xref: /netbsd-src/common/lib/libc/atomic/atomic_load.c (revision d231a5d2553a5d505de0e0aec217c41ebd0b9aba)
1 /*	$NetBSD: atomic_load.c,v 1.5 2024/02/14 18:00:02 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: atomic_load.c,v 1.5 2024/02/14 18:00:02 christos Exp $");
31 
32 #include "atomic_op_namespace.h"
33 
34 #include <sys/types.h>
35 #include <sys/atomic.h>
36 
37 #define atomic_load_n(n,b) \
38 uint ## b ## _t __atomic_load_ ## n(const volatile void *, int); \
39 /*ARGSUSED*/ \
40 uint ## b ## _t \
41 __atomic_load_ ## n(const volatile void *ptr, int memmodel __unused) \
42 { \
43 	uint## b ##_t val; \
44 	val = *(const volatile uint ## b ## _t *)ptr; \
45 	membar_acquire(); \
46 	return val; \
47 }
48 
49 atomic_load_n(1, 8)
50 atomic_load_n(2, 16)
51 atomic_load_n(4, 32)
52 #ifdef	__HAVE_ATOMIC_CAS_64_UP
53 atomic_load_n(8, 64)
54 #endif
55