diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/list.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/list.h')
-rw-r--r-- | include/linux/list.h | 707 |
1 files changed, 707 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h new file mode 100644 index 000000000000..dd7cd54fa831 --- /dev/null +++ b/include/linux/list.h | |||
@@ -0,0 +1,707 @@ | |||
1 | #ifndef _LINUX_LIST_H | ||
2 | #define _LINUX_LIST_H | ||
3 | |||
4 | #ifdef __KERNEL__ | ||
5 | |||
6 | #include <linux/stddef.h> | ||
7 | #include <linux/prefetch.h> | ||
8 | #include <asm/system.h> | ||
9 | |||
10 | /* | ||
11 | * These are non-NULL pointers that will result in page faults | ||
12 | * under normal circumstances, used to verify that nobody uses | ||
13 | * non-initialized list entries. | ||
14 | */ | ||
15 | #define LIST_POISON1 ((void *) 0x00100100) | ||
16 | #define LIST_POISON2 ((void *) 0x00200200) | ||
17 | |||
18 | /* | ||
19 | * Simple doubly linked list implementation. | ||
20 | * | ||
21 | * Some of the internal functions ("__xxx") are useful when | ||
22 | * manipulating whole lists rather than single entries, as | ||
23 | * sometimes we already know the next/prev entries and we can | ||
24 | * generate better code by using them directly rather than | ||
25 | * using the generic single-entry routines. | ||
26 | */ | ||
27 | |||
28 | struct list_head { | ||
29 | struct list_head *next, *prev; | ||
30 | }; | ||
31 | |||
32 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | ||
33 | |||
34 | #define LIST_HEAD(name) \ | ||
35 | struct list_head name = LIST_HEAD_INIT(name) | ||
36 | |||
37 | #define INIT_LIST_HEAD(ptr) do { \ | ||
38 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ | ||
39 | } while (0) | ||
40 | |||
41 | /* | ||
42 | * Insert a new entry between two known consecutive entries. | ||
43 | * | ||
44 | * This is only for internal list manipulation where we know | ||
45 | * the prev/next entries already! | ||
46 | */ | ||
47 | static inline void __list_add(struct list_head *new, | ||
48 | struct list_head *prev, | ||
49 | struct list_head *next) | ||
50 | { | ||
51 | next->prev = new; | ||
52 | new->next = next; | ||
53 | new->prev = prev; | ||
54 | prev->next = new; | ||
55 | } | ||
56 | |||
57 | /** | ||
58 | * list_add - add a new entry | ||
59 | * @new: new entry to be added | ||
60 | * @head: list head to add it after | ||
61 | * | ||
62 | * Insert a new entry after the specified head. | ||
63 | * This is good for implementing stacks. | ||
64 | */ | ||
65 | static inline void list_add(struct list_head *new, struct list_head *head) | ||
66 | { | ||
67 | __list_add(new, head, head->next); | ||
68 | } | ||
69 | |||
70 | /** | ||
71 | * list_add_tail - add a new entry | ||
72 | * @new: new entry to be added | ||
73 | * @head: list head to add it before | ||
74 | * | ||
75 | * Insert a new entry before the specified head. | ||
76 | * This is useful for implementing queues. | ||
77 | */ | ||
78 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | ||
79 | { | ||
80 | __list_add(new, head->prev, head); | ||
81 | } | ||
82 | |||
83 | /* | ||
84 | * Insert a new entry between two known consecutive entries. | ||
85 | * | ||
86 | * This is only for internal list manipulation where we know | ||
87 | * the prev/next entries already! | ||
88 | */ | ||
89 | static inline void __list_add_rcu(struct list_head * new, | ||
90 | struct list_head * prev, struct list_head * next) | ||
91 | { | ||
92 | new->next = next; | ||
93 | new->prev = prev; | ||
94 | smp_wmb(); | ||
95 | next->prev = new; | ||
96 | prev->next = new; | ||
97 | } | ||
