/* * 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) { unsigned long long ret = 0; #ifndef CONFIG_X86_TSC if (!cpu_has_tsc) return 0; #endif rdtscll(ret); return ret; } static inline cycles_t vget_cycles(void) { /* * We only do VDSOs on TSC capable CPUs, so this shouldnt * access boot_cpu_data (which is not VDSO-safe): */ #ifndef CONFIG_X86_TSC if (!cpu_has_tsc) return 0; #endif return (cycles_t)__native_read_tsc(); } extern void tsc_init(void); extern void mark_tsc_unstable(char *reason); extern int unsynchronized_tsc(void); extern void init_tsc_clocksource(void); int check_tsc_unstable(void); /* * 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 void tsc_calibrate(void); extern int notsc_setup(char *); #endif