1/*	$NetBSD$	*/
2
3/*-
4 * Copyright (c) 2002, 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe and Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _HPPA_MUTEX_H_
33#define	_HPPA_MUTEX_H_
34
35/*
36 * The HPPA mutex implementation is troublesome, because HPPA lacks
37 * a compare-and-set operation, yet there are many SMP HPPA machines
38 * in circulation.  SMP for spin mutexes is easy - we don't need to
39 * know who owns the lock.  For adaptive mutexes, we need an owner
40 * field and additional interlock
41 */
42
43#ifndef __ASSEMBLER__
44
45#include <machine/lock.h>
46
47struct kmutex {
48	union {
49		/*
50		 * Only the 16 bytes aligned word of __cpu_simple_lock_t will
51		 * be used. It's 16 bytes to simplify the allocation.
52		 * See hppa/lock.h
53		 */
54#ifdef __MUTEX_PRIVATE
55		struct {
56			__cpu_simple_lock_t	mtxu_lock;	/* 0-15 */
57			volatile uint32_t	mtxs_owner;	/* 16-19 */
58			ipl_cookie_t		mtxs_ipl;	/* 20-23 */
59			volatile uint8_t	mtxs_waiters;	/* 24 */
60
61			/* For LOCKDEBUG */
62			uint8_t			mtxs_dodebug;	/* 25 */
63		} s;
64#endif
65		uint8_t			mtxu_pad[32];	/* 0 - 32 */
66	} u;
67} __aligned (16);
68#endif
69
70#ifdef __MUTEX_PRIVATE
71
72#define	__HAVE_MUTEX_STUBS	1
73
74#define	mtx_lock	u.s.mtxu_lock
75#define	mtx_owner	u.s.mtxs_owner
76#define	mtx_ipl		u.s.mtxs_ipl
77#define	mtx_waiters	u.s.mtxs_waiters
78#define	mtx_dodebug	u.s.mtxs_dodebug
79
80/* Magic constants for mtx_owner */
81#define	MUTEX_ADAPTIVE_UNOWNED		0xffffff00
82#define	MUTEX_SPIN_FLAG			0xffffff10
83#define	MUTEX_UNOWNED_OR_SPIN(x)	(((x) & 0xffffffef) == 0xffffff00)
84
85#ifndef __ASSEMBLER__
86
87static inline uintptr_t
88MUTEX_OWNER(uintptr_t owner)
89{
90	return owner;
91}
92
93static inline int
94MUTEX_OWNED(uintptr_t owner)
95{
96	return owner != MUTEX_ADAPTIVE_UNOWNED;
97}
98
99static inline int
100MUTEX_SET_WAITERS(struct kmutex *mtx, uintptr_t owner)
101{
102	mb_write();
103	mtx->mtx_waiters = 1;
104	mb_memory();
105	return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED;
106}
107
108static inline int
109MUTEX_HAS_WAITERS(volatile struct kmutex *mtx)
110{
111	return mtx->mtx_waiters != 0;
112}
113
114static inline void
115MUTEX_INITIALIZE_SPIN(struct kmutex *mtx, bool dodebug, int ipl)
116{
117	mtx->mtx_ipl = makeiplcookie(ipl);
118	mtx->mtx_dodebug = dodebug;
119	mtx->mtx_owner = MUTEX_SPIN_FLAG;
120	__cpu_simple_lock_init(&mtx->mtx_lock);
121}
122
123static inline void
124MUTEX_INITIALIZE_ADAPTIVE(struct kmutex *mtx, bool dodebug)
125{
126	mtx->mtx_dodebug = dodebug;
127	mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED;
128	__cpu_simple_lock_init(&mtx->mtx_lock);
129}
130
131static inline void
132MUTEX_DESTROY(struct kmutex *mtx)
133{
134	mtx->mtx_owner = 0xffffffff;
135}
136
137static inline bool
138MUTEX_DEBUG_P(struct kmutex *mtx)
139{
140	return mtx->mtx_dodebug != 0;
141}
142
143static inline int
144MUTEX_SPIN_P(volatile struct kmutex *mtx)
145{
146	return mtx->mtx_owner == MUTEX_SPIN_FLAG;
147}
148
149static inline int
150MUTEX_ADAPTIVE_P(volatile struct kmutex *mtx)
151{
152	return mtx->mtx_owner != MUTEX_SPIN_FLAG;
153}
154
155/* Acquire an adaptive mutex */
156static inline int
157MUTEX_ACQUIRE(struct kmutex *mtx, uintptr_t curthread)
158{
159	if (!__cpu_simple_lock_try(&mtx->mtx_lock))
160		return 0;
161	mtx->mtx_owner = curthread;
162	return 1;
163}
164
165/* Release an adaptive mutex */
166static inline void
167MUTEX_RELEASE(struct kmutex *mtx)
168{
169	mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED;
170	__cpu_simple_unlock(&mtx->mtx_lock);
171	mtx->mtx_waiters = 0;
172}
173
174static inline void
175MUTEX_CLEAR_WAITERS(struct kmutex *mtx)
176{
177	mtx->mtx_waiters = 0;
178}
179
180#endif	/* __ASSEMBLER__ */
181
182#endif	/* __MUTEX_PRIVATE */
183
184#endif /* _HPPA_MUTEX_H_ */
185