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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_LIST_H |
3 | #define _LINUX_LIST_H | |
4 | ||
de5d9bf6 | 5 | #include <linux/types.h> |
1da177e4 | 6 | #include <linux/stddef.h> |
c9cf5528 | 7 | #include <linux/poison.h> |
e66eed65 | 8 | #include <linux/const.h> |
8b21d9ca | 9 | #include <linux/kernel.h> |
1da177e4 | 10 | |
1da177e4 LT |
11 | /* |
12 | * Simple doubly linked list implementation. | |
13 | * | |
14 | * Some of the internal functions ("__xxx") are useful when | |
15 | * manipulating whole lists rather than single entries, as | |
16 | * sometimes we already know the next/prev entries and we can | |
17 | * generate better code by using them directly rather than | |
18 | * using the generic single-entry routines. | |
19 | */ | |
20 | ||
1da177e4 LT |
21 | #define LIST_HEAD_INIT(name) { &(name), &(name) } |
22 | ||
23 | #define LIST_HEAD(name) \ | |
24 | struct list_head name = LIST_HEAD_INIT(name) | |
25 | ||
490d6ab1 ZB |
26 | static inline void INIT_LIST_HEAD(struct list_head *list) |
27 | { | |
2f073848 | 28 | WRITE_ONCE(list->next, list); |
490d6ab1 ZB |
29 | list->prev = list; |
30 | } | |
1da177e4 | 31 | |
d7c81673 KC |
32 | #ifdef CONFIG_DEBUG_LIST |
33 | extern bool __list_add_valid(struct list_head *new, | |
34 | struct list_head *prev, | |
35 | struct list_head *next); | |
0cd340dc | 36 | extern bool __list_del_entry_valid(struct list_head *entry); |
d7c81673 KC |
37 | #else |
38 | static inline bool __list_add_valid(struct list_head *new, | |
39 | struct list_head *prev, | |
40 | struct list_head *next) | |
41 | { | |
42 | return true; | |
43 | } | |
0cd340dc KC |
44 | static inline bool __list_del_entry_valid(struct list_head *entry) |
45 | { | |
46 | return true; | |
47 | } | |
d7c81673 KC |
48 | #endif |
49 | ||
1da177e4 LT |
50 | /* |
51 | * Insert a new entry between two known consecutive entries. | |
52 | * | |
53 | * This is only for internal list manipulation where we know | |
54 | * the prev/next entries already! | |
55 | */ | |
56 | static inline void __list_add(struct list_head *new, | |
57 | struct list_head *prev, | |
58 | struct list_head *next) | |
59 | { | |
d7c81673 KC |
60 | if (!__list_add_valid(new, prev, next)) |
61 | return; | |
62 | ||
1da177e4 LT |
63 | next->prev = new; |
64 | new->next = next; | |
65 | new->prev = prev; | |
1c97be67 | 66 | WRITE_ONCE(prev->next, new); |
1da177e4 LT |
67 | } |
68 | ||
69 | /** | |
70 | * list_add - add a new entry | |
71 | * @new: new entry to be added | |
72 | * @head: list head to add it after | |
73 | * | |
74 | * Insert a new entry after the specified head. | |
75 | * This is good for implementing stacks. | |
76 | */ | |
77 | static inline void list_add(struct list_head *new, struct list_head *head) | |
78 | { | |
79 | __list_add(new, head, head->next); | |
80 | } | |
199a9afc | 81 | |
1da177e4 LT |
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 | ||
1da177e4 LT |
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; | |
7f5f873c | 106 | WRITE_ONCE(prev->next, next); |
1da177e4 LT |
107 | } |
108 | ||
109 | /** | |
110 | * list_del - deletes entry from list. | |
111 | * @entry: the element to delete from the list. | |
72fd4a35 | 112 | * Note: list_empty() on entry does not return true after this, the entry is |
1da177e4 LT |
113 | * in an undefined state. |
114 | */ | |
3c18d4de LT |
115 | static inline void __list_del_entry(struct list_head *entry) |
116 | { | |
0cd340dc KC |
117 | if (!__list_del_entry_valid(entry)) |
118 | return; | |
119 | ||
3c18d4de LT |
120 | __list_del(entry->prev, entry->next); |
121 | } | |
122 | ||
1da177e4 LT |
123 | static inline void list_del(struct list_head *entry) |
124 | { | |
0cd340dc | 125 | __list_del_entry(entry); |
1da177e4 LT |
126 | entry->next = LIST_POISON1; |
127 | entry->prev = LIST_POISON2; | |
128 | } | |
129 | ||
54e73770 ON |
130 | /** |
131 | * list_replace - replace old entry by new one | |
132 | * @old : the element to be replaced | |
133 | * @new : the new element to insert | |
72fd4a35 RD |
134 | * |
135 | * If @old was empty, it will be overwritten. | |
54e73770 ON |
136 | */ |
137 | static inline void list_replace(struct list_head *old, | |
138 | struct list_head *new) | |
139 | { | |
140 | new->next = old->next; | |
141 | new->next->prev = new; | |
142 | new->prev = old->prev; | |
