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/cputhreads.h>
22 #include <asm/smp.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  */
30 struct 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  */
40 struct 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 */
48 struct 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 
69 static 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  */
117 struct 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 	int group_id;                  /* id of the group of threads that share this cache */
123 	struct list_head list;         /* global list of cache objects */
124 	struct cache *next_local;      /* next cache of >= level */
125 };
126 
127 static 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  */
132 static LIST_HEAD(cache_list);
133 
kobj_to_cache_index_dir(struct kobject * k)134 static 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 
cache_type_string(const struct cache * cache)139 static const char *cache_type_string(const struct cache *cache)
140 {
141 	return cache_type_info[cache->type].name;
142 }
143 
cache_init(struct cache * cache,int type,int level,struct device_node * ofnode,int group_id)144 static void cache_init(struct cache *cache, int type, int level,
145 		       struct device_node *ofnode, int group_id)
146 {
147 	cache->type = type;
148 	cache->level = level;
149 	cache->ofnode = of_node_get(ofnode);
150 	cache->group_id = group_id;
151 	INIT_LIST_HEAD(&cache->list);
152 	list_add(&cache->list, &cache_list);
153 }
154 
new_cache(int type,int level,struct device_node * ofnode,int group_id)155 static struct cache *new_cache(int type, int level,
156 			       struct device_node *ofnode, int group_id)
157 {
158 	struct cache *cache;
159 
160 	cache = kzalloc(sizeof(*cache), GFP_KERNEL);
161 	if (cache)
162 		cache_init(cache, type, level, ofnode, group_id);
163 
164 	return cache;
165 }
166 
release_cache_debugcheck(struct cache * cache)167 static void release_cache_debugcheck(struct cache *cache)
168 {
169 	struct cache *iter;
170 
171 	list_for_each_entry(iter, &cache_list, list)
172 		WARN_ONCE(iter->next_local == cache,
173 			  "cache for %pOFP(%s) refers to cache for %pOFP(%s)\n",
174 			  iter->ofnode,
175 			  cache_type_string(iter),
176 			  cache->ofnode,
177 			  cache_type_string(cache));
178 }
179 
release_cache(struct cache * cache)180 static void release_cache(struct cache *cache)
181 {
182 	if (!cache)
183 		return;
184 
185 	pr_debug("freeing L%d %s cache for %pOFP\n", cache->level,
186 		 cache_type_string(cache), cache->ofnode);
187 
188 	release_cache_debugcheck(cache);
189 	list_del(&cache->list);
190 	of_node_put(cache->ofnode);
191 	kfree(cache);
192 }
193 
cache_cpu_set(struct cache * cache,int cpu)194 static void cache_cpu_set(struct cache *cache, int cpu)
195 {
196 	struct cache *next = cache;
197 
198 	while (next) {
199 		WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
200 			  "CPU %i already accounted in %pOFP(%s)\n",
201 			  cpu, next->ofnode,
202 			  cache_type_string(next));
203 		cpumask_set_cpu(cpu, &next->shared_cpu_map);
204 		next = next->next_local;
205 	}
206 }
207 
cache_size(const struct cache * cache,unsigned int * ret)208 static int cache_size(const struct cache *cache, unsigned int *ret)
209 {
210 	const char *propname;
211 	const __be32 *cache_size;
212 
213 	propname = cache_type_info[cache->type].size_prop;
214 
215 	cache_size = of_get_property(cache->ofnode, propname, NULL);
216 	if (!cache_size)
217 		return -ENODEV;
218 
219 	*ret = of_read_number(cache_size, 1);
220 	return 0;
221 }
222 
cache_size_kb(const struct cache * cache,unsigned int * ret)223 static int cache_size_kb(const struct cache *cache, unsigned int *ret)
224 {
225 	unsigned int size;
226 
227 	if (cache_size(cache, &size))
228 		return -ENODEV;
229 
230 	*ret = size / 1024;
231 	return 0;
232 }
233 
234 /* not cache_line_size() because that's a macro in include/linux/cache.h */
cache_get_line_size(const struct cache * cache,unsigned int * ret)235 static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
236 {
237 	const __be32 *line_size;
238 	int i, lim;
239 
240 	lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
241 
242 	for (i = 0; i < lim; i++) {
243 		const char *propname;
244 
245 		propname = cache_type_info[cache->type].line_size_props[i];
246 		line_size = of_get_property(cache->ofnode, propname, NULL);
247 		if (line_size)
248 			break;
249 	}
250 
251 	if (!line_size)
252 		return -ENODEV;
253 
254 	*ret = of_read_number(line_size, 1);
255 	return 0;
256 }
257 
cache_nr_sets(const struct cache * cache,unsigned int * ret)258 static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
259 {
260 	const char *propname;
261 	const __be32 *nr_sets;
262 
263 	propname = cache_type_info[cache->type].nr_sets_prop;
264 
265 	nr_sets = of_get_property(cache->ofnode, propname, NULL);
266 	if (!nr_sets)
267 		return -ENODEV;
268 
269 	*ret = of_read_number(nr_sets, 1);
270 	return 0;
271 }
272 
cache_associativity(const struct cache * cache,unsigned int * ret)273 static int cache_associativity(const struct cache *cache, unsigned int *ret)
274 {
275 	unsigned int line_size;
276 	unsigned int nr_sets;
277 	unsigned int size;
278 
279 	if (cache_nr_sets(cache, &nr_sets))
280 		goto err;
281 
282 	/* If the cache is fully associative, there is no need to
283 	 * check the other properties.
