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1/*
2 * drivers/cpufreq/cpufreq_governor.h
3 *
4 * Header file for CPUFreq governors common code
5 *
6 * Copyright (C) 2001 Russell King
7 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
8 * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
9 * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
10 * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#ifndef _CPUFREQ_GOVERNER_H
18#define _CPUFREQ_GOVERNER_H
19
20#include <asm/cputime.h>
21#include <linux/cpufreq.h>
22#include <linux/kobject.h>
23#include <linux/mutex.h>
24#include <linux/workqueue.h>
25#include <linux/sysfs.h>
26
27/*
28 * The polling frequency depends on the capability of the processor. Default
29 * polling frequency is 1000 times the transition latency of the processor. The
30 * governor will work on any processor with transition latency <= 10mS, using
31 * appropriate sampling rate.
32 *
33 * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
34 * this governor will not work. All times here are in uS.
35 */
36#define MIN_SAMPLING_RATE_RATIO (2)
37#define LATENCY_MULTIPLIER (1000)
38#define MIN_LATENCY_MULTIPLIER (100)
39#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
40
41/* Ondemand Sampling types */
42enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
43
44/* Macro creating sysfs show routines */
45#define show_one(_gov, file_name, object) \
46static ssize_t show_##file_name \
47(struct kobject *kobj, struct attribute *attr, char *buf) \
48{ \
49 return sprintf(buf, "%u\n", _gov##_tuners.object); \
50}
51
52#define define_get_cpu_dbs_routines(_dbs_info) \
53static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \
54{ \
55 return &per_cpu(_dbs_info, cpu).cdbs; \
56} \
57 \
58static void *get_cpu_dbs_info_s(int cpu) \
59{ \
60 return &per_cpu(_dbs_info, cpu); \
61}
62
63/*
64 * Abbreviations:
65 * dbs: used as a shortform for demand based switching It helps to keep variable
66 * names smaller, simpler
67 * cdbs: common dbs
68 * on_*: On-demand governor
69 * cs_*: Conservative governor
70 */
71
72/* Per cpu structures */
73struct cpu_dbs_common_info {
74 int cpu;
75 cputime64_t prev_cpu_idle;
76 cputime64_t prev_cpu_wall;
77 cputime64_t prev_cpu_nice;
78 struct cpufreq_policy *cur_policy;
79 struct delayed_work work;
80 /*
81 * percpu mutex that serializes governor limit change with gov_dbs_timer
82 * invocation. We do not want gov_dbs_timer to run when user is changing
83 * the governor or limits.
84 */
85 struct mutex timer_mutex;
86};
87
88struct od_cpu_dbs_info_s {
89 struct cpu_dbs_common_info cdbs;
90 cputime64_t prev_cpu_iowait;
91 struct cpufreq_frequency_table *freq_table;
92 unsigned int freq_lo;
93 unsigned int freq_lo_jiffies;
94 unsigned int freq_hi_jiffies;
95 unsigned int rate_mult;
96 unsigned int sample_type:1;
97};
98
99struct cs_cpu_dbs_info_s {
100 struct cpu_dbs_common_info cdbs;
101 unsigned int down_skip;
102 unsigned int requested_freq;
103 unsigned int enable:1;
104};
105
106/* Governers sysfs tunables */
107struct od_dbs_tuners {
108 unsigned int ignore_nice;
109 unsigned int sampling_rate;
110 unsigned int sampling_down_factor;
111 unsigned int up_threshold;
112 unsigned int down_differential;
113 unsigned int powersave_bias;
114 unsigned int io_is_busy;
115};
116
117struct cs_dbs_tuners {
118 unsigned int ignore_nice;
119 unsigned int sampling_rate;
120 unsigned int sampling_down_factor;
121 unsigned int up_threshold;
122 unsigned int down_threshold;
123 unsigned int freq_step;
124};
125
126/* Per Governer data */
127struct dbs_data {
128 /* Common across governors */
129 #define GOV_ONDEMAND 0
130 #define GOV_CONSERVATIVE 1
131 int governor;
132 unsigned int min_sampling_rate;
133 unsigned int enable; /* number of CPUs using this policy */
134 struct attribute_group *attr_group;
135 void *tuners;
136
137 /* dbs_mutex protects dbs_enable in governor start/stop */
138 struct mutex mutex;
139
140 struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu);
141 void *(*get_cpu_dbs_info_s)(int cpu);
142 void (*gov_dbs_timer)(struct work_struct *work);
143 void (*gov_check_cpu)(int cpu, unsigned int load);
144
145 /* Governor specific ops, see below */
146 void *gov_ops;
147};
148
149/* Governor specific ops, will be passed to dbs_data->gov_ops */
150struct od_ops {
151 int (*io_busy)(void);
152 void (*powersave_bias_init_cpu)(int cpu);
153 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
154 unsigned int freq_next, unsigned int relation);
155 void (*freq_increase)(struct cpufreq_policy *p, unsigned int freq);
156};
157
158struct cs_ops {
159 struct notifier_block *notifier_block;
160};
161
162static inline int delay_for_sampling_rate(unsigned int sampling_rate)
163{
164 int delay = usecs_to_jiffies(sampling_rate);
165
166 /* We want all CPUs to do sampling nearly on same jiffy */
167 if (num_online_cpus() > 1)
168 delay -= jiffies % delay;
169
170 return delay;
171}
172
173cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall);
174void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
175int cpufreq_governor_dbs(struct dbs_data *dbs_data,
176 struct cpufreq_policy *policy, unsigned int event);
177#endif /* _CPUFREQ_GOVERNER_H */
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