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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * cacheinfo support - processor cache information via sysfs
  4 *
  5 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
  6 * Author: Sudeep Holla <sudeep.holla@arm.com>
  7 */
  8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  9
 10#include <linux/acpi.h>
 11#include <linux/bitops.h>
 12#include <linux/cacheinfo.h>
 13#include <linux/compiler.h>
 14#include <linux/cpu.h>
 15#include <linux/device.h>
 16#include <linux/init.h>
 17#include <linux/of_device.h>
 18#include <linux/sched.h>
 19#include <linux/slab.h>
 20#include <linux/smp.h>
 21#include <linux/sysfs.h>
 22
 23/* pointer to per cpu cacheinfo */
 24static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
 25#define ci_cacheinfo(cpu)	(&per_cpu(ci_cpu_cacheinfo, cpu))
 26#define cache_leaves(cpu)	(ci_cacheinfo(cpu)->num_leaves)
 27#define per_cpu_cacheinfo(cpu)	(ci_cacheinfo(cpu)->info_list)
 28#define per_cpu_cacheinfo_idx(cpu, idx)		\
 29				(per_cpu_cacheinfo(cpu) + (idx))
 30
 31struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
 32{
 33	return ci_cacheinfo(cpu);
 34}
 35
 36static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 37					   struct cacheinfo *sib_leaf)
 38{
 39	/*
 40	 * For non DT/ACPI systems, assume unique level 1 caches,
 41	 * system-wide shared caches for all other levels. This will be used
 42	 * only if arch specific code has not populated shared_cpu_map
 43	 */
 44	if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
 45		return !(this_leaf->level == 1);
 46
 47	if ((sib_leaf->attributes & CACHE_ID) &&
 48	    (this_leaf->attributes & CACHE_ID))
 49		return sib_leaf->id == this_leaf->id;
 50
 51	return sib_leaf->fw_token == this_leaf->fw_token;
 52}
 53
 54bool last_level_cache_is_valid(unsigned int cpu)
 55{
 56	struct cacheinfo *llc;
 57
 58	if (!cache_leaves(cpu))
 59		return false;
 60
 61	llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
 62
 63	return (llc->attributes & CACHE_ID) || !!llc->fw_token;
 64
 65}
 66
 67bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
 68{
 69	struct cacheinfo *llc_x, *llc_y;
 70
 71	if (!last_level_cache_is_valid(cpu_x) ||
 72	    !last_level_cache_is_valid(cpu_y))
 73		return false;
 74
 75	llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
 76	llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
 77
 78	return cache_leaves_are_shared(llc_x, llc_y);
 79}
 80
 81#ifdef CONFIG_OF
 82/* OF properties to query for a given cache type */
 83struct cache_type_info {
 84	const char *size_prop;
 85	const char *line_size_props[2];
 86	const char *nr_sets_prop;
 87};
 88
 89static const struct cache_type_info cache_type_info[] = {
 90	{
 91		.size_prop       = "cache-size",
 92		.line_size_props = { "cache-line-size",
 93				     "cache-block-size", },
 94		.nr_sets_prop    = "cache-sets",
 95	}, {
 96		.size_prop       = "i-cache-size",
 97		.line_size_props = { "i-cache-line-size",
 98				     "i-cache-block-size", },
 99		.nr_sets_prop    = "i-cache-sets",
100	}, {
101		.size_prop       = "d-cache-size",
102		.line_size_props = { "d-cache-line-size",
103				     "d-cache-block-size", },
104		.nr_sets_prop    = "d-cache-sets",
105	},
106};
107
108static inline int get_cacheinfo_idx(enum cache_type type)
109{
110	if (type == CACHE_TYPE_UNIFIED)
111		return 0;
112	return type;
113}
114
115static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
116{
117	const char *propname;
118	int ct_idx;
119
120	ct_idx = get_cacheinfo_idx(this_leaf->type);
121	propname = cache_type_info[ct_idx].size_prop;
122
123	of_property_read_u32(np, propname, &this_leaf->size);
124}
125
126/* not cache_line_size() because that's a macro in include/linux/cache.h */
127static void cache_get_line_size(struct cacheinfo *this_leaf,
128				struct device_node *np)
129{
130	int i, lim, ct_idx;
131
132	ct_idx = get_cacheinfo_idx(this_leaf->type);
133	lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
134
135	for (i = 0; i < lim; i++) {
136		int ret;
137		u32 line_size;
138		const char *propname;
139
140		propname = cache_type_info[ct_idx].line_size_props[i];
141		ret = of_property_read_u32(np, propname, &line_size);
142		if (!ret) {
143			this_leaf->coherency_line_size = line_size;
144			break;
145		}
146	}
147}
148
149static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
150{
151	const char *propname;
152	int ct_idx;
153
154	ct_idx = get_cacheinfo_idx(this_leaf->type);
155	propname = cache_type_info[ct_idx].nr_sets_prop;
156
157	of_property_read_u32(np, propname, &this_leaf->number_of_sets);
158}
159
160static void cache_associativity(struct cacheinfo *this_leaf)
161{
162	unsigned int line_size = this_leaf->coherency_line_size;
163	unsigned int nr_sets = this_leaf->number_of_sets;
164	unsigned int size = this_leaf->size;
165
166	/*
167	 * If the cache is fully associative, there is no need to
168	 * check the other properties.
