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246246cb SH |
1 | /* |
2 | * cacheinfo support - processor cache information via sysfs | |
3 | * | |
4 | * Based on arch/x86/kernel/cpu/intel_cacheinfo.c | |
5 | * Author: Sudeep Holla <sudeep.holla@arm.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
12 | * kind, whether express or implied; without even the implied warranty | |
13 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
18 | */ | |
19 | #include <linux/bitops.h> | |
20 | #include <linux/cacheinfo.h> | |
21 | #include <linux/compiler.h> | |
22 | #include <linux/cpu.h> | |
23 | #include <linux/device.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/of.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/smp.h> | |
29 | #include <linux/sysfs.h> | |
30 | ||
31 | /* pointer to per cpu cacheinfo */ | |
32 | static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo); | |
33 | #define ci_cacheinfo(cpu) (&per_cpu(ci_cpu_cacheinfo, cpu)) | |
34 | #define cache_leaves(cpu) (ci_cacheinfo(cpu)->num_leaves) | |
35 | #define per_cpu_cacheinfo(cpu) (ci_cacheinfo(cpu)->info_list) | |
36 | ||
37 | struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu) | |
38 | { | |
39 | return ci_cacheinfo(cpu); | |
40 | } | |
41 | ||
42 | #ifdef CONFIG_OF | |
43 | static int cache_setup_of_node(unsigned int cpu) | |
44 | { | |
45 | struct device_node *np; | |
46 | struct cacheinfo *this_leaf; | |
47 | struct device *cpu_dev = get_cpu_device(cpu); | |
48 | struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); | |
49 | unsigned int index = 0; | |
50 | ||
51 | /* skip if of_node is already populated */ | |
52 | if (this_cpu_ci->info_list->of_node) | |
53 | return 0; | |
54 | ||
55 | if (!cpu_dev) { | |
56 | pr_err("No cpu device for CPU %d\n", cpu); | |
57 | return -ENODEV; | |
58 | } | |
59 | np = cpu_dev->of_node; | |
60 | if (!np) { | |
61 | pr_err("Failed to find cpu%d device node\n", cpu); | |
62 | return -ENOENT; | |
63 | } | |
64 | ||
65 | while (np && index < cache_leaves(cpu)) { | |
66 | this_leaf = this_cpu_ci->info_list + index; | |
67 | if (this_leaf->level != 1) | |
68 | np = of_find_next_cache_node(np); | |
69 | else | |
70 | np = of_node_get(np);/* cpu node itself */ | |
71 | this_leaf->of_node = np; | |
72 | index++; | |
73 | } | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, | |
78 | struct cacheinfo *sib_leaf) | |
79 | { | |
80 | return sib_leaf->of_node == this_leaf->of_node; | |
81 | } | |
82 | #else | |
83 | static inline int cache_setup_of_node(unsigned int cpu) { return 0; } | |
84 | static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, | |
85 | struct cacheinfo *sib_leaf) | |
86 | { | |
87 | /* | |
88 | * For non-DT systems, assume unique level 1 cache, system-wide | |
89 | * shared caches for all other levels. This will be used only if | |
90 | * arch specific code has not populated shared_cpu_map | |
91 | */ | |
92 | return !(this_leaf->level == 1); | |
93 | } | |
94 | #endif | |
95 | ||
96 | static int cache_shared_cpu_map_setup(unsigned int cpu) | |
97 | { | |
98 | struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); | |
99 | struct cacheinfo *this_leaf, *sib_leaf; | |
100 | unsigned int index; | |
101 | int ret; | |
102 | ||
103 | ret = cache_setup_of_node(cpu); | |
104 | if (ret) | |
105 | return ret; | |
106 | ||
107 | for (index = 0; index < cache_leaves(cpu); index++) { | |
108 | unsigned int i; | |
109 | ||
110 | this_leaf = this_cpu_ci->info_list + index; | |
111 | /* skip if shared_cpu_map is already populated */ | |
112 | if (!cpumask_empty(&this_leaf->shared_cpu_map)) | |
113 | continue; | |
114 | ||
