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2aacdfff | 1 | /* |
2 | * drivers/cpufreq/cpufreq_governor.c | |
3 | * | |
4 | * CPUFREQ governors common code | |
5 | * | |
4471a34f VK |
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 | * | |
2aacdfff | 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 | ||
4471a34f VK |
17 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
18 | ||
2aacdfff | 19 | #include <asm/cputime.h> |
4471a34f VK |
20 | #include <linux/cpufreq.h> |
21 | #include <linux/cpumask.h> | |
2aacdfff | 22 | #include <linux/export.h> |
23 | #include <linux/kernel_stat.h> | |
4471a34f | 24 | #include <linux/mutex.h> |
2aacdfff | 25 | #include <linux/tick.h> |
26 | #include <linux/types.h> | |
4471a34f VK |
27 | #include <linux/workqueue.h> |
28 | ||
29 | #include "cpufreq_governor.h" | |
30 | ||
2aacdfff | 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) | |
a0e5af3c | 48 | *wall = cputime_to_usecs(cur_wall_time); |
2aacdfff | 49 | |
a0e5af3c | 50 | return cputime_to_usecs(idle_time); |
2aacdfff | 51 | } |
52 | ||
1e7586a1 | 53 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall) |
2aacdfff | 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); | |
4471a34f VK |
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; | |
1e7586a1 | 86 | u64 cur_wall_time, cur_idle_time, cur_iowait_time; |
4471a34f VK |
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); |