blob: 64b24650e4f8c1d43f5cf151b46478f5a602e277 [file] [log] [blame] [edit]
/*
* Extract CPU cache information and expose them via sysfs.
*
* Copyright IBM Corp. 2012
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/notifier.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <asm/facility.h>
struct cache {
unsigned long size;
unsigned int line_size;
unsigned int associativity;
unsigned int nr_sets;
unsigned int level : 3;
unsigned int type : 2;
unsigned int private : 1;
struct list_head list;
};
struct cache_dir {
struct kobject *kobj;
struct cache_index_dir *index;
};
struct cache_index_dir {
struct kobject kobj;
int cpu;
struct cache *cache;
struct cache_index_dir *next;
};
enum {
CACHE_SCOPE_NOTEXISTS,
CACHE_SCOPE_PRIVATE,
CACHE_SCOPE_SHARED,
CACHE_SCOPE_RESERVED,
};
enum {
CACHE_TYPE_SEPARATE,
CACHE_TYPE_DATA,
CACHE_TYPE_INSTRUCTION,
CACHE_TYPE_UNIFIED,
};
enum {
EXTRACT_TOPOLOGY,
EXTRACT_LINE_SIZE,
EXTRACT_SIZE,
EXTRACT_ASSOCIATIVITY,
};
enum {
CACHE_TI_UNIFIED = 0,
CACHE_TI_DATA = 0,
CACHE_TI_INSTRUCTION,
};
struct cache_info {
unsigned char : 4;
unsigned char scope : 2;
unsigned char type : 2;
};
#define CACHE_MAX_LEVEL 8
union cache_topology {
struct cache_info ci[CACHE_MAX_LEVEL];
unsigned long long raw;
};
static const char * const cache_type_string[] = {
"Data",
"Instruction",
"Unified",
};
static struct cache_dir *cache_dir_cpu[NR_CPUS];
static LIST_HEAD(cache_list);
void show_cacheinfo(struct seq_file *m)
{
struct cache *cache;
int index = 0;
list_for_each_entry(cache, &cache_list, list) {
seq_printf(m, "cache%-11d: ", index);
seq_printf(m, "level=%d ", cache->level);
seq_printf(m, "type=%s ", cache_type_string[cache->type]);
seq_printf(m, "scope=%s ", cache->private ? "Private" : "Shared");
seq_printf(m, "size=%luK ", cache->size >> 10);
seq_printf(m, "line_size=%u ", cache->line_size);
seq_printf(m, "associativity=%d", cache->associativity);
seq_puts(m, "\n");
index++;
}
}
static inline unsigned long ecag(int ai, int li, int ti)
{
unsigned long cmd, val;
cmd = ai << 4 | li << 1 | ti;
asm volatile(".insn rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
: "=d" (val) : "a" (cmd));
return val;
}
static int __init cache_add(int level, int private, int type)
{
struct cache *cache;
int ti;
cache = kzalloc(sizeof(*cache), GFP_KERNEL);
if (!cache)
return -ENOMEM;
if (type == CACHE_TYPE_INSTRUCTION)
ti = CACHE_TI_INSTRUCTION;
else
ti = CACHE_TI_UNIFIED;
cache->size = ecag(EXTRACT_SIZE, level, ti);
cache->line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
cache->associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
cache->nr_sets = cache->size / cache->associativity;
cache->nr_sets /= cache->line_size;
cache->private = private;
cache->level = level + 1;
cache->type = type - 1;
list_add_tail(&cache->list, &cache_list);
return 0;
}
static void __init cache_build_info(void)
{
struct cache *cache, *next;
union cache_topology ct;
int level, private, rc;
ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
for (level = 0; level < CACHE_MAX_LEVEL; level++) {
switch (ct.ci[level].scope) {
case CACHE_SCOPE_NOTEXISTS:
case CACHE_SCOPE_RESERVED:
return;
case CACHE_SCOPE_SHARED:
private = 0;
break;
case CACHE_SCOPE_PRIVATE:
private = 1;
break;
}
if (ct.ci[level].type == CACHE_TYPE_SEPARATE) {
rc = cache_add(level, private, CACHE_TYPE_DATA);
rc |= cache_add(level, private, CACHE_TYPE_INSTRUCTION);
} else {
rc = cache_add(level, private, ct.ci[level].type);
}
if (rc)
goto error;
}
return;
error:
list_for_each_entry_safe(cache, next, &cache_list, list) {
list_del(&cache->list);
kfree(cache);
}
}
static struct cache_dir *__cpuinit cache_create_cache_dir(int cpu)
{
struct cache_dir *cache_dir;
struct kobject *kobj = NULL;
struct device *dev;
dev = get_cpu_device(cpu);
if (!dev)
goto out;
kobj = kobject_create_and_add("cache", &dev->kobj);
if (!kobj)
goto out;
cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
if (!cache_dir)
goto out;
cache_dir->kobj = kobj;
cache_dir_cpu[cpu] = cache_dir;
return cache_dir;
out:
kobject_put(kobj);
return NULL;
}
static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *kobj)
{
return container_of(kobj, struct cache_index_dir, kobj);
}
static void cache_index_release(struct kobject *kobj)
{
struct cache_index_dir *index;
