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Note: File does not exist in v5.9.
   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_update_target_pid(struct damon_target *target, int pid)
1166{
1167	struct pid *pid_new;
1168
1169	pid_new = find_get_pid(pid);
1170	if (!pid_new)
1171		return -EINVAL;
1172
1173	if (pid_new == target->pid) {
1174		put_pid(pid_new);
1175		return 0;
1176	}
1177
1178	put_pid(target->pid);
1179	target->pid = pid_new;
1180	return 0;
1181}
1182
1183static int damon_sysfs_update_target(struct damon_target *target,
1184		struct damon_ctx *ctx,
1185		struct damon_sysfs_target *sys_target)
1186{
1187	int err = 0;
1188
1189	if (damon_target_has_pid(ctx)) {
1190		err = damon_sysfs_update_target_pid(target, sys_target->pid);
1191		if (err)
1192			return err;
1193	}
1194
1195	/*
1196	 * Do monitoring target region boundary update only if one or more
1197	 * regions are set by the user.  This is for keeping current monitoring
1198	 * target results and range easier, especially for dynamic monitoring
1199	 * target regions update ops like 'vaddr'.
1200	 */
1201	if (sys_target->regions->nr)
1202		err = damon_sysfs_set_regions(target, sys_target->regions);
1203	return err;
1204}
1205
1206static int damon_sysfs_set_targets(struct damon_ctx *ctx,
1207		struct damon_sysfs_targets *sysfs_targets)
1208{
1209	struct damon_target *t, *next;
1210	int i = 0, err;
1211
1212	/* Multiple physical address space monitoring targets makes no sense */
1213	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
1214		return -EINVAL;
1215
1216	damon_for_each_target_safe(t, next, ctx) {
1217		if (i < sysfs_targets->nr) {
1218			err = damon_sysfs_update_target(t, ctx,
1219					sysfs_targets->targets_arr[i]);
1220			if (err)
1221				return err;
1222		} else {
1223			if (damon_target_has_pid(ctx))
1224				put_pid(t->pid);
1225			damon_destroy_target(t);
1226		}
1227		i++;
1228	}
1229
1230	for (; i < sysfs_targets->nr; i++) {
1231		struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];
1232
1233		err = damon_sysfs_add_target(st, ctx);
1234		if (err)
1235			return err;
1236	}
1237	return 0;
1238}
1239
1240static bool damon_sysfs_schemes_regions_updating;
1241
1242static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
1243{
1244	struct damon_target *t, *next;
1245	struct damon_sysfs_kdamond *kdamond;
1246	enum damon_sysfs_cmd cmd;
1247
1248	/* damon_sysfs_schemes_update_regions_stop() might not yet called */
1249	kdamond = damon_sysfs_cmd_request.kdamond;
1250	cmd = damon_sysfs_cmd_request.cmd;
1251	if (kdamond && ctx == kdamond->damon_ctx &&
1252			(cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS ||
1253			 cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES) &&
1254			damon_sysfs_schemes_regions_updating) {
1255		damon_sysfs_schemes_update_regions_stop(ctx);
1256		damon_sysfs_schemes_regions_updating = false;
1257		mutex_unlock(&damon_sysfs_lock);
1258	}
1259
1260	if (!damon_target_has_pid(ctx))
1261		return;
1262
1263	mutex_lock(&ctx->kdamond_lock);
1264	damon_for_each_target_safe(t, next, ctx) {
1265		put_pid(t->pid);
1266		damon_destroy_target(t);
1267	}
1268	mutex_unlock(&ctx->kdamond_lock);
1269}
1270
1271/*
1272 * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.
1273 * @kdamond:	The kobject wrapper that associated to the kdamond thread.
1274 *
1275 * This function reads the schemes stats of specific kdamond and update the
1276 * related values for sysfs files.  This function should be called from DAMON
1277 * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON
1278 * contexts-internal data and DAMON sysfs variables.
