2 * drivers/cpufreq/cpufreq_governor.h
4 * Header file for CPUFreq governors common code
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>
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.
17 #ifndef _CPUFREQ_GOVERNOR_H
18 #define _CPUFREQ_GOVERNOR_H
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>
28 * The polling frequency depends on the capability of the processor. Default
29 * polling frequency is 1000 times the transition latency of the processor. The
30 * governor will work on any processor with transition latency <= 10ms, using
31 * appropriate sampling rate.
33 * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL)
34 * this governor will not work. All times here are in us (micro seconds).
36 #define MIN_SAMPLING_RATE_RATIO (2)
37 #define LATENCY_MULTIPLIER (1000)
38 #define MIN_LATENCY_MULTIPLIER (20)
39 #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
41 /* Ondemand Sampling types */
42 enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
45 * Macro for creating governors sysfs routines
47 * - gov_sys: One governor instance per whole system
48 * - gov_pol: One governor instance per policy
51 /* Create attributes */
52 #define gov_sys_attr_ro(_name) \
53 static struct global_attr _name##_gov_sys = \
54 __ATTR(_name, 0444, show_##_name##_gov_sys, NULL)
56 #define gov_sys_attr_rw(_name) \
57 static struct global_attr _name##_gov_sys = \
58 __ATTR(_name, 0644, show_##_name##_gov_sys, store_##_name##_gov_sys)
60 #define gov_pol_attr_ro(_name) \
61 static struct freq_attr _name##_gov_pol = \
62 __ATTR(_name, 0444, show_##_name##_gov_pol, NULL)
64 #define gov_pol_attr_rw(_name) \
65 static struct freq_attr _name##_gov_pol = \
66 __ATTR(_name, 0644, show_##_name##_gov_pol, store_##_name##_gov_pol)
68 #define gov_sys_pol_attr_rw(_name) \
69 gov_sys_attr_rw(_name); \
70 gov_pol_attr_rw(_name)
72 #define gov_sys_pol_attr_ro(_name) \
73 gov_sys_attr_ro(_name); \
74 gov_pol_attr_ro(_name)
76 /* Create show/store routines */
77 #define show_one(_gov, file_name) \
78 static ssize_t show_##file_name##_gov_sys \
79 (struct kobject *kobj, struct attribute *attr, char *buf) \
81 struct _gov##_dbs_tuners *tuners = _gov##_dbs_gov.gdbs_data->tuners; \
82 return sprintf(buf, "%u\n", tuners->file_name); \
85 static ssize_t show_##file_name##_gov_pol \
86 (struct cpufreq_policy *policy, char *buf) \
88 struct dbs_data *dbs_data = policy->governor_data; \
89 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \
90 return sprintf(buf, "%u\n", tuners->file_name); \
93 #define store_one(_gov, file_name) \
94 static ssize_t store_##file_name##_gov_sys \
95 (struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) \
97 struct dbs_data *dbs_data = _gov##_dbs_gov.gdbs_data; \
98 return store_##file_name(dbs_data, buf, count); \
101 static ssize_t store_##file_name##_gov_pol \
102 (struct cpufreq_policy *policy, const char *buf, size_t count) \
104 struct dbs_data *dbs_data = policy->governor_data; \
105 return store_##file_name(dbs_data, buf, count); \
108 #define show_store_one(_gov, file_name) \
109 show_one(_gov, file_name); \
110 store_one(_gov, file_name)
112 /* create helper routines */
113 #define define_get_cpu_dbs_routines(_dbs_info) \
114 static struct cpu_dbs_info *get_cpu_cdbs(int cpu) \
116 return &per_cpu(_dbs_info, cpu).cdbs; \
119 static void *get_cpu_dbs_info_s(int cpu) \
121 return &per_cpu(_dbs_info, cpu); \
126 * dbs: used as a shortform for demand based switching It helps to keep variable
127 * names smaller, simpler
129 * od_*: On-demand governor
130 * cs_*: Conservative governor
133 /* Common to all CPUs of a policy */
134 struct cpu_common_dbs_info {
135 struct cpufreq_policy *policy;
137 * Per policy mutex that serializes load evaluation from limit-change
140 struct mutex timer_mutex;
142 u64 last_sample_time;
145 struct irq_work irq_work;
146 struct work_struct work;
