| 1 |
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| 2 | #ifndef LIST_H
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| 3 | #define LIST_H
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| 4 |
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| 5 | #include <stddef.h>
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| 6 |
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| 7 | #include "list_types.h"
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| 8 |
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| 9 |
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| 10 | #define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
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| 11 |
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| 12 | |
| 13 | * container_of - cast a member of a structure out to the containing structure
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| 14 | * @ptr: the pointer to the member.
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| 15 | * @type: the type of the container struct this is embedded in.
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| 16 | * @member: the name of the member within the struct.
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| 17 | *
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| 18 |
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| 19 | #define container_of(ptr, type, member) ({ \
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| 20 | void *__mptr = (void *)(ptr); \
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| 21 | _Static_assert(__same_type(*(ptr), ((type *)0)->member) || \
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| 22 | __same_type(*(ptr), void), \
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| 23 | "pointer type mismatch in container_of()"); \
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| 24 | ((type *)(__mptr - offsetof(type, member))); })
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| 25 |
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| 26 | #define LIST_POISON1 ((void *) 0x100)
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| 27 | #define LIST_POISON2 ((void *) 0x122)
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| 28 |
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| 29 | |
| 30 | * Circular doubly linked list implementation.
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| 31 | *
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| 32 | * Some of the internal functions ("__xxx") are useful when
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| 33 | * manipulating whole lists rather than single entries, as
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| 34 | * sometimes we already know the next/prev entries and we can
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| 35 | * generate better code by using them directly rather than
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| 36 | * using the generic single-entry routines.
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| 37 |
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| 38 |
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| 39 | #define LIST_HEAD_INIT(name) { &(name), &(name) }
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| 40 |
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| 41 | #define LIST_HEAD(name) \
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| 42 | struct list_head name = LIST_HEAD_INIT(name)
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| 43 |
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| 44 | |
| 45 | * INIT_LIST_HEAD - Initialize a list_head structure
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| 46 | * @list: list_head structure to be initialized.
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| 47 | *
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| 48 | * Initializes the list_head to point to itself. If it is a list header,
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| 49 | * the result is an empty list.
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| 50 |
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| 51 | static inline void INIT_LIST_HEAD(struct list_head *list)
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| 52 | {
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| 53 | list->next = list;
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| 54 | list->prev = list;
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| 55 | }
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| 56 |
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| 57 | |
| 58 | * Insert a new entry between two known consecutive entries.
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| 59 | *
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| 60 | * This is only for internal list manipulation where we know
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| 61 | * the prev/next entries already!
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| 62 |
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| 63 | static inline void __list_add(struct list_head *new,
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| 64 | struct list_head *prev,
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| 65 | struct list_head *next)
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| 66 | {
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| 67 | next->prev = new;
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| 68 | new->next = next;
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| 69 | new->prev = prev;
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| 70 | prev->next = new;
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| 71 | }
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| 72 |
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| 73 | |
| 74 | * list_add - add a new entry
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| 75 | * @new: new entry to be added
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| 76 | * @head: list head to add it after
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| 77 | *
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| 78 | * Insert a new entry after the specified head.
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| 79 | * This is good for implementing stacks.
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| 80 |
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| 81 | static inline void list_add(struct list_head *new, struct list_head *head)
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| 82 | {
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| 83 | __list_add(new, head, head->next);
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| 84 | }
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| 85 |
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| 86 | |
| 87 | * list_add_tail - add a new entry
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| 88 | * @new: new entry to be added
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| 89 | * @head: list head to add it before
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| 90 | *
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| 91 | * Insert a new entry before the specified head.
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| 92 | * This is useful for implementing queues.
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| 93 |
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| 94 | static inline void list_add_tail(struct list_head *new, struct list_head *head)
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| 95 | {
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| 96 | __list_add(new, head->prev, head);
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| 97 | }
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| 98 |
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| 99 | |
| 100 | * Delete a list entry by making the prev/next entries
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| 101 | * point to each other.
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| 102 | *
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| 103 | * This is only for internal list manipulation where we know
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| 104 | * the prev/next entries already!
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| 105 |
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| 106 | static inline void __list_del(struct list_head *prev, struct list_head *next)
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| 107 | {
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| 108 | next->prev = prev;
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| 109 | prev->next = next;
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| 110 | }
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| 111 |
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| 112 | static inline void __list_del_entry(struct list_head *entry)
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| 113 | {
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| 114 | __list_del(entry->prev, entry->next);
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| 115 | }
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| 116 |
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| 117 | |
| 118 | * list_del - deletes entry from list.
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| 119 | * @entry: the element to delete from the list.
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| 120 | * Note: list_empty() on entry does not return true after this, the entry is
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| 121 | * in an undefined state.
