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
|
/**
* \file drm_atomic.h
* Atomic operations used in the DRM which may or may not be provided by the OS.
*
* \author Eric Anholt <anholt@FreeBSD.org>
*/
/*-
* Copyright 2004 Eric Anholt
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/* Many of these implementations are rather fake, but good enough. */
typedef u_int32_t atomic_t;
#ifdef __FreeBSD__
#define atomic_set(p, v) (*(p) = (v))
#define atomic_read(p) (*(p))
#define atomic_inc(p) atomic_add_int(p, 1)
#define atomic_dec(p) atomic_subtract_int(p, 1)
#define atomic_add(n, p) atomic_add_int(p, n)
#define atomic_sub(n, p) atomic_subtract_int(p, n)
#else /* __FreeBSD__ */
/* FIXME */
#define atomic_set(p, v) (*(p) = (v))
#define atomic_read(p) (*(p))
#define atomic_inc(p) (*(p) += 1)
#define atomic_dec(p) (*(p) -= 1)
#define atomic_add(n, p) (*(p) += (n))
#define atomic_sub(n, p) (*(p) -= (n))
/* FIXME */
#define atomic_add_int(p, v) *(p) += v
#define atomic_subtract_int(p, v) *(p) -= v
#define atomic_set_int(p, bits) *(p) |= (bits)
#define atomic_clear_int(p, bits) *(p) &= ~(bits)
#endif /* !__FreeBSD__ */
#if !defined(__FreeBSD_version) || (__FreeBSD_version < 500000)
#if defined(__i386__)
/* The extra atomic functions from 5.0 haven't been merged to 4.x */
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
int res = exp;
__asm __volatile (
" lock ; "
" cmpxchgl %1,%2 ; "
" setz %%al ; "
" movzbl %%al,%0 ; "
"1: "
"# atomic_cmpset_int"
: "+a" (res) /* 0 (result) */
: "r" (src), /* 1 */
"m" (*(dst)) /* 2 */
: "memory");
return (res);
}
#else /* __i386__ */
static __inline int
atomic_cmpset_int(__volatile__ int *dst, int old, int new)
{
int s = splhigh();
if (*dst==old) {
*dst = new;
splx(s);
return 1;
}
splx(s);
return 0;
}
#endif /* !__i386__ */
#endif /* !__FreeBSD_version || __FreeBSD_version < 500000 */
static __inline atomic_t
test_and_set_bit(int b, volatile void *p)
{
int s = splhigh();
unsigned int m = 1<<b;
unsigned int r = *(volatile int *)p & m;
*(volatile int *)p |= m;
splx(s);
return r;
}
static __inline void
clear_bit(int b, volatile void *p)
{
atomic_clear_int(((volatile int *)p) + (b >> 5), 1 << (b & 0x1f));
}
static __inline void
set_bit(int b, volatile void *p)
{
atomic_set_int(((volatile int *)p) + (b >> 5), 1 << (b & 0x1f));
}
static __inline int
test_bit(int b, volatile void *p)
{
return ((volatile int *)p)[b >> 5] & (1 << (b & 0x1f));
}
static __inline int
find_first_zero_bit(volatile void *p, int max)
{
int b;
volatile int *ptr = (volatile int *)p;
for (b = 0; b < max; b += 32) {
if (ptr[b >> 5] != ~0) {
for (;;) {
if ((ptr[b >> 5] & (1 << (b & 0x1f))) == 0)
return b;
b++;
}
}
}
return max;
}
|
