1 /* $NetBSD: list.h,v 1.32 2021/12/19 11:39:24 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Notes on porting:
34 *
35 * - LIST_HEAD(x) means a declaration `struct list_head x =
36 * LIST_HEAD_INIT(x)' in Linux, but something else in NetBSD.
37 * Replace by the expansion.
38 */
39
40 #ifndef _LINUX_LIST_H_
41 #define _LINUX_LIST_H_
42
43 #include <sys/null.h>
44 #include <sys/pslist.h>
45 #include <sys/queue.h>
46
47 #include <linux/kernel.h>
48 #include <linux/types.h>
49
50 #define POISON_INUSE 0x5a /* XXX */
51
52 /*
53 * Doubly-linked lists. Type defined in <linux/types.h>.
54 */
55
56 #define LIST_HEAD_INIT(name) { .prev = &(name), .next = &(name) }
57
58 #define LINUX_LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)
59
60 static inline void
INIT_LIST_HEAD(struct list_head * head)61 INIT_LIST_HEAD(struct list_head *head)
62 {
63 head->prev = head;
64 head->next = head;
65 }
66
67 static inline struct list_head *
list_first(const struct list_head * head)68 list_first(const struct list_head *head)
69 {
70 return head->next;
71 }
72
73 static inline struct list_head *
list_last(const struct list_head * head)74 list_last(const struct list_head *head)
75 {
76 return head->prev;
77 }
78
79 static inline struct list_head *
list_next(const struct list_head * node)80 list_next(const struct list_head *node)
81 {
82 return node->next;
83 }
84
85 static inline struct list_head *
list_prev(const struct list_head * node)86 list_prev(const struct list_head *node)
87 {
88 return node->prev;
89 }
90
91 static inline int
list_empty(const struct list_head * head)92 list_empty(const struct list_head *head)
93 {
94 return (head->next == head);
95 }
96
97 static inline int
list_is_singular(const struct list_head * head)98 list_is_singular(const struct list_head *head)
99 {
100
101 if (list_empty(head))
102 return false;
103 if (head->next != head->prev)
104 return false;
105 return true;
106 }
107
108 static inline bool
list_is_first(const struct list_head * entry,const struct list_head * head)109 list_is_first(const struct list_head *entry, const struct list_head *head)
110 {
111 return head == entry->prev;
112 }
113
114 static inline bool
list_is_last(const struct list_head * entry,const struct list_head * head)115 list_is_last(const struct list_head *entry, const struct list_head *head)
116 {
117 return head == entry->next;
118 }
119
120 static inline void
__list_add_between(struct list_head * prev,struct list_head * node,struct list_head * next)121 __list_add_between(struct list_head *prev, struct list_head *node,
122 struct list_head *next)
123 {
124 prev->next = node;
125 node->prev = prev;
126 node->next = next;
127 next->prev = node;
128 }
129
130 static inline void
list_add(struct list_head * node,struct list_head * head)131 list_add(struct list_head *node, struct list_head *head)
132 {
133 __list_add_between(head, node, head->next);
134 }
135
136 static inline void
list_add_rcu(struct list_head * node,struct list_head * head)137 list_add_rcu(struct list_head *node, struct list_head *head)
138 {
139 struct list_head *next = head->next;
140
141 /* Initialize the new node first. */
142 node->next = next;
143 node->prev = head;
144
145 /* Now publish it. */
146 atomic_store_release(&head->next, node);
147
148 /* Fix up back pointers, not protected by RCU. */
149 next->prev = node;
150 }
151
152 static inline void
