// SPDX-License-Identifier: GPL-2.0-only
/*
* 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
*/
#define pr_fmt(fmt) "cacheinfo: " fmt
#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/cputhreads.h>
#include <asm/smp.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 */
int group_id; /* id of the group of threads that share this cache */
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, int group_id)
{
cache->type = type;
cache->level = level;
cache->ofnode = of_node_get(ofnode);
cache->group_id = group_id;
INIT_LIST_HEAD(&cache->list);
list_add(&cache->list, &cache_list);
}
static struct cache *new_cache(int type, int level,
struct device_node *ofnode, int group_id)
{
struct cache *cache;
cache = kzalloc(sizeof(*cache), GFP_KERNEL);
if (cache)
cache_init(cache, type, level, ofnode, group_id);
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 %pOFP(%s) refers to cache for %pOFP(%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 %pOFP\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 %pOFP(%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->group_id == cache->group_id &&
iter->next_local == cache)
return iter;
return cache;
}
/* return the first cache on a local list matching node and thread-group id */
static struct cache *cache_lookup_by_node_group(const struct device_node *node,
int group_id)
{
struct cache *cache = NULL;
struct cache *iter;
list_for_each_entry(iter, &cache_list, list) {
if (iter->ofnode != node ||
iter->group_id != group_id)
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 group_id,
int level)
{
pr_debug("creating L%d ucache for %pOFP\n", level, node);
return new_cache(cache_is_unified_d(node), level, node, group_id);
}
static struct cache *cache_do_one_devnode_split(struct device_node *node, int group_id,
int level)
{
struct cache *dcache, *icache;
pr_debug("creating L%d dcache and icache for %pOFP\n", level,
node);
dcache = new_cache(CACHE_TYPE_DATA, level, node, group_id);
icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node, group_id);
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 group_id, int level)
{
struct cache *cache;
if (cache_node_is_unified(node))
cache = cache_do_one_devnode_unified(node, group_id, level);
else
cache = cache_do_one_devnode_split(node, group_id, level);
return cache;
}
static struct cache *cache_lookup_or_instantiate(struct device_node *node,
int group_id,
int level)
{
struct cache *cache;
cache = cache_lookup_by_node_group(node, group_id);
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, group_id, 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;
/*
* The cache->next_local list sorts by level ascending:
* L1d -> L1i -> L2 -> L3 ...
*/
WARN_ONCE((smaller->level == 1 && bigger->level > 2) ||
(smaller->level > 1 && bigger->level != smaller->level + 1),
"linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n",
smaller->level, smaller->ofnode, bigger->level, bigger->ofnode);
}
static void do_subsidiary_caches_debugcheck(struct cache *cache)
{
WARN_ONCE(cache->level != 1,
"instantiating cache chain from L%d %s cache for "
"%pOFP instead of an L1\n", cache->level,
cache_type_string(cache), cache->ofnode);
WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"),
"instantiating cache chain from node %pOFP of type '%s' "
"instead of a cpu node\n", cache->ofnode,
of_node_get_device_type(cache->ofnode));
}
/*
* If sub-groups of threads in a core containing @cpu_id share the
* L@level-cache (information obtained via "ibm,thread-groups"
* device-tree property), then we identify the group by the first
* thread-sibling in the group. We define this to be the group-id.
*
* In the absence of any thread-group information for L@level-cache,
* this function returns -1.
*/
static int get_group_id(unsigned int cpu_id, int level)
{
if (has_big_cores && level == 1)
return cpumask_first(per_cpu(thread_group_l1_cache_map,
cpu_id));
else if (thread_group_shares_l2 && level == 2)
return cpumask_first(per_cpu(thread_group_l2_cache_map,
cpu_id));
else if (thread_group_shares_l3 && level == 3)
return cpumask_first(per_cpu(thread_group_l3_cache_map,
cpu_id));
return -1;
}
static void do_subsidiary_caches(struct cache *cache, unsigned int cpu_id)
{
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;
int group_id;
level++;
group_id = get_group_id(cpu_id, level);
subcache = cache_lookup_or_instantiate(subcache_node, group_id, 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;
int group_id;
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;
group_id = get_group_id(cpu_id, 1);
cpu_cache = cache_lookup_or_instantiate(cpu_node, group_id, 1);
if (!cpu_cache)
goto out;
do_subsidiary_caches(cpu_cache, cpu_id);
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
show_shared_cpumap(struct kobject *k, struct kobj_attribute *attr, char *buf, bool list)
{
struct cache_index_dir *index;
struct cache *cache;
const struct cpumask *mask;
index = kobj_to_cache_index_dir(k);
cache = index->cache;
mask = &cache->shared_cpu_map;
return cpumap_print_to_pagebuf(list, buf, mask);
}
static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
{
return show_shared_cpumap(k, attr, buf, false);
}
static ssize_t shared_cpu_list_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
{
return show_shared_cpumap(k, attr, buf, true);
}
static struct kobj_attribute cache_shared_cpu_map_attr =
__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
static struct kobj_attribute cache_shared_cpu_list_attr =
__ATTR(shared_cpu_list, 0444, shared_cpu_list_show, NULL);
/* Attributes which should always be created -- the kobject/sysfs core
* does this automatically via kobj_type->default_groups. 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,
&cache_shared_cpu_list_attr.attr,
NULL,
};
ATTRIBUTE_GROUPS(cache_index_default);
/* 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_groups = cache_index_default_groups,
};
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 "
"%pOFP(%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 %pOFP(%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)
return;
index_dir->cache = cache;
rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
cache_dir->kobj, "index%d", index);
if (rc) {
kobject_put(&index_dir->kobj);
return;
}
index_dir->next = cache_dir->index;
cache_dir->index = index_dir;
cacheinfo_create_index_opt_attrs(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;
int group_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)
return NULL;
group_id = get_group_id(cpu_id, 1);
cache = cache_lookup_by_node_group(cpu_node, group_id);
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 %pOFP(%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 */
Codebase Browser
linux