mm/damon/sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * DAMON sysfs Interface
   4  *
   5  * Copyright (c) 2022 SeongJae Park <[email protected]>
   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         "lru_prio",
 766         "lru_deprio",
 767         "stat",
 768 };
 769
 770 static struct damon_sysfs_scheme *damon_sysfs_scheme_alloc(
 771                 enum damos_action action)
 772 {
 773         struct damon_sysfs_scheme *scheme = kmalloc(sizeof(*scheme),
 774                                 GFP_KERNEL);
 775
 776         if (!scheme)
 777                 return NULL;
 778         scheme->kobj = (struct kobject){};
 779         scheme->action = action;
 780         return scheme;
 781 }
 782
 783 static int damon_sysfs_scheme_set_access_pattern(
 784                 struct damon_sysfs_scheme *scheme)
 785 {
 786         struct damon_sysfs_access_pattern *access_pattern;
 787         int err;
 788
 789         access_pattern = damon_sysfs_access_pattern_alloc();
 790         if (!access_pattern)
 791                 return -ENOMEM;
 792         err = kobject_init_and_add(&access_pattern->kobj,
 793                         &damon_sysfs_access_pattern_ktype, &scheme->kobj,
 794                         "access_pattern");
 795         if (err)
 796                 goto out;
 797         err = damon_sysfs_access_pattern_add_dirs(access_pattern);
 798         if (err)
 799                 goto out;
 800         scheme->access_pattern = access_pattern;
 801         return 0;
 802
 803 out:
 804         kobject_put(&access_pattern->kobj);
 805         return err;
 806 }
 807
 808 static int damon_sysfs_scheme_set_quotas(struct damon_sysfs_scheme *scheme)
 809 {
 810         struct damon_sysfs_quotas *quotas = damon_sysfs_quotas_alloc();
 811         int err;
 812
 813         if (!quotas)
 814                 return -ENOMEM;
 815         err = kobject_init_and_add(&quotas->kobj, &damon_sysfs_quotas_ktype,
 816                         &scheme->kobj, "quotas");
 817         if (err)
 818                 goto out;
 819         err = damon_sysfs_quotas_add_dirs(quotas);
 820         if (err)
 821                 goto out;
 822         scheme->quotas = quotas;
 823         return 0;
 824
 825 out:
 826         kobject_put(&quotas->kobj);
 827         return err;
 828 }
 829
 830 static int damon_sysfs_scheme_set_watermarks(struct damon_sysfs_scheme *scheme)
 831 {
 832         struct damon_sysfs_watermarks *watermarks =
 833                 damon_sysfs_watermarks_alloc(DAMOS_WMARK_NONE, 0, 0, 0, 0);
 834         int err;
 835
 836         if (!watermarks)
 837                 return -ENOMEM;
 838         err = kobject_init_and_add(&watermarks->kobj,
 839                         &damon_sysfs_watermarks_ktype, &scheme->kobj,
 840                         "watermarks");
 841         if (err)
 842                 kobject_put(&watermarks->kobj);
 843         else
 844                 scheme->watermarks = watermarks;
 845         return err;
 846 }
 847
 848 static int damon_sysfs_scheme_set_stats(struct damon_sysfs_scheme *scheme)
 849 {
 850         struct damon_sysfs_stats *stats = damon_sysfs_stats_alloc();
 851         int err;
 852
 853         if (!stats)
 854                 return -ENOMEM;
 855         err = kobject_init_and_add(&stats->kobj, &damon_sysfs_stats_ktype,
 856                         &scheme->kobj, "stats");
 857         if (err)
 858                 kobject_put(&stats->kobj);
 859         else
 860                 scheme->stats = stats;
 861         return err;
 862 }
 863
 864 static int damon_sysfs_scheme_add_dirs(struct damon_sysfs_scheme *scheme)
 865 {
 866         int err;
 867
 868         err = damon_sysfs_scheme_set_access_pattern(scheme);
 869         if (err)
 870                 return err;
 871         err = damon_sysfs_scheme_set_quotas(scheme);
 872         if (err)
 873                 goto put_access_pattern_out;
 874         err = damon_sysfs_scheme_set_watermarks(scheme);
 875         if (err)
 876                 goto put_quotas_access_pattern_out;
 877         err = damon_sysfs_scheme_set_stats(scheme);
 878         if (err)
 879                 goto put_watermarks_quotas_access_pattern_out;
 880         return 0;
 881
 882 put_watermarks_quotas_access_pattern_out:
 883         kobject_put(&scheme->watermarks->kobj);
 884         scheme->watermarks = NULL;
 885 put_quotas_access_pattern_out:
 886         kobject_put(&scheme->quotas->kobj);
 887         scheme->quotas = NULL;
 888 put_access_pattern_out:
 889         kobject_put(&scheme->access_pattern->kobj);
 890         scheme->access_pattern = NULL;
 891         return err;
 892 }
 893
 894 static void damon_sysfs_scheme_rm_dirs(struct damon_sysfs_scheme *scheme)
 895 {
 896         damon_sysfs_access_pattern_rm_dirs(scheme->access_pattern);
 897         kobject_put(&scheme->access_pattern->kobj);
 898         damon_sysfs_quotas_rm_dirs(scheme->quotas);
 899         kobject_put(&scheme->quotas->kobj);
 900         kobject_put(&scheme->watermarks->kobj);
 901         kobject_put(&scheme->stats->kobj);
 902 }
 903
 904 static ssize_t action_show(struct kobject *kobj, struct kobj_attribute *attr,
 905                 char *buf)
 906 {
 907         struct damon_sysfs_scheme *scheme = container_of(kobj,
 908                         struct damon_sysfs_scheme, kobj);
 909
 910         return sysfs_emit(buf, "%s\n",
 911                         damon_sysfs_damos_action_strs[scheme->action]);
 912 }
 913
 914 static ssize_t action_store(struct kobject *kobj, struct kobj_attribute *attr,
 915                 const char *buf, size_t count)
 916 {
 917         struct damon_sysfs_scheme *scheme = container_of(kobj,
 918                         struct damon_sysfs_scheme, kobj);
 919         enum damos_action action;
 920
 921         for (action = 0; action < NR_DAMOS_ACTIONS; action++) {
 922                 if (sysfs_streq(buf, damon_sysfs_damos_action_strs[action])) {
 923                         scheme->action = action;
 924                         return count;
 925                 }
 926         }
 927         return -EINVAL;
 928 }
 929
 930 static void damon_sysfs_scheme_release(struct kobject *kobj)
 931 {
 932         kfree(container_of(kobj, struct damon_sysfs_scheme, kobj));
 933 }
 934
 935 static struct kobj_attribute damon_sysfs_scheme_action_attr =
 936                 __ATTR_RW_MODE(action, 0600);
 937
 938 static struct attribute *damon_sysfs_scheme_attrs[] = {
 939         &damon_sysfs_scheme_action_attr.attr,
 940         NULL,
 941 };
 942 ATTRIBUTE_GROUPS(damon_sysfs_scheme);
 943
 944 static struct kobj_type damon_sysfs_scheme_ktype = {
 945         .release = damon_sysfs_scheme_release,
 946         .sysfs_ops = &kobj_sysfs_ops,
 947         .default_groups = damon_sysfs_scheme_groups,
 948 };
 949
 950 /*
 951  * schemes directory
 952  */
 953
 954 struct damon_sysfs_schemes {
 955         struct kobject kobj;
 956         struct damon_sysfs_scheme **schemes_arr;
 957         int nr;
 958 };
 959
 960 static struct damon_sysfs_schemes *damon_sysfs_schemes_alloc(void)
 961 {
 962         return kzalloc(sizeof(struct damon_sysfs_schemes), GFP_KERNEL);
 963 }
 964
 965 static void damon_sysfs_schemes_rm_dirs(struct damon_sysfs_schemes *schemes)
 966 {
 967         struct damon_sysfs_scheme **schemes_arr = schemes->schemes_arr;
 968         int i;
 969
 970         for (i = 0; i < schemes->nr; i++) {
 971                 damon_sysfs_scheme_rm_dirs(schemes_arr[i]);
 972                 kobject_put(&schemes_arr[i]->kobj);
 973         }
 974         schemes->nr = 0;
 975         kfree(schemes_arr);
 976         schemes->schemes_arr = NULL;
 977 }
 978
 979 static int damon_sysfs_schemes_add_dirs(struct damon_sysfs_schemes *schemes,
 980                 int nr_schemes)
 981 {
 982         struct damon_sysfs_scheme **schemes_arr, *scheme;
 983         int err, i;
 984
 985         damon_sysfs_schemes_rm_dirs(schemes);
 986         if (!nr_schemes)
 987                 return 0;
 988
 989         schemes_arr = kmalloc_array(nr_schemes, sizeof(*schemes_arr),
 990                         GFP_KERNEL | __GFP_NOWARN);
 991         if (!schemes_arr)
 992                 return -ENOMEM;
 993         schemes->schemes_arr = schemes_arr;
 994
 995         for (i = 0; i < nr_schemes; i++) {
 996                 scheme = damon_sysfs_scheme_alloc(DAMOS_STAT);
 997                 if (!scheme) {
 998                         damon_sysfs_schemes_rm_dirs(schemes);
 999                         return -ENOMEM;
1000                 }
1001
1002                 err = kobject_init_and_add(&scheme->kobj,
1003                                 &damon_sysfs_scheme_ktype, &schemes->kobj,
1004                                 "%d", i);
1005                 if (err)
1006                         goto out;
1007                 err = damon_sysfs_scheme_add_dirs(scheme);
1008                 if (err)
1009                         goto out;
1010
1011                 schemes_arr[i] = scheme;
1012                 schemes->nr++;
1013         }
1014         return 0;
1015
1016 out:
1017         damon_sysfs_schemes_rm_dirs(schemes);