169	 */
170	if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
171		this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
172}
173
174static bool cache_node_is_unified(struct cacheinfo *this_leaf,
175				  struct device_node *np)
176{
177	return of_property_read_bool(np, "cache-unified");
178}
179
180static void cache_of_set_props(struct cacheinfo *this_leaf,
181			       struct device_node *np)
182{
183	/*
184	 * init_cache_level must setup the cache level correctly
185	 * overriding the architecturally specified levels, so
186	 * if type is NONE at this stage, it should be unified
187	 */
188	if (this_leaf->type == CACHE_TYPE_NOCACHE &&
189	    cache_node_is_unified(this_leaf, np))
190		this_leaf->type = CACHE_TYPE_UNIFIED;
191	cache_size(this_leaf, np);
192	cache_get_line_size(this_leaf, np);
193	cache_nr_sets(this_leaf, np);
194	cache_associativity(this_leaf);
195}
196
197static int cache_setup_of_node(unsigned int cpu)
198{
199	struct device_node *np, *prev;
200	struct cacheinfo *this_leaf;
201	unsigned int index = 0;
202
203	np = of_cpu_device_node_get(cpu);
204	if (!np) {
205		pr_err("Failed to find cpu%d device node\n", cpu);
206		return -ENOENT;
207	}
208
209	prev = np;
210
211	while (index < cache_leaves(cpu)) {
212		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
213		if (this_leaf->level != 1) {
214			np = of_find_next_cache_node(np);
215			of_node_put(prev);
216			prev = np;
217			if (!np)
218				break;
219		}
220		cache_of_set_props(this_leaf, np);
221		this_leaf->fw_token = np;
222		index++;
223	}
224
225	of_node_put(np);
226
227	if (index != cache_leaves(cpu)) /* not all OF nodes populated */
228		return -ENOENT;
229
230	return 0;
231}
232#else
233static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
234#endif
235
236int __weak cache_setup_acpi(unsigned int cpu)
237{
238	return -ENOTSUPP;
239}
240
241unsigned int coherency_max_size;
242
243static int cache_setup_properties(unsigned int cpu)
244{
245	int ret = 0;
246
247	if (of_have_populated_dt())
248		ret = cache_setup_of_node(cpu);
249	else if (!acpi_disabled)
250		ret = cache_setup_acpi(cpu);
251
252	return ret;
253}
254
255static int cache_shared_cpu_map_setup(unsigned int cpu)
256{
257	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
258	struct cacheinfo *this_leaf, *sib_leaf;
259	unsigned int index;
260	int ret = 0;
261
262	if (this_cpu_ci->cpu_map_populated)
263		return 0;
264
265	/*
266	 * skip setting up cache properties if LLC is valid, just need
267	 * to update the shared cpu_map if the cache attributes were
268	 * populated early before all the cpus are brought online
269	 */
270	if (!last_level_cache_is_valid(cpu)) {
271		ret = cache_setup_properties(cpu);
272		if (ret)
273			return ret;
274	}
275
276	for (index = 0; index < cache_leaves(cpu); index++) {
277		unsigned int i;
278
279		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
280
281		cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
282		for_each_online_cpu(i) {
283			struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
284
285			if (i == cpu || !sib_cpu_ci->info_list)
286				continue;/* skip if itself or no cacheinfo */
287
288			sib_leaf = per_cpu_cacheinfo_idx(i, index);
289			if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
290				cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
291				cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
292			}
293		}
294		/* record the maximum cache line size */
295		if (this_leaf->coherency_line_size > coherency_max_size)
296			coherency_max_size = this_leaf->coherency_line_size;
297	}
298
299	return 0;
300}
301
302static void cache_shared_cpu_map_remove(unsigned int cpu)
303{
304	struct cacheinfo *this_leaf, *sib_leaf;
305	unsigned int sibling, index;
306
307	for (index = 0; index < cache_leaves(cpu); index++) {
308		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
309		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
