arch/powerpc/kernel/cacheinfo.c

   1 /*
   2  * Processor cache information made available to userspace via sysfs;
   3  * intended to be compatible with x86 intel_cacheinfo implementation.
   4  *
   5  * Copyright 2008 IBM Corporation
   6  * Author: Nathan Lynch
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/cpu.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/kobject.h>
  18 #include <linux/list.h>
  19 #include <linux/notifier.h>
  20 #include <linux/of.h>
  21 #include <linux/percpu.h>
  22 #include <linux/slab.h>
  23 #include <asm/prom.h>
  24
  25 #include "cacheinfo.h"
  26
  27 /* per-cpu object for tracking:
  28  * - a "cache" kobject for the top-level directory
  29  * - a list of "index" objects representing the cpu's local cache hierarchy
  30  */
  31 struct cache_dir {
  32         struct kobject *kobj; /* bare (not embedded) kobject for cache
  33                                * directory */
  34         struct cache_index_dir *index; /* list of index objects */
  35 };
  36
  37 /* "index" object: each cpu's cache directory has an index
  38  * subdirectory corresponding to a cache object associated with the
  39  * cpu.  This object's lifetime is managed via the embedded kobject.
  40  */
  41 struct cache_index_dir {
  42         struct kobject kobj;
  43         struct cache_index_dir *next; /* next index in parent directory */
  44         struct cache *cache;
  45 };
  46
  47 /* Template for determining which OF properties to query for a given
  48  * cache type */
  49 struct cache_type_info {
  50         const char *name;
  51         const char *size_prop;
  52
  53         /* Allow for both [di]-cache-line-size and
  54          * [di]-cache-block-size properties.  According to the PowerPC
  55          * Processor binding, -line-size should be provided if it
  56          * differs from the cache block size (that which is operated
  57          * on by cache instructions), so we look for -line-size first.
  58          * See cache_get_line_size(). */
  59
  60         const char *line_size_props[2];
  61         const char *nr_sets_prop;
  62 };
  63
  64 /* These are used to index the cache_type_info array. */
  65 #define CACHE_TYPE_UNIFIED     0
  66 #define CACHE_TYPE_INSTRUCTION 1
  67 #define CACHE_TYPE_DATA        2
  68
  69 static const struct cache_type_info cache_type_info[] = {
  70         {
  71                 /* PowerPC Processor binding says the [di]-cache-*
  72                  * must be equal on unified caches, so just use
  73                  * d-cache properties. */
  74                 .name            = "Unified",
  75                 .size_prop       = "d-cache-size",
  76                 .line_size_props = { "d-cache-line-size",
  77                                      "d-cache-block-size", },
  78                 .nr_sets_prop    = "d-cache-sets",
  79         },
  80         {
  81                 .name            = "Instruction",
  82                 .size_prop       = "i-cache-size",
  83                 .line_size_props = { "i-cache-line-size",
  84                                      "i-cache-block-size", },
  85                 .nr_sets_prop    = "i-cache-sets",
  86         },
  87         {
  88                 .name            = "Data",
  89                 .size_prop       = "d-cache-size",
  90                 .line_size_props = { "d-cache-line-size",
  91                                      "d-cache-block-size", },
  92                 .nr_sets_prop    = "d-cache-sets",
  93         },
  94 };
  95
  96 /* Cache object: each instance of this corresponds to a distinct cache
  97  * in the system.  There are separate objects for Harvard caches: one
  98  * each for instruction and data, and each refers to the same OF node.
  99  * The refcount of the OF node is elevated for the lifetime of the
 100  * cache object.  A cache object is released when its shared_cpu_map
 101  * is cleared (see cache_cpu_clear).
 102  *
 103  * A cache object is on two lists: an unsorted global list
 104  * (cache_list) of cache objects; and a singly-linked list
 105  * representing the local cache hierarchy, which is ordered by level
 106  * (e.g. L1d -> L1i -> L2 -> L3).