1018         kobject_put(&scheme->kobj);
1019         return err;
1020 }
1021
1022 static ssize_t nr_schemes_show(struct kobject *kobj,
1023                 struct kobj_attribute *attr, char *buf)
1024 {
1025         struct damon_sysfs_schemes *schemes = container_of(kobj,
1026                         struct damon_sysfs_schemes, kobj);
1027
1028         return sysfs_emit(buf, "%d\n", schemes->nr);
1029 }
1030
1031 static ssize_t nr_schemes_store(struct kobject *kobj,
1032                 struct kobj_attribute *attr, const char *buf, size_t count)
1033 {
1034         struct damon_sysfs_schemes *schemes = container_of(kobj,
1035                         struct damon_sysfs_schemes, kobj);
1036         int nr, err = kstrtoint(buf, 0, &nr);
1037
1038         if (err)
1039                 return err;
1040         if (nr < 0)
1041                 return -EINVAL;
1042
1043         if (!mutex_trylock(&damon_sysfs_lock))
1044                 return -EBUSY;
1045         err = damon_sysfs_schemes_add_dirs(schemes, nr);
1046         mutex_unlock(&damon_sysfs_lock);
1047         if (err)
1048                 return err;
1049         return count;
1050 }
1051
1052 static void damon_sysfs_schemes_release(struct kobject *kobj)
1053 {
1054         kfree(container_of(kobj, struct damon_sysfs_schemes, kobj));
1055 }
1056
1057 static struct kobj_attribute damon_sysfs_schemes_nr_attr =
1058                 __ATTR_RW_MODE(nr_schemes, 0600);
1059
1060 static struct attribute *damon_sysfs_schemes_attrs[] = {
1061         &damon_sysfs_schemes_nr_attr.attr,
1062         NULL,
1063 };
1064 ATTRIBUTE_GROUPS(damon_sysfs_schemes);
1065
1066 static struct kobj_type damon_sysfs_schemes_ktype = {
1067         .release = damon_sysfs_schemes_release,
1068         .sysfs_ops = &kobj_sysfs_ops,
1069         .default_groups = damon_sysfs_schemes_groups,
1070 };
1071
1072 /*
1073  * init region directory
1074  */
1075
1076 struct damon_sysfs_region {
1077         struct kobject kobj;
1078         unsigned long start;
1079         unsigned long end;
1080 };
1081
1082 static struct damon_sysfs_region *damon_sysfs_region_alloc(
1083                 unsigned long start,
1084                 unsigned long end)
1085 {
1086         struct damon_sysfs_region *region = kmalloc(sizeof(*region),
1087                         GFP_KERNEL);
1088
1089         if (!region)
1090                 return NULL;
1091         region->kobj = (struct kobject){};
1092         region->start = start;
1093         region->end = end;
1094         return region;
1095 }
1096
1097 static ssize_t start_show(struct kobject *kobj, struct kobj_attribute *attr,
1098                 char *buf)
1099 {
1100         struct damon_sysfs_region *region = container_of(kobj,
1101                         struct damon_sysfs_region, kobj);
1102
1103         return sysfs_emit(buf, "%lu\n", region->start);
1104 }
1105
1106 static ssize_t start_store(struct kobject *kobj, struct kobj_attribute *attr,
1107                 const char *buf, size_t count)
1108 {
1109         struct damon_sysfs_region *region = container_of(kobj,
1110                         struct damon_sysfs_region, kobj);
1111         int err = kstrtoul(buf, 0, &region->start);
1112
1113         if (err)
1114                 return -EINVAL;
1115         return count;
1116 }
1117
1118 static ssize_t end_show(struct kobject *kobj, struct kobj_attribute *attr,
1119                 char *buf)
1120 {
1121         struct damon_sysfs_region *region = container_of(kobj,
1122                         struct damon_sysfs_region, kobj);
1123
1124         return sysfs_emit(buf, "%lu\n", region->end);
1125 }
1126
1127 static ssize_t end_store(struct kobject *kobj, struct kobj_attribute *attr,
1128                 const char *buf, size_t count)
1129 {
1130         struct damon_sysfs_region *region = container_of(kobj,
1131                         struct damon_sysfs_region, kobj);
1132         int err = kstrtoul(buf, 0, &region->end);
1133
1134         if (err)
1135                 return -EINVAL;
1136         return count;
1137 }
1138
1139 static void damon_sysfs_region_release(struct kobject *kobj)
1140 {
1141         kfree(container_of(kobj, struct damon_sysfs_region, kobj));
1142 }
1143
1144 static struct kobj_attribute damon_sysfs_region_start_attr =
1145                 __ATTR_RW_MODE(start, 0600);
1146
1147 static struct kobj_attribute damon_sysfs_region_end_attr =
1148                 __ATTR_RW_MODE(end, 0600);
1149
1150 static struct attribute *damon_sysfs_region_attrs[] = {
1151         &damon_sysfs_region_start_attr.attr,
1152         &damon_sysfs_region_end_attr.attr,
1153         NULL,
1154 };
1155 ATTRIBUTE_GROUPS(damon_sysfs_region);
1156
1157 static struct kobj_type damon_sysfs_region_ktype = {
1158         .release = damon_sysfs_region_release,
1159         .sysfs_ops = &kobj_sysfs_ops,
1160         .default_groups = damon_sysfs_region_groups,
1161 };
1162
1163 /*
1164  * init_regions directory
1165  */
1166
1167 struct damon_sysfs_regions {
1168         struct kobject kobj;
1169         struct damon_sysfs_region **regions_arr;
1170         int nr;
1171 };
1172
1173 static struct damon_sysfs_regions *damon_sysfs_regions_alloc(void)
1174 {
1175         return kzalloc(sizeof(struct damon_sysfs_regions), GFP_KERNEL);
1176 }
1177
1178 static void damon_sysfs_regions_rm_dirs(struct damon_sysfs_regions *regions)
1179 {
1180         struct damon_sysfs_region **regions_arr = regions->regions_arr;
1181         int i;
1182
1183         for (i = 0; i < regions->nr; i++)
1184                 kobject_put(&regions_arr[i]->kobj);
1185         regions->nr = 0;
1186         kfree(regions_arr);
1187         regions->regions_arr = NULL;
1188 }
1189
1190 static int damon_sysfs_regions_add_dirs(struct damon_sysfs_regions *regions,
1191                 int nr_regions)
1192 {
1193         struct damon_sysfs_region **regions_arr, *region;
1194         int err, i;
1195
1196         damon_sysfs_regions_rm_dirs(regions);
1197         if (!nr_regions)
1198                 return 0;
1199
1200         regions_arr = kmalloc_array(nr_regions, sizeof(*regions_arr),
1201                         GFP_KERNEL | __GFP_NOWARN);
1202         if (!regions_arr)
1203                 return -ENOMEM;
1204         regions->regions_arr = regions_arr;
1205
1206         for (i = 0; i < nr_regions; i++) {
1207                 region = damon_sysfs_region_alloc(0, 0);
1208                 if (!region) {
1209                         damon_sysfs_regions_rm_dirs(regions);
1210                         return -ENOMEM;
1211                 }
1212
1213                 err = kobject_init_and_add(&region->kobj,
1214                                 &damon_sysfs_region_ktype, &regions->kobj,
1215                                 "%d", i);
1216                 if (err) {
1217                         kobject_put(&region->kobj);
1218                         damon_sysfs_regions_rm_dirs(regions);
1219                         return err;
1220                 }
1221
1222                 regions_arr[i] = region;
1223                 regions->nr++;
1224         }
1225         return 0;
1226 }
1227
1228 static ssize_t nr_regions_show(struct kobject *kobj,
1229                 struct kobj_attribute *attr, char *buf)
1230 {
1231         struct damon_sysfs_regions *regions = container_of(kobj,
1232                         struct damon_sysfs_regions, kobj);
1233
1234         return sysfs_emit(buf, "%d\n", regions->nr);
1235 }
1236
1237 static ssize_t nr_regions_store(struct kobject *kobj,
1238                 struct kobj_attribute *attr, const char *buf, size_t count)
1239 {
1240         struct damon_sysfs_regions *regions = container_of(kobj,
1241                         struct damon_sysfs_regions, kobj);
1242         int nr, err = kstrtoint(buf, 0, &nr);
1243
1244         if (err)
1245                 return err;
1246         if (nr < 0)
1247                 return -EINVAL;
1248
1249         if (!mutex_trylock(&damon_sysfs_lock))
1250                 return -EBUSY;
1251         err = damon_sysfs_regions_add_dirs(regions, nr);
1252         mutex_unlock(&damon_sysfs_lock);
1253         if (err)
1254                 return err;
1255
1256         return count;
1257 }
1258
1259 static void damon_sysfs_regions_release(struct kobject *kobj)
1260 {
1261         kfree(container_of(kobj, struct damon_sysfs_regions, kobj));
1262 }
1263
1264 static struct kobj_attribute damon_sysfs_regions_nr_attr =
1265                 __ATTR_RW_MODE(nr_regions, 0600);
1266
1267 static struct attribute *damon_sysfs_regions_attrs[] = {
1268         &damon_sysfs_regions_nr_attr.attr,
1269         NULL,
1270 };
1271 ATTRIBUTE_GROUPS(damon_sysfs_regions);
1272
1273 static struct kobj_type damon_sysfs_regions_ktype = {
1274         .release = damon_sysfs_regions_release,
1275         .sysfs_ops = &kobj_sysfs_ops,
1276         .default_groups = damon_sysfs_regions_groups,
1277 };
1278
1279 /*
1280  * target directory
1281  */
1282
1283 struct damon_sysfs_target {
1284         struct kobject kobj;
1285         struct damon_sysfs_regions *regions;
1286         int pid;
1287 };
1288
