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