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   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
  18struct damon_sysfs_region {
  19	struct kobject kobj;
  20	struct damon_addr_range ar;
  21};
  22
  23static struct damon_sysfs_region *damon_sysfs_region_alloc(void)
  24{
  25	return kzalloc(sizeof(struct damon_sysfs_region), GFP_KERNEL);
  26}
  27
  28static 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
  37static 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
  47static 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
  56static 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
  66static void damon_sysfs_region_release(struct kobject *kobj)
  67{
  68	kfree(container_of(kobj, struct damon_sysfs_region, kobj));
  69}
  70
  71static struct kobj_attribute damon_sysfs_region_start_attr =
  72		__ATTR_RW_MODE(start, 0600);
  73
  74static struct kobj_attribute damon_sysfs_region_end_attr =
  75		__ATTR_RW_MODE(end, 0600);
  76
  77static struct attribute *damon_sysfs_region_attrs[] = {
  78	&damon_sysfs_region_start_attr.attr,
  79	&damon_sysfs_region_end_attr.attr,
  80	NULL,
  81};
  82ATTRIBUTE_GROUPS(damon_sysfs_region);
  83
  84static 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
  94struct damon_sysfs_regions {
  95	struct kobject kobj;
  96	struct damon_sysfs_region **regions_arr;
  97	int nr;
  98};
  99
 100static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
 101{
 102	return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);
 103}
 104
 105static 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
 117static 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_array(nr_regions, sizeof(*regions_arr),
 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
 155static 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
 164static 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
 187static void damon_sysfs_regions_release(struct kobject *kobj)
 188{
 189	kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
 190}
 191
 192static struct kobj_attribute damon_sysfs_regions_nr_attr =
 193		__ATTR_RW_MODE(nr_regions, 0600);
 194
 195static struct attribute *damon_sysfs_regions_attrs[] = {
 196	&damon_sysfs_regions_nr_attr.attr,
 197	NULL,
 198};
 199ATTRIBUTE_GROUPS(damon_sysfs_regions);
 200
 201static 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
 211struct damon_sysfs_target {
 212	struct kobject kobj;
 213	struct damon_sysfs_regions *regions;
 214	int pid;
 215};
 216
 217static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
 218{
 219	return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);
 220}
 221
 222static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
 223{
 224	struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
 225	int err;
 226
 227	if (!regions)
 228		return -ENOMEM;
 229
 230	err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
 231			&target->kobj, "regions");
 232	if (err)
 233		kobject_put(&regions->kobj);
 234	else
 235		target->regions = regions;
 236	return err;
 237}
 238
 239static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
 240{
 241	damon_sysfs_regions_rm_dirs(target->regions);
 242	kobject_put(&target->regions->kobj);
 243}
 244
 245static ssize_t pid_target_show(struct kobject *kobj,
 246		struct kobj_attribute *attr, char *buf)
 247{
 248	struct damon_sysfs_target *target = container_of(kobj,
 249			struct damon_sysfs_target, kobj);
 250
 251	return sysfs_emit(buf, "%d\n", target->pid);
 252}
 253
 254static ssize_t pid_target_store(struct kobject *kobj,
 255		struct kobj_attribute *attr, const char *buf, size_t count)
 256{
 257	struct damon_sysfs_target *target = container_of(kobj,
 258			struct damon_sysfs_target, kobj);
 259	int err = kstrtoint(buf, 0, &target->pid);
 260
 261	if (err)
 262		return -EINVAL;
 263	return count;
 264}
 265
 266static void damon_sysfs_target_release(struct kobject *kobj)
 267{
 268	kfree(container_of(kobj, struct damon_sysfs_target, kobj));
 269}
 270
 271static struct kobj_attribute damon_sysfs_target_pid_attr =
 272		__ATTR_RW_MODE(pid_target, 0600);
 273
 274static struct attribute *damon_sysfs_target_attrs[] = {
 275	&damon_sysfs_target_pid_attr.attr,
 276	NULL,
 277};
 278ATTRIBUTE_GROUPS(damon_sysfs_target);
 279
 280static const struct kobj_type damon_sysfs_target_ktype = {
 281	.release = damon_sysfs_target_release,
 282	.sysfs_ops = &kobj_sysfs_ops,
 283	.default_groups = damon_sysfs_target_groups,
 284};
 285
 286/*
 287 * targets directory
 288 */
 289
 290struct damon_sysfs_targets {
 291	struct kobject kobj;
 292	struct damon_sysfs_target **targets_arr;
 293	int nr;
 294};
 295
 296static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)
 297{
 298	return kzalloc(sizeof(struct damon_sysfs_targets), GFP_KERNEL);
 299}
 300
 301static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
 302{
 303	struct damon_sysfs_target **targets_arr = targets->targets_arr;
 304	int i;
 305
 306	for (i = 0; i < targets->nr; i++) {
 307		damon_sysfs_target_rm_dirs(targets_arr[i]);
 308		kobject_put(&targets_arr[i]->kobj);
 309	}
 310	targets->nr = 0;
 311	kfree(targets_arr);
 312	targets->targets_arr = NULL;
 313}
 314
 315static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
 316		int nr_targets)
 317{
 318	struct damon_sysfs_target **targets_arr, *target;
 319	int err, i;
 320
 321	damon_sysfs_targets_rm_dirs(targets);
 322	if (!nr_targets)
 323		return 0;
 324
 325	targets_arr = kmalloc_array(nr_targets, sizeof(*targets_arr),
 326			GFP_KERNEL | __GFP_NOWARN);
 327	if (!targets_arr)
 328		return -ENOMEM;
 329	targets->targets_arr = targets_arr;
 330
 331	for (i = 0; i < nr_targets; i++) {
 332		target = damon_sysfs_target_alloc();
 333		if (!target) {
 334			damon_sysfs_targets_rm_dirs(targets);
 335			return -ENOMEM;
 336		}
 337
 338		err = kobject_init_and_add(&target->kobj,
 339				&damon_sysfs_target_ktype, &targets->kobj,
 340				"%d", i);
 341		if (err)
 342			goto out;
 343
 344		err = damon_sysfs_target_add_dirs(target);
 345		if (err)
 346			goto out;
 347
 348		targets_arr[i] = target;
 349		targets->nr++;
 350	}
 351	return 0;
 352
 353out:
 354	damon_sysfs_targets_rm_dirs(targets);
 355	kobject_put(&target->kobj);
 356	return err;
 357}
 358
 359static ssize_t nr_targets_show(struct kobject *kobj,
 360		struct kobj_attribute *attr, char *buf)
 361{
 362	struct damon_sysfs_targets *targets = container_of(kobj,
