/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch.h>
#ifdef __SMP__
#include <arch/atomic.h>
#endif
#include <synch/spinlock.h>
#ifdef __SMP__
void spinlock_initialize(spinlock_t *sl)
{
sl->val = 0;
}
#ifdef DEBUG_SPINLOCK
void spinlock_lock(spinlock_t *sl)
{
int i = 0;
__address caller = ((__u32 *) &sl)[-1];
while (test_and_set(&sl->val)) {
if (i++ > 300000) {
printf("cpu%d: looping on spinlock %X, caller=%X\n", the
->cpu
->id
, sl
, caller
);
i = 0;
}
}
}
#else
void spinlock_lock(spinlock_t *sl)
{
/*
* Each architecture has its own efficient/recommended
* implementation of spinlock.
*/
spinlock_arch(&sl->val);
}
#endif
int spinlock_trylock(spinlock_t *sl)
{
return !test_and_set(&sl->val);
}
void spinlock_unlock(spinlock_t *sl)
{
sl->val = 0;
}
#endif