xref: /freebsd/sys/cddl/boot/zfs/fletcher.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*#pragma ident	"%Z%%M%	%I%	%E% SMI"*/
27 
28 static void
29 fletcher_2_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
30 {
31 	const uint64_t *ip = buf;
32 	const uint64_t *ipend = ip + (size / sizeof (uint64_t));
33 	uint64_t a0, b0, a1, b1;
34 
35 	for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
36 		a0 += ip[0];
37 		a1 += ip[1];
38 		b0 += a0;
39 		b1 += a1;
40 	}
41 
42 	ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
43 }
44 
45 static void
46 fletcher_2_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp)
47 {
48 	const uint64_t *ip = buf;
49 	const uint64_t *ipend = ip + (size / sizeof (uint64_t));
50 	uint64_t a0, b0, a1, b1;
51 
52 	for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
53 		a0 += BSWAP_64(ip[0]);
54 		a1 += BSWAP_64(ip[1]);
55 		b0 += a0;
56 		b1 += a1;
57 	}
58 
59 	ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
60 }
61 
62 static void
63 fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
64 {
65 	const uint32_t *ip = buf;
66 	const uint32_t *ipend = ip + (size / sizeof (uint32_t));
67 	uint64_t a, b, c, d;
68 
69 	for (a = b = c = d = 0; ip < ipend; ip++) {
70 		a += ip[0];
71 		b += a;
72 		c += b;
73 		d += c;
74 	}
75 
76 	ZIO_SET_CHECKSUM(zcp, a, b, c, d);
77 }
78 
79 static void
80 fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp)
81 {
82 	const uint32_t *ip = buf;
83 	const uint32_t *ipend = ip + (size / sizeof (uint32_t));
84 	uint64_t a, b, c, d;
85 
86 	for (a = b = c = d = 0; ip < ipend; ip++) {
87 		a += BSWAP_32(ip[0]);
88 		b += a;
89 		c += b;
90 		d += c;
91 	}
92 
93 	ZIO_SET_CHECKSUM(zcp, a, b, c, d);
94 }
95