index = kobj_to_cache_index_dir(kobj);
kfree(index);
}
static ssize_t cache_index_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct kobj_attribute *kobj_attr;
kobj_attr = container_of(attr, struct kobj_attribute, attr);
return kobj_attr->show(kobj, kobj_attr, buf);
}
#define DEFINE_CACHE_ATTR(_name, _format, _value) \
static ssize_t cache_##_name##_show(struct kobject *kobj, \
struct kobj_attribute *attr, \
char *buf) \
{ \
struct cache_index_dir *index; \
\
index = kobj_to_cache_index_dir(kobj); \
return sprintf(buf, _format, _value); \
} \
static struct kobj_attribute cache_##_name##_attr = \
__ATTR(_name, 0444, cache_##_name##_show, NULL);
DEFINE_CACHE_ATTR(size, "%luK\n", index->cache->size >> 10);
DEFINE_CACHE_ATTR(coherency_line_size, "%u\n", index->cache->line_size);
DEFINE_CACHE_ATTR(number_of_sets, "%u\n", index->cache->nr_sets);
DEFINE_CACHE_ATTR(ways_of_associativity, "%u\n", index->cache->associativity);
DEFINE_CACHE_ATTR(type, "%s\n", cache_type_string[index->cache->type]);
DEFINE_CACHE_ATTR(level, "%d\n", index->cache->level);
static ssize_t shared_cpu_map_func(struct kobject *kobj, int type, char *buf)
{
struct cache_index_dir *index;
int len;
index = kobj_to_cache_index_dir(kobj);
len = type ?
cpulist_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu)) :
cpumask_scnprintf(buf, PAGE_SIZE - 2, cpumask_of(index->cpu));
len += sprintf(&buf[len], "\n");
return len;
}
static ssize_t shared_cpu_map_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return shared_cpu_map_func(kobj, 0, buf);
}
static struct kobj_attribute cache_shared_cpu_map_attr =
__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
static ssize_t shared_cpu_list_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return shared_cpu_map_func(kobj, 1, buf);
}
static struct kobj_attribute cache_shared_cpu_list_attr =
__ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
static struct attribute *cache_index_default_attrs[] = {
&cache_type_attr.attr,
&cache_size_attr.attr,
&cache_number_of_sets_attr.attr,
&cache_ways_of_associativity_attr.attr,
&cache_level_attr.attr,
&cache_coherency_line_size_attr.attr,
&cache_shared_cpu_map_attr.attr,
&cache_shared_cpu_list_attr.attr,
NULL,
};
static const struct sysfs_ops cache_index_ops = {
.show = cache_index_show,
};
static struct kobj_type cache_index_type = {
.sysfs_ops = &cache_index_ops,
.release = cache_index_release,
.default_attrs = cache_index_default_attrs,
};
static int __cpuinit cache_create_index_dir(struct cache_dir *cache_dir,
struct cache *cache, int index,
int cpu)
{
struct cache_index_dir *index_dir;
int rc;
index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
if (!index_dir)
return -ENOMEM;
index_dir->cache = cache;
index_dir->cpu = cpu;
rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
cache_dir->kobj, "index%d", index);
if (rc)
goto out;
index_dir->next = cache_dir->index;
cache_dir->index = index_dir;
return 0;
out:
kfree(index_dir);
return rc;
}
static int __cpuinit cache_add_cpu(int cpu)
{
struct cache_dir *cache_dir;
struct cache *cache;
int rc, index = 0;
if (list_empty(&cache_list))
return 0;
cache_dir = cache_create_cache_dir(cpu);
if (!cache_dir)
return -ENOMEM;
list_for_each_entry(cache, &cache_list, list) {
if (!cache->private)
break;
rc = cache_create_index_dir(cache_dir, cache, index, cpu);
if (rc)
return rc;
index++;
}
return 0;
}
static void __cpuinit cache_remove_cpu(int cpu)
{
struct cache_index_dir *index, *next;
struct cache_dir *cache_dir;
cache_dir = cache_dir_cpu[cpu];
if (!cache_dir)
return;
index = cache_dir->index;
while (index) {
next = index->next;
kobject_put(&index->kobj);
index = next;
}
kobject_put(cache_dir->kobj);
kfree(cache_dir);
cache_dir_cpu[cpu] = NULL;
}
static int __cpuinit cache_hotplug(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
int cpu = (long)hcpu;
int rc = 0;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
rc = cache_add_cpu(cpu);
if (rc)
cache_remove_cpu(cpu);
break;
case CPU_DEAD:
cache_remove_cpu(cpu);
break;
}
return rc ? NOTIFY_BAD : NOTIFY_OK;
}
static int __init cache_init(void)
{
int cpu;
if (!test_facility(34))
return 0;
cache_build_info();
for_each_online_cpu(cpu)
cache_add_cpu(cpu);
hotcpu_notifier(cache_hotplug, 0);
return 0;
}
device_initcall(cache_init);