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 */
30struct 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 */
40struct 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 */
48struct 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
69static 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 */
117struct 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
127static 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 */
132static LIST_HEAD(cache_list);
133
134static 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
139static const char *cache_type_string(const struct cache *cache)
140{
141 return cache_type_info[cache->type].name;
142}
143
144static 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(node: ofnode);
150 cache->group_id = group_id;
151 INIT_LIST_HEAD(list: &cache->list);
152 list_add(new: &cache->list, head: &cache_list);
153}
154
155static 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(size: sizeof(*cache), GFP_KERNEL);
161 if (cache)
162 cache_init(cache, type, level, ofnode, group_id);
163
164 return cache;
165}
166
167static 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
180static 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(entry: &cache->list);
190 of_node_put(node: cache->ofnode);
191 kfree(objp: cache);
192}
193
194static 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, dstp: &next->shared_cpu_map);
204 next = next->next_local;
205 }
206}
207
208static 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(node: cache->ofnode, name: propname, NULL);
216 if (!cache_size)
217 return -ENODEV;
218
219 *ret = of_read_number(cell: cache_size, size: 1);
220 return 0;
221}
222
223static int cache_size_kb(const struct cache *cache, unsigned int *ret)
224{
225 unsigned int size;
226
227 if (cache_size(cache, ret: &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 */
235static 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(node: cache->ofnode, name: propname, NULL);
247 if (line_size)
248 break;
249 }
250
251 if (!line_size)
252 return -ENODEV;
253
254 *ret = of_read_number(cell: line_size, size: 1);
255 return 0;
256}
257
258static 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(node: cache->ofnode, name: propname, NULL);
266 if (!nr_sets)
267 return -ENODEV;
268
269 *ret = of_read_number(cell: nr_sets, size: 1);
270 return 0;
271}
272
273static 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, ret: &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, ret: &line_size))
291 goto err;
292 if (cache_size(cache, ret: &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;
300err:
301 return -ENODEV;
302}
303
304/* helper for dealing with split caches */
305static 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 */
323static 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(cache: iter);
334 break;
335 }
336
337 return cache;
338}
339
340static bool cache_node_is_unified(const struct device_node *np)
341{
342 return of_get_property(node: np, name: "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 */
354static int cache_is_unified_d(const struct device_node *np)
355{
356 return of_get_property(node: np,
357 name: cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
358 CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
359}
360
361static 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(type: cache_is_unified_d(np: node), level, ofnode: node, group_id);
367}
368
369static 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, ofnode: node, group_id);
378 icache = new_cache(CACHE_TYPE_INSTRUCTION, level, ofnode: node, group_id);
379
380 if (!dcache || !icache)
381 goto err;
382
383 dcache->next_local = icache;
384
385 return dcache;
386err:
387 release_cache(cache: dcache);
388 release_cache(cache: icache);
389 return NULL;
390}
391
392static 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(np: 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
404static 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
422static 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
442static 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 */
463static 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
477static 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(node: subcache_node, group_id, level);
491 of_node_put(node: subcache_node);
492 if (!subcache)
493 break;
494
495 link_cache_lists(smaller: cache, bigger: subcache);
496 cache = subcache;
497 }
498}
499
500static 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: 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, level: 1);
514
515 cpu_cache = cache_lookup_or_instantiate(node: cpu_node, group_id, level: 1);
516 if (!cpu_cache)
517 goto out;
518
519 do_subsidiary_caches(cache: cpu_cache, cpu_id);
520
521 cache_cpu_set(cache: cpu_cache, cpu: cpu_id);
522out:
523 of_node_put(node: cpu_node);
524
525 return cpu_cache;
526}
527
528static 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: 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(name: "cache", parent: &dev->kobj);
540 if (!kobj)
541 goto err;
542
543 cache_dir = kzalloc(size: 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;
554err:
555 kobject_put(kobj);
556 return NULL;
557}
558
559static void cache_index_release(struct kobject *kobj)
560{
561 struct cache_index_dir *index;
562
563 index = kobj_to_cache_index_dir(k: 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(objp: index);
569}
570
571static 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
580static 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
589static 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, ret: &size_kb))
597 return -ENODEV;
598
599 return sprintf(buf, fmt: "%uK\n", size_kb);
600}
601
602static struct kobj_attribute cache_size_attr =
603 __ATTR(size, 0444, size_show, NULL);
604
605
606static 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, ret: &line_size))
614 return -ENODEV;
615
616 return sprintf(buf, fmt: "%u\n", line_size);
617}
618
619static struct kobj_attribute cache_line_size_attr =
620 __ATTR(coherency_line_size, 0444, line_size_show, NULL);
621
622static 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, ret: &nr_sets))
630 return -ENODEV;
631
632 return sprintf(buf, fmt: "%u\n", nr_sets);
633}
634
635static struct kobj_attribute cache_nr_sets_attr =
636 __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
637
638static 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, ret: &associativity))
646 return -ENODEV;
647
648 return sprintf(buf, fmt: "%u\n", associativity);
649}
650
651static struct kobj_attribute cache_assoc_attr =
652 __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
653
654static 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, fmt: "%s\n", cache_type_string(cache));
661}
662
663static struct kobj_attribute cache_type_attr =
664 __ATTR(type, 0444, type_show, NULL);
665
666static 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, fmt: "%d\n", cache->level);
675}
676
677static struct kobj_attribute cache_level_attr =
678 __ATTR(level, 0444, level_show, NULL);
679
680static ssize_t
681show_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
695static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
696{
697 return show_shared_cpumap(k, attr, buf, list: false);
698}
699
700static ssize_t shared_cpu_list_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
701{
702 return show_shared_cpumap(k, attr, buf, list: true);
703}
704
705static struct kobj_attribute cache_shared_cpu_map_attr =
706 __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
707
708static 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 */
715static 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};
722ATTRIBUTE_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 */
727static 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
734static const struct sysfs_ops cache_index_ops = {
735 .show = cache_index_show,
736};
737
738static 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
744static 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(kobj: &dir->kobj, attr: &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(objp: buf);
783}
784
785static 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(size: sizeof(*index_dir), GFP_KERNEL);
792 if (!index_dir)
793 return;
794
795 index_dir->cache = cache;
796
797 rc = kobject_init_and_add(kobj: &index_dir->kobj, ktype: &cache_index_type,
798 parent: cache_dir->kobj, fmt: "index%d", index);
799 if (rc) {
800 kobject_put(kobj: &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(dir: index_dir);
808}
809
810static 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
829void 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_list: 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
845static 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: 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, level: 1);
857 cache = cache_lookup_by_node_group(node: cpu_node, group_id);
858 of_node_put(node: cpu_node);
859
860 return cache;
861}
862
863static 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(kobj: &index->kobj);
874 index = next;
875 }
876}
877
878static 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(kobj: cache_dir->kobj);
884
885 kobject_put(kobj: cache_dir->kobj);
886
887 kfree(objp: cache_dir);
888}
889
890static 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, dstp: &cache->shared_cpu_map);
901
902 /* Release the cache object if all the cpus using it
903 * are offline */
904 if (cpumask_empty(srcp: &cache->shared_cpu_map))
905 release_cache(cache);
906
907 cache = next;
908 }
909}
910
911void 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: cpu_id);
931}
932
933void 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_id: cpu);
941}
942
943void 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_id: cpu);
951}
952
953#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
954

source code of linux/arch/powerpc/kernel/cacheinfo.c