list_add_tail(struct list_head * node,struct list_head * head)153 list_add_tail(struct list_head *node, struct list_head *head)
154 {
155 __list_add_between(head->prev, node, head);
156 }
157
158 static inline void
__list_del_entry(struct list_head * entry)159 __list_del_entry(struct list_head *entry)
160 {
161 entry->prev->next = entry->next;
162 entry->next->prev = entry->prev;
163 }
164
165 static inline void
list_del(struct list_head * entry)166 list_del(struct list_head *entry)
167 {
168 __list_del_entry(entry);
169 entry->next = (void *)(uintptr_t)1;
170 entry->prev = (void *)(uintptr_t)2;
171 }
172
173 static inline void
__list_splice_between(struct list_head * prev,const struct list_head * list,struct list_head * next)174 __list_splice_between(struct list_head *prev, const struct list_head *list,
175 struct list_head *next)
176 {
177 struct list_head *first = list->next;
178 struct list_head *last = list->prev;
179
180 first->prev = prev;
181 prev->next = first;
182
183 last->next = next;
184 next->prev = last;
185 }
186
187 static inline void
list_splice(const struct list_head * list,struct list_head * head)188 list_splice(const struct list_head *list, struct list_head *head)
189 {
190 if (!list_empty(list))
191 __list_splice_between(head, list, head->next);
192 }
193
194 static inline void
list_splice_init(struct list_head * list,struct list_head * head)195 list_splice_init(struct list_head *list, struct list_head *head)
196 {
197 if (!list_empty(list)) {
198 __list_splice_between(head, list, head->next);
199 INIT_LIST_HEAD(list);
200 }
201 }
202
203 static inline void
list_splice_tail(const struct list_head * list,struct list_head * head)204 list_splice_tail(const struct list_head *list, struct list_head *head)
205 {
206 if (!list_empty(list))
207 __list_splice_between(head->prev, list, head);
208 }
209
210 static inline void
list_splice_tail_init(struct list_head * list,struct list_head * head)211 list_splice_tail_init(struct list_head *list, struct list_head *head)
212 {
213 if (!list_empty(list)) {
214 __list_splice_between(head->prev, list, head);
215 INIT_LIST_HEAD(list);
216 }
217 }
218
219 static inline void
list_move(struct list_head * node,struct list_head * head)220 list_move(struct list_head *node, struct list_head *head)
221 {
222 list_del(node);
223 list_add(node, head);
224 }
225
226 static inline void
list_move_tail(struct list_head * node,struct list_head * head)227 list_move_tail(struct list_head *node, struct list_head *head)
228 {
229 list_del(node);
230 list_add_tail(node, head);
231 }
232
233 static inline void
list_bulk_move_tail(struct list_head * head,struct list_head * first,struct list_head * last)234 list_bulk_move_tail(struct list_head *head, struct list_head *first,
235 struct list_head *last)
236 {
237
238 first->prev->next = last->next;
239 last->next->prev = first->prev;
240
241 head->prev->next = first;
242 first->prev = head->prev;
243
244 last->next = head;
245 head->prev = last;
246 }
247
248 static inline void
list_replace(struct list_head * old,struct list_head * new)249 list_replace(struct list_head *old, struct list_head *new)
250 {
251 new->prev = old->prev;
252 old->prev->next = new;
253 new->next = old->next;
254 old->next->prev = new;
255 }
256
257 static inline void
list_replace_init(struct list_head * old,struct list_head * new)258 list_replace_init(struct list_head *old, struct list_head *new)
259 {
