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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 <[email protected]>
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 */
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
31 /* Set if no cache information is found in DT/ACPI. */
32 static bool use_arch_info;
33
34 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
35 {
36         return ci_cacheinfo(cpu);
37 }
38
39 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
40                                            struct cacheinfo *sib_leaf)
41 {
42         /*
43          * For non DT/ACPI systems, assume unique level 1 caches,
44          * system-wide shared caches for all other levels.
45          */
46         if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)) ||
47             use_arch_info)
48                 return (this_leaf->level != 1) && (sib_leaf->level != 1);
49
50         if ((sib_leaf->attributes & CACHE_ID) &&
51             (this_leaf->attributes & CACHE_ID))
52                 return sib_leaf->id == this_leaf->id;
53
54         return sib_leaf->fw_token == this_leaf->fw_token;
55 }
56
57 bool last_level_cache_is_valid(unsigned int cpu)
58 {
59         struct cacheinfo *llc;
60
61         if (!cache_leaves(cpu))
62                 return false;
63
64         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
65
66         return (llc->attributes & CACHE_ID) || !!llc->fw_token;
67
68 }
69
70 bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
71 {
72         struct cacheinfo *llc_x, *llc_y;
73
74         if (!last_level_cache_is_valid(cpu_x) ||
75             !last_level_cache_is_valid(cpu_y))
76                 return false;
77
78         llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
79         llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
80
81         return cache_leaves_are_shared(llc_x, llc_y);
82 }
83
84 #ifdef CONFIG_OF
85
86 static bool of_check_cache_nodes(struct device_node *np);
87
88 /* OF properties to query for a given cache type */
89 struct cache_type_info {
90         const char *size_prop;
91         const char *line_size_props[2];
92         const char *nr_sets_prop;
93 };
94
95 static const struct cache_type_info cache_type_info[] = {
96         {
97                 .size_prop       = "cache-size",
98                 .line_size_props = { "cache-line-size",
99                                      "cache-block-size", },
100                 .nr_sets_prop    = "cache-sets",
101         }, {
102                 .size_prop       = "i-cache-size",
103                 .line_size_props = { "i-cache-line-size",
104                                      "i-cache-block-size", },
105                 .nr_sets_prop    = "i-cache-sets",
106         }, {
107                 .size_prop       = "d-cache-size",
108                 .line_size_props = { "d-cache-line-size",
109                                      "d-cache-block-size", },
110                 .nr_sets_prop    = "d-cache-sets",
111         },
112 };
113
114 static inline int get_cacheinfo_idx(enum cache_type type)
115 {
116         if (type == CACHE_TYPE_UNIFIED)
117                 return 0;
118         return type;
119 }
120
121 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
122 {
123         const char *propname;
124         int ct_idx;
125
126         ct_idx = get_cacheinfo_idx(this_leaf->type);
127         propname = cache_type_info[ct_idx].size_prop;
128
129         of_property_read_u32(np, propname, &this_leaf->size);
130 }
131
132 /* not cache_line_size() because that's a macro in include/linux/cache.h */
133 static void cache_get_line_size(struct cacheinfo *this_leaf,
134                                 struct device_node *np)
135 {
136         int i, lim, ct_idx;
137
138         ct_idx = get_cacheinfo_idx(this_leaf->type);
139         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
140
141         for (i = 0; i < lim; i++) {
142                 int ret;
143                 u32 line_size;
144                 const char *propname;
145
146                 propname = cache_type_info[ct_idx].line_size_props[i];
147                 ret = of_property_read_u32(np, propname, &line_size);
148                 if (!ret) {
149                         this_leaf->coherency_line_size = line_size;
150                         break;
151                 }
152         }
153 }
154
155 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
156 {
157         const char *propname;
158         int ct_idx;
159
160         ct_idx = get_cacheinfo_idx(this_leaf->type);
161         propname = cache_type_info[ct_idx].nr_sets_prop;
162
163         of_property_read_u32(np, propname, &this_leaf->number_of_sets);
164 }
165
166 static void cache_associativity(struct cacheinfo *this_leaf)
167 {
168         unsigned int line_size = this_leaf->coherency_line_size;
169         unsigned int nr_sets = this_leaf->number_of_sets;
170         unsigned int size = this_leaf->size;
171
172         /*
173          * If the cache is fully associative, there is no need to
174          * check the other properties.
