xref: /linux/mm/damon/sysfs.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DAMON sysfs Interface
4  *
5  * Copyright (c) 2022 SeongJae Park <sj@kernel.org>
6  */
7 
8 #include <linux/pid.h>
9 #include <linux/sched.h>
10 #include <linux/slab.h>
11 
12 #include "sysfs-common.h"
13 
14 /*
15  * init region directory
16  */
17 
18 struct damon_sysfs_region {
19 	struct kobject kobj;
20 	struct damon_addr_range ar;
21 };
22 
23 static struct damon_sysfs_region *damon_sysfs_region_alloc(void)
24 {
25 	return kzalloc_obj(struct damon_sysfs_region);
26 }
27 
28 static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
29 		char *buf)
30 {
31 	struct damon_sysfs_region *region = container_of(kobj,
32 			struct damon_sysfs_region, kobj);
33 
34 	return sysfs_emit(buf, "%lu\n", region->ar.start);
35 }
36 
37 static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
38 		const char *buf, size_t count)
39 {
40 	struct damon_sysfs_region *region = container_of(kobj,
41 			struct damon_sysfs_region, kobj);
42 	int err = kstrtoul(buf, 0, &region->ar.start);
43 
44 	return err ? err : count;
45 }
46 
47 static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
48 		char *buf)
49 {
50 	struct damon_sysfs_region *region = container_of(kobj,
51 			struct damon_sysfs_region, kobj);
52 
53 	return sysfs_emit(buf, "%lu\n", region->ar.end);
54 }
55 
56 static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
57 		const char *buf, size_t count)
58 {
59 	struct damon_sysfs_region *region = container_of(kobj,
60 			struct damon_sysfs_region, kobj);
61 	int err = kstrtoul(buf, 0, &region->ar.end);
62 
63 	return err ? err : count;
64 }
65 
66 static void damon_sysfs_region_release(struct kobject *kobj)
67 {
68 	kfree(container_of(kobj, struct damon_sysfs_region, kobj));
69 }
70 
71 static struct kobj_attribute damon_sysfs_region_start_attr =
72 		__ATTR_RW_MODE(start, 0600);
73 
74 static struct kobj_attribute damon_sysfs_region_end_attr =
75 		__ATTR_RW_MODE(end, 0600);
76 
77 static struct attribute *damon_sysfs_region_attrs[] = {
78 	&damon_sysfs_region_start_attr.attr,
79 	&damon_sysfs_region_end_attr.attr,
80 	NULL,
81 };
82 ATTRIBUTE_GROUPS(damon_sysfs_region);
83 
84 static const struct kobj_type damon_sysfs_region_ktype = {
85 	.release = damon_sysfs_region_release,
86 	.sysfs_ops = &kobj_sysfs_ops,
87 	.default_groups = damon_sysfs_region_groups,
88 };
89 
90 /*
91  * init_regions directory
92  */
93 
94 struct damon_sysfs_regions {
95 	struct kobject kobj;
96 	struct damon_sysfs_region **regions_arr;
97 	int nr;
98 };
99 
100 static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
101 {
102 	return kzalloc_obj(struct damon_sysfs_regions);
103 }
104 
105 static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)
106 {
107 	struct damon_sysfs_region **regions_arr = regions->regions_arr;
108 	int i;
109 
110 	for (i = 0; i < regions->nr; i++)
111 		kobject_put(&regions_arr[i]->kobj);
112 	regions->nr = 0;
113 	kfree(regions_arr);
114 	regions->regions_arr = NULL;
115 }
116 
117 static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
118 		int nr_regions)
119 {
120 	struct damon_sysfs_region **regions_arr, *region;
121 	int err, i;
122 
123 	damon_sysfs_regions_rm_dirs(regions);
124 	if (!nr_regions)
125 		return 0;
126 
127 	regions_arr = kmalloc_objs(*regions_arr, nr_regions,
128 				   GFP_KERNEL | __GFP_NOWARN);
129 	if (!regions_arr)
130 		return -ENOMEM;
131 	regions->regions_arr = regions_arr;
132 
133 	for (i = 0; i < nr_regions; i++) {
134 		region = damon_sysfs_region_alloc();
135 		if (!region) {
136 			damon_sysfs_regions_rm_dirs(regions);
137 			return -ENOMEM;
138 		}
139 
140 		err = kobject_init_and_add(&region->kobj,
141 				&damon_sysfs_region_ktype, &regions->kobj,
142 				"%d", i);
143 		if (err) {
144 			kobject_put(&region->kobj);
145 			damon_sysfs_regions_rm_dirs(regions);
146 			return err;
147 		}
148 
149 		regions_arr[i] = region;
150 		regions->nr++;
151 	}
152 	return 0;
153 }
154 
155 static ssize_t nr_regions_show(struct kobject *kobj,
156 		struct kobj_attribute *attr, char *buf)
157 {
158 	struct damon_sysfs_regions *regions = container_of(kobj,
159 			struct damon_sysfs_regions, kobj);
160 
161 	return sysfs_emit(buf, "%d\n", regions->nr);
162 }
163 
164 static ssize_t nr_regions_store(struct kobject *kobj,
165 		struct kobj_attribute *attr, const char *buf, size_t count)
166 {
167 	struct damon_sysfs_regions *regions;
168 	int nr, err = kstrtoint(buf, 0, &nr);
169 
170 	if (err)
171 		return err;
172 	if (nr < 0)
173 		return -EINVAL;
174 
175 	regions = container_of(kobj, struct damon_sysfs_regions, kobj);
176 
177 	if (!mutex_trylock(&damon_sysfs_lock))
178 		return -EBUSY;
179 	err = damon_sysfs_regions_add_dirs(regions, nr);
180 	mutex_unlock(&damon_sysfs_lock);
181 	if (err)
182 		return err;
183 
184 	return count;
185 }
186 
187 static void damon_sysfs_regions_release(struct kobject *kobj)
188 {
189 	kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
190 }
191 
192 static struct kobj_attribute damon_sysfs_regions_nr_attr =
193 		__ATTR_RW_MODE(nr_regions, 0600);
194 
195 static struct attribute *damon_sysfs_regions_attrs[] = {
196 	&damon_sysfs_regions_nr_attr.attr,
197 	NULL,
198 };
199 ATTRIBUTE_GROUPS(damon_sysfs_regions);
200 
201 static const struct kobj_type damon_sysfs_regions_ktype = {
202 	.release = damon_sysfs_regions_release,
203 	.sysfs_ops = &kobj_sysfs_ops,
204 	.default_groups = damon_sysfs_regions_groups,
205 };
206 
207 /*
208  * target directory
209  */
210 
211 struct damon_sysfs_target {
212 	struct kobject kobj;
213 	struct damon_sysfs_regions *regions;
214 	int pid;
215 	bool obsolete;
216 };
217 
218 static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
219 {
220 	return kzalloc_obj(struct damon_sysfs_target);
221 }
222 
223 static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
224 {
225 	struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
226 	int err;
227 
228 	if (!regions)
229 		return -ENOMEM;
230 
231 	err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
232 			&target->kobj, "regions");
233 	if (err)
234 		kobject_put(&regions->kobj);
235 	else
236 		target->regions = regions;
237 	return err;
238 }
239 
240 static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
241 {
242 	damon_sysfs_regions_rm_dirs(target->regions);
243 	kobject_put(&target->regions->kobj);
244 }
245 
246 static ssize_t pid_target_show(struct kobject *kobj,
247 		struct kobj_attribute *attr, char *buf)
248 {
249 	struct damon_sysfs_target *target = container_of(kobj,
250 			struct damon_sysfs_target, kobj);
251 
252 	return sysfs_emit(buf, "%d\n", target->pid);
253 }
254 
255 static ssize_t pid_target_store(struct kobject *kobj,
256 		struct kobj_attribute *attr, const char *buf, size_t count)
257 {
258 	struct damon_sysfs_target *target = container_of(kobj,
259 			struct damon_sysfs_target, kobj);
260 	int err = kstrtoint(buf, 0, &target->pid);
261 
262 	if (err)
263 		return -EINVAL;
264 	return count;
265 }
266 
267 static ssize_t obsolete_target_show(struct kobject *kobj,
268 		struct kobj_attribute *attr, char *buf)
269 {
270 	struct damon_sysfs_target *target = container_of(kobj,
271 			struct damon_sysfs_target, kobj);
272 
273 	return sysfs_emit(buf, "%c\n", target->obsolete ? 'Y' : 'N');
274 }
275 
276 static ssize_t obsolete_target_store(struct kobject *kobj,
277 		struct kobj_attribute *attr, const char *buf, size_t count)
278 {
279 	struct damon_sysfs_target *target = container_of(kobj,
280 			struct damon_sysfs_target, kobj);
