list: Add list_last_entry() to find the last entry

We have list_first_entry() but in some cases it is useful to find the last item added to the list. Add a macro for this. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

list: Add list_last_entry() to find the last entry
We have list_first_entry() but in some cases it is useful to find the last item added to the list. Add a macro for this. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Simon Glass · Bin Meng
1 parent b91c6a1209
Showing 1 changed file with 11 additions and 0 deletions Side-by-side Diff
include/linux/list.h
@@ -338,6 +338,17 @@
 	list_entry((ptr)->next, type, member)
  
 /**
+ * list_last_entry - get the last element from a list
+ * @ptr:	the list head to take the element from.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ */
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, 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.
...	...	@@ -338,6 +338,17 @@
338	338	list_entry((ptr)->next, type, member)
339	339
340	340	/**
	341	+ * list_last_entry - get the last element from a list
	342	+ * @ptr: the list head to take the element from.
	343	+ * @type: the type of the struct this is embedded in.
	344	+ * @member: the name of the list_struct within the struct.
	345	+ *
	346	+ * Note, that list is expected to be not empty.
	347	+ */
	348	+#define list_last_entry(ptr, type, member) \
	349	+ list_entry((ptr)->prev, type, member)
	350	+
	351	+/**
341	352	* list_for_each - iterate over a list
342	353	* @pos: the &struct list_head to use as a loop cursor.
343	354	* @head: the head for your list.