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1 #ifndef _LINUX_LIST_H
2 #define _LINUX_LIST_H
3 
4 #include <linux/types.h>
5 #include <linux/stddef.h>
6 #include <linux/poison.h>
7 #include <linux/const.h>
8 
9 /*
10  * Simple doubly linked list implementation.
11  *
12  * Some of the internal functions ("__xxx") are useful when
13  * manipulating whole lists rather than single entries, as
14  * sometimes we already know the next/prev entries and we can
15  * generate better code by using them directly rather than
16  * using the generic single-entry routines.
17  */
18 
19 #define LIST_HEAD_INIT(name) { &(name), &(name) }
20 
21 #define LIST_HEAD(name) \
22 	struct list_head name = LIST_HEAD_INIT(name)
23 
INIT_LIST_HEAD(struct list_head * list)24 static inline void INIT_LIST_HEAD(struct list_head *list)
25 {
26 	list->next = list;
27 	list->prev = list;
28 }
29 
30 /*
31  * Insert a new entry between two known consecutive entries.
32  *
33  * This is only for internal list manipulation where we know
34  * the prev/next entries already!
35  */
36 #ifndef CONFIG_DEBUG_LIST
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)37 static inline void __list_add(struct list_head *new,
38 			      struct list_head *prev,
39 			      struct list_head *next)
40 {
41 	next->prev = new;
42 	new->next = next;
43 	new->prev = prev;
44 	prev->next = new;
45 }
46 #else
47 extern void __list_add(struct list_head *new,
48 			      struct list_head *prev,
49 			      struct list_head *next);
50 #endif
51 
52 /**
53  * list_add - add a new entry
54  * @new: new entry to be added
55  * @head: list head to add it after
56  *
57  * Insert a new entry after the specified head.
58  * This is good for implementing stacks.
59  */
list_add(struct list_head * new,struct list_head * head)60 static inline void list_add(struct list_head *new, struct list_head *head)
61 {
62 	__list_add(new, head, head->next);
63 }
64 
65 
66 /**
67  * list_add_tail - add a new entry
68  * @new: new entry to be added
69  * @head: list head to add it before
70  *
71  * Insert a new entry before the specified head.
72  * This is useful for implementing queues.
73  */
list_add_tail(struct list_head * new,struct list_head * head)74 static inline void list_add_tail(struct list_head *new, struct list_head *head)
75 {
76 	__list_add(new, head->prev, head);
77 }
78 
79 /*
80  * Delete a list entry by making the prev/next entries
81  * point to each other.
82  *
83  * This is only for internal list manipulation where we know
84  * the prev/next entries already!
85  */
__list_del(struct list_head * prev,struct list_head * next)86 static inline void __list_del(struct list_head * prev, struct list_head * next)
87 {
88 	next->prev = prev;
89 	prev->next = next;
90 }
91 
92 /**
93  * list_del - deletes entry from list.
94  * @entry: the element to delete from the list.
95  * Note: list_empty() on entry does not return true after this, the entry is
96  * in an undefined state.
97  */
98 #ifndef CONFIG_DEBUG_LIST
__list_del_entry(struct list_head * entry)99 static inline void __list_del_entry(struct list_head *entry)
100 {
101 	__list_del(entry->prev, entry->next);
102 }
103 
list_del(struct list_head * entry)104 static inline void list_del(struct list_head *entry)
105 {
106 	__list_del(entry->prev, entry->next);
107 	entry->next = LIST_POISON1;
108 	entry->prev = LIST_POISON2;
109 }
110 #else
111 extern void __list_del_entry(struct list_head *entry);
112 extern void list_del(struct list_head *entry);
113 #endif
114 
115 /**
116  * list_replace - replace old entry by new one
117  * @old : the element to be replaced
118  * @new : the new element to insert
119  *
120  * If @old was empty, it will be overwritten.
121  */
list_replace(struct list_head * old,struct list_head * new)122 static inline void list_replace(struct list_head *old,
123 				struct list_head *new)
124 {
125 	new->next = old->next;
126 	new->next->prev = new;
127 	new->prev = old->prev;
128 	new->prev->next = new;
129 }
130 
list_replace_init(struct list_head * old,struct list_head * new)131 static inline void list_replace_init(struct list_head *old,
132 					struct list_head *new)
133 {
134 	list_replace(old, new);
135 	INIT_LIST_HEAD(old);
136 }
137 
138 /**
139  * list_del_init - deletes entry from list and reinitialize it.
