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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * drivers/cpufreq/cpufreq_governor.h
4 *
5 * Header file for CPUFreq governors common code
6 *
7 * Copyright (C) 2001 Russell King
8 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
9 * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
10 * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
11 * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
12 */
13
14#ifndef _CPUFREQ_GOVERNOR_H
15#define _CPUFREQ_GOVERNOR_H
16
17#include <linux/atomic.h>
18#include <linux/irq_work.h>
19#include <linux/cpufreq.h>
20#include <linux/sched/cpufreq.h>
21#include <linux/kernel_stat.h>
22#include <linux/module.h>
23#include <linux/mutex.h>
24#include <linux/sysfs.h>
25
26/* Ondemand Sampling types */
27enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
28
29/*
30 * Abbreviations:
31 * dbs: used as a shortform for demand based switching It helps to keep variable
32 * names smaller, simpler
33 * cdbs: common dbs
34 * od_*: On-demand governor
35 * cs_*: Conservative governor
36 */
37
38/* Governor demand based switching data (per-policy or global). */
39struct dbs_data {
40 struct gov_attr_set attr_set;
41 struct dbs_governor *gov;
42 void *tuners;
43 unsigned int ignore_nice_load;
44 unsigned int sampling_rate;
45 unsigned int sampling_down_factor;
46 unsigned int up_threshold;
47 unsigned int io_is_busy;
48};
49
50static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
51{
52 return container_of(attr_set, struct dbs_data, attr_set);
53}
54
55#define gov_show_one(_gov, file_name) \
56static ssize_t file_name##_show \
57(struct gov_attr_set *attr_set, char *buf) \
58{ \
59 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
60 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
61 return sysfs_emit(buf, "%u\n", tuners->file_name); \
62}
63
64#define gov_show_one_common(file_name) \
65static ssize_t file_name##_show \
66(struct gov_attr_set *attr_set, char *buf) \
67{ \
68 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
69 return sysfs_emit(buf, "%u\n", dbs_data->file_name); \
70}
71
72#define gov_attr_ro(_name) \
73static struct governor_attr _name = __ATTR_RO(_name)
74
75#define gov_attr_rw(_name) \
76static struct governor_attr _name = __ATTR_RW(_name)
77
78/* Common to all CPUs of a policy */
79struct policy_dbs_info {
80 struct cpufreq_policy *policy;
81 /*
82 * Per policy mutex that serializes load evaluation from limit-change
83 * and work-handler.
84 */
85 struct mutex update_mutex;
86
87 u64 last_sample_time;
88 s64 sample_delay_ns;
89 atomic_t work_count;
90 struct irq_work irq_work;
91 struct work_struct work;
92 /* dbs_data may be shared between multiple policy objects */
93 struct dbs_data *dbs_data;
94 struct list_head list;
95 /* Multiplier for increasing sample delay temporarily. */
96 unsigned int rate_mult;
97 unsigned int idle_periods; /* For conservative */
98 /* Status indicators */
99 bool is_shared; /* This object is used by multiple CPUs */
100 bool work_in_progress; /* Work is being queued up or in progress */
101};
102
103static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
104 unsigned int delay_us)
105{
106 policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
107}
108
109/* Per cpu structures */
110struct cpu_dbs_info {
111 u64 prev_cpu_idle;
112 u64 prev_update_time;
113 u64 prev_cpu_nice;
114 /*
115 * Used to keep track of load in the previous interval. However, when
116 * explicitly set to zero, it is used as a flag to ensure that we copy
117 * the previous load to the current interval only once, upon the first
118 * wake-up from idle.
119 */
120 unsigned int prev_load;
121 struct update_util_data update_util;
122 struct policy_dbs_info *policy_dbs;
123};
124
125/* Common Governor data across policies */
126struct dbs_governor {
127 struct cpufreq_governor gov;
128 struct kobj_type kobj_type;
129
130 /*
131 * Common data for platforms that don't set
132 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
133 */
134 struct dbs_data *gdbs_data;
135
136 unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
137 struct policy_dbs_info *(*alloc)(void);
138 void (*free)(struct policy_dbs_info *policy_dbs);
139 int (*init)(struct dbs_data *dbs_data);
140 void (*exit)(struct dbs_data *dbs_data);
141 void (*start)(struct cpufreq_policy *policy);
142 void (*limits)(struct cpufreq_policy *policy);
143};
144
145static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
146{
147 return container_of(policy->governor, struct dbs_governor, gov);
148}
149
150/* Governor callback routines */
151int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
152void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
153int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
154void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
155void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
156
157#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \
158 { \
159 .name = _name_, \
160 .flags = CPUFREQ_GOV_DYNAMIC_SWITCHING, \
161 .owner = THIS_MODULE, \
162 .init = cpufreq_dbs_governor_init, \
163 .exit = cpufreq_dbs_governor_exit, \
164 .start = cpufreq_dbs_governor_start, \
165 .stop = cpufreq_dbs_governor_stop, \
166 .limits = cpufreq_dbs_governor_limits, \
167 }
168
169/* Governor specific operations */
170struct od_ops {
171 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
172 unsigned int freq_next, unsigned int relation);
173};
174
175unsigned int dbs_update(struct cpufreq_policy *policy);
176void od_register_powersave_bias_handler(unsigned int (*f)
177 (struct cpufreq_policy *, unsigned int, unsigned int),
178 unsigned int powersave_bias);
179void od_unregister_powersave_bias_handler(void);
180ssize_t sampling_rate_store(struct gov_attr_set *attr_set, const char *buf,
181 size_t count);
182void gov_update_cpu_data(struct dbs_data *dbs_data);
183#endif /* _CPUFREQ_GOVERNOR_H */