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->fw_token == this_leaf->fw_token;
  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         int ct_idx;
  78
  79         ct_idx = get_cacheinfo_idx(this_leaf->type);
  80         propname = cache_type_info[ct_idx].size_prop;
  81
  82         of_property_read_u32(np, propname, &this_leaf->size);
  83 }
  84
  85 /* not cache_line_size() because that's a macro in include/linux/cache.h */
  86 static void cache_get_line_size(struct cacheinfo *this_leaf,
  87                                 struct device_node *np)
  88 {
  89         int i, lim, ct_idx;
  90
  91         ct_idx = get_cacheinfo_idx(this_leaf->type);
  92         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
  93
  94         for (i = 0; i < lim; i++) {
  95                 int ret;
  96                 u32 line_size;
  97                 const char *propname;
  98
  99                 propname = cache_type_info[ct_idx].line_size_props[i];
 100                 ret = of_property_read_u32(np, propname, &line_size);
 101                 if (!ret) {
 102                         this_leaf->coherency_line_size = line_size;
 103                         break;
 104                 }
 105         }
 106 }
 107
 108 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 109 {
 110         const char *propname;
 111         int ct_idx;
 112
 113         ct_idx = get_cacheinfo_idx(this_leaf->type);
 114         propname = cache_type_info[ct_idx].nr_sets_prop;
 115
 116         of_property_read_u32(np, propname, &this_leaf->number_of_sets);
 117 }
 118
 119 static void cache_associativity(struct cacheinfo *this_leaf)
 120 {
 121         unsigned int line_size = this_leaf->coherency_line_size;
 122         unsigned int nr_sets = this_leaf->number_of_sets;
 123         unsigned int size = this_leaf->size;
 124
 125         /*
 126          * If the cache is fully associative, there is no need to
 127          * check the other properties.
 128          */
 129         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 130                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 131 }
 132
 133 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 134                                   struct device_node *np)
 135 {
 136         return of_property_read_bool(np, "cache-unified");
 137 }
 138
 139 static void cache_of_set_props(struct cacheinfo *this_leaf,
 140                                struct device_node *np)
 141 {
 142         /*
 143          * init_cache_level must setup the cache level correctly
 144          * overriding the architecturally specified levels, so
 145          * if type is NONE at this stage, it should be unified
 146          */
 147         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 148             cache_node_is_unified(this_leaf, np))
 149                 this_leaf->type = CACHE_TYPE_UNIFIED;
 150         cache_size(this_leaf, np);
 151         cache_get_line_size(this_leaf, np);
 152         cache_nr_sets(this_leaf, np);
 153         cache_associativity(this_leaf);
 154 }
 155
 156 static int cache_setup_of_node(unsigned int cpu)
 157 {
 158         struct device_node *np;
 159         struct cacheinfo *this_leaf;
 160         struct device *cpu_dev = get_cpu_device(cpu);
 161         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 162         unsigned int index = 0;
 163
 164         /* skip if fw_token is already populated */
 165         if (this_cpu_ci->info_list->fw_token) {
 166                 return 0;
 167         }
 168
 169         if (!cpu_dev) {
 170                 pr_err("No cpu device for CPU %d\n", cpu);
 171                 return -ENODEV;
 172         }
 173         np = cpu_dev->of_node;
 174         if (!np) {
 175                 pr_err("Failed to find cpu%d device node\n", cpu);
 176                 return -ENOENT;
 177         }
 178
 179         while (index < cache_leaves(cpu)) {
 180                 this_leaf = this_cpu_ci->info_list + index;
 181                 if (this_leaf->level != 1)
 182                         np = of_find_next_cache_node(np);
 183                 else
 184                         np = of_node_get(np);/* cpu node itself */
 185                 if (!np)
 186                         break;
 187                 cache_of_set_props(this_leaf, np);
 188                 this_leaf->fw_token = np;
 189                 index++;
 190         }
 191
 192         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 193                 return -ENOENT;
 194
 195         return 0;
 196 }
 197 #else
 198 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 199 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 200                                            struct cacheinfo *sib_leaf)
 201 {
 202         /*
