2 * cacheinfo support - processor cache information via sysfs
4 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
5 * Author: Sudeep Holla <sudeep.holla@arm.com>
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.
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.
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/>.
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/acpi.h>
22 #include <linux/bitops.h>
23 #include <linux/cacheinfo.h>
24 #include <linux/compiler.h>
25 #include <linux/cpu.h>
26 #include <linux/device.h>
27 #include <linux/init.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/smp.h>
32 #include <linux/sysfs.h>
34 /* pointer to per cpu cacheinfo */
35 static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
36 #define ci_cacheinfo(cpu) (&per_cpu(ci_cpu_cacheinfo, cpu))
37 #define cache_leaves(cpu) (ci_cacheinfo(cpu)->num_leaves)
38 #define per_cpu_cacheinfo(cpu) (ci_cacheinfo(cpu)->info_list)
40 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
42 return ci_cacheinfo(cpu);
46 static int cache_setup_of_node(unsigned int cpu)
48 struct device_node *np;
49 struct cacheinfo *this_leaf;
50 struct device *cpu_dev = get_cpu_device(cpu);
51 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
52 unsigned int index = 0;
54 /* skip if of_node is already populated */
55 if (this_cpu_ci->info_list->of_node)
59 pr_err("No cpu device for CPU %d\n", cpu);
62 np = cpu_dev->of_node;
64 pr_err("Failed to find cpu%d device node\n", cpu);
68 while (index < cache_leaves(cpu)) {
69 this_leaf = this_cpu_ci->info_list + index;
70 if (this_leaf->level != 1)
71 np = of_find_next_cache_node(np);
73 np = of_node_get(np);/* cpu node itself */
76 this_leaf->of_node = np;
80 if (index != cache_leaves(cpu)) /* not all OF nodes populated */
86 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
87 struct cacheinfo *sib_leaf)
89 return sib_leaf->of_node == this_leaf->of_node;
92 /* OF properties to query for a given cache type */
93 struct cache_type_info {
94 const char *size_prop;
95 const char *line_size_props[2];
96 const char *nr_sets_prop;
99 static const struct cache_type_info cache_type_info[] = {
101 .size_prop = "cache-size",
102 .line_size_props = { "cache-line-size",
103 "cache-block-size", },
104 .nr_sets_prop = "cache-sets",
106 .size_prop = "i-cache-size",
107 .line_size_props = { "i-cache-line-size",
108 "i-cache-block-size", },
109 .nr_sets_prop = "i-cache-sets",
111 .size_prop = "d-cache-size",
112 .line_size_props = { "d-cache-line-size",
113 "d-cache-block-size", },
114 .nr_sets_prop = "d-cache-sets",
118 static inline int get_cacheinfo_idx(enum cache_type type)
120 if (type == CACHE_TYPE_UNIFIED)
125 static void cache_size(struct cacheinfo *this_leaf)
127 const char *propname;
128 const __be32 *cache_size;
131 ct_idx = get_cacheinfo_idx(this_leaf->type);
132 propname = cache_type_info[ct_idx].size_prop;
134 cache_size = of_get_property(this_leaf->of_node, propname, NULL);
136 this_leaf->size = of_read_number(cache_size, 1);
139 /* not cache_line_size() because that's a macro in include/linux/cache.h */
140 static void cache_get_line_size(struct cacheinfo *this_leaf)
142 const __be32 *line_size;
145 ct_idx = get_cacheinfo_idx(this_leaf->type);
146 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
148 for (i = 0; i < lim; i++) {
149 const char *propname;
151 propname = cache_type_info[ct_idx].line_size_props[i];
152 line_size = of_get_property(this_leaf->of_node, propname, NULL);
158 this_leaf->coherency_line_size = of_read_number(line_size, 1);
161 static void cache_nr_sets(struct cacheinfo *this_leaf)
163 const char *propname;
164 const __be32 *nr_sets;
167 ct_idx = get_cacheinfo_idx(this_leaf->type);
168 propname = cache_type_info[ct_idx].nr_sets_prop;
170 nr_sets = of_get_property(this_leaf->of_node, propname, NULL);
172 this_leaf->number_of_sets = of_read_number(nr_sets, 1);
175 static void cache_associativity(struct cacheinfo *this_leaf)
177 unsigned int line_size = this_leaf->coherency_line_size;
178 unsigned int nr_sets = this_leaf->number_of_sets;
179 unsigned int size = this_leaf->size;
182 * If the cache is fully associative, there is no need to
183 * check the other properties.
