mm/damon/sysfs.c

   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/damon.h>
   9 #include <linux/kobject.h>
  10 #include <linux/pid.h>
  11 #include <linux/sched.h>
  12 #include <linux/slab.h>
  13
  14 static DEFINE_MUTEX(damon_sysfs_lock);
  15
  16 /*
  17  * unsigned long range directory
  18  */
  19
  20 struct damon_sysfs_ul_range {
  21         struct kobject kobj;
  22         unsigned long min;
  23         unsigned long max;
  24 };
  25
  26 static struct damon_sysfs_ul_range *damon_sysfs_ul_range_alloc(
  27                 unsigned long min,
  28                 unsigned long max)
  29 {
  30         struct damon_sysfs_ul_range *range = kmalloc(sizeof(*range),
  31                         GFP_KERNEL);
  32
  33         if (!range)
  34                 return NULL;
  35         range->kobj = (struct kobject){};
  36         range->min = min;
  37         range->max = max;
  38
  39         return range;
  40 }
  41
  42 static ssize_t min_show(struct kobject *kobj, struct kobj_attribute *attr,
  43                 char *buf)
  44 {
  45         struct damon_sysfs_ul_range *range = container_of(kobj,
  46                         struct damon_sysfs_ul_range, kobj);
  47
  48         return sysfs_emit(buf, "%lu\n", range->min);
  49 }
  50
  51 static ssize_t min_store(struct kobject *kobj, struct kobj_attribute *attr,
  52                 const char *buf, size_t count)
  53 {
  54         struct damon_sysfs_ul_range *range = container_of(kobj,
  55                         struct damon_sysfs_ul_range, kobj);
  56         unsigned long min;
  57         int err;
  58
  59         err = kstrtoul(buf, 0, &min);
  60         if (err)
  61                 return -EINVAL;
  62
  63         range->min = min;
  64         return count;
  65 }
  66
  67 static ssize_t max_show(struct kobject *kobj, struct kobj_attribute *attr,
  68                 char *buf)
  69 {
  70         struct damon_sysfs_ul_range *range = container_of(kobj,
  71                         struct damon_sysfs_ul_range, kobj);
  72
  73         return sysfs_emit(buf, "%lu\n", range->max);
  74 }
  75
  76 static ssize_t max_store(struct kobject *kobj, struct kobj_attribute *attr,
  77                 const char *buf, size_t count)
  78 {
  79         struct damon_sysfs_ul_range *range = container_of(kobj,
  80                         struct damon_sysfs_ul_range, kobj);
  81         unsigned long max;
  82         int err;
  83
  84         err = kstrtoul(buf, 0, &max);
  85         if (err)
  86                 return -EINVAL;
  87
  88         range->max = max;
  89         return count;
  90 }
  91
  92 static void damon_sysfs_ul_range_release(struct kobject *kobj)
  93 {
  94         kfree(container_of(kobj, struct damon_sysfs_ul_range, kobj));
  95 }
  96
  97 static struct kobj_attribute damon_sysfs_ul_range_min_attr =
  98                 __ATTR_RW_MODE(min, 0600);
  99
 100 static struct kobj_attribute damon_sysfs_ul_range_max_attr =
 101                 __ATTR_RW_MODE(max, 0600);
 102
 103 static struct attribute *damon_sysfs_ul_range_attrs[] = {
 104         &damon_sysfs_ul_range_min_attr.attr,
 105         &damon_sysfs_ul_range_max_attr.attr,
 106         NULL,
 107 };
 108 ATTRIBUTE_GROUPS(damon_sysfs_ul_range);
 109
 110 static struct kobj_type damon_sysfs_ul_range_ktype = {
 111         .release = damon_sysfs_ul_range_release,
 112         .sysfs_ops = &kobj_sysfs_ops,
 113         .default_groups = damon_sysfs_ul_range_groups,
 114 };
 115
 116 /*
 117  * schemes/stats directory
 118  */
 119
 120 struct damon_sysfs_stats {
 121         struct kobject kobj;
 122         unsigned long nr_tried;
 123         unsigned long sz_tried;
 124         unsigned long nr_applied;
 125         unsigned long sz_applied;
 126         unsigned long qt_exceeds;
 127 };
 128
 129 static struct damon_sysfs_stats *damon_sysfs_stats_alloc(void)
 130 {
 131         return kzalloc(sizeof(struct damon_sysfs_stats), GFP_KERNEL);
 132 }
 133
 134 static ssize_t nr_tried_show(struct kobject *kobj, struct kobj_attribute *attr,
 135                 char *buf)
 136 {
 137         struct damon_sysfs_stats *stats = container_of(kobj,
 138                         struct damon_sysfs_stats, kobj);
 139
 140         return sysfs_emit(buf, "%lu\n", stats->nr_tried);
 141 }
 142
 143 static ssize_t sz_tried_show(struct kobject *kobj, struct kobj_attribute *attr,
 144                 char *buf)
 145 {
 146         struct damon_sysfs_stats *stats = container_of(kobj,
 147                         struct damon_sysfs_stats, kobj);
 148
 149         return sysfs_emit(buf, "%lu\n", stats->sz_tried);
 150 }
 151
 152 static ssize_t nr_applied_show(struct kobject *kobj,
 153                 struct kobj_attribute *attr, char *buf)
 154 {
 155         struct damon_sysfs_stats *stats = container_of(kobj,
 156                         struct damon_sysfs_stats, kobj);
 157
 158         return sysfs_emit(buf, "%lu\n", stats->nr_applied);
 159 }
 160
 161 static ssize_t sz_applied_show(struct kobject *kobj,
 162                 struct kobj_attribute *attr, char *buf)
 163 {
 164         struct damon_sysfs_stats *stats = container_of(kobj,
 165                         struct damon_sysfs_stats, kobj);
 166
 167         return sysfs_emit(buf, "%lu\n", stats->sz_applied);
 168 }
 169
 170 static ssize_t qt_exceeds_show(struct kobject *kobj,
 171                 struct kobj_attribute *attr, char *buf)
 172 {
 173         struct damon_sysfs_stats *stats = container_of(kobj,
 174                         struct damon_sysfs_stats, kobj);
 175
 176         return sysfs_emit(buf, "%lu\n", stats->qt_exceeds);
 177 }
 178
 179 static void damon_sysfs_stats_release(struct kobject *kobj)
 180 {
 181         kfree(container_of(kobj, struct damon_sysfs_stats, kobj));
 182 }
 183
 184 static struct kobj_attribute damon_sysfs_stats_nr_tried_attr =
 185                 __ATTR_RO_MODE(nr_tried, 0400);
 186
 187 static struct kobj_attribute damon_sysfs_stats_sz_tried_attr =
 188                 __ATTR_RO_MODE(sz_tried, 0400);
 189
 190 static struct kobj_attribute damon_sysfs_stats_nr_applied_attr =
 191                 __ATTR_RO_MODE(nr_applied, 0400);
 192
 193 static struct kobj_attribute damon_sysfs_stats_sz_applied_attr =
 194                 __ATTR_RO_MODE(sz_applied, 0400);
 195
 196 static struct kobj_attribute damon_sysfs_stats_qt_exceeds_attr =
 197                 __ATTR_RO_MODE(qt_exceeds, 0400);
 198
 199 static struct attribute *damon_sysfs_stats_attrs[] = {
 200         &damon_sysfs_stats_nr_tried_attr.attr,
 201         &damon_sysfs_stats_sz_tried_attr.attr,
 202         &damon_sysfs_stats_nr_applied_attr.attr,
 203         &damon_sysfs_stats_sz_applied_attr.attr,
 204         &damon_sysfs_stats_qt_exceeds_attr.attr,
 205         NULL,
 206 };
 207 ATTRIBUTE_GROUPS(damon_sysfs_stats);
 208
 209 static struct kobj_type damon_sysfs_stats_ktype = {
 210         .release = damon_sysfs_stats_release,
 211         .sysfs_ops = &kobj_sysfs_ops,
 212         .default_groups = damon_sysfs_stats_groups,
 213 };
 214
 215 /*
 216  * watermarks directory
 217  */
 218
 219 struct damon_sysfs_watermarks {
 220         struct kobject kobj;
 221         enum damos_wmark_metric metric;
 222         unsigned long interval_us;
 223         unsigned long high;
 224         unsigned long mid;
 225         unsigned long low;
 226 };
 227
 228 static struct damon_sysfs_watermarks *damon_sysfs_watermarks_alloc(
 229                 enum damos_wmark_metric metric, unsigned long interval_us,
 230                 unsigned long high, unsigned long mid, unsigned long low)
 231 {
 232         struct damon_sysfs_watermarks *watermarks = kmalloc(
 233                         sizeof(*watermarks), GFP_KERNEL);
 234
 235         if (!watermarks)
 236                 return NULL;
 237         watermarks->kobj = (struct kobject){};
 238         watermarks->metric = metric;
 239         watermarks->interval_us = interval_us;
 240         watermarks->high = high;
 241         watermarks->mid = mid;
 242         watermarks->low = low;
 243         return watermarks;
 244 }
 245
 246 /* Should match with enum damos_wmark_metric */
 247 static const char * const damon_sysfs_wmark_metric_strs[] = {
 248         "none",
 249         "free_mem_rate",
 250 };
 251
 252 static ssize_t metric_show(struct kobject *kobj, struct kobj_attribute *attr,
 253                 char *buf)
 254 {
 255         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 256                         struct damon_sysfs_watermarks, kobj);
 257
 258         return sysfs_emit(buf, "%s\n",
 259                         damon_sysfs_wmark_metric_strs[watermarks->metric]);
 260 }
 261
 262 static ssize_t metric_store(struct kobject *kobj, struct kobj_attribute *attr,
 263                 const char *buf, size_t count)
 264 {
 265         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 266                         struct damon_sysfs_watermarks, kobj);
 267         enum damos_wmark_metric metric;
 268
 269         for (metric = 0; metric < NR_DAMOS_WMARK_METRICS; metric++) {
 270                 if (sysfs_streq(buf, damon_sysfs_wmark_metric_strs[metric])) {
 271                         watermarks->metric = metric;
 272                         return count;
 273                 }
 274         }
 275         return -EINVAL;
 276 }
 277
 278 static ssize_t interval_us_show(struct kobject *kobj,
 279                 struct kobj_attribute *attr, char *buf)
 280 {
 281         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 282                         struct damon_sysfs_watermarks, kobj);
 283
 284         return sysfs_emit(buf, "%lu\n", watermarks->interval_us);
 285 }
 286
 287 static ssize_t interval_us_store(struct kobject *kobj,
 288                 struct kobj_attribute *attr, const char *buf, size_t count)
 289 {
 290         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 291                         struct damon_sysfs_watermarks, kobj);
 292         int err = kstrtoul(buf, 0, &watermarks->interval_us);
 293
 294         if (err)
 295                 return -EINVAL;
 296         return count;
 297 }
 298
 299 static ssize_t high_show(struct kobject *kobj,
 300                 struct kobj_attribute *attr, char *buf)
 301 {
 302         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 303                         struct damon_sysfs_watermarks, kobj);
 304
 305         return sysfs_emit(buf, "%lu\n", watermarks->high);
 306 }
 307
 308 static ssize_t high_store(struct kobject *kobj,
 309                 struct kobj_attribute *attr, const char *buf, size_t count)
 310 {
 311         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 312                         struct damon_sysfs_watermarks, kobj);
 313         int err = kstrtoul(buf, 0, &watermarks->high);
 314
 315         if (err)
 316                 return -EINVAL;
 317         return count;
 318 }
 319
 320 static ssize_t mid_show(struct kobject *kobj,
 321                 struct kobj_attribute *attr, char *buf)
 322 {
 323         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 324                         struct damon_sysfs_watermarks, kobj);
 325
 326         return sysfs_emit(buf, "%lu\n", watermarks->mid);
 327 }
 328
