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83b069c6 | 1 | /* |
2232cac8 GKH |
2 | * Copied from the Linux kernel source tree, version 2.6.0-test1. |
3 | * | |
4 | * Licensed under the GPL v2 as per the whole kernel source tree. | |
5 | * | |
2232cac8 GKH |
6 | */ |
7 | ||
83b069c6 KS |
8 | #ifndef _LIST_H |
9 | #define _LIST_H | |
2232cac8 | 10 | |
2232cac8 GKH |
11 | /** |
12 | * container_of - cast a member of a structure out to the containing structure | |
13 | * | |
83b069c6 KS |
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. | |
2232cac8 GKH |
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 | ||
2232cac8 GKH |
23 | /* |
24 | * These are non-NULL pointers that will result in page faults | |
25 | * under normal circumstances, used to verify that nobody uses | |
26 | * non-initialized list entries. | |
27 | */ | |
28 | #define LIST_POISON1 ((void *) 0x00100100) | |
29 | #define LIST_POISON2 ((void *) 0x00200200) | |
30 | ||
31 | /* | |
32 | * Simple doubly linked list implementation. | |
33 | * | |
34 | * Some of the internal functions ("__xxx") are useful when | |
35 | * manipulating whole lists rather than single entries, as | |
36 | * sometimes we already know the next/prev entries and we can | |
37 | * generate better code by using them directly rather than | |
38 | * using the generic single-entry routines. | |
39 | */ | |
40 | ||
41 | struct list_head { | |
42 | struct list_head *next, *prev; | |
43 | }; | |
44 | ||
45 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
46 | ||
47 | #define LIST_HEAD(name) \ | |
48 | struct list_head name = LIST_HEAD_INIT(name) | |
49 | ||
50 | #define INIT_LIST_HEAD(ptr) do { \ | |
51 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ | |
52 | } while (0) | |
53 | ||
54 | /* | |
55 | * Insert a new entry between two known consecutive entries. | |
56 | * | |
57 | * This is only for internal list manipulation where we know | |
58 | * the prev/next entries already! | |
59 | */ | |
60 | static inline void __list_add(struct list_head *new, | |
61 | struct list_head *prev, | |
62 | struct list_head *next) | |
63 | { | |
64 | next->prev = new; | |
65 | new->next = next; | |
66 | new->prev = prev; | |
67 | prev->next = new; | |
68 | } | |
69 | ||
70 | /** | |
71 | * list_add - add a new entry | |
72 | * @new: new entry to be added | |
73 | * @head: list head to add it after | |
74 | * | |
75 | * Insert a new entry after the specified head. | |
76 | * This is good for implementing stacks. | |
77 | */ | |
78 | static inline void list_add(struct list_head *new, struct list_head *head) | |
79 | { | |
80 | __list_add(new, head, head->next); | |
81 | } | |
82 | ||
83 | /** | |
84 | * list_add_tail - add a new entry | |
85 | * @new: new entry to be added | |
86 | * @head: list head to add it before | |
87 | * | |
88 | * Insert a new entry before the specified head. | |
89 | * This is useful for implementing queues. | |
90 | */ | |
91 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
92 | { | |
93 | __list_add(new, head->prev, head); | |
94 | } | |
95 | ||
96 | /* | |
97 | * Delete a list entry by making the prev/next entries | |
98 | * point to each other. | |
99 | * | |
100 | * This is only for internal list manipulation where we know | |
101 | * the prev/next entries already! | |
102 | */ | |
103 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
104 | { | |
105 | next->prev = prev; | |
106 | prev->next = next; | |
107 | } | |
108 | ||
109 | /** | |
110 | * list_del - deletes entry from list. | |
111 | * @entry: the element to delete from the list. | |
112 | * Note: list_empty on entry does not return true after this, the entry is | |
113 | * in an undefined state. | |
114 | */ | |
115 | static inline void list_del(struct list_head *entry) | |
116 | { | |
117 | __list_del(entry->prev, entry->next); | |
118 | entry->next = LIST_POISON1; | |
119 | entry->prev = LIST_POISON2; | |
120 | } | |
121 | ||
122 | /** | |
123 | * list_del_init - deletes entry from list and reinitialize it. | |
124 | * @entry: the element to delete from the list. | |
125 | */ | |
126 | static inline void list_del_init(struct list_head *entry) | |
127 | { | |
128 | __list_del(entry->prev, entry->next); | |
129 | INIT_LIST_HEAD(entry); | |
130 | } | |
131 | ||
132 | /** | |
133 | * list_move - delete from one list and add as another's head | |
134 | * @list: the entry to move | |
135 | * @head: the head that will precede our entry | |
136 | */ | |
137 | static inline void list_move(struct list_head *list, struct list_head *head) | |
138 | { | |
83b069c6 KS |
139 | __list_del(list->prev, list->next); |
140 | list_add(list, head); | |
2232cac8 GKH |
141 | } |
142 | ||
143 | /** | |
144 | * list_move_tail - delete from one list and add as another's tail | |
145 | * @list: the entry to move | |
146 | * @head: the head that will follow our entry | |
147 | */ | |
148 | static inline void list_move_tail(struct list_head *list, | |
149 | struct list_head *head) | |
150 | { | |
83b069c6 KS |
151 | __list_del(list->prev, list->next); |
152 | list_add_tail(list, head); | |
2232cac8 GKH |
153 | } |
154 | ||
155 | /** | |
156 | * list_empty - tests whether a list is empty | |
157 | * @head: the list to test. | |
