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, sib_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                         for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
 283                                 sib_leaf = per_cpu_cacheinfo_idx(i, sib_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                                         break;
 288                                 }
 289                         }
 290                 }
 291                 /* record the maximum cache line size */
 292                 if (this_leaf->coherency_line_size > coherency_max_size)
 293                         coherency_max_size = this_leaf->coherency_line_size;
 294         }
 295
 296         return 0;
 297 }
 298
 299 static void cache_shared_cpu_map_remove(unsigned int cpu)
 300 {
 301         struct cacheinfo *this_leaf, *sib_leaf;
 302         unsigned int sibling, index, sib_index;
 303
 304         for (index = 0; index < cache_leaves(cpu); index++) {
 305                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 306                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 307                         struct cpu_cacheinfo *sib_cpu_ci =
 308                                                 get_cpu_cacheinfo(sibling);
 309
 310                         if (sibling == cpu || !sib_cpu_ci->info_list)
 311                                 continue;/* skip if itself or no cacheinfo */
 312
 313                         for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
 314                                 sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
 315                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 316                                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 317                                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 318                                         break;
 319                                 }
 320                         }
 321                 }
 322                 if (of_have_populated_dt())
 323                         of_node_put(this_leaf->fw_token);
 324         }
 325 }
 326
 327 static void free_cache_attributes(unsigned int cpu)
 328 {
 329         if (!per_cpu_cacheinfo(cpu))
 330                 return;
 331
 332         cache_shared_cpu_map_remove(cpu);
 333
 334         kfree(per_cpu_cacheinfo(cpu));
 335         per_cpu_cacheinfo(cpu) = NULL;
 336         cache_leaves(cpu) = 0;
 337 }
 338
 339 int __weak init_cache_level(unsigned int cpu)
 340 {
 341         return -ENOENT;
 342 }
 343
 344 int __weak populate_cache_leaves(unsigned int cpu)
 345 {
 346         return -ENOENT;
 347 }
 348
 349 int detect_cache_attributes(unsigned int cpu)
 350 {
 351         int ret;
 352
 353         /* Since early detection of the cacheinfo is allowed via this
 354          * function and this also gets called as CPU hotplug callbacks via
 355          * cacheinfo_cpu_online, the initialisation can be skipped and only
 356          * CPU maps can be updated as the CPU online status would be update
 357          * if called via cacheinfo_cpu_online path.
 358          */
 359         if (per_cpu_cacheinfo(cpu))
 360                 goto update_cpu_map;
 361
 362         if (init_cache_level(cpu) || !cache_leaves(cpu))
 363                 return -ENOENT;
 364
 365         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 366                                          sizeof(struct cacheinfo), GFP_ATOMIC);
 367         if (per_cpu_cacheinfo(cpu) == NULL) {
 368                 cache_leaves(cpu) = 0;
 369                 return -ENOMEM;
 370         }
 371
 372         /*
 373          * populate_cache_leaves() may completely setup the cache leaves and
 374          * shared_cpu_map or it may leave it partially setup.
 375          */
 376         ret = populate_cache_leaves(cpu);
 377         if (ret)
 378                 goto free_ci;
 379
 380 update_cpu_map:
 381         /*
 382          * For systems using DT for cache hierarchy, fw_token
 383          * and shared_cpu_map will be set up here only if they are
 384          * not populated already
 385          */
 386         ret = cache_shared_cpu_map_setup(cpu);
 387         if (ret) {
 388                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 389                 goto free_ci;
 390         }
 391
 392         return 0;
 393
 394 free_ci:
 395         free_cache_attributes(cpu);
 396         return ret;
 397 }
 398
 399 /* pointer to cpuX/cache device */
 400 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 401 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 402
 403 static cpumask_t cache_dev_map;
 404
 405 /* pointer to array of devices for cpuX/cache/indexY */
 406 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 407 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 408 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 409
 410 #define show_one(file_name, object)                             \
 411 static ssize_t file_name##_show(struct device *dev,             \
 412                 struct device_attribute *attr, char *buf)       \
 413 {                                                               \
 414         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 415         return sysfs_emit(buf, "%u\n", this_leaf->object);      \
 416 }
 417
 418 show_one(id, id);
 419 show_one(level, level);
 420 show_one(coherency_line_size, coherency_line_size);
 421 show_one(number_of_sets, number_of_sets);
 422 show_one(physical_line_partition, physical_line_partition);