 107  */
 108 struct cache {
 109         struct device_node *ofnode;    /* OF node for this cache, may be cpu */
 110         struct cpumask shared_cpu_map; /* online CPUs using this cache */
 111         int type;                      /* split cache disambiguation */
 112         int level;                     /* level not explicit in device tree */
 113         struct list_head list;         /* global list of cache objects */
 114         struct cache *next_local;      /* next cache of >= level */
 115 };
 116
 117 static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
 118
 119 /* traversal/modification of this list occurs only at cpu hotplug time;
 120  * access is serialized by cpu hotplug locking
 121  */
 122 static LIST_HEAD(cache_list);
 123
 124 static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
 125 {
 126         return container_of(k, struct cache_index_dir, kobj);
 127 }
 128
 129 static const char *cache_type_string(const struct cache *cache)
 130 {
 131         return cache_type_info[cache->type].name;
 132 }
 133
 134 static void cache_init(struct cache *cache, int type, int level,
 135                        struct device_node *ofnode)
 136 {
 137         cache->type = type;
 138         cache->level = level;
 139         cache->ofnode = of_node_get(ofnode);
 140         INIT_LIST_HEAD(&cache->list);
 141         list_add(&cache->list, &cache_list);
 142 }
 143
 144 static struct cache *new_cache(int type, int level, struct device_node *ofnode)
 145 {
 146         struct cache *cache;
 147
 148         cache = kzalloc(sizeof(*cache), GFP_KERNEL);
 149         if (cache)
 150                 cache_init(cache, type, level, ofnode);
 151
 152         return cache;
 153 }
 154
 155 static void release_cache_debugcheck(struct cache *cache)
 156 {
 157         struct cache *iter;
 158
 159         list_for_each_entry(iter, &cache_list, list)
 160                 WARN_ONCE(iter->next_local == cache,
 161                           "cache for %s(%s) refers to cache for %s(%s)\n",
 162                           iter->ofnode->full_name,
 163                           cache_type_string(iter),
 164                           cache->ofnode->full_name,
 165                           cache_type_string(cache));
 166 }
 167
 168 static void release_cache(struct cache *cache)
 169 {
 170         if (!cache)
 171                 return;
 172
 173         pr_debug("freeing L%d %s cache for %s\n", cache->level,
 174                  cache_type_string(cache), cache->ofnode->full_name);
 175
 176         release_cache_debugcheck(cache);
 177         list_del(&cache->list);
 178         of_node_put(cache->ofnode);
 179         kfree(cache);
 180 }
 181
 182 static void cache_cpu_set(struct cache *cache, int cpu)
 183 {
 184         struct cache *next = cache;
 185
 186         while (next) {
 187                 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
 188                           "CPU %i already accounted in %s(%s)\n",
 189                           cpu, next->ofnode->full_name,
 190                           cache_type_string(next));
 191                 cpumask_set_cpu(cpu, &next->shared_cpu_map);
 192                 next = next->next_local;
 193         }
 194 }
 195
 196 static int cache_size(const struct cache *cache, unsigned int *ret)
 197 {
 198         const char *propname;
 199         const __be32 *cache_size;
 200
 201         propname = cache_type_info[cache->type].size_prop;
 202
 203         cache_size = of_get_property(cache->ofnode, propname, NULL);
 204         if (!cache_size)
 205                 return -ENODEV;
 206
 207         *ret = of_read_number(cache_size, 1);
 208         return 0;
 209 }
 210
 211 static int cache_size_kb(const struct cache *cache, unsigned int *ret)
 212 {
 213         unsigned int size;
 214
 215         if (cache_size(cache, &size))
 216                 return -ENODEV;
 217
 218         *ret = size / 1024;
 219         return 0;
 220 }
 221
 222 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 223 static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
 224 {
 225         const __be32 *line_size;
 226         int i, lim;
 227
 228         lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
 229
 230         for (i = 0; i < lim; i++) {
 231                 const char *propname;
 232
 233                 propname = cache_type_info[cache->type].line_size_props[i];
 234                 line_size = of_get_property(cache->ofnode, propname, NULL);
 235                 if (line_size)
 236                         break;
 237         }
 238
 239         if (!line_size)
 240                 return -ENODEV;
 241
 242         *ret = of_read_number(line_size, 1);
 243         return 0;
 244 }
 245
 246 static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
 247 {
 248         const char *propname;
 249         const __be32 *nr_sets;
 250
 251         propname = cache_type_info[cache->type].nr_sets_prop;
 252
 253         nr_sets = of_get_property(cache->ofnode, propname, NULL);
 254         if (!nr_sets)
 255                 return -ENODEV;
 256
 257         *ret = of_read_number(nr_sets, 1);
 258         return 0;
 259 }
 260
 261 static int cache_associativity(const struct cache *cache, unsigned int *ret)
 262 {
 263         unsigned int line_size;
 264         unsigned int nr_sets;
 265         unsigned int size;
 266
 267         if (cache_nr_sets(cache, &nr_sets))
 268                 goto err;
 269
 270         /* If the cache is fully associative, there is no need to
 271          * check the other properties.
