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_device.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 #define per_cpu_cacheinfo_idx(cpu, idx)         \
  29                                 (per_cpu_cacheinfo(cpu) + (idx))
  30
  31 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
  32 {
  33         return ci_cacheinfo(cpu);
  34 }
  35
  36 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
  37                                            struct cacheinfo *sib_leaf)
  38 {
  39         /*
  40          * For non DT/ACPI systems, assume unique level 1 caches,
  41          * system-wide shared caches for all other levels. This will be used
  42          * only if arch specific code has not populated shared_cpu_map
  43          */
  44         if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
  45                 return !(this_leaf->level == 1);
  46
  47         if ((sib_leaf->attributes & CACHE_ID) &&
  48             (this_leaf->attributes & CACHE_ID))
  49                 return sib_leaf->id == this_leaf->id;
  50
  51         return sib_leaf->fw_token == this_leaf->fw_token;
  52 }
  53
  54 bool last_level_cache_is_valid(unsigned int cpu)
  55 {
  56         struct cacheinfo *llc;
  57
  58         if (!cache_leaves(cpu))
  59                 return false;
  60
  61         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
  62
  63         return (llc->attributes & CACHE_ID) || !!llc->fw_token;
  64
  65 }
  66
  67 bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
  68 {
  69         struct cacheinfo *llc_x, *llc_y;
  70
  71         if (!last_level_cache_is_valid(cpu_x) ||
  72             !last_level_cache_is_valid(cpu_y))
  73                 return false;
  74
  75         llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
  76         llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
  77
  78         return cache_leaves_are_shared(llc_x, llc_y);
  79 }
  80
  81 #ifdef CONFIG_OF
  82 /* OF properties to query for a given cache type */
  83 struct cache_type_info {
  84         const char *size_prop;
  85         const char *line_size_props[2];
  86         const char *nr_sets_prop;
  87 };
  88
  89 static const struct cache_type_info cache_type_info[] = {
  90         {
  91                 .size_prop       = "cache-size",
  92                 .line_size_props = { "cache-line-size",
  93                                      "cache-block-size", },
  94                 .nr_sets_prop    = "cache-sets",
  95         }, {
  96                 .size_prop       = "i-cache-size",
  97                 .line_size_props = { "i-cache-line-size",
  98                                      "i-cache-block-size", },
  99                 .nr_sets_prop    = "i-cache-sets",
 100         }, {
 101                 .size_prop       = "d-cache-size",
 102                 .line_size_props = { "d-cache-line-size",
 103                                      "d-cache-block-size", },
 104                 .nr_sets_prop    = "d-cache-sets",
 105         },
 106 };
 107
 108 static inline int get_cacheinfo_idx(enum cache_type type)
 109 {
 110         if (type == CACHE_TYPE_UNIFIED)
 111                 return 0;
 112         return type;
 113 }
 114
 115 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
 116 {
 117         const char *propname;
 118         int ct_idx;
 119
 120         ct_idx = get_cacheinfo_idx(this_leaf->type);
 121         propname = cache_type_info[ct_idx].size_prop;
 122
 123         of_property_read_u32(np, propname, &this_leaf->size);
 124 }
 125
 126 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 127 static void cache_get_line_size(struct cacheinfo *this_leaf,
 128                                 struct device_node *np)
 129 {
 130         int i, lim, ct_idx;
 131
 132         ct_idx = get_cacheinfo_idx(this_leaf->type);
 133         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
 134
 135         for (i = 0; i < lim; i++) {
 136                 int ret;
 137                 u32 line_size;
 138                 const char *propname;
 139
 140                 propname = cache_type_info[ct_idx].line_size_props[i];
 141                 ret = of_property_read_u32(np, propname, &line_size);
 142                 if (!ret) {
 143                         this_leaf->coherency_line_size = line_size;
 144                         break;
 145                 }
 146         }
 147 }
 148
 149 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 150 {
 151         const char *propname;
 152         int ct_idx;
 153
 154         ct_idx = get_cacheinfo_idx(this_leaf->type);
 155         propname = cache_type_info[ct_idx].nr_sets_prop;
 156
 157         of_property_read_u32(np, propname, &this_leaf->number_of_sets);
 158 }
 159
 160 static void cache_associativity(struct cacheinfo *this_leaf)
 161 {
 162         unsigned int line_size = this_leaf->coherency_line_size;
 163         unsigned int nr_sets = this_leaf->number_of_sets;
 164         unsigned int size = this_leaf->size;
 165
 166         /*
 167          * If the cache is fully associative, there is no need to
 168          * check the other properties.
