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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 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
b9170836 | 16 | #include <linux/init.h> |
b9170836 | 17 | #include <linux/cpufreq.h> |
138a0128 | 18 | #include <linux/cpu.h> |
b9170836 DJ |
19 | #include <linux/jiffies.h> |
20 | #include <linux/kernel_stat.h> | |
3fc54d37 | 21 | #include <linux/mutex.h> |
8e677ce8 AC |
22 | #include <linux/hrtimer.h> |
23 | #include <linux/tick.h> | |
24 | #include <linux/ktime.h> | |
25 | #include <linux/sched.h> | |
26 | ||
b9170836 DJ |
27 | /* |
28 | * dbs is used in this file as a shortform for demandbased switching | |
29 | * It helps to keep variable names smaller, simpler | |
30 | */ | |
31 | ||
32 | #define DEF_FREQUENCY_UP_THRESHOLD (80) | |
b9170836 | 33 | #define DEF_FREQUENCY_DOWN_THRESHOLD (20) |
b9170836 | 34 | |
18a7247d DJ |
35 | /* |
36 | * The polling frequency of this governor depends on the capability of | |
b9170836 | 37 | * the processor. Default polling frequency is 1000 times the transition |
18a7247d DJ |
38 | * latency of the processor. The governor will work on any processor with |
39 | * transition latency <= 10mS, using appropriate sampling | |
b9170836 | 40 | * rate. |
8e677ce8 AC |
41 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) |
42 | * this governor will not work. | |
b9170836 DJ |
43 | * All times here are in uS. |
44 | */ | |
2c906b31 | 45 | #define MIN_SAMPLING_RATE_RATIO (2) |
112124ab | 46 | |
cef9615a TR |
47 | static unsigned int min_sampling_rate; |
48 | ||
112124ab | 49 | #define LATENCY_MULTIPLIER (1000) |
cef9615a | 50 | #define MIN_LATENCY_MULTIPLIER (100) |
2c906b31 AC |
51 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
52 | #define MAX_SAMPLING_DOWN_FACTOR (10) | |
1c256245 | 53 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
b9170836 | 54 | |
c4028958 | 55 | static void do_dbs_timer(struct work_struct *work); |
b9170836 DJ |
56 | |
57 | struct cpu_dbs_info_s { | |
8e677ce8 AC |
58 | cputime64_t prev_cpu_idle; |
59 | cputime64_t prev_cpu_wall; | |
60 | cputime64_t prev_cpu_nice; | |
18a7247d | 61 | struct cpufreq_policy *cur_policy; |
8e677ce8 | 62 | struct delayed_work work; |
18a7247d DJ |
63 | unsigned int down_skip; |
64 | unsigned int requested_freq; | |
8e677ce8 AC |
65 | int cpu; |
66 | unsigned int enable:1; | |
ee88415c | 67 | /* |
68 | * percpu mutex that serializes governor limit change with | |
69 | * do_dbs_timer invocation. We do not want do_dbs_timer to run | |
70 | * when user is changing the governor or limits. | |
71 | */ | |
72 | struct mutex timer_mutex; | |
b9170836 | 73 | }; |
245b2e70 | 74 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info); |
b9170836 DJ |
75 | |
76 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
77 | ||
4ec223d0 | 78 | /* |
7d26e2d5 | 79 | * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on |
ee88415c | 80 | * different CPUs. It protects dbs_enable in governor start/stop. |
4ec223d0 | 81 | */ |
9acef487 | 82 | static DEFINE_MUTEX(dbs_mutex); |
b9170836 | 83 | |
8e677ce8 | 84 | static struct dbs_tuners { |
18a7247d DJ |
85 | unsigned int sampling_rate; |
86 | unsigned int sampling_down_factor; | |
87 | unsigned int up_threshold; | |
88 | unsigned int down_threshold; | |
89 | unsigned int ignore_nice; | |
90 | unsigned int freq_step; | |
8e677ce8 | 91 | } dbs_tuners_ins = { |
18a7247d DJ |
92 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
93 | .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD, | |
