arch/ia64/include/asm/timex.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_IA64_TIMEX_H
   3 #define _ASM_IA64_TIMEX_H
   4
   5 /*
   6  * Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
   7  *      David Mosberger-Tang <davidm@hpl.hp.com>
   8  */
   9 /*
  10  * 2001/01/18 davidm    Removed CLOCK_TICK_RATE.  It makes no sense on IA-64.
  11  *                      Also removed cacheflush_time as it's entirely unused.
  12  */
  13
  14 #include <asm/intrinsics.h>
  15 #include <asm/processor.h>
  16
  17 typedef unsigned long cycles_t;
  18
  19 extern void (*ia64_udelay)(unsigned long usecs);
  20
  21 /*
  22  * For performance reasons, we don't want to define CLOCK_TICK_TRATE as
  23  * local_cpu_data->itc_rate.  Fortunately, we don't have to, either: according to George
  24  * Anzinger, 1/CLOCK_TICK_RATE is taken as the resolution of the timer clock.  The time
  25  * calculation assumes that you will use enough of these so that your tick size <= 1/HZ.
  26  * If the calculation shows that your CLOCK_TICK_RATE can not supply exactly 1/HZ ticks,
  27  * the actual value is calculated and used to update the wall clock each jiffie.  Setting
  28  * the CLOCK_TICK_RATE to x*HZ insures that the calculation will find no errors.  Hence we
  29  * pick a multiple of HZ which gives us a (totally virtual) CLOCK_TICK_RATE of about
  30  * 100MHz.
  31  */
  32 #define CLOCK_TICK_RATE         (HZ * 100000UL)
  33
  34 static inline cycles_t
  35 get_cycles (void)
  36 {
  37         cycles_t ret;
  38
  39         ret = ia64_getreg(_IA64_REG_AR_ITC);
  40         return ret;
  41 }
  42
  43 extern void ia64_cpu_local_tick (void);
  44 extern unsigned long long ia64_native_sched_clock (void);
  45
  46 #endif /* _ASM_IA64_TIMEX_H */