Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/module.h> | |
1da177e4 | 15 | #include <linux/init.h> |
1da177e4 | 16 | #include <linux/cpufreq.h> |
138a0128 | 17 | #include <linux/cpu.h> |
1da177e4 LT |
18 | #include <linux/jiffies.h> |
19 | #include <linux/kernel_stat.h> | |
3fc54d37 | 20 | #include <linux/mutex.h> |
80800913 | 21 | #include <linux/hrtimer.h> |
22 | #include <linux/tick.h> | |
23 | #include <linux/ktime.h> | |
1da177e4 LT |
24 | |
25 | /* | |
26 | * dbs is used in this file as a shortform for demandbased switching | |
27 | * It helps to keep variable names smaller, simpler | |
28 | */ | |
29 | ||
e9d95bf7 | 30 | #define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10) |
1da177e4 | 31 | #define DEF_FREQUENCY_UP_THRESHOLD (80) |
80800913 | 32 | #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) |
33 | #define MICRO_FREQUENCY_UP_THRESHOLD (95) | |
c29f1403 | 34 | #define MIN_FREQUENCY_UP_THRESHOLD (11) |
1da177e4 LT |
35 | #define MAX_FREQUENCY_UP_THRESHOLD (100) |
36 | ||
32ee8c3e DJ |
37 | /* |
38 | * The polling frequency of this governor depends on the capability of | |
1da177e4 | 39 | * the processor. Default polling frequency is 1000 times the transition |
32ee8c3e DJ |
40 | * latency of the processor. The governor will work on any processor with |
41 | * transition latency <= 10mS, using appropriate sampling | |
1da177e4 LT |
42 | * rate. |
43 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) | |
44 | * this governor will not work. | |
45 | * All times here are in uS. | |
46 | */ | |
32ee8c3e | 47 | static unsigned int def_sampling_rate; |
df8b59be DJ |
48 | #define MIN_SAMPLING_RATE_RATIO (2) |
49 | /* for correct statistics, we need at least 10 ticks between each measure */ | |
e08f5f5b GS |
50 | #define MIN_STAT_SAMPLING_RATE \ |
51 | (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) | |
52 | #define MIN_SAMPLING_RATE \ | |
53 | (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) | |
1da177e4 LT |
54 | #define MAX_SAMPLING_RATE (500 * def_sampling_rate) |
55 | #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) | |
1c256245 | 56 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
1da177e4 | 57 | |
c4028958 DH |
58 | static void do_dbs_timer(struct work_struct *work); |
59 | ||
60 | /* Sampling types */ | |
529af7a1 | 61 | enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; |
1da177e4 LT |
62 | |
63 | struct cpu_dbs_info_s { | |
ccb2fe20 VP |
64 | cputime64_t prev_cpu_idle; |
65 | cputime64_t prev_cpu_wall; | |
80800913 | 66 | cputime64_t prev_cpu_nice; |
32ee8c3e | 67 | struct cpufreq_policy *cur_policy; |
c4028958 | 68 | struct delayed_work work; |
05ca0350 AS |
69 | struct cpufreq_frequency_table *freq_table; |
70 | unsigned int freq_lo; | |
71 | unsigned int freq_lo_jiffies; | |
72 | unsigned int freq_hi_jiffies; | |
529af7a1 VP |
73 | int cpu; |
74 | unsigned int enable:1, | |
75 | sample_type:1; | |
1da177e4 LT |
76 | }; |
77 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); | |
78 | ||
79 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
80 | ||
4ec223d0 VP |
81 | /* |
82 | * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug | |
83 | * lock and dbs_mutex. cpu_hotplug lock should always be held before | |
84 | * dbs_mutex. If any function that can potentially take cpu_hotplug lock | |
