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 __cpuinit cache_init(struct cache *cache, int type, int level, struct device_node *ofnode)
 135 {
 136         cache->type = type;
 137         cache->level = level;
 138         cache->ofnode = of_node_get(ofnode);
 139         INIT_LIST_HEAD(&cache->list);
 140         list_add(&cache->list, &cache_list);
 141 }
 142
 143 static struct cache *__cpuinit new_cache(int type, int level, struct device_node *ofnode)
 144 {
 145         struct cache *cache;
 146
 147         cache = kzalloc(sizeof(*cache), GFP_KERNEL);
 148         if (cache)
 149                 cache_init(cache, type, level, ofnode);
 150
 151         return cache;
 152 }
 153
 154 static void release_cache_debugcheck(struct cache *cache)
 155 {
 156         struct cache *iter;
 157
 158         list_for_each_entry(iter, &cache_list, list)
 159                 WARN_ONCE(iter->next_local == cache,
 160                           "cache for %s(%s) refers to cache for %s(%s)\n",
 161                           iter->ofnode->full_name,
 162                           cache_type_string(iter),
 163                           cache->ofnode->full_name,
 164                           cache_type_string(cache));
 165 }
 166
 167 static void release_cache(struct cache *cache)
 168 {
 169         if (!cache)
 170                 return;
 171
 172         pr_debug("freeing L%d %s cache for %s\n", cache->level,
 173                  cache_type_string(cache), cache->ofnode->full_name);
 174
 175         release_cache_debugcheck(cache);
 176         list_del(&cache->list);
 177         of_node_put(cache->ofnode);
 178         kfree(cache);
 179 }
 180
 181 static void cache_cpu_set(struct cache *cache, int cpu)
 182 {
 183         struct cache *next = cache;
 184
 185         while (next) {
 186                 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
 187                           "CPU %i already accounted in %s(%s)\n",
 188                           cpu, next->ofnode->full_name,
 189                           cache_type_string(next));
 190                 cpumask_set_cpu(cpu, &next->shared_cpu_map);
 191                 next = next->next_local;
 192         }
 193 }
 194
 195 static int cache_size(const struct cache *cache, unsigned int *ret)
 196 {
 197         const char *propname;
 198         const u32 *cache_size;
 199
 200         propname = cache_type_info[cache->type].size_prop;
 201
 202         cache_size = of_get_property(cache->ofnode, propname, NULL);
 203         if (!cache_size)
 204                 return -ENODEV;
 205
 206         *ret = *cache_size;
 207         return 0;
 208 }
 209
 210 static int cache_size_kb(const struct cache *cache, unsigned int *ret)
 211 {
 212         unsigned int size;
 213
 214         if (cache_size(cache, &size))
 215                 return -ENODEV;
 216
 217         *ret = size / 1024;
 218         return 0;
 219 }
 220
 221 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 222 static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
 223 {
 224         const u32 *line_size;
 225         int i, lim;
 226
 227         lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
 228
 229         for (i = 0; i < lim; i++) {
 230                 const char *propname;
 231
 232                 propname = cache_type_info[cache->type].line_size_props[i];
 233                 line_size = of_get_property(cache->ofnode, propname, NULL);
 234                 if (line_size)
 235                         break;
 236         }
 237
 238         if (!line_size)
 239                 return -ENODEV;
 240
 241         *ret = *line_size;
 242         return 0;
 243 }
 244
 245 static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
 246 {
 247         const char *propname;
 248         const u32 *nr_sets;
 249
 250         propname = cache_type_info[cache->type].nr_sets_prop;
 251
 252         nr_sets = of_get_property(cache->ofnode, propname, NULL);
 253         if (!nr_sets)
 254                 return -ENODEV;
 255
 256         *ret = *nr_sets;
 257         return 0;
 258 }
 259
 260 static int cache_associativity(const struct cache *cache, unsigned int *ret)
 261 {
 262         unsigned int line_size;
 263         unsigned int nr_sets;
 264         unsigned int size;
 265
 266         if (cache_nr_sets(cache, &nr_sets))
 267                 goto err;
 268
 269         /* If the cache is fully associative, there is no need to
 270          * check the other properties.
