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
10#define NS_SCALE	10 /* 2^10, carefully chosen */
11#define US_SCALE	32 /* 2^32, arbitralrily chosen */
12
13/*
14 * Standard way to access the cycle counter.
15 */
16typedef unsigned long long cycles_t;
17
18extern unsigned int cpu_khz;
19extern unsigned int tsc_khz;
20
21extern void disable_TSC(void);
22
23static inline cycles_t get_cycles(void)
24{
25#ifndef CONFIG_X86_TSC
26	if (!boot_cpu_has(X86_FEATURE_TSC))
27		return 0;
28#endif
29
30	return rdtsc();
31}
 
32
33extern struct system_counterval_t convert_art_to_tsc(u64 art);
34extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
35
36extern void tsc_early_delay_calibrate(void);
37extern void tsc_init(void);
 
38extern void mark_tsc_unstable(char *reason);
39extern int unsynchronized_tsc(void);
40extern int check_tsc_unstable(void);
41extern void mark_tsc_async_resets(char *reason);
42extern unsigned long native_calibrate_cpu(void);
43extern unsigned long native_calibrate_tsc(void);
44extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
45
46extern int tsc_clocksource_reliable;
47#ifdef CONFIG_X86_TSC
48extern bool tsc_async_resets;
49#else
50# define tsc_async_resets	false
51#endif
52
53/*
54 * Boot-time check whether the TSCs are synchronized across
55 * all CPUs/cores:
56 */
57#ifdef CONFIG_X86_TSC
58extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
59extern void tsc_verify_tsc_adjust(bool resume);
60extern void check_tsc_sync_source(int cpu);
61extern void check_tsc_sync_target(void);
62#else
63static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
64static inline void tsc_verify_tsc_adjust(bool resume) { }
65static inline void check_tsc_sync_source(int cpu) { }
66static inline void check_tsc_sync_target(void) { }
67#endif
68
69extern int notsc_setup(char *);
70extern void tsc_save_sched_clock_state(void);
71extern void tsc_restore_sched_clock_state(void);
72
73unsigned long cpu_khz_from_msr(void);
74
75#endif /* _ASM_X86_TSC_H */

 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 */
14typedef unsigned long long cycles_t;
15
16extern unsigned int cpu_khz;
17extern unsigned int tsc_khz;
18
19extern void disable_TSC(void);
20
21static 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
30extern struct system_counterval_t convert_art_to_tsc(u64 art);
31extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
32
33extern void tsc_early_init(void);
34extern void tsc_init(void);
35extern unsigned long calibrate_delay_is_known(void);
36extern void mark_tsc_unstable(char *reason);
37extern int unsynchronized_tsc(void);
38extern int check_tsc_unstable(void);
39extern void mark_tsc_async_resets(char *reason);
40extern unsigned long native_calibrate_cpu_early(void);
41extern unsigned long native_calibrate_tsc(void);
42extern unsigned long long native_sched_clock_from_tsc(u64 tsc);
43
44extern int tsc_clocksource_reliable;
45#ifdef CONFIG_X86_TSC
46extern bool tsc_async_resets;
47#else
48# define tsc_async_resets	false
49#endif
50
51/*
52 * Boot-time check whether the TSCs are synchronized across
53 * all CPUs/cores:
54 */
55#ifdef CONFIG_X86_TSC
56extern bool tsc_store_and_check_tsc_adjust(bool bootcpu);
57extern void tsc_verify_tsc_adjust(bool resume);
58extern void check_tsc_sync_source(int cpu);
59extern void check_tsc_sync_target(void);
60#else
61static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; }
62static inline void tsc_verify_tsc_adjust(bool resume) { }
63static inline void check_tsc_sync_source(int cpu) { }
64static inline void check_tsc_sync_target(void) { }
65#endif
66
67extern int notsc_setup(char *);
68extern void tsc_save_sched_clock_state(void);
69extern void tsc_restore_sched_clock_state(void);
70
71unsigned long cpu_khz_from_msr(void);
72
73#endif /* _ASM_X86_TSC_H */