85 | * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then | |
86 | * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock | |
87 | * is recursive for the same process. -Venki | |
88 | */ | |
ffac80e9 | 89 | static DEFINE_MUTEX(dbs_mutex); |
1da177e4 | 90 | |
2f8a835c | 91 | static struct workqueue_struct *kondemand_wq; |
6810b548 | 92 | |
05ca0350 | 93 | static struct dbs_tuners { |
32ee8c3e | 94 | unsigned int sampling_rate; |
32ee8c3e | 95 | unsigned int up_threshold; |
e9d95bf7 | 96 | unsigned int down_differential; |
32ee8c3e | 97 | unsigned int ignore_nice; |
05ca0350 AS |
98 | unsigned int powersave_bias; |
99 | } dbs_tuners_ins = { | |
32ee8c3e | 100 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
e9d95bf7 | 101 | .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, |
9cbad61b | 102 | .ignore_nice = 0, |
05ca0350 | 103 | .powersave_bias = 0, |
1da177e4 LT |
104 | }; |
105 | ||
80800913 | 106 | static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu, |
107 | cputime64_t *wall) | |
dac1c1a5 | 108 | { |
ea487615 | 109 | cputime64_t idle_time; |
3430502d | 110 | cputime64_t cur_wall_time; |
ea487615 | 111 | cputime64_t busy_time; |
ccb2fe20 | 112 | |
3430502d | 113 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); |
ea487615 VP |
114 | busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user, |
115 | kstat_cpu(cpu).cpustat.system); | |
ccb2fe20 | 116 | |
ea487615 VP |
117 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq); |
118 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq); | |
119 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal); | |
ccb2fe20 | 120 | |
ea487615 VP |
121 | if (!dbs_tuners_ins.ignore_nice) { |
122 | busy_time = cputime64_add(busy_time, | |
123 | kstat_cpu(cpu).cpustat.nice); | |
124 | } | |
125 | ||
3430502d | 126 | idle_time = cputime64_sub(cur_wall_time, busy_time); |
127 | if (wall) | |
128 | *wall = cur_wall_time; | |
129 | ||
ea487615 | 130 | return idle_time; |
dac1c1a5 DJ |
131 | } |
132 | ||
80800913 | 133 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) |
134 | { | |
135 | u64 idle_time = get_cpu_idle_time_us(cpu, wall); | |
136 | ||
137 | if (idle_time == -1ULL) | |
138 | return get_cpu_idle_time_jiffy(cpu, wall); | |
139 | ||
140 | if (dbs_tuners_ins.ignore_nice) { | |
141 | cputime64_t cur_nice; | |
142 | unsigned long cur_nice_jiffies; | |
143 | struct cpu_dbs_info_s *dbs_info; | |
144 | ||
145 | dbs_info = &per_cpu(cpu_dbs_info, cpu); | |
146 | cur_nice = cputime64_sub(kstat_cpu(cpu).cpustat.nice, | |
147 | dbs_info->prev_cpu_nice); | |
148 | /* | |
149 | * Assumption: nice time between sampling periods will be | |
150 | * less than 2^32 jiffies for 32 bit sys | |
151 | */ | |
152 | cur_nice_jiffies = (unsigned long) | |
153 | cputime64_to_jiffies64(cur_nice); | |
154 | dbs_info->prev_cpu_nice = kstat_cpu(cpu).cpustat.nice; | |
155 | return idle_time + jiffies_to_usecs(cur_nice_jiffies); | |
156 | } | |
157 | return idle_time; | |
158 | } | |
159 | ||
05ca0350 AS |
160 | /* |
161 | * Find right freq to be set now with powersave_bias on. | |
162 | * Returns the freq_hi to be used right now and will set freq_hi_jiffies, | |
163 | * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. | |
164 | */ | |
b5ecf60f AB |