 272          */
 273         if (nr_sets == 1) {
 274                 *ret = 0;
 275                 return 0;
 276         }
 277
 278         if (cache_get_line_size(cache, &line_size))
 279                 goto err;
 280         if (cache_size(cache, &size))
 281                 goto err;
 282
 283         if (!(nr_sets > 0 && size > 0 && line_size > 0))
 284                 goto err;
 285
 286         *ret = (size / nr_sets) / line_size;
 287         return 0;
 288 err:
 289         return -ENODEV;
 290 }
 291
 292 /* helper for dealing with split caches */
 293 static struct cache *cache_find_first_sibling(struct cache *cache)
 294 {
 295         struct cache *iter;
 296
 297         if (cache->type == CACHE_TYPE_UNIFIED)
 298                 return cache;
 299
 300         list_for_each_entry(iter, &cache_list, list)
 301                 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
 302                         return iter;
 303
 304         return cache;
 305 }
 306
 307 /* return the first cache on a local list matching node */
 308 static struct cache *cache_lookup_by_node(const struct device_node *node)
 309 {
 310         struct cache *cache = NULL;
 311         struct cache *iter;
 312
 313         list_for_each_entry(iter, &cache_list, list) {
 314                 if (iter->ofnode != node)
 315                         continue;
 316                 cache = cache_find_first_sibling(iter);
 317                 break;
 318         }
 319
 320         return cache;
 321 }
 322
 323 static bool cache_node_is_unified(const struct device_node *np)
 324 {
 325         return of_get_property(np, "cache-unified", NULL);
 326 }
 327
 328 static struct cache *cache_do_one_devnode_unified(struct device_node *node,
 329                                                   int level)
 330 {
 331         struct cache *cache;
 332
 333         pr_debug("creating L%d ucache for %s\n", level, node->full_name);
 334
 335         cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
 336
 337         return cache;
 338 }
 339
 340 static struct cache *cache_do_one_devnode_split(struct device_node *node,
 341                                                 int level)
 342 {
 343         struct cache *dcache, *icache;
 344
 345         pr_debug("creating L%d dcache and icache for %s\n", level,
 346                  node->full_name);
 347
 348         dcache = new_cache(CACHE_TYPE_DATA, level, node);
 349         icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
 350
 351         if (!dcache || !icache)
 352                 goto err;
 353
 354         dcache->next_local = icache;
 355
 356         return dcache;
 357 err:
 358         release_cache(dcache);
 359         release_cache(icache);
 360         return NULL;
 361 }
 362
 363 static struct cache *cache_do_one_devnode(struct device_node *node, int level)
 364 {
 365         struct cache *cache;
 366
 367         if (cache_node_is_unified(node))
 368                 cache = cache_do_one_devnode_unified(node, level);
 369         else
 370                 cache = cache_do_one_devnode_split(node, level);
 371
 372         return cache;
 373 }
 374
 375 static struct cache *cache_lookup_or_instantiate(struct device_node *node,
 376                                                  int level)
 377 {
 378         struct cache *cache;
 379
 380         cache = cache_lookup_by_node(node);
 381
 382         WARN_ONCE(cache && cache->level != level,
 383                   "cache level mismatch on lookup (got %d, expected %d)\n",
 384                   cache->level, level);
 385
 386         if (!cache)
 387                 cache = cache_do_one_devnode(node, level);
 388
 389         return cache;
 390 }
 391
 392 static void link_cache_lists(struct cache *smaller, struct cache *bigger)
 393 {
 394         while (smaller->next_local) {
 395                 if (smaller->next_local == bigger)
 396                         return; /* already linked */
 397                 smaller = smaller->next_local;
 398         }
 399
 400         smaller->next_local = bigger;
 401 }
 402
 403 static void do_subsidiary_caches_debugcheck(struct cache *cache)
 404 {
 405         WARN_ON_ONCE(cache->level != 1);