 329 static ssize_t mid_store(struct kobject *kobj,
 330                 struct kobj_attribute *attr, const char *buf, size_t count)
 331 {
 332         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 333                         struct damon_sysfs_watermarks, kobj);
 334         int err = kstrtoul(buf, 0, &watermarks->mid);
 335
 336         if (err)
 337                 return -EINVAL;
 338         return count;
 339 }
 340
 341 static ssize_t low_show(struct kobject *kobj,
 342                 struct kobj_attribute *attr, char *buf)
 343 {
 344         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 345                         struct damon_sysfs_watermarks, kobj);
 346
 347         return sysfs_emit(buf, "%lu\n", watermarks->low);
 348 }
 349
 350 static ssize_t low_store(struct kobject *kobj,
 351                 struct kobj_attribute *attr, const char *buf, size_t count)
 352 {
 353         struct damon_sysfs_watermarks *watermarks = container_of(kobj,
 354                         struct damon_sysfs_watermarks, kobj);
 355         int err = kstrtoul(buf, 0, &watermarks->low);
 356
 357         if (err)
 358                 return -EINVAL;
 359         return count;
 360 }
 361
 362 static void damon_sysfs_watermarks_release(struct kobject *kobj)
 363 {
 364         kfree(container_of(kobj, struct damon_sysfs_watermarks, kobj));
 365 }
 366
 367 static struct kobj_attribute damon_sysfs_watermarks_metric_attr =
 368                 __ATTR_RW_MODE(metric, 0600);
 369
 370 static struct kobj_attribute damon_sysfs_watermarks_interval_us_attr =
 371                 __ATTR_RW_MODE(interval_us, 0600);
 372
 373 static struct kobj_attribute damon_sysfs_watermarks_high_attr =
 374                 __ATTR_RW_MODE(high, 0600);
 375
 376 static struct kobj_attribute damon_sysfs_watermarks_mid_attr =
 377                 __ATTR_RW_MODE(mid, 0600);
 378
 379 static struct kobj_attribute damon_sysfs_watermarks_low_attr =
 380                 __ATTR_RW_MODE(low, 0600);
 381
 382 static struct attribute *damon_sysfs_watermarks_attrs[] = {
 383         &damon_sysfs_watermarks_metric_attr.attr,
 384         &damon_sysfs_watermarks_interval_us_attr.attr,
 385         &damon_sysfs_watermarks_high_attr.attr,
 386         &damon_sysfs_watermarks_mid_attr.attr,
 387         &damon_sysfs_watermarks_low_attr.attr,
 388         NULL,
 389 };
 390 ATTRIBUTE_GROUPS(damon_sysfs_watermarks);
 391
 392 static struct kobj_type damon_sysfs_watermarks_ktype = {
 393         .release = damon_sysfs_watermarks_release,
 394         .sysfs_ops = &kobj_sysfs_ops,
 395         .default_groups = damon_sysfs_watermarks_groups,
 396 };
 397
 398 /*
 399  * scheme/weights directory
 400  */
 401
 402 struct damon_sysfs_weights {
 403         struct kobject kobj;
 404         unsigned int sz;
 405         unsigned int nr_accesses;
 406         unsigned int age;
 407 };
 408
 409 static struct damon_sysfs_weights *damon_sysfs_weights_alloc(unsigned int sz,
 410                 unsigned int nr_accesses, unsigned int age)
 411 {
 412         struct damon_sysfs_weights *weights = kmalloc(sizeof(*weights),
 413                         GFP_KERNEL);
 414
 415         if (!weights)
 416                 return NULL;
 417         weights->kobj = (struct kobject){};
 418         weights->sz = sz;
 419         weights->nr_accesses = nr_accesses;
 420         weights->age = age;
 421         return weights;
 422 }
 423
 424 static ssize_t sz_permil_show(struct kobject *kobj,
 425                 struct kobj_attribute *attr, char *buf)
 426 {
 427         struct damon_sysfs_weights *weights = container_of(kobj,
 428                         struct damon_sysfs_weights, kobj);
 429
 430         return sysfs_emit(buf, "%u\n", weights->sz);
 431 }
 432
 433 static ssize_t sz_permil_store(struct kobject *kobj,
 434                 struct kobj_attribute *attr, const char *buf, size_t count)
 435 {
 436         struct damon_sysfs_weights *weights = container_of(kobj,
 437                         struct damon_sysfs_weights, kobj);
 438         int err = kstrtouint(buf, 0, &weights->sz);
 439
 440         if (err)
 441                 return -EINVAL;
 442         return count;
 443 }
 444
 445 static ssize_t nr_accesses_permil_show(struct kobject *kobj,
 446                 struct kobj_attribute *attr, char *buf)
 447 {
 448         struct damon_sysfs_weights *weights = container_of(kobj,
 449                         struct damon_sysfs_weights, kobj);
 450
 451         return sysfs_emit(buf, "%u\n", weights->nr_accesses);
 452 }
 453
 454 static ssize_t nr_accesses_permil_store(struct kobject *kobj,
 455                 struct kobj_attribute *attr, const char *buf, size_t count)
 456 {
 457         struct damon_sysfs_weights *weights = container_of(kobj,
 458                         struct damon_sysfs_weights, kobj);
 459         int err = kstrtouint(buf, 0, &weights->nr_accesses);
 460
 461         if (err)
 462                 return -EINVAL;
 463         return count;
 464 }
 465
 466 static ssize_t age_permil_show(struct kobject *kobj,
 467                 struct kobj_attribute *attr, char *buf)
 468 {
 469         struct damon_sysfs_weights *weights = container_of(kobj,
 470                         struct damon_sysfs_weights, kobj);
 471
 472         return sysfs_emit(buf, "%u\n", weights->age);
 473 }
 474
 475 static ssize_t age_permil_store(struct kobject *kobj,
 476                 struct kobj_attribute *attr, const char *buf, size_t count)
 477 {
 478         struct damon_sysfs_weights *weights = container_of(kobj,
 479                         struct damon_sysfs_weights, kobj);
 480         int err = kstrtouint(buf, 0, &weights->age);
 481
 482         if (err)
 483                 return -EINVAL;
 484         return count;
 485 }
 486
 487 static void damon_sysfs_weights_release(struct kobject *kobj)
 488 {
 489         kfree(container_of(kobj, struct damon_sysfs_weights, kobj));
 490 }
 491
 492 static struct kobj_attribute damon_sysfs_weights_sz_attr =
 493                 __ATTR_RW_MODE(sz_permil, 0600);
 494
 495 static struct kobj_attribute damon_sysfs_weights_nr_accesses_attr =
 496                 __ATTR_RW_MODE(nr_accesses_permil, 0600);
 497
 498 static struct kobj_attribute damon_sysfs_weights_age_attr =
 499                 __ATTR_RW_MODE(age_permil, 0600);
 500
 501 static struct attribute *damon_sysfs_weights_attrs[] = {
 502         &damon_sysfs_weights_sz_attr.attr,
 503         &damon_sysfs_weights_nr_accesses_attr.attr,
 504         &damon_sysfs_weights_age_attr.attr,
 505         NULL,
 506 };
 507 ATTRIBUTE_GROUPS(damon_sysfs_weights);
 508
 509 static struct kobj_type damon_sysfs_weights_ktype = {
 510         .release = damon_sysfs_weights_release,
 511         .sysfs_ops = &kobj_sysfs_ops,
 512         .default_groups = damon_sysfs_weights_groups,
 513 };
 514
 515 /*
 516  * quotas directory
 517  */
 518
 519 struct damon_sysfs_quotas {
 520         struct kobject kobj;
 521         struct damon_sysfs_weights *weights;
 522         unsigned long ms;
 523         unsigned long sz;
 524         unsigned long reset_interval_ms;
 525 };
 526
 527 static struct damon_sysfs_quotas *damon_sysfs_quotas_alloc(void)
 528 {
 529         return kzalloc(sizeof(struct damon_sysfs_quotas), GFP_KERNEL);
 530 }
 531
 532 static int damon_sysfs_quotas_add_dirs(struct damon_sysfs_quotas *quotas)
 533 {
 534         struct damon_sysfs_weights *weights;
 535         int err;
 536
 537         weights = damon_sysfs_weights_alloc(0, 0, 0);
 538         if (!weights)
 539                 return -ENOMEM;
 540
 541         err = kobject_init_and_add(&weights->kobj, &damon_sysfs_weights_ktype,
 542                         &quotas->kobj, "weights");
 543         if (err)
 544                 kobject_put(&weights->kobj);
 545         else
 546                 quotas->weights = weights;
 547         return err;
 548 }
 549
 550 static void damon_sysfs_quotas_rm_dirs(struct damon_sysfs_quotas *quotas)
 551 {
 552         kobject_put(&quotas->weights->kobj);
 553 }
 554
 555 static ssize_t ms_show(struct kobject *kobj, struct kobj_attribute *attr,
 556                 char *buf)
 557 {
 558         struct damon_sysfs_quotas *quotas = container_of(kobj,
 559                         struct damon_sysfs_quotas, kobj);
 560
 561         return sysfs_emit(buf, "%lu\n", quotas->ms);
 562 }
 563
 564 static ssize_t ms_store(struct kobject *kobj, struct kobj_attribute *attr,
 565                 const char *buf, size_t count)
 566 {
 567         struct damon_sysfs_quotas *quotas = container_of(kobj,
 568                         struct damon_sysfs_quotas, kobj);
 569         int err = kstrtoul(buf, 0, &quotas->ms);
 570
 571         if (err)
 572                 return -EINVAL;
 573         return count;
 574 }
 575
 576 static ssize_t bytes_show(struct kobject *kobj, struct kobj_attribute *attr,
 577                 char *buf)
 578 {
 579         struct damon_sysfs_quotas *quotas = container_of(kobj,
 580                         struct damon_sysfs_quotas, kobj);
 581
 582         return sysfs_emit(buf, "%lu\n", quotas->sz);
 583 }
 584
 585 static ssize_t bytes_store(struct kobject *kobj,
 586                 struct kobj_attribute *attr, const char *buf, size_t count)
 587 {
 588         struct damon_sysfs_quotas *quotas = container_of(kobj,
 589                         struct damon_sysfs_quotas, kobj);
 590         int err = kstrtoul(buf, 0, &quotas->sz);
 591
 592         if (err)
 593                 return -EINVAL;
 594         return count;
 595 }
 596
 597 static ssize_t reset_interval_ms_show(struct kobject *kobj,
 598                 struct kobj_attribute *attr, char *buf)
 599 {
 600         struct damon_sysfs_quotas *quotas = container_of(kobj,
 601                         struct damon_sysfs_quotas, kobj);
 602
 603         return sysfs_emit(buf, "%lu\n", quotas->reset_interval_ms);
 604 }
 605
 606 static ssize_t reset_interval_ms_store(struct kobject *kobj,
 607                 struct kobj_attribute *attr, const char *buf, size_t count)
 608 {
 609         struct damon_sysfs_quotas *quotas = container_of(kobj,
 610                         struct damon_sysfs_quotas, kobj);
 611         int err = kstrtoul(buf, 0, &quotas->reset_interval_ms);
 612
 613         if (err)
 614                 return -EINVAL;
 615         return count;
 616 }
 617
 618 static void damon_sysfs_quotas_release(struct kobject *kobj)
 619 {
 620         kfree(container_of(kobj, struct damon_sysfs_quotas, kobj));
 621 }
 622
 623 static struct kobj_attribute damon_sysfs_quotas_ms_attr =
 624                 __ATTR_RW_MODE(ms, 0600);
 625
 626 static struct kobj_attribute damon_sysfs_quotas_sz_attr =
 627                 __ATTR_RW_MODE(bytes, 0600);
 628
 629 static struct kobj_attribute damon_sysfs_quotas_reset_interval_ms_attr =
 630                 __ATTR_RW_MODE(reset_interval_ms, 0600);
 631
 632 static struct attribute *damon_sysfs_quotas_attrs[] = {
 633         &damon_sysfs_quotas_ms_attr.attr,
 634         &damon_sysfs_quotas_sz_attr.attr,
 635         &damon_sysfs_quotas_reset_interval_ms_attr.attr,
 636         NULL,
 637 };
 638 ATTRIBUTE_GROUPS(damon_sysfs_quotas);
 639
 640 static struct kobj_type damon_sysfs_quotas_ktype = {
 641         .release = damon_sysfs_quotas_release,
