1 /* 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. 6 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice unmodified, this list of conditions, and the following 14 * disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 #ifndef _LINUX_LIST_H_ 31 #define _LINUX_LIST_H_ 32 33 #include <linux/types.h> 34 #include <linux/stddef.h> 35 #include <linux/poison.h> 36 #include <linux/kernel.h> 37 38 #include <sys/queue.h> 39 40 #define prefetch(x) 41 42 struct list_head { 43 struct list_head *next; 44 struct list_head *prev; 45 }; 46 47 #define LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) } 48 49 #define DRM_LIST_HEAD(name) \ 50 struct list_head name = LIST_HEAD_INIT(name) 51 52 static inline void 53 INIT_LIST_HEAD(struct list_head *list) 54 { 55 56 list->next = list->prev = list; 57 } 58 59 static inline struct list_head * 60 list_first(const struct list_head *head) 61 { 62 return head->next; 63 } 64 65 static inline struct list_head * 66 list_last(const struct list_head *head) 67 { 68 return head->prev; 69 } 70 71 static inline int 72 list_empty(const struct list_head *head) 73 { 74 return (head->next == head); 75 } 76 77 static inline int 78 list_empty_careful(const struct list_head *head) 79 { 80 return (head == head->next) && (head == head->prev); 81 } 82 83 static inline void 84 __list_del(struct list_head *prev, struct list_head *next) 85 { 86 next->prev = prev; 87 WRITE_ONCE(prev->next, next); 88 } 89 90 static inline void 91 __list_del_entry(struct list_head *entry) 92 { 93 __list_del(entry->prev, entry->next); 94 } 95 96 static inline void 97 list_del(struct list_head *entry) 98 { 99 100 entry->next->prev = entry->prev; 101 entry->prev->next = entry->next; 102 } 103 104 static inline void list_replace(struct list_head *old, 105 struct list_head *new) 106 { 107 new->next = old->next; 108 new->next->prev = new; 109 new->prev = old->prev; 110 new->prev->next = new; 111 } 112 113 static inline void list_replace_init(struct list_head *old, 114 struct list_head *new) 115 { 116 list_replace(old, new); 117 INIT_LIST_HEAD(old); 118 } 119 120 static inline void 121 _list_add(struct list_head *new, struct list_head *prev, 122 struct list_head *next) 123 { 124 125 next->prev = new; 126 new->next = next; 127 new->prev = prev; 128 prev->next = new; 129 } 130 131 static inline void 132 list_del_init(struct list_head *entry) 133 { 134 135 list_del(entry); 136 INIT_LIST_HEAD(entry); 137 } 138 139 #define list_entry(ptr, type, field) container_of(ptr, type, field) 140 141 #define list_first_entry(ptr, type, member) \ 142 list_entry((ptr)->next, type, member) 143 144 #define list_first_entry_or_null(ptr, type, member) \ 145 (list_empty(ptr) ? NULL: list_first_entry(ptr, type, member)) 146 147 #define list_last_entry(ptr, type, field) \ 148 list_entry(list_last((ptr)), type, field) 149 150 #define list_next_entry(ptr, member) \ 151 list_entry(((ptr)->member.next), typeof(*(ptr)), member) 152 153 #define list_safe_reset_next(ptr, n, member) \ 154 (n) = list_next_entry(ptr, member) 155 156 #define list_prev_entry(ptr, member) \ 157 list_entry(((ptr)->member.prev), typeof(*(ptr)), member) 158 159 #define list_for_each(p, head) \ 160 for (p = (head)->next; p != (head); p = p->next) 161 162 #define list_for_each_safe(p, n, head) \ 163 for (p = (head)->next, n = p->next; p != (head); p = n, n = p->next) 164 165 #define list_for_each_entry(p, h, field) \ 166 for (p = list_entry((h)->next, typeof(*p), field); &p->field != (h); \ 167 p = list_entry(p->field.next, typeof(*p), field)) 168 169 #define list_for_each_entry_safe(p, n, h, field) \ 170 for (p = list_entry((h)->next, typeof(*p), field), \ 171 n = list_entry(p->field.next, typeof(*p), field); &p->field != (h);\ 172 p = n, n = list_entry(n->field.next, typeof(*n), field)) 173 174 #define list_for_each_entry_from(p, h, field) \ 175 for ( ; &(p)->field != (h); \ 176 p = list_entry((p)->field.next, typeof(*p), field)) 177 178 #define