1 #ifndef _LINUX_LIST_H
2 #define _LINUX_LIST_H
3
4 #include "compiler.h"
5
6 /*
7 * Simple doubly linked list implementation.
8 *
9 * Some of the internal functions ("__xxx") are useful when
10 * manipulating whole lists rather than single entries, as
11 * sometimes we already know the next/prev entries and we can
12 * generate better code by using them directly rather than
13 * using the generic single-entry routines.
14 */
15
16 struct list_head {
17 struct list_head *next, *prev;
18 };
19
20 #define LIST_HEAD_INIT(name) { &(name), &(name) }
21
22 #define INIT_LIST_HEAD(ptr) do { \
23 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
24 } while (0)
25
26 #if (!defined(__GNUC__) && !defined(__WATCOMC__))
27 #define __inline__
28 #endif
29
30 /*
31 * Insert a new entry between two known consecutive entries.
32 *
33 * This is only for internal list manipulation where we know
34 * the prev/next entries already!
35 */
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)36 static __inline__ void __list_add(struct list_head * new,
37 struct list_head * prev,
38 struct list_head * next)
39 {
40 next->prev = new;
41 new->next = next;
42 new->prev = prev;
43 prev->next = new;
44 }
45
46 /*
47 * Insert a new entry after the specified head..
48 */
list_add(struct list_head * new,struct list_head * head)49 static __inline__ void list_add(struct list_head *new, struct list_head *head)
50 {
51 __list_add(new, head, head->next);
52 }
53
54 /*
55 * Insert a new entry at the tail
56 */
list_add_tail(struct list_head * new,struct list_head * head)57 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head)
58 {
59 __list_add(new, head->prev, head);
60 }
61
62 /*
63 * Delete a list entry by making the prev/next entries
64 * point to each other.
65 *
66 * This is only for internal list manipulation where we know
67 * the prev/next entries already!
68 */
__list_del(struct list_head * prev,struct list_head * next)69 static __inline__ void __list_del(struct list_head * prev,
70 struct list_head * next)
71 {
72 next->prev = prev;
73 prev->next = next;
74 }
75
list_del(struct list_head * entry)76 static __inline__ void list_del(struct list_head *entry)
77 {
78 __list_del(entry->prev, entry->next);
79 }
80
list_empty(struct list_head * head)81 static __inline__ int list_empty(struct list_head *head)
82 {
83 return head->next == head;
84 }
85
86 /*
87 * Splice in "list" into "head"
88 */
list_splice(struct list_head * list,struct list_head * head)89 static __inline__ void list_splice(struct list_head *list, struct list_head *head)
90 {
91 struct list_head *first = list->next;
92
93 if (first != list) {
94 struct list_head *last = list->prev;
95 struct list_head *at = head->next;
96
97 first->prev = head;
98 head->next = first;
99
100 last->next = at;
101 at->prev = last;
102 }
103 }
104
105 #define list_entry(ptr, type, member) \
106 container_of(ptr, type, member)
107
108 #define list_for_each(pos, head) \
109 for (pos = (head)->next; pos != (head); pos = pos->next)
110
111 #endif
112