165 | static unsigned int powersave_bias_target(struct cpufreq_policy *policy, |
166 | unsigned int freq_next, | |
167 | unsigned int relation) | |
05ca0350 AS |
168 | { |
169 | unsigned int freq_req, freq_reduc, freq_avg; | |
170 | unsigned int freq_hi, freq_lo; | |
171 | unsigned int index = 0; | |
172 | unsigned int jiffies_total, jiffies_hi, jiffies_lo; | |
173 | struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, policy->cpu); | |
174 | ||
175 | if (!dbs_info->freq_table) { | |
176 | dbs_info->freq_lo = 0; | |
177 | dbs_info->freq_lo_jiffies = 0; | |
178 | return freq_next; | |
179 | } | |
180 | ||
181 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, | |
182 | relation, &index); | |
183 | freq_req = dbs_info->freq_table[index].frequency; | |
184 | freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000; | |
185 | freq_avg = freq_req - freq_reduc; | |
186 | ||
187 | /* Find freq bounds for freq_avg in freq_table */ | |
188 | index = 0; | |
189 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
190 | CPUFREQ_RELATION_H, &index); | |
191 | freq_lo = dbs_info->freq_table[index].frequency; | |
192 | index = 0; | |
193 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
194 | CPUFREQ_RELATION_L, &index); | |
195 | freq_hi = dbs_info->freq_table[index].frequency; | |
196 | ||
197 | /* Find out how long we have to be in hi and lo freqs */ | |
198 | if (freq_hi == freq_lo) { | |
199 | dbs_info->freq_lo = 0; | |
200 | dbs_info->freq_lo_jiffies = 0; | |
201 | return freq_lo; | |
202 | } | |
203 | jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
204 | jiffies_hi = (freq_avg - freq_lo) * jiffies_total; | |
205 | jiffies_hi += ((freq_hi - freq_lo) / 2); | |
206 | jiffies_hi /= (freq_hi - freq_lo); | |
207 | jiffies_lo = jiffies_total - jiffies_hi; | |
208 | dbs_info->freq_lo = freq_lo; | |
209 | dbs_info->freq_lo_jiffies = jiffies_lo; | |
210 | dbs_info->freq_hi_jiffies = jiffies_hi; | |
211 | return freq_hi; | |
212 | } | |
213 | ||
214 | static void ondemand_powersave_bias_init(void) | |
215 | { | |
216 | int i; | |
217 | for_each_online_cpu(i) { | |
218 | struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, i); | |
219 | dbs_info->freq_table = cpufreq_frequency_get_table(i); | |
220 | dbs_info->freq_lo = 0; | |
221 | } | |
222 | } | |
223 | ||
1da177e4 LT |
224 | /************************** sysfs interface ************************/ |
225 | static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) | |
226 | { | |
227 | return sprintf (buf, "%u\n", MAX_SAMPLING_RATE); | |
228 | } | |
229 | ||
230 | static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) | |
231 | { | |
232 | return sprintf (buf, "%u\n", MIN_SAMPLING_RATE); | |
233 | } | |
234 | ||
32ee8c3e DJ |
235 | #define define_one_ro(_name) \ |
236 | static struct freq_attr _name = \ | |
1da177e4 LT |
237 | __ATTR(_name, 0444, show_##_name, NULL) |
238 | ||
239 | define_one_ro(sampling_rate_max); | |
240 | define_one_ro(sampling_rate_min); | |
241 | ||
242 | /* cpufreq_ondemand Governor Tunables */ | |
243 | #define show_one(file_name, object) \ | |
244 | static ssize_t show_##file_name \ | |
245 | (struct cpufreq_policy *unused, char *buf) \ | |
246 | { \ | |
247 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
248 | } | |
