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1da177e4 LT |
1 | #ifndef _LINUX_LIST_H |
2 | #define _LINUX_LIST_H | |
3 | ||
de5d9bf6 | 4 | #include <linux/types.h> |
1da177e4 | 5 | #include <linux/stddef.h> |
c9cf5528 | 6 | #include <linux/poison.h> |
1da177e4 LT |
7 | #include <linux/prefetch.h> |
8 | #include <asm/system.h> | |
9 | ||
1da177e4 LT |
10 | /* |
11 | * Simple doubly linked list implementation. | |
12 | * | |
13 | * Some of the internal functions ("__xxx") are useful when | |
14 | * manipulating whole lists rather than single entries, as | |
15 | * sometimes we already know the next/prev entries and we can | |
16 | * generate better code by using them directly rather than | |
17 | * using the generic single-entry routines. | |
18 | */ | |
19 | ||
1da177e4 LT |
20 | #define LIST_HEAD_INIT(name) { &(name), &(name) } |
21 | ||
22 | #define LIST_HEAD(name) \ | |
23 | struct list_head name = LIST_HEAD_INIT(name) | |
24 | ||
490d6ab1 ZB |
25 | static inline void INIT_LIST_HEAD(struct list_head *list) |
26 | { | |
27 | list->next = list; | |
28 | list->prev = list; | |
29 | } | |
1da177e4 LT |
30 | |
31 | /* | |
32 | * Insert a new entry between two known consecutive entries. | |
33 | * | |
34 | * This is only for internal list manipulation where we know | |
35 | * the prev/next entries already! | |
36 | */ | |
199a9afc | 37 | #ifndef CONFIG_DEBUG_LIST |
1da177e4 LT |
38 | static inline void __list_add(struct list_head *new, |
39 | struct list_head *prev, | |
40 | struct list_head *next) | |
41 | { | |
42 | next->prev = new; | |
43 | new->next = next; | |
44 | new->prev = prev; | |
45 | prev->next = new; | |
46 | } | |
199a9afc DJ |
47 | #else |
48 | extern void __list_add(struct list_head *new, | |
49 | struct list_head *prev, | |
50 | struct list_head *next); | |
51 | #endif | |
1da177e4 LT |
52 | |
53 | /** | |
54 | * list_add - add a new entry | |
55 | * @new: new entry to be added | |
56 | * @head: list head to add it after | |
57 | * | |
58 | * Insert a new entry after the specified head. | |
59 | * This is good for implementing stacks. | |
60 | */ | |
61 | static inline void list_add(struct list_head *new, struct list_head *head) | |
62 | { | |
63 | __list_add(new, head, head->next); | |
64 | } | |
199a9afc | 65 | |
1da177e4 LT |
66 | |
67 | /** | |
68 | * list_add_tail - add a new entry | |
69 | * @new: new entry to be added | |
70 | * @head: list head to add it before | |
71 | * | |
72 | * Insert a new entry before the specified head. | |
73 | * This is useful for implementing queues. | |
74 | */ | |
75 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
76 | { | |
77 | __list_add(new, head->prev, head); | |
78 | } | |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Delete a list entry by making the prev/next entries | |
82 | * point to each other. | |
83 | * | |
84 | * This is only for internal list manipulation where we know | |
85 | * the prev/next entries already! | |
86 | */ | |
87 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
88 | { | |
89 | next->prev = prev; | |
90 | prev->next = next; | |
91 | } | |
92 | ||
93 | /** | |
94 | * list_del - deletes entry from list. | |
95 | * @entry: the element to delete from the list. | |
72fd4a35 | 96 | * Note: list_empty() on entry does not return true after this, the entry is |
1da177e4 LT |
97 | * in an undefined state. |
98 | */ | |
199a9afc | 99 | #ifndef CONFIG_DEBUG_LIST |
1da177e4 LT |
100 | static inline void list_del(struct list_head *entry) |
101 | { | |
102 | __list_del(entry->prev, entry->next); | |
103 | entry->next = LIST_POISON1; | |
104 | entry->prev = LIST_POISON2; | |
105 | } | |
199a9afc DJ |
106 | #else |
107 | extern void list_del(struct list_head *entry); | |
108 | #endif | |
1da177e4 | 109 | |
54e73770 ON |
110 | /** |
111 | * list_replace - replace old entry by new one | |
112 | * @old : the element to be replaced | |
113 | * @new : the new element to insert | |
72fd4a35 RD |
114 | * |
115 | * If @old was empty, it will be overwritten. | |
54e73770 ON |
116 | */ |
117 | static inline void list_replace(struct list_head *old, | |
