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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * drivers/cpufreq/cpufreq_ondemand.c
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
6 * Jun Nakajima <jun.nakajima@intel.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
Viresh Kumar4471a342012-10-26 00:47:42 +020013#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/cpufreq.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020016#include <linux/init.h>
17#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/kernel_stat.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020019#include <linux/kobject.h>
20#include <linux/module.h>
akpm@osdl.org3fc54d32006-01-13 15:54:22 -080021#include <linux/mutex.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020022#include <linux/percpu-defs.h>
23#include <linux/sysfs.h>
venkatesh.pallipadi@intel.com80800912008-08-04 11:59:12 -070024#include <linux/tick.h>
Viresh Kumar4471a342012-10-26 00:47:42 +020025#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Viresh Kumar4471a342012-10-26 00:47:42 +020027#include "cpufreq_governor.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
Viresh Kumar4471a342012-10-26 00:47:42 +020029/* On-demand governor macors */
venkatesh.pallipadi@intel.come9d95bf2008-08-04 11:59:10 -070030#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#define DEF_FREQUENCY_UP_THRESHOLD (80)
David C Niemi3f78a9f72010-10-06 16:54:24 -040032#define DEF_SAMPLING_DOWN_FACTOR (1)
33#define MAX_SAMPLING_DOWN_FACTOR (100000)
venkatesh.pallipadi@intel.com80800912008-08-04 11:59:12 -070034#define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3)
35#define MICRO_FREQUENCY_UP_THRESHOLD (95)
Thomas Renningercef96152009-04-22 13:48:29 +020036#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
Dave Jonesc29f1402005-05-31 19:03:50 -070037#define MIN_FREQUENCY_UP_THRESHOLD (11)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#define MAX_FREQUENCY_UP_THRESHOLD (100)
39
Viresh Kumar4471a342012-10-26 00:47:42 +020040static struct dbs_data od_dbs_data;
41static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info);
Thomas Renninger112124a2009-02-04 11:55:12 +010042
Viresh Kumar4471a342012-10-26 00:47:42 +020043static struct od_dbs_tuners od_tuners = {
Dave Jones32ee8c32006-02-28 00:43:23 -050044 .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
David C Niemi3f78a9f72010-10-06 16:54:24 -040045 .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
venkatesh.pallipadi@intel.come9d95bf2008-08-04 11:59:10 -070046 .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
Eric Piel9cbad612006-03-10 11:35:27 +020047 .ignore_nice = 0,
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +040048 .powersave_bias = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -070049};
50
Viresh Kumar4471a342012-10-26 00:47:42 +020051static void ondemand_powersave_bias_init_cpu(int cpu)
Arjan van de Ven6b8fcd92010-05-09 08:26:06 -070052{
Viresh Kumar4471a342012-10-26 00:47:42 +020053 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
Arjan van de Ven6b8fcd92010-05-09 08:26:06 -070054
Viresh Kumar4471a342012-10-26 00:47:42 +020055 dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
56 dbs_info->freq_lo = 0;
57}
Arjan van de Ven6b8fcd92010-05-09 08:26:06 -070058
Viresh Kumar4471a342012-10-26 00:47:42 +020059/*
60 * Not all CPUs want IO time to be accounted as busy; this depends on how
61 * efficient idling at a higher frequency/voltage is.
62 * Pavel Machek says this is not so for various generations of AMD and old
63 * Intel systems.
64 * Mike Chan (androidlcom) calis this is also not true for ARM.
65 * Because of this, whitelist specific known (series) of CPUs by default, and
66 * leave all others up to the user.
67 */
68static int should_io_be_busy(void)
69{
70#if defined(CONFIG_X86)
71 /*
72 * For Intel, Core 2 (model 15) andl later have an efficient idle.
73 */
74 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
75 boot_cpu_data.x86 == 6 &&
76 boot_cpu_data.x86_model >= 15)
77 return 1;
78#endif
79 return 0;
Arjan van de Ven6b8fcd92010-05-09 08:26:06 -070080}
81
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +040082/*
83 * Find right freq to be set now with powersave_bias on.