249 | show_one(sampling_rate, sampling_rate); | |
1da177e4 | 250 | show_one(up_threshold, up_threshold); |
001893cd | 251 | show_one(ignore_nice_load, ignore_nice); |
05ca0350 | 252 | show_one(powersave_bias, powersave_bias); |
1da177e4 | 253 | |
32ee8c3e | 254 | static ssize_t store_sampling_rate(struct cpufreq_policy *unused, |
1da177e4 LT |
255 | const char *buf, size_t count) |
256 | { | |
257 | unsigned int input; | |
258 | int ret; | |
ffac80e9 | 259 | ret = sscanf(buf, "%u", &input); |
1da177e4 | 260 | |
3fc54d37 | 261 | mutex_lock(&dbs_mutex); |
e08f5f5b GS |
262 | if (ret != 1 || input > MAX_SAMPLING_RATE |
263 | || input < MIN_SAMPLING_RATE) { | |
3fc54d37 | 264 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
265 | return -EINVAL; |
266 | } | |
267 | ||
268 | dbs_tuners_ins.sampling_rate = input; | |
3fc54d37 | 269 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
270 | |
271 | return count; | |
272 | } | |
273 | ||
32ee8c3e | 274 | static ssize_t store_up_threshold(struct cpufreq_policy *unused, |
1da177e4 LT |
275 | const char *buf, size_t count) |
276 | { | |
277 | unsigned int input; | |
278 | int ret; | |
ffac80e9 | 279 | ret = sscanf(buf, "%u", &input); |
1da177e4 | 280 | |
3fc54d37 | 281 | mutex_lock(&dbs_mutex); |
32ee8c3e | 282 | if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || |
c29f1403 | 283 | input < MIN_FREQUENCY_UP_THRESHOLD) { |
3fc54d37 | 284 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
285 | return -EINVAL; |
286 | } | |
287 | ||
288 | dbs_tuners_ins.up_threshold = input; | |
3fc54d37 | 289 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
290 | |
291 | return count; | |
292 | } | |
293 | ||
001893cd | 294 | static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy, |
3d5ee9e5 DJ |
295 | const char *buf, size_t count) |
296 | { | |
297 | unsigned int input; | |
298 | int ret; | |
299 | ||
300 | unsigned int j; | |
32ee8c3e | 301 | |
ffac80e9 | 302 | ret = sscanf(buf, "%u", &input); |
3d5ee9e5 DJ |
303 | if ( ret != 1 ) |
304 | return -EINVAL; | |
305 | ||
306 | if ( input > 1 ) | |
307 | input = 1; | |
32ee8c3e | 308 | |
3fc54d37 | 309 | mutex_lock(&dbs_mutex); |
3d5ee9e5 | 310 | if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */ |
3fc54d37 | 311 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
312 | return count; |
313 | } | |
314 | dbs_tuners_ins.ignore_nice = input; | |
315 | ||
ccb2fe20 | 316 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 317 | for_each_online_cpu(j) { |
ccb2fe20 VP |
318 | struct cpu_dbs_info_s *dbs_info; |
319 | dbs_info = &per_cpu(cpu_dbs_info, j); | |
3430502d | 320 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
321 | &dbs_info->prev_cpu_wall); | |
3d5ee9e5 | 322 | } |
3fc54d37 | 323 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
324 | |
325 | return count; | |
326 | } | |
327 | ||
05ca0350 AS |
328 | static ssize_t store_powersave_bias(struct cpufreq_policy *unused, |
329 | const char *buf, size_t count) | |
330 | { | |
331 | unsigned int input; | |
332 | int ret; | |
333 | ret = sscanf(buf, "%u", &input); | |
334 | ||
335 | if (ret != 1) | |
336 | return -EINVAL; | |
337 | ||
338 | if (input > 1000) | |
339 | input = 1000; | |
340 | ||
341 | mutex_lock(&dbs_mutex); | |
342 | dbs_tuners_ins.powersave_bias = input; | |
343 | ondemand_powersave_bias_init(); | |
