Commit | Line | Data |
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108c35a9 | 1 | // SPDX-License-Identifier: GPL-2.0 |
9bdcb44e RW |
2 | /* |
3 | * CPUFreq governor based on scheduler-provided CPU utilization data. | |
4 | * | |
5 | * Copyright (C) 2016, Intel Corporation | |
6 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
9bdcb44e RW |
7 | */ |
8 | ||
9eca544b RW |
9 | #define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8) |
10 | ||
9bdcb44e | 11 | struct sugov_tunables { |
97fb7a0a IM |
12 | struct gov_attr_set attr_set; |
13 | unsigned int rate_limit_us; | |
9bdcb44e RW |
14 | }; |
15 | ||
16 | struct sugov_policy { | |
97fb7a0a IM |
17 | struct cpufreq_policy *policy; |
18 | ||
19 | struct sugov_tunables *tunables; | |
20 | struct list_head tunables_hook; | |
21 | ||
e209cb51 | 22 | raw_spinlock_t update_lock; |
97fb7a0a IM |
23 | u64 last_freq_update_time; |
24 | s64 freq_update_delay_ns; | |
25 | unsigned int next_freq; | |
26 | unsigned int cached_raw_freq; | |
27 | ||
28 | /* The next fields are only needed if fast switch cannot be used: */ | |
29 | struct irq_work irq_work; | |
30 | struct kthread_work work; | |
31 | struct mutex work_lock; | |
32 | struct kthread_worker worker; | |
33 | struct task_struct *thread; | |
34 | bool work_in_progress; | |
35 | ||
600f5bad | 36 | bool limits_changed; |
97fb7a0a | 37 | bool need_freq_update; |
9bdcb44e RW |
38 | }; |
39 | ||
40 | struct sugov_cpu { | |
97fb7a0a IM |
41 | struct update_util_data update_util; |
42 | struct sugov_policy *sg_policy; | |
43 | unsigned int cpu; | |
9bdcb44e | 44 | |
97fb7a0a IM |
45 | bool iowait_boost_pending; |
46 | unsigned int iowait_boost; | |
fd7d5287 | 47 | u64 last_update; |
5cbea469 | 48 | |
ca6827de | 49 | unsigned long util; |
8cc90515 | 50 | unsigned long bw_dl; |
b7eaf1aa | 51 | |
97fb7a0a | 52 | /* The field below is for single-CPU policies only: */ |
b7eaf1aa | 53 | #ifdef CONFIG_NO_HZ_COMMON |
97fb7a0a | 54 | unsigned long saved_idle_calls; |
b7eaf1aa | 55 | #endif |
9bdcb44e RW |
56 | }; |
57 | ||
58 | static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); | |
59 | ||
60 | /************************ Governor internals ***********************/ | |
61 | ||
62 | static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) | |
63 | { | |
64 | s64 delta_ns; | |
65 | ||
674e7541 VK |
66 | /* |
67 | * Since cpufreq_update_util() is called with rq->lock held for | |
97fb7a0a | 68 | * the @target_cpu, our per-CPU data is fully serialized. |
674e7541 | 69 | * |
97fb7a0a | 70 | * However, drivers cannot in general deal with cross-CPU |
674e7541 | 71 | * requests, so while get_next_freq() will work, our |
c49cbc19 | 72 | * sugov_update_commit() call may not for the fast switching platforms. |
674e7541 VK |
73 | * |
74 | * Hence stop here for remote requests if they aren't supported | |
75 | * by the hardware, as calculating the frequency is pointless if | |
76 | * we cannot in fact act on it. | |
c49cbc19 | 77 | * |
85572c2c RW |
78 | * This is needed on the slow switching platforms too to prevent CPUs |
79 | * going offline from leaving stale IRQ work items behind. | |
674e7541 | 80 | */ |
85572c2c | 81 | if (!cpufreq_this_cpu_can_update(sg_policy->policy)) |
674e7541 VK |
82 | return false; |
83 | ||
600f5bad VK |
84 | if (unlikely(sg_policy->limits_changed)) { |
85 | sg_policy->limits_changed = false; | |
86 | sg_policy->need_freq_update = true; | |
9bdcb44e | 87 | return true; |
600f5bad | 88 | } |
9bdcb44e RW |
89 | |
90 | delta_ns = time - sg_policy->last_freq_update_time; | |
97fb7a0a | 91 | |
9bdcb44e RW |
92 | return delta_ns >= sg_policy->freq_update_delay_ns; |
93 | } | |
94 | ||
a61dec74 RW |
95 | static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time, |
96 | unsigned int next_freq) | |
9bdcb44e | 97 | { |
90ac908a | 98 | if (sg_policy->need_freq_update) |
23a88185 | 99 | sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); |
90ac908a RW |
100 | else if (sg_policy->next_freq == next_freq) |
101 | return false; | |
38d4ea22 RW |
102 | |
103 | sg_policy->next_freq = next_freq; | |
9bdcb44e RW |
104 | sg_policy->last_freq_update_time = time; |
105 | ||
a61dec74 RW |
106 | return true; |
107 | } | |
9bdcb44e | 108 | |
389e4ecf | 109 | static void sugov_deferred_update(struct sugov_policy *sg_policy) |