94 | .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, | |
95 | .ignore_nice = 0, | |
96 | .freq_step = 5, | |
b9170836 DJ |
97 | }; |
98 | ||
8e677ce8 AC |
99 | static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu, |
100 | cputime64_t *wall) | |
dac1c1a5 | 101 | { |
8e677ce8 AC |
102 | cputime64_t idle_time; |
103 | cputime64_t cur_wall_time; | |
104 | cputime64_t busy_time; | |
105 | ||
106 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
107 | busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user, | |
108 | kstat_cpu(cpu).cpustat.system); | |
e08f5f5b | 109 | |
8e677ce8 AC |
110 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq); |
111 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq); | |
112 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal); | |
113 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice); | |
e08f5f5b | 114 | |
8e677ce8 AC |
115 | idle_time = cputime64_sub(cur_wall_time, busy_time); |
116 | if (wall) | |
54c9a35d | 117 | *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time); |
e08f5f5b | 118 | |
2feb690c | 119 | return (cputime64_t)jiffies_to_usecs(idle_time); |
8e677ce8 AC |
120 | } |
121 | ||
122 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) | |
123 | { | |
124 | u64 idle_time = get_cpu_idle_time_us(cpu, wall); | |
125 | ||
126 | if (idle_time == -1ULL) | |
127 | return get_cpu_idle_time_jiffy(cpu, wall); | |
128 | ||
129 | return idle_time; | |
dac1c1a5 DJ |
130 | } |
131 | ||
a8d7c3bc EO |
132 | /* keep track of frequency transitions */ |
133 | static int | |
134 | dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, | |
135 | void *data) | |
136 | { | |
137 | struct cpufreq_freqs *freq = data; | |
245b2e70 | 138 | struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info, |
a8d7c3bc EO |
139 | freq->cpu); |
140 | ||
f407a08b AC |
141 | struct cpufreq_policy *policy; |
142 | ||
a8d7c3bc EO |
143 | if (!this_dbs_info->enable) |
144 | return 0; | |
145 | ||
f407a08b AC |
146 | policy = this_dbs_info->cur_policy; |
147 | ||
148 | /* | |
149 | * we only care if our internally tracked freq moves outside | |
150 | * the 'valid' ranges of freqency available to us otherwise | |
151 | * we do not change it | |
152 | */ | |
153 | if (this_dbs_info->requested_freq > policy->max | |
154 | || this_dbs_info->requested_freq < policy->min) | |
155 | this_dbs_info->requested_freq = freq->new; | |
a8d7c3bc EO |
156 | |
157 | return 0; | |
158 | } | |
159 | ||
160 | static struct notifier_block dbs_cpufreq_notifier_block = { | |
161 | .notifier_call = dbs_cpufreq_notifier | |
162 | }; | |
163 | ||
b9170836 | 164 | /************************** sysfs interface ************************/ |
49b015ce TR |
165 | static ssize_t show_sampling_rate_min(struct kobject *kobj, |
166 | struct attribute *attr, char *buf) | |
b9170836 | 167 | { |
cef9615a | 168 | return sprintf(buf, "%u\n", min_sampling_rate); |
b9170836 DJ |
169 | } |
170 | ||
6dad2a29 | 171 | define_one_global_ro(sampling_rate_min); |
b9170836 DJ |
172 | |
173 | /* cpufreq_conservative Governor Tunables */ | |
174 | #define show_one(file_name, object) \ | |
175 | static ssize_t show_##file_name \ | |
49b015ce | 176 | (struct kobject *kobj, struct attribute *attr, char *buf) \ |
b9170836 DJ |
177 | { \ |
178 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
179 | } | |
180 | show_one(sampling_rate, sampling_rate); | |
181 | show_one(sampling_down_factor, sampling_down_factor); | |
182 | show_one(up_threshold, up_threshold); | |