175          */
176         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
177                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
178 }
179
180 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
181                                   struct device_node *np)
182 {
183         return of_property_read_bool(np, "cache-unified");
184 }
185
186 static void cache_of_set_props(struct cacheinfo *this_leaf,
187                                struct device_node *np)
188 {
189         /*
190          * init_cache_level must setup the cache level correctly
191          * overriding the architecturally specified levels, so
192          * if type is NONE at this stage, it should be unified
193          */
194         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
195             cache_node_is_unified(this_leaf, np))
196                 this_leaf->type = CACHE_TYPE_UNIFIED;
197         cache_size(this_leaf, np);
198         cache_get_line_size(this_leaf, np);
199         cache_nr_sets(this_leaf, np);
200         cache_associativity(this_leaf);
201 }
202
203 static int cache_setup_of_node(unsigned int cpu)
204 {
205         struct cacheinfo *this_leaf;
206         unsigned int index = 0;
207
208         struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
209         if (!np) {
210                 pr_err("Failed to find cpu%d device node\n", cpu);
211                 return -ENOENT;
212         }
213
214         if (!of_check_cache_nodes(np)) {
215                 return -ENOENT;
216         }
217
218         while (index < cache_leaves(cpu)) {
219                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
220                 if (this_leaf->level != 1) {
221                         struct device_node *prev __free(device_node) = np;
222                         np = of_find_next_cache_node(np);
223                         if (!np)
224                                 break;
225                 }
226                 cache_of_set_props(this_leaf, np);
227                 this_leaf->fw_token = np;
228                 index++;
229         }
230
231         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
232                 return -ENOENT;
233
234         return 0;
235 }
236
237 static bool of_check_cache_nodes(struct device_node *np)
238 {
239         if (of_property_present(np, "cache-size")   ||
240             of_property_present(np, "i-cache-size") ||
241             of_property_present(np, "d-cache-size") ||
242             of_property_present(np, "cache-unified"))
243                 return true;
244
245         struct device_node *next __free(device_node) = of_find_next_cache_node(np);
246         if (next) {
247                 return true;
248         }
249
250         return false;
251 }
252
253 static int of_count_cache_leaves(struct device_node *np)
254 {
255         unsigned int leaves = 0;
256
257         if (of_property_read_bool(np, "cache-size"))
258                 ++leaves;
259         if (of_property_read_bool(np, "i-cache-size"))
260                 ++leaves;
261         if (of_property_read_bool(np, "d-cache-size"))
262                 ++leaves;
263
264         if (!leaves) {
265                 /* The '[i-|d-|]cache-size' property is required, but
266                  * if absent, fallback on the 'cache-unified' property.
267                  */
268                 if (of_property_read_bool(np, "cache-unified"))
269                         return 1;
270                 else
271                         return 2;
272         }
273
274         return leaves;
275 }
276
277 int init_of_cache_level(unsigned int cpu)
278 {
279         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
280         struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
281         unsigned int levels = 0, leaves, level;
282
283         if (!of_check_cache_nodes(np)) {
284                 return -ENOENT;
285         }
286
287         leaves = of_count_cache_leaves(np);
288         if (leaves > 0)
289                 levels = 1;
290
291         while (1) {
292                 struct device_node *prev __free(device_node) = np;
293                 np = of_find_next_cache_node(np);
294                 if (!np)
295                         break;
296
297                 if (!of_device_is_compatible(np, "cache"))
298                         return -EINVAL;
299                 if (of_property_read_u32(np, "cache-level", &level))
300                         return -EINVAL;
301                 if (level <= levels)
302                         return -EINVAL;
303
304                 leaves += of_count_cache_leaves(np);
305                 levels = level;
306         }
307
308         this_cpu_ci->num_levels = levels;
309         this_cpu_ci->num_leaves = leaves;
310
311         return 0;
312 }
313
314 #else
315 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
316 int init_of_cache_level(unsigned int cpu) { return 0; }
317 #endif
318
319 int __weak cache_setup_acpi(unsigned int cpu)
320 {
321         return -ENOTSUPP;
322 }
323
324 unsigned int coherency_max_size;
325
326 static int cache_setup_properties(unsigned int cpu)
327 {
328         int ret = 0;
329
330         if (of_have_populated_dt())
331                 ret = cache_setup_of_node(cpu);
332         else if (!acpi_disabled)
333                 ret = cache_setup_acpi(cpu);
334
335         // Assume there is no cache information available in DT/ACPI from now.
