1 /* $OpenBSD: mplock.h,v 1.1 2010/03/25 14:26:21 jsing Exp $ */ 2 3 /* 4 * Copyright (c) 2004 Niklas Hallqvist. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #ifndef _MACHINE_MPLOCK_H_ 28 #define _MACHINE_MPLOCK_H_ 29 30 /* 31 * Really simple spinlock implementation with recursive capabilities. 32 * Correctness is paramount, no fancyness allowed. 33 */ 34 35 #define MPL_LOCKED 0 36 #define MPL_UNLOCKED 1 37 38 struct __mp_lock { 39 volatile int mpl_lock[4]; 40 volatile struct cpu_info *mpl_cpu; 41 volatile long mpl_count; 42 }; 43 44 #ifndef _LOCORE 45 46 void __mp_lock_init(struct __mp_lock *); 47 void __mp_lock(struct __mp_lock *); 48 void __mp_unlock(struct __mp_lock *); 49 int __mp_release_all(struct __mp_lock *); 50 int __mp_release_all_but_one(struct __mp_lock *); 51 void __mp_acquire_count(struct __mp_lock *, int); 52 int __mp_lock_held(struct __mp_lock *); 53 54 #endif 55 56 #endif /* !_MACHINE_MPLOCK_H */ 57