xref: /openbmc/linux/net/batman-adv/hash.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2006-2020  B.A.T.M.A.N. contributors:
3  *
4  * Simon Wunderlich, Marek Lindner
5  */
6 
7 #include "hash.h"
8 #include "main.h"
9 
10 #include <linux/gfp.h>
11 #include <linux/lockdep.h>
12 #include <linux/slab.h>
13 
14 /* clears the hash */
15 static void batadv_hash_init(struct batadv_hashtable *hash)
16 {
17 	u32 i;
18 
19 	for (i = 0; i < hash->size; i++) {
20 		INIT_HLIST_HEAD(&hash->table[i]);
21 		spin_lock_init(&hash->list_locks[i]);
22 	}
23 
24 	atomic_set(&hash->generation, 0);
25 }
26 
27 /**
28  * batadv_hash_destroy() - Free only the hashtable and the hash itself
29  * @hash: hash object to destroy
30  */
31 void batadv_hash_destroy(struct batadv_hashtable *hash)
32 {
33 	kfree(hash->list_locks);
34 	kfree(hash->table);
35 	kfree(hash);
36 }
37 
38 /**
39  * batadv_hash_new() - Allocates and clears the hashtable
40  * @size: number of hash buckets to allocate
41  *
42  * Return: newly allocated hashtable, NULL on errors
43  */
44 struct batadv_hashtable *batadv_hash_new(u32 size)
45 {
46 	struct batadv_hashtable *hash;
47 
48 	hash = kmalloc(sizeof(*hash), GFP_ATOMIC);
49 	if (!hash)
50 		return NULL;
51 
52 	hash->table = kmalloc_array(size, sizeof(*hash->table), GFP_ATOMIC);
53 	if (!hash->table)
54 		goto free_hash;
55 
56 	hash->list_locks = kmalloc_array(size, sizeof(*hash->list_locks),
57 					 GFP_ATOMIC);
58 	if (!hash->list_locks)
59 		goto free_table;
60 
61 	hash->size = size;
62 	batadv_hash_init(hash);
63 	return hash;
64 
65 free_table:
66 	kfree(hash->table);
67 free_hash:
68 	kfree(hash);
69 	return NULL;
70 }
71 
72 /**
73  * batadv_hash_set_lock_class() - Set specific lockdep class for hash spinlocks
74  * @hash: hash object to modify
75  * @key: lockdep class key address
76  */
77 void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
78 				struct lock_class_key *key)
79 {
80 	u32 i;
81 
82 	for (i = 0; i < hash->size; i++)
83 		lockdep_set_class(&hash->list_locks[i], key);
84 }
85