Commit | Line | Data |
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9bdcb44e RW |
1 | /* |
2 | * CPUFreq governor based on scheduler-provided CPU utilization data. | |
3 | * | |
4 | * Copyright (C) 2016, Intel Corporation | |
5 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
60f05e86 VK |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
9bdcb44e | 14 | #include <linux/cpufreq.h> |
02a7b1ee | 15 | #include <linux/kthread.h> |
ae7e81c0 | 16 | #include <uapi/linux/sched/types.h> |
9bdcb44e RW |
17 | #include <linux/slab.h> |
18 | #include <trace/events/power.h> | |
19 | ||
20 | #include "sched.h" | |
21 | ||
02a7b1ee VK |
22 | #define SUGOV_KTHREAD_PRIORITY 50 |
23 | ||
9bdcb44e RW |
24 | struct sugov_tunables { |
25 | struct gov_attr_set attr_set; | |
26 | unsigned int rate_limit_us; | |
27 | }; | |
28 | ||
29 | struct sugov_policy { | |
30 | struct cpufreq_policy *policy; | |
31 | ||
32 | struct sugov_tunables *tunables; | |
33 | struct list_head tunables_hook; | |
34 | ||
35 | raw_spinlock_t update_lock; /* For shared policies */ | |
36 | u64 last_freq_update_time; | |
37 | s64 freq_update_delay_ns; | |
38 | unsigned int next_freq; | |
6c4f0fa6 | 39 | unsigned int cached_raw_freq; |
9bdcb44e RW |
40 | |
41 | /* The next fields are only needed if fast switch cannot be used. */ | |
42 | struct irq_work irq_work; | |
02a7b1ee | 43 | struct kthread_work work; |
9bdcb44e | 44 | struct mutex work_lock; |
02a7b1ee VK |
45 | struct kthread_worker worker; |
46 | struct task_struct *thread; | |
9bdcb44e RW |
47 | bool work_in_progress; |
48 | ||
49 | bool need_freq_update; | |
50 | }; | |
51 | ||
52 | struct sugov_cpu { | |
53 | struct update_util_data update_util; | |
54 | struct sugov_policy *sg_policy; | |
55 | ||
21ca6d2c RW |
56 | unsigned long iowait_boost; |
57 | unsigned long iowait_boost_max; | |
58 | u64 last_update; | |
5cbea469 | 59 | |
9bdcb44e RW |
60 | /* The fields below are only needed when sharing a policy. */ |
61 | unsigned long util; | |
62 | unsigned long max; | |
58919e83 | 63 | unsigned int flags; |
b7eaf1aa RW |
64 | |
65 | /* The field below is for single-CPU policies only. */ | |
66 | #ifdef CONFIG_NO_HZ_COMMON | |
67 | unsigned long saved_idle_calls; | |
68 | #endif | |
9bdcb44e RW |
69 | }; |
70 | ||
71 | static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); | |
72 | ||
73 | /************************ Governor internals ***********************/ | |
74 | ||
75 | static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) | |
76 | { | |
77 | s64 delta_ns; | |
78 | ||
79 | if (sg_policy->work_in_progress) | |
80 | return false; | |
81 | ||
82 | if (unlikely(sg_policy->need_freq_update)) { | |
83 | sg_policy->need_freq_update = false; | |
84 | /* | |
85 | * This happens when limits change, so forget the previous | |
86 | * next_freq value and force an update. | |
87 | */ | |
88 | sg_policy->next_freq = UINT_MAX; | |
89 | return true; | |
90 | } | |
91 | ||
92 | delta_ns = time - sg_policy->last_freq_update_time; | |
93 | return delta_ns >= sg_policy->freq_update_delay_ns; | |
94 | } | |
95 | ||
96 | static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time, | |
97 | unsigned int next_freq) | |
98 | { | |
99 | struct cpufreq_policy *policy = sg_policy->policy; | |
100 | ||
38d4ea22 RW |
101 | if (sg_policy->next_freq == next_freq) |
102 | return; | |
103 | ||
104 | sg_policy->next_freq = next_freq; | |
9bdcb44e RW |
105 | sg_policy->last_freq_update_time = time; |
106 | ||
107 | if (policy->fast_switch_enabled) { | |