260 list_replace(old, new);
261 INIT_LIST_HEAD(old);
262 }
263
264 static inline void
list_del_init(struct list_head * node)265 list_del_init(struct list_head *node)
266 {
267 list_del(node);
268 INIT_LIST_HEAD(node);
269 }
270
271 #define list_entry(PTR, TYPE, FIELD) container_of(PTR, TYPE, FIELD)
272 #define list_first_entry(PTR, TYPE, FIELD) \
273 list_entry(list_first((PTR)), TYPE, FIELD)
274 #define list_first_entry_or_null(PTR, TYPE, FIELD) \
275 (list_empty((PTR)) ? NULL : list_entry(list_first((PTR)), TYPE, FIELD))
276 #define list_last_entry(PTR, TYPE, FIELD) \
277 list_entry(list_last((PTR)), TYPE, FIELD)
278 #define list_next_entry(ENTRY, FIELD) \
279 list_entry(list_next(&(ENTRY)->FIELD), typeof(*(ENTRY)), FIELD)
280 #define list_prev_entry(ENTRY, FIELD) \
281 list_entry(list_prev(&(ENTRY)->FIELD), typeof(*(ENTRY)), FIELD)
282
283 #define list_for_each(VAR, HEAD) \
284 for ((VAR) = list_first((HEAD)); \
285 (VAR) != (HEAD); \
286 (VAR) = list_next((VAR)))
287
288 #define list_for_each_prev(VAR, HEAD) \
289 for ((VAR) = list_last((HEAD)); \
290 (VAR) != (HEAD); \
291 (VAR) = list_prev((VAR)))
292
293 #define list_for_each_safe(VAR, NEXT, HEAD) \
294 for ((VAR) = list_first((HEAD)); \
295 ((VAR) != (HEAD)) && ((NEXT) = list_next((VAR)), 1); \
296 (VAR) = (NEXT))
297
298 #define list_safe_reset_next(VAR, NEXT, FIELD) \
299 (NEXT) = list_next_entry(VAR, FIELD)
300
301 #define list_for_each_entry(VAR, HEAD, FIELD) \
302 for ((VAR) = list_entry(list_first((HEAD)), typeof(*(VAR)), FIELD); \
303 &(VAR)->FIELD != (HEAD); \
304 (VAR) = list_entry(list_next(&(VAR)->FIELD), typeof(*(VAR)), \
305 FIELD))
306
307 #define list_for_each_entry_safe(VAR, NEXT, HEAD, FIELD) \
308 for ((VAR) = list_entry(list_first((HEAD)), typeof(*(VAR)), FIELD); \
309 (&(VAR)->FIELD != (HEAD)) && \
310 ((NEXT) = list_entry(list_next(&(VAR)->FIELD), \
311 typeof(*(VAR)), FIELD), 1); \
312 (VAR) = (NEXT))
313
314 #define list_for_each_entry_safe_reverse(VAR, NEXT, HEAD, FIELD) \
315 for ((VAR) = list_entry(list_last((HEAD)), typeof(*(VAR)), FIELD); \
316 (&(VAR)->FIELD != (HEAD)) && \
317 ((NEXT) = list_entry(list_prev(&(VAR)->FIELD), \
318 typeof(*(VAR)), FIELD), 1); \
319 (VAR) = (NEXT))
320
321 #define list_for_each_entry_reverse(VAR, HEAD, FIELD) \
322 for ((VAR) = list_entry(list_last((HEAD)), typeof(*(VAR)), FIELD); \
323 &(VAR)->FIELD != (HEAD); \
324 (VAR) = list_entry(list_prev(&(VAR)->FIELD), typeof(*(VAR)), \
325 FIELD))
326
327 #define list_for_each_entry_continue(VAR, HEAD, FIELD) \
328 for ((VAR) = list_next_entry((VAR), FIELD); \
329 &(VAR)->FIELD != (HEAD); \
330 (VAR) = list_next_entry((VAR), FIELD))
331
332 #define list_for_each_entry_continue_reverse(VAR, HEAD, FIELD) \
333 for ((VAR) = list_prev_entry((VAR), FIELD); \
334 &(VAR)->FIELD != (HEAD); \
335 (VAR) = list_prev_entry((VAR), FIELD))
336
337 #define list_for_each_entry_from(VAR, HEAD, FIELD) \
338 for (; \
339 (&(VAR)->FIELD != (HEAD)); \
340 (VAR) = list_next_entry((VAR), FIELD))
341
342 #define list_for_each_entry_from_reverse(VAR, HEAD, FIELD) \
343 for (; \
344 (&(VAR)->FIELD != (HEAD)); \
345 (VAR) = list_prev_entry((VAR), FIELD))
346
347 #define list_for_each_entry_safe_from(VAR, NEXT, HEAD, FIELD) \
348 for (; \
349 (&(VAR)->FIELD != (HEAD)) && \
350 ((NEXT) = list_next_entry((VAR), FIELD)); \
351 (VAR) = (NEXT))
352
353 /*
354 * `H'ead-only/`H'ash-table doubly-linked lists.
