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