viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 1 | /* |
| 2 | * drivers/cpufreq/cpufreq_governor.c |
| 3 | * |
| 4 | * CPUFREQ governors common code |
| 5 | * |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 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 | * |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 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 | |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 18 | |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 19 | #include <asm/cputime.h> |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 20 | #include <linux/cpufreq.h> |
| 21 | #include <linux/cpumask.h> |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 22 | #include <linux/export.h> |
| 23 | #include <linux/kernel_stat.h> |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 24 | #include <linux/mutex.h> |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 25 | #include <linux/tick.h> |
| 26 | #include <linux/types.h> |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 27 | #include <linux/workqueue.h> |
| 28 | |
| 29 | #include "cpufreq_governor.h" |
| 30 | |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 31 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
| 32 | { |
| 33 | u64 idle_time; |
| 34 | u64 cur_wall_time; |
| 35 | u64 busy_time; |
| 36 | |
| 37 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); |
| 38 | |
| 39 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; |
| 40 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; |
| 41 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; |
| 42 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; |
| 43 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; |
| 44 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; |
| 45 | |
| 46 | idle_time = cur_wall_time - busy_time; |
| 47 | if (wall) |
Rafael J. Wysocki | a0e5af3 | 2012-11-24 10:08:47 +0100 | [diff] [blame^] | 48 | *wall = cputime_to_usecs(cur_wall_time); |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 49 | |
Rafael J. Wysocki | a0e5af3 | 2012-11-24 10:08:47 +0100 | [diff] [blame^] | 50 | return cputime_to_usecs(idle_time); |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 51 | } |
| 52 | |
Viresh Kumar | 1e7586a | 2012-10-26 00:51:21 +0200 | [diff] [blame] | 53 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall) |
viresh kumar | 2aacdff | 2012-10-23 01:28:05 +0200 | [diff] [blame] | 54 | { |
| 55 | u64 idle_time = get_cpu_idle_time_us(cpu, NULL); |
| 56 | |
| 57 | if (idle_time == -1ULL) |
| 58 | return get_cpu_idle_time_jiffy(cpu, wall); |
| 59 | else |
| 60 | idle_time += get_cpu_iowait_time_us(cpu, wall); |
| 61 | |
| 62 | return idle_time; |
| 63 | } |
| 64 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 65 | |
| 66 | void dbs_check_cpu(struct dbs_data *dbs_data, int cpu) |
| 67 | { |
| 68 | struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu); |
| 69 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 70 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
| 71 | struct cpufreq_policy *policy; |
| 72 | unsigned int max_load = 0; |
| 73 | unsigned int ignore_nice; |
| 74 | unsigned int j; |
| 75 | |
| 76 | if (dbs_data->governor == GOV_ONDEMAND) |
| 77 | ignore_nice = od_tuners->ignore_nice; |
| 78 | else |
| 79 | ignore_nice = cs_tuners->ignore_nice; |
| 80 | |
| 81 | policy = cdbs->cur_policy; |
| 82 | |
| 83 | /* Get Absolute Load (in terms of freq for ondemand gov) */ |
| 84 | for_each_cpu(j, policy->cpus) { |
| 85 | struct cpu_dbs_common_info *j_cdbs; |
Viresh Kumar | 1e7586a | 2012-10-26 00:51:21 +0200 | [diff] [blame] | 86 | u64 cur_wall_time, cur_idle_time, cur_iowait_time; |
Viresh Kumar | 4471a34 | 2012-10-26 00:47:42 +0200 | [diff] [blame] | 87 | unsigned int idle_time, wall_time, iowait_time; |
| 88 | unsigned int load; |
| 89 | |
| 90 | j_cdbs = dbs_data->get_cpu_cdbs(j); |
| 91 | |
| 92 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); |
| 93 | |
