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viresh kumar2aacdff2012-10-23 01:28:05 +02001/*
2 * drivers/cpufreq/cpufreq_governor.c
3 *
4 * CPUFREQ governors common code
5 *
Viresh Kumar4471a342012-10-26 00:47:42 +02006 * 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 kumar2aacdff2012-10-23 01:28:05 +020012 * 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 Kumar4471a342012-10-26 00:47:42 +020017#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
viresh kumar2aacdff2012-10-23 01:28:05 +020019#include <asm/cputime.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020020#include <linux/cpufreq.h>
21#include <linux/cpumask.h>
viresh kumar2aacdff2012-10-23 01:28:05 +020022#include <linux/export.h>
23#include <linux/kernel_stat.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020024#include <linux/mutex.h>
Viresh Kumar4d5dcc42013-03-27 15:58:58 +000025#include <linux/slab.h>
viresh kumar2aacdff2012-10-23 01:28:05 +020026#include <linux/types.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020027#include <linux/workqueue.h>
28
29#include "cpufreq_governor.h"
30
Viresh Kumar4d5dcc42013-03-27 15:58:58 +000031static struct attribute_group *get_sysfs_attr(struct dbs_data *dbs_data)
32{
33 if (have_governor_per_policy())
34 return dbs_data->cdata->attr_group_gov_pol;
35 else
36 return dbs_data->cdata->attr_group_gov_sys;
37}
38
Viresh Kumar4471a342012-10-26 00:47:42 +020039void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
40{
Viresh Kumar4d5dcc42013-03-27 15:58:58 +000041 struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
Viresh Kumar4471a342012-10-26 00:47:42 +020042 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
43 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
44 struct cpufreq_policy *policy;
45 unsigned int max_load = 0;
46 unsigned int ignore_nice;
47 unsigned int j;
48
Viresh Kumar4d5dcc42013-03-27 15:58:58 +000049 if (dbs_data->cdata->governor == GOV_ONDEMAND)
Viresh Kumar4471a342012-10-26 00:47:42 +020050 ignore_nice = od_tuners->ignore_nice;
51 else
52 ignore_nice = cs_tuners->ignore_nice;
53
54 policy = cdbs->cur_policy;
55
56 /* Get Absolute Load (in terms of freq for ondemand gov) */
57 for_each_cpu(j, policy->cpus) {
58 struct cpu_dbs_common_info *j_cdbs;
Stratos Karafotis9366d842013-02-28 16:57:32 +000059 u64 cur_wall_time, cur_idle_time;
60 unsigned int idle_time, wall_time;
Viresh Kumar4471a342012-10-26 00:47:42 +020061 unsigned int load;
Stratos Karafotis9366d842013-02-28 16:57:32 +000062 int io_busy = 0;
Viresh Kumar4471a342012-10-26 00:47:42 +020063
Viresh Kumar4d5dcc42013-03-27 15:58:58 +000064 j_cdbs = dbs_data->cdata->get_cpu_cdbs(j);
Viresh Kumar4471a342012-10-26 00:47:42 +020065
Stratos Karafotis9366d842013-02-28 16:57:32 +000066 /*
67 * For the purpose of ondemand, waiting for disk IO is
68 * an indication that you're performance critical, and
69 * not that the system is actually idle. So do not add
70 * the iowait time to the cpu idle time.
