Ard Biesheuvel | d0a3431 | 2016-12-05 18:42:28 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions |
| 3 | * |
| 4 | * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> |
| 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 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | /* GPL HEADER START |
| 12 | * |
| 13 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 14 | * |
| 15 | * This program is free software; you can redistribute it and/or modify |
| 16 | * it under the terms of the GNU General Public License version 2 only, |
| 17 | * as published by the Free Software Foundation. |
| 18 | * |
| 19 | * This program is distributed in the hope that it will be useful, but |
| 20 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 22 | * General Public License version 2 for more details (a copy is included |
| 23 | * in the LICENSE file that accompanied this code). |
| 24 | * |
| 25 | * You should have received a copy of the GNU General Public License |
| 26 | * version 2 along with this program; If not, see http://www.gnu.org/licenses |
| 27 | * |
| 28 | * Please visit http://www.xyratex.com/contact if you need additional |
| 29 | * information or have any questions. |
| 30 | * |
| 31 | * GPL HEADER END |
| 32 | */ |
| 33 | |
| 34 | /* |
| 35 | * Copyright 2012 Xyratex Technology Limited |
| 36 | * |
| 37 | * Using hardware provided PCLMULQDQ instruction to accelerate the CRC32 |
| 38 | * calculation. |
| 39 | * CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE) |
| 40 | * PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found |
| 41 | * at: |
| 42 | * http://www.intel.com/products/processor/manuals/ |
| 43 | * Intel(R) 64 and IA-32 Architectures Software Developer's Manual |
| 44 | * Volume 2B: Instruction Set Reference, N-Z |
| 45 | * |
| 46 | * Authors: Gregory Prestas <Gregory_Prestas@us.xyratex.com> |
| 47 | * Alexander Boyko <Alexander_Boyko@xyratex.com> |
| 48 | */ |
| 49 | |
| 50 | #include <linux/linkage.h> |
| 51 | #include <asm/assembler.h> |
| 52 | |
| 53 | .text |
| 54 | .align 6 |
| 55 | .arch armv8-a |
| 56 | .arch_extension crc |
| 57 | .fpu crypto-neon-fp-armv8 |
| 58 | |
| 59 | .Lcrc32_constants: |
| 60 | /* |
| 61 | * [x4*128+32 mod P(x) << 32)]' << 1 = 0x154442bd4 |
| 62 | * #define CONSTANT_R1 0x154442bd4LL |
| 63 | * |
| 64 | * [(x4*128-32 mod P(x) << 32)]' << 1 = 0x1c6e41596 |
| 65 | * #define CONSTANT_R2 0x1c6e41596LL |
| 66 | */ |
| 67 | .quad 0x0000000154442bd4 |
| 68 | .quad 0x00000001c6e41596 |
| 69 | |
| 70 | /* |
| 71 | * [(x128+32 mod P(x) << 32)]' << 1 = 0x1751997d0 |
| 72 | * #define CONSTANT_R3 0x1751997d0LL |
| 73 | * |
| 74 | * [(x128-32 mod P(x) << 32)]' << 1 = 0x0ccaa009e |
| 75 | * #define CONSTANT_R4 0x0ccaa009eLL |
| 76 | */ |
| 77 | .quad 0x00000001751997d0 |
| 78 | .quad 0x00000000ccaa009e |
| 79 | |
| 80 | /* |
| 81 | * [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124 |
| 82 | * #define CONSTANT_R5 0x163cd6124LL |
| 83 | */ |
| 84 | .quad 0x0000000163cd6124 |
| 85 | .quad 0x00000000FFFFFFFF |
| 86 | |
| 87 | /* |
