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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/prom.h>
22#include <asm/cputhreads.h>
23#include <asm/smp.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 /* cache-size, cache-block-size, etc. */
66#define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */
67#define CACHE_TYPE_INSTRUCTION 2
68#define CACHE_TYPE_DATA 3
69
70static const struct cache_type_info cache_type_info[] = {
71 {
72 /* Embedded systems that use cache-size, cache-block-size,
73 * etc. for the Unified (typically L2) cache. */
74 .name = "Unified",
75 .size_prop = "cache-size",
76 .line_size_props = { "cache-line-size",
77 "cache-block-size", },
78 .nr_sets_prop = "cache-sets",
79 },
80 {
81 /* PowerPC Processor binding says the [di]-cache-*
82 * must be equal on unified caches, so just use
83 * d-cache properties. */
84 .name = "Unified",
85 .size_prop = "d-cache-size",
86 .line_size_props = { "d-cache-line-size",
87 "d-cache-block-size", },
88 .nr_sets_prop = "d-cache-sets",
89 },
90 {
91 .name = "Instruction",
92 .size_prop = "i-cache-size",
93 .line_size_props = { "i-cache-line-size",
94 "i-cache-block-size", },
95 .nr_sets_prop = "i-cache-sets",
96 },
97 {
98 .name = "Data",
99 .size_prop = "d-cache-size",
100 .line_size_props = { "d-cache-line-size",
101 "d-cache-block-size", },
102 .nr_sets_prop = "d-cache-sets",
103 },
104};
105
106/* Cache object: each instance of this corresponds to a distinct cache
107 * in the system. There are separate objects for Harvard caches: one
108 * each for instruction and data, and each refers to the same OF node.
109 * The refcount of the OF node is elevated for the lifetime of the
110 * cache object. A cache object is released when its shared_cpu_map
111 * is cleared (see cache_cpu_clear).
112 *
113 * A cache object is on two lists: an unsorted global list
114 * (cache_list) of cache objects; and a singly-linked list
115 * representing the local cache hierarchy, which is ordered by level
116 * (e.g. L1d -> L1i -> L2 -> L3).
117 */
118struct cache {
119 struct device_node *ofnode; /* OF node for this cache, may be cpu */
120 struct cpumask shared_cpu_map; /* online CPUs using this cache */
121 int type; /* split cache disambiguation */
122 int level; /* level not explicit in device tree */
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)
146{
147 cache->type = type;
148 cache->level = level;
149 cache->ofnode = of_node_get(ofnode);
150 INIT_LIST_HEAD(&cache->list);
151 list_add(&cache->list, &cache_list);
152}
153
154static struct cache *new_cache(int type, int level, struct device_node *ofnode)
155{
156 struct cache *cache;
157
158 cache = kzalloc(sizeof(*cache), GFP_KERNEL);
159 if (cache)
160 cache_init(cache, type, level, ofnode);
161
162 return cache;
163}
164
165static void release_cache_debugcheck(struct cache *cache)
166{
167 struct cache *iter;
168
169 list_for_each_entry(iter, &cache_list, list)
170 WARN_ONCE(iter->next_local == cache,
171 "cache for %pOFP(%s) refers to cache for %pOFP(%s)\n",
172 iter->ofnode,
173 cache_type_string(iter),
174 cache->ofnode,
175 cache_type_string(cache));
176}
177
178static void release_cache(struct cache *cache)
179{
180 if (!cache)
181 return;
182
183 pr_debug("freeing L%d %s cache for %pOFP\n", cache->level,
184 cache_type_string(cache), cache->ofnode);
185
186 release_cache_debugcheck(cache);
187 list_del(&cache->list);
188 of_node_put(cache->ofnode);
189 kfree(cache);
190}
191
192static void cache_cpu_set(struct cache *cache, int cpu)
193{
194 struct cache *next = cache;
195
196 while (next) {
197 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
198 "CPU %i already accounted in %pOFP(%s)\n",
199 cpu, next->ofnode,
200 cache_type_string(next));
201 cpumask_set_cpu(cpu, &next->shared_cpu_map);
202 next = next->next_local;
203 }
204}
205
206static int cache_size(const struct cache *cache, unsigned int *ret)
207{
208 const char *propname;
209 const __be32 *cache_size;
210
211 propname = cache_type_info[cache->type].size_prop;
212
213 cache_size = of_get_property(cache->ofnode, propname, NULL);
214 if (!cache_size)
215 return -ENODEV;
216
217 *ret = of_read_number(cache_size, 1);
218 return 0;
219}
220
221static int cache_size_kb(const struct cache *cache, unsigned int *ret)
222{
223 unsigned int size;
224
225 if (cache_size(cache, &size))
226 return -ENODEV;
227
228 *ret = size / 1024;
229 return 0;
230}
231
232/* not cache_line_size() because that's a macro in include/linux/cache.h */
233static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
234{
235 const __be32 *line_size;
236 int i, lim;
237
238 lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
239
240 for (i = 0; i < lim; i++) {
241 const char *propname;
242
243 propname = cache_type_info[cache->type].line_size_props[i];
244 line_size = of_get_property(cache->ofnode, propname, NULL);
245 if (line_size)
246 break;
247 }
248
249 if (!line_size)
250 return -ENODEV;
251
252 *ret = of_read_number(line_size, 1);
253 return 0;
254}
255
256static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
257{
258 const char *propname;
259 const __be32 *nr_sets;
260
261 propname = cache_type_info[cache->type].nr_sets_prop;
262
263 nr_sets = of_get_property(cache->ofnode, propname, NULL);
264 if (!nr_sets)
265 return -ENODEV;
266
267 *ret = of_read_number(nr_sets, 1);
268 return 0;
269}
270
271static int cache_associativity(const struct cache *cache, unsigned int *ret)
272{
273 unsigned int line_size;
274 unsigned int nr_sets;
275 unsigned int size;
276
277 if (cache_nr_sets(cache, &nr_sets))
278 goto err;
279
280 /* If the cache is fully associative, there is no need to
281 * check the other properties.