 406         WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
 407 }
 408
 409 static void do_subsidiary_caches(struct cache *cache)
 410 {
 411         struct device_node *subcache_node;
 412         int level = cache->level;
 413
 414         do_subsidiary_caches_debugcheck(cache);
 415
 416         while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
 417                 struct cache *subcache;
 418
 419                 level++;
 420                 subcache = cache_lookup_or_instantiate(subcache_node, level);
 421                 of_node_put(subcache_node);
 422                 if (!subcache)
 423                         break;
 424
 425                 link_cache_lists(cache, subcache);
 426                 cache = subcache;
 427         }
 428 }
 429
 430 static struct cache *cache_chain_instantiate(unsigned int cpu_id)
 431 {
 432         struct device_node *cpu_node;
 433         struct cache *cpu_cache = NULL;
 434
 435         pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
 436
 437         cpu_node = of_get_cpu_node(cpu_id, NULL);
 438         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 439         if (!cpu_node)
 440                 goto out;
 441
 442         cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
 443         if (!cpu_cache)
 444                 goto out;
 445
 446         do_subsidiary_caches(cpu_cache);
 447
 448         cache_cpu_set(cpu_cache, cpu_id);
 449 out:
 450         of_node_put(cpu_node);
 451
 452         return cpu_cache;
 453 }
 454
 455 static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
 456 {
 457         struct cache_dir *cache_dir;
 458         struct device *dev;
 459         struct kobject *kobj = NULL;
 460
 461         dev = get_cpu_device(cpu_id);
 462         WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
 463         if (!dev)
 464                 goto err;
 465
 466         kobj = kobject_create_and_add("cache", &dev->kobj);
 467         if (!kobj)
 468                 goto err;
 469
 470         cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
 471         if (!cache_dir)
 472                 goto err;
 473
 474         cache_dir->kobj = kobj;
 475
 476         WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
 477
 478         per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
 479
 480         return cache_dir;
 481 err:
 482         kobject_put(kobj);
 483         return NULL;
 484 }
 485
 486 static void cache_index_release(struct kobject *kobj)
 487 {
 488         struct cache_index_dir *index;
 489
 490         index = kobj_to_cache_index_dir(kobj);
 491
 492         pr_debug("freeing index directory for L%d %s cache\n",
 493                  index->cache->level, cache_type_string(index->cache));
 494
 495         kfree(index);
 496 }
 497
 498 static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
 499 {
 500         struct kobj_attribute *kobj_attr;
 501
 502         kobj_attr = container_of(attr, struct kobj_attribute, attr);
 503
 504         return kobj_attr->show(k, kobj_attr, buf);
 505 }
 506
 507 static struct cache *index_kobj_to_cache(struct kobject *k)
 508 {
 509         struct cache_index_dir *index;
 510
 511         index = kobj_to_cache_index_dir(k);
 512
 513         return index->cache;
 514 }
 515
 516 static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 517 {
 518         unsigned int size_kb;
 519         struct cache *cache;
 520
 521         cache = index_kobj_to_cache(k);
 522
 523         if (cache_size_kb(cache, &size_kb))
 524                 return -ENODEV;
 525
 526         return sprintf(buf, "%uK\n", size_kb);
 527 }
 528
 529 static struct kobj_attribute cache_size_attr =
 530         __ATTR(size, 0444, size_show, NULL);
 531
 532
 533 static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 534 {
 535         unsigned int line_size;
 536         struct cache *cache;
 537
 538         cache = index_kobj_to_cache(k);
 539
 540         if (cache_get_line_size(cache, &line_size))
 541                 return -ENODEV;
 542
 543         return sprintf(buf, "%u\n", line_size);
 544 }
 545
 546 static struct kobj_attribute cache_line_size_attr =
 547         __ATTR(coherency_line_size, 0444, line_size_show, NULL);
 548
