/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004-2009 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
 */

#ifndef _G_GATE_H_
#define _G_GATE_H_

#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/queue.h>

#include <geom/geom.h>

#define G_GATE_CLASS_NAME       "GATE"
#define G_GATE_PROVIDER_NAME    "ggate"
#define G_GATE_MOD_NAME         "ggate"
#define G_GATE_CTL_NAME         "ggctl"

#define G_GATE_VERSION          3

/*
 * Maximum number of request that can be stored in
 * the queue when there are no workers.
 */
#define G_GATE_MAX_QUEUE_SIZE   4096

#define G_GATE_FLAG_READONLY    0x0001
#define G_GATE_FLAG_WRITEONLY   0x0002
#define G_GATE_FLAG_DESTROY     0x1000
#define G_GATE_USERFLAGS        (G_GATE_FLAG_READONLY | G_GATE_FLAG_WRITEONLY)

/*
 * Pick unit number automatically in /dev/ggate<unit>.
 */
#define G_GATE_UNIT_AUTO        (-1)
/*
 * Full provider name is given, so don't use ggate<unit>.
 */
#define G_GATE_NAME_GIVEN       (-2)

#define G_GATE_CMD_CREATE       _IOWR('m', 0, struct g_gate_ctl_create)
#define G_GATE_CMD_MODIFY       _IOWR('m', 1, struct g_gate_ctl_modify)
#define G_GATE_CMD_DESTROY      _IOWR('m', 2, struct g_gate_ctl_destroy)
#define G_GATE_CMD_CANCEL       _IOWR('m', 3, struct g_gate_ctl_cancel)
#define G_GATE_CMD_START        _IOWR('m', 4, struct g_gate_ctl_io)
#define G_GATE_CMD_DONE         _IOWR('m', 5, struct g_gate_ctl_io)

#define G_GATE_INFOSIZE         2048

#ifdef _KERNEL
/*
 * 'P:' means 'Protected by'.
 */
struct g_gate_softc {
        char                    *sc_name;               /* P: (read-only) */
        int                      sc_unit;               /* P: (read-only) */
        int                      sc_ref;                /* P: g_gate_list_mtx */
        struct g_provider       *sc_provider;           /* P: (read-only) */
        uint32_t                 sc_flags;              /* P: sc_queue_mtx */

        struct bio_queue_head    sc_inqueue;            /* P: sc_queue_mtx */
        struct bio_queue_head    sc_outqueue;           /* P: sc_queue_mtx */
        struct mtx               sc_queue_mtx;
        uint32_t                 sc_queue_count;        /* P: sc_queue_mtx */
        uint32_t                 sc_queue_size;         /* P: (read-only) */
        u_int                    sc_timeout;            /* P: (read-only) */
        struct g_consumer       *sc_readcons;           /* P: sc_read_mtx */
        off_t                    sc_readoffset;         /* P: sc_read_mtx */
        struct callout           sc_callout;            /* P: (modified only
                                                               from callout
                                                               thread) */
        uintptr_t                sc_seq;                /* P: sc_queue_mtx */
        LIST_ENTRY(g_gate_softc) sc_next;               /* P: g_gate_list_mtx */
        char                     sc_info[G_GATE_INFOSIZE]; /* P: (read-only) */
        struct mtx               sc_read_mtx;
};

#define G_GATE_DEBUG(lvl, ...) \
    _GEOM_DEBUG("GEOM_GATE", g_gate_debug, (lvl), NULL, __VA_ARGS__)
#define G_GATE_LOGREQ(lvl, bp, ...) \
    _GEOM_DEBUG("GEOM_GATE", g_gate_debug, (lvl), (bp), __VA_ARGS__)
#endif  /* !_KERNEL */

struct g_gate_ctl_create {
        u_int   gctl_version;
        off_t   gctl_mediasize;
        u_int   gctl_sectorsize;
        u_int   gctl_flags;
        u_int   gctl_maxcount;
        u_int   gctl_timeout;
        char    gctl_name[NAME_MAX];
        char    gctl_info[G_GATE_INFOSIZE];
        char    gctl_readprov[NAME_MAX];
        off_t   gctl_readoffset;
        int     gctl_unit;      /* in/out */
};

#define GG_MODIFY_MEDIASIZE     0x01
#define GG_MODIFY_INFO          0x02
#define GG_MODIFY_READPROV      0x04
#define GG_MODIFY_READOFFSET    0x08
struct g_gate_ctl_modify {
        u_int           gctl_version;
        int             gctl_unit;
        uint32_t        gctl_modify;
        off_t           gctl_mediasize;
        char            gctl_info[G_GATE_INFOSIZE];
        char            gctl_readprov[NAME_MAX];
        off_t           gctl_readoffset;
};

struct g_gate_ctl_destroy {
        u_int   gctl_version;
        int     gctl_unit;
        int     gctl_force;
        char    gctl_name[NAME_MAX];
};

struct g_gate_ctl_cancel {
        u_int           gctl_version;
        int             gctl_unit;
        uintptr_t       gctl_seq;
        char            gctl_name[NAME_MAX];
};

struct g_gate_ctl_io {
        u_int            gctl_version;
        int              gctl_unit;
        uintptr_t        gctl_seq;
        u_int            gctl_cmd;
        off_t            gctl_offset;
        off_t            gctl_length;
        void            *gctl_data;
        int              gctl_error;
};
#endif  /* !_G_GATE_H_ */