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 <asm/prom.h>
  23
  24 #include "cacheinfo.h"
  25
  26 /* per-cpu object for tracking:
  27  * - a "cache" kobject for the top-level directory
  28  * - a list of "index" objects representing the cpu's local cache hierarchy
  29  */
  30 struct cache_dir {
  31         struct kobject *kobj; /* bare (not embedded) kobject for cache
  32                                * directory */
  33         struct cache_index_dir *index; /* list of index objects */
  34 };
  35
  36 /* "index" object: each cpu's cache directory has an index
  37  * subdirectory corresponding to a cache object associated with the
  38  * cpu.  This object's lifetime is managed via the embedded kobject.
  39  */
  40 struct cache_index_dir {
  41         struct kobject kobj;
  42         struct cache_index_dir *next; /* next index in parent directory */
  43         struct cache *cache;
  44 };
  45
  46 /* Template for determining which OF properties to query for a given
  47  * cache type */
  48 struct cache_type_info {
  49         const char *name;
  50         const char *size_prop;
  51
  52         /* Allow for both [di]-cache-line-size and
  53          * [di]-cache-block-size properties.  According to the PowerPC
  54          * Processor binding, -line-size should be provided if it
  55          * differs from the cache block size (that which is operated
  56          * on by cache instructions), so we look for -line-size first.
  57          * See cache_get_line_size(). */
  58
  59         const char *line_size_props[2];
  60         const char *nr_sets_prop;
  61 };
  62
  63 /* These are used to index the cache_type_info array. */
  64 #define CACHE_TYPE_UNIFIED     0
  65 #define CACHE_TYPE_INSTRUCTION 1
  66 #define CACHE_TYPE_DATA        2
  67
  68 static const struct cache_type_info cache_type_info[] = {
  69         {
  70                 /* PowerPC Processor binding says the [di]-cache-*
  71                  * must be equal on unified caches, so just use
  72                  * d-cache properties. */
  73                 .name            = "Unified",
  74                 .size_prop       = "d-cache-size",
  75                 .line_size_props = { "d-cache-line-size",
  76                                      "d-cache-block-size", },
  77                 .nr_sets_prop    = "d-cache-sets",
  78         },
  79         {
  80                 .name            = "Instruction",
  81                 .size_prop       = "i-cache-size",
  82                 .line_size_props = { "i-cache-line-size",
  83                                      "i-cache-block-size", },
  84                 .nr_sets_prop    = "i-cache-sets",
  85         },
  86         {
  87                 .name            = "Data",
  88                 .size_prop       = "d-cache-size",
  89                 .line_size_props = { "d-cache-line-size",
  90                                      "d-cache-block-size", },
  91                 .nr_sets_prop    = "d-cache-sets",
  92         },
  93 };
  94
  95 /* Cache object: each instance of this corresponds to a distinct cache
  96  * in the system.  There are separate objects for Harvard caches: one
  97  * each for instruction and data, and each refers to the same OF node.
  98  * The refcount of the OF node is elevated for the lifetime of the
  99  * cache object.  A cache object is released when its shared_cpu_map
 100  * is cleared (see cache_cpu_clear).
 101  *
 102  * A cache object is on two lists: an unsorted global list
 103  * (cache_list) of cache objects; and a singly-linked list
 104  * representing the local cache hierarchy, which is ordered by level
 105  * (e.g. L1d -> L1i -> L2 -> L3).