84 * Returns the freq_hi to be used right now and will set freq_hi_jiffies,
85 * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
86 */
Adrian Bunkb5ecf602006-08-13 23:00:08 +020087static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
Viresh Kumar4471a342012-10-26 00:47:42 +020088 unsigned int freq_next, unsigned int relation)
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +040089{
90 unsigned int freq_req, freq_reduc, freq_avg;
91 unsigned int freq_hi, freq_lo;
92 unsigned int index = 0;
93 unsigned int jiffies_total, jiffies_hi, jiffies_lo;
Viresh Kumar4471a342012-10-26 00:47:42 +020094 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
Tejun Heo245b2e72009-06-24 15:13:48 +090095 policy->cpu);
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +040096
97 if (!dbs_info->freq_table) {
98 dbs_info->freq_lo = 0;
99 dbs_info->freq_lo_jiffies = 0;
100 return freq_next;
101 }
102
103 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next,
104 relation, &index);
105 freq_req = dbs_info->freq_table[index].frequency;
Viresh Kumar4471a342012-10-26 00:47:42 +0200106 freq_reduc = freq_req * od_tuners.powersave_bias / 1000;
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400107 freq_avg = freq_req - freq_reduc;
108
109 /* Find freq bounds for freq_avg in freq_table */
110 index = 0;
111 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
112 CPUFREQ_RELATION_H, &index);
113 freq_lo = dbs_info->freq_table[index].frequency;
114 index = 0;
115 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
116 CPUFREQ_RELATION_L, &index);
117 freq_hi = dbs_info->freq_table[index].frequency;
118
119 /* Find out how long we have to be in hi and lo freqs */
120 if (freq_hi == freq_lo) {
121 dbs_info->freq_lo = 0;
122 dbs_info->freq_lo_jiffies = 0;
123 return freq_lo;
124 }
Viresh Kumar4471a342012-10-26 00:47:42 +0200125 jiffies_total = usecs_to_jiffies(od_tuners.sampling_rate);
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400126 jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
127 jiffies_hi += ((freq_hi - freq_lo) / 2);
128 jiffies_hi /= (freq_hi - freq_lo);
129 jiffies_lo = jiffies_total - jiffies_hi;
130 dbs_info->freq_lo = freq_lo;
131 dbs_info->freq_lo_jiffies = jiffies_lo;
132 dbs_info->freq_hi_jiffies = jiffies_hi;
133 return freq_hi;
134}
135
136static void ondemand_powersave_bias_init(void)
137{
138 int i;
139 for_each_online_cpu(i) {
venkatesh.pallipadi@intel.com5a75c822009-07-02 17:08:32 -0700140 ondemand_powersave_bias_init_cpu(i);
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400141 }
142}
143
Viresh Kumar4471a342012-10-26 00:47:42 +0200144static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
145{
146 if (od_tuners.powersave_bias)
147 freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
148 else if (p->cur == p->max)
149 return;
150
151 __cpufreq_driver_target(p, freq, od_tuners.powersave_bias ?
152 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
153}
154
155/*
156 * Every sampling_rate, we check, if current idle time is less than 20%
157 * (default), then we try to increase frequency Every sampling_rate, we look for
158 * a the lowest frequency which can sustain the load while keeping idle time
159 * over 30%. If such a frequency exist, we try to decrease to this frequency.
160 *
161 * Any frequency increase takes it to the maximum frequency. Frequency reduction
162 * happens at minimum steps of 5% (default) of current frequency
163 */
164static void od_check_cpu(int cpu, unsigned int load_freq)
165{
166 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
167 struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
168
169 dbs_info->freq_lo = 0;
170
171 /* Check for frequency increase */
172 if (load_freq > od_tuners.up_threshold * policy->cur) {
173 /* If switching to max speed, apply sampling_down_factor */
174 if (policy->cur < policy->max)
175 dbs_info->rate_mult =
176 od_tuners.sampling_down_factor;
177 dbs_freq_increase(policy, policy->max);
178 return;
179 }
180
181 /* Check for frequency decrease */
182 /* if we cannot reduce the frequency anymore, break out early */
183 if (policy->cur == policy->min)
184 return;
185
186 /*
187 * The optimal frequency is the frequency that is the lowest that can
188 * support the current CPU usage without triggering the up policy. To be
189 * safe, we focus 10 points under the threshold.