71 */
72 if (dbs_data->cdata->governor == GOV_ONDEMAND)
73 io_busy = od_tuners->io_is_busy;
74 cur_idle_time = get_cpu_idle_time(j, &cur_wall_time, io_busy);
Viresh Kumar4471a342012-10-26 00:47:42 +020075
76 wall_time = (unsigned int)
77 (cur_wall_time - j_cdbs->prev_cpu_wall);
78 j_cdbs->prev_cpu_wall = cur_wall_time;
79
80 idle_time = (unsigned int)
81 (cur_idle_time - j_cdbs->prev_cpu_idle);
82 j_cdbs->prev_cpu_idle = cur_idle_time;
83
84 if (ignore_nice) {
85 u64 cur_nice;
86 unsigned long cur_nice_jiffies;
87
88 cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
89 cdbs->prev_cpu_nice;
90 /*
91 * Assumption: nice time between sampling periods will
92 * be less than 2^32 jiffies for 32 bit sys
93 */
94 cur_nice_jiffies = (unsigned long)
95 cputime64_to_jiffies64(cur_nice);
96
97 cdbs->prev_cpu_nice =
98 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
99 idle_time += jiffies_to_usecs(cur_nice_jiffies);
100 }
101
Viresh Kumar4471a342012-10-26 00:47:42 +0200102 if (unlikely(!wall_time || wall_time < idle_time))
103 continue;
104
105 load = 100 * (wall_time - idle_time) / wall_time;
106
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000107 if (dbs_data->cdata->governor == GOV_ONDEMAND) {
Viresh Kumar4471a342012-10-26 00:47:42 +0200108 int freq_avg = __cpufreq_driver_getavg(policy, j);
109 if (freq_avg <= 0)
110 freq_avg = policy->cur;
111
112 load *= freq_avg;
113 }
114
115 if (load > max_load)
116 max_load = load;
117 }
118
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000119 dbs_data->cdata->gov_check_cpu(cpu, max_load);
Viresh Kumar4471a342012-10-26 00:47:42 +0200120}
121EXPORT_SYMBOL_GPL(dbs_check_cpu);
122
Viresh Kumar031299b2013-02-27 12:24:03 +0530123static inline void __gov_queue_work(int cpu, struct dbs_data *dbs_data,
124 unsigned int delay)
Viresh Kumar4471a342012-10-26 00:47:42 +0200125{
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000126 struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
Viresh Kumar4471a342012-10-26 00:47:42 +0200127
Viresh Kumar031299b2013-02-27 12:24:03 +0530128 mod_delayed_work_on(cpu, system_wq, &cdbs->work, delay);
Viresh Kumar4471a342012-10-26 00:47:42 +0200129}
130
Viresh Kumar031299b2013-02-27 12:24:03 +0530131void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
132 unsigned int delay, bool all_cpus)
Viresh Kumar4471a342012-10-26 00:47:42 +0200133{
Viresh Kumar031299b2013-02-27 12:24:03 +0530134 int i;
Fabio Baltieri58ddcea2013-01-30 13:53:37 +0000135
Viresh Kumar031299b2013-02-27 12:24:03 +0530136 if (!all_cpus) {
137 __gov_queue_work(smp_processor_id(), dbs_data, delay);
138 } else {
139 for_each_cpu(i, policy->cpus)
140 __gov_queue_work(i, dbs_data, delay);
141 }
142}
143EXPORT_SYMBOL_GPL(gov_queue_work);
144
145static inline void gov_cancel_work(struct dbs_data *dbs_data,
146 struct cpufreq_policy *policy)
147{
148 struct cpu_dbs_common_info *cdbs;
149 int i;
150
151 for_each_cpu(i, policy->cpus) {
152 cdbs = dbs_data->cdata->get_cpu_cdbs(i);
153 cancel_delayed_work_sync(&cdbs->work);
154 }
Viresh Kumar4471a342012-10-26 00:47:42 +0200155}
156
Viresh Kumar44472662013-01-31 17:28:02 +0000157/* Will return if we need to evaluate cpu load again or not */
158bool need_load_eval(struct cpu_dbs_common_info *cdbs,
159 unsigned int sampling_rate)
160{
161 if (policy_is_shared(cdbs->cur_policy)) {
162 ktime_t time_now = ktime_get();
163 s64 delta_us = ktime_us_delta(time_now, cdbs->time_stamp);
164
165 /* Do nothing if we recently have sampled */
166 if (delta_us < (s64)(sampling_rate / 2))
167 return false;
168 else
169 cdbs->time_stamp = time_now;
170 }
171
172 return true;
173}
174EXPORT_SYMBOL_GPL(need_load_eval);
175
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000176static void set_sampling_rate(struct dbs_data *dbs_data,
177 unsigned int sampling_rate)
Viresh Kumar4471a342012-10-26 00:47:42 +0200178{
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000179 if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
180 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
181 cs_tuners->sampling_rate = sampling_rate;
182 } else {
183 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
184 od_tuners->sampling_rate = sampling_rate;
185 }
186}
187
188int cpufreq_governor_dbs(struct cpufreq_policy *policy,
