1 /****************************************************************************** 2 * 3 * Copyright International Business Machines Corp., 2008 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * NAME 20 * list.h 21 * 22 * DESCRIPTION 23 * This code was kindly borrowed from linux/include/linux/list.h 24 * Some of the unneeded functions were removed for brevity sake. 25 * In addition, the container functions were added so we could 26 * access the container of the list from the list_head struct. 27 * 28 * USAGE: 29 * To be included in test cases 30 * 31 * AUTHOR 32 * Darren Hart <dvhltc (at) us.ibm.com> 33 * 34 * HISTORY 35 * 2006-Oct-17: Initial version by Darren Hart 36 * 37 *****************************************************************************/ 38 39 #ifndef _LINUX_LIST_H 40 #define _LINUX_LIST_H 41 42 /* 43 * These are non-NULL pointers that will result in page faults 44 * under normal circumstances, used to verify that nobody uses 45 * non-initialized list entries. 46 */ 47 #define LIST_POISON1 ((void *) 0x00100100) 48 #define LIST_POISON2 ((void *) 0x00200200) 49 50 /* 51 * Simple doubly linked list implementation. 52 * 53 * Some of the internal functions ("__xxx") are useful when 54 * manipulating whole lists rather than single entries, as 55 * sometimes we already know the next/prev entries and we can 56 * generate better code by using them directly rather than 57 * using the generic single-entry routines. 58 */ 59 60 struct list_head { 61 struct list_head *next, *prev; 62 }; 63 64 #define LIST_HEAD_INIT(name) { &(name), &(name) } 65 66 #define LIST_HEAD(name) \ 67 struct list_head name = LIST_HEAD_INIT(name) 68 69 static inline void INIT_LIST_HEAD(struct list_head *list) 70 { 71 list->next = list; 72 list->prev = list; 73 } 74 75 /* 76 * Insert a new entry between two known consecutive entries. 77 * 78 * This is only for internal list manipulation where we know 79 * the prev/next entries already! 80 */ 81 static inline void __list_add(struct list_head *new, 82 struct list_head *prev, 83 struct list_head *next) 84 { 85 next->prev = new; 86 new->next = next; 87 new->prev = prev; 88 prev->next = new; 89 } 90 91 /** 92 * list_add - add a new entry 93 * @new: new entry to be added 94 * @head: list head to add it after 95 * 96 * Insert a new entry after the specified head. 97 * This is good for implementing stacks. 98 */ 99 static inline void list_add(struct list_head *new, struct list_head *head) 100 { 101 __list_add(new, head, head->next); 102 } 103 104 /** 105 * list_add_tail - add a new entry 106 * @new: new entry to be added 107 * @head: list head to add it before 108 * 109 * Insert a new entry before the specified head. 110 * This is useful for implementing queues. 111 */ 112 static inline void list_add_tail(struct list_head *new, struct list_head *head) 113 { 114 __list_add(new, head->prev, head); 115 } 116 117 /* 118 * Delete a list entry by making the prev/next entries 119 * point to each other. 120 * 121 * This is only for internal list manipulation where we know 122 * the prev/next entries already! 123 */ 124 static inline void __list_del(struct list_head * prev, struct list_head * next) 125 { 126 next->prev = prev; 127 prev->next = next; 128 } 129 130 /** 131 * list_del - deletes entry from list. 132 * @entry: the element to delete from the list. 133 * Note: list_empty on entry does not return true after this, the entry is 134 * in an undefined state. 