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