xref: /linux/net/batman-adv/hash.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
1 /*
2  * Copyright (C) 2006-2012 B.A.T.M.A.N. contributors:
3  *
4  * Simon Wunderlich, Marek Lindner
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA
19  *
20  */
21 
22 #include "main.h"
23 #include "hash.h"
24 
25 /* clears the hash */
26 static void hash_init(struct hashtable_t *hash)
27 {
28 	uint32_t i;
29 
30 	for (i = 0 ; i < hash->size; i++) {
31 		INIT_HLIST_HEAD(&hash->table[i]);
32 		spin_lock_init(&hash->list_locks[i]);
33 	}
34 }
35 
36 /* free only the hashtable and the hash itself. */
37 void hash_destroy(struct hashtable_t *hash)
38 {
39 	kfree(hash->list_locks);
40 	kfree(hash->table);
41 	kfree(hash);
42 }
43 
44 /* allocates and clears the hash */
45 struct hashtable_t *hash_new(uint32_t size)
46 {
47 	struct hashtable_t *hash;
48 
49 	hash = kmalloc(sizeof(*hash), GFP_ATOMIC);
50 	if (!hash)
51 		return NULL;
52 
53 	hash->table = kmalloc(sizeof(*hash->table) * size, GFP_ATOMIC);
54 	if (!hash->table)
55 		goto free_hash;
56 
57 	hash->list_locks = kmalloc(sizeof(*hash->list_locks) * size,
58 				   GFP_ATOMIC);
59 	if (!hash->list_locks)
60 		goto free_table;
61 
62 	hash->size = size;
63 	hash_init(hash);
64 	return hash;
65 
66 free_table:
67 	kfree(hash->table);
68 free_hash:
69 	kfree(hash);
70 	return NULL;
71 }
72