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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/kernel.h>
16#include <linux/kobject.h>
17#include <linux/list.h>
18#include <linux/notifier.h>
19#include <linux/of.h>
20#include <linux/percpu.h>
21#include <linux/slab.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 */
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 struct list_head list; /* global list of cache objects */
123 struct cache *next_local; /* next cache of >= level */
124};
125
126static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
127
128/* traversal/modification of this list occurs only at cpu hotplug time;
129 * access is serialized by cpu hotplug locking
130 */
131static LIST_HEAD(cache_list);
132
133static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
134{
135 return container_of(k, struct cache_index_dir, kobj);
136}
137
138static const char *cache_type_string(const struct cache *cache)
139{
140 return cache_type_info[cache->type].name;
141}
142
143static void cache_init(struct cache *cache, int type, int level,
144 struct device_node *ofnode)
145{
146 cache->type = type;
147 cache->level = level;
148 cache->ofnode = of_node_get(ofnode);
149 INIT_LIST_HEAD(&cache->list);
150 list_add(&cache->list, &cache_list);
151}
152
153static struct cache *new_cache(int type, int level, struct device_node *ofnode)
154{
155 struct cache *cache;
156
157 cache = kzalloc(sizeof(*cache), GFP_KERNEL);
158 if (cache)
159 cache_init(cache, type, level, ofnode);
160
161 return cache;
162}
163
164static void release_cache_debugcheck(struct cache *cache)
165{
166 struct cache *iter;
167
168 list_for_each_entry(iter, &cache_list, list)
169 WARN_ONCE(iter->next_local == cache,
170 "cache for %pOF(%s) refers to cache for %pOF(%s)\n",
171 iter->ofnode,
172 cache_type_string(iter),
173 cache->ofnode,
174 cache_type_string(cache));
175}
176
177static void release_cache(struct cache *cache)
178{
179 if (!cache)
180 return;
181
182 pr_debug("freeing L%d %s cache for %pOF\n", cache->level,
183 cache_type_string(cache), cache->ofnode);
184
185 release_cache_debugcheck(cache);
186 list_del(&cache->list);
187 of_node_put(cache->ofnode);
188 kfree(cache);
189}
190
191static void cache_cpu_set(struct cache *cache, int cpu)
192{
193 struct cache *next = cache;
194
195 while (next) {
196 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
197 "CPU %i already accounted in %pOF(%s)\n",
198 cpu, next->ofnode,
199 cache_type_string(next));
200 cpumask_set_cpu(cpu, &next->shared_cpu_map);
201 next = next->next_local;
202 }
203}
204
205static int cache_size(const struct cache *cache, unsigned int *ret)
206{
207 const char *propname;
208 const __be32 *cache_size;
209
210 propname = cache_type_info[cache->type].size_prop;
211
212 cache_size = of_get_property(cache->ofnode, propname, NULL);
213 if (!cache_size)
214 return -ENODEV;
215
216 *ret = of_read_number(cache_size, 1);
217 return 0;
218}
219
220static int cache_size_kb(const struct cache *cache, unsigned int *ret)
221{
222 unsigned int size;
223
224 if (cache_size(cache, &size))
225 return -ENODEV;
226
227 *ret = size / 1024;
228 return 0;
229}
230
231/* not cache_line_size() because that's a macro in include/linux/cache.h */
232static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
233{
234 const __be32 *line_size;
235 int i, lim;
236
237 lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
238
239 for (i = 0; i < lim; i++) {
240 const char *propname;
241
242 propname = cache_type_info[cache->type].line_size_props[i];
243 line_size = of_get_property(cache->ofnode, propname, NULL);
244 if (line_size)
245 break;
246 }
247
248 if (!line_size)
249 return -ENODEV;
250
251 *ret = of_read_number(line_size, 1);
252 return 0;
253}
254
255static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
256{
257 const char *propname;
258 const __be32 *nr_sets;
259
260 propname = cache_type_info[cache->type].nr_sets_prop;
261
262 nr_sets = of_get_property(cache->ofnode, propname, NULL);
263 if (!nr_sets)
264 return -ENODEV;
265
266 *ret = of_read_number(nr_sets, 1);
267 return 0;
268}
269
270static int cache_associativity(const struct cache *cache, unsigned int *ret)
271{
272 unsigned int line_size;
273 unsigned int nr_sets;
274 unsigned int size;
275
276 if (cache_nr_sets(cache, &nr_sets))
277 goto err;
278
279 /* If the cache is fully associative, there is no need to
280 * check the other properties.
