linuxdebug/arch/arm64/lib/crc32.S

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ArmAsm
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2024-07-16 15:50:57 +02:00
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Accelerated CRC32(C) using AArch64 CRC instructions
*
* Copyright (C) 2016 - 2018 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/assembler.h>
.arch armv8-a+crc
.macro byteorder, reg, be
.if \be
CPU_LE( rev \reg, \reg )
.else
CPU_BE( rev \reg, \reg )
.endif
.endm
.macro byteorder16, reg, be
.if \be
CPU_LE( rev16 \reg, \reg )
.else
CPU_BE( rev16 \reg, \reg )
.endif
.endm
.macro bitorder, reg, be
.if \be
rbit \reg, \reg
.endif
.endm
.macro bitorder16, reg, be
.if \be
rbit \reg, \reg
lsr \reg, \reg, #16
.endif
.endm
.macro bitorder8, reg, be
.if \be
rbit \reg, \reg
lsr \reg, \reg, #24
.endif
.endm
.macro __crc32, c, be=0
bitorder w0, \be
cmp x2, #16
b.lt 8f // less than 16 bytes
and x7, x2, #0x1f
and x2, x2, #~0x1f
cbz x7, 32f // multiple of 32 bytes
and x8, x7, #0xf
ldp x3, x4, [x1]
add x8, x8, x1
add x1, x1, x7
ldp x5, x6, [x8]
byteorder x3, \be
byteorder x4, \be
byteorder x5, \be
byteorder x6, \be
bitorder x3, \be
bitorder x4, \be
bitorder x5, \be
bitorder x6, \be
tst x7, #8
crc32\c\()x w8, w0, x3
csel x3, x3, x4, eq
csel w0, w0, w8, eq
tst x7, #4
lsr x4, x3, #32
crc32\c\()w w8, w0, w3
csel x3, x3, x4, eq
csel w0, w0, w8, eq
tst x7, #2
lsr w4, w3, #16
crc32\c\()h w8, w0, w3
csel w3, w3, w4, eq
csel w0, w0, w8, eq
tst x7, #1
crc32\c\()b w8, w0, w3
csel w0, w0, w8, eq
tst x7, #16
crc32\c\()x w8, w0, x5
crc32\c\()x w8, w8, x6
csel w0, w0, w8, eq
cbz x2, 0f
32: ldp x3, x4, [x1], #32
sub x2, x2, #32
ldp x5, x6, [x1, #-16]
byteorder x3, \be
byteorder x4, \be
byteorder x5, \be
byteorder x6, \be
bitorder x3, \be
bitorder x4, \be
bitorder x5, \be
bitorder x6, \be
crc32\c\()x w0, w0, x3
crc32\c\()x w0, w0, x4
crc32\c\()x w0, w0, x5
crc32\c\()x w0, w0, x6
cbnz x2, 32b
0: bitorder w0, \be
ret
8: tbz x2, #3, 4f
ldr x3, [x1], #8
byteorder x3, \be
bitorder x3, \be
crc32\c\()x w0, w0, x3
4: tbz x2, #2, 2f
ldr w3, [x1], #4
byteorder w3, \be
bitorder w3, \be
crc32\c\()w w0, w0, w3
2: tbz x2, #1, 1f
ldrh w3, [x1], #2
byteorder16 w3, \be
bitorder16 w3, \be
crc32\c\()h w0, w0, w3
1: tbz x2, #0, 0f
ldrb w3, [x1]
bitorder8 w3, \be
crc32\c\()b w0, w0, w3
0: bitorder w0, \be
ret
.endm
.align 5
SYM_FUNC_START(crc32_le)
alternative_if_not ARM64_HAS_CRC32
b crc32_le_base
alternative_else_nop_endif
__crc32
SYM_FUNC_END(crc32_le)
.align 5
SYM_FUNC_START(__crc32c_le)
alternative_if_not ARM64_HAS_CRC32
b __crc32c_le_base
alternative_else_nop_endif
__crc32 c
SYM_FUNC_END(__crc32c_le)
.align 5
SYM_FUNC_START(crc32_be)
alternative_if_not ARM64_HAS_CRC32
b crc32_be_base
alternative_else_nop_endif
__crc32 be=1
SYM_FUNC_END(crc32_be)