282 */
283 if (nr_sets == 1) {
284 *ret = 0;
285 return 0;
286 }
287
288 if (cache_get_line_size(cache, &line_size))
289 goto err;
290 if (cache_size(cache, &size))
291 goto err;
292
293 if (!(nr_sets > 0 && size > 0 && line_size > 0))
294 goto err;
295
296 *ret = (size / nr_sets) / line_size;
297 return 0;
298err:
299 return -ENODEV;
300}
301
302/* helper for dealing with split caches */
303static struct cache *cache_find_first_sibling(struct cache *cache)
304{
305 struct cache *iter;
306
307 if (cache->type == CACHE_TYPE_UNIFIED ||
308 cache->type == CACHE_TYPE_UNIFIED_D)
309 return cache;
310
311 list_for_each_entry(iter, &cache_list, list)
312 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
313 return iter;
314
315 return cache;
316}
317
318/* return the first cache on a local list matching node */
319static struct cache *cache_lookup_by_node(const struct device_node *node)
320{
321 struct cache *cache = NULL;
322 struct cache *iter;
323
324 list_for_each_entry(iter, &cache_list, list) {
325 if (iter->ofnode != node)
326 continue;
327 cache = cache_find_first_sibling(iter);
328 break;
329 }
330
331 return cache;
332}
333
334static bool cache_node_is_unified(const struct device_node *np)
335{
336 return of_get_property(np, "cache-unified", NULL);
337}
338
339/*
340 * Unified caches can have two different sets of tags. Most embedded
341 * use cache-size, etc. for the unified cache size, but open firmware systems
342 * use d-cache-size, etc. Check on initialization for which type we have, and
343 * return the appropriate structure type. Assume it's embedded if it isn't
344 * open firmware. If it's yet a 3rd type, then there will be missing entries
345 * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need
346 * to be extended further.
347 */
348static int cache_is_unified_d(const struct device_node *np)
349{
350 return of_get_property(np,
351 cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
352 CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
353}
354
355static struct cache *cache_do_one_devnode_unified(struct device_node *node, int level)
356{
357 pr_debug("creating L%d ucache for %pOFP\n", level, node);
358
359 return new_cache(cache_is_unified_d(node), level, node);
360}
361
362static struct cache *cache_do_one_devnode_split(struct device_node *node,
363 int level)
364{
365 struct cache *dcache, *icache;
366
367 pr_debug("creating L%d dcache and icache for %pOFP\n", level,
368 node);
369
370 dcache = new_cache(CACHE_TYPE_DATA, level, node);
371 icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
372
373 if (!dcache || !icache)
374 goto err;
375
376 dcache->next_local = icache;
377
378 return dcache;
379err:
380 release_cache(dcache);
381 release_cache(icache);
382 return NULL;
383}
384
385static struct cache *cache_do_one_devnode(struct device_node *node, int level)
386{
387 struct cache *cache;
388
389 if (cache_node_is_unified(node))
390 cache = cache_do_one_devnode_unified(node, level);
391 else
392 cache = cache_do_one_devnode_split(node, level);
393
394 return cache;
395}
396
397static struct cache *cache_lookup_or_instantiate(struct device_node *node,
398 int level)
399{
400 struct cache *cache;
401
402 cache = cache_lookup_by_node(node);
403
404 WARN_ONCE(cache && cache->level != level,
405 "cache level mismatch on lookup (got %d, expected %d)\n",
406 cache->level, level);
407
408 if (!cache)
409 cache = cache_do_one_devnode(node, level);
410
411 return cache;
412}
413
414static void link_cache_lists(struct cache *smaller, struct cache *bigger)
415{
416 while (smaller->next_local) {
417 if (smaller->next_local == bigger)
418 return; /* already linked */
419 smaller = smaller->next_local;
420 }
421
422 smaller->next_local = bigger;
423
424 /*
425 * The cache->next_local list sorts by level ascending:
426 * L1d -> L1i -> L2 -> L3 ...
427 */
428 WARN_ONCE((smaller->level == 1 && bigger->level > 2) ||
429 (smaller->level > 1 && bigger->level != smaller->level + 1),
430 "linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n",
431 smaller->level, smaller->ofnode, bigger->level, bigger->ofnode);
432}
433
434static void do_subsidiary_caches_debugcheck(struct cache *cache)
435{
436 WARN_ONCE(cache->level != 1,
437 "instantiating cache chain from L%d %s cache for "
438 "%pOFP instead of an L1\n", cache->level,
439 cache_type_string(cache), cache->ofnode);
440 WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"),
441 "instantiating cache chain from node %pOFP of type '%s' "
442 "instead of a cpu node\n", cache->ofnode,
443 of_node_get_device_type(cache->ofnode));
444}
445
446static void do_subsidiary_caches(struct cache *cache)
447{
448 struct device_node *subcache_node;
449 int level = cache->level;
450
451 do_subsidiary_caches_debugcheck(cache);
452
453 while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
454 struct cache *subcache;
455
456 level++;
457 subcache = cache_lookup_or_instantiate(subcache_node, level);
458 of_node_put(subcache_node);
459 if (!subcache)
460 break;
461
462 link_cache_lists(cache, subcache);
463 cache = subcache;
464 }
465}
466
467static struct cache *cache_chain_instantiate(unsigned int cpu_id)
468{
469 struct device_node *cpu_node;
470 struct cache *cpu_cache = NULL;
471
472 pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
473
474 cpu_node = of_get_cpu_node(cpu_id, NULL);
475 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
476 if (!cpu_node)
477 goto out;
478
479 cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
480 if (!cpu_cache)
481 goto out;
482
483 do_subsidiary_caches(cpu_cache);
484
485 cache_cpu_set(cpu_cache, cpu_id);
486out:
487 of_node_put(cpu_node);
488
489 return cpu_cache;
490}
491
492static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
493{
494 struct cache_dir *cache_dir;
495 struct device *dev;
496 struct kobject *kobj = NULL;
497
498 dev = get_cpu_device(cpu_id);
499 WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
500 if (!dev)
501 goto err;
502
