/*-
 * Copyright (c) 2010 Isilon Systems, Inc.
 * Copyright (c) 2010 iX Systems, Inc.
 * Copyright (c) 2010 Panasas, Inc.
 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
 * All rights reserved.
 *
 * 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 unmodified, 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 THE AUTHOR ``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 THE AUTHOR 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.
 */
#ifndef _LINUXKPI_LINUX_KDEV_T_H_
#define _LINUXKPI_LINUX_KDEV_T_H_

#include <sys/types.h>

/*
 * The encoding of major/minor on FreeBSD is complex to take into account the
 * compatibility with 16-bit dev_t (see <sys/types.h>). It is not possible to
 * use a simple shift and thus, we can't have a proper definition of
 * `MINORBITS`.
 *
 * At the time this is added to linuxkpi, this is used by the DRM generic code
 * as the upper limit to allocate an ID using an xarray. It is not used to
 * decode a minor, therefore any arbitrary value here is fine in this context.
 *
 * On Linux, the value is set to 20. Because of the above, we reuse this value,
 * even so it does not correspond to the actual minor encoding on FreeBSD.
 */
#define MINORBITS       20

#define MAJOR(dev)      major(dev)
#define MINOR(dev)      minor(dev)
#define MKDEV(ma, mi)   makedev(ma, mi)

static inline uint16_t
old_encode_dev(dev_t dev)
{
        return ((MAJOR(dev) << 8) | MINOR(dev));
}

#endif  /* _LINUXKPI_LINUX_KDEV_T_H_ */