143 | new->prev->next = new; | |
144 | } | |
145 | ||
146 | static inline void list_replace_init(struct list_head *old, | |
147 | struct list_head *new) | |
148 | { | |
149 | list_replace(old, new); | |
150 | INIT_LIST_HEAD(old); | |
151 | } | |
152 | ||
e900a918 DW |
153 | /** |
154 | * list_swap - replace entry1 with entry2 and re-add entry1 at entry2's position | |
155 | * @entry1: the location to place entry2 | |
156 | * @entry2: the location to place entry1 | |
157 | */ | |
158 | static inline void list_swap(struct list_head *entry1, | |
159 | struct list_head *entry2) | |
160 | { | |
161 | struct list_head *pos = entry2->prev; | |
162 | ||
163 | list_del(entry2); | |
164 | list_replace(entry1, entry2); | |
165 | if (pos == entry1) | |
166 | pos = entry2; | |
167 | list_add(entry1, pos); | |
168 | } | |
169 | ||
1da177e4 LT |
170 | /** |
171 | * list_del_init - deletes entry from list and reinitialize it. | |
172 | * @entry: the element to delete from the list. | |
173 | */ | |
174 | static inline void list_del_init(struct list_head *entry) | |
175 | { | |
3c18d4de | 176 | __list_del_entry(entry); |
1da177e4 LT |
177 | INIT_LIST_HEAD(entry); |
178 | } | |
179 | ||
180 | /** | |
181 | * list_move - delete from one list and add as another's head | |
182 | * @list: the entry to move | |
183 | * @head: the head that will precede our entry | |
184 | */ | |
185 | static inline void list_move(struct list_head *list, struct list_head *head) | |
186 | { | |
3c18d4de | 187 | __list_del_entry(list); |
78db2ad6 | 188 | list_add(list, head); |
1da177e4 LT |
189 | } |
190 | ||
191 | /** | |
192 | * list_move_tail - delete from one list and add as another's tail | |
193 | * @list: the entry to move | |
194 | * @head: the head that will follow our entry | |
195 | */ | |
196 | static inline void list_move_tail(struct list_head *list, | |
197 | struct list_head *head) | |
198 | { | |
3c18d4de | 199 | __list_del_entry(list); |
78db2ad6 | 200 | list_add_tail(list, head); |
1da177e4 LT |
201 | } |
202 | ||
df2fc43d CK |
203 | /** |
204 | * list_bulk_move_tail - move a subsection of a list to its tail | |
205 | * @head: the head that will follow our entry | |
206 | * @first: first entry to move | |
207 | * @last: last entry to move, can be the same as first | |
208 | * | |
209 | * Move all entries between @first and including @last before @head. | |
210 | * All three entries must belong to the same linked list. | |
211 | */ | |
212 | static inline void list_bulk_move_tail(struct list_head *head, | |
213 | struct list_head *first, | |
214 | struct list_head *last) | |
215 | { | |
216 | first->prev->next = last->next; | |
217 | last->next->prev = first->prev; | |
218 | ||
219 | head->prev->next = first; | |
220 | first->prev = head->prev; | |
221 | ||
222 | last->next = head; | |
223 | head->prev = last; | |
224 | } | |
225 | ||
70b44595 | 226 | /** |
b736523f | 227 | * list_is_first -- tests whether @list is the first entry in list @head |
70b44595 MG |
228 | * @list: the entry to test |
229 | * @head: the head of the list | |
230 | */ | |
231 | static inline int list_is_first(const struct list_head *list, | |
232 | const struct list_head *head) | |
233 | { | |
234 | return list->prev == head; | |
235 | } | |
236 | ||
e8f4d97e SN |
237 | /** |
238 | * list_is_last - tests whether @list is the last entry in list @head | |
239 | * @list: the entry to test | |
240 | * @head: the head of the list | |
241 | */ | |
242 | static inline int list_is_last(const struct list_head *list, | |
243 | const struct list_head *head) | |
244 | { | |
245 | return list->next == head; | |
246 | } | |
247 | ||
1da177e4 LT |
248 | /** |
249 | * list_empty - tests whether a list is empty | |
250 | * @head: the list to test. | |
251 | */ | |
252 | static inline int list_empty(const struct list_head *head) | |
253 | { | |
1658d35e | 254 | return READ_ONCE(head->next) == head; |
1da177e4 LT |
255 | } |
256 | ||
257 | /** | |
fe96e57d RD |
258 | * list_empty_careful - tests whether a list is empty and not being modified |
259 | * @head: the list to test | |
260 | * | |
261 | * Description: | |
262 | * tests whether a list is empty _and_ checks that no other CPU might be | |
263 | * in the process of modifying either member (next or prev) | |
1da177e4 LT |
264 | * |
265 | * NOTE: using list_empty_careful() without synchronization | |