336         if (ret && use_arch_cache_info())
337                 use_arch_info = true;
338
339         return ret;
340 }
341
342 static int cache_shared_cpu_map_setup(unsigned int cpu)
343 {
344         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
345         struct cacheinfo *this_leaf, *sib_leaf;
346         unsigned int index, sib_index;
347         int ret = 0;
348
349         if (this_cpu_ci->cpu_map_populated)
350                 return 0;
351
352         /*
353          * skip setting up cache properties if LLC is valid, just need
354          * to update the shared cpu_map if the cache attributes were
355          * populated early before all the cpus are brought online
356          */
357         if (!last_level_cache_is_valid(cpu) && !use_arch_info) {
358                 ret = cache_setup_properties(cpu);
359                 if (ret)
360                         return ret;
361         }
362
363         for (index = 0; index < cache_leaves(cpu); index++) {
364                 unsigned int i;
365
366                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
367
368                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
369                 for_each_online_cpu(i) {
370                         struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
371
372                         if (i == cpu || !sib_cpu_ci->info_list)
373                                 continue;/* skip if itself or no cacheinfo */
374                         for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
375                                 sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
376
377                                 /*
378                                  * Comparing cache IDs only makes sense if the leaves
379                                  * belong to the same cache level of same type. Skip
380                                  * the check if level and type do not match.
381                                  */
382                                 if (sib_leaf->level != this_leaf->level ||
383                                     sib_leaf->type != this_leaf->type)
384                                         continue;
385
386                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
387                                         cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
388                                         cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
389                                         break;
390                                 }
391                         }
392                 }
393                 /* record the maximum cache line size */
394                 if (this_leaf->coherency_line_size > coherency_max_size)
395                         coherency_max_size = this_leaf->coherency_line_size;
396         }
397
398         /* shared_cpu_map is now populated for the cpu */
399         this_cpu_ci->cpu_map_populated = true;
400         return 0;
401 }
402
403 static void cache_shared_cpu_map_remove(unsigned int cpu)
404 {
405         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
406         struct cacheinfo *this_leaf, *sib_leaf;
407         unsigned int sibling, index, sib_index;
408
409         for (index = 0; index < cache_leaves(cpu); index++) {
410                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
411                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
412                         struct cpu_cacheinfo *sib_cpu_ci =
413                                                 get_cpu_cacheinfo(sibling);
414
415                         if (sibling == cpu || !sib_cpu_ci->info_list)
416                                 continue;/* skip if itself or no cacheinfo */
417
418                         for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
419                                 sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
420
421                                 /*
422                                  * Comparing cache IDs only makes sense if the leaves
423                                  * belong to the same cache level of same type. Skip
424                                  * the check if level and type do not match.
425                                  */
426                                 if (sib_leaf->level != this_leaf->level ||
427                                     sib_leaf->type != this_leaf->type)
428                                         continue;
429
430                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
431                                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
