1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3 #ifndef __LINUX_LIST_H
4 #define __LINUX_LIST_H
5
6 #define LIST_HEAD_INIT(name) { &(name), &(name) }
7 #define LIST_HEAD(name) \
8 struct list_head name = LIST_HEAD_INIT(name)
9
10 #define POISON_POINTER_DELTA 0
11 #define LIST_POISON1 ((void *) 0x100 + POISON_POINTER_DELTA)
12 #define LIST_POISON2 ((void *) 0x200 + POISON_POINTER_DELTA)
13
14
INIT_LIST_HEAD(struct list_head * list)15 static inline void INIT_LIST_HEAD(struct list_head *list)
16 {
17 list->next = list;
18 list->prev = list;
19 }
20
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)21 static inline void __list_add(struct list_head *new,
22 struct list_head *prev,
23 struct list_head *next)
24 {
25 next->prev = new;
26 new->next = next;
27 new->prev = prev;
28 prev->next = new;
29 }
30
31 /**
32 * list_add - add a new entry
33 * @new: new entry to be added
34 * @head: list head to add it after
35 *
36 * Insert a new entry after the specified head.
37 * This is good for implementing stacks.
38 */
list_add(struct list_head * new,struct list_head * head)39 static inline void list_add(struct list_head *new, struct list_head *head)
40 {
41 __list_add(new, head, head->next);
42 }
43
44 /*
45 * Delete a list entry by making the prev/next entries
46 * point to each other.
47 *
48 * This is only for internal list manipulation where we know
49 * the prev/next entries already!
50 */
__list_del(struct list_head * prev,struct list_head * next)51 static inline void __list_del(struct list_head * prev, struct list_head * next)
52 {
53 next->prev = prev;
54 prev->next = next;
55 }
56
57 /**
58 * list_del - deletes entry from list.
59 * @entry: the element to delete from the list.
60 * Note: list_empty() on entry does not return true after this, the entry is
61 * in an undefined state.
62 */
__list_del_entry(struct list_head * entry)63 static inline void __list_del_entry(struct list_head *entry)
64 {
65 __list_del(entry->prev, entry->next);
66 }
67
list_del(struct list_head * entry)68 static inline void list_del(struct list_head *entry)
69 {
70 __list_del(entry->prev, entry->next);
71 entry->next = LIST_POISON1;
72 entry->prev = LIST_POISON2;
73 }
74
list_empty(const struct list_head * head)75 static inline int list_empty(const struct list_head *head)
76 {
77 return head->next == head;
78 }
79
80 #define list_entry(ptr, type, member) \
81 container_of(ptr, type, member)
82 #define list_first_entry(ptr, type, member) \
83 list_entry((ptr)->next, type, member)
84 #define list_next_entry(pos, member) \
85 list_entry((pos)->member.next, typeof(*(pos)), member)
86 #define list_for_each_entry(pos, head, member) \
87 for (pos = list_first_entry(head, typeof(*pos), member); \
88 &pos->member != (head); \
89 pos = list_next_entry(pos, member))
90
91 #endif
92