freebsd-dev/sys/alpha/include/lock.h
Jason Evans 0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00

75 lines
2.4 KiB
C

/*
* Copyright (c) 1997, by Steve Passe
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the developer 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#ifndef _MACHINE_LOCK_H_
#define _MACHINE_LOCK_H_
/*
* Simple spin lock.
* It is an error to hold one of these locks while a process is sleeping.
*/
struct simplelock {
volatile u_int lock_data;
};
/* functions in mp_machdep.c */
void s_lock_init __P((struct simplelock *));
void s_lock __P((struct simplelock *));
int s_lock_try __P((struct simplelock *));
void ss_lock __P((struct simplelock *));
void ss_unlock __P((struct simplelock *));
void s_lock_np __P((struct simplelock *));
void s_unlock_np __P((struct simplelock *));
/* inline simplelock functions */
static __inline void
s_unlock(struct simplelock *lkp)
{
alpha_mb();
lkp->lock_data = 0;
}
#if !defined(SIMPLELOCK_DEBUG) && NCPUS > 1
/*
* This set of defines turns on the real functions in i386/isa/apic_ipl.s.
*/
#define simple_lock_init(alp) s_lock_init(alp)
#define simple_lock(alp) s_lock(alp)
#define simple_lock_try(alp) s_lock_try(alp)
#define simple_unlock(alp) s_unlock(alp)
#endif /* !SIMPLELOCK_DEBUG && NCPUS > 1 */
#define COM_LOCK()
#define COM_UNLOCK()
#define COM_DISABLE_INTR() COM_LOCK()
#define COM_ENABLE_INTR() COM_UNLOCK()
#endif /* !_MACHINE_LOCK_H_ */