183 | show_one(down_threshold, down_threshold); | |
001893cd | 184 | show_one(ignore_nice_load, ignore_nice); |
b9170836 DJ |
185 | show_one(freq_step, freq_step); |
186 | ||
49b015ce TR |
187 | static ssize_t store_sampling_down_factor(struct kobject *a, |
188 | struct attribute *b, | |
189 | const char *buf, size_t count) | |
b9170836 DJ |
190 | { |
191 | unsigned int input; | |
192 | int ret; | |
9acef487 | 193 | ret = sscanf(buf, "%u", &input); |
8e677ce8 | 194 | |
2c906b31 | 195 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
b9170836 DJ |
196 | return -EINVAL; |
197 | ||
3fc54d37 | 198 | mutex_lock(&dbs_mutex); |
b9170836 | 199 | dbs_tuners_ins.sampling_down_factor = input; |
3fc54d37 | 200 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
201 | |
202 | return count; | |
203 | } | |
204 | ||
49b015ce TR |
205 | static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, |
206 | const char *buf, size_t count) | |
b9170836 DJ |
207 | { |
208 | unsigned int input; | |
209 | int ret; | |
9acef487 | 210 | ret = sscanf(buf, "%u", &input); |
b9170836 | 211 | |
8e677ce8 | 212 | if (ret != 1) |
b9170836 | 213 | return -EINVAL; |
8e677ce8 AC |
214 | |
215 | mutex_lock(&dbs_mutex); | |
cef9615a | 216 | dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); |
3fc54d37 | 217 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
218 | |
219 | return count; | |
220 | } | |
221 | ||
49b015ce TR |
222 | static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, |
223 | const char *buf, size_t count) | |
b9170836 DJ |
224 | { |
225 | unsigned int input; | |
226 | int ret; | |
9acef487 | 227 | ret = sscanf(buf, "%u", &input); |
b9170836 | 228 | |
3fc54d37 | 229 | mutex_lock(&dbs_mutex); |
9acef487 | 230 | if (ret != 1 || input > 100 || |
8e677ce8 | 231 | input <= dbs_tuners_ins.down_threshold) { |
3fc54d37 | 232 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
233 | return -EINVAL; |
234 | } | |
235 | ||
236 | dbs_tuners_ins.up_threshold = input; | |
3fc54d37 | 237 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
238 | |
239 | return count; | |
240 | } | |
241 | ||
49b015ce TR |
242 | static ssize_t store_down_threshold(struct kobject *a, struct attribute *b, |
243 | const char *buf, size_t count) | |
b9170836 DJ |
244 | { |
245 | unsigned int input; | |
246 | int ret; | |
9acef487 | 247 | ret = sscanf(buf, "%u", &input); |
b9170836 | 248 | |
3fc54d37 | 249 | mutex_lock(&dbs_mutex); |
8e677ce8 AC |
250 | /* cannot be lower than 11 otherwise freq will not fall */ |
251 | if (ret != 1 || input < 11 || input > 100 || | |
252 | input >= dbs_tuners_ins.up_threshold) { | |
3fc54d37 | 253 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
254 | return -EINVAL; |
255 | } | |
256 | ||
257 | dbs_tuners_ins.down_threshold = input; | |
3fc54d37 | 258 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
259 | |
260 | return count; | |
261 | } | |
262 | ||
49b015ce TR |
263 | static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b, |
264 | const char *buf, size_t count) | |
b9170836 DJ |
265 | { |
266 | unsigned int input; | |
267 | int ret; | |
268 | ||
269 | unsigned int j; | |
18a7247d DJ |
270 | |
271 | ret = sscanf(buf, "%u", &input); | |
272 | if (ret != 1) | |
b9170836 DJ |
273 | return -EINVAL; |
274 | ||
18a7247d | 275 | if (input > 1) |
b9170836 | 276 | input = 1; |
18a7247d | 277 | |
3fc54d37 | 278 | mutex_lock(&dbs_mutex); |
18a7247d | 279 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
3fc54d37 | 280 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
281 | return count; |
