1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LIST_H
3#define LIST_H
4
5/*
6 * Copied from include/linux/...
7 */
8
9#undef offsetof
10#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
11
12/**
13 * container_of - cast a member of a structure out to the containing structure
14 * @ptr:        the pointer to the member.
15 * @type:       the type of the container struct this is embedded in.
16 * @member:     the name of the member within the struct.
17 *
18 */
19#define container_of(ptr, type, member) ({                      \
20	const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
21	(type *)( (char *)__mptr - offsetof(type,member) );})
22
23
24struct list_head {
25	struct list_head *next, *prev;
26};
27
28
29#define LIST_HEAD_INIT(name) { &(name), &(name) }
30
31#define LIST_HEAD(name) \
32	struct list_head name = LIST_HEAD_INIT(name)
33
34/**
35 * list_entry - get the struct for this entry
36 * @ptr:	the &struct list_head pointer.
37 * @type:	the type of the struct this is embedded in.
38 * @member:	the name of the list_head within the struct.
39 */
40#define list_entry(ptr, type, member) \
41	container_of(ptr, type, member)
42
43/**
44 * list_for_each_entry	-	iterate over list of given type
45 * @pos:	the type * to use as a loop cursor.
46 * @head:	the head for your list.
47 * @member:	the name of the list_head within the struct.
48 */
49#define list_for_each_entry(pos, head, member)				\
50	for (pos = list_entry((head)->next, typeof(*pos), member);	\
51	     &pos->member != (head);	\
52	     pos = list_entry(pos->member.next, typeof(*pos), member))
53
54/**
55 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
56 * @pos:	the type * to use as a loop cursor.
57 * @n:		another type * to use as temporary storage
58 * @head:	the head for your list.
59 * @member:	the name of the list_head within the struct.
60 */
61#define list_for_each_entry_safe(pos, n, head, member)			\
62	for (pos = list_entry((head)->next, typeof(*pos), member),	\
63		n = list_entry(pos->member.next, typeof(*pos), member);	\
64	     &pos->member != (head);					\
65	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
66
67/**
68 * list_empty - tests whether a list is empty
69 * @head: the list to test.
70 */
71static inline int list_empty(const struct list_head *head)
72{
73	return head->next == head;
74}
75
76/*
77 * Insert a new entry between two known consecutive entries.
78 *
79 * This is only for internal list manipulation where we know
80 * the prev/next entries already!
81 */
82static inline void __list_add(struct list_head *_new,
83			      struct list_head *prev,
84			      struct list_head *next)
85{
86	next->prev = _new;
87	_new->next = next;
88	_new->prev = prev;
89	prev->next = _new;
90}
91
92/**
93 * list_add_tail - add a new entry
94 * @new: new entry to be added
95 * @head: list head to add it before
96 *
97 * Insert a new entry before the specified head.
98 * This is useful for implementing queues.
99 */
100static inline void list_add_tail(struct list_head *_new, struct list_head *head)
101{
102	__list_add(_new, head->prev, head);
103}
104
105/*
106 * Delete a list entry by making the prev/next entries
107 * point to each other.
108 *
109 * This is only for internal list manipulation where we know
110 * the prev/next entries already!
111 */
112static inline void __list_del(struct list_head *prev, struct list_head *next)
113{
114	next->prev = prev;
115	prev->next = next;
116}
117
118#define LIST_POISON1  ((void *) 0x00100100)
119#define LIST_POISON2  ((void *) 0x00200200)
120/**
121 * list_del - deletes entry from list.
122 * @entry: the element to delete from the list.
123 * Note: list_empty() on entry does not return true after this, the entry is
124 * in an undefined state.
125 */
126static inline void list_del(struct list_head *entry)
127{
128	__list_del(entry->prev, entry->next);
129	entry->next = (struct list_head*)LIST_POISON1;
130	entry->prev = (struct list_head*)LIST_POISON2;
131}
132#endif
133