 169          */
 170         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 171                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 172 }
 173
 174 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 175                                   struct device_node *np)
 176 {
 177         return of_property_read_bool(np, "cache-unified");
 178 }
 179
 180 static void cache_of_set_props(struct cacheinfo *this_leaf,
 181                                struct device_node *np)
 182 {
 183         /*
 184          * init_cache_level must setup the cache level correctly
 185          * overriding the architecturally specified levels, so
 186          * if type is NONE at this stage, it should be unified
 187          */
 188         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 189             cache_node_is_unified(this_leaf, np))
 190                 this_leaf->type = CACHE_TYPE_UNIFIED;
 191         cache_size(this_leaf, np);
 192         cache_get_line_size(this_leaf, np);
 193         cache_nr_sets(this_leaf, np);
 194         cache_associativity(this_leaf);
 195 }
 196
 197 static int cache_setup_of_node(unsigned int cpu)
 198 {
 199         struct device_node *np;
 200         struct cacheinfo *this_leaf;
 201         unsigned int index = 0;
 202
 203         np = of_cpu_device_node_get(cpu);
 204         if (!np) {
 205                 pr_err("Failed to find cpu%d device node\n", cpu);
 206                 return -ENOENT;
 207         }
 208
 209         while (index < cache_leaves(cpu)) {
 210                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 211                 if (this_leaf->level != 1)
 212                         np = of_find_next_cache_node(np);
 213                 else
 214                         np = of_node_get(np);/* cpu node itself */
 215                 if (!np)
 216                         break;
 217                 cache_of_set_props(this_leaf, np);
 218                 this_leaf->fw_token = np;
 219                 index++;
 220         }
 221
 222         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 223                 return -ENOENT;
 224
 225         return 0;
 226 }
 227 #else
 228 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 229 #endif
 230
 231 int __weak cache_setup_acpi(unsigned int cpu)
 232 {
 233         return -ENOTSUPP;
 234 }
 235
 236 unsigned int coherency_max_size;
 237
 238 static int cache_setup_properties(unsigned int cpu)
 239 {
 240         int ret = 0;
 241
 242         if (of_have_populated_dt())
 243                 ret = cache_setup_of_node(cpu);
 244         else if (!acpi_disabled)
 245                 ret = cache_setup_acpi(cpu);
 246
 247         return ret;
 248 }
 249
 250 static int cache_shared_cpu_map_setup(unsigned int cpu)
 251 {
 252         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 253         struct cacheinfo *this_leaf, *sib_leaf;
 254         unsigned int index;
 255         int ret = 0;
 256
 257         if (this_cpu_ci->cpu_map_populated)
 258                 return 0;
 259
 260         /*
 261          * skip setting up cache properties if LLC is valid, just need
 262          * to update the shared cpu_map if the cache attributes were
 263          * populated early before all the cpus are brought online
 264          */
 265         if (!last_level_cache_is_valid(cpu)) {
 266                 ret = cache_setup_properties(cpu);
 267                 if (ret)
 268                         return ret;
 269         }
 270
 271         for (index = 0; index < cache_leaves(cpu); index++) {
 272                 unsigned int i;
 273
 274                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 275
 276                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 277                 for_each_online_cpu(i) {
 278                         struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
 279
 280                         if (i == cpu || !sib_cpu_ci->info_list)
 281                                 continue;/* skip if itself or no cacheinfo */
 282
 283                         sib_leaf = per_cpu_cacheinfo_idx(i, index);
 284                         if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 285                                 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 286                                 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
 287                         }
 288                 }
 289                 /* record the maximum cache line size */
 290                 if (this_leaf->coherency_line_size > coherency_max_size)
 291                         coherency_max_size = this_leaf->coherency_line_size;
 292         }
 293
 294         return 0;
 295 }
 296
 297 static void cache_shared_cpu_map_remove(unsigned int cpu)
 298 {
 299         struct cacheinfo *this_leaf, *sib_leaf;
 300         unsigned int sibling, index;
 301
 302         for (index = 0; index < cache_leaves(cpu); index++) {
 303                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 304                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 305                         struct cpu_cacheinfo *sib_cpu_ci =