432                                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
433                                         break;
434                                 }
435                         }
436                 }
437         }
438
439         /* cpu is no longer populated in the shared map */
440         this_cpu_ci->cpu_map_populated = false;
441 }
442
443 static void free_cache_attributes(unsigned int cpu)
444 {
445         if (!per_cpu_cacheinfo(cpu))
446                 return;
447
448         cache_shared_cpu_map_remove(cpu);
449 }
450
451 int __weak early_cache_level(unsigned int cpu)
452 {
453         return -ENOENT;
454 }
455
456 int __weak init_cache_level(unsigned int cpu)
457 {
458         return -ENOENT;
459 }
460
461 int __weak populate_cache_leaves(unsigned int cpu)
462 {
463         return -ENOENT;
464 }
465
466 static inline
467 int allocate_cache_info(int cpu)
468 {
469         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
470                                          sizeof(struct cacheinfo), GFP_ATOMIC);
471         if (!per_cpu_cacheinfo(cpu)) {
472                 cache_leaves(cpu) = 0;
473                 return -ENOMEM;
474         }
475
476         return 0;
477 }
478
479 int fetch_cache_info(unsigned int cpu)
480 {
481         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
482         unsigned int levels = 0, split_levels = 0;
483         int ret;
484
485         if (acpi_disabled) {
486                 ret = init_of_cache_level(cpu);
487         } else {
488                 ret = acpi_get_cache_info(cpu, &levels, &split_levels);
489                 if (!ret) {
490                         this_cpu_ci->num_levels = levels;
491                         /*
492                          * This assumes that:
493                          * - there cannot be any split caches (data/instruction)
494                          *   above a unified cache
495                          * - data/instruction caches come by pair
496                          */
497                         this_cpu_ci->num_leaves = levels + split_levels;
498                 }
499         }
500
501         if (ret || !cache_leaves(cpu)) {
502                 ret = early_cache_level(cpu);
503                 if (ret)
504                         return ret;
505
506                 if (!cache_leaves(cpu))
507                         return -ENOENT;
508
509                 this_cpu_ci->early_ci_levels = true;
510         }
511
512         return allocate_cache_info(cpu);
513 }
514
515 static inline int init_level_allocate_ci(unsigned int cpu)
516 {
517         unsigned int early_leaves = cache_leaves(cpu);
518
519         /* Since early initialization/allocation of the cacheinfo is allowed
520          * via fetch_cache_info() and this also gets called as CPU hotplug
521          * callbacks via cacheinfo_cpu_online, the init/alloc can be skipped
522          * as it will happen only once (the cacheinfo memory is never freed).
523          * Just populate the cacheinfo. However, if the cacheinfo has been
524          * allocated early through the arch-specific early_cache_level() call,
525          * there is a chance the info is wrong (this can happen on arm64). In
526          * that case, call init_cache_level() anyway to give the arch-specific
527          * code a chance to make things right.
528          */
529         if (per_cpu_cacheinfo(cpu) && !ci_cacheinfo(cpu)->early_ci_levels)
530                 return 0;
531
532         if (init_cache_level(cpu) || !cache_leaves(cpu))
533                 return -ENOENT;
534
535         /*
536          * Now that we have properly initialized the cache level info, make
537          * sure we don't try to do that again the next time we are called
538          * (e.g. as CPU hotplug callbacks).
539          */
540         ci_cacheinfo(cpu)->early_ci_levels = false;
541
542         if (cache_leaves(cpu) <= early_leaves)
543                 return 0;
544
545         kfree(per_cpu_cacheinfo(cpu));
546         return allocate_cache_info(cpu);
547 }
548
549 int detect_cache_attributes(unsigned int cpu)
550 {
551         int ret;
552
553         ret = init_level_allocate_ci(cpu);
554         if (ret)
555                 return ret;
556
557         /*
558          * If LLC is valid the cache leaves were already populated so just go to
559          * update the cpu map.
560          */
561         if (!last_level_cache_is_valid(cpu)) {
562                 /*
563                  * populate_cache_leaves() may completely setup the cache leaves and
564                  * shared_cpu_map or it may leave it partially setup.
