lock.h revision 1.12 
1/*	$NetBSD: lock.h,v 1.12 2003/06/23 11:01:49 martin 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#include "opt_multiprocessor.h"
38#include <machine/cpu.h>
39#endif
40
41typedef __volatile int		__cpu_simple_lock_t;
42
43#define __SIMPLELOCK_LOCKED	1
44#define __SIMPLELOCK_UNLOCKED	0
45
46static __inline void
47__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
48{
49#ifdef _KERNEL
50	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
51		: /* No output */
52		: "g"(alp)
53		: "r1","cc","memory");
54#else
55	__asm__ __volatile ("bbcci $0,%0,1f;1:"
56		: /* No output */
57		: "m"(*alp)
58		: "cc");
59#endif
60}
61
62static __inline int
63__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
64{
65	int ret;
66
67#ifdef _KERNEL
68	__asm__ __volatile ("movl %1,%%r1;jsb Slocktry;movl %%r0,%0"
69		: "=&r"(ret)
70		: "g"(alp)
71		: "r0","r1","cc","memory");
72#else
73	__asm__ __volatile ("clrl %0;bbssi $0,%1,1f;incl %0;1:"
74		: "=&r"(ret)
75		: "m"(*alp)
76		: "cc");
77#endif
78
79	return ret;
80}
81
82#ifdef _KERNEL
83#define	VAX_LOCK_CHECKS ((1 << IPI_SEND_CNCHAR) | (1 << IPI_DDB))
84#define	__cpu_simple_lock(alp)						\
85do {									\
86	struct cpu_info *__ci = curcpu();				\
87									\
88	while (__cpu_simple_lock_try(alp) == 0) {			\
89		int __s;						\
90									\
91		if (__ci->ci_ipimsgs & VAX_LOCK_CHECKS) {		\
92			__s = splipi();					\
93			cpu_handle_ipi();				\
94			splx(__s);					\
95		}							\
96	}								\
97} while (0)
98#else
99static __inline void
100__cpu_simple_lock(__cpu_simple_lock_t *alp)
101{
102	__asm__ __volatile ("1:bbssi $0,%0,1b"
103		: /* No outputs */
104		: "m"(*alp)
105		: "cc");
106}
107#endif /* _KERNEL */
108
109#if 0
110static __inline void
111__cpu_simple_lock(__cpu_simple_lock_t *alp)
112{
113	struct cpu_info *ci = curcpu();
114
115	while (__cpu_simple_lock_try(alp) == 0) {
116		int s;
117
118		if (ci->ci_ipimsgs & IPI_SEND_CNCHAR) {
119			s = splipi();
120			cpu_handle_ipi();
121			splx(s);
122		}
123	}
124
125#if 0
126	__asm__ __volatile ("movl %0,%%r1;jsb Slock"
127		: /* No output */
128		: "g"(alp)
129		: "r0","r1","cc","memory");
130#endif
131#if 0
132	__asm__ __volatile ("1:;bbssi $0, %0, 1b"
133		: /* No output */
134		: "m"(*alp));
135#endif
136}
137#endif
138
139static __inline void
140__cpu_simple_unlock(__cpu_simple_lock_t *alp)
141{
142#ifdef _KERNEL
143	__asm__ __volatile ("movl %0,%%r1;jsb Sunlock"
144		: /* No output */
145		: "g"(alp)
146		: "r1","cc","memory");
147#else
148	__asm__ __volatile ("bbcci $0,%0,1f;1:"
149		: /* No output */
150		: "m"(*alp)
151		: "cc");
152#endif
153}
154
155#if defined(MULTIPROCESSOR)
156/*
157 * On the Vax, interprocessor interrupts can come in at device priority
158 * level or lower. This can cause some problems while waiting for r/w
159 * spinlocks from a high'ish priority level: IPIs that come in will not
160 * be processed. This can lead to deadlock.
161 *
162 * This hook allows IPIs to be processed while a spinlock's interlock
163 * is released.
164 */
165#define SPINLOCK_SPIN_HOOK						\
166do {									\
167	struct cpu_info *__ci = curcpu();				\
168	int __s;							\
169									\
170	if (__ci->ci_ipimsgs != 0) {					\
171		/* printf("CPU %lu has IPIs pending\n",			\
172		    __ci->ci_cpuid); */					\
173		__s = splipi();						\
174		cpu_handle_ipi();					\
175		splx(__s);						\
176	}								\
177} while (0)
178#endif /* MULTIPROCESSOR */
179#endif /* _VAX_LOCK_H_ */
180