68a600de9a
While it can be slightly beneficial for the build performance to use forward declarations instead of includes, the handling of them together with changes in the included headers makes it unnecessary complicated and fragile. Just replace them with actual includes since some parts (hwmon, ..) of the kernel even request avoidance of forward declarations and net/ is mostly not using them in *.c file. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
158 lines
3.9 KiB
C
158 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (C) 2006-2019 B.A.T.M.A.N. contributors:
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*
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* Simon Wunderlich, Marek Lindner
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*/
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#ifndef _NET_BATMAN_ADV_HASH_H_
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#define _NET_BATMAN_ADV_HASH_H_
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#include "main.h"
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#include <linux/atomic.h>
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#include <linux/compiler.h>
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#include <linux/list.h>
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#include <linux/lockdep.h>
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#include <linux/rculist.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/types.h>
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/* callback to a compare function. should compare 2 element datas for their
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* keys
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*
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* Return: true if same and false if not same
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*/
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typedef bool (*batadv_hashdata_compare_cb)(const struct hlist_node *,
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const void *);
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/* the hashfunction
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*
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* Return: an index based on the key in the data of the first argument and the
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* size the second
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*/
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typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32);
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typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *);
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/**
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* struct batadv_hashtable - Wrapper of simple hlist based hashtable
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*/
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struct batadv_hashtable {
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/** @table: the hashtable itself with the buckets */
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struct hlist_head *table;
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/** @list_locks: spinlock for each hash list entry */
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spinlock_t *list_locks;
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/** @size: size of hashtable */
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u32 size;
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/** @generation: current (generation) sequence number */
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atomic_t generation;
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};
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/* allocates and clears the hash */
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struct batadv_hashtable *batadv_hash_new(u32 size);
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/* set class key for all locks */
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void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
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struct lock_class_key *key);
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/* free only the hashtable and the hash itself. */
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void batadv_hash_destroy(struct batadv_hashtable *hash);
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/**
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* batadv_hash_add() - adds data to the hashtable
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* @hash: storage hash table
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* @compare: callback to determine if 2 hash elements are identical
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* @choose: callback calculating the hash index
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* @data: data passed to the aforementioned callbacks as argument
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* @data_node: to be added element
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*
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* Return: 0 on success, 1 if the element already is in the hash
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* and -1 on error.
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*/
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static inline int batadv_hash_add(struct batadv_hashtable *hash,
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batadv_hashdata_compare_cb compare,
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batadv_hashdata_choose_cb choose,
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const void *data,
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struct hlist_node *data_node)
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{
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u32 index;
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int ret = -1;
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struct hlist_head *head;
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struct hlist_node *node;
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spinlock_t *list_lock; /* spinlock to protect write access */
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if (!hash)
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goto out;
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index = choose(data, hash->size);
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head = &hash->table[index];
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list_lock = &hash->list_locks[index];
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spin_lock_bh(list_lock);
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hlist_for_each(node, head) {
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if (!compare(node, data))
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continue;
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ret = 1;
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goto unlock;
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}
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/* no duplicate found in list, add new element */
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hlist_add_head_rcu(data_node, head);
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atomic_inc(&hash->generation);
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ret = 0;
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unlock:
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spin_unlock_bh(list_lock);
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out:
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return ret;
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}
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/**
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* batadv_hash_remove() - Removes data from hash, if found
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* @hash: hash table
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* @compare: callback to determine if 2 hash elements are identical
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* @choose: callback calculating the hash index
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* @data: data passed to the aforementioned callbacks as argument
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*
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* ata could be the structure you use with just the key filled, we just need
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* the key for comparing.
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*
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* Return: returns pointer do data on success, so you can remove the used
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* structure yourself, or NULL on error
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*/
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static inline void *batadv_hash_remove(struct batadv_hashtable *hash,
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batadv_hashdata_compare_cb compare,
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batadv_hashdata_choose_cb choose,
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void *data)
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{
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u32 index;
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struct hlist_node *node;
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struct hlist_head *head;
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void *data_save = NULL;
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index = choose(data, hash->size);
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head = &hash->table[index];
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spin_lock_bh(&hash->list_locks[index]);
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hlist_for_each(node, head) {
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if (!compare(node, data))
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continue;
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data_save = node;
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hlist_del_rcu(node);
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atomic_inc(&hash->generation);
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break;
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}
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spin_unlock_bh(&hash->list_locks[index]);
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return data_save;
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}
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#endif /* _NET_BATMAN_ADV_HASH_H_ */
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