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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [include/] [linux/] [delay.h] - Rev 1781

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#ifndef _LINUX_DELAY_H
#define _LINUX_DELAY_H
 
/*
 * Copyright (C) 1993 Linus Torvalds
 *
 * Delay routines, using a pre-computed "loops_per_jiffy" value.
 */
 
extern unsigned long loops_per_jiffy;
 
#include <asm/delay.h>
 
/*
 * Using udelay() for intervals greater than a few milliseconds can
 * risk overflow for high loops_per_jiffy (high bogomips) machines. The
 * mdelay() provides a wrapper to prevent this.  For delays greater
 * than MAX_UDELAY_MS milliseconds, the wrapper is used.  Architecture
 * specific values can be defined in asm-???/delay.h as an override.
 * The 2nd mdelay() definition ensures GCC will optimize away the 
 * while loop for the common cases where n <= MAX_UDELAY_MS  --  Paul G.
 */
 
#ifndef MAX_UDELAY_MS
#define MAX_UDELAY_MS	5
#endif
 
#ifdef notdef
#define mdelay(n) (\
	{unsigned long msec=(n); while (msec--) udelay(1000);})
#else
#define mdelay(n) (\
	(__builtin_constant_p(n) && (n)<=MAX_UDELAY_MS) ? udelay((n)*1000) : \
	({unsigned long msec=(n); while (msec--) udelay(1000);}))
#endif
 
#endif /* defined(_LINUX_DELAY_H) */
 

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