xref: /netbsd-src/sys/external/bsd/common/include/linux/srcu.h (revision 9e5fbd4f7f25d0a357b482f4591196ee62d90ed5)
1 /*	$NetBSD: srcu.h,v 1.4 2021/12/19 11:49:11 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2018 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Taylor R. Campbell.
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 #ifndef	_LINUX_SRCU_H_
33 #define	_LINUX_SRCU_H_
34 
35 #include <sys/types.h>
36 #include <sys/condvar.h>
37 #include <sys/mutex.h>
38 
39 /* namespace */
40 #define	_init_srcu_struct	linux__init_init_srcu_struct
41 #define	cleanup_srcu_struct	linux_cleanup_srcu_struct
42 #define	srcu_read_lock		linux_srcu_read_lock
43 #define	srcu_read_unlock	linux_srcu_read_unlock
44 #define	synchronize_srcu	linux_synchronize_srcu
45 #define	synchronize_srcu_expedited linux_synchronize_srcu_expedited
46 
47 struct lwp;
48 struct percpu;
49 
50 struct srcu_struct {
51 	struct percpu		*srcu_percpu;	/* struct srcu_cpu */
52 	kmutex_t		srcu_lock;
53 	kcondvar_t		srcu_cv;
54 	struct lwp		*srcu_sync;
55 	int64_t			srcu_total;
56 	volatile unsigned	srcu_gen;
57 };
58 
59 #define	init_srcu_struct(S)	_init_srcu_struct(S, #S)
60 
61 void	_init_srcu_struct(struct srcu_struct *, const char *);
62 void	cleanup_srcu_struct(struct srcu_struct *);
63 
64 int	srcu_read_lock(struct srcu_struct *);
65 void	srcu_read_unlock(struct srcu_struct *, int);
66 
67 void	synchronize_srcu(struct srcu_struct *);
68 void	synchronize_srcu_expedited(struct srcu_struct *);
69 
70 #endif	/* _LINUX_SRCU_H_ */
71