From 2d8364bae4db144df75ba85e92d2b8619ba8eedc Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Fri, 17 Nov 2017 15:30:57 -0800 Subject: [PATCH] kernel/reboot.c: add devm_register_reboot_notifier() Add devm_* wrapper around register_reboot_notifier to simplify device specific reboot notifier registration/unregistration. [akpm@linux-foundation.org: move `struct device' forward decl to top-of-file] Link: http://lkml.kernel.org/r/20170320171753.1705-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/reboot.h | 4 ++++ kernel/reboot.c | 27 +++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index d03da0eb95ca..e63799a6e895 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -6,6 +6,8 @@ #include #include +struct device; + #define SYS_DOWN 0x0001 /* Notify of system down */ #define SYS_RESTART SYS_DOWN #define SYS_HALT 0x0002 /* Notify of system halt */ @@ -39,6 +41,8 @@ extern int reboot_force; extern int register_reboot_notifier(struct notifier_block *); extern int unregister_reboot_notifier(struct notifier_block *); +extern int devm_register_reboot_notifier(struct device *, struct notifier_block *); + extern int register_restart_handler(struct notifier_block *); extern int unregister_restart_handler(struct notifier_block *); extern void do_kernel_restart(char *cmd); diff --git a/kernel/reboot.c b/kernel/reboot.c index bd30a973fe94..e4ced883d8de 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -104,6 +104,33 @@ int unregister_reboot_notifier(struct notifier_block *nb) } EXPORT_SYMBOL(unregister_reboot_notifier); +static void devm_unregister_reboot_notifier(struct device *dev, void *res) +{ + WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res)); +} + +int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb) +{ + struct notifier_block **rcnb; + int ret; + + rcnb = devres_alloc(devm_unregister_reboot_notifier, + sizeof(*rcnb), GFP_KERNEL); + if (!rcnb) + return -ENOMEM; + + ret = register_reboot_notifier(nb); + if (!ret) { + *rcnb = nb; + devres_add(dev, rcnb); + } else { + devres_free(rcnb); + } + + return ret; +} +EXPORT_SYMBOL(devm_register_reboot_notifier); + /* * Notifier list for kernel code which wants to be called * to restart the system. -- 2.30.2