284 	 */
285 	if (nr_sets == 1) {
286 		*ret = 0;
287 		return 0;
288 	}
289 
290 	if (cache_get_line_size(cache, &line_size))
291 		goto err;
292 	if (cache_size(cache, &size))
293 		goto err;
294 
295 	if (!(nr_sets > 0 && size > 0 && line_size > 0))
296 		goto err;
297 
298 	*ret = (size / nr_sets) / line_size;
299 	return 0;
300 err:
301 	return -ENODEV;
302 }
303 
304 /* helper for dealing with split caches */
cache_find_first_sibling(struct cache * cache)305 static struct cache *cache_find_first_sibling(struct cache *cache)
306 {
307 	struct cache *iter;
308 
309 	if (cache->type == CACHE_TYPE_UNIFIED ||
310 	    cache->type == CACHE_TYPE_UNIFIED_D)
311 		return cache;
312 
313 	list_for_each_entry(iter, &cache_list, list)
314 		if (iter->ofnode == cache->ofnode &&
315 		    iter->group_id == cache->group_id &&
316 		    iter->next_local == cache)
317 			return iter;
318 
319 	return cache;
320 }
321 
322 /* return the first cache on a local list matching node and thread-group id */
cache_lookup_by_node_group(const struct device_node * node,int group_id)323 static struct cache *cache_lookup_by_node_group(const struct device_node *node,
324 						int group_id)
325 {
326 	struct cache *cache = NULL;
327 	struct cache *iter;
328 
329 	list_for_each_entry(iter, &cache_list, list) {
330 		if (iter->ofnode != node ||
331 		    iter->group_id != group_id)
332 			continue;
333 		cache = cache_find_first_sibling(iter);
334 		break;
335 	}
336 
337 	return cache;
338 }
339 
cache_node_is_unified(const struct device_node * np)340 static bool cache_node_is_unified(const struct device_node *np)
341 {
342 	return of_get_property(np, "cache-unified", NULL);
343 }
344 
345 /*
346  * Unified caches can have two different sets of tags.  Most embedded
347  * use cache-size, etc. for the unified cache size, but open firmware systems
348  * use d-cache-size, etc.   Check on initialization for which type we have, and
349  * return the appropriate structure type.  Assume it's embedded if it isn't
350  * open firmware.  If it's yet a 3rd type, then there will be missing entries
351  * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need
352  * to be extended further.
