Loading...
1/*
2 * drivers/cpufreq/cpufreq_conservative.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 * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/slab.h>
15#include "cpufreq_governor.h"
16
17/* Conservative governor macros */
18#define DEF_FREQUENCY_UP_THRESHOLD (80)
19#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
20#define DEF_FREQUENCY_STEP (5)
21#define DEF_SAMPLING_DOWN_FACTOR (1)
22#define MAX_SAMPLING_DOWN_FACTOR (10)
23
24static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
25
26static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
27 struct cpufreq_policy *policy)
28{
29 unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;
30
31 /* max freq cannot be less than 100. But who knows... */
32 if (unlikely(freq_target == 0))
33 freq_target = DEF_FREQUENCY_STEP;
34
35 return freq_target;
36}
37
38/*
39 * Every sampling_rate, we check, if current idle time is less than 20%
40 * (default), then we try to increase frequency. Every sampling_rate *
41 * sampling_down_factor, we check, if current idle time is more than 80%
42 * (default), then we try to decrease frequency
43 *
44 * Any frequency increase takes it to the maximum frequency. Frequency reduction
45 * happens at minimum steps of 5% (default) of maximum frequency
46 */
47static void cs_check_cpu(int cpu, unsigned int load)
48{
49 struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
50 struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
51 struct dbs_data *dbs_data = policy->governor_data;
52 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
53
54 /*
55 * break out if we 'cannot' reduce the speed as the user might
56 * want freq_step to be zero
57 */
58 if (cs_tuners->freq_step == 0)
59 return;
60
61 /* Check for frequency increase */
62 if (load > cs_tuners->up_threshold) {
63 dbs_info->down_skip = 0;
64
65 /* if we are already at full speed then break out early */
66 if (dbs_info->requested_freq == policy->max)
67 return;
68
69 dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
70
71 if (dbs_info->requested_freq > policy->max)
72 dbs_info->requested_freq = policy->max;
73
74 __cpufreq_driver_target(policy, dbs_info->requested_freq,
75 CPUFREQ_RELATION_H);
76 return;
77 }
78
79 /* if sampling_down_factor is active break out early */
80 if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
81 return;
82 dbs_info->down_skip = 0;
83
84 /* Check for frequency decrease */
85 if (load < cs_tuners->down_threshold) {
86 unsigned int freq_target;
87 /*
88 * if we cannot reduce the frequency anymore, break out early
89 */
90 if (policy->cur == policy->min)
91 return;
92
93 freq_target = get_freq_target(cs_tuners, policy);
94 if (dbs_info->requested_freq > freq_target)
95 dbs_info->requested_freq -= freq_target;
96 else
97 dbs_info->requested_freq = policy->min;
98
99 __cpufreq_driver_target(policy, dbs_info->requested_freq,
100 CPUFREQ_RELATION_L);
101 return;
102 }
103}
104
105static void cs_dbs_timer(struct work_struct *work)
106{
107 struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
108 struct cs_cpu_dbs_info_s, cdbs.work.work);
109 unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
110 struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
111 cpu);
112 struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
113 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
114 int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
115 bool modify_all = true;
116
117 mutex_lock(&core_dbs_info->cdbs.timer_mutex);
118 if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
119 modify_all = false;
120 else
121 dbs_check_cpu(dbs_data, cpu);
122
123 gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
124 mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
125}
126
127static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
128 void *data)
129{
130 struct cpufreq_freqs *freq = data;
131 struct cs_cpu_dbs_info_s *dbs_info =
132 &per_cpu(cs_cpu_dbs_info, freq->cpu);
133 struct cpufreq_policy *policy;
134
135 if (!dbs_info->enable)
136 return 0;
137
138 policy = dbs_info->cdbs.cur_policy;
139
140 /*
141 * we only care if our internally tracked freq moves outside the 'valid'
142 * ranges of frequency available to us otherwise we do not change it
143 */
144 if (dbs_info->requested_freq > policy->max
145 || dbs_info->requested_freq < policy->min)
146 dbs_info->requested_freq = freq->new;
147
148 return 0;
149}
150
151/************************** sysfs interface ************************/
152static struct common_dbs_data cs_dbs_cdata;
153
154static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
155 const char *buf, size_t count)
156{
157 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