1279 */
1280static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)
1281{
1282	struct damon_ctx *ctx = kdamond->damon_ctx;
1283
1284	if (!ctx)
1285		return -EINVAL;
1286	damon_sysfs_schemes_update_stats(
1287			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1288	return 0;
1289}
1290
1291static int damon_sysfs_upd_schemes_regions_start(
1292		struct damon_sysfs_kdamond *kdamond, bool total_bytes_only)
1293{
1294	struct damon_ctx *ctx = kdamond->damon_ctx;
1295
1296	if (!ctx)
1297		return -EINVAL;
1298	return damon_sysfs_schemes_update_regions_start(
1299			kdamond->contexts->contexts_arr[0]->schemes, ctx,
1300			total_bytes_only);
1301}
1302
1303static int damon_sysfs_upd_schemes_regions_stop(
1304		struct damon_sysfs_kdamond *kdamond)
1305{
1306	struct damon_ctx *ctx = kdamond->damon_ctx;
1307
1308	if (!ctx)
1309		return -EINVAL;
1310	return damon_sysfs_schemes_update_regions_stop(ctx);
1311}
1312
1313static int damon_sysfs_clear_schemes_regions(
1314		struct damon_sysfs_kdamond *kdamond)
1315{
1316	struct damon_ctx *ctx = kdamond->damon_ctx;
1317
1318	if (!ctx)
1319		return -EINVAL;
1320	return damon_sysfs_schemes_clear_regions(
1321			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1322}
1323
1324static inline bool damon_sysfs_kdamond_running(
1325		struct damon_sysfs_kdamond *kdamond)
1326{
1327	return kdamond->damon_ctx &&
1328		damon_sysfs_ctx_running(kdamond->damon_ctx);
1329}
1330
1331static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
1332		struct damon_sysfs_context *sys_ctx)
1333{
1334	int err;
1335
1336	err = damon_select_ops(ctx, sys_ctx->ops_id);
1337	if (err)
1338		return err;
1339	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
1340	if (err)
1341		return err;
1342	err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
1343	if (err)
1344		return err;
1345	return damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
1346}
1347
1348/*
1349 * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
1350 * @kdamond:	The kobject wrapper for the associated kdamond.
1351 *
1352 * If the sysfs input is wrong, the kdamond will be terminated.
1353 */
1354static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
1355{
1356	if (!damon_sysfs_kdamond_running(kdamond))
1357		return -EINVAL;
1358	/* TODO: Support multiple contexts per kdamond */
1359	if (kdamond->contexts->nr != 1)
1360		return -EINVAL;
1361
1362	return damon_sysfs_apply_inputs(kdamond->damon_ctx,
1363			kdamond->contexts->contexts_arr[0]);
1364}
1365
1366static int damon_sysfs_commit_schemes_quota_goals(
1367		struct damon_sysfs_kdamond *sysfs_kdamond)
1368{
1369	struct damon_ctx *ctx;
1370	struct damon_sysfs_context *sysfs_ctx;
1371
1372	if (!damon_sysfs_kdamond_running(sysfs_kdamond))
1373		return -EINVAL;
1374	/* TODO: Support multiple contexts per kdamond */
1375	if (sysfs_kdamond->contexts->nr != 1)
1376		return -EINVAL;
1377
1378	ctx = sysfs_kdamond->damon_ctx;
1379	sysfs_ctx = sysfs_kdamond->contexts->contexts_arr[0];
1380	return damos_sysfs_set_quota_scores(sysfs_ctx->schemes, ctx);
1381}
1382
1383/*
1384 * damon_sysfs_upd_schemes_effective_quotas() - Update schemes effective quotas
1385 * sysfs files.
1386 * @kdamond:	The kobject wrapper that associated to the kdamond thread.
1387 *
1388 * This function reads the schemes' effective quotas of specific kdamond and
1389 * update the related values for sysfs files.  This function should be called
1390 * from DAMON callbacks while holding ``damon_syfs_lock``, to safely access the
1391 * DAMON contexts-internal data and DAMON sysfs variables.
1392 */
1393static int damon_sysfs_upd_schemes_effective_quotas(
1394		struct damon_sysfs_kdamond *kdamond)
1395{
1396	struct damon_ctx *ctx = kdamond->damon_ctx;
1397
1398	if (!ctx)
1399		return -EINVAL;
1400	damos_sysfs_update_effective_quotas(
1401			kdamond->contexts->contexts_arr[0]->schemes, ctx);
1402	return 0;
1403}
1404
1405
1406/*
1407 * damon_sysfs_cmd_request_callback() - DAMON callback for handling requests.
1408 * @c:		The DAMON context of the callback.
1409 * @active:	Whether @c is not deactivated due to watermarks.
1410 * @after_aggr:	Whether this is called from after_aggregation() callback.
1411 *
1412 * This function is periodically called back from the kdamond thread for @c.
