1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __TOOLS_LINUX_LIST_H
3 #define __TOOLS_LINUX_LIST_H
4 
5 #include <linux/types.h>
6 #include <linux/poison.h>
7 #include <linux/kernel.h>
8 #include <linux/compiler.h>
9 
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 
20 #define LIST_HEAD_INIT(name) { &(name), &(name) }
21 
22 #define LIST_HEAD(name) \
23 	struct list_head name = LIST_HEAD_INIT(name)
24 
INIT_LIST_HEAD(struct list_head * list)25 static inline void INIT_LIST_HEAD(struct list_head *list)
26 {
27 	list->next = list;
28 	list->prev = list;
29 }
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  */
37 #ifndef CONFIG_DEBUG_LIST
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)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 }
47 #else
48 extern void __list_add(struct list_head *new,
49 			      struct list_head *prev,
50 			      struct list_head *next);
51 #endif
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  */
list_add(struct list_head * new,struct list_head * head)61 static inline void list_add(struct list_head *new, struct list_head *head)
62 {
63 	__list_add(new, head, head->next);
64 }
65 
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  */
list_add_tail(struct list_head * new,struct list_head * head)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 
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  */
__list_del(struct list_head * prev,struct list_head * next)87 static inline void __list_del(struct list_head * prev, struct list_head * next)
88 {
89 	next->prev = prev;
90 	WRITE_ONCE(prev->next, next);
91 }
92 
93 /**
94  * list_del - deletes entry from list.
95  * @entry: the element to delete from the list.
96  * Note: list_empty() on entry does not return true after this, the entry is
97  * in an undefined state.
98  */
99 #ifndef CONFIG_DEBUG_LIST
__list_del_entry(struct list_head * entry)100 static inline void __list_del_entry(struct list_head *entry)
101 {
102 	__list_del(entry->prev, entry->next);
103 }
104 
list_del(struct list_head * entry)105 static inline void list_del(struct list_head *entry)
106 {
107 	__list_del(entry->prev, entry->next);
108 	entry->next = LIST_POISON1;
109 	entry->prev = LIST_POISON2;
110 }
111 #else
112 extern void __list_del_entry(struct list_head *entry);
113 extern void list_del(struct list_head *entry);
114 #endif
115 
116 /**
117  * list_replace - replace old entry by new one
118  * @old : the element to be replaced
119  * @new : the new element to insert
120  *
121  * If @old was empty, it will be overwritten.
122  */
list_replace(struct list_head * old,struct list_head * new)123 static inline void list_replace(struct list_head *old,
124 				struct list_head *new)
125 {
126 	new->next = old->next;
127 	new->next->prev = new;
128 	new->prev = old->prev;
129 	new->prev->next = new;
130 }
131 
list_replace_init(struct list_head * old,struct list_head * new)132 static inline void list_replace_init(struct list_head *old,
133 					struct list_head *new)
134 {
135 	list_replace(old, new);
136 	INIT_LIST_HEAD(old);
137 }
138 
139 /**
140  * list_del_init - deletes entry from list and reinitialize it.
141  * @entry: the element to delete from the list.
142  */
list_del_init(struct list_head * entry)143 static inline void list_del_init(struct list_head *entry)
144 {
145 	__list_del_entry(entry);
146 	INIT_LIST_HEAD(entry);
147 }
148 
149 /**
150  * list_move - delete from one list and add as another's head
151  * @list: the entry to move
152  * @head: the head that will precede our entry
153  */
list_move(struct list_head * list,struct list_head * head)154 static inline void list_move(struct list_head *list, struct list_head *head)
155 {
156 	__list_del_entry(list);
157 	list_add(list, head);
158 }
159 
160 /**
161  * list_move_tail - delete from one list and add as another's tail
162  * @list: the entry to move
163  * @head: the head that will follow our entry
164  */
list_move_tail(struct list_head * list,struct list_head * head)165 static inline void list_move_tail(struct list_head *list,
166 				  struct list_head *head)
167 {
168 	__list_del_entry(list);
169 	list_add_tail(list, head);
170 }
171 
172 /**
173  * list_is_last - tests whether @list is the last entry in list @head
174  * @list: the entry to test
175  * @head: the head of the list
176  */
list_is_last(const struct list_head * list,const struct list_head * head)177 static inline int list_is_last(const struct list_head *list,
178 				const struct list_head *head)
179 {
180 	return list->next == head;
181 }
182 
183 /**
184  * list_empty - tests whether a list is empty
185  * @head: the list to test.
