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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internal.h
/*
 * Cryptographic API.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 *
 * 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.
 *
 */
#ifndef _CRYPTO_INTERNAL_H
#define _CRYPTO_INTERNAL_H
#include <linux/crypto.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <asm/kmap_types.h>

extern enum km_type crypto_km_types[];

static inline enum km_type crypto_kmap_type(int out)
{
	return crypto_km_types[(in_softirq() ? 2 : 0) + out];
}

static inline void *crypto_kmap(struct page *page, int out)
{
	return kmap_atomic(page, crypto_kmap_type(out));
}

static inline void crypto_kunmap(void *vaddr, int out)
{
	kunmap_atomic(vaddr, crypto_kmap_type(out));
}

static inline void crypto_yield(struct crypto_tfm *tfm)
{
	if (!in_softirq())
		cond_resched();
}

static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
{
	return (void *)&tfm[1];
}

struct crypto_alg *crypto_alg_lookup(const char *name);

/* A far more intelligent version of this is planned.  For now, just
 * try an exact match on the name of the algorithm. */
static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
{
	return try_then_request_module(crypto_alg_lookup(name), name);
}

#ifdef CONFIG_CRYPTO_HMAC
int crypto_alloc_hmac_block(struct crypto_tfm *tfm);
void crypto_free_hmac_block(struct crypto_tfm *tfm);
#else
static inline int crypto_alloc_hmac_block(struct crypto_tfm *tfm)
{
	return 0;
}

static inline void crypto_free_hmac_block(struct crypto_tfm *tfm)
{ }
#endif

#ifdef CONFIG_PROC_FS
void __init crypto_init_proc(void);
#else
static inline void crypto_init_proc(void)
{ }
#endif

int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags);
int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags);
int crypto_init_compress_flags(struct crypto_tfm *tfm, u32 flags);

int crypto_init_digest_ops(struct crypto_tfm *tfm);
int crypto_init_cipher_ops(struct crypto_tfm *tfm);
int crypto_init_compress_ops(struct crypto_tfm *tfm);

void crypto_exit_digest_ops(struct crypto_tfm *tfm);
void crypto_exit_cipher_ops(struct crypto_tfm *tfm);
void crypto_exit_compress_ops(struct crypto_tfm *tfm);

#endif	/* _CRYPTO_INTERNAL_H */

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