1289 static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
1290 {
1291         return kzalloc(sizeof(struct damon_sysfs_target), GFP_KERNEL);
1292 }
1293
1294 static int damon_sysfs_target_add_dirs(struct damon_sysfs_target *target)
1295 {
1296         struct damon_sysfs_regions *regions = damon_sysfs_regions_alloc();
1297         int err;
1298
1299         if (!regions)
1300                 return -ENOMEM;
1301
1302         err = kobject_init_and_add(&regions->kobj, &damon_sysfs_regions_ktype,
1303                         &target->kobj, "regions");
1304         if (err)
1305                 kobject_put(&regions->kobj);
1306         else
1307                 target->regions = regions;
1308         return err;
1309 }
1310
1311 static void damon_sysfs_target_rm_dirs(struct damon_sysfs_target *target)
1312 {
1313         damon_sysfs_regions_rm_dirs(target->regions);
1314         kobject_put(&target->regions->kobj);
1315 }
1316
1317 static ssize_t pid_target_show(struct kobject *kobj,
1318                 struct kobj_attribute *attr, char *buf)
1319 {
1320         struct damon_sysfs_target *target = container_of(kobj,
1321                         struct damon_sysfs_target, kobj);
1322
1323         return sysfs_emit(buf, "%d\n", target->pid);
1324 }
1325
1326 static ssize_t pid_target_store(struct kobject *kobj,
1327                 struct kobj_attribute *attr, const char *buf, size_t count)
1328 {
1329         struct damon_sysfs_target *target = container_of(kobj,
1330                         struct damon_sysfs_target, kobj);
1331         int err = kstrtoint(buf, 0, &target->pid);
1332
1333         if (err)
1334                 return -EINVAL;
1335         return count;
1336 }
1337
1338 static void damon_sysfs_target_release(struct kobject *kobj)
1339 {
1340         kfree(container_of(kobj, struct damon_sysfs_target, kobj));
1341 }
1342
1343 static struct kobj_attribute damon_sysfs_target_pid_attr =
1344                 __ATTR_RW_MODE(pid_target, 0600);
1345
1346 static struct attribute *damon_sysfs_target_attrs[] = {
1347         &damon_sysfs_target_pid_attr.attr,
1348         NULL,
1349 };
1350 ATTRIBUTE_GROUPS(damon_sysfs_target);
1351
1352 static struct kobj_type damon_sysfs_target_ktype = {
1353         .release = damon_sysfs_target_release,
1354         .sysfs_ops = &kobj_sysfs_ops,
1355         .default_groups = damon_sysfs_target_groups,
1356 };
1357
1358 /*
1359  * targets directory
1360  */
1361
1362 struct damon_sysfs_targets {
1363         struct kobject kobj;
1364         struct damon_sysfs_target **targets_arr;
1365         int nr;
1366 };
1367
1368 static struct damon_sysfs_targets *damon_sysfs_targets_alloc(void)
1369 {
1370         return kzalloc(sizeof(struct damon_sysfs_targets), GFP_KERNEL);
1371 }
1372
1373 static void damon_sysfs_targets_rm_dirs(struct damon_sysfs_targets *targets)
1374 {
1375         struct damon_sysfs_target **targets_arr = targets->targets_arr;
1376         int i;
1377
1378         for (i = 0; i < targets->nr; i++) {
1379                 damon_sysfs_target_rm_dirs(targets_arr[i]);
1380                 kobject_put(&targets_arr[i]->kobj);
1381         }
1382         targets->nr = 0;
1383         kfree(targets_arr);
1384         targets->targets_arr = NULL;
1385 }
1386
1387 static int damon_sysfs_targets_add_dirs(struct damon_sysfs_targets *targets,
1388                 int nr_targets)
1389 {
1390         struct damon_sysfs_target **targets_arr, *target;
1391         int err, i;
1392
1393         damon_sysfs_targets_rm_dirs(targets);
1394         if (!nr_targets)
1395                 return 0;
1396
1397         targets_arr = kmalloc_array(nr_targets, sizeof(*targets_arr),
1398                         GFP_KERNEL | __GFP_NOWARN);
1399         if (!targets_arr)
1400                 return -ENOMEM;
1401         targets->targets_arr = targets_arr;
1402
1403         for (i = 0; i < nr_targets; i++) {
1404                 target = damon_sysfs_target_alloc();
1405                 if (!target) {
1406                         damon_sysfs_targets_rm_dirs(targets);
1407                         return -ENOMEM;
1408                 }
1409
1410                 err = kobject_init_and_add(&target->kobj,
1411                                 &damon_sysfs_target_ktype, &targets->kobj,
1412                                 "%d", i);
1413                 if (err)
1414                         goto out;
1415
1416                 err = damon_sysfs_target_add_dirs(target);
1417                 if (err)
1418                         goto out;
1419
1420                 targets_arr[i] = target;
1421                 targets->nr++;
1422         }
1423         return 0;
1424
1425 out:
1426         damon_sysfs_targets_rm_dirs(targets);
1427         kobject_put(&target->kobj);
1428         return err;
1429 }
1430
1431 static ssize_t nr_targets_show(struct kobject *kobj,
1432                 struct kobj_attribute *attr, char *buf)
1433 {
1434         struct damon_sysfs_targets *targets = container_of(kobj,
1435                         struct damon_sysfs_targets, kobj);
1436
1437         return sysfs_emit(buf, "%d\n", targets->nr);
1438 }
1439
1440 static ssize_t nr_targets_store(struct kobject *kobj,
1441                 struct kobj_attribute *attr, const char *buf, size_t count)
1442 {
1443         struct damon_sysfs_targets *targets = container_of(kobj,
1444                         struct damon_sysfs_targets, kobj);
1445         int nr, err = kstrtoint(buf, 0, &nr);
1446
1447         if (err)
1448                 return err;
1449         if (nr < 0)
1450                 return -EINVAL;
1451
1452         if (!mutex_trylock(&damon_sysfs_lock))
1453                 return -EBUSY;
1454         err = damon_sysfs_targets_add_dirs(targets, nr);
1455         mutex_unlock(&damon_sysfs_lock);
1456         if (err)
1457                 return err;
1458
1459         return count;
1460 }
1461
1462 static void damon_sysfs_targets_release(struct kobject *kobj)
1463 {
1464         kfree(container_of(kobj, struct damon_sysfs_targets, kobj));
1465 }
1466
1467 static struct kobj_attribute damon_sysfs_targets_nr_attr =
1468                 __ATTR_RW_MODE(nr_targets, 0600);
1469
1470 static struct attribute *damon_sysfs_targets_attrs[] = {
1471         &damon_sysfs_targets_nr_attr.attr,
1472         NULL,
1473 };
1474 ATTRIBUTE_GROUPS(damon_sysfs_targets);
1475
1476 static struct kobj_type damon_sysfs_targets_ktype = {
1477         .release = damon_sysfs_targets_release,
1478         .sysfs_ops = &kobj_sysfs_ops,
1479         .default_groups = damon_sysfs_targets_groups,
1480 };
1481
1482 /*
1483  * intervals directory
1484  */
1485
1486 struct damon_sysfs_intervals {
1487         struct kobject kobj;
1488         unsigned long sample_us;
1489         unsigned long aggr_us;
1490         unsigned long update_us;
1491 };
1492
1493 static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
1494                 unsigned long sample_us, unsigned long aggr_us,
1495                 unsigned long update_us)
1496 {
1497         struct damon_sysfs_intervals *intervals = kmalloc(sizeof(*intervals),
1498                         GFP_KERNEL);
1499
1500         if (!intervals)
1501                 return NULL;
1502
1503         intervals->kobj = (struct kobject){};
1504         intervals->sample_us = sample_us;
1505         intervals->aggr_us = aggr_us;
1506         intervals->update_us = update_us;
1507         return intervals;
1508 }
1509
1510 static ssize_t sample_us_show(struct kobject *kobj,
1511                 struct kobj_attribute *attr, char *buf)
1512 {
1513         struct damon_sysfs_intervals *intervals = container_of(kobj,
1514                         struct damon_sysfs_intervals, kobj);
1515
1516         return sysfs_emit(buf, "%lu\n", intervals->sample_us);
1517 }
1518
1519 static ssize_t sample_us_store(struct kobject *kobj,
1520                 struct kobj_attribute *attr, const char *buf, size_t count)
1521 {
1522         struct damon_sysfs_intervals *intervals = container_of(kobj,
1523                         struct damon_sysfs_intervals, kobj);
1524         unsigned long us;
1525         int err = kstrtoul(buf, 0, &us);
1526
1527         if (err)
1528                 return -EINVAL;
1529
1530         intervals->sample_us = us;
1531         return count;
1532 }
1533
1534 static ssize_t aggr_us_show(struct kobject *kobj, struct kobj_attribute *attr,
1535                 char *buf)
1536 {
1537         struct damon_sysfs_intervals *intervals = container_of(kobj,
1538                         struct damon_sysfs_intervals, kobj);
1539
1540         return sysfs_emit(buf, "%lu\n", intervals->aggr_us);
1541 }
1542
1543 static ssize_t aggr_us_store(struct kobject *kobj, struct kobj_attribute *attr,
1544                 const char *buf, size_t count)
1545 {
1546         struct damon_sysfs_intervals *intervals = container_of(kobj,
1547                         struct damon_sysfs_intervals, kobj);
1548         unsigned long us;
1549         int err = kstrtoul(buf, 0, &us);
1550
1551         if (err)
1552                 return -EINVAL;
1553
1554         intervals->aggr_us = us;
1555         return count;
1556 }
1557