266 | * can only be safe if the only activity that can happen | |
267 | * to the list entry is list_del_init(). Eg. it cannot be used | |
268 | * if another CPU could re-list_add() it. | |
1da177e4 LT |
269 | */ |
270 | static inline int list_empty_careful(const struct list_head *head) | |
271 | { | |
272 | struct list_head *next = head->next; | |
273 | return (next == head) && (next == head->prev); | |
99602572 MH |
274 | } |
275 | ||
5908cdc8 FW |
276 | /** |
277 | * list_rotate_left - rotate the list to the left | |
278 | * @head: the head of the list | |
279 | */ | |
280 | static inline void list_rotate_left(struct list_head *head) | |
281 | { | |
282 | struct list_head *first; | |
283 | ||
284 | if (!list_empty(head)) { | |
285 | first = head->next; | |
286 | list_move_tail(first, head); | |
287 | } | |
288 | } | |
289 | ||
a16b5384 TH |
290 | /** |
291 | * list_rotate_to_front() - Rotate list to specific item. | |
292 | * @list: The desired new front of the list. | |
293 | * @head: The head of the list. | |
294 | * | |
295 | * Rotates list so that @list becomes the new front of the list. | |
296 | */ | |
297 | static inline void list_rotate_to_front(struct list_head *list, | |
298 | struct list_head *head) | |
299 | { | |
300 | /* | |
301 | * Deletes the list head from the list denoted by @head and | |
302 | * places it as the tail of @list, this effectively rotates the | |
303 | * list so that @list is at the front. | |
304 | */ | |
305 | list_move_tail(head, list); | |
306 | } | |
307 | ||
99602572 MH |
308 | /** |
309 | * list_is_singular - tests whether a list has just one entry. | |
310 | * @head: the list to test. | |
311 | */ | |
312 | static inline int list_is_singular(const struct list_head *head) | |
313 | { | |
314 | return !list_empty(head) && (head->next == head->prev); | |
1da177e4 LT |
315 | } |
316 | ||
00e8a4da LR |
317 | static inline void __list_cut_position(struct list_head *list, |
318 | struct list_head *head, struct list_head *entry) | |
319 | { | |
320 | struct list_head *new_first = entry->next; | |
321 | list->next = head->next; | |
322 | list->next->prev = list; | |
323 | list->prev = entry; | |
324 | entry->next = list; | |
325 | head->next = new_first; | |
326 | new_first->prev = head; | |
327 | } | |
328 | ||
329 | /** | |
330 | * list_cut_position - cut a list into two | |
331 | * @list: a new list to add all removed entries | |
332 | * @head: a list with entries | |
333 | * @entry: an entry within head, could be the head itself | |
334 | * and if so we won't cut the list | |
335 | * | |
336 | * This helper moves the initial part of @head, up to and | |
337 | * including @entry, from @head to @list. You should | |
338 | * pass on @entry an element you know is on @head. @list | |
339 | * should be an empty list or a list you do not care about | |
340 | * losing its data. | |
341 | * | |
342 | */ | |
343 | static inline void list_cut_position(struct list_head *list, | |
344 | struct list_head *head, struct list_head *entry) | |
345 | { | |
346 | if (list_empty(head)) | |
347 | return; | |
348 | if (list_is_singular(head) && | |
349 | (head->next != entry && head != entry)) | |
350 | return; | |
351 | if (entry == head) | |
352 | INIT_LIST_HEAD(list); | |
353 | else | |
354 | __list_cut_position(list, head, entry); | |
355 | } | |
356 | ||
4ce0017a EC |
357 | /** |
358 | * list_cut_before - cut a list into two, before given entry | |
359 | * @list: a new list to add all removed entries | |
360 | * @head: a list with entries | |
361 | * @entry: an entry within head, could be the head itself | |
362 | * | |
363 | * This helper moves the initial part of @head, up to but | |
364 | * excluding @entry, from @head to @list. You should pass | |
365 | * in @entry an element you know is on @head. @list should | |
366 | * be an empty list or a list you do not care about losing | |
367 | * its data. | |
368 | * If @entry == @head, all entries on @head are moved to | |
369 | * @list. | |
370 | */ | |
371 | static inline void list_cut_before(struct list_head *list, | |
372 | struct list_head *head, | |
373 | struct list_head *entry) | |
374 | { | |
375 | if (head->next == entry) { | |
376 | INIT_LIST_HEAD(list); | |
377 | return; | |
378 | } | |
379 | list->next = head->next; | |
380 | list->next->prev = list; | |
381 | list->prev = entry->prev; | |
382 | list->prev->next = list; | |
383 | head->next = entry; | |
