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, 2014 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29 #ifndef _LINUX_RBTREE_H_
30 #define _LINUX_RBTREE_H_
31
32 #include <linux/kernel.h>
33 #include <linux/stddef.h>
34 #include <linux/rcupdate.h>
35
36 #include <sys/tree.h>
37 #include <sys/spinlock.h>
38
39 struct rb_node {
40 RB_ENTRY(rb_node) __entry;
41 };
42 #define rb_left __entry.rbe_left
43 #define rb_right __entry.rbe_right
44
45 /*
46 * This must match enough of sys/tree.h so the macros still work.
47 */
48 struct rb_root {
49 struct rb_node *rb_node; /* only member under linux */
50 void *rbh_inprog; /* so we can use sys/tree macros */
51 struct spinlock rbh_spin; /* so we can use sys/tree macros */
52 };
53
54 /*
55 * Leftmost-cached rbtrees.
56 *
57 * We do not cache the rightmost node based on footprint
58 * size vs number of potential users that could benefit
59 * from O(1) rb_last(). Just not worth it, users that want
60 * this feature can always implement the logic explicitly.
61 * Furthermore, users that want to cache both pointers may
62 * find it a bit asymmetric, but that's ok.
63 */
64 struct rb_root_cached {
65 struct rb_root rb_root;
66 struct rb_node *rb_leftmost;
67 };
68
69 /*
70 * In linux all of the comparisons are done by the caller.
71 */
72 int panic_cmp(struct rb_node *one, struct rb_node *two);
73
74 RB_HEAD(linux_root, rb_node);
75 RB_PROTOTYPE(linux_root, rb_node, __entry, panic_cmp);
76
77 #define rb_parent(r) RB_PARENT(r, __entry)
78 #define rb_color(r) RB_COLOR(r, __entry)
79 #define rb_is_red(r) (rb_color(r) == RB_RED)
80 #define rb_is_black(r) (rb_color(r) == RB_BLACK)
81 #define rb_set_parent(r, p) rb_parent((r)) = (p)
82 #define rb_set_color(r, c) rb_color((r)) = (c)
83 #define rb_entry(ptr, type, member) container_of(ptr, type, member)
84 #define rb_entry_safe(ptr, type, member) \
85 (ptr ? rb_entry(ptr, type, member) : NULL)
86
87 #define RB_EMPTY_ROOT(root) RB_EMPTY((struct linux_root *)root)
88 #define RB_EMPTY_NODE(node) (rb_parent(node) == node)
89 #define RB_CLEAR_NODE(node) (rb_set_parent(node, node))
90
91 #define rb_insert_color(node, root) \
92 linux_root_RB_INSERT_COLOR((struct linux_root *)(root), (node))
93 #define rb_erase(node, root) \
94 linux_root_RB_REMOVE((struct linux_root *)(root), (node))
95 #define rb_next(node) RB_NEXT(linux_root, NULL, (node))
96 #define rb_prev(node) RB_PREV(linux_root, NULL, (node))
97 #define rb_first(root) RB_MIN(linux_root, (struct linux_root *)(root))
98 #define rb_last(root) RB_MAX(linux_root, (struct linux_root *)(root))
99
100 #define rb_insert_color_cached(node, root, leftmost) \
101 linux_root_RB_INSERT_COLOR((struct linux_root *)(&(root)->rb_root), (node))
102 #define rb_erase_cached(node, root) \
103 linux_root_RB_REMOVE((struct linux_root *)(&(root)->rb_root), (node))
104 #define rb_first_cached(root) RB_MIN(linux_root, (struct linux_root *)(&(root)->rb_root))
105
106 static inline struct rb_node *
__rb_deepest_left(struct rb_node * node)107 __rb_deepest_left(struct rb_node *node)
108 {
109 struct rb_node *parent = NULL;
110 while (node) {
111 parent = node;
112 if (RB_LEFT(node, __entry))
113 node = RB_LEFT(node, __entry);
114 else
115 node = RB_RIGHT(node, __entry);
116 }
117 return parent;
118 }
119
120 static inline struct rb_node *
rb_next_postorder(const struct rb_node * node)121 rb_next_postorder(const struct rb_node *node)
122 {
123 struct rb_node *parent = RB_PARENT(node, __entry);
124 /* left -> right, right -> root */
125 if (parent != NULL &&
126 (node == RB_LEFT(parent, __entry)) &&
127 (RB_RIGHT(parent, __entry)))
128 return __rb_deepest_left(RB_RIGHT(parent, __entry));
129 else
130 return parent;
131 }
132
133 #define rbtree_postorder_for_each_entry_safe(x, y, head, member) \
134 for ((x) = rb_entry_safe(__rb_deepest_left((head)->rb_node), \
135 __typeof(*x), member); \
136 ((x) != NULL) && ((y) = \
137 rb_entry_safe(rb_next_postorder(&x->member), typeof(*x), member), 1); \
138 (x) = (y))
139
140 static inline void
rb_link_node(struct rb_node * node,struct rb_node * parent,struct rb_node ** rb_link)141 rb_link_node(struct rb_node *node, struct rb_node *parent,
142 struct rb_node **rb_link)
143 {
144 rb_set_parent(node, parent);
145 rb_set_color(node, RB_RED);
146 node->__entry.rbe_left = node->__entry.rbe_right = NULL;
147 *rb_link = node;
148 }
149
150 static inline void
rb_replace_node(struct rb_node * victim,struct rb_node * new,struct rb_root * root)151 rb_replace_node(struct rb_node *victim, struct rb_node *new,
152 struct rb_root *root)
153 {
154 struct rb_node *p;
155
156 p = rb_parent(victim);
157 if (p) {
158 if (p->rb_left == victim)
159 p->rb_left = new;
160 else
161 p->rb_right = new;
162 } else
163 root->rb_node = new;
164 if (victim->rb_left)
165 rb_set_parent(victim->rb_left, new);
166 if (victim->rb_right)
167 rb_set_parent(victim->rb_right, new);
168 *new = *victim;
169 }
170
171 #define LINUX_RB_ROOT (struct rb_root) { NULL }
172
173 #define LINUX_RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL }
174
175 #endif /* _LINUX_RBTREE_H_ */
176