/* * Processor cache information made available to userspace via sysfs; * intended to be compatible with x86 intel_cacheinfo implementation. * * Copyright 2008 IBM Corporation * Author: Nathan Lynch * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. */ #include <linux/cpu.h> #include <linux/cpumask.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/kobject.h> #include <linux/list.h> #include <linux/notifier.h> #include <linux/of.h> #include <linux/percpu.h> #include <linux/slab.h> #include <asm/prom.h> #include "cacheinfo.h" /* per-cpu object for tracking: * - a "cache" kobject for the top-level directory * - a list of "index" objects representing the cpu's local cache hierarchy */ struct cache_dir { struct kobject *kobj; /* bare (not embedded) kobject for cache * directory */ struct cache_index_dir *index; /* list of index objects */ }; /* "index" object: each cpu's cache directory has an index * subdirectory corresponding to a cache object associated with the * cpu. This object's lifetime is managed via the embedded kobject. */ struct cache_index_dir { struct kobject kobj; struct cache_index_dir *next; /* next index in parent directory */ struct cache *cache; }; /* Template for determining which OF properties to query for a given * cache type */ struct cache_type_info { const char *name; const char *size_prop; /* Allow for both [di]-cache-line-size and * [di]-cache-block-size properties. According to the PowerPC * Processor binding, -line-size should be provided if it * differs from the cache block size (that which is operated * on by cache instructions), so we look for -line-size first. * See cache_get_line_size(). */ const char *line_size_props[2]; const char *nr_sets_prop; }; /* These are used to index the cache_type_info array. */ #define CACHE_TYPE_UNIFIED 0 #define CACHE_TYPE_INSTRUCTION 1 #define CACHE_TYPE_DATA 2 static const struct cache_type_info cache_type_info[] = { { /* PowerPC Processor binding says the [di]-cache-* * must be equal on unified caches, so just use * d-cache properties. */ .name = "Unified", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, { .name = "Instruction", .size_prop = "i-cache-size", .line_size_props = { "i-cache-line-size", "i-cache-block-size", }, .nr_sets_prop = "i-cache-sets", }, { .name = "Data", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, }; /* Cache object: each instance of this corresponds to a distinct cache * in the system. There are separate objects for Harvard caches: one * each for instruction and data, and each refers to the same OF node. * The refcount of the OF node is elevated for the lifetime of the * cache object. A cache object is released when its shared_cpu_map * is cleared (see cache_cpu_clear). * * A cache object is on two lists: an unsorted global list * (cache_list) of cache objects; and a singly-linked list * representing the local cache hierarchy, which is ordered by level * (e.g. L1d -> L1i -> L2 -> L3). */ struct cache { struct device_node *ofnode; /* OF node for this cache, may be cpu */ struct cpumask shared_cpu_map; /* online CPUs using this cache */ int type; /* split cache disambiguation */ int level; /* level not explicit in device tree */ struct list_head list; /* global list of cache objects */ struct cache *next_local; /* next cache of >= level */ }; static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu); /* traversal/modification of this list occurs only at cpu hotplug time; * access is serialized by cpu hotplug locking */ static LIST_HEAD(cache_list); static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k) { return container_of(k, struct cache_index_dir, kobj); } static const char *cache_type_string(const struct cache *cache) { return cache_type_info[cache->type].name; } static void __cpuinit cache_init(struct cache *cache, int type, int level, struct device_node *ofnode) { cache->type = type; cache->level = level; cache->ofnode = of_node_get(ofnode); INIT_LIST_HEAD(&cache->list); list_add(&cache->list, &cache_list); } static struct cache *__cpuinit new_cache(int type, int level, struct device_node *ofnode) { struct cache *cache; cache = kzalloc(sizeof(*cache), GFP_KERNEL); if (cache) cache_init(cache, type, level, ofnode); return cache; } static void release_cache_debugcheck(struct cache *cache) { struct cache *iter; list_for_each_entry(iter, &cache_list, list) WARN_ONCE(iter->next_local == cache, "cache for %s(%s) refers to cache for %s(%s)\n", iter->ofnode->full_name, cache_type_string(iter), cache->ofnode->full_name, cache_type_string(cache)); } static void release_cache(struct cache *cache) { if (!cache) return; pr_debug("freeing L%d %s cache for %s\n", cache->level, cache_type_string(cache), cache->ofnode->full_name); release_cache_debugcheck(cache); list_del(&cache->list); of_node_put(cache->ofnode); kfree(cache); } static void cache_cpu_set(struct cache *cache, int cpu) { struct cache *next = cache; while (next) { WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map), "CPU %i already accounted in %s(%s)\n", cpu, next->ofnode->full_name, cache_type_string(next)); cpumask_set_cpu(cpu, &next->shared_cpu_map); next = next->next_local; } } static int cache_size(const struct cache *cache, unsigned int *ret) { const char *propname; const u32 *cache_size; propname = cache_type_info[cache->type].size_prop; cache_size = of_get_property(cache->ofnode, propname, NULL); if (!cache_size) return -ENODEV; *ret = *cache_size; return 0; } static int cache_size_kb(const struct cache *cache, unsigned int *ret) { unsigned int size; if (cache_size(cache, &size)) return -ENODEV; *ret = size / 1024; return 0; } /* not cache_line_size() because that's a macro in include/linux/cache.h */ static int cache_get_line_size(const struct cache *cache, unsigned int *ret) { const u32 *line_size; int i, lim; lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props); for (i = 0; i < lim; i++) { const char *propname; propname = cache_type_info[cache->type].line_size_props[i]; line_size = of_get_property(cache->ofnode, propname, NULL); if (line_size) break; } if (!line_size) return -ENODEV; *ret = *line_size; return 0; } static int cache_nr_sets(const struct cache *cache, unsigned int *ret) { const char *propname; const u32 *nr_sets; propname = cache_type_info[cache->type].nr_sets_prop; nr_sets = of_get_property(cache->ofnode, propname, NULL); if (!nr_sets) return -ENODEV; *ret = *nr_sets; return 0; } static int cache_associativity(const struct cache *cache, unsigned int *ret) { unsigned int line_size; unsigned int nr_sets; unsigned int size; if (cache_nr_sets(cache, &nr_sets)) goto err; /* If the cache is fully associative, there is no need to * check the other properties. */ if (nr_sets == 1) { *ret = 0; return 0; } if (cache_get_line_size(cache, &line_size)) goto err; if (cache_size(cache, &size)) goto err; if (!(nr_sets > 0 && size > 0 && line_size > 0)) goto err; *ret = (size / nr_sets) / line_size; return 0; err: return -ENODEV; } /* helper for dealing with split caches */ static struct cache *cache_find_first_sibling(struct cache *cache) { struct cache *iter; if (cache->type == CACHE_TYPE_UNIFIED) return cache; list_for_each_entry(iter, &cache_list, list) if (iter->ofnode == cache->ofnode && iter->next_local == cache) return iter; return cache; } /* return the first cache on a local list matching node */ static struct cache *cache_lookup_by_node(const struct device_node *node) { struct cache *cache = NULL; struct cache *iter; list_for_each_entry(iter, &cache_list, list) { if (iter->ofnode != node) continue; cache = cache_find_first_sibling(iter); break; } return cache; } static bool cache_node_is_unified(const struct device_node *np) { return of_get_property(np, "cache-unified", NULL); } static struct cache *__cpuinit cache_do_one_devnode_unified(struct device_node *node, int level) { struct cache *cache; pr_debug("creating L%d ucache for %s\n", level, node->full_name); cache = new_cache(CACHE_TYPE_UNIFIED, level, node); return cache; } static struct cache *__cpuinit cache_do_one_devnode_split(struct device_node *node, int level) { struct cache *dcache, *icache; pr_debug("creating L%d dcache and icache for %s\n", level, node->full_name); dcache = new_cache(CACHE_TYPE_DATA, level, node); icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node); if (!dcache || !icache) goto err; dcache->next_local = icache; return dcache; err: release_cache(dcache); release_cache(icache); return NULL; } static struct cache *__cpuinit cache_do_one_devnode(struct device_node *node, int level) { struct cache *cache; if (cache_node_is_unified(node)) cache = cache_do_one_devnode_unified(node, level); else cache = cache_do_one_devnode_split(node, level); return cache; } static struct cache *__cpuinit cache_lookup_or_instantiate(struct device_node *node, int level) { struct cache *cache; cache = cache_lookup_by_node(node); WARN_ONCE(cache && cache->level != level, "cache level mismatch on lookup (got %d, expected %d)\n", cache->level, level); if (!cache) cache = cache_do_one_devnode(node, level); return cache; } static void __cpuinit link_cache_lists(struct cache *smaller, struct cache *bigger) { while (smaller->next_local) { if (smaller->next_local == bigger) return; /* already linked */ smaller = smaller->next_local; } smaller->next_local = bigger; } static void __cpuinit do_subsidiary_caches_debugcheck(struct