1413 * Then, it checks if there is a waiting DAMON sysfs request and handles it.
1414 */
1415static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,
1416		bool after_aggregation)
1417{
1418	struct damon_sysfs_kdamond *kdamond;
1419	bool total_bytes_only = false;
1420	int err = 0;
1421
1422	/* avoid deadlock due to concurrent state_store('off') */
1423	if (!damon_sysfs_schemes_regions_updating &&
1424			!mutex_trylock(&damon_sysfs_lock))
1425		return 0;
1426	kdamond = damon_sysfs_cmd_request.kdamond;
1427	if (!kdamond || kdamond->damon_ctx != c)
1428		goto out;
1429	switch (damon_sysfs_cmd_request.cmd) {
1430	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
1431		err = damon_sysfs_upd_schemes_stats(kdamond);
1432		break;
1433	case DAMON_SYSFS_CMD_COMMIT:
1434		if (!after_aggregation)
1435			goto out;
1436		err = damon_sysfs_commit_input(kdamond);
1437		break;
1438	case DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS:
1439		err = damon_sysfs_commit_schemes_quota_goals(kdamond);
1440		break;
1441	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:
1442		total_bytes_only = true;
1443		fallthrough;
1444	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:
1445		if (!damon_sysfs_schemes_regions_updating) {
1446			err = damon_sysfs_upd_schemes_regions_start(kdamond,
1447					total_bytes_only);
1448			if (!err) {
1449				damon_sysfs_schemes_regions_updating = true;
1450				goto keep_lock_out;
1451			}
1452		} else {
1453			damos_sysfs_mark_finished_regions_updates(c);
1454			/*
1455			 * Continue regions updating if DAMON is till
1456			 * active and the update for all schemes is not
1457			 * finished.
1458			 */
1459			if (active && !damos_sysfs_regions_upd_done())
1460				goto keep_lock_out;
1461			err = damon_sysfs_upd_schemes_regions_stop(kdamond);
1462			damon_sysfs_schemes_regions_updating = false;
1463		}
1464		break;
1465	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:
1466		err = damon_sysfs_clear_schemes_regions(kdamond);
1467		break;
1468	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS:
1469		err = damon_sysfs_upd_schemes_effective_quotas(kdamond);
1470		break;
1471	default:
1472		break;
1473	}
1474	/* Mark the request as invalid now. */
1475	damon_sysfs_cmd_request.kdamond = NULL;
1476out:
1477	if (!damon_sysfs_schemes_regions_updating)
1478		mutex_unlock(&damon_sysfs_lock);
1479keep_lock_out:
1480	return err;
1481}
1482
1483static int damon_sysfs_after_wmarks_check(struct damon_ctx *c)
1484{
1485	/*
1486	 * after_wmarks_check() is called back while the context is deactivated
1487	 * by watermarks.
1488	 */
1489	return damon_sysfs_cmd_request_callback(c, false, false);
1490}
1491
1492static int damon_sysfs_after_sampling(struct damon_ctx *c)
1493{
1494	/*
1495	 * after_sampling() is called back only while the context is not
1496	 * deactivated by watermarks.
1497	 */
1498	return damon_sysfs_cmd_request_callback(c, true, false);
1499}
1500
1501static int damon_sysfs_after_aggregation(struct damon_ctx *c)
1502{
1503	/*
1504	 * after_aggregation() is called back only while the context is not
1505	 * deactivated by watermarks.