a61dec74 | 110 | { |
a61dec74 | 111 | if (!sg_policy->work_in_progress) { |
9bdcb44e RW |
112 | sg_policy->work_in_progress = true; |
113 | irq_work_queue(&sg_policy->irq_work); | |
114 | } | |
115 | } | |
116 | ||
117 | /** | |
118 | * get_next_freq - Compute a new frequency for a given cpufreq policy. | |
655cb1eb | 119 | * @sg_policy: schedutil policy object to compute the new frequency for. |
9bdcb44e RW |
120 | * @util: Current CPU utilization. |
121 | * @max: CPU capacity. | |
122 | * | |
123 | * If the utilization is frequency-invariant, choose the new frequency to be | |
124 | * proportional to it, that is | |
125 | * | |
126 | * next_freq = C * max_freq * util / max | |
127 | * | |
128 | * Otherwise, approximate the would-be frequency-invariant utilization by | |
129 | * util_raw * (curr_freq / max_freq) which leads to | |
130 | * | |
131 | * next_freq = C * curr_freq * util_raw / max | |
132 | * | |
133 | * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8. | |
5cbea469 SM |
134 | * |
135 | * The lowest driver-supported frequency which is equal or greater than the raw | |
136 | * next_freq (as calculated above) is returned, subject to policy min/max and | |
137 | * cpufreq driver limitations. | |
9bdcb44e | 138 | */ |
655cb1eb VK |
139 | static unsigned int get_next_freq(struct sugov_policy *sg_policy, |
140 | unsigned long util, unsigned long max) | |
9bdcb44e | 141 | { |
5cbea469 | 142 | struct cpufreq_policy *policy = sg_policy->policy; |
9bdcb44e RW |
143 | unsigned int freq = arch_scale_freq_invariant() ? |
144 | policy->cpuinfo.max_freq : policy->cur; | |
145 | ||
8f1b971b | 146 | util = map_util_perf(util); |
938e5e4b | 147 | freq = map_util_freq(util, freq, max); |
5cbea469 | 148 | |
ecd28842 | 149 | if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) |
5cbea469 | 150 | return sg_policy->next_freq; |
ecd28842 | 151 | |
6c4f0fa6 | 152 | sg_policy->cached_raw_freq = freq; |
5cbea469 | 153 | return cpufreq_driver_resolve_freq(policy, freq); |
9bdcb44e RW |
154 | } |
155 | ||
ca6827de | 156 | static void sugov_get_util(struct sugov_cpu *sg_cpu) |
938e5e4b QP |
157 | { |
158 | struct rq *rq = cpu_rq(sg_cpu->cpu); | |
938e5e4b | 159 | |
938e5e4b | 160 | sg_cpu->bw_dl = cpu_bw_dl(rq); |
bb447999 | 161 | sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), |
ca6827de | 162 | FREQUENCY_UTIL, NULL); |
58919e83 RW |
163 | } |
164 | ||
fd7d5287 PB |
165 | /** |
166 | * sugov_iowait_reset() - Reset the IO boost status of a CPU. | |
167 | * @sg_cpu: the sugov data for the CPU to boost | |
168 | * @time: the update time from the caller | |
169 | * @set_iowait_boost: true if an IO boost has been requested | |
170 | * | |
171 | * The IO wait boost of a task is disabled after a tick since the last update | |
172 | * of a CPU. If a new IO wait boost is requested after more then a tick, then | |
9eca544b RW |
173 | * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy |
174 | * efficiency by ignoring sporadic wakeups from IO. | |
fd7d5287 PB |
175 | */ |
176 | static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time, | |
177 | bool set_iowait_boost) | |
21ca6d2c | 178 | { |
fd7d5287 | 179 | s64 delta_ns = time - sg_cpu->last_update; |
a5a0809b | 180 | |
fd7d5287 PB |
181 | /* Reset boost only if a tick has elapsed since last request */ |
182 | if (delta_ns <= TICK_NSEC) | |
183 | return false; | |
a5a0809b | 184 | |
9eca544b | 185 | sg_cpu->iowait_boost = set_iowait_boost ? IOWAIT_BOOST_MIN : 0; |
fd7d5287 | 186 | sg_cpu->iowait_boost_pending = set_iowait_boost; |
21ca6d2c | 187 | |
fd7d5287 PB |
188 | return true; |
189 | } | |
a5a0809b | 190 | |
fd7d5287 PB |
191 | /** |
192 | * sugov_iowait_boost() - Updates the IO boost status of a CPU. | |
193 | * @sg_cpu: the sugov data for the CPU to boost | |
194 | * @time: the update time from the caller | |
195 | * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait | |
196 | * | |
197 | * Each time a task wakes up after an IO operation, the CPU utilization can be | |
198 | * boosted to a certain utilization which doubles at each "frequent and | |
9eca544b RW |
199 | * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization |
200 | * of the maximum OPP. | |
201 | * | |
fd7d5287 PB |
202 | * To keep doubling, an IO boost has to be requested at least once per tick, |
