Harald Welte | 52b1f98 | 2008-12-23 20:25:15 +0000 | [diff] [blame] | 1 | #ifndef _LINUX_LLIST_H |
| 2 | #define _LINUX_LLIST_H |
| 3 | |
| 4 | #include <stddef.h> |
| 5 | |
| 6 | #ifndef inline |
| 7 | #define inline __inline__ |
| 8 | #endif |
| 9 | |
| 10 | static inline void prefetch(const void *x) {;} |
| 11 | |
| 12 | /** |
| 13 | * container_of - cast a member of a structure out to the containing structure |
| 14 | * |
| 15 | * @ptr: the pointer to the member. |
| 16 | * @type: the type of the container struct this is embedded in. |
| 17 | * @member: the name of the member within the struct. |
| 18 | * |
| 19 | */ |
| 20 | #define container_of(ptr, type, member) ({ \ |
| 21 | const typeof( ((type *)0)->member ) *__mptr = (ptr); \ |
| 22 | (type *)( (char *)__mptr - offsetof(type,member) );}) |
| 23 | |
| 24 | |
| 25 | /* |
| 26 | * These are non-NULL pointers that will result in page faults |
| 27 | * under normal circumstances, used to verify that nobody uses |
| 28 | * non-initialized llist entries. |
| 29 | */ |
| 30 | #define LLIST_POISON1 ((void *) 0x00100100) |
| 31 | #define LLIST_POISON2 ((void *) 0x00200200) |
| 32 | |
| 33 | /* |
| 34 | * Simple doubly linked llist implementation. |
| 35 | * |
| 36 | * Some of the internal functions ("__xxx") are useful when |
| 37 | * manipulating whole llists rather than single entries, as |
| 38 | * sometimes we already know the next/prev entries and we can |
| 39 | * generate better code by using them directly rather than |
| 40 | * using the generic single-entry routines. |
| 41 | */ |
| 42 | |
| 43 | struct llist_head { |
| 44 | struct llist_head *next, *prev; |
| 45 | }; |
| 46 | |
| 47 | #define LLIST_HEAD_INIT(name) { &(name), &(name) } |
| 48 | |
| 49 | #define LLIST_HEAD(name) \ |
| 50 | struct llist_head name = LLIST_HEAD_INIT(name) |
| 51 | |
| 52 | #define INIT_LLIST_HEAD(ptr) do { \ |
| 53 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ |
| 54 | } while (0) |
| 55 | |
| 56 | /* |
| 57 | * Insert a new entry between two known consecutive entries. |
| 58 | * |
| 59 | * This is only for internal llist manipulation where we know |
| 60 | * the prev/next entries already! |
| 61 | */ |
| 62 | static inline void __llist_add(struct llist_head *new, |
| 63 | struct llist_head *prev, |
| 64 | struct llist_head *next) |
| 65 | { |
| 66 | next->prev = new; |
| 67 | new->next = next; |
| 68 | new->prev = prev; |
| 69 | prev->next = new; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * llist_add - add a new entry |
| 74 | * @new: new entry to be added |
| 75 | * @head: llist head to add it after |
| 76 | * |
| 77 | * Insert a new entry after the specified head. |
| 78 | * This is good for implementing stacks. |
| 79 | */ |
| 80 | static inline void llist_add(struct llist_head *new, struct llist_head *head) |
| 81 | { |
| 82 | __llist_add(new, head, head->next); |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * llist_add_tail - add a new entry |
| 87 | * @new: new entry to be added |
| 88 | * @head: llist head to add it before |
| 89 | * |
| 90 | * Insert a new entry before the specified head. |
| 91 | * This is useful for implementing queues. |
| 92 | */ |
| 93 | static inline void llist_add_tail(struct llist_head *new, struct llist_head *head) |
| 94 | { |
| 95 | __llist_add(new, head->prev, head); |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Delete a llist entry by making the prev/next entries |
| 100 | * point to each other. |
| 101 | * |
| 102 | * This is only for internal llist manipulation where we know |