 642         .sysfs_ops = &kobj_sysfs_ops,
 643         .default_groups = damon_sysfs_quotas_groups,
 644 };
 645
 646 /*
 647  * access_pattern directory
 648  */
 649
 650 struct damon_sysfs_access_pattern {
 651         struct kobject kobj;
 652         struct damon_sysfs_ul_range *sz;
 653         struct damon_sysfs_ul_range *nr_accesses;
 654         struct damon_sysfs_ul_range *age;
 655 };
 656
 657 static
 658 struct damon_sysfs_access_pattern *damon_sysfs_access_pattern_alloc(void)
 659 {
 660         struct damon_sysfs_access_pattern *access_pattern =
 661                 kmalloc(sizeof(*access_pattern), GFP_KERNEL);
 662
 663         if (!access_pattern)
 664                 return NULL;
 665         access_pattern->kobj = (struct kobject){};
 666         return access_pattern;
 667 }
 668
 669 static int damon_sysfs_access_pattern_add_range_dir(
 670                 struct damon_sysfs_access_pattern *access_pattern,
 671                 struct damon_sysfs_ul_range **range_dir_ptr,
 672                 char *name)
 673 {
 674         struct damon_sysfs_ul_range *range = damon_sysfs_ul_range_alloc(0, 0);
 675         int err;
 676
 677         if (!range)
 678                 return -ENOMEM;
 679         err = kobject_init_and_add(&range->kobj, &damon_sysfs_ul_range_ktype,
 680                         &access_pattern->kobj, name);
 681         if (err)
 682                 kobject_put(&range->kobj);
 683         else
 684                 *range_dir_ptr = range;
 685         return err;
 686 }
 687
 688 static int damon_sysfs_access_pattern_add_dirs(
 689                 struct damon_sysfs_access_pattern *access_pattern)
 690 {
 691         int err;
 692
 693         err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
 694                         &access_pattern->sz, "sz");
 695         if (err)
 696                 goto put_sz_out;
 697
 698         err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
 699                         &access_pattern->nr_accesses, "nr_accesses");
 700         if (err)
 701                 goto put_nr_accesses_sz_out;
 702
 703         err = damon_sysfs_access_pattern_add_range_dir(access_pattern,
 704                         &access_pattern->age, "age");
 705         if (err)
 706                 goto put_age_nr_accesses_sz_out;
 707         return 0;
 708
 709 put_age_nr_accesses_sz_out:
 710         kobject_put(&access_pattern->age->kobj);
 711         access_pattern->age = NULL;
 712 put_nr_accesses_sz_out:
 713         kobject_put(&access_pattern->nr_accesses->kobj);
 714         access_pattern->nr_accesses = NULL;
 715 put_sz_out:
 716         kobject_put(&access_pattern->sz->kobj);
 717         access_pattern->sz = NULL;
 718         return err;
 719 }
 720
 721 static void damon_sysfs_access_pattern_rm_dirs(
 722                 struct damon_sysfs_access_pattern *access_pattern)
 723 {
 724         kobject_put(&access_pattern->sz->kobj);
 725         kobject_put(&access_pattern->nr_accesses->kobj);
 726         kobject_put(&access_pattern->age->kobj);
 727 }
 728
 729 static void damon_sysfs_access_pattern_release(struct kobject *kobj)
 730 {
 731         kfree(container_of(kobj, struct damon_sysfs_access_pattern, kobj));
 732 }
 733
 734 static struct attribute *damon_sysfs_access_pattern_attrs[] = {
 735         NULL,
 736 };
 737 ATTRIBUTE_GROUPS(damon_sysfs_access_pattern);
 738
 739 static struct kobj_type damon_sysfs_access_pattern_ktype = {
 740         .release = damon_sysfs_access_pattern_release,
 741         .sysfs_ops = &kobj_sysfs_ops,
 742         .default_groups = damon_sysfs_access_pattern_groups,
 743 };
 744
 745 /*
 746  * scheme directory
 747  */
 748
 749 struct damon_sysfs_scheme {
 750         struct kobject kobj;
 751         enum damos_action action;
 752         struct damon_sysfs_access_pattern *access_pattern;
 753         struct damon_sysfs_quotas *quotas;
 754         struct damon_sysfs_watermarks *watermarks;
 755         struct damon_sysfs_stats *stats;
 756 };
 757
 758 /* This should match with enum damos_action */
 759 static const char * const damon_sysfs_damos_action_strs[] = {
 760         "willneed",
 761         "cold",
 762         "pageout",
 763         "hugepage",
 764         "nohugepage",
 765         "stat",
 766 };
 767
 768 static struct damon_sysfs_scheme *damon_sysfs_scheme_alloc(
 769                 enum damos_action action)
 770 {
 771         struct damon_sysfs_scheme *scheme = kmalloc(sizeof(*scheme),
 772                                 GFP_KERNEL);
 773
 774         if (!scheme)
 775                 return NULL;
 776         scheme->kobj = (struct kobject){};
 777         scheme->action = action;
 778         return scheme;
 779 }
 780
 781 static int damon_sysfs_scheme_set_access_pattern(
 782                 struct damon_sysfs_scheme *scheme)
 783 {
 784         struct damon_sysfs_access_pattern *access_pattern;
 785         int err;
 786
 787         access_pattern = damon_sysfs_access_pattern_alloc();
 788         if (!access_pattern)
 789                 return -ENOMEM;
 790         err = kobject_init_and_add(&access_pattern->kobj,
 791                         &damon_sysfs_access_pattern_ktype, &scheme->kobj,
 792                         "access_pattern");
 793         if (err)
 794                 goto out;
 795         err = damon_sysfs_access_pattern_add_dirs(access_pattern);
 796         if (err)
 797                 goto out;
 798         scheme->access_pattern = access_pattern;
 799         return 0;
 800
 801 out:
 802         kobject_put(&access_pattern->kobj);
 803         return err;
 804 }
 805
 806 static int damon_sysfs_scheme_set_quotas(struct damon_sysfs_scheme *scheme)
 807 {
 808         struct damon_sysfs_quotas *quotas = damon_sysfs_quotas_alloc();
 809         int err;
 810
 811         if (!quotas)
 812                 return -ENOMEM;
 813         err = kobject_init_and_add(&quotas->kobj, &damon_sysfs_quotas_ktype,
 814                         &scheme->kobj, "quotas");
 815         if (err)
 816                 goto out;
 817         err = damon_sysfs_quotas_add_dirs(quotas);
 818         if (err)
 819                 goto out;
 820         scheme->quotas = quotas;
 821         return 0;
 822
 823 out:
 824         kobject_put(&quotas->kobj);
 825         return err;
 826 }
 827
 828 static int damon_sysfs_scheme_set_watermarks(struct damon_sysfs_scheme *scheme)
 829 {
 830         struct damon_sysfs_watermarks *watermarks =
 831                 damon_sysfs_watermarks_alloc(DAMOS_WMARK_NONE, 0, 0, 0, 0);
 832         int err;
 833
 834         if (!watermarks)
 835                 return -ENOMEM;
 836         err = kobject_init_and_add(&watermarks->kobj,
 837                         &damon_sysfs_watermarks_ktype, &scheme->kobj,
 838                         "watermarks");
 839         if (err)
 840                 kobject_put(&watermarks->kobj);
 841         else
 842                 scheme->watermarks = watermarks;
 843         return err;
 844 }
 845
 846 static int damon_sysfs_scheme_set_stats(struct damon_sysfs_scheme *scheme)
 847 {
 848         struct damon_sysfs_stats *stats = damon_sysfs_stats_alloc();
 849         int err;
 850
 851         if (!stats)
 852                 return -ENOMEM;
 853         err = kobject_init_and_add(&stats->kobj, &damon_sysfs_stats_ktype,
 854                         &scheme->kobj, "stats");
 855         if (err)
 856                 kobject_put(&stats->kobj);
 857         else
 858                 scheme->stats = stats;
 859         return err;
 860 }
 861
 862 static int damon_sysfs_scheme_add_dirs(struct damon_sysfs_scheme *scheme)
 863 {
 864         int err;
 865
 866         err = damon_sysfs_scheme_set_access_pattern(scheme);
 867         if (err)
 868                 return err;
 869         err = damon_sysfs_scheme_set_quotas(scheme);
 870         if (err)
 871                 goto put_access_pattern_out;
 872         err = damon_sysfs_scheme_set_watermarks(scheme);
 873         if (err)
 874                 goto put_quotas_access_pattern_out;
 875         err = damon_sysfs_scheme_set_stats(scheme);
 876         if (err)
 877                 goto put_watermarks_quotas_access_pattern_out;
 878         return 0;
 879
 880 put_watermarks_quotas_access_pattern_out:
 881         kobject_put(&scheme->watermarks->kobj);
 882         scheme->watermarks = NULL;
 883 put_quotas_access_pattern_out:
 884         kobject_put(&scheme->quotas->kobj);
 885         scheme->quotas = NULL;
 886 put_access_pattern_out:
 887         kobject_put(&scheme->access_pattern->kobj);
 888         scheme->access_pattern = NULL;
 889         return err;
 890 }
 891
 892 static void damon_sysfs_scheme_rm_dirs(struct damon_sysfs_scheme *scheme)
 893 {
 894         damon_sysfs_access_pattern_rm_dirs(scheme->access_pattern);
 895         kobject_put(&scheme->access_pattern->kobj);
 896         damon_sysfs_quotas_rm_dirs(scheme->quotas);
 897         kobject_put(&scheme->quotas->kobj);
 898         kobject_put(&scheme->watermarks->kobj);
 899         kobject_put(&scheme->stats->kobj);
 900 }
 901
 902 static ssize_t action_show(struct kobject *kobj, struct kobj_attribute *attr,
 903                 char *buf)
 904 {
 905         struct damon_sysfs_scheme *scheme = container_of(kobj,
 906                         struct damon_sysfs_scheme, kobj);
 907
 908         return sysfs_emit(buf, "%s\n",
 909                         damon_sysfs_damos_action_strs[scheme->action]);
 910 }
 911
 912 static ssize_t action_store(struct kobject *kobj, struct kobj_attribute *attr,
 913                 const char *buf, size_t count)
 914 {
 915         struct damon_sysfs_scheme *scheme = container_of(kobj,
 916                         struct damon_sysfs_scheme, kobj);
 917         enum damos_action action;
 918
 919         for (action = 0; action < NR_DAMOS_ACTIONS; action++) {
 920                 if (sysfs_streq(buf, damon_sysfs_damos_action_strs[action])) {
 921                         scheme->action = action;
 922                         return count;
 923                 }
 924         }
 925         return -EINVAL;
 926 }
 927
 928 static void damon_sysfs_scheme_release(struct kobject *kobj)
 929 {
 930         kfree(container_of(kobj, struct damon_sysfs_scheme, kobj));
 931 }
 932
 933 static struct kobj_attribute damon_sysfs_scheme_action_attr =
 934                 __ATTR_RW_MODE(action, 0600);
 935
 936 static struct attribute *damon_sysfs_scheme_attrs[] = {
 937         &damon_sysfs_scheme_action_attr.attr,
 938         NULL,
 939 };
 940 ATTRIBUTE_GROUPS(damon_sysfs_scheme);
 941
 942 static struct kobj_type damon_sysfs_scheme_ktype = {
 943         .release = damon_sysfs_scheme_release,
 944         .sysfs_ops = &kobj_sysfs_ops,
 945         .default_groups = damon_sysfs_scheme_groups,
 946 };
 947
 948 /*
 949  * schemes directory
 950  */
 951
 952 struct damon_sysfs_schemes {
 953         struct kobject kobj;
 954         struct damon_sysfs_scheme **schemes_arr;
 955         int nr;
 956 };
 957
 958 static struct damon_sysfs_schemes *damon_sysfs_schemes_alloc(void)
 959 {
 960         return kzalloc(sizeof(struct damon_sysfs_schemes), GFP_KERNEL);
 961 }
 962
 963 static void damon_sysfs_schemes_rm_dirs(struct damon_sysfs_schemes *schemes)