565                  */
566                 ret = populate_cache_leaves(cpu);
567                 if (ret)
568                         goto free_ci;
569         }
570
571         /*
572          * For systems using DT for cache hierarchy, fw_token
573          * and shared_cpu_map will be set up here only if they are
574          * not populated already
575          */
576         ret = cache_shared_cpu_map_setup(cpu);
577         if (ret) {
578                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
579                 goto free_ci;
580         }
581
582         return 0;
583
584 free_ci:
585         free_cache_attributes(cpu);
586         return ret;
587 }
588
589 /* pointer to cpuX/cache device */
590 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
591 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
592
593 static cpumask_t cache_dev_map;
594
595 /* pointer to array of devices for cpuX/cache/indexY */
596 static DEFINE_PER_CPU(struct device **, ci_index_dev);
597 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
598 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
599
600 #define show_one(file_name, object)                             \
601 static ssize_t file_name##_show(struct device *dev,             \
602                 struct device_attribute *attr, char *buf)       \
603 {                                                               \
604         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
605         return sysfs_emit(buf, "%u\n", this_leaf->object);      \
606 }
607
608 show_one(id, id);
609 show_one(level, level);
610 show_one(coherency_line_size, coherency_line_size);
611 show_one(number_of_sets, number_of_sets);
612 show_one(physical_line_partition, physical_line_partition);
613 show_one(ways_of_associativity, ways_of_associativity);
614
615 static ssize_t size_show(struct device *dev,
616                          struct device_attribute *attr, char *buf)
617 {
618         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
619
620         return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
621 }
622
623 static ssize_t shared_cpu_map_show(struct device *dev,
624                                    struct device_attribute *attr, char *buf)
625 {
626         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
627         const struct cpumask *mask = &this_leaf->shared_cpu_map;
628
629         return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
630 }
631
632 static ssize_t shared_cpu_list_show(struct device *dev,
633                                     struct device_attribute *attr, char *buf)
634 {
635         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
636         const struct cpumask *mask = &this_leaf->shared_cpu_map;
637
638         return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
639 }
640
641 static ssize_t type_show(struct device *dev,
642                          struct device_attribute *attr, char *buf)
643 {
644         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
645         const char *output;
646
647         switch (this_leaf->type) {
648         case CACHE_TYPE_DATA:
649                 output = "Data";
650                 break;
651         case CACHE_TYPE_INST:
652                 output = "Instruction";
653                 break;
654         case CACHE_TYPE_UNIFIED:
655                 output = "Unified";
656                 break;
657         default:
658                 return -EINVAL;
659         }
660
661         return sysfs_emit(buf, "%s\n", output);
662 }
663
664 static ssize_t allocation_policy_show(struct device *dev,
665                                       struct device_attribute *attr, char *buf)
666 {
667         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
668         unsigned int ci_attr = this_leaf->attributes;
669         const char *output;
670
671         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
672                 output = "ReadWriteAllocate";
673         else if (ci_attr & CACHE_READ_ALLOCATE)
674                 output = "ReadAllocate";
675         else if (ci_attr & CACHE_WRITE_ALLOCATE)
676                 output = "WriteAllocate";
677         else
678                 return 0;
679
680         return sysfs_emit(buf, "%s\n", output);
681 }
682
683 static ssize_t write_policy_show(struct device *dev,
684                                  struct device_attribute *attr, char *buf)
685 {
686         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
687         unsigned int ci_attr = this_leaf->attributes;
688         int n = 0;
689
690         if (ci_attr & CACHE_WRITE_THROUGH)
691                 n = sysfs_emit(buf, "WriteThrough\n");
692         else if (ci_attr & CACHE_WRITE_BACK)
693                 n = sysfs_emit(buf, "WriteBack\n");
694         return n;
695 }
696
697 static DEVICE_ATTR_RO(id);
698 static DEVICE_ATTR_RO(level);
699 static DEVICE_ATTR_RO(type);
700 static DEVICE_ATTR_RO(coherency_line_size);
701 static DEVICE_ATTR_RO(ways_of_associativity);
702 static DEVICE_ATTR_RO(number_of_sets);
703 static DEVICE_ATTR_RO(size);
704 static DEVICE_ATTR_RO(allocation_policy);
705 static DEVICE_ATTR_RO(write_policy);
706 static DEVICE_ATTR_RO(shared_cpu_map);
707 static DEVICE_ATTR_RO(shared_cpu_list);
708 static DEVICE_ATTR_RO(physical_line_partition);
