1 /* Stripped down version of the Linux 2.6.30 list.h */
2
3 #include <stddef.h>
4
5 /*
6 * These are non-NULL pointers that will result in page faults
7 * under normal circumstances, used to verify that nobody uses
8 * non-initialized list entries.
9 */
10 #define LIST_POISON1 ((void *) 0x00100100)
11 #define LIST_POISON2 ((void *) 0x00200200)
12
13 /**
14 * container_of - cast a member of a structure out to the containing structure
15 * @ptr: the pointer to the member.
16 * @type: the type of the container struct this is embedded in.
17 * @member: the name of the member within the struct.
18 *
19 */
20 #define container_of(ptr, type, member) ({ \
21 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
22 (type *)( (char *)__mptr - offsetof(type,member) );})
23
24 struct list_head {
25 struct list_head *next, *prev;
26 };
27
28 #define LIST_HEAD_INIT(name) { &(name), &(name) }
29
30 #define LIST_HEAD(name) \
31 struct list_head name = LIST_HEAD_INIT(name)
32
INIT_LIST_HEAD(struct list_head * list)33 static inline void INIT_LIST_HEAD(struct list_head *list)
34 {
35 list->next = list;
36 list->prev = list;
37 }
38
39 /*
40 * Insert a new entry between two known consecutive entries.
41 *
42 * This is only for internal list manipulation where we know
43 * the prev/next entries already!
44 */
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)45 static inline void __list_add(struct list_head *new,
46 struct list_head *prev,
47 struct list_head *next)
48 {
49 next->prev = new;
50 new->next = next;
51 new->prev = prev;
52 prev->next = new;
53 }
54
55 /**
56 * list_add - add a new entry
57 * @new: new entry to be added
58 * @head: list head to add it after
59 *
60 * Insert a new entry after the specified head.
61 * This is good for implementing stacks.
62 */
list_add(struct list_head * new,struct list_head * head)63 static inline void list_add(struct list_head *new, struct list_head *head)
64 {
65 __list_add(new, head, head->next);
66 }
67
68
69 /**
70 * list_add_tail - add a new entry
71 * @new: new entry to be added
72 * @head: list head to add it before
73 *
74 * Insert a new entry before the specified head.
75 * This is useful for implementing queues.
76 */
list_add_tail(struct list_head * new,struct list_head * head)77 static inline void list_add_tail(struct list_head *new, struct list_head *head)
78 {
79 __list_add(new, head->prev, head);
80 }
81
82 /*
83 * Delete a list entry by making the prev/next entries
84 * point to each other.
85 *
86 * This is only for internal list manipulation where we know
87 * the prev/next entries already!
88 */
__list_del(struct list_head * prev,struct list_head * next)89 static inline void __list_del(struct list_head * prev, struct list_head * next)
90 {
91 next->prev = prev;
92 prev->next = next;
93 }
94
list_del(struct list_head * entry)95 static inline void list_del(struct list_head *entry)
96 {
97 __list_del(entry->prev, entry->next);
98 entry->next = LIST_POISON1;
99 entry->prev = LIST_POISON2;
100 }
101
102 /**
103 * list_is_last - tests whether @list is the last entry in list @head
104 * @list: the entry to test
105 * @head: the head of the list
106 */
list_is_last(const struct list_head * list,const struct list_head * head)107 static inline int list_is_last(const struct list_head *list,
108 const struct list_head *head)
109 {
110 return list->next == head;
111 }
112
113 /**
114 * list_is_first - tests whether @list is the first entry in list @head
115 * @list: the entry to test
116 * @head: the head of the list
117 */
list_is_first(const struct list_head * list,const struct list_head * head)118 static inline int list_is_first(const struct list_head *list,
119 const struct list_head *head)
120 {
121 return list == head->next;
122 }
123
124 /**
125 * list_empty - tests whether a list is empty
126 * @head: the list to test.
