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/*
* x86 TSC related functions
*/
#ifndef _ASM_X86_TSC_H
#define _ASM_X86_TSC_H
#include <asm/processor.h>
#define NS_SCALE 10 /* 2^10, carefully chosen */
#define US_SCALE 32 /* 2^32, arbitralrily chosen */
/*
* Standard way to access the cycle counter.
*/
typedef unsigned long long cycles_t;
extern unsigned int cpu_khz;
extern unsigned int tsc_khz;
extern void disable_TSC(void);
static inline cycles_t get_cycles(void)
{
#ifndef CONFIG_X86_TSC
if (!cpu_has_tsc)
return 0;
#endif
return rdtsc();
}
extern struct system_counterval_t convert_art_to_tsc(cycle_t art);
extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
extern int unsynchronized_tsc(void);
extern int check_tsc_unstable(void);
extern int check_tsc_disabled(void);
extern unsigned long native_calibrate_tsc(void);
extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
extern int tsc_clocksource_reliable;
/*
* Boot-time check whether the TSCs are synchronized across
* all CPUs/cores:
*/
extern void check_tsc_sync_source(int cpu);
extern void check_tsc_sync_target(void);
extern int notsc_setup(char *);
extern void tsc_save_sched_clock_state(void);
extern void tsc_restore_sched_clock_state(void);
/* MSR based TSC calibration for Intel Atom SoC platforms */
unsigned long try_msr_calibrate_tsc(void);
#endif /* _ASM_X86_TSC_H */