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 #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>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28 #include <linux/smp.h>
29 #include <linux/sysfs.h>
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)
37 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
39 return ci_cacheinfo(cpu);
43 static int cache_setup_of_node(unsigned int cpu)
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;
51 /* skip if of_node is already populated */
52 if (this_cpu_ci->info_list->of_node)
56 pr_err("No cpu device for CPU %d\n", cpu);
59 np = cpu_dev->of_node;
61 pr_err("Failed to find cpu%d device node\n", cpu);
65 while (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);
70 np = of_node_get(np);/* cpu node itself */
73 this_leaf->of_node = np;
77 if (index != cache_leaves(cpu)) /* not all OF nodes populated */
83 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
84 struct cacheinfo *sib_leaf)
86 return sib_leaf->of_node == this_leaf->of_node;
89 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
90 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
91 struct cacheinfo *sib_leaf)
94 * For non-DT systems, assume unique level 1 cache, system-wide
95 * shared caches for all other levels. This will be used only if
96 * arch specific code has not populated shared_cpu_map
98 return !(this_leaf->level == 1);
102 static int cache_shared_cpu_map_setup(unsigned int cpu)
104 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
105 struct cacheinfo *this_leaf, *sib_leaf;
109 ret = cache_setup_of_node(cpu);
113 for (index = 0; index < cache_leaves(cpu); index++) {
116 this_leaf = this_cpu_ci->info_list + index;
117 /* skip if shared_cpu_map is already populated */
118 if (!cpumask_empty(&this_leaf->shared_cpu_map))
121 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
122 for_each_online_cpu(i) {
123 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
125 if (i == cpu || !sib_cpu_ci->info_list)
126 continue;/* skip if itself or no cacheinfo */
127 sib_leaf = sib_cpu_ci->info_list + index;
128 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
129 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
130 cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
138 static void cache_shared_cpu_map_remove(unsigned int cpu)
140 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
141 struct cacheinfo *this_leaf, *sib_leaf;
142 unsigned int sibling, index;
144 for (index = 0; index < cache_leaves(cpu); index++) {
145 this_leaf = this_cpu_ci->info_list + index;
146 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
147 struct cpu_cacheinfo *sib_cpu_ci;
149 if (sibling == cpu) /* skip itself */
152 sib_cpu_ci = get_cpu_cacheinfo(sibling);
153 if (!sib_cpu_ci->info_list)
156 sib_leaf = sib_cpu_ci->info_list + index;
157 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
158 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
160 of_node_put(this_leaf->of_node);
164 static void free_cache_attributes(unsigned int cpu)
166 if (!per_cpu_cacheinfo(cpu))
169 cache_shared_cpu_map_remove(cpu);
171 kfree(per_cpu_cacheinfo(cpu));
172 per_cpu_cacheinfo(cpu) = NULL;
175 int __weak init_cache_level(unsigned int cpu)
180 int __weak populate_cache_leaves(unsigned int cpu)
185 static int detect_cache_attributes(unsigned int cpu)
189 if (init_cache_level(cpu) || !cache_leaves(cpu))
192 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
193 sizeof(struct cacheinfo), GFP_KERNEL);
194 if (per_cpu_cacheinfo(cpu) == NULL)
197 ret = populate_cache_leaves(cpu);
201 * For systems using DT for cache hierarchy, of_node and shared_cpu_map
202 * will be set up here only if they are not populated already
204 ret = cache_shared_cpu_map_setup(cpu);
206 pr_warn("Unable to detect cache hierarchy from DT for CPU %d\n",
213 free_cache_attributes(cpu);
217 /* pointer to cpuX/cache device */
218 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
219 #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu))
221 static cpumask_t cache_dev_map;
