lock.h revision 1.13 
1/*	$NetBSD: lock.h,v 1.13 2003/06/26 13:20:55 he Exp $	*/
2
3/*
4 * Copyright (c) 2000 Ludd, University of Lule}, Sweden.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *     This product includes software developed at Ludd, University of Lule}.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#ifndef _VAX_LOCK_H_
34#define _VAX_LOCK_H_
35
36#ifdef _KERNEL
37#ifdef _KERNEL_OPT
38#include "opt_multiprocessor.h"
39#endif
40#include <machine/cpu.h>
41#endif
42
43typedef __volatile int		__cpu_simple_lock_t;
44
45#define __SIMPLELOCK_LOCKED	1
46#define __SIMPLELOCK_UNLOCKED	0
47
48static __inline void
49__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
50{
51#ifdef _KERNEL
52	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
53		: /* No output */
54		: "g"(alp)
55		: "r1","cc","memory");
56#else
57	__asm__ __volatile ("bbcci $0,%0,1f;1:"
58		: /* No output */
59		: "m"(*alp)
60		: "cc");
61#endif
62}
63
64static __inline int
65__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
66{
67	int ret;
68
69#ifdef _KERNEL
70	__asm__ __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
71		: "=&r"(ret)
72		: "g"(alp)
73		: "r0","r1","cc","memory");
74#else
75	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
76		: "=&r"(ret)
77		: "m"(*alp)
78		: "cc");
79#endif
80
81	return ret;
82}
83
84#ifdef _KERNEL
85#define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
86#define	__cpu_simple_lock(alp)						\
87do {									\
88	struct cpu_info *__ci = curcpu();				\
89									\
90	while (__cpu_simple_lock_try(alp) == 0) {			\
91		int __s;						\
92									\
93		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
94			__s = splipi();					\
95			cpu_handle_ipi();				\
96			splx(__s);					\
97		}							\
98	}								\
99} while (0)
100#else
101static __inline void
102__cpu_simple_lock(__cpu_simple_lock_t *alp)
103{
104	__asm__ __volatile ("1:bbssi $0,%0,1b"
105		: /* No outputs */
106		: "m"(*alp)
107		: "cc");
108}
109#endif /* _KERNEL */
110
111#if 0
112static __inline void
113__cpu_simple_lock(__cpu_simple_lock_t *alp)
114{
115	struct cpu_info *ci = curcpu();
116
117	while (__cpu_simple_lock_try(alp) == 0) {
118		int s;
119
120		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
121			s = splipi();
122			cpu_handle_ipi();
123			splx(s);
124		}
125	}
126
127#if 0
128	__asm__ __volatile ("movl %0,%%r1;jsb Slock"
129		: /* No output */
130		: "g"(alp)
131		: "r0","r1","cc","memory");
132#endif
133#if 0
134	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
135		: /* No output */
136		: "m"(*alp));
137#endif
138}
139#endif
140
141static __inline void
142__cpu_simple_unlock(__cpu_simple_lock_t *alp)
143{
144#ifdef _KERNEL
145	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
146		: /* No output */
147		: "g"(alp)
148		: "r1","cc","memory");
149#else
150	__asm__ __volatile ("bbcci $0,%0,1f;1:"
151		: /* No output */
152		: "m"(*alp)
153		: "cc");
154#endif
155}
156
157#if defined(MULTIPROCESSOR)
158/*
159 * On the Vax, interprocessor interrupts can come in at device priority
160 * level or lower. This can cause some problems while waiting for r/w
161 * spinlocks from a high'ish priority level: IPIs that come in will not
162 * be processed. This can lead to deadlock.
163 *
164 * This hook allows IPIs to be processed while a spinlock's interlock
165 * is released.
166 */
167#define SPINLOCK_SPIN_HOOK						\
168do {									\
169	struct cpu_info *__ci = curcpu();				\
170	int __s;							\
171									\
172	if (__ci->ci_ipimsgs != 0) {					\
173		/* printf("CPU %lu has IPIs pending\n",			\
174		    __ci->ci_cpuid); */					\
175		__s = splipi();						\
176		cpu_handle_ipi();					\
177		splx(__s);						\
178	}								\
179} while (0)
180#endif /* MULTIPROCESSOR */
181#endif /* _VAX_LOCK_H_ */
182