Revision dda50e716dc9451f40eebfb2902c260e4f62cf34 authored by Andi Kleen on 17 May 2005, 04:53:25 UTC, committed by Linus Torvalds on 17 May 2005, 14:59:14 UTC
The new TSC sync algorithm recently submitted did not work too well. The result was that some MP machines where the TSC came up of the BIOS very unsynchronized and that did not have HPET support were nearly unusable because the time would jump forwards and backwards between CPUs. After a lot of research ;-) and some more prototypes I ended up with just using the one from IA64 which looks best. It has some internal self tuning that should adapt to changing interconnect latencies. It holds up in my tests so far. I believe it was originally written by David Mosberger, I just ported it over to x86-64. See the inline comment for a description. This cleans up the code because it uses smp_call_function for syncing instead of having custom hooks in SMP bootup. Please note that the cycle numbers it outputs are too optimistic because they do not take into account the latency of WRMSR and RDTSC, which can be hundreds of cycles. It seems to be able to sync a dual Opteron to 200-300 cycles, which is probably good enough. There is a timing window during AP bootup where interrupts can see inconsistent time before the TSC is synced. It is hard to avoid unfortunately because we can only do the TSC sync after some setup, and we need to enable interrupts before that. I just ignored it for now. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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api.c
/*
* Scatterlist Cryptographic API.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2002 David S. Miller (davem@redhat.com)
*
* Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
* and Nettle, by Niels Mé—¤ler.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <linux/init.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include "internal.h"
LIST_HEAD(crypto_alg_list);
DECLARE_RWSEM(crypto_alg_sem);
static inline int crypto_alg_get(struct crypto_alg *alg)
{
return try_module_get(alg->cra_module);
}
static inline void crypto_alg_put(struct crypto_alg *alg)
{
module_put(alg->cra_module);
}
struct crypto_alg *crypto_alg_lookup(const char *name)
{
struct crypto_alg *q, *alg = NULL;
if (!name)
return NULL;
down_read(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (!(strcmp(q->cra_name, name))) {
if (crypto_alg_get(q))
alg = q;
break;
}
}
up_read(&crypto_alg_sem);
return alg;
}
static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
{
tfm->crt_flags = 0;
switch (crypto_tfm_alg_type(tfm)) {
case CRYPTO_ALG_TYPE_CIPHER:
return crypto_init_cipher_flags(tfm, flags);
case CRYPTO_ALG_TYPE_DIGEST:
return crypto_init_digest_flags(tfm, flags);
case CRYPTO_ALG_TYPE_COMPRESS:
return crypto_init_compress_flags(tfm, flags);
default:
break;
}
BUG();
return -EINVAL;
}
static int crypto_init_ops(struct crypto_tfm *tfm)
{
switch (crypto_tfm_alg_type(tfm)) {
case CRYPTO_ALG_TYPE_CIPHER:
return crypto_init_cipher_ops(tfm);
case CRYPTO_ALG_TYPE_DIGEST:
return crypto_init_digest_ops(tfm);
case CRYPTO_ALG_TYPE_COMPRESS:
return crypto_init_compress_ops(tfm);
default:
break;
}
BUG();
return -EINVAL;
}
static void crypto_exit_ops(struct crypto_tfm *tfm)
{
switch (crypto_tfm_alg_type(tfm)) {
case CRYPTO_ALG_TYPE_CIPHER:
crypto_exit_cipher_ops(tfm);
break;
case CRYPTO_ALG_TYPE_DIGEST:
crypto_exit_digest_ops(tfm);
break;
case CRYPTO_ALG_TYPE_COMPRESS:
crypto_exit_compress_ops(tfm);
break;
default:
BUG();
}
}
struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
{
struct crypto_tfm *tfm = NULL;
struct crypto_alg *alg;
alg = crypto_alg_mod_lookup(name);
if (alg == NULL)
goto out;
tfm = kmalloc(sizeof(*tfm) + alg->cra_ctxsize, GFP_KERNEL);
if (tfm == NULL)
goto out_put;
memset(tfm, 0, sizeof(*tfm) + alg->cra_ctxsize);
tfm->__crt_alg = alg;
if (crypto_init_flags(tfm, flags))
goto out_free_tfm;
if (crypto_init_ops(tfm)) {
crypto_exit_ops(tfm);
goto out_free_tfm;
}
goto out;
out_free_tfm:
kfree(tfm);
tfm = NULL;
out_put:
crypto_alg_put(alg);
out:
return tfm;
}
void crypto_free_tfm(struct crypto_tfm *tfm)
{
struct crypto_alg *alg = tfm->__crt_alg;
int size = sizeof(*tfm) + alg->cra_ctxsize;
crypto_exit_ops(tfm);
crypto_alg_put(alg);
memset(tfm, 0, size);
kfree(tfm);
}
int crypto_register_alg(struct crypto_alg *alg)
{
int ret = 0;
struct crypto_alg *q;
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (!(strcmp(q->cra_name, alg->cra_name))) {
ret = -EEXIST;
goto out;
}
}
list_add_tail(&alg->cra_list, &crypto_alg_list);
out:
up_write(&crypto_alg_sem);
return ret;
}
int crypto_unregister_alg(struct crypto_alg *alg)
{
int ret = -ENOENT;
struct crypto_alg *q;
BUG_ON(!alg->cra_module);
down_write(&crypto_alg_sem);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (alg == q) {
list_del(&alg->cra_list);
ret = 0;
goto out;
}
}
out:
up_write(&crypto_alg_sem);
return ret;
}
int crypto_alg_available(const char *name, u32 flags)
{
int ret = 0;
struct crypto_alg *alg = crypto_alg_mod_lookup(name);
if (alg) {
crypto_alg_put(alg);
ret = 1;
}
return ret;
}
static int __init init_crypto(void)
{
printk(KERN_INFO "Initializing Cryptographic API\n");
crypto_init_proc();
return 0;
}
__initcall(init_crypto);
EXPORT_SYMBOL_GPL(crypto_register_alg);
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
EXPORT_SYMBOL_GPL(crypto_free_tfm);
EXPORT_SYMBOL_GPL(crypto_alg_available);
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