1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Processor cache information made available to userspace via sysfs; 4 * intended to be compatible with x86 intel_cacheinfo implementation. 5 * 6 * Copyright 2008 IBM Corporation 7 * Author: Nathan Lynch 8 */ 9 10 #define pr_fmt(fmt) "cacheinfo: " fmt 11 12 #include <linux/cpu.h> 13 #include <linux/cpumask.h> 14 #include <linux/kernel.h> 15 #include <linux/kobject.h> 16 #include <linux/list.h> 17 #include <linux/notifier.h> 18 #include <linux/of.h> 19 #include <linux/percpu.h> 20 #include <linux/slab.h> 21 #include <asm/cputhreads.h> 22 #include <asm/smp.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 /* cache-size, cache-block-size, etc. */ 65 #define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */ 66 #define CACHE_TYPE_INSTRUCTION 2 67 #define CACHE_TYPE_DATA 3 68 69 static const struct cache_type_info cache_type_info[] = { 70 { 71 /* Embedded systems that use cache-size, cache-block-size, 72 * etc. for the Unified (typically L2) cache. */ 73 .name = "Unified", 74 .size_prop = "cache-size", 75 .line_size_props = { "cache-line-size", 76 "cache-block-size", }, 77 .nr_sets_prop = "cache-sets", 78 }, 79 { 80 /* PowerPC Processor binding says the [di]-cache-* 81 * must be equal on unified caches, so just use 82 * d-cache properties. */ 83 .name = "Unified", 84 .size_prop = "d-cache-size", 85 .line_size_props = { "d-cache-line-size", 86 "d-cache-block-size", }, 87 .nr_sets_prop = "d-cache-sets", 88 }, 89 { 90 .name = "Instruction", 91 .size_prop = "i-cache-size", 92 .line_size_props = { "i-cache-line-size", 93 "i-cache-block-size", }, 94 .nr_sets_prop = "i-cache-sets", 95 }, 96 { 97 .name = "Data", 98 .size_prop = "d-cache-size", 99 .line_size_props = { "d-cache-line-size", 100 "d-cache-block-size", }, 101 .nr_sets_prop = "d-cache-sets", 102 }, 103 }; 104 105 /* Cache object: each instance of this corresponds to a distinct cache 106 * in the system. There are separate objects for Harvard caches: one 107 * each for instruction and data, and each refers to the same OF node. 108 * The refcount of the OF node is elevated for the lifetime of the 109 * cache object. A cache object is released when its shared_cpu_map 110 * is cleared (see cache_cpu_clear). 111 * 112 * A cache object is on two lists: an unsorted global list 113 * (cache_list) of cache objects; and a singly-linked list 114 * representing the local cache hierarchy, which is ordered by level 115 * (e.g. L1d -> L1i -> L2 -> L3). 116 */ 117 struct cache { 118 struct device_node *ofnode; /* OF node for this cache, may be cpu */ 119 struct cpumask shared_cpu_map; /* online CPUs using this cache */ 120 int type; /* split cache disambiguation */ 121 int level; /* level not explicit in device tree */ 122 int group_id; /* id of the group of threads that share this cache */ 123 struct list_head list; /* global list of cache objects */ 124 struct cache *next_local; /* next cache of >= level */ 125 }; 126 127 static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu); 128 129 /* traversal/modification of this list occurs only at cpu hotplug time; 130 * access is serialized by cpu hotplug locking 131 */ 132 static LIST_HEAD(cache_list); 133 134 static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k) 135 { 136 return container_of(k, struct cache_index_dir, kobj); 137 } 138 139 static const char *cache_type_string(const struct cache *cache) 140 { 141 return cache_type_info[cache->type].name; 142 } 143 144 static void cache_init(struct cache *cache, int type, int level, 145 struct device_node *ofnode, int group_id) 146 { 147 cache->type = type; 148 cache->level = level; 149 cache->ofnode = of_node_get(ofnode); 150 cache->group_id = group_id; 151 INIT_LIST_HEAD(&cache->list); 152 list_add(&cache->list, &cache_list); 153 } 154 155 static struct cache *new_cache(int type, int level, 156 struct device_node *ofnode, int group_id) 157 { 158 struct cache *cache; 159 160 cache = kzalloc(sizeof(*cache), GFP_KERNEL); 161 if (cache) 162 cache_init(cache, type, level, ofnode, group_id); 163 164 return cache; 165 } 166 167 static void release_cache_debugcheck(struct cache *cache) 168 { 169 struct cache *iter; 170 171 list_for_each_entry(iter, &cache_list, list) 172 WARN_ONCE(iter->next_local == cache, 173 "cache for %pOFP(%s) refers to cache for %pOFP(%s)\n", 174 iter->ofnode, 175 cache_type_string(iter), 176 cache->ofnode, 177 cache_type_string(cache)); 178 } 179 180 static void release_cache(struct cache *cache) 181 { 182 if (!cache) 183 return; 184 185 pr_debug("freeing L%d %s cache for %pOFP\n", cache->level, 186 cache_type_string(cache), cache->ofnode); 187 188 release_cache_debugcheck(cache); 189 list_del(&cache->list); 190 of_node_put(cache->ofnode); 191 kfree(cache); 192 } 193 194 static void cache_cpu_set(struct cache *cache, int cpu) 195 { 196 struct cache *next = cache; 197 198 while (next) { 199 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map), 200 "CPU %i already accounted in %pOFP(%s)\n", 201 cpu, next->ofnode, 202 cache_type_string(next)); 203 cpumask_set_cpu(cpu, &next->shared_cpu_map); 204 next = next->next_local; 205 } 206 } 207 208 static int cache_size(const struct cache *cache, unsigned int *ret) 209 { 210 const char *propname; 211 const __be32 *cache_size; 212 213 propname = cache_type_info[cache->type].size_prop; 214 215 cache_size = of_get_property(cache->ofnode, propname, NULL); 216 if (!cache_size) 217 return -ENODEV; 218 219 *ret = of_read_number(cache_size, 1); 220 return 0; 221 } 222 223 static int cache_size_kb(const struct cache *cache, unsigned int *ret) 224 { 225 unsigned int size; 226 227 if (cache_size(cache, &size)) 228 return -ENODEV; 229 230 *ret = size / 1024; 231 return 0; 232 } 233 234 /* not cache_line_size() because that's a macro in include/linux/cache.h */ 235 static int cache_get_line_size(const struct cache *cache, unsigned int *ret) 236 { 237 const __be32 *line_size; 238 int i, lim; 239 240 lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props); 241 242 for (i = 0; i < lim; i++) { 243 const char *propname; 244 245 propname = cache_type_info[cache->type].line_size_props[i]; 246 line_size = of_get_property(cache->ofnode, propname, NULL); 247 if (line_size) 248 break; 249 } 250 251 if (!line_size) 252 return -ENODEV; 253 254 *ret = of_read_number(line_size, 1); 255 return 0; 256 } 257 258 static int cache_nr_sets(const struct cache *cache, unsigned int *ret) 259 { 260 const char *propname; 261 const __be32 *nr_sets; 262 263 propname = cache_type_info[cache->type].nr_sets_prop; 264 265 nr_sets = of_get_property(cache->ofnode, propname, NULL); 266 if (!nr_sets) 267 return -ENODEV; 268 269 *ret = of_read_number(nr_sets, 1); 270 return 0; 271 } 272 273 static int cache_associativity(const struct cache *cache, unsigned int *ret) 274 { 275 unsigned int line_size; 276 unsigned int nr_sets; 277 unsigned int size; 278 279 if (cache_nr_sets(cache, &nr_sets)) 280 goto err; 281 282 /* If the cache is fully associative, there is no need to 283 * check the other properties. 