 363			struct damon_sysfs_targets, kobj);
 364
 365	return sysfs_emit(buf, "%d\n", targets->nr);
 366}
 367
 368static ssize_t nr_targets_store(struct kobject *kobj,
 369		struct kobj_attribute *attr, const char *buf, size_t count)
 370{
 371	struct damon_sysfs_targets *targets;
 372	int nr, err = kstrtoint(buf, 0, &nr);
 373
 374	if (err)
 375		return err;
 376	if (nr < 0)
 377		return -EINVAL;
 378
 379	targets = container_of(kobj, struct damon_sysfs_targets, kobj);
 380
 381	if (!mutex_trylock(&damon_sysfs_lock))
 382		return -EBUSY;
 383	err = damon_sysfs_targets_add_dirs(targets, nr);
 384	mutex_unlock(&damon_sysfs_lock);
 385	if (err)
 386		return err;
 387
 388	return count;
 389}
 390
 391static void damon_sysfs_targets_release(struct kobject *kobj)
 392{
 393	kfree(container_of(kobj, struct damon_sysfs_targets, kobj));
 394}
 395
 396static struct kobj_attribute damon_sysfs_targets_nr_attr =
 397		__ATTR_RW_MODE(nr_targets, 0600);
 398
 399static struct attribute *damon_sysfs_targets_attrs[] = {
 400	&damon_sysfs_targets_nr_attr.attr,
 401	NULL,
 402};
 403ATTRIBUTE_GROUPS(damon_sysfs_targets);
 404
 405static const struct kobj_type damon_sysfs_targets_ktype = {
 406	.release = damon_sysfs_targets_release,
 407	.sysfs_ops = &kobj_sysfs_ops,
 408	.default_groups = damon_sysfs_targets_groups,
 409};
 410
 411/*
 412 * intervals directory
 413 */
 414
 415struct damon_sysfs_intervals {
 416	struct kobject kobj;
 417	unsigned long sample_us;
 418	unsigned long aggr_us;
 419	unsigned long update_us;
 420};
 421
 422static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
 423		unsigned long sample_us, unsigned long aggr_us,
 424		unsigned long update_us)
 425{
 426	struct damon_sysfs_intervals *intervals = kmalloc(sizeof(*intervals),
 427			GFP_KERNEL);
 428
 429	if (!intervals)
 430		return NULL;
 431
 432	intervals->kobj = (struct kobject){};
 433	intervals->sample_us = sample_us;
 434	intervals->aggr_us = aggr_us;
 435	intervals->update_us = update_us;
 436	return intervals;
 437}
 438
 439static ssize_t sample_us_show(struct kobject *kobj,
 440		struct kobj_attribute *attr, char *buf)
 441{
 442	struct damon_sysfs_intervals *intervals = container_of(kobj,
 443			struct damon_sysfs_intervals, kobj);
 444
 445	return sysfs_emit(buf, "%lu\n", intervals->sample_us);
 446}
 447
 448static ssize_t sample_us_store(struct kobject *kobj,
 449		struct kobj_attribute *attr, const char *buf, size_t count)
 450{
 451	struct damon_sysfs_intervals *intervals = container_of(kobj,
 452			struct damon_sysfs_intervals, kobj);
 453	unsigned long us;
 454	int err = kstrtoul(buf, 0, &us);
 455
 456	if (err)
 457		return err;
 458
 459	intervals->sample_us = us;
 460	return count;
 461}
 462
 463static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,
 464		char *buf)
 465{
 466	struct damon_sysfs_intervals *intervals = container_of(kobj,
 467			struct damon_sysfs_intervals, kobj);
 468
 469	return sysfs_emit(buf, "%lu\n", intervals->aggr_us);
 470}
 471
 472static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
 473		const char *buf, size_t count)
 474{
 475	struct damon_sysfs_intervals *intervals = container_of(kobj,
 476			struct damon_sysfs_intervals, kobj);
 477	unsigned long us;
 478	int err = kstrtoul(buf, 0, &us);
 479
 480	if (err)
 481		return err;
 482
 483	intervals->aggr_us = us;
 484	return count;
 485}
 486
 487static ssize_t update_us_show(struct kobject *kobj,
 488		struct kobj_attribute *attr, char *buf)
 489{
 490	struct damon_sysfs_intervals *intervals = container_of(kobj,
 491			struct damon_sysfs_intervals, kobj);
 492
 493	return sysfs_emit(buf, "%lu\n", intervals->update_us);
 494}
 495
 496static ssize_t update_us_store(struct kobject *kobj,
 497		struct kobj_attribute *attr, const char *buf, size_t count)
 498{
 499	struct damon_sysfs_intervals *intervals = container_of(kobj,
 500			struct damon_sysfs_intervals, kobj);
 501	unsigned long us;
 502	int err = kstrtoul(buf, 0, &us);
 503
 504	if (err)
 505		return err;
 506
 507	intervals->update_us = us;
 508	return count;
 509}
 510
 511static void damon_sysfs_intervals_release(struct kobject *kobj)
 512{
 513	kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));
 514}
 515
 516static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =
 517		__ATTR_RW_MODE(sample_us, 0600);
 518
 519static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =
 520		__ATTR_RW_MODE(aggr_us, 0600);
 521
 522static struct kobj_attribute damon_sysfs_intervals_update_us_attr =
 523		__ATTR_RW_MODE(update_us, 0600);
 524
 525static struct attribute *damon_sysfs_intervals_attrs[] = {
 526	&damon_sysfs_intervals_sample_us_attr.attr,
 527	&damon_sysfs_intervals_aggr_us_attr.attr,
 528	&damon_sysfs_intervals_update_us_attr.attr,
 529	NULL,
 530};
 531ATTRIBUTE_GROUPS(damon_sysfs_intervals);
 532
 533static const struct kobj_type damon_sysfs_intervals_ktype = {
 534	.release = damon_sysfs_intervals_release,
 535	.sysfs_ops = &kobj_sysfs_ops,
 536	.default_groups = damon_sysfs_intervals_groups,
 537};
 538
 539/*
 540 * monitoring_attrs directory
 541 */
 542
 543struct damon_sysfs_attrs {
 544	struct kobject kobj;
 545	struct damon_sysfs_intervals *intervals;
 546	struct damon_sysfs_ul_range *nr_regions_range;
 547};
 548
 549static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)
 550{
 551	struct damon_sysfs_attrs *attrs = kmalloc(sizeof(*attrs), GFP_KERNEL);
 552
 553	if (!attrs)
 554		return NULL;
 555	attrs->kobj = (struct kobject){};
 556	return attrs;
 557}
 558
 559static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
 560{
 561	struct damon_sysfs_intervals *intervals;
 562	struct damon_sysfs_ul_range *nr_regions_range;
 563	int err;
 564
 565	intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);
 566	if (!intervals)
 567		return -ENOMEM;
 568
 569	err = kobject_init_and_add(&intervals->kobj,
 570			&damon_sysfs_intervals_ktype, &attrs->kobj,
 571			"intervals");
 572	if (err)
 573		goto put_intervals_out;
 574	attrs->intervals = intervals;
 575
 576	nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);
 577	if (!nr_regions_range) {
 578		err = -ENOMEM;
 579		goto put_intervals_out;
 580	}
 581
 582	err = kobject_init_and_add(&nr_regions_range->kobj,
 583			&damon_sysfs_ul_range_ktype, &attrs->kobj,
 584			"nr_regions");
 585	if (err)
 586		goto put_nr_regions_intervals_out;
