net/batman-adv/hash.c

   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 }