1 /* $NetBSD: atomic_swap_64_cas.c,v 1.9 2014/06/28 20:18:55 joerg 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "atomic_op_namespace.h"
33
34 #include <sys/atomic.h>
35
36 #ifdef __HAVE_ATOMIC64_OPS
37
38 uint64_t
atomic_swap_64(volatile uint64_t * addr,uint64_t new)39 atomic_swap_64(volatile uint64_t *addr, uint64_t new)
40 {
41 uint64_t old;
42
43 do {
44 old = *addr;
45 } while (atomic_cas_64(addr, old, new) != old);
46
47 return (old);
48 }
49
50 crt_alias(__atomic_exchange_8,_atomic_swap_8)
51
52 #undef atomic_swap_64
53 atomic_op_alias(atomic_swap_64,_atomic_swap_64)
54 crt_alias(__sync_lock_test_and_set_8,_atomic_swap_64)
55 #if defined(_LP64)
56 #undef atomic_swap_ulong
57 atomic_op_alias(atomic_swap_ulong,_atomic_swap_64)
58 __strong_alias(_atomic_swap_ulong,_atomic_swap_64)
59 #undef atomic_swap_ptr
60 atomic_op_alias(atomic_swap_ptr,_atomic_swap_64)
61 __strong_alias(_atomic_swap_ptr,_atomic_swap_64)
62 #endif /* _LP64 */
63
64 #endif
65