 271          */
 272         if (nr_sets == 1) {
 273                 *ret = 0;
 274                 return 0;
 275         }
 276
 277         if (cache_get_line_size(cache, &line_size))
 278                 goto err;
 279         if (cache_size(cache, &size))
 280                 goto err;
 281
 282         if (!(nr_sets > 0 && size > 0 && line_size > 0))
 283                 goto err;
 284
 285         *ret = (size / nr_sets) / line_size;
 286         return 0;
 287 err:
 288         return -ENODEV;
 289 }
 290
 291 /* helper for dealing with split caches */
 292 static struct cache *cache_find_first_sibling(struct cache *cache)
 293 {
 294         struct cache *iter;
 295
 296         if (cache->type == CACHE_TYPE_UNIFIED)
 297                 return cache;
 298
 299         list_for_each_entry(iter, &cache_list, list)
 300                 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
 301                         return iter;
 302
 303         return cache;
 304 }
 305
 306 /* return the first cache on a local list matching node */
 307 static struct cache *cache_lookup_by_node(const struct device_node *node)
 308 {
 309         struct cache *cache = NULL;
 310         struct cache *iter;
 311
 312         list_for_each_entry(iter, &cache_list, list) {
 313                 if (iter->ofnode != node)
 314                         continue;
 315                 cache = cache_find_first_sibling(iter);
 316                 break;
 317         }
 318
 319         return cache;
 320 }
 321
 322 static bool cache_node_is_unified(const struct device_node *np)
 323 {
 324         return of_get_property(np, "cache-unified", NULL);
 325 }
 326
 327 static struct cache *__cpuinit cache_do_one_devnode_unified(struct device_node *node, int level)
 328 {
 329         struct cache *cache;
 330
 331         pr_debug("creating L%d ucache for %s\n", level, node->full_name);
 332
 333         cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
 334
 335         return cache;
 336 }
 337
 338 static struct cache *__cpuinit cache_do_one_devnode_split(struct device_node *node, int level)
 339 {
 340         struct cache *dcache, *icache;
 341
 342         pr_debug("creating L%d dcache and icache for %s\n", level,
 343                  node->full_name);
 344
 345         dcache = new_cache(CACHE_TYPE_DATA, level, node);
 346         icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
 347
 348         if (!dcache || !icache)
 349                 goto err;
 350
 351         dcache->next_local = icache;
 352
 353         return dcache;
 354 err:
 355         release_cache(dcache);
 356         release_cache(icache);
 357         return NULL;
 358 }
 359
 360 static struct cache *__cpuinit cache_do_one_devnode(struct device_node *node, int level)
 361 {
 362         struct cache *cache;
 363
 364         if (cache_node_is_unified(node))
 365                 cache = cache_do_one_devnode_unified(node, level);
 366         else
 367                 cache = cache_do_one_devnode_split(node, level);
 368
 369         return cache;
 370 }
 371
 372 static struct cache *__cpuinit cache_lookup_or_instantiate(struct device_node *node, int level)
 373 {
 374         struct cache *cache;
 375
 376         cache = cache_lookup_by_node(node);
 377
 378         WARN_ONCE(cache && cache->level != level,
 379                   "cache level mismatch on lookup (got %d, expected %d)\n",
 380                   cache->level, level);
 381
 382         if (!cache)
 383                 cache = cache_do_one_devnode(node, level);
 384
 385         return cache;
 386 }
 387
 388 static void __cpuinit link_cache_lists(struct cache *smaller, struct cache *bigger)
 389 {
 390         while (smaller->next_local) {
 391                 if (smaller->next_local == bigger)
 392                         return; /* already linked */
 393                 smaller = smaller->next_local;
 394         }
 395
 396         smaller->next_local = bigger;
 397 }
 398
 399 static void __cpuinit do_subsidiary_caches_debugcheck(struct cache *cache)
 400 {
 401         WARN_ON_ONCE(cache->level != 1);
 402         WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
 403 }
 404
 405 static void __cpuinit do_subsidiary_caches(struct cache *cache)