cache *cache) { WARN_ON_ONCE(cache->level != 1); WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu")); } static void __cpuinit do_subsidiary_caches(struct cache *cache) { struct device_node *subcache_node; int level = cache->level; do_subsidiary_caches_debugcheck(cache); while ((subcache_node = of_find_next_cache_node(cache->ofnode))) { struct cache *subcache; level++; subcache = cache_lookup_or_instantiate(subcache_node, level); of_node_put(subcache_node); if (!subcache) break; link_cache_lists(cache, subcache); cache = subcache; } } static struct cache *__cpuinit cache_chain_instantiate(unsigned int cpu_id) { struct device_node *cpu_node; struct cache *cpu_cache = NULL; pr_debug("creating cache object(s) for CPU %i\n", cpu_id); cpu_node = of_get_cpu_node(cpu_id, NULL); WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id); if (!cpu_node) goto out; cpu_cache = cache_lookup_or_instantiate(cpu_node, 1); if (!cpu_cache) goto out; do_subsidiary_caches(cpu_cache); cache_cpu_set(cpu_cache, cpu_id); out: of_node_put(cpu_node); return cpu_cache; } static struct cache_dir *__cpuinit cacheinfo_create_cache_dir(unsigned int cpu_id) { struct cache_dir *cache_dir; struct sys_device *sysdev; struct kobject *kobj = NULL; sysdev = get_cpu_sysdev(cpu_id); WARN_ONCE(!sysdev, "no sysdev for CPU %i\n", cpu_id); if (!sysdev) goto err; kobj = kobject_create_and_add("cache", &sysdev->kobj); if (!kobj) goto err; cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL); if (!cache_dir) goto err; cache_dir->kobj = kobj; WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL); per_cpu(cache_dir_pcpu, cpu_id) = cache_dir; return cache_dir; err: kobject_put(kobj); return NULL; } static void cache_index_release(struct kobject *kobj) { struct cache_index_dir *index; index = kobj_to_cache_index_dir(kobj); pr_debug("freeing index directory for L%d %s cache\n", index->cache->level, cache_type_string(index->cache)); kfree(index); } static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf) { struct kobj_attribute *kobj_attr; kobj_attr = container_of(attr, struct kobj_attribute, attr); return kobj_attr->show(k, kobj_attr, buf); } static struct cache *index_kobj_to_cache(struct kobject *k) { struct cache_index_dir *index; index = kobj_to_cache_index_dir(k); return index->cache; } static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { unsigned int size_kb; struct cache *cache; cache = index_kobj_to_cache(k); if (cache_size_kb(cache, &size_kb)) return -ENODEV; return sprintf(buf, "%uK\n", size_kb); } static struct kobj_attribute cache_size_attr = __ATTR(size, 0444, size_show, NULL); static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { unsigned int line_size; struct cache *cache; cache = index_kobj_to_cache(k); if (cache_get_line_size(cache, &line_size)) return -ENODEV; return sprintf(buf, "%u\n", line_size); } static struct kobj_attribute cache_line_size_attr = __ATTR(coherency_line_size, 0444, line_size_show, NULL); static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { unsigned int nr_sets; struct cache *cache; cache = index_kobj_to_cache(k); if (cache_nr_sets(cache, &nr_sets)) return -ENODEV; return sprintf(buf, "%u\n", nr_sets); } static struct kobj_attribute cache_nr_sets_attr = __ATTR(number_of_sets, 0444, nr_sets_show, NULL); static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { unsigned int associativity; struct cache *cache; cache = index_kobj_to_cache(k); if (cache_associativity(cache, &associativity)) return -ENODEV; return sprintf(buf, "%u\n", associativity); } static struct kobj_attribute cache_assoc_attr = __ATTR(ways_of_associativity, 0444, associativity_show, NULL); static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { struct cache *cache; cache = index_kobj_to_cache(k); return sprintf(buf, "%s\n", cache_type_string(cache)); } static struct kobj_attribute cache_type_attr = __ATTR(type, 0444, type_show, NULL); static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { struct cache_index_dir *index; struct cache *cache; index = kobj_to_cache_index_dir(k); cache = index->cache; return sprintf(buf, "%d\n", cache->level); } static struct kobj_attribute cache_level_attr = __ATTR(level, 0444, level_show, NULL); static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf) { struct cache_index_dir *index; struct cache *cache; int len; int n = 0; index = kobj_to_cache_index_dir(k); cache = index->cache; len = PAGE_SIZE - 2; if (len > 1) { n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map); buf[n++] = '\n'; buf[n] = '\0'; } return n; } static struct kobj_attribute cache_shared_cpu_map_attr = __ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL); /* Attributes which should