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 */
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 #define per_cpu_cacheinfo_idx(cpu, idx)		\
29 				(per_cpu_cacheinfo(cpu) + (idx))
30 
get_cpu_cacheinfo(unsigned int cpu)31 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
32 {
33 	return ci_cacheinfo(cpu);
34 }
35 
cache_leaves_are_shared(struct cacheinfo * this_leaf,struct cacheinfo * sib_leaf)36 static 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 
last_level_cache_is_valid(unsigned int cpu)54 bool 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 
last_level_cache_is_shared(unsigned int cpu_x,unsigned int cpu_y)67 bool 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 */
83 struct cache_type_info {
84 	const char *size_prop;
85 	const char *line_size_props[2];
86 	const char *nr_sets_prop;
87 };
88 
89 static 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 
get_cacheinfo_idx(enum cache_type type)108 static inline int get_cacheinfo_idx(enum cache_type type)
109 {
110 	if (type == CACHE_TYPE_UNIFIED)
111 		return 0;
112 	return type;
113 }
114 
cache_size(struct cacheinfo * this_leaf,struct device_node * np)115 static 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 */
cache_get_line_size(struct cacheinfo * this_leaf,struct device_node * np)127 static 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 
cache_nr_sets(struct cacheinfo * this_leaf,struct device_node * np)149 static 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 
cache_associativity(struct cacheinfo * this_leaf)160 static 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 
cache_node_is_unified(struct cacheinfo * this_leaf,struct device_node * np)174 static 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 
cache_of_set_props(struct cacheinfo * this_leaf,struct device_node * np)180 static 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 
cache_setup_of_node(unsigned int cpu)197 static int cache_setup_of_node(unsigned int cpu)
198 {
199 	struct device_node *np;
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 	while (index < cache_leaves(cpu)) {
210 		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
211 		if (this_leaf->level != 1)
212 			np = of_find_next_cache_node(np);
213 		else
214 			np = of_node_get(np);/* cpu node itself */
215 		if (!np)
216 			break;
217 		cache_of_set_props(this_leaf, np);
218 		this_leaf->fw_token = np;
219 		index++;
220 	}
221 
222 	if (index != cache_leaves(cpu)) /* not all OF nodes populated */
223 		return -ENOENT;
224 
225 	return 0;
226 }
227 #else
cache_setup_of_node(unsigned int cpu)228 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
229 #endif
230 
cache_setup_acpi(unsigned int cpu)231 int __weak cache_setup_acpi(unsigned int cpu)
232 {
233 	return -ENOTSUPP;
234 }
235 
236 unsigned int coherency_max_size;
237 
cache_setup_properties(unsigned int cpu)238 static int cache_setup_properties(unsigned int cpu)
239 {
240 	int ret = 0;
241 
242 	if (of_have_populated_dt())
243 		ret = cache_setup_of_node(cpu);
244 	else if (!acpi_disabled)
245 		ret = cache_setup_acpi(cpu);
246 
247 	return ret;
248 }
249 
cache_shared_cpu_map_setup(unsigned int cpu)250 static int cache_shared_cpu_map_setup(unsigned int cpu)
251 {
252 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
253 	struct cacheinfo *this_leaf, *sib_leaf;
254 	unsigned int index;
255 	int ret = 0;
256 
257 	if (this_cpu_ci->cpu_map_populated)
258 		return 0;
259 
260 	/*
261 	 * skip setting up cache properties if LLC is valid, just need
