1*0a6a1f1dSLionel Sambuc /* $NetBSD: atomic_swap_8_cas.c,v 1.3 2014/06/28 20:18:55 joerg Exp $ */
2*0a6a1f1dSLionel Sambuc
3*0a6a1f1dSLionel Sambuc /*-
4*0a6a1f1dSLionel Sambuc * Copyright (c) 2014 The NetBSD Foundation, Inc.
5*0a6a1f1dSLionel Sambuc * All rights reserved.
6*0a6a1f1dSLionel Sambuc *
7*0a6a1f1dSLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation
8*0a6a1f1dSLionel Sambuc * by Jason R. Thorpe.
9*0a6a1f1dSLionel Sambuc *
10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without
11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions
12*0a6a1f1dSLionel Sambuc * are met:
13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright
14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer.
15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright
16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the
17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution.
18*0a6a1f1dSLionel Sambuc *
19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE.
30*0a6a1f1dSLionel Sambuc */
31*0a6a1f1dSLionel Sambuc
32*0a6a1f1dSLionel Sambuc #include "atomic_op_namespace.h"
33*0a6a1f1dSLionel Sambuc
34*0a6a1f1dSLionel Sambuc #include <sys/atomic.h>
35*0a6a1f1dSLionel Sambuc
36*0a6a1f1dSLionel Sambuc uint8_t
37*0a6a1f1dSLionel Sambuc atomic_swap_8(volatile uint8_t *addr, uint8_t new)
38*0a6a1f1dSLionel Sambuc asm("__sync_lock_test_and_set_1");
39*0a6a1f1dSLionel Sambuc
40*0a6a1f1dSLionel Sambuc uint8_t
atomic_swap_8(volatile uint8_t * addr,uint8_t new)41*0a6a1f1dSLionel Sambuc atomic_swap_8(volatile uint8_t *addr, uint8_t new)
42*0a6a1f1dSLionel Sambuc {
43*0a6a1f1dSLionel Sambuc uint8_t old;
44*0a6a1f1dSLionel Sambuc
45*0a6a1f1dSLionel Sambuc do {
46*0a6a1f1dSLionel Sambuc old = *addr;
47*0a6a1f1dSLionel Sambuc } while (atomic_cas_8(addr, old, new) != old);
48*0a6a1f1dSLionel Sambuc
49*0a6a1f1dSLionel Sambuc return old;
50*0a6a1f1dSLionel Sambuc }
51*0a6a1f1dSLionel Sambuc
52*0a6a1f1dSLionel Sambuc crt_alias(__atomic_exchange_1,__sync_lock_test_and_set_1)
53