127 */
list_empty(const struct list_head * head)128 static inline int list_empty(const struct list_head *head)
129 {
130 return head->next == head;
131 }
132
133
134 /**
135 * list_entry - get the struct for this entry
136 * @ptr: the &struct list_head pointer.
137 * @type: the type of the struct this is embedded in.
138 * @member: the name of the list_struct within the struct.
139 */
140 #define list_entry(ptr, type, member) \
141 container_of(ptr, type, member)
142
143 /**
144 * list_first_entry - get the first element from a list
145 * @ptr: the list head to take the element from.
146 * @type: the type of the struct this is embedded in.
147 * @member: the name of the list_struct within the struct.
148 *
149 * Note, that list is expected to be not empty.
150 */
151 #define list_first_entry(ptr, type, member) \
152 list_entry((ptr)->next, type, member)
153
154 /**
155 * list_last_entry - get the last element from a list
156 * @ptr: the list head to take the element from.
157 * @type: the type of the struct this is embedded in.
158 * @member: the name of the list_head within the struct.
159 *
160 * Note, that list is expected to be not empty.
161 */
162 #define list_last_entry(ptr, type, member) \
163 list_entry((ptr)->prev, type, member)
164
165 /**
166 * list_for_each - iterate over a list
167 * @pos: the &struct list_head to use as a loop cursor.
168 * @head: the head for your list.
169 */
170 #define list_for_each(pos, head) \
171 for (pos = (head)->next; pos != (head); \
172 pos = pos->next)
173
174 /**
175 * list_for_each_prev - iterate over a list backwards
176 * @pos: the &struct list_head to use as a loop cursor.
177 * @head: the head for your list.
178 */
179 #define list_for_each_prev(pos, head) \
180 for (pos = (head)->prev; pos != (head); \
181 pos = pos->prev)
182
183 /**
184 * list_for_each_safe - iterate over a list safe against removal of list entry
185 * @pos: the &struct list_head to use as a loop cursor.
186 * @n: another &struct list_head to use as temporary storage
187 * @head: the head for your list.
188 */
189 #define list_for_each_safe(pos, n, head) \
190 for (pos = (head)->next, n = pos->next; pos != (head); \
191 pos = n, n = pos->next)
192
193
194 /**
195 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
196 * @pos: the &struct list_head to use as a loop cursor.
197 * @n: another &struct list_head to use as temporary storage
198 * @head: the head for your list.
199 */
200 #define list_for_each_prev_safe(pos, n, head) \
201 for (pos = (head)->prev, n = pos->prev; \
202 pos != (head); \
203 pos = n, n = pos->prev)
204
205 /**
206 * list_for_each_entry - iterate over list of given type
207 * @pos: the type * to use as a loop cursor.
208 * @head: the head for your list.
209 * @member: the name of the list_struct within the struct.
210 */
211 #define list_for_each_entry(pos, head, member) \
212 for (pos = list_entry((head)->next, typeof(*pos), member); \
213 &pos->member != (head); \
214 pos = list_entry(pos->member.next, typeof(*pos), member))
215
216
217 /**
218 * list_for_each_entry_reverse - iterate backwards over list of given type.
219 * @pos: the type * to use as a loop cursor.
220 * @head: the head for your list.
221 * @member: the name of the list_struct within the struct.
222 */
223 #define list_for_each_entry_reverse(pos, head, member) \
224 for (pos = list_entry((head)->prev, typeof(*pos), member); \
225 &pos->member != (head); \
226 pos = list_entry(pos->member.prev, typeof(*pos), member))
227
228 /**
229 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
230 * @pos: the type * to use as a loop cursor.
231 * @n: another type * to use as temporary storage
232 * @head: the head for your list.
233 * @member: the name of the list_struct within the struct.
234 */
235 #define list_for_each_entry_safe(pos, n, head, member) \
236 for (pos = list_entry((head)->next, typeof(*pos), member), \
237 n = list_entry(pos->member.next, typeof(*pos), member); \
238 &pos->member != (head); \
239 pos = n, n = list_entry(n->member.next, typeof(*n), member))
240