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ed2ff2cb CM |
1 | #ifndef _LINUX_LIST_H |
2 | #define _LINUX_LIST_H | |
3 | ||
4 | #define LIST_POISON1 ((void *) 0x00100100) | |
5 | #define LIST_POISON2 ((void *) 0x00200200) | |
6 | ||
7 | /* | |
8 | * Simple doubly linked list implementation. | |
9 | * | |
10 | * Some of the internal functions ("__xxx") are useful when | |
11 | * manipulating whole lists rather than single entries, as | |
12 | * sometimes we already know the next/prev entries and we can | |
13 | * generate better code by using them directly rather than | |
14 | * using the generic single-entry routines. | |
15 | */ | |
16 | ||
17 | struct list_head { | |
18 | struct list_head *next, *prev; | |
19 | }; | |
20 | ||
21 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
22 | ||
23 | #define LIST_HEAD(name) \ | |
24 | struct list_head name = LIST_HEAD_INIT(name) | |
25 | ||
26 | static inline void INIT_LIST_HEAD(struct list_head *list) | |
27 | { | |
28 | list->next = list; | |
29 | list->prev = list; | |
30 | } | |
31 | ||
32 | /* | |
33 | * Insert a new entry between two known consecutive entries. | |
34 | * | |
35 | * This is only for internal list manipulation where we know | |
36 | * the prev/next entries already! | |
37 | */ | |
38 | #ifndef CONFIG_DEBUG_LIST | |
39 | static inline void __list_add(struct list_head *new, | |
40 | struct list_head *prev, | |
41 | struct list_head *next) | |
42 | { | |
43 | next->prev = new; | |
44 | new->next = next; | |
45 | new->prev = prev; | |
46 | prev->next = new; | |
47 | } | |
48 | #else | |
49 | extern void __list_add(struct list_head *new, | |
50 | struct list_head *prev, | |
51 | struct list_head *next); | |
52 | #endif | |
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 | #ifndef CONFIG_DEBUG_LIST | |
63 | static inline void list_add(struct list_head *new, struct list_head *head) | |
64 | { | |
65 | __list_add(new, head, head->next); | |
66 | } | |
67 | #else | |
68 | extern void list_add(struct list_head *new, struct list_head *head); | |
69 | #endif | |
70 | ||
71 | ||
72 | /** | |
73 | * list_add_tail - add a new entry | |
74 | * @new: new entry to be added | |
75 | * @head: list head to add it before | |
76 | * | |
77 | * Insert a new entry before the specified head. | |
78 | * This is useful for implementing queues. | |
79 | */ | |
80 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
81 | { | |
82 | __list_add(new, head->prev, head); | |
83 | } | |
84 | ||
85 | /* | |
86 | * Delete a list entry by making the prev/next entries | |
87 | * point to each other. | |
88 | * | |
89 | * This is only for internal list manipulation where we know | |
90 | * the prev/next entries already! | |
91 | */ | |
92 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
93 | { | |
94 | next->prev = prev; | |
95 | prev->next = next; | |
96 | } | |
97 | ||
98 | /** | |
99 | * list_del - deletes entry from list. | |
100 | * @entry: the element to delete from the list. | |
101 | * Note: list_empty on entry does not return true after this, the entry is | |
102 | * in an undefined state. | |
103 | */ | |
104 | #ifndef CONFIG_DEBUG_LIST | |
105 | static inline void list_del(struct list_head *entry) | |
106 | { | |
107 | __list_del(entry->prev, entry->next); | |
108 | entry->next = LIST_POISON1; | |
109 | entry->prev = LIST_POISON2; | |
110 | } | |
111 | #else | |
112 | extern void list_del(struct list_head *entry); | |
113 | #endif | |
114 | ||
115 | /** | |
116 | * list_replace - replace old entry by new one | |
117 | * @old : the element to be replaced | |
118 | * @new : the new element to insert | |
119 | * Note: if 'old' was empty, it will be overwritten. | |
120 | */ | |
121 | static inline void list_replace(struct list_head *old, | |
122 | struct list_head *new) | |
123 | { | |
124 | new->next = old->next; | |
125 | new->next->prev = new; | |
126 | new->prev = old->prev; | |