185 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
186 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
189 static void cache_of_override_properties(unsigned int cpu)
192 struct cacheinfo *this_leaf;
193 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
195 for (index = 0; index < cache_leaves(cpu); index++) {
196 this_leaf = this_cpu_ci->info_list + index;
197 cache_size(this_leaf);
198 cache_get_line_size(this_leaf);
199 cache_nr_sets(this_leaf);
200 cache_associativity(this_leaf);
204 static void cache_of_override_properties(unsigned int cpu) { }
205 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
206 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
207 struct cacheinfo *sib_leaf)
210 * For non-DT systems, assume unique level 1 cache, system-wide
211 * shared caches for all other levels. This will be used only if
212 * arch specific code has not populated shared_cpu_map
214 return !(this_leaf->level == 1);
218 static int cache_shared_cpu_map_setup(unsigned int cpu)
220 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
221 struct cacheinfo *this_leaf, *sib_leaf;
225 if (this_cpu_ci->cpu_map_populated)
228 if (of_have_populated_dt())
229 ret = cache_setup_of_node(cpu);
230 else if (!acpi_disabled)
231 /* No cache property/hierarchy support yet in ACPI */
236 for (index = 0; index < cache_leaves(cpu); index++) {
239 this_leaf = this_cpu_ci->info_list + index;
240 /* skip if shared_cpu_map is already populated */
241 if (!cpumask_empty(&this_leaf->shared_cpu_map))
244 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
245 for_each_online_cpu(i) {
246 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
248 if (i == cpu || !sib_cpu_ci->info_list)
249 continue;/* skip if itself or no cacheinfo */
250 sib_leaf = sib_cpu_ci->info_list + index;
251 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
252 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
253 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
261 static void cache_shared_cpu_map_remove(unsigned int cpu)
263 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
264 struct cacheinfo *this_leaf, *sib_leaf;
265 unsigned int sibling, index;
267 for (index = 0; index < cache_leaves(cpu); index++) {
268 this_leaf = this_cpu_ci->info_list + index;
269 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
270 struct cpu_cacheinfo *sib_cpu_ci;
272 if (sibling == cpu) /* skip itself */
275 sib_cpu_ci = get_cpu_cacheinfo(sibling);
276 if (!sib_cpu_ci->info_list)
279 sib_leaf = sib_cpu_ci->info_list + index;
280 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
281 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
283 of_node_put(this_leaf->of_node);
287 static void cache_override_properties(unsigned int cpu)
289 if (of_have_populated_dt())
290 return cache_of_override_properties(cpu);
293 static void free_cache_attributes(unsigned int cpu)
295 if (!per_cpu_cacheinfo(cpu))
298 cache_shared_cpu_map_remove(cpu);
300 kfree(per_cpu_cacheinfo(cpu));
301 per_cpu_cacheinfo(cpu) = NULL;
304 int __weak init_cache_level(unsigned int cpu)
309 int __weak populate_cache_leaves(unsigned int cpu)
314 static int detect_cache_attributes(unsigned int cpu)
318 if (init_cache_level(cpu) || !cache_leaves(cpu))
321 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
322 sizeof(struct cacheinfo), GFP_KERNEL);
323 if (per_cpu_cacheinfo(cpu) == NULL)
326 ret = populate_cache_leaves(cpu);
330 * For systems using DT for cache hierarchy, of_node and shared_cpu_map
331 * will be set up here only if they are not populated already
333 ret = cache_shared_cpu_map_setup(cpu);
335 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
339 cache_override_properties(cpu);
343 free_cache_attributes(cpu);
347 /* pointer to cpuX/cache device */
348 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
349 #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu))
351 static cpumask_t cache_dev_map;