384 | entry->prev = head; | |
385 | } | |
386 | ||
95d8c365 | 387 | static inline void __list_splice(const struct list_head *list, |
7d283aee LR |
388 | struct list_head *prev, |
389 | struct list_head *next) | |
1da177e4 LT |
390 | { |
391 | struct list_head *first = list->next; | |
392 | struct list_head *last = list->prev; | |
1da177e4 | 393 | |
7d283aee LR |
394 | first->prev = prev; |
395 | prev->next = first; | |
1da177e4 | 396 | |
7d283aee LR |
397 | last->next = next; |
398 | next->prev = last; | |
1da177e4 LT |
399 | } |
400 | ||
401 | /** | |
7d283aee | 402 | * list_splice - join two lists, this is designed for stacks |
1da177e4 LT |
403 | * @list: the new list to add. |
404 | * @head: the place to add it in the first list. | |
405 | */ | |
95d8c365 RD |
406 | static inline void list_splice(const struct list_head *list, |
407 | struct list_head *head) | |
1da177e4 LT |
408 | { |
409 | if (!list_empty(list)) | |
7d283aee LR |
410 | __list_splice(list, head, head->next); |
411 | } | |
412 | ||
413 | /** | |
414 | * list_splice_tail - join two lists, each list being a queue | |
415 | * @list: the new list to add. | |
416 | * @head: the place to add it in the first list. | |
417 | */ | |
418 | static inline void list_splice_tail(struct list_head *list, | |
419 | struct list_head *head) | |
420 | { | |
421 | if (!list_empty(list)) | |
422 | __list_splice(list, head->prev, head); | |
1da177e4 LT |
423 | } |
424 | ||
425 | /** | |
426 | * list_splice_init - join two lists and reinitialise the emptied list. | |
427 | * @list: the new list to add. | |
428 | * @head: the place to add it in the first list. | |
429 | * | |
430 | * The list at @list is reinitialised | |
431 | */ | |
432 | static inline void list_splice_init(struct list_head *list, | |
433 | struct list_head *head) | |
434 | { | |
435 | if (!list_empty(list)) { | |
7d283aee LR |
436 | __list_splice(list, head, head->next); |
437 | INIT_LIST_HEAD(list); | |
438 | } | |
439 | } | |
440 | ||
441 | /** | |
6724cce8 | 442 | * list_splice_tail_init - join two lists and reinitialise the emptied list |
7d283aee LR |
443 | * @list: the new list to add. |
444 | * @head: the place to add it in the first list. | |
445 | * | |
6724cce8 | 446 | * Each of the lists is a queue. |
7d283aee LR |
447 | * The list at @list is reinitialised |
448 | */ | |
449 | static inline void list_splice_tail_init(struct list_head *list, | |
450 | struct list_head *head) | |
451 | { | |
452 | if (!list_empty(list)) { | |
453 | __list_splice(list, head->prev, head); | |
1da177e4 LT |
454 | INIT_LIST_HEAD(list); |
455 | } | |
456 | } | |
457 | ||
458 | /** | |
459 | * list_entry - get the struct for this entry | |
460 | * @ptr: the &struct list_head pointer. | |
461 | * @type: the type of the struct this is embedded in. | |
3943f42c | 462 | * @member: the name of the list_head within the struct. |
1da177e4 LT |
463 | */ |
464 | #define list_entry(ptr, type, member) \ | |
465 | container_of(ptr, type, member) | |
466 | ||
b5e61818 PE |
467 | /** |
468 | * list_first_entry - get the first element from a list | |
469 | * @ptr: the list head to take the element from. | |
470 | * @type: the type of the struct this is embedded in. | |
3943f42c | 471 | * @member: the name of the list_head within the struct. |
b5e61818 PE |
472 | * |
473 | * Note, that list is expected to be not empty. | |
474 | */ | |
475 | #define list_first_entry(ptr, type, member) \ | |
476 | list_entry((ptr)->next, type, member) | |
477 | ||
93be3c2e ON |
478 | /** |
479 | * list_last_entry - get the last element from a list | |
480 | * @ptr: the list head to take the element from. | |
481 | * @type: the type of the struct this is embedded in. | |
3943f42c | 482 | * @member: the name of the list_head within the struct. |
93be3c2e ON |
483 | * |
484 | * Note, that list is expected to be not empty. | |
485 | */ | |
486 | #define list_last_entry(ptr, type, member) \ | |
487 | list_entry((ptr)->prev, type, member) | |
488 | ||
6d7581e6 JP |
489 | /** |
490 | * list_first_entry_or_null - get the first element from a list | |
491 | * @ptr: the list head to take the element from. | |
492 | * @type: the type of the struct this is embedded in. | |
3943f42c | 493 | * @member: the name of the list_head within the struct. |
6d7581e6 JP |
494 | * |
495 | * Note that if the list is empty, it returns NULL. | |
496 | */ | |