9bdcb44e RW |
108 | next_freq = cpufreq_driver_fast_switch(policy, next_freq); |
109 | if (next_freq == CPUFREQ_ENTRY_INVALID) | |
110 | return; | |
111 | ||
112 | policy->cur = next_freq; | |
113 | trace_cpu_frequency(next_freq, smp_processor_id()); | |
38d4ea22 | 114 | } else { |
9bdcb44e RW |
115 | sg_policy->work_in_progress = true; |
116 | irq_work_queue(&sg_policy->irq_work); | |
117 | } | |
118 | } | |
119 | ||
120 | /** | |
121 | * get_next_freq - Compute a new frequency for a given cpufreq policy. | |
655cb1eb | 122 | * @sg_policy: schedutil policy object to compute the new frequency for. |
9bdcb44e RW |
123 | * @util: Current CPU utilization. |
124 | * @max: CPU capacity. | |
125 | * | |
126 | * If the utilization is frequency-invariant, choose the new frequency to be | |
127 | * proportional to it, that is | |
128 | * | |
129 | * next_freq = C * max_freq * util / max | |
130 | * | |
131 | * Otherwise, approximate the would-be frequency-invariant utilization by | |
132 | * util_raw * (curr_freq / max_freq) which leads to | |
133 | * | |
134 | * next_freq = C * curr_freq * util_raw / max | |
135 | * | |
136 | * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8. | |
5cbea469 SM |
137 | * |
138 | * The lowest driver-supported frequency which is equal or greater than the raw | |
139 | * next_freq (as calculated above) is returned, subject to policy min/max and | |
140 | * cpufreq driver limitations. | |
9bdcb44e | 141 | */ |
655cb1eb VK |
142 | static unsigned int get_next_freq(struct sugov_policy *sg_policy, |
143 | unsigned long util, unsigned long max) | |
9bdcb44e | 144 | { |
5cbea469 | 145 | struct cpufreq_policy *policy = sg_policy->policy; |
9bdcb44e RW |
146 | unsigned int freq = arch_scale_freq_invariant() ? |
147 | policy->cpuinfo.max_freq : policy->cur; | |
148 | ||
5cbea469 SM |
149 | freq = (freq + (freq >> 2)) * util / max; |
150 | ||
6c4f0fa6 | 151 | if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX) |
5cbea469 | 152 | return sg_policy->next_freq; |
6c4f0fa6 | 153 | sg_policy->cached_raw_freq = freq; |
5cbea469 | 154 | return cpufreq_driver_resolve_freq(policy, freq); |
9bdcb44e RW |
155 | } |
156 | ||
58919e83 RW |
157 | static void sugov_get_util(unsigned long *util, unsigned long *max) |
158 | { | |
159 | struct rq *rq = this_rq(); | |
8314bc83 SM |
160 | unsigned long cfs_max; |
161 | ||
162 | cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id()); | |
58919e83 RW |
163 | |
164 | *util = min(rq->cfs.avg.util_avg, cfs_max); | |
165 | *max = cfs_max; | |
166 | } | |
167 | ||
21ca6d2c RW |
168 | static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, |
169 | unsigned int flags) | |
170 | { | |
171 | if (flags & SCHED_CPUFREQ_IOWAIT) { | |
172 | sg_cpu->iowait_boost = sg_cpu->iowait_boost_max; | |
173 | } else if (sg_cpu->iowait_boost) { | |
174 | s64 delta_ns = time - sg_cpu->last_update; | |
175 | ||
176 | /* Clear iowait_boost if the CPU apprears to have been idle. */ | |
177 | if (delta_ns > TICK_NSEC) | |
178 | sg_cpu->iowait_boost = 0; | |
179 | } | |
180 | } | |
181 | ||
182 | static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util, | |
183 | unsigned long *max) | |
184 | { | |
185 | unsigned long boost_util = sg_cpu->iowait_boost; | |
186 | unsigned long boost_max = sg_cpu->iowait_boost_max; | |
187 | ||
188 | if (!boost_util) | |
189 | return; | |
190 | ||
191 | if (*util * boost_max < *max * boost_util) { | |
192 | *util = boost_util; | |
193 | *max = boost_max; | |
194 | } | |
