kobject: introduce kobj_completion

A common way to handle kobject lifetimes in embedded in objects with
different lifetime rules is to pair the kobject with a struct completion.

This introduces a kobj_completion structure that can be used in place
of the pairing, along with several convenience functions for
initialization, release, and put-and-wait.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/kobj_completion.h b/include/linux/kobj_completion.h
new file mode 100644
index 000000000000..a428f6436063
--- /dev/null
+++ b/include/linux/kobj_completion.h
@@ -0,0 +1,18 @@
+#ifndef _KOBJ_COMPLETION_H_
+#define _KOBJ_COMPLETION_H_
+
+#include <linux/kobject.h>
+#include <linux/completion.h>
+
+struct kobj_completion {
+	struct kobject kc_kobj;
+	struct completion kc_unregister;
+};
+
+#define kobj_to_kobj_completion(kobj) \
+	container_of(kobj, struct kobj_completion, kc_kobj)
+
+void kobj_completion_init(struct kobj_completion *kc, struct kobj_type *ktype);
+void kobj_completion_release(struct kobject *kobj);
+void kobj_completion_del_and_wait(struct kobj_completion *kc);
+#endif /* _KOBJ_COMPLETION_H_ */