118 | struct list_head *new) | |
119 | { | |
120 | new->next = old->next; | |
121 | new->next->prev = new; | |
122 | new->prev = old->prev; | |
123 | new->prev->next = new; | |
124 | } | |
125 | ||
126 | static inline void list_replace_init(struct list_head *old, | |
127 | struct list_head *new) | |
128 | { | |
129 | list_replace(old, new); | |
130 | INIT_LIST_HEAD(old); | |
131 | } | |
132 | ||
1da177e4 LT |
133 | /** |
134 | * list_del_init - deletes entry from list and reinitialize it. | |
135 | * @entry: the element to delete from the list. | |
136 | */ | |
137 | static inline void list_del_init(struct list_head *entry) | |
138 | { | |
139 | __list_del(entry->prev, entry->next); | |
140 | INIT_LIST_HEAD(entry); | |
141 | } | |
142 | ||
143 | /** | |
144 | * list_move - delete from one list and add as another's head | |
145 | * @list: the entry to move | |
146 | * @head: the head that will precede our entry | |
147 | */ | |
148 | static inline void list_move(struct list_head *list, struct list_head *head) | |
149 | { | |
78db2ad6 DW |
150 | __list_del(list->prev, list->next); |
151 | list_add(list, head); | |
1da177e4 LT |
152 | } |
153 | ||
154 | /** | |
155 | * list_move_tail - delete from one list and add as another's tail | |
156 | * @list: the entry to move | |
157 | * @head: the head that will follow our entry | |
158 | */ | |
159 | static inline void list_move_tail(struct list_head *list, | |
160 | struct list_head *head) | |
161 | { | |
78db2ad6 DW |
162 | __list_del(list->prev, list->next); |
163 | list_add_tail(list, head); | |
1da177e4 LT |
164 | } |
165 | ||
e8f4d97e SN |
166 | /** |
167 | * list_is_last - tests whether @list is the last entry in list @head | |
168 | * @list: the entry to test | |
169 | * @head: the head of the list | |
170 | */ | |
171 | static inline int list_is_last(const struct list_head *list, | |
172 | const struct list_head *head) | |
173 | { | |
174 | return list->next == head; | |
175 | } | |
176 | ||
1da177e4 LT |
177 | /** |
178 | * list_empty - tests whether a list is empty | |
179 | * @head: the list to test. | |
180 | */ | |
181 | static inline int list_empty(const struct list_head *head) | |
182 | { | |
183 | return head->next == head; | |
184 | } | |
185 | ||
186 | /** | |
fe96e57d RD |
187 | * list_empty_careful - tests whether a list is empty and not being modified |
188 | * @head: the list to test | |
189 | * | |
190 | * Description: | |
191 | * tests whether a list is empty _and_ checks that no other CPU might be | |
192 | * in the process of modifying either member (next or prev) | |
1da177e4 LT |
193 | * |
194 | * NOTE: using list_empty_careful() without synchronization | |
195 | * can only be safe if the only activity that can happen | |
196 | * to the list entry is list_del_init(). Eg. it cannot be used | |
197 | * if another CPU could re-list_add() it. | |
1da177e4 LT |
198 | */ |
199 | static inline int list_empty_careful(const struct list_head *head) | |
200 | { | |
201 | struct list_head *next = head->next; | |
202 | return (next == head) && (next == head->prev); | |
99602572 MH |
203 | } |
204 | ||
5908cdc8 FW |
205 | /** |
206 | * list_rotate_left - rotate the list to the left | |
207 | * @head: the head of the list | |
208 | */ | |
209 | static inline void list_rotate_left(struct list_head *head) | |
210 | { | |
211 | struct list_head *first; | |
212 | ||
213 | if (!list_empty(head)) { | |
214 | first = head->next; | |
215 | list_move_tail(first, head); | |
216 | } | |
217 | } | |
218 | ||
99602572 MH |
219 | /** |
220 | * list_is_singular - tests whether a list has just one entry. | |
221 | * @head: the list to test. | |
222 | */ | |
223 | static inline int list_is_singular(const struct list_head *head) | |
224 | { | |
225 | return !list_empty(head) && (head->next == head->prev); | |
1da177e4 LT |
226 | } |
227 | ||
00e8a4da LR |
228 | static inline void __list_cut_position(struct list_head *list, |
229 | struct list_head *head, struct list_head *entry) | |
230 | { | |
231 | struct list_head *new_first = entry->next; | |