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| 122 |
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| 123 | static inline void list_del(struct list_head *entry)
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| 124 | {
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| 125 | __list_del_entry(entry);
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| 126 | entry->next = LIST_POISON1;
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| 127 | entry->prev = LIST_POISON2;
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| 128 | }
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| 129 |
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| 130 | |
| 131 | * list_move - delete from one list and add as another's head
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| 132 | * @list: the entry to move
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| 133 | * @head: the head that will precede our entry
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| 134 |
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| 135 | static inline void list_move(struct list_head *list, struct list_head *head)
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| 136 | {
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| 137 | __list_del_entry(list);
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| 138 | list_add(list, head);
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| 139 | }
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| 140 |
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| 141 | |
| 142 | * list_move_tail - delete from one list and add as another's tail
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| 143 | * @list: the entry to move
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| 144 | * @head: the head that will follow our entry
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| 145 |
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| 146 | static inline void list_move_tail(struct list_head *list,
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| 147 | struct list_head *head)
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| 148 | {
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| 149 | __list_del_entry(list);
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| 150 | list_add_tail(list, head);
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| 151 | }
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| 152 |
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| 153 | |
| 154 | * list_is_head - tests whether @list is the list @head
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| 155 | * @list: the entry to test
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| 156 | * @head: the head of the list
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| 157 |
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| 158 | static inline int list_is_head(const struct list_head *list, const struct list_head *head)
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| 159 | {
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| 160 | return list == head;
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| 161 | }
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| 162 |
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| 163 | |
| 164 | * list_empty - tests whether a list is empty
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| 165 | * @head: the list to test.
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| 166 |
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| 167 | static inline int list_empty(const struct list_head *head)
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| 168 | {
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| 169 | return head->next == head;
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| 170 | }
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| 171 |
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| 172 | |
| 173 | * list_entry - get the struct for this entry
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| 174 | * @ptr: the &struct list_head pointer.
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| 175 | * @type: the type of the struct this is embedded in.
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| 176 | * @member: the name of the list_head within the struct.
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| 177 |
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| 178 | #define list_entry(ptr, type, member) \
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| 179 | container_of(ptr, type, member)
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| 180 |
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| 181 | |
| 182 | * list_first_entry - get the first element from a list
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| 183 | * @ptr: the list head to take the element from.
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| 184 | * @type: the type of the struct this is embedded in.
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| 185 | * @member: the name of the list_head within the struct.
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| 186 | *
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| 187 | * Note, that list is expected to be not empty.
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| 188 |
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| 189 | #define list_first_entry(ptr, type, member) \
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| 190 | list_entry((ptr)->next, type, member)
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| 191 |
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| 192 | |
| 193 | * list_last_entry - get the last element from a list
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| 194 | * @ptr: the list head to take the element from.
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| 195 | * @type: the type of the struct this is embedded in.
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| 196 | * @member: the name of the list_head within the struct.
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| 197 | *
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| 198 | * Note, that list is expected to be not empty.
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| 199 |
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| 200 | #define list_last_entry(ptr, type, member) \
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| 201 | list_entry((ptr)->prev, type, member)
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| 202 |
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| 203 | |
| 204 | * list_next_entry - get the next element in list
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| 205 | * @pos: the type * to cursor
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| 206 | * @member: the name of the list_head within the struct.
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| 207 |
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| 208 | #define list_next_entry(pos, member) \
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| 209 | list_entry((pos)->member.next, typeof(*(pos)), member)
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| 210 |
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| 211 | |
| 212 | * list_prev_entry - get the prev element in list
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| 213 | * @pos: the type * to cursor
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| 214 | * @member: the name of the list_head within the struct.
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| 215 |
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| 216 | #define list_prev_entry(pos, member) \
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| 217 | list_entry((pos)->member.prev, typeof(*(pos)), member)
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| 218 |
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| 219 | |
| 220 | * list_entry_is_head - test if the entry points to the head of the list
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| 221 | * @pos: the type * to cursor
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| 222 | * @head: the head for your list.
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| 223 | * @member: the name of the list_head within the struct.
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| 224 |
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| 225 | #define list_entry_is_head(pos, head, member) \
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| 226 | (&pos->member == (head))
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| 227 |
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| 228 | |
| 229 | * list_for_each_entry - iterate over list of given type
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| 230 | * @pos: the type * to use as a loop cursor.
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| 231 | * @head: the head for your list.
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| 232 | * @member: the name of the list_head within the struct.
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| 233 |
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| 234 | #define list_for_each_entry(pos, head, member) \
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| 235 | for (pos = list_first_entry(head, typeof(*pos), member); \
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| 236 | !list_entry_is_head(pos, head, member); \
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| 237 | pos = list_next_entry(pos, member))
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| 238 |
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| 239 | |
| 240 | * list_for_each_entry_reverse - iterate backwards over list of given type.
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| 241 | * @pos: the type * to use as a loop cursor.
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| 242 | * @head: the head for your list.
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| 243 | * @member: the name of the list_head within the struct.
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| 244 |
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| 245 | #define list_for_each_entry_reverse(pos, head, member) \
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| 246 | for (pos = list_last_entry(head, typeof(*pos), member); \
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| 247 | !list_entry_is_head(pos, head, member); \
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| 248 | pos = list_prev_entry(pos, member))
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| 249 |
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| 250 | |
| 251 | * list_for_each_entry_safe - iterate over list of given type. Safe against removal of list entry
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| 252 | * @pos: the type * to use as a loop cursor.
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| 253 | * @n: another type * to use as temporary storage
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| 254 | * @head: the head for your list.
