xref: /third_party/libbpf/include/linux/list.h (revision 7c2aad20) 
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
15static inline void INIT_LIST_HEAD(struct list_head *list)
16{
17        list->next = list;
18        list->prev = list;
19}
20
21static 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 */
39static 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 */
51static 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 */
63static inline void __list_del_entry(struct list_head *entry)
64{
65        __list_del(entry->prev, entry->next);
66}
67
68static 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
75static 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