 423 show_one(ways_of_associativity, ways_of_associativity);
 424
 425 static ssize_t size_show(struct device *dev,
 426                          struct device_attribute *attr, char *buf)
 427 {
 428         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 429
 430         return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 431 }
 432
 433 static ssize_t shared_cpu_map_show(struct device *dev,
 434                                    struct device_attribute *attr, char *buf)
 435 {
 436         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 437         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 438
 439         return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
 440 }
 441
 442 static ssize_t shared_cpu_list_show(struct device *dev,
 443                                     struct device_attribute *attr, char *buf)
 444 {
 445         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 446         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 447
 448         return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
 449 }
 450
 451 static ssize_t type_show(struct device *dev,
 452                          struct device_attribute *attr, char *buf)
 453 {
 454         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 455         const char *output;
 456
 457         switch (this_leaf->type) {
 458         case CACHE_TYPE_DATA:
 459                 output = "Data";
 460                 break;
 461         case CACHE_TYPE_INST:
 462                 output = "Instruction";
 463                 break;
 464         case CACHE_TYPE_UNIFIED:
 465                 output = "Unified";
 466                 break;
 467         default:
 468                 return -EINVAL;
 469         }
 470
 471         return sysfs_emit(buf, "%s\n", output);
 472 }
 473
 474 static ssize_t allocation_policy_show(struct device *dev,
 475                                       struct device_attribute *attr, char *buf)
 476 {
 477         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 478         unsigned int ci_attr = this_leaf->attributes;
 479         const char *output;
 480
 481         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 482                 output = "ReadWriteAllocate";
 483         else if (ci_attr & CACHE_READ_ALLOCATE)
 484                 output = "ReadAllocate";
 485         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 486                 output = "WriteAllocate";
 487         else
 488                 return 0;
 489
 490         return sysfs_emit(buf, "%s\n", output);
 491 }
 492
 493 static ssize_t write_policy_show(struct device *dev,
 494                                  struct device_attribute *attr, char *buf)
 495 {
 496         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 497         unsigned int ci_attr = this_leaf->attributes;
 498         int n = 0;
 499
 500         if (ci_attr & CACHE_WRITE_THROUGH)
 501                 n = sysfs_emit(buf, "WriteThrough\n");
 502         else if (ci_attr & CACHE_WRITE_BACK)
 503                 n = sysfs_emit(buf, "WriteBack\n");
 504         return n;
 505 }
 506
 507 static DEVICE_ATTR_RO(id);
 508 static DEVICE_ATTR_RO(level);
 509 static DEVICE_ATTR_RO(type);
 510 static DEVICE_ATTR_RO(coherency_line_size);
 511 static DEVICE_ATTR_RO(ways_of_associativity);
 512 static DEVICE_ATTR_RO(number_of_sets);
 513 static DEVICE_ATTR_RO(size);
 514 static DEVICE_ATTR_RO(allocation_policy);
 515 static DEVICE_ATTR_RO(write_policy);
 516 static DEVICE_ATTR_RO(shared_cpu_map);
 517 static DEVICE_ATTR_RO(shared_cpu_list);
 518 static DEVICE_ATTR_RO(physical_line_partition);
 519
 520 static struct attribute *cache_default_attrs[] = {
 521         &dev_attr_id.attr,
 522         &dev_attr_type.attr,
 523         &dev_attr_level.attr,
 524         &dev_attr_shared_cpu_map.attr,
 525         &dev_attr_shared_cpu_list.attr,
 526         &dev_attr_coherency_line_size.attr,
 527         &dev_attr_ways_of_associativity.attr,
 528         &dev_attr_number_of_sets.attr,
 529         &dev_attr_size.attr,
 530         &dev_attr_allocation_policy.attr,
 531         &dev_attr_write_policy.attr,
 532         &dev_attr_physical_line_partition.attr,
 533         NULL
 534 };
 535
 536 static umode_t
 537 cache_default_attrs_is_visible(struct kobject *kobj,
 538                                struct attribute *attr, int unused)
 539 {
 540         struct device *dev = kobj_to_dev(kobj);
 541         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 542         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 543         umode_t mode = attr->mode;
 544
 545         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 546                 return mode;
 547         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 548                 return mode;
 549         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 550                 return mode;
 551         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 552                 return mode;
 553         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 554                 return mode;
 555         if ((attr == &dev_attr_coherency_line_size.attr) &&
 556             this_leaf->coherency_line_size)
 557                 return mode;
 558         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 559             this_leaf->size) /* allow 0 = full associativity */
 560                 return mode;
 561         if ((attr == &dev_attr_number_of_sets.attr) &&
 562             this_leaf->number_of_sets)