195 | sg_cpu->iowait_boost >>= 1; | |
196 | } | |
197 | ||
b7eaf1aa RW |
198 | #ifdef CONFIG_NO_HZ_COMMON |
199 | static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) | |
200 | { | |
201 | unsigned long idle_calls = tick_nohz_get_idle_calls(); | |
202 | bool ret = idle_calls == sg_cpu->saved_idle_calls; | |
203 | ||
204 | sg_cpu->saved_idle_calls = idle_calls; | |
205 | return ret; | |
206 | } | |
207 | #else | |
208 | static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } | |
209 | #endif /* CONFIG_NO_HZ_COMMON */ | |
210 | ||
9bdcb44e | 211 | static void sugov_update_single(struct update_util_data *hook, u64 time, |
58919e83 | 212 | unsigned int flags) |
9bdcb44e RW |
213 | { |
214 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
215 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
216 | struct cpufreq_policy *policy = sg_policy->policy; | |
58919e83 | 217 | unsigned long util, max; |
9bdcb44e | 218 | unsigned int next_f; |
b7eaf1aa | 219 | bool busy; |
9bdcb44e | 220 | |
21ca6d2c RW |
221 | sugov_set_iowait_boost(sg_cpu, time, flags); |
222 | sg_cpu->last_update = time; | |
223 | ||
9bdcb44e RW |
224 | if (!sugov_should_update_freq(sg_policy, time)) |
225 | return; | |
226 | ||
b7eaf1aa RW |
227 | busy = sugov_cpu_is_busy(sg_cpu); |
228 | ||
58919e83 RW |
229 | if (flags & SCHED_CPUFREQ_RT_DL) { |
230 | next_f = policy->cpuinfo.max_freq; | |
231 | } else { | |
232 | sugov_get_util(&util, &max); | |
21ca6d2c | 233 | sugov_iowait_boost(sg_cpu, &util, &max); |
655cb1eb | 234 | next_f = get_next_freq(sg_policy, util, max); |
b7eaf1aa RW |
235 | /* |
236 | * Do not reduce the frequency if the CPU has not been idle | |
237 | * recently, as the reduction is likely to be premature then. | |
238 | */ | |
239 | if (busy && next_f < sg_policy->next_freq) | |
240 | next_f = sg_policy->next_freq; | |
58919e83 | 241 | } |
9bdcb44e RW |
242 | sugov_update_commit(sg_policy, time, next_f); |
243 | } | |
244 | ||
d86ab9cf | 245 | static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) |
9bdcb44e | 246 | { |
5cbea469 | 247 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
9bdcb44e | 248 | struct cpufreq_policy *policy = sg_policy->policy; |
cba1dfb5 | 249 | unsigned long util = 0, max = 1; |
9bdcb44e RW |
250 | unsigned int j; |
251 | ||
9bdcb44e | 252 | for_each_cpu(j, policy->cpus) { |
cba1dfb5 | 253 | struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); |
9bdcb44e RW |
254 | unsigned long j_util, j_max; |
255 | s64 delta_ns; | |
256 | ||
9bdcb44e RW |
257 | /* |
258 | * If the CPU utilization was last updated before the previous | |
259 | * frequency update and the time elapsed between the last update | |
260 | * of the CPU utilization and the last frequency update is long | |
261 | * enough, don't take the CPU into account as it probably is | |
21ca6d2c | 262 | * idle now (and clear iowait_boost for it). |
9bdcb44e | 263 | */ |
d86ab9cf | 264 | delta_ns = time - j_sg_cpu->last_update; |
21ca6d2c RW |
265 | if (delta_ns > TICK_NSEC) { |
266 | j_sg_cpu->iowait_boost = 0; | |
9bdcb44e | 267 | continue; |
21ca6d2c | 268 | } |
58919e83 | 269 | if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_DL) |
cba1dfb5 | 270 | return policy->cpuinfo.max_freq; |
9bdcb44e | 271 | |
58919e83 | 272 | j_util = j_sg_cpu->util; |
9bdcb44e RW |
273 | j_max = j_sg_cpu->max; |
274 | if (j_util * max > j_max * util) { | |
275 | util = j_util; | |
276 | max = j_max; | |
277 | } | |
21ca6d2c RW |
278 | |
279 | sugov_iowait_boost(j_sg_cpu, &util, &max); | |
