diff options
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/Kconfig | 5 | ||||
| -rw-r--r-- | kernel/time/timekeeping_internal.h | 9 |
2 files changed, 14 insertions, 0 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index feccfd888732..d626dc98e8df 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -12,6 +12,11 @@ config CLOCKSOURCE_WATCHDOG config ARCH_CLOCKSOURCE_DATA bool +# Clocksources require validation of the clocksource against the last +# cycle update - x86/TSC misfeature +config CLOCKSOURCE_VALIDATE_LAST_CYCLE + bool + # Timekeeping vsyscall support config GENERIC_TIME_VSYSCALL bool diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h index 05dfa6b25dc4..4ea005a7f9da 100644 --- a/kernel/time/timekeeping_internal.h +++ b/kernel/time/timekeeping_internal.h @@ -12,9 +12,18 @@ extern void tk_debug_account_sleep_time(struct timespec64 *t); #define tk_debug_account_sleep_time(x) #endif +#ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE +static inline cycle_t clocksource_delta(cycle_t now, cycle_t last, cycle_t mask) +{ + cycle_t ret = (now - last) & mask; + + return (s64) ret > 0 ? ret : 0; +} +#else static inline cycle_t clocksource_delta(cycle_t now, cycle_t last, cycle_t mask) { return (now - last) & mask; } +#endif #endif /* _TIMEKEEPING_INTERNAL_H */ |