2 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/llist.h b/include/linux/llist.h
index ca91875286b..27bbdf5ddf8 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -142,8 +142,10 @@ static inline bool llist_empty(const struct llist_head *head)
  * llist_add - add a new entry
  * @new:        new entry to be added
  * @head:       the head for your lock-less list
+ *
+ * Return whether list is empty before adding.
  */
-static inline void llist_add(struct llist_node *new, struct llist_head *head)
+static inline bool llist_add(struct llist_node *new, struct llist_head *head)
 {
         struct llist_node *entry, *old_entry;
 
@@ -156,6 +158,8 @@ static inline void llist_add(struct llist_node *new, struct llist_head *head)
                         break;
                 cpu_relax();
         }
+
+        return old_entry == NULL;
 }
 
 /**
diff --git a/lib/llist.c b/lib/llist.c
index 6c69f1d14c4..878985c4d19 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -34,8 +34,10 @@
  * @new_first:  first entry in batch to be added
  * @new_last:   last entry in batch to be added
  * @head:       the head for your lock-less list
+ *
+ * Return whether list is empty before adding.
  */
-void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
+bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
                      struct llist_head *head)
 {
         struct llist_node *entry, *old_entry;
@@ -49,6 +51,8 @@ void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
                         break;
                 cpu_relax();
         }
+
+        return old_entry == NULL;
 }
 EXPORT_SYMBOL_GPL(llist_add_batch);