LXR linux/arch/alpha/include/asm/timex.h

   1/*
   2 * linux/include/asm-alpha/timex.h
   3 *
   4 * ALPHA architecture timex specifications
   5 */
   6#ifndef _ASMALPHA_TIMEX_H
   7#define _ASMALPHA_TIMEX_H
   8
   9/* With only one or two oddballs, we use the RTC as the ticker, selecting
  10   the 32.768kHz reference clock, which nicely divides down to our HZ.  */
  11#define CLOCK_TICK_RATE 32768
  12
  13/*
  14 * Standard way to access the cycle counter.
  15 * Currently only used on SMP for scheduling.
  16 *
  17 * Only the low 32 bits are available as a continuously counting entity. 
  18 * But this only means we'll force a reschedule every 8 seconds or so,
  19 * which isn't an evil thing.
  20 */
  21
  22typedef unsigned int cycles_t;
  23
  24static inline cycles_t get_cycles (void)
  25{
  26        cycles_t ret;
  27        __asm__ __volatile__ ("rpcc %0" : "=r"(ret));
  28        return ret;
  29}
  30
  31#endif
  32