1// 2// Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions 3// 4// Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> 5// Copyright (C) 2019 Google LLC <ebiggers@google.com> 6// 7// This program is free software; you can redistribute it and/or modify 8// it under the terms of the GNU General Public License version 2 as 9// published by the Free Software Foundation. 10// 11 12// Derived from the x86 version: 13// 14// Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions 15// 16// Copyright (c) 2013, Intel Corporation 17// 18// Authors: 19// Erdinc Ozturk <erdinc.ozturk@intel.com> 20// Vinodh Gopal <vinodh.gopal@intel.com> 21// James Guilford <james.guilford@intel.com> 22// Tim Chen <tim.c.chen@linux.intel.com> 23// 24// This software is available to you under a choice of one of two 25// licenses. You may choose to be licensed under the terms of the GNU 26// General Public License (GPL) Version 2, available from the file 27// COPYING in the main directory of this source tree, or the 28// OpenIB.org BSD license below: 29// 30// Redistribution and use in source and binary forms, with or without 31// modification, are permitted provided that the following conditions are 32// met: 33// 34// * Redistributions of source code must retain the above copyright 35// notice, this list of conditions and the following disclaimer. 36// 37// * Redistributions in binary form must reproduce the above copyright 38// notice, this list of conditions and the following disclaimer in the 39// documentation and/or other materials provided with the 40// distribution. 41// 42// * Neither the name of the Intel Corporation nor the names of its 43// contributors may be used to endorse or promote products derived from 44// this software without specific prior written permission. 45// 46// 47// THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION ""AS IS"" AND ANY 48// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 49// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 50// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL CORPORATION OR 51// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 52// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 53// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 54// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 55// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 56// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 57// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 58// 59// Reference paper titled "Fast CRC Computation for Generic 60// Polynomials Using PCLMULQDQ Instruction" 61// URL: http://www.intel.com/content/dam/www/public/us/en/documents 62// /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf 63// 64 65#include <linux/linkage.h> 66#include <asm/assembler.h> 67 68 .text 69 .arch armv8-a+crypto 70 71 init_crc .req w0 72 buf .req x1 73 len .req x2 74 fold_consts_ptr .req x3 75 76 fold_consts .req v10 77 78 ad .req v14 79 80 k00_16 .req v15 81 k32_48 .req v16 82 83 t3 .req v17 84 t4 .req v18 85 t5 .req v19 86 t6 .req v20 87 t7 .req v21 88 t8 .req v22 89 t9 .req v23 90 91 perm1 .req v24 92 perm2 .req v25 93 perm3 .req v26 94 perm4 .req v27 95 96 bd1 .req v28 97 bd2 .req v29 98 bd3 .req v30 99 bd4 .req v31 100 101 .macro __pmull_init_p64 102 .endm 103 104 .macro __pmull_pre_p64, bd 105 .endm 106 107 .macro __pmull_init_p8 108 // k00_16 := 0x0000000000000000_000000000000ffff 109 // k32_48 := 0x00000000ffffffff_0000ffffffffffff 110 movi k32_48.2d, #0xffffffff 111 mov k32_48.h[2], k32_48.h[0] 112 ushr k00_16.2d, k32_48.2d, #32 113 114 // prepare the permutation vectors 115 mov_q x5, 0x080f0e0d0c0b0a09 116 movi perm4.8b, #8 117 dup perm1.2d, x5 118 eor perm1.16b, perm1.16b, perm4.16b 119 ushr perm2.2d, perm1.2d, #8 120 ushr perm3.2d, perm1.2d, #16 121 ushr perm4.2d, perm1.2d, #24 122 sli perm2.2d, perm1.2d, #56 123 sli perm3.2d, perm1.2d, #48 124 sli perm4.2d, perm1.2d, #40 125 .endm 126 127 .macro __pmull_pre_p8, bd 128 tbl bd1.16b, {\bd\().16b}, perm1.16b 129 tbl bd2.16b, {\bd\().16b}, perm2.16b 130 tbl bd3.16b, {\bd\().16b}, perm3.16b 131 tbl bd4.16b, {\bd\().16b}, perm4.16b 132 .endm 133 134SYM_FUNC_START_LOCAL(__pmull_p8_core) 135.L__pmull_p8_core: 136 ext t4.8b, ad.8b, ad.8b, #1 // A1 137 ext t5.8b, ad.8b, ad.8b, #2 // A2 138 ext t6.8b, ad.8b, ad.8b, #3 // A3 139 140 pmull t4.8h, t4.8b, fold_consts.8b // F = A1*B 141 pmull t8.8h, ad.8b, bd1.8b // E = A*B1 142 pmull t5.8h, t5.8b, fold_consts.8b // H = A2*B 143 pmull t7.8h, ad.8b, bd2.8b // G = A*B2 144 pmull t6.8h, t6.8b, fold_consts.8b // J = A3*B 145 pmull t9.8h, ad.8b, bd3.8b // I = A*B3 146 pmull t3.8h, ad.8b, bd4.8b // K = A*B4 147 b 0f 148 149.L__pmull_p8_core2: 150 tbl t4.16b, {ad.16b}, perm1.16b // A1 151 tbl t5.16b, {ad.16b}, perm2.16b // A2 152 tbl t6.16b, {ad.16b}, perm3.16b // A3 153 154 pmull2 t4.8h, t4.16b, fold_consts.16b // F = A1*B 155 pmull2 t8.8h, ad.16b, bd1.16b // E = A*B1 156 pmull2 t5.8h, t5.16b, fold_consts.16b // H = A2*B 157 pmull2 t7.8h, ad.16b, bd2.16b // G = A*B2 158 pmull2 t6.8h, t6.16b, fold_consts.16b // J = A3*B 159 pmull2 t9.8h, ad.16b, bd3.16b // I = A*B3 160 pmull2 t3.8h, ad.16b, bd4.16b // K = A*B4 161 1620: eor t4.16b, t4.16b, t8.16b // L = E + F 163 eor t5.16b, t5.16b, t7.16b // M = G + H 164 eor t6.16b, t6.16b, t9.16b // N = I + J 165 166 uzp1 t8.2d, t4.2d, t5.2d 167 uzp2 t4.2d, t4.2d, t5.2d 168 uzp1 t7.2d, t6.2d, t3.2d 169 uzp2 t6.2d, t6.2d, t3.2d 170 171 // t4 = (L) (P0 + P1) << 8 172 // t5 = (M) (P2 + P3) << 16 173 eor t8.16b, t8.16b, t4.16b 174 and t4.16b, t4.16b, k32_48.16b 175 176 // t6 = (N) (P4 + P5) << 24 177 // t7 = (K) (P6 + P7) << 32 178 eor t7.16b, t7.16b, t6.16b 179 and t6.16b, t6.16b, k00_16.16b 180 181 eor t8.16b, t8.16b, t4.16b 182 eor t7.16b, t7.16b, t6.16b 183 184 zip2 t5.2d, t8.2d, t4.2d 185 zip1 t4.2d, t8.2d, t4.2d 186 zip2 t3.2d, t7.2d, t6.2d 187 zip1 t6.2d, t7.2d, t6.2d 188 189 ext t4.16b, t4.16b, t4.16b, #15 190 ext t5.16b, t5.16b, t5.16b, #14 191 ext t6.16b, t6.16b, t6.16b, #13 192 ext t3.16b, t3.16b, t3.16b, #12 193 194 eor t4.16b, t4.16b, t5.16b 195 eor t6.16b, t6.16b, t3.16b 196 ret 197SYM_FUNC_END(__pmull_p8_core) 198 199 .macro __pmull_p8, rq, ad, bd, i 200 .ifnc \bd, fold_consts 201 .err 202 .endif 203 mov ad.16b, \ad\().16b 204 .ifb \i 205 pmull \rq\().8h, \ad\().8b, \bd\().8b // D = A*B 206 .else 207 pmull2 \rq\().8h, \ad\().16b, \bd\().16b // D = A*B 208 .endif 209 210 bl .L__pmull_p8_core\i 211 212 eor \rq\().16b, \rq\().16b, t4.16b 213 eor \rq\().16b, \rq\().16b, t6.16b 214 .endm 215 216 // Fold reg1, reg2 into the next 32 data bytes, storing the result back 217 // into reg1, reg2. 