1558 static ssize_t update_us_show(struct kobject *kobj,
1559                 struct kobj_attribute *attr, char *buf)
1560 {
1561         struct damon_sysfs_intervals *intervals = container_of(kobj,
1562                         struct damon_sysfs_intervals, kobj);
1563
1564         return sysfs_emit(buf, "%lu\n", intervals->update_us);
1565 }
1566
1567 static ssize_t update_us_store(struct kobject *kobj,
1568                 struct kobj_attribute *attr, const char *buf, size_t count)
1569 {
1570         struct damon_sysfs_intervals *intervals = container_of(kobj,
1571                         struct damon_sysfs_intervals, kobj);
1572         unsigned long us;
1573         int err = kstrtoul(buf, 0, &us);
1574
1575         if (err)
1576                 return -EINVAL;
1577
1578         intervals->update_us = us;
1579         return count;
1580 }
1581
1582 static void damon_sysfs_intervals_release(struct kobject *kobj)
1583 {
1584         kfree(container_of(kobj, struct damon_sysfs_intervals, kobj));
1585 }
1586
1587 static struct kobj_attribute damon_sysfs_intervals_sample_us_attr =
1588                 __ATTR_RW_MODE(sample_us, 0600);
1589
1590 static struct kobj_attribute damon_sysfs_intervals_aggr_us_attr =
1591                 __ATTR_RW_MODE(aggr_us, 0600);
1592
1593 static struct kobj_attribute damon_sysfs_intervals_update_us_attr =
1594                 __ATTR_RW_MODE(update_us, 0600);
1595
1596 static struct attribute *damon_sysfs_intervals_attrs[] = {
1597         &damon_sysfs_intervals_sample_us_attr.attr,
1598         &damon_sysfs_intervals_aggr_us_attr.attr,
1599         &damon_sysfs_intervals_update_us_attr.attr,
1600         NULL,
1601 };
1602 ATTRIBUTE_GROUPS(damon_sysfs_intervals);
1603
1604 static struct kobj_type damon_sysfs_intervals_ktype = {
1605         .release = damon_sysfs_intervals_release,
1606         .sysfs_ops = &kobj_sysfs_ops,
1607         .default_groups = damon_sysfs_intervals_groups,
1608 };
1609
1610 /*
1611  * monitoring_attrs directory
1612  */
1613
1614 struct damon_sysfs_attrs {
1615         struct kobject kobj;
1616         struct damon_sysfs_intervals *intervals;
1617         struct damon_sysfs_ul_range *nr_regions_range;
1618 };
1619
1620 static struct damon_sysfs_attrs *damon_sysfs_attrs_alloc(void)
1621 {
1622         struct damon_sysfs_attrs *attrs = kmalloc(sizeof(*attrs), GFP_KERNEL);
1623
1624         if (!attrs)
1625                 return NULL;
1626         attrs->kobj = (struct kobject){};
1627         return attrs;
1628 }
1629
1630 static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
1631 {
1632         struct damon_sysfs_intervals *intervals;
1633         struct damon_sysfs_ul_range *nr_regions_range;
1634         int err;
1635
1636         intervals = damon_sysfs_intervals_alloc(5000, 100000, 60000000);
1637         if (!intervals)
1638                 return -ENOMEM;
1639
1640         err = kobject_init_and_add(&intervals->kobj,
1641                         &damon_sysfs_intervals_ktype, &attrs->kobj,
1642                         "intervals");
1643         if (err)
1644                 goto put_intervals_out;
1645         attrs->intervals = intervals;
1646
1647         nr_regions_range = damon_sysfs_ul_range_alloc(10, 1000);
1648         if (!nr_regions_range) {
1649                 err = -ENOMEM;
1650                 goto put_intervals_out;
1651         }
1652
1653         err = kobject_init_and_add(&nr_regions_range->kobj,
1654                         &damon_sysfs_ul_range_ktype, &attrs->kobj,
1655                         "nr_regions");
1656         if (err)
1657                 goto put_nr_regions_intervals_out;
1658         attrs->nr_regions_range = nr_regions_range;
1659         return 0;
1660
1661 put_nr_regions_intervals_out:
1662         kobject_put(&nr_regions_range->kobj);
1663         attrs->nr_regions_range = NULL;
1664 put_intervals_out:
1665         kobject_put(&intervals->kobj);
1666         attrs->intervals = NULL;
1667         return err;
1668 }
1669
1670 static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
1671 {
1672         kobject_put(&attrs->nr_regions_range->kobj);
1673         kobject_put(&attrs->intervals->kobj);
1674 }
1675
1676 static void damon_sysfs_attrs_release(struct kobject *kobj)
1677 {
1678         kfree(container_of(kobj, struct damon_sysfs_attrs, kobj));
1679 }
1680
1681 static struct attribute *damon_sysfs_attrs_attrs[] = {
1682         NULL,
1683 };
1684 ATTRIBUTE_GROUPS(damon_sysfs_attrs);
1685
1686 static struct kobj_type damon_sysfs_attrs_ktype = {
1687         .release = damon_sysfs_attrs_release,
1688         .sysfs_ops = &kobj_sysfs_ops,
1689         .default_groups = damon_sysfs_attrs_groups,
1690 };
1691
1692 /*
1693  * context directory
1694  */
1695
1696 /* This should match with enum damon_ops_id */
1697 static const char * const damon_sysfs_ops_strs[] = {
1698         "vaddr",
1699         "fvaddr",
1700         "paddr",
1701 };
1702
1703 struct damon_sysfs_context {
1704         struct kobject kobj;
1705         enum damon_ops_id ops_id;
1706         struct damon_sysfs_attrs *attrs;
1707         struct damon_sysfs_targets *targets;
1708         struct damon_sysfs_schemes *schemes;
1709 };
1710
1711 static struct damon_sysfs_context *damon_sysfs_context_alloc(
1712                 enum damon_ops_id ops_id)
1713 {
1714         struct damon_sysfs_context *context = kmalloc(sizeof(*context),
1715                                 GFP_KERNEL);
1716
1717         if (!context)
1718                 return NULL;
1719         context->kobj = (struct kobject){};
1720         context->ops_id = ops_id;
1721         return context;
1722 }
1723
1724 static int damon_sysfs_context_set_attrs(struct damon_sysfs_context *context)
1725 {
1726         struct damon_sysfs_attrs *attrs = damon_sysfs_attrs_alloc();
1727         int err;
1728
1729         if (!attrs)
1730                 return -ENOMEM;
1731         err = kobject_init_and_add(&attrs->kobj, &damon_sysfs_attrs_ktype,
1732                         &context->kobj, "monitoring_attrs");
1733         if (err)
1734                 goto out;
1735         err = damon_sysfs_attrs_add_dirs(attrs);
1736         if (err)
1737                 goto out;
1738         context->attrs = attrs;
1739         return 0;
1740
1741 out:
1742         kobject_put(&attrs->kobj);
1743         return err;
1744 }
1745
1746 static int damon_sysfs_context_set_targets(struct damon_sysfs_context *context)
1747 {
1748         struct damon_sysfs_targets *targets = damon_sysfs_targets_alloc();
1749         int err;
1750
1751         if (!targets)
1752                 return -ENOMEM;
1753         err = kobject_init_and_add(&targets->kobj, &damon_sysfs_targets_ktype,
1754                         &context->kobj, "targets");
1755         if (err) {
1756                 kobject_put(&targets->kobj);
1757                 return err;
1758         }
1759         context->targets = targets;
1760         return 0;
1761 }
1762
1763 static int damon_sysfs_context_set_schemes(struct damon_sysfs_context *context)
1764 {
1765         struct damon_sysfs_schemes *schemes = damon_sysfs_schemes_alloc();
1766         int err;
1767
1768         if (!schemes)
1769                 return -ENOMEM;
1770         err = kobject_init_and_add(&schemes->kobj, &damon_sysfs_schemes_ktype,
1771                         &context->kobj, "schemes");
1772         if (err) {
1773                 kobject_put(&schemes->kobj);
1774                 return err;
1775         }
1776         context->schemes = schemes;
1777         return 0;
1778 }
1779
1780 static int damon_sysfs_context_add_dirs(struct damon_sysfs_context *context)
1781 {
1782         int err;
1783
1784         err = damon_sysfs_context_set_attrs(context);
1785         if (err)
1786                 return err;
1787
1788         err = damon_sysfs_context_set_targets(context);
1789         if (err)
1790                 goto put_attrs_out;
1791
1792         err = damon_sysfs_context_set_schemes(context);
1793         if (err)
1794                 goto put_targets_attrs_out;
1795         return 0;
1796
1797 put_targets_attrs_out:
1798         kobject_put(&context->targets->kobj);
1799         context->targets = NULL;
1800 put_attrs_out:
1801         kobject_put(&context->attrs->kobj);
1802         context->attrs = NULL;
1803         return err;
1804 }
1805
1806 static void damon_sysfs_context_rm_dirs(struct damon_sysfs_context *context)
1807 {
1808         damon_sysfs_attrs_rm_dirs(context->attrs);
1809         kobject_put(&context->attrs->kobj);
1810         damon_sysfs_targets_rm_dirs(context->targets);
1811         kobject_put(&context->targets->kobj);
1812         damon_sysfs_schemes_rm_dirs(context->schemes);
1813         kobject_put(&context->schemes->kobj);
1814 }
1815
1816 static ssize_t avail_operations_show(struct kobject *kobj,
1817                 struct kobj_attribute *attr, char *buf)
1818 {
1819         enum damon_ops_id id;
1820         int len = 0;
1821
1822         for (id = 0; id < NR_DAMON_OPS; id++) {
1823                 if (!damon_is_registered_ops(id))
1824                         continue;
1825                 len += sysfs_emit_at(buf, len, "%s\n",
