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