/* *	Precise Delay Loops for i386 * *	Copyright (C) 1993 Linus Torvalds *	Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz> * *	The __delay function must _NOT_ be inlined as its execution time *	depends wildly on alignment on many x86 processors. The additional *	jump magic is needed to get the timing stable on all the CPU's *	we have to worry about. */#include <linux/config.h>#include <linux/sched.h>#include <linux/delay.h>#include <asm/processor.h>#include <asm/delay.h>#ifdef CONFIG_SMP#include <asm/smp.h>#endifint x86_udelay_tsc = 0;		/* Delay via TSC */	/* *	Do a udelay using the TSC for any CPU that happens *	to have one that we trust. */static void __rdtsc_delay(unsigned long loops){	unsigned long bclock, now;		rdtscl(bclock);	do	{		rep_nop();		rdtscl(now);	} while ((now-bclock) < loops);}/* *	Non TSC based delay loop for 386, 486, MediaGX */ static void __loop_delay(unsigned long loops){	int d0;	__asm__ __volatile__(		"\tjmp 1f\n"		".align 16\n"		"1:\tjmp 2f\n"		".align 16\n"		"2:\tdecl %0\n\tjns 2b"		:"=&a" (d0)		:"0" (loops));}extern void __cyclone_delay(unsigned long loops);extern int use_cyclone;void __delay(unsigned long loops){	if (use_cyclone)		__cyclone_delay(loops);	else if (x86_udelay_tsc)		__rdtsc_delay(loops);	else		__loop_delay(loops);}inline void __const_udelay(unsigned long xloops){	int d0;	__asm__("mull %0"		:"=d" (xloops), "=&a" (d0)		:"1" (xloops),"0" (current_cpu_data.loops_per_jiffy));        __delay(xloops * HZ);}void __udelay(unsigned long usecs){	__const_udelay(usecs * 0x000010c6);  /* 2**32 / 1000000 */}void __ndelay(unsigned long nsecs){	__const_udelay(nsecs * 0x00005);  /* 2**32 / 1000000000 (rounded up) */}