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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * cacheinfo support - processor cache information via sysfs
4 *
5 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
6 * Author: Sudeep Holla <sudeep.holla@arm.com>
7 */
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/acpi.h>
11#include <linux/bitops.h>
12#include <linux/cacheinfo.h>
13#include <linux/compiler.h>
14#include <linux/cpu.h>
15#include <linux/device.h>
16#include <linux/init.h>
17#include <linux/of.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/smp.h>
21#include <linux/sysfs.h>
22
23/* pointer to per cpu cacheinfo */
24static 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
29struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
30{
31 return ci_cacheinfo(cpu);
32}
33
34#ifdef CONFIG_OF
35static int cache_setup_of_node(unsigned int cpu)
36{
37 struct device_node *np;
38 struct cacheinfo *this_leaf;
39 struct device *cpu_dev = get_cpu_device(cpu);
40 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
41 unsigned int index = 0;
42
43 /* skip if of_node is already populated */
44 if (this_cpu_ci->info_list->of_node)
45 return 0;
46
47 if (!cpu_dev) {
48 pr_err("No cpu device for CPU %d\n", cpu);
49 return -ENODEV;
50 }
51 np = cpu_dev->of_node;
52 if (!np) {
53 pr_err("Failed to find cpu%d device node\n", cpu);
54 return -ENOENT;
55 }
56
57 while (index < cache_leaves(cpu)) {
58 this_leaf = this_cpu_ci->info_list + index;
59 if (this_leaf->level != 1)
60 np = of_find_next_cache_node(np);
61 else
62 np = of_node_get(np);/* cpu node itself */
63 if (!np)
64 break;
65 this_leaf->of_node = np;
66 index++;
67 }
68
69 if (index != cache_leaves(cpu)) /* not all OF nodes populated */
70 return -ENOENT;
71
72 return 0;
73}
74
75static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
76 struct cacheinfo *sib_leaf)
77{
78 return sib_leaf->of_node == this_leaf->of_node;
79}
80
81/* OF properties to query for a given cache type */
82struct cache_type_info {
83 const char *size_prop;
84 const char *line_size_props[2];
85 const char *nr_sets_prop;
86};
87
88static const struct cache_type_info cache_type_info[] = {
89 {
90 .size_prop = "cache-size",
91 .line_size_props = { "cache-line-size",
92 "cache-block-size", },
93 .nr_sets_prop = "cache-sets",
94 }, {
95 .size_prop = "i-cache-size",
96 .line_size_props = { "i-cache-line-size",
97 "i-cache-block-size", },
98 .nr_sets_prop = "i-cache-sets",
99 }, {
100 .size_prop = "d-cache-size",
101 .line_size_props = { "d-cache-line-size",
102 "d-cache-block-size", },
103 .nr_sets_prop = "d-cache-sets",
104 },
105};
106
107static inline int get_cacheinfo_idx(enum cache_type type)
108{
109 if (type == CACHE_TYPE_UNIFIED)
110 return 0;
111 return type;
112}
113
114static void cache_size(struct cacheinfo *this_leaf)
115{
116 const char *propname;
117 const __be32 *cache_size;
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 cache_size = of_get_property(this_leaf->of_node, propname, NULL);
124 if (cache_size)
125 this_leaf->size = of_read_number(cache_size, 1);
126}
127
128/* not cache_line_size() because that's a macro in include/linux/cache.h */
129static void cache_get_line_size(struct cacheinfo *this_leaf)
130{
131 const __be32 *line_size;
132 int i, lim, ct_idx;
133
134 ct_idx = get_cacheinfo_idx(this_leaf->type);
135 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
136
137 for (i = 0; i < lim; i++) {
138 const char *propname;
139
140 propname = cache_type_info[ct_idx].line_size_props[i];
141 line_size = of_get_property(this_leaf->of_node, propname, NULL);
142 if (line_size)
143 break;
144 }
145
146 if (line_size)
147 this_leaf->coherency_line_size = of_read_number(line_size, 1);
148}
149
150static void cache_nr_sets(struct cacheinfo *this_leaf)
151{
152 const char *propname;
153 const __be32 *nr_sets;
154 int ct_idx;
155
156 ct_idx = get_cacheinfo_idx(this_leaf->type);
157 propname = cache_type_info[ct_idx].nr_sets_prop;
158
159 nr_sets = of_get_property(this_leaf->of_node, propname, NULL);
160 if (nr_sets)
161 this_leaf->number_of_sets = of_read_number(nr_sets, 1);
162}
163
164static void cache_associativity(struct cacheinfo *this_leaf)
165{
166 unsigned int line_size = this_leaf->coherency_line_size;
167 unsigned int nr_sets = this_leaf->number_of_sets;
168 unsigned int size = this_leaf->size;
169
170 /*
171 * If the cache is fully associative, there is no need to
172 * check the other properties.