284 */ 285 if (nr_sets == 1) { 286 *ret = 0; 287 return 0; 288 } 289 290 if (cache_get_line_size(cache, &line_size)) 291 goto err; 292 if (cache_size(cache, &size)) 293 goto err; 294 295 if (!(nr_sets > 0 && size > 0 && line_size > 0)) 296 goto err; 297 298 *ret = (size / nr_sets) / line_size; 299 return 0; 300 err: 301 return -ENODEV; 302 } 303 304 /* helper for dealing with split caches */ 305 static struct cache *cache_find_first_sibling(struct cache *cache) 306 { 307 struct cache *iter; 308 309 if (cache->type == CACHE_TYPE_UNIFIED || 310 cache->type == CACHE_TYPE_UNIFIED_D) 311 return cache; 312 313 list_for_each_entry(iter, &cache_list, list) 314 if (iter->ofnode == cache->ofnode && 315 iter->group_id == cache->group_id && 316 iter->next_local == cache) 317 return iter; 318 319 return cache; 320 } 321 322 /* return the first cache on a local list matching node and thread-group id */ 323 static struct cache *cache_lookup_by_node_group(const struct device_node *node, 324 int group_id) 325 { 326 struct cache *cache = NULL; 327 struct cache *iter; 328 329 list_for_each_entry(iter, &cache_list, list) { 330 if (iter->ofnode != node || 331 iter->group_id != group_id) 332 continue; 333 cache = cache_find_first_sibling(iter); 334 break; 335 } 336 337 return cache; 338 } 339 340 static bool cache_node_is_unified(const struct device_node *np) 341 { 342 return of_get_property(np, "cache-unified", NULL); 343 } 344 345 /* 346 * Unified caches can have two different sets of tags. Most embedded 347 * use cache-size, etc. for the unified cache size, but open firmware systems 348 * use d-cache-size, etc. Check on initialization for which type we have, and 349 * return the appropriate structure type. Assume it's embedded if it isn't 350 * open firmware. If it's yet a 3rd type, then there will be missing entries 351 * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need 352 * to be extended further. 353 */ 354 static int cache_is_unified_d(const struct device_node *np) 355 { 356 return of_get_property(np, 357 cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ? 358 CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED; 359 } 360 361 static struct cache *cache_do_one_devnode_unified(struct device_node *node, int group_id, 362 int level) 363 { 364 pr_debug("creating L%d ucache for %pOFP\n", level, node); 365 366 return new_cache(cache_is_unified_d(node), level, node, group_id); 367 } 368 369 static struct cache *cache_do_one_devnode_split(struct device_node *node, int group_id, 370 int level) 371 { 372 struct cache *dcache, *icache; 373 374 pr_debug("creating L%d dcache and icache for %pOFP\n", level, 375 node); 376 377 dcache = new_cache(CACHE_TYPE_DATA, level, node, group_id); 378 icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node, group_id); 379 380 if (!dcache || !icache) 381 goto err; 382 383 dcache->next_local = icache; 384 385 return dcache; 386 err: 387 release_cache(dcache); 388 release_cache(icache); 389 return NULL; 390 } 391 392 static struct cache *cache_do_one_devnode(struct device_node *node, int group_id, int level) 393 { 394 struct cache *cache; 395 396 if (cache_node_is_unified(node)) 397 cache = cache_do_one_devnode_unified(node, group_id, level); 398 else 399 cache = cache_do_one_devnode_split(node, group_id, level); 400 401 return cache; 402 } 403 404 static struct cache *cache_lookup_or_instantiate(struct device_node *node, 405 int group_id, 406 int level) 407 { 408 struct cache *cache; 409 410 cache = cache_lookup_by_node_group(node, group_id); 411 412 WARN_ONCE(cache && cache->level != level, 413 "cache level mismatch on lookup (got %d, expected %d)\n", 414 cache->level, level); 415 416 if (!cache) 417 cache = cache_do_one_devnode(node, group_id, level); 418 419 return cache; 420 } 421 422 static void link_cache_lists(struct cache *smaller, struct cache *bigger) 423 { 424 while (smaller->next_local) { 425 if (smaller->next_local == bigger) 426 return; /* already linked */ 427 smaller = smaller->next_local; 428 } 429 430 smaller->next_local = bigger; 431 432 /* 433 * The cache->next_local list sorts by level ascending: 434 * L1d -> L1i -> L2 -> L3 ... 