root/usr/src/grub/grub-0.97/stage2/zfs-include/vdev_impl.h
/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SYS_VDEV_IMPL_H
#define _SYS_VDEV_IMPL_H

/* helper macros */
#undef  offsetof
#define offsetof(t, m)          ((int)&(((t *)0)->m))
#define MAX(x, y)               ((x) > (y) ? (x) : (y))

#define VDEV_PAD_SIZE           (8 << 10)
/* 2 padding areas (vl_pad1 and vl_pad2) to skip */
#define VDEV_SKIP_SIZE          VDEV_PAD_SIZE * 2
#define VDEV_PHYS_SIZE          (112 << 10)
#define VDEV_UBERBLOCK_RING     (128 << 10)

#define VDEV_UBERBLOCK_SHIFT(sh)                \
        MAX((sh), UBERBLOCK_SHIFT)
#define VDEV_UBERBLOCK_COUNT(sh)                \
        (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(sh))
#define VDEV_UBERBLOCK_OFFSET(sh, n)    \
        offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(sh)])
#define VDEV_UBERBLOCK_SIZE(sh)                 \
        (1ULL << VDEV_UBERBLOCK_SHIFT(sh))

typedef struct vdev_phys {
        char            vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_eck_t)];
        zio_eck_t       vp_zbt;
} vdev_phys_t;

typedef struct vdev_label {
        char            vl_pad1[VDEV_PAD_SIZE];                 /*  8K  */
        char            vl_pad2[VDEV_PAD_SIZE];                 /*  8K  */
        vdev_phys_t     vl_vdev_phys;                           /* 112K */
        char            vl_uberblock[VDEV_UBERBLOCK_RING];      /* 128K */
} vdev_label_t;                                                 /* 256K total */

/*
 * Size and offset of embedded boot loader region on each label.
 * The total size of the first two labels plus the boot area is 4MB.
 */
#define VDEV_BOOT_OFFSET        (2 * sizeof (vdev_label_t))
#define VDEV_BOOT_SIZE          (7ULL << 19)                    /* 3.5M */

/*
 * Size of label regions at the start and end of each leaf device.
 */
#define VDEV_LABEL_START_SIZE   (2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
#define VDEV_LABEL_END_SIZE     (2 * sizeof (vdev_label_t))
#define VDEV_LABELS             4

#endif  /* _SYS_VDEV_IMPL_H */