Yet another rate fixup
[fio.git] / flist.h
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1#ifndef _LINUX_FLIST_H
2#define _LINUX_FLIST_H
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3
4#undef offsetof
5#ifdef __compiler_offsetof
6#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
7#else
8#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
9#endif
10
11#define container_of(ptr, type, member) ({ \
12 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
13 (type *)( (char *)__mptr - offsetof(type,member) );})
14
15/*
16 * Simple doubly linked list implementation.
17 *
18 * Some of the internal functions ("__xxx") are useful when
19 * manipulating whole lists rather than single entries, as
20 * sometimes we already know the next/prev entries and we can
21 * generate better code by using them directly rather than
22 * using the generic single-entry routines.
23 */
24
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25struct flist_head {
26 struct flist_head *next, *prev;
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27};
28
01743ee1 29#define FLIST_HEAD_INIT(name) { &(name), &(name) }
ebac4655 30
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31#define FLIST_HEAD(name) \
32 struct flist_head name = FLIST_HEAD_INIT(name)
5f350952 33
01743ee1 34#define INIT_FLIST_HEAD(ptr) do { \
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35 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
36} while (0)
37
38/*
39 * Insert a new entry between two known consecutive entries.
40 *
41 * This is only for internal list manipulation where we know
42 * the prev/next entries already!
43 */
2b52511f 44static inline void __flist_add(struct flist_head *new_entry,
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45 struct flist_head *prev,
46 struct flist_head *next)
ebac4655 47{
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48 next->prev = new_entry;
49 new_entry->next = next;
50 new_entry->prev = prev;
51 prev->next = new_entry;
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52}
53
54/**
01743ee1 55 * flist_add - add a new entry
2b52511f 56 * @new_entry: new entry to be added
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57 * @head: list head to add it after
58 *
59 * Insert a new entry after the specified head.
60 * This is good for implementing stacks.
61 */
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62static inline void flist_add(struct flist_head *new_entry,
63 struct flist_head *head)
ebac4655 64{
2b52511f 65 __flist_add(new_entry, head, head->next);
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66}
67
2b52511f 68static inline void flist_add_tail(struct flist_head *new_entry,
01743ee1 69 struct flist_head *head)
ebac4655 70{
2b52511f 71 __flist_add(new_entry, head->prev, head);
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72}
73
74/*
75 * Delete a list entry by making the prev/next entries
76 * point to each other.
77 *
78 * This is only for internal list manipulation where we know
79 * the prev/next entries already!
80 */
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81static inline void __flist_del(struct flist_head *prev,
82 struct flist_head * next)
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83{
84 next->prev = prev;
85 prev->next = next;
86}
87
88/**
01743ee1 89 * flist_del - deletes entry from list.
ebac4655 90 * @entry: the element to delete from the list.
01743ee1 91 * Note: flist_empty on entry does not return true after this, the entry is
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92 * in an undefined state.
93 */
01743ee1 94static inline void flist_del(struct flist_head *entry)
ebac4655 95{
01743ee1 96 __flist_del(entry->prev, entry->next);
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97 entry->next = NULL;
98 entry->prev = NULL;
99}
100
94a08ec6 101/**
01743ee1 102 * flist_del_init - deletes entry from list and reinitialize it.
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103 * @entry: the element to delete from the list.
104 */
01743ee1 105static inline void flist_del_init(struct flist_head *entry)
94a08ec6 106{
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107 __flist_del(entry->prev, entry->next);
108 INIT_FLIST_HEAD(entry);
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109}
110
ebac4655 111/**
01743ee1 112 * flist_empty - tests whether a list is empty
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113 * @head: the list to test.
114 */
01743ee1 115static inline int flist_empty(const struct flist_head *head)
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116{
117 return head->next == head;
118}
119
120/**
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121 * flist_entry - get the struct for this entry
122 * @ptr: the &struct flist_head pointer.
ebac4655 123 * @type: the type of the struct this is embedded in.
01743ee1 124 * @member: the name of the flist_struct within the struct.
ebac4655 125 */
01743ee1 126#define flist_entry(ptr, type, member) \
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127 container_of(ptr, type, member)
128
129/**
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130 * flist_for_each - iterate over a list
131 * @pos: the &struct flist_head to use as a loop counter.
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132 * @head: the head for your list.
133 */
01743ee1 134#define flist_for_each(pos, head) \
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135 for (pos = (head)->next; pos != (head); pos = pos->next)
136
137/**
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138 * flist_for_each_safe - iterate over a list safe against removal of list entry
139 * @pos: the &struct flist_head to use as a loop counter.
140 * @n: another &struct flist_head to use as temporary storage
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141 * @head: the head for your list.
142 */
01743ee1 143#define flist_for_each_safe(pos, n, head) \
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144 for (pos = (head)->next, n = pos->next; pos != (head); \
145 pos = n, n = pos->next)
146
147#endif