140  * @entry: the element to delete from the list.
141  */
list_del_init(struct list_head * entry)142 static inline void list_del_init(struct list_head *entry)
143 {
144 	__list_del_entry(entry);
145 	INIT_LIST_HEAD(entry);
146 }
147 
148 /**
149  * list_move - delete from one list and add as another's head
150  * @list: the entry to move
151  * @head: the head that will precede our entry
152  */
list_move(struct list_head * list,struct list_head * head)153 static inline void list_move(struct list_head *list, struct list_head *head)
154 {
155 	__list_del_entry(list);
156 	list_add(list, head);
157 }
158 
159 /**
160  * list_move_tail - delete from one list and add as another's tail
161  * @list: the entry to move
162  * @head: the head that will follow our entry
163  */
list_move_tail(struct list_head * list,struct list_head * head)164 static inline void list_move_tail(struct list_head *list,
165 				  struct list_head *head)
166 {
167 	__list_del_entry(list);
168 	list_add_tail(list, head);
169 }
170 
171 /**
172  * list_is_last - tests whether @list is the last entry in list @head
173  * @list: the entry to test
174  * @head: the head of the list
175  */
list_is_last(const struct list_head * list,const struct list_head * head)176 static inline int list_is_last(const struct list_head *list,
177 				const struct list_head *head)
178 {
179 	return list->next == head;
180 }
181 
182 /**
183  * list_empty - tests whether a list is empty
184  * @head: the list to test.
185  */
list_empty(const struct list_head * head)186 static inline int list_empty(const struct list_head *head)
187 {
188 	return head->next == head;
189 }
190 
191 /**
192  * list_empty_careful - tests whether a list is empty and not being modified
193  * @head: the list to test
194  *
195  * Description:
196  * tests whether a list is empty _and_ checks that no other CPU might be
197  * in the process of modifying either member (next or prev)
198  *
199  * NOTE: using list_empty_careful() without synchronization
200  * can only be safe if the only activity that can happen
201  * to the list entry is list_del_init(). Eg. it cannot be used
202  * if another CPU could re-list_add() it.
203  */
list_empty_careful(const struct list_head * head)204 static inline int list_empty_careful(const struct list_head *head)
205 {
206 	struct list_head *next = head->next;
207 	return (next == head) && (next == head->prev);
208 }
209 
210 /**
211  * list_rotate_left - rotate the list to the left
212  * @head: the head of the list
213  */
list_rotate_left(struct list_head * head)214 static inline void list_rotate_left(struct list_head *head)
215 {
216 	struct list_head *first;
217 
218 	if (!list_empty(head)) {
219 		first = head->next;
220 		list_move_tail(first, head);
221 	}
222 }
223 
224 /**
225  * list_is_singular - tests whether a list has just one entry.
226  * @head: the list to test.
227  */
list_is_singular(const struct list_head * head)228 static inline int list_is_singular(const struct list_head *head)
229 {
230 	return !list_empty(head) && (head->next == head->prev);
231 }
232 
__list_cut_position(struct list_head * list,struct list_head * head,struct list_head * entry)233 static inline void __list_cut_position(struct list_head *list,
234 		struct list_head *head, struct list_head *entry)
235 {
236 	struct list_head *new_first = entry->next;
237 	list->next = head->next;
238 	list->next->prev = list;
239 	list->prev = entry;
240 	entry->next = list;
241 	head->next = new_first;
242 	new_first->prev = head;
243 }
244 
245 /**
246  * list_cut_position - cut a list into two
247  * @list: a new list to add all removed entries
248  * @head: a list with entries
249  * @entry: an entry within head, could be the head itself
250  *	and if so we won't cut the list
251  *
252  * This helper moves the initial part of @head, up to and
253  * including @entry, from @head to @list. You should
254  * pass on @entry an element you know is on @head. @list
255  * should be an empty list or a list you do not care about
256  * losing its data.