353 /* pointer to array of devices for cpuX/cache/indexY */
354 static DEFINE_PER_CPU(struct device **, ci_index_dev);
355 #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu))
356 #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx])
358 #define show_one(file_name, object) \
359 static ssize_t file_name##_show(struct device *dev, \
360 struct device_attribute *attr, char *buf) \
362 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \
363 return sprintf(buf, "%u\n", this_leaf->object); \
366 show_one(level, level);
367 show_one(coherency_line_size, coherency_line_size);
368 show_one(number_of_sets, number_of_sets);
369 show_one(physical_line_partition, physical_line_partition);
370 show_one(ways_of_associativity, ways_of_associativity);
372 static ssize_t size_show(struct device *dev,
373 struct device_attribute *attr, char *buf)
375 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
377 return sprintf(buf, "%uK\n", this_leaf->size >> 10);
380 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
382 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
383 const struct cpumask *mask = &this_leaf->shared_cpu_map;
385 return cpumap_print_to_pagebuf(list, buf, mask);
388 static ssize_t shared_cpu_map_show(struct device *dev,
389 struct device_attribute *attr, char *buf)
391 return shared_cpumap_show_func(dev, false, buf);
394 static ssize_t shared_cpu_list_show(struct device *dev,
395 struct device_attribute *attr, char *buf)
397 return shared_cpumap_show_func(dev, true, buf);
400 static ssize_t type_show(struct device *dev,
401 struct device_attribute *attr, char *buf)
403 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
405 switch (this_leaf->type) {
406 case CACHE_TYPE_DATA:
407 return sprintf(buf, "Data\n");
408 case CACHE_TYPE_INST:
409 return sprintf(buf, "Instruction\n");
410 case CACHE_TYPE_UNIFIED:
411 return sprintf(buf, "Unified\n");
417 static ssize_t allocation_policy_show(struct device *dev,
418 struct device_attribute *attr, char *buf)
420 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
421 unsigned int ci_attr = this_leaf->attributes;
424 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
425 n = sprintf(buf, "ReadWriteAllocate\n");
426 else if (ci_attr & CACHE_READ_ALLOCATE)
427 n = sprintf(buf, "ReadAllocate\n");
428 else if (ci_attr & CACHE_WRITE_ALLOCATE)
429 n = sprintf(buf, "WriteAllocate\n");
433 static ssize_t write_policy_show(struct device *dev,
434 struct device_attribute *attr, char *buf)
436 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
437 unsigned int ci_attr = this_leaf->attributes;
440 if (ci_attr & CACHE_WRITE_THROUGH)
441 n = sprintf(buf, "WriteThrough\n");
442 else if (ci_attr & CACHE_WRITE_BACK)
443 n = sprintf(buf, "WriteBack\n");
447 static DEVICE_ATTR_RO(level);
448 static DEVICE_ATTR_RO(type);
449 static DEVICE_ATTR_RO(coherency_line_size);
450 static DEVICE_ATTR_RO(ways_of_associativity);
451 static DEVICE_ATTR_RO(number_of_sets);
452 static DEVICE_ATTR_RO(size);
453 static DEVICE_ATTR_RO(allocation_policy);
454 static DEVICE_ATTR_RO(write_policy);
455 static DEVICE_ATTR_RO(shared_cpu_map);
456 static DEVICE_ATTR_RO(shared_cpu_list);
457 static DEVICE_ATTR_RO(physical_line_partition);
459 static struct attribute *cache_default_attrs[] = {
461 &dev_attr_level.attr,
462 &dev_attr_shared_cpu_map.attr,
463 &dev_attr_shared_cpu_list.attr,
464 &dev_attr_coherency_line_size.attr,
465 &dev_attr_ways_of_associativity.attr,
466 &dev_attr_number_of_sets.attr,
468 &dev_attr_allocation_policy.attr,
469 &dev_attr_write_policy.attr,
470 &dev_attr_physical_line_partition.attr,
475 cache_default_attrs_is_visible(struct kobject *kobj,
476 struct attribute *attr, int unused)
478 struct device *dev = kobj_to_dev(kobj);
479 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
480 const struct cpumask *mask = &this_leaf->shared_cpu_map;
481 umode_t mode = attr->mode;
