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linux-next/net/core/flow.c
Paul Gortmaker 013dbb325b net: delete __cpuinit usage from all net files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the net/* uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-07-14 19:36:58 -04:00

498 lines
12 KiB
C

/* flow.c: Generic flow cache.
*
* Copyright (C) 2003 Alexey N. Kuznetsov (kuznet@ms2.inr.ac.ru)
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/completion.h>
#include <linux/percpu.h>
#include <linux/bitops.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/mutex.h>
#include <net/flow.h>
#include <linux/atomic.h>
#include <linux/security.h>
struct flow_cache_entry {
union {
struct hlist_node hlist;
struct list_head gc_list;
} u;
struct net *net;
u16 family;
u8 dir;
u32 genid;
struct flowi key;
struct flow_cache_object *object;
};
struct flow_cache_percpu {
struct hlist_head *hash_table;
int hash_count;
u32 hash_rnd;
int hash_rnd_recalc;
struct tasklet_struct flush_tasklet;
};
struct flow_flush_info {
struct flow_cache *cache;
atomic_t cpuleft;
struct completion completion;
};
struct flow_cache {
u32 hash_shift;
struct flow_cache_percpu __percpu *percpu;
struct notifier_block hotcpu_notifier;
int low_watermark;
int high_watermark;
struct timer_list rnd_timer;
};
atomic_t flow_cache_genid = ATOMIC_INIT(0);
EXPORT_SYMBOL(flow_cache_genid);
static struct flow_cache flow_cache_global;
static struct kmem_cache *flow_cachep __read_mostly;
static DEFINE_SPINLOCK(flow_cache_gc_lock);
static LIST_HEAD(flow_cache_gc_list);
#define flow_cache_hash_size(cache) (1 << (cache)->hash_shift)
#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ)
static void flow_cache_new_hashrnd(unsigned long arg)
{
struct flow_cache *fc = (void *) arg;
int i;
for_each_possible_cpu(i)
per_cpu_ptr(fc->percpu, i)->hash_rnd_recalc = 1;
fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
add_timer(&fc->rnd_timer);
}
static int flow_entry_valid(struct flow_cache_entry *fle)
{
if (atomic_read(&flow_cache_genid) != fle->genid)
return 0;
if (fle->object && !fle->object->ops->check(fle->object))
return 0;
return 1;
}
static void flow_entry_kill(struct flow_cache_entry *fle)
{
if (fle->object)
fle->object->ops->delete(fle->object);
kmem_cache_free(flow_cachep, fle);
}
static void flow_cache_gc_task(struct work_struct *work)
{
struct list_head gc_list;
struct flow_cache_entry *fce, *n;
INIT_LIST_HEAD(&gc_list);
spin_lock_bh(&flow_cache_gc_lock);
list_splice_tail_init(&flow_cache_gc_list, &gc_list);
spin_unlock_bh(&flow_cache_gc_lock);
list_for_each_entry_safe(fce, n, &gc_list, u.gc_list)
flow_entry_kill(fce);
}
static DECLARE_WORK(flow_cache_gc_work, flow_cache_gc_task);
static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp,
int deleted, struct list_head *gc_list)
{
if (deleted) {
fcp->hash_count -= deleted;
spin_lock_bh(&flow_cache_gc_lock);
list_splice_tail(gc_list, &flow_cache_gc_list);
spin_unlock_bh(&flow_cache_gc_lock);
schedule_work(&flow_cache_gc_work);
}
}
static void __flow_cache_shrink(struct flow_cache *fc,
struct flow_cache_percpu *fcp,
int shrink_to)
{
struct flow_cache_entry *fle;
struct hlist_node *tmp;
LIST_HEAD(gc_list);
int i, deleted = 0;
for (i = 0; i < flow_cache_hash_size(fc); i++) {
int saved = 0;
hlist_for_each_entry_safe(fle, tmp,
&fcp->hash_table[i], u.hlist) {
if (saved < shrink_to &&
flow_entry_valid(fle)) {
saved++;
} else {
deleted++;
hlist_del(&fle->u.hlist);
list_add_tail(&fle->u.gc_list, &gc_list);
}
}
}
flow_cache_queue_garbage(fcp, deleted, &gc_list);
}
static void flow_cache_shrink(struct flow_cache *fc,
struct flow_cache_percpu *fcp)
{
int shrink_to = fc->low_watermark / flow_cache_hash_size(fc);
__flow_cache_shrink(fc, fcp, shrink_to);
}
static void flow_new_hash_rnd(struct flow_cache *fc,
struct flow_cache_percpu *fcp)
{
get_random_bytes(&fcp->hash_rnd, sizeof(u32));
fcp->hash_rnd_recalc = 0;
__flow_cache_shrink(fc, fcp, 0);
}
static u32 flow_hash_code(struct flow_cache *fc,
struct flow_cache_percpu *fcp,
const struct flowi *key,
size_t keysize)
{
const u32 *k = (const u32 *) key;
const u32 length = keysize * sizeof(flow_compare_t) / sizeof(u32);
return jhash2(k, length, fcp->hash_rnd)
& (flow_cache_hash_size(fc) - 1);
}
/* I hear what you're saying, use memcmp. But memcmp cannot make
* important assumptions that we can here, such as alignment.
