Merge tag 'drm-intel-next-2022-06-22' of git://anongit.freedesktop.org/drm/drm-intel...
[linux-2.6-microblaze.git] / drivers / cpufreq / cpufreq_governor.h
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
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 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)                                  \
64 static 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)                                              \
72 static struct governor_attr _name = __ATTR_RO(_name)
73
74 #define gov_attr_rw(_name)                                              \
75 static struct governor_attr _name = __ATTR_RW(_name)
76
77 /* Common to all CPUs of a policy */
78 struct 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
102 static 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 */
109 struct 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 */
125 struct 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
143 static 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 */
149 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
150 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
151 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
152 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
153 void 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 */
168 struct od_ops {
169         unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
170                         unsigned int freq_next, unsigned int relation);
171 };
172
173 unsigned int dbs_update(struct cpufreq_policy *policy);
174 void od_register_powersave_bias_handler(unsigned int (*f)
175                 (struct cpufreq_policy *, unsigned int, unsigned int),
176                 unsigned int powersave_bias);
177 void od_unregister_powersave_bias_handler(void);
178 ssize_t sampling_rate_store(struct gov_attr_set *attr_set, const char *buf,
179                             size_t count);
180 void gov_update_cpu_data(struct dbs_data *dbs_data);
181 #endif /* _CPUFREQ_GOVERNOR_H */