1826                                 damon_sysfs_ops_strs[id]);
1827         }
1828         return len;
1829 }
1830
1831 static ssize_t operations_show(struct kobject *kobj,
1832                 struct kobj_attribute *attr, char *buf)
1833 {
1834         struct damon_sysfs_context *context = container_of(kobj,
1835                         struct damon_sysfs_context, kobj);
1836
1837         return sysfs_emit(buf, "%s\n", damon_sysfs_ops_strs[context->ops_id]);
1838 }
1839
1840 static ssize_t operations_store(struct kobject *kobj,
1841                 struct kobj_attribute *attr, const char *buf, size_t count)
1842 {
1843         struct damon_sysfs_context *context = container_of(kobj,
1844                         struct damon_sysfs_context, kobj);
1845         enum damon_ops_id id;
1846
1847         for (id = 0; id < NR_DAMON_OPS; id++) {
1848                 if (sysfs_streq(buf, damon_sysfs_ops_strs[id])) {
1849                         context->ops_id = id;
1850                         return count;
1851                 }
1852         }
1853         return -EINVAL;
1854 }
1855
1856 static void damon_sysfs_context_release(struct kobject *kobj)
1857 {
1858         kfree(container_of(kobj, struct damon_sysfs_context, kobj));
1859 }
1860
1861 static struct kobj_attribute damon_sysfs_context_avail_operations_attr =
1862                 __ATTR_RO_MODE(avail_operations, 0400);
1863
1864 static struct kobj_attribute damon_sysfs_context_operations_attr =
1865                 __ATTR_RW_MODE(operations, 0600);
1866
1867 static struct attribute *damon_sysfs_context_attrs[] = {
1868         &damon_sysfs_context_avail_operations_attr.attr,
1869         &damon_sysfs_context_operations_attr.attr,
1870         NULL,
1871 };
1872 ATTRIBUTE_GROUPS(damon_sysfs_context);
1873
1874 static struct kobj_type damon_sysfs_context_ktype = {
1875         .release = damon_sysfs_context_release,
1876         .sysfs_ops = &kobj_sysfs_ops,
1877         .default_groups = damon_sysfs_context_groups,
1878 };
1879
1880 /*
1881  * contexts directory
1882  */
1883
1884 struct damon_sysfs_contexts {
1885         struct kobject kobj;
1886         struct damon_sysfs_context **contexts_arr;
1887         int nr;
1888 };
1889
1890 static struct damon_sysfs_contexts *damon_sysfs_contexts_alloc(void)
1891 {
1892         return kzalloc(sizeof(struct damon_sysfs_contexts), GFP_KERNEL);
1893 }
1894
1895 static void damon_sysfs_contexts_rm_dirs(struct damon_sysfs_contexts *contexts)
1896 {
1897         struct damon_sysfs_context **contexts_arr = contexts->contexts_arr;
1898         int i;
1899
1900         for (i = 0; i < contexts->nr; i++) {
1901                 damon_sysfs_context_rm_dirs(contexts_arr[i]);
1902                 kobject_put(&contexts_arr[i]->kobj);
1903         }
1904         contexts->nr = 0;
1905         kfree(contexts_arr);
1906         contexts->contexts_arr = NULL;
1907 }
1908
1909 static int damon_sysfs_contexts_add_dirs(struct damon_sysfs_contexts *contexts,
1910                 int nr_contexts)
1911 {
1912         struct damon_sysfs_context **contexts_arr, *context;
1913         int err, i;
1914
1915         damon_sysfs_contexts_rm_dirs(contexts);
1916         if (!nr_contexts)
1917                 return 0;
1918
1919         contexts_arr = kmalloc_array(nr_contexts, sizeof(*contexts_arr),
1920                         GFP_KERNEL | __GFP_NOWARN);
1921         if (!contexts_arr)
1922                 return -ENOMEM;
1923         contexts->contexts_arr = contexts_arr;
1924
1925         for (i = 0; i < nr_contexts; i++) {
1926                 context = damon_sysfs_context_alloc(DAMON_OPS_VADDR);
1927                 if (!context) {
1928                         damon_sysfs_contexts_rm_dirs(contexts);
1929                         return -ENOMEM;
1930                 }
1931
1932                 err = kobject_init_and_add(&context->kobj,
1933                                 &damon_sysfs_context_ktype, &contexts->kobj,
1934                                 "%d", i);
1935                 if (err)
1936                         goto out;
1937
1938                 err = damon_sysfs_context_add_dirs(context);
1939                 if (err)
1940                         goto out;
1941
1942                 contexts_arr[i] = context;
1943                 contexts->nr++;
1944         }
1945         return 0;
1946
1947 out:
1948         damon_sysfs_contexts_rm_dirs(contexts);
1949         kobject_put(&context->kobj);
1950         return err;
1951 }
1952
1953 static ssize_t nr_contexts_show(struct kobject *kobj,
1954                 struct kobj_attribute *attr, char *buf)
1955 {
1956         struct damon_sysfs_contexts *contexts = container_of(kobj,
1957                         struct damon_sysfs_contexts, kobj);
1958
1959         return sysfs_emit(buf, "%d\n", contexts->nr);
1960 }
1961
1962 static ssize_t nr_contexts_store(struct kobject *kobj,
1963                 struct kobj_attribute *attr, const char *buf, size_t count)
1964 {
1965         struct damon_sysfs_contexts *contexts = container_of(kobj,
1966                         struct damon_sysfs_contexts, kobj);
1967         int nr, err;
1968
1969         err = kstrtoint(buf, 0, &nr);
1970         if (err)
1971                 return err;
1972         /* TODO: support multiple contexts per kdamond */
1973         if (nr < 0 || 1 < nr)
1974                 return -EINVAL;
1975
1976         if (!mutex_trylock(&damon_sysfs_lock))
1977                 return -EBUSY;
1978         err = damon_sysfs_contexts_add_dirs(contexts, nr);
1979         mutex_unlock(&damon_sysfs_lock);
1980         if (err)
1981                 return err;
1982
1983         return count;
1984 }
1985
1986 static void damon_sysfs_contexts_release(struct kobject *kobj)
1987 {
1988         kfree(container_of(kobj, struct damon_sysfs_contexts, kobj));
1989 }
1990
1991 static struct kobj_attribute damon_sysfs_contexts_nr_attr
1992                 = __ATTR_RW_MODE(nr_contexts, 0600);
1993
1994 static struct attribute *damon_sysfs_contexts_attrs[] = {
1995         &damon_sysfs_contexts_nr_attr.attr,
1996         NULL,
1997 };
1998 ATTRIBUTE_GROUPS(damon_sysfs_contexts);
1999
2000 static struct kobj_type damon_sysfs_contexts_ktype = {
2001         .release = damon_sysfs_contexts_release,
2002         .sysfs_ops = &kobj_sysfs_ops,
2003         .default_groups = damon_sysfs_contexts_groups,
2004 };
2005
2006 /*
2007  * kdamond directory
2008  */
2009
2010 struct damon_sysfs_kdamond {
2011         struct kobject kobj;
2012         struct damon_sysfs_contexts *contexts;
2013         struct damon_ctx *damon_ctx;
2014 };
2015
2016 static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
2017 {
2018         return kzalloc(sizeof(struct damon_sysfs_kdamond), GFP_KERNEL);
2019 }
2020
2021 static int damon_sysfs_kdamond_add_dirs(struct damon_sysfs_kdamond *kdamond)
2022 {
2023         struct damon_sysfs_contexts *contexts;
2024         int err;
2025
2026         contexts = damon_sysfs_contexts_alloc();
2027         if (!contexts)
2028                 return -ENOMEM;
2029
2030         err = kobject_init_and_add(&contexts->kobj,
2031                         &damon_sysfs_contexts_ktype, &kdamond->kobj,
2032                         "contexts");
2033         if (err) {
2034                 kobject_put(&contexts->kobj);
2035                 return err;
2036         }
2037         kdamond->contexts = contexts;
2038
2039         return err;
2040 }
2041
2042 static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
2043 {
2044         damon_sysfs_contexts_rm_dirs(kdamond->contexts);
2045         kobject_put(&kdamond->contexts->kobj);
2046 }
2047
2048 static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)
2049 {
2050         bool running;
2051
2052         mutex_lock(&ctx->kdamond_lock);
2053         running = ctx->kdamond != NULL;
2054         mutex_unlock(&ctx->kdamond_lock);
2055         return running;
2056 }
2057
2058 /*
2059  * enum damon_sysfs_cmd - Commands for a specific kdamond.
2060  */
2061 enum damon_sysfs_cmd {
2062         /* @DAMON_SYSFS_CMD_ON: Turn the kdamond on. */
2063         DAMON_SYSFS_CMD_ON,
2064         /* @DAMON_SYSFS_CMD_OFF: Turn the kdamond off. */
2065         DAMON_SYSFS_CMD_OFF,
2066         /* @DAMON_SYSFS_CMD_COMMIT: Update kdamond inputs. */
2067         DAMON_SYSFS_CMD_COMMIT,
2068         /*
2069          * @DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS: Update scheme stats sysfs
2070          * files.
2071          */
2072         DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS,
2073         /*
2074          * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.
2075          */
2076         NR_DAMON_SYSFS_CMDS,
2077 };
2078
2079 /* Should match with enum damon_sysfs_cmd */
2080 static const char * const damon_sysfs_cmd_strs[] = {
2081         "on",
2082         "off",
2083         "commit",
2084         "update_schemes_stats",
2085 };
2086
2087 /*
2088  * struct damon_sysfs_cmd_request - A request to the DAMON callback.
2089  * @cmd:        The command that needs to be handled by the callback.
2090  * @kdamond:    The kobject wrapper that associated to the kdamond thread.
