projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * linux/include/asm-i386/timex.h | |
| 3 | * | |
| 4 | * i386 architecture timex specifications | |
| 5 | */ | |
| 6 | #ifndef _ASMi386_TIMEX_H | |
| 7 | #define _ASMi386_TIMEX_H | |
| 8 | ||
| 9 | #include <linux/config.h> | |
| 10 | #include <asm/processor.h> | |
| 11 | ||
| 12 | #ifdef CONFIG_X86_ELAN | |
| 13 | # define CLOCK_TICK_RATE 1189200 /* AMD Elan has different frequency! */ | |
| 14 | #else | |
| 15 | # define CLOCK_TICK_RATE 1193182 /* Underlying HZ */ | |
| 16 | #endif | |
| 17 | ||
| 18 | ||
| 19 | /* | |
| 20 | * Standard way to access the cycle counter on i586+ CPUs. | |
| 21 | * Currently only used on SMP. | |
| 22 | * | |
| 23 | * If you really have a SMP machine with i486 chips or older, | |
| 24 | * compile for that, and this will just always return zero. | |
| 25 | * That's ok, it just means that the nicer scheduling heuristics | |
| 26 | * won't work for you. | |
| 27 | * | |
| 28 | * We only use the low 32 bits, and we'd simply better make sure | |
| 29 | * that we reschedule before that wraps. Scheduling at least every | |
| 30 | * four billion cycles just basically sounds like a good idea, | |
| 31 | * regardless of how fast the machine is. | |
| 32 | */ | |
| 33 | typedef unsigned long long cycles_t; | |
| 34 | ||
| 35 | static inline cycles_t get_cycles (void) | |
| 36 | { | |
| 37 | unsigned long long ret=0; | |
| 38 | ||
| 39 | #ifndef CONFIG_X86_TSC | |
| 40 | if (!cpu_has_tsc) | |
| 41 | return 0; | |
| 42 | #endif | |
| 43 | ||
| 44 | #if defined(CONFIG_X86_GENERIC) || defined(CONFIG_X86_TSC) | |
| 45 | rdtscll(ret); | |
| 46 | #endif | |
| 47 | return ret; | |
| 48 | } | |
| 49 | ||
| a3a255e7 | 50 | extern unsigned int cpu_khz; |
| 1da177e4 | 51 | |
| 8a9e1b0f VP |
52 | extern int read_current_timer(unsigned long *timer_value); |
| 53 | #define ARCH_HAS_READ_CURRENT_TIMER 1 | |
| 54 | ||
| 1da177e4 | 55 | #endif |