310			struct cpu_cacheinfo *sib_cpu_ci =
311						get_cpu_cacheinfo(sibling);
312
313			if (sibling == cpu || !sib_cpu_ci->info_list)
314				continue;/* skip if itself or no cacheinfo */
315
316			sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
317			cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
318			cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
319		}
320	}
321}
322
323static void free_cache_attributes(unsigned int cpu)
324{
325	if (!per_cpu_cacheinfo(cpu))
326		return;
327
328	cache_shared_cpu_map_remove(cpu);
329
330	kfree(per_cpu_cacheinfo(cpu));
331	per_cpu_cacheinfo(cpu) = NULL;
332	cache_leaves(cpu) = 0;
333}
334
335int __weak init_cache_level(unsigned int cpu)
336{
337	return -ENOENT;
338}
339
340int __weak populate_cache_leaves(unsigned int cpu)
341{
342	return -ENOENT;
343}
344
345int detect_cache_attributes(unsigned int cpu)
346{
347	int ret;
348
349	/* Since early detection of the cacheinfo is allowed via this
350	 * function and this also gets called as CPU hotplug callbacks via
351	 * cacheinfo_cpu_online, the initialisation can be skipped and only
352	 * CPU maps can be updated as the CPU online status would be update
353	 * if called via cacheinfo_cpu_online path.
354	 */
355	if (per_cpu_cacheinfo(cpu))
356		goto update_cpu_map;
357
358	if (init_cache_level(cpu) || !cache_leaves(cpu))
359		return -ENOENT;
360
361	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
362					 sizeof(struct cacheinfo), GFP_ATOMIC);
363	if (per_cpu_cacheinfo(cpu) == NULL) {
364		cache_leaves(cpu) = 0;
365		return -ENOMEM;
366	}
367
368	/*
369	 * populate_cache_leaves() may completely setup the cache leaves and
370	 * shared_cpu_map or it may leave it partially setup.
371	 */
372	ret = populate_cache_leaves(cpu);
373	if (ret)
374		goto free_ci;
375
376update_cpu_map:
377	/*
378	 * For systems using DT for cache hierarchy, fw_token
379	 * and shared_cpu_map will be set up here only if they are
380	 * not populated already
381	 */
382	ret = cache_shared_cpu_map_setup(cpu);
383	if (ret) {
384		pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
385		goto free_ci;
386	}
387
388	return 0;
389
390free_ci:
391	free_cache_attributes(cpu);
392	return ret;
393}
394
395/* pointer to cpuX/cache device */
396static DEFINE_PER_CPU(struct device *, ci_cache_dev);
397#define per_cpu_cache_dev(cpu)	(per_cpu(ci_cache_dev, cpu))
398
399static cpumask_t cache_dev_map;
400
401/* pointer to array of devices for cpuX/cache/indexY */
402static DEFINE_PER_CPU(struct device **, ci_index_dev);
403#define per_cpu_index_dev(cpu)	(per_cpu(ci_index_dev, cpu))
404#define per_cache_index_dev(cpu, idx)	((per_cpu_index_dev(cpu))[idx])
405
406#define show_one(file_name, object)				\
407static ssize_t file_name##_show(struct device *dev,		\
408		struct device_attribute *attr, char *buf)	\
409{								\
410	struct cacheinfo *this_leaf = dev_get_drvdata(dev);	\
411	return sysfs_emit(buf, "%u\n", this_leaf->object);	\
412}
413
414show_one(id, id);
415show_one(level, level);
416show_one(coherency_line_size, coherency_line_size);
417show_one(number_of_sets, number_of_sets);
418show_one(physical_line_partition, physical_line_partition);
419show_one(ways_of_associativity, ways_of_associativity);
420
421static ssize_t size_show(struct device *dev,
422			 struct device_attribute *attr, char *buf)
423{
424	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
425
426	return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
427}
428
429static ssize_t shared_cpu_map_show(struct device *dev,
430				   struct device_attribute *attr, char *buf)
431{
432	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
433	const struct cpumask *mask = &this_leaf->shared_cpu_map;
434
435	return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
436}
437
438static ssize_t shared_cpu_list_show(struct device *dev,
439				    struct device_attribute *attr, char *buf)
440{
441	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