203 | * otherwise we restart from the utilization of the minimum OPP. | |
204 | */ | |
205 | static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, | |
206 | unsigned int flags) | |
207 | { | |
208 | bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT; | |
209 | ||
210 | /* Reset boost if the CPU appears to have been idle enough */ | |
211 | if (sg_cpu->iowait_boost && | |
212 | sugov_iowait_reset(sg_cpu, time, set_iowait_boost)) | |
213 | return; | |
214 | ||
215 | /* Boost only tasks waking up after IO */ | |
216 | if (!set_iowait_boost) | |
217 | return; | |
218 | ||
219 | /* Ensure boost doubles only one time at each request */ | |
220 | if (sg_cpu->iowait_boost_pending) | |
221 | return; | |
222 | sg_cpu->iowait_boost_pending = true; | |
223 | ||
224 | /* Double the boost at each request */ | |
225 | if (sg_cpu->iowait_boost) { | |
a23314e9 PZ |
226 | sg_cpu->iowait_boost = |
227 | min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE); | |
fd7d5287 | 228 | return; |
21ca6d2c | 229 | } |
fd7d5287 PB |
230 | |
231 | /* First wakeup after IO: start with minimum boost */ | |
9eca544b | 232 | sg_cpu->iowait_boost = IOWAIT_BOOST_MIN; |
21ca6d2c RW |
233 | } |
234 | ||
fd7d5287 PB |
235 | /** |
236 | * sugov_iowait_apply() - Apply the IO boost to a CPU. | |
237 | * @sg_cpu: the sugov data for the cpu to boost | |
238 | * @time: the update time from the caller | |
948fb4c4 | 239 | * @max_cap: the max CPU capacity |
fd7d5287 PB |
240 | * |
241 | * A CPU running a task which woken up after an IO operation can have its | |
242 | * utilization boosted to speed up the completion of those IO operations. | |
243 | * The IO boost value is increased each time a task wakes up from IO, in | |
244 | * sugov_iowait_apply(), and it's instead decreased by this function, | |
245 | * each time an increase has not been requested (!iowait_boost_pending). | |
246 | * | |
247 | * A CPU which also appears to have been idle for at least one tick has also | |
248 | * its IO boost utilization reset. | |
249 | * | |
250 | * This mechanism is designed to boost high frequently IO waiting tasks, while | |
251 | * being more conservative on tasks which does sporadic IO operations. | |
252 | */ | |
948fb4c4 LL |
253 | static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, |
254 | unsigned long max_cap) | |
21ca6d2c | 255 | { |
a23314e9 | 256 | unsigned long boost; |
21ca6d2c | 257 | |
fd7d5287 | 258 | /* No boost currently required */ |
a5a0809b | 259 | if (!sg_cpu->iowait_boost) |
ca6827de | 260 | return; |
21ca6d2c | 261 | |
fd7d5287 PB |
262 | /* Reset boost if the CPU appears to have been idle enough */ |
263 | if (sugov_iowait_reset(sg_cpu, time, false)) | |
ca6827de | 264 | return; |
fd7d5287 | 265 | |
a23314e9 | 266 | if (!sg_cpu->iowait_boost_pending) { |
fd7d5287 | 267 | /* |
a23314e9 | 268 | * No boost pending; reduce the boost value. |
fd7d5287 | 269 | */ |
a5a0809b | 270 | sg_cpu->iowait_boost >>= 1; |
9eca544b | 271 | if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) { |
a5a0809b | 272 | sg_cpu->iowait_boost = 0; |
ca6827de | 273 | return; |
a5a0809b JF |
274 | } |
275 | } | |
276 | ||
a23314e9 PZ |
277 | sg_cpu->iowait_boost_pending = false; |
278 | ||
fd7d5287 | 279 | /* |
ca6827de | 280 | * sg_cpu->util is already in capacity scale; convert iowait_boost |
a23314e9 | 281 | * into the same scale so we can compare. |
fd7d5287 | 282 | */ |
948fb4c4 | 283 | boost = (sg_cpu->iowait_boost * max_cap) >> SCHED_CAPACITY_SHIFT; |
d37aee90 | 284 | boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL); |
ca6827de RW |
285 | if (sg_cpu->util < boost) |
286 | sg_cpu->util = boost; | |
21ca6d2c RW |
287 | } |
288 | ||
b7eaf1aa RW |
289 | #ifdef CONFIG_NO_HZ_COMMON |
290 | static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) | |
291 | { | |
466a2b42 | 292 | unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu); |
b7eaf1aa RW |
293 | bool ret = idle_calls == sg_cpu->saved_idle_calls; |
294 | ||
295 | sg_cpu->saved_idle_calls = idle_calls; | |
296 | return ret; | |
297 | } | |
298 | #else | |
299 | static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } | |
300 | #endif /* CONFIG_NO_HZ_COMMON */ | |
301 | ||
e97a90f7 CS |
302 | /* |
303 | * Make sugov_should_update_freq() ignore the rate limit when DL | |
304 | * has increased the utilization. | |
305 | */ | |
