mm/damon/sysfs.c

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