9bdcb44e RW |
280 | } |
281 | ||
655cb1eb | 282 | return get_next_freq(sg_policy, util, max); |
9bdcb44e RW |
283 | } |
284 | ||
285 | static void sugov_update_shared(struct update_util_data *hook, u64 time, | |
58919e83 | 286 | unsigned int flags) |
9bdcb44e RW |
287 | { |
288 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
289 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
58919e83 | 290 | unsigned long util, max; |
9bdcb44e RW |
291 | unsigned int next_f; |
292 | ||
58919e83 RW |
293 | sugov_get_util(&util, &max); |
294 | ||
9bdcb44e RW |
295 | raw_spin_lock(&sg_policy->update_lock); |
296 | ||
297 | sg_cpu->util = util; | |
298 | sg_cpu->max = max; | |
58919e83 | 299 | sg_cpu->flags = flags; |
21ca6d2c RW |
300 | |
301 | sugov_set_iowait_boost(sg_cpu, time, flags); | |
9bdcb44e RW |
302 | sg_cpu->last_update = time; |
303 | ||
304 | if (sugov_should_update_freq(sg_policy, time)) { | |
cba1dfb5 VK |
305 | if (flags & SCHED_CPUFREQ_RT_DL) |
306 | next_f = sg_policy->policy->cpuinfo.max_freq; | |
307 | else | |
d86ab9cf | 308 | next_f = sugov_next_freq_shared(sg_cpu, time); |
cba1dfb5 | 309 | |
9bdcb44e RW |
310 | sugov_update_commit(sg_policy, time, next_f); |
311 | } | |
312 | ||
313 | raw_spin_unlock(&sg_policy->update_lock); | |
314 | } | |
315 | ||
02a7b1ee | 316 | static void sugov_work(struct kthread_work *work) |
9bdcb44e RW |
317 | { |
318 | struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work); | |
319 | ||
320 | mutex_lock(&sg_policy->work_lock); | |
321 | __cpufreq_driver_target(sg_policy->policy, sg_policy->next_freq, | |
322 | CPUFREQ_RELATION_L); | |
323 | mutex_unlock(&sg_policy->work_lock); | |
324 | ||
325 | sg_policy->work_in_progress = false; | |
326 | } | |
327 | ||
328 | static void sugov_irq_work(struct irq_work *irq_work) | |
329 | { | |
330 | struct sugov_policy *sg_policy; | |
331 | ||
332 | sg_policy = container_of(irq_work, struct sugov_policy, irq_work); | |
02a7b1ee VK |
333 | |
334 | /* | |
d06e622d VK |
335 | * For RT and deadline tasks, the schedutil governor shoots the |
336 | * frequency to maximum. Special care must be taken to ensure that this | |
337 | * kthread doesn't result in the same behavior. | |
02a7b1ee VK |
338 | * |
339 | * This is (mostly) guaranteed by the work_in_progress flag. The flag is | |
d06e622d VK |
340 | * updated only at the end of the sugov_work() function and before that |
341 | * the schedutil governor rejects all other frequency scaling requests. | |
02a7b1ee | 342 | * |
d06e622d | 343 | * There is a very rare case though, where the RT thread yields right |
02a7b1ee VK |
344 | * after the work_in_progress flag is cleared. The effects of that are |
345 | * neglected for now. | |
346 | */ | |
347 | kthread_queue_work(&sg_policy->worker, &sg_policy->work); | |
9bdcb44e RW |
348 | } |
349 | ||
350 | /************************** sysfs interface ************************/ | |
351 | ||
352 | static struct sugov_tunables *global_tunables; | |
353 | static DEFINE_MUTEX(global_tunables_lock); | |
354 | ||
355 | static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set) | |
356 | { | |
357 | return container_of(attr_set, struct sugov_tunables, attr_set); | |
358 | } | |
359 | ||
360 | static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) | |
361 | { | |
362 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
363 | ||
364 | return sprintf(buf, "%u\n", tunables->rate_limit_us); | |
365 | } | |
366 | ||
367 | static ssize_t rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, | |