281 */
282 if (nr_sets == 1) {
283 *ret = 0;
284 return 0;
285 }
286
287 if (cache_get_line_size(cache, &line_size))
288 goto err;
289 if (cache_size(cache, &size))
290 goto err;
291
292 if (!(nr_sets > 0 && size > 0 && line_size > 0))
293 goto err;
294
295 *ret = (size / nr_sets) / line_size;
296 return 0;
297err:
298 return -ENODEV;
299}
300
301/* helper for dealing with split caches */
302static struct cache *cache_find_first_sibling(struct cache *cache)
303{
304 struct cache *iter;
305
306 if (cache->type == CACHE_TYPE_UNIFIED ||
307 cache->type == CACHE_TYPE_UNIFIED_D)
308 return cache;
309
310 list_for_each_entry(iter, &cache_list, list)
311 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
312 return iter;
313
314 return cache;
315}
316
317/* return the first cache on a local list matching node */
318static struct cache *cache_lookup_by_node(const struct device_node *node)
319{
320 struct cache *cache = NULL;
321 struct cache *iter;
322
323 list_for_each_entry(iter, &cache_list, list) {
324 if (iter->ofnode != node)
325 continue;
326 cache = cache_find_first_sibling(iter);
327 break;
328 }
329
330 return cache;
331}
332
333static bool cache_node_is_unified(const struct device_node *np)
334{
335 return of_get_property(np, "cache-unified", NULL);
336}
337
338/*
339 * Unified caches can have two different sets of tags. Most embedded
340 * use cache-size, etc. for the unified cache size, but open firmware systems
341 * use d-cache-size, etc. Check on initialization for which type we have, and
342 * return the appropriate structure type. Assume it's embedded if it isn't
343 * open firmware. If it's yet a 3rd type, then there will be missing entries
344 * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need
345 * to be extended further.
346 */
347static int cache_is_unified_d(const struct device_node *np)
348{
349 return of_get_property(np,
350 cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
351 CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
352}
353
354/*
355 */
356static struct cache *cache_do_one_devnode_unified(struct device_node *node, int level)
357{
358 pr_debug("creating L%d ucache for %pOF\n", level, node);
359
360 return new_cache(cache_is_unified_d(node), level, node);
361}
362
363static struct cache *cache_do_one_devnode_split(struct device_node *node,
364 int level)
365{
366 struct cache *dcache, *icache;
367
368 pr_debug("creating L%d dcache and icache for %pOF\n", level,
369 node);
370
371 dcache = new_cache(CACHE_TYPE_DATA, level, node);
372 icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
373
374 if (!dcache || !icache)
375 goto err;
376
377 dcache->next_local = icache;
378
379 return dcache;
380err:
381 release_cache(dcache);
382 release_cache(icache);
383 return NULL;
384}
385
386static struct cache *cache_do_one_devnode(struct device_node *node, int level)
387{
388 struct cache *cache;
389
390 if (cache_node_is_unified(node))
391 cache = cache_do_one_devnode_unified(node, level);
392 else
393 cache = cache_do_one_devnode_split(node, level);
394
395 return cache;
396}
397
398static struct cache *cache_lookup_or_instantiate(struct device_node *node,
399 int level)
400{
401 struct cache *cache;
402
403 cache = cache_lookup_by_node(node);
404
405 WARN_ONCE(cache && cache->level != level,
406 "cache level mismatch on lookup (got %d, expected %d)\n",
407 cache->level, level);
408
409 if (!cache)
410 cache = cache_do_one_devnode(node, level);
411
412 return cache;
413}
414
415static void link_cache_lists(struct cache *smaller, struct cache *bigger)
416{