189 struct common_dbs_data *cdata, unsigned int event)
190{
191 struct dbs_data *dbs_data;
Viresh Kumar4471a342012-10-26 00:47:42 +0200192 struct od_cpu_dbs_info_s *od_dbs_info = NULL;
193 struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
Viresh Kumar8eeed092013-01-31 17:28:01 +0000194 struct od_ops *od_ops = NULL;
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000195 struct od_dbs_tuners *od_tuners = NULL;
196 struct cs_dbs_tuners *cs_tuners = NULL;
Viresh Kumar4471a342012-10-26 00:47:42 +0200197 struct cpu_dbs_common_info *cpu_cdbs;
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000198 unsigned int sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
Stratos Karafotis9366d842013-02-28 16:57:32 +0000199 int io_busy = 0;
Viresh Kumar4471a342012-10-26 00:47:42 +0200200 int rc;
201
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000202 if (have_governor_per_policy())
203 dbs_data = policy->governor_data;
204 else
205 dbs_data = cdata->gdbs_data;
Viresh Kumar4471a342012-10-26 00:47:42 +0200206
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000207 WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT));
208
209 switch (event) {
210 case CPUFREQ_GOV_POLICY_INIT:
211 if (have_governor_per_policy()) {
212 WARN_ON(dbs_data);
213 } else if (dbs_data) {
Viresh Kumara97c98a2013-04-30 14:32:17 +0000214 dbs_data->usage_count++;
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000215 policy->governor_data = dbs_data;
216 return 0;
217 }
218
219 dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL);
220 if (!dbs_data) {
221 pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
222 return -ENOMEM;
223 }
224
225 dbs_data->cdata = cdata;
Viresh Kumara97c98a2013-04-30 14:32:17 +0000226 dbs_data->usage_count = 1;
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000227 rc = cdata->init(dbs_data);
228 if (rc) {
229 pr_err("%s: POLICY_INIT: init() failed\n", __func__);
230 kfree(dbs_data);
231 return rc;
232 }
233
Viresh Kumar2361be22013-05-17 16:09:09 +0530234 if (!have_governor_per_policy())
235 WARN_ON(cpufreq_get_global_kobject());
236
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000237 rc = sysfs_create_group(get_governor_parent_kobj(policy),
238 get_sysfs_attr(dbs_data));
239 if (rc) {
240 cdata->exit(dbs_data);
241 kfree(dbs_data);
242 return rc;
243 }
244
245 policy->governor_data = dbs_data;
246
247 /* policy latency is in nS. Convert it to uS first */
248 latency = policy->cpuinfo.transition_latency / 1000;
249 if (latency == 0)
250 latency = 1;
251
252 /* Bring kernel and HW constraints together */
253 dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
254 MIN_LATENCY_MULTIPLIER * latency);
255 set_sampling_rate(dbs_data, max(dbs_data->min_sampling_rate,
256 latency * LATENCY_MULTIPLIER));
257
Viresh Kumara97c98a2013-04-30 14:32:17 +0000258 if ((cdata->governor == GOV_CONSERVATIVE) &&
259 (!policy->governor->initialized)) {
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000260 struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;
261
262 cpufreq_register_notifier(cs_ops->notifier_block,
263 CPUFREQ_TRANSITION_NOTIFIER);
264 }
265
266 if (!have_governor_per_policy())
267 cdata->gdbs_data = dbs_data;
268
269 return 0;
270 case CPUFREQ_GOV_POLICY_EXIT:
Viresh Kumara97c98a2013-04-30 14:32:17 +0000271 if (!--dbs_data->usage_count) {
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000272 sysfs_remove_group(get_governor_parent_kobj(policy),
273 get_sysfs_attr(dbs_data));
274
Viresh Kumar2361be22013-05-17 16:09:09 +0530275 if (!have_governor_per_policy())
276 cpufreq_put_global_kobject();
277
Viresh Kumara97c98a2013-04-30 14:32:17 +0000278 if ((dbs_data->cdata->governor == GOV_CONSERVATIVE) &&
279 (policy->governor->initialized == 1)) {
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000280 struct cs_ops *cs_ops = dbs_data->cdata->gov_ops;
281
282 cpufreq_unregister_notifier(cs_ops->notifier_block,
283 CPUFREQ_TRANSITION_NOTIFIER);
284 }
285
286 cdata->exit(dbs_data);
287 kfree(dbs_data);
288 cdata->gdbs_data = NULL;
289 }
290
291 policy->governor_data = NULL;
292 return 0;
293 }
294
295 cpu_cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
296
297 if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
