H */ 416