353  */
cache_is_unified_d(const struct device_node * np)354 static int cache_is_unified_d(const struct device_node *np)
355 {
356 	return of_get_property(np,
357 		cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
358 		CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
359 }
360 
cache_do_one_devnode_unified(struct device_node * node,int group_id,int level)361 static struct cache *cache_do_one_devnode_unified(struct device_node *node, int group_id,
362 						  int level)
363 {
364 	pr_debug("creating L%d ucache for %pOFP\n", level, node);
365 
366 	return new_cache(cache_is_unified_d(node), level, node, group_id);
367 }
368 
cache_do_one_devnode_split(struct device_node * node,int group_id,int level)369 static struct cache *cache_do_one_devnode_split(struct device_node *node, int group_id,
370 						int level)
371 {
372 	struct cache *dcache, *icache;
373 
374 	pr_debug("creating L%d dcache and icache for %pOFP\n", level,
375 		 node);
376 
377 	dcache = new_cache(CACHE_TYPE_DATA, level, node, group_id);
378 	icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node, group_id);
379 
380 	if (!dcache || !icache)
381 		goto err;
382 
383 	dcache->next_local = icache;
384 
385 	return dcache;
386 err:
387 	release_cache(dcache);
388 	release_cache(icache);
389 	return NULL;
390 }
391 
cache_do_one_devnode(struct device_node * node,int group_id,int level)392 static struct cache *cache_do_one_devnode(struct device_node *node, int group_id, int level)
393 {
394 	struct cache *cache;
395 
396 	if (cache_node_is_unified(node))
397 		cache = cache_do_one_devnode_unified(node, group_id, level);
398 	else
399 		cache = cache_do_one_devnode_split(node, group_id, level);
400 
401 	return cache;
402 }
403 
cache_lookup_or_instantiate(struct device_node * node,int group_id,int level)404 static struct cache *cache_lookup_or_instantiate(struct device_node *node,
405 						 int group_id,
406 						 int level)
407 {
408 	struct cache *cache;
409 
410 	cache = cache_lookup_by_node_group(node, group_id);
411 
412 	WARN_ONCE(cache && cache->level != level,
413 		  "cache level mismatch on lookup (got %d, expected %d)\n",
414 		  cache->level, level);
415 
416 	if (!cache)
417 		cache = cache_do_one_devnode(node, group_id, level);
418 
419 	return cache;
420 }
421 
link_cache_lists(struct cache * smaller,struct cache * bigger)422 static void link_cache_lists(struct cache *smaller, struct cache *bigger)
423 {
424 	while (smaller->next_local) {
425 		if (smaller->next_local == bigger)
426 			return; /* already linked */
427 		smaller = smaller->next_local;
428 	}
429 
430 	smaller->next_local = bigger;
431 
432 	/*
433 	 * The cache->next_local list sorts by level ascending:
434 	 * L1d -> L1i -> L2 -> L3 ...
435 	 */
436 	WARN_ONCE((smaller->level == 1 && bigger->level > 2) ||
437 		  (smaller->level > 1 && bigger->level != smaller->level + 1),
438 		  "linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n",
439 		  smaller->level, smaller->ofnode, bigger->level, bigger->ofnode);
440 }
441 
do_subsidiary_caches_debugcheck(struct cache * cache)442 static void do_subsidiary_caches_debugcheck(struct cache *cache)
443 {
444 	WARN_ONCE(cache->level != 1,
445 		  "instantiating cache chain from L%d %s cache for "
446 		  "%pOFP instead of an L1\n", cache->level,
447 		  cache_type_string(cache), cache->ofnode);
448 	WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"),
449 		  "instantiating cache chain from node %pOFP of type '%s' "
450 		  "instead of a cpu node\n", cache->ofnode,
451 		  of_node_get_device_type(cache->ofnode));
452 }
453 
454 /*
455  * If sub-groups of threads in a core containing @cpu_id share the
456  * L@level-cache (information obtained via "ibm,thread-groups"
457  * device-tree property), then we identify the group by the first
458  * thread-sibling in the group. We define this to be the group-id.
459  *
460  * In the absence of any thread-group information for L@level-cache,
461  * this function returns -1.
