drivers/base/cacheinfo.c

   1 /*
   2  * cacheinfo support - processor cache information via sysfs
   3  *
   4  * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
   5  * Author: Sudeep Holla <sudeep.holla@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  12  * kind, whether express or implied; without even the implied warranty
  13  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/acpi.h>
  22 #include <linux/bitops.h>
  23 #include <linux/cacheinfo.h>
  24 #include <linux/compiler.h>
  25 #include <linux/cpu.h>
  26 #include <linux/device.h>
  27 #include <linux/init.h>
  28 #include <linux/of.h>
  29 #include <linux/sched.h>
  30 #include <linux/slab.h>
  31 #include <linux/smp.h>
  32 #include <linux/sysfs.h>
  33
  34 /* pointer to per cpu cacheinfo */
  35 static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
  36 #define ci_cacheinfo(cpu)       (&per_cpu(ci_cpu_cacheinfo, cpu))
  37 #define cache_leaves(cpu)       (ci_cacheinfo(cpu)->num_leaves)
  38 #define per_cpu_cacheinfo(cpu)  (ci_cacheinfo(cpu)->info_list)
  39
  40 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
  41 {
  42         return ci_cacheinfo(cpu);
  43 }
  44
  45 #ifdef CONFIG_OF
  46 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
  47                                            struct cacheinfo *sib_leaf)
  48 {
  49         return sib_leaf->fw_token == this_leaf->fw_token;
  50 }
  51
  52 /* OF properties to query for a given cache type */
  53 struct cache_type_info {
  54         const char *size_prop;
  55         const char *line_size_props[2];
  56         const char *nr_sets_prop;
  57 };
  58
  59 static const struct cache_type_info cache_type_info[] = {
  60         {
  61                 .size_prop       = "cache-size",
  62                 .line_size_props = { "cache-line-size",
  63                                      "cache-block-size", },
  64                 .nr_sets_prop    = "cache-sets",
  65         }, {
  66                 .size_prop       = "i-cache-size",
  67                 .line_size_props = { "i-cache-line-size",
  68                                      "i-cache-block-size", },
  69                 .nr_sets_prop    = "i-cache-sets",
  70         }, {
  71                 .size_prop       = "d-cache-size",
  72                 .line_size_props = { "d-cache-line-size",
  73                                      "d-cache-block-size", },
  74                 .nr_sets_prop    = "d-cache-sets",
  75         },
  76 };
  77
  78 static inline int get_cacheinfo_idx(enum cache_type type)
  79 {
  80         if (type == CACHE_TYPE_UNIFIED)
  81                 return 0;
  82         return type;
  83 }
  84
  85 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
  86 {
  87         const char *propname;
  88         const __be32 *cache_size;
  89         int ct_idx;
  90
  91         ct_idx = get_cacheinfo_idx(this_leaf->type);
  92         propname = cache_type_info[ct_idx].size_prop;
  93
  94         cache_size = of_get_property(np, propname, NULL);
  95         if (cache_size)
  96                 this_leaf->size = of_read_number(cache_size, 1);
  97 }
  98
  99 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 100 static void cache_get_line_size(struct cacheinfo *this_leaf,
 101                                 struct device_node *np)
 102 {
 103         const __be32 *line_size;
 104         int i, lim, ct_idx;
 105
 106         ct_idx = get_cacheinfo_idx(this_leaf->type);
 107         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
 108
 109         for (i = 0; i < lim; i++) {
 110                 const char *propname;
 111
 112                 propname = cache_type_info[ct_idx].line_size_props[i];
 113                 line_size = of_get_property(np, propname, NULL);
 114                 if (line_size)
 115                         break;
 116         }
 117
 118         if (line_size)
 119                 this_leaf->coherency_line_size = of_read_number(line_size, 1);
 120 }
 121
 122 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 123 {
 124         const char *propname;
 125         const __be32 *nr_sets;
 126         int ct_idx;
 127
 128         ct_idx = get_cacheinfo_idx(this_leaf->type);
 129         propname = cache_type_info[ct_idx].nr_sets_prop;
 130
 131         nr_sets = of_get_property(np, propname, NULL);
 132         if (nr_sets)
 133                 this_leaf->number_of_sets = of_read_number(nr_sets, 1);
 134 }
 135
 136 static void cache_associativity(struct cacheinfo *this_leaf)
 137 {
 138         unsigned int line_size = this_leaf->coherency_line_size;
 139         unsigned int nr_sets = this_leaf->number_of_sets;
 140         unsigned int size = this_leaf->size;
 141
 142         /*
 143          * If the cache is fully associative, there is no need to
 144          * check the other properties.