| 94 | wall_time = (unsigned int) |
| 95 | (cur_wall_time - j_cdbs->prev_cpu_wall); |
| 96 | j_cdbs->prev_cpu_wall = cur_wall_time; |
| 97 | |
| 98 | idle_time = (unsigned int) |
| 99 | (cur_idle_time - j_cdbs->prev_cpu_idle); |
| 100 | j_cdbs->prev_cpu_idle = cur_idle_time; |
| 101 | |
| 102 | if (ignore_nice) { |
| 103 | u64 cur_nice; |
| 104 | unsigned long cur_nice_jiffies; |
| 105 | |
| 106 | cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] - |
| 107 | cdbs->prev_cpu_nice; |
| 108 | /* |
| 109 | * Assumption: nice time between sampling periods will |
| 110 | * be less than 2^32 jiffies for 32 bit sys |
| 111 | */ |
| 112 | cur_nice_jiffies = (unsigned long) |
| 113 | cputime64_to_jiffies64(cur_nice); |
| 114 | |
| 115 | cdbs->prev_cpu_nice = |
| 116 | kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| 117 | idle_time += jiffies_to_usecs(cur_nice_jiffies); |
| 118 | } |
| 119 | |
| 120 | if (dbs_data->governor == GOV_ONDEMAND) { |
| 121 | struct od_cpu_dbs_info_s *od_j_dbs_info = |
| 122 | dbs_data->get_cpu_dbs_info_s(cpu); |
| 123 | |
| 124 | cur_iowait_time = get_cpu_iowait_time_us(j, |
| 125 | &cur_wall_time); |
| 126 | if (cur_iowait_time == -1ULL) |
| 127 | cur_iowait_time = 0; |
| 128 | |
| 129 | iowait_time = (unsigned int) (cur_iowait_time - |
| 130 | od_j_dbs_info->prev_cpu_iowait); |
| 131 | od_j_dbs_info->prev_cpu_iowait = cur_iowait_time; |
| 132 | |
| 133 | /* |
| 134 | * For the purpose of ondemand, waiting for disk IO is |
| 135 | * an indication that you're performance critical, and |
| 136 | * not that the system is actually idle. So subtract the |
| 137 | * iowait time from the cpu idle time. |
| 138 | */ |
| 139 | if (od_tuners->io_is_busy && idle_time >= iowait_time) |
| 140 | idle_time -= iowait_time; |
| 141 | } |
| 142 | |
| 143 | if (unlikely(!wall_time || wall_time < idle_time)) |
| 144 | continue; |
| 145 | |
| 146 | load = 100 * (wall_time - idle_time) / wall_time; |
| 147 | |
| 148 | if (dbs_data->governor == GOV_ONDEMAND) { |
| 149 | int freq_avg = __cpufreq_driver_getavg(policy, j); |
| 150 | if (freq_avg <= 0) |
| 151 | freq_avg = policy->cur; |
| 152 | |
| 153 | load *= freq_avg; |
| 154 | } |
| 155 | |
| 156 | if (load > max_load) |
| 157 | max_load = load; |
| 158 | } |
| 159 | |
| 160 | dbs_data->gov_check_cpu(cpu, max_load); |
| 161 | } |
| 162 | EXPORT_SYMBOL_GPL(dbs_check_cpu); |
| 163 | |
| 164 | static inline void dbs_timer_init(struct dbs_data *dbs_data, |
| 165 | struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate) |
| 166 | { |
| 167 | int delay = delay_for_sampling_rate(sampling_rate); |
| 168 | |
| 169 | INIT_DEFERRABLE_WORK(&cdbs->work, dbs_data->gov_dbs_timer); |
| 170 | schedule_delayed_work_on(cdbs->cpu, &cdbs->work, delay); |
| 171 | } |
| 172 | |
| 173 | static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs) |
| 174 | { |
| 175 | cancel_delayed_work_sync(&cdbs->work); |
| 176 | } |
| 177 | |
| 178 | int cpufreq_governor_dbs(struct dbs_data *dbs_data, |
| 179 | struct cpufreq_policy *policy, unsigned int event) |
| 180 | { |
| 181 | struct od_cpu_dbs_info_s *od_dbs_info = NULL; |
| 182 | struct cs_cpu_dbs_info_s *cs_dbs_info = NULL; |
| 183 | struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| 184 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
| 185 | struct cpu_dbs_common_info *cpu_cdbs; |
| 186 | unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu; |
| 187 | int rc; |
| 188 | |
| 189 | cpu_cdbs = dbs_data->get_cpu_cdbs(cpu); |
| 190 | |
| 191 | if (dbs_data->governor == GOV_CONSERVATIVE) { |
| 192 | cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu); |
| 193 | sampling_rate = &cs_tuners->sampling_rate; |
| 194 | ignore_nice = cs_tuners->ignore_nice; |
| 195 | } else { |
| 196 | od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu); |
| 197 | sampling_rate = &od_tuners->sampling_rate; |
| 198 | ignore_nice = od_tuners->ignore_nice; |
| 199 | } |
| 200 | |
| 201 | switch (event) { |
| 202 | case CPUFREQ_GOV_START: |
