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Diffstat (limited to 'arch/arm/lib/crc-t10dif-core.S')
| -rw-r--r-- | arch/arm/lib/crc-t10dif-core.S | 468 |
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diff --git a/arch/arm/lib/crc-t10dif-core.S b/arch/arm/lib/crc-t10dif-core.S new file mode 100644 index 000000000000..2bbf2df9c1e2 --- /dev/null +++ b/arch/arm/lib/crc-t10dif-core.S @@ -0,0 +1,468 @@ +// +// Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions +// +// Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> +// Copyright (C) 2019 Google LLC <ebiggers@google.com> +// +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License version 2 as +// published by the Free Software Foundation. +// + +// Derived from the x86 version: +// +// Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions +// +// Copyright (c) 2013, Intel Corporation +// +// Authors: +// Erdinc Ozturk <erdinc.ozturk@intel.com> +// Vinodh Gopal <vinodh.gopal@intel.com> +// James Guilford <james.guilford@intel.com> +// Tim Chen <tim.c.chen@linux.intel.com> +// +// This software is available to you under a choice of one of two +// licenses. You may choose to be licensed under the terms of the GNU +// General Public License (GPL) Version 2, available from the file +// COPYING in the main directory of this source tree, or the +// OpenIB.org BSD license below: +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the +// distribution. +// +// * Neither the name of the Intel Corporation nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// +// THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION ""AS IS"" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL CORPORATION OR +// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, +// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +// Reference paper titled "Fast CRC Computation for Generic +// Polynomials Using PCLMULQDQ Instruction" +// URL: http://www.intel.com/content/dam/www/public/us/en/documents +// /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf +// + +#include <linux/linkage.h> +#include <asm/assembler.h> + +#ifdef CONFIG_CPU_ENDIAN_BE8 +#define CPU_LE(code...) +#else +#define CPU_LE(code...) code +#endif + + .text + .arch armv8-a + .fpu crypto-neon-fp-armv8 + + init_crc .req r0 + buf .req r1 + len .req r2 + + fold_consts_ptr .req ip + + q0l .req d0 + q0h .req d1 + q1l .req d2 + q1h .req d3 + q2l .req d4 + q2h .req d5 + q3l .req d6 + q3h .req d7 + q4l .req d8 + q4h .req d9 + q5l .req d10 + q5h .req d11 + q6l .req d12 + q6h .req d13 + q7l .req d14 + q7h .req d15 + q8l .req d16 + q8h .req d17 + q9l .req d18 + q9h .req d19 + q10l .req d20 + q10h .req d21 + q11l .req d22 + q11h .req d23 + q12l .req d24 + q12h .req d25 + + FOLD_CONSTS .req q10 + FOLD_CONST_L .req q10l + FOLD_CONST_H .req q10h + + /* + * Pairwise long polynomial multiplication of two 16-bit values + * + * { w0, w1 }, { y0, y1 } + * + * by two 64-bit values + * + * { x0, x1, x2, x3, x4, x5, x6, x7 }, { z0, z1, z2, z3, z4, z5, z6, z7 } + * + * where each vector element is a byte, ordered from least to most + * significant. The resulting 80-bit vectors are XOR'ed together. + * + * This can be implemented using 8x8 long polynomial multiplication, by + * reorganizing the input so that each pairwise 8x8 multiplication + * produces one of the terms from the decomposition below, and + * combining the results of each rank and shifting them into place. + * + * Rank + * 0 w0*x0 ^ | y0*z0 ^ + * 1 (w0*x1 ^ w1*x0) << 8 ^ | (y0*z1 ^ y1*z0) << 8 ^ + * 2 (w0*x2 ^ w1*x1) << 16 ^ | (y0*z2 ^ y1*z1) << 