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ebac4655 JA |
1 | #ifndef _LINUX_LIST_H |
2 | #define _LINUX_LIST_H | |
3 | ||
4 | #undef offsetof | |
5 | #ifdef __compiler_offsetof | |
6 | #define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER) | |
7 | #else | |
8 | #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) | |
9 | #endif | |
10 | ||
11 | #define container_of(ptr, type, member) ({ \ | |
12 | const typeof( ((type *)0)->member ) *__mptr = (ptr); \ | |
13 | (type *)( (char *)__mptr - offsetof(type,member) );}) | |
14 | ||
15 | /* | |
16 | * Simple doubly linked list implementation. | |
17 | * | |
18 | * Some of the internal functions ("__xxx") are useful when | |
19 | * manipulating whole lists rather than single entries, as | |
20 | * sometimes we already know the next/prev entries and we can | |
21 | * generate better code by using them directly rather than | |
22 | * using the generic single-entry routines. | |
23 | */ | |
24 | ||
25 | struct list_head { | |
26 | struct list_head *next, *prev; | |
27 | }; | |
28 | ||
29 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
30 | ||
5f350952 JA |
31 | #define LIST_HEAD(name) \ |
32 | struct list_head name = LIST_HEAD_INIT(name) | |
33 | ||
ebac4655 JA |
34 | #define INIT_LIST_HEAD(ptr) do { \ |
35 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ | |
36 | } while (0) | |
37 | ||
38 | /* | |
39 | * Insert a new entry between two known consecutive entries. | |
40 | * | |
41 | * This is only for internal list manipulation where we know | |
42 | * the prev/next entries already! | |
43 | */ | |
44 | static inline void __list_add(struct list_head *new, | |
45 | struct list_head *prev, | |
46 | struct list_head *next) | |
47 | { | |
48 | next->prev = new; | |
49 | new->next = next; | |
50 | new->prev = prev; | |
51 | prev->next = new; | |
52 | } | |
53 | ||
54 | /** | |
55 | * list_add - add a new entry | |
56 | * @new: new entry to be added | |
57 | * @head: list head to add it after | |
58 | * | |
59 | * Insert a new entry after the specified head. | |
60 | * This is good for implementing stacks. | |
61 | */ | |
62 | static inline void list_add(struct list_head *new, struct list_head *head) | |
63 | { | |
64 | __list_add(new, head, head->next); | |
65 | } | |
66 | ||
67 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
68 | { | |
69 | __list_add(new, head->prev, head); | |
70 | } | |
71 | ||
72 | /* | |
73 | * Delete a list entry by making the prev/next entries | |
74 | * point to each other. | |
75 | * | |
76 | * This is only for internal list manipulation where we know | |
77 | * the prev/next entries already! | |
78 | */ | |
79 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
80 | { | |
81 | next->prev = prev; | |
82 | prev->next = next; | |
83 | } | |
84 | ||
85 | /** | |
86 | * list_del - deletes entry from list. | |
87 | * @entry: the element to delete from the list. | |
88 | * Note: list_empty on entry does not return true after this, the entry is | |
89 | * in an undefined state. | |
90 | */ | |
91 | static inline void list_del(struct list_head *entry) | |
92 | { | |
93 | __list_del(entry->prev, entry->next); | |
94 | entry->next = NULL; | |
95 | entry->prev = NULL; | |
96 | } | |
97 | ||
98 | /** | |
99 | * list_empty - tests whether a list is empty | |
100 | * @head: the list to test. | |
101 | */ | |
102 | static inline int list_empty(const struct list_head *head) | |
103 | { | |
104 | return head->next == head; | |
105 | } | |
106 | ||
107 | /** | |
108 | * list_entry - get the struct for this entry | |
109 | * @ptr: the &struct list_head pointer. | |
110 | * @type: the type of the struct this is embedded in. | |
111 | * @member: the name of the list_struct within the struct. | |
112 | */ | |
113 | #define list_entry(ptr, type, member) \ | |
114 | container_of(ptr, type, member) | |
115 | ||
116 | /** | |
117 | * list_for_each - iterate over a list | |
118 | * @pos: the &struct list_head to use as a loop counter. | |
119 | * @head: the head for your list. | |
120 | */ | |
121 | #define list_for_each(pos, head) \ | |
122 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
123 | ||
124 | /** | |
125 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
126 | * @pos: the &struct list_head to use as a loop counter. | |
127 | * @n: another &struct list_head to use as temporary storage | |
128 | * @head: the head for your list. | |
129 | */ | |
130 | #define list_for_each_safe(pos, n, head) \ | |
131 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
132 | pos = n, n = pos->next) | |
133 | ||
134 | #endif |