71f1309f | 306 | static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu) |
e97a90f7 | 307 | { |
8cc90515 | 308 | if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) |
71f1309f | 309 | sg_cpu->sg_policy->limits_changed = true; |
e97a90f7 CS |
310 | } |
311 | ||
ee2cc427 | 312 | static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, |
948fb4c4 LL |
313 | u64 time, unsigned long max_cap, |
314 | unsigned int flags) | |
9bdcb44e | 315 | { |
fd7d5287 | 316 | sugov_iowait_boost(sg_cpu, time, flags); |
21ca6d2c RW |
317 | sg_cpu->last_update = time; |
318 | ||
71f1309f | 319 | ignore_dl_rate_limit(sg_cpu); |
e97a90f7 | 320 | |
71f1309f | 321 | if (!sugov_should_update_freq(sg_cpu->sg_policy, time)) |
ee2cc427 | 322 | return false; |
9bdcb44e | 323 | |
ca6827de | 324 | sugov_get_util(sg_cpu); |
948fb4c4 | 325 | sugov_iowait_apply(sg_cpu, time, max_cap); |
ca6827de | 326 | |
ee2cc427 RW |
327 | return true; |
328 | } | |
329 | ||
330 | static void sugov_update_single_freq(struct update_util_data *hook, u64 time, | |
331 | unsigned int flags) | |
332 | { | |
333 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
334 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
335 | unsigned int cached_freq = sg_policy->cached_raw_freq; | |
948fb4c4 | 336 | unsigned long max_cap; |
ee2cc427 RW |
337 | unsigned int next_f; |
338 | ||
948fb4c4 LL |
339 | max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
340 | ||
341 | if (!sugov_update_single_common(sg_cpu, time, max_cap, flags)) | |
9bdcb44e RW |
342 | return; |
343 | ||
948fb4c4 | 344 | next_f = get_next_freq(sg_policy, sg_cpu->util, max_cap); |
8f111bc3 PZ |
345 | /* |
346 | * Do not reduce the frequency if the CPU has not been idle | |
347 | * recently, as the reduction is likely to be premature then. | |
7a17e1db QY |
348 | * |
349 | * Except when the rq is capped by uclamp_max. | |
8f111bc3 | 350 | */ |
7a17e1db QY |
351 | if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) && |
352 | sugov_cpu_is_busy(sg_cpu) && next_f < sg_policy->next_freq) { | |
8f111bc3 | 353 | next_f = sg_policy->next_freq; |
07458f6a | 354 | |
0070ea29 WW |
355 | /* Restore cached freq as next_freq has changed */ |
356 | sg_policy->cached_raw_freq = cached_freq; | |
58919e83 | 357 | } |
8f111bc3 | 358 | |
389e4ecf YH |
359 | if (!sugov_update_next_freq(sg_policy, time, next_f)) |
360 | return; | |
361 | ||
a61dec74 RW |
362 | /* |
363 | * This code runs under rq->lock for the target CPU, so it won't run | |
364 | * concurrently on two different CPUs for the same target and it is not | |
365 | * necessary to acquire the lock in the fast switch case. | |
366 | */ | |
367 | if (sg_policy->policy->fast_switch_enabled) { | |
389e4ecf | 368 | cpufreq_driver_fast_switch(sg_policy->policy, next_f); |
a61dec74 RW |
369 | } else { |
370 | raw_spin_lock(&sg_policy->update_lock); | |
389e4ecf | 371 | sugov_deferred_update(sg_policy); |
a61dec74 RW |
372 | raw_spin_unlock(&sg_policy->update_lock); |
373 | } | |
9bdcb44e RW |
374 | } |
375 | ||
ee2cc427 RW |
376 | static void sugov_update_single_perf(struct update_util_data *hook, u64 time, |
377 | unsigned int flags) | |
378 | { | |
379 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
380 | unsigned long prev_util = sg_cpu->util; | |
948fb4c4 | 381 | unsigned long max_cap; |
ee2cc427 RW |
382 | |
383 | /* | |
384 | * Fall back to the "frequency" path if frequency invariance is not | |
385 | * supported, because the direct mapping between the utilization and | |
386 | * the performance levels depends on the frequency invariance. | |
387 | */ | |
388 | if (!arch_scale_freq_invariant()) { | |
389 | sugov_update_single_freq(hook, time, flags); | |
390 | return; | |
391 | } | |
392 | ||
948fb4c4 LL |
393 | max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
394 | ||
395 | if (!sugov_update_single_common(sg_cpu, time, max_cap, flags)) | |
ee2cc427 RW |
396 | return; |
397 | ||
398 | /* | |
399 | * Do not reduce the target performance level if the CPU has not been | |
400 | * idle recently, as the reduction is likely to be premature then. | |
7a17e1db QY |
401 | * |
402 | * Except when the rq is capped by uclamp_max. | |
ee2cc427 | 403 | */ |
7a17e1db QY |
404 | if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) && |
405 | sugov_cpu_is_busy(sg_cpu) && sg_cpu->util < prev_util) | |
