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54f1c58c JB |
1 | #ifndef __LIST_H |
2 | #define __LIST_H | |
3 | ||
4 | /* This file is from Linux Kernel (include/linux/list.h) | |
5 | * and modified by simply removing hardware prefetching of list items. | |
6 | * Here by copyright, credits attributed to wherever they belong. | |
7 | * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu) | |
8 | */ | |
9 | ||
10 | /* | |
11 | * Simple doubly linked list implementation. | |
12 | * | |
13 | * Some of the internal functions ("__xxx") are useful when | |
14 | * manipulating whole lists rather than single entries, as | |
15 | * sometimes we already know the next/prev entries and we can | |
16 | * generate better code by using them directly rather than | |
17 | * using the generic single-entry routines. | |
18 | */ | |
19 | ||
20 | struct list_head { | |
21 | struct list_head *next, *prev; | |
22 | }; | |
23 | ||
24 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
25 | ||
26 | #define LIST_HEAD(name) \ | |
27 | struct list_head name = LIST_HEAD_INIT(name) | |
28 | ||
29 | #define INIT_LIST_HEAD(ptr) do { \ | |
30 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ | |
31 | } while (0) | |
32 | ||
33 | /* | |
34 | * Insert a new entry between two known consecutive entries. | |
35 | * | |
36 | * This is only for internal list manipulation where we know | |
37 | * the prev/next entries already! | |
38 | */ | |
39 | static inline void __list_add(struct list_head *new, | |
40 | struct list_head *prev, | |
41 | struct list_head *next) | |
42 | { | |
43 | next->prev = new; | |
44 | new->next = next; | |
45 | new->prev = prev; | |
46 | prev->next = new; | |
47 | } | |
48 | ||
49 | /** | |
50 | * list_add - add a new entry | |
51 | * @new: new entry to be added | |
52 | * @head: list head to add it after | |
53 | * | |
54 | * Insert a new entry after the specified head. | |
55 | * This is good for implementing stacks. | |
56 | */ | |
57 | static inline void list_add(struct list_head *new, struct list_head *head) | |
58 | { | |
59 | __list_add(new, head, head->next); | |
60 | } | |
61 | ||
62 | /** | |
63 | * list_add_tail - add a new entry | |
64 | * @new: new entry to be added | |
65 | * @head: list head to add it before | |
66 | * | |
67 | * Insert a new entry before the specified head. | |
68 | * This is useful for implementing queues. | |
69 | */ | |
70 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
71 | { | |
72 | __list_add(new, head->prev, head); | |
73 | } | |
74 | ||
75 | /* | |
76 | * Delete a list entry by making the prev/next entries | |
77 | * point to each other. | |
78 | * | |
79 | * This is only for internal list manipulation where we know | |
80 | * the prev/next entries already! | |
81 | */ | |
82 | static inline void __list_del(struct list_head *prev, struct list_head *next) | |
83 | { | |
84 | next->prev = prev; | |
85 | prev->next = next; | |
86 | } | |
87 | ||
88 | /** | |
89 | * list_del - deletes entry from list. | |
90 | * @entry: the element to delete from the list. | |
91 | * Note: list_empty on entry does not return true after this, the entry is in an undefined state. | |
92 | */ | |
93 | static inline void list_del(struct list_head *entry) | |
94 | { | |
95 | __list_del(entry->prev, entry->next); | |
96 | entry->next = (void *) 0; | |
97 | entry->prev = (void *) 0; | |
98 | } | |
99 | ||
100 | /** | |
101 | * list_del_init - deletes entry from list and reinitialize it. | |
102 | * @entry: the element to delete from the list. | |
103 | */ | |
104 | static inline void list_del_init(struct list_head *entry) | |
105 | { | |
106 | __list_del(entry->prev, entry->next); | |
107 | INIT_LIST_HEAD(entry); | |
108 | } | |
109 | ||
110 | /** | |
111 | * list_move - delete from one list and add as another's head | |
112 | * @list: the entry to move | |
113 | * @head: the head that will precede our entry | |
114 | */ | |
115 | static inline void list_move(struct list_head *list, struct list_head *head) | |
116 | { | |
117 | __list_del(list->prev, list->next); | |
118 | list_add(list, head); | |
119 | } | |
120 | ||
121 | /** | |
122 | * list_move_tail - delete from one list and add as another's tail | |
123 | * @list: the entry to move | |
124 | * @head: the head that will follow our entry | |
125 | */ | |