115 | cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); | |
116 | for_each_online_cpu(i) { | |
117 | struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i); | |
118 | ||
119 | if (i == cpu || !sib_cpu_ci->info_list) | |
120 | continue;/* skip if itself or no cacheinfo */ | |
121 | sib_leaf = sib_cpu_ci->info_list + index; | |
122 | if (cache_leaves_are_shared(this_leaf, sib_leaf)) { | |
123 | cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); | |
124 | cpumask_set_cpu(i, &this_leaf->shared_cpu_map); | |
125 | } | |
126 | } | |
127 | } | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | static void cache_shared_cpu_map_remove(unsigned int cpu) | |
133 | { | |
134 | struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); | |
135 | struct cacheinfo *this_leaf, *sib_leaf; | |
136 | unsigned int sibling, index; | |
137 | ||
138 | for (index = 0; index < cache_leaves(cpu); index++) { | |
139 | this_leaf = this_cpu_ci->info_list + index; | |
140 | for_each_cpu(sibling, &this_leaf->shared_cpu_map) { | |
141 | struct cpu_cacheinfo *sib_cpu_ci; | |
142 | ||
143 | if (sibling == cpu) /* skip itself */ | |
144 | continue; | |
145 | sib_cpu_ci = get_cpu_cacheinfo(sibling); | |
146 | sib_leaf = sib_cpu_ci->info_list + index; | |
147 | cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); | |
148 | cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); | |
149 | } | |
150 | of_node_put(this_leaf->of_node); | |
151 | } | |
152 | } | |
153 | ||
154 | static void free_cache_attributes(unsigned int cpu) | |
155 | { | |
156 | cache_shared_cpu_map_remove(cpu); | |
157 | ||
158 | kfree(per_cpu_cacheinfo(cpu)); | |
159 | per_cpu_cacheinfo(cpu) = NULL; | |
160 | } | |
161 | ||
162 | int __weak init_cache_level(unsigned int cpu) | |
163 | { | |
164 | return -ENOENT; | |
165 | } | |
166 | ||
167 | int __weak populate_cache_leaves(unsigned int cpu) | |
168 | { | |
169 | return -ENOENT; | |
170 | } | |
171 | ||
172 | static int detect_cache_attributes(unsigned int cpu) | |
173 | { | |
174 | int ret; | |
175 | ||
176 | if (init_cache_level(cpu)) | |
177 | return -ENOENT; | |
178 | ||
179 | per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), | |
180 | sizeof(struct cacheinfo), GFP_KERNEL); | |
181 | if (per_cpu_cacheinfo(cpu) == NULL) | |
182 | return -ENOMEM; | |
183 | ||
184 | ret = populate_cache_leaves(cpu); | |
185 | if (ret) | |
186 | goto free_ci; | |
187 | /* | |
188 | * For systems using DT for cache hierarcy, of_node and shared_cpu_map | |
189 | * will be set up here only if they are not populated already | |
190 | */ | |
191 | ret = cache_shared_cpu_map_setup(cpu); | |
192 | if (ret) | |
193 | goto free_ci; | |
194 | return 0; | |
195 | ||
196 | free_ci: | |
197 | free_cache_attributes(cpu); | |
198 | return ret; | |
199 | } | |
200 | ||
201 | /* pointer to cpuX/cache device */ | |
202 | static DEFINE_PER_CPU(struct device *, ci_cache_dev); | |
203 | #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu)) | |
204 | ||
205 | static cpumask_t cache_dev_map; | |
206 | ||
207 | /* pointer to array of devices for cpuX/cache/indexY */ | |
208 | static DEFINE_PER_CPU(struct device **, ci_index_dev); | |
209 | #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu)) | |
210 | #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx]) | |
211 | ||
212 | #define show_one(file_name, object) \ | |
213 | static ssize_t file_name##_show(struct device *dev, \ | |
214 | struct device_attribute *attr, char *buf) \ | |
215 | { \ | |
216 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); \ | |
217 | return sprintf(buf, "%u\n", this_leaf->object); \ | |
218 | } | |
219 | ||
220 | show_one(level, level); | |
