net/batman-adv/hash.c

   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 }