xref: /onnv-gate/usr/src/uts/common/sys/mutex.h (revision 6138:1b7a278742d4)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
53914Spm145316  * Common Development and Distribution License (the "License").
63914Spm145316  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
210Sstevel@tonic-gate /*
225834Spt157919  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
233914Spm145316  * Use is subject to license terms.
240Sstevel@tonic-gate  */
250Sstevel@tonic-gate 
260Sstevel@tonic-gate #ifndef _SYS_MUTEX_H
270Sstevel@tonic-gate #define	_SYS_MUTEX_H
280Sstevel@tonic-gate 
290Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
300Sstevel@tonic-gate 
310Sstevel@tonic-gate #ifndef	_ASM
320Sstevel@tonic-gate #include <sys/types.h>
330Sstevel@tonic-gate #endif
340Sstevel@tonic-gate 
350Sstevel@tonic-gate #ifdef	__cplusplus
360Sstevel@tonic-gate extern "C" {
370Sstevel@tonic-gate #endif
380Sstevel@tonic-gate 
390Sstevel@tonic-gate #ifndef	_ASM
400Sstevel@tonic-gate 
410Sstevel@tonic-gate /*
420Sstevel@tonic-gate  * Public interface to mutual exclusion locks.  See mutex(9F) for details.
430Sstevel@tonic-gate  *
440Sstevel@tonic-gate  * The basic mutex type is MUTEX_ADAPTIVE, which is expected to be used
450Sstevel@tonic-gate  * in almost all of the kernel.  MUTEX_SPIN provides interrupt blocking
460Sstevel@tonic-gate  * and must be used in interrupt handlers above LOCK_LEVEL.  The iblock
470Sstevel@tonic-gate  * cookie argument to mutex_init() encodes the interrupt level to block.
480Sstevel@tonic-gate  * The iblock cookie must be NULL for adaptive locks.
490Sstevel@tonic-gate  *
500Sstevel@tonic-gate  * MUTEX_DEFAULT is the type usually specified (except in drivers) to
510Sstevel@tonic-gate  * mutex_init().  It is identical to MUTEX_ADAPTIVE.
520Sstevel@tonic-gate  *
530Sstevel@tonic-gate  * MUTEX_DRIVER is always used by drivers.  mutex_init() converts this to
540Sstevel@tonic-gate  * either MUTEX_ADAPTIVE or MUTEX_SPIN depending on the iblock cookie.
550Sstevel@tonic-gate  *
560Sstevel@tonic-gate  * Mutex statistics can be gathered on the fly, without rebooting or
570Sstevel@tonic-gate  * recompiling the kernel, via the lockstat driver (lockstat(7D)).
580Sstevel@tonic-gate  */
590Sstevel@tonic-gate typedef enum {
600Sstevel@tonic-gate 	MUTEX_ADAPTIVE = 0,	/* spin if owner is running, otherwise block */
610Sstevel@tonic-gate 	MUTEX_SPIN = 1,		/* block interrupts and spin */
620Sstevel@tonic-gate 	MUTEX_DRIVER = 4,	/* driver (DDI) mutex */
630Sstevel@tonic-gate 	MUTEX_DEFAULT = 6	/* kernel default mutex */
640Sstevel@tonic-gate } kmutex_type_t;
650Sstevel@tonic-gate 
660Sstevel@tonic-gate typedef struct mutex {
670Sstevel@tonic-gate #ifdef _LP64
680Sstevel@tonic-gate 	void	*_opaque[1];
690Sstevel@tonic-gate #else
700Sstevel@tonic-gate 	void	*_opaque[2];
710Sstevel@tonic-gate #endif
720Sstevel@tonic-gate } kmutex_t;
730Sstevel@tonic-gate 
740Sstevel@tonic-gate #ifdef _KERNEL
750Sstevel@tonic-gate 
760Sstevel@tonic-gate #define	MUTEX_HELD(x)		(mutex_owned(x))
770Sstevel@tonic-gate #define	MUTEX_NOT_HELD(x)	(!mutex_owned(x) || panicstr)
780Sstevel@tonic-gate 
790Sstevel@tonic-gate extern	void	mutex_init(kmutex_t *, char *, kmutex_type_t, void *);
800Sstevel@tonic-gate extern	void	mutex_destroy(kmutex_t *);
810Sstevel@tonic-gate extern	void	mutex_enter(kmutex_t *);
820Sstevel@tonic-gate extern	int	mutex_tryenter(kmutex_t *);
830Sstevel@tonic-gate extern	void	mutex_exit(kmutex_t *);
840Sstevel@tonic-gate extern	int	mutex_owned(kmutex_t *);
850Sstevel@tonic-gate extern	struct _kthread *mutex_owner(kmutex_t *);
865834Spt157919 
875834Spt157919 extern  ushort_t mutex_backoff_base;
885834Spt157919 extern  uint_t mutex_backoff_cap;
895834Spt157919 extern  ushort_t mutex_cap_factor;
905834Spt157919 extern  uchar_t mutex_backoff_shift;
915834Spt157919 extern  void (*mutex_lock_delay)(uint_t);
925834Spt157919 extern  uint_t (*mutex_lock_backoff)(uint_t);
935834Spt157919 extern  void (*mutex_delay)(void);
945834Spt157919 extern  void mutex_delay_default(void);
955834Spt157919 extern  void mutex_sync(void);
960Sstevel@tonic-gate 
97*6138Ssvemuri extern	void default_lock_delay(uint_t);
98*6138Ssvemuri extern	uint_t default_lock_backoff(uint_t);
99*6138Ssvemuri 
1000Sstevel@tonic-gate #endif	/* _KERNEL */
1010Sstevel@tonic-gate 
1020Sstevel@tonic-gate #endif	/* _ASM */
1030Sstevel@tonic-gate 
1040Sstevel@tonic-gate #ifdef	__cplusplus
1050Sstevel@tonic-gate }
1060Sstevel@tonic-gate #endif
1070Sstevel@tonic-gate 
1080Sstevel@tonic-gate #endif	/* _SYS_MUTEX_H */
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