/*
 * Copyright 2010 Red Hat, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY RED HAT, INC. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL RED HAT, INC. OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Red Hat author: Jan Chadima <jchadima@redhat.com>
 */

#include <sys/types.h>
#include <fcntl.h>
#include <pthread.h>
#include <unistd.h>
#include <linux/ncr.h>
#include "ncrypto.h"
#include "ncrypto_internal.h"

int __ncr_file_descriptor = -1;
static int open_count = 0;
static pthread_mutex_t open_lock = PTHREAD_MUTEX_INITIALIZER;

int
__ncr_global_init()
{
	int rv = 0;

	/* Open the crypto device unles is not already initialized */
	pthread_mutex_lock(&open_lock);
	if ((__ncr_file_descriptor < 0) && ((__ncr_file_descriptor = open("/dev/crypto", O_RDWR|O_CLOEXEC)) < 0))
		rv = -1;
	else
		++open_count;
	pthread_mutex_unlock(&open_lock);
	return rv;
}

int
ncr_global_init(unsigned int flags)
{
	return __ncr_global_init();
}

void
ncr_global_deinit(void)
{
	pthread_mutex_lock(&open_lock);
	if (!--open_count && (__ncr_file_descriptor >= 0)) {
		close(__ncr_file_descriptor);
		__ncr_file_descriptor = -1;
	}
	pthread_mutex_unlock(&open_lock);
}