 106  */
 107 struct cache {
 108         struct device_node *ofnode;    /* OF node for this cache, may be cpu */
 109         struct cpumask shared_cpu_map; /* online CPUs using this cache */
 110         int type;                      /* split cache disambiguation */
 111         int level;                     /* level not explicit in device tree */
 112         struct list_head list;         /* global list of cache objects */
 113         struct cache *next_local;      /* next cache of >= level */
 114 };
 115
 116 static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
 117
 118 /* traversal/modification of this list occurs only at cpu hotplug time;
 119  * access is serialized by cpu hotplug locking
 120  */
 121 static LIST_HEAD(cache_list);
 122
 123 static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
 124 {
 125         return container_of(k, struct cache_index_dir, kobj);
 126 }
 127
 128 static const char *cache_type_string(const struct cache *cache)
 129 {
 130         return cache_type_info[cache->type].name;
 131 }
 132
 133 static void __cpuinit cache_init(struct cache *cache, int type, int level, struct device_node *ofnode)
 134 {
 135         cache->type = type;
 136         cache->level = level;
 137         cache->ofnode = of_node_get(ofnode);
 138         INIT_LIST_HEAD(&cache->list);
 139         list_add(&cache->list, &cache_list);
 140 }
 141
 142 static struct cache *__cpuinit new_cache(int type, int level, struct device_node *ofnode)
 143 {
 144         struct cache *cache;
 145
 146         cache = kzalloc(sizeof(*cache), GFP_KERNEL);
 147         if (cache)
 148                 cache_init(cache, type, level, ofnode);
 149
 150         return cache;
 151 }
 152
 153 static void release_cache_debugcheck(struct cache *cache)
 154 {
 155         struct cache *iter;
 156
 157         list_for_each_entry(iter, &cache_list, list)
 158                 WARN_ONCE(iter->next_local == cache,
 159                           "cache for %s(%s) refers to cache for %s(%s)\n",
 160                           iter->ofnode->full_name,
 161                           cache_type_string(iter),
 162                           cache->ofnode->full_name,
 163                           cache_type_string(cache));
 164 }
 165
 166 static void release_cache(struct cache *cache)
 167 {
 168         if (!cache)
 169                 return;
 170
 171         pr_debug("freeing L%d %s cache for %s\n", cache->level,
 172                  cache_type_string(cache), cache->ofnode->full_name);
 173
 174         release_cache_debugcheck(cache);
 175         list_del(&cache->list);
 176         of_node_put(cache->ofnode);
 177         kfree(cache);
 178 }
 179
 180 static void cache_cpu_set(struct cache *cache, int cpu)
 181 {
 182         struct cache *next = cache;
 183
 184         while (next) {
 185                 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
 186                           "CPU %i already accounted in %s(%s)\n",
 187                           cpu, next->ofnode->full_name,
 188                           cache_type_string(next));
 189                 cpumask_set_cpu(cpu, &next->shared_cpu_map);
 190                 next = next->next_local;
 191         }
 192 }
 193
 194 static int cache_size(const struct cache *cache, unsigned int *ret)
 195 {
 196         const char *propname;
 197         const u32 *cache_size;
 198
 199         propname = cache_type_info[cache->type].size_prop;
 200
 201         cache_size = of_get_property(cache->ofnode, propname, NULL);
 202         if (!cache_size)
 203                 return -ENODEV;
 204
 205         *ret = *cache_size;
 206         return 0;
 207 }
 208
 209 static int cache_size_kb(const struct cache *cache, unsigned int *ret)
 210 {
 211         unsigned int size;
 212
 213         if (cache_size(cache, &size))
 214                 return -ENODEV;
 215
 216         *ret = size / 1024;
 217         return 0;
 218 }
 219
 220 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 221 static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
 222 {
 223         const u32 *line_size;
 224         int i, lim;
 225
 226         lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
 227
 228         for (i = 0; i < lim; i++) {
 229                 const char *propname;
 230
 231                 propname = cache_type_info[cache->type].line_size_props[i];
 232                 line_size = of_get_property(cache->ofnode, propname, NULL);
 233                 if (line_size)
 234                         break;
 235         }
 236
 237         if (!line_size)
 238                 return -ENODEV;
 239
 240         *ret = *line_size;
 241         return 0;
 242 }
 243
 244 static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
 245 {
 246         const char *propname;
 247         const u32 *nr_sets;
 248
 249         propname = cache_type_info[cache->type].nr_sets_prop;
 250
 251         nr_sets = of_get_property(cache->ofnode, propname, NULL);
 252         if (!nr_sets)
 253                 return -ENODEV;
 254
 255         *ret = *nr_sets;
 256         return 0;
 257 }
 258
 259 static int cache_associativity(const struct cache *cache, unsigned int *ret)
 260 {
 261         unsigned int line_size;
 262         unsigned int nr_sets;
 263         unsigned int size;
 264
 265         if (cache_nr_sets(cache, &nr_sets))
 266                 goto err;
 267
 268         /* If the cache is fully associative, there is no need to
 269          * check the other properties.