435 */ 436 WARN_ONCE((smaller->level == 1 && bigger->level > 2) || 437 (smaller->level > 1 && bigger->level != smaller->level + 1), 438 "linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n", 439 smaller->level, smaller->ofnode, bigger->level, bigger->ofnode); 440 } 441 442 static void do_subsidiary_caches_debugcheck(struct cache *cache) 443 { 444 WARN_ONCE(cache->level != 1, 445 "instantiating cache chain from L%d %s cache for " 446 "%pOFP instead of an L1\n", cache->level, 447 cache_type_string(cache), cache->ofnode); 448 WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"), 449 "instantiating cache chain from node %pOFP of type '%s' " 450 "instead of a cpu node\n", cache->ofnode, 451 of_node_get_device_type(cache->ofnode)); 452 } 453 454 /* 455 * If sub-groups of threads in a core containing @cpu_id share the 456 * L@level-cache (information obtained via "ibm,thread-groups" 457 * device-tree property), then we identify the group by the first 458 * thread-sibling in the group. We define this to be the group-id. 459 * 460 * In the absence of any thread-group information for L@level-cache, 461 * this function returns -1. 462 */ 463 static int get_group_id(unsigned int cpu_id, int level) 464 { 465 if (has_big_cores && level == 1) 466 return cpumask_first(per_cpu(thread_group_l1_cache_map, 467 cpu_id)); 468 else if (thread_group_shares_l2 && level == 2) 469 return cpumask_first(per_cpu(thread_group_l2_cache_map, 470 cpu_id)); 471 else if (thread_group_shares_l3 && level == 3) 472 return cpumask_first(per_cpu(thread_group_l3_cache_map, 473 cpu_id)); 474 return -1; 475 } 476 477 static void do_subsidiary_caches(struct cache *cache, unsigned int cpu_id) 478 { 479 struct device_node *subcache_node; 480 int level = cache->level; 481 482 do_subsidiary_caches_debugcheck(cache); 483 484 while ((subcache_node = of_find_next_cache_node(cache->ofnode))) { 485 struct cache *subcache; 486 int group_id; 487 488 level++; 489 group_id = get_group_id(cpu_id, level); 490 subcache = cache_lookup_or_instantiate(subcache_node, group_id, level); 491 of_node_put(subcache_node); 492 if (!subcache) 493 break; 494 495 link_cache_lists(cache, subcache); 496 cache = subcache; 497 } 498 } 499 500 static struct cache *cache_chain_instantiate(unsigned int cpu_id) 501 { 502 struct device_node *cpu_node; 503 struct cache *cpu_cache = NULL; 504 int group_id; 505 506 pr_debug("creating cache object(s) for CPU %i\n", cpu_id); 507 508 cpu_node = of_get_cpu_node(cpu_id, NULL); 509 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id); 510 if (!cpu_node) 511 goto out; 512 513 group_id = get_group_id(cpu_id, 1); 514 515 cpu_cache = cache_lookup_or_instantiate(cpu_node, group_id, 1); 516 if (!cpu_cache) 517 goto out; 518 519 do_subsidiary_caches(cpu_cache, cpu_id); 520 521 cache_cpu_set(cpu_cache, cpu_id); 522 out: 523 of_node_put(cpu_node); 524 525 return cpu_cache; 526 } 527 528 static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id) 529 { 530 struct cache_dir *cache_dir; 531 struct device *dev; 532 struct kobject *kobj = NULL; 533 534 dev = get_cpu_device(cpu_id); 535 WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id); 536 if (!dev) 537 goto err; 538 539 kobj = kobject_create_and_add("cache", &dev->kobj); 540 if (!kobj) 541 goto err; 542 543 cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL); 544 if (!cache_dir) 545 goto err; 546 547 cache_dir->kobj = kobj; 548 549 WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL); 550 551 per_cpu(cache_dir_pcpu, cpu_id) = cache_dir; 552 553 return cache_dir; 554 err: 555 kobject_put(kobj); 556 return NULL; 557 } 558 559 static void cache_index_release(struct kobject *kobj) 560 { 561 struct cache_index_dir *index; 562 563 index = kobj_to_cache_index_dir(kobj); 564 565 pr_debug("freeing index directory for L%d %s cache\n", 566 index->cache->level, cache_type_string(index->cache)); 567 568 kfree(index); 569 } 570 571 static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf) 572 { 573 struct kobj_attribute *kobj_attr; 574 575 kobj_attr = container_of(attr, struct kobj_attribute, attr); 576 577 return kobj_attr->show(k, kobj_attr, buf); 578 } 579 580 static struct cache *index_kobj_to_cache(struct kobject *k) 581 { 582 struct cache_index_dir *index; 583 584 index = kobj_to_cache_index_dir(k); 585 586 return index->cache; 587 } 588 589 static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 590 { 591 unsigned int size_kb; 592 struct cache *cache; 593 594 cache = index_kobj_to_cache(k); 595 596 if (cache_size_kb(cache, &size_kb)) 597 return -ENODEV; 598 599 return sprintf(buf, "%uK\n", size_kb); 600 } 601 602 static struct kobj_attribute cache_size_attr = 603 __ATTR(size, 0444, size_show, NULL); 604 605 606 static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 607 { 608 unsigned int line_size; 609 struct cache *cache; 610 611 cache = index_kobj_to_cache(k); 612 613 if (cache_get_line_size(cache, &line_size)) 614 return -ENODEV; 615 616 return sprintf(buf, "%u\n", line_size); 617 } 618 619 static struct kobj_attribute cache_line_size_attr = 620 __ATTR(coherency_line_size, 0444, line_size_show, NULL); 621 622 static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 623 { 624 unsigned int nr_sets; 625 struct cache *cache; 626 627 cache = index_kobj_to_cache(k); 628 629 if (cache_nr_sets(cache, &nr_sets)) 630 return -ENODEV; 631 632 return sprintf(buf, "%u\n", nr_sets); 633 } 634 635 static struct kobj_attribute cache_nr_sets_attr = 636 __ATTR(number_of_sets, 0444, nr_sets_show, NULL); 637 638 static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 639 { 640 unsigned int associativity; 641 struct cache *cache; 642 643 cache = index_kobj_to_cache(k); 644 645 if (cache_associativity(cache, &associativity)) 646 return -ENODEV; 647 648 return sprintf(buf, "%u\n", associativity); 649 } 650 651 static struct kobj_attribute cache_assoc_attr = 652 __ATTR(ways_of_associativity, 0444, associativity_show, NULL); 653 654 static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 655 { 656 struct cache *cache; 657 658 cache = index_kobj_to_cache(k); 659 660 return sprintf(buf, "%s\n", cache_type_string(cache)); 661 } 662 663 static struct kobj_attribute cache_type_attr = 664 __ATTR(type, 0444, type_show, NULL); 665 666 static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 667 { 668 struct cache_index_dir *index; 669 struct cache *cache; 670 671 index = kobj_to_cache_index_dir(k); 672 cache = index->cache; 673 674 return sprintf(buf, "%d\n", cache->level); 675 } 676 677 static struct kobj_attribute cache_level_attr = 678 __ATTR(level, 0444, level_show, NULL); 