1506	 */
1507	return damon_sysfs_cmd_request_callback(c, true, true);
1508}
1509
1510static struct damon_ctx *damon_sysfs_build_ctx(
1511		struct damon_sysfs_context *sys_ctx)
1512{
1513	struct damon_ctx *ctx = damon_new_ctx();
1514	int err;
1515
1516	if (!ctx)
1517		return ERR_PTR(-ENOMEM);
1518
1519	err = damon_sysfs_apply_inputs(ctx, sys_ctx);
1520	if (err) {
1521		damon_destroy_ctx(ctx);
1522		return ERR_PTR(err);
1523	}
1524
1525	ctx->callback.after_wmarks_check = damon_sysfs_after_wmarks_check;
1526	ctx->callback.after_sampling = damon_sysfs_after_sampling;
1527	ctx->callback.after_aggregation = damon_sysfs_after_aggregation;
1528	ctx->callback.before_terminate = damon_sysfs_before_terminate;
1529	return ctx;
1530}
1531
1532static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
1533{
1534	struct damon_ctx *ctx;
1535	int err;
1536
1537	if (damon_sysfs_kdamond_running(kdamond))
1538		return -EBUSY;
1539	if (damon_sysfs_cmd_request.kdamond == kdamond)
1540		return -EBUSY;
1541	/* TODO: support multiple contexts per kdamond */
1542	if (kdamond->contexts->nr != 1)
1543		return -EINVAL;
1544
1545	if (kdamond->damon_ctx)
1546		damon_destroy_ctx(kdamond->damon_ctx);
1547	kdamond->damon_ctx = NULL;
1548
1549	ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
1550	if (IS_ERR(ctx))
1551		return PTR_ERR(ctx);
1552	err = damon_start(&ctx, 1, false);
1553	if (err) {
1554		damon_destroy_ctx(ctx);
1555		return err;
1556	}
1557	kdamond->damon_ctx = ctx;
1558	return err;
1559}
1560
1561static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
1562{
1563	if (!kdamond->damon_ctx)
1564		return -EINVAL;
1565	return damon_stop(&kdamond->damon_ctx, 1);
1566	/*
1567	 * To allow users show final monitoring results of already turned-off
1568	 * DAMON, we free kdamond->damon_ctx in next
1569	 * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
1570	 */
1571}
1572
1573/*
1574 * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
1575 * @cmd:	The command to handle.
1576 * @kdamond:	The kobject wrapper for the associated kdamond.
1577 *
1578 * This function handles a DAMON sysfs command for a kdamond.  For commands
1579 * that need to access running DAMON context-internal data, it requests
1580 * handling of the command to the DAMON callback
1581 * (@damon_sysfs_cmd_request_callback()) and wait until it is properly handled,
1582 * or the context is completed.
1583 *
1584 * Return: 0 on success, negative error code otherwise.
1585 */
1586static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
1587		struct damon_sysfs_kdamond *kdamond)
1588{
1589	bool need_wait = true;
1590
1591	/* Handle commands that doesn't access DAMON context-internal data */
1592	switch (cmd) {
1593	case DAMON_SYSFS_CMD_ON:
1594		return damon_sysfs_turn_damon_on(kdamond);
1595	case DAMON_SYSFS_CMD_OFF:
1596		return damon_sysfs_turn_damon_off(kdamond);
1597	default:
1598		break;
1599	}
1600
1601	/* Pass the command to DAMON callback for safe DAMON context access */
1602	if (damon_sysfs_cmd_request.kdamond)
1603		return -EBUSY;
1604	if (!damon_sysfs_kdamond_running(kdamond))
1605		return -EINVAL;
1606	damon_sysfs_cmd_request.cmd = cmd;
1607	damon_sysfs_cmd_request.kdamond = kdamond;
1608
1609	/*
1610	 * wait until damon_sysfs_cmd_request_callback() handles the request
1611	 * from kdamond context
1612	 */
1613	mutex_unlock(&damon_sysfs_lock);
1614	while (need_wait) {
1615		schedule_timeout_idle(msecs_to_jiffies(100));
1616		if (!mutex_trylock(&damon_sysfs_lock))
1617			continue;
1618		if (!damon_sysfs_cmd_request.kdamond) {
1619			/* damon_sysfs_cmd_request_callback() handled */
1620			need_wait = false;
1621		} else if (!damon_sysfs_kdamond_running(kdamond)) {
1622			/* kdamond has already finished */
1623			need_wait = false;
1624			damon_sysfs_cmd_request.kdamond = NULL;
1625		}
1626		mutex_unlock(&damon_sysfs_lock);
1627	}
1628	mutex_lock(&damon_sysfs_lock);
1629	return 0;
1630}
1631
1632static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