 270          */
 271         if (nr_sets == 1) {
 272                 *ret = 0;
 273                 return 0;
 274         }
 275
 276         if (cache_get_line_size(cache, &line_size))
 277                 goto err;
 278         if (cache_size(cache, &size))
 279                 goto err;
 280
 281         if (!(nr_sets > 0 && size > 0 && line_size > 0))
 282                 goto err;
 283
 284         *ret = (size / nr_sets) / line_size;
 285         return 0;
 286 err:
 287         return -ENODEV;
 288 }
 289
 290 /* helper for dealing with split caches */
 291 static struct cache *cache_find_first_sibling(struct cache *cache)
 292 {
 293         struct cache *iter;
 294
 295         if (cache->type == CACHE_TYPE_UNIFIED)
 296                 return cache;
 297
 298         list_for_each_entry(iter, &cache_list, list)
 299                 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
 300                         return iter;
 301
 302         return cache;
 303 }
 304
 305 /* return the first cache on a local list matching node */
 306 static struct cache *cache_lookup_by_node(const struct device_node *node)
 307 {
 308         struct cache *cache = NULL;
 309         struct cache *iter;
 310
 311         list_for_each_entry(iter, &cache_list, list) {
 312                 if (iter->ofnode != node)
 313                         continue;
 314                 cache = cache_find_first_sibling(iter);
 315                 break;
 316         }
 317
 318         return cache;
 319 }
 320
 321 static bool cache_node_is_unified(const struct device_node *np)
 322 {
 323         return of_get_property(np, "cache-unified", NULL);
 324 }
 325
 326 static struct cache *__cpuinit cache_do_one_devnode_unified(struct device_node *node, int level)
 327 {
 328         struct cache *cache;
 329
 330         pr_debug("creating L%d ucache for %s\n", level, node->full_name);
 331
 332         cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
 333
 334         return cache;
 335 }
 336
 337 static struct cache *__cpuinit cache_do_one_devnode_split(struct device_node *node, int level)
 338 {
 339         struct cache *dcache, *icache;
 340
 341         pr_debug("creating L%d dcache and icache for %s\n", level,
 342                  node->full_name);
 343
 344         dcache = new_cache(CACHE_TYPE_DATA, level, node);
 345         icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
 346
 347         if (!dcache || !icache)
 348                 goto err;
 349
 350         dcache->next_local = icache;
 351
 352         return dcache;
 353 err:
 354         release_cache(dcache);
 355         release_cache(icache);
 356         return NULL;
 357 }
 358
 359 static struct cache *__cpuinit cache_do_one_devnode(struct device_node *node, int level)
 360 {
 361         struct cache *cache;
 362
 363         if (cache_node_is_unified(node))
 364                 cache = cache_do_one_devnode_unified(node, level);
 365         else
 366                 cache = cache_do_one_devnode_split(node, level);
 367
 368         return cache;
 369 }
 370
 371 static struct cache *__cpuinit cache_lookup_or_instantiate(struct device_node *node, int level)
 372 {
 373         struct cache *cache;
 374
 375         cache = cache_lookup_by_node(node);
 376
 377         WARN_ONCE(cache && cache->level != level,
 378                   "cache level mismatch on lookup (got %d, expected %d)\n",
 379                   cache->level, level);
 380
 381         if (!cache)
 382                 cache = cache_do_one_devnode(node, level);
 383
 384         return cache;
 385 }
 386
 387 static void __cpuinit link_cache_lists(struct cache *smaller, struct cache *bigger)
 388 {
 389         while (smaller->next_local) {
 390                 if (smaller->next_local == bigger)
 391                         return; /* already linked */
 392                 smaller = smaller->next_local;
 393         }
 394
 395         smaller->next_local = bigger;
 396 }
 397
 398 static void __cpuinit do_subsidiary_caches_debugcheck(struct cache *cache)
 399 {
 400         WARN_ON_ONCE(cache->level != 1);
 401         WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
 402 }
 403
 404 static void __cpuinit do_subsidiary_caches(struct cache *cache)
