xref: /openbmc/linux/arch/ia64/include/asm/timex.h (revision 82ced6fd)
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 
16 typedef unsigned long cycles_t;
17 
18 extern void (*ia64_udelay)(unsigned long usecs);
19 
20 /*
21  * For performance reasons, we don't want to define CLOCK_TICK_TRATE as
22  * local_cpu_data->itc_rate.  Fortunately, we don't have to, either: according to George
23  * Anzinger, 1/CLOCK_TICK_RATE is taken as the resolution of the timer clock.  The time
24  * calculation assumes that you will use enough of these so that your tick size <= 1/HZ.
25  * If the calculation shows that your CLOCK_TICK_RATE can not supply exactly 1/HZ ticks,
26  * the actual value is calculated and used to update the wall clock each jiffie.  Setting
27  * the CLOCK_TICK_RATE to x*HZ insures that the calculation will find no errors.  Hence we
28  * pick a multiple of HZ which gives us a (totally virtual) CLOCK_TICK_RATE of about
29  * 100MHz.
30  */
31 #define CLOCK_TICK_RATE		(HZ * 100000UL)
32 
33 static inline cycles_t
34 get_cycles (void)
35 {
36 	cycles_t ret;
37 
38 	ret = ia64_getreg(_IA64_REG_AR_ITC);
39 	return ret;
40 }
41 
42 extern void ia64_cpu_local_tick (void);
43 extern unsigned long long ia64_native_sched_clock (void);
44 
45 #endif /* _ASM_IA64_TIMEX_H */
46