218 .macro fold_32_bytes, p, reg1, reg2 219 ldp q11, q12, [buf], #0x20 220 221 __pmull_\p v8, \reg1, fold_consts, 2 222 __pmull_\p \reg1, \reg1, fold_consts 223 224CPU_LE( rev64 v11.16b, v11.16b ) 225CPU_LE( rev64 v12.16b, v12.16b ) 226 227 __pmull_\p v9, \reg2, fold_consts, 2 228 __pmull_\p \reg2, \reg2, fold_consts 229 230CPU_LE( ext v11.16b, v11.16b, v11.16b, #8 ) 231CPU_LE( ext v12.16b, v12.16b, v12.16b, #8 ) 232 233 eor \reg1\().16b, \reg1\().16b, v8.16b 234 eor \reg2\().16b, \reg2\().16b, v9.16b 235 eor \reg1\().16b, \reg1\().16b, v11.16b 236 eor \reg2\().16b, \reg2\().16b, v12.16b 237 .endm 238 239 // Fold src_reg into dst_reg, optionally loading the next fold constants 240 .macro fold_16_bytes, p, src_reg, dst_reg, load_next_consts 241 __pmull_\p v8, \src_reg, fold_consts 242 __pmull_\p \src_reg, \src_reg, fold_consts, 2 243 .ifnb \load_next_consts 244 ld1 {fold_consts.2d}, [fold_consts_ptr], #16 245 __pmull_pre_\p fold_consts 246 .endif 247 eor \dst_reg\().16b, \dst_reg\().16b, v8.16b 248 eor \dst_reg\().16b, \dst_reg\().16b, \src_reg\().16b 249 .endm 250 251 .macro __pmull_p64, rd, rn, rm, n 252 .ifb \n 253 pmull \rd\().1q, \rn\().1d, \rm\().1d 254 .else 255 pmull2 \rd\().1q, \rn\().2d, \rm\().2d 256 .endif 257 .endm 258 259 .macro crc_t10dif_pmull, p 260 __pmull_init_\p 261 262 // For sizes less than 256 bytes, we can't fold 128 bytes at a time. 263 cmp len, #256 264 b.lt .Lless_than_256_bytes_\@ 265 266 adr_l fold_consts_ptr, .Lfold_across_128_bytes_consts 267 268 // Load the first 128 data bytes. Byte swapping is necessary to make 269 // the bit order match the polynomial coefficient order. 270 ldp q0, q1, [buf] 271 ldp q2, q3, [buf, #0x20] 272 ldp q4, q5, [buf, #0x40] 273 ldp q6, q7, [buf, #0x60] 274 add buf, buf, #0x80 275CPU_LE( rev64 v0.16b, v0.16b ) 276CPU_LE( rev64 v1.16b, v1.16b ) 277CPU_LE( rev64 v2.16b, v2.16b ) 278CPU_LE( rev64 v3.16b, v3.16b ) 279CPU_LE( rev64 v4.16b, v4.16b ) 280CPU_LE( rev64 v5.16b, v5.16b ) 281CPU_LE( rev64 v6.16b, v6.16b ) 282CPU_LE( rev64 v7.16b, v7.16b ) 283CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) 284CPU_LE( ext v1.16b, v1.16b, v1.16b, #8 ) 285CPU_LE( ext v2.16b, v2.16b, v2.16b, #8 ) 286CPU_LE( ext v3.16b, v3.16b, v3.16b, #8 ) 287CPU_LE( ext v4.16b, v4.16b, v4.16b, #8 ) 288CPU_LE( ext v5.16b, v5.16b, v5.16b, #8 ) 289CPU_LE( ext v6.16b, v6.16b, v6.16b, #8 ) 290CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 ) 291 292 // XOR the first 16 data *bits* with the initial CRC value. 293 movi v8.16b, #0 294 mov v8.h[7], init_crc 295 eor v0.16b, v0.16b, v8.16b 296 297 // Load the constants for folding across 128 bytes. 298 ld1 {fold_consts.2d}, [fold_consts_ptr] 299 __pmull_pre_\p fold_consts 300 301 // Subtract 128 for the 128 data bytes just consumed. Subtract another 302 // 128 to simplify the termination condition of the following loop. 303 sub len, len, #256 304 305 // While >= 128 data bytes remain (not counting v0-v7), fold the 128 306 // bytes v0-v7 into them, storing the result back into v0-v7. 307.Lfold_128_bytes_loop_\@: 308 fold_32_bytes \p, v0, v1 309 fold_32_bytes \p, v2, v3 310 fold_32_bytes \p, v4, v5 311 fold_32_bytes \p, v6, v7 312 313 subs len, len, #128 314 b.ge .Lfold_128_bytes_loop_\@ 315 316 // Now fold the 112 bytes in v0-v6 into the 16 bytes in v7. 317 318 // Fold across 64 bytes. 319 add fold_consts_ptr, fold_consts_ptr, #16 320 ld1 {fold_consts.2d}, [fold_consts_ptr], #16 321 __pmull_pre_\p fold_consts 322 fold_16_bytes \p, v0, v4 323 fold_16_bytes \p, v1, v5 324 fold_16_bytes \p, v2, v6 325 fold_16_bytes \p, v3, v7, 1 326 // Fold across 32 bytes. 327 fold_16_bytes \p, v4, v6 328 fold_16_bytes \p, v5, v7, 1 329 // Fold across 16 bytes. 