1 /* SPDX-License-Identifier: GPL-2.0 */
3 * x86 TSC related functions
8 #include <asm/cpufeature.h>
9 #include <asm/processor.h>
13 * Standard way to access the cycle counter.
15 typedef unsigned long long cycles_t;
17 extern unsigned int cpu_khz;
18 extern unsigned int tsc_khz;
20 extern void disable_TSC(void);
22 static inline cycles_t get_cycles(void)
24 if (!IS_ENABLED(CONFIG_X86_TSC) &&
25 !cpu_feature_enabled(X86_FEATURE_TSC))
29 #define get_cycles get_cycles
31 extern struct system_counterval_t convert_art_to_tsc(u64 art);
32 extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
34 extern void tsc_early_init(void);
35 extern void tsc_init(void);
36 extern void mark_tsc_unstable(char *reason);
37 extern int unsynchronized_tsc(void);
38 extern int check_tsc_unstable(void);
39 extern void mark_tsc_async_resets(char *reason);
40 extern unsigned long native_calibrate_cpu_early(void);
41 extern unsigned long native_calibrate_tsc(void);
42 extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
44 extern int tsc_clocksource_reliable;
46 extern bool tsc_async_resets;
48 # define tsc_async_resets false
52 * Boot-time check whether the TSCs are synchronized across
56 extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
57 extern void tsc_verify_tsc_adjust(bool resume);
58 extern void check_tsc_sync_target(void);
60 static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
61 static inline void tsc_verify_tsc_adjust(bool resume) { }
62 static inline void check_tsc_sync_target(void) { }
65 extern int notsc_setup(char *);
66 extern void tsc_save_sched_clock_state(void);
67 extern void tsc_restore_sched_clock_state(void);
69 unsigned long cpu_khz_from_msr(void);
71 #endif /* _ASM_X86_TSC_H */