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 */