/* $OpenBSD: lock_machdep.c,v 1.6 2007/05/29 18:18:20 tom Exp $ */ /* $NetBSD: lock_machdep.c,v 1.1.2.3 2000/05/03 14:40:30 sommerfeld Exp $ */ /*- * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center. * * 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. 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ #include /* RCS ID & Copyright macro defns */ /* * Machine-dependent spin lock operations. */ #include #include #include #include #include #include #include #ifdef LOCKDEBUG void __cpu_simple_lock_init(__cpu_simple_lock_t *lockp) { *lockp = __SIMPLELOCK_UNLOCKED; } #if defined (DEBUG) && defined(DDB) int spin_limit = 10000000; #endif void __cpu_simple_lock(__cpu_simple_lock_t *lockp) { #if defined (DEBUG) && defined(DDB) int spincount = 0; #endif while (i386_atomic_testset_i(lockp, __SIMPLELOCK_LOCKED) == __SIMPLELOCK_LOCKED) { #if defined(DEBUG) && defined(DDB) spincount++; if (spincount == spin_limit) { extern int db_active; db_printf("spundry\n"); if (db_active) { db_printf("but already in debugger\n"); } else { Debugger(); } } #endif } } int __cpu_simple_lock_try(__cpu_simple_lock_t *lockp) { if (i386_atomic_testset_i(lockp, __SIMPLELOCK_LOCKED) == __SIMPLELOCK_UNLOCKED) return (1); return (0); } void __cpu_simple_unlock(__cpu_simple_lock_t *lockp) { *lockp = __SIMPLELOCK_UNLOCKED; } #endif int rw_cas_486(volatile unsigned long *p, unsigned long o, unsigned long n) { return (i486_atomic_cas_int((u_int *)p, o, n) != o); }