1 /* Stolen From Linux list implementation */
2 /* 2008, Modifications by Jack Lange <jarusl@cs.northwestern.edu> */
11 #include <palacios/vmm_string.h>
14 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
17 #define container_of(ptr, type, member) ({ \
18 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
19 (type *)( (char *)__mptr - offsetof(type,member) );})
22 static inline void prefetch(const void *x) {const void * foo; foo = x;}
25 * These are non-NULL pointers that will result in page faults
26 * under normal circumstances, used to verify that nobody uses
27 * non-initialized list entries.
29 #define LIST_POISON1 ((void *) 0x00100100)
30 #define LIST_POISON2 ((void *) 0x00200200)
33 * Simple doubly linked list implementation.
35 * Some of the internal functions ("__xxx") are useful when
36 * manipulating whole lists rather than single entries, as
37 * sometimes we already know the next/prev entries and we can
38 * generate better code by using them directly rather than
39 * using the generic single-entry routines.
43 struct list_head *next, *prev;
46 #define LIST_HEAD_INIT(name) { &(name), &(name) }
48 #define LIST_HEAD(name) \
49 struct list_head name = LIST_HEAD_INIT(name)
51 static inline void INIT_LIST_HEAD(struct list_head *list)
58 * Insert a new entry between two known consecutive entries.
60 * This is only for internal list manipulation where we know
61 * the prev/next entries already!
63 static inline void __list_add(struct list_head *new,
64 struct list_head *prev,
65 struct list_head *next)
74 * list_add - add a new entry
75 * @new: new entry to be added
76 * @head: list head to add it after
78 * Insert a new entry after the specified head.
79 * This is good for implementing stacks.
81 static inline void list_add(struct list_head *new, struct list_head *head)
83 __list_add(new, head, head->next);
87 * list_add_tail - add a new entry
88 * @new: new entry to be added
89 * @head: list head to add it before
91 * Insert a new entry before the specified head.
92 * This is useful for implementing queues.
94 static inline void list_add_tail(struct list_head *new, struct list_head *head)
96 __list_add(new, head->prev, head);
100 * Delete a list entry by making the prev/next entries
101 * point to each other.
103 * This is only for internal list manipulation where we know
104 * the prev/next entries already!
106 static inline void __list_del(struct list_head * prev, struct list_head * next)
113 * list_del - deletes entry from list.
114 * @entry: the element to delete from the list.
115 * Note: list_empty on entry does not return true after this, the entry is
116 * in an undefined state.
118 static inline void list_del(struct list_head *entry)
120 __list_del(entry->prev, entry->next);
121 entry->next = LIST_POISON1;
122 entry->prev = LIST_POISON2;
126 * list_del_init - deletes entry from list and reinitialize it.
127 * @entry: the element to delete from the list.
129 static inline void list_del_init(struct list_head *entry)
131 __list_del(entry->prev, entry->next);
132 INIT_LIST_HEAD(entry);
136 * list_move - delete from one list and add as another's head
137 * @list: the entry to move
138 * @head: the head that will precede our entry
140 static inline void list_move(struct list_head *list, struct list_head *head)
142 __list_del(list->prev, list->next);
143 list_add(list, head);
147 * list_move_tail - delete from one list and add as another's tail
148 * @list: the entry to move
149 * @head: the head that will follow our entry
151 static inline void list_move_tail(struct list_head *list,
152 struct list_head *head)
154 __list_del(list->prev, list->next);
155 list_add_tail(list, head);
159 * list_empty - tests whether a list is empty
160 * @head: the list to test.
162 static inline int list_empty(const struct list_head *head)
164 return head->next == head;
168 * list_empty_careful - tests whether a list is
169 * empty _and_ checks that no other CPU might be
170 * in the process of still modifying either member
172 * NOTE: using list_empty_careful() without synchronization
173 * can only be safe if the only activity that can happen
174 * to the list entry is list_del_init(). Eg. it cannot be used
175 * if another CPU could re-list_add() it.
177 * @head: the list to test.
179 static inline int list_empty_careful(const struct list_head *head)
181 struct list_head *next = head->next;
182 return (next == head) && (next == head->prev);
185 static inline void __list_splice(struct list_head *list,
186 struct list_head *head)
188 struct list_head *first = list->next;
189 struct list_head *last = list->prev;
190 struct list_head *at = head->next;
200 * list_splice - join two lists
201 * @list: the new list to add.
202 * @head: the place to add it in the first list.
204 static inline void list_splice(struct list_head *list, struct list_head *head)
206 if (!list_empty(list))
207 __list_splice(list, head);
211 * list_splice_init - join two lists and reinitialise the emptied list.
212 * @list: the new list to add.
213 * @head: the place to add it in the first list.