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| 255 | * @member: the name of the list_head within the struct.
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| 256 |
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| 257 | #define list_for_each_entry_safe(pos, n, head, member) \
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| 258 | for (pos = list_first_entry(head, typeof(*pos), member), \
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| 259 | n = list_next_entry(pos, member); \
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| 260 | !list_entry_is_head(pos, head, member); \
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| 261 | pos = n, n = list_next_entry(n, member))
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| 262 |
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| 263 | |
| 264 | * Double linked lists with a single pointer list head.
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| 265 | * Mostly useful for hash tables where the two pointer list head is
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| 266 | * too wasteful.
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| 267 | * You lose the ability to access the tail in O(1).
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| 268 |
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| 269 |
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| 270 | #define HLIST_HEAD_INIT { .first = NULL }
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| 271 | #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
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| 272 | static inline void INIT_HLIST_NODE(struct hlist_node *h)
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| 273 | {
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| 274 | h->next = NULL;
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| 275 | h->pprev = NULL;
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| 276 | }
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| 277 |
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| 278 | |
| 279 | * hlist_unhashed - Has node been removed from list and reinitialized?
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| 280 | * @h: Node to be checked
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| 281 | *
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| 282 | * Not that not all removal functions will leave a node in unhashed
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| 283 | * state. For example, hlist_nulls_del_init_rcu() does leave the
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| 284 | * node in unhashed state, but hlist_nulls_del() does not.
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| 285 |
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| 286 | static inline int hlist_unhashed(const struct hlist_node *h)
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| 287 | {
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| 288 | return !h->pprev;
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| 289 | }
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| 290 |
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| 291 | static inline void __hlist_del(struct hlist_node *n)
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| 292 | {
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| 293 | struct hlist_node *next = n->next;
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| 294 | struct hlist_node **pprev = n->pprev;
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| 295 |
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| 296 | *pprev = next;
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| 297 | if (next)
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| 298 | next->pprev = pprev;
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| 299 | }
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| 300 |
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| 301 | |
| 302 | * hlist_del - Delete the specified hlist_node from its list
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| 303 | * @n: Node to delete.
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| 304 | *
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| 305 | * Note that this function leaves the node in hashed state. Use
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| 306 | * hlist_del_init() or similar instead to unhash @n.
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| 307 |
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| 308 | static inline void hlist_del(struct hlist_node *n)
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| 309 | {
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| 310 | __hlist_del(n);
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| 311 | n->next = LIST_POISON1;
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| 312 | n->pprev = LIST_POISON2;
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| 313 | }
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| 314 |
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| 315 | |
| 316 | * hlist_del_init - Delete the specified hlist_node from its list and initialize
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| 317 | * @n: Node to delete.
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| 318 | *
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| 319 | * Note that this function leaves the node in unhashed state.
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| 320 |
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| 321 | static inline void hlist_del_init(struct hlist_node *n)
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| 322 | {
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| 323 | if (!hlist_unhashed(n)) {
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| 324 | __hlist_del(n);
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| 325 | INIT_HLIST_NODE(n);
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| 326 | }
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| 327 | }
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| 328 |
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| 329 | |
| 330 | * hlist_add_head - add a new entry at the beginning of the hlist
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| 331 | * @n: new entry to be added
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| 332 | * @h: hlist head to add it after
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| 333 | *
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| 334 | * Insert a new entry after the specified head.
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| 335 | * This is good for implementing stacks.
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| 336 |
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| 337 | static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
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| 338 | {
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| 339 | struct hlist_node *first = h->first;
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| 340 |
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| 341 | n->next = first;
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| 342 | if (first)
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| 343 | first->pprev = &n->next;
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| 344 | h->first = n;
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| 345 | n->pprev = &h->first;
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| 346 | }
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| 347 |
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| 348 | #define hlist_entry(ptr, type, member) container_of(ptr, type, member)
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| 349 |
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| 350 | #define hlist_entry_safe(ptr, type, member) \
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| 351 | ({ typeof(ptr) ____ptr = (ptr); \
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| 352 | ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
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| 353 | })
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| 354 |
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| 355 | |
| 356 | * hlist_for_each_entry - iterate over list of given type
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| 357 | * @pos: the type * to use as a loop cursor.
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| 358 | * @head: the head for your list.
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| 359 | * @member: the name of the hlist_node within the struct.
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| 360 |
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| 361 | #define hlist_for_each_entry(pos, head, member) \
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| 362 | for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
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| 363 | pos; \
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| 364 | pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
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| 365 |
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| 366 | |
| 367 | * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
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| 368 | * @pos: the type * to use as a loop cursor.
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| 369 | * @n: a &struct hlist_node to use as temporary storage
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| 370 | * @head: the head for your list.
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| 371 | * @member: the name of the hlist_node within the struct.
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| 372 |
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| 373 | #define hlist_for_each_entry_safe(pos, n, head, member) \
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| 374 | for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
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| 375 | pos && ({ n = pos->member.next; 1; }); \
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| 376 | pos = hlist_entry_safe(n, typeof(*pos), member))
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| 377 |
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| 378 | #endif
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