linux-stable/kernel/time/timekeeping_internal.h
Thomas Gleixner dbdcf8c4ca timekeeping: Encapsulate locking/unlocking of timekeeper_lock
timekeeper_lock protects updates of timekeeper (tk_core). It is also used
by vdso_update_begin/end() and not only internally by the timekeeper code.

As long as there is only a single timekeeper, this works fine.  But when
the timekeeper infrastructure will be reused for per ptp clock timekeepers,
timekeeper_lock needs to be part of tk_core..

Therefore encapuslate locking/unlocking of timekeeper_lock and make the
lock static.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-8-554456a44a15@linutronix.de
2024-10-25 19:49:13 +02:00

56 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TIMEKEEPING_INTERNAL_H
#define _TIMEKEEPING_INTERNAL_H
#include <linux/clocksource.h>
#include <linux/spinlock.h>
#include <linux/time.h>
/*
* timekeeping debug functions
*/
#ifdef CONFIG_DEBUG_FS
DECLARE_PER_CPU(unsigned long, timekeeping_mg_floor_swaps);
static inline void timekeeping_inc_mg_floor_swaps(void)
{
this_cpu_inc(timekeeping_mg_floor_swaps);
}
extern void tk_debug_account_sleep_time(const struct timespec64 *t);
#else
#define tk_debug_account_sleep_time(x)
static inline void timekeeping_inc_mg_floor_swaps(void)
{
}
#endif
#ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE
static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
{
u64 ret = (now - last) & mask;
/*
* Prevent time going backwards by checking the MSB of mask in
* the result. If set, return 0.
*/
return ret & ~(mask >> 1) ? 0 : ret;
}
#else
static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
{
return (now - last) & mask;
}
#endif
/* Semi public for serialization of non timekeeper VDSO updates. */
unsigned long timekeeper_lock_irqsave(void);
void timekeeper_unlock_irqrestore(unsigned long flags);
#endif /* _TIMEKEEPING_INTERNAL_H */