232 | list->next = head->next; | |
233 | list->next->prev = list; | |
234 | list->prev = entry; | |
235 | entry->next = list; | |
236 | head->next = new_first; | |
237 | new_first->prev = head; | |
238 | } | |
239 | ||
240 | /** | |
241 | * list_cut_position - cut a list into two | |
242 | * @list: a new list to add all removed entries | |
243 | * @head: a list with entries | |
244 | * @entry: an entry within head, could be the head itself | |
245 | * and if so we won't cut the list | |
246 | * | |
247 | * This helper moves the initial part of @head, up to and | |
248 | * including @entry, from @head to @list. You should | |
249 | * pass on @entry an element you know is on @head. @list | |
250 | * should be an empty list or a list you do not care about | |
251 | * losing its data. | |
252 | * | |
253 | */ | |
254 | static inline void list_cut_position(struct list_head *list, | |
255 | struct list_head *head, struct list_head *entry) | |
256 | { | |
257 | if (list_empty(head)) | |
258 | return; | |
259 | if (list_is_singular(head) && | |
260 | (head->next != entry && head != entry)) | |
261 | return; | |
262 | if (entry == head) | |
263 | INIT_LIST_HEAD(list); | |
264 | else | |
265 | __list_cut_position(list, head, entry); | |
266 | } | |
267 | ||
95d8c365 | 268 | static inline void __list_splice(const struct list_head *list, |
7d283aee LR |
269 | struct list_head *prev, |
270 | struct list_head *next) | |
1da177e4 LT |
271 | { |
272 | struct list_head *first = list->next; | |
273 | struct list_head *last = list->prev; | |
1da177e4 | 274 | |
7d283aee LR |
275 | first->prev = prev; |
276 | prev->next = first; | |
1da177e4 | 277 | |
7d283aee LR |
278 | last->next = next; |
279 | next->prev = last; | |
1da177e4 LT |
280 | } |
281 | ||
282 | /** | |
7d283aee | 283 | * list_splice - join two lists, this is designed for stacks |
1da177e4 LT |
284 | * @list: the new list to add. |
285 | * @head: the place to add it in the first list. | |
286 | */ | |
95d8c365 RD |
287 | static inline void list_splice(const struct list_head *list, |
288 | struct list_head *head) | |
1da177e4 LT |
289 | { |
290 | if (!list_empty(list)) | |
7d283aee LR |
291 | __list_splice(list, head, head->next); |
292 | } | |
293 | ||
294 | /** | |
295 | * list_splice_tail - join two lists, each list being a queue | |
296 | * @list: the new list to add. | |
297 | * @head: the place to add it in the first list. | |
298 | */ | |
299 | static inline void list_splice_tail(struct list_head *list, | |
300 | struct list_head *head) | |
301 | { | |
302 | if (!list_empty(list)) | |
303 | __list_splice(list, head->prev, head); | |
1da177e4 LT |
304 | } |
305 | ||
306 | /** | |
307 | * list_splice_init - join two lists and reinitialise the emptied list. | |
308 | * @list: the new list to add. | |
309 | * @head: the place to add it in the first list. | |
310 | * | |
311 | * The list at @list is reinitialised | |
312 | */ | |
313 | static inline void list_splice_init(struct list_head *list, | |
314 | struct list_head *head) | |
315 | { | |
316 | if (!list_empty(list)) { | |
7d283aee LR |
317 | __list_splice(list, head, head->next); |
318 | INIT_LIST_HEAD(list); | |
319 | } | |
320 | } | |
321 | ||
322 | /** | |
6724cce8 | 323 | * list_splice_tail_init - join two lists and reinitialise the emptied list |
7d283aee LR |
324 | * @list: the new list to add. |
325 | * @head: the place to add it in the first list. | |
326 | * | |
6724cce8 | 327 | * Each of the lists is a queue. |
7d283aee LR |
328 | * The list at @list is reinitialised |
329 | */ | |
330 | static inline void list_splice_tail_init(struct list_head *list, | |
331 | struct list_head *head) | |
332 | { | |
333 | if (!list_empty(list)) { | |
334 | __list_splice(list, head->prev, head); | |
1da177e4 LT |
335 | INIT_LIST_HEAD(list); |
336 | } | |
337 | } | |
338 | ||
339 | /** | |
340 | * list_entry - get the struct for this entry | |
341 | * @ptr: the &struct list_head pointer. | |
342 | * @type: the type of the struct this is embedded in. | |
343 | * @member: the name of the list_struct within the struct. | |