12adfd88 CW |
497 | #define list_first_entry_or_null(ptr, type, member) ({ \ |
498 | struct list_head *head__ = (ptr); \ | |
499 | struct list_head *pos__ = READ_ONCE(head__->next); \ | |
500 | pos__ != head__ ? list_entry(pos__, type, member) : NULL; \ | |
501 | }) | |
6d7581e6 | 502 | |
008208c6 ON |
503 | /** |
504 | * list_next_entry - get the next element in list | |
505 | * @pos: the type * to cursor | |
3943f42c | 506 | * @member: the name of the list_head within the struct. |
008208c6 ON |
507 | */ |
508 | #define list_next_entry(pos, member) \ | |
509 | list_entry((pos)->member.next, typeof(*(pos)), member) | |
510 | ||
511 | /** | |
512 | * list_prev_entry - get the prev element in list | |
513 | * @pos: the type * to cursor | |
3943f42c | 514 | * @member: the name of the list_head within the struct. |
008208c6 ON |
515 | */ |
516 | #define list_prev_entry(pos, member) \ | |
517 | list_entry((pos)->member.prev, typeof(*(pos)), member) | |
518 | ||
1da177e4 LT |
519 | /** |
520 | * list_for_each - iterate over a list | |
8e3a67a9 | 521 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
522 | * @head: the head for your list. |
523 | */ | |
524 | #define list_for_each(pos, head) \ | |
e66eed65 | 525 | for (pos = (head)->next; pos != (head); pos = pos->next) |
1da177e4 | 526 | |
1da177e4 LT |
527 | /** |
528 | * list_for_each_prev - iterate over a list backwards | |
8e3a67a9 | 529 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
530 | * @head: the head for your list. |
531 | */ | |
532 | #define list_for_each_prev(pos, head) \ | |
e66eed65 | 533 | for (pos = (head)->prev; pos != (head); pos = pos->prev) |
1da177e4 LT |
534 | |
535 | /** | |
fe96e57d | 536 | * list_for_each_safe - iterate over a list safe against removal of list entry |
8e3a67a9 | 537 | * @pos: the &struct list_head to use as a loop cursor. |
1da177e4 LT |
538 | * @n: another &struct list_head to use as temporary storage |
539 | * @head: the head for your list. | |
540 | */ | |
541 | #define list_for_each_safe(pos, n, head) \ | |
542 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
543 | pos = n, n = pos->next) | |
544 | ||
37c42524 | 545 | /** |
8f731f7d | 546 | * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry |
37c42524 DL |
547 | * @pos: the &struct list_head to use as a loop cursor. |
548 | * @n: another &struct list_head to use as temporary storage | |
549 | * @head: the head for your list. | |
550 | */ | |
551 | #define list_for_each_prev_safe(pos, n, head) \ | |
552 | for (pos = (head)->prev, n = pos->prev; \ | |
e66eed65 | 553 | pos != (head); \ |
37c42524 DL |
554 | pos = n, n = pos->prev) |
555 | ||
1da177e4 LT |
556 | /** |
557 | * list_for_each_entry - iterate over list of given type | |
8e3a67a9 | 558 | * @pos: the type * to use as a loop cursor. |
1da177e4 | 559 | * @head: the head for your list. |
3943f42c | 560 | * @member: the name of the list_head within the struct. |
1da177e4 LT |
561 | */ |
562 | #define list_for_each_entry(pos, head, member) \ | |
93be3c2e | 563 | for (pos = list_first_entry(head, typeof(*pos), member); \ |
8120e2e5 ON |
564 | &pos->member != (head); \ |
565 | pos = list_next_entry(pos, member)) | |
1da177e4 LT |
566 | |
567 | /** | |
568 | * list_for_each_entry_reverse - iterate backwards over list of given type. | |
8e3a67a9 | 569 | * @pos: the type * to use as a loop cursor. |
1da177e4 | 570 | * @head: the head for your list. |
3943f42c | 571 | * @member: the name of the list_head within the struct. |
1da177e4 LT |
572 | */ |
573 | #define list_for_each_entry_reverse(pos, head, member) \ | |
93be3c2e | 574 | for (pos = list_last_entry(head, typeof(*pos), member); \ |
8120e2e5 ON |
575 | &pos->member != (head); \ |
576 | pos = list_prev_entry(pos, member)) | |
1da177e4 LT |
577 | |
578 | /** | |
72fd4a35 | 579 | * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() |
1da177e4 LT |
580 | * @pos: the type * to use as a start point |
581 | * @head: the head of the list | |
3943f42c | 582 | * @member: the name of the list_head within the struct. |
fe96e57d | 583 | * |
72fd4a35 | 584 | * Prepares a pos entry for use as a start point in list_for_each_entry_continue(). |
1da177e4 LT |
585 | */ |
586 | #define list_prepare_entry(pos, head, member) \ | |
587 | ((pos) ? : list_entry(head, typeof(*pos), member)) | |
588 | ||
589 | /** | |
