xref: /illumos-gate/usr/src/uts/intel/sys/machlock.h (revision 88f8b78a88cbdc6d8c1af5c3e54bc49d25095c98)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #ifndef _SYS_MACHLOCK_H
28 #define	_SYS_MACHLOCK_H
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #ifndef _ASM
33 #include <sys/types.h>
34 #include <sys/time.h>
35 #endif /* _ASM */
36 
37 #ifdef	__cplusplus
38 extern "C" {
39 #endif
40 
41 #ifndef	_ASM
42 
43 #ifdef _KERNEL
44 
45 extern void	lock_set(lock_t *lp);
46 extern int	lock_try(lock_t *lp);
47 extern int	lock_spin_try(lock_t *lp);
48 extern int	ulock_try(lock_t *lp);
49 extern void	lock_clear(lock_t *lp);
50 extern void	ulock_clear(lock_t *lp);
51 extern void	lock_set_spl(lock_t *lp, int new_pil, ushort_t *old_pil);
52 extern void	lock_clear_splx(lock_t *lp, int s);
53 
54 #endif	/* _KERNEL */
55 
56 #define	LOCK_HELD_VALUE		0xff
57 #define	LOCK_INIT_CLEAR(lp)	(*(lp) = 0)
58 #define	LOCK_INIT_HELD(lp)	(*(lp) = LOCK_HELD_VALUE)
59 #define	LOCK_HELD(lp)		(*(volatile lock_t *)(lp) != 0)
60 
61 typedef	lock_t	disp_lock_t;		/* dispatcher lock type */
62 
63 /*
64  * SPIN_LOCK() macro indicates whether lock is implemented as a spin lock or
65  * an adaptive mutex, depending on what interrupt levels use it.
66  */
67 #define	SPIN_LOCK(pl)	((pl) > ipltospl(LOCK_LEVEL))
68 
69 /*
70  * Macro to control loops which spin on a lock and then check state
71  * periodically.  Its passed an integer, and returns a boolean value
72  * that if true indicates its a good time to get the scheduler lock and
73  * check the state of the current owner of the lock.
74  */
75 #define	LOCK_SAMPLE_INTERVAL(i)	(((i) & 0xff) == 0)
76 
77 /*
78  * Externs for CLOCK_LOCK and clock resolution
79  */
80 #ifdef __STDC__
81 extern volatile int hres_lock;
82 #else
83 extern int hres_lock;
84 #endif
85 extern hrtime_t hrtime_base;
86 extern int clock_res;
87 
88 #endif	/* _ASM */
89 
90 /*
91  * The definitions of the symbolic interrupt levels:
92  *
93  *   CLOCK_LEVEL =>  The level at which one must be to block the clock.
94  *
95  *   LOCK_LEVEL  =>  The highest level at which one may block (and thus the
96  *                   highest level at which one may acquire adaptive locks)
97  *                   Also the highest level at which one may be preempted.
98  *
99  *   DISP_LEVEL  =>  The level at which one must be to perform dispatcher
100  *                   operations.
101  *
102  * The constraints on the platform:
103  *
104  *  - CLOCK_LEVEL must be less than or equal to LOCK_LEVEL
105  *  - LOCK_LEVEL must be less than DISP_LEVEL
106  *  - DISP_LEVEL should be as close to LOCK_LEVEL as possible
107  *
108  * Note that LOCK_LEVEL and CLOCK_LEVEL have historically always been equal;
109  * changing this relationship is probably possible but not advised.
110  *
111  */
112 
113 #define	PIL_MAX		15
114 
115 #define	CLOCK_LEVEL	10
116 #define	LOCK_LEVEL	10
117 #define	DISP_LEVEL	(LOCK_LEVEL + 1)
118 
119 #define	HIGH_LEVELS	(PIL_MAX - LOCK_LEVEL)
120 
121 /*
122  * The following mask is for the cpu_intr_actv bits corresponding to
123  * high-level PILs. It should equal:
124  * ((((1 << PIL_MAX + 1) - 1) >> LOCK_LEVEL + 1) << LOCK_LEVEL + 1)
125  */
126 #define	CPU_INTR_ACTV_HIGH_LEVEL_MASK	0xF800
127 
128 /*
129  * The semaphore code depends on being able to represent a lock plus
130  * owner in a single 32-bit word.  (Mutexes used to have a similar
131  * dependency, but no longer.)  Thus the owner must contain at most
132  * 24 significant bits.  At present only threads and semaphores
133  * must be aware of this vile constraint.  Different ISAs may handle this
134  * differently depending on their capabilities (e.g. compare-and-swap)
135  * and limitations (e.g. constraints on alignment and/or KERNELBASE).
136  */
137 #define	PTR24_LSB	5			/* lower bits all zero */
138 #define	PTR24_MSB	(PTR24_LSB + 24)	/* upper bits all one */
139 #define	PTR24_ALIGN	32		/* minimum alignment (1 << lsb) */
140 #define	PTR24_BASE	0xe0000000	/* minimum ptr value (-1 >> (32-msb)) */
141 
142 #ifdef	__cplusplus
143 }
144 #endif
145 
146 #endif	/* _SYS_MACHLOCK_H */
147