1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 */
30 /*
31 * This file is part of Lustre, http://www.lustre.org/
32 * Lustre is a trademark of Sun Microsystems, Inc.
33 */
34
35 #ifndef __OBD_CKSUM
36 #define __OBD_CKSUM
37 #include "../../include/linux/libcfs/libcfs.h"
38 #include "lustre/lustre_idl.h"
39
cksum_obd2cfs(cksum_type_t cksum_type)40 static inline unsigned char cksum_obd2cfs(cksum_type_t cksum_type)
41 {
42 switch (cksum_type) {
43 case OBD_CKSUM_CRC32:
44 return CFS_HASH_ALG_CRC32;
45 case OBD_CKSUM_ADLER:
46 return CFS_HASH_ALG_ADLER32;
47 case OBD_CKSUM_CRC32C:
48 return CFS_HASH_ALG_CRC32C;
49 default:
50 CERROR("Unknown checksum type (%x)!!!\n", cksum_type);
51 LBUG();
52 }
53 return 0;
54 }
55
56 /* The OBD_FL_CKSUM_* flags is packed into 5 bits of o_flags, since there can
57 * only be a single checksum type per RPC.
58 *
59 * The OBD_CHECKSUM_* type bits passed in ocd_cksum_types are a 32-bit bitmask
60 * since they need to represent the full range of checksum algorithms that
61 * both the client and server can understand.
62 *
63 * In case of an unsupported types/flags we fall back to ADLER
64 * because that is supported by all clients since 1.8
65 *
66 * In case multiple algorithms are supported the best one is used. */
cksum_type_pack(cksum_type_t cksum_type)67 static inline u32 cksum_type_pack(cksum_type_t cksum_type)
68 {
69 unsigned int performance = 0, tmp;
70 u32 flag = OBD_FL_CKSUM_ADLER;
71
72 if (cksum_type & OBD_CKSUM_CRC32) {
73 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32));
74 if (tmp > performance) {
75 performance = tmp;
76 flag = OBD_FL_CKSUM_CRC32;
77 }
78 }
79 if (cksum_type & OBD_CKSUM_CRC32C) {
80 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C));
81 if (tmp > performance) {
82 performance = tmp;
83 flag = OBD_FL_CKSUM_CRC32C;
84 }
85 }
86 if (cksum_type & OBD_CKSUM_ADLER) {
87 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER));
88 if (tmp > performance) {
89 performance = tmp;
90 flag = OBD_FL_CKSUM_ADLER;
91 }
92 }
93 if (unlikely(cksum_type && !(cksum_type & (OBD_CKSUM_CRC32C |
94 OBD_CKSUM_CRC32 |
95 OBD_CKSUM_ADLER))))
96 CWARN("unknown cksum type %x\n", cksum_type);
97
98 return flag;
99 }
100
cksum_type_unpack(u32 o_flags)101 static inline cksum_type_t cksum_type_unpack(u32 o_flags)
102 {
103 switch (o_flags & OBD_FL_CKSUM_ALL) {
104 case OBD_FL_CKSUM_CRC32C:
105 return OBD_CKSUM_CRC32C;
106 case OBD_FL_CKSUM_CRC32:
107 return OBD_CKSUM_CRC32;
108 default:
109 break;
110 }
111
112 return OBD_CKSUM_ADLER;
113 }
114
115 /* Return a bitmask of the checksum types supported on this system.
116 * 1.8 supported ADLER it is base and not depend on hw
117 * Client uses all available local algos
118 */
cksum_types_supported_client(void)119 static inline cksum_type_t cksum_types_supported_client(void)
120 {
121 cksum_type_t ret = OBD_CKSUM_ADLER;
122
123 CDEBUG(D_INFO, "Crypto hash speed: crc %d, crc32c %d, adler %d\n",
124 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)),
125 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)),
126 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)));
127
128 if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)) > 0)
129 ret |= OBD_CKSUM_CRC32C;
130 if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)) > 0)
131 ret |= OBD_CKSUM_CRC32;
132
133 return ret;
134 }
135
136 /* Server uses algos that perform at 50% or better of the Adler */
cksum_types_supported_server(void)137 static inline cksum_type_t cksum_types_supported_server(void)
138 {
139 int base_speed;
140 cksum_type_t ret = OBD_CKSUM_ADLER;
141
142 CDEBUG(D_INFO, "Crypto hash speed: crc %d, crc32c %d, adler %d\n",
143 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)),
144 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)),
145 cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)));
146
147 base_speed = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)) / 2;
148
149 if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)) >=
150 base_speed)
151 ret |= OBD_CKSUM_CRC32C;
152 if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)) >=
153 base_speed)
154 ret |= OBD_CKSUM_CRC32;
155
156 return ret;
157 }
158
159 /* Select the best checksum algorithm among those supplied in the cksum_types
160 * input.
161 *
162 * Currently, calling cksum_type_pack() with a mask will return the fastest
163 * checksum type due to its benchmarking at libcfs module load.
164 * Caution is advised, however, since what is fastest on a single client may
165 * not be the fastest or most efficient algorithm on the server. */
cksum_type_select(cksum_type_t cksum_types)166 static inline cksum_type_t cksum_type_select(cksum_type_t cksum_types)
167 {
168 return cksum_type_unpack(cksum_type_pack(cksum_types));
169 }
170
171 /* Checksum algorithm names. Must be defined in the same order as the
172 * OBD_CKSUM_* flags. */
173 #define DECLARE_CKSUM_NAME char *cksum_name[] = {"crc32", "adler", "crc32c"}
174
175 #endif /* __OBD_H */
176