include/asm-powerpc/delay.h

   1 #ifndef _ASM_POWERPC_DELAY_H
   2 #define _ASM_POWERPC_DELAY_H
   3 #ifdef __KERNEL__
   4
   5 /*
   6  * Copyright 1996, Paul Mackerras.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  *
  13  * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
  14  * Anton Blanchard.
  15  */
  16
  17 extern void __delay(unsigned long loops);
  18 extern void udelay(unsigned long usecs);
  19
  20 /*
  21  * On shared processor machines the generic implementation of mdelay can
  22  * result in large errors. While each iteration of the loop inside mdelay
  23  * is supposed to take 1ms, the hypervisor could sleep our partition for
  24  * longer (eg 10ms). With the right timing these errors can add up.
  25  *
  26  * Since there is no 32bit overflow issue on 64bit kernels, just call
  27  * udelay directly.
  28  */
  29 #ifdef CONFIG_PPC64
  30 #define mdelay(n)       udelay((n) * 1000)
  31 #endif
  32
  33 #endif /* __KERNEL__ */
  34 #endif /* _ASM_POWERPC_DELAY_H */