215 * The list at @list is reinitialised
217 static inline void list_splice_init(struct list_head *list,
218 struct list_head *head)
220 if (!list_empty(list)) {
221 __list_splice(list, head);
222 INIT_LIST_HEAD(list);
227 * list_entry - get the struct for this entry
228 * @ptr: the &struct list_head pointer.
229 * @type: the type of the struct this is embedded in.
230 * @member: the name of the list_struct within the struct.
232 #define list_entry(ptr, type, member) \
233 container_of(ptr, type, member)
236 * list_entry - get the struct for the tail entry
237 * @ptr: the list_head head pointer.
238 * @type: the type of the struct this is embedded in.
239 * @member: the name of the list_struct within the struct.
241 #define list_tail_entry(head, type, member) ({ \
242 type * tail = NULL; \
243 if ((head)->prev != (head)) { \
244 tail = list_entry((head)->prev, type, member); \
250 * list_for_each - iterate over a list
251 * @pos: the &struct list_head to use as a loop counter.
252 * @head: the head for your list.
254 #define list_for_each(pos, head) \
255 for (pos = (head)->next; prefetch(pos->next), pos != (head); \
259 * __list_for_each - iterate over a list
260 * @pos: the &struct list_head to use as a loop counter.
261 * @head: the head for your list.
263 * This variant differs from list_for_each() in that it's the
264 * simplest possible list iteration code, no prefetching is done.
265 * Use this for code that knows the list to be very short (empty
266 * or 1 entry) most of the time.
268 #define __list_for_each(pos, head) \
269 for (pos = (head)->next; pos != (head); pos = pos->next)
272 * list_for_each_prev - iterate over a list backwards
273 * @pos: the &struct list_head to use as a loop counter.
274 * @head: the head for your list.
276 #define list_for_each_prev(pos, head) \
277 for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
281 * list_for_each_safe - iterate over a list safe against removal of list entry
282 * @pos: the &struct list_head to use as a loop counter.
283 * @n: another &struct list_head to use as temporary storage
284 * @head: the head for your list.
286 #define list_for_each_safe(pos, n, head) \
287 for (pos = (head)->next, n = pos->next; pos != (head); \
288 pos = n, n = pos->next)
291 * list_for_each_entry - iterate over list of given type
292 * @pos: the type * to use as a loop counter.
293 * @head: the head for your list.
294 * @member: the name of the list_struct within the struct.
296 #define list_for_each_entry(pos, head, member) \
297 for (pos = list_entry((head)->next, typeof(*pos), member); \
298 prefetch(pos->member.next), &pos->member != (head); \
299 pos = list_entry(pos->member.next, typeof(*pos), member))
302 * list_for_each_entry_reverse - iterate backwards over list of given type.
303 * @pos: the type * to use as a loop counter.
304 * @head: the head for your list.
305 * @member: the name of the list_struct within the struct.
307 #define list_for_each_entry_reverse(pos, head, member) \
308 for (pos = list_entry((head)->prev, typeof(*pos), member); \
309 prefetch(pos->member.prev), &pos->member != (head); \
310 pos = list_entry(pos->member.prev, typeof(*pos), member))
313 * list_prepare_entry - prepare a pos entry for use as a start point in
314 * list_for_each_entry_continue
315 * @pos: the type * to use as a start point
316 * @head: the head of the list
317 * @member: the name of the list_struct within the struct.
319 #define list_prepare_entry(pos, head, member) \
320 ((pos) ? : list_entry(head, typeof(*pos), member))
323 * list_for_each_entry_continue - iterate over list of given type
324 * continuing after existing point
325 * @pos: the type * to use as a loop counter.
326 * @head: the head for your list.
327 * @member: the name of the list_struct within the struct.
329 #define list_for_each_entry_continue(pos, head, member) \
330 for (pos = list_entry(pos->member.next, typeof(*pos), member); \
331 prefetch(pos->member.next), &pos->member != (head); \
332 pos = list_entry(pos->member.next, typeof(*pos), member))
335 * list_for_each_entry_from - iterate over list of given type
336 * continuing from existing point
337 * @pos: the type * to use as a loop counter.
338 * @head: the head for your list.
339 * @member: the name of the list_struct within the struct.
341 #define list_for_each_entry_from(pos, head, member) \
342 for (; prefetch(pos->member.next), &pos->member != (head); \
343 pos = list_entry(pos->member.next, typeof(*pos), member))
346 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
347 * @pos: the type * to use as a loop counter.
348 * @n: another type * to use as temporary storage
349 * @head: the head for your list.
350 * @member: the name of the list_struct within the struct.
352 #define list_for_each_entry_safe(pos, n, head, member) \
353 for (pos = list_entry((head)->next, typeof(*pos), member), \
354 n = list_entry(pos->member.next, typeof(*pos), member); \
355 &pos->member != (head); \
356 pos = n, n = list_entry(n->member.next, typeof(*n), member))
359 * list_for_each_entry_safe_continue - iterate over list of given type
360 * continuing after existing point safe against removal of list entry
361 * @pos: the type * to use as a loop counter.
