xref: /openbmc/linux/scripts/kconfig/list.h (revision b6bec26c)
1 #ifndef LIST_H
2 #define LIST_H
3 
4 /*
5  * Copied from include/linux/...
6  */
7 
8 #undef offsetof
9 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
10 
11 /**
12  * container_of - cast a member of a structure out to the containing structure
13  * @ptr:        the pointer to the member.
14  * @type:       the type of the container struct this is embedded in.
15  * @member:     the name of the member within the struct.
16  *
17  */
18 #define container_of(ptr, type, member) ({                      \
19 	const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
20 	(type *)( (char *)__mptr - offsetof(type,member) );})
21 
22 
23 struct list_head {
24 	struct list_head *next, *prev;
25 };
26 
27 
28 #define LIST_HEAD_INIT(name) { &(name), &(name) }
29 
30 #define LIST_HEAD(name) \
31 	struct list_head name = LIST_HEAD_INIT(name)
32 
33 /**
34  * list_entry - get the struct for this entry
35  * @ptr:	the &struct list_head pointer.
36  * @type:	the type of the struct this is embedded in.
37  * @member:	the name of the list_struct within the struct.
38  */
39 #define list_entry(ptr, type, member) \
40 	container_of(ptr, type, member)
41 
42 /**
43  * list_for_each_entry	-	iterate over list of given type
44  * @pos:	the type * to use as a loop cursor.
45  * @head:	the head for your list.
46  * @member:	the name of the list_struct within the struct.
47  */
48 #define list_for_each_entry(pos, head, member)				\
49 	for (pos = list_entry((head)->next, typeof(*pos), member);	\
50 	     &pos->member != (head); 	\
51 	     pos = list_entry(pos->member.next, typeof(*pos), member))
52 
53 /**
54  * list_empty - tests whether a list is empty
55  * @head: the list to test.
56  */
57 static inline int list_empty(const struct list_head *head)
58 {
59 	return head->next == head;
60 }
61 
62 /*
63  * Insert a new entry between two known consecutive entries.
64  *
65  * This is only for internal list manipulation where we know
66  * the prev/next entries already!
67  */
68 static inline void __list_add(struct list_head *_new,
69 			      struct list_head *prev,
70 			      struct list_head *next)
71 {
72 	next->prev = _new;
73 	_new->next = next;
74 	_new->prev = prev;
75 	prev->next = _new;
76 }
77 
78 /**
79  * list_add_tail - add a new entry
80  * @new: new entry to be added
81  * @head: list head to add it before
82  *
83  * Insert a new entry before the specified head.
84  * This is useful for implementing queues.
85  */
86 static inline void list_add_tail(struct list_head *_new, struct list_head *head)
87 {
88 	__list_add(_new, head->prev, head);
89 }
90 
91 #endif
92