ee2cc427 RW |
406 | sg_cpu->util = prev_util; |
407 | ||
408 | cpufreq_driver_adjust_perf(sg_cpu->cpu, map_util_perf(sg_cpu->bw_dl), | |
948fb4c4 | 409 | map_util_perf(sg_cpu->util), max_cap); |
ee2cc427 RW |
410 | |
411 | sg_cpu->sg_policy->last_freq_update_time = time; | |
412 | } | |
413 | ||
d86ab9cf | 414 | static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) |
9bdcb44e | 415 | { |
5cbea469 | 416 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; |
9bdcb44e | 417 | struct cpufreq_policy *policy = sg_policy->policy; |
948fb4c4 | 418 | unsigned long util = 0, max_cap; |
9bdcb44e RW |
419 | unsigned int j; |
420 | ||
948fb4c4 LL |
421 | max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
422 | ||
9bdcb44e | 423 | for_each_cpu(j, policy->cpus) { |
cba1dfb5 | 424 | struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); |
9bdcb44e | 425 | |
ca6827de | 426 | sugov_get_util(j_sg_cpu); |
948fb4c4 | 427 | sugov_iowait_apply(j_sg_cpu, time, max_cap); |
fd7d5287 | 428 | |
948fb4c4 | 429 | util = max(j_sg_cpu->util, util); |
9bdcb44e RW |
430 | } |
431 | ||
948fb4c4 | 432 | return get_next_freq(sg_policy, util, max_cap); |
9bdcb44e RW |
433 | } |
434 | ||
97fb7a0a IM |
435 | static void |
436 | sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags) | |
9bdcb44e RW |
437 | { |
438 | struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); | |
439 | struct sugov_policy *sg_policy = sg_cpu->sg_policy; | |
440 | unsigned int next_f; | |
441 | ||
442 | raw_spin_lock(&sg_policy->update_lock); | |
443 | ||
fd7d5287 | 444 | sugov_iowait_boost(sg_cpu, time, flags); |
9bdcb44e RW |
445 | sg_cpu->last_update = time; |
446 | ||
71f1309f | 447 | ignore_dl_rate_limit(sg_cpu); |
cba1dfb5 | 448 | |
9bdcb44e | 449 | if (sugov_should_update_freq(sg_policy, time)) { |
8f111bc3 | 450 | next_f = sugov_next_freq_shared(sg_cpu, time); |
a61dec74 | 451 | |
389e4ecf YH |
452 | if (!sugov_update_next_freq(sg_policy, time, next_f)) |
453 | goto unlock; | |
454 | ||
a61dec74 | 455 | if (sg_policy->policy->fast_switch_enabled) |
389e4ecf | 456 | cpufreq_driver_fast_switch(sg_policy->policy, next_f); |
a61dec74 | 457 | else |
389e4ecf | 458 | sugov_deferred_update(sg_policy); |
9bdcb44e | 459 | } |
389e4ecf | 460 | unlock: |
9bdcb44e RW |
461 | raw_spin_unlock(&sg_policy->update_lock); |
462 | } | |
463 | ||
02a7b1ee | 464 | static void sugov_work(struct kthread_work *work) |
9bdcb44e RW |
465 | { |
466 | struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work); | |
152db033 JFG |
467 | unsigned int freq; |
468 | unsigned long flags; | |
469 | ||
470 | /* | |
471 | * Hold sg_policy->update_lock shortly to handle the case where: | |
3b03706f | 472 | * in case sg_policy->next_freq is read here, and then updated by |
a61dec74 | 473 | * sugov_deferred_update() just before work_in_progress is set to false |
152db033 JFG |
474 | * here, we may miss queueing the new update. |
475 | * | |
476 | * Note: If a work was queued after the update_lock is released, | |
a61dec74 | 477 | * sugov_work() will just be called again by kthread_work code; and the |
152db033 JFG |
478 | * request will be proceed before the sugov thread sleeps. |
479 | */ | |
480 | raw_spin_lock_irqsave(&sg_policy->update_lock, flags); | |
481 | freq = sg_policy->next_freq; | |
482 | sg_policy->work_in_progress = false; | |
483 | raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags); | |
9bdcb44e RW |
484 | |
485 | mutex_lock(&sg_policy->work_lock); | |
152db033 | 486 | __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L); |
9bdcb44e | 487 | mutex_unlock(&sg_policy->work_lock); |
9bdcb44e RW |
488 | } |
489 | ||
490 | static void sugov_irq_work(struct irq_work *irq_work) | |
491 | { | |
492 | struct sugov_policy *sg_policy; | |
493 | ||
494 | sg_policy = container_of(irq_work, struct sugov_policy, irq_work); | |
02a7b1ee | 495 | |
02a7b1ee | 496 | kthread_queue_work(&sg_policy->worker, &sg_policy->work); |
9bdcb44e RW |
497 | } |
498 | ||
499 | /************************** sysfs interface ************************/ | |
500 | ||
501 | static struct sugov_tunables *global_tunables; | |
502 | static DEFINE_MUTEX(global_tunables_lock); | |
503 | ||
504 | static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set) | |
505 | { | |