344 | */ | |
345 | #define list_entry(ptr, type, member) \ | |
346 | container_of(ptr, type, member) | |
347 | ||
b5e61818 PE |
348 | /** |
349 | * list_first_entry - get the first element from a list | |
350 | * @ptr: the list head to take the element from. | |
351 | * @type: the type of the struct this is embedded in. | |
352 | * @member: the name of the list_struct within the struct. | |
353 | * | |
354 | * Note, that list is expected to be not empty. | |
355 | */ | |
356 | #define list_first_entry(ptr, type, member) \ | |
357 | list_entry((ptr)->next, type, member) | |
358 | ||
1da177e4 LT |
359 | /** |
360 | * list_for_each - iterate over a list | |
8e3a67a9 | 361 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
362 | * @head: the head for your list. |
363 | */ | |
364 | #define list_for_each(pos, head) \ | |
365 | for (pos = (head)->next; prefetch(pos->next), pos != (head); \ | |
366 | pos = pos->next) | |
367 | ||
368 | /** | |
369 | * __list_for_each - iterate over a list | |
8e3a67a9 | 370 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
371 | * @head: the head for your list. |
372 | * | |
373 | * This variant differs from list_for_each() in that it's the | |
374 | * simplest possible list iteration code, no prefetching is done. | |
375 | * Use this for code that knows the list to be very short (empty | |
376 | * or 1 entry) most of the time. | |
377 | */ | |
378 | #define __list_for_each(pos, head) \ | |
379 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
380 | ||
381 | /** | |
382 | * list_for_each_prev - iterate over a list backwards | |
8e3a67a9 | 383 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
384 | * @head: the head for your list. |
385 | */ | |
386 | #define list_for_each_prev(pos, head) \ | |
387 | for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \ | |
388 | pos = pos->prev) | |
389 | ||
390 | /** | |
fe96e57d | 391 | * list_for_each_safe - iterate over a list safe against removal of list entry |
8e3a67a9 | 392 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
393 | * @n: another &struct list_head to use as temporary storage |
394 | * @head: the head for your list. | |
395 | */ | |
396 | #define list_for_each_safe(pos, n, head) \ | |
397 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
398 | pos = n, n = pos->next) | |
399 | ||
37c42524 | 400 | /** |
8f731f7d | 401 | * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry |
37c42524 DL |
402 | * @pos: the &struct list_head to use as a loop cursor. |
403 | * @n: another &struct list_head to use as temporary storage | |
404 | * @head: the head for your list. | |
405 | */ | |
406 | #define list_for_each_prev_safe(pos, n, head) \ | |
407 | for (pos = (head)->prev, n = pos->prev; \ | |
408 | prefetch(pos->prev), pos != (head); \ | |
409 | pos = n, n = pos->prev) | |
410 | ||
1da177e4 LT |
411 | /** |
412 | * list_for_each_entry - iterate over list of given type | |
8e3a67a9 | 413 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
414 | * @head: the head for your list. |
415 | * @member: the name of the list_struct within the struct. | |
416 | */ | |
417 | #define list_for_each_entry(pos, head, member) \ | |
418 | for (pos = list_entry((head)->next, typeof(*pos), member); \ | |
419 | prefetch(pos->member.next), &pos->member != (head); \ | |
420 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
421 | ||
422 | /** | |
423 | * list_for_each_entry_reverse - iterate backwards over list of given type. | |
8e3a67a9 | 424 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
425 | * @head: the head for your list. |
426 | * @member: the name of the list_struct within the struct. | |
427 | */ | |
428 | #define list_for_each_entry_reverse(pos, head, member) \ | |
429 | for (pos = list_entry((head)->prev, typeof(*pos), member); \ | |
430 | prefetch(pos->member.prev), &pos->member != (head); \ | |
431 | pos = list_entry(pos->member.prev, typeof(*pos), member)) | |
432 | ||
433 | /** | |
72fd4a35 | 434 | * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() |
1da177e4 LT |
435 | * @pos: the type * to use as a start point |
