xref: /freebsd/sys/sys/membarrier.h (revision 069ac184)
1 /*-
2  * Copyright (c) 2021 The FreeBSD Foundation
3  *
4  * This software were developed by Konstantin Belousov <kib@FreeBSD.org>
5  * under sponsorship from the FreeBSD Foundation.
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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef __SYS_MEMBARRIER_H__
30 #define	__SYS_MEMBARRIER_H__
31 
32 #include <sys/cdefs.h>
33 
34 /*
35  * The enum membarrier_cmd values are bits.  The MEMBARRIER_CMD_QUERY
36  * command returns a bitset indicating which commands are supported.
37  * Also the value of MEMBARRIER_CMD_QUERY is zero, so it is
38  * effectively not returned by the query.
39  */
40 enum membarrier_cmd {
41 	MEMBARRIER_CMD_QUERY =				0x00000000,
42 	MEMBARRIER_CMD_GLOBAL =				0x00000001,
43 	MEMBARRIER_CMD_SHARED =				MEMBARRIER_CMD_GLOBAL,
44 	MEMBARRIER_CMD_GLOBAL_EXPEDITED =		0x00000002,
45 	MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED =	0x00000004,
46 	MEMBARRIER_CMD_PRIVATE_EXPEDITED =		0x00000008,
47 	MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED =	0x00000010,
48 	MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE =	0x00000020,
49 	MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE =	0x00000040,
50 
51 	/*
52 	 * RSEQ constants are defined for source compatibility but are
53 	 * not yes supported, MEMBARRIER_CMD_QUERY does not return
54 	 * them in the mask.
55 	 */
56 	MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ =		0x00000080,
57 	MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ = 0x00000100,
58 };
59 
60 enum membarrier_cmd_flag {
61 	MEMBARRIER_CMD_FLAG_CPU =			0x00000001,
62 };
63 
64 #ifndef _KERNEL
65 __BEGIN_DECLS
66 int membarrier(int, unsigned, int);
67 __END_DECLS
68 #endif	/* _KERNEL */
69 
70 #endif /* __SYS_MEMBARRIER_H__ */
71