5 * Simple doubly linked list implementation.
7 * Some of the internal functions ("__xxx") are useful when
8 * manipulating whole lists rather than single entries, as
9 * sometimes we already know the next/prev entries and we can
10 * generate better code by using them directly rather than
11 * using the generic single-entry routines.
15 struct list_head *next, *prev;
18 #define LIST_HEAD_INIT(name) { &(name), &(name) }
20 #define INIT_LIST_HEAD(ptr) do { \
21 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
24 #if (!defined(__GNUC__) && !defined(__WATCOMC__))
29 * Insert a new entry between two known consecutive entries.
31 * This is only for internal list manipulation where we know
32 * the prev/next entries already!
34 static __inline__ void __list_add(struct list_head * new,
35 struct list_head * prev,
36 struct list_head * next)
45 * Insert a new entry after the specified head..
47 static __inline__ void list_add(struct list_head *new, struct list_head *head)
49 __list_add(new, head, head->next);
53 * Insert a new entry at the tail
55 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head)
57 __list_add(new, head->prev, head);
61 * Delete a list entry by making the prev/next entries
62 * point to each other.
64 * This is only for internal list manipulation where we know
65 * the prev/next entries already!
67 static __inline__ void __list_del(struct list_head * prev,
68 struct list_head * next)
74 static __inline__ void list_del(struct list_head *entry)
76 __list_del(entry->prev, entry->next);
79 static __inline__ int list_empty(struct list_head *head)
81 return head->next == head;
85 * Splice in "list" into "head"
87 static __inline__ void list_splice(struct list_head *list, struct list_head *head)
89 struct list_head *first = list->next;
92 struct list_head *last = list->prev;
93 struct list_head *at = head->next;
103 #define list_entry(ptr, type, member) \
104 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
106 #define list_for_each(pos, head) \
107 for (pos = (head)->next; pos != (head); pos = pos->next)