xref: /freebsd/sys/compat/linuxkpi/common/include/linux/rculist.h (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * Copyright (c) 2015 François Tigeot
3  * Copyright (c) 2016-2020 Mellanox Technologies, Ltd.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice unmodified, this list of conditions, and the following
11  *    disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #ifndef _LINUX_RCULIST_H_
31 #define	_LINUX_RCULIST_H_
32 
33 #include <linux/list.h>
34 #include <linux/rcupdate.h>
35 
36 #define	list_entry_rcu(ptr, type, member) \
37 	container_of(READ_ONCE(ptr), type, member)
38 
39 #define	list_next_rcu(head)	(*((struct list_head **)(&(head)->next)))
40 #define	list_prev_rcu(head)	(*((struct list_head **)(&(head)->prev)))
41 
42 #define	list_for_each_entry_rcu(pos, head, member) \
43 	for (pos = list_entry_rcu((head)->next, typeof(*(pos)), member); \
44 	     &(pos)->member != (head);					\
45 	     pos = list_entry_rcu((pos)->member.next, typeof(*(pos)), member))
46 
47 #define	list_for_each_entry_lockless(pos, head, member) \
48 	list_for_each_entry_rcu(pos, head, member)
49 
50 static inline void
51 linux_list_add_rcu(struct list_head *new, struct list_head *prev,
52     struct list_head *next)
53 {
54 	new->next = next;
55 	new->prev = prev;
56 	rcu_assign_pointer(list_next_rcu(prev), new);
57 	next->prev = new;
58 }
59 
60 static inline void
61 list_add_rcu(struct list_head *new, struct list_head *head)
62 {
63 	linux_list_add_rcu(new, head, head->next);
64 }
65 
66 static inline void
67 list_add_tail_rcu(struct list_head *new, struct list_head *head)
68 {
69 	linux_list_add_rcu(new, head->prev, head);
70 }
71 
72 static inline void
73 __list_del_rcu(struct list_head *prev, struct list_head *next)
74 {
75 	next->prev = prev;
76 	rcu_assign_pointer(list_next_rcu(prev), next);
77 }
78 
79 static inline void
80 __list_del_entry_rcu(struct list_head *entry)
81 {
82 	__list_del_rcu(entry->prev, entry->next);
83 }
84 
85 static inline void
86 list_del_rcu(struct list_head *entry)
87 {
88 	__list_del_rcu(entry->prev, entry->next);
89 }
90 
91 #define	hlist_first_rcu(head)	(*((struct hlist_node **)(&(head)->first)))
92 #define	hlist_next_rcu(node)	(*((struct hlist_node **)(&(node)->next)))
93 #define	hlist_pprev_rcu(node)	(*((struct hlist_node **)((node)->pprev)))
94 
95 static inline void
96 hlist_add_behind_rcu(struct hlist_node *n, struct hlist_node *prev)
97 {
98 	n->next = prev->next;
99 	n->pprev = &prev->next;
100 	rcu_assign_pointer(hlist_next_rcu(prev), n);
101 	if (n->next)
102 		n->next->pprev = &n->next;
103 }
104 
105 #define	hlist_for_each_entry_rcu(pos, head, member)			\
106 	for (pos = hlist_entry_safe (rcu_dereference_raw(hlist_first_rcu(head)),\
107 	        typeof(*(pos)), member);				\
108 	     (pos);							\
109 	     pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(	\
110 			&(pos)->member)), typeof(*(pos)), member))
111 
112 static inline void
113 hlist_del_rcu(struct hlist_node *n)
114 {
115 	struct hlist_node *next = n->next;
116 	struct hlist_node **pprev = n->pprev;
117 
118 	WRITE_ONCE(*pprev, next);
119 	if (next)
120 		next->pprev = pprev;
121 }
122 
123 static inline void
124 hlist_add_head_rcu(struct hlist_node *n, struct hlist_head *h)
125 {
126 	struct hlist_node *first = h->first;
127 
128 	n->next = first;
129 	n->pprev = &h->first;
130 	rcu_assign_pointer(hlist_first_rcu(h), n);
131 	if (first)
132 		first->pprev = &n->next;
133 }
134 
135 static inline void
136 hlist_del_init_rcu(struct hlist_node *n)
137 {
138 	if (!hlist_unhashed(n)) {
139 		hlist_del_rcu(n);
140 		n->pprev = NULL;
141 	}
142 }
143 
144 #endif					/* _LINUX_RCULIST_H_ */
145