221 | show_one(coherency_line_size, coherency_line_size); | |
222 | show_one(number_of_sets, number_of_sets); | |
223 | show_one(physical_line_partition, physical_line_partition); | |
224 | show_one(ways_of_associativity, ways_of_associativity); | |
225 | ||
226 | static ssize_t size_show(struct device *dev, | |
227 | struct device_attribute *attr, char *buf) | |
228 | { | |
229 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
230 | ||
231 | return sprintf(buf, "%uK\n", this_leaf->size >> 10); | |
232 | } | |
233 | ||
234 | static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) | |
235 | { | |
236 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
237 | const struct cpumask *mask = &this_leaf->shared_cpu_map; | |
238 | ||
239 | return cpumap_print_to_pagebuf(list, buf, mask); | |
240 | } | |
241 | ||
242 | static ssize_t shared_cpu_map_show(struct device *dev, | |
243 | struct device_attribute *attr, char *buf) | |
244 | { | |
245 | return shared_cpumap_show_func(dev, false, buf); | |
246 | } | |
247 | ||
248 | static ssize_t shared_cpu_list_show(struct device *dev, | |
249 | struct device_attribute *attr, char *buf) | |
250 | { | |
251 | return shared_cpumap_show_func(dev, true, buf); | |
252 | } | |
253 | ||
254 | static ssize_t type_show(struct device *dev, | |
255 | struct device_attribute *attr, char *buf) | |
256 | { | |
257 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
258 | ||
259 | switch (this_leaf->type) { | |
260 | case CACHE_TYPE_DATA: | |
261 | return sprintf(buf, "Data\n"); | |
262 | case CACHE_TYPE_INST: | |
263 | return sprintf(buf, "Instruction\n"); | |
264 | case CACHE_TYPE_UNIFIED: | |
265 | return sprintf(buf, "Unified\n"); | |
266 | default: | |
267 | return -EINVAL; | |
268 | } | |
269 | } | |
270 | ||
271 | static ssize_t allocation_policy_show(struct device *dev, | |
272 | struct device_attribute *attr, char *buf) | |
273 | { | |
274 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
275 | unsigned int ci_attr = this_leaf->attributes; | |
276 | int n = 0; | |
277 | ||
278 | if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) | |
279 | n = sprintf(buf, "ReadWriteAllocate\n"); | |
280 | else if (ci_attr & CACHE_READ_ALLOCATE) | |
281 | n = sprintf(buf, "ReadAllocate\n"); | |
282 | else if (ci_attr & CACHE_WRITE_ALLOCATE) | |
283 | n = sprintf(buf, "WriteAllocate\n"); | |
284 | return n; | |
285 | } | |
286 | ||
287 | static ssize_t write_policy_show(struct device *dev, | |
288 | struct device_attribute *attr, char *buf) | |
289 | { | |
290 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
291 | unsigned int ci_attr = this_leaf->attributes; | |
292 | int n = 0; | |
293 | ||
294 | if (ci_attr & CACHE_WRITE_THROUGH) | |
295 | n = sprintf(buf, "WriteThrough\n"); | |
296 | else if (ci_attr & CACHE_WRITE_BACK) | |
297 | n = sprintf(buf, "WriteBack\n"); | |
298 | return n; | |
299 | } | |
300 | ||
301 | static DEVICE_ATTR_RO(level); | |
302 | static DEVICE_ATTR_RO(type); | |
303 | static DEVICE_ATTR_RO(coherency_line_size); | |
304 | static DEVICE_ATTR_RO(ways_of_associativity); | |
305 | static DEVICE_ATTR_RO(number_of_sets); | |
306 | static DEVICE_ATTR_RO(size); | |
307 | static DEVICE_ATTR_RO(allocation_policy); | |
308 | static DEVICE_ATTR_RO(write_policy); | |
309 | static DEVICE_ATTR_RO(shared_cpu_map); | |
310 | static DEVICE_ATTR_RO(shared_cpu_list); | |
311 | static DEVICE_ATTR_RO(physical_line_partition); | |
312 | ||
313 | static struct attribute *cache_default_attrs[] = { | |
314 | &dev_attr_type.attr, | |
315 | &dev_attr_level.attr, | |
316 | &dev_attr_shared_cpu_map.attr, | |
317 | &dev_attr_shared_cpu_list.attr, | |