158 unsigned int input;
159 int ret;
160 ret = sscanf(buf, "%u", &input);
161
162 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
163 return -EINVAL;
164
165 cs_tuners->sampling_down_factor = input;
166 return count;
167}
168
169static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf,
170 size_t count)
171{
172 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
173 unsigned int input;
174 int ret;
175 ret = sscanf(buf, "%u", &input);
176
177 if (ret != 1)
178 return -EINVAL;
179
180 cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
181 return count;
182}
183
184static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf,
185 size_t count)
186{
187 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
188 unsigned int input;
189 int ret;
190 ret = sscanf(buf, "%u", &input);
191
192 if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
193 return -EINVAL;
194
195 cs_tuners->up_threshold = input;
196 return count;
197}
198
199static ssize_t store_down_threshold(struct dbs_data *dbs_data, const char *buf,
200 size_t count)
201{
202 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
203 unsigned int input;
204 int ret;
205 ret = sscanf(buf, "%u", &input);
206
207 /* cannot be lower than 11 otherwise freq will not fall */
208 if (ret != 1 || input < 11 || input > 100 ||
209 input >= cs_tuners->up_threshold)
210 return -EINVAL;
211
212 cs_tuners->down_threshold = input;
213 return count;
214}
215
216static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
217 const char *buf, size_t count)
218{
219 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
220 unsigned int input, j;
221 int ret;
222
223 ret = sscanf(buf, "%u", &input);
224 if (ret != 1)
225 return -EINVAL;
226
227 if (input > 1)
228 input = 1;
229
230 if (input == cs_tuners->ignore_nice_load) /* nothing to do */
231 return count;
232
233 cs_tuners->ignore_nice_load = input;
234
235 /* we need to re-evaluate prev_cpu_idle */
236 for_each_online_cpu(j) {
237 struct cs_cpu_dbs_info_s *dbs_info;
238 dbs_info = &per_cpu(cs_cpu_dbs_info, j);
239 dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
240 &dbs_info->cdbs.prev_cpu_wall, 0);
241 if (cs_tuners->ignore_nice_load)
242 dbs_info->cdbs.prev_cpu_nice =
243 kcpustat_cpu(j).cpustat[CPUTIME_NICE];
244 }
245 return count;
246}
247
248static ssize_t store_freq_step(struct dbs_data *dbs_data, const char *buf,
249 size_t count)
250{
251 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
252 unsigned int input;
253 int ret;
254 ret = sscanf(buf, "%u", &input);
255
256 if (ret != 1)
257 return -EINVAL;
258
259 if (input > 100)
260 input = 100;
261
262 /*
263 * no need to test here if freq_step is zero as the user might actually
264 * want this, they would be crazy though :)
265 */
266 cs_tuners->freq_step = input;
267 return count;
268}
269
270show_store_one(cs, sampling_rate);
271show_store_one(cs, sampling_down_factor);
272show_store_one(cs, up_threshold);
273show_store_one(cs, down_threshold);
274show_store_one(cs, ignore_nice_load);
275show_store_one(cs, freq_step);
276declare_show_sampling_rate_min(cs);
277
278gov_sys_pol_attr_rw(sampling_rate);
279gov_sys_pol_attr_rw(sampling_down_factor);
280gov_sys_pol_attr_rw(up_threshold);
281gov_sys_pol_attr_rw(down_threshold);
282gov_sys_pol_attr_rw(ignore_nice_load);
283gov_sys_pol_attr_rw(freq_step);
284gov_sys_pol_attr_ro(sampling_rate_min);
285
286static struct attribute *dbs_attributes_gov_sys[] = {
287 &sampling_rate_min_gov_sys.attr,
288 &sampling_rate_gov_sys.attr,
289 &sampling_down_factor_gov_sys.attr,
290 &up_threshold_gov_sys.attr,
291 &down_threshold_gov_sys.attr,
292 &ignore_nice_load_gov_sys.attr,
293 &freq_step_gov_sys.attr,
294 NULL
295};
296
297static struct attribute_group cs_attr_group_gov_sys = {
298 .attrs = dbs_attributes_gov_sys,
299 .name = "conservative",
300};
301
302static struct attribute *dbs_attributes_gov_pol[] = {
303 &sampling_rate_min_gov_pol.attr,
304 &sampling_rate_gov_pol.attr,
305 &sampling_down_factor_gov_pol.attr,
306 &up_threshold_gov_pol.attr,
307 &down_threshold_gov_pol.attr,
308 &ignore_nice_load_gov_pol.attr,
309 &freq_step_gov_pol.attr,
310 NULL
311};
312
313static struct attribute_group cs_attr_group_gov_pol = {
314 .attrs = dbs_attributes_gov_pol,
315 .name = "conservative",
316};
317
318/************************** sysfs end ************************/
319
320static int cs_init(struct dbs_data *dbs_data)
321{
322 struct cs_dbs_tuners *tuners;
323
324 tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
325 if (!tuners) {
326 pr_err("%s: kzalloc failed\n", __func__);
327 return -ENOMEM;
328 }
329
330 tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
331 tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