 964 {
 965         struct damon_sysfs_scheme **schemes_arr = schemes->schemes_arr;
 966         int i;
 967
 968         for (i = 0; i < schemes->nr; i++) {
 969                 damon_sysfs_scheme_rm_dirs(schemes_arr[i]);
 970                 kobject_put(&schemes_arr[i]->kobj);
 971         }
 972         schemes->nr = 0;
 973         kfree(schemes_arr);
 974         schemes->schemes_arr = NULL;
 975 }
 976
 977 static int damon_sysfs_schemes_add_dirs(struct damon_sysfs_schemes *schemes,
 978                 int nr_schemes)
 979 {
 980         struct damon_sysfs_scheme **schemes_arr, *scheme;
 981         int err, i;
 982
 983         damon_sysfs_schemes_rm_dirs(schemes);
 984         if (!nr_schemes)
 985                 return 0;
 986
 987         schemes_arr = kmalloc_array(nr_schemes, sizeof(*schemes_arr),
 988                         GFP_KERNEL | __GFP_NOWARN);
 989         if (!schemes_arr)
 990                 return -ENOMEM;
 991         schemes->schemes_arr = schemes_arr;
 992
 993         for (i = 0; i < nr_schemes; i++) {
 994                 scheme = damon_sysfs_scheme_alloc(DAMOS_STAT);
 995                 if (!scheme) {
 996                         damon_sysfs_schemes_rm_dirs(schemes);
 997                         return -ENOMEM;
 998                 }
 999
1000                 err = kobject_init_and_add(&scheme->kobj,
1001                                 &damon_sysfs_scheme_ktype, &schemes->kobj,
1002                                 "%d", i);
1003                 if (err)
1004                         goto out;
1005                 err = damon_sysfs_scheme_add_dirs(scheme);
1006                 if (err)
1007                         goto out;
1008
1009                 schemes_arr[i] = scheme;
1010                 schemes->nr++;
1011         }
1012         return 0;
1013
1014 out:
1015         damon_sysfs_schemes_rm_dirs(schemes);
1016         kobject_put(&scheme->kobj);
1017         return err;
1018 }
1019
1020 static ssize_t nr_schemes_show(struct kobject *kobj,
1021                 struct kobj_attribute *attr, char *buf)
1022 {
1023         struct damon_sysfs_schemes *schemes = container_of(kobj,
1024                         struct damon_sysfs_schemes, kobj);
1025
1026         return sysfs_emit(buf, "%d\n", schemes->nr);
1027 }
1028
1029 static ssize_t nr_schemes_store(struct kobject *kobj,
1030                 struct kobj_attribute *attr, const char *buf, size_t count)
1031 {
1032         struct damon_sysfs_schemes *schemes = container_of(kobj,
1033                         struct damon_sysfs_schemes, kobj);
1034         int nr, err = kstrtoint(buf, 0, &nr);
1035
1036         if (err)
1037                 return err;
1038         if (nr < 0)
1039                 return -EINVAL;
1040
1041         if (!mutex_trylock(&damon_sysfs_lock))
1042                 return -EBUSY;
1043         err = damon_sysfs_schemes_add_dirs(schemes, nr);
1044         mutex_unlock(&damon_sysfs_lock);
1045         if (err)
1046                 return err;
1047         return count;
1048 }
1049
1050 static void damon_sysfs_schemes_release(struct kobject *kobj)
1051 {
1052         kfree(container_of(kobj, struct damon_sysfs_schemes, kobj));
1053 }
1054
1055 static struct kobj_attribute damon_sysfs_schemes_nr_attr =
1056                 __ATTR_RW_MODE(nr_schemes, 0600);
1057
1058 static struct attribute *damon_sysfs_schemes_attrs[] = {
1059         &damon_sysfs_schemes_nr_attr.attr,
1060         NULL,
1061 };
1062 ATTRIBUTE_GROUPS(damon_sysfs_schemes);
1063
1064 static struct kobj_type damon_sysfs_schemes_ktype = {
1065         .release = damon_sysfs_schemes_release,
1066         .sysfs_ops = &kobj_sysfs_ops,
1067         .default_groups = damon_sysfs_schemes_groups,
1068 };
1069
1070 /*
1071  * init region directory
1072  */
1073
1074 struct damon_sysfs_region {
1075         struct kobject kobj;
1076         unsigned long start;
1077         unsigned long end;
1078 };
1079
1080 static struct damon_sysfs_region *damon_sysfs_region_alloc(
1081                 unsigned long start,
1082                 unsigned long end)
1083 {
1084         struct damon_sysfs_region *region = kmalloc(sizeof(*region),
1085                         GFP_KERNEL);
1086
1087         if (!region)
1088                 return NULL;
1089         region->kobj = (struct kobject){};
1090         region->start = start;
1091         region->end = end;
1092         return region;
1093 }
1094
1095 static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
1096                 char *buf)
1097 {
1098         struct damon_sysfs_region *region = container_of(kobj,
1099                         struct damon_sysfs_region, kobj);
1100
1101         return sysfs_emit(buf, "%lu\n", region->start);
1102 }
1103
1104 static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
1105                 const char *buf, size_t count)
1106 {
1107         struct damon_sysfs_region *region = container_of(kobj,
1108                         struct damon_sysfs_region, kobj);
1109         int err = kstrtoul(buf, 0, &region->start);
1110
1111         if (err)
1112                 return -EINVAL;
1113         return count;
1114 }
1115
1116 static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
1117                 char *buf)
1118 {
1119         struct damon_sysfs_region *region = container_of(kobj,
1120                         struct damon_sysfs_region, kobj);
1121
1122         return sysfs_emit(buf, "%lu\n", region->end);
1123 }
1124
1125 static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
1126                 const char *buf, size_t count)
1127 {
1128         struct damon_sysfs_region *region = container_of(kobj,
1129                         struct damon_sysfs_region, kobj);
1130         int err = kstrtoul(buf, 0, &region->end);
1131
1132         if (err)
1133                 return -EINVAL;
1134         return count;
1135 }
1136
1137 static void damon_sysfs_region_release(struct kobject *kobj)
1138 {
1139         kfree(container_of(kobj, struct damon_sysfs_region, kobj));
1140 }
1141
1142 static struct kobj_attribute damon_sysfs_region_start_attr =
1143                 __ATTR_RW_MODE(start, 0600);
1144
1145 static struct kobj_attribute damon_sysfs_region_end_attr =
1146                 __ATTR_RW_MODE(end, 0600);
1147
1148 static struct attribute *damon_sysfs_region_attrs[] = {
1149         &damon_sysfs_region_start_attr.attr,
1150         &damon_sysfs_region_end_attr.attr,
1151         NULL,
1152 };
1153 ATTRIBUTE_GROUPS(damon_sysfs_region);
1154
1155 static struct kobj_type damon_sysfs_region_ktype = {
1156         .release = damon_sysfs_region_release,
1157         .sysfs_ops = &kobj_sysfs_ops,
1158         .default_groups = damon_sysfs_region_groups,
1159 };
1160
1161 /*
1162  * init_regions directory
1163  */
1164
1165 struct damon_sysfs_regions {
1166         struct kobject kobj;
1167         struct damon_sysfs_region **regions_arr;
1168         int nr;
1169 };
1170
1171 static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
1172 {
1173         return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);
1174 }
1175
1176 static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)
1177 {
1178         struct damon_sysfs_region **regions_arr = regions->regions_arr;
1179         int i;
1180
1181         for (i = 0; i < regions->nr; i++)
1182                 kobject_put(&regions_arr[i]->kobj);
1183         regions->nr = 0;
1184         kfree(regions_arr);
1185         regions->regions_arr = NULL;
1186 }
1187
1188 static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
1189                 int nr_regions)
1190 {
1191         struct damon_sysfs_region **regions_arr, *region;
1192         int err, i;
1193
1194         damon_sysfs_regions_rm_dirs(regions);
1195         if (!nr_regions)
1196                 return 0;
1197
1198         regions_arr = kmalloc_array(nr_regions, sizeof(*regions_arr),
1199                         GFP_KERNEL | __GFP_NOWARN);
1200         if (!regions_arr)
1201                 return -ENOMEM;
1202         regions->regions_arr = regions_arr;
1203
1204         for (i = 0; i < nr_regions; i++) {
1205                 region = damon_sysfs_region_alloc(0, 0);
1206                 if (!region) {
1207                         damon_sysfs_regions_rm_dirs(regions);
1208                         return -ENOMEM;
1209                 }
1210
1211                 err = kobject_init_and_add(&region->kobj,
1212                                 &damon_sysfs_region_ktype, &regions->kobj,
1213                                 "%d", i);
1214                 if (err) {
1215                         kobject_put(&region->kobj);
1216                         damon_sysfs_regions_rm_dirs(regions);
1217                         return err;
1218                 }
1219
1220                 regions_arr[i] = region;
1221                 regions->nr++;
1222         }
1223         return 0;
1224 }
1225
1226 static ssize_t nr_regions_show(struct kobject *kobj,
1227                 struct kobj_attribute *attr, char *buf)
1228 {
1229         struct damon_sysfs_regions *regions = container_of(kobj,
1230                         struct damon_sysfs_regions, kobj);
1231
1232         return sysfs_emit(buf, "%d\n", regions->nr);
1233 }
1234
1235 static ssize_t nr_regions_store(struct kobject *kobj,
1236                 struct kobj_attribute *attr, const char *buf, size_t count)
1237 {
1238         struct damon_sysfs_regions *regions = container_of(kobj,
1239                         struct damon_sysfs_regions, kobj);
1240         int nr, err = kstrtoint(buf, 0, &nr);
1241
1242         if (err)
1243                 return err;
1244         if (nr < 0)
1245                 return -EINVAL;
1246
1247         if (!mutex_trylock(&damon_sysfs_lock))
1248                 return -EBUSY;
1249         err = damon_sysfs_regions_add_dirs(regions, nr);
1250         mutex_unlock(&damon_sysfs_lock);
1251         if (err)
1252                 return err;
1253
1254         return count;
1255 }
1256
1257 static void damon_sysfs_regions_release(struct kobject *kobj)
1258 {
1259         kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
1260 }
1261
1262 static struct kobj_attribute damon_sysfs_regions_nr_attr =
1263                 __ATTR_RW_MODE(nr_regions, 0600);
1264
1265 static struct attribute *damon_sysfs_regions_attrs[] = {
1266         &damon_sysfs_regions_nr_attr.attr,
1267         NULL,
1268 };
1269 ATTRIBUTE_GROUPS(damon_sysfs_regions);
1270
1271 static struct kobj_type damon_sysfs_regions_ktype = {
1272         .release = damon_sysfs_regions_release,
1273         .sysfs_ops = &kobj_sysfs_ops,
1274         .default_groups = damon_sysfs_regions_groups,
1275 };
1276
1277 /*
1278  * target directory
1279  */
1280
1281 struct damon_sysfs_target {
1282         struct kobject kobj;
1283         struct damon_sysfs_regions *regions;
1284         int pid;
1285 };
1286
1287 static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
1288 {
1289         return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);
1290 }
1291
1292 static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
1293 {
1294         struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
1295         int err;
1296
1297         if (!regions)
1298                 return -ENOMEM;
