#ifndef _I386_DELAY_H #define _I386_DELAY_H /* * Copyright (C) 1993 Linus Torvalds * * Delay routines, using a pre-computed "loops_per_second" value. */ #include #ifdef __SMP__ #include #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) */