282 | } | |
283 | dbs_tuners_ins.ignore_nice = input; | |
284 | ||
8e677ce8 | 285 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 286 | for_each_online_cpu(j) { |
8e677ce8 | 287 | struct cpu_dbs_info_s *dbs_info; |
245b2e70 | 288 | dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
289 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
290 | &dbs_info->prev_cpu_wall); | |
291 | if (dbs_tuners_ins.ignore_nice) | |
292 | dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
b9170836 | 293 | } |
3fc54d37 | 294 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
295 | |
296 | return count; | |
297 | } | |
298 | ||
49b015ce TR |
299 | static ssize_t store_freq_step(struct kobject *a, struct attribute *b, |
300 | const char *buf, size_t count) | |
b9170836 DJ |
301 | { |
302 | unsigned int input; | |
303 | int ret; | |
18a7247d | 304 | ret = sscanf(buf, "%u", &input); |
b9170836 | 305 | |
18a7247d | 306 | if (ret != 1) |
b9170836 DJ |
307 | return -EINVAL; |
308 | ||
18a7247d | 309 | if (input > 100) |
b9170836 | 310 | input = 100; |
18a7247d | 311 | |
b9170836 DJ |
312 | /* no need to test here if freq_step is zero as the user might actually |
313 | * want this, they would be crazy though :) */ | |
3fc54d37 | 314 | mutex_lock(&dbs_mutex); |
b9170836 | 315 | dbs_tuners_ins.freq_step = input; |
3fc54d37 | 316 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
317 | |
318 | return count; | |
319 | } | |
320 | ||
6dad2a29 BP |
321 | define_one_global_rw(sampling_rate); |
322 | define_one_global_rw(sampling_down_factor); | |
323 | define_one_global_rw(up_threshold); | |
324 | define_one_global_rw(down_threshold); | |
325 | define_one_global_rw(ignore_nice_load); | |
326 | define_one_global_rw(freq_step); | |
b9170836 | 327 | |
9acef487 | 328 | static struct attribute *dbs_attributes[] = { |
b9170836 DJ |
329 | &sampling_rate_min.attr, |
330 | &sampling_rate.attr, | |
331 | &sampling_down_factor.attr, | |
332 | &up_threshold.attr, | |
333 | &down_threshold.attr, | |
001893cd | 334 | &ignore_nice_load.attr, |
b9170836 DJ |
335 | &freq_step.attr, |
336 | NULL | |
337 | }; | |
338 | ||
339 | static struct attribute_group dbs_attr_group = { | |
340 | .attrs = dbs_attributes, | |
341 | .name = "conservative", | |
342 | }; | |
343 | ||
344 | /************************** sysfs end ************************/ | |
345 | ||
8e677ce8 | 346 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
b9170836 | 347 | { |
8e677ce8 | 348 | unsigned int load = 0; |
fd187aaf | 349 | unsigned int max_load = 0; |
f068c04b | 350 | unsigned int freq_target; |
b9170836 | 351 | |
8e677ce8 AC |
352 | struct cpufreq_policy *policy; |
353 | unsigned int j; | |
b9170836 | 354 | |
08a28e2e AC |
355 | policy = this_dbs_info->cur_policy; |
356 | ||
18a7247d | 357 | /* |
8e677ce8 AC |
358 | * Every sampling_rate, we check, if current idle time is less |
359 | * than 20% (default), then we try to increase frequency | |
360 | * Every sampling_rate*sampling_down_factor, we check, if current | |
361 | * idle time is more than 80%, then we try to decrease frequency | |
b9170836 | 362 | * |
18a7247d DJ |
363 | * Any frequency increase takes it to the maximum frequency. |
364 | * Frequency reduction happens at minimum steps of | |
8e677ce8 | 365 | * 5% (default) of maximum frequency |
b9170836 DJ |
366 | */ |
367 | ||
8e677ce8 AC |
368 | /* Get Absolute Load */ |
369 | for_each_cpu(j, policy->cpus) { | |
370 | struct cpu_dbs_info_s *j_dbs_info; | |
371 | cputime64_t cur_wall_time, cur_idle_time; | |
