xref: /openbmc/linux/net/batman-adv/hash.c (revision 93f5715e)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2006-2018  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, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "hash.h"
20 #include "main.h"
21 
22 #include <linux/gfp.h>
23 #include <linux/lockdep.h>
24 #include <linux/slab.h>
25 
26 /* clears the hash */
27 static void batadv_hash_init(struct batadv_hashtable *hash)
28 {
29 	u32 i;
30 
31 	for (i = 0; i < hash->size; i++) {
32 		INIT_HLIST_HEAD(&hash->table[i]);
33 		spin_lock_init(&hash->list_locks[i]);
34 	}
35 }
36 
37 /**
38  * batadv_hash_destroy() - Free only the hashtable and the hash itself
39  * @hash: hash object to destroy
40  */
41 void batadv_hash_destroy(struct batadv_hashtable *hash)
42 {
43 	kfree(hash->list_locks);
44 	kfree(hash->table);
45 	kfree(hash);
46 }
47 
48 /**
49  * batadv_hash_new() - Allocates and clears the hashtable
50  * @size: number of hash buckets to allocate
51  *
52  * Return: newly allocated hashtable, NULL on errors
53  */
54 struct batadv_hashtable *batadv_hash_new(u32 size)
55 {
56 	struct batadv_hashtable *hash;
57 
58 	hash = kmalloc(sizeof(*hash), GFP_ATOMIC);
59 	if (!hash)
60 		return NULL;
61 
62 	hash->table = kmalloc_array(size, sizeof(*hash->table), GFP_ATOMIC);
63 	if (!hash->table)
64 		goto free_hash;
65 
66 	hash->list_locks = kmalloc_array(size, sizeof(*hash->list_locks),
67 					 GFP_ATOMIC);
68 	if (!hash->list_locks)
69 		goto free_table;
70 
71 	hash->size = size;
72 	batadv_hash_init(hash);
73 	return hash;
74 
75 free_table:
76 	kfree(hash->table);
77 free_hash:
78 	kfree(hash);
79 	return NULL;
80 }
81 
82 /**
83  * batadv_hash_set_lock_class() - Set specific lockdep class for hash spinlocks
84  * @hash: hash object to modify
85  * @key: lockdep class key address
86  */
87 void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
88 				struct lock_class_key *key)
89 {
90 	u32 i;
91 
92 	for (i = 0; i < hash->size; i++)
93 		lockdep_set_class(&hash->list_locks[i], key);
94 }
95