#ifndef _LIST_H_#define _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. */typedef struct list_head {	struct list_head *next, *prev;} list_t;#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)#ifdef __cplusplus#define new		__new__#endif/* * 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);}/** * 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 __cplusplus#undef new#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. */#define list_entry(ptr, type, member) \	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))/** * 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))#endif