list.h

#ifndef __CR_LIST_H__
#define __CR_LIST_H__

#include "compiler.h"

/*
 * Double linked lists.
 */

#define POISON_POINTER_DELTA 0
#define LIST_POISON1  ((void *) 0x00100100 + POISON_POINTER_DELTA)
#define LIST_POISON2  ((void *) 0x00200200 + POISON_POINTER_DELTA)

struct list_head {
	struct list_head *prev, *next;
};

#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;
}

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;
}

static inline void list_add(struct list_head *new, struct list_head *head)
{
	__list_add(new, head, head->next);
}

static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
	__list_add(new, head->prev, head);
}

static inline void __list_del(struct list_head * prev, struct list_head * next)
{
	next->prev = prev;
	prev->next = next;
}

static inline void __list_del_entry(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
}

static inline void list_del(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
	entry->next = LIST_POISON1;
	entry->prev = LIST_POISON2;
}

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);
}

static inline void list_del_init(struct list_head *entry)
{
	__list_del_entry(entry);
	INIT_LIST_HEAD(entry);
}

static inline void list_move(struct list_head *list, struct list_head *head)
{
	__list_del_entry(list);
	list_add(list, head);
}

static inline void list_move_tail(struct list_head *list,
				  struct list_head *head)
{
	__list_del_entry(list);
	list_add_tail(list, head);
}

static inline int list_is_last(const struct list_head *list,
				const struct list_head *head)
{
	return list->next == head;
}

static inline int list_is_first(const struct list_head *list,
				const struct list_head *head)
{
	return list->prev == head;
}

static inline int list_empty(const struct list_head *head)
{
	return head->next == head;
}

static inline int list_empty_careful(const struct list_head *head)
{
	struct list_head *next = head->next;
	return (next == head) && (next == head->prev);
}
static inline void list_rotate_left(struct list_head *head)
{
	struct list_head *first;

	if (!list_empty(head)) {
		first = head->next;
		list_move_tail(first, head);
	}
}

static inline int list_is_singular(const struct list_head *head)
{
	return !list_empty(head) && (head->next == head->prev);
}

static inline void __list_cut_position(struct list_head *list,
		struct list_head *head, struct list_head *entry)
{
	struct list_head *new_first = entry->next;
	list->next = head->next;
	list->next->prev = list;
	list->prev = entry;
	entry->next = list;
	head->next = new_first;
	new_first->prev = head;
}

static inline void list_cut_position(struct list_head *list,
		struct list_head *head, struct list_head *entry)
{
	if (list_empty(head))
		return;
	if (list_is_singular(head) &&
		(head->next != entry && head != entry))
		return;
	if (entry == head)
		INIT_LIST_HEAD(list);
	else
		__list_cut_position(list, head, entry);
}

static inline void __list_splice(const struct list_head *list,
				 struct list_head *prev,
				 struct list_head *next)
{
	struct list_head *first = list->next;
	struct list_head *last = list->prev;

	first->prev	= prev;
	prev->next	= first;

	last->next	= next;
	next->prev	= last;
}

static inline void list_splice(const struct list_head *list,
				struct list_head *head)
{
	if (!list_empty(list))
		__list_splice(list, head, head->next);
}

static inline void list_splice_tail(struct list_head *list,
				struct list_head *head)
{
	if (!list_empty(list))
		__list_splice(list, head->prev, head);
}

static inline void list_splice_init(struct list_head *list,
				    struct list_head *head)
{
	if (!list_empty(list)) {
		__list_splice(list, head, head->next);
		INIT_LIST_HEAD(list);
	}
}

static inline void list_splice_tail_init(struct list_head *list,
					 struct list_head *head)
{
	if (!list_empty(list)) {
		__list_splice(list, head->prev, head);
		INIT_LIST_HEAD(list);
	}
}

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

#define list_first_entry(ptr, type, member)			\
	list_entry((ptr)->next, type, member)

#define list_for_each(pos, head)				\
	for (pos = (head)->next; pos != (head); pos = pos->next)

#define __list_for_each(pos, head)				\
	for (pos = (head)->next; pos != (head); pos = pos->next)

#define list_for_each_prev(pos, head)				\
	for (pos = (head)->prev; pos != (head); pos = pos->prev)

#define list_for_each_safe(pos, n, head)			\
	for (pos = (head)->next, n = pos->next; pos != (head);	\
		pos = n, n = pos->next)

#define list_for_each_prev_safe(pos, n, head)			\
	for (pos = (head)->prev, n = pos->prev;			\
	     pos != (head);					\
	     pos = n, n = pos->prev)

#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))