503 kobj = kobject_create_and_add("cache", &dev->kobj);
504 if (!kobj)
505 goto err;
506
507 cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
508 if (!cache_dir)
509 goto err;
510
511 cache_dir->kobj = kobj;
512
513 WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
514
515 per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
516
517 return cache_dir;
518err:
519 kobject_put(kobj);
520 return NULL;
521}
522
523static void cache_index_release(struct kobject *kobj)
524{
525 struct cache_index_dir *index;
526
527 index = kobj_to_cache_index_dir(kobj);
528
529 pr_debug("freeing index directory for L%d %s cache\n",
530 index->cache->level, cache_type_string(index->cache));
531
532 kfree(index);
533}
534
535static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
536{
537 struct kobj_attribute *kobj_attr;
538
539 kobj_attr = container_of(attr, struct kobj_attribute, attr);
540
541 return kobj_attr->show(k, kobj_attr, buf);
542}
543
544static struct cache *index_kobj_to_cache(struct kobject *k)
545{
546 struct cache_index_dir *index;
547
548 index = kobj_to_cache_index_dir(k);
549
550 return index->cache;
551}
552
553static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
554{
555 unsigned int size_kb;
556 struct cache *cache;
557
558 cache = index_kobj_to_cache(k);
559
560 if (cache_size_kb(cache, &size_kb))
561 return -ENODEV;
562
563 return sprintf(buf, "%uK\n", size_kb);
564}
565
566static struct kobj_attribute cache_size_attr =
567 __ATTR(size, 0444, size_show, NULL);
568
569
570static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
571{
572 unsigned int line_size;
573 struct cache *cache;
574
575 cache = index_kobj_to_cache(k);
576
577 if (cache_get_line_size(cache, &line_size))
578 return -ENODEV;
579
580 return sprintf(buf, "%u\n", line_size);
581}
582
583static struct kobj_attribute cache_line_size_attr =
584 __ATTR(coherency_line_size, 0444, line_size_show, NULL);
585
586static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
587{
588 unsigned int nr_sets;
589 struct cache *cache;
590
591 cache = index_kobj_to_cache(k);
592
593 if (cache_nr_sets(cache, &nr_sets))
594 return -ENODEV;
595
596 return sprintf(buf, "%u\n", nr_sets);
597}
598
599static struct kobj_attribute cache_nr_sets_attr =
600 __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
601
602static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
603{
604 unsigned int associativity;
605 struct cache *cache;
606
607 cache = index_kobj_to_cache(k);
608
609 if (cache_associativity(cache, &associativity))
610 return -ENODEV;
611
612 return sprintf(buf, "%u\n", associativity);
613}
614
615static struct kobj_attribute cache_assoc_attr =
616 __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
617
618static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
619{
620 struct cache *cache;
621
622 cache = index_kobj_to_cache(k);
623
624 return sprintf(buf, "%s\n", cache_type_string(cache));
625}
626
627static struct kobj_attribute cache_type_attr =
628 __ATTR(type, 0444, type_show, NULL);
629
630static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
631{
632 struct cache_index_dir *index;
633 struct cache *cache;
634
635 index = kobj_to_cache_index_dir(k);
636 cache = index->cache;
637
638 return sprintf(buf, "%d\n", cache->level);
639}
640
641static struct kobj_attribute cache_level_attr =
642 __ATTR(level, 0444, level_show, NULL);
643
644static unsigned int index_dir_to_cpu(struct cache_index_dir *index)
645{
646 struct kobject *index_dir_kobj = &index->kobj;
647 struct kobject *cache_dir_kobj = index_dir_kobj->parent;
648 struct kobject *cpu_dev_kobj = cache_dir_kobj->parent;
649 struct device *dev = kobj_to_dev(cpu_dev_kobj);
650
651 return dev->id;
652}
653
654/*
655 * On big-core systems, each core has two groups of CPUs each of which
656 * has its own L1-cache. The thread-siblings which share l1-cache with
657 * @cpu can be obtained via cpu_smallcore_mask().
658 *
659 * On some big-core systems, the L2 cache is shared only between some
660 * groups of siblings. This is already parsed and encoded in
661 * cpu_l2_cache_mask().
662 *
663 * TODO: cache_lookup_or_instantiate() needs to be made aware of the
664 * "ibm,thread-groups" property so that cache->shared_cpu_map
665 * reflects the correct siblings on platforms that have this
666 * device-tree property. This helper function is only a stop-gap
667 * solution so that we report the correct siblings to the
668 * userspace via sysfs.
669 */
670static const struct cpumask *get_shared_cpu_map(struct cache_index_dir *index, struct cache *cache)
671{
672 if (has_big_cores) {
673 int cpu = index_dir_to_cpu(index);
674 if (cache->level == 1)
675 return cpu_smallcore_mask(cpu);
676 if (cache->level == 2 && thread_group_shares_l2)
677 return cpu_l2_cache_mask(cpu);
678 }
679
680 return &cache->shared_cpu_map;
681}
682
683static ssize_t
684show_shared_cpumap(struct kobject *k, struct kobj_attribute *attr, char *buf, bool list)
685{
686 struct cache_index_dir *index;
687 struct cache *cache;
688 const struct cpumask *mask;
689
690 index = kobj_to_cache_index_dir(k);
691 cache = index->cache;
692
693 mask = get_shared_cpu_map(index, cache);
694
695 return cpumap_print_to_pagebuf(list, buf, mask);
696}
697
698static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
699{
700 return show_shared_cpumap(k, attr, buf, false);
701}
702
703static ssize_t shared_cpu_list_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
704{
705 return show_shared_cpumap(k, attr, buf, true);
706}
707
708static struct kobj_attribute cache_shared_cpu_map_attr =
709 __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
710
711static struct kobj_attribute cache_shared_cpu_list_attr =
712 __ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
713
714/* Attributes which should always be created -- the kobject/sysfs core
715 * does this automatically via kobj_type->default_attrs. This is the
716 * minimum data required to uniquely identify a cache.
