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authorHerbert Xu <herbert@gondor.apana.org.au>2008-11-07 02:11:47 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2008-12-24 19:01:40 -0500
commit69c35efcf1576ab5f00cba83e8ca740923afb6c9 (patch)
treefaf3bba45be45d530e3355c46d6bf2cd99d0e83c /crypto
parent8e3ee85e68c5d5c95451afd3e8f0997eec6f99e5 (diff)
libcrc32c: Move implementation to crypto crc32c
This patch swaps the role of libcrc32c and crc32c. Previously the implementation was in libcrc32c and crc32c was a wrapper. Now the code is in crc32c and libcrc32c just calls the crypto layer. The reason for the change is to tap into the algorithm selection capability of the crypto API so that optimised implementations such as the one utilising Intel's CRC32C instruction can be used where available. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/Kconfig4
-rw-r--r--crypto/crc32c.c113
2 files changed, 112 insertions, 5 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig
index dc20a34ba5ef..aede80246df2 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -256,12 +256,10 @@ comment "Digest"
256config CRYPTO_CRC32C 256config CRYPTO_CRC32C
257 tristate "CRC32c CRC algorithm" 257 tristate "CRC32c CRC algorithm"
258 select CRYPTO_HASH 258 select CRYPTO_HASH
259 select LIBCRC32C
260 help 259 help
261 Castagnoli, et al Cyclic Redundancy-Check Algorithm. Used 260 Castagnoli, et al Cyclic Redundancy-Check Algorithm. Used
262 by iSCSI for header and data digests and by others. 261 by iSCSI for header and data digests and by others.
263 See Castagnoli93. This implementation uses lib/libcrc32c. 262 See Castagnoli93. Module will be crc32c.
264 Module will be crc32c.
265 263
266config CRYPTO_CRC32C_INTEL 264config CRYPTO_CRC32C_INTEL
267 tristate "CRC32c INTEL hardware acceleration" 265 tristate "CRC32c INTEL hardware acceleration"
diff --git a/crypto/crc32c.c b/crypto/crc32c.c
index b21b93f2bb90..973bc2cfab2e 100644
--- a/crypto/crc32c.c
+++ b/crypto/crc32c.c
@@ -3,8 +3,29 @@
3 * 3 *
4 * CRC32C chksum 4 * CRC32C chksum
5 * 5 *
6 * This module file is a wrapper to invoke the lib/crc32c routines. 6 *@Article{castagnoli-crc,
7 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
8 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
9 * and 32 Parity Bits}},
10 * journal = IEEE Transactions on Communication,
11 * year = {1993},
12 * volume = {41},
13 * number = {6},
14 * pages = {},
15 * month = {June},
16 *}
17 * Used by the iSCSI driver, possibly others, and derived from the
18 * the iscsi-crc.c module of the linux-iscsi driver at
19 * http://linux-iscsi.sourceforge.net.
7 * 20 *
21 * Following the example of lib/crc32, this function is intended to be
22 * flexible and useful for all users. Modules that currently have their
23 * own crc32c, but hopefully may be able to use this one are:
24 * net/sctp (please add all your doco to here if you change to
25 * use this one!)
26 * <endoflist>
27 *
28 * Copyright (c) 2004 Cisco Systems, Inc.
8 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au> 29 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
9 * 30 *
10 * This program is free software; you can redistribute it and/or modify it 31 * This program is free software; you can redistribute it and/or modify it
@@ -18,7 +39,6 @@
18#include <linux/init.h> 39#include <linux/init.h>
19#include <linux/module.h> 40#include <linux/module.h>
20#include <linux/string.h> 41#include <linux/string.h>
21#include <linux/crc32c.h>
22#include <linux/kernel.h> 42#include <linux/kernel.h>
23 43
24#define CHKSUM_BLOCK_SIZE 1 44#define CHKSUM_BLOCK_SIZE 1
@@ -33,6 +53,95 @@ struct chksum_desc_ctx {
33}; 53};
34 54
35/* 55/*
56 * This is the CRC-32C table
57 * Generated with:
58 * width = 32 bits
59 * poly = 0x1EDC6F41
60 * reflect input bytes = true
61 * reflect output bytes = true
62 */
63
64static const u32 crc32c_table[256] = {
65 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
66 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
67 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
68 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
69 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
70 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
71 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
72 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
73 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
74 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
75 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
76 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
77 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
78 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
79 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
80 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
81 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
82 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
83 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
84 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
85 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
86 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
87 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
88 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
89 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
90 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
91 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
92 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
93 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
94 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
95 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
96 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
97 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
98 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
99 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
100 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
101 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
102 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
103 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
104 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
105 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
106 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
107 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
108 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
109 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
110 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
111 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
112 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
113 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
114 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
115 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
116 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
117 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
118 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
119 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
120 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
121 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
122 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
123 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
124 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
125 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
126 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
127 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
128 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
129};
130
131/*
132 * Steps through buffer one byte at at time, calculates reflected
133 * crc using table.
134 */
135
136static u32 crc32c(u32 crc, const u8 *data, unsigned int length)
137{
138 while (length--)
139 crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
140
141 return crc;
142}
143
144/*
36 * Steps through buffer one byte at at time, calculates reflected 145 * Steps through buffer one byte at at time, calculates reflected
37 * crc using table. 146 * crc using table.
38 */ 147 */