| 103 | * the prev/next entries already! |
| 104 | */ |
| 105 | static inline void __llist_del(struct llist_head * prev, struct llist_head * next) |
| 106 | { |
| 107 | next->prev = prev; |
| 108 | prev->next = next; |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * llist_del - deletes entry from llist. |
| 113 | * @entry: the element to delete from the llist. |
| 114 | * Note: llist_empty on entry does not return true after this, the entry is |
| 115 | * in an undefined state. |
| 116 | */ |
| 117 | static inline void llist_del(struct llist_head *entry) |
| 118 | { |
| 119 | __llist_del(entry->prev, entry->next); |
| 120 | entry->next = LLIST_POISON1; |
| 121 | entry->prev = LLIST_POISON2; |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * llist_del_init - deletes entry from llist and reinitialize it. |
| 126 | * @entry: the element to delete from the llist. |
| 127 | */ |
| 128 | static inline void llist_del_init(struct llist_head *entry) |
| 129 | { |
| 130 | __llist_del(entry->prev, entry->next); |
| 131 | INIT_LLIST_HEAD(entry); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * llist_move - delete from one llist and add as another's head |
| 136 | * @llist: the entry to move |
| 137 | * @head: the head that will precede our entry |
| 138 | */ |
| 139 | static inline void llist_move(struct llist_head *llist, struct llist_head *head) |
| 140 | { |
| 141 | __llist_del(llist->prev, llist->next); |
| 142 | llist_add(llist, head); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * llist_move_tail - delete from one llist and add as another's tail |
| 147 | * @llist: the entry to move |
| 148 | * @head: the head that will follow our entry |
| 149 | */ |
| 150 | static inline void llist_move_tail(struct llist_head *llist, |
| 151 | struct llist_head *head) |
| 152 | { |
| 153 | __llist_del(llist->prev, llist->next); |
| 154 | llist_add_tail(llist, head); |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * llist_empty - tests whether a llist is empty |
| 159 | * @head: the llist to test. |
| 160 | */ |
| 161 | static inline int llist_empty(const struct llist_head *head) |
| 162 | { |
| 163 | return head->next == head; |
| 164 | } |
| 165 | |
| 166 | static inline void __llist_splice(struct llist_head *llist, |
| 167 | struct llist_head *head) |
| 168 | { |
| 169 | struct llist_head *first = llist->next; |
| 170 | struct llist_head *last = llist->prev; |
| 171 | struct llist_head *at = head->next; |
| 172 | |
| 173 | first->prev = head; |
| 174 | head->next = first; |
| 175 | |
| 176 | last->next = at; |
| 177 | at->prev = last; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * llist_splice - join two llists |
| 182 | * @llist: the new llist to add. |
| 183 | * @head: the place to add it in the first llist. |
| 184 | */ |
| 185 | static inline void llist_splice(struct llist_head *llist, struct llist_head *head) |
| 186 | { |
| 187 | if (!llist_empty(llist)) |
| 188 | __llist_splice(llist, head); |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * llist_splice_init - join two llists and reinitialise the emptied llist. |
| 193 | * @llist: the new llist to add. |
| 194 | * @head: the place to add it in the first llist. |
| 195 | * |
| 196 | * The llist at @llist is reinitialised |
| 197 | */ |
| 198 | static inline void llist_splice_init(struct llist_head *llist, |
| 199 | struct llist_head *head) |
| 200 | { |
| 201 | if (!llist_empty(llist)) { |
| 202 | __llist_splice(llist, head); |
