/*      $OpenBSD: specdev.h,v 1.41 2022/06/26 05:20:42 visa Exp $       */
/*      $NetBSD: specdev.h,v 1.12 1996/02/13 13:13:01 mycroft Exp $     */

/*
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  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, 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
 *
 *      @(#)specdev.h   8.3 (Berkeley) 8/10/94
 */

SLIST_HEAD(vnodechain, vnode);

/*
 * This structure defines the information maintained about
 * special devices. It is allocated in checkalias and freed
 * in vgone.
 */
struct specinfo {
        struct  vnodechain *si_hashchain;
        SLIST_ENTRY(vnode) si_specnext;
        struct  mount *si_mountpoint;
        dev_t   si_rdev;
        struct  lockf_state *si_lockf;
        daddr_t si_lastr;
        union {
                struct vnode *ci_parent; /* pointer back to parent device */
                u_int8_t *ci_bitmap; /* bitmap of devices cloned off us */
        } si_ci;
};

struct cloneinfo {
        struct vnode *ci_vp; /* cloned vnode */
        void *ci_data; /* original vnode's v_data */
};

/*
 * Exported shorthand
 */
#define v_rdev v_specinfo->si_rdev
#define v_hashchain v_specinfo->si_hashchain
#define v_specnext v_specinfo->si_specnext
#define v_specmountpoint v_specinfo->si_mountpoint
#define v_speclockf v_specinfo->si_lockf
#define v_specparent v_specinfo->si_ci.ci_parent
#define v_specbitmap v_specinfo->si_ci.ci_bitmap

/*
 * We use the upper 16 bits of the minor to record the clone instance.
 * This gives us 8 bits for encoding the real minor number.
 */
#define CLONE_SHIFT     8
#define CLONE_MAPSZ     128

/*
 * Special device management
 */
#define SPECHSZ 64
#if     ((SPECHSZ&(SPECHSZ-1)) == 0)
#define SPECHASH(rdev)  (((rdev>>5)+(rdev))&(SPECHSZ-1))
#else
#define SPECHASH(rdev)  (((unsigned)((rdev>>5)+(rdev)))%SPECHSZ)
#endif

#ifdef  _KERNEL

extern struct vnodechain speclisth[SPECHSZ];

/*
 * Prototypes for special file operations on vnodes.
 */
int     spec_getattr(void *);
int     spec_setattr(void *);
int     spec_access(void *);
int     spec_open(void *);
int     spec_close(void *);
int     spec_read(void *);
int     spec_write(void *);
int     spec_ioctl(void *);
int     spec_kqfilter(void *);
int     spec_fsync(void *);
int     spec_inactive(void *);
int     spec_strategy(void *);
int     spec_print(void *);
int     spec_pathconf(void *);
int     spec_advlock(void *);

#endif  /* _KERNEL */