| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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 */ |