436 | * @head: the head of the list | |
437 | * @member: the name of the list_struct within the struct. | |
fe96e57d | 438 | * |
72fd4a35 | 439 | * Prepares a pos entry for use as a start point in list_for_each_entry_continue(). |
1da177e4 LT |
440 | */ |
441 | #define list_prepare_entry(pos, head, member) \ | |
442 | ((pos) ? : list_entry(head, typeof(*pos), member)) | |
443 | ||
444 | /** | |
fe96e57d | 445 | * list_for_each_entry_continue - continue iteration over list of given type |
8e3a67a9 | 446 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
447 | * @head: the head for your list. |
448 | * @member: the name of the list_struct within the struct. | |
fe96e57d RD |
449 | * |
450 | * Continue to iterate over list of given type, continuing after | |
451 | * the current position. | |
1da177e4 LT |
452 | */ |
453 | #define list_for_each_entry_continue(pos, head, member) \ | |
454 | for (pos = list_entry(pos->member.next, typeof(*pos), member); \ | |
455 | prefetch(pos->member.next), &pos->member != (head); \ | |
456 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
457 | ||
768f3591 PE |
458 | /** |
459 | * list_for_each_entry_continue_reverse - iterate backwards from the given point | |
460 | * @pos: the type * to use as a loop cursor. | |
461 | * @head: the head for your list. | |
462 | * @member: the name of the list_struct within the struct. | |
463 | * | |
464 | * Start to iterate over list of given type backwards, continuing after | |
465 | * the current position. | |
466 | */ | |
467 | #define list_for_each_entry_continue_reverse(pos, head, member) \ | |
468 | for (pos = list_entry(pos->member.prev, typeof(*pos), member); \ | |
469 | prefetch(pos->member.prev), &pos->member != (head); \ | |
470 | pos = list_entry(pos->member.prev, typeof(*pos), member)) | |
471 | ||
e229c2fb | 472 | /** |
fe96e57d | 473 | * list_for_each_entry_from - iterate over list of given type from the current point |
8e3a67a9 | 474 | * @pos: the type * to use as a loop cursor. |
e229c2fb ACM |
475 | * @head: the head for your list. |
476 | * @member: the name of the list_struct within the struct. | |
fe96e57d RD |
477 | * |
478 | * Iterate over list of given type, continuing from current position. | |
e229c2fb ACM |
479 | */ |
480 | #define list_for_each_entry_from(pos, head, member) \ | |
481 | for (; prefetch(pos->member.next), &pos->member != (head); \ | |
482 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
483 | ||
1da177e4 LT |
484 | /** |
485 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
8e3a67a9 | 486 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
487 | * @n: another type * to use as temporary storage |
488 | * @head: the head for your list. | |
489 | * @member: the name of the list_struct within the struct. | |
490 | */ | |
491 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
492 | for (pos = list_entry((head)->next, typeof(*pos), member), \ | |
493 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
494 | &pos->member != (head); \ | |
495 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
496 | ||
74459dc7 | 497 | /** |
9a86e2ba | 498 | * list_for_each_entry_safe_continue - continue list iteration safe against removal |
8e3a67a9 | 499 | * @pos: the type * to use as a loop cursor. |
74459dc7 ACM |
500 | * @n: another type * to use as temporary storage |
501 | * @head: the head for your list. | |
502 | * @member: the name of the list_struct within the struct. | |
fe96e57d RD |
503 | * |
504 | * Iterate over list of given type, continuing after current point, | |
505 | * safe against removal of list entry. | |
74459dc7 ACM |
506 | */ |
507 | #define list_for_each_entry_safe_continue(pos, n, head, member) \ | |
8c60f3fa ACM |
508 | for (pos = list_entry(pos->member.next, typeof(*pos), member), \ |
509 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
d8dcffee ACM |
510 | &pos->member != (head); \ |
511 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
512 | ||
513 | /** | |
9a86e2ba | 514 | * list_for_each_entry_safe_from - iterate over list from current point safe against removal |