135 */ 136 static inline void list_del(struct list_head *entry) 137 { 138 __list_del(entry->prev, entry->next); 139 entry->next = LIST_POISON1; 140 entry->prev = LIST_POISON2; 141 } 142 143 /** 144 * list_del_init - deletes entry from list and reinitialize it. 145 * @entry: the element to delete from the list. 146 */ 147 static inline void list_del_init(struct list_head *entry) 148 { 149 __list_del(entry->prev, entry->next); 150 INIT_LIST_HEAD(entry); 151 } 152 153 /** 154 * list_move - delete from one list and add as another's head 155 * @list: the entry to move 156 * @head: the head that will precede our entry 157 */ 158 static inline void list_move(struct list_head *list, struct list_head *head) 159 { 160 __list_del(list->prev, list->next); 161 list_add(list, head); 162 } 163 164 /** 165 * list_move_tail - delete from one list and add as another's tail 166 * @list: the entry to move 167 * @head: the head that will follow our entry 168 */ 169 static inline void list_move_tail(struct list_head *list, 170 struct list_head *head) 171 { 172 __list_del(list->prev, list->next); 173 list_add_tail(list, head); 174 } 175 176 /** 177 * list_empty - tests whether a list is empty 178 * @head: the list to test. 179 */ 180 static inline int list_empty(const struct list_head *head) 181 { 182 return head->next == head; 183 } 184 185 /** 186 * list_empty_careful - tests whether a list is 187 * empty _and_ checks that no other CPU might be 188 * in the process of still modifying either member 189 * 190 * NOTE: using list_empty_careful() without synchronization 191 * can only be safe if the only activity that can happen 192 * to the list entry is list_del_init(). Eg. it cannot be used 193 * if another CPU could re-list_add() it. 194 * 195 * @head: the list to test. 196 */ 197 static inline int list_empty_careful(const struct list_head *head) 198 { 199 struct list_head *next = head->next; 200 return (next == head) && (next == head->prev); 201 } 202 203 static inline void __list_splice(struct list_head *list, 204 struct list_head *head) 205 { 206 struct list_head *first = list->next; 207 struct list_head *last = list->prev; 208 struct list_head *at = head->next; 209 210 first->prev = head; 211 head->next = first; 212 213 last->next = at; 214 at->prev = last; 215 } 216 217 /** 218 * list_splice - join two lists 219 * @list: the new list to add. 220 * @head: the place to add it in the first list. 221 */ 222 static inline void list_splice(struct list_head *list, struct list_head *head) 223 { 224 if (!list_empty(list)) 225 __list_splice(list, head); 226 } 227 228 /** 229 * list_splice_init - join two lists and reinitialise the emptied list. 230 * @list: the new list to add. 231 * @head: the place to add it in the first list. 232 * 233 * The list at @list is reinitialised 234 */ 235 static inline void list_splice_init(struct list_head *list, 236 struct list_head *head) 237 { 238 if (!list_empty(list)) { 239 __list_splice(list, head); 240 INIT_LIST_HEAD(list); 241 } 242 } 243 244 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) 245 /** 246 * container_of - cast a member of a structure out to the containing structure 247 * @ptr: the pointer to the member. 248 * @type: the type of the container struct this is embedded in. 249 * @member: the name of the member within the struct. 250 * 251 */ 252 #define container_of(ptr, type, member) ({ \ 253 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 254 (type *)( (char *)__mptr - offsetof(type,member) );}) 255 256 257 /** 258 * list_entry - get the struct for this entry 259 * @ptr: the &struct list_head pointer. 260 * @type: the type of the struct this is embedded in. 261 * @member: the name of the list_struct within the struct. 262 */ 263 #define list_entry(ptr, type, member) \ 264 container_of(ptr, type, member) 265 266 /** 267 * list_for_each - iterate over a list 268 * @pos: the &struct list_head to use as a loop counter. 269 * @head: the head for your list. 270 */ 271 #define list_for_each(pos, head) \ 272 for (pos = (head)->next; pos != (head); \ 273 pos = pos->next) 274 275 /** 276 * list_for_each_prev - iterate over a list backwards 277 * @pos: the &struct list_head to use as a loop counter. 278 * @head: the head for your list. 279 */ 280 #define list_for_each_prev(pos, head) \ 281 for (pos = (head)->prev; pos != (head); \ 282 pos = pos->prev) 283 284 /** 285 * list_for_each_safe - iterate over a list safe against removal of list entry 286 * @pos: the &struct list_head to use as a loop counter. 