1 /* $NetBSD: atomic_swap_32_cas.c,v 1.3 2007/11/28 16:59:11 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include "atomic_op_namespace.h" 40 41 #include <sys/atomic.h> 42 43 uint32_t 44 atomic_swap_32(volatile uint32_t *addr, uint32_t new) 45 { 46 uint32_t old; 47 48 do { 49 old = *addr; 50 } while (atomic_cas_32(addr, old, new) != old); 51 52 return (old); 53 } 54 55 #undef atomic_swap_32 56 atomic_op_alias(atomic_swap_32,_atomic_swap_32) 57 #undef atomic_swap_uint 58 atomic_op_alias(atomic_swap_uint,_atomic_swap_32) 59 __strong_alias(_atomic_swap_uint,_atomic_swap_32) 60 #if !defined(_LP64) 61 #undef atomic_swap_ulong 62 atomic_op_alias(atomic_swap_ulong,_atomic_swap_32) 63 __strong_alias(_atomic_swap_ulong,_atomic_swap_32) 64 #undef atomic_swap_ptr 65 atomic_op_alias(atomic_swap_ptr,_atomic_swap_32) 66 __strong_alias(_atomic_swap_ptr,_atomic_swap_32) 67 #endif /* _LP64 */ 68