 306                                                 get_cpu_cacheinfo(sibling);
 307
 308                         if (sibling == cpu || !sib_cpu_ci->info_list)
 309                                 continue;/* skip if itself or no cacheinfo */
 310
 311                         sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
 312                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 313                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 314                 }
 315                 if (of_have_populated_dt())
 316                         of_node_put(this_leaf->fw_token);
 317         }
 318 }
 319
 320 static void free_cache_attributes(unsigned int cpu)
 321 {
 322         if (!per_cpu_cacheinfo(cpu))
 323                 return;
 324
 325         cache_shared_cpu_map_remove(cpu);
 326
 327         kfree(per_cpu_cacheinfo(cpu));
 328         per_cpu_cacheinfo(cpu) = NULL;
 329         cache_leaves(cpu) = 0;
 330 }
 331
 332 int __weak init_cache_level(unsigned int cpu)
 333 {
 334         return -ENOENT;
 335 }
 336
 337 int __weak populate_cache_leaves(unsigned int cpu)
 338 {
 339         return -ENOENT;
 340 }
 341
 342 int detect_cache_attributes(unsigned int cpu)
 343 {
 344         int ret;
 345
 346         /* Since early detection of the cacheinfo is allowed via this
 347          * function and this also gets called as CPU hotplug callbacks via
 348          * cacheinfo_cpu_online, the initialisation can be skipped and only
 349          * CPU maps can be updated as the CPU online status would be update
 350          * if called via cacheinfo_cpu_online path.
 351          */
 352         if (per_cpu_cacheinfo(cpu))
 353                 goto update_cpu_map;
 354
 355         if (init_cache_level(cpu) || !cache_leaves(cpu))
 356                 return -ENOENT;
 357
 358         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 359                                          sizeof(struct cacheinfo), GFP_ATOMIC);
 360         if (per_cpu_cacheinfo(cpu) == NULL) {
 361                 cache_leaves(cpu) = 0;
 362                 return -ENOMEM;
 363         }
 364
 365         /*
 366          * populate_cache_leaves() may completely setup the cache leaves and
 367          * shared_cpu_map or it may leave it partially setup.
 368          */
 369         ret = populate_cache_leaves(cpu);
 370         if (ret)
 371                 goto free_ci;
 372
 373 update_cpu_map:
 374         /*
 375          * For systems using DT for cache hierarchy, fw_token
 376          * and shared_cpu_map will be set up here only if they are
 377          * not populated already
 378          */
 379         ret = cache_shared_cpu_map_setup(cpu);
 380         if (ret) {
 381                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 382                 goto free_ci;
 383         }
 384
 385         return 0;
 386
 387 free_ci:
 388         free_cache_attributes(cpu);
 389         return ret;
 390 }
 391
 392 /* pointer to cpuX/cache device */
 393 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 394 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 395
 396 static cpumask_t cache_dev_map;
 397
 398 /* pointer to array of devices for cpuX/cache/indexY */
 399 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 400 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 401 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 402
 403 #define show_one(file_name, object)                             \
 404 static ssize_t file_name##_show(struct device *dev,             \
 405                 struct device_attribute *attr, char *buf)       \
 406 {                                                               \
 407         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 408         return sysfs_emit(buf, "%u\n", this_leaf->object);      \
 409 }
 410
 411 show_one(id, id);
 412 show_one(level, level);
 413 show_one(coherency_line_size, coherency_line_size);
 414 show_one(number_of_sets, number_of_sets);
 415 show_one(physical_line_partition, physical_line_partition);
 416 show_one(ways_of_associativity, ways_of_associativity);
 417
 418 static ssize_t size_show(struct device *dev,
 419                          struct device_attribute *attr, char *buf)
 420 {
 421         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 422
 423         return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 424 }
 425
 426 static ssize_t shared_cpu_map_show(struct device *dev,
 427                                    struct device_attribute *attr, char *buf)
 428 {
 429         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 430         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 431
 432         return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
 433 }
 434
 435 static ssize_t shared_cpu_list_show(struct device *dev,
 436                                     struct device_attribute *attr, char *buf)
 437 {