442	const struct cpumask *mask = &this_leaf->shared_cpu_map;
443
444	return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
445}
446
447static ssize_t type_show(struct device *dev,
448			 struct device_attribute *attr, char *buf)
449{
450	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
451	const char *output;
452
453	switch (this_leaf->type) {
454	case CACHE_TYPE_DATA:
455		output = "Data";
456		break;
457	case CACHE_TYPE_INST:
458		output = "Instruction";
459		break;
460	case CACHE_TYPE_UNIFIED:
461		output = "Unified";
462		break;
463	default:
464		return -EINVAL;
465	}
466
467	return sysfs_emit(buf, "%s\n", output);
468}
469
470static ssize_t allocation_policy_show(struct device *dev,
471				      struct device_attribute *attr, char *buf)
472{
473	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
474	unsigned int ci_attr = this_leaf->attributes;
475	const char *output;
476
477	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
478		output = "ReadWriteAllocate";
479	else if (ci_attr & CACHE_READ_ALLOCATE)
480		output = "ReadAllocate";
481	else if (ci_attr & CACHE_WRITE_ALLOCATE)
482		output = "WriteAllocate";
483	else
484		return 0;
485
486	return sysfs_emit(buf, "%s\n", output);
487}
488
489static ssize_t write_policy_show(struct device *dev,
490				 struct device_attribute *attr, char *buf)
491{
492	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
493	unsigned int ci_attr = this_leaf->attributes;
494	int n = 0;
495
496	if (ci_attr & CACHE_WRITE_THROUGH)
497		n = sysfs_emit(buf, "WriteThrough\n");
498	else if (ci_attr & CACHE_WRITE_BACK)
499		n = sysfs_emit(buf, "WriteBack\n");
500	return n;
501}
502
503static DEVICE_ATTR_RO(id);
504static DEVICE_ATTR_RO(level);
505static DEVICE_ATTR_RO(type);
506static DEVICE_ATTR_RO(coherency_line_size);
507static DEVICE_ATTR_RO(ways_of_associativity);
508static DEVICE_ATTR_RO(number_of_sets);
509static DEVICE_ATTR_RO(size);
510static DEVICE_ATTR_RO(allocation_policy);
511static DEVICE_ATTR_RO(write_policy);
512static DEVICE_ATTR_RO(shared_cpu_map);
513static DEVICE_ATTR_RO(shared_cpu_list);
514static DEVICE_ATTR_RO(physical_line_partition);
515
516static struct attribute *cache_default_attrs[] = {
517	&dev_attr_id.attr,
518	&dev_attr_type.attr,
519	&dev_attr_level.attr,
520	&dev_attr_shared_cpu_map.attr,
521	&dev_attr_shared_cpu_list.attr,
522	&dev_attr_coherency_line_size.attr,
523	&dev_attr_ways_of_associativity.attr,
524	&dev_attr_number_of_sets.attr,
525	&dev_attr_size.attr,
526	&dev_attr_allocation_policy.attr,
527	&dev_attr_write_policy.attr,
528	&dev_attr_physical_line_partition.attr,
529	NULL
530};
531
532static umode_t
533cache_default_attrs_is_visible(struct kobject *kobj,
534			       struct attribute *attr, int unused)
535{
536	struct device *dev = kobj_to_dev(kobj);
537	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
538	const struct cpumask *mask = &this_leaf->shared_cpu_map;
539	umode_t mode = attr->mode;
540
541	if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
542		return mode;
543	if ((attr == &dev_attr_type.attr) && this_leaf->type)
544		return mode;
545	if ((attr == &dev_attr_level.attr) && this_leaf->level)
546		return mode;
547	if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
548		return mode;
549	if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
550		return mode;
551	if ((attr == &dev_attr_coherency_line_size.attr) &&
552	    this_leaf->coherency_line_size)
553		return mode;
554	if ((attr == &dev_attr_ways_of_associativity.attr) &&
555	    this_leaf->size) /* allow 0 = full associativity */
556		return mode;
557	if ((attr == &dev_attr_number_of_sets.attr) &&
558	    this_leaf->number_of_sets)
559		return mode;
560	if ((attr == &dev_attr_size.attr) && this_leaf->size)
561		return mode;
562	if ((attr == &dev_attr_write_policy.attr) &&
563	    (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
564		return mode;
565	if ((attr == &dev_attr_allocation_policy.attr) &&