287 * @n: another &struct list_head to use as temporary storage 288 * @head: the head for your list. 289 */ 290 #define list_for_each_safe(pos, n, head) \ 291 for (pos = (head)->next, n = pos->next; pos != (head); \ 292 pos = n, n = pos->next) 293 294 /** 295 * list_for_each_entry - iterate over list of given type 296 * @pos: the type * to use as a loop counter. 297 * @head: the head for your list. 298 * @member: the name of the list_struct within the struct. 299 */ 300 #define list_for_each_entry(pos, head, member) \ 301 for (pos = list_entry((head)->next, typeof(*pos), member); \ 302 &pos->member != (head); \ 303 pos = list_entry(pos->member.next, typeof(*pos), member)) 304 305 /** 306 * list_for_each_entry_reverse - iterate backwards over list of given type. 307 * @pos: the type * to use as a loop counter. 308 * @head: the head for your list. 309 * @member: the name of the list_struct within the struct. 310 */ 311 #define list_for_each_entry_reverse(pos, head, member) \ 312 for (pos = list_entry((head)->prev, typeof(*pos), member); \ 313 &pos->member != (head); \ 314 pos = list_entry(pos->member.prev, typeof(*pos), member)) 315 316 /** 317 * list_prepare_entry - prepare a pos entry for use as a start point in 318 * list_for_each_entry_continue 319 * @pos: the type * to use as a start point 320 * @head: the head of the list 321 * @member: the name of the list_struct within the struct. 322 */ 323 #define list_prepare_entry(pos, head, member) \ 324 ((pos) ? : list_entry(head, typeof(*pos), member)) 325 326 /** 327 * list_for_each_entry_continue - iterate over list of given type 328 * continuing after existing point 329 * @pos: the type * to use as a loop counter. 330 * @head: the head for your list. 331 * @member: the name of the list_struct within the struct. 332 */ 333 #define list_for_each_entry_continue(pos, head, member) \ 334 for (pos = list_entry(pos->member.next, typeof(*pos), member); \ 335 &pos->member != (head); \ 336 pos = list_entry(pos->member.next, typeof(*pos), member)) 337 338 /** 339 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry 340 * @pos: the type * to use as a loop counter. 341 * @n: another type * to use as temporary storage 342 * @head: the head for your list. 343 * @member: the name of the list_struct within the struct. 344 */ 345 #define list_for_each_entry_safe(pos, n, head, member) \ 346 for (pos = list_entry((head)->next, typeof(*pos), member), \ 347 n = list_entry(pos->member.next, typeof(*pos), member); \ 348 &pos->member != (head); \ 349 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 350 351 /** 352 * list_for_each_entry_safe_continue - iterate over list of given type 353 * continuing after existing point safe against removal of list entry 354 * @pos: the type * to use as a loop counter. 355 * @n: another type * to use as temporary storage 356 * @head: the head for your list. 357 * @member: the name of the list_struct within the struct. 358 */ 359 #define list_for_each_entry_safe_continue(pos, n, head, member) \ 360 for (pos = list_entry(pos->member.next, typeof(*pos), member), \ 361 n = list_entry(pos->member.next, typeof(*pos), member); \ 362 &pos->member != (head); \ 363 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 364 365 /** 366 * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against 367 * removal of list entry 368 * @pos: the type * to use as a loop counter. 369 * @n: another type * to use as temporary storage 370 * @head: the head for your list. 371 * @member: the name of the list_struct within the struct. 372 */ 373 #define list_for_each_entry_safe_reverse(pos, n, head, member) \ 374 for (pos = list_entry((head)->prev, typeof(*pos), member), \ 375 n = list_entry(pos->member.prev, typeof(*pos), member); \ 376 &pos->member != (head); \ 377 pos = n, n = list_entry(n->member.prev, typeof(*n), member)) 378 379 #endif 380