372 | unsigned int idle_time, wall_time; | |
b9170836 | 373 | |
245b2e70 | 374 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
375 | |
376 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
377 | ||
378 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, | |
379 | j_dbs_info->prev_cpu_wall); | |
380 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
08a28e2e | 381 | |
8e677ce8 AC |
382 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
383 | j_dbs_info->prev_cpu_idle); | |
384 | j_dbs_info->prev_cpu_idle = cur_idle_time; | |
b9170836 | 385 | |
8e677ce8 AC |
386 | if (dbs_tuners_ins.ignore_nice) { |
387 | cputime64_t cur_nice; | |
388 | unsigned long cur_nice_jiffies; | |
389 | ||
390 | cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice, | |
391 | j_dbs_info->prev_cpu_nice); | |
392 | /* | |
393 | * Assumption: nice time between sampling periods will | |
394 | * be less than 2^32 jiffies for 32 bit sys | |
395 | */ | |
396 | cur_nice_jiffies = (unsigned long) | |
397 | cputime64_to_jiffies64(cur_nice); | |
398 | ||
399 | j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
400 | idle_time += jiffies_to_usecs(cur_nice_jiffies); | |
401 | } | |
402 | ||
403 | if (unlikely(!wall_time || wall_time < idle_time)) | |
404 | continue; | |
405 | ||
406 | load = 100 * (wall_time - idle_time) / wall_time; | |
fd187aaf DB |
407 | |
408 | if (load > max_load) | |
409 | max_load = load; | |
8e677ce8 AC |
410 | } |
411 | ||
412 | /* | |
413 | * break out if we 'cannot' reduce the speed as the user might | |
414 | * want freq_step to be zero | |
415 | */ | |
416 | if (dbs_tuners_ins.freq_step == 0) | |
417 | return; | |
b9170836 | 418 | |
8e677ce8 | 419 | /* Check for frequency increase */ |
fd187aaf | 420 | if (max_load > dbs_tuners_ins.up_threshold) { |
a159b827 | 421 | this_dbs_info->down_skip = 0; |
790d76fa | 422 | |
b9170836 | 423 | /* if we are already at full speed then break out early */ |
a159b827 | 424 | if (this_dbs_info->requested_freq == policy->max) |
b9170836 | 425 | return; |
18a7247d | 426 | |
f068c04b | 427 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 DJ |
428 | |
429 | /* max freq cannot be less than 100. But who knows.... */ | |
f068c04b DJ |
430 | if (unlikely(freq_target == 0)) |
431 | freq_target = 5; | |
18a7247d | 432 | |
f068c04b | 433 | this_dbs_info->requested_freq += freq_target; |
a159b827 AC |
434 | if (this_dbs_info->requested_freq > policy->max) |
435 | this_dbs_info->requested_freq = policy->max; | |
b9170836 | 436 | |
a159b827 | 437 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
b9170836 | 438 | CPUFREQ_RELATION_H); |
b9170836 DJ |
439 | return; |
440 | } | |
441 | ||
8e677ce8 AC |
442 | /* |
443 | * The optimal frequency is the frequency that is the lowest that | |
444 | * can support the current CPU usage without triggering the up | |
445 | * policy. To be safe, we focus 10 points under the threshold. | |
446 | */ | |
fd187aaf | 447 | if (max_load < (dbs_tuners_ins.down_threshold - 10)) { |
f068c04b | 448 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 | 449 | |
f068c04b | 450 | this_dbs_info->requested_freq -= freq_target; |
a159b827 AC |
451 | if (this_dbs_info->requested_freq < policy->min) |
452 | this_dbs_info->requested_freq = policy->min; | |
b9170836 | 453 | |
8e677ce8 AC |
454 | /* |
455 | * if we cannot reduce the frequency anymore, break out early | |
456 | */ | |
457 | if (policy->cur == policy->min) | |
458 | return; | |
459 | ||
a159b827 | 460 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