 145          */
 146         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 147                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 148 }
 149
 150 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 151                                   struct device_node *np)
 152 {
 153         return of_property_read_bool(np, "cache-unified");
 154 }
 155
 156 static void cache_of_set_props(struct cacheinfo *this_leaf,
 157                                struct device_node *np)
 158 {
 159         /*
 160          * init_cache_level must setup the cache level correctly
 161          * overriding the architecturally specified levels, so
 162          * if type is NONE at this stage, it should be unified
 163          */
 164         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 165             cache_node_is_unified(this_leaf, np))
 166                 this_leaf->type = CACHE_TYPE_UNIFIED;
 167         cache_size(this_leaf, np);
 168         cache_get_line_size(this_leaf, np);
 169         cache_nr_sets(this_leaf, np);
 170         cache_associativity(this_leaf);
 171 }
 172
 173 static int cache_setup_of_node(unsigned int cpu)
 174 {
 175         struct device_node *np;
 176         struct cacheinfo *this_leaf;
 177         struct device *cpu_dev = get_cpu_device(cpu);
 178         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 179         unsigned int index = 0;
 180
 181         /* skip if fw_token is already populated */
 182         if (this_cpu_ci->info_list->fw_token) {
 183                 return 0;
 184         }
 185
 186         if (!cpu_dev) {
 187                 pr_err("No cpu device for CPU %d\n", cpu);
 188                 return -ENODEV;
 189         }
 190         np = cpu_dev->of_node;
 191         if (!np) {
 192                 pr_err("Failed to find cpu%d device node\n", cpu);
 193                 return -ENOENT;
 194         }
 195
 196         while (index < cache_leaves(cpu)) {
 197                 this_leaf = this_cpu_ci->info_list + index;
 198                 if (this_leaf->level != 1)
 199                         np = of_find_next_cache_node(np);
 200                 else
 201                         np = of_node_get(np);/* cpu node itself */
 202                 if (!np)
 203                         break;
 204                 cache_of_set_props(this_leaf, np);
 205                 this_leaf->fw_token = np;
 206                 index++;
 207         }
 208
 209         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 210                 return -ENOENT;
 211
 212         return 0;
 213 }
 214 #else
 215 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 216 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 217                                            struct cacheinfo *sib_leaf)
 218 {
 219         /*
 220          * For non-DT/ACPI systems, assume unique level 1 caches, system-wide
 221          * shared caches for all other levels. This will be used only if
 222          * arch specific code has not populated shared_cpu_map
 223          */
 224         return !(this_leaf->level == 1);
 225 }
 226 #endif
 227
 228 int __weak cache_setup_acpi(unsigned int cpu)
 229 {
 230         return -ENOTSUPP;
 231 }
 232
 233 static int cache_shared_cpu_map_setup(unsigned int cpu)
 234 {
 235         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 236         struct cacheinfo *this_leaf, *sib_leaf;
 237         unsigned int index;
 238         int ret = 0;
 239
 240         if (this_cpu_ci->cpu_map_populated)
 241                 return 0;
 242
 243         if (of_have_populated_dt())
 244                 ret = cache_setup_of_node(cpu);
 245         else if (!acpi_disabled)
 246                 ret = cache_setup_acpi(cpu);
 247
 248         if (ret)
 249                 return ret;
 250
 251         for (index = 0; index < cache_leaves(cpu); index++) {
 252                 unsigned int i;
 253
 254                 this_leaf = this_cpu_ci->info_list + index;
 255                 /* skip if shared_cpu_map is already populated */
 256                 if (!cpumask_empty(&this_leaf->shared_cpu_map))
 257                         continue;
 258
 259                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 260                 for_each_online_cpu(i) {
 261                         struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
 262
 263                         if (i == cpu || !sib_cpu_ci->info_list)
 264                                 continue;/* skip if itself or no cacheinfo */
 265                         sib_leaf = sib_cpu_ci->info_list + index;
 266                         if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 267                                 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 268                                 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
 269                         }
 270                 }
 271         }
 272