127 | new->prev->next = new; | |
128 | } | |
129 | ||
130 | static inline void list_replace_init(struct list_head *old, | |
131 | struct list_head *new) | |
132 | { | |
133 | list_replace(old, new); | |
134 | INIT_LIST_HEAD(old); | |
135 | } | |
136 | /** | |
137 | * list_del_init - deletes entry from list and reinitialize it. | |
138 | * @entry: the element to delete from the list. | |
139 | */ | |
140 | static inline void list_del_init(struct list_head *entry) | |
141 | { | |
142 | __list_del(entry->prev, entry->next); | |
143 | INIT_LIST_HEAD(entry); | |
144 | } | |
145 | ||
146 | /** | |
147 | * list_move - delete from one list and add as another's head | |
148 | * @list: the entry to move | |
149 | * @head: the head that will precede our entry | |
150 | */ | |
151 | static inline void list_move(struct list_head *list, struct list_head *head) | |
152 | { | |
153 | __list_del(list->prev, list->next); | |
154 | list_add(list, head); | |
155 | } | |
156 | ||
157 | /** | |
158 | * list_move_tail - delete from one list and add as another's tail | |
159 | * @list: the entry to move | |
160 | * @head: the head that will follow our entry | |
161 | */ | |
162 | static inline void list_move_tail(struct list_head *list, | |
163 | struct list_head *head) | |
164 | { | |
165 | __list_del(list->prev, list->next); | |
166 | list_add_tail(list, head); | |
167 | } | |
168 | ||
169 | /** | |
170 | * list_is_last - tests whether @list is the last entry in list @head | |
171 | * @list: the entry to test | |
172 | * @head: the head of the list | |
173 | */ | |
174 | static inline int list_is_last(const struct list_head *list, | |
175 | const struct list_head *head) | |
176 | { | |
177 | return list->next == head; | |
178 | } | |
179 | ||
180 | /** | |
181 | * list_empty - tests whether a list is empty | |
182 | * @head: the list to test. | |
183 | */ | |
184 | static inline int list_empty(const struct list_head *head) | |
185 | { | |
186 | return head->next == head; | |
187 | } | |
188 | ||
189 | /** | |
190 | * list_empty_careful - tests whether a list is empty and not being modified | |
191 | * @head: the list to test | |
192 | * | |
193 | * Description: | |
194 | * tests whether a list is empty _and_ checks that no other CPU might be | |
195 | * in the process of modifying either member (next or prev) | |
196 | * | |
197 | * NOTE: using list_empty_careful() without synchronization | |
198 | * can only be safe if the only activity that can happen | |
199 | * to the list entry is list_del_init(). Eg. it cannot be used | |
200 | * if another CPU could re-list_add() it. | |
201 | */ | |
202 | static inline int list_empty_careful(const struct list_head *head) | |
203 | { | |
204 | struct list_head *next = head->next; | |
205 | return (next == head) && (next == head->prev); | |
206 | } | |
207 | ||
208 | static inline void __list_splice(struct list_head *list, | |
209 | struct list_head *head) | |
210 | { | |
211 | struct list_head *first = list->next; | |
212 | struct list_head *last = list->prev; | |
213 | struct list_head *at = head->next; | |
214 | ||
215 | first->prev = head; | |
216 | head->next = first; | |
217 | ||
218 | last->next = at; | |
219 | at->prev = last; | |
220 | } | |
221 | ||
222 | /** | |
223 | * list_splice - join two lists | |
224 | * @list: the new list to add. | |
225 | * @head: the place to add it in the first list. | |
226 | */ | |
227 | static inline void list_splice(struct list_head *list, struct list_head *head) | |
228 | { | |
229 | if (!list_empty(list)) | |
230 | __list_splice(list, head); | |
231 | } | |
232 | ||
233 | /** | |
234 | * list_splice_init - join two lists and reinitialise the emptied list. | |
235 | * @list: the new list to add. | |
236 | * @head: the place to add it in the first list. | |
237 | * | |
238 | * The list at @list is reinitialised | |
239 | */ | |
240 | static inline void list_splice_init(struct list_head *list, | |