173 */
174 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
175 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
176}
177
178static bool cache_node_is_unified(struct cacheinfo *this_leaf)
179{
180 return of_property_read_bool(this_leaf->of_node, "cache-unified");
181}
182
183static void cache_of_override_properties(unsigned int cpu)
184{
185 int index;
186 struct cacheinfo *this_leaf;
187 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
188
189 for (index = 0; index < cache_leaves(cpu); index++) {
190 this_leaf = this_cpu_ci->info_list + index;
191 /*
192 * init_cache_level must setup the cache level correctly
193 * overriding the architecturally specified levels, so
194 * if type is NONE at this stage, it should be unified
195 */
196 if (this_leaf->type == CACHE_TYPE_NOCACHE &&
197 cache_node_is_unified(this_leaf))
198 this_leaf->type = CACHE_TYPE_UNIFIED;
199 cache_size(this_leaf);
200 cache_get_line_size(this_leaf);
201 cache_nr_sets(this_leaf);
202 cache_associativity(this_leaf);
203 }
204}
205#else
206static void cache_of_override_properties(unsigned int cpu) { }
207static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
208static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
209 struct cacheinfo *sib_leaf)
210{
211 /*
212 * For non-DT systems, assume unique level 1 cache, system-wide
213 * shared caches for all other levels. This will be used only if
214 * arch specific code has not populated shared_cpu_map
215 */
216 return !(this_leaf->level == 1);
217}
218#endif
219
220static int cache_shared_cpu_map_setup(unsigned int cpu)
221{
222 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
223 struct cacheinfo *this_leaf, *sib_leaf;
224 unsigned int index;
225 int ret = 0;
226
227 if (this_cpu_ci->cpu_map_populated)
228 return 0;
229
230 if (of_have_populated_dt())
231 ret = cache_setup_of_node(cpu);
232 else if (!acpi_disabled)
233 /* No cache property/hierarchy support yet in ACPI */
234 ret = -ENOTSUPP;
235 if (ret)
236 return ret;
237
238 for (index = 0; index < cache_leaves(cpu); index++) {
239 unsigned int i;
240
241 this_leaf = this_cpu_ci->info_list + index;
242 /* skip if shared_cpu_map is already populated */
243 if (!cpumask_empty(&this_leaf->shared_cpu_map))
244 continue;
245
246 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
247 for_each_online_cpu(i) {
248 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
249
250 if (i == cpu || !sib_cpu_ci->info_list)
251 continue;/* skip if itself or no cacheinfo */
252 sib_leaf = sib_cpu_ci->info_list + index;
253 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
254 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
255 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
256 }
257 }
258 }
259
260 return 0;
261}
262
263static void cache_shared_cpu_map_remove(unsigned int cpu)
264{
265 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
266 struct cacheinfo *this_leaf, *sib_leaf;
267 unsigned int sibling, index;
268
269 for (index = 0; index < cache_leaves(cpu); index++) {
270 this_leaf = this_cpu_ci->info_list + index;
271 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
272 struct cpu_cacheinfo *sib_cpu_ci;
273
274 if (sibling == cpu) /* skip itself */
275 continue;
276
277 sib_cpu_ci = get_cpu_cacheinfo(sibling);
278 if (!sib_cpu_ci->info_list)
279 continue;
280
281 sib_leaf = sib_cpu_ci->info_list + index;
282 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
283 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
284 }
285 of_node_put(this_leaf->of_node);
286 }
287}
288