16 ^ + * 3 (w0*x3 ^ w1*x2) << 24 ^ | (y0*z3 ^ y1*z2) << 24 ^ + * 4 (w0*x4 ^ w1*x3) << 32 ^ | (y0*z4 ^ y1*z3) << 32 ^ + * 5 (w0*x5 ^ w1*x4) << 40 ^ | (y0*z5 ^ y1*z4) << 40 ^ + * 6 (w0*x6 ^ w1*x5) << 48 ^ | (y0*z6 ^ y1*z5) << 48 ^ + * 7 (w0*x7 ^ w1*x6) << 56 ^ | (y0*z7 ^ y1*z6) << 56 ^ + * 8 w1*x7 << 64 | y1*z7 << 64 + * + * The inputs can be reorganized into + * + * { w0, w0, w0, w0, y0, y0, y0, y0 }, { w1, w1, w1, w1, y1, y1, y1, y1 } + * { x0, x2, x4, x6, z0, z2, z4, z6 }, { x1, x3, x5, x7, z1, z3, z5, z7 } + * + * and after performing 8x8->16 bit long polynomial multiplication of + * each of the halves of the first vector with those of the second one, + * we obtain the following four vectors of 16-bit elements: + * + * a := { w0*x0, w0*x2, w0*x4, w0*x6 }, { y0*z0, y0*z2, y0*z4, y0*z6 } + * b := { w0*x1, w0*x3, w0*x5, w0*x7 }, { y0*z1, y0*z3, y0*z5, y0*z7 } + * c := { w1*x0, w1*x2, w1*x4, w1*x6 }, { y1*z0, y1*z2, y1*z4, y1*z6 } + * d := { w1*x1, w1*x3, w1*x5, w1*x7 }, { y1*z1, y1*z3, y1*z5, y1*z7 } + * + * Results b and c can be XORed together, as the vector elements have + * matching ranks. Then, the final XOR can be pulled forward, and + * applied between the halves of each of the remaining three vectors, + * which are then shifted into place, and XORed together to produce the + * final 80-bit result. + */ + .macro pmull16x64_p8, v16, v64 + vext.8 q11, \v64, \v64, #1 + vld1.64 {q12}, [r4, :128] + vuzp.8 q11, \v64 + vtbl.8 d24, {\v16\()_L-\v16\()_H}, d24 + vtbl.8 d25, {\v16\()_L-\v16\()_H}, d25 + bl __pmull16x64_p8 + veor \v64, q12, q14 + .endm + +__pmull16x64_p8: + vmull.p8 q13, d23, d24 + vmull.p8 q14, d23, d25 + vmull.p8 q15, d22, d24 + vmull.p8 q12, d22, d25 + + veor q14, q14, q15 + veor d24, d24, d25 + veor d26, d26, d27 + veor d28, d28, d29 + vmov.i32 d25, #0 + vmov.i32 d29, #0 + vext.8 q12, q12, q12, #14 + vext.8 q14, q14, q14, #15 + veor d24, d24, d26 + bx lr +ENDPROC(__pmull16x64_p8) + + .macro pmull16x64_p64, v16, v64 + vmull.p64 q11, \v64\()l, \v16\()_L + vmull.p64 \v64, \v64\()h, \v16\()_H + veor \v64, \v64, q11 + .endm + + // Fold reg1, reg2 into the next 32 data bytes, storing the result back + // into reg1, reg2. + .macro fold_32_bytes, reg1, reg2, p + vld1.64 {q8-q9}, [buf]! + + pmull16x64_\p FOLD_CONST, \reg1 + pmull16x64_\p FOLD_CONST, \reg2 + +CPU_LE( vrev64.8 q8, q8 ) +CPU_LE( vrev64.8 q9, q9 ) + vswp q8l, q8h + vswp q9l, q9h + + veor.8 \reg1, \reg1, q8 + veor.8 \reg2, \reg2, q9 + .endm + + // Fold src_reg into dst_reg, optionally loading the next fold constants + .macro fold_16_bytes, src_reg, dst_reg, p, load_next_consts + pmull16x64_\p FOLD_CONST, \src_reg + .ifnb \load_next_consts + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]! + .endif + veor.8 \dst_reg, \dst_reg, \src_reg + .endm + + .macro crct10dif, p + // For sizes less than 256 bytes, we can't fold 128 bytes at a time. + cmp len, #256 + blt .Lless_than_256_bytes\@ + + mov_l fold_consts_ptr, .Lfold_across_128_bytes_consts + + // Load the first 128 data bytes. Byte swapping is necessary to make + // the bit order match the polynomial coefficient order. + vld1.64 {q0-q1}, [buf]! + vld1.64 {q2-q3}, [buf]! + vld1.64 {q4-q5}, [buf]! + vld1.64 {q6-q7}, [buf]! +CPU_LE( vrev64.8 q0, q0 ) +CPU_LE( vrev64.8 q1, q1 ) +CPU_LE( vrev64.8 q2, q2 ) +CPU_LE( vrev64.8 q3, q3 ) +CPU_LE( vrev64.8 q4, q4 ) +CPU_LE( vrev64.8 q5, q5 ) +CPU_LE( vrev64.8 q6, q6 ) +CPU_LE( vrev64.8 q7, q7 ) + vswp q0l, q0h + vswp q1l, q1h + vswp q2l, q2h + vswp q3l, q3h + vswp q4l, q4h + vswp q5l, q5h + vswp q6l, q6h + vswp q7l, q7h + + // XOR the first 16 