crypto: arm64/aes-neon-blk - tweak performance for low end cores

The non-bitsliced AES implementation using the NEON is highly sensitive
to micro-architectural details, and, as it turns out, the Cortex-A53 on
the Raspberry Pi 3 is a core that can benefit from this code, given that
its scalar AES performance is abysmal (32.9 cycles per byte).

The new bitsliced AES code manages 19.8 cycles per byte on this core,
but can only operate on 8 blocks at a time, which is not supported by
all chaining modes. With a bit of tweaking, we can get the plain NEON
code to run at 22.0 cycles per byte, making it useful for sequential
modes like CBC encryption. (Like bitsliced NEON, the plain NEON
implementation does not use any lookup tables, which makes it easy on
the D-cache, and invulnerable to cache timing attacks)

So tweak the plain NEON AES code to use tbl instructions rather than
shl/sri pairs, and to avoid the need to reload permutation vectors or
other constants from memory in every round. Also, improve the decryption
performance by switching to 16x8 pmul instructions for the performing
the multiplications in GF(2^8).

To allow the ECB and CBC encrypt routines to be reused by the bitsliced
NEON code in a subsequent patch, export them from the module.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2017-01-28 23:25:38 +00:00 коммит произвёл Herbert Xu
Родитель c458c4ada0
Коммит 4edd7d015b
2 изменённых файлов: 108 добавлений и 141 удалений

Просмотреть файл

@ -409,5 +409,7 @@ unregister_simds:
module_cpu_feature_match(AES, aes_init);
#else
module_init(aes_init);
EXPORT_SYMBOL(neon_aes_ecb_encrypt);
EXPORT_SYMBOL(neon_aes_cbc_encrypt);
#endif
module_exit(aes_exit);

