Commit | Line | Data |
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b9170836 DJ |
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> | |
11a80a9c | 7 | * (C) 2009 Alexander Clouter <alex@digriz.org.uk> |
b9170836 DJ |
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 | ||
b9170836 | 14 | #include <linux/cpufreq.h> |
4471a34f VK |
15 | #include <linux/init.h> |
16 | #include <linux/kernel.h> | |
b9170836 | 17 | #include <linux/kernel_stat.h> |
4471a34f VK |
18 | #include <linux/kobject.h> |
19 | #include <linux/module.h> | |
3fc54d37 | 20 | #include <linux/mutex.h> |
4471a34f VK |
21 | #include <linux/notifier.h> |
22 | #include <linux/percpu-defs.h> | |
4d5dcc42 | 23 | #include <linux/slab.h> |
4471a34f VK |
24 | #include <linux/sysfs.h> |
25 | #include <linux/types.h> | |
8e677ce8 | 26 | |
4471a34f | 27 | #include "cpufreq_governor.h" |
b9170836 | 28 | |
c88883cd | 29 | /* Conservative governor macros */ |
b9170836 | 30 | #define DEF_FREQUENCY_UP_THRESHOLD (80) |
b9170836 | 31 | #define DEF_FREQUENCY_DOWN_THRESHOLD (20) |
98765847 | 32 | #define DEF_FREQUENCY_STEP (5) |
2c906b31 AC |
33 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
34 | #define MAX_SAMPLING_DOWN_FACTOR (10) | |
b9170836 | 35 | |
4471a34f | 36 | static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info); |
b9170836 | 37 | |
98765847 SK |
38 | static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners, |
39 | struct cpufreq_policy *policy) | |
40 | { | |
41 | unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100; | |
42 | ||
43 | /* max freq cannot be less than 100. But who knows... */ | |
44 | if (unlikely(freq_target == 0)) | |
45 | freq_target = DEF_FREQUENCY_STEP; | |
46 | ||
47 | return freq_target; | |
48 | } | |
49 | ||
4471a34f VK |
50 | /* |
51 | * Every sampling_rate, we check, if current idle time is less than 20% | |
7af1c056 SK |
52 | * (default), then we try to increase frequency. Every sampling_rate * |
53 | * sampling_down_factor, we check, if current idle time is more than 80% | |
54 | * (default), then we try to decrease frequency | |
4471a34f VK |
55 | * |
56 | * Any frequency increase takes it to the maximum frequency. Frequency reduction | |
57 | * happens at minimum steps of 5% (default) of maximum frequency | |
58 | */ | |
59 | static void cs_check_cpu(int cpu, unsigned int load) | |
a8d7c3bc | 60 | { |
4471a34f VK |
61 | struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu); |
62 | struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy; | |
4d5dcc42 VK |
63 | struct dbs_data *dbs_data = policy->governor_data; |
64 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; | |
4471a34f VK |
65 | |
66 | /* | |
67 | * break out if we 'cannot' reduce the speed as the user might | |
68 | * want freq_step to be zero | |
69 | */ | |
4d5dcc42 | 70 | if (cs_tuners->freq_step == 0) |
4471a34f VK |
71 | return; |
72 | ||
73 | /* Check for frequency increase */ | |
4d5dcc42 | 74 | if (load > cs_tuners->up_threshold) { |
4471a34f VK |
75 | dbs_info->down_skip = 0; |
76 | ||
77 | /* if we are already at full speed then break out early */ | |
78 | if (dbs_info->requested_freq == policy->max) | |
79 | return; | |
80 | ||
98765847 | 81 | dbs_info->requested_freq += get_freq_target(cs_tuners, policy); |
4471a34f VK |
