xref: /netbsd-src/sys/external/bsd/common/include/linux/list.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: list.h,v 1.2 2014/07/03 20:48:19 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  * - The `_rcu' routines here are not actually pserialize(9)-safe.
40  *   They need dependent read memory barriers added.  Please fix this
41  *   if you need to use them with pserialize(9).
42  */
43 
44 #ifndef _LINUX_LIST_H_
45 #define _LINUX_LIST_H_
46 
47 #include <sys/null.h>
48 #include <sys/queue.h>
49 
50 #include <linux/kernel.h>
51 
52 /*
53  * Doubly-linked lists.
54  */
55 
56 struct list_head {
57 	struct list_head *prev;
58 	struct list_head *next;
59 };
60 
61 #define	LIST_HEAD_INIT(name)	{ .prev = &(name), .next = &(name) }
62 
63 static inline void
64 INIT_LIST_HEAD(struct list_head *head)
65 {
66 	head->prev = head;
67 	head->next = head;
68 }
69 
70 static inline struct list_head *
71 list_first(const struct list_head *head)
72 {
73 	return head->next;
74 }
75 
76 static inline struct list_head *
77 list_next(const struct list_head *node)
78 {
79 	return node->next;
80 }
81 
82 static inline struct list_head *
83 list_prev(const struct list_head *node)
84 {
85 	return node->prev;
86 }
87 
88 static inline int
89 list_empty(const struct list_head *head)
90 {
91 	return (head->next == head);
92 }
93 
94 static inline void
95 __list_add_between(struct list_head *prev, struct list_head *node,
96     struct list_head *next)
97 {
98 	prev->next = node;
99 	node->prev = prev;
100 	node->next = next;
101 	next->prev = node;
102 }
103 
104 static inline void
105 list_add(struct list_head *node, struct list_head *head)
106 {
107 	__list_add_between(head, node, head->next);
108 }
109 
110 static inline void
111 list_add_tail(struct list_head *node, struct list_head *head)
112 {
113 	__list_add_between(head->prev, node, head);
114 }
115 
116 static inline void
117 list_del(struct list_head *entry)
118 {
119 	entry->prev->next = entry->next;
120 	entry->next->prev = entry->prev;
121 }
122 
123 static inline void
124 __list_splice_between(struct list_head *prev, const struct list_head *list,
125     struct list_head *next)
126 {
127 	struct list_head *first = list->next;
128 	struct list_head *last = list->prev;
129 
130 	first->prev = prev;
131 	prev->next = first;
132 
133 	last->next = next;
134 	next->prev = last;
135 }
136 
137 static inline void
138 list_splice(const struct list_head *list, struct list_head *head)
139 {
140 	if (!list_empty(list))
141 		__list_splice_between(head, list, head->next);
142 }
143 
144 static inline void
145 list_splice_tail(const struct list_head *list, struct list_head *head)
146 {
147 	if (!list_empty(list))
148 		__list_splice_between(head->prev, list, head);
149 }
150 
151 static inline void
152 list_move(struct list_head *node, struct list_head *head)
153 {
154 	list_del(node);
155 	list_add(node, head);
156 }
157 
158 static inline void
159 list_move_tail(struct list_head *node, struct list_head *head)
160 {
161 	list_del(node);
162 	list_add_tail(node, head);
163 }
164 
165 static inline void
166 list_replace(struct list_head *old, struct list_head *new)
167 {
168 	new->prev = old->prev;
169 	old->prev->next = new;