709
710 static struct attribute *cache_default_attrs[] = {
711         &dev_attr_id.attr,
712         &dev_attr_type.attr,
713         &dev_attr_level.attr,
714         &dev_attr_shared_cpu_map.attr,
715         &dev_attr_shared_cpu_list.attr,
716         &dev_attr_coherency_line_size.attr,
717         &dev_attr_ways_of_associativity.attr,
718         &dev_attr_number_of_sets.attr,
719         &dev_attr_size.attr,
720         &dev_attr_allocation_policy.attr,
721         &dev_attr_write_policy.attr,
722         &dev_attr_physical_line_partition.attr,
723         NULL
724 };
725
726 static umode_t
727 cache_default_attrs_is_visible(struct kobject *kobj,
728                                struct attribute *attr, int unused)
729 {
730         struct device *dev = kobj_to_dev(kobj);
731         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
732         const struct cpumask *mask = &this_leaf->shared_cpu_map;
733         umode_t mode = attr->mode;
734
735         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
736                 return mode;
737         if ((attr == &dev_attr_type.attr) && this_leaf->type)
738                 return mode;
739         if ((attr == &dev_attr_level.attr) && this_leaf->level)
740                 return mode;
741         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
742                 return mode;
743         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
744                 return mode;
745         if ((attr == &dev_attr_coherency_line_size.attr) &&
746             this_leaf->coherency_line_size)
747                 return mode;
748         if ((attr == &dev_attr_ways_of_associativity.attr) &&
749             this_leaf->size) /* allow 0 = full associativity */
750                 return mode;
751         if ((attr == &dev_attr_number_of_sets.attr) &&
752             this_leaf->number_of_sets)
753                 return mode;
754         if ((attr == &dev_attr_size.attr) && this_leaf->size)
755                 return mode;
756         if ((attr == &dev_attr_write_policy.attr) &&
757             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
758                 return mode;
759         if ((attr == &dev_attr_allocation_policy.attr) &&
760             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
761                 return mode;
762         if ((attr == &dev_attr_physical_line_partition.attr) &&
763             this_leaf->physical_line_partition)
764                 return mode;
765
766         return 0;
767 }
768
769 static const struct attribute_group cache_default_group = {
770         .attrs = cache_default_attrs,
771         .is_visible = cache_default_attrs_is_visible,
772 };
773
774 static const struct attribute_group *cache_default_groups[] = {
775         &cache_default_group,
776         NULL,
777 };
778
779 static const struct attribute_group *cache_private_groups[] = {
780         &cache_default_group,
781         NULL, /* Place holder for private group */
782         NULL,
783 };
784
785 const struct attribute_group *
786 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
787 {
788         return NULL;
789 }
790
791 static const struct attribute_group **
792 cache_get_attribute_groups(struct cacheinfo *this_leaf)
793 {
794         const struct attribute_group *priv_group =
795                         cache_get_priv_group(this_leaf);
796
797         if (!priv_group)
798                 return cache_default_groups;
799
800         if (!cache_private_groups[1])
801                 cache_private_groups[1] = priv_group;
802
803         return cache_private_groups;
804 }
805
806 /* Add/Remove cache interface for CPU device */
807 static void cpu_cache_sysfs_exit(unsigned int cpu)
808 {
809         int i;
810         struct device *ci_dev;
811
812         if (per_cpu_index_dev(cpu)) {
813                 for (i = 0; i < cache_leaves(cpu); i++) {
814                         ci_dev = per_cache_index_dev(cpu, i);
815                         if (!ci_dev)
816                                 continue;
817                         device_unregister(ci_dev);
818                 }
819                 kfree(per_cpu_index_dev(cpu));
820                 per_cpu_index_dev(cpu) = NULL;
821         }
822         device_unregister(per_cpu_cache_dev(cpu));
823         per_cpu_cache_dev(cpu) = NULL;
824 }
825
826 static int cpu_cache_sysfs_init(unsigned int cpu)
827 {
828         struct device *dev = get_cpu_device(cpu);
829
830         if (per_cpu_cacheinfo(cpu) == NULL)
831                 return -ENOENT;
832
833         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
834         if (IS_ERR(per_cpu_cache_dev(cpu)))
835                 return PTR_ERR(per_cpu_cache_dev(cpu));
836
837         /* Allocate all required memory */
838         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
839                                          sizeof(struct device *), GFP_KERNEL);
840         if (unlikely(per_cpu_index_dev(cpu) == NULL))
841                 goto err_out;
842
843         return 0;
844
845 err_out:
846         cpu_cache_sysfs_exit(cpu);
847         return -ENOMEM;
848 }
849
850 static int cache_add_dev(unsigned int cpu)
851 {
852         unsigned int i;
853         int rc;
854         struct device *ci_dev, *parent;