281 	bool obsolete;
282 	int err = kstrtobool(buf, &obsolete);
283 
284 	if (err)
285 		return err;
286 	target->obsolete = obsolete;
287 	return count;
288 }
289 
290 static void damon_sysfs_target_release(struct kobject *kobj)
291 {
292 	kfree(container_of(kobj, struct damon_sysfs_target, kobj));
293 }
294 
295 static struct kobj_attribute damon_sysfs_target_pid_attr =
296 		__ATTR_RW_MODE(pid_target, 0600);
297 
298 static struct kobj_attribute damon_sysfs_target_obsolete_attr =
299 		__ATTR_RW_MODE(obsolete_target, 0600);
300 
301 static struct attribute *damon_sysfs_target_attrs[] = {
302 	&damon_sysfs_target_pid_attr.attr,
303 	&damon_sysfs_target_obsolete_attr.attr,
304 	NULL,
305 };
306 ATTRIBUTE_GROUPS(damon_sysfs_target);
307 
308 static const struct kobj_type damon_sysfs_target_ktype = {
309 	.release = damon_sysfs_target_release,
310 	.sysfs_ops = &kobj_sysfs_ops,
311 	.default_groups = damon_sysfs_target_groups,
312 };
313 
314 /*
315  * targets directory
316  */
317 
318 struct damon_sysfs_targets {
319 	struct kobject kobj;
320 	struct damon_sysfs_target **targets_arr;
321 	int nr;
322 };
323 
324 static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)
325 {
326 	return kzalloc_obj(struct damon_sysfs_targets);
327 }
328 
329 static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
330 {
331 	struct damon_sysfs_target **targets_arr = targets->targets_arr;
332 	int i;
333 
334 	for (i = 0; i < targets->nr; i++) {
335 		damon_sysfs_target_rm_dirs(targets_arr[i]);
336 		kobject_put(&targets_arr[i]->kobj);
337 	}
338 	targets->nr = 0;
339 	kfree(targets_arr);
340 	targets->targets_arr = NULL;
341 }
342 
343 static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
344 		int nr_targets)
345 {
346 	struct damon_sysfs_target **targets_arr, *target;
347 	int err, i;
348 
349 	damon_sysfs_targets_rm_dirs(targets);
350 	if (!nr_targets)
351 		return 0;
352 
353 	targets_arr = kmalloc_objs(*targets_arr, nr_targets,
354 				   GFP_KERNEL | __GFP_NOWARN);
355 	if (!targets_arr)
356 		return -ENOMEM;
357 	targets->targets_arr = targets_arr;
358 
359 	for (i = 0; i < nr_targets; i++) {
360 		target = damon_sysfs_target_alloc();
361 		if (!target) {
362 			damon_sysfs_targets_rm_dirs(targets);
363 			return -ENOMEM;
364 		}
365 
366 		err = kobject_init_and_add(&target->kobj,
367 				&damon_sysfs_target_ktype, &targets->kobj,
368 				"%d", i);
369 		if (err)
370 			goto out;
371 
372 		err = damon_sysfs_target_add_dirs(target);
373 		if (err)
374 			goto out;
375 
376 		targets_arr[i] = target;
377 		targets->nr++;
378 	}
379 	return 0;
380 
381 out:
382 	damon_sysfs_targets_rm_dirs(targets);
383 	kobject_put(&target->kobj);
384 	return err;
385 }
386 
387 static ssize_t nr_targets_show(struct kobject *kobj,
388 		struct kobj_attribute *attr, char *buf)
389 {
390 	struct damon_sysfs_targets *targets = container_of(kobj,
391 			struct damon_sysfs_targets, kobj);
392 
393 	return sysfs_emit(buf, "%d\n", targets->nr);
394 }
395 
396 static ssize_t nr_targets_store(struct kobject *kobj,
397 		struct kobj_attribute *attr, const char *buf, size_t count)
398 {
399 	struct damon_sysfs_targets *targets;
400 	int nr, err = kstrtoint(buf, 0, &nr);
401 
402 	if (err)
403 		return err;
404 	if (nr < 0)
405 		return -EINVAL;
406 
407 	targets = container_of(kobj, struct damon_sysfs_targets, kobj);
408 
409 	if (!mutex_trylock(&damon_sysfs_lock))
410 		return -EBUSY;
411 	err = damon_sysfs_targets_add_dirs(targets, nr);
412 	mutex_unlock(&damon_sysfs_lock);
413 	if (err)
414 		return err;
415 
416 	return count;
417 }
418 
419 static void damon_sysfs_targets_release(struct kobject *kobj)
420 {
421 	kfree(container_of(kobj, struct damon_sysfs_targets, kobj));
422 }
423 
424 static struct kobj_attribute damon_sysfs_targets_nr_attr =
425 		__ATTR_RW_MODE(nr_targets, 0600);
426 
427 static struct attribute *damon_sysfs_targets_attrs[] = {
428 	&damon_sysfs_targets_nr_attr.attr,
429 	NULL,
430 };
431 ATTRIBUTE_GROUPS(damon_sysfs_targets);
432 
433 static const struct kobj_type damon_sysfs_targets_ktype = {
434 	.release = damon_sysfs_targets_release,
435 	.sysfs_ops = &kobj_sysfs_ops,
436 	.default_groups = damon_sysfs_targets_groups,
437 };
438 
439 /*
440  * intervals goal directory
441  */
442 
443 struct damon_sysfs_intervals_goal {
444 	struct kobject kobj;
445 	unsigned long access_bp;
446 	unsigned long aggrs;
447 	unsigned long min_sample_us;
448 	unsigned long max_sample_us;
449 };
450 
451 static struct damon_sysfs_intervals_goal *damon_sysfs_intervals_goal_alloc(
452 		unsigned long access_bp, unsigned long aggrs,
453 		unsigned long min_sample_us, unsigned long max_sample_us)
454 {
455 	struct damon_sysfs_intervals_goal *goal = kmalloc_obj(*goal);
456 
457 	if (!goal)
458 		return NULL;
459 
460 	goal->kobj = (struct kobject){};
461 	goal->access_bp = access_bp;
462 	goal->aggrs = aggrs;
463 	goal->min_sample_us = min_sample_us;
464 	goal->max_sample_us = max_sample_us;
465 	return goal;
466 }
467 
468 static ssize_t access_bp_show(struct kobject *kobj,
469 		struct kobj_attribute *attr, char *buf)
470 {
471 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
472 			struct damon_sysfs_intervals_goal, kobj);
473 
474 	return sysfs_emit(buf, "%lu\n", goal->access_bp);
475 }
476 
477 static ssize_t access_bp_store(struct kobject *kobj,
478 		struct kobj_attribute *attr, const char *buf, size_t count)
479 {
480 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
481 			struct damon_sysfs_intervals_goal, kobj);
482 	unsigned long nr;
483 	int err = kstrtoul(buf, 0, &nr);
484 
485 	if (err)
486 		return err;
487 
488 	goal->access_bp = nr;
489 	return count;
490 }
491 
492 static ssize_t aggrs_show(struct kobject *kobj,
493 		struct kobj_attribute *attr, char *buf)
494 {
495 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
496 			struct damon_sysfs_intervals_goal, kobj);
497 
498 	return sysfs_emit(buf, "%lu\n", goal->aggrs);
499 }
500 
501 static ssize_t aggrs_store(struct kobject *kobj,
502 		struct kobj_attribute *attr, const char *buf, size_t count)
503 {
504 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
505 			struct damon_sysfs_intervals_goal, kobj);
506 	unsigned long nr;
507 	int err = kstrtoul(buf, 0, &nr);
508 
509 	if (err)
510 		return err;
511 
512 	goal->aggrs = nr;
513 	return count;
514 }
515 
516 static ssize_t min_sample_us_show(struct kobject *kobj,
517 		struct kobj_attribute *attr, char *buf)
518 {
519 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
520 			struct damon_sysfs_intervals_goal, kobj);
521 
522 	return sysfs_emit(buf, "%lu\n", goal->min_sample_us);
523 }
524 
525 static ssize_t min_sample_us_store(struct kobject *kobj,
526 		struct kobj_attribute *attr, const char *buf, size_t count)
527 {
528 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
529 			struct damon_sysfs_intervals_goal, kobj);
530 	unsigned long nr;
531 	int err = kstrtoul(buf, 0, &nr);
532 
533 	if (err)
534 		return err;
535 
536 	goal->min_sample_us = nr;
537 	return count;
538 }
539 
540 static ssize_t max_sample_us_show(struct kobject *kobj,
541 		struct kobj_attribute *attr, char *buf)
542 {
543 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
544 			struct damon_sysfs_intervals_goal, kobj);
545 
546 	return sysfs_emit(buf, "%lu\n", goal->max_sample_us);
547 }
548 
549 static ssize_t max_sample_us_store(struct kobject *kobj,
550 		struct kobj_attribute *attr, const char *buf, size_t count)
551 {
552 	struct damon_sysfs_intervals_goal *goal = container_of(kobj,