506 | return container_of(attr_set, struct sugov_tunables, attr_set); | |
507 | } | |
508 | ||
509 | static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) | |
510 | { | |
511 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
512 | ||
513 | return sprintf(buf, "%u\n", tunables->rate_limit_us); | |
514 | } | |
515 | ||
97fb7a0a IM |
516 | static ssize_t |
517 | rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count) | |
9bdcb44e RW |
518 | { |
519 | struct sugov_tunables *tunables = to_sugov_tunables(attr_set); | |
520 | struct sugov_policy *sg_policy; | |
521 | unsigned int rate_limit_us; | |
522 | ||
523 | if (kstrtouint(buf, 10, &rate_limit_us)) | |
524 | return -EINVAL; | |
525 | ||
526 | tunables->rate_limit_us = rate_limit_us; | |
527 | ||
528 | list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) | |
529 | sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC; | |
530 | ||
531 | return count; | |
532 | } | |
533 | ||
534 | static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us); | |
535 | ||
9782adeb | 536 | static struct attribute *sugov_attrs[] = { |
9bdcb44e RW |
537 | &rate_limit_us.attr, |
538 | NULL | |
539 | }; | |
9782adeb | 540 | ATTRIBUTE_GROUPS(sugov); |
9bdcb44e | 541 | |
e5c6b312 KH |
542 | static void sugov_tunables_free(struct kobject *kobj) |
543 | { | |
53725c4c | 544 | struct gov_attr_set *attr_set = to_gov_attr_set(kobj); |
e5c6b312 KH |
545 | |
546 | kfree(to_sugov_tunables(attr_set)); | |
547 | } | |
548 | ||
70ba26cb | 549 | static const struct kobj_type sugov_tunables_ktype = { |
9782adeb | 550 | .default_groups = sugov_groups, |
9bdcb44e | 551 | .sysfs_ops = &governor_sysfs_ops, |
e5c6b312 | 552 | .release = &sugov_tunables_free, |
9bdcb44e RW |
553 | }; |
554 | ||
555 | /********************** cpufreq governor interface *********************/ | |
556 | ||
531b5c9f | 557 | struct cpufreq_governor schedutil_gov; |
9bdcb44e RW |
558 | |
559 | static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) | |
560 | { | |
561 | struct sugov_policy *sg_policy; | |
562 | ||
563 | sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL); | |
564 | if (!sg_policy) | |
565 | return NULL; | |
566 | ||
567 | sg_policy->policy = policy; | |
9bdcb44e RW |
568 | raw_spin_lock_init(&sg_policy->update_lock); |
569 | return sg_policy; | |
570 | } | |
571 | ||
572 | static void sugov_policy_free(struct sugov_policy *sg_policy) | |
573 | { | |
9bdcb44e RW |
574 | kfree(sg_policy); |
575 | } | |
576 | ||
02a7b1ee VK |
577 | static int sugov_kthread_create(struct sugov_policy *sg_policy) |
578 | { | |
579 | struct task_struct *thread; | |
794a56eb | 580 | struct sched_attr attr = { |
97fb7a0a IM |
581 | .size = sizeof(struct sched_attr), |
582 | .sched_policy = SCHED_DEADLINE, | |
583 | .sched_flags = SCHED_FLAG_SUGOV, | |
584 | .sched_nice = 0, | |
585 | .sched_priority = 0, | |
794a56eb JL |
586 | /* |
587 | * Fake (unused) bandwidth; workaround to "fix" | |
588 | * priority inheritance. | |
589 | */ | |
590 | .sched_runtime = 1000000, | |
591 | .sched_deadline = 10000000, | |
592 | .sched_period = 10000000, | |
593 | }; | |
02a7b1ee VK |
594 | struct cpufreq_policy *policy = sg_policy->policy; |
595 | int ret; | |
596 | ||
597 | /* kthread only required for slow path */ | |
598 | if (policy->fast_switch_enabled) | |
599 | return 0; | |
600 | ||
601 | kthread_init_work(&sg_policy->work, sugov_work); | |
602 | kthread_init_worker(&sg_policy->worker); | |
603 | thread = kthread_create(kthread_worker_fn, &sg_policy->worker, | |
604 | "sugov:%d", | |
605 | cpumask_first(policy->related_cpus)); | |
606 | if (IS_ERR(thread)) { | |
607 | pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread)); | |
608 | return PTR_ERR(thread); | |
609 | } | |
610 | ||
794a56eb | 611 | ret = sched_setattr_nocheck(thread, &attr); |
02a7b1ee VK |
612 | if (ret) { |
613 | kthread_stop(thread); | |
794a56eb | 614 | pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); |
02a7b1ee VK |
615 | return ret; |
616 | } | |
617 | ||
618 | sg_policy->thread = thread; | |
1b04722c | 619 | kthread_bind_mask(thread, policy->related_cpus); |
21ef5729 VK |
620 | init_irq_work(&sg_policy->irq_work, sugov_irq_work); |
621 | mutex_init(&sg_policy->work_lock); | |
622 | ||
02a7b1ee VK |
623 | wake_up_process(thread); |
624 | ||
625 | return 0; | |
626 | } | |
627 | ||
