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 */ 31struct 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 */ 41struct 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 */ 49struct 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 69static 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 */ 108struct 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 117static 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 */ 122static LIST_HEAD(cache_list); 123 124static 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 129static const char *cache_type_string(const struct cache *cache) 130{ 131 return cache_type_info[cache->type].name; 132} 133 134static 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 143static 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 154static 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 167static 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 181static 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 195static 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 210static 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 */ 222static 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 245static 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 260static 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; 287err: 288 return -ENODEV; 289} 290 291/* helper for dealing with split caches */ 292static 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 */ 307static 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 322static bool cache_node_is_unified(const struct device_node *np) 323{ 324 return of_get_property(np, "cache-unified", NULL); 325} 326 327static 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 338static 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; 354err: 355 release_cache(dcache); 356 release_cache(icache); 357 return NULL; 358} 359 360static 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 372static 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 388static 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 399static 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 405static 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 426static 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); 445out: 446 of_node_put(cpu_node); 447 448 return cpu_cache; 449} 450 451static 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; 477err: 478 kobject_put(kobj); 479 return NULL; 480} 481 482static 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 494static 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 503static 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 512static 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 525static struct kobj_attribute cache_size_attr = 526 __ATTR(size, 0444, size_show, NULL); 527 528 529static 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 542static struct kobj_attribute cache_line_size_attr = 543 __ATTR(coherency_line_size, 0444, line_size_show, NULL); 544 545static 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 558static struct kobj_attribute cache_nr_sets_attr = 559 __ATTR(number_of_sets, 0444, nr_sets_show, NULL); 560 561static 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 574static struct kobj_attribute cache_assoc_attr = 575 __ATTR(ways_of_associativity, 0444, associativity_show, NULL); 576 577static 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 586static struct kobj_attribute cache_type_attr = 587 __ATTR(type, 0444, type_show, NULL); 588 589static 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 600static struct kobj_attribute cache_level_attr = 601 __ATTR(level, 0444, level_show, NULL); 602 603static 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 622static 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 */ 629static 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 */ 639static 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 646static const struct sysfs_ops cache_index_ops = { 647 .show = cache_index_show, 648}; 649 650static 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 656static 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 699static 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; 721err: 722 kfree(index_dir); 723} 724 725static 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 743void __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 756static 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 772static 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 787static 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 796static 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 817void 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 */ 839