 273         return 0;
 274 }
 275
 276 static void cache_shared_cpu_map_remove(unsigned int cpu)
 277 {
 278         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 279         struct cacheinfo *this_leaf, *sib_leaf;
 280         unsigned int sibling, index;
 281
 282         for (index = 0; index < cache_leaves(cpu); index++) {
 283                 this_leaf = this_cpu_ci->info_list + index;
 284                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 285                         struct cpu_cacheinfo *sib_cpu_ci;
 286
 287                         if (sibling == cpu) /* skip itself */
 288                                 continue;
 289
 290                         sib_cpu_ci = get_cpu_cacheinfo(sibling);
 291                         if (!sib_cpu_ci->info_list)
 292                                 continue;
 293
 294                         sib_leaf = sib_cpu_ci->info_list + index;
 295                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 296                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 297                 }
 298                 if (of_have_populated_dt())
 299                         of_node_put(this_leaf->fw_token);
 300         }
 301 }
 302
 303 static void free_cache_attributes(unsigned int cpu)
 304 {
 305         if (!per_cpu_cacheinfo(cpu))
 306                 return;
 307
 308         cache_shared_cpu_map_remove(cpu);
 309
 310         kfree(per_cpu_cacheinfo(cpu));
 311         per_cpu_cacheinfo(cpu) = NULL;
 312 }
 313
 314 int __weak init_cache_level(unsigned int cpu)
 315 {
 316         return -ENOENT;
 317 }
 318
 319 int __weak populate_cache_leaves(unsigned int cpu)
 320 {
 321         return -ENOENT;
 322 }
 323
 324 static int detect_cache_attributes(unsigned int cpu)
 325 {
 326         int ret;
 327
 328         if (init_cache_level(cpu) || !cache_leaves(cpu))
 329                 return -ENOENT;
 330
 331         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 332                                          sizeof(struct cacheinfo), GFP_KERNEL);
 333         if (per_cpu_cacheinfo(cpu) == NULL)
 334                 return -ENOMEM;
 335
 336         /*
 337          * populate_cache_leaves() may completely setup the cache leaves and
 338          * shared_cpu_map or it may leave it partially setup.
 339          */
 340         ret = populate_cache_leaves(cpu);
 341         if (ret)
 342                 goto free_ci;
 343         /*
 344          * For systems using DT for cache hierarchy, fw_token
 345          * and shared_cpu_map will be set up here only if they are
 346          * not populated already
 347          */
 348         ret = cache_shared_cpu_map_setup(cpu);
 349         if (ret) {
 350                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 351                 goto free_ci;
 352         }
 353
 354         return 0;
 355
 356 free_ci:
 357         free_cache_attributes(cpu);
 358         return ret;
 359 }
 360
 361 /* pointer to cpuX/cache device */
 362 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 363 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 364
 365 static cpumask_t cache_dev_map;
 366
 367 /* pointer to array of devices for cpuX/cache/indexY */
 368 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 369 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 370 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 371
 372 #define show_one(file_name, object)                             \
 373 static ssize_t file_name##_show(struct device *dev,             \
 374                 struct device_attribute *attr, char *buf)       \
 375 {                                                               \
 376         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 377         return sprintf(buf, "%u\n", this_leaf->object);         \
 378 }
 379
 380 show_one(id, id);
 381 show_one(level, level);
 382 show_one(coherency_line_size, coherency_line_size);
 383 show_one(number_of_sets, number_of_sets);
 384 show_one(physical_line_partition, physical_line_partition);
 385 show_one(ways_of_associativity, ways_of_associativity);
 386
 387 static ssize_t size_show(struct device *dev,
 388                          struct device_attribute *attr, char *buf)
 389 {
 390         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 391
 392         return sprintf(buf, "%uK\n", this_leaf->size >> 10);
 393 }
 394
 395 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
 396 {
 397         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 398         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 399
 400         return cpumap_print_to_pagebuf(list, buf, mask);
 401 }
 402
 403 static ssize_t shared_cpu_map_show(struct device *dev,
 404                                    struct device_attribute *attr, char *buf)
 405 {
 406         return shared_cpumap_show_func(dev, false, buf);
 407 }
 408
 409 static ssize_t shared_cpu_list_show(struct device *dev,