241 | struct list_head *head) | |
242 | { | |
243 | if (!list_empty(list)) { | |
244 | __list_splice(list, head); | |
245 | INIT_LIST_HEAD(list); | |
246 | } | |
247 | } | |
248 | ||
249 | /** | |
250 | * list_entry - get the struct for this entry | |
251 | * @ptr: the &struct list_head pointer. | |
252 | * @type: the type of the struct this is embedded in. | |
253 | * @member: the name of the list_struct within the struct. | |
254 | */ | |
255 | #define list_entry(ptr, type, member) \ | |
256 | container_of(ptr, type, member) | |
257 | ||
258 | /** | |
259 | * list_for_each - iterate over a list | |
260 | * @pos: the &struct list_head to use as a loop cursor. | |
261 | * @head: the head for your list. | |
262 | */ | |
263 | #define list_for_each(pos, head) \ | |
264 | for (pos = (head)->next; prefetch(pos->next), pos != (head); \ | |
265 | pos = pos->next) | |
266 | ||
267 | /** | |
268 | * __list_for_each - iterate over a list | |
269 | * @pos: the &struct list_head to use as a loop cursor. | |
270 | * @head: the head for your list. | |
271 | * | |
272 | * This variant differs from list_for_each() in that it's the | |
273 | * simplest possible list iteration code, no prefetching is done. | |
274 | * Use this for code that knows the list to be very short (empty | |
275 | * or 1 entry) most of the time. | |
276 | */ | |
277 | #define __list_for_each(pos, head) \ | |
278 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
279 | ||
280 | /** | |
281 | * list_for_each_prev - iterate over a list backwards | |
282 | * @pos: the &struct list_head to use as a loop cursor. | |
283 | * @head: the head for your list. | |
284 | */ | |
285 | #define list_for_each_prev(pos, head) \ | |
286 | for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \ | |
287 | pos = pos->prev) | |
288 | ||
289 | /** | |
290 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
291 | * @pos: the &struct list_head to use as a loop cursor. | |
292 | * @n: another &struct list_head to use as temporary storage | |
293 | * @head: the head for your list. | |
294 | */ | |
295 | #define list_for_each_safe(pos, n, head) \ | |
296 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
297 | pos = n, n = pos->next) | |
298 | ||
299 | /** | |
300 | * list_for_each_entry - iterate over list of given type | |
301 | * @pos: the type * to use as a loop cursor. | |
302 | * @head: the head for your list. | |
303 | * @member: the name of the list_struct within the struct. | |
304 | */ | |
305 | #define list_for_each_entry(pos, head, member) \ | |
306 | for (pos = list_entry((head)->next, typeof(*pos), member); \ | |
307 | prefetch(pos->member.next), &pos->member != (head); \ | |
308 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
309 | ||
310 | /** | |
311 | * list_for_each_entry_reverse - iterate backwards over list of given type. | |
312 | * @pos: the type * to use as a loop cursor. | |
313 | * @head: the head for your list. | |
314 | * @member: the name of the list_struct within the struct. | |
315 | */ | |
316 | #define list_for_each_entry_reverse(pos, head, member) \ | |
317 | for (pos = list_entry((head)->prev, typeof(*pos), member); \ | |
318 | prefetch(pos->member.prev), &pos->member != (head); \ | |
319 | pos = list_entry(pos->member.prev, typeof(*pos), member)) | |
320 | ||
321 | /** | |
322 | * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue | |
323 | * @pos: the type * to use as a start point | |
324 | * @head: the head of the list | |
325 | * @member: the name of the list_struct within the struct. | |
326 | * | |
327 | * Prepares a pos entry for use as a start point in list_for_each_entry_continue. | |
328 | */ | |
329 | #define list_prepare_entry(pos, head, member) \ | |
330 | ((pos) ? : list_entry(head, typeof(*pos), member)) | |
331 | ||
332 | /** | |
333 | * list_for_each_entry_continue - continue iteration over list of given type | |
