u-boot/fs/yaffs2/yaffs_list.h

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/*
* YAFFS: Yet another Flash File System . A NAND-flash specific file system.
*
* Copyright (C) 2002-2011 Aleph One Ltd.
* for Toby Churchill Ltd and Brightstar Engineering
*
* Created by Charles Manning <charles@aleph1.co.uk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1 as
* published by the Free Software Foundation.
*
* Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
*/
/*
* This file is just holds extra declarations of macros that would normally
* be providesd in the Linux kernel. These macros have been written from
* scratch but are functionally equivalent to the Linux ones.
*
*/
#ifndef __YAFFS_LIST_H__
#define __YAFFS_LIST_H__
/*
* This is a simple doubly linked list implementation that matches the
* way the Linux kernel doubly linked list implementation works.
*/
struct list_head {
struct list_head *next; /* next in chain */
struct list_head *prev; /* previous in chain */
};
/* Initialise a static list */
#define LIST_HEAD(name) \
struct list_head name = { &(name), &(name)}
/* Initialise a list head to an empty list */
#define INIT_LIST_HEAD(p) \
do { \
(p)->next = (p);\
(p)->prev = (p); \
} while (0)
/* Add an element to a list */
static inline void list_add(struct list_head *new_entry,
struct list_head *list)
{
struct list_head *list_next = list->next;
list->next = new_entry;
new_entry->prev = list;
new_entry->next = list_next;
list_next->prev = new_entry;
}
static inline void list_add_tail(struct list_head *new_entry,
struct list_head *list)
{
struct list_head *list_prev = list->prev;
list->prev = new_entry;
new_entry->next = list;
new_entry->prev = list_prev;
list_prev->next = new_entry;
}
/* Take an element out of its current list, with or without
* reinitialising the links.of the entry*/
static inline void list_del(struct list_head *entry)
{
struct list_head *list_next = entry->next;
struct list_head *list_prev = entry->prev;
list_next->prev = list_prev;
list_prev->next = list_next;
}
static inline void list_del_init(struct list_head *entry)
{
list_del(entry);
entry->next = entry->prev = entry;
}
/* Test if the list is empty */
static inline int list_empty(struct list_head *entry)
{
return (entry->next == entry);
}
/* list_entry takes a pointer to a list entry and offsets it to that
* we can find a pointer to the object it is embedded in.
*/
#define list_entry(entry, type, member) \
((type *)((char *)(entry)-(unsigned long)(&((type *)NULL)->member)))
/* list_for_each and list_for_each_safe iterate over lists.
* list_for_each_safe uses temporary storage to make the list delete safe
*/
#define list_for_each(itervar, list) \
for (itervar = (list)->next; itervar != (list); itervar = itervar->next)
#define list_for_each_safe(itervar, save_var, list) \
for (itervar = (list)->next, save_var = (list)->next->next; \
itervar != (list); \
itervar = save_var, save_var = save_var->next)
#endif