[7242996] | 1 | #ifndef _LINUX_LIST_H |
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| 2 | #define _LINUX_LIST_H |
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| 3 | |
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| 4 | #include <stddef.h> |
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| 5 | |
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| 6 | #define container_of(ptr, type, member) ({ \ |
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| 7 | typeof( ((type *)0)->member ) *__mptr = (ptr); \ |
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| 8 | (type *)( (char *)__mptr - offsetof(type,member) );}) |
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| 9 | |
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| 10 | /* |
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| 11 | * These are non-NULL pointers that will result in page faults |
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| 12 | * under normal circumstances, used to verify that nobody uses |
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| 13 | * non-initialized list entries. |
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| 14 | */ |
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| 15 | #define LIST_POISON1 ((void *) 0x00100100) |
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| 16 | #define LIST_POISON2 ((void *) 0x00200200) |
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| 17 | |
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| 18 | /* |
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| 19 | * Simple doubly linked list implementation. |
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| 20 | * |
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| 21 | * Some of the internal functions ("__xxx") are useful when |
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| 22 | * manipulating whole lists rather than single entries, as |
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| 23 | * sometimes we already know the next/prev entries and we can |
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| 24 | * generate better code by using them directly rather than |
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| 25 | * using the generic single-entry routines. |
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| 26 | */ |
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| 27 | |
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| 28 | struct list_head { |
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| 29 | struct list_head *next, *prev; |
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| 30 | }; |
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| 31 | |
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| 32 | #define LIST_HEAD_INIT(name) { &(name), &(name) } |
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| 33 | |
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| 34 | #define LIST_HEAD(name) \ |
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| 35 | struct list_head name = LIST_HEAD_INIT(name) |
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| 36 | |
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| 37 | #define INIT_LIST_HEAD(ptr) do { \ |
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| 38 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ |
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| 39 | } while (0) |
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| 40 | |
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| 41 | /* |
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| 42 | * Insert a new entry between two known consecutive entries. |
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| 43 | * |
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| 44 | * This is only for internal list manipulation where we know |
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| 45 | * the prev/next entries already! |
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| 46 | */ |
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| 47 | static inline void __list_add(struct list_head *new, |
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| 48 | struct list_head *prev, |
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| 49 | struct list_head *next) |
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| 50 | { |
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| 51 | next->prev = new; |
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| 52 | new->next = next; |
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| 53 | new->prev = prev; |
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| 54 | prev->next = new; |
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| 55 | } |
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| 56 | |
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| 57 | /** |
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| 58 | * list_add - add a new entry |
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| 59 | * @new: new entry to be added |
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| 60 | * @head: list head to add it after |
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| 61 | * |
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| 62 | * Insert a new entry after the specified head. |
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| 63 | * This is good for implementing stacks. |
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| 64 | */ |
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| 65 | static inline void list_add(struct list_head *new, struct list_head *head) |
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| 66 | { |
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| 67 | __list_add(new, head, head->next); |
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| 68 | } |
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| 69 | |
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| 70 | /** |
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| 71 | * list_add_tail - add a new entry |
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| 72 | * @new: new entry to be added |
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| 73 | * @head: list head to add it before |
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| 74 | * |
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| 75 | * Insert a new entry before the specified head. |
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| 76 | * This is useful for implementing queues. |
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| 77 | */ |
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| 78 | static inline void list_add_tail(struct list_head *new, struct list_head *head) |
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| 79 | { |
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| 80 | __list_add(new, head->prev, head); |
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| 81 | } |
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| 82 | |
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| 83 | /* |
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| 84 | * Delete a list entry by making the prev/next entries |
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| 85 | * point to each other. |
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| 86 | * |
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| 87 | * This is only for internal list manipulation where we know |
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| 88 | * the prev/next entries already! |
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| 89 | */ |
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| 90 | static inline void __list_del(struct list_head * prev, struct list_head * next) |
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| 91 | { |
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| 92 | next->prev = prev; |
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| 93 | prev->next = next; |
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| 94 | } |
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| 95 | |
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| 96 | /** |
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| 97 | * list_del - deletes entry from list. |
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| 98 | * @entry: the element to delete from the list. |
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| 99 | * Note: list_empty on entry does not return true after this, the entry is |
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| 100 | * in an undefined state. |
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| 101 | */ |
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| 102 | static inline void list_del(struct list_head *entry) |
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| 103 | { |
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| 104 | __list_del(entry->prev, entry->next); |
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| 105 | entry->next = LIST_POISON1; |
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| 106 | entry->prev = LIST_POISON2; |
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| 107 | } |
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| 108 | |
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| 109 | /** |
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| 110 | * list_empty - tests whether a list is empty |
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| 111 | * @head: the list to test. |
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| 112 | */ |
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| 113 | static inline int list_empty(const struct list_head *head) |
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| 114 | { |
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| 115 | return head->next == head; |
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| 116 | } |
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| 117 | |
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| 118 | /** |
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| 119 | * list_entry - get the struct for this entry |
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| 120 | * @ptr: the &struct list_head pointer. |
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| 121 | * @type: the type of the struct this is embedded in. |
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| 122 | * @member: the name of the list_struct within the struct. |
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| 123 | */ |
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| 124 | #define list_entry(ptr, type, member) \ |
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| 125 | container_of(ptr, type, member) |
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| 126 | |
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| 127 | /** |
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| 128 | * list_first_entry - get the first element from a list |
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| 129 | * @ptr: the list head to take the element from. |
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| 130 | * @type: the type of the struct this is embedded in. |
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| 131 | * @member: the name of the list_head within the struct. |
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| 132 | * |
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| 133 | * Note, that list is expected to be not empty. |
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| 134 | */ |
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| 135 | #define list_first_entry(ptr, type, member) \ |
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| 136 | list_entry((ptr)->next, type, member) |
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| 137 | |
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| 138 | /** |
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| 139 | * list_for_each_entry - iterate over list of given type |
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| 140 | * @pos: the type * to use as a loop counter. |
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| 141 | * @head: the head for your list. |
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| 142 | * @member: the name of the list_struct within the struct. |
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| 143 | */ |
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| 144 | #define list_for_each_entry(pos, head, member) \ |
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| 145 | for (pos = list_entry((head)->next, typeof(*pos), member); \ |
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| 146 | &pos->member != (head); \ |
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| 147 | pos = list_entry(pos->member.next, typeof(*pos), member)) |
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| 148 | |
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| 149 | /** |
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| 150 | * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry |
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| 151 | * @pos: the type * to use as a loop counter. |
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| 152 | * @n: another type * to use as temporary storage |
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| 153 | * @head: the head for your list. |
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| 154 | * @member: the name of the list_struct within the struct. |
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| 155 | */ |
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| 156 | #define list_for_each_entry_safe(pos, n, head, member) \ |
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| 157 | for (pos = list_entry((head)->next, typeof(*pos), member), \ |
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| 158 | n = list_entry(pos->member.next, typeof(*pos), member); \ |
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| 159 | &pos->member != (head); \ |
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| 160 | pos = n, n = list_entry(n->member.next, typeof(*n), member)) |
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| 161 | |
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| 162 | #endif |
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