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
);