 405 {
 406         struct device_node *subcache_node;
 407         int level = cache->level;
 408
 409         do_subsidiary_caches_debugcheck(cache);
 410
 411         while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
 412                 struct cache *subcache;
 413
 414                 level++;
 415                 subcache = cache_lookup_or_instantiate(subcache_node, level);
 416                 of_node_put(subcache_node);
 417                 if (!subcache)
 418                         break;
 419
 420                 link_cache_lists(cache, subcache);
 421                 cache = subcache;
 422         }
 423 }
 424
 425 static struct cache *__cpuinit cache_chain_instantiate(unsigned int cpu_id)
 426 {
 427         struct device_node *cpu_node;
 428         struct cache *cpu_cache = NULL;
 429
 430         pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
 431
 432         cpu_node = of_get_cpu_node(cpu_id, NULL);
 433         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 434         if (!cpu_node)
 435                 goto out;
 436
 437         cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
 438         if (!cpu_cache)
 439                 goto out;
 440
 441         do_subsidiary_caches(cpu_cache);
 442
 443         cache_cpu_set(cpu_cache, cpu_id);
 444 out:
 445         of_node_put(cpu_node);
 446
 447         return cpu_cache;
 448 }
 449
 450 static struct cache_dir *__cpuinit cacheinfo_create_cache_dir(unsigned int cpu_id)
 451 {
 452         struct cache_dir *cache_dir;
 453         struct sys_device *sysdev;
 454         struct kobject *kobj = NULL;
 455
 456         sysdev = get_cpu_sysdev(cpu_id);
 457         WARN_ONCE(!sysdev, "no sysdev for CPU %i\n", cpu_id);
 458         if (!sysdev)
 459                 goto err;
 460
 461         kobj = kobject_create_and_add("cache", &sysdev->kobj);
 462         if (!kobj)
 463                 goto err;
 464
 465         cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
 466         if (!cache_dir)
 467                 goto err;
 468
 469         cache_dir->kobj = kobj;
 470
 471         WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
 472
 473         per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
 474
 475         return cache_dir;
 476 err:
 477         kobject_put(kobj);
 478         return NULL;
 479 }
 480
 481 static void cache_index_release(struct kobject *kobj)
 482 {
 483         struct cache_index_dir *index;
 484
 485         index = kobj_to_cache_index_dir(kobj);
 486
 487         pr_debug("freeing index directory for L%d %s cache\n",
 488                  index->cache->level, cache_type_string(index->cache));
 489
 490         kfree(index);
 491 }
 492
 493 static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
 494 {
 495         struct kobj_attribute *kobj_attr;
 496
 497         kobj_attr = container_of(attr, struct kobj_attribute, attr);
 498
 499         return kobj_attr->show(k, kobj_attr, buf);
 500 }
 501
 502 static struct cache *index_kobj_to_cache(struct kobject *k)
 503 {
 504         struct cache_index_dir *index;
 505
 506         index = kobj_to_cache_index_dir(k);
 507
 508         return index->cache;
 509 }
 510
 511 static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 512 {
 513         unsigned int size_kb;
 514         struct cache *cache;
 515
 516         cache = index_kobj_to_cache(k);
 517
 518         if (cache_size_kb(cache, &size_kb))
 519                 return -ENODEV;
 520
 521         return sprintf(buf, "%uK\n", size_kb);
 522 }
 523
 524 static struct kobj_attribute cache_size_attr =
 525         __ATTR(size, 0444, size_show, NULL);
 526
 527
 528 static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 529 {
 530         unsigned int line_size;
 531         struct cache *cache;
 532
 533         cache = index_kobj_to_cache(k);
 534
 535         if (cache_get_line_size(cache, &line_size))
 536                 return -ENODEV;
 537
 538         return sprintf(buf, "%u\n", line_size);
 539 }
 540
 541 static struct kobj_attribute cache_line_size_attr =
 542         __ATTR(coherency_line_size, 0444, line_size_show, NULL);
 543
 544 static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 545 {
