50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
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/*
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* Precise Delay Loops for i386
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*
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* Copyright (C) 1993 Linus Torvalds
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* Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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*
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* The __delay function must _NOT_ be inlined as its execution time
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* depends wildly on alignment on many x86 processors. The additional
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* jump magic is needed to get the timing stable on all the CPU's
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* we have to worry about.
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*/
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#include <linux/config.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <asm/processor.h>
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#include <asm/delay.h>
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#include <asm/timer.h>
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#ifdef CONFIG_SMP
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#include <asm/smp.h>
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#endif
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extern struct timer_opts* timer;
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void __delay(unsigned long loops)
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{
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cur_timer->delay(loops);
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}
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inline void __const_udelay(unsigned long xloops)
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{
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int d0;
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xloops *= 4;
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__asm__("mull %0"
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:"=d" (xloops), "=&a" (d0)
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:"1" (xloops),"0" (cpu_data[_smp_processor_id()].loops_per_jiffy * (HZ/4)));
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__delay(++xloops);
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}
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void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
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}
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void __ndelay(unsigned long nsecs)
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{
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__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
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}
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