ubuntu-linux-kernel/arch/x86/include/asm/tsc.h

75 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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 (!boot_cpu_has(X86_FEATURE_TSC))
return 0;
#endif
return rdtsc();
}
extern struct system_counterval_t convert_art_to_tsc(u64 art);
extern void tsc_early_delay_calibrate(void);
extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
extern int unsynchronized_tsc(void);
extern int check_tsc_unstable(void);
extern void mark_tsc_async_resets(char *reason);
extern unsigned long native_calibrate_cpu(void);
extern unsigned long native_calibrate_tsc(void);
extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
extern int tsc_clocksource_reliable;
#ifdef CONFIG_X86_TSC
extern bool tsc_async_resets;
#else
# define tsc_async_resets false
#endif
/*
* Boot-time check whether the TSCs are synchronized across
* all CPUs/cores:
*/
#ifdef CONFIG_X86_TSC
extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
extern void tsc_verify_tsc_adjust(bool resume);
extern void check_tsc_sync_source(int cpu);
extern void check_tsc_sync_target(void);
#else
static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
static inline void tsc_verify_tsc_adjust(bool resume) { }
static inline void check_tsc_sync_source(int cpu) { }
static inline void check_tsc_sync_target(void) { }
#endif
extern int notsc_setup(char *);
extern void tsc_save_sched_clock_state(void);
extern void tsc_restore_sched_clock_state(void);
unsigned long cpu_khz_from_msr(void);
#endif /* _ASM_X86_TSC_H */