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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_GOVERNOR_H
18#define _CPUFREQ_GOVERNOR_H
19
20#include <linux/atomic.h>
21#include <linux/irq_work.h>
22#include <linux/cpufreq.h>
23#include <linux/sched/cpufreq.h>
24#include <linux/kernel_stat.h>
25#include <linux/module.h>
26#include <linux/mutex.h>
27
28/* Ondemand Sampling types */
29enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
30
31/*
32 * Abbreviations:
33 * dbs: used as a shortform for demand based switching It helps to keep variable
34 * names smaller, simpler
35 * cdbs: common dbs
36 * od_*: On-demand governor
37 * cs_*: Conservative governor
38 */
39
40/* Governor demand based switching data (per-policy or global). */
41struct dbs_data {
42 struct gov_attr_set attr_set;
43 void *tuners;
44 unsigned int ignore_nice_load;
45 unsigned int sampling_rate;
46 unsigned int sampling_down_factor;
47 unsigned int up_threshold;
48 unsigned int io_is_busy;
49};
50
51static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
52{
53 return container_of(attr_set, struct dbs_data, attr_set);
54}
55
56#define gov_show_one(_gov, file_name) \
57static ssize_t show_##file_name \
58(struct gov_attr_set *attr_set, char *buf) \
59{ \
60 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
61 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
62 return sprintf(buf, "%u\n", tuners->file_name); \
63}
64
65#define gov_show_one_common(file_name) \
66static ssize_t show_##file_name \
67(struct gov_attr_set *attr_set, char *buf) \
68{ \
69 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
70 return sprintf(buf, "%u\n", dbs_data->file_name); \
71}
72
73#define gov_attr_ro(_name) \
74static struct governor_attr _name = \
75__ATTR(_name, 0444, show_##_name, NULL)
76
77#define gov_attr_rw(_name) \
78static struct governor_attr _name = \
79__ATTR(_name, 0644, show_##_name, store_##_name)
80
81/* Common to all CPUs of a policy */
82struct policy_dbs_info {
83 struct cpufreq_policy *policy;
84 /*
85 * Per policy mutex that serializes load evaluation from limit-change
86 * and work-handler.
87 */
88 struct mutex update_mutex;
89
90 u64 last_sample_time;
91 s64 sample_delay_ns;
92 atomic_t work_count;
93 struct irq_work irq_work;
94 struct work_struct work;
95 /* dbs_data may be shared between multiple policy objects */
96 struct dbs_data *dbs_data;
97 struct list_head list;
98 /* Multiplier for increasing sample delay temporarily. */
99 unsigned int rate_mult;
100 unsigned int idle_periods; /* For conservative */
101 /* Status indicators */
102 bool is_shared; /* This object is used by multiple CPUs */
103 bool work_in_progress; /* Work is being queued up or in progress */
104};
105
106static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
107 unsigned int delay_us)
108{
109 policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
110}
111
112/* Per cpu structures */
113struct cpu_dbs_info {
114 u64 prev_cpu_idle;
115 u64 prev_update_time;
116 u64 prev_cpu_nice;
117 /*
118 * Used to keep track of load in the previous interval. However, when
119 * explicitly set to zero, it is used as a flag to ensure that we copy
120 * the previous load to the current interval only once, upon the first
121 * wake-up from idle.
122 */
123 unsigned int prev_load;
124 struct update_util_data update_util;
125 struct policy_dbs_info *policy_dbs;
126};
127
128/* Common Governor data across policies */
129struct dbs_governor {
130 struct cpufreq_governor gov;
131 struct kobj_type kobj_type;
132
133 /*
134 * Common data for platforms that don't set
135 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
136 */
137 struct dbs_data *gdbs_data;
138
139 unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
140 struct policy_dbs_info *(*alloc)(void);
141 void (*free)(struct policy_dbs_info *policy_dbs);
142 int (*init)(struct dbs_data *dbs_data);
143 void (*exit)(struct dbs_data *dbs_data);
144 void (*start)(struct cpufreq_policy *policy);
145};
146
147static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
148{
149 return container_of(policy->governor, struct dbs_governor, gov);
150}
151
152/* Governor callback routines */
153int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
154void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
155int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
156void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
157void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
158
159#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \
160 { \
161 .name = _name_, \
162 .dynamic_switching = true, \
163 .owner = THIS_MODULE, \
164 .init = cpufreq_dbs_governor_init, \
165 .exit = cpufreq_dbs_governor_exit, \
166 .start = cpufreq_dbs_governor_start, \
167 .stop = cpufreq_dbs_governor_stop, \
168 .limits = cpufreq_dbs_governor_limits, \
169 }
170
171/* Governor specific operations */
172struct od_ops {
173 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
174 unsigned int freq_next, unsigned int relation);
175};
176
177unsigned int dbs_update(struct cpufreq_policy *policy);
178void od_register_powersave_bias_handler(unsigned int (*f)
179 (struct cpufreq_policy *, unsigned int, unsigned int),
180 unsigned int powersave_bias);
181void od_unregister_powersave_bias_handler(void);
182ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
183 size_t count);
184void gov_update_cpu_data(struct dbs_data *dbs_data);
185#endif /* _CPUFREQ_GOVERNOR_H */