717 */
718static struct attribute *cache_index_default_attrs[] = {
719 &cache_type_attr.attr,
720 &cache_level_attr.attr,
721 &cache_shared_cpu_map_attr.attr,
722 &cache_shared_cpu_list_attr.attr,
723 NULL,
724};
725
726/* Attributes which should be created if the cache device node has the
727 * right properties -- see cacheinfo_create_index_opt_attrs
728 */
729static struct kobj_attribute *cache_index_opt_attrs[] = {
730 &cache_size_attr,
731 &cache_line_size_attr,
732 &cache_nr_sets_attr,
733 &cache_assoc_attr,
734};
735
736static const struct sysfs_ops cache_index_ops = {
737 .show = cache_index_show,
738};
739
740static struct kobj_type cache_index_type = {
741 .release = cache_index_release,
742 .sysfs_ops = &cache_index_ops,
743 .default_attrs = cache_index_default_attrs,
744};
745
746static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
747{
748 const char *cache_type;
749 struct cache *cache;
750 char *buf;
751 int i;
752
753 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
754 if (!buf)
755 return;
756
757 cache = dir->cache;
758 cache_type = cache_type_string(cache);
759
760 /* We don't want to create an attribute that can't provide a
761 * meaningful value. Check the return value of each optional
762 * attribute's ->show method before registering the
763 * attribute.
764 */
765 for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
766 struct kobj_attribute *attr;
767 ssize_t rc;
768
769 attr = cache_index_opt_attrs[i];
770
771 rc = attr->show(&dir->kobj, attr, buf);
772 if (rc <= 0) {
773 pr_debug("not creating %s attribute for "
774 "%pOFP(%s) (rc = %zd)\n",
775 attr->attr.name, cache->ofnode,
776 cache_type, rc);
777 continue;
778 }
779 if (sysfs_create_file(&dir->kobj, &attr->attr))
780 pr_debug("could not create %s attribute for %pOFP(%s)\n",
781 attr->attr.name, cache->ofnode, cache_type);
782 }
783
784 kfree(buf);
785}
786
787static void cacheinfo_create_index_dir(struct cache *cache, int index,
788 struct cache_dir *cache_dir)
789{
790 struct cache_index_dir *index_dir;
791 int rc;
792
793 index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
794 if (!index_dir)
795 return;
796
797 index_dir->cache = cache;
798
799 rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
800 cache_dir->kobj, "index%d", index);
801 if (rc) {
802 kobject_put(&index_dir->kobj);
803 return;
804 }
805
806 index_dir->next = cache_dir->index;
807 cache_dir->index = index_dir;
808
809 cacheinfo_create_index_opt_attrs(index_dir);
810}
811
812static void cacheinfo_sysfs_populate(unsigned int cpu_id,
813 struct cache *cache_list)
814{
815 struct cache_dir *cache_dir;
816 struct cache *cache;
817 int index = 0;
818
819 cache_dir = cacheinfo_create_cache_dir(cpu_id);
820 if (!cache_dir)
821 return;
822
823 cache = cache_list;
824 while (cache) {
825 cacheinfo_create_index_dir(cache, index, cache_dir);
826 index++;
827 cache = cache->next_local;
828 }
829}
830
831void cacheinfo_cpu_online(unsigned int cpu_id)
832{
833 struct cache *cache;
834
835 cache = cache_chain_instantiate(cpu_id);
836 if (!cache)
837 return;
838
839 cacheinfo_sysfs_populate(cpu_id, cache);
840}
841
842/* functions needed to remove cache entry for cpu offline or suspend/resume */
843
844#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
845 defined(CONFIG_HOTPLUG_CPU)
846
847static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
848{
849 struct device_node *cpu_node;
850 struct cache *cache;
851
852 cpu_node = of_get_cpu_node(cpu_id, NULL);
853 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
854 if (!cpu_node)
855 return NULL;
856
857 cache = cache_lookup_by_node(cpu_node);
858 of_node_put(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(&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(cache_dir->kobj);
884
885 kobject_put(cache_dir->kobj);
886
887 kfree(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, &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
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_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);
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);
951}
952
953#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
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#include <linux/cpu.h>
11#include <linux/cpumask.h>
12#include <linux/kernel.h>
13#include <linux/kobject.h>
14#include <linux/list.h>
15#include <linux/notifier.h>
16#include <linux/of.h>
17#include <linux/percpu.h>
18#include <linux/slab.h>
19#include <asm/prom.h>
20#include <asm/cputhreads.h>
21#include <asm/smp.h>
22
23#include "cacheinfo.h"
24
25/* per-cpu object for tracking:
26 * - a "cache" kobject for the top-level directory
27 * - a list of "index" objects representing the cpu's local cache hierarchy
28 */
29struct cache_dir {
30 struct kobject *kobj; /* bare (not embedded) kobject for cache
31 * directory */
32 struct cache_index_dir *index; /* list of index objects */
33};
34
35/* "index" object: each cpu's cache directory has an index
36 * subdirectory corresponding to a cache object associated with the
37 * cpu. This object's lifetime is managed via the embedded kobject.
38 */
39struct cache_index_dir {
40 struct kobject kobj;
41 struct cache_index_dir *next; /* next index in parent directory */
42 struct cache *cache;
43};
44
45/* Template for determining which OF properties to query for a given
46 * cache type */
47struct cache_type_info {
48 const char *name;
49 const char *size_prop;
50
51 /* Allow for both [di]-cache-line-size and
52 * [di]-cache-block-size properties. According to the PowerPC
53 * Processor binding, -line-size should be provided if it
54 * differs from the cache block size (that which is operated
55 * on by cache instructions), so we look for -line-size first.