2091  *
2092  * This structure represents a sysfs command request that need to access some
2093  * DAMON context-internal data.  Because DAMON context-internal data can be
2094  * safely accessed from DAMON callbacks without additional synchronization, the
2095  * request will be handled by the DAMON callback.  None-``NULL`` @kdamond means
2096  * the request is valid.
2097  */
2098 struct damon_sysfs_cmd_request {
2099         enum damon_sysfs_cmd cmd;
2100         struct damon_sysfs_kdamond *kdamond;
2101 };
2102
2103 /* Current DAMON callback request.  Protected by damon_sysfs_lock. */
2104 static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;
2105
2106 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
2107                 char *buf)
2108 {
2109         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2110                         struct damon_sysfs_kdamond, kobj);
2111         struct damon_ctx *ctx = kdamond->damon_ctx;
2112         bool running;
2113
2114         if (!ctx)
2115                 running = false;
2116         else
2117                 running = damon_sysfs_ctx_running(ctx);
2118
2119         return sysfs_emit(buf, "%s\n", running ?
2120                         damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
2121                         damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);
2122 }
2123
2124 static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
2125                 struct damon_sysfs_attrs *sys_attrs)
2126 {
2127         struct damon_sysfs_intervals *sys_intervals = sys_attrs->intervals;
2128         struct damon_sysfs_ul_range *sys_nr_regions =
2129                 sys_attrs->nr_regions_range;
2130
2131         return damon_set_attrs(ctx, sys_intervals->sample_us,
2132                         sys_intervals->aggr_us, sys_intervals->update_us,
2133                         sys_nr_regions->min, sys_nr_regions->max);
2134 }
2135
2136 static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
2137 {
2138         struct damon_target *t, *next;
2139
2140         damon_for_each_target_safe(t, next, ctx) {
2141                 if (damon_target_has_pid(ctx))
2142                         put_pid(t->pid);
2143                 damon_destroy_target(t);
2144         }
2145 }
2146
2147 static int damon_sysfs_set_regions(struct damon_target *t,
2148                 struct damon_sysfs_regions *sysfs_regions)
2149 {
2150         struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,
2151                         sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
2152         int i, err = -EINVAL;
2153
2154         if (!ranges)
2155                 return -ENOMEM;
2156         for (i = 0; i < sysfs_regions->nr; i++) {
2157                 struct damon_sysfs_region *sys_region =
2158                         sysfs_regions->regions_arr[i];
2159
2160                 if (sys_region->start > sys_region->end)
2161                         goto out;
2162
2163                 ranges[i].start = sys_region->start;
2164                 ranges[i].end = sys_region->end;
2165                 if (i == 0)
2166                         continue;
2167                 if (ranges[i - 1].end > ranges[i].start)
2168                         goto out;
2169         }
2170         err = damon_set_regions(t, ranges, sysfs_regions->nr);
2171 out:
2172         kfree(ranges);
2173         return err;
2174
2175 }
2176
2177 static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
2178                 struct damon_ctx *ctx)
2179 {
2180         struct damon_target *t = damon_new_target();
2181         int err = -EINVAL;
2182
2183         if (!t)
2184                 return -ENOMEM;
2185         if (damon_target_has_pid(ctx)) {
2186                 t->pid = find_get_pid(sys_target->pid);
2187                 if (!t->pid)
2188                         goto destroy_targets_out;
2189         }
2190         damon_add_target(ctx, t);
2191         err = damon_sysfs_set_regions(t, sys_target->regions);
2192         if (err)
2193                 goto destroy_targets_out;
2194         return 0;
2195
2196 destroy_targets_out:
2197         damon_sysfs_destroy_targets(ctx);
2198         return err;
2199 }
2200
2201 /*
2202  * Search a target in a context that corresponds to the sysfs target input.
2203  *
2204  * Return: pointer to the target if found, NULL if not found, or negative
2205  * error code if the search failed.
2206  */
2207 static struct damon_target *damon_sysfs_existing_target(
2208                 struct damon_sysfs_target *sys_target, struct damon_ctx *ctx)
2209 {
2210         struct pid *pid;
2211         struct damon_target *t;
2212
2213         if (!damon_target_has_pid(ctx)) {
2214                 /* Up to only one target for paddr could exist */
2215                 damon_for_each_target(t, ctx)
2216                         return t;
2217                 return NULL;
2218         }
2219
2220         /* ops.id should be DAMON_OPS_VADDR or DAMON_OPS_FVADDR */
2221         pid = find_get_pid(sys_target->pid);
2222         if (!pid)
2223                 return ERR_PTR(-EINVAL);
2224         damon_for_each_target(t, ctx) {
2225                 if (t->pid == pid) {
2226                         put_pid(pid);
2227                         return t;
2228                 }
2229         }
2230         put_pid(pid);
2231         return NULL;
2232 }
2233
2234 static int damon_sysfs_set_targets(struct damon_ctx *ctx,
2235                 struct damon_sysfs_targets *sysfs_targets)
2236 {
2237         int i, err;
2238
2239         /* Multiple physical address space monitoring targets makes no sense */
2240         if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
2241                 return -EINVAL;
2242
2243         for (i = 0; i < sysfs_targets->nr; i++) {
2244                 struct damon_sysfs_target *st = sysfs_targets->targets_arr[i];
2245                 struct damon_target *t = damon_sysfs_existing_target(st, ctx);
2246
2247                 if (IS_ERR(t))
2248                         return PTR_ERR(t);
2249                 if (!t)
2250                         err = damon_sysfs_add_target(st, ctx);
2251                 else
2252                         err = damon_sysfs_set_regions(t, st->regions);
2253                 if (err)
2254                         return err;
2255         }
2256         return 0;
2257 }
2258
2259 static struct damos *damon_sysfs_mk_scheme(
2260                 struct damon_sysfs_scheme *sysfs_scheme)
2261 {
2262         struct damon_sysfs_access_pattern *pattern =
2263                 sysfs_scheme->access_pattern;
2264         struct damon_sysfs_quotas *sysfs_quotas = sysfs_scheme->quotas;
2265         struct damon_sysfs_weights *sysfs_weights = sysfs_quotas->weights;
2266         struct damon_sysfs_watermarks *sysfs_wmarks = sysfs_scheme->watermarks;
2267         struct damos_quota quota = {
2268                 .ms = sysfs_quotas->ms,
2269                 .sz = sysfs_quotas->sz,
2270                 .reset_interval = sysfs_quotas->reset_interval_ms,
2271                 .weight_sz = sysfs_weights->sz,
2272                 .weight_nr_accesses = sysfs_weights->nr_accesses,
2273                 .weight_age = sysfs_weights->age,
2274         };
2275         struct damos_watermarks wmarks = {
2276                 .metric = sysfs_wmarks->metric,
2277                 .interval = sysfs_wmarks->interval_us,
2278                 .high = sysfs_wmarks->high,
2279                 .mid = sysfs_wmarks->mid,
2280                 .low = sysfs_wmarks->low,
2281         };
2282
2283         return damon_new_scheme(pattern->sz->min, pattern->sz->max,
2284                         pattern->nr_accesses->min, pattern->nr_accesses->max,
2285                         pattern->age->min, pattern->age->max,
2286                         sysfs_scheme->action, &quota, &wmarks);
2287 }
2288
2289 static int damon_sysfs_set_schemes(struct damon_ctx *ctx,
2290                 struct damon_sysfs_schemes *sysfs_schemes)
2291 {
2292         int i;
2293
2294         for (i = 0; i < sysfs_schemes->nr; i++) {
2295                 struct damos *scheme, *next;
2296
2297                 scheme = damon_sysfs_mk_scheme(sysfs_schemes->schemes_arr[i]);
2298                 if (!scheme) {
2299                         damon_for_each_scheme_safe(scheme, next, ctx)
2300                                 damon_destroy_scheme(scheme);
2301                         return -ENOMEM;
2302                 }
2303                 damon_add_scheme(ctx, scheme);
2304         }
2305         return 0;
2306 }
2307
2308 static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
2309 {
2310         struct damon_target *t, *next;
2311
2312         if (ctx->ops.id != DAMON_OPS_VADDR && ctx->ops.id != DAMON_OPS_FVADDR)
2313                 return;
2314
2315         mutex_lock(&ctx->kdamond_lock);
2316         damon_for_each_target_safe(t, next, ctx) {
2317                 put_pid(t->pid);
2318                 damon_destroy_target(t);
2319         }
2320         mutex_unlock(&ctx->kdamond_lock);
2321 }
2322
2323 /*
2324  * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.
2325  * @kdamond:    The kobject wrapper that associated to the kdamond thread.
2326  *
2327  * This function reads the schemes stats of specific kdamond and update the
2328  * related values for sysfs files.  This function should be called from DAMON
2329  * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON
2330  * contexts-internal data and DAMON sysfs variables.
2331  */
2332 static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)
2333 {
2334         struct damon_ctx *ctx = kdamond->damon_ctx;
2335         struct damon_sysfs_schemes *sysfs_schemes;
2336         struct damos *scheme;
2337         int schemes_idx = 0;
2338
2339         if (!ctx)
2340                 return -EINVAL;
2341         sysfs_schemes = kdamond->contexts->contexts_arr[0]->schemes;
2342         damon_for_each_scheme(scheme, ctx) {
2343                 struct damon_sysfs_stats *sysfs_stats;
2344
2345                 sysfs_stats = sysfs_schemes->schemes_arr[schemes_idx++]->stats;
2346                 sysfs_stats->nr_tried = scheme->stat.nr_tried;
2347                 sysfs_stats->sz_tried = scheme->stat.sz_tried;
2348                 sysfs_stats->nr_applied = scheme->stat.nr_applied;
2349                 sysfs_stats->sz_applied = scheme->stat.sz_applied;
2350                 sysfs_stats->qt_exceeds = scheme->stat.qt_exceeds;
2351         }
2352         return 0;
2353 }
2354
2355 static inline bool damon_sysfs_kdamond_running(
2356                 struct damon_sysfs_kdamond *kdamond)
2357 {
2358         return kdamond->damon_ctx &&
2359                 damon_sysfs_ctx_running(kdamond->damon_ctx);
2360 }
2361
2362 static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
2363                 struct damon_sysfs_context *sys_ctx)
2364 {
2365         int err;
2366
2367         err = damon_select_ops(ctx, sys_ctx->ops_id);
2368         if (err)
2369                 return err;
2370         err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
2371         if (err)
2372                 return err;
2373         err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
2374         if (err)
2375                 return err;
2376         return damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
2377 }
2378
2379 /*
2380  * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
2381  * @kdamond:    The kobject wrapper for the associated kdamond.
