diff options
Diffstat (limited to 'include/asm-i386/tsc.h')
-rw-r--r-- | include/asm-i386/tsc.h | 49 |
1 files changed, 1 insertions, 48 deletions
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h index c13933185c1c..e997891cc7cc 100644 --- a/include/asm-i386/tsc.h +++ b/include/asm-i386/tsc.h | |||
@@ -1,48 +1 @@ | |||
1 | /* | #include <asm-x86_64/tsc.h> | |
2 | * linux/include/asm-i386/tsc.h | ||
3 | * | ||
4 | * i386 TSC related functions | ||
5 | */ | ||
6 | #ifndef _ASM_i386_TSC_H | ||
7 | #define _ASM_i386_TSC_H | ||
8 | |||
9 | #include <asm/processor.h> | ||
10 | |||
11 | /* | ||
12 | * Standard way to access the cycle counter on i586+ CPUs. | ||
13 | * Currently only used on SMP. | ||
14 | * | ||
15 | * If you really have a SMP machine with i486 chips or older, | ||
16 | * compile for that, and this will just always return zero. | ||
17 | * That's ok, it just means that the nicer scheduling heuristics | ||
18 | * won't work for you. | ||
19 | * | ||
20 | * We only use the low 32 bits, and we'd simply better make sure | ||
21 | * that we reschedule before that wraps. Scheduling at least every | ||
22 | * four billion cycles just basically sounds like a good idea, | ||
23 | * regardless of how fast the machine is. | ||
24 | */ | ||
25 | typedef unsigned long long cycles_t; | ||
26 | |||
27 | extern unsigned int cpu_khz; | ||
28 | extern unsigned int tsc_khz; | ||
29 | |||
30 | static inline cycles_t get_cycles(void) | ||
31 | { | ||
32 | unsigned long long ret = 0; | ||
33 | |||
34 | #ifndef CONFIG_X86_TSC | ||
35 | if (!cpu_has_tsc) | ||
36 | return 0; | ||
37 | #endif | ||
38 | |||
39 | #if defined(CONFIG_X86_GENERIC) || defined(CONFIG_X86_TSC) | ||
40 | rdtscll(ret); | ||
41 | #endif | ||
42 | return ret; | ||
43 | } | ||
44 | |||
45 | extern void tsc_init(void); | ||
46 | extern void mark_tsc_unstable(void); | ||
47 | |||
48 | #endif | ||