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_GOVERNER_H 18 #define _CPUFREQ_GOVERNER_H 19 20 #include <linux/cpufreq.h> 21 #include <linux/kobject.h> 22 #include <linux/mutex.h> 23 #include <linux/workqueue.h> 24 #include <linux/sysfs.h> 25 26 /* 27 * The polling frequency depends on the capability of the processor. Default 28 * polling frequency is 1000 times the transition latency of the processor. The 29 * governor will work on any processor with transition latency <= 10mS, using 30 * appropriate sampling rate. 31 * 32 * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) 33 * this governor will not work. All times here are in uS. 34 */ 35 #define MIN_SAMPLING_RATE_RATIO (2) 36 #define LATENCY_MULTIPLIER (1000) 37 #define MIN_LATENCY_MULTIPLIER (100) 38 #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) 39 40 /* Ondemand Sampling types */ 41 enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE}; 42 43 /* Macro creating sysfs show routines */ 44 #define show_one(_gov, file_name, object) \ 45 static ssize_t show_##file_name \ 46 (struct kobject *kobj, struct attribute *attr, char *buf) \ 47 { \ 48 return sprintf(buf, "%u\n", _gov##_tuners.object); \ 49 } 50 51 #define define_get_cpu_dbs_routines(_dbs_info) \ 52 static struct cpu_dbs_common_info *get_cpu_cdbs(int cpu) \ 53 { \ 54 return &per_cpu(_dbs_info, cpu).cdbs; \ 55 } \ 56 \ 57 static void *get_cpu_dbs_info_s(int cpu) \ 58 { \ 59 return &per_cpu(_dbs_info, cpu); \ 60 } 61 62 /* 63 * Abbreviations: 64 * dbs: used as a shortform for demand based switching It helps to keep variable 65 * names smaller, simpler 66 * cdbs: common dbs 67 * on_*: On-demand governor 68 * cs_*: Conservative governor 69 */ 70 71 /* Per cpu structures */ 72 struct cpu_dbs_common_info { 73 int cpu; 74 u64 prev_cpu_idle; 75 u64 prev_cpu_wall; 76 u64 prev_cpu_nice; 77 struct cpufreq_policy *cur_policy; 78 struct delayed_work work; 79 /* 80 * percpu mutex that serializes governor limit change with gov_dbs_timer 81 * invocation. We do not want gov_dbs_timer to run when user is changing 82 * the governor or limits. 83 */ 84 struct mutex timer_mutex; 85 }; 86 87 struct od_cpu_dbs_info_s { 88 struct cpu_dbs_common_info cdbs; 89 u64 prev_cpu_iowait; 90 struct cpufreq_frequency_table *freq_table; 91 unsigned int freq_lo; 92 unsigned int freq_lo_jiffies; 93 unsigned int freq_hi_jiffies; 94 unsigned int rate_mult; 95 unsigned int sample_type:1; 96 }; 97 98 struct cs_cpu_dbs_info_s { 99 struct cpu_dbs_common_info cdbs; 100 unsigned int down_skip; 101 unsigned int requested_freq; 102 unsigned int enable:1; 103 }; 104 105 /* Governers sysfs tunables */ 106 struct od_dbs_tuners { 107 unsigned int ignore_nice; 108 unsigned int sampling_rate; 109 unsigned int sampling_down_factor; 110 unsigned int up_threshold; 111 unsigned int down_differential; 112 unsigned int powersave_bias; 113 unsigned int io_is_busy; 114 }; 115 116 struct cs_dbs_tuners { 117 unsigned int ignore_nice; 118 unsigned int sampling_rate; 119 unsigned int sampling_down_factor; 120 unsigned int up_threshold; 121 unsigned int down_threshold; 122 unsigned int freq_step; 123 }; 124 125 /* Per Governer data */ 126 struct dbs_data { 127 /* Common across governors */ 128 #define GOV_ONDEMAND 0 129 #define GOV_CONSERVATIVE 1 130 int governor; 131 unsigned int min_sampling_rate; 132 unsigned int enable; /* number of CPUs using this policy */ 133 struct attribute_group *attr_group; 134 void *tuners; 135 136 /* dbs_mutex protects dbs_enable in governor start/stop */ 137 struct mutex mutex; 138 139 struct cpu_dbs_common_info *(*get_cpu_cdbs)(int cpu); 140 void *(*get_cpu_dbs_info_s)(int cpu); 141 void (*gov_dbs_timer)(struct work_struct *work); 142 void (*gov_check_cpu)(int cpu, unsigned int load); 143 144 /* Governor specific ops, see below */ 145 void *gov_ops; 146 }; 147 148 /* Governor specific ops, will be passed to dbs_data->gov_ops */ 149 struct od_ops { 150 int (*io_busy)(void); 151 void (*powersave_bias_init_cpu)(int cpu); 152 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, 153 unsigned int freq_next, unsigned int relation); 154 void (*freq_increase)(struct cpufreq_policy *p, unsigned int freq); 155 }; 156 157 struct cs_ops { 158 struct notifier_block *notifier_block; 159 }; 160 161 static inline int delay_for_sampling_rate(unsigned int sampling_rate) 162 { 163 int delay = usecs_to_jiffies(sampling_rate); 164 165 /* We want all CPUs to do sampling nearly on same jiffy */ 166 if (num_online_cpus() > 1) 167 delay -= jiffies % delay; 168 169 return delay; 170 } 171 172 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall); 173 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu); 174 int cpufreq_governor_dbs(struct dbs_data *dbs_data, 175 struct cpufreq_policy *policy, unsigned int event); 176 #endif /* _CPUFREQ_GOVERNER_H */ 177