*/
static int flow_key_compare(const struct flowi *key1, const struct flowi *key2,
size_t keysize)
{
const flow_compare_t *k1, *k1_lim, *k2;
k1 = (const flow_compare_t *) key1;
k1_lim = k1 + keysize;
k2 = (const flow_compare_t *) key2;
do {
if (*k1++ != *k2++)
return 1;
} while (k1 < k1_lim);
return 0;
}
struct flow_cache_object *
flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
flow_resolve_t resolver, void *ctx)
{
struct flow_cache *fc = &flow_cache_global;
struct flow_cache_percpu *fcp;
struct flow_cache_entry *fle, *tfle;
struct flow_cache_object *flo;
size_t keysize;
unsigned int hash;
local_bh_disable();
fcp = this_cpu_ptr(fc->percpu);
fle = NULL;
flo = NULL;
keysize = flow_key_size(family);
if (!keysize)
goto nocache;
/* Packet really early in init? Making flow_cache_init a
* pre-smp initcall would solve this. --RR */
if (!fcp->hash_table)
goto nocache;
if (fcp->hash_rnd_recalc)
flow_new_hash_rnd(fc, fcp);
hash = flow_hash_code(fc, fcp, key, keysize);
hlist_for_each_entry(tfle, &fcp->hash_table[hash], u.hlist) {
if (tfle->net == net &&
tfle->family == family &&
tfle->dir == dir &&
flow_key_compare(key, &tfle->key, keysize) == 0) {
fle = tfle;
break;
}
}
if (unlikely(!fle)) {
if (fcp->hash_count > fc->high_watermark)
flow_cache_shrink(fc, fcp);
fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
if (fle) {
fle->net = net;
fle->family = family;
fle->dir = dir;
memcpy(&fle->key, key, keysize * sizeof(flow_compare_t));
fle->object = NULL;
hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]);
fcp->hash_count++;
}
} else if (likely(fle->genid == atomic_read(&flow_cache_genid))) {
flo = fle->object;
if (!flo)
goto ret_object;
flo = flo->ops->get(flo);
if (flo)
goto ret_object;
} else if (fle->object) {
flo = fle->object;
flo->ops->delete(flo);
fle->object = NULL;
}
nocache:
flo = NULL;
if (fle) {
flo = fle->object;
fle->object = NULL;
}
flo = resolver(net, key, family, dir, flo, ctx);
if (fle) {
fle->genid = atomic_read(&flow_cache_genid);
if (!IS_ERR(flo))
fle->object = flo;
else
fle->genid--;
} else {
if (!IS_ERR_OR_NULL(flo))
flo->ops->delete(flo);
}
ret_object:
local_bh_enable();
return flo;
}
EXPORT_SYMBOL(flow_cache_lookup);
static void flow_cache_flush_tasklet(unsigned long data)
{
struct flow_flush_info *info = (void *)data;
struct flow_cache *fc = info->cache;
struct flow_cache_percpu *fcp;
struct flow_cache_entry *fle;
struct hlist_node *tmp;
LIST_HEAD(gc_list);
int i, deleted = 0;
fcp = this_cpu_ptr(fc->percpu);
for (i = 0; i < flow_cache_hash_size(fc); i++) {
hlist_for_each_entry_safe(fle, tmp,
&fcp->hash_table[i], u.hlist) {
if (flow_entry_valid(fle))
continue;
deleted++;
hlist_del(&fle->u.hlist);
list_add_tail(&fle->u.gc_list, &gc_list);
}
}
flow_cache_queue_garbage(fcp, deleted, &gc_list);
if (atomic_dec_and_test(&info->cpuleft))
complete(&info->completion);
}
/*
* Return whether a cpu needs flushing. Conservatively, we assume
* the presence of any entries means the core may require flushing,
* since the flow_cache_ops.check() function may assume it's running
* on the same core as the per-cpu cache component.
