1#ifndef _LINUX_FLIST_H
2#define _LINUX_FLIST_H
3
4#include <stdlib.h>
5
6#undef offsetof
7#ifdef __compiler_offsetof
8#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
9#else
10#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
11#endif
12
13#define container_of(ptr, type, member) ({			\
14	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
15	(type *)( (char *)__mptr - offsetof(type,member) );})
16
17/*
18 * Simple doubly linked list implementation.
19 *
20 * Some of the internal functions ("__xxx") are useful when
21 * manipulating whole lists rather than single entries, as
22 * sometimes we already know the next/prev entries and we can
23 * generate better code by using them directly rather than
24 * using the generic single-entry routines.
25 */
26
27struct flist_head {
28	struct flist_head *next, *prev;
29};
30
31#define FLIST_HEAD_INIT(name) { &(name), &(name) }
32
33#define FLIST_HEAD(name) \
34	struct flist_head name = FLIST_HEAD_INIT(name)
35
36#define INIT_FLIST_HEAD(ptr) do { \
37	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
38} while (0)
39
40/*
41 * Insert a new entry between two known consecutive entries.
42 *
43 * This is only for internal list manipulation where we know
44 * the prev/next entries already!
45 */
46static inline void __flist_add(struct flist_head *new_entry,
47			       struct flist_head *prev,
48			       struct flist_head *next)
49{
50	next->prev = new_entry;
51	new_entry->next = next;
52	new_entry->prev = prev;
53	prev->next = new_entry;
54}
55
56/**
57 * flist_add - add a new entry
58 * @new_entry: new entry to be added
59 * @head: list head to add it after
60 *
61 * Insert a new entry after the specified head.
62 * This is good for implementing stacks.
63 */
64static inline void flist_add(struct flist_head *new_entry,
65                             struct flist_head *head)
66{
67	__flist_add(new_entry, head, head->next);
68}
69
70static inline void flist_add_tail(struct flist_head *new_entry,
71				  struct flist_head *head)
72{
73	__flist_add(new_entry, head->prev, head);
74}
75
76/*
77 * Delete a list entry by making the prev/next entries
78 * point to each other.
79 *
80 * This is only for internal list manipulation where we know
81 * the prev/next entries already!
82 */
83static inline void __flist_del(struct flist_head *prev,
84			       struct flist_head * next)
85{
86	next->prev = prev;
87	prev->next = next;
88}
89
90/**
91 * flist_del - deletes entry from list.
92 * @entry: the element to delete from the list.
93 * Note: flist_empty on entry does not return true after this, the entry is
94 * in an undefined state.
95 */
96static inline void flist_del(struct flist_head *entry)
97{
98	__flist_del(entry->prev, entry->next);
99	entry->next = NULL;
100	entry->prev = NULL;
101}
102
103/**
104 * flist_del_init - deletes entry from list and reinitialize it.
105 * @entry: the element to delete from the list.
106 */
107static inline void flist_del_init(struct flist_head *entry)
108{
109	__flist_del(entry->prev, entry->next);
110	INIT_FLIST_HEAD(entry);
111}
112
113/**
114 * flist_empty - tests whether a list is empty
115 * @head: the list to test.
116 */
117static inline int flist_empty(const struct flist_head *head)
118{
119	return head->next == head;
120}
121
122static inline void __flist_splice(const struct flist_head *list,
123				  struct flist_head *prev,
124				  struct flist_head *next)
125{
126	struct flist_head *first = list->next;
127	struct flist_head *last = list->prev;
128
129	first->prev = prev;
130	prev->next = first;
131
132	last->next = next;
133	next->prev = last;
134}
135
136static inline void flist_splice(const struct flist_head *list,
137				struct flist_head *head)
138{
139	if (!flist_empty(list))
140		__flist_splice(list, head, head->next);
141}
142
143static inline void flist_splice_tail(struct flist_head *list,
144				     struct flist_head *head)
145{
146	if (!flist_empty(list))
147		__flist_splice(list, head->prev, head);
148}
149
150static inline void flist_splice_tail_init(struct flist_head *list,
151					  struct flist_head *head)
152{
153	if (!flist_empty(list)) {
154		__flist_splice(list, head->prev, head);
155		INIT_FLIST_HEAD(list);
156	}
157}
158
159static inline void flist_splice_init(struct flist_head *list,
160				    struct flist_head *head)
161{
162	if (!flist_empty(list)) {
163		__flist_splice(list, head, head->next);
164		INIT_FLIST_HEAD(list);
165	}
166}
167
168/**
169 * flist_entry - get the struct for this entry
170 * @ptr:	the &struct flist_head pointer.
171 * @type:	the type of the struct this is embedded in.
172 * @member:	the name of the flist_struct within the struct.
173 */
174#define flist_entry(ptr, type, member) \
175	container_of(ptr, type, member)
176
177#define flist_first_entry(ptr, type, member) \
178	flist_entry((ptr)->next, type, member)
179
180/**
181 * flist_for_each	-	iterate over a list
182 * @pos:	the &struct flist_head to use as a loop counter.
183 * @head:	the head for your list.
184 */
185#define flist_for_each(pos, head) \
186	for (pos = (head)->next; pos != (head); pos = pos->next)
187
188/**
189 * flist_for_each_safe	-	iterate over a list safe against removal of list entry
190 * @pos:	the &struct flist_head to use as a loop counter.
191 * @n:		another &struct flist_head to use as temporary storage
192 * @head:	the head for your list.
193 */
194#define flist_for_each_safe(pos, n, head) \
195	for (pos = (head)->next, n = pos->next; pos != (head); \
196		pos = n, n = pos->next)
197
198extern void flist_sort(void *priv, struct flist_head *head,
199	int (*cmp)(void *priv, struct flist_head *a, struct flist_head *b));
200
201#endif
202