332 tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
333 tuners->ignore_nice_load = 0;
334 tuners->freq_step = DEF_FREQUENCY_STEP;
335
336 dbs_data->tuners = tuners;
337 dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
338 jiffies_to_usecs(10);
339 mutex_init(&dbs_data->mutex);
340 return 0;
341}
342
343static void cs_exit(struct dbs_data *dbs_data)
344{
345 kfree(dbs_data->tuners);
346}
347
348define_get_cpu_dbs_routines(cs_cpu_dbs_info);
349
350static struct notifier_block cs_cpufreq_notifier_block = {
351 .notifier_call = dbs_cpufreq_notifier,
352};
353
354static struct cs_ops cs_ops = {
355 .notifier_block = &cs_cpufreq_notifier_block,
356};
357
358static struct common_dbs_data cs_dbs_cdata = {
359 .governor = GOV_CONSERVATIVE,
360 .attr_group_gov_sys = &cs_attr_group_gov_sys,
361 .attr_group_gov_pol = &cs_attr_group_gov_pol,
362 .get_cpu_cdbs = get_cpu_cdbs,
363 .get_cpu_dbs_info_s = get_cpu_dbs_info_s,
364 .gov_dbs_timer = cs_dbs_timer,
365 .gov_check_cpu = cs_check_cpu,
366 .gov_ops = &cs_ops,
367 .init = cs_init,
368 .exit = cs_exit,
369};
370
371static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
372 unsigned int event)
373{
374 return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
375}
376
377#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
378static
379#endif
380struct cpufreq_governor cpufreq_gov_conservative = {
381 .name = "conservative",
382 .governor = cs_cpufreq_governor_dbs,
383 .max_transition_latency = TRANSITION_LATENCY_LIMIT,
384 .owner = THIS_MODULE,
385};
386
387static int __init cpufreq_gov_dbs_init(void)
388{
389 return cpufreq_register_governor(&cpufreq_gov_conservative);
390}
391
392static void __exit cpufreq_gov_dbs_exit(void)
393{
394 cpufreq_unregister_governor(&cpufreq_gov_conservative);
395}
396
397MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
398MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
399 "Low Latency Frequency Transition capable processors "
400 "optimised for use in a battery environment");
401MODULE_LICENSE("GPL");
402
403#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
404fs_initcall(cpufreq_gov_dbs_init);
405#else
406module_init(cpufreq_gov_dbs_init);
407#endif
408module_exit(cpufreq_gov_dbs_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/cpufreq/cpufreq_conservative.c
4 *
5 * Copyright (C) 2001 Russell King
6 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
7 * Jun Nakajima <jun.nakajima@intel.com>
8 * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
9 */
10
11#include <linux/slab.h>
12#include "cpufreq_governor.h"
13
14struct cs_policy_dbs_info {
15 struct policy_dbs_info policy_dbs;
16 unsigned int down_skip;
17 unsigned int requested_freq;
18};
19
20static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
21{
22 return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
23}
24
25struct cs_dbs_tuners {
26 unsigned int down_threshold;
27 unsigned int freq_step;
28};
29
30/* Conservative governor macros */
31#define DEF_FREQUENCY_UP_THRESHOLD (80)
32#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
33#define DEF_FREQUENCY_STEP (5)
34#define DEF_SAMPLING_DOWN_FACTOR (1)
35#define MAX_SAMPLING_DOWN_FACTOR (10)
36
37static inline unsigned int get_freq_step(struct cs_dbs_tuners *cs_tuners,
38 struct cpufreq_policy *policy)
39{
40 unsigned int freq_step = (cs_tuners->freq_step * policy->max) / 100;
41
42 /* max freq cannot be less than 100. But who knows... */
43 if (unlikely(freq_step == 0))
44 freq_step = DEF_FREQUENCY_STEP;
45
46 return freq_step;
47}
48
49/*
50 * Every sampling_rate, we check, if current idle time is less than 20%
51 * (default), then we try to increase frequency. Every sampling_rate *
52 * sampling_down_factor, we check, if current idle time is more than 80%
53 * (default), then we try to decrease frequency
54 *
55 * Frequency updates happen at minimum steps of 5% (default) of maximum
56 * frequency
57 */
58static unsigned int cs_dbs_update(struct cpufreq_policy *policy)
59{
60 struct policy_dbs_info *policy_dbs = policy->governor_data;
61 struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
62 unsigned int requested_freq = dbs_info->requested_freq;
63 struct dbs_data *dbs_data = policy_dbs->dbs_data;
64 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
65 unsigned int load = dbs_update(policy);
66 unsigned int freq_step;
67
68 /*
69 * break out if we 'cannot' reduce the speed as the user might
70 * want freq_step to be zero
71 */
72 if (cs_tuners->freq_step == 0)
73 goto out;
74
75 /*
76 * If requested_freq is out of range, it is likely that the limits
77 * changed in the meantime, so fall back to current frequency in that
78 * case.