 587	attrs->nr_regions_range = nr_regions_range;
 588	return 0;
 589
 590put_nr_regions_intervals_out:
 591	kobject_put(&nr_regions_range->kobj);
 592	attrs->nr_regions_range = NULL;
 593put_intervals_out:
 594	kobject_put(&intervals->kobj);
 595	attrs->intervals = NULL;
 596	return err;
 597}
 598
 599static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
 600{
 601	kobject_put(&attrs->nr_regions_range->kobj);
 602	kobject_put(&attrs->intervals->kobj);
 603}
 604
 605static void damon_sysfs_attrs_release(struct kobject *kobj)
 606{
 607	kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));
 608}
 609
 610static struct attribute *damon_sysfs_attrs_attrs[] = {
 611	NULL,
 612};
 613ATTRIBUTE_GROUPS(damon_sysfs_attrs);
 614
 615static const struct kobj_type damon_sysfs_attrs_ktype = {
 616	.release = damon_sysfs_attrs_release,
 617	.sysfs_ops = &kobj_sysfs_ops,
 618	.default_groups = damon_sysfs_attrs_groups,
 619};
 620
 621/*
 622 * context directory
 623 */
 624
 625/* This should match with enum damon_ops_id */
 626static const char * const damon_sysfs_ops_strs[] = {
 627	"vaddr",
 628	"fvaddr",
 629	"paddr",
 630};
 631
 632struct damon_sysfs_context {
 633	struct kobject kobj;
 634	enum damon_ops_id ops_id;
 635	struct damon_sysfs_attrs *attrs;
 636	struct damon_sysfs_targets *targets;
 637	struct damon_sysfs_schemes *schemes;
 638};
 639
 640static struct damon_sysfs_context *damon_sysfs_context_alloc(
 641		enum damon_ops_id ops_id)
 642{
 643	struct damon_sysfs_context *context = kmalloc(sizeof(*context),
 644				GFP_KERNEL);
 645
 646	if (!context)
 647		return NULL;
 648	context->kobj = (struct kobject){};
 649	context->ops_id = ops_id;
 650	return context;
 651}
 652
 653static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)
 654{
 655	struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();
 656	int err;
 657
 658	if (!attrs)
 659		return -ENOMEM;
 660	err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,
 661			&context->kobj, "monitoring_attrs");
 662	if (err)
 663		goto out;
 664	err = damon_sysfs_attrs_add_dirs(attrs);
 665	if (err)
 666		goto out;
 667	context->attrs = attrs;
 668	return 0;
 669
 670out:
 671	kobject_put(&attrs->kobj);
 672	return err;
 673}
 674
 675static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)
 676{
 677	struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();
 678	int err;
 679
 680	if (!targets)
 681		return -ENOMEM;
 682	err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,
 683			&context->kobj, "targets");
 684	if (err) {
 685		kobject_put(&targets->kobj);
 686		return err;
 687	}
 688	context->targets = targets;
 689	return 0;
 690}
 691
 692static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)
 693{
 694	struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();
 695	int err;
 696
 697	if (!schemes)
 698		return -ENOMEM;
 699	err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,
 700			&context->kobj, "schemes");
 701	if (err) {
 702		kobject_put(&schemes->kobj);
 703		return err;
 704	}
 705	context->schemes = schemes;
 706	return 0;
 707}
 708
 709static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)
 710{
 711	int err;
 712
 713	err = damon_sysfs_context_set_attrs(context);
 714	if (err)
 715		return err;
 716
 717	err = damon_sysfs_context_set_targets(context);
 718	if (err)
 719		goto put_attrs_out;
 720
 721	err = damon_sysfs_context_set_schemes(context);
 722	if (err)
 723		goto put_targets_attrs_out;
 724	return 0;
 725
 726put_targets_attrs_out:
 727	kobject_put(&context->targets->kobj);
 728	context->targets = NULL;
 729put_attrs_out:
 730	kobject_put(&context->attrs->kobj);
 731	context->attrs = NULL;
 732	return err;
 733}
 734
 735static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)
 736{
 737	damon_sysfs_attrs_rm_dirs(context->attrs);
 738	kobject_put(&context->attrs->kobj);
 739	damon_sysfs_targets_rm_dirs(context->targets);
 740	kobject_put(&context->targets->kobj);
 741	damon_sysfs_schemes_rm_dirs(context->schemes);
 742	kobject_put(&context->schemes->kobj);
 743}
 744
 745static ssize_t avail_operations_show(struct kobject *kobj,
 746		struct kobj_attribute *attr, char *buf)
 747{
 748	enum damon_ops_id id;
 749	int len = 0;
 750
 751	for (id = 0; id < NR_DAMON_OPS; id++) {
 752		if (!damon_is_registered_ops(id))
 753			continue;
 754		len += sysfs_emit_at(buf, len, "%s\n",
 755				damon_sysfs_ops_strs[id]);
 756	}
 757	return len;
 758}
 759
 760static ssize_t operations_show(struct kobject *kobj,
 761		struct kobj_attribute *attr, char *buf)
 762{
 763	struct damon_sysfs_context *context = container_of(kobj,
 764			struct damon_sysfs_context, kobj);
 765
 766	return sysfs_emit(buf, "%s\n", damon_sysfs_ops_strs[context->ops_id]);
 767}
 768
 769static ssize_t operations_store(struct kobject *kobj,
 770		struct kobj_attribute *attr, const char *buf, size_t count)
 771{
 772	struct damon_sysfs_context *context = container_of(kobj,
 773			struct damon_sysfs_context, kobj);
 774	enum damon_ops_id id;
 775
 776	for (id = 0; id < NR_DAMON_OPS; id++) {
 777		if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {
 778			context->ops_id = id;
 779			return count;
 780		}
 781	}
 782	return -EINVAL;
 783}
 784
 785static void damon_sysfs_context_release(struct kobject *kobj)
 786{
 787	kfree(container_of(kobj, struct damon_sysfs_context, kobj));
 788}
 789
 790static struct kobj_attribute damon_sysfs_context_avail_operations_attr =
 791		__ATTR_RO_MODE(avail_operations, 0400);
 792
 793static struct kobj_attribute damon_sysfs_context_operations_attr =
 794		__ATTR_RW_MODE(operations, 0600);
 795
 796static struct attribute *damon_sysfs_context_attrs[] = {
 797	&damon_sysfs_context_avail_operations_attr.attr,
 798	&damon_sysfs_context_operations_attr.attr,
 799	NULL,
 800};
 801ATTRIBUTE_GROUPS(damon_sysfs_context);
 802
 803static const struct kobj_type damon_sysfs_context_ktype = {
 804	.release = damon_sysfs_context_release,
 805	.sysfs_ops = &kobj_sysfs_ops,
 806	.default_groups = damon_sysfs_context_groups,
 807};
 808
 809/*
 810 * contexts directory
 811 */
 812
 813struct damon_sysfs_contexts {
 814	struct kobject kobj;
 815	struct damon_sysfs_context **contexts_arr;
 816	int nr;
 817};
 818
 819static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)
 820{
 821	return kzalloc(sizeof(struct damon_sysfs_contexts), GFP_KERNEL);
 822}
 823
