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