blob: 7ff5f769ccb69af9fa604f04ff4d4c01b6bb5a4a (
plain)
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
|
#ifndef _I386_DELAY_H
#define _I386_DELAY_H
/*
* Copyright (C) 1993 Linus Torvalds
*
* Delay routines, using a pre-computed "loops_per_second" value.
*/
extern __inline__ void __delay(int loops)
{
__asm__(".align 2,0x90\n1:\tdecl %0\n\tjns 1b": :"a" (loops):"ax");
}
/*
* division by multiplication: you don't have to worry about
* loss of precision.
*
* Use only for very small delays ( < 1 msec). Should probably use a
* lookup table, really, as the multiplications take much too long with
* short delays. This is a "reasonable" implementation, though (and the
* first constant multiplications gets optimized away if the delay is
* a constant)
*/
extern __inline__ void udelay(unsigned long usecs)
{
usecs *= 0x000010c6; /* 2**32 / 1000000 */
__asm__("mull %0"
:"=d" (usecs)
:"a" (usecs),"0" (loops_per_sec)
:"ax");
__delay(usecs);
}
#endif /* defined(_I386_DELAY_H) */
|
