xref: /illumos-gate/usr/src/uts/intel/sys/machlock.h (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #ifndef _ASM
32 #include <sys/types.h>
33 #include <sys/time.h>
34 #endif /* _ASM */
35 
36 #ifdef	__cplusplus
37 extern "C" {
38 #endif
39 
40 #ifndef	_ASM
41 
42 #ifdef _KERNEL
43 
44 extern void	lock_set(lock_t *lp);
45 extern int	lock_try(lock_t *lp);
46 extern int	lock_spin_try(lock_t *lp);
47 extern int	ulock_try(lock_t *lp);
48 extern void	lock_clear(lock_t *lp);
49 extern void	ulock_clear(lock_t *lp);
50 extern void	lock_set_spl(lock_t *lp, int new_pil, ushort_t *old_pil);
51 extern void	lock_clear_splx(lock_t *lp, int s);
52 
53 #endif	/* _KERNEL */
54 
55 #define	LOCK_HELD_VALUE		0xff
56 #define	LOCK_INIT_CLEAR(lp)	(*(lp) = 0)
57 #define	LOCK_INIT_HELD(lp)	(*(lp) = LOCK_HELD_VALUE)
58 #define	LOCK_HELD(lp)		(*(volatile lock_t *)(lp) != 0)
59 
60 typedef	lock_t	disp_lock_t;		/* dispatcher lock type */
61 
62 /*
63  * SPIN_LOCK() macro indicates whether lock is implemented as a spin lock or
64  * an adaptive mutex, depending on what interrupt levels use it.
65  */
66 #define	SPIN_LOCK(pl)	((pl) > ipltospl(LOCK_LEVEL))
67 
68 /*
69  * Macro to control loops which spin on a lock and then check state
70  * periodically.  Its passed an integer, and returns a boolean value
71  * that if true indicates its a good time to get the scheduler lock and
72  * check the state of the current owner of the lock.
73  */
74 #define	LOCK_SAMPLE_INTERVAL(i)	(((i) & 0xff) == 0)
75 
76 /*
77  * Externs for CLOCK_LOCK and clock resolution
78  */
79 extern volatile int hres_lock;
80 extern hrtime_t hrtime_base;
81 extern int clock_res;
82 
83 #endif	/* _ASM */
84 
85 /*
86  * The definitions of the symbolic interrupt levels:
87  *
88  *   CLOCK_LEVEL =>  The level at which one must be to block the clock.
89  *
90  *   LOCK_LEVEL  =>  The highest level at which one may block (and thus the
91  *                   highest level at which one may acquire adaptive locks)
92  *                   Also the highest level at which one may be preempted.
93  *
94  *   DISP_LEVEL  =>  The level at which one must be to perform dispatcher
95  *                   operations.
96  *
97  * The constraints on the platform:
98  *
99  *  - CLOCK_LEVEL must be less than or equal to LOCK_LEVEL
100  *  - LOCK_LEVEL must be less than DISP_LEVEL
101  *  - DISP_LEVEL should be as close to LOCK_LEVEL as possible
102  *
103  * Note that LOCK_LEVEL and CLOCK_LEVEL have historically always been equal;
104  * changing this relationship is probably possible but not advised.
105  *
106  */
107 
108 #define	PIL_MAX		15
109 
110 #define	CLOCK_LEVEL	10
111 #define	LOCK_LEVEL	10
112 #define	DISP_LEVEL	(LOCK_LEVEL + 1)
113 
114 #define	HIGH_LEVELS	(PIL_MAX - LOCK_LEVEL)
115 
116 /*
117  * The following mask is for the cpu_intr_actv bits corresponding to
118  * high-level PILs. It should equal:
119  * ((((1 << PIL_MAX + 1) - 1) >> LOCK_LEVEL + 1) << LOCK_LEVEL + 1)
120  */
121 #define	CPU_INTR_ACTV_HIGH_LEVEL_MASK	0xF800
122 
123 /*
124  * The semaphore code depends on being able to represent a lock plus
125  * owner in a single 32-bit word.  (Mutexes used to have a similar
126  * dependency, but no longer.)  Thus the owner must contain at most
127  * 24 significant bits.  At present only threads and semaphores
128  * must be aware of this vile constraint.  Different ISAs may handle this
129  * differently depending on their capabilities (e.g. compare-and-swap)
130  * and limitations (e.g. constraints on alignment and/or KERNELBASE).
131  */
132 #define	PTR24_LSB	5			/* lower bits all zero */
133 #define	PTR24_MSB	(PTR24_LSB + 24)	/* upper bits all one */
134 #define	PTR24_ALIGN	32		/* minimum alignment (1 << lsb) */
135 #define	PTR24_BASE	0xe0000000	/* minimum ptr value (-1 >> (32-msb)) */
136 
137 #ifdef	__cplusplus
138 }
139 #endif
140 
141 #endif	/* _SYS_MACHLOCK_H */
142