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| 1 | +/* GPL HEADER START |
| 2 | + * |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | + * |
| 5 | + * This program is free software; you can redistribute it and/or modify |
| 6 | + * it under the terms of the GNU General Public License version 2 only, |
| 7 | + * as published by the Free Software Foundation. |
| 8 | + * |
| 9 | + * This program is distributed in the hope that it will be useful, but |
| 10 | + * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | + * General Public License version 2 for more details (a copy is included |
| 13 | + * in the LICENSE file that accompanied this code). |
| 14 | + * |
| 15 | + * You should have received a copy of the GNU General Public License |
| 16 | + * version 2 along with this program; If not, see http://www.gnu.org/licenses |
| 17 | + * |
| 18 | + * Please visit http://www.xyratex.com/contact if you need additional |
| 19 | + * information or have any questions. |
| 20 | + * |
| 21 | + * GPL HEADER END |
| 22 | + */ |
| 23 | + |
| 24 | +/* |
| 25 | + * Copyright 2012 Xyratex Technology Limited |
| 26 | + * |
| 27 | + * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32 |
| 28 | + * calculation. |
| 29 | + * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE) |
| 30 | + * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found |
| 31 | + * at: |
| 32 | + * http://www.intel.com/products/processor/manuals/ |
| 33 | + * Intel(R) 64 and IA-32 Architectures Software Developer's Manual |
| 34 | + * Volume 2B: Instruction Set Reference, N-Z |
| 35 | + * |
| 36 | + * Authors: Gregory Prestas <[email protected]> |
| 37 | + * Alexander Boyko <[email protected]> |
| 38 | + */ |
| 39 | + |
| 40 | +#include <linux/linkage.h> |
| 41 | +#include <asm/inst.h> |
| 42 | + |
| 43 | + |
| 44 | +.align 16 |
| 45 | +/* |
| 46 | + * [x4*128+32 mod P(x) << 32)]' << 1 = 0x154442bd4 |
| 47 | + * #define CONSTANT_R1 0x154442bd4LL |
| 48 | + * |
| 49 | + * [(x4*128-32 mod P(x) << 32)]' << 1 = 0x1c6e41596 |
| 50 | + * #define CONSTANT_R2 0x1c6e41596LL |
| 51 | + */ |
| 52 | +.Lconstant_R2R1: |
| 53 | + .octa 0x00000001c6e415960000000154442bd4 |
| 54 | +/* |
| 55 | + * [(x128+32 mod P(x) << 32)]' << 1 = 0x1751997d0 |
| 56 | + * #define CONSTANT_R3 0x1751997d0LL |
| 57 | + * |
| 58 | + * [(x128-32 mod P(x) << 32)]' << 1 = 0x0ccaa009e |
| 59 | + * #define CONSTANT_R4 0x0ccaa009eLL |
| 60 | + */ |
| 61 | +.Lconstant_R4R3: |
| 62 | + .octa 0x00000000ccaa009e00000001751997d0 |
| 63 | +/* |
| 64 | + * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124 |
| 65 | + * #define CONSTANT_R5 0x163cd6124LL |
| 66 | + */ |
| 67 | +.Lconstant_R5: |
| 68 | + .octa 0x00000000000000000000000163cd6124 |
| 69 | +.Lconstant_mask32: |
| 70 | + .octa 0x000000000000000000000000FFFFFFFF |
| 71 | +/* |
| 72 | + * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL |
| 73 | + * |
