1 #ifndef _LINUX_LIST_H 2 #define _LINUX_LIST_H 3 4 #include <stdio.h> 5 6 #ifndef offsetof 7 /** 8 * Get offset of a member 9 */ 10 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) 11 #endif 12 13 #ifndef container_of 14 /** 15 * Casts a member of a structure out to the containing structure 16 * @param ptr the pointer to the member. 17 * @param type the type of the container struct this is embedded in. 18 * @param member the name of the member within the struct. 19 * 20 */ 21 #define container_of(ptr, type, member) ({ \ 22 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 23 (type *)( (char *)__mptr - offsetof(type,member) );}) 24 #endif 25 26 /* 27 * These are non-NULL pointers that will result in page faults 28 * under normal circumstances, used to verify that nobody uses 29 * non-initialized list entries. 30 */ 31 #define LIST_POISON1 ((void *) 0x00100100) 32 #define LIST_POISON2 ((void *) 0x00200200) 33 34 struct list_head { 35 struct list_head *next, *prev; 36 }; 37 38 #define LIST_HEAD_INIT(name) { &(name), &(name) } 39 40 #define LIST_HEAD(name) \ 41 struct list_head name = LIST_HEAD_INIT(name) 42 43 static inline void INIT_LIST_HEAD(struct list_head *list) 44 { 45 list->next = list; 46 list->prev = list; 47 } 48 49 /* 50 * Insert a new entry between two known consecutive entries. 51 * 52 * This is only for internal list manipulation where we know 53 * the prev/next entries already! 54 */ 55 static inline void __list_add(struct list_head *new, 56 struct list_head *prev, 57 struct list_head *next) 58 { 59 next->prev = new; 60 new->next = next; 61 new->prev = prev; 62 prev->next = new; 63 } 64 65 /** 66 * list_add - add a new entry 67 * @new: new entry to be added 68 * @head: list head to add it after 69 * 70 * Insert a new entry after the specified head. 71 * This is good for implementing stacks. 72 */ 73 static inline void list_add(struct list_head *new, struct list_head *head) 74 { 75 __list_add(new, head, head->next); 76 } 77 78 /** 79 * list_add_tail - add a new entry 80 * @new: new entry to be added 81 * @head: list head to add it before 82 * 83 * Insert a new entry before the specified head. 84 * This is useful for implementing queues. 85 */ 86 static inline void list_add_tail(struct list_head *new, struct list_head *head) 87 { 88 __list_add(new, head->prev, head); 89 } 90 91 /* 92 * Delete a list entry by making the prev/next entries 93 * point to each other. 94 * 95 * This is only for internal list manipulation where we know 96 * the prev/next entries already! 97 */ 98 static inline void __list_del(struct list_head * prev, struct list_head * next) 99 { 100 next->prev = prev; 101 prev->next = next; 102 } 103 104 /** 105 * list_del - deletes entry from list. 106 * @entry: the element to delete from the list. 107 * Note: list_empty on entry does not return true after this, the entry is 108 * in an undefined state. 109 */ 110 static inline void list_del(struct list_head *entry) 111 { 112 __list_del(entry->prev, entry->next); 113 entry->next = LIST_POISON1; 114 entry->prev = LIST_POISON2; 115 } 116 117 /** 118 * __list_for_each - iterate over a list 119 * @pos: the &struct list_head to use as a loop counter. 120 * @head: the head for your list. 121 * 122 * This variant differs from list_for_each() in that it's the 123 * simplest possible list iteration code, no prefetching is done. 124 * Use this for code that knows the list to be very short (empty 125 * or 1 entry) most of the time. 126 */ 127 #define __list_for_each(pos, head) \ 128 for (pos = (head)->next; pos != (head); pos = pos->next) 129 130 /** 131 * list_for_each_safe - iterate over a list safe against removal of list entry 132 * @pos: the &struct list_head to use as a loop counter. 133 * @n: another &struct list_head to use as temporary storage 134 * @head: the head for your list. 135 */ 136 #define list_for_each_safe(pos, n, head) \ 137 for (pos = (head)->next, n = pos->next; pos != (head); \ 138 pos = n, n = pos->next) 139 140 /** 141 * list_entry - get the struct for this entry 142 * @ptr: the &struct list_head pointer. 143 * @type: the type of the struct this is embedded in. 144 * @member: the name of the list_struct within the struct. 145 */ 146 #define list_entry(ptr, type, member) \ 147 container_of(ptr, type, member) 148 149 static inline int list_len(struct list_head *head_p) 150 { 151 struct list_head *p; 152 int n = 0; 153 154 __list_for_each(p, head_p) { 155 n++; 156 } 157 158 return n; 159 } 160 161 /** 162 * list_empty - tests whether a list is empty 163 * @head: the list to test. 164 */ 165 static inline int list_empty(const struct list_head *head) 166 { 167 return head->next == head; 168 } 169 170 /** 171 * list_first - Returns first entry on list, or NULL if empty 172 * @head: the list 173 */ 174 static inline struct list_head *list_first(const struct list_head *head) 175 { 176 return list_empty(head) ? NULL : head->next; 177 } 178 179 /** 180 * list_move_tail - delete from one list and add as another's tail 181 * @list: the entry to move 182 * @head: the head that will follow our entry 183 */ 184 static inline void list_move_tail(struct list_head *list, 185 struct list_head *head) 186 { 187 __list_del(list->prev, list->next); 188 list_add_tail(list, head); 189 } 190 191 static inline void __list_splice(struct list_head *list, 192 struct list_head *head) 193 { 194 struct list_head *first = list->next; 195 struct list_head *last = list->prev; 196 struct list_head *at = head->next; 197 198 first->prev = head; 199 head->next = first; 200 201 last->next = at; 202 at->prev = last; 203 } 204 205 /** 206 * * list_splice - join two lists 207 * * @list: the new list to add. 208 * * @head: the place to add it in the first list. 209 * */ 210 static inline void list_splice(struct list_head *list, struct list_head *head) 211 { 212 if (!list_empty(list)) 213 __list_splice(list, head); 214 } 215 216 /** 217 * list_replace - replace old entry by new one 218 * @old : the element to be replaced 219 * @new : the new element to insert 220 * 221 * If @old was empty, it will be overwritten. 222 */ 223 static inline void list_replace(struct list_head *old, 224 struct list_head *new) 225 { 226 new->next = old->next; 227 new->next->prev = new; 228 new->prev = old->prev; 229 new->prev->next = new; 230 } 231 232 static inline void list_replace_init(struct list_head *old, 233 struct list_head *new) 234 { 235 list_replace(old, new); 236 INIT_LIST_HEAD(old); 237 } 238 239 #endif 240
