Merge branch 'writeback-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / arch / x86 / include / asm / tsc.h
CommitLineData
2272b0e0 1/*
2f0798a3 2 * x86 TSC related functions
2272b0e0 3 */
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PA
4#ifndef _ASM_X86_TSC_H
5#define _ASM_X86_TSC_H
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AS
6
7#include <asm/processor.h>
8
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TG
9#define NS_SCALE 10 /* 2^10, carefully chosen */
10#define US_SCALE 32 /* 2^32, arbitralrily chosen */
11
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AS
12/*
13 * Standard way to access the cycle counter.
14 */
15typedef unsigned long long cycles_t;
16
17extern unsigned int cpu_khz;
18extern unsigned int tsc_khz;
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GOC
19
20extern void disable_TSC(void);
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21
22static inline cycles_t get_cycles(void)
23{
24 unsigned long long ret = 0;
25
26#ifndef CONFIG_X86_TSC
27 if (!cpu_has_tsc)
28 return 0;
29#endif
2272b0e0 30 rdtscll(ret);
75f2ce03 31
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AS
32 return ret;
33}
34
97520825 35static __always_inline cycles_t vget_cycles(void)
2272b0e0 36{
c5bcb563 37 /*
0d2eb44f 38 * We only do VDSOs on TSC capable CPUs, so this shouldn't
6d63de8d 39 * access boot_cpu_data (which is not VDSO-safe):
c5bcb563 40 */
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AK
41#ifndef CONFIG_X86_TSC
42 if (!cpu_has_tsc)
43 return 0;
4e87173e 44#endif
cb9e35dc 45 return (cycles_t)__native_read_tsc();
6d63de8d 46}
4e87173e 47
2272b0e0 48extern void tsc_init(void);
5a90cf20 49extern void mark_tsc_unstable(char *reason);
2272b0e0 50extern int unsynchronized_tsc(void);
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TG
51extern int check_tsc_unstable(void);
52extern unsigned long native_calibrate_tsc(void);
2272b0e0 53
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54extern int tsc_clocksource_reliable;
55
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56/*
57 * Boot-time check whether the TSCs are synchronized across
58 * all CPUs/cores:
59 */
60extern void check_tsc_sync_source(int cpu);
61extern void check_tsc_sync_target(void);
62
80ca9c98 63extern int notsc_setup(char *);
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MT
64extern void tsc_save_sched_clock_state(void);
65extern void tsc_restore_sched_clock_state(void);
d371698e 66
1965aae3 67#endif /* _ASM_X86_TSC_H */
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