82 | if (dbs_info->requested_freq > policy->max) |
83 | dbs_info->requested_freq = policy->max; | |
a8d7c3bc | 84 | |
4471a34f VK |
85 | __cpufreq_driver_target(policy, dbs_info->requested_freq, |
86 | CPUFREQ_RELATION_H); | |
87 | return; | |
88 | } | |
89 | ||
7af1c056 SK |
90 | /* if sampling_down_factor is active break out early */ |
91 | if (++dbs_info->down_skip < cs_tuners->sampling_down_factor) | |
92 | return; | |
93 | dbs_info->down_skip = 0; | |
94 | ||
27ed3cd2 SK |
95 | /* Check for frequency decrease */ |
96 | if (load < cs_tuners->down_threshold) { | |
4471a34f VK |
97 | /* |
98 | * if we cannot reduce the frequency anymore, break out early | |
99 | */ | |
100 | if (policy->cur == policy->min) | |
101 | return; | |
102 | ||
98765847 | 103 | dbs_info->requested_freq -= get_freq_target(cs_tuners, policy); |
ad529a9c NK |
104 | if (dbs_info->requested_freq < policy->min) |
105 | dbs_info->requested_freq = policy->min; | |
106 | ||
4471a34f | 107 | __cpufreq_driver_target(policy, dbs_info->requested_freq, |
fed573d5 | 108 | CPUFREQ_RELATION_L); |
4471a34f VK |
109 | return; |
110 | } | |
111 | } | |
112 | ||
4447266b | 113 | static void cs_dbs_timer(struct work_struct *work) |
4471a34f | 114 | { |
4447266b VK |
115 | struct cs_cpu_dbs_info_s *dbs_info = container_of(work, |
116 | struct cs_cpu_dbs_info_s, cdbs.work.work); | |
09dca5ae | 117 | unsigned int cpu = dbs_info->cdbs.cur_policy->cpu; |
4447266b VK |
118 | struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info, |
119 | cpu); | |
4d5dcc42 VK |
120 | struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data; |
121 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; | |
122 | int delay = delay_for_sampling_rate(cs_tuners->sampling_rate); | |
031299b3 | 123 | bool modify_all = true; |
4471a34f | 124 | |
4447266b | 125 | mutex_lock(&core_dbs_info->cdbs.timer_mutex); |
031299b3 VK |
126 | if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate)) |
127 | modify_all = false; | |
128 | else | |
4d5dcc42 | 129 | dbs_check_cpu(dbs_data, cpu); |
66df2a01 | 130 | |
031299b3 | 131 | gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all); |
4447266b | 132 | mutex_unlock(&core_dbs_info->cdbs.timer_mutex); |
66df2a01 FB |
133 | } |
134 | ||
4471a34f VK |
135 | static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, |
136 | void *data) | |
137 | { | |
138 | struct cpufreq_freqs *freq = data; | |
139 | struct cs_cpu_dbs_info_s *dbs_info = | |
140 | &per_cpu(cs_cpu_dbs_info, freq->cpu); | |
f407a08b AC |
141 | struct cpufreq_policy *policy; |
142 | ||
4471a34f | 143 | if (!dbs_info->enable) |
a8d7c3bc EO |
144 | return 0; |
145 | ||
4471a34f | 146 | policy = dbs_info->cdbs.cur_policy; |
f407a08b AC |
147 | |
148 | /* | |
4471a34f | 149 | * we only care if our internally tracked freq moves outside the 'valid' |
c88883cd | 150 | * ranges of frequency available to us otherwise we do not change it |
f407a08b | 151 | */ |
4471a34f VK |
152 | if (dbs_info->requested_freq > policy->max |
153 | || dbs_info->requested_freq < policy->min) | |
154 | dbs_info->requested_freq = freq->new; | |
a8d7c3bc EO |
155 | |
156 | return 0; | |
157 | } | |
158 | ||
b9170836 | 159 | /************************** sysfs interface ************************/ |
4d5dcc42 | 160 | static struct common_dbs_data cs_dbs_cdata; |
b9170836 | 161 | |