318 | &dev_attr_coherency_line_size.attr, | |
319 | &dev_attr_ways_of_associativity.attr, | |
320 | &dev_attr_number_of_sets.attr, | |
321 | &dev_attr_size.attr, | |
322 | &dev_attr_allocation_policy.attr, | |
323 | &dev_attr_write_policy.attr, | |
324 | &dev_attr_physical_line_partition.attr, | |
325 | NULL | |
326 | }; | |
327 | ||
328 | static umode_t | |
329 | cache_default_attrs_is_visible(struct kobject *kobj, | |
330 | struct attribute *attr, int unused) | |
331 | { | |
332 | struct device *dev = kobj_to_dev(kobj); | |
333 | struct cacheinfo *this_leaf = dev_get_drvdata(dev); | |
334 | const struct cpumask *mask = &this_leaf->shared_cpu_map; | |
335 | umode_t mode = attr->mode; | |
336 | ||
337 | if ((attr == &dev_attr_type.attr) && this_leaf->type) | |
338 | return mode; | |
339 | if ((attr == &dev_attr_level.attr) && this_leaf->level) | |
340 | return mode; | |
341 | if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask)) | |
342 | return mode; | |
343 | if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask)) | |
344 | return mode; | |
345 | if ((attr == &dev_attr_coherency_line_size.attr) && | |
346 | this_leaf->coherency_line_size) | |
347 | return mode; | |
348 | if ((attr == &dev_attr_ways_of_associativity.attr) && | |
349 | this_leaf->size) /* allow 0 = full associativity */ | |
350 | return mode; | |
351 | if ((attr == &dev_attr_number_of_sets.attr) && | |
352 | this_leaf->number_of_sets) | |
353 | return mode; | |
354 | if ((attr == &dev_attr_size.attr) && this_leaf->size) | |
355 | return mode; | |
356 | if ((attr == &dev_attr_write_policy.attr) && | |
357 | (this_leaf->attributes & CACHE_WRITE_POLICY_MASK)) | |
358 | return mode; | |
359 | if ((attr == &dev_attr_allocation_policy.attr) && | |
360 | (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK)) | |
361 | return mode; | |
362 | if ((attr == &dev_attr_physical_line_partition.attr) && | |
363 | this_leaf->physical_line_partition) | |
364 | return mode; | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
369 | static const struct attribute_group cache_default_group = { | |
370 | .attrs = cache_default_attrs, | |
371 | .is_visible = cache_default_attrs_is_visible, | |
372 | }; | |
373 | ||
374 | static const struct attribute_group *cache_default_groups[] = { | |
375 | &cache_default_group, | |
376 | NULL, | |
377 | }; | |
378 | ||
379 | static const struct attribute_group *cache_private_groups[] = { | |
380 | &cache_default_group, | |
381 | NULL, /* Place holder for private group */ | |
382 | NULL, | |
383 | }; | |
384 | ||
385 | const struct attribute_group * | |
386 | __weak cache_get_priv_group(struct cacheinfo *this_leaf) | |
387 | { | |
388 | return NULL; | |
389 | } | |
390 | ||
391 | static const struct attribute_group ** | |
392 | cache_get_attribute_groups(struct cacheinfo *this_leaf) | |
393 | { | |
394 | const struct attribute_group *priv_group = | |
395 | cache_get_priv_group(this_leaf); | |
396 | ||
397 | if (!priv_group) | |
398 | return cache_default_groups; | |
399 | ||
400 | if (!cache_private_groups[1]) | |
401 | cache_private_groups[1] = priv_group; | |
402 | ||
403 | return cache_private_groups; | |
404 | } | |
405 | ||
406 | /* Add/Remove cache interface for CPU device */ | |
407 | static void cpu_cache_sysfs_exit(unsigned int cpu) | |
408 | { | |
409 | int i; | |
410 | struct device *ci_dev; | |
411 | ||
412 | if (per_cpu_index_dev(cpu)) { | |
413 | for (i = 0; i < cache_leaves(cpu); i++) { | |
414 | ci_dev = per_cache_index_dev(cpu, i); | |
415 | if (!ci_dev) | |
416 | continue; | |
417 | device_unregister(ci_dev); | |
418 | } | |
419 | kfree(per_cpu_index_dev(cpu)); | |