 824static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)
 825{
 826	struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;
 827	int i;
 828
 829	for (i = 0; i < contexts->nr; i++) {
 830		damon_sysfs_context_rm_dirs(contexts_arr[i]);
 831		kobject_put(&contexts_arr[i]->kobj);
 832	}
 833	contexts->nr = 0;
 834	kfree(contexts_arr);
 835	contexts->contexts_arr = NULL;
 836}
 837
 838static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,
 839		int nr_contexts)
 840{
 841	struct damon_sysfs_context **contexts_arr, *context;
 842	int err, i;
 843
 844	damon_sysfs_contexts_rm_dirs(contexts);
 845	if (!nr_contexts)
 846		return 0;
 847
 848	contexts_arr = kmalloc_array(nr_contexts, sizeof(*contexts_arr),
 849			GFP_KERNEL | __GFP_NOWARN);
 850	if (!contexts_arr)
 851		return -ENOMEM;
 852	contexts->contexts_arr = contexts_arr;
 853
 854	for (i = 0; i < nr_contexts; i++) {
 855		context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);
 856		if (!context) {
 857			damon_sysfs_contexts_rm_dirs(contexts);
 858			return -ENOMEM;
 859		}
 860
 861		err = kobject_init_and_add(&context->kobj,
 862				&damon_sysfs_context_ktype, &contexts->kobj,
 863				"%d", i);
 864		if (err)
 865			goto out;
 866
 867		err = damon_sysfs_context_add_dirs(context);
 868		if (err)
 869			goto out;
 870
 871		contexts_arr[i] = context;
 872		contexts->nr++;
 873	}
 874	return 0;
 875
 876out:
 877	damon_sysfs_contexts_rm_dirs(contexts);
 878	kobject_put(&context->kobj);
 879	return err;
 880}
 881
 882static ssize_t nr_contexts_show(struct kobject *kobj,
 883		struct kobj_attribute *attr, char *buf)
 884{
 885	struct damon_sysfs_contexts *contexts = container_of(kobj,
 886			struct damon_sysfs_contexts, kobj);
 887
 888	return sysfs_emit(buf, "%d\n", contexts->nr);
 889}
 890
 891static ssize_t nr_contexts_store(struct kobject *kobj,
 892		struct kobj_attribute *attr, const char *buf, size_t count)
 893{
 894	struct damon_sysfs_contexts *contexts;
 895	int nr, err;
 896
 897	err = kstrtoint(buf, 0, &nr);
 898	if (err)
 899		return err;
 900	/* TODO: support multiple contexts per kdamond */
 901	if (nr < 0 || 1 < nr)
 902		return -EINVAL;
 903
 904	contexts = container_of(kobj, struct damon_sysfs_contexts, kobj);
 905	if (!mutex_trylock(&damon_sysfs_lock))
 906		return -EBUSY;
 907	err = damon_sysfs_contexts_add_dirs(contexts, nr);
 908	mutex_unlock(&damon_sysfs_lock);
 909	if (err)
 910		return err;
 911
 912	return count;
 913}
 914
 915static void damon_sysfs_contexts_release(struct kobject *kobj)
 916{
 917	kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));
 918}
 919
 920static struct kobj_attribute damon_sysfs_contexts_nr_attr
 921		= __ATTR_RW_MODE(nr_contexts, 0600);
 922
 923static struct attribute *damon_sysfs_contexts_attrs[] = {
 924	&damon_sysfs_contexts_nr_attr.attr,
 925	NULL,
 926};
 927ATTRIBUTE_GROUPS(damon_sysfs_contexts);
 928
 929static const struct kobj_type damon_sysfs_contexts_ktype = {
 930	.release = damon_sysfs_contexts_release,
 931	.sysfs_ops = &kobj_sysfs_ops,
 932	.default_groups = damon_sysfs_contexts_groups,
 933};
 934
 935/*
 936 * kdamond directory
 937 */
 938
 939struct damon_sysfs_kdamond {
 940	struct kobject kobj;
 941	struct damon_sysfs_contexts *contexts;
 942	struct damon_ctx *damon_ctx;
 943};
 944
 945static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
 946{
 947	return kzalloc(sizeof(struct damon_sysfs_kdamond), GFP_KERNEL);
 948}
 949
 950static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)
 951{
 952	struct damon_sysfs_contexts *contexts;
 953	int err;
 954
 955	contexts = damon_sysfs_contexts_alloc();
 956	if (!contexts)
 957		return -ENOMEM;
 958
 959	err = kobject_init_and_add(&contexts->kobj,
 960			&damon_sysfs_contexts_ktype, &kdamond->kobj,
 961			"contexts");
 962	if (err) {
 963		kobject_put(&contexts->kobj);
 964		return err;
 965	}
 966	kdamond->contexts = contexts;
 967
 968	return err;
 969}
 970
 971static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
 972{
 973	damon_sysfs_contexts_rm_dirs(kdamond->contexts);
 974	kobject_put(&kdamond->contexts->kobj);
 975}
 976
 977static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)
 978{
 979	bool running;
 980
 981	mutex_lock(&ctx->kdamond_lock);
 982	running = ctx->kdamond != NULL;
 983	mutex_unlock(&ctx->kdamond_lock);
 984	return running;
 985}
 986
 987/*
 988 * enum damon_sysfs_cmd - Commands for a specific kdamond.
 989 */
 990enum damon_sysfs_cmd {
 991	/* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */
 992	DAMON_SYSFS_CMD_ON,
 993	/* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */
 994	DAMON_SYSFS_CMD_OFF,
 995	/* @DAMON_SYSFS_CMD_COMMIT: Update kdamond inputs. */
 996	DAMON_SYSFS_CMD_COMMIT,
 997	/*
 998	 * @DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS: Commit the quota goals
 999	 * to DAMON.
1000	 */
1001	DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS,
1002	/*
1003	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs
1004	 * files.
1005	 */
1006	DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,
1007	/*
1008	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES: Update
1009	 * tried_regions/total_bytes sysfs files for each scheme.
1010	 */
1011	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES,
1012	/*
1013	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS: Update schemes tried
1014	 * regions
1015	 */
1016	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS,
1017	/*
1018	 * @DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: Clear schemes tried
1019	 * regions
1020	 */
1021	DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS,
1022	/*
1023	 * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS: Update the
1024	 * effective size quota of the scheme in bytes.
1025	 */
1026	DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS,
1027	/*
1028	 * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.
1029	 */
1030	NR_DAMON_SYSFS_CMDS,
1031};
1032
1033/* Should match with enum damon_sysfs_cmd */
1034static const char * const damon_sysfs_cmd_strs[] = {
1035	"on",
1036	"off",
1037	"commit",
1038	"commit_schemes_quota_goals",
1039	"update_schemes_stats",
1040	"update_schemes_tried_bytes",
1041	"update_schemes_tried_regions",
1042	"clear_schemes_tried_regions",
1043	"update_schemes_effective_quotas",
1044};
1045
1046/*
1047 * struct damon_sysfs_cmd_request - A request to the DAMON callback.
