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 void *tuners;
41 unsigned int ignore_nice_load;
42 unsigned int sampling_rate;
43 unsigned int sampling_down_factor;
44 unsigned int up_threshold;
45 unsigned int io_is_busy;
46 };
47
to_dbs_data(struct gov_attr_set * attr_set)48 static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
49 {
50 return container_of(attr_set, struct dbs_data, attr_set);
51 }
52
53 #define gov_show_one(_gov, file_name) \
54 static ssize_t show_##file_name \
55 (struct gov_attr_set *attr_set, char *buf) \
56 { \
57 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
58 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
59 return sprintf(buf, "%u\n", tuners->file_name); \
60 }
61
62 #define gov_show_one_common(file_name) \
63 static ssize_t show_##file_name \
64 (struct gov_attr_set *attr_set, char *buf) \
65 { \
66 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
67 return sprintf(buf, "%u\n", dbs_data->file_name); \
68 }
69
70 #define gov_attr_ro(_name) \
71 static struct governor_attr _name = \
72 __ATTR(_name, 0444, show_##_name, NULL)
73
74 #define gov_attr_rw(_name) \
75 static struct governor_attr _name = \
76 __ATTR(_name, 0644, show_##_name, store_##_name)
77
78 /* Common to all CPUs of a policy */
79 struct 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
gov_update_sample_delay(struct policy_dbs_info * policy_dbs,unsigned int delay_us)103 static 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 */
110 struct 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 */
126 struct 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 };
143
dbs_governor_of(struct cpufreq_policy * policy)144 static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
145 {
146 return container_of(policy->governor, struct dbs_governor, gov);
147 }
148
149 /* Governor callback routines */
150 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
151 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
152 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
153 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
154 void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
155
156 #define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \
157 { \
158 .name = _name_, \
159 .flags = CPUFREQ_GOV_DYNAMIC_SWITCHING, \
160 .owner = THIS_MODULE, \
161 .init = cpufreq_dbs_governor_init, \
162 .exit = cpufreq_dbs_governor_exit, \
163 .start = cpufreq_dbs_governor_start, \
164 .stop = cpufreq_dbs_governor_stop, \
165 .limits = cpufreq_dbs_governor_limits, \
166 }
167
168 /* Governor specific operations */
169 struct od_ops {
170 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
171 unsigned int freq_next, unsigned int relation);
172 };
173
174 unsigned int dbs_update(struct cpufreq_policy *policy);
175 void od_register_powersave_bias_handler(unsigned int (*f)
176 (struct cpufreq_policy *, unsigned int, unsigned int),
177 unsigned int powersave_bias);
178 void od_unregister_powersave_bias_handler(void);
179 ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
180 size_t count);
181 void gov_update_cpu_data(struct dbs_data *dbs_data);
182 #endif /* _CPUFREQ_GOVERNOR_H */
183