344 | mutex_unlock(&dbs_mutex); | |
345 | ||
346 | return count; | |
347 | } | |
348 | ||
1da177e4 LT |
349 | #define define_one_rw(_name) \ |
350 | static struct freq_attr _name = \ | |
351 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
352 | ||
353 | define_one_rw(sampling_rate); | |
1da177e4 | 354 | define_one_rw(up_threshold); |
001893cd | 355 | define_one_rw(ignore_nice_load); |
05ca0350 | 356 | define_one_rw(powersave_bias); |
1da177e4 LT |
357 | |
358 | static struct attribute * dbs_attributes[] = { | |
359 | &sampling_rate_max.attr, | |
360 | &sampling_rate_min.attr, | |
361 | &sampling_rate.attr, | |
1da177e4 | 362 | &up_threshold.attr, |
001893cd | 363 | &ignore_nice_load.attr, |
05ca0350 | 364 | &powersave_bias.attr, |
1da177e4 LT |
365 | NULL |
366 | }; | |
367 | ||
368 | static struct attribute_group dbs_attr_group = { | |
369 | .attrs = dbs_attributes, | |
370 | .name = "ondemand", | |
371 | }; | |
372 | ||
373 | /************************** sysfs end ************************/ | |
374 | ||
2f8a835c | 375 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
1da177e4 | 376 | { |
c43aa3bd | 377 | unsigned int max_load_freq; |
1da177e4 LT |
378 | |
379 | struct cpufreq_policy *policy; | |
380 | unsigned int j; | |
381 | ||
1da177e4 LT |
382 | if (!this_dbs_info->enable) |
383 | return; | |
384 | ||
05ca0350 | 385 | this_dbs_info->freq_lo = 0; |
1da177e4 | 386 | policy = this_dbs_info->cur_policy; |
ea487615 | 387 | |
32ee8c3e | 388 | /* |
c29f1403 DJ |
389 | * Every sampling_rate, we check, if current idle time is less |
390 | * than 20% (default), then we try to increase frequency | |
ccb2fe20 | 391 | * Every sampling_rate, we look for a the lowest |
c29f1403 DJ |
392 | * frequency which can sustain the load while keeping idle time over |
393 | * 30%. If such a frequency exist, we try to decrease to this frequency. | |
1da177e4 | 394 | * |
32ee8c3e DJ |
395 | * Any frequency increase takes it to the maximum frequency. |
396 | * Frequency reduction happens at minimum steps of | |
397 | * 5% (default) of current frequency | |
1da177e4 LT |
398 | */ |
399 | ||
c43aa3bd | 400 | /* Get Absolute Load - in terms of freq */ |
401 | max_load_freq = 0; | |
402 | ||
835481d9 | 403 | for_each_cpu(j, policy->cpus) { |
1da177e4 | 404 | struct cpu_dbs_info_s *j_dbs_info; |
c43aa3bd | 405 | cputime64_t cur_wall_time, cur_idle_time; |
406 | unsigned int idle_time, wall_time; | |
407 | unsigned int load, load_freq; | |
408 | int freq_avg; | |
1da177e4 | 409 | |
1da177e4 | 410 | j_dbs_info = &per_cpu(cpu_dbs_info, j); |
3430502d | 411 | |
412 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
413 | ||
c43aa3bd | 414 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, |
415 | j_dbs_info->prev_cpu_wall); | |
416 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
417 | ||
c43aa3bd | 418 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
ccb2fe20 | 419 | j_dbs_info->prev_cpu_idle); |
c43aa3bd | 420 | j_dbs_info->prev_cpu_idle = cur_idle_time; |
1da177e4 | 421 | |
3430502d | 422 | if (unlikely(!wall_time || wall_time < idle_time)) |
c43aa3bd | 423 | continue; |
c43aa3bd | 424 | |
425 | load = 100 * (wall_time - idle_time) / wall_time; | |
426 | ||
427 | freq_avg = __cpufreq_driver_getavg(policy, j); | |
428 | if (freq_avg <= 0) | |
