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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/cpufreq.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/cpufreq.h')
-rw-r--r-- | include/linux/cpufreq.h | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h new file mode 100644 index 000000000000..910eca35583d --- /dev/null +++ b/include/linux/cpufreq.h @@ -0,0 +1,328 @@ +/* + * linux/include/linux/cpufreq.h + * + * Copyright (C) 2001 Russell King + * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> + * + * + * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef _LINUX_CPUFREQ_H +#define _LINUX_CPUFREQ_H + +#include <linux/config.h> +#include <linux/notifier.h> +#include <linux/threads.h> +#include <linux/device.h> +#include <linux/kobject.h> +#include <linux/sysfs.h> +#include <linux/completion.h> +#include <linux/workqueue.h> +#include <linux/cpumask.h> + +#define CPUFREQ_NAME_LEN 16 + + +/********************************************************************* + * CPUFREQ NOTIFIER INTERFACE * + *********************************************************************/ + +int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); +int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); + +#define CPUFREQ_TRANSITION_NOTIFIER (0) +#define CPUFREQ_POLICY_NOTIFIER (1) + + +/* if (cpufreq_driver->target) exists, the ->governor decides what frequency + * within the limits is used. If (cpufreq_driver->setpolicy> exists, these + * two generic policies are available: + */ + +#define CPUFREQ_POLICY_POWERSAVE (1) +#define CPUFREQ_POLICY_PERFORMANCE (2) + +/* Frequency values here are CPU kHz so that hardware which doesn't run + * with some frequencies can complain without having to guess what per + * cent / per mille means. + * Maximum transition latency is in microseconds - if it's unknown, + * CPUFREQ_ETERNAL shall be used. + */ + +struct cpufreq_governor; + +#define CPUFREQ_ETERNAL (-1) +struct cpufreq_cpuinfo { + unsigned int max_freq; + unsigned int min_freq; + unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ +}; + +struct cpufreq_real_policy { + unsigned int min; /* in kHz */ + unsigned int max; /* in kHz */ + unsigned int policy; /* see above */ + struct cpufreq_governor *governor; /* see below */ +}; + +struct cpufreq_policy { + cpumask_t cpus; /* affected CPUs */ + unsigned int cpu; /* cpu nr of registered CPU */ + struct cpufreq_cpuinfo cpuinfo;/* see above */ + + unsigned int min; /* in kHz */ + unsigned int max; /* in kHz */ + unsigned int cur; /* in kHz, only needed if cpufreq + * governors are used */ + unsigned int policy; /* see above */ + struct cpufreq_governor *governor; /* see below */ + + struct semaphore lock; /* CPU ->setpolicy or ->target may + only be called once a time */ + + struct work_struct update; /* if update_policy() needs to be + * called, but you're in IRQ context */ + + struct cpufreq_real_policy user_policy; + + struct kobject kobj; + struct completion kobj_unregister; +}; + +#define CPUFREQ_ADJUST (0) +#define CPUFREQ_INCOMPATIBLE (1) +#define CPUFREQ_NOTIFY (2) + + +/******************** cpufreq transition notifiers *******************/ + +#define CPUFREQ_PRECHANGE (0) +#define CPUFREQ_POSTCHANGE (1) +#define CPUFREQ_RESUMECHANGE (8) + +struct cpufreq_freqs { + unsigned int cpu; /* cpu nr */ + unsigned int old; + unsigned int new; + u8 flags; /* flags of cpufreq_driver, see below. */ +}; + + +/** + * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) + * @old: old value + * @div: divisor + * @mult: multiplier + * + * + * new = old * mult / div + */ +static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) +{ +#if BITS_PER_LONG == 32 + + u64 result = ((u64) old) * ((u64) mult); + do_div(result, div); + return (unsigned long) result; + +#elif BITS_PER_LONG == 64 + + unsigned long result = old * ((u64) mult); + result /= div; + return result; + +#endif +}; + +/********************************************************************* + * CPUFREQ GOVERNORS * + *********************************************************************/ + +#define CPUFREQ_GOV_START 1 +#define CPUFREQ_GOV_STOP 2 +#define CPUFREQ_GOV_LIMITS 3 + +struct cpufreq_governor { + char name[CPUFREQ_NAME_LEN]; + int (*governor) (struct cpufreq_policy *policy, + unsigned int event); + struct list_head governor_list; + struct module *owner; +}; + +/* pass a target to the cpufreq driver + */ +extern int cpufreq_driver_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation); +extern int __cpufreq_driver_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation); + + +/* pass an event to the cpufreq governor */ +int cpufreq_governor(unsigned int cpu, unsigned int event); + +int cpufreq_register_governor(struct cpufreq_governor *governor); +void cpufreq_unregister_governor(struct cpufreq_governor *governor); + + +/********************************************************************* + * CPUFREQ DRIVER INTERFACE * + *********************************************************************/ + +#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ +#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ + +struct freq_attr; + +struct cpufreq_driver { + struct module *owner; + char name[CPUFREQ_NAME_LEN]; + u8 flags; + + /* needed by all drivers */ + int (*init) (struct cpufreq_policy *policy); + int (*verify) (struct cpufreq_policy *policy); + + /* define one out of two */ + int (*setpolicy) (struct cpufreq_policy *policy); + int (*target) (struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation); + + /* should be defined, if possible */ + unsigned int (*get) (unsigned int cpu); + + /* optional */ + int (*exit) (struct cpufreq_policy *policy); + int (*resume) (struct cpufreq_policy *policy); + struct freq_attr **attr; +}; + +/* flags */ + +#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if + * all ->init() calls failed */ +#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel + * "constants" aren't affected by + * frequency transitions */ + + +int cpufreq_register_driver(struct cpufreq_driver *driver_data); +int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); + + +void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); + + +static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) +{ + if (policy->min < min) + policy->min = min; + if (policy->max < min) + policy->max = min; + if (policy->min > max) + policy->min = max; + if (policy->max > max) + policy->max = max; + if (policy->min > policy->max) + policy->min = policy->max; + return; +} + +struct freq_attr { + struct attribute attr; + ssize_t (*show)(struct cpufreq_policy *, char *); + ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); +}; + + +/********************************************************************* + * CPUFREQ 2.6. INTERFACE * + *********************************************************************/ +int cpufreq_set_policy(struct cpufreq_policy *policy); +int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); +int cpufreq_update_policy(unsigned int cpu); + +/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ +unsigned int cpufreq_get(unsigned int cpu); + + +/********************************************************************* + * CPUFREQ DEFAULT GOVERNOR * + *********************************************************************/ + + +#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE +extern struct cpufreq_governor cpufreq_gov_performance; +#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance +#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) +extern struct cpufreq_governor cpufreq_gov_userspace; +#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace +#endif + + +/********************************************************************* + * FREQUENCY TABLE HELPERS * + *********************************************************************/ + +#define CPUFREQ_ENTRY_INVALID ~0 +#define CPUFREQ_TABLE_END ~1 + +struct cpufreq_frequency_table { + unsigned int index; /* any */ + unsigned int frequency; /* kHz - doesn't need to be in ascending + * order */ +}; + +int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, + struct cpufreq_frequency_table *table); + +int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, + struct cpufreq_frequency_table *table); + +int cpufreq_frequency_table_target(struct cpufreq_policy *policy, + struct cpufreq_frequency_table *table, + unsigned int target_freq, + unsigned int relation, + unsigned int *index); + +/* the following 3 funtions are for cpufreq core use only */ +struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); +struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); +void cpufreq_cpu_put (struct cpufreq_policy *data); + +/* the following are really really optional */ +extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; + +void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, + unsigned int cpu); + +void cpufreq_frequency_table_put_attr(unsigned int cpu); + + +/********************************************************************* + * UNIFIED DEBUG HELPERS * + *********************************************************************/ + +#define CPUFREQ_DEBUG_CORE 1 +#define CPUFREQ_DEBUG_DRIVER 2 +#define CPUFREQ_DEBUG_GOVERNOR 4 + +#ifdef CONFIG_CPU_FREQ_DEBUG + +extern void cpufreq_debug_printk(unsigned int type, const char *prefix, + const char *fmt, ...); + +#else + +#define cpufreq_debug_printk(msg...) do { } while(0) + +#endif /* CONFIG_CPU_FREQ_DEBUG */ + +#endif /* _LINUX_CPUFREQ_H */ |