289static void cache_override_properties(unsigned int cpu)
290{
291 if (of_have_populated_dt())
292 return cache_of_override_properties(cpu);
293}
294
295static void free_cache_attributes(unsigned int cpu)
296{
297 if (!per_cpu_cacheinfo(cpu))
298 return;
299
300 cache_shared_cpu_map_remove(cpu);
301
302 kfree(per_cpu_cacheinfo(cpu));
303 per_cpu_cacheinfo(cpu) = NULL;
304}
305
306int __weak init_cache_level(unsigned int cpu)
307{
308 return -ENOENT;
309}
310
311int __weak populate_cache_leaves(unsigned int cpu)
312{
313 return -ENOENT;
314}
315
316static int detect_cache_attributes(unsigned int cpu)
317{
318 int ret;
319
320 if (init_cache_level(cpu) || !cache_leaves(cpu))
321 return -ENOENT;
322
323 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
324 sizeof(struct cacheinfo), GFP_KERNEL);
325 if (per_cpu_cacheinfo(cpu) == NULL)
326 return -ENOMEM;
327
328 ret = populate_cache_leaves(cpu);
329 if (ret)
330 goto free_ci;
331 /*
332 * For systems using DT for cache hierarchy, of_node and shared_cpu_map
333 * will be set up here only if they are not populated already
334 */
335 ret = cache_shared_cpu_map_setup(cpu);
336 if (ret) {
337 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
338 goto free_ci;
339 }
340
341 cache_override_properties(cpu);
342 return 0;
343
344free_ci:
345 free_cache_attributes(cpu);
346 return ret;
347}
348
349/* pointer to cpuX/cache device */
350static DEFINE_PER_CPU(struct device *, ci_cache_dev);
351#define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu))
352
353static cpumask_t cache_dev_map;
354
355/* pointer to array of devices for cpuX/cache/indexY */
356static DEFINE_PER_CPU(struct device **, ci_index_dev);
357#define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu))
358#define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx])
359
360#define show_one(file_name, object) \
361static ssize_t file_name##_show(struct device *dev, \
362 struct device_attribute *attr, char *buf) \
363{ \
364 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \
365 return sprintf(buf, "%u\n", this_leaf->object); \
366}
367
368show_one(id, id);
369show_one(level, level);
370show_one(coherency_line_size, coherency_line_size);
371show_one(number_of_sets, number_of_sets);
372show_one(physical_line_partition, physical_line_partition);
373show_one(ways_of_associativity, ways_of_associativity);
374
375static ssize_t size_show(struct device *dev,
376 struct device_attribute *attr, char *buf)
377{
378 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
379
380 return sprintf(buf, "%uK\n", this_leaf->size >> 10);
381}
382
383static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
384{
385 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
386 const struct cpumask *mask = &this_leaf->shared_cpu_map;
387
388 return cpumap_print_to_pagebuf(list, buf, mask);
389}
390
391static ssize_t shared_cpu_map_show(struct device *dev,
392 struct device_attribute *attr, char *buf)
393{
394 return shared_cpumap_show_func(dev, false, buf);
395}
396
397static ssize_t shared_cpu_list_show(struct device *dev,
398 struct device_attribute *attr, char *buf)
399{
400 return shared_cpumap_show_func(dev, true, buf);
401}
402
403static ssize_t type_show(struct device *dev,
404 struct device_attribute *attr, char *buf)
405{
406 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
407
408 switch (this_leaf->type) {
409 case CACHE_TYPE_DATA:
410 return sprintf(buf, "Data\n");
411 case CACHE_TYPE_INST:
412 return sprintf(buf, "Instruction\n");
413 case CACHE_TYPE_UNIFIED:
