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
17typedef unsigned long cycles_t;
18
19extern 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
34static inline cycles_t
35get_cycles (void)
36{
37	cycles_t ret;
38
39	ret = ia64_getreg(_IA64_REG_AR_ITC);
40	return ret;
41}
42
43extern void ia64_cpu_local_tick (void);
44extern unsigned long long ia64_native_sched_clock (void);
45
46#endif /* _ASM_IA64_TIMEX_H */