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/sched/cpufreq.h> 24 #include <linux/kernel_stat.h> 25 #include <linux/module.h> 26 #include <linux/mutex.h> 27 28 /* Ondemand Sampling types */ 29 enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE}; 30 31 /* 32 * Abbreviations: 33 * dbs: used as a shortform for demand based switching It helps to keep variable 34 * names smaller, simpler 35 * cdbs: common dbs 36 * od_*: On-demand governor 37 * cs_*: Conservative governor 38 */ 39 40 /* Governor demand based switching data (per-policy or global). */ 41 struct dbs_data { 42 struct gov_attr_set attr_set; 43 void *tuners; 44 unsigned int min_sampling_rate; 45 unsigned int ignore_nice_load; 46 unsigned int sampling_rate; 47 unsigned int sampling_down_factor; 48 unsigned int up_threshold; 49 unsigned int io_is_busy; 50 }; 51 52 static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set) 53 { 54 return container_of(attr_set, struct dbs_data, attr_set); 55 } 56 57 #define gov_show_one(_gov, file_name) \ 58 static ssize_t show_##file_name \ 59 (struct gov_attr_set *attr_set, char *buf) \ 60 { \ 61 struct dbs_data *dbs_data = to_dbs_data(attr_set); \ 62 struct _gov##_dbs_tuners *tuners = dbs_data->tuners; \ 63 return sprintf(buf, "%u\n", tuners->file_name); \ 64 } 65 66 #define gov_show_one_common(file_name) \ 67 static ssize_t show_##file_name \ 68 (struct gov_attr_set *attr_set, char *buf) \ 69 { \ 70 struct dbs_data *dbs_data = to_dbs_data(attr_set); \ 71 return sprintf(buf, "%u\n", dbs_data->file_name); \ 72 } 73 74 #define gov_attr_ro(_name) \ 75 static struct governor_attr _name = \ 76 __ATTR(_name, 0444, show_##_name, NULL) 77 78 #define gov_attr_rw(_name) \ 79 static struct governor_attr _name = \ 80 __ATTR(_name, 0644, show_##_name, store_##_name) 81 82 /* Common to all CPUs of a policy */ 83 struct policy_dbs_info { 84 struct cpufreq_policy *policy; 85 /* 86 * Per policy mutex that serializes load evaluation from limit-change 87 * and work-handler. 88 */ 89 struct mutex update_mutex; 90 91 u64 last_sample_time; 92 s64 sample_delay_ns; 93 atomic_t work_count; 94 struct irq_work irq_work; 95 struct work_struct work; 96 /* dbs_data may be shared between multiple policy objects */ 97 struct dbs_data *dbs_data; 98 struct list_head list; 99 /* Multiplier for increasing sample delay temporarily. */ 100 unsigned int rate_mult; 101 unsigned int idle_periods; /* For conservative */ 102 /* Status indicators */ 103 bool is_shared; /* This object is used by multiple CPUs */ 104 bool work_in_progress; /* Work is being queued up or in progress */ 105 }; 106 107 static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs, 108 unsigned int delay_us) 109 { 110 policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC; 111 } 112 113 /* Per cpu structures */ 114 struct cpu_dbs_info { 115 u64 prev_cpu_idle; 116 u64 prev_update_time; 117 u64 prev_cpu_nice; 118 /* 119 * Used to keep track of load in the previous interval. However, when 120 * explicitly set to zero, it is used as a flag to ensure that we copy 121 * the previous load to the current interval only once, upon the first 122 * wake-up from idle. 123 */ 124 unsigned int prev_load; 125 struct update_util_data update_util; 126 struct policy_dbs_info *policy_dbs; 127 }; 128 129 /* Common Governor data across policies */ 130 struct dbs_governor { 131 struct cpufreq_governor gov; 132 struct kobj_type kobj_type; 133 134 /* 135 * Common data for platforms that don't set 136 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY 137 */ 138 struct dbs_data *gdbs_data; 139 140 unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy); 141 struct policy_dbs_info *(*alloc)(void); 142 void (*free)(struct policy_dbs_info *policy_dbs); 143 int (*init)(struct dbs_data *dbs_data); 144 void (*exit)(struct dbs_data *dbs_data); 145 void (*start)(struct cpufreq_policy *policy); 146 }; 147 148 static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy) 149 { 150 return container_of(policy->governor, struct dbs_governor, gov); 151 } 152 153 /* Governor callback routines */ 154 int cpufreq_dbs_governor_init(struct cpufreq_policy *policy); 155 void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy); 156 int cpufreq_dbs_governor_start(struct cpufreq_policy *policy); 157 void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy); 158 void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy); 159 160 #define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \ 161 { \ 162 .name = _name_, \ 163 .max_transition_latency = TRANSITION_LATENCY_LIMIT, \ 164 .owner = THIS_MODULE, \ 165 .init = cpufreq_dbs_governor_init, \ 166 .exit = cpufreq_dbs_governor_exit, \ 167 .start = cpufreq_dbs_governor_start, \ 168 .stop = cpufreq_dbs_governor_stop, \ 169 .limits = cpufreq_dbs_governor_limits, \ 170 } 171 172 /* Governor specific operations */ 173 struct od_ops { 174 unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy, 175 unsigned int freq_next, unsigned int relation); 176 }; 177 178 unsigned int dbs_update(struct cpufreq_policy *policy); 179 void od_register_powersave_bias_handler(unsigned int (*f) 180 (struct cpufreq_policy *, unsigned int, unsigned int), 181 unsigned int powersave_bias); 182 void od_unregister_powersave_bias_handler(void); 183 ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf, 184 size_t count); 185 void gov_update_cpu_data(struct dbs_data *dbs_data); 186 #endif /* _CPUFREQ_GOVERNOR_H */ 187