330 fold_16_bytes \p, v6, v7 331 332 // Add 128 to get the correct number of data bytes remaining in 0...127 333 // (not counting v7), following the previous extra subtraction by 128. 334 // Then subtract 16 to simplify the termination condition of the 335 // following loop. 336 adds len, len, #(128-16) 337 338 // While >= 16 data bytes remain (not counting v7), fold the 16 bytes v7 339 // into them, storing the result back into v7. 340 b.lt .Lfold_16_bytes_loop_done_\@ 341.Lfold_16_bytes_loop_\@: 342 __pmull_\p v8, v7, fold_consts 343 __pmull_\p v7, v7, fold_consts, 2 344 eor v7.16b, v7.16b, v8.16b 345 ldr q0, [buf], #16 346CPU_LE( rev64 v0.16b, v0.16b ) 347CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) 348 eor v7.16b, v7.16b, v0.16b 349 subs len, len, #16 350 b.ge .Lfold_16_bytes_loop_\@ 351 352.Lfold_16_bytes_loop_done_\@: 353 // Add 16 to get the correct number of data bytes remaining in 0...15 354 // (not counting v7), following the previous extra subtraction by 16. 355 adds len, len, #16 356 b.eq .Lreduce_final_16_bytes_\@ 357 358.Lhandle_partial_segment_\@: 359 // Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first 360 // 16 bytes are in v7 and the rest are the remaining data in 'buf'. To 361 // do this without needing a fold constant for each possible 'len', 362 // redivide the bytes into a first chunk of 'len' bytes and a second 363 // chunk of 16 bytes, then fold the first chunk into the second. 364 365 // v0 = last 16 original data bytes 366 add buf, buf, len 367 ldr q0, [buf, #-16] 368CPU_LE( rev64 v0.16b, v0.16b ) 369CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) 370 371 // v1 = high order part of second chunk: v7 left-shifted by 'len' bytes. 372 adr_l x4, .Lbyteshift_table + 16 373 sub x4, x4, len 374 ld1 {v2.16b}, [x4] 375 tbl v1.16b, {v7.16b}, v2.16b 376 377 // v3 = first chunk: v7 right-shifted by '16-len' bytes. 378 movi v3.16b, #0x80 379 eor v2.16b, v2.16b, v3.16b 380 tbl v3.16b, {v7.16b}, v2.16b 381 382 // Convert to 8-bit masks: 'len' 0x00 bytes, then '16-len' 0xff bytes. 383 sshr v2.16b, v2.16b, #7 384 385 // v2 = second chunk: 'len' bytes from v0 (low-order bytes), 386 // then '16-len' bytes from v1 (high-order bytes). 387 bsl v2.16b, v1.16b, v0.16b 388 389 // Fold the first chunk into the second chunk, storing the result in v7. 390 __pmull_\p v0, v3, fold_consts 391 __pmull_\p v7, v3, fold_consts, 2 392 eor v7.16b, v7.16b, v0.16b 393 eor v7.16b, v7.16b, v2.16b 394 395.Lreduce_final_16_bytes_\@: 396 // Reduce the 128-bit value M(x), stored in v7, to the final 16-bit CRC. 397 398 movi v2.16b, #0 // init zero register 399 400 // Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'. 401 ld1 {fold_consts.2d}, [fold_consts_ptr], #16 402 __pmull_pre_\p fold_consts 403 404 // Fold the high 64 bits into the low 64 bits, while also multiplying by 405 // x^64. This produces a 128-bit value congruent to x^64 * M(x) and 406 // whose low 48 bits are 0. 407 ext v0.16b, v2.16b, v7.16b, #8 408 __pmull_\p v7, v7, fold_consts, 2 // high bits * x^48 * (x^80 mod G(x)) 409 eor v0.16b, v0.16b, v7.16b // + low bits * x^64 410 411 // Fold the high 32 bits into the low 96 bits. This produces a 96-bit 412 // value congruent to x^64 * M(x) and whose low 48 bits are 0. 413 ext v1.16b, v0.16b, v2.16b, #12 // extract high 32 bits 414 mov v0.s[3], v2.s[0] // zero high 32 bits 415 __pmull_\p v1, v1, fold_consts // high 32 bits * x^48 * (x^48 mod G(x)) 416 eor v0.16b, v0.16b, v1.16b // + low bits 417 418 // Load G(x) and floor(x^48 / G(x)). 