190 */
191 if (load_freq < (od_tuners.up_threshold - od_tuners.down_differential) *
192 policy->cur) {
193 unsigned int freq_next;
194 freq_next = load_freq / (od_tuners.up_threshold -
195 od_tuners.down_differential);
196
197 /* No longer fully busy, reset rate_mult */
198 dbs_info->rate_mult = 1;
199
200 if (freq_next < policy->min)
201 freq_next = policy->min;
202
203 if (!od_tuners.powersave_bias) {
204 __cpufreq_driver_target(policy, freq_next,
205 CPUFREQ_RELATION_L);
206 } else {
207 int freq = powersave_bias_target(policy, freq_next,
208 CPUFREQ_RELATION_L);
209 __cpufreq_driver_target(policy, freq,
210 CPUFREQ_RELATION_L);
211 }
212 }
213}
214
215static void od_dbs_timer(struct work_struct *work)
216{
217 struct od_cpu_dbs_info_s *dbs_info =
218 container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work);
219 unsigned int cpu = dbs_info->cdbs.cpu;
220 int delay, sample_type = dbs_info->sample_type;
221
222 mutex_lock(&dbs_info->cdbs.timer_mutex);
223
224 /* Common NORMAL_SAMPLE setup */
225 dbs_info->sample_type = OD_NORMAL_SAMPLE;
226 if (sample_type == OD_SUB_SAMPLE) {
227 delay = dbs_info->freq_lo_jiffies;
228 __cpufreq_driver_target(dbs_info->cdbs.cur_policy,
229 dbs_info->freq_lo, CPUFREQ_RELATION_H);
230 } else {
231 dbs_check_cpu(&od_dbs_data, cpu);
232 if (dbs_info->freq_lo) {
233 /* Setup timer for SUB_SAMPLE */
234 dbs_info->sample_type = OD_SUB_SAMPLE;
235 delay = dbs_info->freq_hi_jiffies;
236 } else {
Fabio Baltierid3c31a72012-11-23 20:48:08 +0100237 delay = delay_for_sampling_rate(od_tuners.sampling_rate
238 * dbs_info->rate_mult);
Viresh Kumar4471a342012-10-26 00:47:42 +0200239 }
240 }
241
242 schedule_delayed_work_on(cpu, &dbs_info->cdbs.work, delay);
243 mutex_unlock(&dbs_info->cdbs.timer_mutex);
244}
245
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246/************************** sysfs interface ************************/
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200247
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200248static ssize_t show_sampling_rate_min(struct kobject *kobj,
249 struct attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250{
Viresh Kumar4471a342012-10-26 00:47:42 +0200251 return sprintf(buf, "%u\n", od_dbs_data.min_sampling_rate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
253
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900254/**
255 * update_sampling_rate - update sampling rate effective immediately if needed.
256 * @new_rate: new sampling rate
257 *
258 * If new rate is smaller than the old, simply updaing
Viresh Kumar4471a342012-10-26 00:47:42 +0200259 * dbs_tuners_int.sampling_rate might not be appropriate. For example, if the
260 * original sampling_rate was 1 second and the requested new sampling rate is 10
261 * ms because the user needs immediate reaction from ondemand governor, but not
262 * sure if higher frequency will be required or not, then, the governor may
263 * change the sampling rate too late; up to 1 second later. Thus, if we are
264 * reducing the sampling rate, we need to make the new value effective
265 * immediately.