98 | |||
99 | /** | ||
100 | * list_add_rcu - add a new entry to rcu-protected list | ||
101 | * @new: new entry to be added | ||
102 | * @head: list head to add it after | ||
103 | * | ||
104 | * Insert a new entry after the specified head. | ||
105 | * This is good for implementing stacks. | ||
106 | * | ||
107 | * The caller must take whatever precautions are necessary | ||
108 | * (such as holding appropriate locks) to avoid racing | ||
109 | * with another list-mutation primitive, such as list_add_rcu() | ||
110 | * or list_del_rcu(), running on this same list. | ||
111 | * However, it is perfectly legal to run concurrently with | ||
112 | * the _rcu list-traversal primitives, such as | ||
113 | * list_for_each_entry_rcu(). | ||
114 | */ | ||
115 | static inline void list_add_rcu(struct list_head *new, struct list_head *head) | ||
116 | { | ||
117 | __list_add_rcu(new, head, head->next); | ||
118 | } | ||
119 | |||
120 | /** | ||
121 | * list_add_tail_rcu - add a new entry to rcu-protected list | ||
122 | * @new: new entry to be added | ||
123 | * @head: list head to add it before | ||
124 | * | ||
125 | * Insert a new entry before the specified head. | ||
126 | * This is useful for implementing queues. | ||
127 | * | ||
128 | * The caller must take whatever precautions are necessary | ||
129 | * (such as holding appropriate locks) to avoid racing | ||
130 | * with another list-mutation primitive, such as list_add_tail_rcu() | ||
131 | * or list_del_rcu(), running on this same list. | ||
132 | * However, it is perfectly legal to run concurrently with | ||
133 | * the _rcu list-traversal primitives, such as | ||
134 | * list_for_each_entry_rcu(). | ||
135 | */ | ||
136 | static inline void list_add_tail_rcu(struct list_head *new, | ||
137 | struct list_head *head) | ||
138 | { | ||
139 | __list_add_rcu(new, head->prev, head); | ||
140 | } | ||
141 | |||
142 | /* | ||
143 | * Delete a list entry by making the prev/next entries | ||
144 | * point to each other. | ||
145 | * | ||
146 | * This is only for internal list manipulation where we know | ||
147 | * the prev/next entries already! | ||
148 | */ | ||
149 | static inline void __list_del(struct list_head * prev, struct list_head * next) | ||
150 | { | ||
151 | next->prev = prev; | ||
152 | prev->next = next; | ||
153 | } | ||
154 | |||
155 | /** | ||
156 | * list_del - deletes entry from list. | ||
157 | * @entry: the element to delete from the list. | ||
158 | * Note: list_empty on entry does not return true after this, the entry is | ||
159 | * in an undefined state. | ||
160 | */ | ||
161 | static inline void list_del(struct list_head *entry) | ||
162 | { | ||
163 | __list_del(entry->prev, entry->next); | ||
164 | entry->next = LIST_POISON1; | ||
165 | entry->prev = LIST_POISON2; | ||
166 | } | ||
167 | |||
168 | /** | ||
169 | * list_del_rcu - deletes entry from list without re-initialization | ||
170 | * @entry: the element to delete from the list. | ||
171 | * | ||
172 | * Note: list_empty on entry does not return true after this, | ||
173 | * the entry is in an undefined state. It is useful for RCU based | ||
174 | * lockfree traversal. | ||
175 | * | ||
176 | * In particular, it means that we can not poison the forward | ||
177 | * pointers that may still be used for walking the list. | ||
178 | * | ||
179 | * The caller must take whatever precautions are necessary | ||
180 | * (such as holding appropriate locks) to avoid racing | ||
181 | * with another list-mutation primitive, such as list_del_rcu() | ||
182 | * or list_add_rcu(), running on this same list. | ||