186  */
list_empty(const struct list_head * head)187 static inline int list_empty(const struct list_head *head)
188 {
189 	return head->next == head;
190 }
191 
192 /**
193  * list_empty_careful - tests whether a list is empty and not being modified
194  * @head: the list to test
195  *
196  * Description:
197  * tests whether a list is empty _and_ checks that no other CPU might be
198  * in the process of modifying either member (next or prev)
199  *
200  * NOTE: using list_empty_careful() without synchronization
201  * can only be safe if the only activity that can happen
202  * to the list entry is list_del_init(). Eg. it cannot be used
203  * if another CPU could re-list_add() it.
204  */
list_empty_careful(const struct list_head * head)205 static inline int list_empty_careful(const struct list_head *head)
206 {
207 	struct list_head *next = head->next;
208 	return (next == head) && (next == head->prev);
209 }
210 
211 /**
212  * list_rotate_left - rotate the list to the left
213  * @head: the head of the list
214  */
list_rotate_left(struct list_head * head)215 static inline void list_rotate_left(struct list_head *head)
216 {
217 	struct list_head *first;
218 
219 	if (!list_empty(head)) {
220 		first = head->next;
221 		list_move_tail(first, head);
222 	}
223 }
224 
225 /**
226  * list_is_singular - tests whether a list has just one entry.
227  * @head: the list to test.
228  */
list_is_singular(const struct list_head * head)229 static inline int list_is_singular(const struct list_head *head)
230 {
231 	return !list_empty(head) && (head->next == head->prev);
232 }
233 
__list_cut_position(struct list_head * list,struct list_head * head,struct list_head * entry)234 static inline void __list_cut_position(struct list_head *list,
235 		struct list_head *head, struct list_head *entry)
236 {
237 	struct list_head *new_first = entry->next;
238 	list->next = head->next;
239 	list->next->prev = list;
240 	list->prev = entry;
241 	entry->next = list;
242 	head->next = new_first;
243 	new_first->prev = head;
244 }
245 
246 /**
247  * list_cut_position - cut a list into two
248  * @list: a new list to add all removed entries
249  * @head: a list with entries
250  * @entry: an entry within head, could be the head itself
251  *	and if so we won't cut the list
252  *
253  * This helper moves the initial part of @head, up to and
254  * including @entry, from @head to @list. You should
255  * pass on @entry an element you know is on @head. @list
256  * should be an empty list or a list you do not care about
257  * losing its data.
258  *
259  */
list_cut_position(struct list_head * list,struct list_head * head,struct list_head * entry)260 static inline void list_cut_position(struct list_head *list,
261 		struct list_head *head, struct list_head *entry)
262 {
263 	if (list_empty(head))
264 		return;
265 	if (list_is_singular(head) &&
266 		(head->next != entry && head != entry))
267 		return;
268 	if (entry == head)
269 		INIT_LIST_HEAD(list);
270 	else
271 		__list_cut_position(list, head, entry);
272 }
273 
__list_splice(const struct list_head * list,struct list_head * prev,struct list_head * next)274 static inline void __list_splice(const struct list_head *list,
275 				 struct list_head *prev,
276 				 struct list_head *next)
277 {
278 	struct list_head *first = list->next;
279 	struct list_head *last = list->prev;
280 
281 	first->prev = prev;
282 	prev->next = first;
283 
284 	last->next = next;
285 	next->prev = last;
286 }
287 
288 /**
289  * list_splice - join two lists, this is designed for stacks
290  * @list: the new list to add.
291  * @head: the place to add it in the first list.
292  */
list_splice(const struct list_head * list,struct list_head * head)293 static inline void list_splice(const struct list_head *list,
294 				struct list_head *head)
295 {
296 	if (!list_empty(list))
297 		__list_splice(list, head, head->next);
298 }
299 
300 /**
301  * list_splice_tail - join two lists, each list being a queue
302  * @list: the new list to add.
303  * @head: the place to add it in the first list.
304  */
list_splice_tail(struct list_head * list,struct list_head * head)305 static inline void list_splice_tail(struct list_head *list,
306 				struct list_head *head)
307 {
308 	if (!list_empty(list))
309 		__list_splice(list, head->prev, head);
310 }
311 
312 /**
313  * list_splice_init - join two lists and reinitialise the emptied list.
