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- #ifndef _LINUX_LIST_H
- #define _LINUX_LIST_H
- /*
- * Simple doubly linked list implementation.
- *
- * Some of the internal functions ("__xxx") are useful when
- * manipulating whole lists rather than single entries, as
- * sometimes we already know the next/prev entries and we can
- * generate better code by using them directly rather than
- * using the generic single-entry routines.
- */
- struct list_head {
- struct list_head *next, *prev;
- };
- #define LIST_HEAD_INIT(name) { &(name), &(name) }
- #define LIST_HEAD(name) \
- struct list_head name = LIST_HEAD_INIT(name)
- #define INIT_LIST_HEAD(ptr) do { \
- (ptr)->next = (ptr); (ptr)->prev = (ptr); \
- } while (0)
- /*
- * Insert a new entry between two known consecutive entries.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
- */
- static inline void __list_add(struct list_head *new,
- struct list_head *prev,
- struct list_head *next)
- {
- next->prev = new;
- new->next = next;
- new->prev = prev;
- prev->next = new;
- }
- /**
- * list_add - add a new entry
- * @new: new entry to be added
- * @head: list head to add it after
- *
- * Insert a new entry after the specified head.
- * This is good for implementing stacks.
- */
- static inline void list_add(struct list_head *new, struct list_head *head)
- {
- __list_add(new, head, head->next);
- }
- /**
- * list_add_tail - add a new entry
- * @new: new entry to be added
- * @head: list head to add it before
- *
- * Insert a new entry before the specified head.
- * This is useful for implementing queues.
- */
- static inline void list_add_tail(struct list_head *new, struct list_head *head)
- {
- __list_add(new, head->prev, head);
- }
- /*
- * Delete a list entry by making the prev/next entries
- * point to each other.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
- */
- static inline void __list_del(struct list_head *prev, struct list_head *next)
- {
- next->prev = prev;
- prev->next = next;
- }
- /**
- * list_del - deletes entry from list.
- * @entry: the element to delete from the list.
- * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
- */
- static inline void list_del(struct list_head *entry)
- {
- __list_del(entry->prev, entry->next);
- entry->next = (void *) 0;
- entry->prev = (void *) 0;
- }
- /**
- * list_del_init - deletes entry from list and reinitialize it.
- * @entry: the element to delete from the list.
- */
- static inline void list_del_init(struct list_head *entry)
- {
- __list_del(entry->prev, entry->next);
- INIT_LIST_HEAD(entry);
- }
- /**
- * list_move - delete from one list and add as another's head
- * @list: the entry to move
- * @head: the head that will precede our entry
- */
- static inline void list_move(struct list_head *list, struct list_head *head)
- {
- __list_del(list->prev, list->next);
- list_add(list, head);
- }
- /**
- * list_move_tail - delete from one list and add as another's tail
- * @list: the entry to move
- * @head: the head that will follow our entry
- */
- static inline void list_move_tail(struct list_head *list,
- struct list_head *head)
- {
- __list_del(list->prev, list->next);
- list_add_tail(list, head);
- }
- /**
- * list_empty - tests whether a list is empty
- * @head: the list to test.
- */
- static inline int list_empty(struct list_head *head)
- {
- return head->next == head;
- }
- static inline void __list_splice(struct list_head *list,
- struct list_head *head)
- {
- struct list_head *first = list->next;
- struct list_head *last = list->prev;
- struct list_head *at = head->next;
- first->prev = head;
- head->next = first;
- last->next = at;
- at->prev = last;
- }
- /**
- * list_splice - join two lists
- * @list: the new list to add.
- * @head: the place to add it in the first list.
- */
- static inline void list_splice(struct list_head *list, struct list_head *head)
- {
- if (!list_empty(list))
- __list_splice(list, head);
- }
- /**
- * list_splice_init - join two lists and reinitialise the emptied list.
- * @list: the new list to add.
- * @head: the place to add it in the first list.
- *
- * The list at @list is reinitialised
- */
- static inline void list_splice_init(struct list_head *list,
- struct list_head *head)
- {
- if (!list_empty(list)) {
- __list_splice(list, head);
- INIT_LIST_HEAD(list);
- }
- }
- #ifdef __clang__
- #define typeof(x) __typeof(x)
- #endif
- /**
- * list_entry - get the struct for this entry
- * @ptr: the &struct list_head pointer.
- * @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
- */
- #ifndef _WIN64
- #define list_entry(ptr, type, member) \
- ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
- #else
- #define list_entry(ptr, type, member) \
- ((type *)((char *)(ptr)-(unsigned long long)(&((type *)0)->member)))
- #endif
- /**
- * list_for_each - iterate over a list
- * @pos: the &struct list_head to use as a loop counter.
- * @head: the head for your list.
- */
- #define list_for_each(pos, head) \
- for (pos = (head)->next; pos != (head); \
- pos = pos->next)
- /**
- * list_for_each_prev - iterate over a list backwards
- * @pos: the &struct list_head to use as a loop counter.
- * @head: the head for your list.
- */
- #define list_for_each_prev(pos, head) \
- for (pos = (head)->prev; pos != (head); \
- pos = pos->prev)
- /**
- * list_for_each_safe - iterate over a list safe against removal of list entry
- * @pos: the &struct list_head to use as a loop counter.
- * @n: another &struct list_head to use as temporary storage
- * @head: the head for your list.
- */
- #define list_for_each_safe(pos, n, head) \
- for (pos = (head)->next, n = pos->next; pos != (head); \
- pos = n, n = pos->next)
- /**
- * list_for_each_entry - iterate over list of given type
- * @pos: the type * to use as a loop counter.
- * @head: the head for your list.
- * @member: the name of the list_struct within the struct.
- */
- #define list_for_each_entry(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member))
- /**
- * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @pos: the type * to use as a loop counter.
- * @n: another type * to use as temporary storage
- * @head: the head for your list.
- * @member: the name of the list_struct within the struct.
- */
- #define list_for_each_entry_safe(pos, n, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- n = list_entry(pos->member.next, typeof(*pos), member); \
- &pos->member != (head); \
- pos = n, n = list_entry(n->member.next, typeof(*n), member))
- /**
- * list_for_each_entry_continue - iterate over list of given type
- * continuing after existing point
- * @pos: the type * to use as a loop counter.
- * @head: the head for your list.
- * @member: the name of the list_struct within the struct.
- */
- #define list_for_each_entry_continue(pos, head, member) \
- for (pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
- #endif
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