553 			struct damon_sysfs_intervals_goal, kobj);
554 	unsigned long nr;
555 	int err = kstrtoul(buf, 0, &nr);
556 
557 	if (err)
558 		return err;
559 
560 	goal->max_sample_us = nr;
561 	return count;
562 }
563 
564 static void damon_sysfs_intervals_goal_release(struct kobject *kobj)
565 {
566 	kfree(container_of(kobj, struct damon_sysfs_intervals_goal, kobj));
567 }
568 
569 static struct kobj_attribute damon_sysfs_intervals_goal_access_bp_attr =
570 		__ATTR_RW_MODE(access_bp, 0600);
571 
572 static struct kobj_attribute damon_sysfs_intervals_goal_aggrs_attr =
573 		__ATTR_RW_MODE(aggrs, 0600);
574 
575 static struct kobj_attribute damon_sysfs_intervals_goal_min_sample_us_attr =
576 		__ATTR_RW_MODE(min_sample_us, 0600);
577 
578 static struct kobj_attribute damon_sysfs_intervals_goal_max_sample_us_attr =
579 		__ATTR_RW_MODE(max_sample_us, 0600);
580 
581 static struct attribute *damon_sysfs_intervals_goal_attrs[] = {
582 	&damon_sysfs_intervals_goal_access_bp_attr.attr,
583 	&damon_sysfs_intervals_goal_aggrs_attr.attr,
584 	&damon_sysfs_intervals_goal_min_sample_us_attr.attr,
585 	&damon_sysfs_intervals_goal_max_sample_us_attr.attr,
586 	NULL,
587 };
588 ATTRIBUTE_GROUPS(damon_sysfs_intervals_goal);
589 
590 static const struct kobj_type damon_sysfs_intervals_goal_ktype = {
591 	.release = damon_sysfs_intervals_goal_release,
592 	.sysfs_ops = &kobj_sysfs_ops,
593 	.default_groups = damon_sysfs_intervals_goal_groups,
594 };
595 
596 /*
597  * intervals directory
598  */
599 
600 struct damon_sysfs_intervals {
601 	struct kobject kobj;
602 	unsigned long sample_us;
603 	unsigned long aggr_us;
604 	unsigned long update_us;
605 	struct damon_sysfs_intervals_goal *intervals_goal;
606 };
607 
608 static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
609 		unsigned long sample_us, unsigned long aggr_us,
610 		unsigned long update_us)
611 {
612 	struct damon_sysfs_intervals *intervals = kmalloc_obj(*intervals,
613 							      GFP_KERNEL);
614 
615 	if (!intervals)
616 		return NULL;
617 
618 	intervals->kobj = (struct kobject){};
619 	intervals->sample_us = sample_us;
620 	intervals->aggr_us = aggr_us;
621 	intervals->update_us = update_us;
622 	return intervals;
623 }
624 
625 static int damon_sysfs_intervals_add_dirs(struct damon_sysfs_intervals *intervals)
626 {
627 	struct damon_sysfs_intervals_goal *goal;
628 	int err;
629 
630 	goal = damon_sysfs_intervals_goal_alloc(0, 0, 0, 0);
631 	if (!goal)
632 		return -ENOMEM;
633 
634 	err = kobject_init_and_add(&goal->kobj,
635 			&damon_sysfs_intervals_goal_ktype, &intervals->kobj,
636 			"intervals_goal");
637 	if (err) {
638 		kobject_put(&goal->kobj);
639 		intervals->intervals_goal = NULL;
640 		return err;
641 	}
642 	intervals->intervals_goal = goal;
643 	return 0;
644 }
645 
646 static void damon_sysfs_intervals_rm_dirs(struct damon_sysfs_intervals *intervals)
647 {
648 	kobject_put(&intervals->intervals_goal->kobj);
649 }
650 
651 static ssize_t sample_us_show(struct kobject *kobj,
652 		struct kobj_attribute *attr, char *buf)
653 {
654 	struct damon_sysfs_intervals *intervals = container_of(kobj,
655 			struct damon_sysfs_intervals, kobj);
656 
657 	return sysfs_emit(buf, "%lu\n", intervals->sample_us);
658 }
659 
660 static ssize_t sample_us_store(struct kobject *kobj,
661 		struct kobj_attribute *attr, const char *buf, size_t count)
662 {
663 	struct damon_sysfs_intervals *intervals = container_of(kobj,
664 			struct damon_sysfs_intervals, kobj);
665 	unsigned long us;
666 	int err = kstrtoul(buf, 0, &us);
667 
668 	if (err)
669 		return err;
670 
671 	intervals->sample_us = us;
672 	return count;
673 }
674 
675 static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,
676 		char *buf)
677 {
678 	struct damon_sysfs_intervals *intervals = container_of(kobj,
679 			struct damon_sysfs_intervals, kobj);
680 
681 	return sysfs_emit(buf, "%lu\n", intervals->aggr_us);
682 }
683 
684 static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
685 		const char *buf, size_t count)
686 {
687 	struct damon_sysfs_intervals *intervals = container_of(kobj,
688 			struct damon_sysfs_intervals, kobj);
689 	unsigned long us;
690 	int err = kstrtoul(buf, 0, &us);
691 
692 	if (err)
693 		return err;
694 
695 	intervals->aggr_us = us;
696 	return count;
697 }
698 
699 static ssize_t update_us_show(struct kobject *kobj,
700 		struct kobj_attribute *attr, char *buf)
701 {
702 	struct damon_sysfs_intervals *intervals = container_of(kobj,
703 			struct damon_sysfs_intervals, kobj);
704 
705 	return sysfs_emit(buf, "%lu\n", intervals->update_us);
706 }
707 
708 static ssize_t update_us_store(struct kobject *kobj,
709 		struct kobj_attribute *attr, const char *buf, size_t count)
710 {
711 	struct damon_sysfs_intervals *intervals = container_of(kobj,
712 			struct damon_sysfs_intervals, kobj);
713 	unsigned long us;
714 	int err = kstrtoul(buf, 0, &us);
715 
716 	if (err)
717 		return err;
718 
719 	intervals->update_us = us;
720 	return count;
721 }
722 
723 static void damon_sysfs_intervals_release(struct kobject *kobj)
724 {
725 	kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));
726 }
727 
728 static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =
729 		__ATTR_RW_MODE(sample_us, 0600);
730 
731 static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =
732 		__ATTR_RW_MODE(aggr_us, 0600);
733 
734 static struct kobj_attribute damon_sysfs_intervals_update_us_attr =
735 		__ATTR_RW_MODE(update_us, 0600);
736 
737 static struct attribute *damon_sysfs_intervals_attrs[] = {
738 	&damon_sysfs_intervals_sample_us_attr.attr,
739 	&damon_sysfs_intervals_aggr_us_attr.attr,
740 	&damon_sysfs_intervals_update_us_attr.attr,
741 	NULL,
742 };
743 ATTRIBUTE_GROUPS(damon_sysfs_intervals);
744 
745 static const struct kobj_type damon_sysfs_intervals_ktype = {
746 	.release = damon_sysfs_intervals_release,
747 	.sysfs_ops = &kobj_sysfs_ops,
748 	.default_groups = damon_sysfs_intervals_groups,
749 };
750 
751 /*
752  * monitoring_attrs directory
753  */
754 
755 struct damon_sysfs_attrs {
756 	struct kobject kobj;
757 	struct damon_sysfs_intervals *intervals;
758 	struct damon_sysfs_ul_range *nr_regions_range;
759 };
760 
761 static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)
762 {
763 	struct damon_sysfs_attrs *attrs = kmalloc_obj(*attrs);
764 
765 	if (!attrs)
766 		return NULL;
767 	attrs->kobj = (struct kobject){};
768 	return attrs;
769 }
770 
771 static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
772 {
773 	struct damon_sysfs_intervals *intervals;
774 	struct damon_sysfs_ul_range *nr_regions_range;
775 	int err;
776 
777 	intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);
778 	if (!intervals)
779 		return -ENOMEM;
780 
781 	err = kobject_init_and_add(&intervals->kobj,
782 			&damon_sysfs_intervals_ktype, &attrs->kobj,
783 			"intervals");
784 	if (err)
785 		goto put_intervals_out;
786 	err = damon_sysfs_intervals_add_dirs(intervals);
787 	if (err)
788 		goto put_intervals_out;
789 	attrs->intervals = intervals;
790 
791 	nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);
792 	if (!nr_regions_range) {
793 		err = -ENOMEM;
794 		goto rmdir_put_intervals_out;
795 	}
796 
797 	err = kobject_init_and_add(&nr_regions_range->kobj,
798 			&damon_sysfs_ul_range_ktype, &attrs->kobj,
799 			"nr_regions");
800 	if (err)
801 		goto put_nr_regions_intervals_out;
802 	attrs->nr_regions_range = nr_regions_range;
803 	return 0;
804 
805 put_nr_regions_intervals_out:
806 	kobject_put(&nr_regions_range->kobj);
807 	attrs->nr_regions_range = NULL;
808 rmdir_put_intervals_out:
