1 #ifndef __LIST_H__
2 #define __LIST_H__
3
4 /* GCS: I ripped this off from the linux kernel. Minor modifications. */
5
6 #if defined (WIN32)
7 #define inline __inline
8 #endif
9
10 /* #define prefetch(a) (a) */
11 #define prefetch(a) 0
12
13 /*
14 * Simple doubly linked list implementation.
15 *
16 * Some of the internal functions ("__xxx") are useful when
17 * manipulating whole lists rather than single entries, as
18 * sometimes we already know the next/prev entries and we can
19 * generate better code by using them directly rather than
20 * using the generic single-entry routines.
21 */
22
23 struct list_head {
24 struct list_head *next, *prev;
25 };
26 typedef struct list_head LIST;
27
28
29 #define LIST_HEAD_INIT(name) { &(name), &(name) }
30
31 #define LIST_HEAD(name) \
32 struct list_head name = LIST_HEAD_INIT(name)
33
34 #define INIT_LIST_HEAD(ptr) do { \
35 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
36 } while (0)
37
38 /*
39 * Insert a new entry between two known consecutive entries.
40 *
41 * This is only for internal list manipulation where we know
42 * the prev/next entries already!
43 */
__list_add(struct list_head * new,struct list_head * prev,struct list_head * next)44 static inline void __list_add(struct list_head *new,
45 struct list_head *prev,
46 struct list_head *next)
47 {
48 next->prev = new;
49 new->next = next;
50 new->prev = prev;
51 prev->next = new;
52 }
53
54 /**
55 * list_add - add a new entry
56 * @new: new entry to be added
57 * @head: list head to add it after
58 *
59 * Insert a new entry after the specified head.
60 * This is good for implementing stacks.
61 */
list_add(struct list_head * new,struct list_head * head)62 static inline void list_add(struct list_head *new, struct list_head *head)
63 {
64 __list_add(new, head, head->next);
65 }
66
67 /**
68 * list_add_tail - add a new entry
69 * @new: new entry to be added
70 * @head: list head to add it before
71 *
72 * Insert a new entry before the specified head.
73 * This is useful for implementing queues.
74 */
list_add_tail(struct list_head * new,struct list_head * head)75 static inline void list_add_tail(struct list_head *new, struct list_head *head)
76 {
77 __list_add(new, head->prev, head);
78 }
79
80 /*
81 * Delete a list entry by making the prev/next entries
82 * point to each other.
83 *
84 * This is only for internal list manipulation where we know
85 * the prev/next entries already!
86 */
__list_del(struct list_head * prev,struct list_head * next)87 static inline void __list_del(struct list_head *prev, struct list_head *next)
88 {
89 next->prev = prev;
90 prev->next = next;
91 }
92
93 /**
94 * list_del - deletes entry from list.
95 * @entry: the element to delete from the list.
96 * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
97 */
list_del(struct list_head * entry)98 static inline void list_del(struct list_head *entry)
99 {
100 __list_del(entry->prev, entry->next);
101 entry->next = (void *) 0;
102 entry->prev = (void *) 0;
103 }
104
105 /**
106 * list_del_init - deletes entry from list and reinitialize it.
107 * @entry: the element to delete from the list.
108 */
list_del_init(struct list_head * entry)109 static inline void list_del_init(struct list_head *entry)
110 {
111 __list_del(entry->prev, entry->next);
112 INIT_LIST_HEAD(entry);
113 }
114
115 /**
116 * list_move - delete from one list and add as another's head
117 * @list: the entry to move
118 * @head: the head that will precede our entry
119 */
list_move(struct list_head * list,struct list_head * head)120 static inline void list_move(struct list_head *list, struct list_head *head)
121 {
122 __list_del(list->prev, list->next);
123 list_add(list, head);
124 }
125
126 /**
127 * list_move_tail - delete from one list and add as another's tail
128 * @list: the entry to move
129 * @head: the head that will follow our entry
130 */
list_move_tail(struct list_head * list,struct list_head * head)131 static inline void list_move_tail(struct list_head *list,
132 struct list_head *head)
133 {
134 __list_del(list->prev, list->next);
135 list_add_tail(list, head);
136 }
137
138 /**
139 * list_empty - tests whether a list is empty
140 * @head: the list to test.
141 */
list_empty(struct list_head * head)142 static inline int list_empty(struct list_head *head)
143 {
144 return head->next == head;
145 }
146
__list_splice(struct list_head * list,struct list_head * head)147 static inline void __list_splice(struct list_head *list,
148 struct list_head *head)
149 {
150 struct list_head *first = list->next;
151 struct list_head *last = list->prev;
152 struct list_head *at = head->next;
153
154 first->prev = head;
155 head->next = first;
156
157 last->next = at;
158 at->prev = last;
159 }
160
161 /**
162 * list_splice - join two lists
163 * @list: the new list to add.