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900266 */
267static void update_sampling_rate(unsigned int new_rate)
268{
269 int cpu;
270
Viresh Kumar4471a342012-10-26 00:47:42 +0200271 od_tuners.sampling_rate = new_rate = max(new_rate,
272 od_dbs_data.min_sampling_rate);
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900273
274 for_each_online_cpu(cpu) {
275 struct cpufreq_policy *policy;
Viresh Kumar4471a342012-10-26 00:47:42 +0200276 struct od_cpu_dbs_info_s *dbs_info;
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900277 unsigned long next_sampling, appointed_at;
278
279 policy = cpufreq_cpu_get(cpu);
280 if (!policy)
281 continue;
282 dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
283 cpufreq_cpu_put(policy);
284
Viresh Kumar4471a342012-10-26 00:47:42 +0200285 mutex_lock(&dbs_info->cdbs.timer_mutex);
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900286
Viresh Kumar4471a342012-10-26 00:47:42 +0200287 if (!delayed_work_pending(&dbs_info->cdbs.work)) {
288 mutex_unlock(&dbs_info->cdbs.timer_mutex);
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900289 continue;
290 }
291
Viresh Kumar4471a342012-10-26 00:47:42 +0200292 next_sampling = jiffies + usecs_to_jiffies(new_rate);
293 appointed_at = dbs_info->cdbs.work.timer.expires;
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900294
295 if (time_before(next_sampling, appointed_at)) {
296
Viresh Kumar4471a342012-10-26 00:47:42 +0200297 mutex_unlock(&dbs_info->cdbs.timer_mutex);
298 cancel_delayed_work_sync(&dbs_info->cdbs.work);
299 mutex_lock(&dbs_info->cdbs.timer_mutex);
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900300
Viresh Kumar4471a342012-10-26 00:47:42 +0200301 schedule_delayed_work_on(dbs_info->cdbs.cpu,
302 &dbs_info->cdbs.work,
303 usecs_to_jiffies(new_rate));
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900304
305 }
Viresh Kumar4471a342012-10-26 00:47:42 +0200306 mutex_unlock(&dbs_info->cdbs.timer_mutex);
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900307 }
308}
309
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200310static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
311 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312{
313 unsigned int input;
314 int ret;
Venkatesh Pallipadiffac80e2006-06-28 13:52:18 -0700315 ret = sscanf(buf, "%u", &input);
venkatesh.pallipadi@intel.com5a75c822009-07-02 17:08:32 -0700316 if (ret != 1)
317 return -EINVAL;
MyungJoo Hamfd0ef7a2012-02-29 17:54:41 +0900318 update_sampling_rate(input);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 return count;
320}
321
Arjan van de Ven19379b12010-05-09 08:26:51 -0700322static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
323 const char *buf, size_t count)
324{
325 unsigned int input;
326 int ret;
327
328 ret = sscanf(buf, "%u", &input);
329 if (ret != 1)
330 return -EINVAL;
Viresh Kumar4471a342012-10-26 00:47:42 +0200331 od_tuners.io_is_busy = !!input;
Arjan van de Ven19379b12010-05-09 08:26:51 -0700332 return count;
333}
334
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200335static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
336 const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337{
338 unsigned int input;
339 int ret;
Venkatesh Pallipadiffac80e2006-06-28 13:52:18 -0700340 ret = sscanf(buf, "%u", &input);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
Dave Jones32ee8c32006-02-28 00:43:23 -0500342 if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
Dave Jonesc29f1402005-05-31 19:03:50 -0700343 input < MIN_FREQUENCY_UP_THRESHOLD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 return -EINVAL;
345 }
Viresh Kumar4471a342012-10-26 00:47:42 +0200346 od_tuners.up_threshold = input;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 return count;
348}
349
David C Niemi3f78a9f72010-10-06 16:54:24 -0400350static ssize_t store_sampling_down_factor(struct kobject *a,
351 struct attribute *b, const char *buf, size_t count)
352{
353 unsigned int input, j;
354 int ret;
355 ret = sscanf(buf, "%u", &input);
356
357 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
358 return -EINVAL;
Viresh Kumar4471a342012-10-26 00:47:42 +0200359 od_tuners.sampling_down_factor = input;
David C Niemi3f78a9f72010-10-06 16:54:24 -0400360
361 /* Reset down sampling multiplier in case it was active */
362 for_each_online_cpu(j) {