809 	damon_sysfs_intervals_rm_dirs(intervals);
810 put_intervals_out:
811 	kobject_put(&intervals->kobj);
812 	attrs->intervals = NULL;
813 	return err;
814 }
815 
816 static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
817 {
818 	kobject_put(&attrs->nr_regions_range->kobj);
819 	damon_sysfs_intervals_rm_dirs(attrs->intervals);
820 	kobject_put(&attrs->intervals->kobj);
821 }
822 
823 static void damon_sysfs_attrs_release(struct kobject *kobj)
824 {
825 	kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));
826 }
827 
828 static struct attribute *damon_sysfs_attrs_attrs[] = {
829 	NULL,
830 };
831 ATTRIBUTE_GROUPS(damon_sysfs_attrs);
832 
833 static const struct kobj_type damon_sysfs_attrs_ktype = {
834 	.release = damon_sysfs_attrs_release,
835 	.sysfs_ops = &kobj_sysfs_ops,
836 	.default_groups = damon_sysfs_attrs_groups,
837 };
838 
839 /*
840  * context directory
841  */
842 
843 struct damon_sysfs_ops_name {
844 	enum damon_ops_id ops_id;
845 	char *name;
846 };
847 
848 static const struct damon_sysfs_ops_name damon_sysfs_ops_names[] = {
849 	{
850 		.ops_id = DAMON_OPS_VADDR,
851 		.name = "vaddr",
852 	},
853 	{
854 		.ops_id = DAMON_OPS_FVADDR,
855 		.name = "fvaddr",
856 	},
857 	{
858 		.ops_id = DAMON_OPS_PADDR,
859 		.name = "paddr",
860 	},
861 };
862 
863 struct damon_sysfs_context {
864 	struct kobject kobj;
865 	enum damon_ops_id ops_id;
866 	unsigned long addr_unit;
867 	struct damon_sysfs_attrs *attrs;
868 	struct damon_sysfs_targets *targets;
869 	struct damon_sysfs_schemes *schemes;
870 };
871 
872 static struct damon_sysfs_context *damon_sysfs_context_alloc(
873 		enum damon_ops_id ops_id)
874 {
875 	struct damon_sysfs_context *context = kmalloc_obj(*context);
876 
877 	if (!context)
878 		return NULL;
879 	context->kobj = (struct kobject){};
880 	context->ops_id = ops_id;
881 	context->addr_unit = 1;
882 	return context;
883 }
884 
885 static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)
886 {
887 	struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();
888 	int err;
889 
890 	if (!attrs)
891 		return -ENOMEM;
892 	err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,
893 			&context->kobj, "monitoring_attrs");
894 	if (err)
895 		goto out;
896 	err = damon_sysfs_attrs_add_dirs(attrs);
897 	if (err)
898 		goto out;
899 	context->attrs = attrs;
900 	return 0;
901 
902 out:
903 	kobject_put(&attrs->kobj);
904 	return err;
905 }
906 
907 static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)
908 {
909 	struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();
910 	int err;
911 
912 	if (!targets)
913 		return -ENOMEM;
914 	err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,
915 			&context->kobj, "targets");
916 	if (err) {
917 		kobject_put(&targets->kobj);
918 		return err;
919 	}
920 	context->targets = targets;
921 	return 0;
922 }
923 
924 static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)
925 {
926 	struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();
927 	int err;
928 
929 	if (!schemes)
930 		return -ENOMEM;
931 	err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,
932 			&context->kobj, "schemes");
933 	if (err) {
934 		kobject_put(&schemes->kobj);
935 		return err;
936 	}
937 	context->schemes = schemes;
938 	return 0;
939 }
940 
941 static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)
942 {
943 	int err;
944 
945 	err = damon_sysfs_context_set_attrs(context);
946 	if (err)
947 		return err;
948 
949 	err = damon_sysfs_context_set_targets(context);
950 	if (err)
951 		goto rmdir_put_attrs_out;
952 
953 	err = damon_sysfs_context_set_schemes(context);
954 	if (err)
955 		goto put_targets_attrs_out;
956 	return 0;
957 
958 put_targets_attrs_out:
959 	kobject_put(&context->targets->kobj);
960 	context->targets = NULL;
961 rmdir_put_attrs_out:
962 	damon_sysfs_attrs_rm_dirs(context->attrs);
963 	kobject_put(&context->attrs->kobj);
964 	context->attrs = NULL;
965 	return err;
966 }
967 
968 static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)
969 {
970 	damon_sysfs_attrs_rm_dirs(context->attrs);
971 	kobject_put(&context->attrs->kobj);
972 	damon_sysfs_targets_rm_dirs(context->targets);
973 	kobject_put(&context->targets->kobj);
974 	damon_sysfs_schemes_rm_dirs(context->schemes);
975 	kobject_put(&context->schemes->kobj);
976 }
977 
978 static ssize_t avail_operations_show(struct kobject *kobj,
979 		struct kobj_attribute *attr, char *buf)
980 {
981 	int len = 0;
982 	int i;
983 
984 	for (i = 0; i < ARRAY_SIZE(damon_sysfs_ops_names); i++) {
985 		const struct damon_sysfs_ops_name *ops_name;
986 
987 		ops_name = &damon_sysfs_ops_names[i];
988 		if (!damon_is_registered_ops(ops_name->ops_id))
989 			continue;
990 		len += sysfs_emit_at(buf, len, "%s\n", ops_name->name);
991 	}
992 	return len;
993 }
994 
995 static ssize_t operations_show(struct kobject *kobj,
996 		struct kobj_attribute *attr, char *buf)
997 {
998 	struct damon_sysfs_context *context = container_of(kobj,
999 			struct damon_sysfs_context, kobj);
1000 	int i;
1001 
1002 	for (i = 0; i < ARRAY_SIZE(damon_sysfs_ops_names); i++) {
1003 		const struct damon_sysfs_ops_name *ops_name;
1004 
1005 		ops_name = &damon_sysfs_ops_names[i];
1006 		if (ops_name->ops_id == context->ops_id)
1007 			return sysfs_emit(buf, "%s\n", ops_name->name);
1008 	}
1009 	return -EINVAL;
1010 }
1011 
1012 static ssize_t operations_store(struct kobject *kobj,
1013 		struct kobj_attribute *attr, const char *buf, size_t count)
1014 {
1015 	struct damon_sysfs_context *context = container_of(kobj,
1016 			struct damon_sysfs_context, kobj);
1017 	int i;
1018 
1019 	for (i = 0; i < ARRAY_SIZE(damon_sysfs_ops_names); i++) {
1020 		const struct damon_sysfs_ops_name *ops_name;
1021 
1022 		ops_name = &damon_sysfs_ops_names[i];
1023 		if (sysfs_streq(buf, ops_name->name)) {
1024 			context->ops_id = ops_name->ops_id;
1025 			return count;
1026 		}
1027 	}
1028 	return -EINVAL;
1029 }
1030 
1031 static ssize_t addr_unit_show(struct kobject *kobj,
1032 		struct kobj_attribute *attr, char *buf)
1033 {
1034 	struct damon_sysfs_context *context = container_of(kobj,
1035 			struct damon_sysfs_context, kobj);
1036 
1037 	return sysfs_emit(buf, "%lu\n", context->addr_unit);
1038 }
1039 
1040 static ssize_t addr_unit_store(struct kobject *kobj,
1041 		struct kobj_attribute *attr, const char *buf, size_t count)
1042 {
1043 	struct damon_sysfs_context *context = container_of(kobj,
1044 			struct damon_sysfs_context, kobj);
1045 	unsigned long input_addr_unit;
1046 	int err = kstrtoul(buf, 0, &input_addr_unit);
1047 
1048 	if (err)
1049 		return err;
1050 	if (!input_addr_unit)
1051 		return -EINVAL;
1052 
1053 	context->addr_unit = input_addr_unit;
1054 	return count;
1055 }
1056 
1057 static void damon_sysfs_context_release(struct kobject *kobj)
1058 {
1059 	kfree(container_of(kobj, struct damon_sysfs_context, kobj));
1060 }
1061 
1062 static struct kobj_attribute damon_sysfs_context_avail_operations_attr =
1063 		__ATTR_RO_MODE(avail_operations, 0400);
1064 
1065 static struct kobj_attribute damon_sysfs_context_operations_attr =
1066 		__ATTR_RW_MODE(operations, 0600);
1067 
1068 static struct kobj_attribute damon_sysfs_context_addr_unit_attr =
1069 		__ATTR_RW_MODE(addr_unit, 0600);
1070 
1071 static struct attribute *damon_sysfs_context_attrs[] = {
1072 	&damon_sysfs_context_avail_operations_attr.attr,
1073 	&damon_sysfs_context_operations_attr.attr,
1074 	&damon_sysfs_context_addr_unit_attr.attr,
1075 	NULL,
1076 };
1077 ATTRIBUTE_GROUPS(damon_sysfs_context);
1078 
