net/batman-adv/hash.c

   1 /*
   2  * Copyright (C) 2006-2011 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         int 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(int 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 }