262 	 * to update the shared cpu_map if the cache attributes were
263 	 * populated early before all the cpus are brought online
264 	 */
265 	if (!last_level_cache_is_valid(cpu)) {
266 		ret = cache_setup_properties(cpu);
267 		if (ret)
268 			return ret;
269 	}
270 
271 	for (index = 0; index < cache_leaves(cpu); index++) {
272 		unsigned int i;
273 
274 		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
275 
276 		cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
277 		for_each_online_cpu(i) {
278 			struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
279 
280 			if (i == cpu || !sib_cpu_ci->info_list)
281 				continue;/* skip if itself or no cacheinfo */
282 
283 			sib_leaf = per_cpu_cacheinfo_idx(i, index);
284 			if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
285 				cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
286 				cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
287 			}
288 		}
289 		/* record the maximum cache line size */
290 		if (this_leaf->coherency_line_size > coherency_max_size)
291 			coherency_max_size = this_leaf->coherency_line_size;
292 	}
293 
294 	return 0;
295 }
296 
cache_shared_cpu_map_remove(unsigned int cpu)297 static void cache_shared_cpu_map_remove(unsigned int cpu)
298 {
299 	struct cacheinfo *this_leaf, *sib_leaf;
300 	unsigned int sibling, index;
301 
302 	for (index = 0; index < cache_leaves(cpu); index++) {
303 		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
304 		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
305 			struct cpu_cacheinfo *sib_cpu_ci =
306 						get_cpu_cacheinfo(sibling);
307 
308 			if (sibling == cpu || !sib_cpu_ci->info_list)
309 				continue;/* skip if itself or no cacheinfo */
310 
311 			sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
312 			cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
313 			cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
314 		}
315 		if (of_have_populated_dt())
316 			of_node_put(this_leaf->fw_token);
317 	}
318 }
319 
free_cache_attributes(unsigned int cpu)320 static void free_cache_attributes(unsigned int cpu)
321 {
322 	if (!per_cpu_cacheinfo(cpu))
323 		return;
324 
325 	cache_shared_cpu_map_remove(cpu);
326 
327 	kfree(per_cpu_cacheinfo(cpu));
328 	per_cpu_cacheinfo(cpu) = NULL;
329 	cache_leaves(cpu) = 0;
330 }
331 
init_cache_level(unsigned int cpu)332 int __weak init_cache_level(unsigned int cpu)
333 {
334 	return -ENOENT;
335 }
336 
populate_cache_leaves(unsigned int cpu)337 int __weak populate_cache_leaves(unsigned int cpu)
338 {
339 	return -ENOENT;
340 }
341 
detect_cache_attributes(unsigned int cpu)342 int detect_cache_attributes(unsigned int cpu)
343 {
344 	int ret;
345 
346 	/* Since early detection of the cacheinfo is allowed via this
347 	 * function and this also gets called as CPU hotplug callbacks via
348 	 * cacheinfo_cpu_online, the initialisation can be skipped and only
349 	 * CPU maps can be updated as the CPU online status would be update
350 	 * if called via cacheinfo_cpu_online path.
351 	 */
352 	if (per_cpu_cacheinfo(cpu))
353 		goto update_cpu_map;
354 
355 	if (init_cache_level(cpu) || !cache_leaves(cpu))
356 		return -ENOENT;
357 
358 	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
359 					 sizeof(struct cacheinfo), GFP_ATOMIC);
360 	if (per_cpu_cacheinfo(cpu) == NULL) {
361 		cache_leaves(cpu) = 0;
362 		return -ENOMEM;
363 	}
364 
365 	/*
366 	 * populate_cache_leaves() may completely setup the cache leaves and
367 	 * shared_cpu_map or it may leave it partially setup.
368 	 */
369 	ret = populate_cache_leaves(cpu);
370 	if (ret)
371 		goto free_ci;
372 
373 update_cpu_map:
374 	/*
375 	 * For systems using DT for cache hierarchy, fw_token
376 	 * and shared_cpu_map will be set up here only if they are
377 	 * not populated already
378 	 */
379 	ret = cache_shared_cpu_map_setup(cpu);
380 	if (ret) {
381 		pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
382 		goto free_ci;
383 	}
384 
385 	return 0;
386 
387 free_ci:
388 	free_cache_attributes(cpu);
389 	return ret;
390 }
391 
392 /* pointer to cpuX/cache device */
393 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
394 #define per_cpu_cache_dev(cpu)	(per_cpu(ci_cache_dev, cpu))
395 
396 static cpumask_t cache_dev_map;
397 
398 /* pointer to array of devices for cpuX/cache/indexY */
399 static DEFINE_PER_CPU(struct device **, ci_index_dev);
400 #define per_cpu_index_dev(cpu)	(per_cpu(ci_index_dev, cpu))
401 #define per_cache_index_dev(cpu, idx)	((per_cpu_index_dev(cpu))[idx])
402 
403 #define show_one(file_name, object)				\
404 static ssize_t file_name##_show(struct device *dev,		\
405 		struct device_attribute *attr, char *buf)	\
406 {								\
407 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);	\
408 	return sysfs_emit(buf, "%u\n", this_leaf->object);	\
409 }
410 
411 show_one(id, id);
412 show_one(level, level);
413 show_one(coherency_line_size, coherency_line_size);
414 show_one(number_of_sets, number_of_sets);
415 show_one(physical_line_partition, physical_line_partition);
416 show_one(ways_of_associativity, ways_of_associativity);
417 
size_show(struct device * dev,struct device_attribute * attr,char * buf)418 static ssize_t size_show(struct device *dev,
419 			 struct device_attribute *attr, char *buf)
420 {
421 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
422 
423 	return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
424 }
425 
shared_cpu_map_show(struct device * dev,struct device_attribute * attr,char * buf)426 static ssize_t shared_cpu_map_show(struct device *dev,
427 				   struct device_attribute *attr, char *buf)
428 {
429 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
430 	const struct cpumask *mask = &this_leaf->shared_cpu_map;
431 
432 	return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
433 }
434 
shared_cpu_list_show(struct device * dev,struct device_attribute * attr,char * buf)435 static ssize_t shared_cpu_list_show(struct device *dev,
436 				    struct device_attribute *attr, char *buf)
437 {
438 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
439 	const struct cpumask *mask = &this_leaf->shared_cpu_map;
440 
441 	return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
442 }
443 
type_show(struct device * dev,struct device_attribute * attr,char * buf)444 static ssize_t type_show(struct device *dev,
445 			 struct device_attribute *attr, char *buf)
446 {
447 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
448 	const char *output;
449 
450 	switch (this_leaf->type) {
451 	case CACHE_TYPE_DATA:
452 		output = "Data";
453 		break;
454 	case CACHE_TYPE_INST:
455 		output = "Instruction";
456 		break;
457 	case CACHE_TYPE_UNIFIED:
458 		output = "Unified";
459 		break;
460 	default:
461 		return -EINVAL;
462 	}
463 
464 	return sysfs_emit(buf, "%s\n", output);
465 }
466 
allocation_policy_show(struct device * dev,struct device_attribute * attr,char * buf)467 static ssize_t allocation_policy_show(struct device *dev,
468 				      struct device_attribute *attr, char *buf)
469 {
470 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
471 	unsigned int ci_attr = this_leaf->attributes;
472 	const char *output;
473 
474 	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
475 		output = "ReadWriteAllocate";
476 	else if (ci_attr & CACHE_READ_ALLOCATE)