1079 static const struct kobj_type damon_sysfs_context_ktype = {
1080 	.release = damon_sysfs_context_release,
1081 	.sysfs_ops = &kobj_sysfs_ops,
1082 	.default_groups = damon_sysfs_context_groups,
1083 };
1084 
1085 /*
1086  * contexts directory
1087  */
1088 
1089 struct damon_sysfs_contexts {
1090 	struct kobject kobj;
1091 	struct damon_sysfs_context **contexts_arr;
1092 	int nr;
1093 };
1094 
1095 static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)
1096 {
1097 	return kzalloc_obj(struct damon_sysfs_contexts);
1098 }
1099 
1100 static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)
1101 {
1102 	struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;
1103 	int i;
1104 
1105 	for (i = 0; i < contexts->nr; i++) {
1106 		damon_sysfs_context_rm_dirs(contexts_arr[i]);
1107 		kobject_put(&contexts_arr[i]->kobj);
1108 	}
1109 	contexts->nr = 0;
1110 	kfree(contexts_arr);
1111 	contexts->contexts_arr = NULL;
1112 }
1113 
1114 static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,
1115 		int nr_contexts)
1116 {
1117 	struct damon_sysfs_context **contexts_arr, *context;
1118 	int err, i;
1119 
1120 	damon_sysfs_contexts_rm_dirs(contexts);
1121 	if (!nr_contexts)
1122 		return 0;
1123 
1124 	contexts_arr = kmalloc_objs(*contexts_arr, nr_contexts,
1125 				    GFP_KERNEL | __GFP_NOWARN);
1126 	if (!contexts_arr)
1127 		return -ENOMEM;
1128 	contexts->contexts_arr = contexts_arr;
1129 
1130 	for (i = 0; i < nr_contexts; i++) {
1131 		context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);
1132 		if (!context) {
1133 			damon_sysfs_contexts_rm_dirs(contexts);
1134 			return -ENOMEM;
1135 		}
1136 
1137 		err = kobject_init_and_add(&context->kobj,
1138 				&damon_sysfs_context_ktype, &contexts->kobj,
1139 				"%d", i);
1140 		if (err)
1141 			goto out;
1142 
1143 		err = damon_sysfs_context_add_dirs(context);
1144 		if (err)
1145 			goto out;
1146 
1147 		contexts_arr[i] = context;
1148 		contexts->nr++;
1149 	}
1150 	return 0;
1151 
1152 out:
1153 	damon_sysfs_contexts_rm_dirs(contexts);
1154 	kobject_put(&context->kobj);
1155 	return err;
1156 }
1157 
1158 static ssize_t nr_contexts_show(struct kobject *kobj,
1159 		struct kobj_attribute *attr, char *buf)
1160 {
1161 	struct damon_sysfs_contexts *contexts = container_of(kobj,
1162 			struct damon_sysfs_contexts, kobj);
1163 
1164 	return sysfs_emit(buf, "%d\n", contexts->nr);
1165 }
1166 
1167 static ssize_t nr_contexts_store(struct kobject *kobj,
1168 		struct kobj_attribute *attr, const char *buf, size_t count)
1169 {
1170 	struct damon_sysfs_contexts *contexts;
1171 	int nr, err;
1172 
1173 	err = kstrtoint(buf, 0, &nr);
1174 	if (err)
1175 		return err;
1176 	/* TODO: support multiple contexts per kdamond */
1177 	if (nr < 0 || 1 < nr)
1178 		return -EINVAL;
1179 
1180 	contexts = container_of(kobj, struct damon_sysfs_contexts, kobj);
1181 	if (!mutex_trylock(&damon_sysfs_lock))
1182 		return -EBUSY;
1183 	err = damon_sysfs_contexts_add_dirs(contexts, nr);
1184 	mutex_unlock(&damon_sysfs_lock);
1185 	if (err)
1186 		return err;
1187 
1188 	return count;
1189 }
1190 
1191 static void damon_sysfs_contexts_release(struct kobject *kobj)
1192 {
1193 	kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));
1194 }
1195 
1196 static struct kobj_attribute damon_sysfs_contexts_nr_attr
1197 		= __ATTR_RW_MODE(nr_contexts, 0600);
1198 
1199 static struct attribute *damon_sysfs_contexts_attrs[] = {
1200 	&damon_sysfs_contexts_nr_attr.attr,
1201 	NULL,
1202 };
1203 ATTRIBUTE_GROUPS(damon_sysfs_contexts);
1204 
1205 static const struct kobj_type damon_sysfs_contexts_ktype = {
1206 	.release = damon_sysfs_contexts_release,
1207 	.sysfs_ops = &kobj_sysfs_ops,
1208 	.default_groups = damon_sysfs_contexts_groups,
1209 };
1210 
1211 /*
1212  * kdamond directory
1213  */
1214 
1215 struct damon_sysfs_kdamond {
1216 	struct kobject kobj;
1217 	struct damon_sysfs_contexts *contexts;
1218 	struct damon_ctx *damon_ctx;
1219 	unsigned int refresh_ms;
1220 };
1221 
1222 static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
1223 {
1224 	return kzalloc_obj(struct damon_sysfs_kdamond);
1225 }
1226 
1227 static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)
1228 {
1229 	struct damon_sysfs_contexts *contexts;
1230 	int err;
1231 
1232 	contexts = damon_sysfs_contexts_alloc();
1233 	if (!contexts)
1234 		return -ENOMEM;
1235 
1236 	err = kobject_init_and_add(&contexts->kobj,
1237 			&damon_sysfs_contexts_ktype, &kdamond->kobj,
1238 			"contexts");
1239 	if (err) {
1240 		kobject_put(&contexts->kobj);
1241 		return err;
1242 	}
1243 	kdamond->contexts = contexts;
1244 
1245 	return err;
1246 }
1247 
1248 static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
1249 {
1250 	damon_sysfs_contexts_rm_dirs(kdamond->contexts);
1251 	kobject_put(&kdamond->contexts->kobj);
1252 }
1253 
1254 /*
1255  * enum damon_sysfs_cmd - Commands for a specific kdamond.
1256  */
1257 enum damon_sysfs_cmd {
1258 	/* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */
1259 	DAMON_SYSFS_CMD_ON,
1260 	/* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */
1261 	DAMON_SYSFS_CMD_OFF,
1262 	/* @DAMON_SYSFS_CMD_COMMIT: Update kdamond inputs. */
1263 	DAMON_SYSFS_CMD_COMMIT,
1264 	/*
1265 	 * @DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS: Commit the quota goals
1266 	 * to DAMON.
1267 	 */
1268 	DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS,
1269 	/*
1270 	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs
1271 	 * files.
1272 	 */
1273 	DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,
1274 	/*
1275 	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES: Update
1276 	 * tried_regions/total_bytes sysfs files for each scheme.
1277 	 */
1278 	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES,
1279 	/*
1280 	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS: Update schemes tried
1281 	 * regions
1282 	 */
1283 	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS,
1284 	/*
1285 	 * @DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: Clear schemes tried
1286 	 * regions
1287 	 */
1288 	DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS,
1289 	/*
1290 	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS: Update the
1291 	 * effective size quota of the scheme in bytes.
1292 	 */
1293 	DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS,
1294 	/*
1295 	 * @DAMON_SYSFS_CMD_UPDATE_TUNED_INTERVALS: Update the tuned monitoring
1296 	 * intervals.
1297 	 */
1298 	DAMON_SYSFS_CMD_UPDATE_TUNED_INTERVALS,
1299 	/*
1300 	 * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.
1301 	 */
1302 	NR_DAMON_SYSFS_CMDS,
1303 };
1304 
1305 /* Should match with enum damon_sysfs_cmd */
1306 static const char * const damon_sysfs_cmd_strs[] = {
1307 	"on",
1308 	"off",
1309 	"commit",
1310 	"commit_schemes_quota_goals",
1311 	"update_schemes_stats",
1312 	"update_schemes_tried_bytes",
1313 	"update_schemes_tried_regions",
1314 	"clear_schemes_tried_regions",
1315 	"update_schemes_effective_quotas",
1316 	"update_tuned_intervals",
1317 };
1318 
1319 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
1320 		char *buf)
1321 {
1322 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1323 			struct damon_sysfs_kdamond, kobj);
1324 	struct damon_ctx *ctx;
1325 	bool running = false;
1326 
1327 	if (!mutex_trylock(&damon_sysfs_lock))
1328 		return -EBUSY;
1329 
1330 	ctx = kdamond->damon_ctx;
1331 	if (ctx)
1332 		running = damon_is_running(ctx);
1333 
1334 	mutex_unlock(&damon_sysfs_lock);
1335 
1336 	return sysfs_emit(buf, "%s\n", running ?