| 88 | * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL |
| 89 | * |
| 90 | * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))` |
| 91 | * = 0x1F7011641LL |
| 92 | * #define CONSTANT_RU 0x1F7011641LL |
| 93 | */ |
| 94 | .quad 0x00000001DB710641 |
| 95 | .quad 0x00000001F7011641 |
| 96 | |
| 97 | .Lcrc32c_constants: |
| 98 | .quad 0x00000000740eef02 |
| 99 | .quad 0x000000009e4addf8 |
| 100 | .quad 0x00000000f20c0dfe |
| 101 | .quad 0x000000014cd00bd6 |
| 102 | .quad 0x00000000dd45aab8 |
| 103 | .quad 0x00000000FFFFFFFF |
| 104 | .quad 0x0000000105ec76f0 |
| 105 | .quad 0x00000000dea713f1 |
| 106 | |
| 107 | dCONSTANTl .req d0 |
| 108 | dCONSTANTh .req d1 |
| 109 | qCONSTANT .req q0 |
| 110 | |
| 111 | BUF .req r0 |
| 112 | LEN .req r1 |
| 113 | CRC .req r2 |
| 114 | |
| 115 | qzr .req q9 |
| 116 | |
| 117 | /** |
| 118 | * Calculate crc32 |
| 119 | * BUF - buffer |
| 120 | * LEN - sizeof buffer (multiple of 16 bytes), LEN should be > 63 |
| 121 | * CRC - initial crc32 |
| 122 | * return %eax crc32 |
| 123 | * uint crc32_pmull_le(unsigned char const *buffer, |
| 124 | * size_t len, uint crc32) |
| 125 | */ |
| 126 | ENTRY(crc32_pmull_le) |
| 127 | adr r3, .Lcrc32_constants |
| 128 | b 0f |
| 129 | |
| 130 | ENTRY(crc32c_pmull_le) |
| 131 | adr r3, .Lcrc32c_constants |
| 132 | |
| 133 | 0: bic LEN, LEN, #15 |
| 134 | vld1.8 {q1-q2}, [BUF, :128]! |
| 135 | vld1.8 {q3-q4}, [BUF, :128]! |
| 136 | vmov.i8 qzr, #0 |
| 137 | vmov.i8 qCONSTANT, #0 |
Ard Biesheuvel | 1fb1683 | 2017-02-28 14:36:56 +0000 | [diff] [blame] | 138 | vmov.32 dCONSTANTl[0], CRC |
Ard Biesheuvel | d0a3431 | 2016-12-05 18:42:28 +0000 | [diff] [blame] | 139 | veor.8 d2, d2, dCONSTANTl |
| 140 | sub LEN, LEN, #0x40 |
| 141 | cmp LEN, #0x40 |
| 142 | blt less_64 |
| 143 | |
| 144 | vld1.64 {qCONSTANT}, [r3] |
| 145 | |
| 146 | loop_64: /* 64 bytes Full cache line folding */ |
| 147 | sub LEN, LEN, #0x40 |
| 148 | |
| 149 | vmull.p64 q5, d3, dCONSTANTh |
| 150 | vmull.p64 q6, d5, dCONSTANTh |
| 151 | vmull.p64 q7, d7, dCONSTANTh |
| 152 | vmull.p64 q8, d9, dCONSTANTh |
| 153 | |
| 154 | vmull.p64 q1, d2, dCONSTANTl |
| 155 | vmull.p64 q2, d4, dCONSTANTl |
| 156 | vmull.p64 q3, d6, dCONSTANTl |
| 157 | vmull.p64 q4, d8, dCONSTANTl |
| 158 | |
| 159 | veor.8 q1, q1, q5 |
| 160 | vld1.8 {q5}, [BUF, :128]! |
| 161 | veor.8 q2, q2, q6 |
| 162 | vld1.8 {q6}, [BUF, :128]! |
| 163 | veor.8 q3, q3, q7 |
| 164 | vld1.8 {q7}, [BUF, :128]! |
| 165 | veor.8 q4, q4, q8 |
| 166 | vld1.8 {q8}, [BUF, :128]! |
| 167 | |
| 168 | veor.8 q1, q1, q5 |
| 169 | veor.8 q2, q2, q6 |
| 170 | veor.8 q3, q3, q7 |
| 171 | veor.8 q4, q4, q8 |
| 172 | |
| 173 | cmp LEN, #0x40 |
| 174 | bge loop_64 |
| 175 | |
| 176 | less_64: /* Folding cache line into 128bit */ |
| 177 | vldr dCONSTANTl, [r3, #16] |
| 178 | vldr dCONSTANTh, [r3, #24] |
| 179 | |
| 180 | vmull.p64 q5, d3, dCONSTANTh |
| 181 | vmull.p64 q1, d2, dCONSTANTl |
| 182 | veor.8 q1, q1, q5 |
| 183 | veor.8 q1, q1, q2 |
| 184 | |
| 185 | vmull.p64 q5, d3, dCONSTANTh |
| 186 | vmull.p64 q1, d2, dCONSTANTl |
