[linux.git] / kernel / time / timekeeping_internal.h

/* 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
extern void tk_debug_account_sleep_time(const struct timespec64 *t);
#else
#define tk_debug_account_sleep_time(x)
#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. */
extern raw_spinlock_t timekeeper_lock;

#endif /* _TIMEKEEPING_INTERNAL_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
5c83545f CC	2	#ifndef _TIMEKEEPING_INTERNAL_H
5c83545f CC	3	#define _TIMEKEEPING_INTERNAL_H
19d0070a	4
3a978377	5	#include <linux/clocksource.h>
19d0070a	6	#include <linux/spinlock.h>
5c83545f CC	7	#include <linux/time.h>
5c83545f CC	8
19d0070a TG	9	/*
	10	* timekeeping debug functions
	11	*/
5c83545f	12	#ifdef CONFIG_DEBUG_FS
985e6950	13	extern void tk_debug_account_sleep_time(const struct timespec64 *t);
5c83545f CC	14	#else
	15	#define tk_debug_account_sleep_time(x)
	16	#endif
	17
09ec5442	18	#ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE
a5a1d1c2	19	static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
09ec5442	20	{
a5a1d1c2	21	u64 ret = (now - last) & mask;
09ec5442	22
1f45f1f3 YY	23	/*
	24	* Prevent time going backwards by checking the MSB of mask in
	25	* the result. If set, return 0.
	26	*/
	27	return ret & ~(mask >> 1) ? 0 : ret;
09ec5442 TG	28	}
09ec5442 TG	29	#else
a5a1d1c2	30	static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
3a978377 TG	31	{
	32	return (now - last) & mask;
	33	}
09ec5442	34	#endif
3a978377	35
19d0070a TG	36	/* Semi public for serialization of non timekeeper VDSO updates. */
	37	extern raw_spinlock_t timekeeper_lock;
	38
5c83545f	39	#endif /* _TIMEKEEPING_INTERNAL_H */