 546         unsigned int nr_sets;
 547         struct cache *cache;
 548
 549         cache = index_kobj_to_cache(k);
 550
 551         if (cache_nr_sets(cache, &nr_sets))
 552                 return -ENODEV;
 553
 554         return sprintf(buf, "%u\n", nr_sets);
 555 }
 556
 557 static struct kobj_attribute cache_nr_sets_attr =
 558         __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
 559
 560 static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 561 {
 562         unsigned int associativity;
 563         struct cache *cache;
 564
 565         cache = index_kobj_to_cache(k);
 566
 567         if (cache_associativity(cache, &associativity))
 568                 return -ENODEV;
 569
 570         return sprintf(buf, "%u\n", associativity);
 571 }
 572
 573 static struct kobj_attribute cache_assoc_attr =
 574         __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
 575
 576 static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 577 {
 578         struct cache *cache;
 579
 580         cache = index_kobj_to_cache(k);
 581
 582         return sprintf(buf, "%s\n", cache_type_string(cache));
 583 }
 584
 585 static struct kobj_attribute cache_type_attr =
 586         __ATTR(type, 0444, type_show, NULL);
 587
 588 static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 589 {
 590         struct cache_index_dir *index;
 591         struct cache *cache;
 592
 593         index = kobj_to_cache_index_dir(k);
 594         cache = index->cache;
 595
 596         return sprintf(buf, "%d\n", cache->level);
 597 }
 598
 599 static struct kobj_attribute cache_level_attr =
 600         __ATTR(level, 0444, level_show, NULL);
 601
 602 static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
 603 {
 604         struct cache_index_dir *index;
 605         struct cache *cache;
 606         int len;
 607         int n = 0;
 608
 609         index = kobj_to_cache_index_dir(k);
 610         cache = index->cache;
 611         len = PAGE_SIZE - 2;
 612
 613         if (len > 1) {
 614                 n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
 615                 buf[n++] = '\n';
 616                 buf[n] = '\0';
 617         }
 618         return n;
 619 }
 620
 621 static struct kobj_attribute cache_shared_cpu_map_attr =
 622         __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
 623
 624 /* Attributes which should always be created -- the kobject/sysfs core
 625  * does this automatically via kobj_type->default_attrs.  This is the
 626  * minimum data required to uniquely identify a cache.
 627  */
 628 static struct attribute *cache_index_default_attrs[] = {
 629         &cache_type_attr.attr,
 630         &cache_level_attr.attr,
 631         &cache_shared_cpu_map_attr.attr,
 632         NULL,
 633 };
 634
 635 /* Attributes which should be created if the cache device node has the
 636  * right properties -- see cacheinfo_create_index_opt_attrs
 637  */
 638 static struct kobj_attribute *cache_index_opt_attrs[] = {
 639         &cache_size_attr,
 640         &cache_line_size_attr,
 641         &cache_nr_sets_attr,
 642         &cache_assoc_attr,
 643 };
 644
 645 static struct sysfs_ops cache_index_ops = {
 646         .show = cache_index_show,
 647 };
 648
 649 static struct kobj_type cache_index_type = {
 650         .release = cache_index_release,
 651         .sysfs_ops = &cache_index_ops,
 652         .default_attrs = cache_index_default_attrs,
 653 };
 654
 655 static void __cpuinit cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
 656 {
 657         const char *cache_name;
 658         const char *cache_type;
 659         struct cache *cache;
 660         char *buf;
 661         int i;
 662
 663         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
 664         if (!buf)
 665                 return;
 666
 667         cache = dir->cache;
 668         cache_name = cache->ofnode->full_name;
 669         cache_type = cache_type_string(cache);
 670
 671         /* We don't want to create an attribute that can't provide a
 672          * meaningful value.  Check the return value of each optional
 673          * attribute's ->show method before registering the
 674          * attribute.