158 | */ | |
159 | static inline int list_empty(struct list_head *head) | |
160 | { | |
161 | return head->next == head; | |
162 | } | |
163 | ||
164 | static inline void __list_splice(struct list_head *list, | |
165 | struct list_head *head) | |
166 | { | |
167 | struct list_head *first = list->next; | |
168 | struct list_head *last = list->prev; | |
169 | struct list_head *at = head->next; | |
170 | ||
171 | first->prev = head; | |
172 | head->next = first; | |
173 | ||
174 | last->next = at; | |
175 | at->prev = last; | |
176 | } | |
177 | ||
178 | /** | |
179 | * list_splice - join two lists | |
180 | * @list: the new list to add. | |
181 | * @head: the place to add it in the first list. | |
182 | */ | |
183 | static inline void list_splice(struct list_head *list, struct list_head *head) | |
184 | { | |
185 | if (!list_empty(list)) | |
186 | __list_splice(list, head); | |
187 | } | |
188 | ||
189 | /** | |
190 | * list_splice_init - join two lists and reinitialise the emptied list. | |
191 | * @list: the new list to add. | |
192 | * @head: the place to add it in the first list. | |
193 | * | |
194 | * The list at @list is reinitialised | |
195 | */ | |
196 | static inline void list_splice_init(struct list_head *list, | |
197 | struct list_head *head) | |
198 | { | |
199 | if (!list_empty(list)) { | |
200 | __list_splice(list, head); | |
201 | INIT_LIST_HEAD(list); | |
202 | } | |
203 | } | |
204 | ||
205 | /** | |
206 | * list_entry - get the struct for this entry | |
207 | * @ptr: the &struct list_head pointer. | |
208 | * @type: the type of the struct this is embedded in. | |
209 | * @member: the name of the list_struct within the struct. | |
210 | */ | |
211 | #define list_entry(ptr, type, member) \ | |
212 | container_of(ptr, type, member) | |
213 | ||
214 | /** | |
215 | * list_for_each - iterate over a list | |
216 | * @pos: the &struct list_head to use as a loop counter. | |
217 | * @head: the head for your list. | |
218 | */ | |
219 | #define list_for_each(pos, head) \ | |
83b069c6 KS |
220 | for (pos = (head)->next; pos != (head); \ |
221 | pos = pos->next) | |
2232cac8 GKH |
222 | |
223 | /** | |
224 | * __list_for_each - iterate over a list | |
225 | * @pos: the &struct list_head to use as a loop counter. | |
226 | * @head: the head for your list. | |
227 | * | |
228 | * This variant differs from list_for_each() in that it's the | |
83b069c6 | 229 | * simplest possible list iteration code. |
2232cac8 GKH |
230 | * Use this for code that knows the list to be very short (empty |
231 | * or 1 entry) most of the time. | |
232 | */ | |
233 | #define __list_for_each(pos, head) \ | |
234 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
235 | ||
236 | /** | |
237 | * list_for_each_prev - iterate over a list backwards | |
238 | * @pos: the &struct list_head to use as a loop counter. | |
239 | * @head: the head for your list. | |
240 | */ | |
241 | #define list_for_each_prev(pos, head) \ | |
83b069c6 KS |
242 | for (pos = (head)->prev; pos != (head); pos = pos->prev) |
243 | ||
2232cac8 GKH |
244 | /** |
245 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
246 | * @pos: the &struct list_head to use as a loop counter. | |
247 | * @n: another &struct list_head to use as temporary storage | |
248 | * @head: the head for your list. | |
249 | */ | |
250 | #define list_for_each_safe(pos, n, head) \ | |
251 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
252 | pos = n, n = pos->next) | |
253 | ||
254 | /** | |
255 | * list_for_each_entry - iterate over list of given type | |
256 | * @pos: the type * to use as a loop counter. | |
257 | * @head: the head for your list. | |
258 | * @member: the name of the list_struct within the struct. | |
259 | */ | |
260 | #define list_for_each_entry(pos, head, member) \ | |
83b069c6 | 261 | for (pos = list_entry((head)->next, typeof(*pos), member); \ |
2232cac8 | 262 | &pos->member != (head); \ |
83b069c6 | 263 | pos = list_entry(pos->member.next, typeof(*pos), member)) |
2232cac8 GKH |
264 | |
265 | /** | |
266 | * list_for_each_entry_reverse - iterate backwards over list of given type. | |
267 | * @pos: the type * to use as a loop counter. | |
268 | * @head: the head for your list. | |
269 | * @member: the name of the list_struct within the struct. | |
270 | */ | |
271 | #define list_for_each_entry_reverse(pos, head, member) \ | |
83b069c6 | 272 | for (pos = list_entry((head)->prev, typeof(*pos), member); \ |
2232cac8 | 273 | &pos->member != (head); \ |
83b069c6 | 274 | pos = list_entry(pos->member.prev, typeof(*pos), member)) |
2232cac8 GKH |
275 | |
276 | /** | |
277 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
278 | * @pos: the type * to use as a loop counter. | |
279 | * @n: another type * to use as temporary storage | |
280 | * @head: the head for your list. | |
281 | * @member: the name of the list_struct within the struct. | |
282 | */ | |
283 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
284 | for (pos = list_entry((head)->next, typeof(*pos), member), \ | |
285 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
286 | &pos->member != (head); \ | |
287 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
288 | ||
83b069c6 | 289 | #endif /* _LIST_H */ |