223 /* pointer to array of devices for cpuX/cache/indexY */
224 static DEFINE_PER_CPU(struct device **, ci_index_dev);
225 #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu))
226 #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx])
228 #define show_one(file_name, object) \
229 static ssize_t file_name##_show(struct device *dev, \
230 struct device_attribute *attr, char *buf) \
232 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \
233 return sprintf(buf, "%u\n", this_leaf->object); \
237 show_one(level, level);
238 show_one(coherency_line_size, coherency_line_size);
239 show_one(number_of_sets, number_of_sets);
240 show_one(physical_line_partition, physical_line_partition);
241 show_one(ways_of_associativity, ways_of_associativity);
243 static ssize_t size_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
246 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
248 return sprintf(buf, "%uK\n", this_leaf->size >> 10);
251 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
253 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
254 const struct cpumask *mask = &this_leaf->shared_cpu_map;
256 return cpumap_print_to_pagebuf(list, buf, mask);
259 static ssize_t shared_cpu_map_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
262 return shared_cpumap_show_func(dev, false, buf);
265 static ssize_t shared_cpu_list_show(struct device *dev,
266 struct device_attribute *attr, char *buf)
268 return shared_cpumap_show_func(dev, true, buf);
271 static ssize_t type_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
276 switch (this_leaf->type) {
277 case CACHE_TYPE_DATA:
278 return sprintf(buf, "Data\n");
279 case CACHE_TYPE_INST:
280 return sprintf(buf, "Instruction\n");
281 case CACHE_TYPE_UNIFIED:
282 return sprintf(buf, "Unified\n");
288 static ssize_t allocation_policy_show(struct device *dev,
289 struct device_attribute *attr, char *buf)
291 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
292 unsigned int ci_attr = this_leaf->attributes;
295 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
296 n = sprintf(buf, "ReadWriteAllocate\n");
297 else if (ci_attr & CACHE_READ_ALLOCATE)
298 n = sprintf(buf, "ReadAllocate\n");
299 else if (ci_attr & CACHE_WRITE_ALLOCATE)
300 n = sprintf(buf, "WriteAllocate\n");
304 static ssize_t write_policy_show(struct device *dev,
305 struct device_attribute *attr, char *buf)
307 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
308 unsigned int ci_attr = this_leaf->attributes;
311 if (ci_attr & CACHE_WRITE_THROUGH)
312 n = sprintf(buf, "WriteThrough\n");
313 else if (ci_attr & CACHE_WRITE_BACK)
314 n = sprintf(buf, "WriteBack\n");
318 static DEVICE_ATTR_RO(id);
319 static DEVICE_ATTR_RO(level);
320 static DEVICE_ATTR_RO(type);
321 static DEVICE_ATTR_RO(coherency_line_size);
322 static DEVICE_ATTR_RO(ways_of_associativity);
323 static DEVICE_ATTR_RO(number_of_sets);
324 static DEVICE_ATTR_RO(size);
325 static DEVICE_ATTR_RO(allocation_policy);
326 static DEVICE_ATTR_RO(write_policy);
327 static DEVICE_ATTR_RO(shared_cpu_map);
328 static DEVICE_ATTR_RO(shared_cpu_list);
329 static DEVICE_ATTR_RO(physical_line_partition);
331 static struct attribute *cache_default_attrs[] = {
334 &dev_attr_level.attr,
335 &dev_attr_shared_cpu_map.attr,
336 &dev_attr_shared_cpu_list.attr,
337 &dev_attr_coherency_line_size.attr,
338 &dev_attr_ways_of_associativity.attr,
339 &dev_attr_number_of_sets.attr,
341 &dev_attr_allocation_policy.attr,
342 &dev_attr_write_policy.attr,
343 &dev_attr_physical_line_partition.attr,
348 cache_default_attrs_is_visible(struct kobject *kobj,
349 struct attribute *attr, int unused)
351 struct device *dev = kobj_to_dev(kobj);
352 struct cacheinfo *this_leaf = dev_get_drvdata(dev);
353 const struct cpumask *mask = &this_leaf->shared_cpu_map;
354 umode_t mode = attr->mode;
356 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
358 if ((attr == &dev_attr_type.attr) && this_leaf->type)
360 if ((attr == &dev_attr_level.attr) && this_leaf->level)
362 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
364 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