| 203 | INIT_LLIST_HEAD(llist); |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * llist_entry - get the struct for this entry |
| 209 | * @ptr: the &struct llist_head pointer. |
| 210 | * @type: the type of the struct this is embedded in. |
| 211 | * @member: the name of the llist_struct within the struct. |
| 212 | */ |
| 213 | #define llist_entry(ptr, type, member) \ |
| 214 | container_of(ptr, type, member) |
| 215 | |
| 216 | /** |
| 217 | * llist_for_each - iterate over a llist |
| 218 | * @pos: the &struct llist_head to use as a loop counter. |
| 219 | * @head: the head for your llist. |
| 220 | */ |
| 221 | #define llist_for_each(pos, head) \ |
| 222 | for (pos = (head)->next, prefetch(pos->next); pos != (head); \ |
| 223 | pos = pos->next, prefetch(pos->next)) |
| 224 | |
| 225 | /** |
| 226 | * __llist_for_each - iterate over a llist |
| 227 | * @pos: the &struct llist_head to use as a loop counter. |
| 228 | * @head: the head for your llist. |
| 229 | * |
| 230 | * This variant differs from llist_for_each() in that it's the |
| 231 | * simplest possible llist iteration code, no prefetching is done. |
| 232 | * Use this for code that knows the llist to be very short (empty |
| 233 | * or 1 entry) most of the time. |
| 234 | */ |
| 235 | #define __llist_for_each(pos, head) \ |
| 236 | for (pos = (head)->next; pos != (head); pos = pos->next) |
| 237 | |
| 238 | /** |
| 239 | * llist_for_each_prev - iterate over a llist backwards |
| 240 | * @pos: the &struct llist_head to use as a loop counter. |
| 241 | * @head: the head for your llist. |
| 242 | */ |
| 243 | #define llist_for_each_prev(pos, head) \ |
| 244 | for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \ |
| 245 | pos = pos->prev, prefetch(pos->prev)) |
| 246 | |
| 247 | /** |
| 248 | * llist_for_each_safe - iterate over a llist safe against removal of llist entry |
| 249 | * @pos: the &struct llist_head to use as a loop counter. |
| 250 | * @n: another &struct llist_head to use as temporary storage |
| 251 | * @head: the head for your llist. |
| 252 | */ |
| 253 | #define llist_for_each_safe(pos, n, head) \ |
| 254 | for (pos = (head)->next, n = pos->next; pos != (head); \ |
| 255 | pos = n, n = pos->next) |
| 256 | |
| 257 | /** |
| 258 | * llist_for_each_entry - iterate over llist of given type |
| 259 | * @pos: the type * to use as a loop counter. |
| 260 | * @head: the head for your llist. |
| 261 | * @member: the name of the llist_struct within the struct. |
| 262 | */ |
| 263 | #define llist_for_each_entry(pos, head, member) \ |
| 264 | for (pos = llist_entry((head)->next, typeof(*pos), member), \ |
| 265 | prefetch(pos->member.next); \ |
| 266 | &pos->member != (head); \ |
| 267 | pos = llist_entry(pos->member.next, typeof(*pos), member), \ |
| 268 | prefetch(pos->member.next)) |
| 269 | |
| 270 | /** |
| 271 | * llist_for_each_entry_reverse - iterate backwards over llist of given type. |
| 272 | * @pos: the type * to use as a loop counter. |
| 273 | * @head: the head for your llist. |
| 274 | * @member: the name of the llist_struct within the struct. |
| 275 | */ |
| 276 | #define llist_for_each_entry_reverse(pos, head, member) \ |
| 277 | for (pos = llist_entry((head)->prev, typeof(*pos), member), \ |
| 278 | prefetch(pos->member.prev); \ |
| 279 | &pos->member != (head); \ |
| 280 | pos = llist_entry(pos->member.prev, typeof(*pos), member), \ |
| 281 | prefetch(pos->member.prev)) |
| 282 | |
| 283 | /** |
| 284 | * llist_for_each_entry_continue - iterate over llist of given type |