420 | per_cpu_index_dev(cpu) = NULL; | |
421 | } | |
422 | device_unregister(per_cpu_cache_dev(cpu)); | |
423 | per_cpu_cache_dev(cpu) = NULL; | |
424 | } | |
425 | ||
426 | static int cpu_cache_sysfs_init(unsigned int cpu) | |
427 | { | |
428 | struct device *dev = get_cpu_device(cpu); | |
429 | ||
430 | if (per_cpu_cacheinfo(cpu) == NULL) | |
431 | return -ENOENT; | |
432 | ||
433 | per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache"); | |
434 | if (IS_ERR(per_cpu_cache_dev(cpu))) | |
435 | return PTR_ERR(per_cpu_cache_dev(cpu)); | |
436 | ||
437 | /* Allocate all required memory */ | |
438 | per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu), | |
439 | sizeof(struct device *), GFP_KERNEL); | |
440 | if (unlikely(per_cpu_index_dev(cpu) == NULL)) | |
441 | goto err_out; | |
442 | ||
443 | return 0; | |
444 | ||
445 | err_out: | |
446 | cpu_cache_sysfs_exit(cpu); | |
447 | return -ENOMEM; | |
448 | } | |
449 | ||
450 | static int cache_add_dev(unsigned int cpu) | |
451 | { | |
452 | unsigned int i; | |
453 | int rc; | |
454 | struct device *ci_dev, *parent; | |
455 | struct cacheinfo *this_leaf; | |
456 | struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); | |
457 | const struct attribute_group **cache_groups; | |
458 | ||
459 | rc = cpu_cache_sysfs_init(cpu); | |
460 | if (unlikely(rc < 0)) | |
461 | return rc; | |
462 | ||
463 | parent = per_cpu_cache_dev(cpu); | |
464 | for (i = 0; i < cache_leaves(cpu); i++) { | |
465 | this_leaf = this_cpu_ci->info_list + i; | |
466 | if (this_leaf->disable_sysfs) | |
467 | continue; | |
468 | cache_groups = cache_get_attribute_groups(this_leaf); | |
469 | ci_dev = cpu_device_create(parent, this_leaf, cache_groups, | |
470 | "index%1u", i); | |
471 | if (IS_ERR(ci_dev)) { | |
472 | rc = PTR_ERR(ci_dev); | |
473 | goto err; | |
474 | } | |
475 | per_cache_index_dev(cpu, i) = ci_dev; | |
476 | } | |
477 | cpumask_set_cpu(cpu, &cache_dev_map); | |
478 | ||
479 | return 0; | |
480 | err: | |
481 | cpu_cache_sysfs_exit(cpu); | |
482 | return rc; | |
483 | } | |
484 | ||
485 | static void cache_remove_dev(unsigned int cpu) | |
486 | { | |
487 | if (!cpumask_test_cpu(cpu, &cache_dev_map)) | |
488 | return; | |
489 | cpumask_clear_cpu(cpu, &cache_dev_map); | |
490 | ||
491 | cpu_cache_sysfs_exit(cpu); | |
492 | } | |
493 | ||
494 | static int cacheinfo_cpu_callback(struct notifier_block *nfb, | |
495 | unsigned long action, void *hcpu) | |
496 | { | |
497 | unsigned int cpu = (unsigned long)hcpu; | |
498 | int rc = 0; | |
499 | ||
500 | switch (action & ~CPU_TASKS_FROZEN) { | |
501 | case CPU_ONLINE: | |
502 | rc = detect_cache_attributes(cpu); | |
503 | if (!rc) | |
504 | rc = cache_add_dev(cpu); | |
505 | break; | |
506 | case CPU_DEAD: | |
507 | cache_remove_dev(cpu); | |
508 | if (per_cpu_cacheinfo(cpu)) | |
509 | free_cache_attributes(cpu); | |
510 | break; | |
511 | } | |
512 | return notifier_from_errno(rc); | |
513 | } | |
514 | ||
515 | static int __init cacheinfo_sysfs_init(void) | |
516 | { | |
517 | int cpu, rc = 0; | |
518 | ||
519 | cpu_notifier_register_begin(); | |
520 | ||
521 | for_each_online_cpu(cpu) { | |
522 | rc = detect_cache_attributes(cpu); | |
6df43c9b | 523 | if (rc) |
246246cb | 524 | goto out; |
246246cb SH |
525 | rc = cache_add_dev(cpu); |
526 | if (rc) { | |
527 | free_cache_attributes(cpu); | |
528 | pr_err("error populating cacheinfo..cpu%d\n", cpu); | |
529 | goto out; | |
530 | } | |
531 | } | |
532 | __hotcpu_notifier(cacheinfo_cpu_callback, 0); | |
533 | ||
534 | out: | |
535 | cpu_notifier_register_done(); | |
536 | return rc; | |
537 | } | |
538 | ||
539 | device_initcall(cacheinfo_sysfs_init); |