xref: /linux/arch/x86/include/asm/tsc.h (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * x86 TSC related functions
4  */
5 #ifndef _ASM_X86_TSC_H
6 #define _ASM_X86_TSC_H
7 
8 #include <asm/processor.h>
9 #include <asm/cpufeature.h>
10 
11 /*
12  * Standard way to access the cycle counter.
13  */
14 typedef unsigned long long cycles_t;
15 
16 extern unsigned int cpu_khz;
17 extern unsigned int tsc_khz;
18 
19 extern void disable_TSC(void);
20 
21 static inline cycles_t get_cycles(void)
22 {
23 	if (!IS_ENABLED(CONFIG_X86_TSC) &&
24 	    !cpu_feature_enabled(X86_FEATURE_TSC))
25 		return 0;
26 	return rdtsc();
27 }
28 #define get_cycles get_cycles
29 
30 extern struct system_counterval_t convert_art_to_tsc(u64 art);
31 extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
32 
33 extern void tsc_early_init(void);
34 extern void tsc_init(void);
35 extern void mark_tsc_unstable(char *reason);
36 extern int unsynchronized_tsc(void);
37 extern int check_tsc_unstable(void);
38 extern void mark_tsc_async_resets(char *reason);
39 extern unsigned long native_calibrate_cpu_early(void);
40 extern unsigned long native_calibrate_tsc(void);
41 extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
42 
43 extern int tsc_clocksource_reliable;
44 #ifdef CONFIG_X86_TSC
45 extern bool tsc_async_resets;
46 #else
47 # define tsc_async_resets	false
48 #endif
49 
50 /*
51  * Boot-time check whether the TSCs are synchronized across
52  * all CPUs/cores:
53  */
54 #ifdef CONFIG_X86_TSC
55 extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
56 extern void tsc_verify_tsc_adjust(bool resume);
57 extern void check_tsc_sync_target(void);
58 #else
59 static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
60 static inline void tsc_verify_tsc_adjust(bool resume) { }
61 static inline void check_tsc_sync_target(void) { }
62 #endif
63 
64 extern int notsc_setup(char *);
65 extern void tsc_save_sched_clock_state(void);
66 extern void tsc_restore_sched_clock_state(void);
67 
68 unsigned long cpu_khz_from_msr(void);
69 
70 #endif /* _ASM_X86_TSC_H */
71