| 74 | + * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))` = 0x1F7011641LL |
| 75 | + * #define CONSTANT_RU 0x1F7011641LL |
| 76 | + */ |
| 77 | +.Lconstant_RUpoly: |
| 78 | + .octa 0x00000001F701164100000001DB710641 |
| 79 | + |
| 80 | +#define CONSTANT %xmm0 |
| 81 | + |
| 82 | +#ifdef __x86_64__ |
| 83 | +#define BUF %rdi |
| 84 | +#define LEN %rsi |
| 85 | +#define CRC %edx |
| 86 | +#else |
| 87 | +#warning Using 32bit code support |
| 88 | +#define BUF %eax |
| 89 | +#define LEN %edx |
| 90 | +#define CRC %ecx |
| 91 | +#endif |
| 92 | + |
| 93 | + |
| 94 | + |
| 95 | +.text |
| 96 | +/** |
| 97 | + * Calculate crc32 |
| 98 | + * BUF - buffer (16 bytes aligned) |
| 99 | + * LEN - sizeof buffer (16 bytes aligned), LEN should be grater than 63 |
| 100 | + * CRC - initial crc32 |
| 101 | + * return %eax crc32 |
| 102 | + * uint crc32_pclmul_le_16(unsigned char const *buffer, |
| 103 | + * size_t len, uint crc32) |
| 104 | + */ |
| 105 | +.globl crc32_pclmul_le_16 |
| 106 | +.align 4, 0x90 |
| 107 | +crc32_pclmul_le_16:/* buffer and buffer size are 16 bytes aligned */ |
| 108 | + movdqa (BUF), %xmm1 |
| 109 | + movdqa 0x10(BUF), %xmm2 |
| 110 | + movdqa 0x20(BUF), %xmm3 |
| 111 | + movdqa 0x30(BUF), %xmm4 |
| 112 | + movd CRC, CONSTANT |
| 113 | + pxor CONSTANT, %xmm1 |
| 114 | + sub $0x40, LEN |
| 115 | + add $0x40, BUF |
| 116 | +#ifndef __x86_64__ |
| 117 | + /* This is for position independent code(-fPIC) support for 32bit */ |
| 118 | + call delta |
| 119 | +delta: |
| 120 | + pop %ecx |
| 121 | +#endif |
| 122 | + cmp $0x40, LEN |
| 123 | + jb less_64 |
| 124 | + |
| 125 | +#ifdef __x86_64__ |
| 126 | + movdqa .Lconstant_R2R1(%rip), CONSTANT |
| 127 | +#else |
| 128 | + movdqa .Lconstant_R2R1 - delta(%ecx), CONSTANT |
| 129 | +#endif |
| 130 | + |
| 131 | +loop_64:/* 64 bytes Full cache line folding */ |
| 132 | + prefetchnta 0x40(BUF) |
| 133 | + movdqa %xmm1, %xmm5 |
| 134 | + movdqa %xmm2, %xmm6 |
| 135 | + movdqa %xmm3, %xmm7 |
| 136 | +#ifdef __x86_64__ |
| 137 | + movdqa %xmm4, %xmm8 |
| 138 | +#endif |
| 139 | + PCLMULQDQ 00, CONSTANT, %xmm1 |
| 140 | + PCLMULQDQ 00, CONSTANT, %xmm2 |
| 141 | + PCLMULQDQ 00, CONSTANT, %xmm3 |
| 142 | +#ifdef __x86_64__ |
| 143 | + PCLMULQDQ 00, CONSTANT, %xmm4 |
| 144 | +#endif |
| 145 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 146 | + PCLMULQDQ 0x11, CONSTANT, %xmm6 |
| 147 | + PCLMULQDQ 0x11, CONSTANT, %xmm7 |
| 148 | +#ifdef __x86_64__ |
| 149 | + PCLMULQDQ 0x11, CONSTANT, %xmm8 |
| 150 | +#endif |
| 151 | + pxor %xmm5, %xmm1 |
| 152 | + pxor %xmm6, %xmm2 |
| 153 | + pxor %xmm7, %xmm3 |
| 154 | +#ifdef __x86_64__ |
| 155 | + pxor %xmm8, %xmm4 |
| 156 | +#else |
| 157 | + /* xmm8 unsupported for x32 */ |
| 158 | + movdqa %xmm4, %xmm5 |
| 159 | + PCLMULQDQ 00, CONSTANT, %xmm4 |
| 160 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 161 | + pxor %xmm5, %xmm4 |
| 162 | +#endif |
| 163 | + |
| 164 | + pxor (BUF), %xmm1 |