1633		const char *buf, size_t count)
1634{
1635	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1636			struct damon_sysfs_kdamond, kobj);
1637	enum damon_sysfs_cmd cmd;
1638	ssize_t ret = -EINVAL;
1639
1640	if (!mutex_trylock(&damon_sysfs_lock))
1641		return -EBUSY;
1642	for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
1643		if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
1644			ret = damon_sysfs_handle_cmd(cmd, kdamond);
1645			break;
1646		}
1647	}
1648	mutex_unlock(&damon_sysfs_lock);
1649	if (!ret)
1650		ret = count;
1651	return ret;
1652}
1653
1654static ssize_t pid_show(struct kobject *kobj,
1655		struct kobj_attribute *attr, char *buf)
1656{
1657	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1658			struct damon_sysfs_kdamond, kobj);
1659	struct damon_ctx *ctx;
1660	int pid = -1;
1661
1662	if (!mutex_trylock(&damon_sysfs_lock))
1663		return -EBUSY;
1664	ctx = kdamond->damon_ctx;
1665	if (!ctx)
1666		goto out;
1667
1668	mutex_lock(&ctx->kdamond_lock);
1669	if (ctx->kdamond)
1670		pid = ctx->kdamond->pid;
1671	mutex_unlock(&ctx->kdamond_lock);
1672out:
1673	mutex_unlock(&damon_sysfs_lock);
1674	return sysfs_emit(buf, "%d\n", pid);
1675}
1676
1677static void damon_sysfs_kdamond_release(struct kobject *kobj)
1678{
1679	struct damon_sysfs_kdamond *kdamond = container_of(kobj,
1680			struct damon_sysfs_kdamond, kobj);
1681
1682	if (kdamond->damon_ctx)
1683		damon_destroy_ctx(kdamond->damon_ctx);
1684	kfree(kdamond);
1685}
1686
1687static struct kobj_attribute damon_sysfs_kdamond_state_attr =
1688		__ATTR_RW_MODE(state, 0600);
1689
1690static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
1691		__ATTR_RO_MODE(pid, 0400);
1692
1693static struct attribute *damon_sysfs_kdamond_attrs[] = {
1694	&damon_sysfs_kdamond_state_attr.attr,
1695	&damon_sysfs_kdamond_pid_attr.attr,
1696	NULL,
1697};
1698ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
1699
1700static const struct kobj_type damon_sysfs_kdamond_ktype = {
1701	.release = damon_sysfs_kdamond_release,
1702	.sysfs_ops = &kobj_sysfs_ops,
1703	.default_groups = damon_sysfs_kdamond_groups,
1704};
1705
1706/*
1707 * kdamonds directory
1708 */
1709
1710struct damon_sysfs_kdamonds {
1711	struct kobject kobj;
1712	struct damon_sysfs_kdamond **kdamonds_arr;
1713	int nr;
1714};
1715
1716static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
1717{
1718	return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);
1719}
1720
1721static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
1722{
1723	struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
1724	int i;
1725
1726	for (i = 0; i < kdamonds->nr; i++) {
1727		damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
1728		kobject_put(&kdamonds_arr[i]->kobj);
1729	}
1730	kdamonds->nr = 0;
1731	kfree(kdamonds_arr);
1732	kdamonds->kdamonds_arr = NULL;
1733}
1734
1735static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds,
1736		int nr_kdamonds)
1737{
1738	int i;
1739
1740	for (i = 0; i < nr_kdamonds; i++) {
1741		if (damon_sysfs_kdamond_running(kdamonds[i]) ||
1742		    damon_sysfs_cmd_request.kdamond == kdamonds[i])
1743			return true;
1744	}
1745
1746	return false;
1747}
1748
1749static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
1750		int nr_kdamonds)
1751{
1752	struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
1753	int err, i;
1754
1755	if (damon_sysfs_kdamonds_busy(kdamonds->kdamonds_arr, kdamonds->nr))
1756		return -EBUSY;
1757
1758	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1759	if (!nr_kdamonds)
1760		return 0;
1761
1762	kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),
1763			GFP_KERNEL | __GFP_NOWARN);
1764	if (!kdamonds_arr)
1765		return -ENOMEM;
1766	kdamonds->kdamonds_arr = kdamonds_arr;
1767
1768	for (i = 0; i < nr_kdamonds; i++) {
1769		kdamond = damon_sysfs_kdamond_alloc();
1770		if (!kdamond) {
1771			damon_sysfs_kdamonds_rm_dirs(kdamonds);
1772			return -ENOMEM;
1773		}
1774
1775		err = kobject_init_and_add(&kdamond->kobj,
1776				&damon_sysfs_kdamond_ktype, &kdamonds->kobj,