*/
static int flow_cache_percpu_empty(struct flow_cache *fc, int cpu)
{
struct flow_cache_percpu *fcp;
int i;
fcp = per_cpu_ptr(fc->percpu, cpu);
for (i = 0; i < flow_cache_hash_size(fc); i++)
if (!hlist_empty(&fcp->hash_table[i]))
return 0;
return 1;
}
static void flow_cache_flush_per_cpu(void *data)
{
struct flow_flush_info *info = data;
struct tasklet_struct *tasklet;
tasklet = &this_cpu_ptr(info->cache->percpu)->flush_tasklet;
tasklet->data = (unsigned long)info;
tasklet_schedule(tasklet);
}
void flow_cache_flush(void)
{
struct flow_flush_info info;
static DEFINE_MUTEX(flow_flush_sem);
cpumask_var_t mask;
int i, self;
/* Track which cpus need flushing to avoid disturbing all cores. */
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return;
cpumask_clear(mask);
/* Don't want cpus going down or up during this. */
get_online_cpus();
mutex_lock(&flow_flush_sem);
info.cache = &flow_cache_global;
for_each_online_cpu(i)
if (!flow_cache_percpu_empty(info.cache, i))
cpumask_set_cpu(i, mask);
atomic_set(&info.cpuleft, cpumask_weight(mask));
if (atomic_read(&info.cpuleft) == 0)
goto done;
init_completion(&info.completion);
local_bh_disable();
self = cpumask_test_and_clear_cpu(smp_processor_id(), mask);
on_each_cpu_mask(mask, flow_cache_flush_per_cpu, &info, 0);
if (self)
flow_cache_flush_tasklet((unsigned long)&info);
local_bh_enable();
wait_for_completion(&info.completion);
done:
mutex_unlock(&flow_flush_sem);
put_online_cpus();
free_cpumask_var(mask);
}
static void flow_cache_flush_task(struct work_struct *work)
{
flow_cache_flush();
}
static DECLARE_WORK(flow_cache_flush_work, flow_cache_flush_task);
void flow_cache_flush_deferred(void)
{
schedule_work(&flow_cache_flush_work);
}
static int flow_cache_cpu_prepare(struct flow_cache *fc, int cpu)
{
struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);
size_t sz = sizeof(struct hlist_head) * flow_cache_hash_size(fc);
if (!fcp->hash_table) {
fcp->hash_table = kzalloc_node(sz, GFP_KERNEL, cpu_to_node(cpu));
if (!fcp->hash_table) {
pr_err("NET: failed to allocate flow cache sz %zu\n", sz);
return -ENOMEM;
}
fcp->hash_rnd_recalc = 1;
fcp->hash_count = 0;
tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0);
}
return 0;
}
static int flow_cache_cpu(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
struct flow_cache *fc = container_of(nfb, struct flow_cache, hotcpu_notifier);
int res, cpu = (unsigned long) hcpu;
struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
res = flow_cache_cpu_prepare(fc, cpu);
if (res)
return notifier_from_errno(res);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
__flow_cache_shrink(fc, fcp, 0);
break;
}
return NOTIFY_OK;
}
static int __init flow_cache_init(struct flow_cache *fc)
{
int i;
fc->hash_shift = 10;
fc->low_watermark = 2 * flow_cache_hash_size(fc);
fc->high_watermark = 4 * flow_cache_hash_size(fc);
fc->percpu = alloc_percpu(struct flow_cache_percpu);
if (!fc->percpu)
return -ENOMEM;
for_each_online_cpu(i) {
if (flow_cache_cpu_prepare(fc, i))
goto err;
}
fc->hotcpu_notifier = (struct notifier_block){
.notifier_call = flow_cache_cpu,
};
register_hotcpu_notifier(&fc->hotcpu_notifier);
setup_timer(&fc->rnd_timer, flow_cache_new_hashrnd,
(unsigned long) fc);
fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
add_timer(&fc->rnd_timer);
return 0;
err:
for_each_possible_cpu(i) {
struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i);
kfree(fcp->hash_table);
fcp->hash_table = NULL;
}
free_percpu(fc->percpu);
fc->percpu = NULL;
return -ENOMEM;
}
static int __init flow_cache_init_global(void)
{
flow_cachep = kmem_cache_create("flow_cache",
sizeof(struct flow_cache_entry),
0, SLAB_PANIC, NULL);
return flow_cache_init(&flow_cache_global);
}
module_init(flow_cache_init_global);