462  */
get_group_id(unsigned int cpu_id,int level)463 static int get_group_id(unsigned int cpu_id, int level)
464 {
465 	if (has_big_cores && level == 1)
466 		return cpumask_first(per_cpu(thread_group_l1_cache_map,
467 					     cpu_id));
468 	else if (thread_group_shares_l2 && level == 2)
469 		return cpumask_first(per_cpu(thread_group_l2_cache_map,
470 					     cpu_id));
471 	else if (thread_group_shares_l3 && level == 3)
472 		return cpumask_first(per_cpu(thread_group_l3_cache_map,
473 					     cpu_id));
474 	return -1;
475 }
476 
do_subsidiary_caches(struct cache * cache,unsigned int cpu_id)477 static void do_subsidiary_caches(struct cache *cache, unsigned int cpu_id)
478 {
479 	struct device_node *subcache_node;
480 	int level = cache->level;
481 
482 	do_subsidiary_caches_debugcheck(cache);
483 
484 	while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
485 		struct cache *subcache;
486 		int group_id;
487 
488 		level++;
489 		group_id = get_group_id(cpu_id, level);
490 		subcache = cache_lookup_or_instantiate(subcache_node, group_id, level);
491 		of_node_put(subcache_node);
492 		if (!subcache)
493 			break;
494 
495 		link_cache_lists(cache, subcache);
496 		cache = subcache;
497 	}
498 }
499 
cache_chain_instantiate(unsigned int cpu_id)500 static struct cache *cache_chain_instantiate(unsigned int cpu_id)
501 {
502 	struct device_node *cpu_node;
503 	struct cache *cpu_cache = NULL;
504 	int group_id;
505 
506 	pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
507 
508 	cpu_node = of_get_cpu_node(cpu_id, NULL);
509 	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
510 	if (!cpu_node)
511 		goto out;
512 
513 	group_id = get_group_id(cpu_id, 1);
514 
515 	cpu_cache = cache_lookup_or_instantiate(cpu_node, group_id, 1);
516 	if (!cpu_cache)
517 		goto out;
518 
519 	do_subsidiary_caches(cpu_cache, cpu_id);
520 
521 	cache_cpu_set(cpu_cache, cpu_id);
522 out:
523 	of_node_put(cpu_node);
524 
525 	return cpu_cache;
526 }
527 
cacheinfo_create_cache_dir(unsigned int cpu_id)528 static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
529 {
530 	struct cache_dir *cache_dir;
531 	struct device *dev;
532 	struct kobject *kobj = NULL;
533 
534 	dev = get_cpu_device(cpu_id);
535 	WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
536 	if (!dev)
537 		goto err;
538 
539 	kobj = kobject_create_and_add("cache", &dev->kobj);
540 	if (!kobj)
541 		goto err;
542 
543 	cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
544 	if (!cache_dir)
545 		goto err;
546 
547 	cache_dir->kobj = kobj;
548 
549 	WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
550 
551 	per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
552 
553 	return cache_dir;
554 err:
555 	kobject_put(kobj);
556 	return NULL;
557 }
558 
cache_index_release(struct kobject * kobj)559 static void cache_index_release(struct kobject *kobj)
560 {
561 	struct cache_index_dir *index;
562 
563 	index = kobj_to_cache_index_dir(kobj);
564 
565 	pr_debug("freeing index directory for L%d %s cache\n",
566 		 index->cache->level, cache_type_string(index->cache));
567 
568 	kfree(index);
569 }
570 
cache_index_show(struct kobject * k,struct attribute * attr,char * buf)571 static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
572 {
573 	struct kobj_attribute *kobj_attr;
574 
575 	kobj_attr = container_of(attr, struct kobj_attribute, attr);
576 
577 	return kobj_attr->show(k, kobj_attr, buf);
578 }
579 
index_kobj_to_cache(struct kobject * k)580 static struct cache *index_kobj_to_cache(struct kobject *k)
581 {
582 	struct cache_index_dir *index;
583 
584 	index = kobj_to_cache_index_dir(k);
585 
586 	return index->cache;
587 }
588 
size_show(struct kobject * k,struct kobj_attribute * attr,char * buf)589 static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
590 {
591 	unsigned int size_kb;
592 	struct cache *cache;
593 
594 	cache = index_kobj_to_cache(k);
595 
596 	if (cache_size_kb(cache, &size_kb))
597 		return -ENODEV;
598 
599 	return sprintf(buf, "%uK\n", size_kb);
600 }
601 
602 static struct kobj_attribute cache_size_attr =
603 	__ATTR(size, 0444, size_show, NULL);
604 
605 
line_size_show(struct kobject * k,struct kobj_attribute * attr,char * buf)606 static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
607 {
608 	unsigned int line_size;
609 	struct cache *cache;
610 
611 	cache = index_kobj_to_cache(k);
612 
613 	if (cache_get_line_size(cache, &line_size))
614 		return -ENODEV;
615 
616 	return sprintf(buf, "%u\n", line_size);
617 }
618 
619 static struct kobj_attribute cache_line_size_attr =
620 	__ATTR(coherency_line_size, 0444, line_size_show, NULL);
621 
