ia64/linux-2.6.18-xen.hg

view net/sctp/crc32c.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /* SCTP kernel reference Implementation
2 * Copyright (c) 1999-2001 Motorola, Inc.
3 * Copyright (c) 2001-2003 International Business Machines, Corp.
4 *
5 * This file is part of the SCTP kernel reference Implementation
6 *
7 * SCTP Checksum functions
8 *
9 * The SCTP reference implementation is free software;
10 * you can redistribute it and/or modify it under the terms of
11 * the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * The SCTP reference implementation is distributed in the hope that it
16 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 * ************************
18 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
19 * See the GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with GNU CC; see the file COPYING. If not, write to
23 * the Free Software Foundation, 59 Temple Place - Suite 330,
24 * Boston, MA 02111-1307, USA.
25 *
26 * Please send any bug reports or fixes you make to the
27 * email address(es):
28 * lksctp developers <lksctp-developers@lists.sourceforge.net>
29 *
30 * Or submit a bug report through the following website:
31 * http://www.sf.net/projects/lksctp
32 *
33 * Written or modified by:
34 * Dinakaran Joseph
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Sridhar Samudrala <sri@us.ibm.com>
37 *
38 * Any bugs reported given to us we will try to fix... any fixes shared will
39 * be incorporated into the next SCTP release.
40 */
42 /* The following code has been taken directly from
43 * draft-ietf-tsvwg-sctpcsum-03.txt
44 *
45 * The code has now been modified specifically for SCTP knowledge.
46 */
48 #include <linux/types.h>
49 #include <net/sctp/sctp.h>
51 #define CRC32C_POLY 0x1EDC6F41
52 #define CRC32C(c,d) (c=(c>>8)^crc_c[(c^(d))&0xFF])
53 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
54 /* Copyright 2001, D. Otis. Use this program, code or tables */
55 /* extracted from it, as desired without restriction. */
56 /* */
57 /* 32 Bit Reflected CRC table generation for SCTP. */
58 /* To accommodate serial byte data being shifted out least */
59 /* significant bit first, the table's 32 bit words are reflected */
60 /* which flips both byte and bit MS and LS positions. The CRC */
61 /* is calculated MS bits first from the perspective of the serial*/
62 /* stream. The x^32 term is implied and the x^0 term may also */
63 /* be shown as +1. The polynomial code used is 0x1EDC6F41. */
64 /* Castagnoli93 */
65 /* x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+ */
66 /* x^11+x^10+x^9+x^8+x^6+x^0 */
67 /* Guy Castagnoli Stefan Braeuer and Martin Herrman */
68 /* "Optimization of Cyclic Redundancy-Check Codes */
69 /* with 24 and 32 Parity Bits", */
70 /* IEEE Transactions on Communications, Vol.41, No.6, June 1993 */
71 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
72 static const __u32 crc_c[256] = {
73 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
74 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
75 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
76 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
77 0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
78 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
79 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
80 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
81 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
82 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
83 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
84 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
85 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
86 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
87 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
88 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
89 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
90 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
91 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
92 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
93 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
94 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
95 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
96 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
97 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
98 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
99 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
100 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
101 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
102 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
103 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
104 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
105 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
106 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
107 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
108 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
109 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
110 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
111 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
112 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
113 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
114 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
115 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
116 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
117 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
118 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
119 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
120 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
121 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
122 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
123 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
124 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
125 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
126 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
127 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
128 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
129 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
130 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
131 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
132 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
133 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
134 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
135 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
136 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351,
137 };
139 __u32 sctp_start_cksum(__u8 *buffer, __u16 length)
140 {
141 __u32 crc32 = ~(__u32) 0;
142 __u32 i;
144 /* Optimize this routine to be SCTP specific, knowing how
145 * to skip the checksum field of the SCTP header.
146 */
148 /* Calculate CRC up to the checksum. */
149 for (i = 0; i < (sizeof(struct sctphdr) - sizeof(__u32)); i++)
150 CRC32C(crc32, buffer[i]);
152 /* Skip checksum field of the header. */
153 for (i = 0; i < sizeof(__u32); i++)
154 CRC32C(crc32, 0);
156 /* Calculate the rest of the CRC. */
157 for (i = sizeof(struct sctphdr); i < length ; i++)
158 CRC32C(crc32, buffer[i]);
160 return crc32;
161 }
163 __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32)
164 {
165 __u32 i;
167 for (i = 0; i < length ; i++)
168 CRC32C(crc32, buffer[i]);
170 return crc32;
171 }
173 __u32 sctp_update_copy_cksum(__u8 *to, __u8 *from, __u16 length, __u32 crc32)
174 {
175 __u32 i;
176 __u32 *_to = (__u32 *)to;
177 __u32 *_from = (__u32 *)from;
179 for (i = 0; i < (length/4); i++) {
180 _to[i] = _from[i];
181 CRC32C(crc32, from[i*4]);
182 CRC32C(crc32, from[i*4+1]);
183 CRC32C(crc32, from[i*4+2]);
184 CRC32C(crc32, from[i*4+3]);
185 }
187 return crc32;
188 }
190 __u32 sctp_end_cksum(__u32 crc32)
191 {
192 __u32 result;
193 __u8 byte0, byte1, byte2, byte3;
195 result = ~crc32;
197 /* result now holds the negated polynomial remainder;
198 * since the table and algorithm is "reflected" [williams95].
199 * That is, result has the same value as if we mapped the message
200 * to a polyomial, computed the host-bit-order polynomial
201 * remainder, performed final negation, then did an end-for-end
202 * bit-reversal.
203 * Note that a 32-bit bit-reversal is identical to four inplace
204 * 8-bit reversals followed by an end-for-end byteswap.
205 * In other words, the bytes of each bit are in the right order,
206 * but the bytes have been byteswapped. So we now do an explicit
207 * byteswap. On a little-endian machine, this byteswap and
208 * the final ntohl cancel out and could be elided.
209 */
210 byte0 = result & 0xff;
211 byte1 = (result>>8) & 0xff;
212 byte2 = (result>>16) & 0xff;
213 byte3 = (result>>24) & 0xff;
215 crc32 = ((byte0 << 24) |
216 (byte1 << 16) |
217 (byte2 << 8) |
218 byte3);
219 return crc32;
220 }