366 if ((attr == &dev_attr_coherency_line_size.attr) &&
367 this_leaf->coherency_line_size)
369 if ((attr == &dev_attr_ways_of_associativity.attr) &&
370 this_leaf->size) /* allow 0 = full associativity */
372 if ((attr == &dev_attr_number_of_sets.attr) &&
373 this_leaf->number_of_sets)
375 if ((attr == &dev_attr_size.attr) && this_leaf->size)
377 if ((attr == &dev_attr_write_policy.attr) &&
378 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
380 if ((attr == &dev_attr_allocation_policy.attr) &&
381 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
383 if ((attr == &dev_attr_physical_line_partition.attr) &&
384 this_leaf->physical_line_partition)
390 static const struct attribute_group cache_default_group = {
391 .attrs = cache_default_attrs,
392 .is_visible = cache_default_attrs_is_visible,
395 static const struct attribute_group *cache_default_groups[] = {
396 &cache_default_group,
400 static const struct attribute_group *cache_private_groups[] = {
401 &cache_default_group,
402 NULL, /* Place holder for private group */
406 const struct attribute_group *
407 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
412 static const struct attribute_group **
413 cache_get_attribute_groups(struct cacheinfo *this_leaf)
415 const struct attribute_group *priv_group =
416 cache_get_priv_group(this_leaf);
419 return cache_default_groups;
421 if (!cache_private_groups[1])
422 cache_private_groups[1] = priv_group;
424 return cache_private_groups;
427 /* Add/Remove cache interface for CPU device */
428 static void cpu_cache_sysfs_exit(unsigned int cpu)
431 struct device *ci_dev;
433 if (per_cpu_index_dev(cpu)) {
434 for (i = 0; i < cache_leaves(cpu); i++) {
435 ci_dev = per_cache_index_dev(cpu, i);
438 device_unregister(ci_dev);
440 kfree(per_cpu_index_dev(cpu));
441 per_cpu_index_dev(cpu) = NULL;
443 device_unregister(per_cpu_cache_dev(cpu));
444 per_cpu_cache_dev(cpu) = NULL;
447 static int cpu_cache_sysfs_init(unsigned int cpu)
449 struct device *dev = get_cpu_device(cpu);
451 if (per_cpu_cacheinfo(cpu) == NULL)
454 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
455 if (IS_ERR(per_cpu_cache_dev(cpu)))
456 return PTR_ERR(per_cpu_cache_dev(cpu));
458 /* Allocate all required memory */
459 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
460 sizeof(struct device *), GFP_KERNEL);
461 if (unlikely(per_cpu_index_dev(cpu) == NULL))
467 cpu_cache_sysfs_exit(cpu);
471 static int cache_add_dev(unsigned int cpu)
475 struct device *ci_dev, *parent;
476 struct cacheinfo *this_leaf;
477 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
478 const struct attribute_group **cache_groups;
480 rc = cpu_cache_sysfs_init(cpu);
481 if (unlikely(rc < 0))
484 parent = per_cpu_cache_dev(cpu);
485 for (i = 0; i < cache_leaves(cpu); i++) {
486 this_leaf = this_cpu_ci->info_list + i;
487 if (this_leaf->disable_sysfs)
489 cache_groups = cache_get_attribute_groups(this_leaf);
490 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
492 if (IS_ERR(ci_dev)) {
493 rc = PTR_ERR(ci_dev);
496 per_cache_index_dev(cpu, i) = ci_dev;
498 cpumask_set_cpu(cpu, &cache_dev_map);
502 cpu_cache_sysfs_exit(cpu);
506 static void cache_remove_dev(unsigned int cpu)
508 if (!cpumask_test_cpu(cpu, &cache_dev_map))
510 cpumask_clear_cpu(cpu, &cache_dev_map);
512 cpu_cache_sysfs_exit(cpu);
515 static int cacheinfo_cpu_callback(struct notifier_block *nfb,
516 unsigned long action, void *hcpu)
518 unsigned int cpu = (unsigned long)hcpu;
521 switch (action & ~CPU_TASKS_FROZEN) {
523 rc = detect_cache_attributes(cpu);
525 rc = cache_add_dev(cpu);
528 cache_remove_dev(cpu);
529 free_cache_attributes(cpu);
532 return notifier_from_errno(rc);
535 static int __init cacheinfo_sysfs_init(void)
539 cpu_notifier_register_begin();
541 for_each_online_cpu(cpu) {
542 rc = detect_cache_attributes(cpu);
545 rc = cache_add_dev(cpu);
547 free_cache_attributes(cpu);
548 pr_err("error populating cacheinfo..cpu%d\n", cpu);
552 __hotcpu_notifier(cacheinfo_cpu_callback, 0);
555 cpu_notifier_register_done();
559 device_initcall(cacheinfo_sysfs_init);