183 | * However, it is perfectly legal to run concurrently with | ||
184 | * the _rcu list-traversal primitives, such as | ||
185 | * list_for_each_entry_rcu(). | ||
186 | * | ||
187 | * Note that the caller is not permitted to immediately free | ||
188 | * the newly deleted entry. Instead, either synchronize_kernel() | ||
189 | * or call_rcu() must be used to defer freeing until an RCU | ||
190 | * grace period has elapsed. | ||
191 | */ | ||
192 | static inline void list_del_rcu(struct list_head *entry) | ||
193 | { | ||
194 | __list_del(entry->prev, entry->next); | ||
195 | entry->prev = LIST_POISON2; | ||
196 | } | ||
197 | |||
198 | /* | ||
199 | * list_replace_rcu - replace old entry by new one | ||
200 | * @old : the element to be replaced | ||
201 | * @new : the new element to insert | ||
202 | * | ||
203 | * The old entry will be replaced with the new entry atomically. | ||
204 | */ | ||
205 | static inline void list_replace_rcu(struct list_head *old, struct list_head *new){ | ||
206 | new->next = old->next; | ||
207 | new->prev = old->prev; | ||
208 | smp_wmb(); | ||
209 | new->next->prev = new; | ||
210 | new->prev->next = new; | ||
211 | } | ||
212 | |||
213 | /** | ||
214 | * list_del_init - deletes entry from list and reinitialize it. | ||
215 | * @entry: the element to delete from the list. | ||
216 | */ | ||
217 | static inline void list_del_init(struct list_head *entry) | ||
218 | { | ||
219 | __list_del(entry->prev, entry->next); | ||
220 | INIT_LIST_HEAD(entry); | ||
221 | } | ||
222 | |||
223 | /** | ||
224 | * list_move - delete from one list and add as another's head | ||
225 | * @list: the entry to move | ||
226 | * @head: the head that will precede our entry | ||
227 | */ | ||
228 | static inline void list_move(struct list_head *list, struct list_head *head) | ||
229 | { | ||
230 | __list_del(list->prev, list->next); | ||
231 | list_add(list, head); | ||
232 | } | ||
233 | |||
234 | /** | ||
235 | * list_move_tail - delete from one list and add as another's tail | ||
236 | * @list: the entry to move | ||
237 | * @head: the head that will follow our entry | ||
238 | */ | ||
239 | static inline void list_move_tail(struct list_head *list, | ||
240 | struct list_head *head) | ||
241 | { | ||
242 | __list_del(list->prev, list->next); | ||
243 | list_add_tail(list, head); | ||
244 | } | ||
245 | |||
246 | /** | ||
247 | * list_empty - tests whether a list is empty | ||
248 | * @head: the list to test. | ||
249 | */ | ||
250 | static inline int list_empty(const struct list_head *head) | ||
251 | { | ||
252 | return head->next == head; | ||
253 | } | ||
254 | |||
255 | /** | ||
256 | * list_empty_careful - tests whether a list is | ||
257 | * empty _and_ checks that no other CPU might be | ||
258 | * in the process of still modifying either member | ||
259 | * | ||
260 | * NOTE: using list_empty_careful() without synchronization | ||
261 | * can only be safe if the only activity that can happen | ||
262 | * to the list entry is list_del_init(). Eg. it cannot be used | ||
263 | * if another CPU could re-list_add() it. | ||
264 | * | ||
265 | * @head: the list to test. | ||
266 | */ | ||
267 | static inline int list_empty_careful(const struct list_head *head) | ||
268 | { | ||
269 | struct list_head *next = head->next; | ||
270 | return (next == head) && (next == head->prev); | ||
271 | } | ||
272 | |||
273 | static inline void __list_splice(struct list_head *list, | ||
274 | struct list_head *head) | ||
275 | { | ||
276 | struct list_head *first = list->next; | ||
277 | struct list_head *last = list->prev; | ||