2382  *
2383  * If the sysfs input is wrong, the kdamond will be terminated.
2384  */
2385 static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
2386 {
2387         if (!damon_sysfs_kdamond_running(kdamond))
2388                 return -EINVAL;
2389         /* TODO: Support multiple contexts per kdamond */
2390         if (kdamond->contexts->nr != 1)
2391                 return -EINVAL;
2392
2393         return damon_sysfs_apply_inputs(kdamond->damon_ctx,
2394                         kdamond->contexts->contexts_arr[0]);
2395 }
2396
2397 /*
2398  * damon_sysfs_cmd_request_callback() - DAMON callback for handling requests.
2399  * @c:  The DAMON context of the callback.
2400  *
2401  * This function is periodically called back from the kdamond thread for @c.
2402  * Then, it checks if there is a waiting DAMON sysfs request and handles it.
2403  */
2404 static int damon_sysfs_cmd_request_callback(struct damon_ctx *c)
2405 {
2406         struct damon_sysfs_kdamond *kdamond;
2407         int err = 0;
2408
2409         /* avoid deadlock due to concurrent state_store('off') */
2410         if (!mutex_trylock(&damon_sysfs_lock))
2411                 return 0;
2412         kdamond = damon_sysfs_cmd_request.kdamond;
2413         if (!kdamond || kdamond->damon_ctx != c)
2414                 goto out;
2415         switch (damon_sysfs_cmd_request.cmd) {
2416         case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
2417                 err = damon_sysfs_upd_schemes_stats(kdamond);
2418                 break;
2419         case DAMON_SYSFS_CMD_COMMIT:
2420                 err = damon_sysfs_commit_input(kdamond);
2421                 break;
2422         default:
2423                 break;
2424         }
2425         /* Mark the request as invalid now. */
2426         damon_sysfs_cmd_request.kdamond = NULL;
2427 out:
2428         mutex_unlock(&damon_sysfs_lock);
2429         return err;
2430 }
2431
2432 static struct damon_ctx *damon_sysfs_build_ctx(
2433                 struct damon_sysfs_context *sys_ctx)
2434 {
2435         struct damon_ctx *ctx = damon_new_ctx();
2436         int err;
2437
2438         if (!ctx)
2439                 return ERR_PTR(-ENOMEM);
2440
2441         err = damon_sysfs_apply_inputs(ctx, sys_ctx);
2442         if (err) {
2443                 damon_destroy_ctx(ctx);
2444                 return ERR_PTR(err);
2445         }
2446
2447         ctx->callback.after_wmarks_check = damon_sysfs_cmd_request_callback;
2448         ctx->callback.after_aggregation = damon_sysfs_cmd_request_callback;
2449         ctx->callback.before_terminate = damon_sysfs_before_terminate;
2450         return ctx;
2451 }
2452
2453 static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
2454 {
2455         struct damon_ctx *ctx;
2456         int err;
2457
2458         if (kdamond->damon_ctx &&
2459                         damon_sysfs_ctx_running(kdamond->damon_ctx))
2460                 return -EBUSY;
2461         if (damon_sysfs_cmd_request.kdamond == kdamond)
2462                 return -EBUSY;
2463         /* TODO: support multiple contexts per kdamond */
2464         if (kdamond->contexts->nr != 1)
2465                 return -EINVAL;
2466
2467         if (kdamond->damon_ctx)
2468                 damon_destroy_ctx(kdamond->damon_ctx);
2469         kdamond->damon_ctx = NULL;
2470
2471         ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
2472         if (IS_ERR(ctx))
2473                 return PTR_ERR(ctx);
2474         err = damon_start(&ctx, 1, false);
2475         if (err) {
2476                 damon_destroy_ctx(ctx);
2477                 return err;
2478         }
2479         kdamond->damon_ctx = ctx;
2480         return err;
2481 }
2482
2483 static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
2484 {
2485         if (!kdamond->damon_ctx)
2486                 return -EINVAL;
2487         return damon_stop(&kdamond->damon_ctx, 1);
2488         /*
2489          * To allow users show final monitoring results of already turned-off
2490          * DAMON, we free kdamond->damon_ctx in next
2491          * damon_sysfs_turn_damon_on(), or kdamonds_nr_store()
2492          */
2493 }
2494
2495 /*
2496  * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.
2497  * @cmd:        The command to handle.
2498  * @kdamond:    The kobject wrapper for the associated kdamond.
2499  *
2500  * This function handles a DAMON sysfs command for a kdamond.  For commands
2501  * that need to access running DAMON context-internal data, it requests
2502  * handling of the command to the DAMON callback
2503  * (@damon_sysfs_cmd_request_callback()) and wait until it is properly handled,
2504  * or the context is completed.
2505  *
2506  * Return: 0 on success, negative error code otherwise.
2507  */
2508 static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd,
2509                 struct damon_sysfs_kdamond *kdamond)
2510 {
2511         bool need_wait = true;
2512
2513         /* Handle commands that doesn't access DAMON context-internal data */
2514         switch (cmd) {
2515         case DAMON_SYSFS_CMD_ON:
2516                 return damon_sysfs_turn_damon_on(kdamond);
2517         case DAMON_SYSFS_CMD_OFF:
2518                 return damon_sysfs_turn_damon_off(kdamond);
2519         default:
2520                 break;
2521         }
2522
2523         /* Pass the command to DAMON callback for safe DAMON context access */
2524         if (damon_sysfs_cmd_request.kdamond)
2525                 return -EBUSY;
2526         if (!damon_sysfs_kdamond_running(kdamond))
2527                 return -EINVAL;
2528         damon_sysfs_cmd_request.cmd = cmd;
2529         damon_sysfs_cmd_request.kdamond = kdamond;
2530
2531         /*
2532          * wait until damon_sysfs_cmd_request_callback() handles the request
2533          * from kdamond context
2534          */
2535         mutex_unlock(&damon_sysfs_lock);
2536         while (need_wait) {
2537                 schedule_timeout_idle(msecs_to_jiffies(100));
2538                 if (!mutex_trylock(&damon_sysfs_lock))
2539                         continue;
2540                 if (!damon_sysfs_cmd_request.kdamond) {
2541                         /* damon_sysfs_cmd_request_callback() handled */
2542                         need_wait = false;
2543                 } else if (!damon_sysfs_kdamond_running(kdamond)) {
2544                         /* kdamond has already finished */
2545                         need_wait = false;
2546                         damon_sysfs_cmd_request.kdamond = NULL;
2547                 }
2548                 mutex_unlock(&damon_sysfs_lock);
2549         }
2550         mutex_lock(&damon_sysfs_lock);
2551         return 0;
2552 }
2553
2554 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
2555                 const char *buf, size_t count)
2556 {
2557         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2558                         struct damon_sysfs_kdamond, kobj);
2559         enum damon_sysfs_cmd cmd;
2560         ssize_t ret = -EINVAL;
2561
2562         if (!mutex_trylock(&damon_sysfs_lock))
2563                 return -EBUSY;
2564         for (cmd = 0; cmd < NR_DAMON_SYSFS_CMDS; cmd++) {
2565                 if (sysfs_streq(buf, damon_sysfs_cmd_strs[cmd])) {
2566                         ret = damon_sysfs_handle_cmd(cmd, kdamond);
2567                         break;
2568                 }
2569         }
2570         mutex_unlock(&damon_sysfs_lock);
2571         if (!ret)
2572                 ret = count;
2573         return ret;
2574 }
2575
2576 static ssize_t pid_show(struct kobject *kobj,
2577                 struct kobj_attribute *attr, char *buf)
2578 {
2579         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2580                         struct damon_sysfs_kdamond, kobj);
2581         struct damon_ctx *ctx;
2582         int pid;
2583
2584         if (!mutex_trylock(&damon_sysfs_lock))
2585                 return -EBUSY;
2586         ctx = kdamond->damon_ctx;
2587         if (!ctx) {
2588                 pid = -1;
2589                 goto out;
2590         }
2591         mutex_lock(&ctx->kdamond_lock);
2592         if (!ctx->kdamond)
2593                 pid = -1;
2594         else
2595                 pid = ctx->kdamond->pid;
2596         mutex_unlock(&ctx->kdamond_lock);
2597 out:
2598         mutex_unlock(&damon_sysfs_lock);
2599         return sysfs_emit(buf, "%d\n", pid);
2600 }
2601
2602 static void damon_sysfs_kdamond_release(struct kobject *kobj)
2603 {
2604         struct damon_sysfs_kdamond *kdamond = container_of(kobj,
2605                         struct damon_sysfs_kdamond, kobj);
2606
2607         if (kdamond->damon_ctx)
