glibc/db2/mutex/parisc.gcc

/*
 * @(#)parisc.gcc	8.8 (Sleepycat) 6/2/98
 *
 * Copyright (c) 1996-1997, The University of Utah and the Computer Systems
 * Laboratory at the University of Utah (CSL).  All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software is hereby
 * granted provided that (1) source code retains these copyright, permission,
 * and disclaimer notices, and (2) redistributions including binaries
 * reproduce the notices in supporting documentation, and (3) all advertising
 * materials mentioning features or use of this software display the following
 * acknowledgement: ``This product includes software developed by the Computer
 * Systems Laboratory at the University of Utah.''
 *
 * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
 * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
 * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * CSL requests users of this software to return to csl-dist@cs.utah.edu any
 * improvements that they make and grant CSL redistribution rights.
 */

/*
 * The PA-RISC has a "load and clear" instead of a "test and set" instruction.
 * The 32-bit word used by that instruction must be 16-byte aligned.  We could
 * use the "aligned" attribute in GCC but that doesn't work for stack variables.
 */
#define	TSL_SET(tsl) ({							\
	register tsl_t *__l = (tsl);					\
	int __r;							\
	asm volatile("ldcws 0(%1),%0" : "=r" (__r) : "r" (__l));	\
	__r & 1;							\
})

#define	TSL_UNSET(tsl)	(*(tsl) = -1)
#define	TSL_INIT(tsl)	TSL_UNSET(tsl)