278 | struct list_head *at = head->next; | ||
279 | |||
280 | first->prev = head; | ||
281 | head->next = first; | ||
282 | |||
283 | last->next = at; | ||
284 | at->prev = last; | ||
285 | } | ||
286 | |||
287 | /** | ||
288 | * list_splice - join two lists | ||
289 | * @list: the new list to add. | ||
290 | * @head: the place to add it in the first list. | ||
291 | */ | ||
292 | static inline void list_splice(struct list_head *list, struct list_head *head) | ||
293 | { | ||
294 | if (!list_empty(list)) | ||
295 | __list_splice(list, head); | ||
296 | } | ||
297 | |||
298 | /** | ||
299 | * list_splice_init - join two lists and reinitialise the emptied list. | ||
300 | * @list: the new list to add. | ||
301 | * @head: the place to add it in the first list. | ||
302 | * | ||
303 | * The list at @list is reinitialised | ||
304 | */ | ||
305 | static inline void list_splice_init(struct list_head *list, | ||
306 | struct list_head *head) | ||
307 | { | ||
308 | if (!list_empty(list)) { | ||
309 | __list_splice(list, head); | ||
310 | INIT_LIST_HEAD(list); | ||
311 | } | ||
312 | } | ||
313 | |||
314 | /** | ||
315 | * list_entry - get the struct for this entry | ||
316 | * @ptr: the &struct list_head pointer. | ||
317 | * @type: the type of the struct this is embedded in. | ||
318 | * @member: the name of the list_struct within the struct. | ||
319 | */ | ||
320 | #define list_entry(ptr, type, member) \ | ||
321 | container_of(ptr, type, member) | ||
322 | |||
323 | /** | ||
324 | * list_for_each - iterate over a list | ||
325 | * @pos: the &struct list_head to use as a loop counter. | ||
326 | * @head: the head for your list. | ||
327 | */ | ||
328 | #define list_for_each(pos, head) \ | ||
329 | for (pos = (head)->next; prefetch(pos->next), pos != (head); \ | ||
330 | pos = pos->next) | ||
331 | |||
332 | /** | ||
333 | * __list_for_each - iterate over a list | ||
334 | * @pos: the &struct list_head to use as a loop counter. | ||
335 | * @head: the head for your list. | ||
336 | * | ||
337 | * This variant differs from list_for_each() in that it's the | ||
338 | * simplest possible list iteration code, no prefetching is done. | ||
339 | * Use this for code that knows the list to be very short (empty | ||
340 | * or 1 entry) most of the time. | ||
341 | */ | ||
342 | #define __list_for_each(pos, head) \ | ||
343 | for (pos = (head)->next; pos != (head); pos = pos->next) | ||
344 | |||
345 | /** | ||
346 | * list_for_each_prev - iterate over a list backwards | ||
347 | * @pos: the &struct list_head to use as a loop counter. | ||
348 | * @head: the head for your list. | ||
349 | */ | ||
350 | #define list_for_each_prev(pos, head) \ | ||
351 | for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \ | ||
352 | pos = pos->prev) | ||
353 | |||
354 | /** | ||
355 | * list_for_each_safe - iterate over a list safe against removal of list entry | ||
356 | * @pos: the &struct list_head to use as a loop counter. | ||
357 | * @n: another &struct list_head to use as temporary storage | ||
358 | * @head: the head for your list. | ||
359 | */ | ||
360 | #define list_for_each_safe(pos, n, head) \ | ||
361 | for (pos = (head)->next, n = pos->next; pos != (head); \ | ||
362 | pos = n, n = pos->next) | ||
363 | |||
364 | /** | ||
365 | * list_for_each_entry - iterate over list of given type | ||
366 | * @pos: the type * to use as a loop counter. | ||
367 | * @head: the head for your list. | ||
368 | * @member: the name of the list_struct within the struct. | ||
369 | */ | ||
370 | #define list_for_each_entry(pos, head, member) \ | ||
