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