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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 /*
27 * Fletcher Checksums
28 * ------------------
29 *
30 * ZFS's 2nd and 4th order Fletcher checksums are defined by the following
31 * recurrence relations:
32 *
33 * a = a + f
34 * i i-1 i-1
35 *
36 * b = b + a
37 * i i-1 i
38 *
39 * c = c + b (fletcher-4 only)
40 * i i-1 i
41 *
42 * d = d + c (fletcher-4 only)
43 * i i-1 i
44 *
114 * Even though fletcher-4 is slower than fletcher-2, it is still a pretty
115 * efficient pass over the data.
116 *
117 * In normal operation, the data which is being checksummed is in a buffer
118 * which has been filled either by:
119 *
120 * 1. a compression step, which will be mostly cached, or
121 * 2. a bcopy() or copyin(), which will be uncached (because the
122 * copy is cache-bypassing).
123 *
124 * For both cached and uncached data, both fletcher checksums are much faster
125 * than sha-256, and slower than 'off', which doesn't touch the data at all.
126 */
127
128 #include <sys/types.h>
129 #include <sys/sysmacros.h>
130 #include <sys/byteorder.h>
131 #include <sys/zio.h>
132 #include <sys/spa.h>
133
134 void
135 fletcher_2_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
136 {
137 const uint64_t *ip = buf;
138 const uint64_t *ipend = ip + (size / sizeof (uint64_t));
139 uint64_t a0, b0, a1, b1;
140
141 for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
142 a0 += ip[0];
143 a1 += ip[1];
144 b0 += a0;
145 b1 += a1;
146 }
147
148 ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
149 }
150
151 void
152 fletcher_2_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp)
153 {
154 const uint64_t *ip = buf;
155 const uint64_t *ipend = ip + (size / sizeof (uint64_t));
156 uint64_t a0, b0, a1, b1;
157
158 for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
159 a0 += BSWAP_64(ip[0]);
160 a1 += BSWAP_64(ip[1]);
161 b0 += a0;
162 b1 += a1;
163 }
164
165 ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
166 }
167
168 void
169 fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
170 {
171 const uint32_t *ip = buf;
172 const uint32_t *ipend = ip + (size / sizeof (uint32_t));
173 uint64_t a, b, c, d;
174
175 for (a = b = c = d = 0; ip < ipend; ip++) {
176 a += ip[0];
177 b += a;
178 c += b;
179 d += c;
180 }
181
182 ZIO_SET_CHECKSUM(zcp, a, b, c, d);
183 }
184
185 void
186 fletcher_4_byteswap(const void *buf, uint64_t size, zio_cksum_t *zcp)
187 {
188 const uint32_t *ip = buf;
189 const uint32_t *ipend = ip + (size / sizeof (uint32_t));
190 uint64_t a, b, c, d;
191
192 for (a = b = c = d = 0; ip < ipend; ip++) {
193 a += BSWAP_32(ip[0]);
194 b += a;
195 c += b;
196 d += c;
197 }
198
199 ZIO_SET_CHECKSUM(zcp, a, b, c, d);
200 }
201
202 void
203 fletcher_4_incremental_native(const void *buf, uint64_t size,
204 zio_cksum_t *zcp)
205 {
206 const uint32_t *ip = buf;
|
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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25 /*
26 * Copyright 2013 Saso Kiselkov. All rights reserved.
27 */
28
29 /*
30 * Fletcher Checksums
31 * ------------------
32 *
33 * ZFS's 2nd and 4th order Fletcher checksums are defined by the following
34 * recurrence relations:
35 *
36 * a = a + f
37 * i i-1 i-1
38 *
39 * b = b + a
40 * i i-1 i
41 *
42 * c = c + b (fletcher-4 only)
43 * i i-1 i
44 *
45 * d = d + c (fletcher-4 only)
46 * i i-1 i
47 *
117 * Even though fletcher-4 is slower than fletcher-2, it is still a pretty
118 * efficient pass over the data.
119 *
120 * In normal operation, the data which is being checksummed is in a buffer
121 * which has been filled either by:
122 *
123 * 1. a compression step, which will be mostly cached, or
124 * 2. a bcopy() or copyin(), which will be uncached (because the
125 * copy is cache-bypassing).
126 *
127 * For both cached and uncached data, both fletcher checksums are much faster
128 * than sha-256, and slower than 'off', which doesn't touch the data at all.
129 */
130
131 #include <sys/types.h>
132 #include <sys/sysmacros.h>
133 #include <sys/byteorder.h>
134 #include <sys/zio.h>
135 #include <sys/spa.h>
136
137 /*ARGSUSED*/
138 void
139 fletcher_2_native(const void *buf, uint64_t size, const zio_cksum_salt_t *salt,
140 const void *ctx_template, zio_cksum_t *zcp)
141 {
142 const uint64_t *ip = buf;
143 const uint64_t *ipend = ip + (size / sizeof (uint64_t));
144 uint64_t a0, b0, a1, b1;
145
146 for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
147 a0 += ip[0];
148 a1 += ip[1];
149 b0 += a0;
150 b1 += a1;
151 }
152
153 ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
154 }
155
156 /*ARGSUSED*/
157 void
158 fletcher_2_byteswap(const void *buf, uint64_t size,
159 const zio_cksum_salt_t *salt, const void *ctx_template, zio_cksum_t *zcp)
160 {
161 const uint64_t *ip = buf;
162 const uint64_t *ipend = ip + (size / sizeof (uint64_t));
163 uint64_t a0, b0, a1, b1;
164
165 for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
166 a0 += BSWAP_64(ip[0]);
167 a1 += BSWAP_64(ip[1]);
168 b0 += a0;
169 b1 += a1;
170 }
171
172 ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
173 }
174
175 /*ARGSUSED*/
176 void
177 fletcher_4_native(const void *buf, uint64_t size, const zio_cksum_salt_t *salt,
178 const void *ctx_template, zio_cksum_t *zcp)
179 {
180 const uint32_t *ip = buf;
181 const uint32_t *ipend = ip + (size / sizeof (uint32_t));
182 uint64_t a, b, c, d;
183
184 for (a = b = c = d = 0; ip < ipend; ip++) {
185 a += ip[0];
186 b += a;
187 c += b;
188 d += c;
189 }
190
191 ZIO_SET_CHECKSUM(zcp, a, b, c, d);
192 }
193
194 /*ARGSUSED*/
195 void
196 fletcher_4_byteswap(const void *buf, uint64_t size,
197 const zio_cksum_salt_t *salt, const void *ctx_template, zio_cksum_t *zcp)
198 {
199 const uint32_t *ip = buf;
200 const uint32_t *ipend = ip + (size / sizeof (uint32_t));
201 uint64_t a, b, c, d;
202
203 for (a = b = c = d = 0; ip < ipend; ip++) {
204 a += BSWAP_32(ip[0]);
205 b += a;
206 c += b;
207 d += c;
208 }
209
210 ZIO_SET_CHECKSUM(zcp, a, b, c, d);
211 }
212
213 void
214 fletcher_4_incremental_native(const void *buf, uint64_t size,
215 zio_cksum_t *zcp)
216 {
217 const uint32_t *ip = buf;
|