spinlock_sparc.h

/*
    m5threads, a pthread library for the M5 simulator
    Copyright (C) 2009, Stanford University

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
*/


#ifndef __SPINLOCK_SPARC_H__
#define __SPINLOCK_SPARC_H__

// routines from /usr/src/linux/include/asm-sparc/spinlock_64.h
// Note: these work even with RMO, but a few barriers could be eliminated for TSO

static __inline__ void spin_lock(volatile int* lock)
{
	unsigned long tmp;

	__asm__ __volatile__(
"1:	ldstub		[%1], %0\n"
"	membar		#StoreLoad | #StoreStore\n"
"	brnz,pn		%0, 2f\n"
"	 nop\n"
"	.subsection	2\n"
"2:	ldub		[%1], %0\n"
"	membar		#LoadLoad\n"
"	brnz,pt		%0, 2b\n"
"	 nop\n"
"	ba,a,pt		%%xcc, 1b\n"
"	.previous"
	: "=&r" (tmp)
	: "r" (lock)
	: "memory");
}

static __inline__ int trylock(volatile int* lock)
{
	unsigned long result;

	__asm__ __volatile__(
"	ldstub		[%1], %0\n"
"	membar		#StoreLoad | #StoreStore"
	: "=r" (result)
	: "r" (lock)
	: "memory");

	return (result == 0);
}

static __inline__ void spin_unlock(volatile int* lock)
{
	__asm__ __volatile__(
"	membar		#StoreStore | #LoadStore\n"
"	stb		%%g0, [%0]"
	: // No outputs 
	: "r" (lock)
	: "memory");
}


#endif  // __SPINLOCK_SPARC_H__