56 * See cache_get_line_size(). */
57
58 const char *line_size_props[2];
59 const char *nr_sets_prop;
60};
61
62/* These are used to index the cache_type_info array. */
63#define CACHE_TYPE_UNIFIED 0 /* cache-size, cache-block-size, etc. */
64#define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */
65#define CACHE_TYPE_INSTRUCTION 2
66#define CACHE_TYPE_DATA 3
67
68static const struct cache_type_info cache_type_info[] = {
69 {
70 /* Embedded systems that use cache-size, cache-block-size,
71 * etc. for the Unified (typically L2) cache. */
72 .name = "Unified",
73 .size_prop = "cache-size",
74 .line_size_props = { "cache-line-size",
75 "cache-block-size", },
76 .nr_sets_prop = "cache-sets",
77 },
78 {
79 /* PowerPC Processor binding says the [di]-cache-*
80 * must be equal on unified caches, so just use
81 * d-cache properties. */
82 .name = "Unified",
83 .size_prop = "d-cache-size",
84 .line_size_props = { "d-cache-line-size",
85 "d-cache-block-size", },
86 .nr_sets_prop = "d-cache-sets",
87 },
88 {
89 .name = "Instruction",
90 .size_prop = "i-cache-size",
91 .line_size_props = { "i-cache-line-size",
92 "i-cache-block-size", },
93 .nr_sets_prop = "i-cache-sets",
94 },
95 {
96 .name = "Data",
97 .size_prop = "d-cache-size",
98 .line_size_props = { "d-cache-line-size",
99 "d-cache-block-size", },
100 .nr_sets_prop = "d-cache-sets",
101 },
102};
103
104/* Cache object: each instance of this corresponds to a distinct cache
105 * in the system. There are separate objects for Harvard caches: one
106 * each for instruction and data, and each refers to the same OF node.
107 * The refcount of the OF node is elevated for the lifetime of the
108 * cache object. A cache object is released when its shared_cpu_map
109 * is cleared (see cache_cpu_clear).
110 *
111 * A cache object is on two lists: an unsorted global list
112 * (cache_list) of cache objects; and a singly-linked list
113 * representing the local cache hierarchy, which is ordered by level
114 * (e.g. L1d -> L1i -> L2 -> L3).
115 */
116struct cache {
117 struct device_node *ofnode; /* OF node for this cache, may be cpu */
118 struct cpumask shared_cpu_map; /* online CPUs using this cache */
119 int type; /* split cache disambiguation */
120 int level; /* level not explicit in device tree */
121 struct list_head list; /* global list of cache objects */
122 struct cache *next_local; /* next cache of >= level */
123};
124
125static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
126
127/* traversal/modification of this list occurs only at cpu hotplug time;
128 * access is serialized by cpu hotplug locking
129 */
130static LIST_HEAD(cache_list);
131
132static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
133{
134 return container_of(k, struct cache_index_dir, kobj);
135}
136
137static const char *cache_type_string(const struct cache *cache)
138{
139 return cache_type_info[cache->type].name;
140}
141
142static void cache_init(struct cache *cache, int type, int level,
143 struct device_node *ofnode)
144{
145 cache->type = type;
146 cache->level = level;
147 cache->ofnode = of_node_get(ofnode);
148 INIT_LIST_HEAD(&cache->list);
149 list_add(&cache->list, &cache_list);
150}
151
152static struct cache *new_cache(int type, int level, struct device_node *ofnode)
153{
154 struct cache *cache;
155
156 cache = kzalloc(sizeof(*cache), GFP_KERNEL);
157 if (cache)
158 cache_init(cache, type, level, ofnode);
159
160 return cache;
161}
162
163static void release_cache_debugcheck(struct cache *cache)
164{
165 struct cache *iter;
166
167 list_for_each_entry(iter, &cache_list, list)
168 WARN_ONCE(iter->next_local == cache,
169 "cache for %pOF(%s) refers to cache for %pOF(%s)\n",
170 iter->ofnode,
171 cache_type_string(iter),
172 cache->ofnode,
173 cache_type_string(cache));
174}
175
176static void release_cache(struct cache *cache)
177{
178 if (!cache)
179 return;
180
181 pr_debug("freeing L%d %s cache for %pOF\n", cache->level,
182 cache_type_string(cache), cache->ofnode);
183
184 release_cache_debugcheck(cache);
185 list_del(&cache->list);
186 of_node_put(cache->ofnode);
187 kfree(cache);
188}
189
190static void cache_cpu_set(struct cache *cache, int cpu)
191{
192 struct cache *next = cache;
193
194 while (next) {
195 WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
196 "CPU %i already accounted in %pOF(%s)\n",
197 cpu, next->ofnode,
198 cache_type_string(next));
199 cpumask_set_cpu(cpu, &next->shared_cpu_map);
200 next = next->next_local;
201 }
202}
203
204static int cache_size(const struct cache *cache, unsigned int *ret)
205{
206 const char *propname;
207 const __be32 *cache_size;
208
209 propname = cache_type_info[cache->type].size_prop;
210
211 cache_size = of_get_property(cache->ofnode, propname, NULL);
212 if (!cache_size)
213 return -ENODEV;
214
215 *ret = of_read_number(cache_size, 1);
216 return 0;
217}
218
219static int cache_size_kb(const struct cache *cache, unsigned int *ret)
220{
221 unsigned int size;
222
223 if (cache_size(cache, &size))
224 return -ENODEV;
225
226 *ret = size / 1024;
227 return 0;
228}
229
230/* not cache_line_size() because that's a macro in include/linux/cache.h */
231static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
232{
233 const __be32 *line_size;
234 int i, lim;
235
236 lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
237
238 for (i = 0; i < lim; i++) {
239 const char *propname;
240
241 propname = cache_type_info[cache->type].line_size_props[i];
242 line_size = of_get_property(cache->ofnode, propname, NULL);
243 if (line_size)
244 break;
245 }
246
247 if (!line_size)
248 return -ENODEV;
249
250 *ret = of_read_number(line_size, 1);
251 return 0;
252}
253
254static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
255{
256 const char *propname;
257 const __be32 *nr_sets;
258
259 propname = cache_type_info[cache->type].nr_sets_prop;
260
261 nr_sets = of_get_property(cache->ofnode, propname, NULL);
262 if (!nr_sets)
263 return -ENODEV;
264
265 *ret = of_read_number(nr_sets, 1);
266 return 0;
267}
268
269static int cache_associativity(const struct cache *cache, unsigned int *ret)
270{
271 unsigned int line_size;
272 unsigned int nr_sets;
273 unsigned int size;
274
275 if (cache_nr_sets(cache, &nr_sets))
276 goto err;
277
278 /* If the cache is fully associative, there is no need to
279 * check the other properties.