 549 static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 550 {
 551         unsigned int nr_sets;
 552         struct cache *cache;
 553
 554         cache = index_kobj_to_cache(k);
 555
 556         if (cache_nr_sets(cache, &nr_sets))
 557                 return -ENODEV;
 558
 559         return sprintf(buf, "%u\n", nr_sets);
 560 }
 561
 562 static struct kobj_attribute cache_nr_sets_attr =
 563         __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
 564
 565 static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 566 {
 567         unsigned int associativity;
 568         struct cache *cache;
 569
 570         cache = index_kobj_to_cache(k);
 571
 572         if (cache_associativity(cache, &associativity))
 573                 return -ENODEV;
 574
 575         return sprintf(buf, "%u\n", associativity);
 576 }
 577
 578 static struct kobj_attribute cache_assoc_attr =
 579         __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
 580
 581 static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 582 {
 583         struct cache *cache;
 584
 585         cache = index_kobj_to_cache(k);
 586
 587         return sprintf(buf, "%s\n", cache_type_string(cache));
 588 }
 589
 590 static struct kobj_attribute cache_type_attr =
 591         __ATTR(type, 0444, type_show, NULL);
 592
 593 static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 594 {
 595         struct cache_index_dir *index;
 596         struct cache *cache;
 597
 598         index = kobj_to_cache_index_dir(k);
 599         cache = index->cache;
 600
 601         return sprintf(buf, "%d\n", cache->level);
 602 }
 603
 604 static struct kobj_attribute cache_level_attr =
 605         __ATTR(level, 0444, level_show, NULL);
 606
 607 static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 608 {
 609         struct cache_index_dir *index;
 610         struct cache *cache;
 611         int len;
 612         int n = 0;
 613
 614         index = kobj_to_cache_index_dir(k);
 615         cache = index->cache;
 616         len = PAGE_SIZE - 2;
 617
 618         if (len > 1) {
 619                 n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
 620                 buf[n++] = '\n';
 621                 buf[n] = '\0';
 622         }
 623         return n;
 624 }
 625
 626 static struct kobj_attribute cache_shared_cpu_map_attr =
 627         __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
 628
 629 /* Attributes which should always be created -- the kobject/sysfs core
 630  * does this automatically via kobj_type->default_attrs.  This is the
 631  * minimum data required to uniquely identify a cache.
 632  */
 633 static struct attribute *cache_index_default_attrs[] = {
 634         &cache_type_attr.attr,
 635         &cache_level_attr.attr,
 636         &cache_shared_cpu_map_attr.attr,
 637         NULL,
 638 };
 639
 640 /* Attributes which should be created if the cache device node has the
 641  * right properties -- see cacheinfo_create_index_opt_attrs
 642  */
 643 static struct kobj_attribute *cache_index_opt_attrs[] = {
 644         &cache_size_attr,
 645         &cache_line_size_attr,
 646         &cache_nr_sets_attr,
 647         &cache_assoc_attr,
 648 };
 649
 650 static const struct sysfs_ops cache_index_ops = {
 651         .show = cache_index_show,
 652 };
 653
 654 static struct kobj_type cache_index_type = {
 655         .release = cache_index_release,
 656         .sysfs_ops = &cache_index_ops,
 657         .default_attrs = cache_index_default_attrs,
 658 };
 659
 660 static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
 661 {
 662         const char *cache_name;
 663         const char *cache_type;
 664         struct cache *cache;
 665         char *buf;
 666         int i;
 667
 668         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 669         if (!buf)
 670                 return;
 671
 672         cache = dir->cache;
 673         cache_name = cache->ofnode->full_name;
 674         cache_type = cache_type_string(cache);
 675
 676         /* We don't want to create an attribute that can't provide a
 677          * meaningful value.  Check the return value of each optional
 678          * attribute's ->show method before registering the
 679          * attribute.
