list_is_first and list_is_last respectively check whether an entry is
the first or last entry of the list. list_size counts the number of
entries. list_at_index retrieves the entry at an index.
list_for_each_from iterates over a list from some entry to the end.
Signed-off-by: Ole Schuerks <ole0811sch@xxxxxxxxx>
---
scripts/include/list.h | 71 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 71 insertions(+)
diff --git a/scripts/include/list.h b/scripts/include/list.h
index fea1e2b79063..f7aff1749a0b 100644
--- a/scripts/include/list.h
+++ b/scripts/include/list.h
@@ -169,6 +169,43 @@ static inline int list_empty(const struct list_head *head)
return head->next == head;
}
+/**
+ * list_is_first - tests whether @list belongs to the first entry
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_first(const struct list_head *list,
+ const struct list_head *head)
+{
+ return list == head->next;
+}
+
+/**
+ * list_is_last - tests whether @list belongs to the last entry
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_last(const struct list_head *list,
+ const struct list_head *head)
+{
+ return list == head->prev;
+}
+
+/**
+ * list_size - counts the number of entries in a list
+ * @head: the list whose entries are counted
+ */
+static inline size_t list_size(const struct list_head *head)
+{
+ size_t ret = 0;
+
+ for (struct list_head *curr = head->next; curr != head;
+ curr = curr->next)
+ ++ret;
+
+ return ret;
+}
+
/**
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
@@ -260,6 +297,40 @@ static inline int list_empty(const struct list_head *head)
!list_entry_is_head(pos, head, member); \
pos = n, n = list_next_entry(n, member))
+/**
+ * list_for_each_entry_from - iterate over list of given type starting at a given node
+ * @pos: the type * to use as a loop cursor.
+ * @start: the node to start iterating at
+ * @head: the head for your list.
+ * @member: the name of the list_head within the struct.
+ */
+#define list_for_each_entry_from(pos, start, head, member) \
+ for (pos = list_entry(start, typeof(*pos), member); \
+ !list_entry_is_head(pos, head, member); \
+ pos = list_next_entry(pos, member))
+
+/**
+ * list_at_index - retrieve the entry at index i in O(n)
+ * @i: index of entry to retrieve.
+ * @head: the head for your list.
+ * @type: the type of the struct the entries are embedded in.
+ * @member: the name of the list_head within the struct.
+ */
+#define list_at_index(i, head, type, member) \
+ ({ \
+ type *__pos; \
+ size_t __counter = 0; \
+ list_for_each_entry(__pos, head, member) { \
+ if (__counter++ == i) \
+ break; \
+ if (__pos->member.next == head) { \
+ __pos = NULL; \
+ break; \
+ } \
+ } \
+ __pos; \
+ })
+
/*
* Double linked lists with a single pointer list head.
* Mostly useful for hash tables where the two pointer list head is
--
2.39.2