nr_sets_show(struct kobject * k,struct kobj_attribute * attr,char * buf)622 static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
623 {
624 	unsigned int nr_sets;
625 	struct cache *cache;
626 
627 	cache = index_kobj_to_cache(k);
628 
629 	if (cache_nr_sets(cache, &nr_sets))
630 		return -ENODEV;
631 
632 	return sprintf(buf, "%u\n", nr_sets);
633 }
634 
635 static struct kobj_attribute cache_nr_sets_attr =
636 	__ATTR(number_of_sets, 0444, nr_sets_show, NULL);
637 
associativity_show(struct kobject * k,struct kobj_attribute * attr,char * buf)638 static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
639 {
640 	unsigned int associativity;
641 	struct cache *cache;
642 
643 	cache = index_kobj_to_cache(k);
644 
645 	if (cache_associativity(cache, &associativity))
646 		return -ENODEV;
647 
648 	return sprintf(buf, "%u\n", associativity);
649 }
650 
651 static struct kobj_attribute cache_assoc_attr =
652 	__ATTR(ways_of_associativity, 0444, associativity_show, NULL);
653 
type_show(struct kobject * k,struct kobj_attribute * attr,char * buf)654 static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
655 {
656 	struct cache *cache;
657 
658 	cache = index_kobj_to_cache(k);
659 
660 	return sprintf(buf, "%s\n", cache_type_string(cache));
661 }
662 
663 static struct kobj_attribute cache_type_attr =
664 	__ATTR(type, 0444, type_show, NULL);
665 
level_show(struct kobject * k,struct kobj_attribute * attr,char * buf)666 static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
667 {
668 	struct cache_index_dir *index;
669 	struct cache *cache;
670 
671 	index = kobj_to_cache_index_dir(k);
672 	cache = index->cache;
673 
674 	return sprintf(buf, "%d\n", cache->level);
675 }
676 
677 static struct kobj_attribute cache_level_attr =
678 	__ATTR(level, 0444, level_show, NULL);
679 
680 static ssize_t
show_shared_cpumap(struct kobject * k,struct kobj_attribute * attr,char * buf,bool list)681 show_shared_cpumap(struct kobject *k, struct kobj_attribute *attr, char *buf, bool list)
682 {
683 	struct cache_index_dir *index;
684 	struct cache *cache;
685 	const struct cpumask *mask;
686 
687 	index = kobj_to_cache_index_dir(k);
688 	cache = index->cache;
689 
690 	mask = &cache->shared_cpu_map;
691 
692 	return cpumap_print_to_pagebuf(list, buf, mask);
693 }
694 
shared_cpu_map_show(struct kobject * k,struct kobj_attribute * attr,char * buf)695 static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
696 {
697 	return show_shared_cpumap(k, attr, buf, false);
698 }
699 
shared_cpu_list_show(struct kobject * k,struct kobj_attribute * attr,char * buf)700 static ssize_t shared_cpu_list_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
701 {
702 	return show_shared_cpumap(k, attr, buf, true);
703 }
704 
705 static struct kobj_attribute cache_shared_cpu_map_attr =
706 	__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
707 
708 static struct kobj_attribute cache_shared_cpu_list_attr =
709 	__ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
710 
711 /* Attributes which should always be created -- the kobject/sysfs core
712  * does this automatically via kobj_type->default_groups.  This is the
713  * minimum data required to uniquely identify a cache.
714  */
715 static struct attribute *cache_index_default_attrs[] = {
716 	&cache_type_attr.attr,
717 	&cache_level_attr.attr,
718 	&cache_shared_cpu_map_attr.attr,
719 	&cache_shared_cpu_list_attr.attr,
720 	NULL,
721 };
722 ATTRIBUTE_GROUPS(cache_index_default);
723 
724 /* Attributes which should be created if the cache device node has the
725  * right properties -- see cacheinfo_create_index_opt_attrs
726  */
727 static struct kobj_attribute *cache_index_opt_attrs[] = {
728 	&cache_size_attr,
729 	&cache_line_size_attr,
730 	&cache_nr_sets_attr,
731 	&cache_assoc_attr,
732 };
733 
734 static const struct sysfs_ops cache_index_ops = {
735 	.show = cache_index_show,
736 };
737 
738 static struct kobj_type cache_index_type = {
739 	.release = cache_index_release,
740 	.sysfs_ops = &cache_index_ops,
741 	.default_groups = cache_index_default_groups,
742 };
743 
cacheinfo_create_index_opt_attrs(struct cache_index_dir * dir)744 static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
745 {
746 	const char *cache_type;
747 	struct cache *cache;
748 	char *buf;
749 	int i;
750 
751 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
752 	if (!buf)
753 		return;
754 
755 	cache = dir->cache;
756 	cache_type = cache_type_string(cache);
757 
758 	/* We don't want to create an attribute that can't provide a
759 	 * meaningful value.  Check the return value of each optional
760 	 * attribute's ->show method before registering the
761 	 * attribute.
