summaryrefslogtreecommitdiffstats
path: root/include/linux/cpufreq.h
blob: 79a2340d83cda45c88138841fe4b2a8a3892bcad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
/*
 *  linux/include/linux/cpufreq.h
 *
 *  Copyright (C) 2001 Russell King
 *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
 *            
 * 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/mutex.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>
#include <asm/div64.h>

#define CPUFREQ_NAME_LEN 16


/*********************************************************************
 *                     CPUFREQ NOTIFIER INTERFACE                    *
 *********************************************************************/

#define CPUFREQ_TRANSITION_NOTIFIER	(0)
#define CPUFREQ_POLICY_NOTIFIER		(1)

#ifdef CONFIG_CPU_FREQ
int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
#else		/* CONFIG_CPU_FREQ */
static inline int cpufreq_register_notifier(struct notifier_block *nb,
						unsigned int list)
{
	return 0;
}
static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
						unsigned int list)
{
	return 0;
}
#endif		/* CONFIG_CPU_FREQ */

/* 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 nanoseconds - if it's unknown,
 * CPUFREQ_ETERNAL shall be used.
 */

struct cpufreq_governor;

/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
extern struct kobject *cpufreq_global_kobject;

#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_var_t		cpus;	/* CPUs requiring sw coordination */
	cpumask_var_t		related_cpus; /* CPUs with any coordination */
	unsigned int		shared_type; /* ANY or ALL affected CPUs
						should set cpufreq */
	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 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)
#define CPUFREQ_START		(3)

#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
#define CPUFREQ_SHARED_TYPE_HW	 (1) /* HW does needed coordination */
#define CPUFREQ_SHARED_TYPE_ALL	 (2) /* All dependent CPUs should set freq */
#define CPUFREQ_SHARED_TYPE_ANY	 (3) /* Freq can be set from any dependent CPU*/

/******************** cpufreq transition notifiers *******************/

#define CPUFREQ_PRECHANGE	(0)
#define CPUFREQ_POSTCHANGE	(1)
#define CPUFREQ_RESUMECHANGE	(8)
#define CPUFREQ_SUSPENDCHANGE	(9)

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);
	ssize_t	(*show_setspeed)	(struct cpufreq_policy *policy,
					 char *buf);
	int 	(*store_setspeed)	(struct cpufreq_policy *policy,
					 unsigned int freq);
	unsigned int max_transition_latency; /* HW must be able to switch to
			next freq faster than this value in nano secs or we
			will fallback to performance governor */
	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);


extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
				   unsigned int cpu);

int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);

int lock_policy_rwsem_read(int cpu);
int lock_policy_rwsem_write(int cpu);
void unlock_policy_rwsem_read(int cpu);
void unlock_policy_rwsem_write(int cpu);


/*********************************************************************
 *                      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 */
	unsigned int (*getavg)	(struct cpufreq_policy *policy,
				 unsigned int cpu);

	int	(*exit)		(struct cpufreq_policy *policy);
	int	(*suspend)	(struct cpufreq_policy *policy, pm_message_t pmsg);
	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 */
#define CPUFREQ_PM_NO_WARN	0x04	/* don't warn on suspend/resume speed
					 * mismatches */

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);
};

struct global_attr {
	struct attribute attr;
	ssize_t (*show)(struct kobject *kobj,
			struct attribute *attr, char *buf);
	ssize_t (*store)(struct kobject *a, struct attribute *b,
			 const char *c, size_t count);
};

/*********************************************************************
 *                        CPUFREQ 2.6. INTERFACE                     *
 *********************************************************************/
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
int cpufreq_update_policy(unsigned int cpu);

#ifdef CONFIG_CPU_FREQ
/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
unsigned int cpufreq_get(unsigned int cpu);
#else
static inline unsigned int cpufreq_get(unsigned int cpu)
{
	return 0;
}
#endif

/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
#ifdef CONFIG_CPU_FREQ
unsigned int cpufreq_quick_get(unsigned int cpu);
#else
static inline unsigned int cpufreq_quick_get(unsigned int cpu)
{
	return 0;
}
#endif


/*********************************************************************
 *                       CPUFREQ DEFAULT GOVERNOR                    *
 *********************************************************************/


/*
  Performance governor is fallback governor if any other gov failed to
  auto load due latency restrictions
*/
#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
extern struct cpufreq_governor cpufreq_gov_performance;
#endif
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_performance)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
extern struct cpufreq_governor cpufreq_gov_powersave;
#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_powersave)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
extern struct cpufreq_governor cpufreq_gov_userspace;
#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_userspace)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
extern struct cpufreq_governor cpufreq_gov_ondemand;
#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_ondemand)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
extern struct cpufreq_governor cpufreq_gov_conservative;
#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_conservative)
#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 */
OpenPOWER on IntegriCloud