always be created -- the kobject/sysfs core * does this automatically via kobj_type->default_attrs. This is the * minimum data required to uniquely identify a cache. */ static struct attribute *cache_index_default_attrs[] = { &cache_type_attr.attr, &cache_level_attr.attr, &cache_shared_cpu_map_attr.attr, NULL, }; /* Attributes which should be created if the cache device node has the * right properties -- see cacheinfo_create_index_opt_attrs */ static struct kobj_attribute *cache_index_opt_attrs[] = { &cache_size_attr, &cache_line_size_attr, &cache_nr_sets_attr, &cache_assoc_attr, }; static const struct sysfs_ops cache_index_ops = { .show = cache_index_show, }; static struct kobj_type cache_index_type = { .release = cache_index_release, .sysfs_ops = &cache_index_ops, .default_attrs = cache_index_default_attrs, }; static void __cpuinit cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir) { const char *cache_name; const char *cache_type; struct cache *cache; char *buf; int i; buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!buf) return; cache = dir->cache; cache_name = cache->ofnode->full_name; cache_type = cache_type_string(cache); /* We don't want to create an attribute that can't provide a * meaningful value. Check the return value of each optional * attribute's ->show method before registering the * attribute. */ for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) { struct kobj_attribute *attr; ssize_t rc; attr = cache_index_opt_attrs[i]; rc = attr->show(&dir->kobj, attr, buf); if (rc <= 0) { pr_debug("not creating %s attribute for " "%s(%s) (rc = %zd)\n", attr->attr.name, cache_name, cache_type, rc); continue; } if (sysfs_create_file(&dir->kobj, &attr->attr)) pr_debug("could not create %s attribute for %s(%s)\n", attr->attr.name, cache_name, cache_type); } kfree(buf); } static void __cpuinit cacheinfo_create_index_dir(struct cache *cache, int index, struct cache_dir *cache_dir) { struct cache_index_dir *index_dir; int rc; index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL); if (!index_dir) goto err; index_dir->cache = cache; rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type, cache_dir->kobj, "index%d", index); if (rc) goto err; index_dir->next = cache_dir->index; cache_dir->index = index_dir; cacheinfo_create_index_opt_attrs(index_dir); return; err: kfree(index_dir); } static void __cpuinit cacheinfo_sysfs_populate(unsigned int cpu_id, struct cache *cache_list) { struct cache_dir *cache_dir; struct cache *cache; int index = 0; cache_dir = cacheinfo_create_cache_dir(cpu_id); if (!cache_dir) return; cache = cache_list; while (cache) { cacheinfo_create_index_dir(cache, index, cache_dir); index++; cache = cache->next_local; } } void __cpuinit cacheinfo_cpu_online(unsigned int cpu_id) { struct cache *cache; cache = cache_chain_instantiate(cpu_id); if (!cache) return; cacheinfo_sysfs_populate(cpu_id, cache); } #ifdef CONFIG_HOTPLUG_CPU /* functions needed for cpu offline */ static struct cache *cache_lookup_by_cpu(unsigned int cpu_id) { struct device_node *cpu_node; struct cache *cache; cpu_node = of_get_cpu_node(cpu_id, NULL); WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id); if (!cpu_node) return NULL; cache = cache_lookup_by_node(cpu_node); of_node_put(cpu_node); return cache; } static void remove_index_dirs(struct cache_dir *cache_dir) { struct cache_index_dir *index; index = cache_dir->index; while (index) { struct cache_index_dir *next; next = index->next; kobject_put(&index->kobj); index = next; } } static void remove_cache_dir(struct cache_dir *cache_dir) { remove_index_dirs(cache_dir); kobject_put(cache_dir->kobj); kfree(cache_dir); } static void cache_cpu_clear(struct cache *cache, int cpu) { while (cache) { struct cache *next = cache->next_local; WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map), "CPU %i not accounted in %s(%s)\n", cpu, cache->ofnode->full_name, cache_type_string(cache)); cpumask_clear_cpu(cpu, &cache->shared_cpu_map); /* Release the cache object if all the cpus using it * are offline */ if (cpumask_empty(&cache->shared_cpu_map)) release_cache(cache); cache = next; } } void cacheinfo_cpu_offline(unsigned int cpu_id) { struct cache_dir *cache_dir; struct cache *cache; /* Prevent userspace from seeing inconsistent state - remove * the sysfs hierarchy first */ cache_dir = per_cpu(cache_dir_pcpu, cpu_id); /* careful, sysfs population may have failed */ if (cache_dir) remove_cache_dir(cache_dir); per_cpu(cache_dir_pcpu, cpu_id) = NULL; /* clear the CPU's bit in its cache chain, possibly freeing * cache objects */ cache = cache_lookup_by_cpu(cpu_id); if (cache) cache_cpu_clear(cache, cpu_id); } #endif /* CONFIG_HOTPLUG_CPU */