355 */
356
357 #define hlist_head pslist_head
358 #define hlist_node pslist_entry
359
360 #define HLIST_HEAD_INIT PSLIST_INITIALIZER
361 #define INIT_HLIST_HEAD PSLIST_INIT
362 #define hlist_empty(h) (pslist_writer_first(h) == NULL)
363 #define hlist_first pslist_writer_first
364 #define hlist_next pslist_writer_next
365
366 static inline void
hlist_add_head(struct hlist_node * node,struct hlist_head * head)367 hlist_add_head(struct hlist_node *node, struct hlist_head *head)
368 {
369
370 pslist_entry_init(node);
371 pslist_writer_insert_head(head, node);
372 }
373
374 static inline void
hlist_del(struct hlist_node * node)375 hlist_del(struct hlist_node *node)
376 {
377
378 pslist_writer_remove(node);
379 /* XXX abstraction violation */
380 node->ple_prevp = _PSLIST_POISON;
381 }
382
383 static inline void
hlist_del_init(struct hlist_node * node)384 hlist_del_init(struct hlist_node *node)
385 {
386
387 /* XXX abstraction violation */
388 if (node->ple_prevp != NULL)
389 pslist_writer_remove(node);
390 }
391
392 #define hlist_entry(PTR, TYPE, FIELD) container_of(PTR, TYPE, FIELD)
393 #define hlist_for_each(VAR, HEAD) \
394 for ((VAR) = hlist_first(HEAD); (VAR) != NULL; (VAR) = hlist_next(VAR))
395 #define hlist_for_each_safe(VAR, NEXT, HEAD) \
396 for ((VAR) = hlist_first(HEAD); \
397 (VAR) != NULL && ((NEXT) = hlist_next(HEAD), 1); \
398 (VAR) = (NEXT))
399 #define hlist_for_each_entry(VAR, HEAD, FIELD) \
400 for ((VAR) = (hlist_first(HEAD) == NULL ? NULL : \
401 hlist_entry(hlist_first(HEAD), typeof(*(VAR)), \
402 FIELD)); \
403 (VAR) != NULL; \
404 (VAR) = (hlist_next(&(VAR)->FIELD) == NULL ? NULL : \
405 hlist_entry(hlist_next(&(VAR)->FIELD), typeof(*(VAR)),\
406 FIELD)))
407
408 #define hlist_for_each_entry_safe(VAR, NEXT, HEAD, FIELD) \
409 for ((VAR) = (hlist_first(HEAD) == NULL ? NULL : \
410 hlist_entry(hlist_first(HEAD), typeof(*(VAR)), \
411 FIELD)); \
412 ((VAR) != NULL && \
413 ((NEXT) = hlist_next(&(VAR)->FIELD), 1)); \
414 (VAR) = hlist_entry((NEXT), typeof(*(VAR)), FIELD))
415
416 static inline void
hlist_add_behind_rcu(struct hlist_node * node,struct hlist_node * prev)417 hlist_add_behind_rcu(struct hlist_node *node, struct hlist_node *prev)
418 {
419
420 pslist_entry_init(node);
421 pslist_writer_insert_after(prev, node);
422 }
423
424 static inline void
hlist_add_head_rcu(struct hlist_node * node,struct hlist_head * head)425 hlist_add_head_rcu(struct hlist_node *node, struct hlist_head *head)
426 {
427
428 pslist_entry_init(node);
429 pslist_writer_insert_head(head, node);
430 }
431
432 #define hlist_del_init_rcu hlist_del_init /* no special needs */
433
434 #define hlist_first_rcu pslist_reader_first
435 #define hlist_next_rcu pslist_reader_next
436
437 #define hlist_for_each_entry_rcu(VAR, HEAD, FIELD) \
438 for ((VAR) = (hlist_first_rcu(HEAD) == NULL ? NULL : \
439 hlist_entry(hlist_first_rcu(HEAD), typeof(*(VAR)), \
440 FIELD)); \
441 (VAR) != NULL; \
442 (VAR) = (hlist_next_rcu(&(VAR)->FIELD) == NULL ? NULL : \
443 hlist_entry(hlist_next_rcu(&(VAR)->FIELD), \
444 typeof(*(VAR)), FIELD)))
445
446 #endif /* _LINUX_LIST_H_ */
447