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