1048 * @cmd:	The command that needs to be handled by the callback.
1049 * @kdamond:	The kobject wrapper that associated to the kdamond thread.
1050 *
1051 * This structure represents a sysfs command request that need to access some
1052 * DAMON context-internal data.  Because DAMON context-internal data can be
1053 * safely accessed from DAMON callbacks without additional synchronization, the
1054 * request will be handled by the DAMON callback.  None-``NULL`` @kdamond means
1055 * the request is valid.
1056 */
1057struct damon_sysfs_cmd_request {
1058	enum damon_sysfs_cmd cmd;
1059	struct damon_sysfs_kdamond *kdamond;
1060};
1061
1062/* Current DAMON callback request.  Protected by damon_sysfs_lock. */
1063static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;
1064
1065static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
1066		char *buf)
1067{
1068	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1069			struct damon_sysfs_kdamond, kobj);
1070	struct damon_ctx *ctx = kdamond->damon_ctx;
1071	bool running;
1072
1073	if (!ctx)
1074		running = false;
1075	else
1076		running = damon_sysfs_ctx_running(ctx);
1077
1078	return sysfs_emit(buf, "%s\n", running ?
1079			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
1080			damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);
1081}
1082
1083static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
1084		struct damon_sysfs_attrs *sys_attrs)
1085{
1086	struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;
1087	struct damon_sysfs_ul_range *sys_nr_regions =
1088		sys_attrs->nr_regions_range;
1089	struct damon_attrs attrs = {
1090		.sample_interval = sys_intervals->sample_us,
1091		.aggr_interval = sys_intervals->aggr_us,
1092		.ops_update_interval = sys_intervals->update_us,
1093		.min_nr_regions = sys_nr_regions->min,
1094		.max_nr_regions = sys_nr_regions->max,
1095	};
1096	return damon_set_attrs(ctx, &attrs);
1097}
1098
1099static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
1100{
1101	struct damon_target *t, *next;
1102	bool has_pid = damon_target_has_pid(ctx);
1103
1104	damon_for_each_target_safe(t, next, ctx) {
1105		if (has_pid)
1106			put_pid(t->pid);
1107		damon_destroy_target(t);
1108	}
1109}
1110
1111static int damon_sysfs_set_regions(struct damon_target *t,
1112		struct damon_sysfs_regions *sysfs_regions)
1113{
1114	struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,
1115			sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
1116	int i, err = -EINVAL;
1117
1118	if (!ranges)
1119		return -ENOMEM;
1120	for (i = 0; i < sysfs_regions->nr; i++) {
1121		struct damon_sysfs_region *sys_region =
1122			sysfs_regions->regions_arr[i];
1123
1124		if (sys_region->ar.start > sys_region->ar.end)
1125			goto out;
1126
1127		ranges[i].start = sys_region->ar.start;
1128		ranges[i].end = sys_region->ar.end;
1129		if (i == 0)
1130			continue;
1131		if (ranges[i - 1].end > ranges[i].start)
1132			goto out;
1133	}
1134	err = damon_set_regions(t, ranges, sysfs_regions->nr);
1135out:
1136	kfree(ranges);
1137	return err;
1138
1139}
1140
1141static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
1142		struct damon_ctx *ctx)
1143{
1144	struct damon_target *t = damon_new_target();
1145	int err = -EINVAL;
1146
1147	if (!t)
1148		return -ENOMEM;
1149	damon_add_target(ctx, t);
1150	if (damon_target_has_pid(ctx)) {
1151		t->pid = find_get_pid(sys_target->pid);
1152		if (!t->pid)
1153			goto destroy_targets_out;
1154	}
1155	err = damon_sysfs_set_regions(t, sys_target->regions);
1156	if (err)
1157		goto destroy_targets_out;
1158	return 0;
1159
1160destroy_targets_out:
1161	damon_sysfs_destroy_targets(ctx);
1162	return err;
1163}
1164
1165static int damon_sysfs_add_targets(struct damon_ctx *ctx,
1166		struct damon_sysfs_targets *sysfs_targets)
1167{
1168	int i, err;
1169
1170	/* Multiple physical address space monitoring targets makes no sense */
1171	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
1172		return -EINVAL;
1173
1174	for (i = 0; i < sysfs_targets->nr; i++) {
1175		struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];
1176
1177		err = damon_sysfs_add_target(st, ctx);
1178		if (err)
1179			return err;
1180	}
1181	return 0;
1182}
1183
1184static bool damon_sysfs_schemes_regions_updating;
1185
1186static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
1187{
1188	struct damon_target *t, *next;
1189	struct damon_sysfs_kdamond *kdamond;
1190	enum damon_sysfs_cmd cmd;
1191
1192	/* damon_sysfs_schemes_update_regions_stop() might not yet called */
1193	kdamond = damon_sysfs_cmd_request.kdamond;
1194	cmd = damon_sysfs_cmd_request.cmd;
1195	if (kdamond && ctx == kdamond->damon_ctx &&
1196			(cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS ||
1197			 cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES) &&
1198			damon_sysfs_schemes_regions_updating) {
1199		damon_sysfs_schemes_update_regions_stop(ctx);
1200		damon_sysfs_schemes_regions_updating = false;
1201		mutex_unlock(&damon_sysfs_lock);
1202	}
1203
1204	if (!damon_target_has_pid(ctx))
1205		return;
1206
1207	mutex_lock(&ctx->kdamond_lock);
1208	damon_for_each_target_safe(t, next, ctx) {
1209		put_pid(t->pid);
1210		damon_destroy_target(t);
1211	}
1212	mutex_unlock(&ctx->kdamond_lock);
1213}
1214
1215/*
1216 * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.
1217 * @kdamond:	The kobject wrapper that associated to the kdamond thread.
1218 *
1219 * This function reads the schemes stats of specific kdamond and update the
1220 * related values for sysfs files.  This function should be called from DAMON
1221 * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON
1222 * contexts-internal data and DAMON sysfs variables.
