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 INIT_LIST_HEAD(ptr) do { \ 21 (ptr)->next = (ptr); (ptr)->prev = (ptr); \ 22 } while (0) 23 24 #if (!defined(__GNUC__) && !defined(__WATCOMC__)) 25 #define __inline__ 26 #endif 27 28 /* 29 * Insert a new entry between two known consecutive entries. 30 * 31 * This is only for internal list manipulation where we know 32 * the prev/next entries already! 33 */ 34 static __inline__ void __list_add(struct list_head * new, 35 struct list_head * prev, 36 struct list_head * next) 37 { 38 next->prev = new; 39 new->next = next; 40 new->prev = prev; 41 prev->next = new; 42 } 43 44 /* 45 * Insert a new entry after the specified head.. 46 */ 47 static __inline__ void list_add(struct list_head *new, struct list_head *head) 48 { 49 __list_add(new, head, head->next); 50 } 51 52 /* 53 * Insert a new entry at the tail 54 */ 55 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head) 56 { 57 __list_add(new, head->prev, head); 58 } 59 60 /* 61 * Delete a list entry by making the prev/next entries 62 * point to each other. 63 * 64 * This is only for internal list manipulation where we know 65 * the prev/next entries already! 66 */ 67 static __inline__ void __list_del(struct list_head * prev, 68 struct list_head * next) 69 { 70 next->prev = prev; 71 prev->next = next; 72 } 73 74 static __inline__ void list_del(struct list_head *entry) 75 { 76 __list_del(entry->prev, entry->next); 77 } 78 79 static __inline__ int list_empty(struct list_head *head) 80 { 81 return head->next == head; 82 } 83 84 /* 85 * Splice in "list" into "head" 86 */ 87 static __inline__ void list_splice(struct list_head *list, struct list_head *head) 88 { 89 struct list_head *first = list->next; 90 91 if (first != list) { 92 struct list_head *last = list->prev; 93 struct list_head *at = head->next; 94 95 first->prev = head; 96 head->next = first; 97 98 last->next = at; 99 at->prev = last; 100 } 101 } 102 103 #define list_entry(ptr, type, member) \ 104 ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) 105 106 #define list_for_each(pos, head) \ 107 for (pos = (head)->next; pos != (head); pos = pos->next) 108 109 #endif 110
