kernel-ark/include/asm-m68k/delay.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

58 lines
1.3 KiB
C

#ifndef _M68K_DELAY_H
#define _M68K_DELAY_H
#include <asm/param.h>
/*
* Copyright (C) 1994 Hamish Macdonald
*
* Delay routines, using a pre-computed "loops_per_jiffy" value.
*/
static inline void __delay(unsigned long loops)
{
__asm__ __volatile__ ("1: subql #1,%0; jcc 1b"
: "=d" (loops) : "0" (loops));
}
extern void __bad_udelay(void);
/*
* 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)
*/
static inline void __const_udelay(unsigned long xloops)
{
unsigned long tmp;
__asm__ ("mulul %2,%0:%1"
: "=d" (xloops), "=d" (tmp)
: "d" (xloops), "1" (loops_per_jiffy));
__delay(xloops * HZ);
}
static inline void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 4295); /* 2**32 / 1000000 */
}
#define udelay(n) (__builtin_constant_p(n) ? \
((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 4295)) : \
__udelay(n))
static inline unsigned long muldiv(unsigned long a, unsigned long b,
unsigned long c)
{
unsigned long tmp;
__asm__ ("mulul %2,%0:%1; divul %3,%0:%1"
: "=d" (tmp), "=d" (a)
: "d" (b), "d" (c), "1" (a));
return a;
}
#endif /* defined(_M68K_DELAY_H) */