298 cs_tuners = dbs_data->tuners;
299 cs_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
300 sampling_rate = cs_tuners->sampling_rate;
Viresh Kumar4471a342012-10-26 00:47:42 +0200301 ignore_nice = cs_tuners->ignore_nice;
302 } else {
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000303 od_tuners = dbs_data->tuners;
304 od_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu);
305 sampling_rate = od_tuners->sampling_rate;
Viresh Kumar4471a342012-10-26 00:47:42 +0200306 ignore_nice = od_tuners->ignore_nice;
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000307 od_ops = dbs_data->cdata->gov_ops;
Stratos Karafotis9366d842013-02-28 16:57:32 +0000308 io_busy = od_tuners->io_is_busy;
Viresh Kumar4471a342012-10-26 00:47:42 +0200309 }
310
311 switch (event) {
312 case CPUFREQ_GOV_START:
Viresh Kumar3361b7b2013-02-04 11:38:51 +0000313 if (!policy->cur)
Viresh Kumar4471a342012-10-26 00:47:42 +0200314 return -EINVAL;
315
316 mutex_lock(&dbs_data->mutex);
317
Viresh Kumar4471a342012-10-26 00:47:42 +0200318 for_each_cpu(j, policy->cpus) {
Viresh Kumar8eeed092013-01-31 17:28:01 +0000319 struct cpu_dbs_common_info *j_cdbs =
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000320 dbs_data->cdata->get_cpu_cdbs(j);
Viresh Kumar4471a342012-10-26 00:47:42 +0200321
Fabio Baltieri09dca5a2013-01-31 10:39:19 +0000322 j_cdbs->cpu = j;
Viresh Kumar4471a342012-10-26 00:47:42 +0200323 j_cdbs->cur_policy = policy;
324 j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
Stratos Karafotis9366d842013-02-28 16:57:32 +0000325 &j_cdbs->prev_cpu_wall, io_busy);
Viresh Kumar4471a342012-10-26 00:47:42 +0200326 if (ignore_nice)
327 j_cdbs->prev_cpu_nice =
328 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
Rickard Andersson2abfa872012-12-27 14:55:38 +0000329
330 mutex_init(&j_cdbs->timer_mutex);
331 INIT_DEFERRABLE_WORK(&j_cdbs->work,
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000332 dbs_data->cdata->gov_dbs_timer);
Viresh Kumar4471a342012-10-26 00:47:42 +0200333 }
334
Viresh Kumar4471a342012-10-26 00:47:42 +0200335 /*
336 * conservative does not implement micro like ondemand
337 * governor, thus we are bound to jiffes/HZ
338 */
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000339 if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
Viresh Kumar8eeed092013-01-31 17:28:01 +0000340 cs_dbs_info->down_skip = 0;
341 cs_dbs_info->enable = 1;
342 cs_dbs_info->requested_freq = policy->cur;
Viresh Kumar4471a342012-10-26 00:47:42 +0200343 } else {
Viresh Kumar8eeed092013-01-31 17:28:01 +0000344 od_dbs_info->rate_mult = 1;
345 od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
346 od_ops->powersave_bias_init_cpu(cpu);
Viresh Kumar4471a342012-10-26 00:47:42 +0200347 }
348
Viresh Kumar4471a342012-10-26 00:47:42 +0200349 mutex_unlock(&dbs_data->mutex);
350
Fabio Baltieri58ddcea2013-01-30 13:53:37 +0000351 /* Initiate timer time stamp */
352 cpu_cdbs->time_stamp = ktime_get();
Fabio Baltierida53d612012-12-27 14:55:40 +0000353
Viresh Kumar031299b2013-02-27 12:24:03 +0530354 gov_queue_work(dbs_data, policy,
355 delay_for_sampling_rate(sampling_rate), true);
Viresh Kumar4471a342012-10-26 00:47:42 +0200356 break;
357
358 case CPUFREQ_GOV_STOP:
Viresh Kumar4d5dcc42013-03-27 15:58:58 +0000359 if (dbs_data->cdata->governor == GOV_CONSERVATIVE)
Viresh Kumar4471a342012-10-26 00:47:42 +0200360 cs_dbs_info->enable = 0;
361
Viresh Kumar031299b2013-02-27 12:24:03 +0530362 gov_cancel_work(dbs_data, policy);
Viresh Kumar4471a342012-10-26 00:47:42 +0200363
364 mutex_lock(&dbs_data->mutex);
365 mutex_destroy(&cpu_cdbs->timer_mutex);
Viresh Kumar4471a342012-10-26 00:47:42 +0200366
Viresh Kumar4471a342012-10-26 00:47:42 +0200367 mutex_unlock(&dbs_data->mutex);
368
369 break;
370
371 case CPUFREQ_GOV_LIMITS:
372 mutex_lock(&cpu_cdbs->timer_mutex);
373 if (policy->max < cpu_cdbs->cur_policy->cur)
374 __cpufreq_driver_target(cpu_cdbs->cur_policy,
375 policy->max, CPUFREQ_RELATION_H);
376 else if (policy->min > cpu_cdbs->cur_policy->cur)
377 __cpufreq_driver_target(cpu_cdbs->cur_policy,
378 policy->min, CPUFREQ_RELATION_L);
379 dbs_check_cpu(dbs_data, cpu);
380 mutex_unlock(&cpu_cdbs->timer_mutex);
381 break;
382 }
383 return 0;
384}
385EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);