#ifndef _LINUX_LIST_H

#define _LINUX_LIST_H

#include <stdio.h>

#ifndef offsetof

/**

 * Get offset of a member

 */

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

#endif

#ifndef container_of

/**

 * Casts a member of a structure out to the containing structure

 * @param ptr        the pointer to the member.

 * @param type       the type of the container struct this is embedded in.

 * @param member     the name of the member within the struct.

 *

 */

#define container_of(ptr, type, member) ({                      \

        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \

	        (type *)( (char *)__mptr - offsetof(type,member) );})

#endif

/*

 * These are non-NULL pointers that will result in page faults

 * under normal circumstances, used to verify that nobody uses

 * non-initialized list entries.

 */

#define LIST_POISON1  ((void *) 0x00100100)

#define LIST_POISON2  ((void *) 0x00200200)

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)

static inline void INIT_LIST_HEAD(struct list_head *list)

{

	list->next = list;

	list->prev = list;

}

/*

 * 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 = LIST_POISON1;

	entry->prev = LIST_POISON2;

}

/**

 * __list_for_each	-	iterate over a list

 * @pos:	the &struct list_head to use as a loop counter.

 * @head:	the head for your list.

 *

 * This variant differs from list_for_each() in that it's the

 * simplest possible list iteration code, no prefetching is done.

 * Use this for code that knows the list to be very short (empty

 * or 1 entry) most of the time.

 */

#define __list_for_each(pos, head) \

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

/**

 * 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_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) \

        container_of(ptr, type, member)

static inline int list_len(struct list_head *head_p)

{

	struct list_head *p;

	int n = 0;

	__list_for_each(p, head_p) {

		n++;

	}

	return n;

}

/**

 * list_empty - tests whether a list is empty

 * @head: the list to test.

 */

static inline int list_empty(const struct list_head *head)

{

	return head->next == head;

}

/**

 * list_first - Returns first entry on list, or NULL if empty

 * @head: the list

 */

static inline struct list_head *list_first(const struct list_head *head)

{

	return list_empty(head) ? NULL : head->next;

}

/**

 * 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);

}

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_replace - replace old entry by new one

 * @old : the element to be replaced

 * @new : the new element to insert

 *

 * If @old was empty, it will be overwritten.

 */

static inline void list_replace(struct list_head *old,

				struct list_head *new)

{

	new->next = old->next;

	new->next->prev = new;

	new->prev = old->prev;

	new->prev->next = new;

}

static inline void list_replace_init(struct list_head *old,

					struct list_head *new)

{

	list_replace(old, new);

	INIT_LIST_HEAD(old);

}

#endif