2c906b31 | 461 | CPUFREQ_RELATION_H); |
b9170836 DJ |
462 | return; |
463 | } | |
464 | } | |
465 | ||
c4028958 | 466 | static void do_dbs_timer(struct work_struct *work) |
18a7247d | 467 | { |
8e677ce8 AC |
468 | struct cpu_dbs_info_s *dbs_info = |
469 | container_of(work, struct cpu_dbs_info_s, work.work); | |
470 | unsigned int cpu = dbs_info->cpu; | |
471 | ||
472 | /* We want all CPUs to do sampling nearly on same jiffy */ | |
473 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
474 | ||
475 | delay -= jiffies % delay; | |
476 | ||
ee88415c | 477 | mutex_lock(&dbs_info->timer_mutex); |
8e677ce8 AC |
478 | |
479 | dbs_check_cpu(dbs_info); | |
480 | ||
57df5573 | 481 | schedule_delayed_work_on(cpu, &dbs_info->work, delay); |
ee88415c | 482 | mutex_unlock(&dbs_info->timer_mutex); |
18a7247d | 483 | } |
b9170836 | 484 | |
8e677ce8 | 485 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 486 | { |
8e677ce8 AC |
487 | /* We want all CPUs to do sampling nearly on same jiffy */ |
488 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
489 | delay -= jiffies % delay; | |
490 | ||
491 | dbs_info->enable = 1; | |
492 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); | |
57df5573 | 493 | schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay); |
b9170836 DJ |
494 | } |
495 | ||
8e677ce8 | 496 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 497 | { |
8e677ce8 | 498 | dbs_info->enable = 0; |
b253d2b2 | 499 | cancel_delayed_work_sync(&dbs_info->work); |
b9170836 DJ |
500 | } |
501 | ||
502 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
503 | unsigned int event) | |
504 | { | |
505 | unsigned int cpu = policy->cpu; | |
506 | struct cpu_dbs_info_s *this_dbs_info; | |
507 | unsigned int j; | |
914f7c31 | 508 | int rc; |
b9170836 | 509 | |
245b2e70 | 510 | this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu); |
b9170836 DJ |
511 | |
512 | switch (event) { | |
513 | case CPUFREQ_GOV_START: | |
18a7247d | 514 | if ((!cpu_online(cpu)) || (!policy->cur)) |
b9170836 DJ |
515 | return -EINVAL; |
516 | ||
3fc54d37 | 517 | mutex_lock(&dbs_mutex); |
914f7c31 | 518 | |
835481d9 | 519 | for_each_cpu(j, policy->cpus) { |
b9170836 | 520 | struct cpu_dbs_info_s *j_dbs_info; |
245b2e70 | 521 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
b9170836 | 522 | j_dbs_info->cur_policy = policy; |
18a7247d | 523 | |
8e677ce8 AC |
524 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
525 | &j_dbs_info->prev_cpu_wall); | |
526 | if (dbs_tuners_ins.ignore_nice) { | |
527 | j_dbs_info->prev_cpu_nice = | |
528 | kstat_cpu(j).cpustat.nice; | |
529 | } | |
b9170836 | 530 | } |
a159b827 AC |
531 | this_dbs_info->down_skip = 0; |
532 | this_dbs_info->requested_freq = policy->cur; | |
914f7c31 | 533 | |
ee88415c | 534 | mutex_init(&this_dbs_info->timer_mutex); |
b9170836 DJ |
535 | dbs_enable++; |
536 | /* | |
537 | * Start the timerschedule work, when this governor | |
538 | * is used for first time | |
539 | */ | |
540 | if (dbs_enable == 1) { | |
541 | unsigned int latency; | |
542 | /* policy latency is in nS. Convert it to uS first */ | |
2c906b31 AC |
543 | latency = policy->cpuinfo.transition_latency / 1000; |
544 | if (latency == 0) | |
545 | latency = 1; | |
b9170836 | 546 | |
49b015ce TR |
547 | rc = sysfs_create_group(cpufreq_global_kobject, |
548 | &dbs_attr_group); | |
549 | if (rc) { | |
550 | mutex_unlock(&dbs_mutex); | |
551 | return rc; | |
552 | } | |
553 | ||
cef9615a TR |
554 | /* |
555 | * conservative does not implement micro like ondemand | |
556 | * governor, thus we are bound to jiffes/HZ | |
