* Copyright (c) 2011 The NetBSD Foundation, Inc.

/* $NetBSD: v7fs_endian.c,v 1.2 2011/07/18 21:51:49 apb Exp $ */

/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by UCHIYAMA Yasushi.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: v7fs_endian.c,v 1.2 2011/07/18 21:51:49 apb Exp $");
#if defined _KERNEL_OPT
#include "opt_v7fs.h"
#endif

#include "v7fs.h"
#include "v7fs_endian.h"
#include "v7fs_impl.h"

#ifndef BYTE_ORDER
#error
#endif

/* PDP to Little */
#define bswap32pdp_le(x) \
((uint32_t) \
((((x) & 0xffff0000) >> 16) | \
(((x) & 0x0000ffff) << 16)))
/* PDP to Big */
#define bswap32pdp_be(x) \
((uint32_t) \
((((x) & 0xff00ff00) >> 8) | \
(((x) & 0x00ff00ff) << 8)))
#ifdef V7FS_EI
static uint32_t val32_normal_order(uint32_t);
static uint32_t val32_reverse_order(uint32_t);
#if BYTE_ORDER == LITTLE_ENDIAN
static uint32_t val32_pdp_to_little(uint32_t);
#else
static uint32_t val32_pdp_to_big(uint32_t);
#endif
static uint16_t val16_normal_order(uint16_t);
static uint16_t val16_reverse_order(uint16_t);
static v7fs_daddr_t val24_reverse_order_read(uint8_t *);
static void val24_reverse_order_write(v7fs_daddr_t, uint8_t *);
static v7fs_daddr_t val24_pdp_read(uint8_t *);
static void val24_pdp_write(v7fs_daddr_t, uint8_t *);

static uint32_t
val32_normal_order(uint32_t v)
{

return v;
}

static uint32_t
val32_reverse_order(uint32_t v)
{

return bswap32(v);
}
#if BYTE_ORDER == LITTLE_ENDIAN
static uint32_t
val32_pdp_to_little(uint32_t v)
{

return bswap32pdp_le(v);
}
#else
static uint32_t
val32_pdp_to_big(uint32_t v)
{

return bswap32pdp_be(v);
}
#endif
static uint16_t
val16_normal_order(uint16_t v)
{

return v;
}

static uint16_t
val16_reverse_order(uint16_t v)
{

return bswap16(v);
}

static v7fs_daddr_t
val24_reverse_order_read(uint8_t *a)
{
#if BYTE_ORDER == LITTLE_ENDIAN
return (a[0] << 16) | (a[1] << 8) | a[2];
#else
return (a[2] << 16) | (a[1] << 8) | a[0];
#endif
}

static void
val24_reverse_order_write(v7fs_daddr_t addr, uint8_t *a)
{
#if BYTE_ORDER == LITTLE_ENDIAN
a[0] = (addr >> 16) & 0xff;
a[1] = (addr >> 8) & 0xff;
a[2] = addr & 0xff;
#else
a[0] = addr & 0xff;
a[1] = (addr >> 8) & 0xff;
a[2] = (addr >> 16) & 0xff;
#endif
}

static v7fs_daddr_t
val24_pdp_read(uint8_t *a)
{

return (a[0] << 16) | a[1] | (a[2] << 8);
}

static void
val24_pdp_write(v7fs_daddr_t addr, uint8_t *a)
{

a[0] = (addr >> 16) & 0xff;
a[1] = addr & 0xff;
a[2] = (addr >> 8) & 0xff;
}

void
v7fs_endian_init(struct v7fs_self *fs)
{
struct endian_conversion_ops *ops = &fs->val;

switch (fs->endian)
{
#if BYTE_ORDER == LITTLE_ENDIAN
case LITTLE_ENDIAN:
ops->conv32 = val32_normal_order;
ops->conv16 = val16_normal_order;
ops->conv24read = val24_normal_order_read;
ops->conv24write = val24_normal_order_write;
break;
case BIG_ENDIAN:
ops->conv32 = val32_reverse_order;
ops->conv16 = val16_reverse_order;
ops->conv24read = val24_reverse_order_read;
ops->conv24write = val24_reverse_order_write;
break;
case PDP_ENDIAN:
ops->conv32 = val32_pdp_to_little;
ops->conv16 = val16_normal_order;
ops->conv24read = val24_pdp_read;
ops->conv24write = val24_pdp_write;
break;
#else /* BIG_ENDIAN */
case LITTLE_ENDIAN:
ops->conv32 = val32_reverse_order;
ops->conv16 = val16_reverse_order;
ops->conv24read = val24_reverse_order_read;
ops->conv24write = val24_reverse_order_write;
break;
case BIG_ENDIAN:
ops->conv32 = val32_normal_order;
ops->conv16 = val16_normal_order;
ops->conv24read = val24_normal_order_read;
ops->conv24write = val24_normal_order_write;
break;
case PDP_ENDIAN:
ops->conv32 = val32_pdp_to_big;
ops->conv16 = val16_reverse_order;
ops->conv24read = val24_pdp_read;
ops->conv24write = val24_pdp_write;
break;
#endif
}
}
#endif /* V7FS_EI */
v7fs_daddr_t
val24_normal_order_read(uint8_t *a)
{
/*(v7fs_daddr_t)cast is required for int 16bit system. */
#if BYTE_ORDER == LITTLE_ENDIAN
return ((v7fs_daddr_t)a[2] << 16) | ((v7fs_daddr_t)a[1] << 8) |
(v7fs_daddr_t)a[0];
#else
return ((v7fs_daddr_t)a[0] << 16) | ((v7fs_daddr_t)a[1] << 8) |
(v7fs_daddr_t)a[2];
#endif
}

void
val24_normal_order_write(v7fs_daddr_t addr, uint8_t *a)
{
#if BYTE_ORDER == LITTLE_ENDIAN
a[0] = addr & 0xff;
a[1] = (addr >> 8) & 0xff;
a[2] = (addr >> 16) & 0xff;
#else
a[0] = (addr >> 16) & 0xff;
a[1] = (addr >> 8) & 0xff;
a[2] = addr & 0xff;
#endif
}