762 	 */
763 	for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
764 		struct kobj_attribute *attr;
765 		ssize_t rc;
766 
767 		attr = cache_index_opt_attrs[i];
768 
769 		rc = attr->show(&dir->kobj, attr, buf);
770 		if (rc <= 0) {
771 			pr_debug("not creating %s attribute for "
772 				 "%pOFP(%s) (rc = %zd)\n",
773 				 attr->attr.name, cache->ofnode,
774 				 cache_type, rc);
775 			continue;
776 		}
777 		if (sysfs_create_file(&dir->kobj, &attr->attr))
778 			pr_debug("could not create %s attribute for %pOFP(%s)\n",
779 				 attr->attr.name, cache->ofnode, cache_type);
780 	}
781 
782 	kfree(buf);
783 }
784 
cacheinfo_create_index_dir(struct cache * cache,int index,struct cache_dir * cache_dir)785 static void cacheinfo_create_index_dir(struct cache *cache, int index,
786 				       struct cache_dir *cache_dir)
787 {
788 	struct cache_index_dir *index_dir;
789 	int rc;
790 
791 	index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
792 	if (!index_dir)
793 		return;
794 
795 	index_dir->cache = cache;
796 
797 	rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
798 				  cache_dir->kobj, "index%d", index);
799 	if (rc) {
800 		kobject_put(&index_dir->kobj);
801 		return;
802 	}
803 
804 	index_dir->next = cache_dir->index;
805 	cache_dir->index = index_dir;
806 
807 	cacheinfo_create_index_opt_attrs(index_dir);
808 }
809 
cacheinfo_sysfs_populate(unsigned int cpu_id,struct cache * cache_list)810 static void cacheinfo_sysfs_populate(unsigned int cpu_id,
811 				     struct cache *cache_list)
812 {
813 	struct cache_dir *cache_dir;
814 	struct cache *cache;
815 	int index = 0;
816 
817 	cache_dir = cacheinfo_create_cache_dir(cpu_id);
818 	if (!cache_dir)
819 		return;
820 
821 	cache = cache_list;
822 	while (cache) {
823 		cacheinfo_create_index_dir(cache, index, cache_dir);
824 		index++;
825 		cache = cache->next_local;
826 	}
827 }
828 
cacheinfo_cpu_online(unsigned int cpu_id)829 void cacheinfo_cpu_online(unsigned int cpu_id)
830 {
831 	struct cache *cache;
832 
833 	cache = cache_chain_instantiate(cpu_id);
834 	if (!cache)
835 		return;
836 
837 	cacheinfo_sysfs_populate(cpu_id, cache);
838 }
839 
840 /* functions needed to remove cache entry for cpu offline or suspend/resume */
841 
842 #if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
843     defined(CONFIG_HOTPLUG_CPU)
844 
cache_lookup_by_cpu(unsigned int cpu_id)845 static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
846 {
847 	struct device_node *cpu_node;
848 	struct cache *cache;
849 	int group_id;
850 
851 	cpu_node = of_get_cpu_node(cpu_id, NULL);
852 	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
853 	if (!cpu_node)
854 		return NULL;
855 
856 	group_id = get_group_id(cpu_id, 1);
857 	cache = cache_lookup_by_node_group(cpu_node, group_id);
858 	of_node_put(cpu_node);
859 
860 	return cache;
861 }
862 
remove_index_dirs(struct cache_dir * cache_dir)863 static 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 
remove_cache_dir(struct cache_dir * cache_dir)878 static 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 
cache_cpu_clear(struct cache * cache,int cpu)890 static 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 
cacheinfo_cpu_offline(unsigned int cpu_id)911 void 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 
cacheinfo_teardown(void)933 void 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 
cacheinfo_rebuild(void)943 void 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 */
954