/*
* 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.
*/
#ifndef __SPINLOCK_H__
#define __SPINLOCK_H__
#include <arch/types.h>
#include <typedefs.h>
#include <preemption.h>
#include <arch/atomic.h>
#ifdef CONFIG_SMP
struct spinlock {
#ifdef CONFIG_DEBUG_SPINLOCK
char *name;
#endif
atomic_t val;
};
/*
* SPINLOCK_DECLARE is to be used for dynamically allocated spinlocks,
* where the lock gets initialized in run time.
*/
#define SPINLOCK_DECLARE(slname) spinlock_t slname
/*
* SPINLOCK_INITIALIZE is to be used for statically allocated spinlocks.
* It declares and initializes the lock.
*/
#ifdef CONFIG_DEBUG_SPINLOCK
#define SPINLOCK_INITIALIZE(slname) \
spinlock_t slname = { \
.name = #slname, \
.val = { 0 } \
}
#else
#define SPINLOCK_INITIALIZE(slname) \
spinlock_t slname = { \
.val = { 0 } \
}
#endif
extern void spinlock_initialize(spinlock_t *sl, char *name);
extern void spinlock_lock(spinlock_t *sl);
extern int spinlock_trylock(spinlock_t *sl);
extern void spinlock_unlock(spinlock_t *sl);
#else
/* On UP systems, spinlocks are effectively left out. */
#define SPINLOCK_DECLARE(name)
#define SPINLOCK_INITIALIZE(name)
#define spinlock_initialize(x,name)
#define spinlock_lock(x) preemption_disable()
#define spinlock_trylock(x) (preemption_disable(), 1)
#define spinlock_unlock(x) preemption_enable()
#endif
#endif