417 while (smaller->next_local) {
418 if (smaller->next_local == bigger)
419 return; /* already linked */
420 smaller = smaller->next_local;
421 }
422
423 smaller->next_local = bigger;
424}
425
426static void do_subsidiary_caches_debugcheck(struct cache *cache)
427{
428 WARN_ON_ONCE(cache->level != 1);
429 WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
430}
431
432static void do_subsidiary_caches(struct cache *cache)
433{
434 struct device_node *subcache_node;
435 int level = cache->level;
436
437 do_subsidiary_caches_debugcheck(cache);
438
439 while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
440 struct cache *subcache;
441
442 level++;
443 subcache = cache_lookup_or_instantiate(subcache_node, level);
444 of_node_put(subcache_node);
445 if (!subcache)
446 break;
447
448 link_cache_lists(cache, subcache);
449 cache = subcache;
450 }
451}
452
453static struct cache *cache_chain_instantiate(unsigned int cpu_id)
454{
455 struct device_node *cpu_node;
456 struct cache *cpu_cache = NULL;
457
458 pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
459
460 cpu_node = of_get_cpu_node(cpu_id, NULL);
461 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
462 if (!cpu_node)
463 goto out;
464
465 cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
466 if (!cpu_cache)
467 goto out;
468
469 do_subsidiary_caches(cpu_cache);
470
471 cache_cpu_set(cpu_cache, cpu_id);
472out:
473 of_node_put(cpu_node);
474
475 return cpu_cache;
476}
477
478static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
479{
480 struct cache_dir *cache_dir;
481 struct device *dev;
482 struct kobject *kobj = NULL;
483
484 dev = get_cpu_device(cpu_id);
485 WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
486 if (!dev)
487 goto err;
488
489 kobj = kobject_create_and_add("cache", &dev->kobj);
490 if (!kobj)
491 goto err;
492
493 cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
494 if (!cache_dir)
495 goto err;
496
497 cache_dir->kobj = kobj;
498
499 WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
500
501 per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
502
503 return cache_dir;
504err:
505 kobject_put(kobj);
506 return NULL;
507}
508
509static void cache_index_release(struct kobject *kobj)
510{
511 struct cache_index_dir *index;
512
513 index = kobj_to_cache_index_dir(kobj);
514
515 pr_debug("freeing index directory for L%d %s cache\n",
516 index->cache->level, cache_type_string(index->cache));
517
518 kfree(index);
519}
520
521static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
522{
523 struct kobj_attribute *kobj_attr;
524
525 kobj_attr = container_of(attr, struct kobj_attribute, attr);
526
527 return kobj_attr->show(k, kobj_attr, buf);
528}
529
530static struct cache *index_kobj_to_cache(struct kobject *k)
531{
532 struct cache_index_dir *index;
533
534 index = kobj_to_cache_index_dir(k);
535
536 return index->cache;
537}
538
539static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
540{
541 unsigned int size_kb;
542 struct cache *cache;
543
544 cache = index_kobj_to_cache(k);
545
546 if (cache_size_kb(cache, &size_kb))
547 return -ENODEV;
548
549 return sprintf(buf, "%uK\n", size_kb);
550}
551
552static struct kobj_attribute cache_size_attr =
553 __ATTR(size, 0444, size_show, NULL);
554
555
556static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
557{
558 unsigned int line_size;
559 struct cache *cache;
560
561 cache = index_kobj_to_cache(k);
562
563 if (cache_get_line_size(cache, &line_size))
564 return -ENODEV;
565
566 return sprintf(buf, "%u\n", line_size);
567}
568
