xref: /linux/kernel/time/timekeeping_internal.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 #ifndef _TIMEKEEPING_INTERNAL_H
2 #define _TIMEKEEPING_INTERNAL_H
3 /*
4  * timekeeping debug functions
5  */
6 #include <linux/clocksource.h>
7 #include <linux/time.h>
8 
9 #ifdef CONFIG_DEBUG_FS
10 extern void tk_debug_account_sleep_time(struct timespec64 *t);
11 #else
12 #define tk_debug_account_sleep_time(x)
13 #endif
14 
15 #ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE
16 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
17 {
18 	u64 ret = (now - last) & mask;
19 
20 	/*
21 	 * Prevent time going backwards by checking the MSB of mask in
22 	 * the result. If set, return 0.
23 	 */
24 	return ret & ~(mask >> 1) ? 0 : ret;
25 }
26 #else
27 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
28 {
29 	return (now - last) & mask;
30 }
31 #endif
32 
33 extern time64_t __ktime_get_real_seconds(void);
34 
35 #endif /* _TIMEKEEPING_INTERNAL_H */
36