257  *
258  */
list_cut_position(struct list_head * list,struct list_head * head,struct list_head * entry)259 static inline void list_cut_position(struct list_head *list,
260 		struct list_head *head, struct list_head *entry)
261 {
262 	if (list_empty(head))
263 		return;
264 	if (list_is_singular(head) &&
265 		(head->next != entry && head != entry))
266 		return;
267 	if (entry == head)
268 		INIT_LIST_HEAD(list);
269 	else
270 		__list_cut_position(list, head, entry);
271 }
272 
__list_splice(const struct list_head * list,struct list_head * prev,struct list_head * next)273 static inline void __list_splice(const struct list_head *list,
274 				 struct list_head *prev,
275 				 struct list_head *next)
276 {
277 	struct list_head *first = list->next;
278 	struct list_head *last = list->prev;
279 
280 	first->prev = prev;
281 	prev->next = first;
282 
283 	last->next = next;
284 	next->prev = last;
285 }
286 
287 /**
288  * list_splice - join two lists, this is designed for stacks
289  * @list: the new list to add.
290  * @head: the place to add it in the first list.
291  */
list_splice(const struct list_head * list,struct list_head * head)292 static inline void list_splice(const struct list_head *list,
293 				struct list_head *head)
294 {
295 	if (!list_empty(list))
296 		__list_splice(list, head, head->next);
297 }
298 
299 /**
300  * list_splice_tail - join two lists, each list being a queue
301  * @list: the new list to add.
302  * @head: the place to add it in the first list.
303  */
list_splice_tail(struct list_head * list,struct list_head * head)304 static inline void list_splice_tail(struct list_head *list,
305 				struct list_head *head)
306 {
307 	if (!list_empty(list))
308 		__list_splice(list, head->prev, head);
309 }
310 
311 /**
312  * list_splice_init - join two lists and reinitialise the emptied list.
313  * @list: the new list to add.
314  * @head: the place to add it in the first list.
315  *
316  * The list at @list is reinitialised
317  */
list_splice_init(struct list_head * list,struct list_head * head)318 static inline void list_splice_init(struct list_head *list,
319 				    struct list_head *head)
320 {
321 	if (!list_empty(list)) {
322 		__list_splice(list, head, head->next);
323 		INIT_LIST_HEAD(list);
324 	}
325 }
326 
327 /**
328  * list_splice_tail_init - join two lists and reinitialise the emptied list
329  * @list: the new list to add.
330  * @head: the place to add it in the first list.
331  *
332  * Each of the lists is a queue.
333  * The list at @list is reinitialised
334  */
list_splice_tail_init(struct list_head * list,struct list_head * head)335 static inline void list_splice_tail_init(struct list_head *list,
336 					 struct list_head *head)
337 {
338 	if (!list_empty(list)) {
339 		__list_splice(list, head->prev, head);
340 		INIT_LIST_HEAD(list);
341 	}
342 }
343 
344 /**
345  * list_entry - get the struct for this entry
346  * @ptr:	the &struct list_head pointer.
347  * @type:	the type of the struct this is embedded in.
348  * @member:	the name of the list_struct within the struct.
349  */
350 #define list_entry(ptr, type, member) \
351 	container_of(ptr, type, member)
352 
353 /**
354  * list_first_entry - get the first element from a list
355  * @ptr:	the list head to take the element from.
356  * @type:	the type of the struct this is embedded in.
357  * @member:	the name of the list_struct within the struct.
358  *
359  * Note, that list is expected to be not empty.
360  */
361 #define list_first_entry(ptr, type, member) \
362 	list_entry((ptr)->next, type, member)
363 
364 /**
365  * list_for_each	-	iterate over a list
366  * @pos:	the &struct list_head to use as a loop cursor.
367  * @head:	the head for your list.
368  */
369 #define list_for_each(pos, head) \
370 	for (pos = (head)->next; pos != (head); pos = pos->next)
371 
372 /**
373  * __list_for_each	-	iterate over a list
374  * @pos:	the &struct list_head to use as a loop cursor.
375  * @head:	the head for your list.
376  *
377  * This variant doesn't differ from list_for_each() any more.
378  * We don't do prefetching in either case.