477 		output = "ReadAllocate";
478 	else if (ci_attr & CACHE_WRITE_ALLOCATE)
479 		output = "WriteAllocate";
480 	else
481 		return 0;
482 
483 	return sysfs_emit(buf, "%s\n", output);
484 }
485 
write_policy_show(struct device * dev,struct device_attribute * attr,char * buf)486 static ssize_t write_policy_show(struct device *dev,
487 				 struct device_attribute *attr, char *buf)
488 {
489 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
490 	unsigned int ci_attr = this_leaf->attributes;
491 	int n = 0;
492 
493 	if (ci_attr & CACHE_WRITE_THROUGH)
494 		n = sysfs_emit(buf, "WriteThrough\n");
495 	else if (ci_attr & CACHE_WRITE_BACK)
496 		n = sysfs_emit(buf, "WriteBack\n");
497 	return n;
498 }
499 
500 static DEVICE_ATTR_RO(id);
501 static DEVICE_ATTR_RO(level);
502 static DEVICE_ATTR_RO(type);
503 static DEVICE_ATTR_RO(coherency_line_size);
504 static DEVICE_ATTR_RO(ways_of_associativity);
505 static DEVICE_ATTR_RO(number_of_sets);
506 static DEVICE_ATTR_RO(size);
507 static DEVICE_ATTR_RO(allocation_policy);
508 static DEVICE_ATTR_RO(write_policy);
509 static DEVICE_ATTR_RO(shared_cpu_map);
510 static DEVICE_ATTR_RO(shared_cpu_list);
511 static DEVICE_ATTR_RO(physical_line_partition);
512 
513 static struct attribute *cache_default_attrs[] = {
514 	&dev_attr_id.attr,
515 	&dev_attr_type.attr,
516 	&dev_attr_level.attr,
517 	&dev_attr_shared_cpu_map.attr,
518 	&dev_attr_shared_cpu_list.attr,
519 	&dev_attr_coherency_line_size.attr,
520 	&dev_attr_ways_of_associativity.attr,
521 	&dev_attr_number_of_sets.attr,
522 	&dev_attr_size.attr,
523 	&dev_attr_allocation_policy.attr,
524 	&dev_attr_write_policy.attr,
525 	&dev_attr_physical_line_partition.attr,
526 	NULL
527 };
528 
529 static umode_t
cache_default_attrs_is_visible(struct kobject * kobj,struct attribute * attr,int unused)530 cache_default_attrs_is_visible(struct kobject *kobj,
531 			       struct attribute *attr, int unused)
532 {
533 	struct device *dev = kobj_to_dev(kobj);
534 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
535 	const struct cpumask *mask = &this_leaf->shared_cpu_map;
536 	umode_t mode = attr->mode;
537 
538 	if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
539 		return mode;
540 	if ((attr == &dev_attr_type.attr) && this_leaf->type)
541 		return mode;
542 	if ((attr == &dev_attr_level.attr) && this_leaf->level)
543 		return mode;
544 	if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
545 		return mode;
546 	if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
547 		return mode;
548 	if ((attr == &dev_attr_coherency_line_size.attr) &&
549 	    this_leaf->coherency_line_size)
550 		return mode;
551 	if ((attr == &dev_attr_ways_of_associativity.attr) &&
552 	    this_leaf->size) /* allow 0 = full associativity */
553 		return mode;
554 	if ((attr == &dev_attr_number_of_sets.attr) &&
555 	    this_leaf->number_of_sets)
556 		return mode;
557 	if ((attr == &dev_attr_size.attr) && this_leaf->size)
558 		return mode;
559 	if ((attr == &dev_attr_write_policy.attr) &&
560 	    (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
561 		return mode;
562 	if ((attr == &dev_attr_allocation_policy.attr) &&
563 	    (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
564 		return mode;
565 	if ((attr == &dev_attr_physical_line_partition.attr) &&
566 	    this_leaf->physical_line_partition)
567 		return mode;
568 
569 	return 0;
570 }
571 
572 static const struct attribute_group cache_default_group = {
573 	.attrs = cache_default_attrs,
574 	.is_visible = cache_default_attrs_is_visible,
575 };
576 
577 static const struct attribute_group *cache_default_groups[] = {
578 	&cache_default_group,
579 	NULL,
580 };
581 
582 static const struct attribute_group *cache_private_groups[] = {
583 	&cache_default_group,