280 */
281 if (nr_sets == 1) {
282 *ret = 0;
283 return 0;
284 }
285
286 if (cache_get_line_size(cache, &line_size))
287 goto err;
288 if (cache_size(cache, &size))
289 goto err;
290
291 if (!(nr_sets > 0 && size > 0 && line_size > 0))
292 goto err;
293
294 *ret = (size / nr_sets) / line_size;
295 return 0;
296err:
297 return -ENODEV;
298}
299
300/* helper for dealing with split caches */
301static struct cache *cache_find_first_sibling(struct cache *cache)
302{
303 struct cache *iter;
304
305 if (cache->type == CACHE_TYPE_UNIFIED ||
306 cache->type == CACHE_TYPE_UNIFIED_D)
307 return cache;
308
309 list_for_each_entry(iter, &cache_list, list)
310 if (iter->ofnode == cache->ofnode && iter->next_local == cache)
311 return iter;
312
313 return cache;
314}
315
316/* return the first cache on a local list matching node */
317static struct cache *cache_lookup_by_node(const struct device_node *node)
318{
319 struct cache *cache = NULL;
320 struct cache *iter;
321
322 list_for_each_entry(iter, &cache_list, list) {
323 if (iter->ofnode != node)
324 continue;
325 cache = cache_find_first_sibling(iter);
326 break;
327 }
328
329 return cache;
330}
331
332static bool cache_node_is_unified(const struct device_node *np)
333{
334 return of_get_property(np, "cache-unified", NULL);
335}
336
337/*
338 * Unified caches can have two different sets of tags. Most embedded
339 * use cache-size, etc. for the unified cache size, but open firmware systems
340 * use d-cache-size, etc. Check on initialization for which type we have, and
341 * return the appropriate structure type. Assume it's embedded if it isn't
342 * open firmware. If it's yet a 3rd type, then there will be missing entries
343 * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need
344 * to be extended further.
345 */
346static int cache_is_unified_d(const struct device_node *np)
347{
348 return of_get_property(np,
349 cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
350 CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
351}
352
353static struct cache *cache_do_one_devnode_unified(struct device_node *node, int level)
354{
355 pr_debug("creating L%d ucache for %pOF\n", level, node);
356
357 return new_cache(cache_is_unified_d(node), level, node);
358}
359
360static struct cache *cache_do_one_devnode_split(struct device_node *node,
361 int level)
362{
363 struct cache *dcache, *icache;
364
365 pr_debug("creating L%d dcache and icache for %pOF\n", level,
366 node);
367
368 dcache = new_cache(CACHE_TYPE_DATA, level, node);
369 icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
370
371 if (!dcache || !icache)
372 goto err;
373
374 dcache->next_local = icache;
375
376 return dcache;
377err:
378 release_cache(dcache);
379 release_cache(icache);
380 return NULL;
381}
382
383static struct cache *cache_do_one_devnode(struct device_node *node, int level)
384{
385 struct cache *cache;
386
387 if (cache_node_is_unified(node))
388 cache = cache_do_one_devnode_unified(node, level);
389 else
390 cache = cache_do_one_devnode_split(node, level);
391
392 return cache;
393}
394
395static struct cache *cache_lookup_or_instantiate(struct device_node *node,
396 int level)
397{
398 struct cache *cache;
399
400 cache = cache_lookup_by_node(node);
401
402 WARN_ONCE(cache && cache->level != level,
403 "cache level mismatch on lookup (got %d, expected %d)\n",
404 cache->level, level);
405
406 if (!cache)
407 cache = cache_do_one_devnode(node, level);
408
409 return cache;
410}
411
412static void link_cache_lists(struct cache *smaller, struct cache *bigger)
413{
414 while (smaller->next_local) {
415 if (smaller->next_local == bigger)
416 return; /* already linked */
417 smaller = smaller->next_local;
418 }
419
420 smaller->next_local = bigger;
421}
422
423static void do_subsidiary_caches_debugcheck(struct cache *cache)
424{
425 WARN_ON_ONCE(cache->level != 1);
426 WARN_ON_ONCE(!of_node_is_type(cache->ofnode, "cpu"));
427}
428
429static void do_subsidiary_caches(struct cache *cache)
430{
431 struct device_node *subcache_node;
432 int level = cache->level;
433
434 do_subsidiary_caches_debugcheck(cache);
435
436 while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
437 struct cache *subcache;
438
439 level++;
440 subcache = cache_lookup_or_instantiate(subcache_node, level);
441 of_node_put(subcache_node);
442 if (!subcache)
443 break;
444
445 link_cache_lists(cache, subcache);
446 cache = subcache;
447 }
448}
449
450static struct cache *cache_chain_instantiate(unsigned int cpu_id)
451{
452 struct device_node *cpu_node;
453 struct cache *cpu_cache = NULL;
454
455 pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
456
457 cpu_node = of_get_cpu_node(cpu_id, NULL);
458 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
459 if (!cpu_node)
460 goto out;
461
462 cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
463 if (!cpu_cache)
464 goto out;
465
466 do_subsidiary_caches(cpu_cache);
467
468 cache_cpu_set(cpu_cache, cpu_id);
469out:
470 of_node_put(cpu_node);
471
472 return cpu_cache;
473}
474
475static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
476{
477 struct cache_dir *cache_dir;
478 struct device *dev;
479 struct kobject *kobj = NULL;
480