Viresh Kumar4471a342012-10-26 00:47:42 +0200363 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
364 j);
David C Niemi3f78a9f72010-10-06 16:54:24 -0400365 dbs_info->rate_mult = 1;
366 }
David C Niemi3f78a9f72010-10-06 16:54:24 -0400367 return count;
368}
369
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200370static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
371 const char *buf, size_t count)
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700372{
373 unsigned int input;
374 int ret;
375
376 unsigned int j;
Dave Jones32ee8c32006-02-28 00:43:23 -0500377
Venkatesh Pallipadiffac80e2006-06-28 13:52:18 -0700378 ret = sscanf(buf, "%u", &input);
Dave Jones2b03f892009-01-18 01:43:44 -0500379 if (ret != 1)
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700380 return -EINVAL;
381
Dave Jones2b03f892009-01-18 01:43:44 -0500382 if (input > 1)
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700383 input = 1;
Dave Jones32ee8c32006-02-28 00:43:23 -0500384
Viresh Kumar4471a342012-10-26 00:47:42 +0200385 if (input == od_tuners.ignore_nice) { /* nothing to do */
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700386 return count;
387 }
Viresh Kumar4471a342012-10-26 00:47:42 +0200388 od_tuners.ignore_nice = input;
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700389
Venkatesh Pallipadiccb2fe22006-06-28 13:49:52 -0700390 /* we need to re-evaluate prev_cpu_idle */
Dave Jonesdac1c1a2005-05-31 19:03:49 -0700391 for_each_online_cpu(j) {
Viresh Kumar4471a342012-10-26 00:47:42 +0200392 struct od_cpu_dbs_info_s *dbs_info;
Tejun Heo245b2e72009-06-24 15:13:48 +0900393 dbs_info = &per_cpu(od_cpu_dbs_info, j);
Viresh Kumar4471a342012-10-26 00:47:42 +0200394 dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
395 &dbs_info->cdbs.prev_cpu_wall);
396 if (od_tuners.ignore_nice)
397 dbs_info->cdbs.prev_cpu_nice =
398 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
Venkatesh Pallipadi1ca3abd2009-01-23 09:25:02 -0500399
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700400 }
Dave Jones3d5ee9e2005-05-31 19:03:47 -0700401 return count;
402}
403
Thomas Renninger0e625ac2009-07-24 15:25:06 +0200404static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
405 const char *buf, size_t count)
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400406{
407 unsigned int input;
408 int ret;
409 ret = sscanf(buf, "%u", &input);
410
411 if (ret != 1)
412 return -EINVAL;
413
414 if (input > 1000)
415 input = 1000;
416
Viresh Kumar4471a342012-10-26 00:47:42 +0200417 od_tuners.powersave_bias = input;
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400418 ondemand_powersave_bias_init();
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400419 return count;
420}
421
Viresh Kumar4471a342012-10-26 00:47:42 +0200422show_one(od, sampling_rate, sampling_rate);
423show_one(od, io_is_busy, io_is_busy);
424show_one(od, up_threshold, up_threshold);
425show_one(od, sampling_down_factor, sampling_down_factor);
426show_one(od, ignore_nice_load, ignore_nice);
427show_one(od, powersave_bias, powersave_bias);
428
Borislav Petkov6dad2a22010-03-31 21:56:46 +0200429define_one_global_rw(sampling_rate);
Linus Torvalds07d77752010-05-18 08:49:13 -0700430define_one_global_rw(io_is_busy);
Borislav Petkov6dad2a22010-03-31 21:56:46 +0200431define_one_global_rw(up_threshold);
David C Niemi3f78a9f72010-10-06 16:54:24 -0400432define_one_global_rw(sampling_down_factor);
Borislav Petkov6dad2a22010-03-31 21:56:46 +0200433define_one_global_rw(ignore_nice_load);
434define_one_global_rw(powersave_bias);
Viresh Kumar4471a342012-10-26 00:47:42 +0200435define_one_global_ro(sampling_rate_min);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
Dave Jones2b03f892009-01-18 01:43:44 -0500437static struct attribute *dbs_attributes[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 &sampling_rate_min.attr,
439 &sampling_rate.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 &up_threshold.attr,
David C Niemi3f78a9f72010-10-06 16:54:24 -0400441 &sampling_down_factor.attr,
Alexander Clouter001893c2005-12-01 01:09:25 -0800442 &ignore_nice_load.attr,
Alexey Starikovskiy05ca0352006-07-31 22:28:12 +0400443 &powersave_bias.attr,
Arjan van de Ven19379b12010-05-09 08:26:51 -0700444 &io_is_busy.attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 NULL
446};
447
Viresh Kumar4471a342012-10-26 00:47:42 +0200448static struct attribute_group od_attr_group = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 .attrs = dbs_attributes,
