/* * 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 <linux/module.h> #include <asm/processor.h> #include <asm/delay.h> #include <asm/timer.h> #ifdef CONFIG_SMP #include <asm/smp.h> #endif extern struct timer_opts* timer; void __delay(unsigned long loops) { cur_timer->delay(loops); } inline void __const_udelay(unsigned long xloops) { int d0; xloops *= 4; __asm__("mull %0" :"=d" (xloops), "=&a" (d0) :"1" (xloops),"0" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4))); __delay(++xloops); } void __udelay(unsigned long usecs) { __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ } void __ndelay(unsigned long nsecs) { __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ } EXPORT_SYMBOL(__delay); EXPORT_SYMBOL(__const_udelay); EXPORT_SYMBOL(__udelay); EXPORT_SYMBOL(__ndelay);