|  | /* SPDX-License-Identifier: GPL-2.0 */ | 
|  | #ifndef _PVCLOCK_GTOD_H | 
|  | #define _PVCLOCK_GTOD_H | 
|  |  | 
|  | #include <linux/notifier.h> | 
|  |  | 
|  | /* | 
|  | * The pvclock gtod notifier is called when the system time is updated | 
|  | * and is used to keep guest time synchronized with host time. | 
|  | * | 
|  | * The 'action' parameter in the notifier function is false (0), or | 
|  | * true (non-zero) if system time was stepped. | 
|  | */ | 
|  | extern int pvclock_gtod_register_notifier(struct notifier_block *nb); | 
|  | extern int pvclock_gtod_unregister_notifier(struct notifier_block *nb); | 
|  |  | 
|  | #endif /* _PVCLOCK_GTOD_H */ |