 438         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 439         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 440
 441         return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
 442 }
 443
 444 static ssize_t type_show(struct device *dev,
 445                          struct device_attribute *attr, char *buf)
 446 {
 447         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 448         const char *output;
 449
 450         switch (this_leaf->type) {
 451         case CACHE_TYPE_DATA:
 452                 output = "Data";
 453                 break;
 454         case CACHE_TYPE_INST:
 455                 output = "Instruction";
 456                 break;
 457         case CACHE_TYPE_UNIFIED:
 458                 output = "Unified";
 459                 break;
 460         default:
 461                 return -EINVAL;
 462         }
 463
 464         return sysfs_emit(buf, "%s\n", output);
 465 }
 466
 467 static ssize_t allocation_policy_show(struct device *dev,
 468                                       struct device_attribute *attr, char *buf)
 469 {
 470         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 471         unsigned int ci_attr = this_leaf->attributes;
 472         const char *output;
 473
 474         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 475                 output = "ReadWriteAllocate";
 476         else if (ci_attr & CACHE_READ_ALLOCATE)
 477                 output = "ReadAllocate";
 478         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 479                 output = "WriteAllocate";
 480         else
 481                 return 0;
 482
 483         return sysfs_emit(buf, "%s\n", output);
 484 }
 485
 486 static ssize_t write_policy_show(struct device *dev,
 487                                  struct device_attribute *attr, char *buf)
 488 {
 489         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 490         unsigned int ci_attr = this_leaf->attributes;
 491         int n = 0;
 492
 493         if (ci_attr & CACHE_WRITE_THROUGH)
 494                 n = sysfs_emit(buf, "WriteThrough\n");
 495         else if (ci_attr & CACHE_WRITE_BACK)
 496                 n = sysfs_emit(buf, "WriteBack\n");
 497         return n;
 498 }
 499
 500 static DEVICE_ATTR_RO(id);
 501 static DEVICE_ATTR_RO(level);
 502 static DEVICE_ATTR_RO(type);
 503 static DEVICE_ATTR_RO(coherency_line_size);
 504 static DEVICE_ATTR_RO(ways_of_associativity);
 505 static DEVICE_ATTR_RO(number_of_sets);
 506 static DEVICE_ATTR_RO(size);
 507 static DEVICE_ATTR_RO(allocation_policy);
 508 static DEVICE_ATTR_RO(write_policy);
 509 static DEVICE_ATTR_RO(shared_cpu_map);
 510 static DEVICE_ATTR_RO(shared_cpu_list);
 511 static DEVICE_ATTR_RO(physical_line_partition);
 512
 513 static struct attribute *cache_default_attrs[] = {
 514         &dev_attr_id.attr,
 515         &dev_attr_type.attr,
 516         &dev_attr_level.attr,
 517         &dev_attr_shared_cpu_map.attr,
 518         &dev_attr_shared_cpu_list.attr,
 519         &dev_attr_coherency_line_size.attr,
 520         &dev_attr_ways_of_associativity.attr,
 521         &dev_attr_number_of_sets.attr,
 522         &dev_attr_size.attr,
 523         &dev_attr_allocation_policy.attr,
 524         &dev_attr_write_policy.attr,
 525         &dev_attr_physical_line_partition.attr,
 526         NULL
 527 };
 528
 529 static umode_t
 530 cache_default_attrs_is_visible(struct kobject *kobj,
 531                                struct attribute *attr, int unused)
 532 {
 533         struct device *dev = kobj_to_dev(kobj);
 534         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 535         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 536         umode_t mode = attr->mode;
 537
 538         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 539                 return mode;
 540         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 541                 return mode;
 542         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 543                 return mode;
 544         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 545                 return mode;
 546         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 547                 return mode;
 548         if ((attr == &dev_attr_coherency_line_size.attr) &&
 549             this_leaf->coherency_line_size)
 550                 return mode;
 551         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 552             this_leaf->size) /* allow 0 = full associativity */
 553                 return mode;
 554         if ((attr == &dev_attr_number_of_sets.attr) &&
 555             this_leaf->number_of_sets)
 556                 return mode;
 557         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 558                 return mode;
 559         if ((attr == &dev_attr_write_policy.attr) &&
 560             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 561                 return mode;
 562         if ((attr == &dev_attr_allocation_policy.attr) &&
 563             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 564                 return mode;