379  */
380 #define __list_for_each(pos, head) \
381 	for (pos = (head)->next; pos != (head); pos = pos->next)
382 
383 /**
384  * list_for_each_prev	-	iterate over a list backwards
385  * @pos:	the &struct list_head to use as a loop cursor.
386  * @head:	the head for your list.
387  */
388 #define list_for_each_prev(pos, head) \
389 	for (pos = (head)->prev; pos != (head); pos = pos->prev)
390 
391 /**
392  * list_for_each_safe - iterate over a list safe against removal of list entry
393  * @pos:	the &struct list_head to use as a loop cursor.
394  * @n:		another &struct list_head to use as temporary storage
395  * @head:	the head for your list.
396  */
397 #define list_for_each_safe(pos, n, head) \
398 	for (pos = (head)->next, n = pos->next; pos != (head); \
399 		pos = n, n = pos->next)
400 
401 /**
402  * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
403  * @pos:	the &struct list_head to use as a loop cursor.
404  * @n:		another &struct list_head to use as temporary storage
405  * @head:	the head for your list.
406  */
407 #define list_for_each_prev_safe(pos, n, head) \
408 	for (pos = (head)->prev, n = pos->prev; \
409 	     pos != (head); \
410 	     pos = n, n = pos->prev)
411 
412 /**
413  * list_for_each_entry	-	iterate over list of given type
414  * @pos:	the type * to use as a loop cursor.
415  * @head:	the head for your list.
416  * @member:	the name of the list_struct within the struct.
417  */
418 #define list_for_each_entry(pos, head, member)				\
419 	for (pos = list_entry((head)->next, typeof(*pos), member);	\
420 	     &pos->member != (head); 	\
421 	     pos = list_entry(pos->member.next, typeof(*pos), member))
422 
423 /**
424  * list_for_each_entry_reverse - iterate backwards over list of given type.
425  * @pos:	the type * to use as a loop cursor.
426  * @head:	the head for your list.
427  * @member:	the name of the list_struct within the struct.
428  */
429 #define list_for_each_entry_reverse(pos, head, member)			\
430 	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
431 	     &pos->member != (head); 	\
432 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
433 
434 /**
435  * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
436  * @pos:	the type * to use as a start point
437  * @head:	the head of the list
438  * @member:	the name of the list_struct within the struct.
439  *
440  * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
441  */
442 #define list_prepare_entry(pos, head, member) \
443 	((pos) ? : list_entry(head, typeof(*pos), member))
444 
445 /**
446  * list_for_each_entry_continue - continue iteration over list of given type
447  * @pos:	the type * to use as a loop cursor.
448  * @head:	the head for your list.
449  * @member:	the name of the list_struct within the struct.
450  *
451  * Continue to iterate over list of given type, continuing after
452  * the current position.
453  */
454 #define list_for_each_entry_continue(pos, head, member) 		\
455 	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
456 	     &pos->member != (head);	\
457 	     pos = list_entry(pos->member.next, typeof(*pos), member))
458 
459 /**
460  * list_for_each_entry_continue_reverse - iterate backwards from the given point
461  * @pos:	the type * to use as a loop cursor.
462  * @head:	the head for your list.
463  * @member:	the name of the list_struct within the struct.
464  *
465  * Start to iterate over list of given type backwards, continuing after
466  * the current position.
467  */
468 #define list_for_each_entry_continue_reverse(pos, head, member)		\
469 	for (pos = list_entry(pos->member.prev, typeof(*pos), member);	\
470 	     &pos->member != (head);	\
471 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
472 
473 /**
474  * list_for_each_entry_from - iterate over list of given type from the current point
475  * @pos:	the type * to use as a loop cursor.
476  * @head:	the head for your list.
477  * @member:	the name of the list_struct within the struct.
478  *
479  * Iterate over list of given type, continuing from current position.
480  */
481 #define list_for_each_entry_from(pos, head, member) 			\
482 	for (; &pos->member != (head);	\
483 	     pos = list_entry(pos->member.next, typeof(*pos), member))
484 
485 /**
486  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
487  * @pos:	the type * to use as a loop cursor.
488  * @n:		another type * to use as temporary storage
489  * @head:	the head for your list.