429 | freq_avg = policy->cur; | |
430 | ||
431 | load_freq = load * freq_avg; | |
432 | if (load_freq > max_load_freq) | |
433 | max_load_freq = load_freq; | |
1da177e4 LT |
434 | } |
435 | ||
ccb2fe20 | 436 | /* Check for frequency increase */ |
c43aa3bd | 437 | if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) { |
c11420a6 | 438 | /* if we are already at full speed then break out early */ |
05ca0350 AS |
439 | if (!dbs_tuners_ins.powersave_bias) { |
440 | if (policy->cur == policy->max) | |
441 | return; | |
442 | ||
443 | __cpufreq_driver_target(policy, policy->max, | |
444 | CPUFREQ_RELATION_H); | |
445 | } else { | |
446 | int freq = powersave_bias_target(policy, policy->max, | |
447 | CPUFREQ_RELATION_H); | |
448 | __cpufreq_driver_target(policy, freq, | |
449 | CPUFREQ_RELATION_L); | |
450 | } | |
1da177e4 LT |
451 | return; |
452 | } | |
453 | ||
454 | /* Check for frequency decrease */ | |
c29f1403 DJ |
455 | /* if we cannot reduce the frequency anymore, break out early */ |
456 | if (policy->cur == policy->min) | |
457 | return; | |
1da177e4 | 458 | |
c29f1403 DJ |
459 | /* |
460 | * The optimal frequency is the frequency that is the lowest that | |
461 | * can support the current CPU usage without triggering the up | |
462 | * policy. To be safe, we focus 10 points under the threshold. | |
463 | */ | |
e9d95bf7 | 464 | if (max_load_freq < |
465 | (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) * | |
466 | policy->cur) { | |
c43aa3bd | 467 | unsigned int freq_next; |
e9d95bf7 | 468 | freq_next = max_load_freq / |
469 | (dbs_tuners_ins.up_threshold - | |
470 | dbs_tuners_ins.down_differential); | |
dfde5d62 | 471 | |
05ca0350 AS |
472 | if (!dbs_tuners_ins.powersave_bias) { |
473 | __cpufreq_driver_target(policy, freq_next, | |
474 | CPUFREQ_RELATION_L); | |
475 | } else { | |
476 | int freq = powersave_bias_target(policy, freq_next, | |
477 | CPUFREQ_RELATION_L); | |
478 | __cpufreq_driver_target(policy, freq, | |
479 | CPUFREQ_RELATION_L); | |
480 | } | |
ccb2fe20 | 481 | } |
1da177e4 LT |
482 | } |
483 | ||
c4028958 | 484 | static void do_dbs_timer(struct work_struct *work) |
32ee8c3e | 485 | { |
529af7a1 VP |
486 | struct cpu_dbs_info_s *dbs_info = |
487 | container_of(work, struct cpu_dbs_info_s, work.work); | |
488 | unsigned int cpu = dbs_info->cpu; | |
489 | int sample_type = dbs_info->sample_type; | |
490 | ||
1ce28d6b AS |
491 | /* We want all CPUs to do sampling nearly on same jiffy */ |
492 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
c4028958 | 493 | |
1ce28d6b | 494 | delay -= jiffies % delay; |
2f8a835c | 495 | |
56463b78 | 496 | if (lock_policy_rwsem_write(cpu) < 0) |
2cd7cbdf | 497 | return; |
56463b78 VP |
498 | |
499 | if (!dbs_info->enable) { | |
500 | unlock_policy_rwsem_write(cpu); | |
501 | return; | |
502 | } | |
503 | ||
05ca0350 | 504 | /* Common NORMAL_SAMPLE setup */ |
c4028958 | 505 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
05ca0350 | 506 | if (!dbs_tuners_ins.powersave_bias || |
c4028958 | 507 | sample_type == DBS_NORMAL_SAMPLE) { |
05ca0350 | 508 | dbs_check_cpu(dbs_info); |
05ca0350 AS |
509 | if (dbs_info->freq_lo) { |
510 | /* Setup timer for SUB_SAMPLE */ | |
c4028958 | 511 | dbs_info->sample_type = DBS_SUB_SAMPLE; |
05ca0350 AS |
