list: introduce list_next_entry() and list_prev_entry()
[ Upstream commit 008208c6b26f21c2648c250a09c55e737c02c5f8 ]
Add two trivial helpers list_next_entry() and list_prev_entry(), they
can have a lot of users including list.h itself. In fact the 1st one is
already defined in events/core.c and bnx2x_sp.c, so the patch simply
moves the definition to list.h.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/list.h b/include/linux/list.h
index cc6d2aa..1712c7e 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -362,6 +362,22 @@
list_entry((ptr)->next, type, member)
/**
+ * list_next_entry - get the next element in list
+ * @pos: the type * to cursor
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_next_entry(pos, member) \
+ list_entry((pos)->member.next, typeof(*(pos)), member)
+
+/**
+ * list_prev_entry - get the prev element in list
+ * @pos: the type * to cursor
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_prev_entry(pos, member) \
+ list_entry((pos)->member.prev, typeof(*(pos)), member)
+
+/**
* list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop cursor.
* @head: the head for your list.