481 dev = get_cpu_device(cpu_id);
482 WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
483 if (!dev)
484 goto err;
485
486 kobj = kobject_create_and_add("cache", &dev->kobj);
487 if (!kobj)
488 goto err;
489
490 cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
491 if (!cache_dir)
492 goto err;
493
494 cache_dir->kobj = kobj;
495
496 WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
497
498 per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
499
500 return cache_dir;
501err:
502 kobject_put(kobj);
503 return NULL;
504}
505
506static void cache_index_release(struct kobject *kobj)
507{
508 struct cache_index_dir *index;
509
510 index = kobj_to_cache_index_dir(kobj);
511
512 pr_debug("freeing index directory for L%d %s cache\n",
513 index->cache->level, cache_type_string(index->cache));
514
515 kfree(index);
516}
517
518static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
519{
520 struct kobj_attribute *kobj_attr;
521
522 kobj_attr = container_of(attr, struct kobj_attribute, attr);
523
524 return kobj_attr->show(k, kobj_attr, buf);
525}
526
527static struct cache *index_kobj_to_cache(struct kobject *k)
528{
529 struct cache_index_dir *index;
530
531 index = kobj_to_cache_index_dir(k);
532
533 return index->cache;
534}
535
536static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
537{
538 unsigned int size_kb;
539 struct cache *cache;
540
541 cache = index_kobj_to_cache(k);
542
543 if (cache_size_kb(cache, &size_kb))
544 return -ENODEV;
545
546 return sprintf(buf, "%uK\n", size_kb);
547}
548
549static struct kobj_attribute cache_size_attr =
550 __ATTR(size, 0444, size_show, NULL);
551
552
553static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
554{
555 unsigned int line_size;
556 struct cache *cache;
557
558 cache = index_kobj_to_cache(k);
559
560 if (cache_get_line_size(cache, &line_size))
561 return -ENODEV;
562
563 return sprintf(buf, "%u\n", line_size);
564}
565
566static struct kobj_attribute cache_line_size_attr =
567 __ATTR(coherency_line_size, 0444, line_size_show, NULL);
568
569static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
570{
571 unsigned int nr_sets;
572 struct cache *cache;
573
574 cache = index_kobj_to_cache(k);
575
576 if (cache_nr_sets(cache, &nr_sets))
577 return -ENODEV;
578
579 return sprintf(buf, "%u\n", nr_sets);
580}
581
582static struct kobj_attribute cache_nr_sets_attr =
583 __ATTR(number_of_sets, 0444, nr_sets_show, NULL);
584
585static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
586{
587 unsigned int associativity;
588 struct cache *cache;
589
590 cache = index_kobj_to_cache(k);
591
592 if (cache_associativity(cache, &associativity))
593 return -ENODEV;
594
595 return sprintf(buf, "%u\n", associativity);
596}
597
598static struct kobj_attribute cache_assoc_attr =
599 __ATTR(ways_of_associativity, 0444, associativity_show, NULL);
600
601static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
602{
603 struct cache *cache;
604
605 cache = index_kobj_to_cache(k);
606
607 return sprintf(buf, "%s\n", cache_type_string(cache));
608}
609
610static struct kobj_attribute cache_type_attr =
611 __ATTR(type, 0444, type_show, NULL);
612
613static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
614{
615 struct cache_index_dir *index;
616 struct cache *cache;
617
618 index = kobj_to_cache_index_dir(k);
619 cache = index->cache;
620
621 return sprintf(buf, "%d\n", cache->level);
622}
623
624static struct kobj_attribute cache_level_attr =
625 __ATTR(level, 0444, level_show, NULL);
626
627static unsigned int index_dir_to_cpu(struct cache_index_dir *index)
628{
629 struct kobject *index_dir_kobj = &index->kobj;
630 struct kobject *cache_dir_kobj = index_dir_kobj->parent;
631 struct kobject *cpu_dev_kobj = cache_dir_kobj->parent;
632 struct device *dev = kobj_to_dev(cpu_dev_kobj);
633
634 return dev->id;
635}
636
637/*
638 * On big-core systems, each core has two groups of CPUs each of which
639 * has its own L1-cache. The thread-siblings which share l1-cache with
640 * @cpu can be obtained via cpu_smallcore_mask().
641 */
642static const struct cpumask *get_big_core_shared_cpu_map(int cpu, struct cache *cache)
643{
644 if (cache->level == 1)
645 return cpu_smallcore_mask(cpu);
646
647 return &cache->shared_cpu_map;
648}
649
650static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
651{
652 struct cache_index_dir *index;
653 struct cache *cache;
654 const struct cpumask *mask;
655 int ret, cpu;
656
657 index = kobj_to_cache_index_dir(k);
658 cache = index->cache;
659
660 if (has_big_cores) {
661 cpu = index_dir_to_cpu(index);
662 mask = get_big_core_shared_cpu_map(cpu, cache);
663 } else {
664 mask = &cache->shared_cpu_map;
665 }
666
667 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pb\n",
668 cpumask_pr_args(mask));
669 buf[ret++] = '\n';
670 buf[ret] = '\0';
671 return ret;
672}
673
674static struct kobj_attribute cache_shared_cpu_map_attr =
675 __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
676
677/* Attributes which should always be created -- the kobject/sysfs core
678 * does this automatically via kobj_type->default_attrs. This is the
679 * minimum data required to uniquely identify a cache.