566	    (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
567		return mode;
568	if ((attr == &dev_attr_physical_line_partition.attr) &&
569	    this_leaf->physical_line_partition)
570		return mode;
571
572	return 0;
573}
574
575static const struct attribute_group cache_default_group = {
576	.attrs = cache_default_attrs,
577	.is_visible = cache_default_attrs_is_visible,
578};
579
580static const struct attribute_group *cache_default_groups[] = {
581	&cache_default_group,
582	NULL,
583};
584
585static const struct attribute_group *cache_private_groups[] = {
586	&cache_default_group,
587	NULL, /* Place holder for private group */
588	NULL,
589};
590
591const struct attribute_group *
592__weak cache_get_priv_group(struct cacheinfo *this_leaf)
593{
594	return NULL;
595}
596
597static const struct attribute_group **
598cache_get_attribute_groups(struct cacheinfo *this_leaf)
599{
600	const struct attribute_group *priv_group =
601			cache_get_priv_group(this_leaf);
602
603	if (!priv_group)
604		return cache_default_groups;
605
606	if (!cache_private_groups[1])
607		cache_private_groups[1] = priv_group;
608
609	return cache_private_groups;
610}
611
612/* Add/Remove cache interface for CPU device */
613static void cpu_cache_sysfs_exit(unsigned int cpu)
614{
615	int i;
616	struct device *ci_dev;
617
618	if (per_cpu_index_dev(cpu)) {
619		for (i = 0; i < cache_leaves(cpu); i++) {
620			ci_dev = per_cache_index_dev(cpu, i);
621			if (!ci_dev)
622				continue;
623			device_unregister(ci_dev);
624		}
625		kfree(per_cpu_index_dev(cpu));
626		per_cpu_index_dev(cpu) = NULL;
627	}
628	device_unregister(per_cpu_cache_dev(cpu));
629	per_cpu_cache_dev(cpu) = NULL;
630}
631
632static int cpu_cache_sysfs_init(unsigned int cpu)
633{
634	struct device *dev = get_cpu_device(cpu);
635
636	if (per_cpu_cacheinfo(cpu) == NULL)
637		return -ENOENT;
638
639	per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
640	if (IS_ERR(per_cpu_cache_dev(cpu)))
641		return PTR_ERR(per_cpu_cache_dev(cpu));
642
643	/* Allocate all required memory */
644	per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
645					 sizeof(struct device *), GFP_KERNEL);
646	if (unlikely(per_cpu_index_dev(cpu) == NULL))
647		goto err_out;
648
649	return 0;
650
651err_out:
652	cpu_cache_sysfs_exit(cpu);
653	return -ENOMEM;
654}
655
656static int cache_add_dev(unsigned int cpu)
657{
658	unsigned int i;
659	int rc;
660	struct device *ci_dev, *parent;
661	struct cacheinfo *this_leaf;
662	const struct attribute_group **cache_groups;
663
664	rc = cpu_cache_sysfs_init(cpu);
665	if (unlikely(rc < 0))
666		return rc;
667
668	parent = per_cpu_cache_dev(cpu);
669	for (i = 0; i < cache_leaves(cpu); i++) {
670		this_leaf = per_cpu_cacheinfo_idx(cpu, i);
671		if (this_leaf->disable_sysfs)
672			continue;
673		if (this_leaf->type == CACHE_TYPE_NOCACHE)
674			break;
675		cache_groups = cache_get_attribute_groups(this_leaf);
676		ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
677					   "index%1u", i);
678		if (IS_ERR(ci_dev)) {
679			rc = PTR_ERR(ci_dev);
680			goto err;
681		}
682		per_cache_index_dev(cpu, i) = ci_dev;
683	}
684	cpumask_set_cpu(cpu, &cache_dev_map);
685
686	return 0;
687err:
688	cpu_cache_sysfs_exit(cpu);
689	return rc;
690}
691
692static int cacheinfo_cpu_online(unsigned int cpu)
693{
694	int rc = detect_cache_attributes(cpu);
695
696	if (rc)
697		return rc;
698	rc = cache_add_dev(cpu);
699	if (rc)
700		free_cache_attributes(cpu);
701	return rc;
702}
703
704static int cacheinfo_cpu_pre_down(unsigned int cpu)
705{
706	if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
707		cpu_cache_sysfs_exit(cpu);
708
709	free_cache_attributes(cpu);
710	return 0;
711}
712
713static int __init cacheinfo_sysfs_init(void)
714{
715	return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
716				 "base/cacheinfo:online",
717				 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
718}
719device_initcall(cacheinfo_sysfs_init);