362 * @n: another type * to use as temporary storage
363 * @head: the head for your list.
364 * @member: the name of the list_struct within the struct.
366 #define list_for_each_entry_safe_continue(pos, n, head, member) \
367 for (pos = list_entry(pos->member.next, typeof(*pos), member), \
368 n = list_entry(pos->member.next, typeof(*pos), member); \
369 &pos->member != (head); \
370 pos = n, n = list_entry(n->member.next, typeof(*n), member))
373 * list_for_each_entry_safe_from - iterate over list of given type
374 * from existing point safe against removal of list entry
375 * @pos: the type * to use as a loop counter.
376 * @n: another type * to use as temporary storage
377 * @head: the head for your list.
378 * @member: the name of the list_struct within the struct.
380 #define list_for_each_entry_safe_from(pos, n, head, member) \
381 for (n = list_entry(pos->member.next, typeof(*pos), member); \
382 &pos->member != (head); \
383 pos = n, n = list_entry(n->member.next, typeof(*n), member))
386 * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against
387 * removal of list entry
388 * @pos: the type * to use as a loop counter.
389 * @n: another type * to use as temporary storage
390 * @head: the head for your list.
391 * @member: the name of the list_struct within the struct.
393 #define list_for_each_entry_safe_reverse(pos, n, head, member) \
394 for (pos = list_entry((head)->prev, typeof(*pos), member), \
395 n = list_entry(pos->member.prev, typeof(*pos), member); \
396 &pos->member != (head); \
397 pos = n, n = list_entry(n->member.prev, typeof(*n), member))
400 * Double linked lists with a single pointer list head.
401 * Mostly useful for hash tables where the two pointer list head is
403 * You lose the ability to access the tail in O(1).
407 struct hlist_node *first;
411 struct hlist_node *next, **pprev;
414 #define HLIST_HEAD_INIT { .first = NULL }
415 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
416 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
417 static inline void INIT_HLIST_NODE(struct hlist_node *h)
423 static inline int hlist_unhashed(const struct hlist_node *h)
428 static inline int hlist_empty(const struct hlist_head *h)
433 static inline void __hlist_del(struct hlist_node *n)
435 struct hlist_node *next = n->next;
436 struct hlist_node **pprev = n->pprev;
442 static inline void hlist_del(struct hlist_node *n)
445 n->next = LIST_POISON1;
446 n->pprev = LIST_POISON2;
449 static inline void hlist_del_init(struct hlist_node *n)
451 if (!hlist_unhashed(n)) {
457 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
459 struct hlist_node *first = h->first;
462 first->pprev = &n->next;
464 n->pprev = &h->first;
467 /* next must be != NULL */
468 static inline void hlist_add_before(struct hlist_node *n,
469 struct hlist_node *next)
471 n->pprev = next->pprev;
473 next->pprev = &n->next;
477 static inline void hlist_add_after(struct hlist_node *n,
478 struct hlist_node *next)
480 next->next = n->next;
482 next->pprev = &n->next;
485 next->next->pprev = &next->next;
488 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
490 #define hlist_for_each(pos, head) \
491 for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
494 #define hlist_for_each_safe(pos, n, head) \
495 for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
499 * hlist_for_each_entry - iterate over list of given type
500 * @tpos: the type * to use as a loop counter.
501 * @pos: the &struct hlist_node to use as a loop counter.
502 * @head: the head for your list.
503 * @member: the name of the hlist_node within the struct.
505 #define hlist_for_each_entry(tpos, pos, head, member) \
506 for (pos = (head)->first; \
507 pos && ({ prefetch(pos->next); 1;}) && \
508 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
512 * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
513 * @tpos: the type * to use as a loop counter.
514 * @pos: the &struct hlist_node to use as a loop counter.
515 * @member: the name of the hlist_node within the struct.
517 #define hlist_for_each_entry_continue(tpos, pos, member) \
518 for (pos = (pos)->next; \
519 pos && ({ prefetch(pos->next); 1;}) && \
520 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
524 * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
525 * @tpos: the type * to use as a loop counter.
526 * @pos: the &struct hlist_node to use as a loop counter.
527 * @member: the name of the hlist_node within the struct.
529 #define hlist_for_each_entry_from(tpos, pos, member) \
530 for (; pos && ({ prefetch(pos->next); 1;}) && \
531 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
535 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
536 * @tpos: the type * to use as a loop counter.
537 * @pos: the &struct hlist_node to use as a loop counter.
538 * @n: another &struct hlist_node to use as temporary storage
539 * @head: the head for your list.
540 * @member: the name of the hlist_node within the struct.
542 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
543 for (pos = (head)->first; \
544 pos && ({ n = pos->next; 1; }) && \
545 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
550 #endif // ! __V3VEE__