2 * Copyright (c) 1998 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #ifndef _MACHINE_ATOMIC_H_
29 #define _MACHINE_ATOMIC_H_
32 * Various simple arithmetic on memory which is atomic in the presence
33 * of interrupts and multiple processors.
35 * atomic_set_char(P, V) (*(u_char*)(P) |= (V))
36 * atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V))
37 * atomic_add_char(P, V) (*(u_char*)(P) += (V))
38 * atomic_subtract_char(P, V) (*(u_char*)(P) -= (V))
40 * atomic_set_short(P, V) (*(u_short*)(P) |= (V))
41 * atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V))
42 * atomic_add_short(P, V) (*(u_short*)(P) += (V))
43 * atomic_subtract_short(P, V) (*(u_short*)(P) -= (V))
45 * atomic_set_int(P, V) (*(u_int*)(P) |= (V))
46 * atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V))
47 * atomic_add_int(P, V) (*(u_int*)(P) += (V))
48 * atomic_subtract_int(P, V) (*(u_int*)(P) -= (V))
50 * atomic_set_long(P, V) (*(u_long*)(P) |= (V))
51 * atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V))
52 * atomic_add_long(P, V) (*(u_long*)(P) += (V))
53 * atomic_subtract_long(P, V) (*(u_long*)(P) -= (V))
57 * The above functions are expanded inline in the statically-linked
58 * kernel. Lock prefixes are generated if an SMP kernel is being
61 * Kernel modules call real functions which are built into the kernel.
62 * This allows kernel modules to be portable between UP and SMP systems.
64 #if defined(KLD_MODULE)
65 #define ATOMIC_ASM(NAME, TYPE, OP, V) \
66 extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v);
68 #else /* !KLD_MODULE */
70 #define MPLOCKED "lock ; "
76 * The assembly is volatilized to demark potential before-and-after side
77 * effects if an interrupt or SMP collision were to occur.
79 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9)
80 /* egcs 1.1.2+ version */
81 #define ATOMIC_ASM(NAME, TYPE, OP, V) \
82 static __inline void \
83 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
85 __asm __volatile(MPLOCKED OP \
87 : "0" (*p), "ir" (V)); \
91 /* gcc <= 2.8 version */
92 #define ATOMIC_ASM(NAME, TYPE, OP, V) \
93 static __inline void \
94 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
96 __asm __volatile(MPLOCKED OP \
101 #endif /* KLD_MODULE */
103 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 9)
105 /* egcs 1.1.2+ version */
106 ATOMIC_ASM(set, char, "orb %2,%0", v)
107 ATOMIC_ASM(clear, char, "andb %2,%0", ~v)
108 ATOMIC_ASM(add, char, "addb %2,%0", v)
109 ATOMIC_ASM(subtract, char, "subb %2,%0", v)
111 ATOMIC_ASM(set, short, "orw %2,%0", v)
112 ATOMIC_ASM(clear, short, "andw %2,%0", ~v)
113 ATOMIC_ASM(add, short, "addw %2,%0", v)
114 ATOMIC_ASM(subtract, short, "subw %2,%0", v)
116 ATOMIC_ASM(set, int, "orl %2,%0", v)
117 ATOMIC_ASM(clear, int, "andl %2,%0", ~v)
118 ATOMIC_ASM(add, int, "addl %2,%0", v)
119 ATOMIC_ASM(subtract, int, "subl %2,%0", v)
121 ATOMIC_ASM(set, long, "orl %2,%0", v)
122 ATOMIC_ASM(clear, long, "andl %2,%0", ~v)
123 ATOMIC_ASM(add, long, "addl %2,%0", v)
124 ATOMIC_ASM(subtract, long, "subl %2,%0", v)
128 /* gcc <= 2.8 version */
129 ATOMIC_ASM(set, char, "orb %1,%0", v)
130 ATOMIC_ASM(clear, char, "andb %1,%0", ~v)
131 ATOMIC_ASM(add, char, "addb %1,%0", v)
132 ATOMIC_ASM(subtract, char, "subb %1,%0", v)
134 ATOMIC_ASM(set, short, "orw %1,%0", v)
135 ATOMIC_ASM(clear, short, "andw %1,%0", ~v)
136 ATOMIC_ASM(add, short, "addw %1,%0", v)
137 ATOMIC_ASM(subtract, short, "subw %1,%0", v)
139 ATOMIC_ASM(set, int, "orl %1,%0", v)
140 ATOMIC_ASM(clear, int, "andl %1,%0", ~v)
141 ATOMIC_ASM(add, int, "addl %1,%0", v)
142 ATOMIC_ASM(subtract, int, "subl %1,%0", v)
144 ATOMIC_ASM(set, long, "orl %1,%0", v)
145 ATOMIC_ASM(clear, long, "andl %1,%0", ~v)
146 ATOMIC_ASM(add, long, "addl %1,%0", v)
147 ATOMIC_ASM(subtract, long, "subl %1,%0", v)
151 #endif /* ! _MACHINE_ATOMIC_H_ */