1299
1300         err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
1301                         &target->kobj, "regions");
1302         if (err)
1303                 kobject_put(&regions->kobj);
1304         else
1305                 target->regions = regions;
1306         return err;
1307 }
1308
1309 static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
1310 {
1311         damon_sysfs_regions_rm_dirs(target->regions);
1312         kobject_put(&target->regions->kobj);
1313 }
1314
1315 static ssize_t pid_target_show(struct kobject *kobj,
1316                 struct kobj_attribute *attr, char *buf)
1317 {
1318         struct damon_sysfs_target *target = container_of(kobj,
1319                         struct damon_sysfs_target, kobj);
1320
1321         return sysfs_emit(buf, "%d\n", target->pid);
1322 }
1323
1324 static ssize_t pid_target_store(struct kobject *kobj,
1325                 struct kobj_attribute *attr, const char *buf, size_t count)
1326 {
1327         struct damon_sysfs_target *target = container_of(kobj,
1328                         struct damon_sysfs_target, kobj);
1329         int err = kstrtoint(buf, 0, &target->pid);
1330
1331         if (err)
1332                 return -EINVAL;
1333         return count;
1334 }
1335
1336 static void damon_sysfs_target_release(struct kobject *kobj)
1337 {
1338         kfree(container_of(kobj, struct damon_sysfs_target, kobj));
1339 }
1340
1341 static struct kobj_attribute damon_sysfs_target_pid_attr =
1342                 __ATTR_RW_MODE(pid_target, 0600);
1343
1344 static struct attribute *damon_sysfs_target_attrs[] = {
1345         &damon_sysfs_target_pid_attr.attr,
1346         NULL,
1347 };
1348 ATTRIBUTE_GROUPS(damon_sysfs_target);
1349
1350 static struct kobj_type damon_sysfs_target_ktype = {
1351         .release = damon_sysfs_target_release,
1352         .sysfs_ops = &kobj_sysfs_ops,
1353         .default_groups = damon_sysfs_target_groups,
1354 };
1355
1356 /*
1357  * targets directory
1358  */
1359
1360 struct damon_sysfs_targets {
1361         struct kobject kobj;
1362         struct damon_sysfs_target **targets_arr;
1363         int nr;
1364 };
1365
1366 static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)
1367 {
1368         return kzalloc(sizeof(struct damon_sysfs_targets), GFP_KERNEL);
1369 }
1370
1371 static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
1372 {
1373         struct damon_sysfs_target **targets_arr = targets->targets_arr;
1374         int i;
1375
1376         for (i = 0; i < targets->nr; i++) {
1377                 damon_sysfs_target_rm_dirs(targets_arr[i]);
1378                 kobject_put(&targets_arr[i]->kobj);
1379         }
1380         targets->nr = 0;
1381         kfree(targets_arr);
1382         targets->targets_arr = NULL;
1383 }
1384
1385 static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
1386                 int nr_targets)
1387 {
1388         struct damon_sysfs_target **targets_arr, *target;
1389         int err, i;
1390
1391         damon_sysfs_targets_rm_dirs(targets);
1392         if (!nr_targets)
1393                 return 0;
1394
1395         targets_arr = kmalloc_array(nr_targets, sizeof(*targets_arr),
1396                         GFP_KERNEL | __GFP_NOWARN);
1397         if (!targets_arr)
1398                 return -ENOMEM;
1399         targets->targets_arr = targets_arr;
1400
1401         for (i = 0; i < nr_targets; i++) {
1402                 target = damon_sysfs_target_alloc();
1403                 if (!target) {
1404                         damon_sysfs_targets_rm_dirs(targets);
1405                         return -ENOMEM;
1406                 }
1407
1408                 err = kobject_init_and_add(&target->kobj,
1409                                 &damon_sysfs_target_ktype, &targets->kobj,
1410                                 "%d", i);
1411                 if (err)
1412                         goto out;
1413
1414                 err = damon_sysfs_target_add_dirs(target);
1415                 if (err)
1416                         goto out;
1417
1418                 targets_arr[i] = target;
1419                 targets->nr++;
1420         }
1421         return 0;
1422
1423 out:
1424         damon_sysfs_targets_rm_dirs(targets);
1425         kobject_put(&target->kobj);
1426         return err;
1427 }
1428
1429 static ssize_t nr_targets_show(struct kobject *kobj,
1430                 struct kobj_attribute *attr, char *buf)
1431 {
1432         struct damon_sysfs_targets *targets = container_of(kobj,
1433                         struct damon_sysfs_targets, kobj);
1434
1435         return sysfs_emit(buf, "%d\n", targets->nr);
1436 }
1437
1438 static ssize_t nr_targets_store(struct kobject *kobj,
1439                 struct kobj_attribute *attr, const char *buf, size_t count)
1440 {
1441         struct damon_sysfs_targets *targets = container_of(kobj,
1442                         struct damon_sysfs_targets, kobj);
1443         int nr, err = kstrtoint(buf, 0, &nr);
1444
1445         if (err)
1446                 return err;
1447         if (nr < 0)
1448                 return -EINVAL;
1449
1450         if (!mutex_trylock(&damon_sysfs_lock))
1451                 return -EBUSY;
1452         err = damon_sysfs_targets_add_dirs(targets, nr);
1453         mutex_unlock(&damon_sysfs_lock);
1454         if (err)
1455                 return err;
1456
1457         return count;
1458 }
1459
1460 static void damon_sysfs_targets_release(struct kobject *kobj)
1461 {
1462         kfree(container_of(kobj, struct damon_sysfs_targets, kobj));
1463 }
1464
1465 static struct kobj_attribute damon_sysfs_targets_nr_attr =
1466                 __ATTR_RW_MODE(nr_targets, 0600);
1467
1468 static struct attribute *damon_sysfs_targets_attrs[] = {
1469         &damon_sysfs_targets_nr_attr.attr,
1470         NULL,
1471 };
1472 ATTRIBUTE_GROUPS(damon_sysfs_targets);
1473
1474 static struct kobj_type damon_sysfs_targets_ktype = {
1475         .release = damon_sysfs_targets_release,
1476         .sysfs_ops = &kobj_sysfs_ops,
1477         .default_groups = damon_sysfs_targets_groups,
1478 };
1479
1480 /*
1481  * intervals directory
1482  */
1483
1484 struct damon_sysfs_intervals {
1485         struct kobject kobj;
1486         unsigned long sample_us;
1487         unsigned long aggr_us;
1488         unsigned long update_us;
1489 };
1490
1491 static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
1492                 unsigned long sample_us, unsigned long aggr_us,
1493                 unsigned long update_us)
1494 {
1495         struct damon_sysfs_intervals *intervals = kmalloc(sizeof(*intervals),
1496                         GFP_KERNEL);
1497
1498         if (!intervals)
1499                 return NULL;
1500
1501         intervals->kobj = (struct kobject){};
1502         intervals->sample_us = sample_us;
1503         intervals->aggr_us = aggr_us;
1504         intervals->update_us = update_us;
1505         return intervals;
1506 }
1507
1508 static ssize_t sample_us_show(struct kobject *kobj,
1509                 struct kobj_attribute *attr, char *buf)
1510 {
1511         struct damon_sysfs_intervals *intervals = container_of(kobj,
1512                         struct damon_sysfs_intervals, kobj);
1513
1514         return sysfs_emit(buf, "%lu\n", intervals->sample_us);
1515 }
1516
1517 static ssize_t sample_us_store(struct kobject *kobj,
1518                 struct kobj_attribute *attr, const char *buf, size_t count)
1519 {
1520         struct damon_sysfs_intervals *intervals = container_of(kobj,
1521                         struct damon_sysfs_intervals, kobj);
1522         unsigned long us;
1523         int err = kstrtoul(buf, 0, &us);
1524
1525         if (err)
1526                 return -EINVAL;
1527
1528         intervals->sample_us = us;
1529         return count;
1530 }
1531
1532 static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,
1533                 char *buf)
1534 {
1535         struct damon_sysfs_intervals *intervals = container_of(kobj,
1536                         struct damon_sysfs_intervals, kobj);
1537
1538         return sysfs_emit(buf, "%lu\n", intervals->aggr_us);
1539 }
1540
1541 static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
1542                 const char *buf, size_t count)
1543 {
1544         struct damon_sysfs_intervals *intervals = container_of(kobj,
1545                         struct damon_sysfs_intervals, kobj);
1546         unsigned long us;
1547         int err = kstrtoul(buf, 0, &us);
1548
1549         if (err)
1550                 return -EINVAL;
1551
1552         intervals->aggr_us = us;
1553         return count;
1554 }
1555
1556 static ssize_t update_us_show(struct kobject *kobj,
1557                 struct kobj_attribute *attr, char *buf)
1558 {
1559         struct damon_sysfs_intervals *intervals = container_of(kobj,
1560                         struct damon_sysfs_intervals, kobj);
1561
1562         return sysfs_emit(buf, "%lu\n", intervals->update_us);
1563 }
1564
1565 static ssize_t update_us_store(struct kobject *kobj,
1566                 struct kobj_attribute *attr, const char *buf, size_t count)
1567 {
1568         struct damon_sysfs_intervals *intervals = container_of(kobj,
1569                         struct damon_sysfs_intervals, kobj);
1570         unsigned long us;
1571         int err = kstrtoul(buf, 0, &us);
1572
1573         if (err)
1574                 return -EINVAL;
1575
1576         intervals->update_us = us;
1577         return count;
1578 }
1579
1580 static void damon_sysfs_intervals_release(struct kobject *kobj)
1581 {
1582         kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));
1583 }
1584
1585 static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =
1586                 __ATTR_RW_MODE(sample_us, 0600);
1587
1588 static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =
1589                 __ATTR_RW_MODE(aggr_us, 0600);
1590
1591 static struct kobj_attribute damon_sysfs_intervals_update_us_attr =
1592                 __ATTR_RW_MODE(update_us, 0600);
1593
1594 static struct attribute *damon_sysfs_intervals_attrs[] = {
1595         &damon_sysfs_intervals_sample_us_attr.attr,
1596         &damon_sysfs_intervals_aggr_us_attr.attr,
1597         &damon_sysfs_intervals_update_us_attr.attr,
1598         NULL,
1599 };
1600 ATTRIBUTE_GROUPS(damon_sysfs_intervals);
1601
1602 static struct kobj_type damon_sysfs_intervals_ktype = {
1603         .release = damon_sysfs_intervals_release,
1604         .sysfs_ops = &kobj_sysfs_ops,
1605         .default_groups = damon_sysfs_intervals_groups,
1606 };
1607
1608 /*
1609  * monitoring_attrs directory
1610  */
1611
1612 struct damon_sysfs_attrs {
1613         struct kobject kobj;
1614         struct damon_sysfs_intervals *intervals;
1615         struct damon_sysfs_ul_range *nr_regions_range;
1616 };
1617
1618 static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)
1619 {
1620         struct damon_sysfs_attrs *attrs = kmalloc(sizeof(*attrs), GFP_KERNEL);
1621
1622         if (!attrs)
1623                 return NULL;
1624         attrs->kobj = (struct kobject){};
1625         return attrs;
1626 }
1627
1628 static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
1629 {
1630         struct damon_sysfs_intervals *intervals;