1777				"%d", i);
1778		if (err)
1779			goto out;
1780
1781		err = damon_sysfs_kdamond_add_dirs(kdamond);
1782		if (err)
1783			goto out;
1784
1785		kdamonds_arr[i] = kdamond;
1786		kdamonds->nr++;
1787	}
1788	return 0;
1789
1790out:
1791	damon_sysfs_kdamonds_rm_dirs(kdamonds);
1792	kobject_put(&kdamond->kobj);
1793	return err;
1794}
1795
1796static ssize_t nr_kdamonds_show(struct kobject *kobj,
1797		struct kobj_attribute *attr, char *buf)
1798{
1799	struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
1800			struct damon_sysfs_kdamonds, kobj);
1801
1802	return sysfs_emit(buf, "%d\n", kdamonds->nr);
1803}
1804
1805static ssize_t nr_kdamonds_store(struct kobject *kobj,
1806		struct kobj_attribute *attr, const char *buf, size_t count)
1807{
1808	struct damon_sysfs_kdamonds *kdamonds;
1809	int nr, err;
1810
1811	err = kstrtoint(buf, 0, &nr);
1812	if (err)
1813		return err;
1814	if (nr < 0)
1815		return -EINVAL;
1816
1817	kdamonds = container_of(kobj, struct damon_sysfs_kdamonds, kobj);
1818
1819	if (!mutex_trylock(&damon_sysfs_lock))
1820		return -EBUSY;
1821	err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
1822	mutex_unlock(&damon_sysfs_lock);
1823	if (err)
1824		return err;
1825
1826	return count;
1827}
1828
1829static void damon_sysfs_kdamonds_release(struct kobject *kobj)
1830{
1831	kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
1832}
1833
1834static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
1835		__ATTR_RW_MODE(nr_kdamonds, 0600);
1836
1837static struct attribute *damon_sysfs_kdamonds_attrs[] = {
1838	&damon_sysfs_kdamonds_nr_attr.attr,
1839	NULL,
1840};
1841ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
1842
1843static const struct kobj_type damon_sysfs_kdamonds_ktype = {
1844	.release = damon_sysfs_kdamonds_release,
1845	.sysfs_ops = &kobj_sysfs_ops,
1846	.default_groups = damon_sysfs_kdamonds_groups,
1847};
1848
1849/*
1850 * damon user interface directory
1851 */
1852
1853struct damon_sysfs_ui_dir {
1854	struct kobject kobj;
1855	struct damon_sysfs_kdamonds *kdamonds;
1856};
1857
1858static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
1859{
1860	return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);
1861}
1862
1863static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
1864{
1865	struct damon_sysfs_kdamonds *kdamonds;
1866	int err;
1867
1868	kdamonds = damon_sysfs_kdamonds_alloc();
1869	if (!kdamonds)
1870		return -ENOMEM;
1871
1872	err = kobject_init_and_add(&kdamonds->kobj,
1873			&damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
1874			"kdamonds");
1875	if (err) {
1876		kobject_put(&kdamonds->kobj);
1877		return err;
1878	}
1879	ui_dir->kdamonds = kdamonds;
1880	return err;
1881}
1882
1883static void damon_sysfs_ui_dir_release(struct kobject *kobj)
1884{
1885	kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
1886}
1887
1888static struct attribute *damon_sysfs_ui_dir_attrs[] = {
1889	NULL,
1890};
1891ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
1892
1893static const struct kobj_type damon_sysfs_ui_dir_ktype = {
1894	.release = damon_sysfs_ui_dir_release,
1895	.sysfs_ops = &kobj_sysfs_ops,
1896	.default_groups = damon_sysfs_ui_dir_groups,
1897};
1898
1899static int __init damon_sysfs_init(void)
1900{
1901	struct kobject *damon_sysfs_root;
1902	struct damon_sysfs_ui_dir *admin;
1903	int err;
1904
1905	damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
1906	if (!damon_sysfs_root)
1907		return -ENOMEM;
1908
1909	admin = damon_sysfs_ui_dir_alloc();
1910	if (!admin) {
1911		kobject_put(damon_sysfs_root);
1912		return -ENOMEM;
1913	}
1914	err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
1915			damon_sysfs_root, "admin");
1916	if (err)
1917		goto out;
1918	err = damon_sysfs_ui_dir_add_dirs(admin);
1919	if (err)
1920		goto out;
1921	return 0;
1922
1923out:
1924	kobject_put(&admin->kobj);
1925	kobject_put(damon_sysfs_root);
1926	return err;
1927}
1928subsys_initcall(damon_sysfs_init);
1929
1930#include "sysfs-test.h"