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-rw-r--r--include/asm-i386/tsc.h49
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 */
25typedef unsigned long long cycles_t;
26
27extern unsigned int cpu_khz;
28extern unsigned int tsc_khz;
29
30static 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
45extern void tsc_init(void);
46extern void mark_tsc_unstable(void);
47
48#endif