1/*
2 * Copyright 2006, Red Hat, Inc., Dave Jones
3 * Released under the General Public License (GPL).
4 *
5 * This file contains the linked list implementations for
6 * DEBUG_LIST.
7 */
8
9#include <linux/module.h>
10#include <linux/list.h>
11
12/*
13 * Insert a new entry between two known consecutive entries.
14 *
15 * This is only for internal list manipulation where we know
16 * the prev/next entries already!
17 */
18
19void __list_add(struct list_head *new,
20			      struct list_head *prev,
21			      struct list_head *next)
22{
23	WARN(next->prev != prev,
24		"list_add corruption. next->prev should be "
25		"prev (%p), but was %p. (next=%p).\n",
26		prev, next->prev, next);
27	WARN(prev->next != next,
28		"list_add corruption. prev->next should be "
29		"next (%p), but was %p. (prev=%p).\n",
30		next, prev->next, prev);
31	next->prev = new;
32	new->next = next;
33	new->prev = prev;
34	prev->next = new;
35}
36EXPORT_SYMBOL(__list_add);
37
38/**
39 * list_del - deletes entry from list.
40 * @entry: the element to delete from the list.
41 * Note: list_empty on entry does not return true after this, the entry is
42 * in an undefined state.
43 */
44void list_del(struct list_head *entry)
45{
46	WARN(entry->next == LIST_POISON1,
47		"list_del corruption, next is LIST_POISON1 (%p)\n",
48		LIST_POISON1);
49	WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2,
50		"list_del corruption, prev is LIST_POISON2 (%p)\n",
51		LIST_POISON2);
52	WARN(entry->prev->next != entry,
53		"list_del corruption. prev->next should be %p, "
54		"but was %p\n", entry, entry->prev->next);
55	WARN(entry->next->prev != entry,
56		"list_del corruption. next->prev should be %p, "
57		"but was %p\n", entry, entry->next->prev);
58	__list_del(entry->prev, entry->next);
59	entry->next = LIST_POISON1;
60	entry->prev = LIST_POISON2;
61}
62EXPORT_SYMBOL(list_del);
63