| 187 | veor.8 q1, q1, q5 |
| 188 | veor.8 q1, q1, q3 |
| 189 | |
| 190 | vmull.p64 q5, d3, dCONSTANTh |
| 191 | vmull.p64 q1, d2, dCONSTANTl |
| 192 | veor.8 q1, q1, q5 |
| 193 | veor.8 q1, q1, q4 |
| 194 | |
| 195 | teq LEN, #0 |
| 196 | beq fold_64 |
| 197 | |
| 198 | loop_16: /* Folding rest buffer into 128bit */ |
| 199 | subs LEN, LEN, #0x10 |
| 200 | |
| 201 | vld1.8 {q2}, [BUF, :128]! |
| 202 | vmull.p64 q5, d3, dCONSTANTh |
| 203 | vmull.p64 q1, d2, dCONSTANTl |
| 204 | veor.8 q1, q1, q5 |
| 205 | veor.8 q1, q1, q2 |
| 206 | |
| 207 | bne loop_16 |
| 208 | |
| 209 | fold_64: |
| 210 | /* perform the last 64 bit fold, also adds 32 zeroes |
| 211 | * to the input stream */ |
| 212 | vmull.p64 q2, d2, dCONSTANTh |
| 213 | vext.8 q1, q1, qzr, #8 |
| 214 | veor.8 q1, q1, q2 |
| 215 | |
| 216 | /* final 32-bit fold */ |
| 217 | vldr dCONSTANTl, [r3, #32] |
| 218 | vldr d6, [r3, #40] |
| 219 | vmov.i8 d7, #0 |
| 220 | |
| 221 | vext.8 q2, q1, qzr, #4 |
| 222 | vand.8 d2, d2, d6 |
| 223 | vmull.p64 q1, d2, dCONSTANTl |
| 224 | veor.8 q1, q1, q2 |
| 225 | |
| 226 | /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */ |
| 227 | vldr dCONSTANTl, [r3, #48] |
| 228 | vldr dCONSTANTh, [r3, #56] |
| 229 | |
| 230 | vand.8 q2, q1, q3 |
| 231 | vext.8 q2, qzr, q2, #8 |
| 232 | vmull.p64 q2, d5, dCONSTANTh |
| 233 | vand.8 q2, q2, q3 |
| 234 | vmull.p64 q2, d4, dCONSTANTl |
| 235 | veor.8 q1, q1, q2 |
| 236 | vmov r0, s5 |
| 237 | |
| 238 | bx lr |
| 239 | ENDPROC(crc32_pmull_le) |
| 240 | ENDPROC(crc32c_pmull_le) |
| 241 | |
| 242 | .macro __crc32, c |
| 243 | subs ip, r2, #8 |
| 244 | bmi .Ltail\c |
| 245 | |
| 246 | tst r1, #3 |
| 247 | bne .Lunaligned\c |
| 248 | |
| 249 | teq ip, #0 |
| 250 | .Laligned8\c: |
| 251 | ldrd r2, r3, [r1], #8 |
| 252 | ARM_BE8(rev r2, r2 ) |
| 253 | ARM_BE8(rev r3, r3 ) |
| 254 | crc32\c\()w r0, r0, r2 |
| 255 | crc32\c\()w r0, r0, r3 |
| 256 | bxeq lr |
| 257 | subs ip, ip, #8 |
| 258 | bpl .Laligned8\c |
| 259 | |
| 260 | .Ltail\c: |
| 261 | tst ip, #4 |
| 262 | beq 2f |
| 263 | ldr r3, [r1], #4 |
| 264 | ARM_BE8(rev r3, r3 ) |
| 265 | crc32\c\()w r0, r0, r3 |
| 266 | |
| 267 | 2: tst ip, #2 |
| 268 | beq 1f |
| 269 | ldrh r3, [r1], #2 |
| 270 | ARM_BE8(rev16 r3, r3 ) |
| 271 | crc32\c\()h r0, r0, r3 |
| 272 | |
| 273 | 1: tst ip, #1 |
| 274 | bxeq lr |
| 275 | ldrb r3, [r1] |
| 276 | crc32\c\()b r0, r0, r3 |
| 277 | bx lr |
| 278 | |
| 279 | .Lunaligned\c: |
| 280 | tst r1, #1 |
| 281 | beq 2f |
| 282 | ldrb r3, [r1], #1 |
| 283 | subs r2, r2, #1 |
| 284 | crc32\c\()b r0, r0, r3 |
| 285 | |
| 286 | tst r1, #2 |
| 287 | beq 0f |
| 288 | 2: ldrh r3, [r1], #2 |
| 289 | subs r2, r2, #2 |
| 290 | ARM_BE8(rev16 r3, r3 ) |
| 291 | crc32\c\()h r0, r0, r3 |
| 292 | |
| 293 | 0: subs ip, r2, #8 |
| 294 | bpl .Laligned8\c |
| 295 | b .Ltail\c |
| 296 | .endm |
| 297 | |
| 298 | .align 5 |
| 299 | ENTRY(crc32_armv8_le) |
| 300 | __crc32 |
| 301 | ENDPROC(crc32_armv8_le) |
| 302 | |
| 303 | .align 5 |
| 304 | ENTRY(crc32c_armv8_le) |
| 305 | __crc32 c |
| 306 | ENDPROC(crc32c_armv8_le) |