| 203 | if ((!cpu_online(cpu)) || (!policy->cur)) |
| 204 | return -EINVAL; |
| 205 | |
| 206 | mutex_lock(&dbs_data->mutex); |
| 207 | |
| 208 | dbs_data->enable++; |
| 209 | cpu_cdbs->cpu = cpu; |
| 210 | for_each_cpu(j, policy->cpus) { |
| 211 | struct cpu_dbs_common_info *j_cdbs; |
| 212 | j_cdbs = dbs_data->get_cpu_cdbs(j); |
| 213 | |
| 214 | j_cdbs->cur_policy = policy; |
| 215 | j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, |
| 216 | &j_cdbs->prev_cpu_wall); |
| 217 | if (ignore_nice) |
| 218 | j_cdbs->prev_cpu_nice = |
| 219 | kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * Start the timerschedule work, when this governor is used for |
| 224 | * first time |
| 225 | */ |
| 226 | if (dbs_data->enable != 1) |
| 227 | goto second_time; |
| 228 | |
| 229 | rc = sysfs_create_group(cpufreq_global_kobject, |
| 230 | dbs_data->attr_group); |
| 231 | if (rc) { |
| 232 | mutex_unlock(&dbs_data->mutex); |
| 233 | return rc; |
| 234 | } |
| 235 | |
| 236 | /* policy latency is in nS. Convert it to uS first */ |
| 237 | latency = policy->cpuinfo.transition_latency / 1000; |
| 238 | if (latency == 0) |
| 239 | latency = 1; |
| 240 | |
| 241 | /* |
| 242 | * conservative does not implement micro like ondemand |
| 243 | * governor, thus we are bound to jiffes/HZ |
| 244 | */ |
| 245 | if (dbs_data->governor == GOV_CONSERVATIVE) { |
| 246 | struct cs_ops *ops = dbs_data->gov_ops; |
| 247 | |
| 248 | cpufreq_register_notifier(ops->notifier_block, |
| 249 | CPUFREQ_TRANSITION_NOTIFIER); |
| 250 | |
| 251 | dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO * |
| 252 | jiffies_to_usecs(10); |
| 253 | } else { |
| 254 | struct od_ops *ops = dbs_data->gov_ops; |
| 255 | |
| 256 | od_tuners->io_is_busy = ops->io_busy(); |
| 257 | } |
| 258 | |
| 259 | /* Bring kernel and HW constraints together */ |
| 260 | dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate, |
| 261 | MIN_LATENCY_MULTIPLIER * latency); |
| 262 | *sampling_rate = max(dbs_data->min_sampling_rate, latency * |
| 263 | LATENCY_MULTIPLIER); |
| 264 | |
| 265 | second_time: |
| 266 | if (dbs_data->governor == GOV_CONSERVATIVE) { |
| 267 | cs_dbs_info->down_skip = 0; |
| 268 | cs_dbs_info->enable = 1; |
| 269 | cs_dbs_info->requested_freq = policy->cur; |
| 270 | } else { |
| 271 | struct od_ops *ops = dbs_data->gov_ops; |
| 272 | od_dbs_info->rate_mult = 1; |
| 273 | od_dbs_info->sample_type = OD_NORMAL_SAMPLE; |
| 274 | ops->powersave_bias_init_cpu(cpu); |
| 275 | } |
| 276 | mutex_unlock(&dbs_data->mutex); |
| 277 | |
| 278 | mutex_init(&cpu_cdbs->timer_mutex); |
| 279 | dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate); |
| 280 | break; |
| 281 | |
| 282 | case CPUFREQ_GOV_STOP: |
| 283 | if (dbs_data->governor == GOV_CONSERVATIVE) |
| 284 | cs_dbs_info->enable = 0; |
| 285 | |
| 286 | dbs_timer_exit(cpu_cdbs); |
| 287 | |
| 288 | mutex_lock(&dbs_data->mutex); |
| 289 | mutex_destroy(&cpu_cdbs->timer_mutex); |
| 290 | dbs_data->enable--; |
| 291 | if (!dbs_data->enable) { |
| 292 | struct cs_ops *ops = dbs_data->gov_ops; |
| 293 | |
| 294 | sysfs_remove_group(cpufreq_global_kobject, |
| 295 | dbs_data->attr_group); |
| 296 | if (dbs_data->governor == GOV_CONSERVATIVE) |
| 297 | cpufreq_unregister_notifier(ops->notifier_block, |
| 298 | CPUFREQ_TRANSITION_NOTIFIER); |
| 299 | } |
| 300 | mutex_unlock(&dbs_data->mutex); |
| 301 | |
| 302 | break; |
| 303 | |
| 304 | case CPUFREQ_GOV_LIMITS: |
| 305 | mutex_lock(&cpu_cdbs->timer_mutex); |
| 306 | if (policy->max < cpu_cdbs->cur_policy->cur) |
| 307 | __cpufreq_driver_target(cpu_cdbs->cur_policy, |
| 308 | policy->max, CPUFREQ_RELATION_H); |
| 309 | else if (policy->min > cpu_cdbs->cur_policy->cur) |
| 310 | __cpufreq_driver_target(cpu_cdbs->cur_policy, |
| 311 | policy->min, CPUFREQ_RELATION_L); |
| 312 | dbs_check_cpu(dbs_data, cpu); |
| 313 | mutex_unlock(&cpu_cdbs->timer_mutex); |
| 314 | break; |
| 315 | } |
| 316 | return 0; |
| 317 | } |
| 318 | EXPORT_SYMBOL_GPL(cpufreq_governor_dbs); |