1223 */
1224static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)
1225{
1226	struct damon_ctx *ctx = kdamond->damon_ctx;
1227
1228	if (!ctx)
1229		return -EINVAL;
1230	damon_sysfs_schemes_update_stats(
1231			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1232	return 0;
1233}
1234
1235static int damon_sysfs_upd_schemes_regions_start(
1236		struct damon_sysfs_kdamond *kdamond, bool total_bytes_only)
1237{
1238	struct damon_ctx *ctx = kdamond->damon_ctx;
1239
1240	if (!ctx)
1241		return -EINVAL;
1242	return damon_sysfs_schemes_update_regions_start(
1243			kdamond->contexts->contexts_arr[0]->schemes, ctx,
1244			total_bytes_only);
1245}
1246
1247static int damon_sysfs_upd_schemes_regions_stop(
1248		struct damon_sysfs_kdamond *kdamond)
1249{
1250	struct damon_ctx *ctx = kdamond->damon_ctx;
1251
1252	if (!ctx)
1253		return -EINVAL;
1254	return damon_sysfs_schemes_update_regions_stop(ctx);
1255}
1256
1257static int damon_sysfs_clear_schemes_regions(
1258		struct damon_sysfs_kdamond *kdamond)
1259{
1260	struct damon_ctx *ctx = kdamond->damon_ctx;
1261
1262	if (!ctx)
1263		return -EINVAL;
1264	return damon_sysfs_schemes_clear_regions(
1265			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1266}
1267
1268static inline bool damon_sysfs_kdamond_running(
1269		struct damon_sysfs_kdamond *kdamond)
1270{
1271	return kdamond->damon_ctx &&
1272		damon_sysfs_ctx_running(kdamond->damon_ctx);
1273}
1274
1275static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
1276		struct damon_sysfs_context *sys_ctx)
1277{
1278	int err;
1279
1280	err = damon_select_ops(ctx, sys_ctx->ops_id);
1281	if (err)
1282		return err;
1283	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
1284	if (err)
1285		return err;
1286	err = damon_sysfs_add_targets(ctx, sys_ctx->targets);
1287	if (err)
1288		return err;
1289	return damon_sysfs_add_schemes(ctx, sys_ctx->schemes);
1290}
1291
1292static struct damon_ctx *damon_sysfs_build_ctx(
1293		struct damon_sysfs_context *sys_ctx);
1294
1295/*
1296 * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
1297 * @kdamond:	The kobject wrapper for the associated kdamond.
1298 *
1299 * If the sysfs input is wrong, the kdamond will be terminated.
1300 */
1301static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
1302{
1303	struct damon_ctx *param_ctx;
1304	int err;
1305
1306	if (!damon_sysfs_kdamond_running(kdamond))
1307		return -EINVAL;
1308	/* TODO: Support multiple contexts per kdamond */
1309	if (kdamond->contexts->nr != 1)
1310		return -EINVAL;
1311
1312	param_ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
1313	if (IS_ERR(param_ctx))
1314		return PTR_ERR(param_ctx);
1315	err = damon_commit_ctx(kdamond->damon_ctx, param_ctx);
1316	damon_sysfs_destroy_targets(param_ctx);
1317	damon_destroy_ctx(param_ctx);
1318	return err;
1319}
1320
1321static int damon_sysfs_commit_schemes_quota_goals(
1322		struct damon_sysfs_kdamond *sysfs_kdamond)
1323{
1324	struct damon_ctx *ctx;
1325	struct damon_sysfs_context *sysfs_ctx;
1326
1327	if (!damon_sysfs_kdamond_running(sysfs_kdamond))
1328		return -EINVAL;
1329	/* TODO: Support multiple contexts per kdamond */
1330	if (sysfs_kdamond->contexts->nr != 1)
1331		return -EINVAL;
1332
1333	ctx = sysfs_kdamond->damon_ctx;
1334	sysfs_ctx = sysfs_kdamond->contexts->contexts_arr[0];
1335	return damos_sysfs_set_quota_scores(sysfs_ctx->schemes, ctx);
1336}
1337
1338/*
1339 * damon_sysfs_upd_schemes_effective_quotas() - Update schemes effective quotas
1340 * sysfs files.
1341 * @kdamond:	The kobject wrapper that associated to the kdamond thread.
1342 *
1343 * This function reads the schemes' effective quotas of specific kdamond and
1344 * update the related values for sysfs files.  This function should be called
1345 * from DAMON callbacks while holding ``damon_syfs_lock``, to safely access the
1346 * DAMON contexts-internal data and DAMON sysfs variables.
1347 */
1348static int damon_sysfs_upd_schemes_effective_quotas(
1349		struct damon_sysfs_kdamond *kdamond)
1350{
1351	struct damon_ctx *ctx = kdamond->damon_ctx;
1352
1353	if (!ctx)
1354		return -EINVAL;
1355	damos_sysfs_update_effective_quotas(
1356			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1357	return 0;
1358}
1359
1360
1361/*
1362 * damon_sysfs_cmd_request_callback() - DAMON callback for handling requests.
1363 * @c:		The DAMON context of the callback.
1364 * @active:	Whether @c is not deactivated due to watermarks.
1365 * @after_aggr:	Whether this is called from after_aggregation() callback.
1366 *
1367 * This function is periodically called back from the kdamond thread for @c.
1368 * Then, it checks if there is a waiting DAMON sysfs request and handles it.
1369 */
1370static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,
1371		bool after_aggregation)
1372{
1373	struct damon_sysfs_kdamond *kdamond;
1374	bool total_bytes_only = false;
1375	int err = 0;
1376
1377	/* avoid deadlock due to concurrent state_store('off') */
1378	if (!damon_sysfs_schemes_regions_updating &&
1379			!mutex_trylock(&damon_sysfs_lock))
1380		return 0;
1381	kdamond = damon_sysfs_cmd_request.kdamond;
1382	if (!kdamond || kdamond->damon_ctx != c)
1383		goto out;
1384	switch (damon_sysfs_cmd_request.cmd) {
1385	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
1386		err = damon_sysfs_upd_schemes_stats(kdamond);
1387		break;
1388	case DAMON_SYSFS_CMD_COMMIT:
1389		if (!after_aggregation)
1390			goto out;
1391		err = damon_sysfs_commit_input(kdamond);
1392		break;
1393	case DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS:
1394		err = damon_sysfs_commit_schemes_quota_goals(kdamond);
1395		break;
1396	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:
1397		total_bytes_only = true;
1398		fallthrough;
1399	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:
1400		if (!damon_sysfs_schemes_regions_updating) {
1401			err = damon_sysfs_upd_schemes_regions_start(kdamond,
1402					total_bytes_only);
1403			if (!err) {
1404				damon_sysfs_schemes_regions_updating = true;
1405				goto keep_lock_out;
1406			}
1407		} else {
1408			damos_sysfs_mark_finished_regions_updates(c);
1409			/*
1410			 * Continue regions updating if DAMON is till
1411			 * active and the update for all schemes is not
1412			 * finished.
1413			 */
1414			if (active && !damos_sysfs_regions_upd_done())
1415				goto keep_lock_out;
1416			err = damon_sysfs_upd_schemes_regions_stop(kdamond);
1417			damon_sysfs_schemes_regions_updating = false;
1418		}
1419		break;
1420	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:
1421		err = damon_sysfs_clear_schemes_regions(kdamond);
1422		break;
1423	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS:
1424		err = damon_sysfs_upd_schemes_effective_quotas(kdamond);
1425		break;
1426	default:
1427		break;
1428	}
1429	/* Mark the request as invalid now. */
1430	damon_sysfs_cmd_request.kdamond = NULL;
1431out:
1432	if (!damon_sysfs_schemes_regions_updating)
1433		mutex_unlock(&damon_sysfs_lock);
1434keep_lock_out:
1435	return err;
1436}
1437
1438static int damon_sysfs_after_wmarks_check(struct damon_ctx *c)
1439{
1440	/*
1441	 * after_wmarks_check() is called back while the context is deactivated
1442	 * by watermarks.