512 | delay = dbs_info->freq_hi_jiffies; |
513 | } | |
514 | } else { | |
515 | __cpufreq_driver_target(dbs_info->cur_policy, | |
516 | dbs_info->freq_lo, | |
517 | CPUFREQ_RELATION_H); | |
518 | } | |
1ce28d6b | 519 | queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); |
56463b78 | 520 | unlock_policy_rwsem_write(cpu); |
32ee8c3e | 521 | } |
1da177e4 | 522 | |
529af7a1 | 523 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 524 | { |
1ce28d6b AS |
525 | /* We want all CPUs to do sampling nearly on same jiffy */ |
526 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
527 | delay -= jiffies % delay; | |
2f8a835c | 528 | |
c18a1483 | 529 | dbs_info->enable = 1; |
05ca0350 | 530 | ondemand_powersave_bias_init(); |
c4028958 | 531 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
28287033 | 532 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); |
529af7a1 VP |
533 | queue_delayed_work_on(dbs_info->cpu, kondemand_wq, &dbs_info->work, |
534 | delay); | |
1da177e4 LT |
535 | } |
536 | ||
2cd7cbdf | 537 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 538 | { |
2cd7cbdf LT |
539 | dbs_info->enable = 0; |
540 | cancel_delayed_work(&dbs_info->work); | |
1da177e4 LT |
541 | } |
542 | ||
543 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
544 | unsigned int event) | |
545 | { | |
546 | unsigned int cpu = policy->cpu; | |
547 | struct cpu_dbs_info_s *this_dbs_info; | |
548 | unsigned int j; | |
914f7c31 | 549 | int rc; |
1da177e4 LT |
550 | |
551 | this_dbs_info = &per_cpu(cpu_dbs_info, cpu); | |
552 | ||
553 | switch (event) { | |
554 | case CPUFREQ_GOV_START: | |
ffac80e9 | 555 | if ((!cpu_online(cpu)) || (!policy->cur)) |
1da177e4 LT |
556 | return -EINVAL; |
557 | ||
1da177e4 LT |
558 | if (this_dbs_info->enable) /* Already enabled */ |
559 | break; | |
32ee8c3e | 560 | |
3fc54d37 | 561 | mutex_lock(&dbs_mutex); |
2f8a835c | 562 | dbs_enable++; |
914f7c31 JG |
563 | |
564 | rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); | |
565 | if (rc) { | |
914f7c31 JG |
566 | dbs_enable--; |
567 | mutex_unlock(&dbs_mutex); | |
568 | return rc; | |
569 | } | |
570 | ||
835481d9 | 571 | for_each_cpu(j, policy->cpus) { |
1da177e4 LT |
572 | struct cpu_dbs_info_s *j_dbs_info; |
573 | j_dbs_info = &per_cpu(cpu_dbs_info, j); | |
574 | j_dbs_info->cur_policy = policy; | |
32ee8c3e | 575 | |
3430502d | 576 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
577 | &j_dbs_info->prev_cpu_wall); | |
1da177e4 | 578 | } |
529af7a1 | 579 | this_dbs_info->cpu = cpu; |
1da177e4 LT |
580 | /* |
581 | * Start the timerschedule work, when this governor | |
582 | * is used for first time | |
583 | */ | |
584 | if (dbs_enable == 1) { | |
585 | unsigned int latency; | |
586 | /* policy latency is in nS. Convert it to uS first */ | |
df8b59be DJ |
587 | latency = policy->cpuinfo.transition_latency / 1000; |
588 | if (latency == 0) | |
589 | latency = 1; | |
1da177e4 | 590 | |
df8b59be | 591 | def_sampling_rate = latency * |
1da177e4 | 592 | DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; |
df8b59be DJ |
593 | |
594 | if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) | |
595 | def_sampling_rate = MIN_STAT_SAMPLING_RATE; | |
596 | ||
1da177e4 | 597 | dbs_tuners_ins.sampling_rate = def_sampling_rate; |
1da177e4 | 598 | } |
529af7a1 | 599 | dbs_timer_init(this_dbs_info); |
