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 LIST_HEAD(name) \
21 struct list_head name = { &name, &name }
23 #define INIT_LIST_HEAD(ptr) do { \
24 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
27 #if (!defined(__GNUC__) && !defined(__WATCOMC__))
32 * Insert a new entry between two known consecutive entries.
34 * This is only for internal list manipulation where we know
35 * the prev/next entries already!
37 static __inline__ void __list_add(struct list_head * new,
38 struct list_head * prev,
39 struct list_head * next)
48 * Insert a new entry after the specified head..
50 static __inline__ void list_add(struct list_head *new, struct list_head *head)
52 __list_add(new, head, head->next);
56 * Insert a new entry at the tail
58 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head)
60 __list_add(new, head->prev, head);
64 * Delete a list entry by making the prev/next entries
65 * point to each other.
67 * This is only for internal list manipulation where we know
68 * the prev/next entries already!
70 static __inline__ void __list_del(struct list_head * prev,
71 struct list_head * next)
77 static __inline__ void list_del(struct list_head *entry)
79 __list_del(entry->prev, entry->next);
82 static __inline__ int list_empty(struct list_head *head)
84 return head->next == head;
88 * Splice in "list" into "head"
90 static __inline__ void list_splice(struct list_head *list, struct list_head *head)
92 struct list_head *first = list->next;
95 struct list_head *last = list->prev;
96 struct list_head *at = head->next;
106 #define list_entry(ptr, type, member) \
107 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
109 #define list_for_each(pos, head) \
110 for (pos = (head)->next; pos != (head); pos = pos->next)