include/asm-i386/delay.h

   1 #ifndef _I386_DELAY_H
   2 #define _I386_DELAY_H
   3
   4 /*
   5  * Copyright (C) 1993 Linus Torvalds
   6  *
   7  * Delay routines calling functions in arch/i386/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 #if defined(CONFIG_PARAVIRT) && !defined(USE_REAL_TIME_DELAY)
  20 #define udelay(n) paravirt_ops.const_udelay((n) * 0x10c7ul)
  21
  22 #define ndelay(n) paravirt_ops.const_udelay((n) * 5ul)
  23
  24 #else /* !PARAVIRT || USE_REAL_TIME_DELAY */
  25
  26 /* 0x10c7 is 2**32 / 1000000 (rounded up) */
  27 #define udelay(n) (__builtin_constant_p(n) ? \
  28         ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
  29         __udelay(n))
  30
  31 /* 0x5 is 2**32 / 1000000000 (rounded up) */
  32 #define ndelay(n) (__builtin_constant_p(n) ? \
  33         ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
  34         __ndelay(n))
  35 #endif
  36
  37 void use_tsc_delay(void);
  38
  39 #endif /* defined(_I386_DELAY_H) */