368 | size_t count) | |
369 | { | |
370 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
371 | struct sugov_policy *sg_policy; | |
372 | unsigned int rate_limit_us; | |
373 | ||
374 | if (kstrtouint(buf, 10, &rate_limit_us)) | |
375 | return -EINVAL; | |
376 | ||
377 | tunables->rate_limit_us = rate_limit_us; | |
378 | ||
379 | list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) | |
380 | sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC; | |
381 | ||
382 | return count; | |
383 | } | |
384 | ||
385 | static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us); | |
386 | ||
387 | static struct attribute *sugov_attributes[] = { | |
388 | &rate_limit_us.attr, | |
389 | NULL | |
390 | }; | |
391 | ||
392 | static struct kobj_type sugov_tunables_ktype = { | |
393 | .default_attrs = sugov_attributes, | |
394 | .sysfs_ops = &governor_sysfs_ops, | |
395 | }; | |
396 | ||
397 | /********************** cpufreq governor interface *********************/ | |
398 | ||
399 | static struct cpufreq_governor schedutil_gov; | |
400 | ||
401 | static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) | |
402 | { | |
403 | struct sugov_policy *sg_policy; | |
404 | ||
405 | sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL); | |
406 | if (!sg_policy) | |
407 | return NULL; | |
408 | ||
409 | sg_policy->policy = policy; | |
9bdcb44e RW |
410 | raw_spin_lock_init(&sg_policy->update_lock); |
411 | return sg_policy; | |
412 | } | |
413 | ||
414 | static void sugov_policy_free(struct sugov_policy *sg_policy) | |
415 | { | |
9bdcb44e RW |
416 | kfree(sg_policy); |
417 | } | |
418 | ||
02a7b1ee VK |
419 | static int sugov_kthread_create(struct sugov_policy *sg_policy) |
420 | { | |
421 | struct task_struct *thread; | |
422 | struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO / 2 }; | |
423 | struct cpufreq_policy *policy = sg_policy->policy; | |
424 | int ret; | |
425 | ||
426 | /* kthread only required for slow path */ | |
427 | if (policy->fast_switch_enabled) | |
428 | return 0; | |
429 | ||
430 | kthread_init_work(&sg_policy->work, sugov_work); | |
431 | kthread_init_worker(&sg_policy->worker); | |
432 | thread = kthread_create(kthread_worker_fn, &sg_policy->worker, | |
433 | "sugov:%d", | |
434 | cpumask_first(policy->related_cpus)); | |
435 | if (IS_ERR(thread)) { | |
436 | pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread)); | |
437 | return PTR_ERR(thread); | |
438 | } | |
439 | ||
440 | ret = sched_setscheduler_nocheck(thread, SCHED_FIFO, ¶m); | |
441 | if (ret) { | |
442 | kthread_stop(thread); | |
443 | pr_warn("%s: failed to set SCHED_FIFO\n", __func__); | |
444 | return ret; | |
445 | } | |
446 | ||
447 | sg_policy->thread = thread; | |
448 | kthread_bind_mask(thread, policy->related_cpus); | |
21ef5729 VK |
449 | init_irq_work(&sg_policy->irq_work, sugov_irq_work); |
450 | mutex_init(&sg_policy->work_lock); | |
451 | ||
02a7b1ee VK |
452 | wake_up_process(thread); |
453 | ||
454 | return 0; | |
455 | } | |
456 | ||
457 | static void sugov_kthread_stop(struct sugov_policy *sg_policy) | |
458 | { | |
459 | /* kthread only required for slow path */ | |
460 | if (sg_policy->policy->fast_switch_enabled) | |
461 | return; | |
462 | ||
463 | kthread_flush_worker(&sg_policy->worker); | |
464 | kthread_stop(sg_policy->thread); | |
21ef5729 | 465 | mutex_destroy(&sg_policy->work_lock); |
02a7b1ee VK |
466 | } |
467 | ||
9bdcb44e RW |
468 | static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy) |
469 | { | |