679 680 static ssize_t 681 show_shared_cpumap(struct kobject *k, struct kobj_attribute *attr, char *buf, bool list) 682 { 683 struct cache_index_dir *index; 684 struct cache *cache; 685 const struct cpumask *mask; 686 687 index = kobj_to_cache_index_dir(k); 688 cache = index->cache; 689 690 mask = &cache->shared_cpu_map; 691 692 return cpumap_print_to_pagebuf(list, buf, mask); 693 } 694 695 static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 696 { 697 return show_shared_cpumap(k, attr, buf, false); 698 } 699 700 static ssize_t shared_cpu_list_show(struct kobject *k, struct kobj_attribute *attr, char *buf) 701 { 702 return show_shared_cpumap(k, attr, buf, true); 703 } 704 705 static struct kobj_attribute cache_shared_cpu_map_attr = 706 __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL); 707 708 static struct kobj_attribute cache_shared_cpu_list_attr = 709 __ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL); 710 711 /* Attributes which should always be created -- the kobject/sysfs core 712 * does this automatically via kobj_type->default_groups. This is the 713 * minimum data required to uniquely identify a cache. 714 */ 715 static struct attribute *cache_index_default_attrs[] = { 716 &cache_type_attr.attr, 717 &cache_level_attr.attr, 718 &cache_shared_cpu_map_attr.attr, 719 &cache_shared_cpu_list_attr.attr, 720 NULL, 721 }; 722 ATTRIBUTE_GROUPS(cache_index_default); 723 724 /* Attributes which should be created if the cache device node has the 725 * right properties -- see cacheinfo_create_index_opt_attrs 726 */ 727 static struct kobj_attribute *cache_index_opt_attrs[] = { 728 &cache_size_attr, 729 &cache_line_size_attr, 730 &cache_nr_sets_attr, 731 &cache_assoc_attr, 732 }; 733 734 static const struct sysfs_ops cache_index_ops = { 735 .show = cache_index_show, 736 }; 737 738 static const struct kobj_type cache_index_type = { 739 .release = cache_index_release, 740 .sysfs_ops = &cache_index_ops, 741 .default_groups = cache_index_default_groups, 742 }; 743 744 static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir) 745 { 746 const char *cache_type; 747 struct cache *cache; 748 char *buf; 749 int i; 750 751 buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 752 if (!buf) 753 return; 754 755 cache = dir->cache; 756 cache_type = cache_type_string(cache); 757 758 /* We don't want to create an attribute that can't provide a 759 * meaningful value. Check the return value of each optional 760 * attribute's ->show method before registering the 761 * attribute. 762 */ 763 for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) { 764 struct kobj_attribute *attr; 765 ssize_t rc; 766 767 attr = cache_index_opt_attrs[i]; 768 769 rc = attr->show(&dir->kobj, attr, buf); 770 if (rc <= 0) { 771 pr_debug("not creating %s attribute for " 772 "%pOFP(%s) (rc = %zd)\n", 773 attr->attr.name, cache->ofnode, 774 cache_type, rc); 775 continue; 776 } 777 if (sysfs_create_file(&dir->kobj, &attr->attr)) 778 pr_debug("could not create %s attribute for %pOFP(%s)\n", 779 attr->attr.name, cache->ofnode, cache_type); 780 } 781 782 kfree(buf); 783 } 784 785 static void cacheinfo_create_index_dir(struct cache *cache, int index, 786 struct cache_dir *cache_dir) 787 { 788 struct cache_index_dir *index_dir; 789 int rc; 790 791 index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL); 792 if (!index_dir) 793 return; 794 795 index_dir->cache = cache; 796 797 rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type, 798 cache_dir->kobj, "index%d", index); 799 if (rc) { 800 kobject_put(&index_dir->kobj); 