1 /* $NetBSD: hashtable.h,v 1.5 2018/08/27 06:39:27 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2018 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 #ifndef _LINUX_HASHTABLE_H_
33 #define _LINUX_HASHTABLE_H_
34
35 #include <linux/list.h>
36 #include <linux/types.h>
37 #include <linux/kernel.h>
38 #include <linux/hash.h>
39 #include <linux/rculist.h>
40
41 #define DECLARE_HASHTABLE(name, bits) \
42 struct hlist_head name[1u << (bits)]
43
44 static inline void
__hash_init(struct hlist_head * hash,unsigned n)45 __hash_init(struct hlist_head *hash, unsigned n)
46 {
47
48 while (n --> 0)
49 INIT_HLIST_HEAD(&hash[n]);
50 }
51
52 static inline bool
__hash_empty(struct hlist_head * hash,unsigned n)53 __hash_empty(struct hlist_head *hash, unsigned n)
54 {
55
56 while (n --> 0) {
57 if (!hlist_empty(&hash[n]))
58 return false;
59 }
60
61 return true;
62 }
63
64 #define __arraycount(array) NELEM(array)
65
66 #define hash_init(h) __hash_init((h), __arraycount(h))
67 #define hash_add(h, n, k) hlist_add_head(n, &(h)[(k) % __arraycount(h)])
68 #define hash_del(n) hlist_del_init(n)
69 #define hash_empty(h) __hash_empty((h), __arraycount(h))
70
71 #define hash_for_each_possible(h, n, f, k) \
72 hlist_for_each_entry(n, &(h)[(k) % __arraycount(h)], f)
73
74 #define hash_for_each_safe(h, i, t, n, f) \
75 for ((i) = 0; (i) < __arraycount(h); (i)++) \
76 hlist_for_each_entry_safe(n, t, &(h)[i], f)
77
78 #endif /*_LINUX_HASHTABLE_H_*/
79