628 | static void sugov_kthread_stop(struct sugov_policy *sg_policy) | |
629 | { | |
630 | /* kthread only required for slow path */ | |
631 | if (sg_policy->policy->fast_switch_enabled) | |
632 | return; | |
633 | ||
634 | kthread_flush_worker(&sg_policy->worker); | |
635 | kthread_stop(sg_policy->thread); | |
21ef5729 | 636 | mutex_destroy(&sg_policy->work_lock); |
02a7b1ee VK |
637 | } |
638 | ||
9bdcb44e RW |
639 | static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy) |
640 | { | |
641 | struct sugov_tunables *tunables; | |
642 | ||
643 | tunables = kzalloc(sizeof(*tunables), GFP_KERNEL); | |
644 | if (tunables) { | |
645 | gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook); | |
646 | if (!have_governor_per_policy()) | |
647 | global_tunables = tunables; | |
648 | } | |
649 | return tunables; | |
650 | } | |
651 | ||
e5c6b312 | 652 | static void sugov_clear_global_tunables(void) |
9bdcb44e RW |
653 | { |
654 | if (!have_governor_per_policy()) | |
655 | global_tunables = NULL; | |
9bdcb44e RW |
656 | } |
657 | ||
658 | static int sugov_init(struct cpufreq_policy *policy) | |
659 | { | |
660 | struct sugov_policy *sg_policy; | |
661 | struct sugov_tunables *tunables; | |
9bdcb44e RW |
662 | int ret = 0; |
663 | ||
664 | /* State should be equivalent to EXIT */ | |
665 | if (policy->governor_data) | |
666 | return -EBUSY; | |
667 | ||
4a71ce43 VK |
668 | cpufreq_enable_fast_switch(policy); |
669 | ||
9bdcb44e | 670 | sg_policy = sugov_policy_alloc(policy); |
4a71ce43 VK |
671 | if (!sg_policy) { |
672 | ret = -ENOMEM; | |
673 | goto disable_fast_switch; | |
674 | } | |
9bdcb44e | 675 | |
02a7b1ee VK |
676 | ret = sugov_kthread_create(sg_policy); |
677 | if (ret) | |
678 | goto free_sg_policy; | |
679 | ||
9bdcb44e RW |
680 | mutex_lock(&global_tunables_lock); |
681 | ||
682 | if (global_tunables) { | |
683 | if (WARN_ON(have_governor_per_policy())) { | |
684 | ret = -EINVAL; | |
02a7b1ee | 685 | goto stop_kthread; |
9bdcb44e RW |
686 | } |
687 | policy->governor_data = sg_policy; | |
688 | sg_policy->tunables = global_tunables; | |
689 | ||
690 | gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook); | |
691 | goto out; | |
692 | } | |
693 | ||
694 | tunables = sugov_tunables_alloc(sg_policy); | |
695 | if (!tunables) { | |
696 | ret = -ENOMEM; | |
02a7b1ee | 697 | goto stop_kthread; |
9bdcb44e RW |
698 | } |
699 | ||
aa7519af | 700 | tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy); |
9bdcb44e RW |
701 | |
702 | policy->governor_data = sg_policy; | |
703 | sg_policy->tunables = tunables; | |
704 | ||
705 | ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype, | |
706 | get_governor_parent_kobj(policy), "%s", | |
707 | schedutil_gov.name); | |
708 | if (ret) | |
709 | goto fail; | |
710 | ||
8e2ddb03 | 711 | out: |
9bdcb44e | 712 | mutex_unlock(&global_tunables_lock); |
9bdcb44e RW |
713 | return 0; |
714 | ||
8e2ddb03 | 715 | fail: |
9a4f26cc | 716 | kobject_put(&tunables->attr_set.kobj); |
9bdcb44e | 717 | policy->governor_data = NULL; |
e5c6b312 | 718 | sugov_clear_global_tunables(); |
9bdcb44e | 719 | |
02a7b1ee VK |
720 | stop_kthread: |
721 | sugov_kthread_stop(sg_policy); | |
9bdcb44e RW |
722 | mutex_unlock(&global_tunables_lock); |
723 | ||
1b5d43cf | 724 | free_sg_policy: |
9bdcb44e | 725 | sugov_policy_free(sg_policy); |
4a71ce43 VK |
726 | |
727 | disable_fast_switch: | |
728 | cpufreq_disable_fast_switch(policy); | |
729 | ||
60f05e86 | 730 | pr_err("initialization failed (error %d)\n", ret); |
9bdcb44e RW |
731 | return ret; |
732 | } | |
733 | ||
e788892b | 734 | static void sugov_exit(struct cpufreq_policy *policy) |
9bdcb44e RW |
735 | { |
736 | struct sugov_policy *sg_policy = policy->governor_data; | |
737 | struct sugov_tunables *tunables = sg_policy->tunables; | |
738 | unsigned int count; | |
739 | ||
740 | mutex_lock(&global_tunables_lock); | |
741 | ||
742 | count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); | |
743 | policy->governor_data = NULL; | |
744 | if (!count) | |
e5c6b312 | 745 | sugov_clear_global_tunables(); |
9bdcb44e RW |
746 | |
747 | mutex_unlock(&global_tunables_lock); | |
748 | ||
02a7b1ee | 749 | sugov_kthread_stop(sg_policy); |
9bdcb44e | 750 | sugov_policy_free(sg_policy); |
4a71ce43 | 751 | cpufreq_disable_fast_switch(policy); |
9bdcb44e RW |
752 | } |
753 | ||
