diff options
Diffstat (limited to 'net/batman-adv/hash.h')
| -rw-r--r-- | net/batman-adv/hash.h | 144 |
1 files changed, 56 insertions, 88 deletions
diff --git a/net/batman-adv/hash.h b/net/batman-adv/hash.h index 1b4da72f2093..fb251c385a1b 100644 --- a/net/batman-adv/hash.h +++ b/net/batman-adv/hash.h @@ -1,48 +1,58 @@ -/* Copyright (C) 2006-2013 B.A.T.M.A.N. contributors: +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors: * * Simon Wunderlich, Marek Lindner - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA */ #ifndef _NET_BATMAN_ADV_HASH_H_ #define _NET_BATMAN_ADV_HASH_H_ -#include <linux/list.h> +#include "main.h" -/* callback to a compare function. should compare 2 element datas for their - * keys, return 0 if same and not 0 if not same +#include <linux/atomic.h> +#include <linux/compiler.h> +#include <linux/list.h> +#include <linux/lockdep.h> +#include <linux/rculist.h> +#include <linux/spinlock.h> +#include <linux/stddef.h> +#include <linux/types.h> + +/* callback to a compare function. should compare 2 element data for their + * keys + * + * Return: true if same and false if not same */ -typedef int (*batadv_hashdata_compare_cb)(const struct hlist_node *, - const void *); +typedef bool (*batadv_hashdata_compare_cb)(const struct hlist_node *, + const void *); -/* the hashfunction, should return an index - * based on the key in the data of the first - * argument and the size the second +/* the hashfunction + * + * Return: an index based on the key in the data of the first argument and the + * size the second */ -typedef uint32_t (*batadv_hashdata_choose_cb)(const void *, uint32_t); +typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32); typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *); +/** + * struct batadv_hashtable - Wrapper of simple hlist based hashtable + */ struct batadv_hashtable { - struct hlist_head *table; /* the hashtable itself with the buckets */ - spinlock_t *list_locks; /* spinlock for each hash list entry */ - uint32_t size; /* size of hashtable */ + /** @table: the hashtable itself with the buckets */ + struct hlist_head *table; + + /** @list_locks: spinlock for each hash list entry */ + spinlock_t *list_locks; + + /** @size: size of hashtable */ + u32 size; + + /** @generation: current (generation) sequence number */ + atomic_t generation; }; /* allocates and clears the hash */ -struct batadv_hashtable *batadv_hash_new(uint32_t size); +struct batadv_hashtable *batadv_hash_new(u32 size); /* set class key for all locks */ void batadv_hash_set_lock_class(struct batadv_hashtable *hash, @@ -51,67 +61,15 @@ void batadv_hash_set_lock_class(struct batadv_hashtable *hash, /* free only the hashtable and the hash itself. */ void batadv_hash_destroy(struct batadv_hashtable *hash); -/* remove the hash structure. if hashdata_free_cb != NULL, this function will be - * called to remove the elements inside of the hash. if you don't remove the - * elements, memory might be leaked. - */ -static inline void batadv_hash_delete(struct batadv_hashtable *hash, - batadv_hashdata_free_cb free_cb, - void *arg) -{ - struct hlist_head *head; - struct hlist_node *node, *node_tmp; - spinlock_t *list_lock; /* spinlock to protect write access */ - uint32_t i; - - for (i = 0; i < hash->size; i++) { - head = &hash->table[i]; - list_lock = &hash->list_locks[i]; - - spin_lock_bh(list_lock); - hlist_for_each_safe(node, node_tmp, head) { - hlist_del_rcu(node); - - if (free_cb) - free_cb(node, arg); - } - spin_unlock_bh(list_lock); - } - - batadv_hash_destroy(hash); -} - /** - * batadv_hash_bytes - hash some bytes and add them to the previous hash - * @hash: previous hash value - * @data: data to be hashed - * @size: number of bytes to be hashed - * - * Returns the new hash value. - */ -static inline uint32_t batadv_hash_bytes(uint32_t hash, const void *data, - uint32_t size) -{ - const unsigned char *key = data; - int i; - - for (i = 0; i < size; i++) { - hash += key[i]; - hash += (hash << 10); - hash ^= (hash >> 6); - } - return hash; -} - -/** - * batadv_hash_add - adds data to the hashtable + * batadv_hash_add() - adds data to the hashtable * @hash: storage hash table * @compare: callback to determine if 2 hash elements are identical * @choose: callback calculating the hash index * @data: data passed to the aforementioned callbacks as argument * @data_node: to be added element * - * Returns 0 on success, 1 if the element already is in the hash + * Return: 0 on success, 1 if the element already is in the hash * and -1 on error. */ static inline int batadv_hash_add(struct batadv_hashtable *hash, @@ -120,7 +78,7 @@ static inline int batadv_hash_add(struct batadv_hashtable *hash, const void *data, struct hlist_node *data_node) { - uint32_t index; + u32 index; int ret = -1; struct hlist_head *head; struct hlist_node *node; @@ -145,6 +103,7 @@ static inline int batadv_hash_add(struct batadv_hashtable *hash, /* no duplicate found in list, add new element */ hlist_add_head_rcu(data_node, head); + atomic_inc(&hash->generation); ret = 0; @@ -154,17 +113,25 @@ out: return ret; } -/* removes data from hash, if found. returns pointer do data on success, so you - * can remove the used structure yourself, or NULL on error . data could be the - * structure you use with just the key filled, we just need the key for - * comparing. +/** + * batadv_hash_remove() - Removes data from hash, if found + * @hash: hash table + * @compare: callback to determine if 2 hash elements are identical + * @choose: callback calculating the hash index + * @data: data passed to the aforementioned callbacks as argument + * + * ata could be the structure you use with just the key filled, we just need + * the key for comparing. + * + * Return: returns pointer do data on success, so you can remove the used + * structure yourself, or NULL on error */ static inline void *batadv_hash_remove(struct batadv_hashtable *hash, batadv_hashdata_compare_cb compare, batadv_hashdata_choose_cb choose, void *data) { - uint32_t index; + u32 index; struct hlist_node *node; struct hlist_head *head; void *data_save = NULL; @@ -179,6 +146,7 @@ static inline void *batadv_hash_remove(struct batadv_hashtable *hash, data_save = node; hlist_del_rcu(node); + atomic_inc(&hash->generation); break; } spin_unlock_bh(&hash->list_locks[index]); |