| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | /* |
| 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 | |
| 31 | static inline cycles_t |
| 32 | get_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 */ |