470 | struct sugov_tunables *tunables; | |
471 | ||
472 | tunables = kzalloc(sizeof(*tunables), GFP_KERNEL); | |
473 | if (tunables) { | |
474 | gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook); | |
475 | if (!have_governor_per_policy()) | |
476 | global_tunables = tunables; | |
477 | } | |
478 | return tunables; | |
479 | } | |
480 | ||
481 | static void sugov_tunables_free(struct sugov_tunables *tunables) | |
482 | { | |
483 | if (!have_governor_per_policy()) | |
484 | global_tunables = NULL; | |
485 | ||
486 | kfree(tunables); | |
487 | } | |
488 | ||
489 | static int sugov_init(struct cpufreq_policy *policy) | |
490 | { | |
491 | struct sugov_policy *sg_policy; | |
492 | struct sugov_tunables *tunables; | |
9bdcb44e RW |
493 | int ret = 0; |
494 | ||
495 | /* State should be equivalent to EXIT */ | |
496 | if (policy->governor_data) | |
497 | return -EBUSY; | |
498 | ||
4a71ce43 VK |
499 | cpufreq_enable_fast_switch(policy); |
500 | ||
9bdcb44e | 501 | sg_policy = sugov_policy_alloc(policy); |
4a71ce43 VK |
502 | if (!sg_policy) { |
503 | ret = -ENOMEM; | |
504 | goto disable_fast_switch; | |
505 | } | |
9bdcb44e | 506 | |
02a7b1ee VK |
507 | ret = sugov_kthread_create(sg_policy); |
508 | if (ret) | |
509 | goto free_sg_policy; | |
510 | ||
9bdcb44e RW |
511 | mutex_lock(&global_tunables_lock); |
512 | ||
513 | if (global_tunables) { | |
514 | if (WARN_ON(have_governor_per_policy())) { | |
515 | ret = -EINVAL; | |
02a7b1ee | 516 | goto stop_kthread; |
9bdcb44e RW |
517 | } |
518 | policy->governor_data = sg_policy; | |
519 | sg_policy->tunables = global_tunables; | |
520 | ||
521 | gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook); | |
522 | goto out; | |
523 | } | |
524 | ||
525 | tunables = sugov_tunables_alloc(sg_policy); | |
526 | if (!tunables) { | |
527 | ret = -ENOMEM; | |
02a7b1ee | 528 | goto stop_kthread; |
9bdcb44e RW |
529 | } |
530 | ||
1b72e7fd RW |
531 | if (policy->transition_delay_us) { |
532 | tunables->rate_limit_us = policy->transition_delay_us; | |
533 | } else { | |
534 | unsigned int lat; | |
535 | ||
536 | tunables->rate_limit_us = LATENCY_MULTIPLIER; | |
537 | lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC; | |
538 | if (lat) | |
539 | tunables->rate_limit_us *= lat; | |
540 | } | |
9bdcb44e RW |
541 | |
542 | policy->governor_data = sg_policy; | |
543 | sg_policy->tunables = tunables; | |
544 | ||
545 | ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype, | |
546 | get_governor_parent_kobj(policy), "%s", | |
547 | schedutil_gov.name); | |
548 | if (ret) | |
549 | goto fail; | |
550 | ||
8e2ddb03 | 551 | out: |
9bdcb44e | 552 | mutex_unlock(&global_tunables_lock); |
9bdcb44e RW |
553 | return 0; |
554 | ||
8e2ddb03 | 555 | fail: |
9bdcb44e RW |
556 | policy->governor_data = NULL; |
557 | sugov_tunables_free(tunables); | |
558 | ||
02a7b1ee VK |
559 | stop_kthread: |
560 | sugov_kthread_stop(sg_policy); | |
561 | ||
8e2ddb03 | 562 | free_sg_policy: |
9bdcb44e RW |
563 | mutex_unlock(&global_tunables_lock); |
564 | ||
565 | sugov_policy_free(sg_policy); | |
4a71ce43 VK |
566 | |
567 | disable_fast_switch: | |
568 | cpufreq_disable_fast_switch(policy); | |
569 | ||
60f05e86 | 570 | pr_err("initialization failed (error %d)\n", ret); |
9bdcb44e RW |
571 | return ret; |
572 | } | |
573 | ||
e788892b | 574 | static void sugov_exit(struct cpufreq_policy *policy) |
9bdcb44e RW |
575 | { |
576 | struct sugov_policy *sg_policy = policy->governor_data; | |
577 | struct sugov_tunables *tunables = sg_policy->tunables; | |
