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 */
26 enum {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). */
38 struct 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
to_dbs_data(struct gov_attr_set * attr_set)49 static 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) \
55 static ssize_t show_##file_name \
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) \
64 static ssize_t show_##file_name \
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) \
72 static struct governor_attr _name = \
73 __ATTR(_name, 0444, show_##_name, NULL)
74
75 #define gov_attr_rw(_name) \
76 static struct governor_attr _name = \
77 __ATTR(_name, 0644, show_##_name, store_##_name)
78
79 /* Common to all CPUs of a policy */
80 struct policy_dbs_info {
81 struct cpufreq_policy *policy;
82 /*
83 * Per policy mutex that serializes load evaluation from limit-change
84 * and work-handler.
85 */
86 struct mutex update_mutex;
87
88 u64 last_sample_time;
89 s64 sample_delay_ns;
90 atomic_t work_count;
91 struct irq_work irq_work;
92 struct work_struct work;
93 /* dbs_data may be shared between multiple policy objects */
94 struct dbs_data *dbs_data;
95 struct list_head list;
96 /* Multiplier for increasing sample delay temporarily. */
97 unsigned int rate_mult;
98 unsigned int idle_periods; /* For conservative */
99 /* Status indicators */
100 bool is_shared; /* This object is used by multiple CPUs */
101 bool work_in_progress; /* Work is being queued up or in progress */
102 };
103
gov_update_sample_delay(struct policy_dbs_info * policy_dbs,unsigned int delay_us)104 static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
105 unsigned int delay_us)
106 {
107 policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
108 }
109
110 /* Per cpu structures */
111 struct cpu_dbs_info {
112 u64 prev_cpu_idle;
113 u64 prev_update_time;
114 u64 prev_cpu_nice;
115 /*
116 * Used to keep track of load in the previous interval. However, when
117 * explicitly set to zero, it is used as a flag to ensure that we copy
118 * the previous load to the current interval only once, upon the first
119 * wake-up from idle.
120 */
121 unsigned int prev_load;
122 struct update_util_data update_util;
123 struct policy_dbs_info *policy_dbs;
124 };
125
126 /* Common Governor data across policies */
127 struct dbs_governor {
128 struct cpufreq_governor gov;
129 struct kobj_type kobj_type;
130
131 /*
132 * Common data for platforms that don't set
133 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
134 */
135 struct dbs_data *gdbs_data;
136
137 unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
138 struct policy_dbs_info *(*alloc)(void);
139 void (*free)(struct policy_dbs_info *policy_dbs);
140 int (*init)(struct dbs_data *dbs_data);
141 void (*exit)(struct dbs_data *dbs_data);
142 void (*start)(struct cpufreq_policy *policy);
143 };
144
dbs_governor_of(struct cpufreq_policy * policy)145 static 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 */
151 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
152 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
153 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
154 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
155 void 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 */
170 struct od_ops {
171 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
172 unsigned int freq_next, unsigned int relation);
173 };
174
175 unsigned int dbs_update(struct cpufreq_policy *policy);
176 void od_register_powersave_bias_handler(unsigned int (*f)
177 (struct cpufreq_policy *, unsigned int, unsigned int),
178 unsigned int powersave_bias);
179 void od_unregister_powersave_bias_handler(void);
180 ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
181 size_t count);
182 void gov_update_cpu_data(struct dbs_data *dbs_data);
183 #endif /* _CPUFREQ_GOVERNOR_H */
184