1/* 2 * x86 TSC related functions 3 */ 4#ifndef _ASM_X86_TSC_H 5#define _ASM_X86_TSC_H 6 7#include <asm/processor.h> 8 9#define NS_SCALE 10 /* 2^10, carefully chosen */ 10#define US_SCALE 32 /* 2^32, arbitralrily chosen */ 11 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; 19 20extern void disable_TSC(void); 21 22static inline cycles_t get_cycles(void) 23{ 24#ifndef CONFIG_X86_TSC 25 if (!boot_cpu_has(X86_FEATURE_TSC)) 26 return 0; 27#endif 28 29 return rdtsc(); 30} 31 32extern struct system_counterval_t convert_art_to_tsc(u64 art); 33 34extern void tsc_init(void); 35extern void mark_tsc_unstable(char *reason); 36extern int unsynchronized_tsc(void); 37extern int check_tsc_unstable(void); 38extern unsigned long native_calibrate_cpu(void); 39extern unsigned long native_calibrate_tsc(void); 40extern unsigned long long native_sched_clock_from_tsc(u64 tsc); 41 42extern int tsc_clocksource_reliable; 43 44/* 45 * Boot-time check whether the TSCs are synchronized across 46 * all CPUs/cores: 47 */ 48#ifdef CONFIG_X86_TSC 49extern bool tsc_store_and_check_tsc_adjust(bool bootcpu); 50extern void tsc_verify_tsc_adjust(bool resume); 51extern void check_tsc_sync_source(int cpu); 52extern void check_tsc_sync_target(void); 53#else 54static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; } 55static inline void tsc_verify_tsc_adjust(bool resume) { } 56static inline void check_tsc_sync_source(int cpu) { } 57static inline void check_tsc_sync_target(void) { } 58#endif 59 60extern int notsc_setup(char *); 61extern void tsc_save_sched_clock_state(void); 62extern void tsc_restore_sched_clock_state(void); 63 64unsigned long cpu_khz_from_msr(void); 65 66#endif /* _ASM_X86_TSC_H */ 67