From e131319669e0ef5e6fcd75174daeffa40492135c Mon Sep 17 00:00:00 2001 From: Damien Riegel Date: Fri, 20 Nov 2015 16:54:51 -0500 Subject: watchdog: core: add reboot notifier support Many watchdog drivers register a reboot notifier in order to stop the watchdog on system reboot. Thus we can factorize this code in the watchdog core. For that purpose, a new notifier block is added in watchdog_device for internal use only, as well as a new watchdog_stop_on_reboot helper function. If this helper is called, watchdog core registers the related notifier block and will stop the watchdog when SYS_HALT or SYS_DOWN is received. Since this operation can be critical on some platforms, abort the device registration if the reboot notifier registration fails. Suggested-by: Vivien Didelot Signed-off-by: Damien Riegel Reviewed-by: Vivien Didelot Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- include/linux/watchdog.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index 5b52c834f7aa..a88f955fde92 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -65,6 +65,7 @@ struct watchdog_ops { * @timeout: The watchdog devices timeout value (in seconds). * @min_timeout:The watchdog devices minimum timeout value (in seconds). * @max_timeout:The watchdog devices maximum timeout value (in seconds). + * @reboot_nb: The notifier block to stop watchdog on reboot. * @restart_nb: The notifier block to register a restart function. * @driver-data:Pointer to the drivers private data. * @lock: Lock for watchdog core internal use only. @@ -92,6 +93,7 @@ struct watchdog_device { unsigned int timeout; unsigned int min_timeout; unsigned int max_timeout; + struct notifier_block reboot_nb; struct notifier_block restart_nb; void *driver_data; struct mutex lock; @@ -102,6 +104,7 @@ struct watchdog_device { #define WDOG_ALLOW_RELEASE 2 /* Did we receive the magic char ? */ #define WDOG_NO_WAY_OUT 3 /* Is 'nowayout' feature set ? */ #define WDOG_UNREGISTERED 4 /* Has the device been unregistered */ +#define WDOG_STOP_ON_REBOOT 5 /* Should be stopped on reboot */ struct list_head deferred; }; @@ -121,6 +124,12 @@ static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool noway set_bit(WDOG_NO_WAY_OUT, &wdd->status); } +/* Use the following function to stop the watchdog on reboot */ +static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) +{ + set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); +} + /* Use the following function to check if a timeout value is invalid */ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) { -- cgit v1.3-18-gd494