126 | static inline void list_move_tail(struct list_head *list, | |
127 | struct list_head *head) | |
128 | { | |
129 | __list_del(list->prev, list->next); | |
130 | list_add_tail(list, head); | |
131 | } | |
132 | ||
133 | /** | |
134 | * list_empty - tests whether a list is empty | |
135 | * @head: the list to test. | |
136 | */ | |
137 | static inline int list_empty(struct list_head *head) | |
138 | { | |
139 | return head->next == head; | |
140 | } | |
141 | ||
142 | static inline void __list_splice(struct list_head *list, | |
143 | struct list_head *head) | |
144 | { | |
145 | struct list_head *first = list->next; | |
146 | struct list_head *last = list->prev; | |
147 | struct list_head *at = head->next; | |
148 | ||
149 | first->prev = head; | |
150 | head->next = first; | |
151 | ||
152 | last->next = at; | |
153 | at->prev = last; | |
154 | } | |
155 | ||
156 | /** | |
157 | * list_splice - join two lists | |
158 | * @list: the new list to add. | |
159 | * @head: the place to add it in the first list. | |
160 | */ | |
161 | static inline void list_splice(struct list_head *list, struct list_head *head) | |
162 | { | |
163 | if (!list_empty(list)) | |
164 | __list_splice(list, head); | |
165 | } | |
166 | ||
167 | /** | |
168 | * list_splice_init - join two lists and reinitialise the emptied list. | |
169 | * @list: the new list to add. | |
170 | * @head: the place to add it in the first list. | |
171 | * | |
172 | * The list at @list is reinitialised | |
173 | */ | |
174 | static inline void list_splice_init(struct list_head *list, | |
175 | struct list_head *head) | |
176 | { | |
177 | if (!list_empty(list)) { | |
178 | __list_splice(list, head); | |
179 | INIT_LIST_HEAD(list); | |
180 | } | |
181 | } | |
182 | ||
183 | /** | |
184 | * list_entry - get the struct for this entry | |
185 | * @ptr: the &struct list_head pointer. | |
186 | * @type: the type of the struct this is embedded in. | |
187 | * @member: the name of the list_struct within the struct. | |
188 | */ | |
189 | #define list_entry(ptr, type, member) \ | |
190 | ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) | |
191 | ||
192 | /** | |
193 | * list_for_each - iterate over a list | |
194 | * @pos: the &struct list_head to use as a loop counter. | |
195 | * @head: the head for your list. | |
196 | */ | |
197 | #define list_for_each(pos, head) \ | |
198 | for (pos = (head)->next; pos != (head); \ | |
199 | pos = pos->next) | |
200 | /** | |
201 | * list_for_each_prev - iterate over a list backwards | |
202 | * @pos: the &struct list_head to use as a loop counter. | |
203 | * @head: the head for your list. | |
204 | */ | |
205 | #define list_for_each_prev(pos, head) \ | |
206 | for (pos = (head)->prev; pos != (head); \ | |
207 | pos = pos->prev) | |
208 | ||
209 | /** | |
210 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
211 | * @pos: the &struct list_head to use as a loop counter. | |
212 | * @n: another &struct list_head to use as temporary storage | |
213 | * @head: the head for your list. | |
214 | */ | |
215 | #define list_for_each_safe(pos, n, head) \ | |
216 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
217 | pos = n, n = pos->next) | |
218 | ||
219 | /** | |
220 | * list_for_each_entry - iterate over list of given type | |
221 | * @pos: the type * to use as a loop counter. | |
222 | * @head: the head for your list. | |
223 | * @member: the name of the list_struct within the struct. | |
224 | */ | |
225 | #define list_for_each_entry(pos, head, member) \ | |
226 | for (pos = list_entry((head)->next, typeof(*pos), member); \ | |
227 | &pos->member != (head); \ | |
228 | pos = list_entry(pos->member.next, typeof(*pos), member)) | |
229 | ||
230 | /** | |
231 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry | |
232 | * @pos: the type * to use as a loop counter. | |
233 | * @n: another type * to use as temporary storage | |
234 | * @head: the head for your list. | |
235 | * @member: the name of the list_struct within the struct. | |
236 | */ | |
237 | #define list_for_each_entry_safe(pos, n, head, member) \ | |
238 | for (pos = list_entry((head)->next, typeof(*pos), member), \ | |
239 | n = list_entry(pos->member.next, typeof(*pos), member); \ | |
240 | &pos->member != (head); \ | |
241 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) | |
242 | ||
243 | ||
244 | #endif |