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63eba147 JA |
1 | #ifndef _LINUX_LIST_H |
2 | #define _LINUX_LIST_H | |
3 | ||
4f931928 AB |
4 | #include <stdio.h> |
5 | ||
6 | #ifndef offsetof | |
7 | /** | |
8 | * Get offset of a member | |
9 | */ | |
10 | #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) | |
11 | #endif | |
12 | ||
13 | #ifndef container_of | |
14 | /** | |
15 | * Casts a member of a structure out to the containing structure | |
16 | * @param ptr the pointer to the member. | |
17 | * @param type the type of the container struct this is embedded in. | |
18 | * @param member the name of the member within the struct. | |
19 | * | |
20 | */ | |
21 | #define container_of(ptr, type, member) ({ \ | |
22 | const typeof( ((type *)0)->member ) *__mptr = (ptr); \ | |
23 | (type *)( (char *)__mptr - offsetof(type,member) );}) | |
24 | #endif | |
25 | ||
63eba147 JA |
26 | /* |
27 | * These are non-NULL pointers that will result in page faults | |
28 | * under normal circumstances, used to verify that nobody uses | |
29 | * non-initialized list entries. | |
30 | */ | |
31 | #define LIST_POISON1 ((void *) 0x00100100) | |
32 | #define LIST_POISON2 ((void *) 0x00200200) | |
33 | ||
34 | struct list_head { | |
35 | struct list_head *next, *prev; | |
36 | }; | |
37 | ||
38 | #define LIST_HEAD_INIT(name) { &(name), &(name) } | |
39 | ||
40 | #define LIST_HEAD(name) \ | |
41 | struct list_head name = LIST_HEAD_INIT(name) | |
42 | ||
43 | static inline void INIT_LIST_HEAD(struct list_head *list) | |
44 | { | |
45 | list->next = list; | |
46 | list->prev = list; | |
47 | } | |
48 | ||
49 | /* | |
50 | * Insert a new entry between two known consecutive entries. | |
51 | * | |
52 | * This is only for internal list manipulation where we know | |
53 | * the prev/next entries already! | |
54 | */ | |
55 | static inline void __list_add(struct list_head *new, | |
56 | struct list_head *prev, | |
57 | struct list_head *next) | |
58 | { | |
59 | next->prev = new; | |
60 | new->next = next; | |
61 | new->prev = prev; | |
62 | prev->next = new; | |
63 | } | |
64 | ||
65 | /** | |
66 | * list_add - add a new entry | |
67 | * @new: new entry to be added | |
68 | * @head: list head to add it after | |
69 | * | |
70 | * Insert a new entry after the specified head. | |
71 | * This is good for implementing stacks. | |
72 | */ | |
73 | static inline void list_add(struct list_head *new, struct list_head *head) | |
74 | { | |
75 | __list_add(new, head, head->next); | |
76 | } | |
77 | ||
78 | /** | |
79 | * list_add_tail - add a new entry | |
80 | * @new: new entry to be added | |
81 | * @head: list head to add it before | |
82 | * | |
83 | * Insert a new entry before the specified head. | |
84 | * This is useful for implementing queues. | |
85 | */ | |
86 | static inline void list_add_tail(struct list_head *new, struct list_head *head) | |
87 | { | |
88 | __list_add(new, head->prev, head); | |
89 | } | |
90 | ||
91 | /* | |
92 | * Delete a list entry by making the prev/next entries | |
93 | * point to each other. | |
94 | * | |
95 | * This is only for internal list manipulation where we know | |
96 | * the prev/next entries already! | |
97 | */ | |
98 | static inline void __list_del(struct list_head * prev, struct list_head * next) | |
99 | { | |
100 | next->prev = prev; | |
101 | prev->next = next; | |
102 | } | |
103 | ||
104 | /** | |
105 | * list_del - deletes entry from list. | |
106 | * @entry: the element to delete from the list. | |
107 | * Note: list_empty on entry does not return true after this, the entry is | |
108 | * in an undefined state. | |
109 | */ | |
110 | static inline void list_del(struct list_head *entry) | |
111 | { | |
112 | __list_del(entry->prev, entry->next); | |
113 | entry->next = LIST_POISON1; | |
114 | entry->prev = LIST_POISON2; | |
115 | } | |
116 | ||
117 | /** | |
118 | * __list_for_each - iterate over a list | |
119 | * @pos: the &struct list_head to use as a loop counter. | |
120 | * @head: the head for your list. | |
