lustre/include/obd_cksum.h

   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  * Copyright (c) 2014, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #ifndef __OBD_CKSUM
  38 #define __OBD_CKSUM
  39 #include <libcfs/libcfs.h>
  40 #include <libcfs/libcfs_crypto.h>
  41 #include <lustre/lustre_idl.h>
  42
  43 static inline unsigned char cksum_obd2cfs(cksum_type_t cksum_type)
  44 {
  45         switch (cksum_type) {
  46         case OBD_CKSUM_CRC32:
  47                 return CFS_HASH_ALG_CRC32;
  48         case OBD_CKSUM_ADLER:
  49                 return CFS_HASH_ALG_ADLER32;
  50         case OBD_CKSUM_CRC32C:
  51                 return CFS_HASH_ALG_CRC32C;
  52         default:
  53                 CERROR("Unknown checksum type (%x)!!!\n", cksum_type);
  54                 LBUG();
  55         }
  56         return 0;
  57 }
  58
  59 /* The OBD_FL_CKSUM_* flags is packed into 5 bits of o_flags, since there can
  60  * only be a single checksum type per RPC.
  61  *
  62  * The OBD_CHECKSUM_* type bits passed in ocd_cksum_types are a 32-bit bitmask
  63  * since they need to represent the full range of checksum algorithms that
  64  * both the client and server can understand.
  65  *
  66  * In case of an unsupported types/flags we fall back to ADLER
  67  * because that is supported by all clients since 1.8
  68  *
  69  * In case multiple algorithms are supported the best one is used. */
  70 static inline u32 cksum_type_pack(cksum_type_t cksum_type)
  71 {
  72         unsigned int    performance = 0, tmp;
  73         u32             flag = OBD_FL_CKSUM_ADLER;
  74
  75         if (cksum_type & OBD_CKSUM_CRC32) {
  76                 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32));
  77                 if (tmp > performance) {
  78                         performance = tmp;
  79                         flag = OBD_FL_CKSUM_CRC32;
  80                 }
  81         }
  82         if (cksum_type & OBD_CKSUM_CRC32C) {
  83                 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C));
  84                 if (tmp > performance) {
  85                         performance = tmp;
  86                         flag = OBD_FL_CKSUM_CRC32C;
  87                 }
  88         }
  89         if (cksum_type & OBD_CKSUM_ADLER) {
  90                 tmp = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER));
  91                 if (tmp > performance) {
  92                         performance = tmp;
  93                         flag = OBD_FL_CKSUM_ADLER;
  94                 }
  95         }
  96         if (unlikely(cksum_type && !(cksum_type & (OBD_CKSUM_CRC32C |
  97                                                    OBD_CKSUM_CRC32 |
  98                                                    OBD_CKSUM_ADLER))))
  99                 CWARN("unknown cksum type %x\n", cksum_type);
 100
 101         return flag;
 102 }
 103
 104 static inline cksum_type_t cksum_type_unpack(u32 o_flags)
 105 {
 106         switch (o_flags & OBD_FL_CKSUM_ALL) {
 107         case OBD_FL_CKSUM_CRC32C:
 108                 return OBD_CKSUM_CRC32C;
 109         case OBD_FL_CKSUM_CRC32:
 110                 return OBD_CKSUM_CRC32;
 111         default:
 112                 break;
 113         }
 114
 115         return OBD_CKSUM_ADLER;
 116 }
 117
 118 /* Return a bitmask of the checksum types supported on this system.
 119  * 1.8 supported ADLER it is base and not depend on hw
 120  * Client uses all available local algos
 121  */
 122 static inline cksum_type_t cksum_types_supported_client(void)
 123 {
 124         cksum_type_t ret = OBD_CKSUM_ADLER;
 125
 126         CDEBUG(D_INFO, "Crypto hash speed: crc %d, crc32c %d, adler %d\n",
 127                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)),
 128                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)),
 129                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)));
 130
 131         if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)) > 0)
 132                 ret |= OBD_CKSUM_CRC32C;
 133         if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)) > 0)
 134                 ret |= OBD_CKSUM_CRC32;
 135
 136         return ret;
 137 }
 138
 139 /* Server uses algos that perform at 50% or better of the Adler */
 140 static inline cksum_type_t cksum_types_supported_server(void)
 141 {
 142         int          base_speed;
 143         cksum_type_t    ret = OBD_CKSUM_ADLER;
 144
 145         CDEBUG(D_INFO, "Crypto hash speed: crc %d, crc32c %d, adler %d\n",
 146                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)),
 147                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)),
 148                cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)));
 149
 150         base_speed = cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_ADLER)) / 2;
 151
 152         if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32C)) >=
 153             base_speed)
 154                 ret |= OBD_CKSUM_CRC32C;
 155         if (cfs_crypto_hash_speed(cksum_obd2cfs(OBD_CKSUM_CRC32)) >=
 156             base_speed)
 157                 ret |= OBD_CKSUM_CRC32;
 158
 159         return ret;
 160 }
 161
 162
 163 /* Select the best checksum algorithm among those supplied in the cksum_types
 164  * input.
 165  *
 166  * Currently, calling cksum_type_pack() with a mask will return the fastest
 167  * checksum type due to its benchmarking at libcfs module load.
 168  * Caution is advised, however, since what is fastest on a single client may
 169  * not be the fastest or most efficient algorithm on the server.  */
 170 static inline cksum_type_t cksum_type_select(cksum_type_t cksum_types)
 171 {
 172         return cksum_type_unpack(cksum_type_pack(cksum_types));
 173 }
 174
 175 /* Checksum algorithm names. Must be defined in the same order as the
 176  * OBD_CKSUM_* flags. */
 177 #define DECLARE_CKSUM_NAME char *cksum_name[] = {"crc32", "adler", "crc32c"}
 178
 179 #endif /* __OBD_H */