--- /dev/null
+/*
+ * 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/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;
+ int level;
+ int type;
+ 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_INSTRUCTION = 0,
+ CACHE_TI_DATA,
+};
+
+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);
+
+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 type)
+{
+ struct cache *cache;
+ int ti;
+
+ cache = kzalloc(sizeof(*cache), GFP_KERNEL);
+ if (!cache)
+ return -ENOMEM;
+ ti = type == CACHE_TYPE_DATA ? CACHE_TI_DATA : 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->level = level + 1;
+ cache->type = type;
+ 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, 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:
+ case CACHE_SCOPE_SHARED:
+ return;
+ case CACHE_SCOPE_PRIVATE:
+ break;
+ }
+ if (ct.ci[level].type == CACHE_TYPE_SEPARATE) {
+ rc = cache_add(level, CACHE_TYPE_DATA);
+ rc |= cache_add(level, CACHE_TYPE_INSTRUCTION);
+ } else {
+ rc = cache_add(level, 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 - 1]);
+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) {
+ 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);
projects / karo-tx-linux.git / commitdiff