 410                                     struct device_attribute *attr, char *buf)
 411 {
 412         return shared_cpumap_show_func(dev, true, buf);
 413 }
 414
 415 static ssize_t type_show(struct device *dev,
 416                          struct device_attribute *attr, char *buf)
 417 {
 418         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 419
 420         switch (this_leaf->type) {
 421         case CACHE_TYPE_DATA:
 422                 return sprintf(buf, "Data\n");
 423         case CACHE_TYPE_INST:
 424                 return sprintf(buf, "Instruction\n");
 425         case CACHE_TYPE_UNIFIED:
 426                 return sprintf(buf, "Unified\n");
 427         default:
 428                 return -EINVAL;
 429         }
 430 }
 431
 432 static ssize_t allocation_policy_show(struct device *dev,
 433                                       struct device_attribute *attr, char *buf)
 434 {
 435         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 436         unsigned int ci_attr = this_leaf->attributes;
 437         int n = 0;
 438
 439         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 440                 n = sprintf(buf, "ReadWriteAllocate\n");
 441         else if (ci_attr & CACHE_READ_ALLOCATE)
 442                 n = sprintf(buf, "ReadAllocate\n");
 443         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 444                 n = sprintf(buf, "WriteAllocate\n");
 445         return n;
 446 }
 447
 448 static ssize_t write_policy_show(struct device *dev,
 449                                  struct device_attribute *attr, char *buf)
 450 {
 451         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 452         unsigned int ci_attr = this_leaf->attributes;
 453         int n = 0;
 454
 455         if (ci_attr & CACHE_WRITE_THROUGH)
 456                 n = sprintf(buf, "WriteThrough\n");
 457         else if (ci_attr & CACHE_WRITE_BACK)
 458                 n = sprintf(buf, "WriteBack\n");
 459         return n;
 460 }
 461
 462 static DEVICE_ATTR_RO(id);
 463 static DEVICE_ATTR_RO(level);
 464 static DEVICE_ATTR_RO(type);
 465 static DEVICE_ATTR_RO(coherency_line_size);
 466 static DEVICE_ATTR_RO(ways_of_associativity);
 467 static DEVICE_ATTR_RO(number_of_sets);
 468 static DEVICE_ATTR_RO(size);
 469 static DEVICE_ATTR_RO(allocation_policy);
 470 static DEVICE_ATTR_RO(write_policy);
 471 static DEVICE_ATTR_RO(shared_cpu_map);
 472 static DEVICE_ATTR_RO(shared_cpu_list);
 473 static DEVICE_ATTR_RO(physical_line_partition);
 474
 475 static struct attribute *cache_default_attrs[] = {
 476         &dev_attr_id.attr,
 477         &dev_attr_type.attr,
 478         &dev_attr_level.attr,
 479         &dev_attr_shared_cpu_map.attr,
 480         &dev_attr_shared_cpu_list.attr,
 481         &dev_attr_coherency_line_size.attr,
 482         &dev_attr_ways_of_associativity.attr,
 483         &dev_attr_number_of_sets.attr,
 484         &dev_attr_size.attr,
 485         &dev_attr_allocation_policy.attr,
 486         &dev_attr_write_policy.attr,
 487         &dev_attr_physical_line_partition.attr,
 488         NULL
 489 };
 490
 491 static umode_t
 492 cache_default_attrs_is_visible(struct kobject *kobj,
 493                                struct attribute *attr, int unused)
 494 {
 495         struct device *dev = kobj_to_dev(kobj);
 496         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 497         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 498         umode_t mode = attr->mode;
 499
 500         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 501                 return mode;
 502         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 503                 return mode;
 504         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 505                 return mode;
 506         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 507                 return mode;
 508         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 509                 return mode;
 510         if ((attr == &dev_attr_coherency_line_size.attr) &&
 511             this_leaf->coherency_line_size)
 512                 return mode;
 513         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 514             this_leaf->size) /* allow 0 = full associativity */
 515                 return mode;
 516         if ((attr == &dev_attr_number_of_sets.attr) &&
 517             this_leaf->number_of_sets)
 518                 return mode;
 519         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 520                 return mode;
 521         if ((attr == &dev_attr_write_policy.attr) &&
 522             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 523                 return mode;
 524         if ((attr == &dev_attr_allocation_policy.attr) &&
 525             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 526                 return mode;
 527         if ((attr == &dev_attr_physical_line_partition.attr) &&
