1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#ifndef _SYS_MACHLOCK_H
27#define	_SYS_MACHLOCK_H
28
29#ifdef	__cplusplus
30extern "C" {
31#endif
32
33#ifndef	_ASM
34
35#include <sys/types.h>
36
37#ifdef _KERNEL
38
39extern void	lock_set(lock_t *lp);
40extern int	lock_try(lock_t *lp);
41extern int	lock_spin_try(lock_t *lp);
42extern int	ulock_try(lock_t *lp);
43extern void	ulock_clear(lock_t *lp);
44extern void	lock_clear(lock_t *lp);
45extern void	lock_set_spl(lock_t *lp, int new_pil, ushort_t *old_pil);
46extern void	lock_clear_splx(lock_t *lp, int s);
47
48#endif	/* _KERNEL */
49
50#define	LOCK_HELD_VALUE		0xff
51#define	LOCK_INIT_CLEAR(lp)	(*(lp) = 0)
52#define	LOCK_INIT_HELD(lp)	(*(lp) = LOCK_HELD_VALUE)
53#define	LOCK_HELD(lp)		(*(volatile lock_t *)(lp) != 0)
54
55typedef	lock_t	disp_lock_t;		/* dispatcher lock type */
56
57/*
58 * SPIN_LOCK() macro indicates whether lock is implemented as a spin lock or
59 * an adaptive mutex, depending on what interrupt levels use it.
60 */
61#define	SPIN_LOCK(pl)	((pl) > ipltospl(LOCK_LEVEL))
62
63/*
64 * Macro to control loops which spin on a lock and then check state
65 * periodically.  Its passed an integer, and returns a boolean value
66 * that if true indicates its a good time to get the scheduler lock and
67 * check the state of the current owner of the lock.
68 */
69#define	LOCK_SAMPLE_INTERVAL(i)	(((i) & 0xff) == 0)
70
71/*
72 * Extern for CLOCK_LOCK.
73 */
74extern	volatile int	hres_lock;
75
76#endif	/* _ASM */
77
78/*
79 * The definitions of the symbolic interrupt levels:
80 *
81 *   CLOCK_LEVEL =>  The level at which one must be to block the clock.
82 *
83 *   LOCK_LEVEL  =>  The highest level at which one may block (and thus the
84 *                   highest level at which one may acquire adaptive locks)
85 *                   Also the highest level at which one may be preempted.
86 *
87 *   DISP_LEVEL  =>  The level at which one must be to perform dispatcher
88 *                   operations.
89 *
90 * The constraints on the platform:
91 *
92 *  - CLOCK_LEVEL must be less than or equal to LOCK_LEVEL
93 *  - LOCK_LEVEL must be less than DISP_LEVEL
94 *  - DISP_LEVEL should be as close to LOCK_LEVEL as possible
95 *
96 * Note that LOCK_LEVEL and CLOCK_LEVEL have historically always been equal;
97 * changing this relationship is probably possible but not advised.
98 *
99 */
100#define	CLOCK_LEVEL	10
101#define	LOCK_LEVEL	10
102#define	DISP_LEVEL	(LOCK_LEVEL + 1)
103
104#define	HIGH_LEVELS	(PIL_MAX - LOCK_LEVEL)
105
106#define	PIL_MAX		15
107
108/*
109 * The mutex and semaphore code depends on being able to represent a lock
110 * plus owner in a single 32-bit word.  Thus the owner must contain at most
111 * 24 significant bits.  At present only threads, mutexes and semaphores
112 * must be aware of this vile constraint.  Different ISAs may handle this
113 * differently depending on their capabilities (e.g. compare-and-swap)
114 * and limitations (e.g. constraints on alignment and/or KERNELBASE).
115 */
116#define	PTR24_LSB	5			/* lower bits all zero */
117#define	PTR24_MSB	(PTR24_LSB + 24)	/* upper bits all one */
118#define	PTR24_ALIGN	32		/* minimum alignment (1 << lsb) */
119#define	PTR24_BASE	0xe0000000	/* minimum ptr value (-1 >> (32-msb)) */
120
121#ifdef	__cplusplus
122}
123#endif
124
125#endif	/* _SYS_MACHLOCK_H */
126