diff options
Diffstat (limited to 'arch/powerpc/kernel/cacheinfo.c')
| -rw-r--r-- | arch/powerpc/kernel/cacheinfo.c | 889 |
1 files changed, 889 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c new file mode 100644 index 000000000..9edb45430 --- /dev/null +++ b/arch/powerpc/kernel/cacheinfo.c @@ -0,0 +1,889 @@ +/* + * 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/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 /* cache-size, cache-block-size, etc. */ +#define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */ +#define CACHE_TYPE_INSTRUCTION 2 +#define CACHE_TYPE_DATA 3 + +static const struct cache_type_info cache_type_info[] = { + { + /* Embedded systems that use cache-size, cache-block-size, + * etc. for the Unified (typically L2) cache. */ + .name = "Unified", + .size_prop = "cache-size", + .line_size_props = { "cache-line-size", + "cache-block-size", }, + .nr_sets_prop = "cache-sets", + }, + { + /* 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 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 *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 %pOF(%s) refers to cache for %pOF(%s)\n", + iter->ofnode, + cache_type_string(iter), + cache->ofnode, + cache_type_string(cache)); +} + +static void release_cache(struct cache *cache) +{ + if (!cache) + return; + + pr_debug("freeing L%d %s cache for %pOF\n", cache->level, + cache_type_string(cache), cache->ofnode); + + 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 %pOF(%s)\n", + cpu, next->ofnode, + 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 __be32 *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 = of_read_number(cache_size, 1); + 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 __be32 *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 = of_read_number(line_size, 1); + return 0; +} + +static int cache_nr_sets(const struct cache *cache, unsigned int *ret) +{ + const char *propname; + const __be32 *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 = of_read_number(nr_sets, 1); + 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 || + cache->type == CACHE_TYPE_UNIFIED_D) + 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); +} + +/* + * Unified caches can have two different sets of tags. Most embedded + * use cache-size, etc. for the unified cache size, but open firmware systems + * use d-cache-size, etc. Check on initialization for which type we have, and + * return the appropriate structure type. Assume it's embedded if it isn't + * open firmware. If it's yet a 3rd type, then there will be missing entries + * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need + * to be extended further. + */ +static int cache_is_unified_d(const struct device_node *np) +{ + return of_get_property(np, + cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ? + CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED; +} + +/* + */ +static struct cache *cache_do_one_devnode_unified(struct device_node *node, int level) +{ + pr_debug("creating L%d ucache for %pOF\n", level, node); + + return new_cache(cache_is_unified_d(node), level, node); +} + +static struct cache *cache_do_one_devnode_split(struct device_node *node, + int level) +{ + struct cache *dcache, *icache; + + pr_debug("creating L%d dcache and icache for %pOF\n", level, + node); + + 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 *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 *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 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 do_subsidiary_caches_debugcheck(struct cache *cache) +{ + WARN_ON_ONCE(cache->level != 1); + WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu")); +} + +static void 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 *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 *cacheinfo_create_cache_dir(unsigned int cpu_id) +{ + struct cache_dir *cache_dir; + struct device *dev; + struct kobject *kobj = NULL; + + dev = get_cpu_device(cpu_id); + WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id); + if (!dev) + goto err; + + kobj = kobject_create_and_add("cache", &dev->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 ret; + + index = kobj_to_cache_index_dir(k); + cache = index->cache; + + ret = scnprintf(buf, PAGE_SIZE - 1, "%*pb\n", + cpumask_pr_args(&cache->shared_cpu_map)); + buf[ret++] = '\n'; + buf[ret] = '\0'; + return ret; +} + +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 cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir) +{ + const char *cache_type; + struct cache *cache; + char *buf; + int i; + + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf) + return; + + cache = dir->cache; + 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 " + "%pOF(%s) (rc = %zd)\n", + attr->attr.name, cache->ofnode, + cache_type, rc); + continue; + } + if (sysfs_create_file(&dir->kobj, &attr->attr)) + pr_debug("could not create %s attribute for %pOF(%s)\n", + attr->attr.name, cache->ofnode, cache_type); + } + + kfree(buf); +} + +static void 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 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 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); +} + +/* functions needed to remove cache entry for cpu offline or suspend/resume */ + +#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \ + defined(CONFIG_HOTPLUG_CPU) + +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); + + /* Remove cache dir from sysfs */ + kobject_del(cache_dir->kobj); + + 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 %pOF(%s)\n", + cpu, cache->ofnode, + 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); +} + +void cacheinfo_teardown(void) +{ + unsigned int cpu; + + lockdep_assert_cpus_held(); + + for_each_online_cpu(cpu) + cacheinfo_cpu_offline(cpu); +} + +void cacheinfo_rebuild(void) +{ + unsigned int cpu; + + lockdep_assert_cpus_held(); + + for_each_online_cpu(cpu) + cacheinfo_cpu_online(cpu); +} + +#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */ |