// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
 *
 * Simon Wunderlich, Marek Lindner
 */

#include "hash.h"
#include "main.h"

#include <linux/gfp.h>
#include <linux/lockdep.h>
#include <linux/slab.h>

/* clears the hash */
static void batadv_hash_init(struct batadv_hashtable *hash)
{
        u32 i;

        for (i = 0; i < hash->size; i++) {
                INIT_HLIST_HEAD(&hash->table[i]);
                spin_lock_init(&hash->list_locks[i]);
        }

        atomic_set(&hash->generation, 0);
}

/**
 * batadv_hash_destroy() - Free only the hashtable and the hash itself
 * @hash: hash object to destroy
 */
void batadv_hash_destroy(struct batadv_hashtable *hash)
{
        kfree(hash->list_locks);
        kfree(hash->table);
        kfree(hash);
}

/**
 * batadv_hash_new() - Allocates and clears the hashtable
 * @size: number of hash buckets to allocate
 *
 * Return: newly allocated hashtable, NULL on errors
 */
struct batadv_hashtable *batadv_hash_new(u32 size)
{
        struct batadv_hashtable *hash;

        hash = kmalloc_obj(*hash, GFP_ATOMIC);
        if (!hash)
                return NULL;

        hash->table = kmalloc_objs(*hash->table, size, GFP_ATOMIC);
        if (!hash->table)
                goto free_hash;

        hash->list_locks = kmalloc_objs(*hash->list_locks, size, GFP_ATOMIC);
        if (!hash->list_locks)
                goto free_table;

        hash->size = size;
        batadv_hash_init(hash);
        return hash;

free_table:
        kfree(hash->table);
free_hash:
        kfree(hash);
        return NULL;
}

/**
 * batadv_hash_set_lock_class() - Set specific lockdep class for hash spinlocks
 * @hash: hash object to modify
 * @key: lockdep class key address
 */
void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
                                struct lock_class_key *key)
{
        u32 i;

        for (i = 0; i < hash->size; i++)
                lockdep_set_class(&hash->list_locks[i], key);
}