add LIST_LENGTH macro

Change-Id: I5a64f1416aadde167a51a1ed5bcd3adeae2be12d

diff --git a/include/tdm_list.h b/include/tdm_list.h
index acdf6c4a3bb88d57fc8fc6cd4270b3b83768acde..a6d6bbb529e5da0b8022b1f190cdbc8f89ca0238 100644 (file)
--- a/include/tdm_list.h
+++ b/include/tdm_list.h
@@ -87,12 +87,27 @@ static inline void list_delinit(struct list_head *item)
        item->prev = item;
 }
 
+static inline int list_length(struct list_head *item)
+{
+       struct list_head *next;
+       int length = 0;
+
+       next = item->next;
+       while (next != item) {
+               length++;
+               next = next->next;
+       }
+
+       return length;
+}
+
 #define LIST_INITHEAD(__item) list_inithead(__item)
 #define LIST_ADD(__item, __list) list_add(__item, __list)
 #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)
 #define LIST_REPLACE(__from, __to) list_replace(__from, __to)
 #define LIST_DEL(__item) list_del(__item)
 #define LIST_DELINIT(__item) list_delinit(__item)
+#define LIST_LENGTH(__item) list_length(__item)
 
 #define LIST_ENTRY(__type, __item, __field)   \
     ((__type *)(((char *)(__item)) - offsetof(__type, __field)))