Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next

[cascardo/linux.git] / lib / llist.c

diff --git a/lib/llist.c b/lib/llist.c
index 4a15115..f76196d 100644 (file)
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -39,18 +39,13 @@
 bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
                     struct llist_head *head)
 {
-       struct llist_node *entry, *old_entry;
+       struct llist_node *first;
 
-       entry = head->first;
-       for (;;) {
-               old_entry = entry;
-               new_last->next = entry;
-               entry = cmpxchg(&head->first, old_entry, new_first);
-               if (entry == old_entry)
-                       break;
-       }
+       do {
+               new_last->next = first = ACCESS_ONCE(head->first);
+       } while (cmpxchg(&head->first, first, new_first) != first);
 
-       return old_entry == NULL;
+       return !first;
 }
 EXPORT_SYMBOL_GPL(llist_add_batch);
 
@@ -86,3 +81,25 @@ struct llist_node *llist_del_first(struct llist_head *head)
        return entry;
 }
 EXPORT_SYMBOL_GPL(llist_del_first);
+
+/**
+ * llist_reverse_order - reverse order of a llist chain
+ * @head:      first item of the list to be reversed
+ *
+ * Reverse the order of a chain of llist entries and return the
+ * new first entry.
+ */
+struct llist_node *llist_reverse_order(struct llist_node *head)
+{
+       struct llist_node *new_head = NULL;
+
+       while (head) {
+               struct llist_node *tmp = head;
+               head = head->next;
+               tmp->next = new_head;
+               new_head = tmp;
+       }
+
+       return new_head;
+}
+EXPORT_SYMBOL_GPL(llist_reverse_order);