include/asm-ppc/timex.h

   1 /*
   2  * linux/include/asm-ppc/timex.h
   3  *
   4  * ppc architecture timex specifications
   5  */
   6 #ifndef _ASMppc_TIMEX_H
   7 #define _ASMppc_TIMEX_H
   8
   9 #include <linux/config.h>
  10
  11 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
  12 #define CLOCK_TICK_FACTOR       20      /* Factor of both 1000000 and CLOCK_TICK_RATE */
  13 #define FINETUNE ((((((long)LATCH * HZ - CLOCK_TICK_RATE) << SHIFT_HZ) * \
  14         (1000000/CLOCK_TICK_FACTOR) / (CLOCK_TICK_RATE/CLOCK_TICK_FACTOR)) \
  15                 << (SHIFT_SCALE-SHIFT_HZ)) / HZ)
  16
  17 typedef unsigned long cycles_t;
  18
  19 /*
  20  * For the "cycle" counter we use the timebase lower half.
  21  * Currently only used on SMP.
  22  *
  23  * Since SMP kernels won't run on the PPC601 CPU (which doesn't have
  24  * the timebase register) anyway, we don't bother checking the CPU version.
  25  */
  26
  27 extern cycles_t cacheflush_time;
  28
  29 static inline cycles_t get_cycles(void)
  30 {
  31 #ifdef CONFIG_SMP
  32         cycles_t ret;
  33
  34         __asm__("mftb %0" : "=r" (ret) : );
  35         return ret;
  36 #else
  37         return 0;
  38 #endif
  39 }
  40
  41 #endif