ia64/linux-2.6.18-xen.hg

annotate lib/libcrc32c.c @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
rev   line source
ian@0 1 /*
ian@0 2 * CRC32C
ian@0 3 *@Article{castagnoli-crc,
ian@0 4 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
ian@0 5 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
ian@0 6 * and 32 Parity Bits}},
ian@0 7 * journal = IEEE Transactions on Communication,
ian@0 8 * year = {1993},
ian@0 9 * volume = {41},
ian@0 10 * number = {6},
ian@0 11 * pages = {},
ian@0 12 * month = {June},
ian@0 13 *}
ian@0 14 * Used by the iSCSI driver, possibly others, and derived from the
ian@0 15 * the iscsi-crc.c module of the linux-iscsi driver at
ian@0 16 * http://linux-iscsi.sourceforge.net.
ian@0 17 *
ian@0 18 * Following the example of lib/crc32, this function is intended to be
ian@0 19 * flexible and useful for all users. Modules that currently have their
ian@0 20 * own crc32c, but hopefully may be able to use this one are:
ian@0 21 * net/sctp (please add all your doco to here if you change to
ian@0 22 * use this one!)
ian@0 23 * <endoflist>
ian@0 24 *
ian@0 25 * Copyright (c) 2004 Cisco Systems, Inc.
ian@0 26 *
ian@0 27 * This program is free software; you can redistribute it and/or modify it
ian@0 28 * under the terms of the GNU General Public License as published by the Free
ian@0 29 * Software Foundation; either version 2 of the License, or (at your option)
ian@0 30 * any later version.
ian@0 31 *
ian@0 32 */
ian@0 33 #include <linux/crc32c.h>
ian@0 34 #include <linux/compiler.h>
ian@0 35 #include <linux/module.h>
ian@0 36 #include <asm/byteorder.h>
ian@0 37
ian@0 38 MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
ian@0 39 MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
ian@0 40 MODULE_LICENSE("GPL");
ian@0 41
ian@0 42 #define CRC32C_POLY_BE 0x1EDC6F41
ian@0 43 #define CRC32C_POLY_LE 0x82F63B78
ian@0 44
ian@0 45 #ifndef CRC_LE_BITS
ian@0 46 # define CRC_LE_BITS 8
ian@0 47 #endif
ian@0 48
ian@0 49
ian@0 50 /*
ian@0 51 * Haven't generated a big-endian table yet, but the bit-wise version
ian@0 52 * should at least work.
ian@0 53 */
ian@0 54 #if defined CRC_BE_BITS && CRC_BE_BITS != 1
ian@0 55 #undef CRC_BE_BITS
ian@0 56 #endif
ian@0 57 #ifndef CRC_BE_BITS
ian@0 58 # define CRC_BE_BITS 1
ian@0 59 #endif
ian@0 60
ian@0 61 EXPORT_SYMBOL(crc32c_le);
ian@0 62
ian@0 63 #if CRC_LE_BITS == 1
ian@0 64 /*
ian@0 65 * Compute things bit-wise, as done in crc32.c. We could share the tight
ian@0 66 * loop below with crc32 and vary the POLY if we don't find value in terms
ian@0 67 * of space and maintainability in keeping the two modules separate.
ian@0 68 */
ian@0 69 u32 __attribute_pure__
ian@0 70 crc32c_le(u32 crc, unsigned char const *p, size_t len)
ian@0 71 {
ian@0 72 int i;
ian@0 73 while (len--) {
ian@0 74 crc ^= *p++;
ian@0 75 for (i = 0; i < 8; i++)
ian@0 76 crc = (crc >> 1) ^ ((crc & 1) ? CRC32C_POLY_LE : 0);
ian@0 77 }
ian@0 78 return crc;
ian@0 79 }
ian@0 80 #else
ian@0 81
ian@0 82 /*
ian@0 83 * This is the CRC-32C table
ian@0 84 * Generated with:
ian@0 85 * width = 32 bits
ian@0 86 * poly = 0x1EDC6F41
ian@0 87 * reflect input bytes = true
ian@0 88 * reflect output bytes = true
ian@0 89 */
ian@0 90
ian@0 91 static const u32 crc32c_table[256] = {
ian@0 92 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
ian@0 93 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
ian@0 94 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
ian@0 95 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
ian@0 96 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
ian@0 97 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
ian@0 98 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
ian@0 99 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
ian@0 100 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
ian@0 101 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
ian@0 102 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
ian@0 103 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
ian@0 104 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
ian@0 105 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
ian@0 106 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
ian@0 107 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
ian@0 108 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
ian@0 109 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
ian@0 110 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
ian@0 111 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
ian@0 112 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
ian@0 113 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
ian@0 114 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
ian@0 115 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
ian@0 116 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
ian@0 117 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
ian@0 118 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
ian@0 119 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
ian@0 120 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
ian@0 121 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
ian@0 122 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
ian@0 123 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
ian@0 124 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
ian@0 125 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
ian@0 126 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
ian@0 127 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
ian@0 128 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
ian@0 129 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
ian@0 130 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
ian@0 131 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
ian@0 132 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
ian@0 133 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
ian@0 134 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
ian@0 135 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
ian@0 136 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
ian@0 137 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
ian@0 138 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
ian@0 139 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
ian@0 140 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
ian@0 141 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
ian@0 142 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
ian@0 143 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
ian@0 144 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
ian@0 145 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
ian@0 146 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
ian@0 147 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
ian@0 148 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
ian@0 149 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
ian@0 150 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
ian@0 151 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
ian@0 152 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
ian@0 153 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
ian@0 154 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
ian@0 155 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
ian@0 156 };
ian@0 157
ian@0 158 /*
ian@0 159 * Steps through buffer one byte at at time, calculates reflected
ian@0 160 * crc using table.
ian@0 161 */
ian@0 162
ian@0 163 u32 __attribute_pure__
ian@0 164 crc32c_le(u32 seed, unsigned char const *data, size_t length)
ian@0 165 {
ian@0 166 u32 crc = __cpu_to_le32(seed);
ian@0 167
ian@0 168 while (length--)
ian@0 169 crc =
ian@0 170 crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
ian@0 171
ian@0 172 return __le32_to_cpu(crc);
ian@0 173 }
ian@0 174
ian@0 175 #endif /* CRC_LE_BITS == 8 */
ian@0 176
ian@0 177 EXPORT_SYMBOL(crc32c_be);
ian@0 178
ian@0 179 #if CRC_BE_BITS == 1
ian@0 180 u32 __attribute_pure__
ian@0 181 crc32c_be(u32 crc, unsigned char const *p, size_t len)
ian@0 182 {
ian@0 183 int i;
ian@0 184 while (len--) {
ian@0 185 crc ^= *p++ << 24;
ian@0 186 for (i = 0; i < 8; i++)
ian@0 187 crc =
ian@0 188 (crc << 1) ^ ((crc & 0x80000000) ? CRC32C_POLY_BE :
ian@0 189 0);
ian@0 190 }
ian@0 191 return crc;
ian@0 192 }
ian@0 193 #endif
ian@0 194
ian@0 195 /*
ian@0 196 * Unit test
ian@0 197 *
ian@0 198 * A small unit test suite is implemented as part of the crypto suite.
ian@0 199 * Select CRYPTO_CRC32C and use the tcrypt module to run the tests.
ian@0 200 */