LXR linux/kernel/time/timekeeping

   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
  11extern 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
  17static 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
  28static 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