fe96e57d | 590 | * list_for_each_entry_continue - continue iteration over list of given type |
8e3a67a9 | 591 | * @pos: the type * to use as a loop cursor. |
1da177e4 | 592 | * @head: the head for your list. |
3943f42c | 593 | * @member: the name of the list_head within the struct. |
fe96e57d RD |
594 | * |
595 | * Continue to iterate over list of given type, continuing after | |
596 | * the current position. | |
1da177e4 LT |
597 | */ |
598 | #define list_for_each_entry_continue(pos, head, member) \ | |
8120e2e5 ON |
599 | for (pos = list_next_entry(pos, member); \ |
600 | &pos->member != (head); \ | |
601 | pos = list_next_entry(pos, member)) | |
1da177e4 | 602 | |
768f3591 PE |
603 | /** |
604 | * list_for_each_entry_continue_reverse - iterate backwards from the given point | |
605 | * @pos: the type * to use as a loop cursor. | |
606 | * @head: the head for your list. | |
3943f42c | 607 | * @member: the name of the list_head within the struct. |
768f3591 PE |
608 | * |
609 | * Start to iterate over list of given type backwards, continuing after | |
610 | * the current position. | |
611 | */ | |
612 | #define list_for_each_entry_continue_reverse(pos, head, member) \ | |
8120e2e5 ON |
613 | for (pos = list_prev_entry(pos, member); \ |
614 | &pos->member != (head); \ | |
615 | pos = list_prev_entry(pos, member)) | |
768f3591 | 616 | |
e229c2fb | 617 | /** |
fe96e57d | 618 | * list_for_each_entry_from - iterate over list of given type from the current point |
8e3a67a9 | 619 | * @pos: the type * to use as a loop cursor. |
e229c2fb | 620 | * @head: the head for your list. |
3943f42c | 621 | * @member: the name of the list_head within the struct. |
fe96e57d RD |
622 | * |
623 | * Iterate over list of given type, continuing from current position. | |
e229c2fb ACM |
624 | */ |
625 | #define list_for_each_entry_from(pos, head, member) \ | |
8120e2e5 ON |
626 | for (; &pos->member != (head); \ |
627 | pos = list_next_entry(pos, member)) | |
e229c2fb | 628 | |
b862815c JP |
629 | /** |
630 | * list_for_each_entry_from_reverse - iterate backwards over list of given type | |
631 | * from the current point | |
632 | * @pos: the type * to use as a loop cursor. | |
633 | * @head: the head for your list. | |
634 | * @member: the name of the list_head within the struct. | |
635 | * | |
636 | * Iterate backwards over list of given type, continuing from current position. | |
637 | */ | |
638 | #define list_for_each_entry_from_reverse(pos, head, member) \ | |
639 | for (; &pos->member != (head); \ | |
640 | pos = list_prev_entry(pos, member)) | |
641 | ||
1da177e4 LT |
642 | /** |
643 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
8e3a67a9 | 644 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
645 | * @n: another type * to use as temporary storage |
646 | * @head: the head for your list. | |
3943f42c | 647 | * @member: the name of the list_head within the struct. |
1da177e4 LT |
648 | */ |
649 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
93be3c2e | 650 | for (pos = list_first_entry(head, typeof(*pos), member), \ |
8120e2e5 | 651 | n = list_next_entry(pos, member); \ |
1da177e4 | 652 | &pos->member != (head); \ |
8120e2e5 | 653 | pos = n, n = list_next_entry(n, member)) |
1da177e4 | 654 | |
74459dc7 | 655 | /** |
9a86e2ba | 656 | * list_for_each_entry_safe_continue - continue list iteration safe against removal |
8e3a67a9 | 657 | * @pos: the type * to use as a loop cursor. |
74459dc7 ACM |
658 | * @n: another type * to use as temporary storage |
659 | * @head: the head for your list. | |
3943f42c | 660 | * @member: the name of the list_head within the struct. |
fe96e57d RD |
661 | * |
662 | * Iterate over list of given type, continuing after current point, | |
663 | * safe against removal of list entry. | |
74459dc7 ACM |
664 | */ |
665 | #define list_for_each_entry_safe_continue(pos, n, head, member) \ | |
8120e2e5 ON |
666 | for (pos = list_next_entry(pos, member), \ |
667 | n = list_next_entry(pos, member); \ | |
d8dcffee | 668 | &pos->member != (head); \ |
8120e2e5 | 669 | pos = n, n = list_next_entry(n, member)) |
d8dcffee ACM |
670 | |
671 | /** | |
9a86e2ba | 672 | * list_for_each_entry_safe_from - iterate over list from current point safe against removal |
8e3a67a9 | 673 | * @pos: the type * to use as a loop cursor. |
d8dcffee ACM |
674 | * @n: another type * to use as temporary storage |
675 | * @head: the head for your list. | |