164 * @head: the place to add it in the first list.
165 */
list_splice(struct list_head * list,struct list_head * head)166 static inline void list_splice(struct list_head *list, struct list_head *head)
167 {
168 if (!list_empty(list))
169 __list_splice(list, head);
170 }
171
172 /**
173 * list_splice_init - join two lists and reinitialise the emptied list.
174 * @list: the new list to add.
175 * @head: the place to add it in the first list.
176 *
177 * The list at @list is reinitialised
178 */
list_splice_init(struct list_head * list,struct list_head * head)179 static inline void list_splice_init(struct list_head *list,
180 struct list_head *head)
181 {
182 if (!list_empty(list)) {
183 __list_splice(list, head);
184 INIT_LIST_HEAD(list);
185 }
186 }
187
188 /**
189 * list_entry - get the struct for this entry
190 * @ptr: the &struct list_head pointer.
191 * @type: the type of the struct this is embedded in.
192 * @member: the name of the list_struct within the struct.
193 */
194 #define list_entry(ptr, type, member) \
195 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
196
197 /**
198 * list_for_each - iterate over a list
199 * @pos: the &struct list_head to use as a loop counter.
200 * @head: the head for your list.
201 */
202 #define list_for_each(pos, head) \
203 for (pos = (head)->next, prefetch(pos->next); pos != (head); \
204 pos = pos->next, prefetch(pos->next))
205 /**
206 * list_for_each_prev - iterate over a list backwards
207 * @pos: the &struct list_head to use as a loop counter.
208 * @head: the head for your list.
209 */
210 #define list_for_each_prev(pos, head) \
211 for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
212 pos = pos->prev, prefetch(pos->prev))
213
214 /**
215 * list_for_each_safe - iterate over a list safe against removal of list entry
216 * @pos: the &struct list_head to use as a loop counter.
217 * @n: another &struct list_head to use as temporary storage
218 * @head: the head for your list.
219 */
220 #define list_for_each_safe(pos, n, head) \
221 for (pos = (head)->next, n = pos->next; pos != (head); \
222 pos = n, n = pos->next)
223
224 /**
225 * list_for_each_entry - iterate over list of given type
226 * @pos: the type * to use as a loop counter.
227 * @type: the type of the struct this is embedded in.
228 * @head: the head for your list.
229 * @member: the name of the list_struct within the struct.
230 */
231 #if defined (commentout)
232 #define list_for_each_entry(pos, head, member) \
233 for (pos = list_entry((head)->next, typeof(*pos), member), \
234 prefetch(pos->member.next); \
235 &pos->member != (head); \
236 pos = list_entry(pos->member.next, typeof(*pos), member), \
237 prefetch(pos->member.next))
238 #endif
239 #define list_for_each_entry(pos, type, head, member) \
240 for (pos = list_entry((head)->next, type, member), \
241 prefetch(pos->member.next); \
242 &pos->member != (head); \
243 pos = list_entry(pos->member.next, type, member), \
244 prefetch(pos->member.next))
245
246 /**
247 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
248 * @pos: the type * to use as a loop counter.
249 * @type: the type of the struct this is embedded in.
250 * @n: another type * to use as temporary storage
251 * @head: the head for your list.
252 * @member: the name of the list_struct within the struct.
253 */
254 #if defined (commentout)
255 #define list_for_each_entry_safe(pos, n, head, member) \
256 for (pos = list_entry((head)->next, typeof(*pos), member), \
257 n = list_entry(pos->member.next, typeof(*pos), member); \
258 &pos->member != (head); \
259 pos = n, n = list_entry(n->member.next, typeof(*n), member))
260 #endif
261 #define list_for_each_entry_safe(pos, type, n, head, member) \
262 for (pos = list_entry((head)->next, type, member), \
263 n = list_entry(pos->member.next, type, member); \
264 &pos->member != (head); \
265 pos = n, n = list_entry(n->member.next, type, member))
266
267 /**
268 * list_for_each_entry_continue - iterate over list of given type
269 * continuing after existing point
270 * @pos: the type * to use as a loop counter.
271 * @head: the head for your list.
272 * @member: the name of the list_struct within the struct.
273 */
274 #define list_for_each_entry_continue(pos, head, member) \
275 for (pos = list_entry(pos->member.next, typeof(*pos), member), \
276 prefetch(pos->member.next); \
277 &pos->member != (head); \
278 pos = list_entry(pos->member.next, typeof(*pos), member), \
279 prefetch(pos->member.next))
280
281 #endif
282