 203          * For non-DT/ACPI systems, assume unique level 1 caches, system-wide
 204          * shared caches for all other levels. This will be used only if
 205          * arch specific code has not populated shared_cpu_map
 206          */
 207         return !(this_leaf->level == 1);
 208 }
 209 #endif
 210
 211 int __weak cache_setup_acpi(unsigned int cpu)
 212 {
 213         return -ENOTSUPP;
 214 }
 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                 ret = cache_setup_acpi(cpu);
 230
 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                 if (of_have_populated_dt())
 282                         of_node_put(this_leaf->fw_token);
 283         }
 284 }
 285
 286 static void free_cache_attributes(unsigned int cpu)
 287 {
 288         if (!per_cpu_cacheinfo(cpu))
 289                 return;
 290
 291         cache_shared_cpu_map_remove(cpu);
 292
 293         kfree(per_cpu_cacheinfo(cpu));
 294         per_cpu_cacheinfo(cpu) = NULL;
 295 }
 296
 297 int __weak init_cache_level(unsigned int cpu)
 298 {
 299         return -ENOENT;
 300 }
 301
 302 int __weak populate_cache_leaves(unsigned int cpu)
 303 {
 304         return -ENOENT;
 305 }
 306
 307 static int detect_cache_attributes(unsigned int cpu)
 308 {
 309         int ret;
 310
 311         if (init_cache_level(cpu) || !cache_leaves(cpu))
 312                 return -ENOENT;
 313
 314         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 315                                          sizeof(struct cacheinfo), GFP_KERNEL);
 316         if (per_cpu_cacheinfo(cpu) == NULL)
 317                 return -ENOMEM;
 318
 319         /*
 320          * populate_cache_leaves() may completely setup the cache leaves and
 321          * shared_cpu_map or it may leave it partially setup.
 322          */
 323         ret = populate_cache_leaves(cpu);
 324         if (ret)
 325                 goto free_ci;
 326         /*
 327          * For systems using DT for cache hierarchy, fw_token
 328          * and shared_cpu_map will be set up here only if they are
 329          * not populated already
 330          */
 331         ret = cache_shared_cpu_map_setup(cpu);
 332         if (ret) {
 333                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 334                 goto free_ci;
 335         }
 336
 337         return 0;
 338
 339 free_ci:
 340         free_cache_attributes(cpu);
 341         return ret;
 342 }
 343
 344 /* pointer to cpuX/cache device */
 345 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 346 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 347
 348 static cpumask_t cache_dev_map;
 349
 350 /* pointer to array of devices for cpuX/cache/indexY */
 351 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 352 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 353 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 354
 355 #define show_one(file_name, object)                             \
 356 static ssize_t file_name##_show(struct device *dev,             \
 357                 struct device_attribute *attr, char *buf)       \
 358 {                                                               \
 359         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 360         return sprintf(buf, "%u\n", this_leaf->object);         \
 361 }
 362
 363 show_one(id, id);
 364 show_one(level, level);
 365 show_one(coherency_line_size, coherency_line_size);
 366 show_one(number_of_sets, number_of_sets);
 367 show_one(physical_line_partition, physical_line_partition);
 368 show_one(ways_of_associativity, ways_of_associativity);
 369
 370 static ssize_t size_show(struct device *dev,
 371                          struct device_attribute *attr, char *buf)
 372 {
 373         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 374
 375         return sprintf(buf, "%uK\n", this_leaf->size >> 10);
 376 }
 377
 378 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
 379 {
 380         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 381         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 382
 383         return cpumap_print_to_pagebuf(list, buf, mask);
 384 }
 385
 386 static ssize_t shared_cpu_map_show(struct device *dev,
 387                                    struct device_attribute *attr, char *buf)
 388 {
 389         return shared_cpumap_show_func(dev, false, buf);
 390 }
 391
 392 static ssize_t shared_cpu_list_show(struct device *dev,
 393                                     struct device_attribute *attr, char *buf)
 394 {
 395         return shared_cpumap_show_func(dev, true, buf);
 396 }
 397
 398 static ssize_t type_show(struct device *dev,
 399                          struct device_attribute *attr, char *buf)
 400 {
 401         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 402