371 | for (pos = list_entry((head)->next, typeof(*pos), member); \ | ||
372 | prefetch(pos->member.next), &pos->member != (head); \ | ||
373 | pos = list_entry(pos->member.next, typeof(*pos), member)) | ||
374 | |||
375 | /** | ||
376 | * list_for_each_entry_reverse - iterate backwards over list of given type. | ||
377 | * @pos: the type * to use as a loop counter. | ||
378 | * @head: the head for your list. | ||
379 | * @member: the name of the list_struct within the struct. | ||
380 | */ | ||
381 | #define list_for_each_entry_reverse(pos, head, member) \ | ||
382 | for (pos = list_entry((head)->prev, typeof(*pos), member); \ | ||
383 | prefetch(pos->member.prev), &pos->member != (head); \ | ||
384 | pos = list_entry(pos->member.prev, typeof(*pos), member)) | ||
385 | |||
386 | /** | ||
387 | * list_prepare_entry - prepare a pos entry for use as a start point in | ||
388 | * list_for_each_entry_continue | ||
389 | * @pos: the type * to use as a start point | ||
390 | * @head: the head of the list | ||
391 | * @member: the name of the list_struct within the struct. | ||
392 | */ | ||
393 | #define list_prepare_entry(pos, head, member) \ | ||
394 | ((pos) ? : list_entry(head, typeof(*pos), member)) | ||
395 | |||
396 | /** | ||
397 | * list_for_each_entry_continue - iterate over list of given type | ||
398 | * continuing after existing point | ||
399 | * @pos: the type * to use as a loop counter. | ||
400 | * @head: the head for your list. | ||
401 | * @member: the name of the list_struct within the struct. | ||
402 | */ | ||
403 | #define list_for_each_entry_continue(pos, head, member) \ | ||
404 | for (pos = list_entry(pos->member.next, typeof(*pos), member); \ | ||
405 | prefetch(pos->member.next), &pos->member != (head); \ | ||
406 | pos = list_entry(pos->member.next, typeof(*pos), member)) | ||
407 | |||
408 | /** | ||
409 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | ||
410 | * @pos: the type * to use as a loop counter. | ||
411 | * @n: another type * to use as temporary storage | ||
412 | * @head: the head for your list. | ||
413 | * @member: the name of the list_struct within the struct. | ||
414 | */ | ||
415 | #define list_for_each_entry_safe(pos, n, head, member) \ | ||
416 | for (pos = list_entry((head)->next, typeof(*pos), member), \ | ||
417 | n = list_entry(pos->member.next, typeof(*pos), member); \ | ||
418 | &pos->member != (head); \ | ||
419 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | ||
420 | |||
421 | /** | ||
422 | * list_for_each_rcu - iterate over an rcu-protected list | ||
423 | * @pos: the &struct list_head to use as a loop counter. | ||
424 | * @head: the head for your list. | ||
425 | * | ||
426 | * This list-traversal primitive may safely run concurrently with | ||
427 | * the _rcu list-mutation primitives such as list_add_rcu() | ||
428 | * as long as the traversal is guarded by rcu_read_lock(). | ||
429 | */ | ||
430 | #define list_for_each_rcu(pos, head) \ | ||
431 | for (pos = (head)->next; prefetch(pos->next), pos != (head); \ | ||
432 | pos = rcu_dereference(pos->next)) | ||
433 | |||
434 | #define __list_for_each_rcu(pos, head) \ | ||
435 | for (pos = (head)->next; pos != (head); \ | ||
436 | pos = rcu_dereference(pos->next)) | ||
437 | |||
438 | /** | ||
439 | * list_for_each_safe_rcu - iterate over an rcu-protected list safe | ||
440 | * against removal of list entry | ||
441 | * @pos: the &struct list_head to use as a loop counter. | ||
442 | * @n: another &struct list_head to use as temporary storage | ||
443 | * @head: the head for your list. | ||
444 | * | ||