314  * @list: the new list to add.
315  * @head: the place to add it in the first list.
316  *
317  * The list at @list is reinitialised
318  */
list_splice_init(struct list_head * list,struct list_head * head)319 static inline void list_splice_init(struct list_head *list,
320 				    struct list_head *head)
321 {
322 	if (!list_empty(list)) {
323 		__list_splice(list, head, head->next);
324 		INIT_LIST_HEAD(list);
325 	}
326 }
327 
328 /**
329  * list_splice_tail_init - join two lists and reinitialise the emptied list
330  * @list: the new list to add.
331  * @head: the place to add it in the first list.
332  *
333  * Each of the lists is a queue.
334  * The list at @list is reinitialised
335  */
list_splice_tail_init(struct list_head * list,struct list_head * head)336 static inline void list_splice_tail_init(struct list_head *list,
337 					 struct list_head *head)
338 {
339 	if (!list_empty(list)) {
340 		__list_splice(list, head->prev, head);
341 		INIT_LIST_HEAD(list);
342 	}
343 }
344 
345 /**
346  * list_entry - get the struct for this entry
347  * @ptr:	the &struct list_head pointer.
348  * @type:	the type of the struct this is embedded in.
349  * @member:	the name of the list_head within the struct.
350  */
351 #define list_entry(ptr, type, member) \
352 	container_of(ptr, type, member)
353 
354 /**
355  * list_first_entry - get the first element from a list
356  * @ptr:	the list head to take the element from.
357  * @type:	the type of the struct this is embedded in.
358  * @member:	the name of the list_head within the struct.
359  *
360  * Note, that list is expected to be not empty.
361  */
362 #define list_first_entry(ptr, type, member) \
363 	list_entry((ptr)->next, type, member)
364 
365 /**
366  * list_last_entry - get the last element from a list
367  * @ptr:	the list head to take the element from.
368  * @type:	the type of the struct this is embedded in.
369  * @member:	the name of the list_head within the struct.
370  *
371  * Note, that list is expected to be not empty.
372  */
373 #define list_last_entry(ptr, type, member) \
374 	list_entry((ptr)->prev, type, member)
375 
376 /**
377  * list_first_entry_or_null - get the first element from a list
378  * @ptr:	the list head to take the element from.
379  * @type:	the type of the struct this is embedded in.
380  * @member:	the name of the list_head within the struct.
381  *
382  * Note that if the list is empty, it returns NULL.
383  */
384 #define list_first_entry_or_null(ptr, type, member) \
385 	(!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
386 
387 /**
388  * list_last_entry_or_null - get the last element from a list
389  * @ptr:       the list head to take the element from.
390  * @type:      the type of the struct this is embedded in.
391  * @member:    the name of the list_head within the struct.
392  *
393  * Note that if the list is empty, it returns NULL.
394  */
395 #define list_last_entry_or_null(ptr, type, member) \
396 	(!list_empty(ptr) ? list_last_entry(ptr, type, member) : NULL)
397 
398 /**
399  * list_next_entry - get the next element in list
400  * @pos:	the type * to cursor
401  * @member:	the name of the list_head within the struct.
402  */
403 #define list_next_entry(pos, member) \
404 	list_entry((pos)->member.next, typeof(*(pos)), member)
405 
406 /**
407  * list_prev_entry - get the prev element in list
408  * @pos:	the type * to cursor
409  * @member:	the name of the list_head within the struct.
410  */
411 #define list_prev_entry(pos, member) \
412 	list_entry((pos)->member.prev, typeof(*(pos)), member)
413 
414 /**
415  * list_for_each	-	iterate over a list
416  * @pos:	the &struct list_head to use as a loop cursor.
417  * @head:	the head for your list.
418  */
419 #define list_for_each(pos, head) \
420 	for (pos = (head)->next; pos != (head); pos = pos->next)
421 
422 /**
423  * list_for_each_prev	-	iterate over a list backwards
424  * @pos:	the &struct list_head to use as a loop cursor.
425  * @head:	the head for your list.
426  */
427 #define list_for_each_prev(pos, head) \
428 	for (pos = (head)->prev; pos != (head); pos = pos->prev)
429 
430 /**
431  * list_for_each_safe - iterate over a list safe against removal of list entry
432  * @pos:	the &struct list_head to use as a loop cursor.
