58 lines
1.4 KiB
C
Executable File
58 lines
1.4 KiB
C
Executable File
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994 by Waldorf Electronics
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* Copyright (C) 1995 - 1998, 2001 by Ralf Baechle
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*/
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#ifndef _ASM_DELAY_H
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#define _ASM_DELAY_H
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#include <linux/config.h>
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extern unsigned long loops_per_jiffy;
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extern __inline__ void
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__delay(unsigned long loops)
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{
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__asm__ __volatile__ (
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".set\tnoreorder\n"
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"1:\tbnez\t%0,1b\n\t"
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"subu\t%0,1\n\t"
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".set\treorder"
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:"=r" (loops)
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:"0" (loops));
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}
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/*
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* division by multiplication: you don't have to worry about
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* loss of precision.
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*
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* Use only for very small delays ( < 1 msec). Should probably use a
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* lookup table, really, as the multiplications take much too long with
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* short delays. This is a "reasonable" implementation, though (and the
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* first constant multiplications gets optimized away if the delay is
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* a constant)
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*/
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extern __inline__ void __udelay(unsigned long usecs, unsigned long lpj)
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{
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unsigned long lo;
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usecs *= 0x00068db8; /* 2**32 / (1000000 / HZ) */
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__asm__("multu\t%2,%3"
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:"=h" (usecs), "=l" (lo)
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:"r" (usecs),"r" (lpj));
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__delay(usecs);
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}
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#ifdef CONFIG_SMP
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#define __udelay_val cpu_data[smp_processor_id()].udelay_val
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#else
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#define __udelay_val loops_per_jiffy
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#endif
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#define udelay(usecs) __udelay((usecs),__udelay_val)
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#endif /* _ASM_DELAY_H */
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