1443	 */
1444	return damon_sysfs_cmd_request_callback(c, false, false);
1445}
1446
1447static int damon_sysfs_after_sampling(struct damon_ctx *c)
1448{
1449	/*
1450	 * after_sampling() is called back only while the context is not
1451	 * deactivated by watermarks.
1452	 */
1453	return damon_sysfs_cmd_request_callback(c, true, false);
1454}
1455
1456static int damon_sysfs_after_aggregation(struct damon_ctx *c)
1457{
1458	/*
1459	 * after_aggregation() is called back only while the context is not
1460	 * deactivated by watermarks.
1461	 */
1462	return damon_sysfs_cmd_request_callback(c, true, true);
1463}
1464
1465static struct damon_ctx *damon_sysfs_build_ctx(
1466		struct damon_sysfs_context *sys_ctx)
1467{
1468	struct damon_ctx *ctx = damon_new_ctx();
1469	int err;
1470
1471	if (!ctx)
1472		return ERR_PTR(-ENOMEM);
1473
1474	err = damon_sysfs_apply_inputs(ctx, sys_ctx);
1475	if (err) {
1476		damon_destroy_ctx(ctx);
1477		return ERR_PTR(err);
1478	}
1479
1480	ctx->callback.after_wmarks_check = damon_sysfs_after_wmarks_check;
1481	ctx->callback.after_sampling = damon_sysfs_after_sampling;
1482	ctx->callback.after_aggregation = damon_sysfs_after_aggregation;
1483	ctx->callback.before_terminate = damon_sysfs_before_terminate;
1484	return ctx;
1485}
1486
1487static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
1488{
1489	struct damon_ctx *ctx;
1490	int err;
1491
1492	if (damon_sysfs_kdamond_running(kdamond))
1493		return -EBUSY;
1494	if (damon_sysfs_cmd_request.kdamond == kdamond)
1495		return -EBUSY;
1496	/* TODO: support multiple contexts per kdamond */
1497	if (kdamond->contexts->nr != 1)
1498		return -EINVAL;
1499
1500	if (kdamond->damon_ctx)
1501		damon_destroy_ctx(kdamond->damon_ctx);
1502	kdamond->damon_ctx = NULL;
1503
1504	ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
1505	if (IS_ERR(ctx))
1506		return PTR_ERR(ctx);
1507	err = damon_start(&ctx, 1, false);
1508	if (err) {
1509		damon_destroy_ctx(ctx);
1510		return err;
1511	}
1512	kdamond->damon_ctx = ctx;
1513	return err;
1514}
1515
1516static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
1517{
1518	if (!kdamond->damon_ctx)
1519		return -EINVAL;
1520	return damon_stop(&kdamond->damon_ctx, 1);
1521	/*
1522	 * To allow users show final monitoring results of already turned-off
1523	 * DAMON, we free kdamond->damon_ctx in next
1524	 * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
1525	 */
1526}
1527
1528/*
1529 * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
1530 * @cmd:	The command to handle.
1531 * @kdamond:	The kobject wrapper for the associated kdamond.
1532 *
1533 * This function handles a DAMON sysfs command for a kdamond.  For commands
1534 * that need to access running DAMON context-internal data, it requests
1535 * handling of the command to the DAMON callback
1536 * (@damon_sysfs_cmd_request_callback()) and wait until it is properly handled,
1537 * or the context is completed.
1538 *
1539 * Return: 0 on success, negative error code otherwise.
1540 */
1541static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
1542		struct damon_sysfs_kdamond *kdamond)
1543{
1544	bool need_wait = true;
1545
1546	/* Handle commands that doesn't access DAMON context-internal data */
1547	switch (cmd) {
1548	case DAMON_SYSFS_CMD_ON:
1549		return damon_sysfs_turn_damon_on(kdamond);
1550	case DAMON_SYSFS_CMD_OFF:
1551		return damon_sysfs_turn_damon_off(kdamond);
1552	default:
1553		break;
1554	}
1555
1556	/* Pass the command to DAMON callback for safe DAMON context access */
1557	if (damon_sysfs_cmd_request.kdamond)
1558		return -EBUSY;
1559	if (!damon_sysfs_kdamond_running(kdamond))
1560		return -EINVAL;
1561	damon_sysfs_cmd_request.cmd = cmd;
1562	damon_sysfs_cmd_request.kdamond = kdamond;
1563
1564	/*
1565	 * wait until damon_sysfs_cmd_request_callback() handles the request
1566	 * from kdamond context
1567	 */
1568	mutex_unlock(&damon_sysfs_lock);
1569	while (need_wait) {
1570		schedule_timeout_idle(msecs_to_jiffies(100));
1571		if (!mutex_trylock(&damon_sysfs_lock))
1572			continue;
1573		if (!damon_sysfs_cmd_request.kdamond) {
1574			/* damon_sysfs_cmd_request_callback() handled */
1575			need_wait = false;
1576		} else if (!damon_sysfs_kdamond_running(kdamond)) {
1577			/* kdamond has already finished */
1578			need_wait = false;
1579			damon_sysfs_cmd_request.kdamond = NULL;
1580		}
1581		mutex_unlock(&damon_sysfs_lock);
1582	}
1583	mutex_lock(&damon_sysfs_lock);
1584	return 0;
1585}
1586
1587static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
1588		const char *buf, size_t count)
1589{
1590	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1591			struct damon_sysfs_kdamond, kobj);
1592	enum damon_sysfs_cmd cmd;
1593	ssize_t ret = -EINVAL;
1594
1595	if (!mutex_trylock(&damon_sysfs_lock))
1596		return -EBUSY;
1597	for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
1598		if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
1599			ret = damon_sysfs_handle_cmd(cmd, kdamond);
1600			break;
1601		}
1602	}
1603	mutex_unlock(&damon_sysfs_lock);
1604	if (!ret)
1605		ret = count;
1606	return ret;
1607}
1608
1609static ssize_t pid_show(struct kobject *kobj,
1610		struct kobj_attribute *attr, char *buf)
1611{
1612	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1613			struct damon_sysfs_kdamond, kobj);
1614	struct damon_ctx *ctx;
1615	int pid = -1;
1616
1617	if (!mutex_trylock(&damon_sysfs_lock))
1618		return -EBUSY;
1619	ctx = kdamond->damon_ctx;
1620	if (!ctx)
1621		goto out;
1622
1623	mutex_lock(&ctx->kdamond_lock);
1624	if (ctx->kdamond)
1625		pid = ctx->kdamond->pid;
1626	mutex_unlock(&ctx->kdamond_lock);
1627out:
1628	mutex_unlock(&damon_sysfs_lock);
1629	return sysfs_emit(buf, "%d\n", pid);
1630}
1631
1632static void damon_sysfs_kdamond_release(struct kobject *kobj)
1633{
1634	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1635			struct damon_sysfs_kdamond, kobj);
1636
1637	if (kdamond->damon_ctx)
1638		damon_destroy_ctx(kdamond->damon_ctx);
1639	kfree(kdamond);
1640}
1641
1642static struct kobj_attribute damon_sysfs_kdamond_state_attr =
1643		__ATTR_RW_MODE(state, 0600);
1644
1645static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
1646		__ATTR_RO_MODE(pid, 0400);
1647
1648static struct attribute *damon_sysfs_kdamond_attrs[] = {
