xref: /onnv-gate/usr/src/uts/common/sys/mutex.h (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright (c) 1991-1998 by Sun Microsystems, Inc.
24*0Sstevel@tonic-gate  * All rights reserved.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #ifndef _SYS_MUTEX_H
28*0Sstevel@tonic-gate #define	_SYS_MUTEX_H
29*0Sstevel@tonic-gate 
30*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate #ifndef	_ASM
33*0Sstevel@tonic-gate #include <sys/types.h>
34*0Sstevel@tonic-gate #endif
35*0Sstevel@tonic-gate 
36*0Sstevel@tonic-gate #ifdef	__cplusplus
37*0Sstevel@tonic-gate extern "C" {
38*0Sstevel@tonic-gate #endif
39*0Sstevel@tonic-gate 
40*0Sstevel@tonic-gate #ifndef	_ASM
41*0Sstevel@tonic-gate 
42*0Sstevel@tonic-gate /*
43*0Sstevel@tonic-gate  * Public interface to mutual exclusion locks.  See mutex(9F) for details.
44*0Sstevel@tonic-gate  *
45*0Sstevel@tonic-gate  * The basic mutex type is MUTEX_ADAPTIVE, which is expected to be used
46*0Sstevel@tonic-gate  * in almost all of the kernel.  MUTEX_SPIN provides interrupt blocking
47*0Sstevel@tonic-gate  * and must be used in interrupt handlers above LOCK_LEVEL.  The iblock
48*0Sstevel@tonic-gate  * cookie argument to mutex_init() encodes the interrupt level to block.
49*0Sstevel@tonic-gate  * The iblock cookie must be NULL for adaptive locks.
50*0Sstevel@tonic-gate  *
51*0Sstevel@tonic-gate  * MUTEX_DEFAULT is the type usually specified (except in drivers) to
52*0Sstevel@tonic-gate  * mutex_init().  It is identical to MUTEX_ADAPTIVE.
53*0Sstevel@tonic-gate  *
54*0Sstevel@tonic-gate  * MUTEX_DRIVER is always used by drivers.  mutex_init() converts this to
55*0Sstevel@tonic-gate  * either MUTEX_ADAPTIVE or MUTEX_SPIN depending on the iblock cookie.
56*0Sstevel@tonic-gate  *
57*0Sstevel@tonic-gate  * Mutex statistics can be gathered on the fly, without rebooting or
58*0Sstevel@tonic-gate  * recompiling the kernel, via the lockstat driver (lockstat(7D)).
59*0Sstevel@tonic-gate  */
60*0Sstevel@tonic-gate typedef enum {
61*0Sstevel@tonic-gate 	MUTEX_ADAPTIVE = 0,	/* spin if owner is running, otherwise block */
62*0Sstevel@tonic-gate 	MUTEX_SPIN = 1,		/* block interrupts and spin */
63*0Sstevel@tonic-gate 	MUTEX_DRIVER = 4,	/* driver (DDI) mutex */
64*0Sstevel@tonic-gate 	MUTEX_DEFAULT = 6	/* kernel default mutex */
65*0Sstevel@tonic-gate } kmutex_type_t;
66*0Sstevel@tonic-gate 
67*0Sstevel@tonic-gate typedef struct mutex {
68*0Sstevel@tonic-gate #ifdef _LP64
69*0Sstevel@tonic-gate 	void	*_opaque[1];
70*0Sstevel@tonic-gate #else
71*0Sstevel@tonic-gate 	void	*_opaque[2];
72*0Sstevel@tonic-gate #endif
73*0Sstevel@tonic-gate } kmutex_t;
74*0Sstevel@tonic-gate 
75*0Sstevel@tonic-gate #ifdef _KERNEL
76*0Sstevel@tonic-gate 
77*0Sstevel@tonic-gate #define	MUTEX_HELD(x)		(mutex_owned(x))
78*0Sstevel@tonic-gate #define	MUTEX_NOT_HELD(x)	(!mutex_owned(x) || panicstr)
79*0Sstevel@tonic-gate 
80*0Sstevel@tonic-gate extern	void	mutex_init(kmutex_t *, char *, kmutex_type_t, void *);
81*0Sstevel@tonic-gate extern	void	mutex_destroy(kmutex_t *);
82*0Sstevel@tonic-gate extern	void	mutex_enter(kmutex_t *);
83*0Sstevel@tonic-gate extern	int	mutex_tryenter(kmutex_t *);
84*0Sstevel@tonic-gate extern	void	mutex_exit(kmutex_t *);
85*0Sstevel@tonic-gate extern	int	mutex_owned(kmutex_t *);
86*0Sstevel@tonic-gate extern	struct _kthread *mutex_owner(kmutex_t *);
87*0Sstevel@tonic-gate 
88*0Sstevel@tonic-gate #endif	/* _KERNEL */
89*0Sstevel@tonic-gate 
90*0Sstevel@tonic-gate #endif	/* _ASM */
91*0Sstevel@tonic-gate 
92*0Sstevel@tonic-gate #ifdef	__cplusplus
93*0Sstevel@tonic-gate }
94*0Sstevel@tonic-gate #endif
95*0Sstevel@tonic-gate 
96*0Sstevel@tonic-gate #endif	/* _SYS_MUTEX_H */
97