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/*
* Accelerated CRC32(C) using arm64 CRC, NEON and Crypto Extensions instructions
*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* 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.
*/
/* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see http://www.gnu.org/licenses
*
* Please visit http://www.xyratex.com/contact if you need additional
* information or have any questions.
*
* GPL HEADER END
*/
/*
* Copyright 2012 Xyratex Technology Limited
*
* Using hardware provided PCLMULQDQ instruction to accelerate the CRC32
* calculation.
* CRC32 polynomial:0x04c11db7(BE)/0xEDB88320(LE)
* PCLMULQDQ is a new instruction in Intel SSE4.2, the reference can be found
* at:
* http://www.intel.com/products/processor/manuals/
* Intel(R) 64 and IA-32 Architectures Software Developer's Manual
* Volume 2B: Instruction Set Reference, N-Z
*
* Authors: Gregory Prestas <Gregory_Prestas@us.xyratex.com>
* Alexander Boyko <Alexander_Boyko@xyratex.com>
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.section ".rodata", "a"
.align 6
.cpu generic+crypto+crc
.Lcrc32_constants:
/*
* [x4*128+32 mod P(x) << 32)]' << 1 = 0x154442bd4
* #define CONSTANT_R1 0x154442bd4LL
*
* [(x4*128-32 mod P(x) << 32)]' << 1 = 0x1c6e41596
* #define CONSTANT_R2 0x1c6e41596LL
*/
.octa 0x00000001c6e415960000000154442bd4
/*
* [(x128+32 mod P(x) << 32)]' << 1 = 0x1751997d0
* #define CONSTANT_R3 0x1751997d0LL
*
* [(x128-32 mod P(x) << 32)]' << 1 = 0x0ccaa009e
* #define CONSTANT_R4 0x0ccaa009eLL
*/
.octa 0x00000000ccaa009e00000001751997d0
/*
* [(x64 mod P(x) << 32)]' << 1 = 0x163cd6124
* #define CONSTANT_R5 0x163cd6124LL
*/
.quad 0x0000000163cd6124
.quad 0x00000000FFFFFFFF
/*
* #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
*
* Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
* = 0x1F7011641LL
* #define CONSTANT_RU 0x1F7011641LL
*/
.octa 0x00000001F701164100000001DB710641
.Lcrc32c_constants:
.octa 0x000000009e4addf800000000740eef02
.octa 0x000000014cd00bd600000000f20c0dfe
.quad 0x00000000dd45aab8
.quad 0x00000000FFFFFFFF
.octa 0x00000000dea713f10000000105ec76f0
vCONSTANT .req v0
dCONSTANT .req d0
qCONSTANT .req q0
BUF .req x0
LEN .req x1
CRC .req x2
vzr .req v9
/**
* Calculate crc32
* BUF - buffer
* LEN - sizeof buffer (multiple of 16 bytes), LEN should be > 63
* CRC - initial crc32
* return %eax crc32
* uint crc32_pmull_le(unsigned char const *buffer,
* size_t len, uint crc32)
*/
.text
ENTRY(crc32_pmull_le)
adr_l x3, .Lcrc32_constants
b 0f
ENTRY(crc32c_pmull_le)
adr_l x3, .Lcrc32c_constants
0: bic LEN, LEN, #15
ld1 {v1.16b-v4.16b}, [BUF], #0x40
movi vzr.16b, #0
fmov dCONSTANT, CRC
eor v1.16b, v1.16b, vCONSTANT.16b
sub LEN, LEN, #0x40
cmp LEN, #0x40
b.lt less_64
ldr qCONSTANT, [x3]