445 | * This list-traversal primitive may safely run concurrently with | ||
446 | * the _rcu list-mutation primitives such as list_add_rcu() | ||
447 | * as long as the traversal is guarded by rcu_read_lock(). | ||
448 | */ | ||
449 | #define list_for_each_safe_rcu(pos, n, head) \ | ||
450 | for (pos = (head)->next, n = pos->next; pos != (head); \ | ||
451 | pos = rcu_dereference(n), n = pos->next) | ||
452 | |||
453 | /** | ||
454 | * list_for_each_entry_rcu - iterate over rcu list of given type | ||
455 | * @pos: the type * to use as a loop counter. | ||
456 | * @head: the head for your list. | ||
457 | * @member: the name of the list_struct within the struct. | ||
458 | * | ||
459 | * This list-traversal primitive may safely run concurrently with | ||
460 | * the _rcu list-mutation primitives such as list_add_rcu() | ||
461 | * as long as the traversal is guarded by rcu_read_lock(). | ||
462 | */ | ||
463 | #define list_for_each_entry_rcu(pos, head, member) \ | ||
464 | for (pos = list_entry((head)->next, typeof(*pos), member); \ | ||
465 | prefetch(pos->member.next), &pos->member != (head); \ | ||
466 | pos = rcu_dereference(list_entry(pos->member.next, \ | ||
467 | typeof(*pos), member))) | ||
468 | |||
469 | |||
470 | /** | ||
471 | * list_for_each_continue_rcu - iterate over an rcu-protected list | ||
472 | * continuing after existing point. | ||
473 | * @pos: the &struct list_head to use as a loop counter. | ||
474 | * @head: the head for your list. | ||
475 | * | ||
476 | * This list-traversal primitive may safely run concurrently with | ||
477 | * the _rcu list-mutation primitives such as list_add_rcu() | ||
478 | * as long as the traversal is guarded by rcu_read_lock(). | ||
479 | */ | ||
480 | #define list_for_each_continue_rcu(pos, head) \ | ||
481 | for ((pos) = (pos)->next; prefetch((pos)->next), (pos) != (head); \ | ||
482 | (pos) = rcu_dereference((pos)->next)) | ||
483 | |||
484 | /* | ||
485 | * Double linked lists with a single pointer list head. | ||
486 | * Mostly useful for hash tables where the two pointer list head is | ||
487 | * too wasteful. | ||
488 | * You lose the ability to access the tail in O(1). | ||
489 | */ | ||
490 | |||
491 | struct hlist_head { | ||
492 | struct hlist_node *first; | ||
493 | }; | ||
494 | |||
495 | struct hlist_node { | ||
496 | struct hlist_node *next, **pprev; | ||
497 | }; | ||
498 | |||
499 | #define HLIST_HEAD_INIT { .first = NULL } | ||
500 | #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } | ||
501 | #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) | ||
502 | #define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL) | ||
503 | |||
504 | static inline int hlist_unhashed(const struct hlist_node *h) | ||
505 | { | ||
506 | return !h->pprev; | ||
507 | } | ||
508 | |||
509 | static inline int hlist_empty(const struct hlist_head *h) | ||
510 | { | ||
511 | return !h->first; | ||
512 | } | ||
513 | |||
514 | static inline void __hlist_del(struct hlist_node *n) | ||
515 | { | ||
516 | struct hlist_node *next = n->next; | ||
517 | struct hlist_node **pprev = n->pprev; | ||
518 | *pprev = next; | ||
519 | if (next) | ||
520 | next->pprev = pprev; | ||
521 | } | ||
522 | |||
523 | static inline void hlist_del(struct hlist_node *n) | ||
524 | { | ||
525 | __hlist_del(n); | ||
526 | n->next = LIST_POISON1; | ||
527 | n->pprev = LIST_POISON2; | ||
528 | } | ||
529 | |||
530 | /** | ||
531 | * hlist_del_rcu - deletes entry from hash list without re-initialization | ||
532 | * @n: the element to delete from the hash list. | ||
533 | * | ||
534 | * Note: list_unhashed() on entry does not return true after this, | ||