| 165 | + pxor 0x10(BUF), %xmm2 |
| 166 | + pxor 0x20(BUF), %xmm3 |
| 167 | + pxor 0x30(BUF), %xmm4 |
| 168 | + |
| 169 | + sub $0x40, LEN |
| 170 | + add $0x40, BUF |
| 171 | + cmp $0x40, LEN |
| 172 | + jge loop_64 |
| 173 | +less_64:/* Folding cache line into 128bit */ |
| 174 | +#ifdef __x86_64__ |
| 175 | + movdqa .Lconstant_R4R3(%rip), CONSTANT |
| 176 | +#else |
| 177 | + movdqa .Lconstant_R4R3 - delta(%ecx), CONSTANT |
| 178 | +#endif |
| 179 | + prefetchnta (BUF) |
| 180 | + |
| 181 | + movdqa %xmm1, %xmm5 |
| 182 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 183 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 184 | + pxor %xmm5, %xmm1 |
| 185 | + pxor %xmm2, %xmm1 |
| 186 | + |
| 187 | + movdqa %xmm1, %xmm5 |
| 188 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 189 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 190 | + pxor %xmm5, %xmm1 |
| 191 | + pxor %xmm3, %xmm1 |
| 192 | + |
| 193 | + movdqa %xmm1, %xmm5 |
| 194 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 195 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 196 | + pxor %xmm5, %xmm1 |
| 197 | + pxor %xmm4, %xmm1 |
| 198 | + |
| 199 | + cmp $0x10, LEN |
| 200 | + jb fold_64 |
| 201 | +loop_16:/* Folding rest buffer into 128bit */ |
| 202 | + movdqa %xmm1, %xmm5 |
| 203 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 204 | + PCLMULQDQ 0x11, CONSTANT, %xmm5 |
| 205 | + pxor %xmm5, %xmm1 |
| 206 | + pxor (BUF), %xmm1 |
| 207 | + sub $0x10, LEN |
| 208 | + add $0x10, BUF |
| 209 | + cmp $0x10, LEN |
| 210 | + jge loop_16 |
| 211 | + |
| 212 | +fold_64: |
| 213 | + /* perform the last 64 bit fold, also adds 32 zeroes |
| 214 | + * to the input stream */ |
| 215 | + PCLMULQDQ 0x01, %xmm1, CONSTANT /* R4 * xmm1.low */ |
| 216 | + psrldq $0x08, %xmm1 |
| 217 | + pxor CONSTANT, %xmm1 |
| 218 | + |
| 219 | + /* final 32-bit fold */ |
| 220 | + movdqa %xmm1, %xmm2 |
| 221 | +#ifdef __x86_64__ |
| 222 | + movdqa .Lconstant_R5(%rip), CONSTANT |
| 223 | + movdqa .Lconstant_mask32(%rip), %xmm3 |
| 224 | +#else |
| 225 | + movdqa .Lconstant_R5 - delta(%ecx), CONSTANT |
| 226 | + movdqa .Lconstant_mask32 - delta(%ecx), %xmm3 |
| 227 | +#endif |
| 228 | + psrldq $0x04, %xmm2 |
| 229 | + pand %xmm3, %xmm1 |
| 230 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 231 | + pxor %xmm2, %xmm1 |
| 232 | + |
| 233 | + /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */ |
| 234 | +#ifdef __x86_64__ |
| 235 | + movdqa .Lconstant_RUpoly(%rip), CONSTANT |
| 236 | +#else |
| 237 | + movdqa .Lconstant_RUpoly - delta(%ecx), CONSTANT |
| 238 | +#endif |
| 239 | + movdqa %xmm1, %xmm2 |
| 240 | + pand %xmm3, %xmm1 |
| 241 | + PCLMULQDQ 0x10, CONSTANT, %xmm1 |
| 242 | + pand %xmm3, %xmm1 |
| 243 | + PCLMULQDQ 0x00, CONSTANT, %xmm1 |
| 244 | + pxor %xmm2, %xmm1 |
| 245 | + pextrd $0x01, %xmm1, %eax |
| 246 | + |
| 247 | + ret |
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