loop_64: /* 64 bytes Full cache line folding */
sub LEN, LEN, #0x40
pmull2 v5.1q, v1.2d, vCONSTANT.2d
pmull2 v6.1q, v2.2d, vCONSTANT.2d
pmull2 v7.1q, v3.2d, vCONSTANT.2d
pmull2 v8.1q, v4.2d, vCONSTANT.2d
pmull v1.1q, v1.1d, vCONSTANT.1d
pmull v2.1q, v2.1d, vCONSTANT.1d
pmull v3.1q, v3.1d, vCONSTANT.1d
pmull v4.1q, v4.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v5.16b
ld1 {v5.16b}, [BUF], #0x10
eor v2.16b, v2.16b, v6.16b
ld1 {v6.16b}, [BUF], #0x10
eor v3.16b, v3.16b, v7.16b
ld1 {v7.16b}, [BUF], #0x10
eor v4.16b, v4.16b, v8.16b
ld1 {v8.16b}, [BUF], #0x10
eor v1.16b, v1.16b, v5.16b
eor v2.16b, v2.16b, v6.16b
eor v3.16b, v3.16b, v7.16b
eor v4.16b, v4.16b, v8.16b
cmp LEN, #0x40
b.ge loop_64
less_64: /* Folding cache line into 128bit */
ldr qCONSTANT, [x3, #16]
pmull2 v5.1q, v1.2d, vCONSTANT.2d
pmull v1.1q, v1.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v5.16b
eor v1.16b, v1.16b, v2.16b
pmull2 v5.1q, v1.2d, vCONSTANT.2d
pmull v1.1q, v1.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v5.16b
eor v1.16b, v1.16b, v3.16b
pmull2 v5.1q, v1.2d, vCONSTANT.2d
pmull v1.1q, v1.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v5.16b
eor v1.16b, v1.16b, v4.16b
cbz LEN, fold_64
loop_16: /* Folding rest buffer into 128bit */
subs LEN, LEN, #0x10
ld1 {v2.16b}, [BUF], #0x10
pmull2 v5.1q, v1.2d, vCONSTANT.2d
pmull v1.1q, v1.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v5.16b
eor v1.16b, v1.16b, v2.16b
b.ne loop_16
fold_64:
/* perform the last 64 bit fold, also adds 32 zeroes
* to the input stream */
ext v2.16b, v1.16b, v1.16b, #8
pmull2 v2.1q, v2.2d, vCONSTANT.2d
ext v1.16b, v1.16b, vzr.16b, #8
eor v1.16b, v1.16b, v2.16b
/* final 32-bit fold */
ldr dCONSTANT, [x3, #32]
ldr d3, [x3, #40]
ext v2.16b, v1.16b, vzr.16b, #4
and v1.16b, v1.16b, v3.16b
pmull v1.1q, v1.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v2.16b
/* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */
ldr qCONSTANT, [x3, #48]
and v2.16b, v1.16b, v3.16b
ext v2.16b, vzr.16b, v2.16b, #8
pmull2 v2.1q, v2.2d, vCONSTANT.2d
and v2.16b, v2.16b, v3.16b
pmull v2.1q, v2.1d, vCONSTANT.1d
eor v1.16b, v1.16b, v2.16b
mov w0, v1.s[1]
ret
ENDPROC(crc32_pmull_le)
ENDPROC(crc32c_pmull_le)
.macro __crc32, c
0: subs x2, x2, #16
b.mi 8f
ldp x3, x4, [x1], #16
CPU_BE( rev x3, x3 )
CPU_BE( rev x4, x4 )
crc32\c\()x w0, w0, x3
crc32\c\()x w0, w0, x4
b.ne 0b
ret
8: tbz x2, #3, 4f
ldr x3, [x1], #8
CPU_BE( rev x3, x3 )
crc32\c\()x w0, w0, x3
4: tbz x2, #2, 2f
ldr w3, [x1], #4
CPU_BE( rev w3, w3 )
crc32\c\()w w0, w0, w3
2: tbz x2, #1, 1f
ldrh w3, [x1], #2
CPU_BE( rev16 w3, w3 )
crc32\c\()h w0, w0, w3
1: tbz x2, #0, 0f
ldrb w3, [x1]
crc32\c\()b w0, w0, w3
0: ret
.endm
.align 5
ENTRY(crc32_armv8_le)
__crc32
ENDPROC(crc32_armv8_le)
.align 5
ENTRY(crc32c_armv8_le)
__crc32 c
ENDPROC(crc32c_armv8_le)