433  * @n:		another &struct list_head to use as temporary storage
434  * @head:	the head for your list.
435  */
436 #define list_for_each_safe(pos, n, head) \
437 	for (pos = (head)->next, n = pos->next; pos != (head); \
438 		pos = n, n = pos->next)
439 
440 /**
441  * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
442  * @pos:	the &struct list_head to use as a loop cursor.
443  * @n:		another &struct list_head to use as temporary storage
444  * @head:	the head for your list.
445  */
446 #define list_for_each_prev_safe(pos, n, head) \
447 	for (pos = (head)->prev, n = pos->prev; \
448 	     pos != (head); \
449 	     pos = n, n = pos->prev)
450 
451 /**
452  * list_for_each_entry	-	iterate over list of given type
453  * @pos:	the type * to use as a loop cursor.
454  * @head:	the head for your list.
455  * @member:	the name of the list_head within the struct.
456  */
457 #define list_for_each_entry(pos, head, member)				\
458 	for (pos = list_first_entry(head, typeof(*pos), member);	\
459 	     &pos->member != (head);					\
460 	     pos = list_next_entry(pos, member))
461 
462 /**
463  * list_for_each_entry_reverse - iterate backwards over list of given type.
464  * @pos:	the type * to use as a loop cursor.
465  * @head:	the head for your list.
466  * @member:	the name of the list_head within the struct.
467  */
468 #define list_for_each_entry_reverse(pos, head, member)			\
469 	for (pos = list_last_entry(head, typeof(*pos), member);		\
470 	     &pos->member != (head); 					\
471 	     pos = list_prev_entry(pos, member))
472 
473 /**
474  * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
475  * @pos:	the type * to use as a start point
476  * @head:	the head of the list
477  * @member:	the name of the list_head within the struct.
478  *
479  * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
480  */
481 #define list_prepare_entry(pos, head, member) \
482 	((pos) ? : list_entry(head, typeof(*pos), member))
483 
484 /**
485  * list_for_each_entry_continue - continue iteration over list of given type
486  * @pos:	the type * to use as a loop cursor.
487  * @head:	the head for your list.
488  * @member:	the name of the list_head within the struct.
489  *
490  * Continue to iterate over list of given type, continuing after
491  * the current position.
492  */
493 #define list_for_each_entry_continue(pos, head, member) 		\
494 	for (pos = list_next_entry(pos, member);			\
495 	     &pos->member != (head);					\
496 	     pos = list_next_entry(pos, member))
497 
498 /**
499  * list_for_each_entry_continue_reverse - iterate backwards from the given point
500  * @pos:	the type * to use as a loop cursor.
501  * @head:	the head for your list.
502  * @member:	the name of the list_head within the struct.
503  *
504  * Start to iterate over list of given type backwards, continuing after
505  * the current position.
506  */
507 #define list_for_each_entry_continue_reverse(pos, head, member)		\
508 	for (pos = list_prev_entry(pos, member);			\
509 	     &pos->member != (head);					\
510 	     pos = list_prev_entry(pos, member))
511 
512 /**
513  * list_for_each_entry_from - iterate over list of given type from the current point
514  * @pos:	the type * to use as a loop cursor.
515  * @head:	the head for your list.
516  * @member:	the name of the list_head within the struct.
517  *
518  * Iterate over list of given type, continuing from current position.
519  */
520 #define list_for_each_entry_from(pos, head, member) 			\
521 	for (; &pos->member != (head);					\
522 	     pos = list_next_entry(pos, member))
523 
524 /**
525  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
526  * @pos:	the type * to use as a loop cursor.
527  * @n:		another type * to use as temporary storage
528  * @head:	the head for your list.
529  * @member:	the name of the list_head within the struct.
530  */
531 #define list_for_each_entry_safe(pos, n, head, member)			\
532 	for (pos = list_first_entry(head, typeof(*pos), member),	\
533 		n = list_next_entry(pos, member);			\
534 	     &pos->member != (head); 					\
535 	     pos = n, n = list_next_entry(n, member))
536 
537 /**
538  * list_for_each_entry_safe_continue - continue list iteration safe against removal
539  * @pos:	the type * to use as a loop cursor.
540  * @n:		another type * to use as temporary storage
541  * @head:	the head for your list.
542  * @member:	the name of the list_head within the struct.