754 | static int sugov_start(struct cpufreq_policy *policy) | |
755 | { | |
756 | struct sugov_policy *sg_policy = policy->governor_data; | |
ee2cc427 | 757 | void (*uu)(struct update_util_data *data, u64 time, unsigned int flags); |
cdcc5ef2 | 758 | unsigned int cpu; |
9bdcb44e | 759 | |
97fb7a0a IM |
760 | sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC; |
761 | sg_policy->last_freq_update_time = 0; | |
ecd28842 | 762 | sg_policy->next_freq = 0; |
97fb7a0a | 763 | sg_policy->work_in_progress = false; |
600f5bad | 764 | sg_policy->limits_changed = false; |
97fb7a0a | 765 | sg_policy->cached_raw_freq = 0; |
9bdcb44e | 766 | |
23a88185 VK |
767 | sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); |
768 | ||
9bdcb44e RW |
769 | for_each_cpu(cpu, policy->cpus) { |
770 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
771 | ||
4296f23e | 772 | memset(sg_cpu, 0, sizeof(*sg_cpu)); |
97fb7a0a IM |
773 | sg_cpu->cpu = cpu; |
774 | sg_cpu->sg_policy = sg_policy; | |
ab2f7cf1 VM |
775 | } |
776 | ||
ee2cc427 RW |
777 | if (policy_is_shared(policy)) |
778 | uu = sugov_update_shared; | |
779 | else if (policy->fast_switch_enabled && cpufreq_driver_has_adjust_perf()) | |
780 | uu = sugov_update_single_perf; | |
781 | else | |
782 | uu = sugov_update_single_freq; | |
783 | ||
ab2f7cf1 VM |
784 | for_each_cpu(cpu, policy->cpus) { |
785 | struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); | |
786 | ||
ee2cc427 | 787 | cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, uu); |
9bdcb44e RW |
788 | } |
789 | return 0; | |
790 | } | |
791 | ||
e788892b | 792 | static void sugov_stop(struct cpufreq_policy *policy) |
9bdcb44e RW |
793 | { |
794 | struct sugov_policy *sg_policy = policy->governor_data; | |
795 | unsigned int cpu; | |
796 | ||
797 | for_each_cpu(cpu, policy->cpus) | |
798 | cpufreq_remove_update_util_hook(cpu); | |
799 | ||
b290ebcf | 800 | synchronize_rcu(); |
9bdcb44e | 801 | |
21ef5729 VK |
802 | if (!policy->fast_switch_enabled) { |
803 | irq_work_sync(&sg_policy->irq_work); | |
804 | kthread_cancel_work_sync(&sg_policy->work); | |
805 | } | |
9bdcb44e RW |
806 | } |
807 | ||
e788892b | 808 | static void sugov_limits(struct cpufreq_policy *policy) |
9bdcb44e RW |
809 | { |
810 | struct sugov_policy *sg_policy = policy->governor_data; | |
811 | ||
812 | if (!policy->fast_switch_enabled) { | |
813 | mutex_lock(&sg_policy->work_lock); | |
bf2be2de | 814 | cpufreq_policy_apply_limits(policy); |
9bdcb44e RW |
815 | mutex_unlock(&sg_policy->work_lock); |
816 | } | |
817 | ||
600f5bad | 818 | sg_policy->limits_changed = true; |
9bdcb44e RW |
819 | } |
820 | ||
531b5c9f | 821 | struct cpufreq_governor schedutil_gov = { |
97fb7a0a IM |
822 | .name = "schedutil", |
823 | .owner = THIS_MODULE, | |
9a2a9ebc | 824 | .flags = CPUFREQ_GOV_DYNAMIC_SWITCHING, |
97fb7a0a IM |
825 | .init = sugov_init, |
826 | .exit = sugov_exit, | |
827 | .start = sugov_start, | |
828 | .stop = sugov_stop, | |
829 | .limits = sugov_limits, | |
9bdcb44e RW |
830 | }; |
831 | ||
9bdcb44e RW |
832 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL |
833 | struct cpufreq_governor *cpufreq_default_governor(void) | |
834 | { | |
835 | return &schedutil_gov; | |
836 | } | |
9bdcb44e | 837 | #endif |
58919e83 | 838 | |
10dd8573 | 839 | cpufreq_governor_init(schedutil_gov); |
531b5c9f QP |
840 | |
841 | #ifdef CONFIG_ENERGY_MODEL | |
531b5c9f QP |
842 | static void rebuild_sd_workfn(struct work_struct *work) |
843 | { | |
31f6a8c0 | 844 | rebuild_sched_domains_energy(); |
531b5c9f QP |
845 | } |
846 | static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); | |
847 | ||
848 | /* | |
849 | * EAS shouldn't be attempted without sugov, so rebuild the sched_domains | |
850 | * on governor changes to make sure the scheduler knows about it. | |
851 | */ | |
852 | void sched_cpufreq_governor_change(struct cpufreq_policy *policy, | |
853 | struct cpufreq_governor *old_gov) | |
854 | { | |
855 | if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) { | |
856 | /* | |
857 | * When called from the cpufreq_register_driver() path, the | |
858 | * cpu_hotplug_lock is already held, so use a work item to | |
859 | * avoid nested locking in rebuild_sched_domains(). | |
860 | */ | |
861 | schedule_work(&rebuild_sd_work); | |
862 | } | |
863 | ||
864 | } | |
865 | #endif |