/*
 * Xilinx Video Library - Double linked lists
 *
 * Copyright (C) 2014-2016 Ideas on board Oy
 *
 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 */

#ifndef __XLNX_LIST_H__
#define __XLNX_LIST_H__

#include <stddef.h>

struct list_entry {
	struct list_entry *prev;
	struct list_entry *next;
};

static inline void list_init(struct list_entry *list)
{
	list->next = list;
	list->prev = list;
}

static inline int list_empty(struct list_entry *list)
{
	return list->next == list;
}

static inline void list_append(struct list_entry *entry, struct list_entry *list)
{
	entry->next = list;
	entry->prev = list->prev;
	list->prev->next = entry;
	list->prev = entry;
}

static inline void list_prepend(struct list_entry *entry, struct list_entry *list)
{
	entry->next = list->next;
	entry->prev = list;
	list->next->prev = entry;
	list->next = entry;
}

static inline void list_insert_after(struct list_entry *entry, struct list_entry *after)
{
	list_prepend(entry, after);
}

static inline void list_insert_before(struct list_entry *entry, struct list_entry *before)
{
	list_append(entry, before);
}

static inline void list_remove(struct list_entry *entry)
{
	entry->prev->next = entry->next;
	entry->next->prev = entry->prev;
}

#define list_entry(entry, type, member) \
	(type *)((char *)(entry) - offsetof(type, member))

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

#define list_last_entry(list, type, member) \
	list_entry((list)->prev, type, member)

#define list_for_each(entry, list) \
	for (entry = (list)->next; entry != (list); entry = entry->next)

#define list_for_each_entry(entry, list, member) \
	for (entry = list_entry((list)->next, typeof(*entry), member); \
	     &entry->member != (list); \
	     entry = list_entry(entry->member.next, typeof(*entry), member))

#define list_for_each_safe(entry, __next, list) \
	for (entry = (list)->next, __next = entry->next; entry != (list); \
	     entry = __next, __next = entry->next)

#define list_for_each_entry_safe(entry, __next, list, member) \
	for (entry = list_entry((list)->next, typeof(*entry), member), \
	     __next = list_entry(entry->member.next, typeof(*entry), member); \
	     &entry->member != (list); \
	     entry = __next, __next = list_entry(entry->member.next, typeof(*entry), member))

#endif /* __XLNX_LIST_H__ */