1337 			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
1338 			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);
1339 }
1340 
1341 static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
1342 		struct damon_sysfs_attrs *sys_attrs)
1343 {
1344 	struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;
1345 	struct damon_sysfs_intervals_goal *sys_goal =
1346 		sys_intervals->intervals_goal;
1347 	struct damon_sysfs_ul_range *sys_nr_regions =
1348 		sys_attrs->nr_regions_range;
1349 	struct damon_attrs attrs = {
1350 		.sample_interval = sys_intervals->sample_us,
1351 		.aggr_interval = sys_intervals->aggr_us,
1352 		.intervals_goal = {
1353 			.access_bp = sys_goal->access_bp,
1354 			.aggrs = sys_goal->aggrs,
1355 			.min_sample_us = sys_goal->min_sample_us,
1356 			.max_sample_us = sys_goal->max_sample_us},
1357 		.ops_update_interval = sys_intervals->update_us,
1358 		.min_nr_regions = sys_nr_regions->min,
1359 		.max_nr_regions = sys_nr_regions->max,
1360 	};
1361 	return damon_set_attrs(ctx, &attrs);
1362 }
1363 
1364 static int damon_sysfs_set_regions(struct damon_target *t,
1365 		struct damon_sysfs_regions *sysfs_regions,
1366 		unsigned long min_region_sz)
1367 {
1368 	struct damon_addr_range *ranges = kmalloc_objs(*ranges,
1369 						       sysfs_regions->nr,
1370 						       GFP_KERNEL | __GFP_NOWARN);
1371 	int i, err = -EINVAL;
1372 
1373 	if (!ranges)
1374 		return -ENOMEM;
1375 	for (i = 0; i < sysfs_regions->nr; i++) {
1376 		struct damon_sysfs_region *sys_region =
1377 			sysfs_regions->regions_arr[i];
1378 
1379 		if (sys_region->ar.start > sys_region->ar.end)
1380 			goto out;
1381 
1382 		ranges[i].start = sys_region->ar.start;
1383 		ranges[i].end = sys_region->ar.end;
1384 		if (i == 0)
1385 			continue;
1386 		if (ranges[i - 1].end > ranges[i].start)
1387 			goto out;
1388 	}
1389 	err = damon_set_regions(t, ranges, sysfs_regions->nr, min_region_sz);
1390 out:
1391 	kfree(ranges);
1392 	return err;
1393 
1394 }
1395 
1396 static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
1397 		struct damon_ctx *ctx)
1398 {
1399 	struct damon_target *t = damon_new_target();
1400 
1401 	if (!t)
1402 		return -ENOMEM;
1403 	damon_add_target(ctx, t);
1404 	if (damon_target_has_pid(ctx)) {
1405 		t->pid = find_get_pid(sys_target->pid);
1406 		if (!t->pid)
1407 			/* caller will destroy targets */
1408 			return -EINVAL;
1409 	}
1410 	t->obsolete = sys_target->obsolete;
1411 	return damon_sysfs_set_regions(t, sys_target->regions,
1412 			ctx->min_region_sz);
1413 }
1414 
1415 static int damon_sysfs_add_targets(struct damon_ctx *ctx,
1416 		struct damon_sysfs_targets *sysfs_targets)
1417 {
1418 	int i, err;
1419 
1420 	/* Multiple physical address space monitoring targets makes no sense */
1421 	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
1422 		return -EINVAL;
1423 
1424 	for (i = 0; i < sysfs_targets->nr; i++) {
1425 		struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];
1426 
1427 		err = damon_sysfs_add_target(st, ctx);
1428 		if (err)
1429 			return err;
1430 	}
1431 	return 0;
1432 }
1433 
1434 /*
1435  * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.
1436  * @data:	The kobject wrapper that associated to the kdamond thread.
1437  *
1438  * This function reads the schemes stats of specific kdamond and update the
1439  * related values for sysfs files.  This function should be called from DAMON
1440  * worker thread,to safely access the DAMON contexts-internal data.  Caller
1441  * should also ensure holding ``damon_syfs_lock``, and ->damon_ctx of @data is
1442  * not NULL but a valid pointer, to safely access DAMON sysfs variables.
1443  */
1444 static int damon_sysfs_upd_schemes_stats(void *data)
1445 {
1446 	struct damon_sysfs_kdamond *kdamond = data;
1447 	struct damon_ctx *ctx = kdamond->damon_ctx;
1448 
1449 	damon_sysfs_schemes_update_stats(
1450 			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1451 	return 0;
1452 }
1453 
1454 static inline bool damon_sysfs_kdamond_running(
1455 		struct damon_sysfs_kdamond *kdamond)
1456 {
1457 	return kdamond->damon_ctx &&
1458 		damon_is_running(kdamond->damon_ctx);
1459 }
1460 
1461 static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
1462 		struct damon_sysfs_context *sys_ctx)
1463 {
1464 	int err;
1465 
1466 	err = damon_select_ops(ctx, sys_ctx->ops_id);
1467 	if (err)
1468 		return err;
1469 	ctx->addr_unit = sys_ctx->addr_unit;
1470 	/* addr_unit is respected by only DAMON_OPS_PADDR */
1471 	if (sys_ctx->ops_id == DAMON_OPS_PADDR)
1472 		ctx->min_region_sz = max(
1473 				DAMON_MIN_REGION_SZ / sys_ctx->addr_unit, 1);
1474 	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
1475 	if (err)
1476 		return err;
1477 	err = damon_sysfs_add_targets(ctx, sys_ctx->targets);
1478 	if (err)
1479 		return err;
1480 	return damon_sysfs_add_schemes(ctx, sys_ctx->schemes);
1481 }
1482 
1483 static struct damon_ctx *damon_sysfs_build_ctx(
1484 		struct damon_sysfs_context *sys_ctx);
1485 
1486 /*
1487  * Return a new damon_ctx for testing new parameters to commit.
1488  */
1489 static struct damon_ctx *damon_sysfs_new_test_ctx(
1490 		struct damon_ctx *running_ctx)
1491 {
1492 	struct damon_ctx *test_ctx;
1493 	int err;
1494 
1495 	test_ctx = damon_new_ctx();
1496 	if (!test_ctx)
1497 		return NULL;
1498 	err = damon_commit_ctx(test_ctx, running_ctx);
1499 	if (err) {
1500 		damon_destroy_ctx(test_ctx);
1501 		return NULL;
1502 	}
1503 	return test_ctx;
1504 }
1505 
1506 /*
1507  * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
1508  * @kdamond:	The kobject wrapper for the associated kdamond.
1509  *
1510  * Returns error if the sysfs input is wrong.
1511  */
1512 static int damon_sysfs_commit_input(void *data)
1513 {
1514 	struct damon_sysfs_kdamond *kdamond = data;
1515 	struct damon_ctx *param_ctx, *test_ctx;
1516 	int err;
1517 
1518 	if (!damon_sysfs_kdamond_running(kdamond))
1519 		return -EINVAL;
1520 	/* TODO: Support multiple contexts per kdamond */
1521 	if (kdamond->contexts->nr != 1)
1522 		return -EINVAL;
1523 
1524 	param_ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
1525 	if (IS_ERR(param_ctx))
1526 		return PTR_ERR(param_ctx);
1527 	test_ctx = damon_sysfs_new_test_ctx(kdamond->damon_ctx);
1528 	if (!test_ctx)
1529 		return -ENOMEM;
1530 	err = damon_commit_ctx(test_ctx, param_ctx);
1531 	if (err)
1532 		goto out;
1533 	err = damon_commit_ctx(kdamond->damon_ctx, param_ctx);
1534 out:
1535 	damon_destroy_ctx(test_ctx);
1536 	damon_destroy_ctx(param_ctx);
1537 	return err;
1538 }
1539 
1540 static int damon_sysfs_commit_schemes_quota_goals(void *data)
1541 {
1542 	struct damon_sysfs_kdamond *sysfs_kdamond = data;
1543 	struct damon_ctx *ctx;
1544 	struct damon_sysfs_context *sysfs_ctx;
1545 
1546 	if (!damon_sysfs_kdamond_running(sysfs_kdamond))
1547 		return -EINVAL;
1548 	/* TODO: Support multiple contexts per kdamond */
1549 	if (sysfs_kdamond->contexts->nr != 1)
1550 		return -EINVAL;
1551 
1552 	ctx = sysfs_kdamond->damon_ctx;
1553 	sysfs_ctx = sysfs_kdamond->contexts->contexts_arr[0];
1554 	return damos_sysfs_set_quota_scores(sysfs_ctx->schemes, ctx);
1555 }
1556 
1557 /*
1558  * damon_sysfs_upd_schemes_effective_quotas() - Update schemes effective quotas
1559  * sysfs files.
1560  * @data:	The kobject wrapper that associated to the kdamond thread.
1561  *
1562  * This function reads the schemes' effective quotas of specific kdamond and
1563  * update the related values for sysfs files.  This function should be called
1564  * from DAMON callbacks while holding ``damon_syfs_lock``, to safely access the
1565  * DAMON contexts-internal data and DAMON sysfs variables.