170 	new->next = old->next;
171 	old->next->prev = new;
172 }
173 
174 static inline void
175 list_del_init(struct list_head *node)
176 {
177 	list_del(node);
178 	INIT_LIST_HEAD(node);
179 }
180 
181 #define	list_entry(PTR, TYPE, FIELD)	container_of(PTR, TYPE, FIELD)
182 #define	list_first_entry(PTR, TYPE, FIELD)				\
183 	list_entry(list_first((PTR)), TYPE, FIELD)
184 
185 #define	list_for_each(VAR, HEAD)					\
186 	for ((VAR) = list_first((HEAD));				\
187 		(VAR) != (HEAD);					\
188 		(VAR) = list_next((VAR)))
189 
190 #define	list_for_each_safe(VAR, NEXT, HEAD)				\
191 	for ((VAR) = list_first((HEAD));				\
192 		((VAR) != (HEAD)) && ((NEXT) = list_next((VAR)), 1);	\
193 		(VAR) = (NEXT))
194 
195 #define	list_for_each_entry(VAR, HEAD, FIELD)				\
196 	for ((VAR) = list_entry(list_first((HEAD)), typeof(*(VAR)), FIELD); \
197 		&(VAR)->FIELD != (HEAD);				\
198 		(VAR) = list_entry(list_next(&(VAR)->FIELD), typeof(*(VAR)), \
199 		    FIELD))
200 
201 #define	list_for_each_entry_safe(VAR, NEXT, HEAD, FIELD)		\
202 	for ((VAR) = list_entry(list_first((HEAD)), typeof(*(VAR)), FIELD); \
203 		(&(VAR)->FIELD != (HEAD)) &&				\
204 		    ((NEXT) = list_entry(list_next(&(VAR)->FIELD),	\
205 			typeof(*(VAR)), FIELD), 1);			\
206 		(VAR) = (NEXT))
207 
208 /*
209  * `H'ead-only/`H'ash-table doubly-linked lists.
210  */
211 
212 LIST_HEAD(hlist_head, hlist_node);
213 struct hlist_node {
214 	LIST_ENTRY(hlist_node) hln_entry;
215 };
216 
217 static inline struct hlist_node *
218 hlist_first(struct hlist_head *head)
219 {
220 	return LIST_FIRST(head);
221 }
222 
223 static inline struct hlist_node *
224 hlist_next(struct hlist_node *node)
225 {
226 	return LIST_NEXT(node, hln_entry);
227 }
228 
229 static inline void
230 hlist_add_head(struct hlist_node *node, struct hlist_head *head)
231 {
232 	LIST_INSERT_HEAD(head, node, hln_entry);
233 }
234 
235 static inline void
236 hlist_add_after(struct hlist_node *node, struct hlist_node *next)
237 {
238 	LIST_INSERT_AFTER(node, next, hln_entry);
239 }
240 
241 static inline void
242 hlist_del(struct hlist_node *node)
243 {
244 	LIST_REMOVE(node, hln_entry);
245 }
246 
247 static inline void
248 hlist_del_init(struct hlist_node *node)
249 {
250 	LIST_REMOVE(node, hln_entry);
251 }
252 
253 #define	hlist_entry(PTR, TYPE, FIELD)	container_of(PTR, TYPE, FIELD)
254 #define	hlist_for_each(VAR, HEAD)	LIST_FOREACH(VAR, HEAD, hln_entry)
255 #define	hlist_for_each_safe(VAR, NEXT, HEAD)				\
256 	LIST_FOREACH_SAFE(VAR, HEAD, hln_entry, NEXT)
257 
258 #define	hlist_for_each_entry(VAR, HLIST, HEAD, FIELD)			\
259 	for ((HLIST) = LIST_FIRST((HEAD));				\
260 		((HLIST) != NULL) &&					\
261 		    ((VAR) = hlist_entry((HLIST), typeof(*(VAR)), FIELD), 1); \
262 		(HLIST) = LIST_NEXT((HLIST), hln_entry))
263 
264 /*
265  * XXX The nominally RCU-safe APIs below lack dependent read barriers,
266  * so they're not actually RCU-safe...on the alpha, anyway.  Someone^TM
267  * should fix this.
268  */
269 
270 #define	hlist_add_after_rcu		hlist_add_after
271 #define	hlist_add_head_rcu		hlist_add_head
272 #define	hlist_del_init_rcu		hlist_del_init
273 #define	hlist_for_each_entry_rcu	hlist_for_each_entry
274 
275 #endif  /* _LINUX_LIST_H_ */
276