Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 1 | #ifndef _LINUX_FLIST_H |
| 2 | #define _LINUX_FLIST_H |
| 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 | |
| 25 | struct flist_head { |
| 26 | struct flist_head *next, *prev; |
| 27 | }; |
| 28 | |
| 29 | #define FLIST_HEAD_INIT(name) { &(name), &(name) } |
| 30 | |
| 31 | #define FLIST_HEAD(name) \ |
| 32 | struct flist_head name = FLIST_HEAD_INIT(name) |
| 33 | |
| 34 | #define INIT_FLIST_HEAD(ptr) do { \ |
| 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 | */ |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 44 | static inline void __flist_add(struct flist_head *new_entry, |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 45 | struct flist_head *prev, |
| 46 | struct flist_head *next) |
| 47 | { |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 48 | next->prev = new_entry; |
| 49 | new_entry->next = next; |
| 50 | new_entry->prev = prev; |
| 51 | prev->next = new_entry; |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 52 | } |
| 53 | |
| 54 | /** |
| 55 | * flist_add - add a new entry |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 56 | * @new_entry: new entry to be added |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 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 | */ |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 62 | static inline void flist_add(struct flist_head *new_entry, |
| 63 | struct flist_head *head) |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 64 | { |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 65 | __flist_add(new_entry, head, head->next); |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 66 | } |
| 67 | |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 68 | static inline void flist_add_tail(struct flist_head *new_entry, |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 69 | struct flist_head *head) |
| 70 | { |
Daniel Rall | 2b52511 | 2008-09-10 08:56:01 +0200 | [diff] [blame] | 71 | __flist_add(new_entry, head->prev, head); |
Jens Axboe | 01743ee | 2008-06-02 12:19:19 +0200 | [diff] [blame] | 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 | */ |
| 81 | static inline void __flist_del(struct flist_head *prev, |
| 82 | struct flist_head * next) |
| 83 | { |
| 84 | next->prev = prev; |
| 85 | prev->next = next; |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * flist_del - deletes entry from list. |
| 90 | * @entry: the element to delete from the list. |
| 91 | * Note: flist_empty on entry does not return true after this, the entry is |
| 92 | * in an undefined state. |
| 93 | */ |
| 94 | static inline void flist_del(struct flist_head *entry) |
| 95 | { |
| 96 | __flist_del(entry->prev, entry->next); |
| 97 | entry->next = NULL; |
| 98 | entry->prev = NULL; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * flist_del_init - deletes entry from list and reinitialize it. |
| 103 | * @entry: the element to delete from the list. |
| 104 | */ |
| 105 | static inline void flist_del_init(struct flist_head *entry) |
| 106 | { |
| 107 | __flist_del(entry->prev, entry->next); |
| 108 | INIT_FLIST_HEAD(entry); |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * flist_empty - tests whether a list is empty |
| 113 | * @head: the list to test. |
| 114 | */ |
| 115 | static inline int flist_empty(const struct flist_head *head) |
| 116 | { |
| 117 | return head->next == head; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * flist_entry - get the struct for this entry |
| 122 | * @ptr: the &struct flist_head pointer. |
| 123 | * @type: the type of the struct this is embedded in. |
| 124 | * @member: the name of the flist_struct within the struct. |
| 125 | */ |
| 126 | #define flist_entry(ptr, type, member) \ |
| 127 | container_of(ptr, type, member) |
| 128 | |
| 129 | /** |
| 130 | * flist_for_each - iterate over a list |
| 131 | * @pos: the &struct flist_head to use as a loop counter. |
| 132 | * @head: the head for your list. |
| 133 | */ |
| 134 | #define flist_for_each(pos, head) \ |
| 135 | for (pos = (head)->next; pos != (head); pos = pos->next) |
| 136 | |
| 137 | /** |
| 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 |
| 141 | * @head: the head for your list. |
| 142 | */ |
| 143 | #define flist_for_each_safe(pos, n, head) \ |
| 144 | for (pos = (head)->next, n = pos->next; pos != (head); \ |
| 145 | pos = n, n = pos->next) |
| 146 | |
| 147 | #endif |