855         struct cacheinfo *this_leaf;
856         const struct attribute_group **cache_groups;
857
858         rc = cpu_cache_sysfs_init(cpu);
859         if (unlikely(rc < 0))
860                 return rc;
861
862         parent = per_cpu_cache_dev(cpu);
863         for (i = 0; i < cache_leaves(cpu); i++) {
864                 this_leaf = per_cpu_cacheinfo_idx(cpu, i);
865                 if (this_leaf->disable_sysfs)
866                         continue;
867                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
868                         break;
869                 cache_groups = cache_get_attribute_groups(this_leaf);
870                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
871                                            "index%1u", i);
872                 if (IS_ERR(ci_dev)) {
873                         rc = PTR_ERR(ci_dev);
874                         goto err;
875                 }
876                 per_cache_index_dev(cpu, i) = ci_dev;
877         }
878         cpumask_set_cpu(cpu, &cache_dev_map);
879
880         return 0;
881 err:
882         cpu_cache_sysfs_exit(cpu);
883         return rc;
884 }
885
886 static unsigned int cpu_map_shared_cache(bool online, unsigned int cpu,
887                                          cpumask_t **map)
888 {
889         struct cacheinfo *llc, *sib_llc;
890         unsigned int sibling;
891
892         if (!last_level_cache_is_valid(cpu))
893                 return 0;
894
895         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
896
897         if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
898                 return 0;
899
900         if (online) {
901                 *map = &llc->shared_cpu_map;
902                 return cpumask_weight(*map);
903         }
904
905         /* shared_cpu_map of offlined CPU will be cleared, so use sibling map */
906         for_each_cpu(sibling, &llc->shared_cpu_map) {
907                 if (sibling == cpu || !last_level_cache_is_valid(sibling))
908                         continue;
909                 sib_llc = per_cpu_cacheinfo_idx(sibling, cache_leaves(sibling) - 1);
910                 *map = &sib_llc->shared_cpu_map;
911                 return cpumask_weight(*map);
912         }
913
914         return 0;
915 }
916
917 /*
918  * Calculate the size of the per-CPU data cache slice.  This can be
919  * used to estimate the size of the data cache slice that can be used
920  * by one CPU under ideal circumstances.  UNIFIED caches are counted
921  * in addition to DATA caches.  So, please consider code cache usage
922  * when use the result.
923  *
924  * Because the cache inclusive/non-inclusive information isn't
925  * available, we just use the size of the per-CPU slice of LLC to make
926  * the result more predictable across architectures.
927  */
928 static void update_per_cpu_data_slice_size_cpu(unsigned int cpu)
929 {
930         struct cpu_cacheinfo *ci;
931         struct cacheinfo *llc;
932         unsigned int nr_shared;
933
934         if (!last_level_cache_is_valid(cpu))
935                 return;
936
937         ci = ci_cacheinfo(cpu);
938         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
939
940         if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
941                 return;
942
943         nr_shared = cpumask_weight(&llc->shared_cpu_map);
944         if (nr_shared)
945                 ci->per_cpu_data_slice_size = llc->size / nr_shared;
946 }
947
948 static void update_per_cpu_data_slice_size(bool cpu_online, unsigned int cpu,
949                                            cpumask_t *cpu_map)
950 {
951         unsigned int icpu;
952
953         for_each_cpu(icpu, cpu_map) {
954                 if (!cpu_online && icpu == cpu)
955                         continue;
956                 update_per_cpu_data_slice_size_cpu(icpu);
957                 setup_pcp_cacheinfo(icpu);
958         }
959 }
960
961 static int cacheinfo_cpu_online(unsigned int cpu)
962 {
963         int rc = detect_cache_attributes(cpu);
964         cpumask_t *cpu_map;
965
966         if (rc)
967                 return rc;
968         rc = cache_add_dev(cpu);
969         if (rc)
970                 goto err;
971         if (cpu_map_shared_cache(true, cpu, &cpu_map))
972                 update_per_cpu_data_slice_size(true, cpu, cpu_map);
973         return 0;
974 err:
975         free_cache_attributes(cpu);
976         return rc;
977 }
978
979 static int cacheinfo_cpu_pre_down(unsigned int cpu)
980 {
981         cpumask_t *cpu_map;
982         unsigned int nr_shared;
983
984         nr_shared = cpu_map_shared_cache(false, cpu, &cpu_map);
985         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
986                 cpu_cache_sysfs_exit(cpu);
987
988         free_cache_attributes(cpu);
989         if (nr_shared > 1)
990                 update_per_cpu_data_slice_size(false, cpu, cpu_map);
991         return 0;
992 }
993
994 static int __init cacheinfo_sysfs_init(void)
995 {
996         return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
997                                  "base/cacheinfo:online",
998                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
999 }
1000 device_initcall(cacheinfo_sysfs_init);
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