4d5dcc42 VK |
162 | static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data, |
163 | const char *buf, size_t count) | |
b9170836 | 164 | { |
4d5dcc42 | 165 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
b9170836 DJ |
166 | unsigned int input; |
167 | int ret; | |
9acef487 | 168 | ret = sscanf(buf, "%u", &input); |
8e677ce8 | 169 | |
2c906b31 | 170 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
b9170836 DJ |
171 | return -EINVAL; |
172 | ||
4d5dcc42 | 173 | cs_tuners->sampling_down_factor = input; |
b9170836 DJ |
174 | return count; |
175 | } | |
176 | ||
4d5dcc42 VK |
177 | static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf, |
178 | size_t count) | |
b9170836 | 179 | { |
4d5dcc42 | 180 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
b9170836 DJ |
181 | unsigned int input; |
182 | int ret; | |
9acef487 | 183 | ret = sscanf(buf, "%u", &input); |
b9170836 | 184 | |
8e677ce8 | 185 | if (ret != 1) |
b9170836 | 186 | return -EINVAL; |
8e677ce8 | 187 | |
4d5dcc42 | 188 | cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate); |
b9170836 DJ |
189 | return count; |
190 | } | |
191 | ||
4d5dcc42 VK |
192 | static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf, |
193 | size_t count) | |
b9170836 | 194 | { |
4d5dcc42 | 195 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
b9170836 DJ |
196 | unsigned int input; |
197 | int ret; | |
9acef487 | 198 | ret = sscanf(buf, "%u", &input); |
b9170836 | 199 | |
4d5dcc42 | 200 | if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold) |
b9170836 | 201 | return -EINVAL; |
b9170836 | 202 | |
4d5dcc42 | 203 | cs_tuners->up_threshold = input; |
b9170836 DJ |
204 | return count; |
205 | } | |
206 | ||
4d5dcc42 VK |
207 | static ssize_t store_down_threshold(struct dbs_data *dbs_data, const char *buf, |
208 | size_t count) | |
b9170836 | 209 | { |
4d5dcc42 | 210 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
b9170836 DJ |
211 | unsigned int input; |
212 | int ret; | |
9acef487 | 213 | ret = sscanf(buf, "%u", &input); |
b9170836 | 214 | |
8e677ce8 AC |
215 | /* cannot be lower than 11 otherwise freq will not fall */ |
216 | if (ret != 1 || input < 11 || input > 100 || | |
4d5dcc42 | 217 | input >= cs_tuners->up_threshold) |
b9170836 | 218 | return -EINVAL; |
b9170836 | 219 | |
4d5dcc42 | 220 | cs_tuners->down_threshold = input; |
b9170836 DJ |
221 | return count; |
222 | } | |
223 | ||
4d5dcc42 VK |
224 | static ssize_t store_ignore_nice(struct dbs_data *dbs_data, const char *buf, |
225 | size_t count) | |
b9170836 | 226 | { |
4d5dcc42 | 227 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
4471a34f | 228 | unsigned int input, j; |
b9170836 DJ |
229 | int ret; |
230 | ||
18a7247d DJ |
231 | ret = sscanf(buf, "%u", &input); |
232 | if (ret != 1) | |
b9170836 DJ |
233 | return -EINVAL; |
234 | ||
18a7247d | 235 | if (input > 1) |
b9170836 | 236 | input = 1; |
18a7247d | 237 | |
4d5dcc42 | 238 | if (input == cs_tuners->ignore_nice) /* nothing to do */ |
b9170836 | 239 | return count; |
326c86de | 240 | |
4d5dcc42 | 241 | cs_tuners->ignore_nice = input; |
b9170836 | 242 | |
8e677ce8 | 243 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 244 | for_each_online_cpu(j) { |
4471a34f | 245 | struct cs_cpu_dbs_info_s *dbs_info; |
245b2e70 | 246 | dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