3943f42c | 676 | * @member: the name of the list_head within the struct. |
fe96e57d RD |
677 | * |
678 | * Iterate over list of given type from current point, safe against | |
679 | * removal of list entry. | |
d8dcffee ACM |
680 | */ |
681 | #define list_for_each_entry_safe_from(pos, n, head, member) \ | |
8120e2e5 | 682 | for (n = list_next_entry(pos, member); \ |
74459dc7 | 683 | &pos->member != (head); \ |
8120e2e5 | 684 | pos = n, n = list_next_entry(n, member)) |
74459dc7 | 685 | |
0ad42352 | 686 | /** |
9a86e2ba | 687 | * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal |
8e3a67a9 | 688 | * @pos: the type * to use as a loop cursor. |
0ad42352 DH |
689 | * @n: another type * to use as temporary storage |
690 | * @head: the head for your list. | |
3943f42c | 691 | * @member: the name of the list_head within the struct. |
fe96e57d RD |
692 | * |
693 | * Iterate backwards over list of given type, safe against removal | |
694 | * of list entry. | |
0ad42352 DH |
695 | */ |
696 | #define list_for_each_entry_safe_reverse(pos, n, head, member) \ | |
93be3c2e | 697 | for (pos = list_last_entry(head, typeof(*pos), member), \ |
8120e2e5 | 698 | n = list_prev_entry(pos, member); \ |
0ad42352 | 699 | &pos->member != (head); \ |
8120e2e5 | 700 | pos = n, n = list_prev_entry(n, member)) |
0ad42352 | 701 | |
57439f87 | 702 | /** |
703 | * list_safe_reset_next - reset a stale list_for_each_entry_safe loop | |
704 | * @pos: the loop cursor used in the list_for_each_entry_safe loop | |
705 | * @n: temporary storage used in list_for_each_entry_safe | |
3943f42c | 706 | * @member: the name of the list_head within the struct. |
57439f87 | 707 | * |
708 | * list_safe_reset_next is not safe to use in general if the list may be | |
709 | * modified concurrently (eg. the lock is dropped in the loop body). An | |
710 | * exception to this is if the cursor element (pos) is pinned in the list, | |
711 | * and list_safe_reset_next is called after re-taking the lock and before | |
712 | * completing the current iteration of the loop body. | |
713 | */ | |
714 | #define list_safe_reset_next(pos, n, member) \ | |
8120e2e5 | 715 | n = list_next_entry(pos, member) |
57439f87 | 716 | |
1da177e4 LT |
717 | /* |
718 | * Double linked lists with a single pointer list head. | |
719 | * Mostly useful for hash tables where the two pointer list head is | |
720 | * too wasteful. | |
721 | * You lose the ability to access the tail in O(1). | |
722 | */ | |
723 | ||
1da177e4 LT |
724 | #define HLIST_HEAD_INIT { .first = NULL } |
725 | #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } | |
726 | #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) | |
490d6ab1 ZB |
727 | static inline void INIT_HLIST_NODE(struct hlist_node *h) |
728 | { | |
729 | h->next = NULL; | |
730 | h->pprev = NULL; | |
731 | } | |
1da177e4 LT |
732 | |
733 | static inline int hlist_unhashed(const struct hlist_node *h) | |
734 | { | |
735 | return !h->pprev; | |
736 | } | |
737 | ||
738 | static inline int hlist_empty(const struct hlist_head *h) | |
739 | { | |
1658d35e | 740 | return !READ_ONCE(h->first); |
1da177e4 LT |
741 | } |
742 | ||
743 | static inline void __hlist_del(struct hlist_node *n) | |
744 | { | |
745 | struct hlist_node *next = n->next; | |
746 | struct hlist_node **pprev = n->pprev; | |
7f5f873c PM |
747 | |
748 | WRITE_ONCE(*pprev, next); | |
1da177e4 LT |
749 | if (next) |
750 | next->pprev = pprev; | |
751 | } | |
752 | ||
753 | static inline void hlist_del(struct hlist_node *n) | |
754 | { | |
755 | __hlist_del(n); | |
756 | n->next = LIST_POISON1; | |
757 | n->pprev = LIST_POISON2; | |
758 | } | |
759 | ||
1da177e4 LT |
760 | static inline void hlist_del_init(struct hlist_node *n) |
761 | { | |
da753bea | 762 | if (!hlist_unhashed(n)) { |
1da177e4 LT |
763 | __hlist_del(n); |
764 | INIT_HLIST_NODE(n); | |
765 | } | |
766 | } | |
767 | ||
768 | static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) | |
769 | { | |
770 | struct hlist_node *first = h->first; | |
771 | n->next = first; | |
772 | if (first) | |
773 | first->pprev = &n->next; | |
1c97be67 | 774 | WRITE_ONCE(h->first, n); |
1da177e4 LT |
775 | n->pprev = &h->first; |
776 | } | |
777 | ||
1da177e4 LT |
778 | /* next must be != NULL */ |
779 | static inline void hlist_add_before(struct hlist_node *n, | |
780 | struct hlist_node *next) | |
781 | { | |