#define list_for_each_entry_reverse(pos, head, member)			\
	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = list_entry(pos->member.prev, typeof(*pos), member))

#define list_prepare_entry(pos, head, member)				\
	((pos) ? : list_entry(head, typeof(*pos), member))

#define list_for_each_entry_continue(pos, head, member)			\
	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = list_entry(pos->member.next, typeof(*pos), member))

#define list_for_each_entry_continue_reverse(pos, head, member)		\
	for (pos = list_entry(pos->member.prev, typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = list_entry(pos->member.prev, typeof(*pos), member))

#define list_for_each_entry_from(pos, head, member)			\
	for (; &pos->member != (head);					\
	     pos = list_entry(pos->member.next, typeof(*pos), member))

#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))

#define list_for_each_entry_safe_continue(pos, n, head, member)			\
	for (pos = list_entry(pos->member.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))

#define list_for_each_entry_safe_from(pos, n, head, member)			\
	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
	     &pos->member != (head);						\
	     pos = n, n = list_entry(n->member.next, typeof(*n), member))

#define list_for_each_entry_safe_reverse(pos, n, head, member)		\
	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
		n = list_entry(pos->member.prev, typeof(*pos), member);	\
	     &pos->member != (head);					\
	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))

#define list_safe_reset_next(pos, n, member)				\
	n = list_entry(pos->member.next, typeof(*pos), member)

/*
 * Double linked lists with a single pointer list head.
 */

struct hlist_head {
	struct hlist_node *first;
};

struct hlist_node {
	struct hlist_node *next, **pprev;
};

#define HLIST_HEAD_INIT		{ .first = NULL }
#define HLIST_HEAD(name)	struct hlist_head name = {  .first = NULL }
#define INIT_HLIST_HEAD(ptr)	((ptr)->first = NULL)

static inline void INIT_HLIST_NODE(struct hlist_node *h)
{
	h->next = NULL;
	h->pprev = NULL;
}

static inline int hlist_unhashed(const struct hlist_node *h)
{
	return !h->pprev;
}

static inline int hlist_empty(const struct hlist_head *h)
{
	return !h->first;
}

static inline void __hlist_del(struct hlist_node *n)
{
	struct hlist_node *next = n->next;
	struct hlist_node **pprev = n->pprev;
	*pprev = next;
	if (next)
		next->pprev = pprev;
}

static inline void hlist_del(struct hlist_node *n)
{
	__hlist_del(n);
	n->next = LIST_POISON1;
	n->pprev = LIST_POISON2;
}

static inline void hlist_del_init(struct hlist_node *n)
{
	if (!hlist_unhashed(n)) {
		__hlist_del(n);
		INIT_HLIST_NODE(n);
	}
}

static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
	struct hlist_node *first = h->first;
	n->next = first;
	if (first)
		first->pprev = &n->next;
	h->first = n;
	n->pprev = &h->first;
}

/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
				    struct hlist_node *next)
{
	n->pprev = next->pprev;
	n->next = next;
	next->pprev = &n->next;
	*(n->pprev) = n;
}

static inline void hlist_add_after(struct hlist_node *n,
				   struct hlist_node *next)
{
	next->next = n->next;
	n->next = next;
	next->pprev = &n->next;

	if (next->next)
		next->next->pprev  = &next->next;
}

/* after that we'll appear to be on some hlist and hlist_del will work */
static inline void hlist_add_fake(struct hlist_node *n)
{
	n->pprev = &n->next;
}

/*
 * Move a list from one list head to another. Fixup the pprev
 * reference of the first entry if it exists.
 */
static inline void hlist_move_list(struct hlist_head *old,
				   struct hlist_head *new)
{
	new->first = old->first;
	if (new->first)
		new->first->pprev = &new->first;
	old->first = NULL;
}

#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define hlist_for_each(pos, head)						\
	for (pos = (head)->first; pos ; pos = pos->next)

#define hlist_for_each_safe(pos, n, head)					\
	for (pos = (head)->first; pos && ({ n = pos->next; 1; });		\
	     pos = n)

#define hlist_entry_safe(ptr, type, member)					\
	(ptr) ? hlist_entry(ptr, type, member) : NULL

#define hlist_for_each_entry(pos, head, member)					\
	for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);	\
	     pos;								\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

#define hlist_for_each_entry_continue(pos, member)				\
	for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\
	     pos;								\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

#define hlist_for_each_entry_from(pos, member)					\
	for (; pos;								\
	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))

#define hlist_for_each_entry_safe(pos, n, head, member)				\
	for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);	\
	     pos && ({ n = pos->member.next; 1; });				\
	     pos = hlist_entry_safe(n, typeof(*pos), member))

#endif /* __CR_LIST_H__ */