1631         struct damon_sysfs_ul_range *nr_regions_range;
1632         int err;
1633
1634         intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);
1635         if (!intervals)
1636                 return -ENOMEM;
1637
1638         err = kobject_init_and_add(&intervals->kobj,
1639                         &damon_sysfs_intervals_ktype, &attrs->kobj,
1640                         "intervals");
1641         if (err)
1642                 goto put_intervals_out;
1643         attrs->intervals = intervals;
1644
1645         nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);
1646         if (!nr_regions_range) {
1647                 err = -ENOMEM;
1648                 goto put_intervals_out;
1649         }
1650
1651         err = kobject_init_and_add(&nr_regions_range->kobj,
1652                         &damon_sysfs_ul_range_ktype, &attrs->kobj,
1653                         "nr_regions");
1654         if (err)
1655                 goto put_nr_regions_intervals_out;
1656         attrs->nr_regions_range = nr_regions_range;
1657         return 0;
1658
1659 put_nr_regions_intervals_out:
1660         kobject_put(&nr_regions_range->kobj);
1661         attrs->nr_regions_range = NULL;
1662 put_intervals_out:
1663         kobject_put(&intervals->kobj);
1664         attrs->intervals = NULL;
1665         return err;
1666 }
1667
1668 static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
1669 {
1670         kobject_put(&attrs->nr_regions_range->kobj);
1671         kobject_put(&attrs->intervals->kobj);
1672 }
1673
1674 static void damon_sysfs_attrs_release(struct kobject *kobj)
1675 {
1676         kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));
1677 }
1678
1679 static struct attribute *damon_sysfs_attrs_attrs[] = {
1680         NULL,
1681 };
1682 ATTRIBUTE_GROUPS(damon_sysfs_attrs);
1683
1684 static struct kobj_type damon_sysfs_attrs_ktype = {
1685         .release = damon_sysfs_attrs_release,
1686         .sysfs_ops = &kobj_sysfs_ops,
1687         .default_groups = damon_sysfs_attrs_groups,
1688 };
1689
1690 /*
1691  * context directory
1692  */
1693
1694 /* This should match with enum damon_ops_id */
1695 static const char * const damon_sysfs_ops_strs[] = {
1696         "vaddr",
1697         "paddr",
1698 };
1699
1700 struct damon_sysfs_context {
1701         struct kobject kobj;
1702         enum damon_ops_id ops_id;
1703         struct damon_sysfs_attrs *attrs;
1704         struct damon_sysfs_targets *targets;
1705         struct damon_sysfs_schemes *schemes;
1706 };
1707
1708 static struct damon_sysfs_context *damon_sysfs_context_alloc(
1709                 enum damon_ops_id ops_id)
1710 {
1711         struct damon_sysfs_context *context = kmalloc(sizeof(*context),
1712                                 GFP_KERNEL);
1713
1714         if (!context)
1715                 return NULL;
1716         context->kobj = (struct kobject){};
1717         context->ops_id = ops_id;
1718         return context;
1719 }
1720
1721 static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)
1722 {
1723         struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();
1724         int err;
1725
1726         if (!attrs)
1727                 return -ENOMEM;
1728         err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,
1729                         &context->kobj, "monitoring_attrs");
1730         if (err)
1731                 goto out;
1732         err = damon_sysfs_attrs_add_dirs(attrs);
1733         if (err)
1734                 goto out;
1735         context->attrs = attrs;
1736         return 0;
1737
1738 out:
1739         kobject_put(&attrs->kobj);
1740         return err;
1741 }
1742
1743 static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)
1744 {
1745         struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();
1746         int err;
1747
1748         if (!targets)
1749                 return -ENOMEM;
1750         err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,
1751                         &context->kobj, "targets");
1752         if (err) {
1753                 kobject_put(&targets->kobj);
1754                 return err;
1755         }
1756         context->targets = targets;
1757         return 0;
1758 }
1759
1760 static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)
1761 {
1762         struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();
1763         int err;
1764
1765         if (!schemes)
1766                 return -ENOMEM;
1767         err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,
1768                         &context->kobj, "schemes");
1769         if (err) {
1770                 kobject_put(&schemes->kobj);
1771                 return err;
1772         }
1773         context->schemes = schemes;
1774         return 0;
1775 }
1776
1777 static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)
1778 {
1779         int err;
1780
1781         err = damon_sysfs_context_set_attrs(context);
1782         if (err)
1783                 return err;
1784
1785         err = damon_sysfs_context_set_targets(context);
1786         if (err)
1787                 goto put_attrs_out;
1788
1789         err = damon_sysfs_context_set_schemes(context);
1790         if (err)
1791                 goto put_targets_attrs_out;
1792         return 0;
1793
1794 put_targets_attrs_out:
1795         kobject_put(&context->targets->kobj);
1796         context->targets = NULL;
1797 put_attrs_out:
1798         kobject_put(&context->attrs->kobj);
1799         context->attrs = NULL;
1800         return err;
1801 }
1802
1803 static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)
1804 {
1805         damon_sysfs_attrs_rm_dirs(context->attrs);
1806         kobject_put(&context->attrs->kobj);
1807         damon_sysfs_targets_rm_dirs(context->targets);
1808         kobject_put(&context->targets->kobj);
1809         damon_sysfs_schemes_rm_dirs(context->schemes);
1810         kobject_put(&context->schemes->kobj);
1811 }
1812
1813 static ssize_t operations_show(struct kobject *kobj,
1814                 struct kobj_attribute *attr, char *buf)
1815 {
1816         struct damon_sysfs_context *context = container_of(kobj,
1817                         struct damon_sysfs_context, kobj);
1818
1819         return sysfs_emit(buf, "%s\n", damon_sysfs_ops_strs[context->ops_id]);
1820 }
1821
1822 static ssize_t operations_store(struct kobject *kobj,
1823                 struct kobj_attribute *attr, const char *buf, size_t count)
1824 {
1825         struct damon_sysfs_context *context = container_of(kobj,
1826                         struct damon_sysfs_context, kobj);
1827         enum damon_ops_id id;
1828
1829         for (id = 0; id < NR_DAMON_OPS; id++) {
1830                 if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {
1831                         context->ops_id = id;
1832                         return count;
1833                 }
1834         }
1835         return -EINVAL;
1836 }
1837
1838 static void damon_sysfs_context_release(struct kobject *kobj)
1839 {
1840         kfree(container_of(kobj, struct damon_sysfs_context, kobj));
1841 }
1842
1843 static struct kobj_attribute damon_sysfs_context_operations_attr =
1844                 __ATTR_RW_MODE(operations, 0600);
1845
1846 static struct attribute *damon_sysfs_context_attrs[] = {
1847         &damon_sysfs_context_operations_attr.attr,
1848         NULL,
1849 };
1850 ATTRIBUTE_GROUPS(damon_sysfs_context);
1851
1852 static struct kobj_type damon_sysfs_context_ktype = {
1853         .release = damon_sysfs_context_release,
1854         .sysfs_ops = &kobj_sysfs_ops,
1855         .default_groups = damon_sysfs_context_groups,
1856 };
1857
1858 /*
1859  * contexts directory
1860  */
1861
1862 struct damon_sysfs_contexts {
1863         struct kobject kobj;
1864         struct damon_sysfs_context **contexts_arr;
1865         int nr;
1866 };
1867
1868 static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)
1869 {
1870         return kzalloc(sizeof(struct damon_sysfs_contexts), GFP_KERNEL);
1871 }
1872
1873 static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)
1874 {
1875         struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;
1876         int i;
1877
1878         for (i = 0; i < contexts->nr; i++) {
1879                 damon_sysfs_context_rm_dirs(contexts_arr[i]);
1880                 kobject_put(&contexts_arr[i]->kobj);
1881         }
1882         contexts->nr = 0;
1883         kfree(contexts_arr);
1884         contexts->contexts_arr = NULL;
1885 }
1886
1887 static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,
1888                 int nr_contexts)
1889 {
1890         struct damon_sysfs_context **contexts_arr, *context;
1891         int err, i;
1892
1893         damon_sysfs_contexts_rm_dirs(contexts);
1894         if (!nr_contexts)
1895                 return 0;
1896
1897         contexts_arr = kmalloc_array(nr_contexts, sizeof(*contexts_arr),
1898                         GFP_KERNEL | __GFP_NOWARN);
1899         if (!contexts_arr)
1900                 return -ENOMEM;
1901         contexts->contexts_arr = contexts_arr;
1902
1903         for (i = 0; i < nr_contexts; i++) {
1904                 context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);
1905                 if (!context) {
1906                         damon_sysfs_contexts_rm_dirs(contexts);
1907                         return -ENOMEM;
1908                 }
1909
1910                 err = kobject_init_and_add(&context->kobj,
1911                                 &damon_sysfs_context_ktype, &contexts->kobj,
1912                                 "%d", i);
1913                 if (err)
1914                         goto out;
1915
1916                 err = damon_sysfs_context_add_dirs(context);
1917                 if (err)
1918                         goto out;
1919
1920                 contexts_arr[i] = context;
1921                 contexts->nr++;
1922         }
1923         return 0;
1924
1925 out:
1926         damon_sysfs_contexts_rm_dirs(contexts);
1927         kobject_put(&context->kobj);
1928         return err;
1929 }
1930
1931 static ssize_t nr_contexts_show(struct kobject *kobj,
1932                 struct kobj_attribute *attr, char *buf)
1933 {
1934         struct damon_sysfs_contexts *contexts = container_of(kobj,
1935                         struct damon_sysfs_contexts, kobj);
1936
1937         return sysfs_emit(buf, "%d\n", contexts->nr);
1938 }
1939
1940 static ssize_t nr_contexts_store(struct kobject *kobj,
1941                 struct kobj_attribute *attr, const char *buf, size_t count)
1942 {
1943         struct damon_sysfs_contexts *contexts = container_of(kobj,
1944                         struct damon_sysfs_contexts, kobj);
1945         int nr, err;
1946
1947         err = kstrtoint(buf, 0, &nr);
1948         if (err)
1949                 return err;
1950         /* TODO: support multiple contexts per kdamond */
1951         if (nr < 0 || 1 < nr)
1952                 return -EINVAL;
1953
1954         if (!mutex_trylock(&damon_sysfs_lock))
1955                 return -EBUSY;
1956         err = damon_sysfs_contexts_add_dirs(contexts, nr);
1957         mutex_unlock(&damon_sysfs_lock);
1958         if (err)
1959                 return err;
1960
1961         return count;
1962 }
1963