414 return sprintf(buf, "Unified\n");
415 default:
416 return -EINVAL;
417 }
418}
419
420static ssize_t allocation_policy_show(struct device *dev,
421 struct device_attribute *attr, char *buf)
422{
423 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
424 unsigned int ci_attr = this_leaf->attributes;
425 int n = 0;
426
427 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
428 n = sprintf(buf, "ReadWriteAllocate\n");
429 else if (ci_attr & CACHE_READ_ALLOCATE)
430 n = sprintf(buf, "ReadAllocate\n");
431 else if (ci_attr & CACHE_WRITE_ALLOCATE)
432 n = sprintf(buf, "WriteAllocate\n");
433 return n;
434}
435
436static ssize_t write_policy_show(struct device *dev,
437 struct device_attribute *attr, char *buf)
438{
439 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
440 unsigned int ci_attr = this_leaf->attributes;
441 int n = 0;
442
443 if (ci_attr & CACHE_WRITE_THROUGH)
444 n = sprintf(buf, "WriteThrough\n");
445 else if (ci_attr & CACHE_WRITE_BACK)
446 n = sprintf(buf, "WriteBack\n");
447 return n;
448}
449
450static DEVICE_ATTR_RO(id);
451static DEVICE_ATTR_RO(level);
452static DEVICE_ATTR_RO(type);
453static DEVICE_ATTR_RO(coherency_line_size);
454static DEVICE_ATTR_RO(ways_of_associativity);
455static DEVICE_ATTR_RO(number_of_sets);
456static DEVICE_ATTR_RO(size);
457static DEVICE_ATTR_RO(allocation_policy);
458static DEVICE_ATTR_RO(write_policy);
459static DEVICE_ATTR_RO(shared_cpu_map);
460static DEVICE_ATTR_RO(shared_cpu_list);
461static DEVICE_ATTR_RO(physical_line_partition);
462
463static struct attribute *cache_default_attrs[] = {
464 &dev_attr_id.attr,
465 &dev_attr_type.attr,
466 &dev_attr_level.attr,
467 &dev_attr_shared_cpu_map.attr,
468 &dev_attr_shared_cpu_list.attr,
469 &dev_attr_coherency_line_size.attr,
470 &dev_attr_ways_of_associativity.attr,
471 &dev_attr_number_of_sets.attr,
472 &dev_attr_size.attr,
473 &dev_attr_allocation_policy.attr,
474 &dev_attr_write_policy.attr,
475 &dev_attr_physical_line_partition.attr,
476 NULL
477};
478
479static umode_t
480cache_default_attrs_is_visible(struct kobject *kobj,
481 struct attribute *attr, int unused)
482{
483 struct device *dev = kobj_to_dev(kobj);
484 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
485 const struct cpumask *mask = &this_leaf->shared_cpu_map;
486 umode_t mode = attr->mode;
487
488 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
489 return mode;
490 if ((attr == &dev_attr_type.attr) && this_leaf->type)
491 return mode;
492 if ((attr == &dev_attr_level.attr) && this_leaf->level)
493 return mode;
494 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
495 return mode;
496 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
497 return mode;
498 if ((attr == &dev_attr_coherency_line_size.attr) &&
499 this_leaf->coherency_line_size)
500 return mode;
501 if ((attr == &dev_attr_ways_of_associativity.attr) &&
502 this_leaf->size) /* allow 0 = full associativity */
503 return mode;
504 if ((attr == &dev_attr_number_of_sets.attr) &&
505 this_leaf->number_of_sets)
506 return mode;
507 if ((attr == &dev_attr_size.attr) && this_leaf->size)
508 return mode;
509 if ((attr == &dev_attr_write_policy.attr) &&
510 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
511 return mode;
512 if ((attr == &dev_attr_allocation_policy.attr) &&
513 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
514 return mode;
515 if ((attr == &dev_attr_physical_line_partition.attr) &&
516 this_leaf->physical_line_partition)
517 return mode;
518
519 return 0;
520}
521
522static const struct attribute_group cache_default_group = {
