From 2d8364bae4db144df75ba85e92d2b8619ba8eedc Mon Sep 17 00:00:00 2001
From: Andrey Smirnov <andrew.smirnov@gmail.com>
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 <andrew.smirnov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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 d03da0eb95ca7..e63799a6e8951 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -6,6 +6,8 @@
#include <linux/notifier.h>
#include <uapi/linux/reboot.h>
+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 bd30a973fe946..e4ced883d8de1 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.
--
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