| /* |
| * 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 *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 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 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 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 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); |