1/*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 *
31 */
32
33/*
34 * mach/i386/flipc_dep.h
35 *
36 * This file will have all of the FLIPC implementation machine dependent
37 * defines that need to be visible to both kernel and AIL (eg. bus locks
38 * and bus synchronization primitives).
39 */
40
41#ifndef _MACH_FLIPC_DEP_H_
42#define _MACH_FLIPC_DEP_H_
43
44/* For the 386, we don't need to wrap synchronization variable writes
45   at all.  */
46#define SYNCVAR_WRITE(statement)  statement
47
48/* And similarly (I believe; check on this), for the 386 there isn't any
49   requirement for write fences.  */
50#define WRITE_FENCE()
51
52/*
53 * Flipc simple lock defines.  These are almost completely for the use
54 * of the AIL; the reason they are in this file is that they need to
55 * be initialized properly in the communications buffer initialization
56 * routine.  Sigh.  Note in particular that the kernel has no defined
57 * "simple_lock_yield_function", so it had better never expand the
58 * macro simple_lock_acquire.
59 *
60 * These locks may be declared by "flipc_simple_lock lock;".  If they
61 * are instead declared by FLIPC_DECL_SIMPLE_LOCK(class,lockname) they
62 * may be used without initialization.
63 */
64
65#define SIMPLE_LOCK_INITIALIZER 0
66#define FLIPC_DECL_SIMPLE_LOCK(class,lockname) \
67class flipc_simple_lock (lockname) = SIMPLE_LOCK_INITIALIZER
68
69/*
70 * Lower case because they may be macros or functions.
71 * I'll include the function prototypes just for examples here.
72 */
73
74#define flipc_simple_lock_init(lock)		\
75do {						\
76    *(lock) = SIMPLE_LOCK_INITIALIZER;		\
77} while (0)
78
79/*
80 * Defines of the actual routines, for gcc.
81 */
82
83#define flipc_simple_lock_locked(lock) ((*lock) != SIMPLE_LOCK_INITIALIZER)
84
85#ifdef __GNUC__
86     extern __inline__ int flipc_simple_lock_try(flipc_simple_lock *lock)
87{
88    int r;
89    __asm__ volatile("movl $1, %0; xchgl %0, %1" : "=&r" (r), "=m" (*lock));
90    return !r;
91}
92
93/* I don't know why this requires an ASM, but I'll follow the leader. */
94extern __inline__ void flipc_simple_lock_release(flipc_simple_lock *lock)
95{
96    register int t;
97
98    __asm__ volatile("xorl %0, %0; xchgl %0, %1" : "=&r" (t), "=m" (*lock));
99}
100#else	/* __GNUC__ */
101/* If we aren't compiling with gcc, the above need to be functions.  */
102#endif	/* __GNUC__ */
103
104#endif /* _MACH_FLIPC_DEP_H_ */
105