79 */
80 if (requested_freq > policy->max || requested_freq < policy->min) {
81 requested_freq = policy->cur;
82 dbs_info->requested_freq = requested_freq;
83 }
84
85 freq_step = get_freq_step(cs_tuners, policy);
86
87 /*
88 * Decrease requested_freq one freq_step for each idle period that
89 * we didn't update the frequency.
90 */
91 if (policy_dbs->idle_periods < UINT_MAX) {
92 unsigned int freq_steps = policy_dbs->idle_periods * freq_step;
93
94 if (requested_freq > policy->min + freq_steps)
95 requested_freq -= freq_steps;
96 else
97 requested_freq = policy->min;
98
99 policy_dbs->idle_periods = UINT_MAX;
100 }
101
102 /* Check for frequency increase */
103 if (load > dbs_data->up_threshold) {
104 dbs_info->down_skip = 0;
105
106 /* if we are already at full speed then break out early */
107 if (requested_freq == policy->max)
108 goto out;
109
110 requested_freq += freq_step;
111 if (requested_freq > policy->max)
112 requested_freq = policy->max;
113
114 __cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_H);
115 dbs_info->requested_freq = requested_freq;
116 goto out;
117 }
118
119 /* if sampling_down_factor is active break out early */
120 if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
121 goto out;
122 dbs_info->down_skip = 0;
123
124 /* Check for frequency decrease */
125 if (load < cs_tuners->down_threshold) {
126 /*
127 * if we cannot reduce the frequency anymore, break out early
128 */
129 if (requested_freq == policy->min)
130 goto out;
131
132 if (requested_freq > freq_step)
133 requested_freq -= freq_step;
134 else
135 requested_freq = policy->min;
136
137 __cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_L);
138 dbs_info->requested_freq = requested_freq;
139 }
140
141 out:
142 return dbs_data->sampling_rate;
143}
144
145/************************** sysfs interface ************************/
146
147static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set,
148 const char *buf, size_t count)
149{
150 struct dbs_data *dbs_data = to_dbs_data(attr_set);
151 unsigned int input;
152 int ret;
153 ret = sscanf(buf, "%u", &input);
154
155 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
156 return -EINVAL;
157
158 dbs_data->sampling_down_factor = input;
159 return count;
160}
161
162static ssize_t store_up_threshold(struct gov_attr_set *attr_set,
163 const char *buf, size_t count)
164{
165 struct dbs_data *dbs_data = to_dbs_data(attr_set);
166 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
167 unsigned int input;
168 int ret;
169 ret = sscanf(buf, "%u", &input);
170
171 if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
172 return -EINVAL;
173
174 dbs_data->up_threshold = input;
175 return count;
176}
177
178static ssize_t store_down_threshold(struct gov_attr_set *attr_set,
179 const char *buf, size_t count)
180{
181 struct dbs_data *dbs_data = to_dbs_data(attr_set);
182 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
183 unsigned int input;
184 int ret;
185 ret = sscanf(buf, "%u", &input);
186
187 /* cannot be lower than 1 otherwise freq will not fall */
188 if (ret != 1 || input < 1 || input > 100 ||
189 input >= dbs_data->up_threshold)
190 return -EINVAL;
191
192 cs_tuners->down_threshold = input;
193 return count;
194}
195
196static ssize_t store_ignore_nice_load(struct gov_attr_set *attr_set,
197 const char *buf, size_t count)
198{
199 struct dbs_data *dbs_data = to_dbs_data(attr_set);
200 unsigned int input;
201 int ret;
202
203 ret = sscanf(buf, "%u", &input);
204 if (ret != 1)
205 return -EINVAL;
206
207 if (input > 1)
208 input = 1;
209