 675          */
 676         for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
 677                 struct kobj_attribute *attr;
 678                 ssize_t rc;
 679
 680                 attr = cache_index_opt_attrs[i];
 681
 682                 rc = attr->show(&dir->kobj, attr, buf);
 683                 if (rc <= 0) {
 684                         pr_debug("not creating %s attribute for "
 685                                  "%s(%s) (rc = %zd)\n",
 686                                  attr->attr.name, cache_name,
 687                                  cache_type, rc);
 688                         continue;
 689                 }
 690                 if (sysfs_create_file(&dir->kobj, &attr->attr))
 691                         pr_debug("could not create %s attribute for %s(%s)\n",
 692                                  attr->attr.name, cache_name, cache_type);
 693         }
 694
 695         kfree(buf);
 696 }
 697
 698 static void __cpuinit cacheinfo_create_index_dir(struct cache *cache, int index, struct cache_dir *cache_dir)
 699 {
 700         struct cache_index_dir *index_dir;
 701         int rc;
 702
 703         index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
 704         if (!index_dir)
 705                 goto err;
 706
 707         index_dir->cache = cache;
 708
 709         rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
 710                                   cache_dir->kobj, "index%d", index);
 711         if (rc)
 712                 goto err;
 713
 714         index_dir->next = cache_dir->index;
 715         cache_dir->index = index_dir;
 716
 717         cacheinfo_create_index_opt_attrs(index_dir);
 718
 719         return;
 720 err:
 721         kfree(index_dir);
 722 }
 723
 724 static void __cpuinit cacheinfo_sysfs_populate(unsigned int cpu_id, struct cache *cache_list)
 725 {
 726         struct cache_dir *cache_dir;
 727         struct cache *cache;
 728         int index = 0;
 729
 730         cache_dir = cacheinfo_create_cache_dir(cpu_id);
 731         if (!cache_dir)
 732                 return;
 733
 734         cache = cache_list;
 735         while (cache) {
 736                 cacheinfo_create_index_dir(cache, index, cache_dir);
 737                 index++;
 738                 cache = cache->next_local;
 739         }
 740 }
 741
 742 void __cpuinit cacheinfo_cpu_online(unsigned int cpu_id)
 743 {
 744         struct cache *cache;
 745
 746         cache = cache_chain_instantiate(cpu_id);
 747         if (!cache)
 748                 return;
 749
 750         cacheinfo_sysfs_populate(cpu_id, cache);
 751 }
 752
 753 #ifdef CONFIG_HOTPLUG_CPU /* functions needed for cpu offline */
 754
 755 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
 756 {
 757         struct device_node *cpu_node;
 758         struct cache *cache;
 759
 760         cpu_node = of_get_cpu_node(cpu_id, NULL);
 761         WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
 762         if (!cpu_node)
 763                 return NULL;
 764
 765         cache = cache_lookup_by_node(cpu_node);
 766         of_node_put(cpu_node);
 767
 768         return cache;
 769 }
 770
 771 static void remove_index_dirs(struct cache_dir *cache_dir)
 772 {
 773         struct cache_index_dir *index;
 774
 775         index = cache_dir->index;
 776
 777         while (index) {
 778                 struct cache_index_dir *next;
 779
 780                 next = index->next;
 781                 kobject_put(&index->kobj);
 782                 index = next;
 783         }
 784 }
 785
 786 static void remove_cache_dir(struct cache_dir *cache_dir)
 787 {
 788         remove_index_dirs(cache_dir);
 789
 790         kobject_put(cache_dir->kobj);
 791
 792         kfree(cache_dir);
 793 }
 794
 795 static void cache_cpu_clear(struct cache *cache, int cpu)
 796 {
 797         while (cache) {
 798                 struct cache *next = cache->next_local;
 799
 800                 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
 801                           "CPU %i not accounted in %s(%s)\n",
 802                           cpu, cache->ofnode->full_name,
 803                           cache_type_string(cache));
 804
 805                 cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
 806
 807                 /* Release the cache object if all the cpus using it
 808                  * are offline */
 809                 if (cpumask_empty(&cache->shared_cpu_map))
 810                         release_cache(cache);
 811
 812                 cache = next;
 813         }
 814 }
 815
 816 void cacheinfo_cpu_offline(unsigned int cpu_id)
 817 {
 818         struct cache_dir *cache_dir;
 819         struct cache *cache;
 820
 821         /* Prevent userspace from seeing inconsistent state - remove
 822          * the sysfs hierarchy first */
 823         cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
 824
 825         /* careful, sysfs population may have failed */
 826         if (cache_dir)
 827                 remove_cache_dir(cache_dir);
 828
 829         per_cpu(cache_dir_pcpu, cpu_id) = NULL;
 830
 831         /* clear the CPU's bit in its cache chain, possibly freeing
 832          * cache objects */
 833         cache = cache_lookup_by_cpu(cpu_id);
 834         if (cache)
 835                 cache_cpu_clear(cache, cpu_id);
 836 }
 837 #endif /* CONFIG_HOTPLUG_CPU */