334 | * @pos: the type * to use as a loop cursor. | |
335 | * @head: the head for your list. | |
336 | * @member: the name of the list_struct within the struct. | |
337 | * | |
338 | * Continue to iterate over list of given type, continuing after | |
339 | * the current position. | |
340 | */ | |
341 | #define list_for_each_entry_continue(pos, head, member) \ | |
342 | for (pos = list_entry(pos->member.next, typeof(*pos), member); \ | |
343 | prefetch(pos->member.next), &pos->member != (head); \ | |
344 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
345 | ||
346 | /** | |
347 | * list_for_each_entry_from - iterate over list of given type from the current point | |
348 | * @pos: the type * to use as a loop cursor. | |
349 | * @head: the head for your list. | |
350 | * @member: the name of the list_struct within the struct. | |
351 | * | |
352 | * Iterate over list of given type, continuing from current position. | |
353 | */ | |
354 | #define list_for_each_entry_from(pos, head, member) \ | |
355 | for (; prefetch(pos->member.next), &pos->member != (head); \ | |
356 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
357 | ||
358 | /** | |
359 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
360 | * @pos: the type * to use as a loop cursor. | |
361 | * @n: another type * to use as temporary storage | |
362 | * @head: the head for your list. | |
363 | * @member: the name of the list_struct within the struct. | |
364 | */ | |
365 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
366 | for (pos = list_entry((head)->next, typeof(*pos), member), \ | |
367 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
368 | &pos->member != (head); \ | |
369 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
370 | ||
371 | /** | |
372 | * list_for_each_entry_safe_continue | |
373 | * @pos: the type * to use as a loop cursor. | |
374 | * @n: another type * to use as temporary storage | |
375 | * @head: the head for your list. | |
376 | * @member: the name of the list_struct within the struct. | |
377 | * | |
378 | * Iterate over list of given type, continuing after current point, | |
379 | * safe against removal of list entry. | |
380 | */ | |
381 | #define list_for_each_entry_safe_continue(pos, n, head, member) \ | |
382 | for (pos = list_entry(pos->member.next, typeof(*pos), member), \ | |
383 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
384 | &pos->member != (head); \ | |
385 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
386 | ||
387 | /** | |
388 | * list_for_each_entry_safe_from | |
389 | * @pos: the type * to use as a loop cursor. | |
390 | * @n: another type * to use as temporary storage | |
391 | * @head: the head for your list. | |
392 | * @member: the name of the list_struct within the struct. | |
393 | * | |
394 | * Iterate over list of given type from current point, safe against | |
395 | * removal of list entry. | |
396 | */ | |
397 | #define list_for_each_entry_safe_from(pos, n, head, member) \ | |
398 | for (n = list_entry(pos->member.next, typeof(*pos), member); \ | |
399 | &pos->member != (head); \ | |
400 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
401 | ||
402 | /** | |
403 | * list_for_each_entry_safe_reverse | |
404 | * @pos: the type * to use as a loop cursor. | |
405 | * @n: another type * to use as temporary storage | |
406 | * @head: the head for your list. | |
407 | * @member: the name of the list_struct within the struct. | |
408 | * | |
409 | * Iterate backwards over list of given type, safe against removal | |
410 | * of list entry. | |
411 | */ | |
412 | #define list_for_each_entry_safe_reverse(pos, n, head, member) \ | |
413 | for (pos = list_entry((head)->prev, typeof(*pos), member), \ | |
414 | n = list_entry(pos->member.prev, typeof(*pos), member); \ | |
415 | &pos->member != (head); \ | |
416 | pos = n, n = list_entry(n->member.prev, typeof(*n), member)) | |
417 | ||
418 | #endif |