 403         switch (this_leaf->type) {
 404         case CACHE_TYPE_DATA:
 405                 return sprintf(buf, "Data\n");
 406         case CACHE_TYPE_INST:
 407                 return sprintf(buf, "Instruction\n");
 408         case CACHE_TYPE_UNIFIED:
 409                 return sprintf(buf, "Unified\n");
 410         default:
 411                 return -EINVAL;
 412         }
 413 }
 414
 415 static ssize_t allocation_policy_show(struct device *dev,
 416                                       struct device_attribute *attr, char *buf)
 417 {
 418         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 419         unsigned int ci_attr = this_leaf->attributes;
 420         int n = 0;
 421
 422         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 423                 n = sprintf(buf, "ReadWriteAllocate\n");
 424         else if (ci_attr & CACHE_READ_ALLOCATE)
 425                 n = sprintf(buf, "ReadAllocate\n");
 426         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 427                 n = sprintf(buf, "WriteAllocate\n");
 428         return n;
 429 }
 430
 431 static ssize_t write_policy_show(struct device *dev,
 432                                  struct device_attribute *attr, char *buf)
 433 {
 434         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 435         unsigned int ci_attr = this_leaf->attributes;
 436         int n = 0;
 437
 438         if (ci_attr & CACHE_WRITE_THROUGH)
 439                 n = sprintf(buf, "WriteThrough\n");
 440         else if (ci_attr & CACHE_WRITE_BACK)
 441                 n = sprintf(buf, "WriteBack\n");
 442         return n;
 443 }
 444
 445 static DEVICE_ATTR_RO(id);
 446 static DEVICE_ATTR_RO(level);
 447 static DEVICE_ATTR_RO(type);
 448 static DEVICE_ATTR_RO(coherency_line_size);
 449 static DEVICE_ATTR_RO(ways_of_associativity);
 450 static DEVICE_ATTR_RO(number_of_sets);
 451 static DEVICE_ATTR_RO(size);
 452 static DEVICE_ATTR_RO(allocation_policy);
 453 static DEVICE_ATTR_RO(write_policy);
 454 static DEVICE_ATTR_RO(shared_cpu_map);
 455 static DEVICE_ATTR_RO(shared_cpu_list);
 456 static DEVICE_ATTR_RO(physical_line_partition);
 457
 458 static struct attribute *cache_default_attrs[] = {
 459         &dev_attr_id.attr,
 460         &dev_attr_type.attr,
 461         &dev_attr_level.attr,
 462         &dev_attr_shared_cpu_map.attr,
 463         &dev_attr_shared_cpu_list.attr,
 464         &dev_attr_coherency_line_size.attr,
 465         &dev_attr_ways_of_associativity.attr,
 466         &dev_attr_number_of_sets.attr,
 467         &dev_attr_size.attr,
 468         &dev_attr_allocation_policy.attr,
 469         &dev_attr_write_policy.attr,
 470         &dev_attr_physical_line_partition.attr,
 471         NULL
 472 };
 473
 474 static umode_t
 475 cache_default_attrs_is_visible(struct kobject *kobj,
 476                                struct attribute *attr, int unused)
 477 {
 478         struct device *dev = kobj_to_dev(kobj);
 479         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 480         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 481         umode_t mode = attr->mode;
 482
 483         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 484                 return mode;
 485         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 486                 return mode;
 487         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 488                 return mode;
 489         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 490                 return mode;
 491         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 492                 return mode;
 493         if ((attr == &dev_attr_coherency_line_size.attr) &&
 494             this_leaf->coherency_line_size)
 495                 return mode;
 496         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 497             this_leaf->size) /* allow 0 = full associativity */
 498                 return mode;
 499         if ((attr == &dev_attr_number_of_sets.attr) &&
 500             this_leaf->number_of_sets)
 501                 return mode;
 502         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 503                 return mode;
 504         if ((attr == &dev_attr_write_policy.attr) &&
 505             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 506                 return mode;
 507         if ((attr == &dev_attr_allocation_policy.attr) &&
 508             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 509                 return mode;
 510         if ((attr == &dev_attr_physical_line_partition.attr) &&
 511             this_leaf->physical_line_partition)
 512                 return mode;
 513
 514         return 0;
 515 }
 516
 517 static const struct attribute_group cache_default_group = {
 518         .attrs = cache_default_attrs,
