1/*	$NetBSD: v7fs_endian.c,v 1.1 2011/06/27 11:52:24 uch Exp $	*/
2
3/*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by UCHIYAMA Yasushi.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#if HAVE_NBTOOL_CONFIG_H
33#include "nbtool_config.h"
34#endif
35
36#include <sys/cdefs.h>
37__KERNEL_RCSID(0, "$NetBSD: v7fs_endian.c,v 1.1 2011/06/27 11:52:24 uch Exp $");
38#if defined _KERNEL_OPT
39#include "opt_v7fs.h"
40#endif
41
42#include "v7fs.h"
43#include "v7fs_endian.h"
44#include "v7fs_impl.h"
45
46#ifndef BYTE_ORDER
47#error
48#endif
49
50/* PDP to Little */
51#define	bswap32pdp_le(x)			\
52	((uint32_t)				\
53	    ((((x) & 0xffff0000) >> 16) |	\
54		(((x) & 0x0000ffff) << 16)))
55/* PDP to Big */
56#define	bswap32pdp_be(x)			\
57	((uint32_t)				\
58	    ((((x) & 0xff00ff00) >> 8) |	\
59		(((x) & 0x00ff00ff) <<  8)))
60#ifdef V7FS_EI
61static uint32_t val32_normal_order(uint32_t);
62static uint32_t val32_reverse_order(uint32_t);
63#if BYTE_ORDER == LITTLE_ENDIAN
64static uint32_t val32_pdp_to_little(uint32_t);
65#else
66static uint32_t val32_pdp_to_big(uint32_t);
67#endif
68static uint16_t val16_normal_order(uint16_t);
69static uint16_t val16_reverse_order(uint16_t);
70static v7fs_daddr_t val24_reverse_order_read(uint8_t *);
71static void val24_reverse_order_write(v7fs_daddr_t, uint8_t *);
72static v7fs_daddr_t val24_pdp_read(uint8_t *);
73static void val24_pdp_write(v7fs_daddr_t, uint8_t *);
74
75static uint32_t
76val32_normal_order(uint32_t v)
77{
78
79	return v;
80}
81
82static uint32_t
83val32_reverse_order(uint32_t v)
84{
85
86	return bswap32(v);
87}
88#if BYTE_ORDER == LITTLE_ENDIAN
89static uint32_t
90val32_pdp_to_little(uint32_t v)
91{
92
93	return bswap32pdp_le(v);
94}
95#else
96static uint32_t
97val32_pdp_to_big(uint32_t v)
98{
99
100	return bswap32pdp_be(v);
101}
102#endif
103static uint16_t
104val16_normal_order(uint16_t v)
105{
106
107	return v;
108}
109
110static uint16_t
111val16_reverse_order(uint16_t v)
112{
113
114	return bswap16(v);
115}
116
117static v7fs_daddr_t
118val24_reverse_order_read(uint8_t *a)
119{
120#if BYTE_ORDER == LITTLE_ENDIAN
121	return (a[0] << 16) | (a[1] << 8) | a[2];
122#else
123	return (a[2] << 16) | (a[1] << 8) | a[0];
124#endif
125}
126
127static void
128val24_reverse_order_write(v7fs_daddr_t addr, uint8_t *a)
129{
130#if BYTE_ORDER == LITTLE_ENDIAN
131	a[0] = (addr >> 16) & 0xff;
132	a[1] = (addr >> 8) & 0xff;
133	a[2] = addr & 0xff;
134#else
135	a[0] = addr & 0xff;
136	a[1] = (addr >> 8) & 0xff;
137	a[2] = (addr >> 16) & 0xff;
138#endif
139}
140
141static v7fs_daddr_t
142val24_pdp_read(uint8_t *a)
143{
144
145	return (a[0] << 16) | a[1] | (a[2] << 8);
146}
147
148static void
149val24_pdp_write(v7fs_daddr_t addr, uint8_t *a)
150{
151
152	a[0] = (addr >> 16) & 0xff;
153	a[1] = addr & 0xff;
154	a[2] = (addr >> 8) & 0xff;
155}
156
157void
158v7fs_endian_init(struct v7fs_self *fs)
159{
160	struct endian_conversion_ops *ops = &fs->val;
161
162	switch (fs->endian)
163	{
164#if BYTE_ORDER == LITTLE_ENDIAN
165	case LITTLE_ENDIAN:
166		ops->conv32 = val32_normal_order;
167		ops->conv16 = val16_normal_order;
168		ops->conv24read = val24_normal_order_read;
169		ops->conv24write = val24_normal_order_write;
170		break;
171	case BIG_ENDIAN:
172		ops->conv32 = val32_reverse_order;
173		ops->conv16 = val16_reverse_order;
174		ops->conv24read = val24_reverse_order_read;
175		ops->conv24write = val24_reverse_order_write;
176		break;
177	case PDP_ENDIAN:
178		ops->conv32 = val32_pdp_to_little;
179		ops->conv16 = val16_normal_order;
180		ops->conv24read = val24_pdp_read;
181		ops->conv24write = val24_pdp_write;
182		break;
183#else /* BIG_ENDIAN */
184	case LITTLE_ENDIAN:
185		ops->conv32 = val32_reverse_order;
186		ops->conv16 = val16_reverse_order;
187		ops->conv24read = val24_reverse_order_read;
188		ops->conv24write = val24_reverse_order_write;
189		break;
190	case BIG_ENDIAN:
191		ops->conv32 = val32_normal_order;
192		ops->conv16 = val16_normal_order;
193		ops->conv24read = val24_normal_order_read;
194		ops->conv24write = val24_normal_order_write;
195		break;
196	case PDP_ENDIAN:
197		ops->conv32 = val32_pdp_to_big;
198		ops->conv16 = val16_reverse_order;
199		ops->conv24read = val24_pdp_read;
200		ops->conv24write = val24_pdp_write;
201		break;
202#endif
203	}
204}
205#endif	/* V7FS_EI */
206v7fs_daddr_t
207val24_normal_order_read(uint8_t *a)
208{
209	/*(v7fs_daddr_t)cast is required for int 16bit system. */
210#if BYTE_ORDER == LITTLE_ENDIAN
211	return ((v7fs_daddr_t)a[2] << 16) | ((v7fs_daddr_t)a[1] << 8) |
212	    (v7fs_daddr_t)a[0];
213#else
214	return ((v7fs_daddr_t)a[0] << 16) | ((v7fs_daddr_t)a[1] << 8) |
215	    (v7fs_daddr_t)a[2];
216#endif
217}
218
219void
220val24_normal_order_write(v7fs_daddr_t addr, uint8_t *a)
221{
222#if BYTE_ORDER == LITTLE_ENDIAN
223	a[0] = addr & 0xff;
224	a[1] = (addr >> 8) & 0xff;
225	a[2] = (addr >> 16) & 0xff;
226#else
227	a[0] = (addr >> 16) & 0xff;
228	a[1] = (addr >> 8) & 0xff;
229	a[2] = addr & 0xff;
230#endif
231}
232