8e3a67a9 | 515 | * @pos: the type * to use as a loop cursor. |
d8dcffee ACM |
516 | * @n: another type * to use as temporary storage |
517 | * @head: the head for your list. | |
518 | * @member: the name of the list_struct within the struct. | |
fe96e57d RD |
519 | * |
520 | * Iterate over list of given type from current point, safe against | |
521 | * removal of list entry. | |
d8dcffee ACM |
522 | */ |
523 | #define list_for_each_entry_safe_from(pos, n, head, member) \ | |
524 | for (n = list_entry(pos->member.next, typeof(*pos), member); \ | |
74459dc7 ACM |
525 | &pos->member != (head); \ |
526 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
527 | ||
0ad42352 | 528 | /** |
9a86e2ba | 529 | * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal |
8e3a67a9 | 530 | * @pos: the type * to use as a loop cursor. |
0ad42352 DH |
531 | * @n: another type * to use as temporary storage |
532 | * @head: the head for your list. | |
533 | * @member: the name of the list_struct within the struct. | |
fe96e57d RD |
534 | * |
535 | * Iterate backwards over list of given type, safe against removal | |
536 | * of list entry. | |
0ad42352 DH |
537 | */ |
538 | #define list_for_each_entry_safe_reverse(pos, n, head, member) \ | |
539 | for (pos = list_entry((head)->prev, typeof(*pos), member), \ | |
540 | n = list_entry(pos->member.prev, typeof(*pos), member); \ | |
541 | &pos->member != (head); \ | |
542 | pos = n, n = list_entry(n->member.prev, typeof(*n), member)) | |
543 | ||
57439f87 | 544 | /** |
545 | * list_safe_reset_next - reset a stale list_for_each_entry_safe loop | |
546 | * @pos: the loop cursor used in the list_for_each_entry_safe loop | |
547 | * @n: temporary storage used in list_for_each_entry_safe | |
548 | * @member: the name of the list_struct within the struct. | |
549 | * | |
550 | * list_safe_reset_next is not safe to use in general if the list may be | |
551 | * modified concurrently (eg. the lock is dropped in the loop body). An | |
552 | * exception to this is if the cursor element (pos) is pinned in the list, | |
553 | * and list_safe_reset_next is called after re-taking the lock and before | |
554 | * completing the current iteration of the loop body. | |
555 | */ | |
556 | #define list_safe_reset_next(pos, n, member) \ | |
557 | n = list_entry(pos->member.next, typeof(*pos), member) | |
558 | ||
1da177e4 LT |
559 | /* |
560 | * Double linked lists with a single pointer list head. | |
561 | * Mostly useful for hash tables where the two pointer list head is | |
562 | * too wasteful. | |
563 | * You lose the ability to access the tail in O(1). | |
564 | */ | |
565 | ||
1da177e4 LT |
566 | #define HLIST_HEAD_INIT { .first = NULL } |
567 | #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } | |
568 | #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) | |
490d6ab1 ZB |
569 | static inline void INIT_HLIST_NODE(struct hlist_node *h) |
570 | { | |
571 | h->next = NULL; | |
572 | h->pprev = NULL; | |
573 | } | |
1da177e4 LT |
574 | |
575 | static inline int hlist_unhashed(const struct hlist_node *h) | |
576 | { | |
577 | return !h->pprev; | |
578 | } | |
579 | ||
580 | static inline int hlist_empty(const struct hlist_head *h) | |
581 | { | |
582 | return !h->first; | |
583 | } | |
584 | ||
585 | static inline void __hlist_del(struct hlist_node *n) | |
586 | { | |
587 | struct hlist_node *next = n->next; | |
588 | struct hlist_node **pprev = n->pprev; | |
589 | *pprev = next; | |
590 | if (next) | |
591 | next->pprev = pprev; | |
592 | } | |
593 | ||
594 | static inline void hlist_del(struct hlist_node *n) | |
595 | { | |
596 | __hlist_del(n); | |
597 | n->next = LIST_POISON1; | |
598 | n->pprev = LIST_POISON2; | |
599 | } | |
600 | ||
1da177e4 LT |
601 | static inline void hlist_del_init(struct hlist_node *n) |
602 | { | |
da753bea | 603 | if (!hlist_unhashed(n)) { |
1da177e4 LT |
604 | __hlist_del(n); |
605 | INIT_HLIST_NODE(n); | |
606 | } | |
607 | } | |
608 | ||
609 | static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) | |
610 | { | |