450 .name = "ondemand",
451};
452
453/************************** sysfs end ************************/
454
Viresh Kumar4471a342012-10-26 00:47:42 +0200455define_get_cpu_dbs_routines(od_cpu_dbs_info);
Mike Chan00e299f2010-01-26 17:06:47 -0800456
Viresh Kumar4471a342012-10-26 00:47:42 +0200457static struct od_ops od_ops = {
458 .io_busy = should_io_be_busy,
459 .powersave_bias_init_cpu = ondemand_powersave_bias_init_cpu,
460 .powersave_bias_target = powersave_bias_target,
461 .freq_increase = dbs_freq_increase,
462};
463
464static struct dbs_data od_dbs_data = {
465 .governor = GOV_ONDEMAND,
466 .attr_group = &od_attr_group,
467 .tuners = &od_tuners,
468 .get_cpu_cdbs = get_cpu_cdbs,
469 .get_cpu_dbs_info_s = get_cpu_dbs_info_s,
470 .gov_dbs_timer = od_dbs_timer,
471 .gov_check_cpu = od_check_cpu,
472 .gov_ops = &od_ops,
473};
474
475static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,
476 unsigned int event)
477{
478 return cpufreq_governor_dbs(&od_dbs_data, policy, event);
Mike Chan00e299f2010-01-26 17:06:47 -0800479}
480
Viresh Kumar4471a342012-10-26 00:47:42 +0200481#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
482static
Arjan van de Ven19379b12010-05-09 08:26:51 -0700483#endif
Viresh Kumar4471a342012-10-26 00:47:42 +0200484struct cpufreq_governor cpufreq_gov_ondemand = {
485 .name = "ondemand",
486 .governor = od_cpufreq_governor_dbs,
487 .max_transition_latency = TRANSITION_LATENCY_LIMIT,
488 .owner = THIS_MODULE,
489};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491static int __init cpufreq_gov_dbs_init(void)
492{
Andrea Righi4f6e6b92008-09-18 10:43:40 +0000493 u64 idle_time;
494 int cpu = get_cpu();
venkatesh.pallipadi@intel.com80800912008-08-04 11:59:12 -0700495
Viresh Kumar4471a342012-10-26 00:47:42 +0200496 mutex_init(&od_dbs_data.mutex);
Kamalesh Babulal21f2e3c2011-12-09 16:18:42 +0530497 idle_time = get_cpu_idle_time_us(cpu, NULL);
Andrea Righi4f6e6b92008-09-18 10:43:40 +0000498 put_cpu();
venkatesh.pallipadi@intel.com80800912008-08-04 11:59:12 -0700499 if (idle_time != -1ULL) {
500 /* Idle micro accounting is supported. Use finer thresholds */
Viresh Kumar4471a342012-10-26 00:47:42 +0200501 od_tuners.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
502 od_tuners.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
Thomas Renningercef96152009-04-22 13:48:29 +0200503 /*
Paul Bollebd74b322011-08-06 14:33:43 +0200504 * In nohz/micro accounting case we set the minimum frequency
Thomas Renningercef96152009-04-22 13:48:29 +0200505 * not depending on HZ, but fixed (very low). The deferred
506 * timer might skip some samples if idle/sleeping as needed.
507 */
Viresh Kumar4471a342012-10-26 00:47:42 +0200508 od_dbs_data.min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
Thomas Renningercef96152009-04-22 13:48:29 +0200509 } else {
510 /* For correct statistics, we need 10 ticks for each measure */
Viresh Kumar4471a342012-10-26 00:47:42 +0200511 od_dbs_data.min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
512 jiffies_to_usecs(10);
venkatesh.pallipadi@intel.com80800912008-08-04 11:59:12 -0700513 }
Akinobu Mita888a7942008-07-14 12:00:45 +0900514
Tejun Heo57df5572011-01-26 12:12:50 +0100515 return cpufreq_register_governor(&cpufreq_gov_ondemand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516}
517
518static void __exit cpufreq_gov_dbs_exit(void)
519{
Thomas Renninger1c256242007-10-02 13:28:12 -0700520 cpufreq_unregister_governor(&cpufreq_gov_ondemand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521}
522
Venkatesh Pallipadiffac80e2006-06-28 13:52:18 -0700523MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
524MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
525MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
Dave Jones2b03f892009-01-18 01:43:44 -0500526 "Low Latency Frequency Transition capable processors");
Venkatesh Pallipadiffac80e2006-06-28 13:52:18 -0700527MODULE_LICENSE("GPL");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
Johannes Weiner69157192008-01-17 15:21:08 -0800529#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
530fs_initcall(cpufreq_gov_dbs_init);
531#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532module_init(cpufreq_gov_dbs_init);
Johannes Weiner69157192008-01-17 15:21:08 -0800533#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534module_exit(cpufreq_gov_dbs_exit);