include/asm-x86_64/delay.h

   1 #ifndef _X8664_DELAY_H
   2 #define _X8664_DELAY_H
   3
   4 /*
   5  * Copyright (C) 1993 Linus Torvalds
   6  *
   7  * Delay routines calling functions in arch/x86_64/lib/delay.c
   8  */
   9
  10 /* Undefined functions to get compile-time errors */
  11 extern void __bad_udelay(void);
  12 extern void __bad_ndelay(void);
  13
  14 extern void __udelay(unsigned long usecs);
  15 extern void __ndelay(unsigned long nsecs);
  16 extern void __const_udelay(unsigned long usecs);
  17 extern void __delay(unsigned long loops);
  18
  19 /* 0x10c7 is 2**32 / 1000000 (rounded up) */
  20 #define udelay(n) (__builtin_constant_p(n) ? \
  21         ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
  22         __udelay(n))
  23
  24 /* 0x5 is 2**32 / 1000000000 (rounded up) */
  25 #define ndelay(n) (__builtin_constant_p(n) ? \
  26        ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
  27        __ndelay(n))
  28
  29
  30 #endif /* defined(_X8664_DELAY_H) */