543  *
544  * Iterate over list of given type, continuing after current point,
545  * safe against removal of list entry.
546  */
547 #define list_for_each_entry_safe_continue(pos, n, head, member) 		\
548 	for (pos = list_next_entry(pos, member), 				\
549 		n = list_next_entry(pos, member);				\
550 	     &pos->member != (head);						\
551 	     pos = n, n = list_next_entry(n, member))
552 
553 /**
554  * list_for_each_entry_safe_from - iterate over list from current point safe against removal
555  * @pos:	the type * to use as a loop cursor.
556  * @n:		another type * to use as temporary storage
557  * @head:	the head for your list.
558  * @member:	the name of the list_head within the struct.
559  *
560  * Iterate over list of given type from current point, safe against
561  * removal of list entry.
562  */
563 #define list_for_each_entry_safe_from(pos, n, head, member) 			\
564 	for (n = list_next_entry(pos, member);					\
565 	     &pos->member != (head);						\
566 	     pos = n, n = list_next_entry(n, member))
567 
568 /**
569  * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
570  * @pos:	the type * to use as a loop cursor.
571  * @n:		another type * to use as temporary storage
572  * @head:	the head for your list.
573  * @member:	the name of the list_head within the struct.
574  *
575  * Iterate backwards over list of given type, safe against removal
576  * of list entry.
577  */
578 #define list_for_each_entry_safe_reverse(pos, n, head, member)		\
579 	for (pos = list_last_entry(head, typeof(*pos), member),		\
580 		n = list_prev_entry(pos, member);			\
581 	     &pos->member != (head); 					\
582 	     pos = n, n = list_prev_entry(n, member))
583 
584 /**
585  * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
586  * @pos:	the loop cursor used in the list_for_each_entry_safe loop
587  * @n:		temporary storage used in list_for_each_entry_safe
588  * @member:	the name of the list_head within the struct.
589  *
590  * list_safe_reset_next is not safe to use in general if the list may be
591  * modified concurrently (eg. the lock is dropped in the loop body). An
592  * exception to this is if the cursor element (pos) is pinned in the list,
593  * and list_safe_reset_next is called after re-taking the lock and before
594  * completing the current iteration of the loop body.
595  */
596 #define list_safe_reset_next(pos, n, member)				\
597 	n = list_next_entry(pos, member)
598 
599 /*
600  * Double linked lists with a single pointer list head.
601  * Mostly useful for hash tables where the two pointer list head is
602  * too wasteful.
603  * You lose the ability to access the tail in O(1).
604  */
605 
606 #define HLIST_HEAD_INIT { .first = NULL }
607 #define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
608 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
INIT_HLIST_NODE(struct hlist_node * h)609 static inline void INIT_HLIST_NODE(struct hlist_node *h)
610 {
611 	h->next = NULL;
612 	h->pprev = NULL;
613 }
614 
hlist_unhashed(const struct hlist_node * h)615 static inline int hlist_unhashed(const struct hlist_node *h)
616 {
617 	return !h->pprev;
618 }
619 
hlist_empty(const struct hlist_head * h)620 static inline int hlist_empty(const struct hlist_head *h)
621 {
622 	return !h->first;
623 }
624 
__hlist_del(struct hlist_node * n)625 static inline void __hlist_del(struct hlist_node *n)
626 {
627 	struct hlist_node *next = n->next;
628 	struct hlist_node **pprev = n->pprev;
629 
630 	WRITE_ONCE(*pprev, next);
631 	if (next)
632 		next->pprev = pprev;
633 }
634 
hlist_del(struct hlist_node * n)635 static inline void hlist_del(struct hlist_node *n)
636 {
637 	__hlist_del(n);
638 	n->next = LIST_POISON1;
639 	n->pprev = LIST_POISON2;
640 }
641 
hlist_del_init(struct hlist_node * n)642 static inline void hlist_del_init(struct hlist_node *n)
643 {
644 	if (!hlist_unhashed(n)) {
645 		__hlist_del(n);
646 		INIT_HLIST_NODE(n);
647 	}
648 }
649 
hlist_add_head(struct hlist_node * n,struct hlist_head * h)650 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
651 {
652 	struct hlist_node *first = h->first;
653 	n->next = first;
654 	if (first)
655 		first->pprev = &n->next;
656 	h->first = n;
657 	n->pprev = &h->first;
658 }
659 
660 /* next must be != NULL */
hlist_add_before(struct hlist_node * n,struct hlist_node * next)661 static inline void hlist_add_before(struct hlist_node *n,
662 					struct hlist_node *next)
663 {
664 	n->pprev = next->pprev;
665 	n->next = next;
666 	next->pprev = &n->next;
667 	*(n->pprev) = n;
668 }
669 
hlist_add_behind(struct hlist_node * n,struct hlist_node * prev)670 static inline void hlist_add_behind(struct hlist_node *n,
671 				    struct hlist_node *prev)
672 {
673 	n->next = prev->next;
674 	prev->next = n;
675 	n->pprev = &prev->next;
676 
677 	if (n->next)
678 		n->next->pprev  = &n->next;
679 }
680 
681 /* after that we'll appear to be on some hlist and hlist_del will work */
hlist_add_fake(struct hlist_node * n)682 static inline void hlist_add_fake(struct hlist_node *n)
683 {
684 	n->pprev = &n->next;
685 }
686 
hlist_fake(struct hlist_node * h)687 static inline bool hlist_fake(struct hlist_node *h)
688 {
689 	return h->pprev == &h->next;
690 }
691 
692 /*
693  * Move a list from one list head to another. Fixup the pprev
694  * reference of the first entry if it exists.
