summaryrefslogtreecommitdiff
path: root/sys/arch/hppa/include/mutex.h
blob: 4850ec425feb800e61ef582cec36eff5e0068701 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*	$NetBSD: mutex.h,v 1.15 2020/01/07 13:44:23 ad Exp $	*/

/*-
 * Copyright (c) 2002, 2007 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe and Andrew Doran.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _HPPA_MUTEX_H_
#define	_HPPA_MUTEX_H_

/*
 * The HPPA mutex implementation is troublesome, because HPPA lacks
 * a compare-and-set operation, yet there are many SMP HPPA machines
 * in circulation.  SMP for spin mutexes is easy - we don't need to
 * know who owns the lock.  For adaptive mutexes, we need an owner
 * field and additional interlock
 */

#ifndef __ASSEMBLER__

#include <machine/lock.h>

struct kmutex {
	union {
		/*
		 * Only the 16 bytes aligned word of __cpu_simple_lock_t will
		 * be used. It's 16 bytes to simplify the allocation.
		 * See hppa/lock.h
		 */
#ifdef __MUTEX_PRIVATE
		struct {
			__cpu_simple_lock_t	mtxu_lock;	/* 0-15 */
			volatile uint32_t	mtxs_owner;	/* 16-19 */
			ipl_cookie_t		mtxs_ipl;	/* 20-23 */
			volatile uint8_t	mtxs_waiters;	/* 24 */

			/* For LOCKDEBUG */
			uint8_t			mtxs_dodebug;	/* 25 */
		} s;
#endif
		uint8_t			mtxu_pad[32];	/* 0 - 32 */
	} u;
} __aligned (16);
#endif

#ifdef __MUTEX_PRIVATE

#define	__HAVE_MUTEX_STUBS	1

#define	mtx_lock	u.s.mtxu_lock
#define	mtx_owner	u.s.mtxs_owner
#define	mtx_ipl		u.s.mtxs_ipl
#define	mtx_waiters	u.s.mtxs_waiters
#define	mtx_dodebug	u.s.mtxs_dodebug

/* Magic constants for mtx_owner */
#define	MUTEX_ADAPTIVE_UNOWNED		0xffffff00
#define	MUTEX_SPIN_FLAG			0xffffff10
#define	MUTEX_UNOWNED_OR_SPIN(x)	(((x) & 0xffffffef) == 0xffffff00)

#ifndef __ASSEMBLER__

static inline uintptr_t
MUTEX_OWNER(uintptr_t owner)
{
	return owner;
}

static inline int
MUTEX_OWNED(uintptr_t owner)
{
	return owner != MUTEX_ADAPTIVE_UNOWNED;
}

static inline int
MUTEX_SET_WAITERS(struct kmutex *mtx, uintptr_t owner)
{
	__sync();		/* formerly mb_read */
	mtx->mtx_waiters = 1;
	__sync();		/* formerly mb_memory */
	return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED;
}

static inline int
MUTEX_HAS_WAITERS(const volatile struct kmutex *mtx)
{
	return mtx->mtx_waiters != 0;
}

static inline void
MUTEX_INITIALIZE_SPIN(struct kmutex *mtx, bool dodebug, int ipl)
{
	mtx->mtx_ipl = makeiplcookie(ipl);
	mtx->mtx_dodebug = dodebug;
	mtx->mtx_owner = MUTEX_SPIN_FLAG;
	__cpu_simple_lock_init(&mtx->mtx_lock);
}

static inline void
MUTEX_INITIALIZE_ADAPTIVE(struct kmutex *mtx, bool dodebug)
{
	mtx->mtx_dodebug = dodebug;
	mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED;
	__cpu_simple_lock_init(&mtx->mtx_lock);
}

static inline void
MUTEX_DESTROY(struct kmutex *mtx)
{
	mtx->mtx_owner = 0xffffffff;
}

static inline bool
MUTEX_DEBUG_P(const volatile struct kmutex *mtx)
{
	return mtx->mtx_dodebug != 0;
}

static inline int
MUTEX_SPIN_P(const uintptr_t owner)
{
	return owner == MUTEX_SPIN_FLAG;
}

static inline int
MUTEX_ADAPTIVE_P(const uintptr_t owner)
{
	return owner != MUTEX_SPIN_FLAG;
}

/* Acquire an adaptive mutex */
static inline int
MUTEX_ACQUIRE(struct kmutex *mtx, uintptr_t curthread)
{
	if (!__cpu_simple_lock_try(&mtx->mtx_lock))
		return 0;
	mtx->mtx_owner = curthread;
	return 1;
}

/* Release an adaptive mutex */
static inline void
MUTEX_RELEASE(struct kmutex *mtx)
{
	mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED;
	__cpu_simple_unlock(&mtx->mtx_lock);
	mtx->mtx_waiters = 0;
}

static inline void
MUTEX_CLEAR_WAITERS(struct kmutex *mtx)
{
	mtx->mtx_waiters = 0;
}

#endif	/* __ASSEMBLER__ */

#endif	/* __MUTEX_PRIVATE */

#endif /* _HPPA_MUTEX_H_ */