1566  */
1567 static int damon_sysfs_upd_schemes_effective_quotas(void *data)
1568 {
1569 	struct damon_sysfs_kdamond *kdamond = data;
1570 	struct damon_ctx *ctx = kdamond->damon_ctx;
1571 
1572 	damos_sysfs_update_effective_quotas(
1573 			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1574 	return 0;
1575 }
1576 
1577 static int damon_sysfs_upd_tuned_intervals(void *data)
1578 {
1579 	struct damon_sysfs_kdamond *kdamond = data;
1580 	struct damon_ctx *ctx = kdamond->damon_ctx;
1581 
1582 	kdamond->contexts->contexts_arr[0]->attrs->intervals->sample_us =
1583 		ctx->attrs.sample_interval;
1584 	kdamond->contexts->contexts_arr[0]->attrs->intervals->aggr_us =
1585 		ctx->attrs.aggr_interval;
1586 	return 0;
1587 }
1588 
1589 static struct damon_ctx *damon_sysfs_build_ctx(
1590 		struct damon_sysfs_context *sys_ctx)
1591 {
1592 	struct damon_ctx *ctx = damon_new_ctx();
1593 	int err;
1594 
1595 	if (!ctx)
1596 		return ERR_PTR(-ENOMEM);
1597 
1598 	err = damon_sysfs_apply_inputs(ctx, sys_ctx);
1599 	if (err) {
1600 		damon_destroy_ctx(ctx);
1601 		return ERR_PTR(err);
1602 	}
1603 
1604 	return ctx;
1605 }
1606 
1607 static unsigned long damon_sysfs_next_update_jiffies;
1608 
1609 static int damon_sysfs_repeat_call_fn(void *data)
1610 {
1611 	struct damon_sysfs_kdamond *sysfs_kdamond = data;
1612 
1613 	if (!sysfs_kdamond->refresh_ms)
1614 		return 0;
1615 	if (time_before(jiffies, damon_sysfs_next_update_jiffies))
1616 		return 0;
1617 	damon_sysfs_next_update_jiffies = jiffies +
1618 		msecs_to_jiffies(sysfs_kdamond->refresh_ms);
1619 
1620 	if (!mutex_trylock(&damon_sysfs_lock))
1621 		return 0;
1622 	damon_sysfs_upd_tuned_intervals(sysfs_kdamond);
1623 	damon_sysfs_upd_schemes_stats(sysfs_kdamond);
1624 	damon_sysfs_upd_schemes_effective_quotas(sysfs_kdamond);
1625 	mutex_unlock(&damon_sysfs_lock);
1626 	return 0;
1627 }
1628 
1629 static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
1630 {
1631 	struct damon_ctx *ctx;
1632 	struct damon_call_control *repeat_call_control;
1633 	int err;
1634 
1635 	if (damon_sysfs_kdamond_running(kdamond))
1636 		return -EBUSY;
1637 	/* TODO: support multiple contexts per kdamond */
1638 	if (kdamond->contexts->nr != 1)
1639 		return -EINVAL;
1640 
1641 	if (kdamond->damon_ctx)
1642 		damon_destroy_ctx(kdamond->damon_ctx);
1643 	kdamond->damon_ctx = NULL;
1644 
1645 	repeat_call_control = kmalloc_obj(*repeat_call_control);
1646 	if (!repeat_call_control)
1647 		return -ENOMEM;
1648 
1649 	ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
1650 	if (IS_ERR(ctx)) {
1651 		kfree(repeat_call_control);
1652 		return PTR_ERR(ctx);
1653 	}
1654 	err = damon_start(&ctx, 1, false);
1655 	if (err) {
1656 		kfree(repeat_call_control);
1657 		damon_destroy_ctx(ctx);
1658 		return err;
1659 	}
1660 	kdamond->damon_ctx = ctx;
1661 
1662 	damon_sysfs_next_update_jiffies =
1663 		jiffies + msecs_to_jiffies(kdamond->refresh_ms);
1664 
1665 	repeat_call_control->fn = damon_sysfs_repeat_call_fn;
1666 	repeat_call_control->data = kdamond;
1667 	repeat_call_control->repeat = true;
1668 	repeat_call_control->dealloc_on_cancel = true;
1669 	damon_call(ctx, repeat_call_control);
1670 	return err;
1671 }
1672 
1673 static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
1674 {
1675 	if (!kdamond->damon_ctx)
1676 		return -EINVAL;
1677 	return damon_stop(&kdamond->damon_ctx, 1);
1678 	/*
1679 	 * To allow users show final monitoring results of already turned-off
1680 	 * DAMON, we free kdamond->damon_ctx in next
1681 	 * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
1682 	 */
1683 }
1684 
1685 static int damon_sysfs_damon_call(int (*fn)(void *data),
1686 		struct damon_sysfs_kdamond *kdamond)
1687 {
1688 	struct damon_call_control call_control = {};
1689 	int err;
1690 
1691 	if (!kdamond->damon_ctx)
1692 		return -EINVAL;
1693 	call_control.fn = fn;
1694 	call_control.data = kdamond;
1695 	err = damon_call(kdamond->damon_ctx, &call_control);
1696 	return err ? err : call_control.return_code;
1697 }
1698 
1699 struct damon_sysfs_schemes_walk_data {
1700 	struct damon_sysfs_kdamond *sysfs_kdamond;
1701 	bool total_bytes_only;
1702 };
1703 
1704 /* populate the region directory */
1705 static void damon_sysfs_schemes_tried_regions_upd_one(void *data, struct damon_ctx *ctx,
1706 		struct damon_target *t, struct damon_region *r,
1707 		struct damos *s, unsigned long sz_filter_passed)
1708 {
1709 	struct damon_sysfs_schemes_walk_data *walk_data = data;
1710 	struct damon_sysfs_kdamond *sysfs_kdamond = walk_data->sysfs_kdamond;
1711 
1712 	damos_sysfs_populate_region_dir(
1713 			sysfs_kdamond->contexts->contexts_arr[0]->schemes,
1714 			ctx, t, r, s, walk_data->total_bytes_only,
1715 			sz_filter_passed);
1716 }
1717 
1718 static int damon_sysfs_update_schemes_tried_regions(
1719 		struct damon_sysfs_kdamond *sysfs_kdamond, bool total_bytes_only)
1720 {
1721 	struct damon_sysfs_schemes_walk_data walk_data = {
1722 		.sysfs_kdamond = sysfs_kdamond,
1723 		.total_bytes_only = total_bytes_only,
1724 	};
1725 	struct damos_walk_control control = {
1726 		.walk_fn = damon_sysfs_schemes_tried_regions_upd_one,
1727 		.data = &walk_data,
1728 	};
1729 	struct damon_ctx *ctx = sysfs_kdamond->damon_ctx;
1730 
1731 	if (!ctx)
1732 		return -EINVAL;
1733 
1734 	damon_sysfs_schemes_clear_regions(
1735 			sysfs_kdamond->contexts->contexts_arr[0]->schemes);
1736 	return damos_walk(ctx, &control);
1737 }
1738 
1739 /*
1740  * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
1741  * @cmd:	The command to handle.
1742  * @kdamond:	The kobject wrapper for the associated kdamond.
1743  *
1744  * This function handles a DAMON sysfs command for a kdamond.
1745  *
1746  * Return: 0 on success, negative error code otherwise.
1747  */
1748 static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
1749 		struct damon_sysfs_kdamond *kdamond)
1750 {
1751 	switch (cmd) {
1752 	case DAMON_SYSFS_CMD_ON:
1753 		return damon_sysfs_turn_damon_on(kdamond);
1754 	case DAMON_SYSFS_CMD_OFF:
1755 		return damon_sysfs_turn_damon_off(kdamond);
1756 	case DAMON_SYSFS_CMD_COMMIT:
1757 		return damon_sysfs_damon_call(
1758 				damon_sysfs_commit_input, kdamond);
1759 	case DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS:
1760 		return damon_sysfs_damon_call(
1761 				damon_sysfs_commit_schemes_quota_goals,
1762 				kdamond);
1763 	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
1764 		return damon_sysfs_damon_call(
1765 				damon_sysfs_upd_schemes_stats, kdamond);
1766 	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:
1767 		return damon_sysfs_update_schemes_tried_regions(kdamond, true);
1768 	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:
1769 		return damon_sysfs_update_schemes_tried_regions(kdamond, false);
1770 	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:
1771 		return damon_sysfs_schemes_clear_regions(
1772 			kdamond->contexts->contexts_arr[0]->schemes);
1773 	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS:
1774 		return damon_sysfs_damon_call(
1775 				damon_sysfs_upd_schemes_effective_quotas,
1776 				kdamond);
1777 	case DAMON_SYSFS_CMD_UPDATE_TUNED_INTERVALS:
1778 		return damon_sysfs_damon_call(
1779 				damon_sysfs_upd_tuned_intervals, kdamond);
1780 	default:
1781 		return -EINVAL;
1782 	}
1783 }
1784 
1785 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
1786 		const char *buf, size_t count)
1787 {
1788 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1789 			struct damon_sysfs_kdamond, kobj);
1790 	enum damon_sysfs_cmd cmd;
1791 	ssize_t ret = -EINVAL;
1792 
1793 	if (!mutex_trylock(&damon_sysfs_lock))
1794 		return -EBUSY;
1795 	for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
1796 		if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
1797 			ret = damon_sysfs_handle_cmd(cmd, kdamond);
1798 			break;
1799 		}
1800 	}
1801 	mutex_unlock(&damon_sysfs_lock);
1802 	if (!ret)
1803 		ret = count;
1804 	return ret;
1805 }
1806 
1807 static ssize_t pid_show(struct kobject *kobj,
1808 		struct kobj_attribute *attr, char *buf)
1809 {
1810 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1811 			struct damon_sysfs_kdamond, kobj);
1812 	struct damon_ctx *ctx;
1813 	int pid = -1;