 565         if ((attr == &dev_attr_physical_line_partition.attr) &&
 566             this_leaf->physical_line_partition)
 567                 return mode;
 568
 569         return 0;
 570 }
 571
 572 static const struct attribute_group cache_default_group = {
 573         .attrs = cache_default_attrs,
 574         .is_visible = cache_default_attrs_is_visible,
 575 };
 576
 577 static const struct attribute_group *cache_default_groups[] = {
 578         &cache_default_group,
 579         NULL,
 580 };
 581
 582 static const struct attribute_group *cache_private_groups[] = {
 583         &cache_default_group,
 584         NULL, /* Place holder for private group */
 585         NULL,
 586 };
 587
 588 const struct attribute_group *
 589 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 590 {
 591         return NULL;
 592 }
 593
 594 static const struct attribute_group **
 595 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 596 {
 597         const struct attribute_group *priv_group =
 598                         cache_get_priv_group(this_leaf);
 599
 600         if (!priv_group)
 601                 return cache_default_groups;
 602
 603         if (!cache_private_groups[1])
 604                 cache_private_groups[1] = priv_group;
 605
 606         return cache_private_groups;
 607 }
 608
 609 /* Add/Remove cache interface for CPU device */
 610 static void cpu_cache_sysfs_exit(unsigned int cpu)
 611 {
 612         int i;
 613         struct device *ci_dev;
 614
 615         if (per_cpu_index_dev(cpu)) {
 616                 for (i = 0; i < cache_leaves(cpu); i++) {
 617                         ci_dev = per_cache_index_dev(cpu, i);
 618                         if (!ci_dev)
 619                                 continue;
 620                         device_unregister(ci_dev);
 621                 }
 622                 kfree(per_cpu_index_dev(cpu));
 623                 per_cpu_index_dev(cpu) = NULL;
 624         }
 625         device_unregister(per_cpu_cache_dev(cpu));
 626         per_cpu_cache_dev(cpu) = NULL;
 627 }
 628
 629 static int cpu_cache_sysfs_init(unsigned int cpu)
 630 {
 631         struct device *dev = get_cpu_device(cpu);
 632
 633         if (per_cpu_cacheinfo(cpu) == NULL)
 634                 return -ENOENT;
 635
 636         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 637         if (IS_ERR(per_cpu_cache_dev(cpu)))
 638                 return PTR_ERR(per_cpu_cache_dev(cpu));
 639
 640         /* Allocate all required memory */
 641         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 642                                          sizeof(struct device *), GFP_KERNEL);
 643         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 644                 goto err_out;
 645
 646         return 0;
 647
 648 err_out:
 649         cpu_cache_sysfs_exit(cpu);
 650         return -ENOMEM;
 651 }
 652
 653 static int cache_add_dev(unsigned int cpu)
 654 {
 655         unsigned int i;
 656         int rc;
 657         struct device *ci_dev, *parent;
 658         struct cacheinfo *this_leaf;
 659         const struct attribute_group **cache_groups;
 660
 661         rc = cpu_cache_sysfs_init(cpu);
 662         if (unlikely(rc < 0))
 663                 return rc;
 664
 665         parent = per_cpu_cache_dev(cpu);
 666         for (i = 0; i < cache_leaves(cpu); i++) {
 667                 this_leaf = per_cpu_cacheinfo_idx(cpu, i);
 668                 if (this_leaf->disable_sysfs)
 669                         continue;
 670                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
 671                         break;
 672                 cache_groups = cache_get_attribute_groups(this_leaf);
 673                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 674                                            "index%1u", i);
 675                 if (IS_ERR(ci_dev)) {
 676                         rc = PTR_ERR(ci_dev);
 677                         goto err;
 678                 }
 679                 per_cache_index_dev(cpu, i) = ci_dev;
 680         }
 681         cpumask_set_cpu(cpu, &cache_dev_map);
 682
 683         return 0;
 684 err:
 685         cpu_cache_sysfs_exit(cpu);
 686         return rc;
 687 }
 688
 689 static int cacheinfo_cpu_online(unsigned int cpu)
 690 {
 691         int rc = detect_cache_attributes(cpu);
 692
 693         if (rc)
 694                 return rc;
 695         rc = cache_add_dev(cpu);
 696         if (rc)
 697                 free_cache_attributes(cpu);
 698         return rc;
 699 }
 700
 701 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 702 {
 703         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 704                 cpu_cache_sysfs_exit(cpu);
 705
 706         free_cache_attributes(cpu);
 707         return 0;
 708 }
 709
 710 static int __init cacheinfo_sysfs_init(void)
 711 {
 712         return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
 713                                  "base/cacheinfo:online",
 714                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 715 }
 716 device_initcall(cacheinfo_sysfs_init);