1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _TIMEKEEPING_INTERNAL_H 3 #define _TIMEKEEPING_INTERNAL_H 4 5 #include <linux/clocksource.h> 6 #include <linux/spinlock.h> 7 #include <linux/time.h> 8 9 /* 10 * timekeeping debug functions 11 */ 12 #ifdef CONFIG_DEBUG_FS 13 extern void tk_debug_account_sleep_time(const struct timespec64 *t); 14 #else 15 #define tk_debug_account_sleep_time(x) 16 #endif 17 18 #ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE 19 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask) 20 { 21 u64 ret = (now - last) & mask; 22 23 /* 24 * Prevent time going backwards by checking the MSB of mask in 25 * the result. If set, return 0. 26 */ 27 return ret & ~(mask >> 1) ? 0 : ret; 28 } 29 #else 30 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask) 31 { 32 return (now - last) & mask; 33 } 34 #endif 35 36 /* Semi public for serialization of non timekeeper VDSO updates. */ 37 extern raw_spinlock_t timekeeper_lock; 38 39 #endif /* _TIMEKEEPING_INTERNAL_H */ 40