/* From linux kernel source */

#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(name) \

	struct list_head name = { &name, &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;

}

/*

 * Insert a new entry after the specified head..

 */

static __inline__ void list_add(struct list_head *new, struct list_head *head)

{

	__list_add(new, head, head->next);

}

/*

 * Insert a new entry before the specified head..

 */

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;

}

static __inline__ void list_del(struct list_head *entry)

{

	__list_del(entry->prev, entry->next);

}

static __inline__ int list_empty(struct list_head *head)

{

	return head->next == head;

}

#define list_entry(ptr, type, member) \

	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))

#define list_for_each(pos, head) \

        for (pos = (head)->next; pos != (head); pos = pos->next)

#endif