801 return; 802 } 803 804 index_dir->next = cache_dir->index; 805 cache_dir->index = index_dir; 806 807 cacheinfo_create_index_opt_attrs(index_dir); 808 } 809 810 static void cacheinfo_sysfs_populate(unsigned int cpu_id, 811 struct cache *cache_list) 812 { 813 struct cache_dir *cache_dir; 814 struct cache *cache; 815 int index = 0; 816 817 cache_dir = cacheinfo_create_cache_dir(cpu_id); 818 if (!cache_dir) 819 return; 820 821 cache = cache_list; 822 while (cache) { 823 cacheinfo_create_index_dir(cache, index, cache_dir); 824 index++; 825 cache = cache->next_local; 826 } 827 } 828 829 void cacheinfo_cpu_online(unsigned int cpu_id) 830 { 831 struct cache *cache; 832 833 cache = cache_chain_instantiate(cpu_id); 834 if (!cache) 835 return; 836 837 cacheinfo_sysfs_populate(cpu_id, cache); 838 } 839 840 /* functions needed to remove cache entry for cpu offline or suspend/resume */ 841 842 #if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \ 843 defined(CONFIG_HOTPLUG_CPU) 844 845 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id) 846 { 847 struct device_node *cpu_node; 848 struct cache *cache; 849 int group_id; 850 851 cpu_node = of_get_cpu_node(cpu_id, NULL); 852 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id); 853 if (!cpu_node) 854 return NULL; 855 856 group_id = get_group_id(cpu_id, 1); 857 cache = cache_lookup_by_node_group(cpu_node, group_id); 858 of_node_put(cpu_node); 859 860 return cache; 861 } 862 863 static void remove_index_dirs(struct cache_dir *cache_dir) 864 { 865 struct cache_index_dir *index; 866 867 index = cache_dir->index; 868 869 while (index) { 870 struct cache_index_dir *next; 871 872 next = index->next; 873 kobject_put(&index->kobj); 874 index = next; 875 } 876 } 877 878 static void remove_cache_dir(struct cache_dir *cache_dir) 879 { 880 remove_index_dirs(cache_dir); 881 882 /* Remove cache dir from sysfs */ 883 kobject_del(cache_dir->kobj); 884 885 kobject_put(cache_dir->kobj); 886 887 kfree(cache_dir); 888 } 889 890 static void cache_cpu_clear(struct cache *cache, int cpu) 891 { 892 while (cache) { 893 struct cache *next = cache->next_local; 894 895 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map), 896 "CPU %i not accounted in %pOFP(%s)\n", 897 cpu, cache->ofnode, 898 cache_type_string(cache)); 899 900 cpumask_clear_cpu(cpu, &cache->shared_cpu_map); 901 902 /* Release the cache object if all the cpus using it 903 * are offline */ 904 if (cpumask_empty(&cache->shared_cpu_map)) 905 release_cache(cache); 906 907 cache = next; 908 } 909 } 910 911 void cacheinfo_cpu_offline(unsigned int cpu_id) 912 { 913 struct cache_dir *cache_dir; 914 struct cache *cache; 915 916 /* Prevent userspace from seeing inconsistent state - remove 917 * the sysfs hierarchy first */ 918 cache_dir = per_cpu(cache_dir_pcpu, cpu_id); 919 920 /* careful, sysfs population may have failed */ 921 if (cache_dir) 922 remove_cache_dir(cache_dir); 923 924 per_cpu(cache_dir_pcpu, cpu_id) = NULL; 925 926 /* clear the CPU's bit in its cache chain, possibly freeing 927 * cache objects */ 928 cache = cache_lookup_by_cpu(cpu_id); 929 if (cache) 930 cache_cpu_clear(cache, cpu_id); 931 } 932 933 void cacheinfo_teardown(void) 934 { 935 unsigned int cpu; 936 937 lockdep_assert_cpus_held(); 938 939 for_each_online_cpu(cpu) 940 cacheinfo_cpu_offline(cpu); 941 } 942 943 void cacheinfo_rebuild(void) 944 { 945 unsigned int cpu; 946 947 lockdep_assert_cpus_held(); 948 949 for_each_online_cpu(cpu) 950 cacheinfo_cpu_online(cpu); 951 } 952 953 #endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */ 954