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#ifndef _I386_DELAY_H
#define _I386_DELAY_H
/*
* Copyright (C) 1993 Linus Torvalds
*
* Delay routines, using a pre-computed "loops_per_second" value.
*/
#include <linux/linkage.h>
#ifdef __SMP__
#include <asm/smp.h>
#endif
extern void __do_delay(void); /* Special register call calling convention */
extern __inline__ void __delay(int loops)
{
__asm__ __volatile__(
"call " SYMBOL_NAME_STR(__do_delay)
:/* no outputs */
:"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)
#ifdef __SMP__
:"a" (usecs),"0" (cpu_data[smp_processor_id()].udelay_val)
#else
:"a" (usecs),"0" (loops_per_sec)
#endif
:"ax");
__delay(usecs);
}
extern __inline__ unsigned long muldiv(unsigned long a, unsigned long b, unsigned long c)
{
__asm__("mull %1 ; divl %2"
:"=a" (a)
:"d" (b),
"r" (c),
"0" (a)
:"dx");
return a;
}
#endif /* defined(_I386_DELAY_H) */
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