210 if (input == dbs_data->ignore_nice_load) /* nothing to do */
211 return count;
212
213 dbs_data->ignore_nice_load = input;
214
215 /* we need to re-evaluate prev_cpu_idle */
216 gov_update_cpu_data(dbs_data);
217
218 return count;
219}
220
221static ssize_t store_freq_step(struct gov_attr_set *attr_set, const char *buf,
222 size_t count)
223{
224 struct dbs_data *dbs_data = to_dbs_data(attr_set);
225 struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
226 unsigned int input;
227 int ret;
228 ret = sscanf(buf, "%u", &input);
229
230 if (ret != 1)
231 return -EINVAL;
232
233 if (input > 100)
234 input = 100;
235
236 /*
237 * no need to test here if freq_step is zero as the user might actually
238 * want this, they would be crazy though :)
239 */
240 cs_tuners->freq_step = input;
241 return count;
242}
243
244gov_show_one_common(sampling_rate);
245gov_show_one_common(sampling_down_factor);
246gov_show_one_common(up_threshold);
247gov_show_one_common(ignore_nice_load);
248gov_show_one(cs, down_threshold);
249gov_show_one(cs, freq_step);
250
251gov_attr_rw(sampling_rate);
252gov_attr_rw(sampling_down_factor);
253gov_attr_rw(up_threshold);
254gov_attr_rw(ignore_nice_load);
255gov_attr_rw(down_threshold);
256gov_attr_rw(freq_step);
257
258static struct attribute *cs_attributes[] = {
259 &sampling_rate.attr,
260 &sampling_down_factor.attr,
261 &up_threshold.attr,
262 &down_threshold.attr,
263 &ignore_nice_load.attr,
264 &freq_step.attr,
265 NULL
266};
267
268/************************** sysfs end ************************/
269
270static struct policy_dbs_info *cs_alloc(void)
271{
272 struct cs_policy_dbs_info *dbs_info;
273
274 dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
275 return dbs_info ? &dbs_info->policy_dbs : NULL;
276}
277
278static void cs_free(struct policy_dbs_info *policy_dbs)
279{
280 kfree(to_dbs_info(policy_dbs));
281}
282
283static int cs_init(struct dbs_data *dbs_data)
284{
285 struct cs_dbs_tuners *tuners;
286
287 tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
288 if (!tuners)
289 return -ENOMEM;
290
291 tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
292 tuners->freq_step = DEF_FREQUENCY_STEP;
293 dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
294 dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
295 dbs_data->ignore_nice_load = 0;
296 dbs_data->tuners = tuners;
297
298 return 0;
299}
300
301static void cs_exit(struct dbs_data *dbs_data)
302{
303 kfree(dbs_data->tuners);
304}
305
306static void cs_start(struct cpufreq_policy *policy)
307{
308 struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
309
310 dbs_info->down_skip = 0;
311 dbs_info->requested_freq = policy->cur;
312}
313
314static struct dbs_governor cs_governor = {
315 .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
316 .kobj_type = { .default_attrs = cs_attributes },
317 .gov_dbs_update = cs_dbs_update,
318 .alloc = cs_alloc,
319 .free = cs_free,
320 .init = cs_init,
321 .exit = cs_exit,
322 .start = cs_start,
323};
324
325#define CPU_FREQ_GOV_CONSERVATIVE (cs_governor.gov)
326
327MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
328MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
329 "Low Latency Frequency Transition capable processors "
330 "optimised for use in a battery environment");
331MODULE_LICENSE("GPL");
332
333#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
334struct cpufreq_governor *cpufreq_default_governor(void)
335{
336 return &CPU_FREQ_GOV_CONSERVATIVE;
337}
338#endif
339
340cpufreq_governor_init(CPU_FREQ_GOV_CONSERVATIVE);
341cpufreq_governor_exit(CPU_FREQ_GOV_CONSERVATIVE);