data *bits* with the initial CRC value. + vmov.i8 q8h, #0 + vmov.u16 q8h[3], init_crc + veor q0h, q0h, q8h + + // Load the constants for folding across 128 bytes. + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]! + + // Subtract 128 for the 128 data bytes just consumed. Subtract another + // 128 to simplify the termination condition of the following loop. + sub len, len, #256 + + // While >= 128 data bytes remain (not counting q0-q7), fold the 128 + // bytes q0-q7 into them, storing the result back into q0-q7. +.Lfold_128_bytes_loop\@: + fold_32_bytes q0, q1, \p + fold_32_bytes q2, q3, \p + fold_32_bytes q4, q5, \p + fold_32_bytes q6, q7, \p + subs len, len, #128 + bge .Lfold_128_bytes_loop\@ + + // Now fold the 112 bytes in q0-q6 into the 16 bytes in q7. + + // Fold across 64 bytes. + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]! + fold_16_bytes q0, q4, \p + fold_16_bytes q1, q5, \p + fold_16_bytes q2, q6, \p + fold_16_bytes q3, q7, \p, 1 + // Fold across 32 bytes. + fold_16_bytes q4, q6, \p + fold_16_bytes q5, q7, \p, 1 + // Fold across 16 bytes. + fold_16_bytes q6, q7, \p + + // Add 128 to get the correct number of data bytes remaining in 0...127 + // (not counting q7), following the previous extra subtraction by 128. + // Then subtract 16 to simplify the termination condition of the + // following loop. + adds len, len, #(128-16) + + // While >= 16 data bytes remain (not counting q7), fold the 16 bytes q7 + // into them, storing the result back into q7. + blt .Lfold_16_bytes_loop_done\@ +.Lfold_16_bytes_loop\@: + pmull16x64_\p FOLD_CONST, q7 + vld1.64 {q0}, [buf]! +CPU_LE( vrev64.8 q0, q0 ) + vswp q0l, q0h + veor.8 q7, q7, q0 + subs len, len, #16 + bge .Lfold_16_bytes_loop\@ + +.Lfold_16_bytes_loop_done\@: + // Add 16 to get the correct number of data bytes remaining in 0...15 + // (not counting q7), following the previous extra subtraction by 16. + adds len, len, #16 + beq .Lreduce_final_16_bytes\@ + +.Lhandle_partial_segment\@: + // Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first + // 16 bytes are in q7 and the rest are the remaining data in 'buf'. To + // do this without needing a fold constant for each possible 'len', + // redivide the bytes into a first chunk of 'len' bytes and a second + // chunk of 16 bytes, then fold the first chunk into the second. + + // q0 = last 16 original data bytes + add buf, buf, len + sub buf, buf, #16 + vld1.64 {q0}, [buf] +CPU_LE( vrev64.8 q0, q0 ) + vswp q0l, q0h + + // q1 = high order part of second chunk: q7 left-shifted by 'len' bytes. + mov_l r1, .Lbyteshift_table + 16 + sub r1, r1, len + vld1.8 {q2}, [r1] + vtbl.8 q1l, {q7l-q7h}, q2l + vtbl.8 q1h, {q7l-q7h}, q2h + + // q3 = first chunk: q7 right-shifted by '16-len' bytes. + vmov.i8 q3, #0x80 + veor.8 q2, q2, q3 + vtbl.8 q3l, {q7l-q7h}, q2l + vtbl.8 q3h, {q7l-q7h}, q2h + + // Convert to 8-bit masks: 'len' 0x00 bytes, then '16-len' 0xff bytes. + vshr.s8 q2, q2, #7 + + // q2 = second chunk: 'len' bytes from q0 (low-order bytes), + // then '16-len' bytes from q1 (high-order bytes). + vbsl.8 q2, q1, q0 + + // Fold the first chunk into the second chunk, storing the result in q7. + pmull16x64_\p FOLD_CONST, q3 + veor.8 q7, q3, q2 + b .Lreduce_final_16_bytes\@ + +.Lless_than_256_bytes\@: + // Checksumming a buffer of length 16...255 bytes + + mov_l fold_consts_ptr, .Lfold_across_16_bytes_consts + + // Load the first 16 data bytes. + vld1.64 {q7}, [buf]! +CPU_LE( vrev64.8 q7, q7 ) + vswp q7l, q7h + + // XOR the first 16 data *bits* with the initial CRC value. + vmov.i8 q0h, #0 + vmov.u16 q0h[3], init_crc + veor.8 q7h, q7h, q0h + + // Load the fold-across-16-bytes constants. + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]! + + cmp len, #16 + beq .Lreduce_final_16_bytes\@ // len == 16 + subs len, len, #32 + addlt len, len, #16 + blt .Lhandle_partial_segment\@ // 17 <= len <= 31 + b .Lfold_16_bytes_loop\@ // 32 <= len <= 255 + +.Lreduce_final_16_bytes\@: + .endm + +// +// u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len); +// +// Assumes len >= 16. +// +ENTRY(crc_t10dif_pmull64) + crct10dif p64 + + // Reduce the 128-bit value M(x), stored in q7, to the final 16-bit CRC. + + // Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'. + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]! + + // Fold the high 64 bits into the low 64 bits, while also multiplying by + // x^64. This produces a 128-bit value congruent to x^64 * M(x) and + // whose low 48 bits are 0. + vmull.p64 q0, q7h, FOLD_CONST_H // high bits * x^48 * (x^80 mod G(x)) + veor.8 q0h, q0h, q7l // + low bits * x^64 + + // Fold the high 32 bits into the low 96 bits. This produces a 96-bit + // value congruent to x^64 * M(x) and whose low 48 bits are 0. + vmov.i8 q1, #0 + vmov s4, s3 // extract high 32 bits + vmov s3, s5 // zero high 32 bits + vmull.p64 q1, q1l, FOLD_CONST_L // high 32 bits * x^48 * (x^48 mod G(x)) + veor.8 q0, q0, q1 // + low bits + + // Load G(x) and floor(x^48 / G(x)). + vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128] + + // Use Barrett reduction to compute the final CRC value. + vmull.p64 q1, q0h, FOLD_CONST_H // high 32 bits * floor(x^48 / G(x)) + vshr.u64 q1l, q1l, #32 // /= x^32 + vmull.p64 q1, q1l, FOLD_CONST_L // *= G(x) + vshr.u64 q0l, q0l, #48 + veor.8 q0l, q0l, q1l // + low 16 nonzero bits + // Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of q0. + + vmov.u16 r0, q0l[0] + bx lr +ENDPROC(crc_t10dif_pmull64) + +ENTRY(crc_t10dif_pmull8) + push {r4, lr} + mov_l r4, .L16x64perm + + crct10dif p8 + +CPU_LE( vrev64.8 q7, q7 ) + vswp q7l, q7h + vst1.64 {q7}, [r3, :128] + pop {r4, pc} +ENDPROC(crc_t10dif_pmull8) + + .section ".rodata", "a" + .align 4 + +// Fold constants precomputed from the polynomial 0x18bb7 +// G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0 +.Lfold_across_128_bytes_consts: + .quad 0x0000000000006123 // x^(8*128) mod G(x) + .quad 0x0000000000002295 // x^(8*128+64) mod G(x) +// .Lfold_across_64_bytes_consts: + .quad 0x0000000000001069 // x^(4*128) mod G(x) + .quad 0x000000000000dd31 // x^(4*128+64) mod G(x) +// .Lfold_across_32_bytes_consts: + .quad 0x000000000000857d // x^(2*128) mod G(x) + .quad 0x0000000000007acc // x^(2*128+64) mod G(x) +.Lfold_across_16_bytes_consts: + .quad 0x000000000000a010 // x^(1*128) mod G(x) + .quad 0x0000000000001faa // x^(1*128+64) mod G(x) +// .Lfinal_fold_consts: + .quad 0x1368000000000000 // x^48 * (x^48 mod G(x)) + .quad 0x2d56000000000000 // x^48 * (x^80 mod G(x)) +// .Lbarrett_reduction_consts: + .quad 0x0000000000018bb7 // G(x) + .quad 0x00000001f65a57f8 // floor(x^48 / G(x)) + +// For 1 <= len <= 15, the 16-byte vector beginning at &byteshift_table[16 - +// len] is the index vector to shift left by 'len' bytes, and is also {0x80, +// ..., 0x80} XOR the index vector to shift right by '16 - len' bytes. +.Lbyteshift_table: + .byte 0x0, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 + .byte 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f + .byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 + .byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe , 0x0 + +.L16x64perm: + .quad 0x808080800000000, 0x909090901010101 |