 528             this_leaf->physical_line_partition)
 529                 return mode;
 530
 531         return 0;
 532 }
 533
 534 static const struct attribute_group cache_default_group = {
 535         .attrs = cache_default_attrs,
 536         .is_visible = cache_default_attrs_is_visible,
 537 };
 538
 539 static const struct attribute_group *cache_default_groups[] = {
 540         &cache_default_group,
 541         NULL,
 542 };
 543
 544 static const struct attribute_group *cache_private_groups[] = {
 545         &cache_default_group,
 546         NULL, /* Place holder for private group */
 547         NULL,
 548 };
 549
 550 const struct attribute_group *
 551 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 552 {
 553         return NULL;
 554 }
 555
 556 static const struct attribute_group **
 557 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 558 {
 559         const struct attribute_group *priv_group =
 560                         cache_get_priv_group(this_leaf);
 561
 562         if (!priv_group)
 563                 return cache_default_groups;
 564
 565         if (!cache_private_groups[1])
 566                 cache_private_groups[1] = priv_group;
 567
 568         return cache_private_groups;
 569 }
 570
 571 /* Add/Remove cache interface for CPU device */
 572 static void cpu_cache_sysfs_exit(unsigned int cpu)
 573 {
 574         int i;
 575         struct device *ci_dev;
 576
 577         if (per_cpu_index_dev(cpu)) {
 578                 for (i = 0; i < cache_leaves(cpu); i++) {
 579                         ci_dev = per_cache_index_dev(cpu, i);
 580                         if (!ci_dev)
 581                                 continue;
 582                         device_unregister(ci_dev);
 583                 }
 584                 kfree(per_cpu_index_dev(cpu));
 585                 per_cpu_index_dev(cpu) = NULL;
 586         }
 587         device_unregister(per_cpu_cache_dev(cpu));
 588         per_cpu_cache_dev(cpu) = NULL;
 589 }
 590
 591 static int cpu_cache_sysfs_init(unsigned int cpu)
 592 {
 593         struct device *dev = get_cpu_device(cpu);
 594
 595         if (per_cpu_cacheinfo(cpu) == NULL)
 596                 return -ENOENT;
 597
 598         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 599         if (IS_ERR(per_cpu_cache_dev(cpu)))
 600                 return PTR_ERR(per_cpu_cache_dev(cpu));
 601
 602         /* Allocate all required memory */
 603         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 604                                          sizeof(struct device *), GFP_KERNEL);
 605         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 606                 goto err_out;
 607
 608         return 0;
 609
 610 err_out:
 611         cpu_cache_sysfs_exit(cpu);
 612         return -ENOMEM;
 613 }
 614
 615 static int cache_add_dev(unsigned int cpu)
 616 {
 617         unsigned int i;
 618         int rc;
 619         struct device *ci_dev, *parent;
 620         struct cacheinfo *this_leaf;
 621         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 622         const struct attribute_group **cache_groups;
 623
 624         rc = cpu_cache_sysfs_init(cpu);
 625         if (unlikely(rc < 0))
 626                 return rc;
 627
 628         parent = per_cpu_cache_dev(cpu);
 629         for (i = 0; i < cache_leaves(cpu); i++) {
 630                 this_leaf = this_cpu_ci->info_list + i;
 631                 if (this_leaf->disable_sysfs)
 632                         continue;
 633                 cache_groups = cache_get_attribute_groups(this_leaf);
 634                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 635                                            "index%1u", i);
 636                 if (IS_ERR(ci_dev)) {
 637                         rc = PTR_ERR(ci_dev);
 638                         goto err;
 639                 }
 640                 per_cache_index_dev(cpu, i) = ci_dev;
 641         }
 642         cpumask_set_cpu(cpu, &cache_dev_map);
 643
 644         return 0;
 645 err:
 646         cpu_cache_sysfs_exit(cpu);
 647         return rc;
 648 }
 649
 650 static int cacheinfo_cpu_online(unsigned int cpu)
 651 {
 652         int rc = detect_cache_attributes(cpu);
 653
 654         if (rc)
 655                 return rc;
 656         rc = cache_add_dev(cpu);
 657         if (rc)
 658                 free_cache_attributes(cpu);
 659         return rc;
 660 }
 661
 662 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 663 {
 664         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 665                 cpu_cache_sysfs_exit(cpu);
 666
 667         free_cache_attributes(cpu);
 668         return 0;
 669 }
 670
 671 static int __init cacheinfo_sysfs_init(void)
 672 {
 673         return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
 674                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 675 }
 676 device_initcall(cacheinfo_sysfs_init);