1 /*
2 * drivers/cpufreq/cpufreq_governor.h
3 *
4 * Header file for CPUFreq governors common code
5 *
6 * Copyright (C) 2001 Russell King
7 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
8 * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
9 * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
10 * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17 #ifndef _CPUFREQ_GOVERNOR_H
18 #define _CPUFREQ_GOVERNOR_H
19
20 #include <linux/atomic.h>
21 #include <linux/irq_work.h>
22 #include <linux/cpufreq.h>
23 #include <linux/kernel_stat.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26
27 /* Ondemand Sampling types */
28 enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
29
30 /*
31 * Abbreviations:
32 * dbs: used as a shortform for demand based switching It helps to keep variable
33 * names smaller, simpler
34 * cdbs: common dbs
35 * od_*: On-demand governor
36 * cs_*: Conservative governor
37 */
38
39 /* Governor demand based switching data (per-policy or global). */
40 struct dbs_data {
41 struct gov_attr_set attr_set;
42 void *tuners;
43 unsigned int min_sampling_rate;
44 unsigned int ignore_nice_load;
45 unsigned int sampling_rate;
46 unsigned int sampling_down_factor;
47 unsigned int up_threshold;
48 unsigned int io_is_busy;
49 };
50
to_dbs_data(struct gov_attr_set * attr_set)51 static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
52 {
53 return container_of(attr_set, struct dbs_data, attr_set);
54 }
55
56 #define gov_show_one(_gov, file_name) \
57 static ssize_t show_##file_name \
58 (struct gov_attr_set *attr_set, char *buf) \
59 { \
60 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
61 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
62 return sprintf(buf, "%u\n", tuners->file_name); \
63 }
64
65 #define gov_show_one_common(file_name) \
66 static ssize_t show_##file_name \
67 (struct gov_attr_set *attr_set, char *buf) \
68 { \
69 struct dbs_data *dbs_data = to_dbs_data(attr_set); \
70 return sprintf(buf, "%u\n", dbs_data->file_name); \
71 }
72
73 #define gov_attr_ro(_name) \
74 static struct governor_attr _name = \
75 __ATTR(_name, 0444, show_##_name, NULL)
76
77 #define gov_attr_rw(_name) \
78 static struct governor_attr _name = \
79 __ATTR(_name, 0644, show_##_name, store_##_name)
80
81 /* Common to all CPUs of a policy */
82 struct policy_dbs_info {
83 struct cpufreq_policy *policy;
84 /*
85 * Per policy mutex that serializes load evaluation from limit-change
86 * and work-handler.
87 */
88 struct mutex timer_mutex;
89
90 u64 last_sample_time;
91 s64 sample_delay_ns;
92 atomic_t work_count;
93 struct irq_work irq_work;
94 struct work_struct work;
95 /* dbs_data may be shared between multiple policy objects */
96 struct dbs_data *dbs_data;
97 struct list_head list;
98 /* Multiplier for increasing sample delay temporarily. */
99 unsigned int rate_mult;
100 /* Status indicators */
101 bool is_shared; /* This object is used by multiple CPUs */
102 bool work_in_progress; /* Work is being queued up or in progress */
103 };
104
gov_update_sample_delay(struct policy_dbs_info * policy_dbs,unsigned int delay_us)105 static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
106 unsigned int delay_us)
107 {
108 policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
109 }
110
111 /* Per cpu structures */
112 struct cpu_dbs_info {
113 u64 prev_cpu_idle;
114 u64 prev_update_time;
115 u64 prev_cpu_nice;
116 /*
117 * Used to keep track of load in the previous interval. However, when
118 * explicitly set to zero, it is used as a flag to ensure that we copy
119 * the previous load to the current interval only once, upon the first
120 * wake-up from idle.
121 */
122 unsigned int prev_load;
123 struct update_util_data update_util;
124 struct policy_dbs_info *policy_dbs;
125 };
126
127 /* Common Governor data across policies */
128 struct dbs_governor {
129 struct cpufreq_governor gov;
130 struct kobj_type kobj_type;
131
132 /*
133 * Common data for platforms that don't set
134 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
135 */
136 struct dbs_data *gdbs_data;
137
138 unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy);
139 struct policy_dbs_info *(*alloc)(void);
140 void (*free)(struct policy_dbs_info *policy_dbs);
141 int (*init)(struct dbs_data *dbs_data);
142 void (*exit)(struct dbs_data *dbs_data);
143 void (*start)(struct cpufreq_policy *policy);
144 };
145
dbs_governor_of(struct cpufreq_policy * policy)146 static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
147 {
148 return container_of(policy->governor, struct dbs_governor, gov);
149 }
150
151 /* Governor callback routines */
152 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
153 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
154 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
155 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
156 void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
157
158 #define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \
159 { \
160 .name = _name_, \
161 .max_transition_latency = TRANSITION_LATENCY_LIMIT, \
162 .owner = THIS_MODULE, \
163 .init = cpufreq_dbs_governor_init, \
164 .exit = cpufreq_dbs_governor_exit, \
165 .start = cpufreq_dbs_governor_start, \
166 .stop = cpufreq_dbs_governor_stop, \
167 .limits = cpufreq_dbs_governor_limits, \
168 }
169
170 /* Governor specific operations */
171 struct od_ops {
172 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
173 unsigned int freq_next, unsigned int relation);
174 };
175
176 unsigned int dbs_update(struct cpufreq_policy *policy);
177 void od_register_powersave_bias_handler(unsigned int (*f)
178 (struct cpufreq_policy *, unsigned int, unsigned int),
179 unsigned int powersave_bias);
180 void od_unregister_powersave_bias_handler(void);
181 ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
182 size_t count);
183 void gov_update_cpu_data(struct dbs_data *dbs_data);
184 #endif /* _CPUFREQ_GOVERNOR_H */
185