 406 {
 407         struct device_node *subcache_node;
 408         int level = cache->level;
 409
 410         do_subsidiary_caches_debugcheck(cache);
 411
 412         while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
 413                 struct cache *subcache;
 414
 415                 level++;
 416                 subcache = cache_lookup_or_instantiate(subcache_node, level);
 417                 of_node_put(subcache_node);
 418                 if (!subcache)
 419                         break;
 420
 421                 link_cache_lists(cache, subcache);
 422                 cache = subcache;
 423         }
 424 }
 425
 426 static struct cache *__cpuinit cache_chain_instantiate(unsigned int cpu_id)
 427 {
 428         struct device_node *cpu_node;
 429         struct cache *cpu_cache = NULL;
 430
 431         pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
 432
 433         cpu_node = of_get_cpu_node(cpu_id, NULL);
 434         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 435         if (!cpu_node)
 436                 goto out;
 437
 438         cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
 439         if (!cpu_cache)
 440                 goto out;
 441
 442         do_subsidiary_caches(cpu_cache);
 443
 444         cache_cpu_set(cpu_cache, cpu_id);
 445 out:
 446         of_node_put(cpu_node);
 447
 448         return cpu_cache;
 449 }
 450
 451 static struct cache_dir *__cpuinit cacheinfo_create_cache_dir(unsigned int cpu_id)
 452 {
 453         struct cache_dir *cache_dir;
 454         struct sys_device *sysdev;
 455         struct kobject *kobj = NULL;
 456
 457         sysdev = get_cpu_sysdev(cpu_id);
 458         WARN_ONCE(!sysdev, "no sysdev for CPU %i\n", cpu_id);
 459         if (!sysdev)
 460                 goto err;
 461
 462         kobj = kobject_create_and_add("cache", &sysdev->kobj);
 463         if (!kobj)
 464                 goto err;
 465
 466         cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
 467         if (!cache_dir)
 468                 goto err;
 469
 470         cache_dir->kobj = kobj;
 471
 472         WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
 473
 474         per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
 475
 476         return cache_dir;
 477 err:
 478         kobject_put(kobj);
 479         return NULL;
 480 }
 481
 482 static void cache_index_release(struct kobject *kobj)
 483 {
 484         struct cache_index_dir *index;
 485
 486         index = kobj_to_cache_index_dir(kobj);
 487
 488         pr_debug("freeing index directory for L%d %s cache\n",
 489                  index->cache->level, cache_type_string(index->cache));
 490
 491         kfree(index);
 492 }
 493
 494 static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
 495 {
 496         struct kobj_attribute *kobj_attr;
 497
 498         kobj_attr = container_of(attr, struct kobj_attribute, attr);
 499
 500         return kobj_attr->show(k, kobj_attr, buf);
 501 }
 502
 503 static struct cache *index_kobj_to_cache(struct kobject *k)
 504 {
 505         struct cache_index_dir *index;
 506
 507         index = kobj_to_cache_index_dir(k);
 508
 509         return index->cache;
 510 }
 511
 512 static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 513 {
 514         unsigned int size_kb;
 515         struct cache *cache;
 516
 517         cache = index_kobj_to_cache(k);
 518
 519         if (cache_size_kb(cache, &size_kb))
 520                 return -ENODEV;
 521
 522         return sprintf(buf, "%uK\n", size_kb);
 523 }
 524
 525 static struct kobj_attribute cache_size_attr =
 526         __ATTR(size, 0444, size_show, NULL);
 527
 528
 529 static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 530 {
 531         unsigned int line_size;
 532         struct cache *cache;
 533
 534         cache = index_kobj_to_cache(k);
 535
 536         if (cache_get_line_size(cache, &line_size))
 537                 return -ENODEV;
 538
 539         return sprintf(buf, "%u\n", line_size);
 540 }
 541
 542 static struct kobj_attribute cache_line_size_attr =
 543         __ATTR(coherency_line_size, 0444, line_size_show, NULL);
 544
 545 static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 546 {