 519         .is_visible = cache_default_attrs_is_visible,
 520 };
 521
 522 static const struct attribute_group *cache_default_groups[] = {
 523         &cache_default_group,
 524         NULL,
 525 };
 526
 527 static const struct attribute_group *cache_private_groups[] = {
 528         &cache_default_group,
 529         NULL, /* Place holder for private group */
 530         NULL,
 531 };
 532
 533 const struct attribute_group *
 534 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 535 {
 536         return NULL;
 537 }
 538
 539 static const struct attribute_group **
 540 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 541 {
 542         const struct attribute_group *priv_group =
 543                         cache_get_priv_group(this_leaf);
 544
 545         if (!priv_group)
 546                 return cache_default_groups;
 547
 548         if (!cache_private_groups[1])
 549                 cache_private_groups[1] = priv_group;
 550
 551         return cache_private_groups;
 552 }
 553
 554 /* Add/Remove cache interface for CPU device */
 555 static void cpu_cache_sysfs_exit(unsigned int cpu)
 556 {
 557         int i;
 558         struct device *ci_dev;
 559
 560         if (per_cpu_index_dev(cpu)) {
 561                 for (i = 0; i < cache_leaves(cpu); i++) {
 562                         ci_dev = per_cache_index_dev(cpu, i);
 563                         if (!ci_dev)
 564                                 continue;
 565                         device_unregister(ci_dev);
 566                 }
 567                 kfree(per_cpu_index_dev(cpu));
 568                 per_cpu_index_dev(cpu) = NULL;
 569         }
 570         device_unregister(per_cpu_cache_dev(cpu));
 571         per_cpu_cache_dev(cpu) = NULL;
 572 }
 573
 574 static int cpu_cache_sysfs_init(unsigned int cpu)
 575 {
 576         struct device *dev = get_cpu_device(cpu);
 577
 578         if (per_cpu_cacheinfo(cpu) == NULL)
 579                 return -ENOENT;
 580
 581         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 582         if (IS_ERR(per_cpu_cache_dev(cpu)))
 583                 return PTR_ERR(per_cpu_cache_dev(cpu));
 584
 585         /* Allocate all required memory */
 586         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 587                                          sizeof(struct device *), GFP_KERNEL);
 588         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 589                 goto err_out;
 590
 591         return 0;
 592
 593 err_out:
 594         cpu_cache_sysfs_exit(cpu);
 595         return -ENOMEM;
 596 }
 597
 598 static int cache_add_dev(unsigned int cpu)
 599 {
 600         unsigned int i;
 601         int rc;
 602         struct device *ci_dev, *parent;
 603         struct cacheinfo *this_leaf;
 604         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 605         const struct attribute_group **cache_groups;
 606
 607         rc = cpu_cache_sysfs_init(cpu);
 608         if (unlikely(rc < 0))
 609                 return rc;
 610
 611         parent = per_cpu_cache_dev(cpu);
 612         for (i = 0; i < cache_leaves(cpu); i++) {
 613                 this_leaf = this_cpu_ci->info_list + i;
 614                 if (this_leaf->disable_sysfs)
 615                         continue;
 616                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
 617                         break;
 618                 cache_groups = cache_get_attribute_groups(this_leaf);
 619                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 620                                            "index%1u", i);
 621                 if (IS_ERR(ci_dev)) {
 622                         rc = PTR_ERR(ci_dev);
 623                         goto err;
 624                 }
 625                 per_cache_index_dev(cpu, i) = ci_dev;
 626         }
 627         cpumask_set_cpu(cpu, &cache_dev_map);
 628
 629         return 0;
 630 err:
 631         cpu_cache_sysfs_exit(cpu);
 632         return rc;
 633 }
 634
 635 static int cacheinfo_cpu_online(unsigned int cpu)
 636 {
 637         int rc = detect_cache_attributes(cpu);
 638
 639         if (rc)
 640                 return rc;
 641         rc = cache_add_dev(cpu);
 642         if (rc)
 643                 free_cache_attributes(cpu);
 644         return rc;
 645 }
 646
 647 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 648 {
 649         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 650                 cpu_cache_sysfs_exit(cpu);
 651
 652         free_cache_attributes(cpu);
 653         return 0;
 654 }
 655
 656 static int __init cacheinfo_sysfs_init(void)
 657 {
 658         return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
 659                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 660 }
 661 device_initcall(cacheinfo_sysfs_init);