578 | unsigned int count; | |
579 | ||
580 | mutex_lock(&global_tunables_lock); | |
581 | ||
582 | count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); | |
583 | policy->governor_data = NULL; | |
584 | if (!count) | |
585 | sugov_tunables_free(tunables); | |
586 | ||
587 | mutex_unlock(&global_tunables_lock); | |
588 | ||
02a7b1ee | 589 | sugov_kthread_stop(sg_policy); |
9bdcb44e | 590 | sugov_policy_free(sg_policy); |
4a71ce43 | 591 | cpufreq_disable_fast_switch(policy); |
9bdcb44e RW |
592 | } |
593 | ||
594 | static int sugov_start(struct cpufreq_policy *policy) | |
595 | { | |
596 | struct sugov_policy *sg_policy = policy->governor_data; | |
597 | unsigned int cpu; | |
598 | ||
599 | sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; | |
600 | sg_policy->last_freq_update_time = 0; | |
601 | sg_policy->next_freq = UINT_MAX; | |
602 | sg_policy->work_in_progress = false; | |
603 | sg_policy->need_freq_update = false; | |
6c4f0fa6 | 604 | sg_policy->cached_raw_freq = 0; |
9bdcb44e RW |
605 | |
606 | for_each_cpu(cpu, policy->cpus) { | |
607 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
608 | ||
4296f23e | 609 | memset(sg_cpu, 0, sizeof(*sg_cpu)); |
9bdcb44e | 610 | sg_cpu->sg_policy = sg_policy; |
4296f23e RW |
611 | sg_cpu->flags = SCHED_CPUFREQ_RT; |
612 | sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; | |
ab2f7cf1 VM |
613 | } |
614 | ||
615 | for_each_cpu(cpu, policy->cpus) { | |
616 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
617 | ||
4296f23e RW |
618 | cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, |
619 | policy_is_shared(policy) ? | |
620 | sugov_update_shared : | |
621 | sugov_update_single); | |
9bdcb44e RW |
622 | } |
623 | return 0; | |
624 | } | |
625 | ||
e788892b | 626 | static void sugov_stop(struct cpufreq_policy *policy) |
9bdcb44e RW |
627 | { |
628 | struct sugov_policy *sg_policy = policy->governor_data; | |
629 | unsigned int cpu; | |
630 | ||
631 | for_each_cpu(cpu, policy->cpus) | |
632 | cpufreq_remove_update_util_hook(cpu); | |
633 | ||
634 | synchronize_sched(); | |
635 | ||
21ef5729 VK |
636 | if (!policy->fast_switch_enabled) { |
637 | irq_work_sync(&sg_policy->irq_work); | |
638 | kthread_cancel_work_sync(&sg_policy->work); | |
639 | } | |
9bdcb44e RW |
640 | } |
641 | ||
e788892b | 642 | static void sugov_limits(struct cpufreq_policy *policy) |
9bdcb44e RW |
643 | { |
644 | struct sugov_policy *sg_policy = policy->governor_data; | |
645 | ||
646 | if (!policy->fast_switch_enabled) { | |
647 | mutex_lock(&sg_policy->work_lock); | |
bf2be2de | 648 | cpufreq_policy_apply_limits(policy); |
9bdcb44e RW |
649 | mutex_unlock(&sg_policy->work_lock); |
650 | } | |
651 | ||
652 | sg_policy->need_freq_update = true; | |
9bdcb44e RW |
653 | } |
654 | ||
655 | static struct cpufreq_governor schedutil_gov = { | |
656 | .name = "schedutil", | |
9bdcb44e | 657 | .owner = THIS_MODULE, |
e788892b RW |
658 | .init = sugov_init, |
659 | .exit = sugov_exit, | |
660 | .start = sugov_start, | |
661 | .stop = sugov_stop, | |
662 | .limits = sugov_limits, | |
9bdcb44e RW |
663 | }; |
664 | ||
9bdcb44e RW |
665 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL |
666 | struct cpufreq_governor *cpufreq_default_governor(void) | |
667 | { | |
668 | return &schedutil_gov; | |
669 | } | |
9bdcb44e | 670 | #endif |
58919e83 RW |
671 | |
672 | static int __init sugov_register(void) | |
673 | { | |
674 | return cpufreq_register_governor(&schedutil_gov); | |
675 | } | |
676 | fs_initcall(sugov_register); |