490  * @member:	the name of the list_struct within the struct.
491  */
492 #define list_for_each_entry_safe(pos, n, head, member)			\
493 	for (pos = list_entry((head)->next, typeof(*pos), member),	\
494 		n = list_entry(pos->member.next, typeof(*pos), member);	\
495 	     &pos->member != (head); 					\
496 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
497 
498 /**
499  * list_for_each_entry_safe_continue - continue list iteration safe against removal
500  * @pos:	the type * to use as a loop cursor.
501  * @n:		another type * to use as temporary storage
502  * @head:	the head for your list.
503  * @member:	the name of the list_struct within the struct.
504  *
505  * Iterate over list of given type, continuing after current point,
506  * safe against removal of list entry.
507  */
508 #define list_for_each_entry_safe_continue(pos, n, head, member) 		\
509 	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
510 		n = list_entry(pos->member.next, typeof(*pos), member);		\
511 	     &pos->member != (head);						\
512 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
513 
514 /**
515  * list_for_each_entry_safe_from - iterate over list from current point safe against removal
516  * @pos:	the type * to use as a loop cursor.
517  * @n:		another type * to use as temporary storage
518  * @head:	the head for your list.
519  * @member:	the name of the list_struct within the struct.
520  *
521  * Iterate over list of given type from current point, safe against
522  * removal of list entry.
523  */
524 #define list_for_each_entry_safe_from(pos, n, head, member) 			\
525 	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
526 	     &pos->member != (head);						\
527 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
528 
529 /**
530  * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
531  * @pos:	the type * to use as a loop cursor.
532  * @n:		another type * to use as temporary storage
533  * @head:	the head for your list.
534  * @member:	the name of the list_struct within the struct.
535  *
536  * Iterate backwards over list of given type, safe against removal
537  * of list entry.
538  */
539 #define list_for_each_entry_safe_reverse(pos, n, head, member)		\
540 	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
541 		n = list_entry(pos->member.prev, typeof(*pos), member);	\
542 	     &pos->member != (head); 					\
543 	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
544 
545 /**
546  * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
547  * @pos:	the loop cursor used in the list_for_each_entry_safe loop
548  * @n:		temporary storage used in list_for_each_entry_safe
549  * @member:	the name of the list_struct within the struct.
550  *
551  * list_safe_reset_next is not safe to use in general if the list may be
552  * modified concurrently (eg. the lock is dropped in the loop body). An
553  * exception to this is if the cursor element (pos) is pinned in the list,
554  * and list_safe_reset_next is called after re-taking the lock and before
555  * completing the current iteration of the loop body.
556  */
557 #define list_safe_reset_next(pos, n, member)				\
558 	n = list_entry(pos->member.next, typeof(*pos), member)
559 
560 /*
561  * Double linked lists with a single pointer list head.
562  * Mostly useful for hash tables where the two pointer list head is
563  * too wasteful.
564  * You lose the ability to access the tail in O(1).