584 	NULL, /* Place holder for private group */
585 	NULL,
586 };
587 
588 const struct attribute_group *
cache_get_priv_group(struct cacheinfo * this_leaf)589 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
590 {
591 	return NULL;
592 }
593 
594 static const struct attribute_group **
cache_get_attribute_groups(struct cacheinfo * this_leaf)595 cache_get_attribute_groups(struct cacheinfo *this_leaf)
596 {
597 	const struct attribute_group *priv_group =
598 			cache_get_priv_group(this_leaf);
599 
600 	if (!priv_group)
601 		return cache_default_groups;
602 
603 	if (!cache_private_groups[1])
604 		cache_private_groups[1] = priv_group;
605 
606 	return cache_private_groups;
607 }
608 
609 /* Add/Remove cache interface for CPU device */
cpu_cache_sysfs_exit(unsigned int cpu)610 static void cpu_cache_sysfs_exit(unsigned int cpu)
611 {
612 	int i;
613 	struct device *ci_dev;
614 
615 	if (per_cpu_index_dev(cpu)) {
616 		for (i = 0; i < cache_leaves(cpu); i++) {
617 			ci_dev = per_cache_index_dev(cpu, i);
618 			if (!ci_dev)
619 				continue;
620 			device_unregister(ci_dev);
621 		}
622 		kfree(per_cpu_index_dev(cpu));
623 		per_cpu_index_dev(cpu) = NULL;
624 	}
625 	device_unregister(per_cpu_cache_dev(cpu));
626 	per_cpu_cache_dev(cpu) = NULL;
627 }
628 
cpu_cache_sysfs_init(unsigned int cpu)629 static int cpu_cache_sysfs_init(unsigned int cpu)
630 {
631 	struct device *dev = get_cpu_device(cpu);
632 
633 	if (per_cpu_cacheinfo(cpu) == NULL)
634 		return -ENOENT;
635 
636 	per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
637 	if (IS_ERR(per_cpu_cache_dev(cpu)))
638 		return PTR_ERR(per_cpu_cache_dev(cpu));
639 
640 	/* Allocate all required memory */
641 	per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
642 					 sizeof(struct device *), GFP_KERNEL);
643 	if (unlikely(per_cpu_index_dev(cpu) == NULL))
644 		goto err_out;
645 
646 	return 0;
647 
648 err_out:
649 	cpu_cache_sysfs_exit(cpu);
650 	return -ENOMEM;
651 }
652 
cache_add_dev(unsigned int cpu)653 static int cache_add_dev(unsigned int cpu)
654 {
655 	unsigned int i;
656 	int rc;
657 	struct device *ci_dev, *parent;
658 	struct cacheinfo *this_leaf;
659 	const struct attribute_group **cache_groups;
660 
661 	rc = cpu_cache_sysfs_init(cpu);
662 	if (unlikely(rc < 0))
663 		return rc;
664 
665 	parent = per_cpu_cache_dev(cpu);
666 	for (i = 0; i < cache_leaves(cpu); i++) {
667 		this_leaf = per_cpu_cacheinfo_idx(cpu, i);
668 		if (this_leaf->disable_sysfs)
669 			continue;
670 		if (this_leaf->type == CACHE_TYPE_NOCACHE)
671 			break;
672 		cache_groups = cache_get_attribute_groups(this_leaf);
673 		ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
674 					   "index%1u", i);
675 		if (IS_ERR(ci_dev)) {
676 			rc = PTR_ERR(ci_dev);
677 			goto err;
678 		}
679 		per_cache_index_dev(cpu, i) = ci_dev;
680 	}
681 	cpumask_set_cpu(cpu, &cache_dev_map);
682 
683 	return 0;
684 err:
685 	cpu_cache_sysfs_exit(cpu);
686 	return rc;
687 }
688 
cacheinfo_cpu_online(unsigned int cpu)689 static int cacheinfo_cpu_online(unsigned int cpu)
690 {
691 	int rc = detect_cache_attributes(cpu);
692 
693 	if (rc)
694 		return rc;
695 	rc = cache_add_dev(cpu);
696 	if (rc)
697 		free_cache_attributes(cpu);
698 	return rc;
699 }
700 
cacheinfo_cpu_pre_down(unsigned int cpu)701 static int cacheinfo_cpu_pre_down(unsigned int cpu)
702 {
703 	if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
704 		cpu_cache_sysfs_exit(cpu);
705 
706 	free_cache_attributes(cpu);
707 	return 0;
708 }
709 
cacheinfo_sysfs_init(void)710 static int __init cacheinfo_sysfs_init(void)
711 {
712 	return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
713 				 "base/cacheinfo:online",
714 				 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
715 }
716 device_initcall(cacheinfo_sysfs_init);
717