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