 547         unsigned int nr_sets;
 548         struct cache *cache;
 549
 550         cache = index_kobj_to_cache(k);
 551
 552         if (cache_nr_sets(cache, &nr_sets))
 553                 return -ENODEV;
 554
 555         return sprintf(buf, "%u\n", nr_sets);
 556 }
 557
 558 static struct kobj_attribute cache_nr_sets_attr =
 559         __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
 560
 561 static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 562 {
 563         unsigned int associativity;
 564         struct cache *cache;
 565
 566         cache = index_kobj_to_cache(k);
 567
 568         if (cache_associativity(cache, &associativity))
 569                 return -ENODEV;
 570
 571         return sprintf(buf, "%u\n", associativity);
 572 }
 573
 574 static struct kobj_attribute cache_assoc_attr =
 575         __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
 576
 577 static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 578 {
 579         struct cache *cache;
 580
 581         cache = index_kobj_to_cache(k);
 582
 583         return sprintf(buf, "%s\n", cache_type_string(cache));
 584 }
 585
 586 static struct kobj_attribute cache_type_attr =
 587         __ATTR(type, 0444, type_show, NULL);
 588
 589 static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 590 {
 591         struct cache_index_dir *index;
 592         struct cache *cache;
 593
 594         index = kobj_to_cache_index_dir(k);
 595         cache = index->cache;
 596
 597         return sprintf(buf, "%d\n", cache->level);
 598 }
 599
 600 static struct kobj_attribute cache_level_attr =
 601         __ATTR(level, 0444, level_show, NULL);
 602
 603 static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 604 {
 605         struct cache_index_dir *index;
 606         struct cache *cache;
 607         int len;
 608         int n = 0;
 609
 610         index = kobj_to_cache_index_dir(k);
 611         cache = index->cache;
 612         len = PAGE_SIZE - 2;
 613
 614         if (len > 1) {
 615                 n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
 616                 buf[n++] = '\n';
 617                 buf[n] = '\0';
 618         }
 619         return n;
 620 }
 621
 622 static struct kobj_attribute cache_shared_cpu_map_attr =
 623         __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
 624
 625 /* Attributes which should always be created -- the kobject/sysfs core
 626  * does this automatically via kobj_type->default_attrs.  This is the
 627  * minimum data required to uniquely identify a cache.
 628  */
 629 static struct attribute *cache_index_default_attrs[] = {
 630         &cache_type_attr.attr,
 631         &cache_level_attr.attr,
 632         &cache_shared_cpu_map_attr.attr,
 633         NULL,
 634 };
 635
 636 /* Attributes which should be created if the cache device node has the
 637  * right properties -- see cacheinfo_create_index_opt_attrs
 638  */
 639 static struct kobj_attribute *cache_index_opt_attrs[] = {
 640         &cache_size_attr,
 641         &cache_line_size_attr,
 642         &cache_nr_sets_attr,
 643         &cache_assoc_attr,
 644 };
 645
 646 static const struct sysfs_ops cache_index_ops = {
 647         .show = cache_index_show,
 648 };
 649
 650 static struct kobj_type cache_index_type = {
 651         .release = cache_index_release,
 652         .sysfs_ops = &cache_index_ops,
 653         .default_attrs = cache_index_default_attrs,
 654 };
 655
 656 static void __cpuinit cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
 657 {
 658         const char *cache_name;
 659         const char *cache_type;
 660         struct cache *cache;
 661         char *buf;
 662         int i;
 663
 664         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 665         if (!buf)
 666                 return;
 667
 668         cache = dir->cache;
 669         cache_name = cache->ofnode->full_name;
 670         cache_type = cache_type_string(cache);
 671
 672         /* We don't want to create an attribute that can't provide a
 673          * meaningful value.  Check the return value of each optional
 674          * attribute's ->show method before registering the
 675          * attribute.
