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Diffstat (limited to 'fs/yaffs2/yaffs_list.h')
-rw-r--r-- | fs/yaffs2/yaffs_list.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_list.h b/fs/yaffs2/yaffs_list.h new file mode 100644 index 0000000..a7afaea --- /dev/null +++ b/fs/yaffs2/yaffs_list.h @@ -0,0 +1,126 @@ +/* + * 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 |