2608                 damon_destroy_ctx(kdamond->damon_ctx);
2609         kfree(kdamond);
2610 }
2611
2612 static struct kobj_attribute damon_sysfs_kdamond_state_attr =
2613                 __ATTR_RW_MODE(state, 0600);
2614
2615 static struct kobj_attribute damon_sysfs_kdamond_pid_attr =
2616                 __ATTR_RO_MODE(pid, 0400);
2617
2618 static struct attribute *damon_sysfs_kdamond_attrs[] = {
2619         &damon_sysfs_kdamond_state_attr.attr,
2620         &damon_sysfs_kdamond_pid_attr.attr,
2621         NULL,
2622 };
2623 ATTRIBUTE_GROUPS(damon_sysfs_kdamond);
2624
2625 static struct kobj_type damon_sysfs_kdamond_ktype = {
2626         .release = damon_sysfs_kdamond_release,
2627         .sysfs_ops = &kobj_sysfs_ops,
2628         .default_groups = damon_sysfs_kdamond_groups,
2629 };
2630
2631 /*
2632  * kdamonds directory
2633  */
2634
2635 struct damon_sysfs_kdamonds {
2636         struct kobject kobj;
2637         struct damon_sysfs_kdamond **kdamonds_arr;
2638         int nr;
2639 };
2640
2641 static struct damon_sysfs_kdamonds *damon_sysfs_kdamonds_alloc(void)
2642 {
2643         return kzalloc(sizeof(struct damon_sysfs_kdamonds), GFP_KERNEL);
2644 }
2645
2646 static void damon_sysfs_kdamonds_rm_dirs(struct damon_sysfs_kdamonds *kdamonds)
2647 {
2648         struct damon_sysfs_kdamond **kdamonds_arr = kdamonds->kdamonds_arr;
2649         int i;
2650
2651         for (i = 0; i < kdamonds->nr; i++) {
2652                 damon_sysfs_kdamond_rm_dirs(kdamonds_arr[i]);
2653                 kobject_put(&kdamonds_arr[i]->kobj);
2654         }
2655         kdamonds->nr = 0;
2656         kfree(kdamonds_arr);
2657         kdamonds->kdamonds_arr = NULL;
2658 }
2659
2660 static int damon_sysfs_nr_running_ctxs(struct damon_sysfs_kdamond **kdamonds,
2661                 int nr_kdamonds)
2662 {
2663         int nr_running_ctxs = 0;
2664         int i;
2665
2666         for (i = 0; i < nr_kdamonds; i++) {
2667                 struct damon_ctx *ctx = kdamonds[i]->damon_ctx;
2668
2669                 if (!ctx)
2670                         continue;
2671                 mutex_lock(&ctx->kdamond_lock);
2672                 if (ctx->kdamond)
2673                         nr_running_ctxs++;
2674                 mutex_unlock(&ctx->kdamond_lock);
2675         }
2676         return nr_running_ctxs;
2677 }
2678
2679 static int damon_sysfs_kdamonds_add_dirs(struct damon_sysfs_kdamonds *kdamonds,
2680                 int nr_kdamonds)
2681 {
2682         struct damon_sysfs_kdamond **kdamonds_arr, *kdamond;
2683         int err, i;
2684
2685         if (damon_sysfs_nr_running_ctxs(kdamonds->kdamonds_arr, kdamonds->nr))
2686                 return -EBUSY;
2687
2688         for (i = 0; i < kdamonds->nr; i++) {
2689                 if (damon_sysfs_cmd_request.kdamond ==
2690                                 kdamonds->kdamonds_arr[i])
2691                         return -EBUSY;
2692         }
2693
2694         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2695         if (!nr_kdamonds)
2696                 return 0;
2697
2698         kdamonds_arr = kmalloc_array(nr_kdamonds, sizeof(*kdamonds_arr),
2699                         GFP_KERNEL | __GFP_NOWARN);
2700         if (!kdamonds_arr)
2701                 return -ENOMEM;
2702         kdamonds->kdamonds_arr = kdamonds_arr;
2703
2704         for (i = 0; i < nr_kdamonds; i++) {
2705                 kdamond = damon_sysfs_kdamond_alloc();
2706                 if (!kdamond) {
2707                         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2708                         return -ENOMEM;
2709                 }
2710
2711                 err = kobject_init_and_add(&kdamond->kobj,
2712                                 &damon_sysfs_kdamond_ktype, &kdamonds->kobj,
2713                                 "%d", i);
2714                 if (err)
2715                         goto out;
2716
2717                 err = damon_sysfs_kdamond_add_dirs(kdamond);
2718                 if (err)
2719                         goto out;
2720
2721                 kdamonds_arr[i] = kdamond;
2722                 kdamonds->nr++;
2723         }
2724         return 0;
2725
2726 out:
2727         damon_sysfs_kdamonds_rm_dirs(kdamonds);
2728         kobject_put(&kdamond->kobj);
2729         return err;
2730 }
2731
2732 static ssize_t nr_kdamonds_show(struct kobject *kobj,
2733                 struct kobj_attribute *attr, char *buf)
2734 {
2735         struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
2736                         struct damon_sysfs_kdamonds, kobj);
2737
2738         return sysfs_emit(buf, "%d\n", kdamonds->nr);
2739 }
2740
2741 static ssize_t nr_kdamonds_store(struct kobject *kobj,
2742                 struct kobj_attribute *attr, const char *buf, size_t count)
2743 {
2744         struct damon_sysfs_kdamonds *kdamonds = container_of(kobj,
2745                         struct damon_sysfs_kdamonds, kobj);
2746         int nr, err;
2747
2748         err = kstrtoint(buf, 0, &nr);
2749         if (err)
2750                 return err;
2751         if (nr < 0)
2752                 return -EINVAL;
2753
2754         if (!mutex_trylock(&damon_sysfs_lock))
2755                 return -EBUSY;
2756         err = damon_sysfs_kdamonds_add_dirs(kdamonds, nr);
2757         mutex_unlock(&damon_sysfs_lock);
2758         if (err)
2759                 return err;
2760
2761         return count;
2762 }
2763
2764 static void damon_sysfs_kdamonds_release(struct kobject *kobj)
2765 {
2766         kfree(container_of(kobj, struct damon_sysfs_kdamonds, kobj));
2767 }
2768
2769 static struct kobj_attribute damon_sysfs_kdamonds_nr_attr =
2770                 __ATTR_RW_MODE(nr_kdamonds, 0600);
2771
2772 static struct attribute *damon_sysfs_kdamonds_attrs[] = {
2773         &damon_sysfs_kdamonds_nr_attr.attr,
2774         NULL,
2775 };
2776 ATTRIBUTE_GROUPS(damon_sysfs_kdamonds);
2777
2778 static struct kobj_type damon_sysfs_kdamonds_ktype = {
2779         .release = damon_sysfs_kdamonds_release,
2780         .sysfs_ops = &kobj_sysfs_ops,
2781         .default_groups = damon_sysfs_kdamonds_groups,
2782 };
2783
2784 /*
2785  * damon user interface directory
2786  */
2787
2788 struct damon_sysfs_ui_dir {
2789         struct kobject kobj;
2790         struct damon_sysfs_kdamonds *kdamonds;
2791 };
2792
2793 static struct damon_sysfs_ui_dir *damon_sysfs_ui_dir_alloc(void)
2794 {
2795         return kzalloc(sizeof(struct damon_sysfs_ui_dir), GFP_KERNEL);
2796 }
2797
2798 static int damon_sysfs_ui_dir_add_dirs(struct damon_sysfs_ui_dir *ui_dir)
2799 {
2800         struct damon_sysfs_kdamonds *kdamonds;
2801         int err;
2802
2803         kdamonds = damon_sysfs_kdamonds_alloc();
2804         if (!kdamonds)
2805                 return -ENOMEM;
2806
2807         err = kobject_init_and_add(&kdamonds->kobj,
2808                         &damon_sysfs_kdamonds_ktype, &ui_dir->kobj,
2809                         "kdamonds");
2810         if (err) {
2811                 kobject_put(&kdamonds->kobj);
2812                 return err;
2813         }
2814         ui_dir->kdamonds = kdamonds;
2815         return err;
2816 }
2817
2818 static void damon_sysfs_ui_dir_release(struct kobject *kobj)
2819 {
2820         kfree(container_of(kobj, struct damon_sysfs_ui_dir, kobj));
2821 }
2822
2823 static struct attribute *damon_sysfs_ui_dir_attrs[] = {
2824         NULL,
2825 };
2826 ATTRIBUTE_GROUPS(damon_sysfs_ui_dir);
2827
2828 static struct kobj_type damon_sysfs_ui_dir_ktype = {
2829         .release = damon_sysfs_ui_dir_release,
2830         .sysfs_ops = &kobj_sysfs_ops,
2831         .default_groups = damon_sysfs_ui_dir_groups,
2832 };
2833
2834 static int __init damon_sysfs_init(void)
2835 {
2836         struct kobject *damon_sysfs_root;
2837         struct damon_sysfs_ui_dir *admin;
2838         int err;
2839
2840         damon_sysfs_root = kobject_create_and_add("damon", mm_kobj);
2841         if (!damon_sysfs_root)
2842                 return -ENOMEM;
2843
2844         admin = damon_sysfs_ui_dir_alloc();
2845         if (!admin) {
2846                 kobject_put(damon_sysfs_root);
2847                 return -ENOMEM;
2848         }
2849         err = kobject_init_and_add(&admin->kobj, &damon_sysfs_ui_dir_ktype,
2850                         damon_sysfs_root, "admin");
2851         if (err)
2852                 goto out;
2853         err = damon_sysfs_ui_dir_add_dirs(admin);
2854         if (err)
2855                 goto out;
2856         return 0;
2857
2858 out:
2859         kobject_put(&admin->kobj);
2860         kobject_put(damon_sysfs_root);
2861         return err;
2862 }
2863 subsys_initcall(damon_sysfs_init);