419 ld1 {fold_consts.2d}, [fold_consts_ptr] 420 __pmull_pre_\p fold_consts 421 422 // Use Barrett reduction to compute the final CRC value. 423 __pmull_\p v1, v0, fold_consts, 2 // high 32 bits * floor(x^48 / G(x)) 424 ushr v1.2d, v1.2d, #32 // /= x^32 425 __pmull_\p v1, v1, fold_consts // *= G(x) 426 ushr v0.2d, v0.2d, #48 427 eor v0.16b, v0.16b, v1.16b // + low 16 nonzero bits 428 // Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of v0. 429 430 umov w0, v0.h[0] 431 .ifc \p, p8 432 frame_pop 433 .endif 434 ret 435 436.Lless_than_256_bytes_\@: 437 // Checksumming a buffer of length 16...255 bytes 438 439 adr_l fold_consts_ptr, .Lfold_across_16_bytes_consts 440 441 // Load the first 16 data bytes. 442 ldr q7, [buf], #0x10 443CPU_LE( rev64 v7.16b, v7.16b ) 444CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 ) 445 446 // XOR the first 16 data *bits* with the initial CRC value. 447 movi v0.16b, #0 448 mov v0.h[7], init_crc 449 eor v7.16b, v7.16b, v0.16b 450 451 // Load the fold-across-16-bytes constants. 452 ld1 {fold_consts.2d}, [fold_consts_ptr], #16 453 __pmull_pre_\p fold_consts 454 455 cmp len, #16 456 b.eq .Lreduce_final_16_bytes_\@ // len == 16 457 subs len, len, #32 458 b.ge .Lfold_16_bytes_loop_\@ // 32 <= len <= 255 459 add len, len, #16 460 b .Lhandle_partial_segment_\@ // 17 <= len <= 31 461 .endm 462 463// 464// u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len); 465// 466// Assumes len >= 16. 467// 468SYM_FUNC_START(crc_t10dif_pmull_p8) 469 frame_push 1 470 crc_t10dif_pmull p8 471SYM_FUNC_END(crc_t10dif_pmull_p8) 472 473 .align 5 474// 475// u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len); 476// 477// Assumes len >= 16. 478// 479SYM_FUNC_START(crc_t10dif_pmull_p64) 480 crc_t10dif_pmull p64 481SYM_FUNC_END(crc_t10dif_pmull_p64) 482 483 .section ".rodata", "a" 484 .align 4 485 486// Fold constants precomputed from the polynomial 0x18bb7 487// G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0 488.Lfold_across_128_bytes_consts: 489 .quad 0x0000000000006123 // x^(8*128) mod G(x) 490 .quad 0x0000000000002295 // x^(8*128+64) mod G(x) 491// .Lfold_across_64_bytes_consts: 492 .quad 0x0000000000001069 // x^(4*128) mod G(x) 493 .quad 0x000000000000dd31 // x^(4*128+64) mod G(x) 494// .Lfold_across_32_bytes_consts: 495 .quad 0x000000000000857d // x^(2*128) mod G(x) 496 .quad 0x0000000000007acc // x^(2*128+64) mod G(x) 497.Lfold_across_16_bytes_consts: 498 .quad 0x000000000000a010 // x^(1*128) mod G(x) 499 .quad 0x0000000000001faa // x^(1*128+64) mod G(x) 500// .Lfinal_fold_consts: 501 .quad 0x1368000000000000 // x^48 * (x^48 mod G(x)) 502 .quad 0x2d56000000000000 // x^48 * (x^80 mod G(x)) 503// .Lbarrett_reduction_consts: 504 .quad 0x0000000000018bb7 // G(x) 505 .quad 0x00000001f65a57f8 // floor(x^48 / G(x)) 506 507// For 1 <= len <= 15, the 16-byte vector beginning at &byteshift_table[16 - 508// len] is the index vector to shift left by 'len' bytes, and is also {0x80, 509// ..., 0x80} XOR the index vector to shift right by '16 - len' bytes. 510.Lbyteshift_table: 511 .byte 0x0, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 512 .byte 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f 513 .byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 514 .byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe , 0x0 515