535 | * the entry is in an undefined state. It is useful for RCU based | ||
536 | * lockfree traversal. | ||
537 | * | ||
538 | * In particular, it means that we can not poison the forward | ||
539 | * pointers that may still be used for walking the hash list. | ||
540 | * | ||
541 | * The caller must take whatever precautions are necessary | ||
542 | * (such as holding appropriate locks) to avoid racing | ||
543 | * with another list-mutation primitive, such as hlist_add_head_rcu() | ||
544 | * or hlist_del_rcu(), running on this same list. | ||
545 | * However, it is perfectly legal to run concurrently with | ||
546 | * the _rcu list-traversal primitives, such as | ||
547 | * hlist_for_each_entry(). | ||
548 | */ | ||
549 | static inline void hlist_del_rcu(struct hlist_node *n) | ||
550 | { | ||
551 | __hlist_del(n); | ||
552 | n->pprev = LIST_POISON2; | ||
553 | } | ||
554 | |||
555 | static inline void hlist_del_init(struct hlist_node *n) | ||
556 | { | ||
557 | if (n->pprev) { | ||
558 | __hlist_del(n); | ||
559 | INIT_HLIST_NODE(n); | ||
560 | } | ||
561 | } | ||
562 | |||
563 | static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) | ||
564 | { | ||
565 | struct hlist_node *first = h->first; | ||
566 | n->next = first; | ||
567 | if (first) | ||
568 | first->pprev = &n->next; | ||
569 | h->first = n; | ||
570 | n->pprev = &h->first; | ||
571 | } | ||
572 | |||
573 | |||
574 | /** | ||
575 | * hlist_add_head_rcu - adds the specified element to the specified hlist, | ||
576 | * while permitting racing traversals. | ||
577 | * @n: the element to add to the hash list. | ||
578 | * @h: the list to add to. | ||
579 | * | ||
580 | * The caller must take whatever precautions are necessary | ||
581 | * (such as holding appropriate locks) to avoid racing | ||
582 | * with another list-mutation primitive, such as hlist_add_head_rcu() | ||
583 | * or hlist_del_rcu(), running on this same list. | ||
584 | * However, it is perfectly legal to run concurrently with | ||
585 | * the _rcu list-traversal primitives, such as | ||
586 | * hlist_for_each_rcu(), used to prevent memory-consistency | ||
587 | * problems on Alpha CPUs. Regardless of the type of CPU, the | ||
588 | * list-traversal primitive must be guarded by rcu_read_lock(). | ||
589 | */ | ||
590 | static inline void hlist_add_head_rcu(struct hlist_node *n, | ||
591 | struct hlist_head *h) | ||
592 | { | ||
593 | struct hlist_node *first = h->first; | ||
594 | n->next = first; | ||
595 | n->pprev = &h->first; | ||
596 | smp_wmb(); | ||
597 | if (first) | ||
598 | first->pprev = &n->next; | ||
599 | h->first = n; | ||
600 | } | ||
601 | |||
602 | /* next must be != NULL */ | ||
603 | static inline void hlist_add_before(struct hlist_node *n, | ||
604 | struct hlist_node *next) | ||
605 | { | ||
606 | n->pprev = next->pprev; | ||
607 | n->next = next; | ||
608 | next->pprev = &n->next; | ||
609 | *(n->pprev) = n; | ||
610 | } | ||
611 | |||
612 | static inline void hlist_add_after(struct hlist_node *n, | ||
613 | struct hlist_node *next) | ||
614 | { | ||
615 | next->next = n->next; | ||
616 | n->next = next; | ||
617 | next->pprev = &n->next; | ||
618 | |||
619 | if(next->next) | ||
620 | next->next->pprev = &next->next; | ||
621 | } | ||
622 | |||
623 | #define hlist_entry(ptr, type, member) container_of(ptr,type,member) | ||
624 | |||
625 | #define hlist_for_each(pos, head) \ | ||
626 | for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \ | ||
627 | pos = pos->next) | ||
628 | |||
629 | #define hlist_for_each_safe(pos, n, head) \ | ||
