triton: implement list_replace*()

Add list_replace() and list_replace_init(), as defined in Linux kernel
sources.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>

1 files changed, 23 insertions, 0 deletions

diff --git a/accel-pppd/triton/list.h b/accel-pppd/triton/list.h
index a650037..20b917d 100644
--- a/accel-pppd/triton/list.h
+++ b/accel-pppd/triton/list.h
@@ -99,6 +99,29 @@ static inline void list_del(struct list_head *entry)
 }
 
 /**
+ * list_replace - replace old entry by new one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * If @old was empty, it will be overwritten.
+ */
+static inline void list_replace(struct list_head *old,
+				struct list_head *new)
+{
+	new->next = old->next;
+	new->next->prev = new;
+	new->prev = old->prev;
+	new->prev->next = new;
+}
+
+static inline void list_replace_init(struct list_head *old,
+					struct list_head *new)
+{
+	list_replace(old, new);
+	INIT_LIST_HEAD(old);
+}
+
+/**
  * list_del_init - deletes entry from list and reinitialize it.
  * @entry: the element to delete from the list.
  */