lock.h revision 1.10 
1/*	$NetBSD: lock.h,v 1.10 2002/10/10 17:12:23 thorpej 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
36typedef __volatile int		__cpu_simple_lock_t;
37
38#define __SIMPLELOCK_LOCKED	1
39#define __SIMPLELOCK_UNLOCKED	0
40
41static __inline void
42__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
43{
44#ifdef _KERNEL
45	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
46		: /* No output */
47		: "g"(alp)
48		: "r1","cc","memory");
49#else
50	__asm__ __volatile ("bbcci $0,%0,1f;1:"
51		: /* No output */
52		: "m"(*alp)
53		: "cc");
54#endif
55}
56
57static __inline int
58__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
59{
60	int ret;
61
62#ifdef _KERNEL
63	__asm__ __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
64		: "=&r"(ret)
65		: "g"(alp)
66		: "r0","r1","cc","memory");
67#else
68	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
69		: "=&r"(ret)
70		: "m"(*alp)
71		: "cc");
72#endif
73
74	return ret;
75}
76
77#ifdef _KERNEL
78#define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
79#define	__cpu_simple_lock(alp)						\
80do {									\
81	struct cpu_info *__ci = curcpu();				\
82									\
83	while (__cpu_simple_lock_try(alp) == 0) {			\
84		int __s;						\
85									\
86		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
87			__s = splipi();					\
88			cpu_handle_ipi();				\
89			splx(__s);					\
90		}							\
91	}								\
92} while (0)
93#else
94static __inline void
95__cpu_simple_lock(__cpu_simple_lock_t *alp)
96{
97	__asm__ __volatile ("1:bbssi $0,%0,1b"
98		: /* No outputs */
99		: "m"(*alp)
100		: "cc");
101}
102#endif /* _KERNEL */
103
104#if 0
105static __inline void
106__cpu_simple_lock(__cpu_simple_lock_t *alp)
107{
108	struct cpu_info *ci = curcpu();
109
110	while (__cpu_simple_lock_try(alp) == 0) {
111		int s;
112
113		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
114			s = splipi();
115			cpu_handle_ipi();
116			splx(s);
117		}
118	}
119
120#if 0
121	__asm__ __volatile ("movl %0,%%r1;jsb Slock"
122		: /* No output */
123		: "g"(alp)
124		: "r0","r1","cc","memory");
125#endif
126#if 0
127	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
128		: /* No output */
129		: "m"(*alp));
130#endif
131}
132#endif
133
134static __inline void
135__cpu_simple_unlock(__cpu_simple_lock_t *alp)
136{
137#ifdef _KERNEL
138	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
139		: /* No output */
140		: "g"(alp)
141		: "r1","cc","memory");
142#else
143	__asm__ __volatile ("bbcci $0,%0,1f;1:"
144		: /* No output */
145		: "m"(*alp)
146		: "cc");
147#endif
148}
149
150#if defined(MULTIPROCESSOR)
151/*
152 * On the Vax, interprocessor interrupts can come in at device priority
153 * level or lower. This can cause some problems while waiting for r/w
154 * spinlocks from a high'ish priority level: IPIs that come in will not
155 * be processed. This can lead to deadlock.
156 *
157 * This hook allows IPIs to be processed while a spinlock's interlock
158 * is released.
159 */
160#define SPINLOCK_SPIN_HOOK						\
161do {									\
162	struct cpu_info *__ci = curcpu();				\
163	int __s;							\
164									\
165	if (__ci->ci_ipimsgs != 0) {					\
166		/* printf("CPU %lu has IPIs pending\n",			\
167		    __ci->ci_cpuid); */					\
168		__s = splipi();						\
169		cpu_handle_ipi();					\
170		splx(__s);						\
171	}								\
172} while (0)
173#endif /* MULTIPROCESSOR */
174#endif /* _VAX_LOCK_H_ */
175