| 285 | * continuing after existing point |
| 286 | * @pos: the type * to use as a loop counter. |
| 287 | * @head: the head for your llist. |
| 288 | * @member: the name of the llist_struct within the struct. |
| 289 | */ |
| 290 | #define llist_for_each_entry_continue(pos, head, member) \ |
| 291 | for (pos = llist_entry(pos->member.next, typeof(*pos), member), \ |
| 292 | prefetch(pos->member.next); \ |
| 293 | &pos->member != (head); \ |
| 294 | pos = llist_entry(pos->member.next, typeof(*pos), member), \ |
| 295 | prefetch(pos->member.next)) |
| 296 | |
| 297 | /** |
| 298 | * llist_for_each_entry_safe - iterate over llist of given type safe against removal of llist entry |
| 299 | * @pos: the type * to use as a loop counter. |
| 300 | * @n: another type * to use as temporary storage |
| 301 | * @head: the head for your llist. |
| 302 | * @member: the name of the llist_struct within the struct. |
| 303 | */ |
| 304 | #define llist_for_each_entry_safe(pos, n, head, member) \ |
| 305 | for (pos = llist_entry((head)->next, typeof(*pos), member), \ |
| 306 | n = llist_entry(pos->member.next, typeof(*pos), member); \ |
| 307 | &pos->member != (head); \ |
| 308 | pos = n, n = llist_entry(n->member.next, typeof(*n), member)) |
| 309 | |
| 310 | /** |
| 311 | * llist_for_each_rcu - iterate over an rcu-protected llist |
| 312 | * @pos: the &struct llist_head to use as a loop counter. |
| 313 | * @head: the head for your llist. |
| 314 | */ |
| 315 | #define llist_for_each_rcu(pos, head) \ |
| 316 | for (pos = (head)->next, prefetch(pos->next); pos != (head); \ |
| 317 | pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next)) |
| 318 | |
| 319 | #define __llist_for_each_rcu(pos, head) \ |
| 320 | for (pos = (head)->next; pos != (head); \ |
| 321 | pos = pos->next, ({ smp_read_barrier_depends(); 0;})) |
| 322 | |
| 323 | /** |
| 324 | * llist_for_each_safe_rcu - iterate over an rcu-protected llist safe |
| 325 | * against removal of llist entry |
| 326 | * @pos: the &struct llist_head to use as a loop counter. |
| 327 | * @n: another &struct llist_head to use as temporary storage |
| 328 | * @head: the head for your llist. |
| 329 | */ |
| 330 | #define llist_for_each_safe_rcu(pos, n, head) \ |
| 331 | for (pos = (head)->next, n = pos->next; pos != (head); \ |
| 332 | pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next) |
| 333 | |
| 334 | /** |
| 335 | * llist_for_each_entry_rcu - iterate over rcu llist of given type |
| 336 | * @pos: the type * to use as a loop counter. |
| 337 | * @head: the head for your llist. |
| 338 | * @member: the name of the llist_struct within the struct. |
| 339 | */ |
| 340 | #define llist_for_each_entry_rcu(pos, head, member) \ |
| 341 | for (pos = llist_entry((head)->next, typeof(*pos), member), \ |
| 342 | prefetch(pos->member.next); \ |
| 343 | &pos->member != (head); \ |
| 344 | pos = llist_entry(pos->member.next, typeof(*pos), member), \ |
| 345 | ({ smp_read_barrier_depends(); 0;}), \ |
| 346 | prefetch(pos->member.next)) |
| 347 | |
| 348 | |
| 349 | /** |
| 350 | * llist_for_each_continue_rcu - iterate over an rcu-protected llist |
| 351 | * continuing after existing point. |
| 352 | * @pos: the &struct llist_head to use as a loop counter. |
| 353 | * @head: the head for your llist. |
| 354 | */ |
| 355 | #define llist_for_each_continue_rcu(pos, head) \ |
| 356 | for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \ |
| 357 | (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next)) |
| 358 | |
| 359 | |
| 360 | #endif |