/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright 2024 Oxide Computer Company
 */

#include "lint.h"
#include <sys/types.h>
#include <sys/mkdev.h>
#include <errno.h>

/*
 * Create a formatted device number
 */
dev_t
__makedev(const int version, const major_t majdev, const minor_t mindev)
{
        dev_t devnum;
        switch (version) {
        case OLDDEV:
                if (majdev > OMAXMAJ || mindev > OMAXMIN) {
                        errno = EINVAL;
                        return ((o_dev_t)NODEV);
                }
                devnum = ((majdev << ONBITSMINOR) | mindev);
                break;

        case NEWDEV:
#if MAXMAJ != 0xfffffffful      /* assumes major_t == uint32_t */
                if (majdev > MAXMAJ) {
                        errno = EINVAL;
                        return (NODEV);
                }
#endif
#if MAXMIN != 0xfffffffful      /* assumes minor_t == uint32_t */
                if (mindev > MAXMIN) {
                        errno = EINVAL;
                        return (NODEV);
                }
#endif
                if ((devnum = (((dev_t)majdev << NBITSMINOR) |
                    mindev)) == NODEV) {
                        errno = EINVAL;
                        return (NODEV);
                }
                break;
        case COMPATDEV:
                if (majdev > MAXMAJ32 || mindev > MAXMIN32) {
                        errno = EINVAL;
                        return (NODEV);
                }

                if ((devnum = (((dev_t)majdev << NBITSMINOR32) |
                    mindev)) == NODEV) {
                        errno = EINVAL;
                        return (NODEV);
                }
                break;
        default:
                errno = EINVAL;
                return (NODEV);
        }

        return (devnum);
}

/*
 * Return major number part of formatted device number
 */
major_t
__major(const int version, const dev_t devnum)
{
        major_t maj;

        switch (version) {
        case OLDDEV:
                maj = (devnum >> ONBITSMINOR);
                if (devnum == NODEV || maj > OMAXMAJ) {
                        errno = EINVAL;
                        return ((major_t)NODEV);
                }
                break;

        case NEWDEV:
                maj = (devnum >> NBITSMINOR);
                if (devnum == NODEV) {
                        errno = EINVAL;
                        return ((major_t)NODEV);
                }
#if MAXMAJ != 0xfffffffful      /* assumes major_t == uint32_t */
                if (maj > MAXMAJ) {
                        errno = EINVAL;
                        return ((major_t)NODEV);
                }
#endif
                break;

        case COMPATDEV:
                maj = devnum >> NBITSMAJOR32;
                if (devnum == NODEV || maj > MAXMAJ32) {
                        errno = EINVAL;
                        return ((major_t)NODEV);
                }
                break;

        default:
                errno = EINVAL;
                return ((major_t)NODEV);
        }

        return (maj);
}


/*
 * Return minor number part of formatted device number
 */
minor_t
__minor(const int version, const dev_t devnum)
{
        if (devnum == NODEV) {
                errno = EINVAL;
                return ((minor_t)NODEV);
        }

        switch (version) {
        case OLDDEV:
                return (devnum & OMAXMIN);
        case NEWDEV:
                return (devnum & MAXMIN);
        case COMPATDEV:
                return (devnum & MAXMIN32);
        default:
                errno = EINVAL;
                return ((minor_t)NODEV);
        }
}