680 */
681static struct attribute *cache_index_default_attrs[] = {
682 &cache_type_attr.attr,
683 &cache_level_attr.attr,
684 &cache_shared_cpu_map_attr.attr,
685 NULL,
686};
687
688/* Attributes which should be created if the cache device node has the
689 * right properties -- see cacheinfo_create_index_opt_attrs
690 */
691static struct kobj_attribute *cache_index_opt_attrs[] = {
692 &cache_size_attr,
693 &cache_line_size_attr,
694 &cache_nr_sets_attr,
695 &cache_assoc_attr,
696};
697
698static const struct sysfs_ops cache_index_ops = {
699 .show = cache_index_show,
700};
701
702static struct kobj_type cache_index_type = {
703 .release = cache_index_release,
704 .sysfs_ops = &cache_index_ops,
705 .default_attrs = cache_index_default_attrs,
706};
707
708static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
709{
710 const char *cache_type;
711 struct cache *cache;
712 char *buf;
713 int i;
714
715 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
716 if (!buf)
717 return;
718
719 cache = dir->cache;
720 cache_type = cache_type_string(cache);
721
722 /* We don't want to create an attribute that can't provide a
723 * meaningful value. Check the return value of each optional
724 * attribute's ->show method before registering the
725 * attribute.
726 */
727 for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
728 struct kobj_attribute *attr;
729 ssize_t rc;
730
731 attr = cache_index_opt_attrs[i];
732
733 rc = attr->show(&dir->kobj, attr, buf);
734 if (rc <= 0) {
735 pr_debug("not creating %s attribute for "
736 "%pOF(%s) (rc = %zd)\n",
737 attr->attr.name, cache->ofnode,
738 cache_type, rc);
739 continue;
740 }
741 if (sysfs_create_file(&dir->kobj, &attr->attr))
742 pr_debug("could not create %s attribute for %pOF(%s)\n",
743 attr->attr.name, cache->ofnode, cache_type);
744 }
745
746 kfree(buf);
747}
748
749static void cacheinfo_create_index_dir(struct cache *cache, int index,
750 struct cache_dir *cache_dir)
751{
752 struct cache_index_dir *index_dir;
753 int rc;
754
755 index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
756 if (!index_dir)
757 return;
758
759 index_dir->cache = cache;
760
761 rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
762 cache_dir->kobj, "index%d", index);
763 if (rc) {
764 kobject_put(&index_dir->kobj);
765 return;
766 }
767
768 index_dir->next = cache_dir->index;
769 cache_dir->index = index_dir;
770
771 cacheinfo_create_index_opt_attrs(index_dir);
772}
773
774static void cacheinfo_sysfs_populate(unsigned int cpu_id,
775 struct cache *cache_list)
776{
777 struct cache_dir *cache_dir;
778 struct cache *cache;
779 int index = 0;
780
781 cache_dir = cacheinfo_create_cache_dir(cpu_id);
782 if (!cache_dir)
783 return;
784
785 cache = cache_list;
786 while (cache) {
787 cacheinfo_create_index_dir(cache, index, cache_dir);
788 index++;
789 cache = cache->next_local;
790 }
791}
792
793void cacheinfo_cpu_online(unsigned int cpu_id)
794{
795 struct cache *cache;
796
797 cache = cache_chain_instantiate(cpu_id);
798 if (!cache)
799 return;
800
801 cacheinfo_sysfs_populate(cpu_id, cache);
802}
803
804/* functions needed to remove cache entry for cpu offline or suspend/resume */
805
806#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
807 defined(CONFIG_HOTPLUG_CPU)
808
809static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
810{
811 struct device_node *cpu_node;
812 struct cache *cache;
813
814 cpu_node = of_get_cpu_node(cpu_id, NULL);
815 WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
816 if (!cpu_node)
817 return NULL;
818
819 cache = cache_lookup_by_node(cpu_node);
820 of_node_put(cpu_node);
821
822 return cache;
823}
824
825static void remove_index_dirs(struct cache_dir *cache_dir)
826{
827 struct cache_index_dir *index;
828
829 index = cache_dir->index;
830
831 while (index) {
832 struct cache_index_dir *next;
833
834 next = index->next;
835 kobject_put(&index->kobj);
836 index = next;
837 }
838}
839
840static void remove_cache_dir(struct cache_dir *cache_dir)
841{
842 remove_index_dirs(cache_dir);
843
844 /* Remove cache dir from sysfs */
845 kobject_del(cache_dir->kobj);
846
847 kobject_put(cache_dir->kobj);
848
849 kfree(cache_dir);
850}
851
852static void cache_cpu_clear(struct cache *cache, int cpu)
853{
854 while (cache) {
855 struct cache *next = cache->next_local;
856
857 WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
858 "CPU %i not accounted in %pOF(%s)\n",
859 cpu, cache->ofnode,
860 cache_type_string(cache));
861
862 cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
863
864 /* Release the cache object if all the cpus using it
865 * are offline */
866 if (cpumask_empty(&cache->shared_cpu_map))
867 release_cache(cache);
868
869 cache = next;
870 }
871}
872
873void cacheinfo_cpu_offline(unsigned int cpu_id)
874{
875 struct cache_dir *cache_dir;
876 struct cache *cache;
877
878 /* Prevent userspace from seeing inconsistent state - remove
879 * the sysfs hierarchy first */
880 cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
881
882 /* careful, sysfs population may have failed */
883 if (cache_dir)
884 remove_cache_dir(cache_dir);
885
886 per_cpu(cache_dir_pcpu, cpu_id) = NULL;
887
888 /* clear the CPU's bit in its cache chain, possibly freeing
889 * cache objects */
890 cache = cache_lookup_by_cpu(cpu_id);
891 if (cache)
892 cache_cpu_clear(cache, cpu_id);
893}
894
895void cacheinfo_teardown(void)
896{
897 unsigned int cpu;
898
899 lockdep_assert_cpus_held();
900
901 for_each_online_cpu(cpu)
902 cacheinfo_cpu_offline(cpu);
903}
904
905void cacheinfo_rebuild(void)
906{
907 unsigned int cpu;
908
909 lockdep_assert_cpus_held();
910
911 for_each_online_cpu(cpu)
912 cacheinfo_cpu_online(cpu);
913}
914
915#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */