drivers/base/cacheinfo.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * cacheinfo support - processor cache information via sysfs
   4  *
   5  * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
   6  * Author: Sudeep Holla <sudeep.holla@arm.com>
   7  */
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/acpi.h>
  11 #include <linux/bitops.h>
  12 #include <linux/cacheinfo.h>
  13 #include <linux/compiler.h>
  14 #include <linux/cpu.h>
  15 #include <linux/device.h>
  16 #include <linux/init.h>
  17 #include <linux/of.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/smp.h>
  21 #include <linux/sysfs.h>
  22
  23 /* pointer to per cpu cacheinfo */
  24 static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
  25 #define ci_cacheinfo(cpu)       (&per_cpu(ci_cpu_cacheinfo, cpu))
  26 #define cache_leaves(cpu)       (ci_cacheinfo(cpu)->num_leaves)
  27 #define per_cpu_cacheinfo(cpu)  (ci_cacheinfo(cpu)->info_list)
  28
  29 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
  30 {
  31         return ci_cacheinfo(cpu);
  32 }
  33
  34 #ifdef CONFIG_OF
  35 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
  36                                            struct cacheinfo *sib_leaf)
  37 {
  38         return sib_leaf->of_node == this_leaf->of_node;
  39 }
  40
  41 /* OF properties to query for a given cache type */
  42 struct cache_type_info {
  43         const char *size_prop;
  44         const char *line_size_props[2];
  45         const char *nr_sets_prop;
  46 };
  47
  48 static const struct cache_type_info cache_type_info[] = {
  49         {
  50                 .size_prop       = "cache-size",
  51                 .line_size_props = { "cache-line-size",
  52                                      "cache-block-size", },
  53                 .nr_sets_prop    = "cache-sets",
  54         }, {
  55                 .size_prop       = "i-cache-size",
  56                 .line_size_props = { "i-cache-line-size",
  57                                      "i-cache-block-size", },
  58                 .nr_sets_prop    = "i-cache-sets",
  59         }, {
  60                 .size_prop       = "d-cache-size",
  61                 .line_size_props = { "d-cache-line-size",
  62                                      "d-cache-block-size", },
  63                 .nr_sets_prop    = "d-cache-sets",
  64         },
  65 };
  66
  67 static inline int get_cacheinfo_idx(enum cache_type type)
  68 {
  69         if (type == CACHE_TYPE_UNIFIED)
  70                 return 0;
  71         return type;
  72 }
  73
  74 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
  75 {
  76         const char *propname;
  77         const __be32 *cache_size;
  78         int ct_idx;
  79
  80         ct_idx = get_cacheinfo_idx(this_leaf->type);
  81         propname = cache_type_info[ct_idx].size_prop;
  82
  83         cache_size = of_get_property(np, propname, NULL);
  84         if (cache_size)
  85                 this_leaf->size = of_read_number(cache_size, 1);
  86 }
  87
  88 /* not cache_line_size() because that's a macro in include/linux/cache.h */
  89 static void cache_get_line_size(struct cacheinfo *this_leaf,
  90                                 struct device_node *np)
  91 {
  92         const __be32 *line_size;
  93         int i, lim, ct_idx;
  94
  95         ct_idx = get_cacheinfo_idx(this_leaf->type);
  96         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
  97
  98         for (i = 0; i < lim; i++) {
  99                 const char *propname;
 100
 101                 propname = cache_type_info[ct_idx].line_size_props[i];
 102                 line_size = of_get_property(np, propname, NULL);
 103                 if (line_size)
 104                         break;
 105         }
 106
 107         if (line_size)
 108                 this_leaf->coherency_line_size = of_read_number(line_size, 1);
 109 }
 110
 111 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 112 {
 113         const char *propname;
 114         const __be32 *nr_sets;
 115         int ct_idx;
 116
 117         ct_idx = get_cacheinfo_idx(this_leaf->type);
 118         propname = cache_type_info[ct_idx].nr_sets_prop;
 119
 120         nr_sets = of_get_property(np, propname, NULL);
 121         if (nr_sets)
 122                 this_leaf->number_of_sets = of_read_number(nr_sets, 1);
 123 }
 124
 125 static void cache_associativity(struct cacheinfo *this_leaf)
 126 {
 127         unsigned int line_size = this_leaf->coherency_line_size;
 128         unsigned int nr_sets = this_leaf->number_of_sets;
 129         unsigned int size = this_leaf->size;
 130
 131         /*
 132          * If the cache is fully associative, there is no need to
 133          * check the other properties.
 134          */
 135         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 136                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 137 }
 138
 139 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 140                                   struct device_node *np)
 141 {
 142         return of_property_read_bool(np, "cache-unified");
 143 }
 144
 145 static void cache_of_set_props(struct cacheinfo *this_leaf,
 146                                struct device_node *np)
 147 {
 148         /*
 149          * init_cache_level must setup the cache level correctly
 150          * overriding the architecturally specified levels, so
 151          * if type is NONE at this stage, it should be unified
 152          */
 153         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 154             cache_node_is_unified(this_leaf, np))
 155                 this_leaf->type = CACHE_TYPE_UNIFIED;
 156         cache_size(this_leaf, np);
 157         cache_get_line_size(this_leaf, np);
 158         cache_nr_sets(this_leaf, np);
 159         cache_associativity(this_leaf);
 160 }
 161
 162 static int cache_setup_of_node(unsigned int cpu)
 163 {
 164         struct device_node *np;
 165         struct cacheinfo *this_leaf;
 166         struct device *cpu_dev = get_cpu_device(cpu);
 167         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 168         unsigned int index = 0;
 169
 170         /* skip if of_node is already populated */
 171         if (this_cpu_ci->info_list->of_node)
 172                 return 0;
 173
 174         if (!cpu_dev) {
 175                 pr_err("No cpu device for CPU %d\n", cpu);
 176                 return -ENODEV;
 177         }
 178         np = cpu_dev->of_node;
 179         if (!np) {
 180                 pr_err("Failed to find cpu%d device node\n", cpu);
 181                 return -ENOENT;
 182         }
 183
 184         while (index < cache_leaves(cpu)) {
 185                 this_leaf = this_cpu_ci->info_list + index;
 186                 if (this_leaf->level != 1)
 187                         np = of_find_next_cache_node(np);
 188                 else
 189                         np = of_node_get(np);/* cpu node itself */
 190                 if (!np)
 191                         break;
 192                 cache_of_set_props(this_leaf, np);
 193                 this_leaf->of_node = np;
 194                 index++;
 195         }
 196
 197         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 198                 return -ENOENT;
 199
 200         return 0;
 201 }
 202 #else
 203 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 204 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 205                                            struct cacheinfo *sib_leaf)
 206 {
 207         /*
 208          * For non-DT systems, assume unique level 1 cache, system-wide
 209          * shared caches for all other levels. This will be used only if
 210          * arch specific code has not populated shared_cpu_map
 211          */
 212         return !(this_leaf->level == 1);
 213 }
 214 #endif
 215
 216 static int cache_shared_cpu_map_setup(unsigned int cpu)
 217 {
 218         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 219         struct cacheinfo *this_leaf, *sib_leaf;
 220         unsigned int index;
 221         int ret = 0;
 222
 223         if (this_cpu_ci->cpu_map_populated)
 224                 return 0;
 225
 226         if (of_have_populated_dt())
 227                 ret = cache_setup_of_node(cpu);
 228         else if (!acpi_disabled)
 229                 /* No cache property/hierarchy support yet in ACPI */
 230                 ret = -ENOTSUPP;
 231         if (ret)
 232                 return ret;
 233
 234         for (index = 0; index < cache_leaves(cpu); index++) {
 235                 unsigned int i;
 236
 237                 this_leaf = this_cpu_ci->info_list + index;
 238                 /* skip if shared_cpu_map is already populated */
 239                 if (!cpumask_empty(&this_leaf->shared_cpu_map))
 240                         continue;
 241
 242                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 243                 for_each_online_cpu(i) {
 244                         struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
 245
 246                         if (i == cpu || !sib_cpu_ci->info_list)
 247                                 continue;/* skip if itself or no cacheinfo */
 248                         sib_leaf = sib_cpu_ci->info_list + index;
 249                         if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 250                                 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 251                                 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
 252                         }
 253                 }
 254         }
 255
 256         return 0;
 257 }
 258
 259 static void cache_shared_cpu_map_remove(unsigned int cpu)
 260 {
 261         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 262         struct cacheinfo *this_leaf, *sib_leaf;
 263         unsigned int sibling, index;
 264
 265         for (index = 0; index < cache_leaves(cpu); index++) {
 266                 this_leaf = this_cpu_ci->info_list + index;
 267                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 268                         struct cpu_cacheinfo *sib_cpu_ci;
 269
 270                         if (sibling == cpu) /* skip itself */
 271                                 continue;
 272
 273                         sib_cpu_ci = get_cpu_cacheinfo(sibling);
 274                         if (!sib_cpu_ci->info_list)
 275                                 continue;
 276
 277                         sib_leaf = sib_cpu_ci->info_list + index;
 278                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 279                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 280                 }
 281                 of_node_put(this_leaf->of_node);
 282         }
 283 }
 284
 285 static void free_cache_attributes(unsigned int cpu)
 286 {
 287         if (!per_cpu_cacheinfo(cpu))
 288                 return;
 289
 290         cache_shared_cpu_map_remove(cpu);
 291
 292         kfree(per_cpu_cacheinfo(cpu));
 293         per_cpu_cacheinfo(cpu) = NULL;
 294 }
 295
 296 int __weak init_cache_level(unsigned int cpu)
 297 {
 298         return -ENOENT;
 299 }
 300
 301 int __weak populate_cache_leaves(unsigned int cpu)
 302 {
 303         return -ENOENT;
 304 }
 305
 306 static int detect_cache_attributes(unsigned int cpu)
 307 {
 308         int ret;
 309
 310         if (init_cache_level(cpu) || !cache_leaves(cpu))
 311                 return -ENOENT;
 312
 313         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 314                                          sizeof(struct cacheinfo), GFP_KERNEL);
 315         if (per_cpu_cacheinfo(cpu) == NULL)
 316                 return -ENOMEM;
 317
 318         /*
 319          * populate_cache_leaves() may completely setup the cache leaves and
 320          * shared_cpu_map or it may leave it partially setup.
 321          */
 322         ret = populate_cache_leaves(cpu);
 323         if (ret)
 324                 goto free_ci;
 325         /*
 326          * For systems using DT for cache hierarchy, of_node and shared_cpu_map
 327          * will be set up here only if they are not populated already
 328          */
 329         ret = cache_shared_cpu_map_setup(cpu);
 330         if (ret) {
 331                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 332                 goto free_ci;
 333         }
 334
 335         return 0;
 336
 337 free_ci:
 338         free_cache_attributes(cpu);
 339         return ret;
 340 }
 341
 342 /* pointer to cpuX/cache device */
 343 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 344 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 345
 346 static cpumask_t cache_dev_map;
 347
 348 /* pointer to array of devices for cpuX/cache/indexY */
 349 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 350 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 351 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 352
 353 #define show_one(file_name, object)                             \
 354 static ssize_t file_name##_show(struct device *dev,             \
 355                 struct device_attribute *attr, char *buf)       \
 356 {                                                               \
 357         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 358         return sprintf(buf, "%u\n", this_leaf->object);         \
 359 }
 360
 361 show_one(id, id);
 362 show_one(level, level);
 363 show_one(coherency_line_size, coherency_line_size);
 364 show_one(number_of_sets, number_of_sets);
 365 show_one(physical_line_partition, physical_line_partition);
 366 show_one(ways_of_associativity, ways_of_associativity);
 367
 368 static ssize_t size_show(struct device *dev,
 369                          struct device_attribute *attr, char *buf)
 370 {
 371         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 372
 373         return sprintf(buf, "%uK\n", this_leaf->size >> 10);
 374 }
 375
 376 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
 377 {
 378         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 379         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 380
 381         return cpumap_print_to_pagebuf(list, buf, mask);
 382 }
 383
 384 static ssize_t shared_cpu_map_show(struct device *dev,
 385                                    struct device_attribute *attr, char *buf)
 386 {
 387         return shared_cpumap_show_func(dev, false, buf);
 388 }
 389
 390 static ssize_t shared_cpu_list_show(struct device *dev,
 391                                     struct device_attribute *attr, char *buf)
 392 {
 393         return shared_cpumap_show_func(dev, true, buf);
 394 }
 395
 396 static ssize_t type_show(struct device *dev,
 397                          struct device_attribute *attr, char *buf)
 398 {
 399         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 400
 401         switch (this_leaf->type) {
 402         case CACHE_TYPE_DATA:
 403                 return sprintf(buf, "Data\n");
 404         case CACHE_TYPE_INST:
 405                 return sprintf(buf, "Instruction\n");
 406         case CACHE_TYPE_UNIFIED:
 407                 return sprintf(buf, "Unified\n");
 408         default:
 409                 return -EINVAL;
 410         }
 411 }
 412
 413 static ssize_t allocation_policy_show(struct device *dev,
 414                                       struct device_attribute *attr, char *buf)
 415 {
 416         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 417         unsigned int ci_attr = this_leaf->attributes;
 418         int n = 0;
 419
 420         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 421                 n = sprintf(buf, "ReadWriteAllocate\n");
 422         else if (ci_attr & CACHE_READ_ALLOCATE)
 423                 n = sprintf(buf, "ReadAllocate\n");
 424         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 425                 n = sprintf(buf, "WriteAllocate\n");
 426         return n;
 427 }
 428
 429 static ssize_t write_policy_show(struct device *dev,
 430                                  struct device_attribute *attr, char *buf)
 431 {
 432         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 433         unsigned int ci_attr = this_leaf->attributes;
 434         int n = 0;
 435
 436         if (ci_attr & CACHE_WRITE_THROUGH)
 437                 n = sprintf(buf, "WriteThrough\n");
 438         else if (ci_attr & CACHE_WRITE_BACK)
 439                 n = sprintf(buf, "WriteBack\n");
 440         return n;
 441 }
 442
 443 static DEVICE_ATTR_RO(id);
 444 static DEVICE_ATTR_RO(level);
 445 static DEVICE_ATTR_RO(type);
 446 static DEVICE_ATTR_RO(coherency_line_size);
 447 static DEVICE_ATTR_RO(ways_of_associativity);
 448 static DEVICE_ATTR_RO(number_of_sets);
 449 static DEVICE_ATTR_RO(size);
 450 static DEVICE_ATTR_RO(allocation_policy);
 451 static DEVICE_ATTR_RO(write_policy);
 452 static DEVICE_ATTR_RO(shared_cpu_map);
 453 static DEVICE_ATTR_RO(shared_cpu_list);
 454 static DEVICE_ATTR_RO(physical_line_partition);
 455
 456 static struct attribute *cache_default_attrs[] = {
 457         &dev_attr_id.attr,
 458         &dev_attr_type.attr,
 459         &dev_attr_level.attr,
 460         &dev_attr_shared_cpu_map.attr,
 461         &dev_attr_shared_cpu_list.attr,
 462         &dev_attr_coherency_line_size.attr,
 463         &dev_attr_ways_of_associativity.attr,
 464         &dev_attr_number_of_sets.attr,
 465         &dev_attr_size.attr,
 466         &dev_attr_allocation_policy.attr,
 467         &dev_attr_write_policy.attr,
 468         &dev_attr_physical_line_partition.attr,
 469         NULL
 470 };
 471
 472 static umode_t
 473 cache_default_attrs_is_visible(struct kobject *kobj,
 474                                struct attribute *attr, int unused)
 475 {
 476         struct device *dev = kobj_to_dev(kobj);
 477         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 478         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 479         umode_t mode = attr->mode;
 480
 481         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 482                 return mode;
 483         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 484                 return mode;
 485         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 486                 return mode;
 487         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 488                 return mode;
 489         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 490                 return mode;
 491         if ((attr == &dev_attr_coherency_line_size.attr) &&
 492             this_leaf->coherency_line_size)
 493                 return mode;
 494         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 495             this_leaf->size) /* allow 0 = full associativity */
 496                 return mode;
 497         if ((attr == &dev_attr_number_of_sets.attr) &&
 498             this_leaf->number_of_sets)
 499                 return mode;
 500         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 501                 return mode;
 502         if ((attr == &dev_attr_write_policy.attr) &&
 503             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 504                 return mode;
 505         if ((attr == &dev_attr_allocation_policy.attr) &&
 506             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 507                 return mode;
 508         if ((attr == &dev_attr_physical_line_partition.attr) &&
 509             this_leaf->physical_line_partition)
 510                 return mode;
 511
 512         return 0;
 513 }
 514
 515 static const struct attribute_group cache_default_group = {
 516         .attrs = cache_default_attrs,
 517         .is_visible = cache_default_attrs_is_visible,
 518 };
 519
 520 static const struct attribute_group *cache_default_groups[] = {
 521         &cache_default_group,
 522         NULL,
 523 };
 524
 525 static const struct attribute_group *cache_private_groups[] = {
 526         &cache_default_group,
 527         NULL, /* Place holder for private group */
 528         NULL,
 529 };
 530
 531 const struct attribute_group *
 532 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 533 {
 534         return NULL;
 535 }
 536
 537 static const struct attribute_group **
 538 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 539 {
 540         const struct attribute_group *priv_group =
 541                         cache_get_priv_group(this_leaf);
 542
 543         if (!priv_group)
 544                 return cache_default_groups;
 545
 546         if (!cache_private_groups[1])
 547                 cache_private_groups[1] = priv_group;
 548
 549         return cache_private_groups;
 550 }
 551
 552 /* Add/Remove cache interface for CPU device */
 553 static void cpu_cache_sysfs_exit(unsigned int cpu)
 554 {
 555         int i;
 556         struct device *ci_dev;
 557
 558         if (per_cpu_index_dev(cpu)) {
 559                 for (i = 0; i < cache_leaves(cpu); i++) {
 560                         ci_dev = per_cache_index_dev(cpu, i);
 561                         if (!ci_dev)
 562                                 continue;
 563                         device_unregister(ci_dev);
 564                 }
 565                 kfree(per_cpu_index_dev(cpu));
 566                 per_cpu_index_dev(cpu) = NULL;
 567         }
 568         device_unregister(per_cpu_cache_dev(cpu));
 569         per_cpu_cache_dev(cpu) = NULL;
 570 }
 571
 572 static int cpu_cache_sysfs_init(unsigned int cpu)
 573 {
 574         struct device *dev = get_cpu_device(cpu);
 575
 576         if (per_cpu_cacheinfo(cpu) == NULL)
 577                 return -ENOENT;
 578
 579         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 580         if (IS_ERR(per_cpu_cache_dev(cpu)))
 581                 return PTR_ERR(per_cpu_cache_dev(cpu));
 582
 583         /* Allocate all required memory */
 584         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 585                                          sizeof(struct device *), GFP_KERNEL);
 586         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 587                 goto err_out;
 588
 589         return 0;
 590
 591 err_out:
 592         cpu_cache_sysfs_exit(cpu);
 593         return -ENOMEM;
 594 }
 595
 596 static int cache_add_dev(unsigned int cpu)
 597 {
 598         unsigned int i;
 599         int rc;
 600         struct device *ci_dev, *parent;
 601         struct cacheinfo *this_leaf;
 602         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 603         const struct attribute_group **cache_groups;
 604
 605         rc = cpu_cache_sysfs_init(cpu);
 606         if (unlikely(rc < 0))
 607                 return rc;
 608
 609         parent = per_cpu_cache_dev(cpu);
 610         for (i = 0; i < cache_leaves(cpu); i++) {
 611                 this_leaf = this_cpu_ci->info_list + i;
 612                 if (this_leaf->disable_sysfs)
 613                         continue;
 614                 cache_groups = cache_get_attribute_groups(this_leaf);
 615                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 616                                            "index%1u", i);
 617                 if (IS_ERR(ci_dev)) {
 618                         rc = PTR_ERR(ci_dev);
 619                         goto err;
 620                 }
 621                 per_cache_index_dev(cpu, i) = ci_dev;
 622         }
 623         cpumask_set_cpu(cpu, &cache_dev_map);
 624
 625         return 0;
 626 err:
 627         cpu_cache_sysfs_exit(cpu);
 628         return rc;
 629 }
 630
 631 static int cacheinfo_cpu_online(unsigned int cpu)
 632 {
 633         int rc = detect_cache_attributes(cpu);
 634
 635         if (rc)
 636                 return rc;
 637         rc = cache_add_dev(cpu);
 638         if (rc)
 639                 free_cache_attributes(cpu);
 640         return rc;
 641 }
 642
 643 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 644 {
 645         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 646                 cpu_cache_sysfs_exit(cpu);
 647
 648         free_cache_attributes(cpu);
 649         return 0;
 650 }
 651
 652 static int __init cacheinfo_sysfs_init(void)
 653 {
 654         return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
 655                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 656 }
 657 device_initcall(cacheinfo_sysfs_init);