121 | * | |
122 | * This variant differs from list_for_each() in that it's the | |
123 | * simplest possible list iteration code, no prefetching is done. | |
124 | * Use this for code that knows the list to be very short (empty | |
125 | * or 1 entry) most of the time. | |
126 | */ | |
127 | #define __list_for_each(pos, head) \ | |
128 | for (pos = (head)->next; pos != (head); pos = pos->next) | |
129 | ||
130 | /** | |
131 | * list_for_each_safe - iterate over a list safe against removal of list entry | |
132 | * @pos: the &struct list_head to use as a loop counter. | |
133 | * @n: another &struct list_head to use as temporary storage | |
134 | * @head: the head for your list. | |
135 | */ | |
136 | #define list_for_each_safe(pos, n, head) \ | |
137 | for (pos = (head)->next, n = pos->next; pos != (head); \ | |
138 | pos = n, n = pos->next) | |
139 | ||
140 | /** | |
141 | * list_entry - get the struct for this entry | |
142 | * @ptr: the &struct list_head pointer. | |
143 | * @type: the type of the struct this is embedded in. | |
144 | * @member: the name of the list_struct within the struct. | |
145 | */ | |
146 | #define list_entry(ptr, type, member) \ | |
147 | container_of(ptr, type, member) | |
148 | ||
149 | static inline int list_len(struct list_head *head_p) | |
150 | { | |
151 | struct list_head *p; | |
152 | int n = 0; | |
153 | ||
154 | __list_for_each(p, head_p) { | |
155 | n++; | |
156 | } | |
157 | ||
158 | return n; | |
159 | } | |
160 | ||
161 | /** | |
162 | * list_empty - tests whether a list is empty | |
163 | * @head: the list to test. | |
164 | */ | |
165 | static inline int list_empty(const struct list_head *head) | |
166 | { | |
167 | return head->next == head; | |
168 | } | |
169 | ||
095181f2 JA |
170 | /** |
171 | * list_first - Returns first entry on list, or NULL if empty | |
172 | * @head: the list | |
173 | */ | |
174 | static inline struct list_head *list_first(const struct list_head *head) | |
175 | { | |
176 | return list_empty(head) ? NULL : head->next; | |
177 | } | |
178 | ||
179 | /** | |
180 | * list_move_tail - delete from one list and add as another's tail | |
181 | * @list: the entry to move | |
182 | * @head: the head that will follow our entry | |
183 | */ | |
184 | static inline void list_move_tail(struct list_head *list, | |
185 | struct list_head *head) | |
186 | { | |
187 | __list_del(list->prev, list->next); | |
188 | list_add_tail(list, head); | |
189 | } | |
190 | ||
4f931928 AB |
191 | static inline void __list_splice(struct list_head *list, |
192 | struct list_head *head) | |
193 | { | |
194 | struct list_head *first = list->next; | |
195 | struct list_head *last = list->prev; | |
196 | struct list_head *at = head->next; | |
197 | ||
198 | first->prev = head; | |
199 | head->next = first; | |
200 | ||
201 | last->next = at; | |
202 | at->prev = last; | |
203 | } | |
204 | ||
205 | /** | |
206 | * * list_splice - join two lists | |
207 | * * @list: the new list to add. | |
208 | * * @head: the place to add it in the first list. | |
209 | * */ | |
210 | static inline void list_splice(struct list_head *list, struct list_head *head) | |
211 | { | |
212 | if (!list_empty(list)) | |
213 | __list_splice(list, head); | |
214 | } | |
215 | ||
3fe0b570 AB |
216 | /** |
217 | * list_replace - replace old entry by new one | |
218 | * @old : the element to be replaced | |
219 | * @new : the new element to insert | |
220 | * | |
221 | * If @old was empty, it will be overwritten. | |
222 | */ | |
223 | static inline void list_replace(struct list_head *old, | |
224 | struct list_head *new) | |
225 | { | |
226 | new->next = old->next; | |
227 | new->next->prev = new; | |
228 | new->prev = old->prev; | |
229 | new->prev->next = new; | |
230 | } | |
231 | ||
232 | static inline void list_replace_init(struct list_head *old, | |
233 | struct list_head *new) | |
234 | { | |
235 | list_replace(old, new); | |
236 | INIT_LIST_HEAD(old); | |
237 | } | |
238 | ||
63eba147 | 239 | #endif |