1 /* SPDX-License-Identifier: BSD-3-Clause
2 *
3 * Copyright(c) 2016 Intel Corporation. All rights reserved.
4 *
5 * Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
6 * Keyon Jie <yang.jie@linux.intel.com>
7 */
8
9 #ifndef __SOF_LIST_H__
10 #define __SOF_LIST_H__
11
12 /* Really simple list manipulation */
13
14 struct list_item;
15
16 struct list_item {
17 struct list_item *next;
18 struct list_item *prev;
19 };
20
21 /* a static list head initialiser */
22 #define LIST_INIT(head) {&head, &head}
23
24 /* initialise list before any use - list will point to itself */
list_init(struct list_item * list)25 static inline void list_init(struct list_item *list)
26 {
27 list->next = list;
28 list->prev = list;
29 }
30
31 /* add new item to the start or head of the list */
list_item_prepend(struct list_item * item,struct list_item * list)32 static inline void list_item_prepend(struct list_item *item,
33 struct list_item *list)
34 {
35 struct list_item *next = list->next;
36
37 next->prev = item;
38 item->next = next;
39 item->prev = list;
40 list->next = item;
41 }
42
43 /* add new item to the end or tail of the list */
list_item_append(struct list_item * item,struct list_item * list)44 static inline void list_item_append(struct list_item *item,
45 struct list_item *list)
46 {
47 struct list_item *tail = list->prev;
48
49 tail->next = item;
50 item->next = list;
51 item->prev = tail;
52 list->prev = item;
53 }
54
55 /* delete item from the list leaves deleted list item
56 *in undefined state list_is_empty will return true
57 */
list_item_del(struct list_item * item)58 static inline void list_item_del(struct list_item *item)
59 {
60 item->next->prev = item->prev;
61 item->prev->next = item->next;
62 list_init(item);
63 }
64
65 /* is list item the last item in list ? */
list_item_is_last(struct list_item * item,struct list_item * list)66 static inline int list_item_is_last(struct list_item *item,
67 struct list_item *list)
68 {
69 return item->next == list;
70 }
71
72 /* is list empty ? */
73 #define list_is_empty(item) \
74 ((item)->next == item)
75
76 #define __list_object(item, type, offset) \
77 ((type *)((char *)(item) - (offset)))
78
79 /* get the container object of the list item */
80 #define list_item(item, type, member) \
81 __list_object(item, type, offsetof(type, member))
82
83 /* get the container object of the first item in the list */
84 #define list_first_item(list, type, member) \
85 __list_object((list)->next, type, offsetof(type, member))
86
87 /* get the next container object in the list */
88 #define list_next_item(object, member) \
89 list_item((object)->member.next, typeof(*(object)), member)
90
91 /* list iterator */
92 #define list_for_item(item, list) \
93 for (item = (list)->next; item != (list); item = item->next)
94
95 /* list iterator */
96 #define list_for_item_prev(item, list) \
97 for (item = (list)->prev; item != (list); item = item->prev)
98
99 /* list iterator - safe to delete items */
100 #define list_for_item_safe(item, tmp, list) \
101 for (item = (list)->next, tmp = item->next;\
102 item != (list); \
103 item = tmp, tmp = item->next)
104
105 /**
106 * Re-links the list when head address changed (list moved).
107 * @param new_list New address of the head.
108 * @param old_list Old address of the head.
109 */
list_relink(struct list_item * new_list,struct list_item * old_list)110 static inline void list_relink(struct list_item *new_list,
111 struct list_item *old_list)
112 {
113 struct list_item *li;
114
115 if (new_list->next == old_list) {
116 list_init(new_list);
117 } else {
118 list_for_item(li, new_list)
119 if (li->next == old_list)
120 li->next = new_list; /* for stops here */
121 list_for_item_prev(li, new_list)
122 if (li->prev == old_list)
123 li->prev = new_list; /* for stops here */
124 }
125 }
126
127 #endif /* __SOF_LIST_H__ */
128