1964 static void damon_sysfs_contexts_release(struct kobject *kobj)
1965 {
1966         kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));
1967 }
1968
1969 static struct kobj_attribute damon_sysfs_contexts_nr_attr
1970                 = __ATTR_RW_MODE(nr_contexts, 0600);
1971
1972 static struct attribute *damon_sysfs_contexts_attrs[] = {
1973         &damon_sysfs_contexts_nr_attr.attr,
1974         NULL,
1975 };
1976 ATTRIBUTE_GROUPS(damon_sysfs_contexts);
1977
1978 static struct kobj_type damon_sysfs_contexts_ktype = {
1979         .release = damon_sysfs_contexts_release,
1980         .sysfs_ops = &kobj_sysfs_ops,
1981         .default_groups = damon_sysfs_contexts_groups,
1982 };
1983
1984 /*
1985  * kdamond directory
1986  */
1987
1988 struct damon_sysfs_kdamond {
1989         struct kobject kobj;
1990         struct damon_sysfs_contexts *contexts;
1991         struct damon_ctx *damon_ctx;
1992 };
1993
1994 static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
1995 {
1996         return kzalloc(sizeof(struct damon_sysfs_kdamond), GFP_KERNEL);
1997 }
1998
1999 static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)
2000 {
2001         struct damon_sysfs_contexts *contexts;
2002         int err;
2003
2004         contexts = damon_sysfs_contexts_alloc();
2005         if (!contexts)
2006                 return -ENOMEM;
2007
2008         err = kobject_init_and_add(&contexts->kobj,
2009                         &damon_sysfs_contexts_ktype, &kdamond->kobj,
2010                         "contexts");
2011         if (err) {
2012                 kobject_put(&contexts->kobj);
2013                 return err;
2014         }
2015         kdamond->contexts = contexts;
2016
2017         return err;
2018 }
2019
2020 static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
2021 {
2022         damon_sysfs_contexts_rm_dirs(kdamond->contexts);
2023         kobject_put(&kdamond->contexts->kobj);
2024 }
2025
2026 static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)
2027 {
2028         bool running;
2029
2030         mutex_lock(&ctx->kdamond_lock);
2031         running = ctx->kdamond != NULL;
2032         mutex_unlock(&ctx->kdamond_lock);
2033         return running;
2034 }
2035
2036 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
2037                 char *buf)
2038 {
2039         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2040                         struct damon_sysfs_kdamond, kobj);
2041         struct damon_ctx *ctx = kdamond->damon_ctx;
2042         bool running;
2043
2044         if (!ctx)
2045                 running = false;
2046         else
2047                 running = damon_sysfs_ctx_running(ctx);
2048
2049         return sysfs_emit(buf, "%s\n", running ? "on" : "off");
2050 }
2051
2052 static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
2053                 struct damon_sysfs_attrs *sys_attrs)
2054 {
2055         struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;
2056         struct damon_sysfs_ul_range *sys_nr_regions =
2057                 sys_attrs->nr_regions_range;
2058
2059         return damon_set_attrs(ctx, sys_intervals->sample_us,
2060                         sys_intervals->aggr_us, sys_intervals->update_us,
2061                         sys_nr_regions->min, sys_nr_regions->max);
2062 }
2063
2064 static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
2065 {
2066         struct damon_target *t, *next;
2067
2068         damon_for_each_target_safe(t, next, ctx) {
2069                 if (ctx->ops.id == DAMON_OPS_VADDR)
2070                         put_pid(t->pid);
2071                 damon_destroy_target(t);
2072         }
2073 }
2074
2075 static int damon_sysfs_set_regions(struct damon_target *t,
2076                 struct damon_sysfs_regions *sysfs_regions)
2077 {
2078         int i;
2079
2080         for (i = 0; i < sysfs_regions->nr; i++) {
2081                 struct damon_sysfs_region *sys_region =
2082                         sysfs_regions->regions_arr[i];
2083                 struct damon_region *prev, *r;
2084
2085                 if (sys_region->start > sys_region->end)
2086                         return -EINVAL;
2087                 r = damon_new_region(sys_region->start, sys_region->end);
2088                 if (!r)
2089                         return -ENOMEM;
2090                 damon_add_region(r, t);
2091                 if (damon_nr_regions(t) > 1) {
2092                         prev = damon_prev_region(r);
2093                         if (prev->ar.end > r->ar.start) {
2094                                 damon_destroy_region(r, t);
2095                                 return -EINVAL;
2096                         }
2097                 }
2098         }
2099         return 0;
2100 }
2101
2102 static int damon_sysfs_set_targets(struct damon_ctx *ctx,
2103                 struct damon_sysfs_targets *sysfs_targets)
2104 {
2105         int i, err;
2106
2107         for (i = 0; i < sysfs_targets->nr; i++) {
2108                 struct damon_sysfs_target *sys_target =
2109                         sysfs_targets->targets_arr[i];
2110                 struct damon_target *t = damon_new_target();
2111
2112                 if (!t) {
2113                         damon_sysfs_destroy_targets(ctx);
2114                         return -ENOMEM;
2115                 }
2116                 if (ctx->ops.id == DAMON_OPS_VADDR) {
2117                         t->pid = find_get_pid(sys_target->pid);
2118                         if (!t->pid) {
2119                                 damon_sysfs_destroy_targets(ctx);
2120                                 return -EINVAL;
2121                         }
2122                 }
2123                 damon_add_target(ctx, t);
2124                 err = damon_sysfs_set_regions(t, sys_target->regions);
2125                 if (err) {
2126                         damon_sysfs_destroy_targets(ctx);
2127                         return err;
2128                 }
2129         }
2130         return 0;
2131 }
2132
2133 static struct damos *damon_sysfs_mk_scheme(
2134                 struct damon_sysfs_scheme *sysfs_scheme)
2135 {
2136         struct damon_sysfs_access_pattern *pattern =
2137                 sysfs_scheme->access_pattern;
2138         struct damon_sysfs_quotas *sysfs_quotas = sysfs_scheme->quotas;
2139         struct damon_sysfs_weights *sysfs_weights = sysfs_quotas->weights;
2140         struct damon_sysfs_watermarks *sysfs_wmarks = sysfs_scheme->watermarks;
2141         struct damos_quota quota = {
2142                 .ms = sysfs_quotas->ms,
2143                 .sz = sysfs_quotas->sz,
2144                 .reset_interval = sysfs_quotas->reset_interval_ms,
2145                 .weight_sz = sysfs_weights->sz,
2146                 .weight_nr_accesses = sysfs_weights->nr_accesses,
2147                 .weight_age = sysfs_weights->age,
2148         };
2149         struct damos_watermarks wmarks = {
2150                 .metric = sysfs_wmarks->metric,
2151                 .interval = sysfs_wmarks->interval_us,
2152                 .high = sysfs_wmarks->high,
2153                 .mid = sysfs_wmarks->mid,
2154                 .low = sysfs_wmarks->low,
2155         };
2156
2157         return damon_new_scheme(pattern->sz->min, pattern->sz->max,
2158                         pattern->nr_accesses->min, pattern->nr_accesses->max,
2159                         pattern->age->min, pattern->age->max,
2160                         sysfs_scheme->action, &quota, &wmarks);
2161 }
2162
2163 static int damon_sysfs_set_schemes(struct damon_ctx *ctx,
2164                 struct damon_sysfs_schemes *sysfs_schemes)
2165 {
2166         int i;
2167
2168         for (i = 0; i < sysfs_schemes->nr; i++) {
2169                 struct damos *scheme, *next;
2170
2171                 scheme = damon_sysfs_mk_scheme(sysfs_schemes->schemes_arr[i]);
2172                 if (!scheme) {
2173                         damon_for_each_scheme_safe(scheme, next, ctx)
2174                                 damon_destroy_scheme(scheme);
2175                         return -ENOMEM;
2176                 }
2177                 damon_add_scheme(ctx, scheme);
2178         }
2179         return 0;
2180 }
2181
2182 static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
2183 {
2184         struct damon_target *t, *next;
2185
2186         if (ctx->ops.id != DAMON_OPS_VADDR)
2187                 return;
2188
2189         mutex_lock(&ctx->kdamond_lock);
2190         damon_for_each_target_safe(t, next, ctx) {
2191                 put_pid(t->pid);
2192                 damon_destroy_target(t);
2193         }
2194         mutex_unlock(&ctx->kdamond_lock);
2195 }
2196
2197 static struct damon_ctx *damon_sysfs_build_ctx(
2198                 struct damon_sysfs_context *sys_ctx)
2199 {
2200         struct damon_ctx *ctx = damon_new_ctx();
2201         int err;
2202
2203         if (!ctx)
2204                 return ERR_PTR(-ENOMEM);
2205
2206         err = damon_select_ops(ctx, sys_ctx->ops_id);
2207         if (err)
2208                 goto out;
2209         err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
2210         if (err)
2211                 goto out;
2212         err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
2213         if (err)
2214                 goto out;
2215         err = damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
2216         if (err)
2217                 goto out;
2218
2219         ctx->callback.before_terminate = damon_sysfs_before_terminate;
2220         return ctx;
2221
2222 out:
2223         damon_destroy_ctx(ctx);
2224         return ERR_PTR(err);
2225 }
2226
2227 static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
2228 {
2229         struct damon_ctx *ctx;
2230         int err;
2231
2232         if (kdamond->damon_ctx &&
2233                         damon_sysfs_ctx_running(kdamond->damon_ctx))
2234                 return -EBUSY;
2235         /* TODO: support multiple contexts per kdamond */
2236         if (kdamond->contexts->nr != 1)
2237                 return -EINVAL;
2238
2239         if (kdamond->damon_ctx)
2240                 damon_destroy_ctx(kdamond->damon_ctx);
2241         kdamond->damon_ctx = NULL;
2242
2243         ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
2244         if (IS_ERR(ctx))
2245                 return PTR_ERR(ctx);
2246         err = damon_start(&ctx, 1, false);
2247         if (err) {
2248                 damon_destroy_ctx(ctx);
2249                 return err;
2250         }
2251         kdamond->damon_ctx = ctx;
2252         return err;
2253 }
2254
2255 static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
2256 {
2257         if (!kdamond->damon_ctx)
2258                 return -EINVAL;
2259         return damon_stop(&kdamond->damon_ctx, 1);
2260         /*
2261          * To allow users show final monitoring results of already turned-off
2262          * DAMON, we free kdamond->damon_ctx in next
2263          * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
2264          */
2265 }
2266
2267 static int damon_sysfs_update_schemes_stats(struct damon_sysfs_kdamond *kdamond)
2268 {
2269         struct damon_ctx *ctx = kdamond->damon_ctx;
2270         struct damos *scheme;
2271         int schemes_idx = 0;
2272
2273         if (!ctx)