695  */
hlist_move_list(struct hlist_head * old,struct hlist_head * new)696 static inline void hlist_move_list(struct hlist_head *old,
697 				   struct hlist_head *new)
698 {
699 	new->first = old->first;
700 	if (new->first)
701 		new->first->pprev = &new->first;
702 	old->first = NULL;
703 }
704 
705 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
706 
707 #define hlist_for_each(pos, head) \
708 	for (pos = (head)->first; pos ; pos = pos->next)
709 
710 #define hlist_for_each_safe(pos, n, head) \
711 	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
712 	     pos = n)
713 
714 #define hlist_entry_safe(ptr, type, member) \
715 	({ typeof(ptr) ____ptr = (ptr); \
716 	   ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
717 	})
718 
719 /**
720  * hlist_for_each_entry	- iterate over list of given type
721  * @pos:	the type * to use as a loop cursor.
722  * @head:	the head for your list.
723  * @member:	the name of the hlist_node within the struct.
724  */
725 #define hlist_for_each_entry(pos, head, member)				\
726 	for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
727 	     pos;							\
728 	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
729 
730 /**
731  * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
732  * @pos:	the type * to use as a loop cursor.
733  * @member:	the name of the hlist_node within the struct.
734  */
735 #define hlist_for_each_entry_continue(pos, member)			\
736 	for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\
737 	     pos;							\
738 	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
739 
740 /**
741  * hlist_for_each_entry_from - iterate over a hlist continuing from current point
742  * @pos:	the type * to use as a loop cursor.
743  * @member:	the name of the hlist_node within the struct.
744  */
745 #define hlist_for_each_entry_from(pos, member)				\
746 	for (; pos;							\
747 	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
748 
749 /**
750  * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
751  * @pos:	the type * to use as a loop cursor.
752  * @n:		another &struct hlist_node to use as temporary storage
753  * @head:	the head for your list.
754  * @member:	the name of the hlist_node within the struct.
755  */
756 #define hlist_for_each_entry_safe(pos, n, head, member) 		\
757 	for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
758 	     pos && ({ n = pos->member.next; 1; });			\
759 	     pos = hlist_entry_safe(n, typeof(*pos), member))
760 
761 /**
762  * list_del_range - deletes range of entries from list.
763  * @begin: first element in the range to delete from the list.
764  * @end: last element in the range to delete from the list.
765  * Note: list_empty on the range of entries does not return true after this,
766  * the entries is in an undefined state.
767  */
list_del_range(struct list_head * begin,struct list_head * end)768 static inline void list_del_range(struct list_head *begin,
769 				  struct list_head *end)
770 {
771 	begin->prev->next = end->next;
772 	end->next->prev = begin->prev;
773 }
774 
775 /**
776  * list_for_each_from	-	iterate over a list from one of its nodes
777  * @pos:  the &struct list_head to use as a loop cursor, from where to start
778  * @head: the head for your list.
779  */
780 #define list_for_each_from(pos, head) \
781 	for (; pos != (head); pos = pos->next)
782 
783 #endif /* __TOOLS_LINUX_LIST_H */
784