569static struct kobj_attribute cache_line_size_attr =
570 __ATTR(coherency_line_size, 0444, line_size_show, NULL);
571
572static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
573{
574 unsigned int nr_sets;
575 struct cache *cache;
576
577 cache = index_kobj_to_cache(k);
578
579 if (cache_nr_sets(cache, &nr_sets))
580 return -ENODEV;
581
582 return sprintf(buf, "%u\n", nr_sets);
583}
584
585static struct kobj_attribute cache_nr_sets_attr =
586 __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
587
588static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
589{
590 unsigned int associativity;
591 struct cache *cache;
592
593 cache = index_kobj_to_cache(k);
594
595 if (cache_associativity(cache, &associativity))
596 return -ENODEV;
597
598 return sprintf(buf, "%u\n", associativity);
599}
600
601static struct kobj_attribute cache_assoc_attr =
602 __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
603
604static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
605{
606 struct cache *cache;
607
608 cache = index_kobj_to_cache(k);
609
610 return sprintf(buf, "%s\n", cache_type_string(cache));
611}
612
613static struct kobj_attribute cache_type_attr =
614 __ATTR(type, 0444, type_show, NULL);
615
616static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
617{
618 struct cache_index_dir *index;
619 struct cache *cache;
620
621 index = kobj_to_cache_index_dir(k);
622 cache = index->cache;
623
624 return sprintf(buf, "%d\n", cache->level);
625}
626
627static struct kobj_attribute cache_level_attr =
628 __ATTR(level, 0444, level_show, NULL);
629
630static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
631{
632 struct cache_index_dir *index;
633 struct cache *cache;
634 int ret;
635
636 index = kobj_to_cache_index_dir(k);
637 cache = index->cache;
638
639 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pb\n",
640 cpumask_pr_args(&cache->shared_cpu_map));
641 buf[ret++] = '\n';
642 buf[ret] = '\0';
643 return ret;
644}
645
646static struct kobj_attribute cache_shared_cpu_map_attr =
647 __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
648
649/* Attributes which should always be created -- the kobject/sysfs core
650 * does this automatically via kobj_type->default_attrs. This is the
651 * minimum data required to uniquely identify a cache.
652 */
653static struct attribute *cache_index_default_attrs[] = {
654 &cache_type_attr.attr,
655 &cache_level_attr.attr,
656 &cache_shared_cpu_map_attr.attr,
657 NULL,
658};
659
660/* Attributes which should be created if the cache device node has the
661 * right properties -- see cacheinfo_create_index_opt_attrs
662 */
663static struct kobj_attribute *cache_index_opt_attrs[] = {
664 &cache_size_attr,
665 &cache_line_size_attr,
666 &cache_nr_sets_attr,
667 &cache_assoc_attr,
668};
669
670static const struct sysfs_ops cache_index_ops = {
671 .show = cache_index_show,
672};
673
674static struct kobj_type cache_index_type = {
675 .release = cache_index_release,
676 .sysfs_ops = &cache_index_ops,
677 .default_attrs = cache_index_default_attrs,
678};
679
680static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
681{
682 const char *cache_type;
683 struct cache *cache;
684 char *buf;
685 int i;
686
687 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
688 if (!buf)
689 return;
690
691 cache = dir->cache;
692 cache_type = cache_type_string(cache);
693
694 /* We don't want to create an attribute that can't provide a
695 * meaningful value. Check the return value of each optional
696 * attribute's ->show method before registering the
697 * attribute.
