Annotation of sys/arch/i386/include/atomic.h, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: atomic.h,v 1.6 2007/05/25 15:55:27 art Exp $ */
2: /* $NetBSD: atomic.h,v 1.1.2.2 2000/02/21 18:54:07 sommerfeld Exp $ */
3:
4: /*-
5: * Copyright (c) 2000 The NetBSD Foundation, Inc.
6: * All rights reserved.
7: *
8: * This code is derived from software contributed to The NetBSD Foundation
9: * by RedBack Networks Inc.
10: *
11: * Author: Bill Sommerfeld
12: *
13: * Redistribution and use in source and binary forms, with or without
14: * modification, are permitted provided that the following conditions
15: * are met:
16: * 1. Redistributions of source code must retain the above copyright
17: * notice, this list of conditions and the following disclaimer.
18: * 2. Redistributions in binary form must reproduce the above copyright
19: * notice, this list of conditions and the following disclaimer in the
20: * documentation and/or other materials provided with the distribution.
21: * 3. All advertising materials mentioning features or use of this software
22: * must display the following acknowledgement:
23: * This product includes software developed by the NetBSD
24: * Foundation, Inc. and its contributors.
25: * 4. Neither the name of The NetBSD Foundation nor the names of its
26: * contributors may be used to endorse or promote products derived
27: * from this software without specific prior written permission.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
30: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
31: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
32: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
33: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
34: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
35: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39: * POSSIBILITY OF SUCH DAMAGE.
40: */
41:
42: #ifndef _I386_ATOMIC_H_
43: #define _I386_ATOMIC_H_
44:
45: /*
46: * Perform atomic operations on memory. Should be atomic with respect
47: * to interrupts and multiple processors.
48: *
49: * void atomic_setbits_int(volatile u_int *a, u_int mask) { *a |= mask; }
50: * void atomic_clearbits_int(volatile u_int *a, u_int mas) { *a &= ~mask; }
51: */
52: #if defined(_KERNEL) && !defined(_LOCORE)
53:
54: #ifdef MULTIPROCESSOR
55: #define LOCK "lock"
56: #else
57: #define LOCK
58: #endif
59:
60: static __inline u_int64_t
61: i386_atomic_testset_uq(volatile u_int64_t *ptr, u_int64_t val)
62: {
63: __asm__ volatile ("\n1:\t" LOCK " cmpxchg8b (%1); jnz 1b" : "+A" (val) :
64: "r" (ptr), "b" ((u_int32_t)val), "c" ((u_int32_t)(val >> 32)));
65: return val;
66: }
67:
68: static __inline u_int32_t
69: i386_atomic_testset_ul(volatile u_int32_t *ptr, unsigned long val)
70: {
71: __asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
72: return val;
73: }
74:
75: static __inline int
76: i386_atomic_testset_i(volatile int *ptr, unsigned long val)
77: {
78: __asm__ volatile ("xchgl %0,(%2)" :"=r" (val):"0" (val),"r" (ptr));
79: return val;
80: }
81:
82: static __inline void
83: i386_atomic_setbits_l(volatile u_int32_t *ptr, unsigned long bits)
84: {
85: __asm __volatile(LOCK " orl %1,%0" : "=m" (*ptr) : "ir" (bits));
86: }
87:
88: static __inline void
89: i386_atomic_clearbits_l(volatile u_int32_t *ptr, unsigned long bits)
90: {
91: bits = ~bits;
92: __asm __volatile(LOCK " andl %1,%0" : "=m" (*ptr) : "ir" (bits));
93: }
94:
95: /*
96: * cas = compare and set
97: */
98: static __inline int
99: i486_atomic_cas_int(volatile u_int *ptr, u_int expect, u_int set)
100: {
101: int res;
102:
103: __asm volatile(LOCK " cmpxchgl %2, %1" : "=a" (res), "=m" (*ptr)
104: : "r" (set), "a" (expect), "m" (*ptr) : "memory");
105:
106: return (res);
107: }
108:
109: #define atomic_setbits_int i386_atomic_setbits_l
110: #define atomic_clearbits_int i386_atomic_clearbits_l
111:
112: #undef LOCK
113:
114: #endif /* defined(_KERNEL) && !defined(_LOCORE) */
115: #endif /* _I386_ATOMIC_H_ */
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