630 | for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ | ||
631 | pos = n) | ||
632 | |||
633 | #define hlist_for_each_rcu(pos, head) \ | ||
634 | for ((pos) = (head)->first; pos && ({ prefetch((pos)->next); 1; }); \ | ||
635 | (pos) = rcu_dereference((pos)->next)) | ||
636 | |||
637 | /** | ||
638 | * hlist_for_each_entry - iterate over list of given type | ||
639 | * @tpos: the type * to use as a loop counter. | ||
640 | * @pos: the &struct hlist_node to use as a loop counter. | ||
641 | * @head: the head for your list. | ||
642 | * @member: the name of the hlist_node within the struct. | ||
643 | */ | ||
644 | #define hlist_for_each_entry(tpos, pos, head, member) \ | ||
645 | for (pos = (head)->first; \ | ||
646 | pos && ({ prefetch(pos->next); 1;}) && \ | ||
647 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | ||
648 | pos = pos->next) | ||
649 | |||
650 | /** | ||
651 | * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point | ||
652 | * @tpos: the type * to use as a loop counter. | ||
653 | * @pos: the &struct hlist_node to use as a loop counter. | ||
654 | * @member: the name of the hlist_node within the struct. | ||
655 | */ | ||
656 | #define hlist_for_each_entry_continue(tpos, pos, member) \ | ||
657 | for (pos = (pos)->next; \ | ||
658 | pos && ({ prefetch(pos->next); 1;}) && \ | ||
659 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | ||
660 | pos = pos->next) | ||
661 | |||
662 | /** | ||
663 | * hlist_for_each_entry_from - iterate over a hlist continuing from existing point | ||
664 | * @tpos: the type * to use as a loop counter. | ||
665 | * @pos: the &struct hlist_node to use as a loop counter. | ||
666 | * @member: the name of the hlist_node within the struct. | ||
667 | */ | ||
668 | #define hlist_for_each_entry_from(tpos, pos, member) \ | ||
669 | for (; pos && ({ prefetch(pos->next); 1;}) && \ | ||
670 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | ||
671 | pos = pos->next) | ||
672 | |||
673 | /** | ||
674 | * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry | ||
675 | * @tpos: the type * to use as a loop counter. | ||
676 | * @pos: the &struct hlist_node to use as a loop counter. | ||
677 | * @n: another &struct hlist_node to use as temporary storage | ||
678 | * @head: the head for your list. | ||
679 | * @member: the name of the hlist_node within the struct. | ||
680 | */ | ||
681 | #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \ | ||
682 | for (pos = (head)->first; \ | ||
683 | pos && ({ n = pos->next; 1; }) && \ | ||
684 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | ||
685 | pos = n) | ||
686 | |||
687 | /** | ||
688 | * hlist_for_each_entry_rcu - iterate over rcu list of given type | ||
689 | * @pos: the type * to use as a loop counter. | ||
690 | * @pos: the &struct hlist_node to use as a loop counter. | ||
691 | * @head: the head for your list. | ||
692 | * @member: the name of the hlist_node within the struct. | ||
693 | * | ||
694 | * This list-traversal primitive may safely run concurrently with | ||
695 | * the _rcu list-mutation primitives such as hlist_add_rcu() | ||
696 | * as long as the traversal is guarded by rcu_read_lock(). | ||
697 | */ | ||
698 | #define hlist_for_each_entry_rcu(tpos, pos, head, member) \ | ||
699 | for (pos = (head)->first; \ | ||
700 | pos && ({ prefetch(pos->next); 1;}) && \ | ||
701 | ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \ | ||
702 | pos = rcu_dereference(pos->next)) | ||
703 | |||
704 | #else | ||
705 | #warning "don't include kernel headers in userspace" | ||
706 | #endif /* __KERNEL__ */ | ||
707 | #endif | ||