565  */
566 
567 #define HLIST_HEAD_INIT { .first = NULL }
568 #define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
569 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
INIT_HLIST_NODE(struct hlist_node * h)570 static inline void INIT_HLIST_NODE(struct hlist_node *h)
571 {
572 	h->next = NULL;
573 	h->pprev = NULL;
574 }
575 
hlist_unhashed(const struct hlist_node * h)576 static inline int hlist_unhashed(const struct hlist_node *h)
577 {
578 	return !h->pprev;
579 }
580 
hlist_empty(const struct hlist_head * h)581 static inline int hlist_empty(const struct hlist_head *h)
582 {
583 	return !h->first;
584 }
585 
__hlist_del(struct hlist_node * n)586 static inline void __hlist_del(struct hlist_node *n)
587 {
588 	struct hlist_node *next = n->next;
589 	struct hlist_node **pprev = n->pprev;
590 	*pprev = next;
591 	if (next)
592 		next->pprev = pprev;
593 }
594 
hlist_del(struct hlist_node * n)595 static inline void hlist_del(struct hlist_node *n)
596 {
597 	__hlist_del(n);
598 	n->next = LIST_POISON1;
599 	n->pprev = LIST_POISON2;
600 }
601 
hlist_del_init(struct hlist_node * n)602 static inline void hlist_del_init(struct hlist_node *n)
603 {
604 	if (!hlist_unhashed(n)) {
605 		__hlist_del(n);
606 		INIT_HLIST_NODE(n);
607 	}
608 }
609 
hlist_add_head(struct hlist_node * n,struct hlist_head * h)610 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
611 {
612 	struct hlist_node *first = h->first;
613 	n->next = first;
614 	if (first)
615 		first->pprev = &n->next;
616 	h->first = n;
617 	n->pprev = &h->first;
618 }
619 
620 /* next must be != NULL */
hlist_add_before(struct hlist_node * n,struct hlist_node * next)621 static inline void hlist_add_before(struct hlist_node *n,
622 					struct hlist_node *next)
623 {
624 	n->pprev = next->pprev;
625 	n->next = next;
626 	next->pprev = &n->next;
627 	*(n->pprev) = n;
628 }
629 
hlist_add_after(struct hlist_node * n,struct hlist_node * next)630 static inline void hlist_add_after(struct hlist_node *n,
631 					struct hlist_node *next)
632 {
633 	next->next = n->next;
634 	n->next = next;
635 	next->pprev = &n->next;
636 
637 	if(next->next)
638 		next->next->pprev  = &next->next;
639 }
640 
641 /* after that we'll appear to be on some hlist and hlist_del will work */
hlist_add_fake(struct hlist_node * n)642 static inline void hlist_add_fake(struct hlist_node *n)
643 {
644 	n->pprev = &n->next;
645 }
646 
647 /*
648  * Move a list from one list head to another. Fixup the pprev
649  * reference of the first entry if it exists.
650  */
hlist_move_list(struct hlist_head * old,struct hlist_head * new)651 static inline void hlist_move_list(struct hlist_head *old,
652 				   struct hlist_head *new)
653 {
654 	new->first = old->first;
655 	if (new->first)
656 		new->first->pprev = &new->first;
657 	old->first = NULL;
658 }
659 
660 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
661 
662 #define hlist_for_each(pos, head) \
663 	for (pos = (head)->first; pos ; pos = pos->next)
664 
665 #define hlist_for_each_safe(pos, n, head) \
666 	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
667 	     pos = n)
668 
669 /**
670  * hlist_for_each_entry	- iterate over list of given type
671  * @tpos:	the type * to use as a loop cursor.
672  * @pos:	the &struct hlist_node to use as a loop cursor.
673  * @head:	the head for your list.
674  * @member:	the name of the hlist_node within the struct.
675  */
676 #define hlist_for_each_entry(tpos, pos, head, member)			 \
677 	for (pos = (head)->first;					 \
678 	     pos &&							 \
679 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
680 	     pos = pos->next)
681 
682 /**
683  * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
684  * @tpos:	the type * to use as a loop cursor.
685  * @pos:	the &struct hlist_node to use as a loop cursor.
686  * @member:	the name of the hlist_node within the struct.
687  */
688 #define hlist_for_each_entry_continue(tpos, pos, member)		 \
689 	for (pos = (pos)->next;						 \
690 	     pos &&							 \
691 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
692 	     pos = pos->next)
693 
694 /**
695  * hlist_for_each_entry_from - iterate over a hlist continuing from current point
696  * @tpos:	the type * to use as a loop cursor.
697  * @pos:	the &struct hlist_node to use as a loop cursor.
698  * @member:	the name of the hlist_node within the struct.
699  */
700 #define hlist_for_each_entry_from(tpos, pos, member)			 \
701 	for (; pos &&							 \
702 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
703 	     pos = pos->next)
704 
705 /**
706  * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
707  * @tpos:	the type * to use as a loop cursor.
708  * @pos:	the &struct hlist_node to use as a loop cursor.
709  * @n:		another &struct hlist_node to use as temporary storage
710  * @head:	the head for your list.
711  * @member:	the name of the hlist_node within the struct.
712  */
713 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
714 	for (pos = (head)->first;					 \
715 	     pos && ({ n = pos->next; 1; }) && 				 \
716 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
717 	     pos = n)
718 
719 #endif
720