list_for_each_entry_continue(p, h, field) \ 179 for (p = list_next_entry((p), field); &p->field != (h); \ 180 p = list_next_entry((p), field)) 181 182 #define list_for_each_entry_continue_reverse(pos, head, member) \ 183 for (pos = list_entry(pos->member.prev, __typeof(*pos), member); \ 184 &pos->member != (head); \ 185 pos = list_entry(pos->member.prev, __typeof(*pos), member)) 186 187 #define list_for_each_entry_safe_from(pos, n, head, member) \ 188 for (n = list_entry(pos->member.next, typeof(*pos), member); \ 189 &pos->member != (head); \ 190 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 191 192 #define list_for_each_entry_reverse(p, h, field) \ 193 for (p = list_entry((h)->prev, typeof(*p), field); &p->field != (h); \ 194 p = list_entry(p->field.prev, typeof(*p), field)) 195 196 #define list_for_each_entry_safe_reverse(p, n, h, field) \ 197 for (p = list_entry((h)->prev, typeof(*p), field), \ 198 n = list_entry((p)->field.prev, typeof(*p), field); &(p)->field != (h); \ 199 p = n, n = list_entry(n->field.prev, typeof(*n), field)) 200 201 #define list_for_each_prev(p, h) for (p = (h)->prev; p != (h); p = p->prev) 202 203 static inline void 204 list_add(struct list_head *new, struct list_head *head) 205 { 206 207 _list_add(new, head, head->next); 208 } 209 210 static inline void 211 list_add_tail(struct list_head *new, struct list_head *head) 212 { 213 214 _list_add(new, head->prev, head); 215 } 216 217 static inline void 218 list_move(struct list_head *list, struct list_head *head) 219 { 220 221 list_del(list); 222 list_add(list, head); 223 } 224 225 static inline void 226 list_move_tail(struct list_head *entry, struct list_head *head) 227 { 228 229 list_del(entry); 230 list_add_tail(entry, head); 231 } 232 233 static inline void 234 _list_splice(const struct list_head *list, struct list_head *prev, 235 struct list_head *next) 236 { 237 struct list_head *first; 238 struct list_head *last; 239 240 if (list_empty(list)) 241 return; 242 first = list->next; 243 last = list->prev; 244 first->prev = prev; 245 prev->next = first; 246 last->next = next; 247 next->prev = last; 248 } 249 250 static inline void 251 list_splice(const struct list_head *list, struct list_head *head) 252 { 253 254 _list_splice(list, head, head->next); 255 } 256 257 static inline void 258 list_splice_tail(struct list_head *list, struct list_head *head) 259 { 260 261 _list_splice(list, head->prev, head); 262 } 263 264 static inline void 265 list_splice_init(struct list_head *list, struct list_head *head) 266 { 267 268 _list_splice(list, head, head->next); 269 INIT_LIST_HEAD(list); 270 } 271 272 static inline void 273 list_splice_tail_init(struct list_head *list, struct list_head *head) 274 { 275 276 _list_splice(list, head->prev, head); 277 INIT_LIST_HEAD(list); 278 } 279 280 #define LINUX_LIST_HEAD(name) struct list_head name = { &(name), &(name) } 281 282 283 struct hlist_head { 284 struct hlist_node *first; 285 }; 286 287 struct hlist_node { 288 struct hlist_node *next, **pprev; 289 }; 290 291 #define HLIST_HEAD_INIT { } 292 #define HLIST_HEAD(name) struct hlist_head name = HLIST_HEAD_INIT 293 #define INIT_HLIST_HEAD(head) (head)->first = NULL 294 #define INIT_HLIST_NODE(node) \ 295 do { \ 296 (node)->next = NULL; \ 297 (node)->pprev = NULL; \ 298 } while (0) 299 300 static inline int 301 hlist_unhashed(const struct hlist_node *h) 302 { 303 304 return !h->pprev; 305 } 306 307 static inline int 308 hlist_empty(const struct hlist_head *h) 309 { 310 311 return !h->first; 312 } 313 314 static inline void 315 hlist_del(struct hlist_node *n) 316 { 317 318 if (n->next) 319 n->next->pprev = n->pprev; 320 *n->pprev = n->next; 321 } 322 323 static inline void 324 hlist_del_init(struct hlist_node *n) 325 { 326 327 if (hlist_unhashed(n)) 328 return; 329 hlist_del(n); 330 INIT_HLIST_NODE(n); 331 } 332 333 static inline void 334 hlist_add_head(struct hlist_node *n, struct hlist_head *h) 335 { 336 337 n->next = h->first; 338 if (h->first) 339 h->first->pprev = &n->next; 340 h->first = n; 341 n->pprev = &h->first; 342 } 343 344 static inline void 345 hlist_add_before(struct hlist_node *n, struct hlist_node *next) 346 { 347 348 n->pprev = next->pprev; 349 n->next = next; 350 next->pprev = &n->next; 351 *(n->pprev) = n; 352 } 353 354 static inline void 355 hlist_add_after(struct hlist_node *n, struct hlist_node *next) 356 { 357 358 next->next = n->next; 359 n->next = next; 360 next->pprev = &n->next; 361 if (next->next) 362 next->next->pprev = &next->next; 363 } 364 365 static inline void 366 hlist_move_list(struct hlist_head *old, struct hlist_head *new) 367 { 368 369 new->first = old->first; 370 if (new->first) 371 new->first->pprev = &new->first; 372 old->first = NULL; 373 } 374 375 /** 376 * list_is_singular - tests whether a list has just one entry. 377 * @head: the list to test. 378 */ 379 static inline int list_is_singular(const struct list_head *head) 380 { 381 return !list_empty(head) && (head->next == head->prev); 382 } 383 384 static inline void __list_cut_position(struct list_head *list, 385 struct list_head *head, struct list_head *entry) 386 { 387 struct list_head *new_first = entry->next; 388 list->next = head->next; 389 list->next->prev = list; 390 list->prev = entry; 391 entry->next = list; 392 head->next = new_first; 393 new_first->prev = head; 394 } 395 396 /** 397 * list_cut_position - cut a list into two 398 * @list: a new list to add all removed entries 399 * @head: a list with entries 400 * @entry: an entry within head, could be the head itself 401 * and if so we won't cut the list 402 * 403 * This helper moves the initial part of @head, up to and 404 * including @entry, from @head to @list. You should 405 * pass on @entry an element you know is on @head. @list 406 * should be an empty list or a list you do not care about 407 * losing its data. 408 * 409 */ 410 static inline void list_cut_position(struct list_head *list, 411 struct list_head *head, struct list_head *entry) 412 { 413 if (list_empty(head)) 414 return; 415 if (list_is_singular(head) && 416 (head->next != entry && head != entry)) 417 return; 418 if (entry == head) 419 INIT_LIST_HEAD(list); 420 else 421 __list_cut_position(list, head, entry); 422 } 423 424 /** 425 * list_is_last - tests whether @list is the last entry in list @head 426 * @list: the entry to test 427 * @head: the head of the list 428 */ 429 static inline int list_is_last(const struct list_head *list, 430 const struct list_head *head) 431 { 432 return list->next == head; 433 } 434 435 #define hlist_entry(ptr, type, field) container_of(ptr, type, field) 436 437 #define hlist_for_each(p, head) \ 438 for (p = (head)->first; p; p = p->next) 439 440 #define hlist_for_each_safe(p, n, head) \ 441 for (p = (head)->first; p && ({ n = p->next; 1; }); p = n) 442 443 #define hlist_entry_safe(ptr, type, member) \ 444 (ptr) ? hlist_entry(ptr, type, member) : NULL 445 446 #define hlist_for_each_entry(pos, head, member) \ 447 for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\ 448 pos; \ 449 pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) 450 451 #define hlist_for_each_entry_continue(tp, p, field) \ 452 for (p = (p)->next; \ 453 p ? (tp = hlist_entry(p, typeof(*tp), field)): NULL; p = p->next) 454 455 #define hlist_for_each_entry_from(tp, p, field) \ 456 for (; p ? (tp = hlist_entry(p, typeof(*tp), field)): NULL; p = p->next) 457 458 #define hlist_for_each_entry_safe(pos, n, head, member) \ 459 for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member); \ 460 (pos) && ({ n = (pos)->member.next; 1; }); \ 461 pos = hlist_entry_safe(n, typeof(*(pos)), member)) 462 463 void drm_list_sort(void *priv, struct list_head *head, int (*cmp)(void *priv, 464 struct list_head *a, struct list_head *b)); 465 466 #define hlist_add_head_rcu(n, h) hlist_add_head(n, h) 467 468 #define hlist_del_init_rcu(n) hlist_del_init(n) 469 470 #endif /* _LINUX_LIST_H_ */ 471