From 13dfd97a341a5cf9d15f415dd469f45e971ef12a Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Thu, 19 May 2022 14:02:32 +0300 Subject: notifier: Add atomic_notifier_call_chain_is_empty() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add atomic_notifier_call_chain_is_empty() that returns true if given atomic call chain is empty. The first user of this new notifier API function will be the kernel power-off core code that will support power-off call chains. The core code will need to check whether there is a power-off handler registered at all in order to decide whether to halt machine or power it off. Reviewed-by: Michał Mirosław Signed-off-by: Dmitry Osipenko Signed-off-by: Rafael J. Wysocki --- include/linux/notifier.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 87069b8459af..95e2440037de 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -173,6 +173,8 @@ extern int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh extern int raw_notifier_call_chain_robust(struct raw_notifier_head *nh, unsigned long val_up, unsigned long val_down, void *v); +extern bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh); + #define NOTIFY_DONE 0x0000 /* Don't care */ #define NOTIFY_OK 0x0001 /* Suits me */ #define NOTIFY_STOP_MASK 0x8000 /* Don't call further */ -- cgit v1.2.3