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