523 .attrs = cache_default_attrs,
524 .is_visible = cache_default_attrs_is_visible,
525};
526
527static const struct attribute_group *cache_default_groups[] = {
528 &cache_default_group,
529 NULL,
530};
531
532static const struct attribute_group *cache_private_groups[] = {
533 &cache_default_group,
534 NULL, /* Place holder for private group */
535 NULL,
536};
537
538const struct attribute_group *
539__weak cache_get_priv_group(struct cacheinfo *this_leaf)
540{
541 return NULL;
542}
543
544static const struct attribute_group **
545cache_get_attribute_groups(struct cacheinfo *this_leaf)
546{
547 const struct attribute_group *priv_group =
548 cache_get_priv_group(this_leaf);
549
550 if (!priv_group)
551 return cache_default_groups;
552
553 if (!cache_private_groups[1])
554 cache_private_groups[1] = priv_group;
555
556 return cache_private_groups;
557}
558
559/* Add/Remove cache interface for CPU device */
560static void cpu_cache_sysfs_exit(unsigned int cpu)
561{
562 int i;
563 struct device *ci_dev;
564
565 if (per_cpu_index_dev(cpu)) {
566 for (i = 0; i < cache_leaves(cpu); i++) {
567 ci_dev = per_cache_index_dev(cpu, i);
568 if (!ci_dev)
569 continue;
570 device_unregister(ci_dev);
571 }
572 kfree(per_cpu_index_dev(cpu));
573 per_cpu_index_dev(cpu) = NULL;
574 }
575 device_unregister(per_cpu_cache_dev(cpu));
576 per_cpu_cache_dev(cpu) = NULL;
577}
578
579static int cpu_cache_sysfs_init(unsigned int cpu)
580{
581 struct device *dev = get_cpu_device(cpu);
582
583 if (per_cpu_cacheinfo(cpu) == NULL)
584 return -ENOENT;
585
586 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
587 if (IS_ERR(per_cpu_cache_dev(cpu)))
588 return PTR_ERR(per_cpu_cache_dev(cpu));
589
590 /* Allocate all required memory */
591 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
592 sizeof(struct device *), GFP_KERNEL);
593 if (unlikely(per_cpu_index_dev(cpu) == NULL))
594 goto err_out;
595
596 return 0;
597
598err_out:
599 cpu_cache_sysfs_exit(cpu);
600 return -ENOMEM;
601}
602
603static int cache_add_dev(unsigned int cpu)
604{
605 unsigned int i;
606 int rc;
607 struct device *ci_dev, *parent;
608 struct cacheinfo *this_leaf;
609 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
610 const struct attribute_group **cache_groups;
611
612 rc = cpu_cache_sysfs_init(cpu);
613 if (unlikely(rc < 0))
614 return rc;
615
616 parent = per_cpu_cache_dev(cpu);
617 for (i = 0; i < cache_leaves(cpu); i++) {
618 this_leaf = this_cpu_ci->info_list + i;
619 if (this_leaf->disable_sysfs)
620 continue;
621 cache_groups = cache_get_attribute_groups(this_leaf);
622 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
623 "index%1u", i);
624 if (IS_ERR(ci_dev)) {
625 rc = PTR_ERR(ci_dev);
626 goto err;
627 }
628 per_cache_index_dev(cpu, i) = ci_dev;
629 }
630 cpumask_set_cpu(cpu, &cache_dev_map);
631
632 return 0;
633err:
634 cpu_cache_sysfs_exit(cpu);
635 return rc;
636}
637
638static int cacheinfo_cpu_online(unsigned int cpu)
639{
640 int rc = detect_cache_attributes(cpu);
641
642 if (rc)
643 return rc;
644 rc = cache_add_dev(cpu);
645 if (rc)
646 free_cache_attributes(cpu);
647 return rc;
648}
649
650static int cacheinfo_cpu_pre_down(unsigned int cpu)
651{
652 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
653 cpu_cache_sysfs_exit(cpu);
654
655 free_cache_attributes(cpu);
656 return 0;
657}
658
659static int __init cacheinfo_sysfs_init(void)
660{
661 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
662 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
663}
664device_initcall(cacheinfo_sysfs_init);