 680          */
 681         for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
 682                 struct kobj_attribute *attr;
 683                 ssize_t rc;
 684
 685                 attr = cache_index_opt_attrs[i];
 686
 687                 rc = attr->show(&dir->kobj, attr, buf);
 688                 if (rc <= 0) {
 689                         pr_debug("not creating %s attribute for "
 690                                  "%s(%s) (rc = %zd)\n",
 691                                  attr->attr.name, cache_name,
 692                                  cache_type, rc);
 693                         continue;
 694                 }
 695                 if (sysfs_create_file(&dir->kobj, &attr->attr))
 696                         pr_debug("could not create %s attribute for %s(%s)\n",
 697                                  attr->attr.name, cache_name, cache_type);
 698         }
 699
 700         kfree(buf);
 701 }
 702
 703 static void cacheinfo_create_index_dir(struct cache *cache, int index,
 704                                        struct cache_dir *cache_dir)
 705 {
 706         struct cache_index_dir *index_dir;
 707         int rc;
 708
 709         index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
 710         if (!index_dir)
 711                 goto err;
 712
 713         index_dir->cache = cache;
 714
 715         rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
 716                                   cache_dir->kobj, "index%d", index);
 717         if (rc)
 718                 goto err;
 719
 720         index_dir->next = cache_dir->index;
 721         cache_dir->index = index_dir;
 722
 723         cacheinfo_create_index_opt_attrs(index_dir);
 724
 725         return;
 726 err:
 727         kfree(index_dir);
 728 }
 729
 730 static void cacheinfo_sysfs_populate(unsigned int cpu_id,
 731                                      struct cache *cache_list)
 732 {
 733         struct cache_dir *cache_dir;
 734         struct cache *cache;
 735         int index = 0;
 736
 737         cache_dir = cacheinfo_create_cache_dir(cpu_id);
 738         if (!cache_dir)
 739                 return;
 740
 741         cache = cache_list;
 742         while (cache) {
 743                 cacheinfo_create_index_dir(cache, index, cache_dir);
 744                 index++;
 745                 cache = cache->next_local;
 746         }
 747 }
 748
 749 void cacheinfo_cpu_online(unsigned int cpu_id)
 750 {
 751         struct cache *cache;
 752
 753         cache = cache_chain_instantiate(cpu_id);
 754         if (!cache)
 755                 return;
 756
 757         cacheinfo_sysfs_populate(cpu_id, cache);
 758 }
 759
 760 #ifdef CONFIG_HOTPLUG_CPU /* functions needed for cpu offline */
 761
 762 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
 763 {
 764         struct device_node *cpu_node;
 765         struct cache *cache;
 766
 767         cpu_node = of_get_cpu_node(cpu_id, NULL);
 768         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 769         if (!cpu_node)
 770                 return NULL;
 771
 772         cache = cache_lookup_by_node(cpu_node);
 773         of_node_put(cpu_node);
 774
 775         return cache;
 776 }
 777
 778 static void remove_index_dirs(struct cache_dir *cache_dir)
 779 {
 780         struct cache_index_dir *index;
 781
 782         index = cache_dir->index;
 783
 784         while (index) {
 785                 struct cache_index_dir *next;
 786
 787                 next = index->next;
 788                 kobject_put(&index->kobj);
 789                 index = next;
 790         }
 791 }
 792
 793 static void remove_cache_dir(struct cache_dir *cache_dir)
 794 {
 795         remove_index_dirs(cache_dir);
 796
 797         /* Remove cache dir from sysfs */
 798         kobject_del(cache_dir->kobj);
 799
 800         kobject_put(cache_dir->kobj);
 801
 802         kfree(cache_dir);
 803 }
 804
 805 static void cache_cpu_clear(struct cache *cache, int cpu)
 806 {
 807         while (cache) {
 808                 struct cache *next = cache->next_local;
 809
 810                 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
 811                           "CPU %i not accounted in %s(%s)\n",
 812                           cpu, cache->ofnode->full_name,
 813                           cache_type_string(cache));
 814
 815                 cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
 816
 817                 /* Release the cache object if all the cpus using it
 818                  * are offline */
 819                 if (cpumask_empty(&cache->shared_cpu_map))
 820                         release_cache(cache);
 821
 822                 cache = next;
 823         }
 824 }
 825
 826 void cacheinfo_cpu_offline(unsigned int cpu_id)
 827 {
 828         struct cache_dir *cache_dir;
 829         struct cache *cache;
 830
 831         /* Prevent userspace from seeing inconsistent state - remove
 832          * the sysfs hierarchy first */
 833         cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
 834
 835         /* careful, sysfs population may have failed */
 836         if (cache_dir)
 837                 remove_cache_dir(cache_dir);
 838
 839         per_cpu(cache_dir_pcpu, cpu_id) = NULL;
 840
 841         /* clear the CPU's bit in its cache chain, possibly freeing
 842          * cache objects */
 843         cache = cache_lookup_by_cpu(cpu_id);
 844         if (cache)
 845                 cache_cpu_clear(cache, cpu_id);
 846 }
 847 #endif /* CONFIG_HOTPLUG_CPU */