32ee8c3e | 600 | |
3fc54d37 | 601 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
602 | break; |
603 | ||
604 | case CPUFREQ_GOV_STOP: | |
3fc54d37 | 605 | mutex_lock(&dbs_mutex); |
2cd7cbdf | 606 | dbs_timer_exit(this_dbs_info); |
1da177e4 LT |
607 | sysfs_remove_group(&policy->kobj, &dbs_attr_group); |
608 | dbs_enable--; | |
3fc54d37 | 609 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
610 | |
611 | break; | |
612 | ||
613 | case CPUFREQ_GOV_LIMITS: | |
3fc54d37 | 614 | mutex_lock(&dbs_mutex); |
1da177e4 | 615 | if (policy->max < this_dbs_info->cur_policy->cur) |
ffac80e9 VP |
616 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
617 | policy->max, | |
618 | CPUFREQ_RELATION_H); | |
1da177e4 | 619 | else if (policy->min > this_dbs_info->cur_policy->cur) |
ffac80e9 VP |
620 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
621 | policy->min, | |
622 | CPUFREQ_RELATION_L); | |
3fc54d37 | 623 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
624 | break; |
625 | } | |
626 | return 0; | |
627 | } | |
628 | ||
c4d14bc0 SW |
629 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
630 | static | |
631 | #endif | |
1c256245 TR |
632 | struct cpufreq_governor cpufreq_gov_ondemand = { |
633 | .name = "ondemand", | |
634 | .governor = cpufreq_governor_dbs, | |
635 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
636 | .owner = THIS_MODULE, | |
1da177e4 | 637 | }; |
1da177e4 LT |
638 | |
639 | static int __init cpufreq_gov_dbs_init(void) | |
640 | { | |
888a794c | 641 | int err; |
80800913 | 642 | cputime64_t wall; |
4f6e6b9f AR |
643 | u64 idle_time; |
644 | int cpu = get_cpu(); | |
80800913 | 645 | |
4f6e6b9f AR |
646 | idle_time = get_cpu_idle_time_us(cpu, &wall); |
647 | put_cpu(); | |
80800913 | 648 | if (idle_time != -1ULL) { |
649 | /* Idle micro accounting is supported. Use finer thresholds */ | |
650 | dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; | |
651 | dbs_tuners_ins.down_differential = | |
652 | MICRO_FREQUENCY_DOWN_DIFFERENTIAL; | |
653 | } | |
888a794c | 654 | |
56463b78 VP |
655 | kondemand_wq = create_workqueue("kondemand"); |
656 | if (!kondemand_wq) { | |
657 | printk(KERN_ERR "Creation of kondemand failed\n"); | |
658 | return -EFAULT; | |
659 | } | |
888a794c AM |
660 | err = cpufreq_register_governor(&cpufreq_gov_ondemand); |
661 | if (err) | |
662 | destroy_workqueue(kondemand_wq); | |
663 | ||
664 | return err; | |
1da177e4 LT |
665 | } |
666 | ||
667 | static void __exit cpufreq_gov_dbs_exit(void) | |
668 | { | |
1c256245 | 669 | cpufreq_unregister_governor(&cpufreq_gov_ondemand); |
56463b78 | 670 | destroy_workqueue(kondemand_wq); |
1da177e4 LT |
671 | } |
672 | ||
673 | ||
ffac80e9 VP |
674 | MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); |
675 | MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); | |
676 | MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " | |
677 | "Low Latency Frequency Transition capable processors"); | |
678 | MODULE_LICENSE("GPL"); | |
1da177e4 | 679 | |
6915719b JW |
680 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
681 | fs_initcall(cpufreq_gov_dbs_init); | |
682 | #else | |
1da177e4 | 683 | module_init(cpufreq_gov_dbs_init); |
6915719b | 684 | #endif |
1da177e4 | 685 | module_exit(cpufreq_gov_dbs_exit); |