557 | */ | |
558 | min_sampling_rate = | |
559 | MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); | |
560 | /* Bring kernel and HW constraints together */ | |
561 | min_sampling_rate = max(min_sampling_rate, | |
562 | MIN_LATENCY_MULTIPLIER * latency); | |
563 | dbs_tuners_ins.sampling_rate = | |
564 | max(min_sampling_rate, | |
565 | latency * LATENCY_MULTIPLIER); | |
b9170836 | 566 | |
a8d7c3bc EO |
567 | cpufreq_register_notifier( |
568 | &dbs_cpufreq_notifier_block, | |
569 | CPUFREQ_TRANSITION_NOTIFIER); | |
b9170836 | 570 | } |
3fc54d37 | 571 | mutex_unlock(&dbs_mutex); |
8e677ce8 | 572 | |
7d26e2d5 | 573 | dbs_timer_init(this_dbs_info); |
574 | ||
b9170836 DJ |
575 | break; |
576 | ||
577 | case CPUFREQ_GOV_STOP: | |
8e677ce8 | 578 | dbs_timer_exit(this_dbs_info); |
7d26e2d5 | 579 | |
580 | mutex_lock(&dbs_mutex); | |
b9170836 | 581 | dbs_enable--; |
ee88415c | 582 | mutex_destroy(&this_dbs_info->timer_mutex); |
8e677ce8 | 583 | |
b9170836 DJ |
584 | /* |
585 | * Stop the timerschedule work, when this governor | |
586 | * is used for first time | |
587 | */ | |
8e677ce8 | 588 | if (dbs_enable == 0) |
a8d7c3bc EO |
589 | cpufreq_unregister_notifier( |
590 | &dbs_cpufreq_notifier_block, | |
591 | CPUFREQ_TRANSITION_NOTIFIER); | |
a8d7c3bc | 592 | |
3fc54d37 | 593 | mutex_unlock(&dbs_mutex); |
49b015ce TR |
594 | if (!dbs_enable) |
595 | sysfs_remove_group(cpufreq_global_kobject, | |
596 | &dbs_attr_group); | |
b9170836 DJ |
597 | |
598 | break; | |
599 | ||
600 | case CPUFREQ_GOV_LIMITS: | |
ee88415c | 601 | mutex_lock(&this_dbs_info->timer_mutex); |
b9170836 DJ |
602 | if (policy->max < this_dbs_info->cur_policy->cur) |
603 | __cpufreq_driver_target( | |
604 | this_dbs_info->cur_policy, | |
18a7247d | 605 | policy->max, CPUFREQ_RELATION_H); |
b9170836 DJ |
606 | else if (policy->min > this_dbs_info->cur_policy->cur) |
607 | __cpufreq_driver_target( | |
608 | this_dbs_info->cur_policy, | |
18a7247d | 609 | policy->min, CPUFREQ_RELATION_L); |
ee88415c | 610 | mutex_unlock(&this_dbs_info->timer_mutex); |
8e677ce8 | 611 | |
b9170836 DJ |
612 | break; |
613 | } | |
614 | return 0; | |
615 | } | |
616 | ||
c4d14bc0 SW |
617 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
618 | static | |
619 | #endif | |
1c256245 TR |
620 | struct cpufreq_governor cpufreq_gov_conservative = { |
621 | .name = "conservative", | |
622 | .governor = cpufreq_governor_dbs, | |
623 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
624 | .owner = THIS_MODULE, | |
b9170836 DJ |
625 | }; |
626 | ||
627 | static int __init cpufreq_gov_dbs_init(void) | |
628 | { | |
57df5573 | 629 | return cpufreq_register_governor(&cpufreq_gov_conservative); |
b9170836 DJ |
630 | } |
631 | ||
632 | static void __exit cpufreq_gov_dbs_exit(void) | |
633 | { | |
1c256245 | 634 | cpufreq_unregister_governor(&cpufreq_gov_conservative); |
b9170836 DJ |
635 | } |
636 | ||
637 | ||
11a80a9c | 638 | MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>"); |
9acef487 | 639 | MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for " |
b9170836 DJ |
640 | "Low Latency Frequency Transition capable processors " |
641 | "optimised for use in a battery environment"); | |
9acef487 | 642 | MODULE_LICENSE("GPL"); |
b9170836 | 643 | |
6915719b JW |
644 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
645 | fs_initcall(cpufreq_gov_dbs_init); | |
646 | #else | |
b9170836 | 647 | module_init(cpufreq_gov_dbs_init); |
6915719b | 648 | #endif |
b9170836 | 649 | module_exit(cpufreq_gov_dbs_exit); |