782 | n->pprev = next->pprev; | |
783 | n->next = next; | |
784 | next->pprev = &n->next; | |
1c97be67 | 785 | WRITE_ONCE(*(n->pprev), n); |
1da177e4 LT |
786 | } |
787 | ||
1d023284 KH |
788 | static inline void hlist_add_behind(struct hlist_node *n, |
789 | struct hlist_node *prev) | |
1da177e4 | 790 | { |
bc18dd33 | 791 | n->next = prev->next; |
ae325dcd | 792 | prev->next = n; |
bc18dd33 | 793 | n->pprev = &prev->next; |
1da177e4 | 794 | |
bc18dd33 KH |
795 | if (n->next) |
796 | n->next->pprev = &n->next; | |
1da177e4 LT |
797 | } |
798 | ||
756acc2d AV |
799 | /* after that we'll appear to be on some hlist and hlist_del will work */ |
800 | static inline void hlist_add_fake(struct hlist_node *n) | |
801 | { | |
802 | n->pprev = &n->next; | |
803 | } | |
804 | ||
cbedaac6 JB |
805 | static inline bool hlist_fake(struct hlist_node *h) |
806 | { | |
807 | return h->pprev == &h->next; | |
808 | } | |
809 | ||
15dba1e3 TG |
810 | /* |
811 | * Check whether the node is the only node of the head without | |
812 | * accessing head: | |
813 | */ | |
814 | static inline bool | |
815 | hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h) | |
816 | { | |
817 | return !n->next && n->pprev == &h->first; | |
818 | } | |
819 | ||
673d62cc VN |
820 | /* |
821 | * Move a list from one list head to another. Fixup the pprev | |
822 | * reference of the first entry if it exists. | |
823 | */ | |
824 | static inline void hlist_move_list(struct hlist_head *old, | |
825 | struct hlist_head *new) | |
826 | { | |
827 | new->first = old->first; | |
828 | if (new->first) | |
829 | new->first->pprev = &new->first; | |
830 | old->first = NULL; | |
831 | } | |
832 | ||
1da177e4 LT |
833 | #define hlist_entry(ptr, type, member) container_of(ptr,type,member) |
834 | ||
835 | #define hlist_for_each(pos, head) \ | |
75d65a42 | 836 | for (pos = (head)->first; pos ; pos = pos->next) |
1da177e4 LT |
837 | |
838 | #define hlist_for_each_safe(pos, n, head) \ | |
839 | for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ | |
840 | pos = n) | |
841 | ||
b67bfe0d | 842 | #define hlist_entry_safe(ptr, type, member) \ |
f65846a1 PM |
843 | ({ typeof(ptr) ____ptr = (ptr); \ |
844 | ____ptr ? hlist_entry(____ptr, type, member) : NULL; \ | |
845 | }) | |
b67bfe0d | 846 | |
1da177e4 LT |
847 | /** |
848 | * hlist_for_each_entry - iterate over list of given type | |
b67bfe0d | 849 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
850 | * @head: the head for your list. |
851 | * @member: the name of the hlist_node within the struct. | |
852 | */ | |
b67bfe0d SL |
853 | #define hlist_for_each_entry(pos, head, member) \ |
854 | for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\ | |
855 | pos; \ | |
856 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
1da177e4 LT |
857 | |
858 | /** | |
fe96e57d | 859 | * hlist_for_each_entry_continue - iterate over a hlist continuing after current point |
b67bfe0d | 860 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
861 | * @member: the name of the hlist_node within the struct. |
862 | */ | |
b67bfe0d SL |
863 | #define hlist_for_each_entry_continue(pos, member) \ |
864 | for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\ | |
865 | pos; \ | |
866 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
1da177e4 LT |
867 | |
868 | /** | |
fe96e57d | 869 | * hlist_for_each_entry_from - iterate over a hlist continuing from current point |
b67bfe0d | 870 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
871 | * @member: the name of the hlist_node within the struct. |
872 | */ | |
b67bfe0d SL |
873 | #define hlist_for_each_entry_from(pos, member) \ |
874 | for (; pos; \ | |
875 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) | |
1da177e4 LT |
876 | |
877 | /** | |
878 | * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
b67bfe0d | 879 | * @pos: the type * to use as a loop cursor. |
1da177e4 LT |
880 | * @n: another &struct hlist_node to use as temporary storage |
881 | * @head: the head for your list. | |
882 | * @member: the name of the hlist_node within the struct. | |
883 | */ | |
b67bfe0d SL |
884 | #define hlist_for_each_entry_safe(pos, n, head, member) \ |
885 | for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\ | |
886 | pos && ({ n = pos->member.next; 1; }); \ | |
887 | pos = hlist_entry_safe(n, typeof(*pos), member)) | |
1da177e4 | 888 | |
1da177e4 | 889 | #endif |