 563                 return mode;
 564         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 565                 return mode;
 566         if ((attr == &dev_attr_write_policy.attr) &&
 567             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 568                 return mode;
 569         if ((attr == &dev_attr_allocation_policy.attr) &&
 570             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 571                 return mode;
 572         if ((attr == &dev_attr_physical_line_partition.attr) &&
 573             this_leaf->physical_line_partition)
 574                 return mode;
 575
 576         return 0;
 577 }
 578
 579 static const struct attribute_group cache_default_group = {
 580         .attrs = cache_default_attrs,
 581         .is_visible = cache_default_attrs_is_visible,
 582 };
 583
 584 static const struct attribute_group *cache_default_groups[] = {
 585         &cache_default_group,
 586         NULL,
 587 };
 588
 589 static const struct attribute_group *cache_private_groups[] = {
 590         &cache_default_group,
 591         NULL, /* Place holder for private group */
 592         NULL,
 593 };
 594
 595 const struct attribute_group *
 596 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 597 {
 598         return NULL;
 599 }
 600
 601 static const struct attribute_group **
 602 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 603 {
 604         const struct attribute_group *priv_group =
 605                         cache_get_priv_group(this_leaf);
 606
 607         if (!priv_group)
 608                 return cache_default_groups;
 609
 610         if (!cache_private_groups[1])
 611                 cache_private_groups[1] = priv_group;
 612
 613         return cache_private_groups;
 614 }
 615
 616 /* Add/Remove cache interface for CPU device */
 617 static void cpu_cache_sysfs_exit(unsigned int cpu)
 618 {
 619         int i;
 620         struct device *ci_dev;
 621
 622         if (per_cpu_index_dev(cpu)) {
 623                 for (i = 0; i < cache_leaves(cpu); i++) {
 624                         ci_dev = per_cache_index_dev(cpu, i);
 625                         if (!ci_dev)
 626                                 continue;
 627                         device_unregister(ci_dev);
 628                 }
 629                 kfree(per_cpu_index_dev(cpu));
 630                 per_cpu_index_dev(cpu) = NULL;
 631         }
 632         device_unregister(per_cpu_cache_dev(cpu));
 633         per_cpu_cache_dev(cpu) = NULL;
 634 }
 635
 636 static int cpu_cache_sysfs_init(unsigned int cpu)
 637 {
 638         struct device *dev = get_cpu_device(cpu);
 639
 640         if (per_cpu_cacheinfo(cpu) == NULL)
 641                 return -ENOENT;
 642
 643         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 644         if (IS_ERR(per_cpu_cache_dev(cpu)))
 645                 return PTR_ERR(per_cpu_cache_dev(cpu));
 646
 647         /* Allocate all required memory */
 648         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 649                                          sizeof(struct device *), GFP_KERNEL);
 650         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 651                 goto err_out;
 652
 653         return 0;
 654
 655 err_out:
 656         cpu_cache_sysfs_exit(cpu);
 657         return -ENOMEM;
 658 }
 659
 660 static int cache_add_dev(unsigned int cpu)
 661 {
 662         unsigned int i;
 663         int rc;
 664         struct device *ci_dev, *parent;
 665         struct cacheinfo *this_leaf;
 666         const struct attribute_group **cache_groups;
 667
 668         rc = cpu_cache_sysfs_init(cpu);
 669         if (unlikely(rc < 0))
 670                 return rc;
 671
 672         parent = per_cpu_cache_dev(cpu);
 673         for (i = 0; i < cache_leaves(cpu); i++) {
 674                 this_leaf = per_cpu_cacheinfo_idx(cpu, i);
 675                 if (this_leaf->disable_sysfs)
 676                         continue;
 677                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
 678                         break;
 679                 cache_groups = cache_get_attribute_groups(this_leaf);
 680                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 681                                            "index%1u", i);
 682                 if (IS_ERR(ci_dev)) {
 683                         rc = PTR_ERR(ci_dev);
 684                         goto err;
 685                 }
 686                 per_cache_index_dev(cpu, i) = ci_dev;
 687         }
 688         cpumask_set_cpu(cpu, &cache_dev_map);
 689
 690         return 0;
 691 err:
 692         cpu_cache_sysfs_exit(cpu);
 693         return rc;
 694 }
 695
 696 static int cacheinfo_cpu_online(unsigned int cpu)
 697 {
 698         int rc = detect_cache_attributes(cpu);
 699
 700         if (rc)
 701                 return rc;
 702         rc = cache_add_dev(cpu);
 703         if (rc)
 704                 free_cache_attributes(cpu);
 705         return rc;
 706 }
 707
 708 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 709 {
 710         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 711                 cpu_cache_sysfs_exit(cpu);
 712
 713         free_cache_attributes(cpu);
 714         return 0;
 715 }
 716
 717 static int __init cacheinfo_sysfs_init(void)
 718 {
 719         return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
 720                                  "base/cacheinfo:online",
 721                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 722 }
 723 device_initcall(cacheinfo_sysfs_init);