xref: /openbmc/linux/arch/ia64/include/asm/timex.h (revision 9a29f5fc)
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 #define get_cycles get_cycles
43 
44 extern void ia64_cpu_local_tick (void);
45 extern unsigned long long ia64_native_sched_clock (void);
46 
47 #endif /* _ASM_IA64_TIMEX_H */
48