611 | struct hlist_node *first = h->first; | |
612 | n->next = first; | |
613 | if (first) | |
614 | first->pprev = &n->next; | |
615 | h->first = n; | |
616 | n->pprev = &h->first; | |
617 | } | |
618 | ||
1da177e4 LT |
619 | /* next must be != NULL */ |
620 | static inline void hlist_add_before(struct hlist_node *n, | |
621 | struct hlist_node *next) | |
622 | { | |
623 | n->pprev = next->pprev; | |
624 | n->next = next; | |
625 | next->pprev = &n->next; | |
626 | *(n->pprev) = n; | |
627 | } | |
628 | ||
629 | static inline void hlist_add_after(struct hlist_node *n, | |
630 | struct hlist_node *next) | |
631 | { | |
632 | next->next = n->next; | |
633 | n->next = next; | |
634 | next->pprev = &n->next; | |
635 | ||
636 | if(next->next) | |
637 | next->next->pprev = &next->next; | |
638 | } | |
639 | ||
673d62cc VN |
640 | /* |
641 | * Move a list from one list head to another. Fixup the pprev | |
642 | * reference of the first entry if it exists. | |
643 | */ | |
644 | static inline void hlist_move_list(struct hlist_head *old, | |
645 | struct hlist_head *new) | |
646 | { | |
647 | new->first = old->first; | |
648 | if (new->first) | |
649 | new->first->pprev = &new->first; | |
650 | old->first = NULL; | |
651 | } | |
652 | ||
1da177e4 LT |
653 | #define hlist_entry(ptr, type, member) container_of(ptr,type,member) |
654 | ||
655 | #define hlist_for_each(pos, head) \ | |
656 | for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \ | |
657 | pos = pos->next) | |
658 | ||
659 | #define hlist_for_each_safe(pos, n, head) \ | |
660 | for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ | |
661 | pos = n) | |
662 | ||
1da177e4 LT |
663 | /** |
664 | * hlist_for_each_entry - iterate over list of given type | |
8e3a67a9 RD |
665 | * @tpos: the type * to use as a loop cursor. |
666 | * @pos: the &struct hlist_node to use as a loop cursor. | |
1da177e4 LT |
667 | * @head: the head for your list. |
668 | * @member: the name of the hlist_node within the struct. | |
669 | */ | |
670 | #define hlist_for_each_entry(tpos, pos, head, member) \ | |
671 | for (pos = (head)->first; \ | |
672 | pos && ({ prefetch(pos->next); 1;}) && \ | |
673 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | |
674 | pos = pos->next) | |
675 | ||
676 | /** | |
fe96e57d | 677 | * hlist_for_each_entry_continue - iterate over a hlist continuing after current point |
8e3a67a9 RD |
678 | * @tpos: the type * to use as a loop cursor. |
679 | * @pos: the &struct hlist_node to use as a loop cursor. | |
1da177e4 LT |
680 | * @member: the name of the hlist_node within the struct. |
681 | */ | |
682 | #define hlist_for_each_entry_continue(tpos, pos, member) \ | |
683 | for (pos = (pos)->next; \ | |
684 | pos && ({ prefetch(pos->next); 1;}) && \ | |
685 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | |
686 | pos = pos->next) | |
687 | ||
688 | /** | |
fe96e57d | 689 | * hlist_for_each_entry_from - iterate over a hlist continuing from current point |
8e3a67a9 RD |
690 | * @tpos: the type * to use as a loop cursor. |
691 | * @pos: the &struct hlist_node to use as a loop cursor. | |
1da177e4 LT |
692 | * @member: the name of the hlist_node within the struct. |
693 | */ | |
694 | #define hlist_for_each_entry_from(tpos, pos, member) \ | |
695 | for (; pos && ({ prefetch(pos->next); 1;}) && \ | |
696 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | |
697 | pos = pos->next) | |
698 | ||
699 | /** | |
700 | * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
8e3a67a9 RD |
701 | * @tpos: the type * to use as a loop cursor. |
702 | * @pos: the &struct hlist_node to use as a loop cursor. | |
1da177e4 LT |
703 | * @n: another &struct hlist_node to use as temporary storage |
704 | * @head: the head for your list. | |
705 | * @member: the name of the hlist_node within the struct. | |
706 | */ | |
707 | #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \ | |
708 | for (pos = (head)->first; \ | |
709 | pos && ({ n = pos->next; 1; }) && \ | |
710 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | |
711 | pos = n) | |
712 | ||
1da177e4 | 713 | #endif |