2274                 return -EINVAL;
2275         mutex_lock(&ctx->kdamond_lock);
2276         damon_for_each_scheme(scheme, ctx) {
2277                 struct damon_sysfs_schemes *sysfs_schemes;
2278                 struct damon_sysfs_stats *sysfs_stats;
2279
2280                 sysfs_schemes = kdamond->contexts->contexts_arr[0]->schemes;
2281                 sysfs_stats = sysfs_schemes->schemes_arr[schemes_idx++]->stats;
2282                 sysfs_stats->nr_tried = scheme->stat.nr_tried;
2283                 sysfs_stats->sz_tried = scheme->stat.sz_tried;
2284                 sysfs_stats->nr_applied = scheme->stat.nr_applied;
2285                 sysfs_stats->sz_applied = scheme->stat.sz_applied;
2286                 sysfs_stats->qt_exceeds = scheme->stat.qt_exceeds;
2287         }
2288         mutex_unlock(&ctx->kdamond_lock);
2289         return 0;
2290 }
2291
2292 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
2293                 const char *buf, size_t count)
2294 {
2295         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2296                         struct damon_sysfs_kdamond, kobj);
2297         ssize_t ret;
2298
2299         if (!mutex_trylock(&damon_sysfs_lock))
2300                 return -EBUSY;
2301         if (sysfs_streq(buf, "on"))
2302                 ret = damon_sysfs_turn_damon_on(kdamond);
2303         else if (sysfs_streq(buf, "off"))
2304                 ret = damon_sysfs_turn_damon_off(kdamond);
2305         else if (sysfs_streq(buf, "update_schemes_stats"))
2306                 ret = damon_sysfs_update_schemes_stats(kdamond);
2307         else
2308                 ret = -EINVAL;
2309         mutex_unlock(&damon_sysfs_lock);
2310         if (!ret)
2311                 ret = count;
2312         return ret;
2313 }
2314
2315 static ssize_t pid_show(struct kobject *kobj,
2316                 struct kobj_attribute *attr, char *buf)
2317 {
2318         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2319                         struct damon_sysfs_kdamond, kobj);
2320         struct damon_ctx *ctx;
2321         int pid;
2322
2323         if (!mutex_trylock(&damon_sysfs_lock))
2324                 return -EBUSY;
2325         ctx = kdamond->damon_ctx;
2326         if (!ctx) {
2327                 pid = -1;
2328                 goto out;
2329         }
2330         mutex_lock(&ctx->kdamond_lock);
2331         if (!ctx->kdamond)
2332                 pid = -1;
2333         else
2334                 pid = ctx->kdamond->pid;
2335         mutex_unlock(&ctx->kdamond_lock);
2336 out:
2337         mutex_unlock(&damon_sysfs_lock);
2338         return sysfs_emit(buf, "%d\n", pid);
2339 }
2340
2341 static void damon_sysfs_kdamond_release(struct kobject *kobj)
2342 {
2343         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2344                         struct damon_sysfs_kdamond, kobj);
2345
2346         if (kdamond->damon_ctx)
2347                 damon_destroy_ctx(kdamond->damon_ctx);
2348         kfree(kdamond);
2349 }
2350
2351 static struct kobj_attribute damon_sysfs_kdamond_state_attr =
2352                 __ATTR_RW_MODE(state, 0600);
2353
2354 static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
2355                 __ATTR_RO_MODE(pid, 0400);
2356
2357 static struct attribute *damon_sysfs_kdamond_attrs[] = {
2358         &damon_sysfs_kdamond_state_attr.attr,
2359         &damon_sysfs_kdamond_pid_attr.attr,
2360         NULL,
2361 };
2362 ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
2363
2364 static struct kobj_type damon_sysfs_kdamond_ktype = {
2365         .release = damon_sysfs_kdamond_release,
2366         .sysfs_ops = &kobj_sysfs_ops,
2367         .default_groups = damon_sysfs_kdamond_groups,
2368 };
2369
2370 /*
2371  * kdamonds directory
2372  */
2373
2374 struct damon_sysfs_kdamonds {
2375         struct kobject kobj;
2376         struct damon_sysfs_kdamond **kdamonds_arr;
2377         int nr;
2378 };
2379
2380 static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
2381 {
2382         return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);
2383 }
2384
2385 static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
2386 {
2387         struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
2388         int i;
2389
2390         for (i = 0; i < kdamonds->nr; i++) {
2391                 damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
2392                 kobject_put(&kdamonds_arr[i]->kobj);
2393         }
2394         kdamonds->nr = 0;
2395         kfree(kdamonds_arr);
2396         kdamonds->kdamonds_arr = NULL;
2397 }
2398
2399 static int damon_sysfs_nr_running_ctxs(struct damon_sysfs_kdamond **kdamonds,
2400                 int nr_kdamonds)
2401 {
2402         int nr_running_ctxs = 0;
2403         int i;
2404
2405         for (i = 0; i < nr_kdamonds; i++) {
2406                 struct damon_ctx *ctx = kdamonds[i]->damon_ctx;
2407
2408                 if (!ctx)
2409                         continue;
2410                 mutex_lock(&ctx->kdamond_lock);
2411                 if (ctx->kdamond)
2412                         nr_running_ctxs++;
2413                 mutex_unlock(&ctx->kdamond_lock);
2414         }
2415         return nr_running_ctxs;
2416 }
2417
2418 static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
2419                 int nr_kdamonds)
2420 {
2421         struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
2422         int err, i;
2423
2424         if (damon_sysfs_nr_running_ctxs(kdamonds->kdamonds_arr, kdamonds->nr))
2425                 return -EBUSY;
2426
2427         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2428         if (!nr_kdamonds)
2429                 return 0;
2430
2431         kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),
2432                         GFP_KERNEL | __GFP_NOWARN);
2433         if (!kdamonds_arr)
2434                 return -ENOMEM;
2435         kdamonds->kdamonds_arr = kdamonds_arr;
2436
2437         for (i = 0; i < nr_kdamonds; i++) {
2438                 kdamond = damon_sysfs_kdamond_alloc();
2439                 if (!kdamond) {
2440                         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2441                         return -ENOMEM;
2442                 }
2443
2444                 err = kobject_init_and_add(&kdamond->kobj,
2445                                 &damon_sysfs_kdamond_ktype, &kdamonds->kobj,
2446                                 "%d", i);
2447                 if (err)
2448                         goto out;
2449
2450                 err = damon_sysfs_kdamond_add_dirs(kdamond);
2451                 if (err)
2452                         goto out;
2453
2454                 kdamonds_arr[i] = kdamond;
2455                 kdamonds->nr++;
2456         }
2457         return 0;
2458
2459 out:
2460         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2461         kobject_put(&kdamond->kobj);
2462         return err;
2463 }
2464
2465 static ssize_t nr_kdamonds_show(struct kobject *kobj,
2466                 struct kobj_attribute *attr, char *buf)
2467 {
2468         struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
2469                         struct damon_sysfs_kdamonds, kobj);
2470
2471         return sysfs_emit(buf, "%d\n", kdamonds->nr);
2472 }
2473
2474 static ssize_t nr_kdamonds_store(struct kobject *kobj,
2475                 struct kobj_attribute *attr, const char *buf, size_t count)
2476 {
2477         struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
2478                         struct damon_sysfs_kdamonds, kobj);
2479         int nr, err;
2480
2481         err = kstrtoint(buf, 0, &nr);
2482         if (err)
2483                 return err;
2484         if (nr < 0)
2485                 return -EINVAL;
2486
2487         if (!mutex_trylock(&damon_sysfs_lock))
2488                 return -EBUSY;
2489         err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
2490         mutex_unlock(&damon_sysfs_lock);
2491         if (err)
2492                 return err;
2493
2494         return count;
2495 }
2496
2497 static void damon_sysfs_kdamonds_release(struct kobject *kobj)
2498 {
2499         kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
2500 }
2501
2502 static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
2503                 __ATTR_RW_MODE(nr_kdamonds, 0600);
2504
2505 static struct attribute *damon_sysfs_kdamonds_attrs[] = {
2506         &damon_sysfs_kdamonds_nr_attr.attr,
2507         NULL,
2508 };
2509 ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
2510
2511 static struct kobj_type damon_sysfs_kdamonds_ktype = {
2512         .release = damon_sysfs_kdamonds_release,
2513         .sysfs_ops = &kobj_sysfs_ops,
2514         .default_groups = damon_sysfs_kdamonds_groups,
2515 };
2516
2517 /*
2518  * damon user interface directory
2519  */
2520
2521 struct damon_sysfs_ui_dir {
2522         struct kobject kobj;
2523         struct damon_sysfs_kdamonds *kdamonds;
2524 };
2525
2526 static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
2527 {
2528         return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);
2529 }
2530
2531 static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
2532 {
2533         struct damon_sysfs_kdamonds *kdamonds;
2534         int err;
2535
2536         kdamonds = damon_sysfs_kdamonds_alloc();
2537         if (!kdamonds)
2538                 return -ENOMEM;
2539
2540         err = kobject_init_and_add(&kdamonds->kobj,
2541                         &damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
2542                         "kdamonds");
2543         if (err) {
2544                 kobject_put(&kdamonds->kobj);
2545                 return err;
2546         }
2547         ui_dir->kdamonds = kdamonds;
2548         return err;
2549 }
2550
2551 static void damon_sysfs_ui_dir_release(struct kobject *kobj)
2552 {
2553         kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
2554 }
2555
2556 static struct attribute *damon_sysfs_ui_dir_attrs[] = {
2557         NULL,
2558 };
2559 ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
2560
2561 static struct kobj_type damon_sysfs_ui_dir_ktype = {
2562         .release = damon_sysfs_ui_dir_release,
2563         .sysfs_ops = &kobj_sysfs_ops,
2564         .default_groups = damon_sysfs_ui_dir_groups,
2565 };
2566
2567 static int __init damon_sysfs_init(void)
2568 {
2569         struct kobject *damon_sysfs_root;
2570         struct damon_sysfs_ui_dir *admin;
2571         int err;
2572
2573         damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
2574         if (!damon_sysfs_root)
2575                 return -ENOMEM;
2576
2577         admin = damon_sysfs_ui_dir_alloc();
2578         if (!admin) {
2579                 kobject_put(damon_sysfs_root);
2580                 return -ENOMEM;
2581         }
2582         err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
2583                         damon_sysfs_root, "admin");
2584         if (err)
2585                 goto out;
2586         err = damon_sysfs_ui_dir_add_dirs(admin);
2587         if (err)
2588                 goto out;
2589         return 0;
2590
2591 out:
2592         kobject_put(&admin->kobj);
2593         kobject_put(damon_sysfs_root);
2594         return err;
2595 }
2596 subsys_initcall(damon_sysfs_init);