4471a34f | 247 | dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, |
9366d840 | 248 | &dbs_info->cdbs.prev_cpu_wall, 0); |
4d5dcc42 | 249 | if (cs_tuners->ignore_nice) |
4471a34f VK |
250 | dbs_info->cdbs.prev_cpu_nice = |
251 | kcpustat_cpu(j).cpustat[CPUTIME_NICE]; | |
b9170836 | 252 | } |
b9170836 DJ |
253 | return count; |
254 | } | |
255 | ||
4d5dcc42 VK |
256 | static ssize_t store_freq_step(struct dbs_data *dbs_data, const char *buf, |
257 | size_t count) | |
b9170836 | 258 | { |
4d5dcc42 | 259 | struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
b9170836 DJ |
260 | unsigned int input; |
261 | int ret; | |
18a7247d | 262 | ret = sscanf(buf, "%u", &input); |
b9170836 | 263 | |
18a7247d | 264 | if (ret != 1) |
b9170836 DJ |
265 | return -EINVAL; |
266 | ||
18a7247d | 267 | if (input > 100) |
b9170836 | 268 | input = 100; |
18a7247d | 269 | |
4471a34f VK |
270 | /* |
271 | * no need to test here if freq_step is zero as the user might actually | |
272 | * want this, they would be crazy though :) | |
273 | */ | |
4d5dcc42 | 274 | cs_tuners->freq_step = input; |
b9170836 DJ |
275 | return count; |
276 | } | |
277 | ||
4d5dcc42 VK |
278 | show_store_one(cs, sampling_rate); |
279 | show_store_one(cs, sampling_down_factor); | |
280 | show_store_one(cs, up_threshold); | |
281 | show_store_one(cs, down_threshold); | |
282 | show_store_one(cs, ignore_nice); | |
283 | show_store_one(cs, freq_step); | |
284 | declare_show_sampling_rate_min(cs); | |
285 | ||
286 | gov_sys_pol_attr_rw(sampling_rate); | |
287 | gov_sys_pol_attr_rw(sampling_down_factor); | |
288 | gov_sys_pol_attr_rw(up_threshold); | |
289 | gov_sys_pol_attr_rw(down_threshold); | |
290 | gov_sys_pol_attr_rw(ignore_nice); | |
291 | gov_sys_pol_attr_rw(freq_step); | |
292 | gov_sys_pol_attr_ro(sampling_rate_min); | |
293 | ||
294 | static struct attribute *dbs_attributes_gov_sys[] = { | |
295 | &sampling_rate_min_gov_sys.attr, | |
296 | &sampling_rate_gov_sys.attr, | |
297 | &sampling_down_factor_gov_sys.attr, | |
298 | &up_threshold_gov_sys.attr, | |
299 | &down_threshold_gov_sys.attr, | |
300 | &ignore_nice_gov_sys.attr, | |
301 | &freq_step_gov_sys.attr, | |
b9170836 DJ |
302 | NULL |
303 | }; | |
304 | ||
4d5dcc42 VK |
305 | static struct attribute_group cs_attr_group_gov_sys = { |
306 | .attrs = dbs_attributes_gov_sys, | |
307 | .name = "conservative", | |
308 | }; | |
309 | ||
310 | static struct attribute *dbs_attributes_gov_pol[] = { | |
311 | &sampling_rate_min_gov_pol.attr, | |
312 | &sampling_rate_gov_pol.attr, | |
313 | &sampling_down_factor_gov_pol.attr, | |
314 | &up_threshold_gov_pol.attr, | |
315 | &down_threshold_gov_pol.attr, | |
316 | &ignore_nice_gov_pol.attr, | |
317 | &freq_step_gov_pol.attr, | |
318 | NULL | |
319 | }; | |
320 | ||
321 | static struct attribute_group cs_attr_group_gov_pol = { | |
322 | .attrs = dbs_attributes_gov_pol, | |
b9170836 DJ |
323 | .name = "conservative", |
324 | }; | |
325 | ||
326 | /************************** sysfs end ************************/ | |
327 | ||
4d5dcc42 VK |
328 | static int cs_init(struct dbs_data *dbs_data) |
329 | { | |
330 | struct cs_dbs_tuners *tuners; | |
331 | ||
332 | tuners = kzalloc(sizeof(struct cs_dbs_tuners), GFP_KERNEL); | |
333 | if (!tuners) { | |
334 | pr_err("%s: kzalloc failed\n", __func__); | |