149 static inline void gov_update_sample_delay(struct cpu_common_dbs_info *shared,
150 unsigned int delay_us)
152 shared->sample_delay_ns = delay_us * NSEC_PER_USEC;
155 /* Per cpu structures */
156 struct cpu_dbs_info {
161 * Used to keep track of load in the previous interval. However, when
162 * explicitly set to zero, it is used as a flag to ensure that we copy
163 * the previous load to the current interval only once, upon the first
166 unsigned int prev_load;
167 struct update_util_data update_util;
168 struct cpu_common_dbs_info *shared;
171 struct od_cpu_dbs_info_s {
172 struct cpu_dbs_info cdbs;
173 struct cpufreq_frequency_table *freq_table;
174 unsigned int freq_lo;
175 unsigned int freq_lo_jiffies;
176 unsigned int freq_hi_jiffies;
177 unsigned int rate_mult;
178 unsigned int sample_type:1;
181 struct cs_cpu_dbs_info_s {
182 struct cpu_dbs_info cdbs;
183 unsigned int down_skip;
184 unsigned int requested_freq;
187 /* Per policy Governors sysfs tunables */
188 struct od_dbs_tuners {
189 unsigned int ignore_nice_load;
190 unsigned int sampling_rate;
191 unsigned int sampling_down_factor;
192 unsigned int up_threshold;
193 unsigned int powersave_bias;
194 unsigned int io_is_busy;
197 struct cs_dbs_tuners {
198 unsigned int ignore_nice_load;
199 unsigned int sampling_rate;
200 unsigned int sampling_down_factor;
201 unsigned int up_threshold;
202 unsigned int down_threshold;
203 unsigned int freq_step;
206 /* Common Governor data across policies */
208 struct dbs_governor {
209 struct cpufreq_governor gov;
211 #define GOV_ONDEMAND 0
212 #define GOV_CONSERVATIVE 1
214 struct attribute_group *attr_group_gov_sys; /* one governor - system */
215 struct attribute_group *attr_group_gov_pol; /* one governor - policy */
218 * Common data for platforms that don't set
219 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
221 struct dbs_data *gdbs_data;
223 struct cpu_dbs_info *(*get_cpu_cdbs)(int cpu);
224 void *(*get_cpu_dbs_info_s)(int cpu);
225 unsigned int (*gov_dbs_timer)(struct cpufreq_policy *policy);
226 void (*gov_check_cpu)(int cpu, unsigned int load);
227 int (*init)(struct dbs_data *dbs_data, bool notify);
228 void (*exit)(struct dbs_data *dbs_data, bool notify);
230 /* Governor specific ops, see below */
234 /* Governor Per policy data */
236 struct dbs_governor *gov;
237 unsigned int min_sampling_rate;
242 /* Governor specific ops, will be passed to dbs_data->gov_ops */
244 void (*powersave_bias_init_cpu)(int cpu);
245 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
246 unsigned int freq_next, unsigned int relation);
247 void (*freq_increase)(struct cpufreq_policy *policy, unsigned int freq);
250 static inline int delay_for_sampling_rate(unsigned int sampling_rate)
252 int delay = usecs_to_jiffies(sampling_rate);
254 /* We want all CPUs to do sampling nearly on same jiffy */
255 if (num_online_cpus() > 1)
256 delay -= jiffies % delay;
261 #define declare_show_sampling_rate_min(_gov) \
262 static ssize_t show_sampling_rate_min_gov_sys \
263 (struct kobject *kobj, struct attribute *attr, char *buf) \
265 struct dbs_data *dbs_data = _gov##_dbs_gov.gdbs_data; \
266 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
269 static ssize_t show_sampling_rate_min_gov_pol \
270 (struct cpufreq_policy *policy, char *buf) \
272 struct dbs_data *dbs_data = policy->governor_data; \
273 return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
276 extern struct mutex dbs_data_mutex;
277 extern struct mutex cpufreq_governor_lock;
278 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
279 int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event);
280 void od_register_powersave_bias_handler(unsigned int (*f)
281 (struct cpufreq_policy *, unsigned int, unsigned int),
282 unsigned int powersave_bias);
283 void od_unregister_powersave_bias_handler(void);
284 #endif /* _CPUFREQ_GOVERNOR_H */