 676          */
 677         for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
 678                 struct kobj_attribute *attr;
 679                 ssize_t rc;
 680
 681                 attr = cache_index_opt_attrs[i];
 682
 683                 rc = attr->show(&dir->kobj, attr, buf);
 684                 if (rc <= 0) {
 685                         pr_debug("not creating %s attribute for "
 686                                  "%s(%s) (rc = %zd)\n",
 687                                  attr->attr.name, cache_name,
 688                                  cache_type, rc);
 689                         continue;
 690                 }
 691                 if (sysfs_create_file(&dir->kobj, &attr->attr))
 692                         pr_debug("could not create %s attribute for %s(%s)\n",
 693                                  attr->attr.name, cache_name, cache_type);
 694         }
 695
 696         kfree(buf);
 697 }
 698
 699 static void __cpuinit cacheinfo_create_index_dir(struct cache *cache, int index, struct cache_dir *cache_dir)
 700 {
 701         struct cache_index_dir *index_dir;
 702         int rc;
 703
 704         index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
 705         if (!index_dir)
 706                 goto err;
 707
 708         index_dir->cache = cache;
 709
 710         rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
 711                                   cache_dir->kobj, "index%d", index);
 712         if (rc)
 713                 goto err;
 714
 715         index_dir->next = cache_dir->index;
 716         cache_dir->index = index_dir;
 717
 718         cacheinfo_create_index_opt_attrs(index_dir);
 719
 720         return;
 721 err:
 722         kfree(index_dir);
 723 }
 724
 725 static void __cpuinit cacheinfo_sysfs_populate(unsigned int cpu_id, struct cache *cache_list)
 726 {
 727         struct cache_dir *cache_dir;
 728         struct cache *cache;
 729         int index = 0;
 730
 731         cache_dir = cacheinfo_create_cache_dir(cpu_id);
 732         if (!cache_dir)
 733                 return;
 734
 735         cache = cache_list;
 736         while (cache) {
 737                 cacheinfo_create_index_dir(cache, index, cache_dir);
 738                 index++;
 739                 cache = cache->next_local;
 740         }
 741 }
 742
 743 void __cpuinit cacheinfo_cpu_online(unsigned int cpu_id)
 744 {
 745         struct cache *cache;
 746
 747         cache = cache_chain_instantiate(cpu_id);
 748         if (!cache)
 749                 return;
 750
 751         cacheinfo_sysfs_populate(cpu_id, cache);
 752 }
 753
 754 #ifdef CONFIG_HOTPLUG_CPU /* functions needed for cpu offline */
 755
 756 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
 757 {
 758         struct device_node *cpu_node;
 759         struct cache *cache;
 760
 761         cpu_node = of_get_cpu_node(cpu_id, NULL);
 762         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 763         if (!cpu_node)
 764                 return NULL;
 765
 766         cache = cache_lookup_by_node(cpu_node);
 767         of_node_put(cpu_node);
 768
 769         return cache;
 770 }
 771
 772 static void remove_index_dirs(struct cache_dir *cache_dir)
 773 {
 774         struct cache_index_dir *index;
 775
 776         index = cache_dir->index;
 777
 778         while (index) {
 779                 struct cache_index_dir *next;
 780
 781                 next = index->next;
 782                 kobject_put(&index->kobj);
 783                 index = next;
 784         }
 785 }
 786
 787 static void remove_cache_dir(struct cache_dir *cache_dir)
 788 {
 789         remove_index_dirs(cache_dir);
 790
 791         kobject_put(cache_dir->kobj);
 792
 793         kfree(cache_dir);
 794 }
 795
 796 static void cache_cpu_clear(struct cache *cache, int cpu)
 797 {
 798         while (cache) {
 799                 struct cache *next = cache->next_local;
 800
 801                 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
 802                           "CPU %i not accounted in %s(%s)\n",
 803                           cpu, cache->ofnode->full_name,
 804                           cache_type_string(cache));
 805
 806                 cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
 807
 808                 /* Release the cache object if all the cpus using it
 809                  * are offline */
 810                 if (cpumask_empty(&cache->shared_cpu_map))
 811                         release_cache(cache);
 812
 813                 cache = next;
 814         }
 815 }
 816
 817 void cacheinfo_cpu_offline(unsigned int cpu_id)
 818 {
 819         struct cache_dir *cache_dir;
 820         struct cache *cache;
 821
 822         /* Prevent userspace from seeing inconsistent state - remove
 823          * the sysfs hierarchy first */
 824         cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
 825
 826         /* careful, sysfs population may have failed */
 827         if (cache_dir)
 828                 remove_cache_dir(cache_dir);
 829
 830         per_cpu(cache_dir_pcpu, cpu_id) = NULL;
 831
 832         /* clear the CPU's bit in its cache chain, possibly freeing
 833          * cache objects */
 834         cache = cache_lookup_by_cpu(cpu_id);
 835         if (cache)
 836                 cache_cpu_clear(cache, cpu_id);
 837 }
 838 #endif /* CONFIG_HOTPLUG_CPU */