1 #ifndef _LINUX_LIST_H 2 #define _LINUX_LIST_H 3 4 /* 5 * Simple doubly linked list implementation. 6 * 7 * Some of the internal functions ("__xxx") are useful when 8 * manipulating whole lists rather than single entries, as 9 * sometimes we already know the next/prev entries and we can 10 * generate better code by using them directly rather than 11 * using the generic single-entry routines. 12 */ 13 14 struct list_head { 15 struct list_head *next, *prev; 16 }; 17 18 #define LIST_HEAD_INIT(name) { &(name), &(name) } 19 20 #define LIST_HEAD(name) \ 21 struct list_head name = { &name, &name } 22 23 #define INIT_LIST_HEAD(ptr) do { \ 24 (ptr)->next = (ptr); (ptr)->prev = (ptr); \ 25 } while (0) 26 27 #if (!defined(__GNUC__) && !defined(__WATCOMC__)) 28 #define __inline__ 29 #endif 30 31 /* 32 * Insert a new entry between two known consecutive entries. 33 * 34 * This is only for internal list manipulation where we know 35 * the prev/next entries already! 36 */ 37 static __inline__ void __list_add(struct list_head * new, 38 struct list_head * prev, 39 struct list_head * next) 40 { 41 next->prev = new; 42 new->next = next; 43 new->prev = prev; 44 prev->next = new; 45 } 46 47 /* 48 * Insert a new entry after the specified head.. 49 */ 50 static __inline__ void list_add(struct list_head *new, struct list_head *head) 51 { 52 __list_add(new, head, head->next); 53 } 54 55 /* 56 * Insert a new entry at the tail 57 */ 58 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head) 59 { 60 __list_add(new, head->prev, head); 61 } 62 63 /* 64 * Delete a list entry by making the prev/next entries 65 * point to each other. 66 * 67 * This is only for internal list manipulation where we know 68 * the prev/next entries already! 69 */ 70 static __inline__ void __list_del(struct list_head * prev, 71 struct list_head * next) 72 { 73 next->prev = prev; 74 prev->next = next; 75 } 76 77 static __inline__ void list_del(struct list_head *entry) 78 { 79 __list_del(entry->prev, entry->next); 80 } 81 82 static __inline__ int list_empty(struct list_head *head) 83 { 84 return head->next == head; 85 } 86 87 /* 88 * Splice in "list" into "head" 89 */ 90 static __inline__ void list_splice(struct list_head *list, struct list_head *head) 91 { 92 struct list_head *first = list->next; 93 94 if (first != list) { 95 struct list_head *last = list->prev; 96 struct list_head *at = head->next; 97 98 first->prev = head; 99 head->next = first; 100 101 last->next = at; 102 at->prev = last; 103 } 104 } 105 106 #define list_entry(ptr, type, member) \ 107 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) 108 109 #define list_for_each(pos, head) \ 110 for (pos = (head)->next; pos != (head); pos = pos->next) 111 112 #endif 113