1814 
1815 	if (!mutex_trylock(&damon_sysfs_lock))
1816 		return -EBUSY;
1817 	ctx = kdamond->damon_ctx;
1818 	if (!ctx)
1819 		goto out;
1820 
1821 	pid = damon_kdamond_pid(ctx);
1822 	if (pid < 0)
1823 		pid = -1;
1824 out:
1825 	mutex_unlock(&damon_sysfs_lock);
1826 	return sysfs_emit(buf, "%d\n", pid);
1827 }
1828 
1829 static ssize_t refresh_ms_show(struct kobject *kobj,
1830 		struct kobj_attribute *attr, char *buf)
1831 {
1832 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1833 			struct damon_sysfs_kdamond, kobj);
1834 
1835 	return sysfs_emit(buf, "%u\n", kdamond->refresh_ms);
1836 }
1837 
1838 static ssize_t refresh_ms_store(struct kobject *kobj,
1839 		struct kobj_attribute *attr, const char *buf, size_t count)
1840 {
1841 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1842 			struct damon_sysfs_kdamond, kobj);
1843 	unsigned int nr;
1844 	int err = kstrtouint(buf, 0, &nr);
1845 
1846 	if (err)
1847 		return err;
1848 
1849 	kdamond->refresh_ms = nr;
1850 	return count;
1851 }
1852 
1853 static void damon_sysfs_kdamond_release(struct kobject *kobj)
1854 {
1855 	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1856 			struct damon_sysfs_kdamond, kobj);
1857 
1858 	if (kdamond->damon_ctx)
1859 		damon_destroy_ctx(kdamond->damon_ctx);
1860 	kfree(kdamond);
1861 }
1862 
1863 static struct kobj_attribute damon_sysfs_kdamond_state_attr =
1864 		__ATTR_RW_MODE(state, 0600);
1865 
1866 static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
1867 		__ATTR_RO_MODE(pid, 0400);
1868 
1869 static struct kobj_attribute damon_sysfs_kdamond_refresh_ms_attr =
1870 		__ATTR_RW_MODE(refresh_ms, 0600);
1871 
1872 static struct attribute *damon_sysfs_kdamond_attrs[] = {
1873 	&damon_sysfs_kdamond_state_attr.attr,
1874 	&damon_sysfs_kdamond_pid_attr.attr,
1875 	&damon_sysfs_kdamond_refresh_ms_attr.attr,
1876 	NULL,
1877 };
1878 ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
1879 
1880 static const struct kobj_type damon_sysfs_kdamond_ktype = {
1881 	.release = damon_sysfs_kdamond_release,
1882 	.sysfs_ops = &kobj_sysfs_ops,
1883 	.default_groups = damon_sysfs_kdamond_groups,
1884 };
1885 
1886 /*
1887  * kdamonds directory
1888  */
1889 
1890 struct damon_sysfs_kdamonds {
1891 	struct kobject kobj;
1892 	struct damon_sysfs_kdamond **kdamonds_arr;
1893 	int nr;
1894 };
1895 
1896 static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
1897 {
1898 	return kzalloc_obj(struct damon_sysfs_kdamonds);
1899 }
1900 
1901 static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
1902 {
1903 	struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
1904 	int i;
1905 
1906 	for (i = 0; i < kdamonds->nr; i++) {
1907 		damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
1908 		kobject_put(&kdamonds_arr[i]->kobj);
1909 	}
1910 	kdamonds->nr = 0;
1911 	kfree(kdamonds_arr);
1912 	kdamonds->kdamonds_arr = NULL;
1913 }
1914 
1915 static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds,
1916 		int nr_kdamonds)
1917 {
1918 	int i;
1919 
1920 	for (i = 0; i < nr_kdamonds; i++) {
1921 		if (damon_sysfs_kdamond_running(kdamonds[i]))
1922 			return true;
1923 	}
1924 
1925 	return false;
1926 }
1927 
1928 static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
1929 		int nr_kdamonds)
1930 {
1931 	struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
1932 	int err, i;
1933 
1934 	if (damon_sysfs_kdamonds_busy(kdamonds->kdamonds_arr, kdamonds->nr))
1935 		return -EBUSY;
1936 
1937 	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1938 	if (!nr_kdamonds)
1939 		return 0;
1940 
1941 	kdamonds_arr = kmalloc_objs(*kdamonds_arr, nr_kdamonds,
1942 				    GFP_KERNEL | __GFP_NOWARN);
1943 	if (!kdamonds_arr)
1944 		return -ENOMEM;
1945 	kdamonds->kdamonds_arr = kdamonds_arr;
1946 
1947 	for (i = 0; i < nr_kdamonds; i++) {
1948 		kdamond = damon_sysfs_kdamond_alloc();
1949 		if (!kdamond) {
1950 			damon_sysfs_kdamonds_rm_dirs(kdamonds);
1951 			return -ENOMEM;
1952 		}
1953 
1954 		err = kobject_init_and_add(&kdamond->kobj,
1955 				&damon_sysfs_kdamond_ktype, &kdamonds->kobj,
1956 				"%d", i);
1957 		if (err)
1958 			goto out;
1959 
1960 		err = damon_sysfs_kdamond_add_dirs(kdamond);
1961 		if (err)
1962 			goto out;
1963 
1964 		kdamonds_arr[i] = kdamond;
1965 		kdamonds->nr++;
1966 	}
1967 	return 0;
1968 
1969 out:
1970 	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1971 	kobject_put(&kdamond->kobj);
1972 	return err;
1973 }
1974 
1975 static ssize_t nr_kdamonds_show(struct kobject *kobj,
1976 		struct kobj_attribute *attr, char *buf)
1977 {
1978 	struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
1979 			struct damon_sysfs_kdamonds, kobj);
1980 
1981 	return sysfs_emit(buf, "%d\n", kdamonds->nr);
1982 }
1983 
1984 static ssize_t nr_kdamonds_store(struct kobject *kobj,
1985 		struct kobj_attribute *attr, const char *buf, size_t count)
1986 {
1987 	struct damon_sysfs_kdamonds *kdamonds;
1988 	int nr, err;
1989 
1990 	err = kstrtoint(buf, 0, &nr);
1991 	if (err)
1992 		return err;
1993 	if (nr < 0)
1994 		return -EINVAL;
1995 
1996 	kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);
1997 
1998 	if (!mutex_trylock(&damon_sysfs_lock))
1999 		return -EBUSY;
2000 	err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
2001 	mutex_unlock(&damon_sysfs_lock);
2002 	if (err)
2003 		return err;
2004 
2005 	return count;
2006 }
2007 
2008 static void damon_sysfs_kdamonds_release(struct kobject *kobj)
2009 {
2010 	kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
2011 }
2012 
2013 static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
2014 		__ATTR_RW_MODE(nr_kdamonds, 0600);
2015 
2016 static struct attribute *damon_sysfs_kdamonds_attrs[] = {
2017 	&damon_sysfs_kdamonds_nr_attr.attr,
2018 	NULL,
2019 };
2020 ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
2021 
2022 static const struct kobj_type damon_sysfs_kdamonds_ktype = {
2023 	.release = damon_sysfs_kdamonds_release,
2024 	.sysfs_ops = &kobj_sysfs_ops,
2025 	.default_groups = damon_sysfs_kdamonds_groups,
2026 };
2027 
2028 /*
2029  * damon user interface directory
2030  */
2031 
2032 struct damon_sysfs_ui_dir {
2033 	struct kobject kobj;
2034 	struct damon_sysfs_kdamonds *kdamonds;
2035 };
2036 
2037 static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
2038 {
2039 	return kzalloc_obj(struct damon_sysfs_ui_dir);
2040 }
2041 
2042 static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
2043 {
2044 	struct damon_sysfs_kdamonds *kdamonds;
2045 	int err;
2046 
2047 	kdamonds = damon_sysfs_kdamonds_alloc();
2048 	if (!kdamonds)
2049 		return -ENOMEM;
2050 
2051 	err = kobject_init_and_add(&kdamonds->kobj,
2052 			&damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
2053 			"kdamonds");
2054 	if (err) {
2055 		kobject_put(&kdamonds->kobj);
2056 		return err;
2057 	}
2058 	ui_dir->kdamonds = kdamonds;
2059 	return err;
2060 }
2061 
2062 static void damon_sysfs_ui_dir_release(struct kobject *kobj)
2063 {
2064 	kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
2065 }
2066 
2067 static struct attribute *damon_sysfs_ui_dir_attrs[] = {
2068 	NULL,
2069 };
2070 ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
2071 
2072 static const struct kobj_type damon_sysfs_ui_dir_ktype = {
2073 	.release = damon_sysfs_ui_dir_release,
2074 	.sysfs_ops = &kobj_sysfs_ops,
2075 	.default_groups = damon_sysfs_ui_dir_groups,
2076 };
2077 
2078 static int __init damon_sysfs_init(void)
2079 {
2080 	struct kobject *damon_sysfs_root;
2081 	struct damon_sysfs_ui_dir *admin;
2082 	int err;
2083 
2084 	damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
2085 	if (!damon_sysfs_root)
2086 		return -ENOMEM;
2087 
2088 	admin = damon_sysfs_ui_dir_alloc();
2089 	if (!admin) {
2090 		kobject_put(damon_sysfs_root);
2091 		return -ENOMEM;
2092 	}
2093 	err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
2094 			damon_sysfs_root, "admin");
2095 	if (err)
2096 		goto out;
2097 	err = damon_sysfs_ui_dir_add_dirs(admin);
2098 	if (err)
2099 		goto out;
2100 	return 0;
2101 
2102 out:
2103 	kobject_put(&admin->kobj);
2104 	kobject_put(damon_sysfs_root);
2105 	return err;
2106 }
2107 subsys_initcall(damon_sysfs_init);
2108 
2109 #include "tests/sysfs-kunit.h"
2110