335 | return -ENOMEM; | |
336 | } | |
337 | ||
338 | tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD; | |
339 | tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD; | |
340 | tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; | |
341 | tuners->ignore_nice = 0; | |
98765847 | 342 | tuners->freq_step = DEF_FREQUENCY_STEP; |
4d5dcc42 VK |
343 | |
344 | dbs_data->tuners = tuners; | |
345 | dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO * | |
346 | jiffies_to_usecs(10); | |
347 | mutex_init(&dbs_data->mutex); | |
348 | return 0; | |
349 | } | |
350 | ||
351 | static void cs_exit(struct dbs_data *dbs_data) | |
352 | { | |
353 | kfree(dbs_data->tuners); | |
354 | } | |
355 | ||
4471a34f | 356 | define_get_cpu_dbs_routines(cs_cpu_dbs_info); |
8e677ce8 | 357 | |
4471a34f VK |
358 | static struct notifier_block cs_cpufreq_notifier_block = { |
359 | .notifier_call = dbs_cpufreq_notifier, | |
360 | }; | |
8e677ce8 | 361 | |
4471a34f VK |
362 | static struct cs_ops cs_ops = { |
363 | .notifier_block = &cs_cpufreq_notifier_block, | |
364 | }; | |
b9170836 | 365 | |
4d5dcc42 | 366 | static struct common_dbs_data cs_dbs_cdata = { |
4471a34f | 367 | .governor = GOV_CONSERVATIVE, |
4d5dcc42 VK |
368 | .attr_group_gov_sys = &cs_attr_group_gov_sys, |
369 | .attr_group_gov_pol = &cs_attr_group_gov_pol, | |
4471a34f VK |
370 | .get_cpu_cdbs = get_cpu_cdbs, |
371 | .get_cpu_dbs_info_s = get_cpu_dbs_info_s, | |
372 | .gov_dbs_timer = cs_dbs_timer, | |
373 | .gov_check_cpu = cs_check_cpu, | |
374 | .gov_ops = &cs_ops, | |
4d5dcc42 VK |
375 | .init = cs_init, |
376 | .exit = cs_exit, | |
4471a34f | 377 | }; |
b9170836 | 378 | |
4471a34f | 379 | static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy, |
b9170836 DJ |
380 | unsigned int event) |
381 | { | |
4d5dcc42 | 382 | return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event); |
b9170836 DJ |
383 | } |
384 | ||
c4d14bc0 SW |
385 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
386 | static | |
387 | #endif | |
1c256245 TR |
388 | struct cpufreq_governor cpufreq_gov_conservative = { |
389 | .name = "conservative", | |
4471a34f | 390 | .governor = cs_cpufreq_governor_dbs, |
1c256245 TR |
391 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, |
392 | .owner = THIS_MODULE, | |
b9170836 DJ |
393 | }; |
394 | ||
395 | static int __init cpufreq_gov_dbs_init(void) | |
396 | { | |
57df5573 | 397 | return cpufreq_register_governor(&cpufreq_gov_conservative); |
b9170836 DJ |
398 | } |
399 | ||
400 | static void __exit cpufreq_gov_dbs_exit(void) | |
401 | { | |
1c256245 | 402 | cpufreq_unregister_governor(&cpufreq_gov_conservative); |
b9170836 DJ |
403 | } |
404 | ||
11a80a9c | 405 | MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>"); |
9acef487 | 406 | MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for " |
b9170836 DJ |
407 | "Low Latency Frequency Transition capable processors " |
408 | "optimised for use in a battery environment"); | |
9acef487 | 409 | MODULE_LICENSE("GPL"); |
b9170836 | 410 | |
6915719b JW |
411 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
412 | fs_initcall(cpufreq_gov_dbs_init); | |
413 | #else | |
b9170836 | 414 | module_init(cpufreq_gov_dbs_init); |
6915719b | 415 | #endif |
b9170836 | 416 | module_exit(cpufreq_gov_dbs_exit); |