698 */
699 for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
700 struct kobj_attribute *attr;
701 ssize_t rc;
702
703 attr = cache_index_opt_attrs[i];
704
705 rc = attr->show(&dir->kobj, attr, buf);
706 if (rc <= 0) {
707 pr_debug("not creating %s attribute for "
708 "%pOF(%s) (rc = %zd)\n",
709 attr->attr.name, cache->ofnode,
710 cache_type, rc);
711 continue;
712 }
713 if (sysfs_create_file(&dir->kobj, &attr->attr))
714 pr_debug("could not create %s attribute for %pOF(%s)\n",
715 attr->attr.name, cache->ofnode, cache_type);
716 }
717
718 kfree(buf);
719}
720
721static void cacheinfo_create_index_dir(struct cache *cache, int index,
722 struct cache_dir *cache_dir)
723{
724 struct cache_index_dir *index_dir;
725 int rc;
726
727 index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
728 if (!index_dir)
729 goto err;
730
731 index_dir->cache = cache;
732
733 rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
734 cache_dir->kobj, "index%d", index);
735 if (rc)
736 goto err;
737
738 index_dir->next = cache_dir->index;
739 cache_dir->index = index_dir;
740
741 cacheinfo_create_index_opt_attrs(index_dir);
742
743 return;
744err:
745 kfree(index_dir);
746}
747
748static void cacheinfo_sysfs_populate(unsigned int cpu_id,
749 struct cache *cache_list)
750{
751 struct cache_dir *cache_dir;
752 struct cache *cache;
753 int index = 0;
754
755 cache_dir = cacheinfo_create_cache_dir(cpu_id);
756 if (!cache_dir)
757 return;
758
759 cache = cache_list;
760 while (cache) {
761 cacheinfo_create_index_dir(cache, index, cache_dir);
762 index++;
763 cache = cache->next_local;
764 }
765}
766
767void cacheinfo_cpu_online(unsigned int cpu_id)
768{
769 struct cache *cache;
770
771 cache = cache_chain_instantiate(cpu_id);
772 if (!cache)
773 return;
774
775 cacheinfo_sysfs_populate(cpu_id, cache);
776}
777
778/* functions needed to remove cache entry for cpu offline or suspend/resume */
779
780#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
781 defined(CONFIG_HOTPLUG_CPU)
782
783static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
784{
785 struct device_node *cpu_node;
786 struct cache *cache;
787
788 cpu_node = of_get_cpu_node(cpu_id, NULL);
789 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
790 if (!cpu_node)
791 return NULL;
792
793 cache = cache_lookup_by_node(cpu_node);
794 of_node_put(cpu_node);
795
796 return cache;
797}
798
799static void remove_index_dirs(struct cache_dir *cache_dir)
800{
801 struct cache_index_dir *index;
802
803 index = cache_dir->index;
804
805 while (index) {
806 struct cache_index_dir *next;
807
808 next = index->next;
809 kobject_put(&index->kobj);
810 index = next;
811 }
812}
813
814static void remove_cache_dir(struct cache_dir *cache_dir)
815{
816 remove_index_dirs(cache_dir);
817
818 /* Remove cache dir from sysfs */
819 kobject_del(cache_dir->kobj);
820
821 kobject_put(cache_dir->kobj);
822
823 kfree(cache_dir);
824}
825
826static void cache_cpu_clear(struct cache *cache, int cpu)
827{
828 while (cache) {
829 struct cache *next = cache->next_local;
830
831 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
832 "CPU %i not accounted in %pOF(%s)\n",
833 cpu, cache->ofnode,
834 cache_type_string(cache));
835
836 cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
837
838 /* Release the cache object if all the cpus using it
839 * are offline */
840 if (cpumask_empty(&cache->shared_cpu_map))
841 release_cache(cache);
842
843 cache = next;
844 }
845}
846
847void cacheinfo_cpu_offline(unsigned int cpu_id)
848{
849 struct cache_dir *cache_dir;
850 struct cache *cache;
851
852 /* Prevent userspace from seeing inconsistent state - remove
853 * the sysfs hierarchy first */
854 cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
855
856 /* careful, sysfs population may have failed */
857 if (cache_dir)
858 remove_cache_dir(cache_dir);
859
860 per_cpu(cache_dir_pcpu, cpu_id) = NULL;
861
862 /* clear the CPU's bit in its cache chain, possibly freeing
863 * cache objects */
864 cache = cache_lookup_by_cpu(cpu_id);
865 if (cache)
866 cache_cpu_clear(cache, cpu_id);
867}
868#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
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 */