1649	&damon_sysfs_kdamond_state_attr.attr,
1650	&damon_sysfs_kdamond_pid_attr.attr,
1651	NULL,
1652};
1653ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
1654
1655static const struct kobj_type damon_sysfs_kdamond_ktype = {
1656	.release = damon_sysfs_kdamond_release,
1657	.sysfs_ops = &kobj_sysfs_ops,
1658	.default_groups = damon_sysfs_kdamond_groups,
1659};
1660
1661/*
1662 * kdamonds directory
1663 */
1664
1665struct damon_sysfs_kdamonds {
1666	struct kobject kobj;
1667	struct damon_sysfs_kdamond **kdamonds_arr;
1668	int nr;
1669};
1670
1671static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
1672{
1673	return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);
1674}
1675
1676static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
1677{
1678	struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
1679	int i;
1680
1681	for (i = 0; i < kdamonds->nr; i++) {
1682		damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
1683		kobject_put(&kdamonds_arr[i]->kobj);
1684	}
1685	kdamonds->nr = 0;
1686	kfree(kdamonds_arr);
1687	kdamonds->kdamonds_arr = NULL;
1688}
1689
1690static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds,
1691		int nr_kdamonds)
1692{
1693	int i;
1694
1695	for (i = 0; i < nr_kdamonds; i++) {
1696		if (damon_sysfs_kdamond_running(kdamonds[i]) ||
1697		    damon_sysfs_cmd_request.kdamond == kdamonds[i])
1698			return true;
1699	}
1700
1701	return false;
1702}
1703
1704static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
1705		int nr_kdamonds)
1706{
1707	struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
1708	int err, i;
1709
1710	if (damon_sysfs_kdamonds_busy(kdamonds->kdamonds_arr, kdamonds->nr))
1711		return -EBUSY;
1712
1713	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1714	if (!nr_kdamonds)
1715		return 0;
1716
1717	kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),
1718			GFP_KERNEL | __GFP_NOWARN);
1719	if (!kdamonds_arr)
1720		return -ENOMEM;
1721	kdamonds->kdamonds_arr = kdamonds_arr;
1722
1723	for (i = 0; i < nr_kdamonds; i++) {
1724		kdamond = damon_sysfs_kdamond_alloc();
1725		if (!kdamond) {
1726			damon_sysfs_kdamonds_rm_dirs(kdamonds);
1727			return -ENOMEM;
1728		}
1729
1730		err = kobject_init_and_add(&kdamond->kobj,
1731				&damon_sysfs_kdamond_ktype, &kdamonds->kobj,
1732				"%d", i);
1733		if (err)
1734			goto out;
1735
1736		err = damon_sysfs_kdamond_add_dirs(kdamond);
1737		if (err)
1738			goto out;
1739
1740		kdamonds_arr[i] = kdamond;
1741		kdamonds->nr++;
1742	}
1743	return 0;
1744
1745out:
1746	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1747	kobject_put(&kdamond->kobj);
1748	return err;
1749}
1750
1751static ssize_t nr_kdamonds_show(struct kobject *kobj,
1752		struct kobj_attribute *attr, char *buf)
1753{
1754	struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
1755			struct damon_sysfs_kdamonds, kobj);
1756
1757	return sysfs_emit(buf, "%d\n", kdamonds->nr);
1758}
1759
1760static ssize_t nr_kdamonds_store(struct kobject *kobj,
1761		struct kobj_attribute *attr, const char *buf, size_t count)
1762{
1763	struct damon_sysfs_kdamonds *kdamonds;
1764	int nr, err;
1765
1766	err = kstrtoint(buf, 0, &nr);
1767	if (err)
1768		return err;
1769	if (nr < 0)
1770		return -EINVAL;
1771
1772	kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);
1773
1774	if (!mutex_trylock(&damon_sysfs_lock))
1775		return -EBUSY;
1776	err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
1777	mutex_unlock(&damon_sysfs_lock);
1778	if (err)
1779		return err;
1780
1781	return count;
1782}
1783
1784static void damon_sysfs_kdamonds_release(struct kobject *kobj)
1785{
1786	kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
1787}
1788
1789static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
1790		__ATTR_RW_MODE(nr_kdamonds, 0600);
1791
1792static struct attribute *damon_sysfs_kdamonds_attrs[] = {
1793	&damon_sysfs_kdamonds_nr_attr.attr,
1794	NULL,
1795};
1796ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
1797
1798static const struct kobj_type damon_sysfs_kdamonds_ktype = {
1799	.release = damon_sysfs_kdamonds_release,
1800	.sysfs_ops = &kobj_sysfs_ops,
1801	.default_groups = damon_sysfs_kdamonds_groups,
1802};
1803
1804/*
1805 * damon user interface directory
1806 */
1807
1808struct damon_sysfs_ui_dir {
1809	struct kobject kobj;
1810	struct damon_sysfs_kdamonds *kdamonds;
1811};
1812
1813static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
1814{
1815	return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);
1816}
1817
1818static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
1819{
1820	struct damon_sysfs_kdamonds *kdamonds;
1821	int err;
1822
1823	kdamonds = damon_sysfs_kdamonds_alloc();
1824	if (!kdamonds)
1825		return -ENOMEM;
1826
1827	err = kobject_init_and_add(&kdamonds->kobj,
1828			&damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
1829			"kdamonds");
1830	if (err) {
1831		kobject_put(&kdamonds->kobj);
1832		return err;
1833	}
1834	ui_dir->kdamonds = kdamonds;
1835	return err;
1836}
1837
1838static void damon_sysfs_ui_dir_release(struct kobject *kobj)
1839{
1840	kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
1841}
1842
1843static struct attribute *damon_sysfs_ui_dir_attrs[] = {
1844	NULL,
1845};
1846ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
1847
1848static const struct kobj_type damon_sysfs_ui_dir_ktype = {
1849	.release = damon_sysfs_ui_dir_release,
1850	.sysfs_ops = &kobj_sysfs_ops,
1851	.default_groups = damon_sysfs_ui_dir_groups,
1852};
1853
1854static int __init damon_sysfs_init(void)
1855{
1856	struct kobject *damon_sysfs_root;
1857	struct damon_sysfs_ui_dir *admin;
1858	int err;
1859
1860	damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
1861	if (!damon_sysfs_root)
1862		return -ENOMEM;
1863
1864	admin = damon_sysfs_ui_dir_alloc();
1865	if (!admin) {
1866		kobject_put(damon_sysfs_root);
1867		return -ENOMEM;
1868	}
1869	err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
1870			damon_sysfs_root, "admin");
1871	if (err)
1872		goto out;
1873	err = damon_sysfs_ui_dir_add_dirs(admin);
1874	if (err)
1875		goto out;
1876	return 0;
1877
1878out:
1879	kobject_put(&admin->kobj);
1880	kobject_put(damon_sysfs_root);
1881	return err;
1882}
1883subsys_initcall(damon_sysfs_init);
1884
1885#include "tests/sysfs-kunit.h"