483 if ((attr == &dev_attr_type.attr) && this_leaf->type)
485 if ((attr == &dev_attr_level.attr) && this_leaf->level)
487 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
489 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
491 if ((attr == &dev_attr_coherency_line_size.attr) &&
492 this_leaf->coherency_line_size)
494 if ((attr == &dev_attr_ways_of_associativity.attr) &&
495 this_leaf->size) /* allow 0 = full associativity */
497 if ((attr == &dev_attr_number_of_sets.attr) &&
498 this_leaf->number_of_sets)
500 if ((attr == &dev_attr_size.attr) && this_leaf->size)
502 if ((attr == &dev_attr_write_policy.attr) &&
503 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
505 if ((attr == &dev_attr_allocation_policy.attr) &&
506 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
508 if ((attr == &dev_attr_physical_line_partition.attr) &&
509 this_leaf->physical_line_partition)
515 static const struct attribute_group cache_default_group = {
516 .attrs = cache_default_attrs,
517 .is_visible = cache_default_attrs_is_visible,
520 static const struct attribute_group *cache_default_groups[] = {
521 &cache_default_group,
525 static const struct attribute_group *cache_private_groups[] = {
526 &cache_default_group,
527 NULL, /* Place holder for private group */
531 const struct attribute_group *
532 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
537 static const struct attribute_group **
538 cache_get_attribute_groups(struct cacheinfo *this_leaf)
540 const struct attribute_group *priv_group =
541 cache_get_priv_group(this_leaf);
544 return cache_default_groups;
546 if (!cache_private_groups[1])
547 cache_private_groups[1] = priv_group;
549 return cache_private_groups;
552 /* Add/Remove cache interface for CPU device */
553 static void cpu_cache_sysfs_exit(unsigned int cpu)
556 struct device *ci_dev;
558 if (per_cpu_index_dev(cpu)) {
559 for (i = 0; i < cache_leaves(cpu); i++) {
560 ci_dev = per_cache_index_dev(cpu, i);
563 device_unregister(ci_dev);
565 kfree(per_cpu_index_dev(cpu));
566 per_cpu_index_dev(cpu) = NULL;
568 device_unregister(per_cpu_cache_dev(cpu));
569 per_cpu_cache_dev(cpu) = NULL;
572 static int cpu_cache_sysfs_init(unsigned int cpu)
574 struct device *dev = get_cpu_device(cpu);
576 if (per_cpu_cacheinfo(cpu) == NULL)
579 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
580 if (IS_ERR(per_cpu_cache_dev(cpu)))
581 return PTR_ERR(per_cpu_cache_dev(cpu));
583 /* Allocate all required memory */
584 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
585 sizeof(struct device *), GFP_KERNEL);
586 if (unlikely(per_cpu_index_dev(cpu) == NULL))
592 cpu_cache_sysfs_exit(cpu);
596 static int cache_add_dev(unsigned int cpu)
600 struct device *ci_dev, *parent;
601 struct cacheinfo *this_leaf;
602 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
603 const struct attribute_group **cache_groups;
605 rc = cpu_cache_sysfs_init(cpu);
606 if (unlikely(rc < 0))
609 parent = per_cpu_cache_dev(cpu);
610 for (i = 0; i < cache_leaves(cpu); i++) {
611 this_leaf = this_cpu_ci->info_list + i;
612 if (this_leaf->disable_sysfs)
614 cache_groups = cache_get_attribute_groups(this_leaf);
615 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
617 if (IS_ERR(ci_dev)) {
618 rc = PTR_ERR(ci_dev);
621 per_cache_index_dev(cpu, i) = ci_dev;
623 cpumask_set_cpu(cpu, &cache_dev_map);
627 cpu_cache_sysfs_exit(cpu);
631 static int cacheinfo_cpu_online(unsigned int cpu)
633 int rc = detect_cache_attributes(cpu);
637 rc = cache_add_dev(cpu);
639 free_cache_attributes(cpu);
643 static int cacheinfo_cpu_pre_down(unsigned int cpu)
645 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
646 cpu_cache_sysfs_exit(cpu);
648 free_cache_attributes(cpu);
652 static int __init cacheinfo_sysfs_init(void)
654 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
655 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
657 device_initcall(cacheinfo_sysfs_init);