Просмотреть файл

@ -1,7 +1,7 @@
/*
* linux/arch/arm64/crypto/aes-neon.S - AES cipher for ARMv8 NEON
*
* Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
* Copyright (C) 2013 - 2017 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
@ -17,17 +17,25 @@
/* multiply by polynomial 'x' in GF(2^8) */
.macro mul_by_x, out, in, temp, const
sshr \temp, \in, #7
add \out, \in, \in
shl \out, \in, #1
and \temp, \temp, \const
eor \out, \out, \temp
.endm
/* multiply by polynomial 'x^2' in GF(2^8) */
.macro mul_by_x2, out, in, temp, const
ushr \temp, \in, #6
shl \out, \in, #2
pmul \temp, \temp, \const
eor \out, \out, \temp
.endm
/* preload the entire Sbox */
.macro prepare, sbox, shiftrows, temp
adr \temp, \sbox
movi v12.16b, #0x40
movi v12.16b, #0x1b
ldr q13, \shiftrows
movi v14.16b, #0x1b
ldr q14, .Lror32by8
ld1 {v16.16b-v19.16b}, [\temp], #64
ld1 {v20.16b-v23.16b}, [\temp], #64
ld1 {v24.16b-v27.16b}, [\temp], #64
@ -50,37 +58,31 @@
/* apply SubBytes transformation using the the preloaded Sbox */
.macro sub_bytes, in
sub v9.16b, \in\().16b, v12.16b
sub v9.16b, \in\().16b, v15.16b
tbl \in\().16b, {v16.16b-v19.16b}, \in\().16b
sub v10.16b, v9.16b, v12.16b
sub v10.16b, v9.16b, v15.16b
tbx \in\().16b, {v20.16b-v23.16b}, v9.16b
sub v11.16b, v10.16b, v12.16b
sub v11.16b, v10.16b, v15.16b
tbx \in\().16b, {v24.16b-v27.16b}, v10.16b
tbx \in\().16b, {v28.16b-v31.16b}, v11.16b
.endm
/* apply MixColumns transformation */
.macro mix_columns, in
mul_by_x v10.16b, \in\().16b, v9.16b, v14.16b
rev32 v8.8h, \in\().8h
eor \in\().16b, v10.16b, \in\().16b
shl v9.4s, v8.4s, #24
shl v11.4s, \in\().4s, #24
sri v9.4s, v8.4s, #8
sri v11.4s, \in\().4s, #8
eor v9.16b, v9.16b, v8.16b
eor v10.16b, v10.16b, v9.16b
eor \in\().16b, v10.16b, v11.16b
.endm
.macro mix_columns, in, enc
.if \enc == 0
/* Inverse MixColumns: pre-multiply by { 5, 0, 4, 0 } */
.macro inv_mix_columns, in
mul_by_x v11.16b, \in\().16b, v10.16b, v14.16b
mul_by_x v11.16b, v11.16b, v10.16b, v14.16b
eor \in\().16b, \in\().16b, v11.16b
rev32 v11.8h, v11.8h
eor \in\().16b, \in\().16b, v11.16b
mix_columns \in
mul_by_x2 v8.16b, \in\().16b, v9.16b, v12.16b
eor \in\().16b, \in\().16b, v8.16b
rev32 v8.8h, v8.8h
eor \in\().16b, \in\().16b, v8.16b
.endif
mul_by_x v9.16b, \in\().16b, v8.16b, v12.16b
rev32 v8.8h, \in\().8h
eor v8.16b, v8.16b, v9.16b
eor \in\().16b, \in\().16b, v8.16b
tbl \in\().16b, {\in\().16b}, v14.16b
eor \in\().16b, \in\().16b, v8.16b
.endm
.macro do_block, enc, in, rounds, rk, rkp, i
@ -88,16 +90,13 @@
add \rkp, \rk, #16
mov \i, \rounds
1111: eor \in\().16b, \in\().16b, v15.16b /* ^round key */
movi v15.16b, #0x40
tbl \in\().16b, {\in\().16b}, v13.16b /* ShiftRows */
sub_bytes \in
ld1 {v15.4s}, [\rkp], #16
subs \i, \i, #1
ld1 {v15.4s}, [\rkp], #16
beq 2222f
.if \enc == 1
mix_columns \in
.else
inv_mix_columns \in
.endif
mix_columns \in, \enc
b 1111b
2222: eor \in\().16b, \in\().16b, v15.16b /* ^round key */
.endm
@ -116,139 +115,114 @@
*/
.macro sub_bytes_2x, in0, in1
sub v8.16b, \in0\().16b, v12.16b
sub v9.16b, \in1\().16b, v12.16b
sub v8.16b, \in0\().16b, v15.16b
tbl \in0\().16b, {v16.16b-v19.16b}, \in0\().16b
sub v9.16b, \in1\().16b, v15.16b
tbl \in1\().16b, {v16.16b-v19.16b}, \in1\().16b
sub v10.16b, v8.16b, v12.16b
sub v11.16b, v9.16b, v12.16b
sub v10.16b, v8.16b, v15.16b
tbx \in0\().16b, {v20.16b-v23.16b}, v8.16b
sub v11.16b, v9.16b, v15.16b
tbx \in1\().16b, {v20.16b-v23.16b}, v9.16b
sub v8.16b, v10.16b, v12.16b
sub v9.16b, v11.16b, v12.16b
sub v8.16b, v10.16b, v15.16b
tbx \in0\().16b, {v24.16b-v27.16b}, v10.16b
sub v9.16b, v11.16b, v15.16b
tbx \in1\().16b, {v24.16b-v27.16b}, v11.16b
tbx \in0\().16b, {v28.16b-v31.16b}, v8.16b
tbx \in1\().16b, {v28.16b-v31.16b}, v9.16b
.endm
.macro sub_bytes_4x, in0, in1, in2, in3
sub v8.16b, \in0\().16b, v12.16b
sub v8.16b, \in0\().16b, v15.16b
tbl \in0\().16b, {v16.16b-v19.16b}, \in0\().16b
sub v9.16b, \in1\().16b, v12.16b
sub v9.16b, \in1\().16b, v15.16b
tbl \in1\().16b, {v16.16b-v19.16b}, \in1\().16b
sub v10.16b, \in2\().16b, v12.16b
sub v10.16b, \in2\().16b, v15.16b
tbl \in2\().16b, {v16.16b-v19.16b}, \in2\().16b
sub v11.16b, \in3\().16b, v12.16b
sub v11.16b, \in3\().16b, v15.16b
tbl \in3\().16b, {v16.16b-v19.16b}, \in3\().16b
tbx \in0\().16b, {v20.16b-v23.16b}, v8.16b
tbx \in1\().16b, {v20.16b-v23.16b}, v9.16b
sub v8.16b, v8.16b, v12.16b
sub v8.16b, v8.16b, v15.16b
tbx \in2\().16b, {v20.16b-v23.16b}, v10.16b
sub v9.16b, v9.16b, v12.16b
sub v9.16b, v9.16b, v15.16b
tbx \in3\().16b, {v20.16b-v23.16b}, v11.16b
sub v10.16b, v10.16b, v12.16b
sub v10.16b, v10.16b, v15.16b
tbx \in0\().16b, {v24.16b-v27.16b}, v8.16b
sub v11.16b, v11.16b, v12.16b
sub v11.16b, v11.16b, v15.16b
tbx \in1\().16b, {v24.16b-v27.16b}, v9.16b
sub v8.16b, v8.16b, v12.16b
sub v8.16b, v8.16b, v15.16b
tbx \in2\().16b, {v24.16b-v27.16b}, v10.16b
sub v9.16b, v9.16b, v12.16b
sub v9.16b, v9.16b, v15.16b
tbx \in3\().16b, {v24.16b-v27.16b}, v11.16b
sub v10.16b, v10.16b, v12.16b
sub v10.16b, v10.16b, v15.16b
tbx \in0\().16b, {v28.16b-v31.16b}, v8.16b
sub v11.16b, v11.16b, v12.16b
sub v11.16b, v11.16b, v15.16b
tbx \in1\().16b, {v28.16b-v31.16b}, v9.16b
tbx \in2\().16b, {v28.16b-v31.16b}, v10.16b
tbx \in3\().16b, {v28.16b-v31.16b}, v11.16b
.endm
.macro mul_by_x_2x, out0, out1, in0, in1, tmp0, tmp1, const
sshr \tmp0\().16b, \in0\().16b, #7
add \out0\().16b, \in0\().16b, \in0\().16b
sshr \tmp1\().16b, \in1\().16b, #7
sshr \tmp0\().16b, \in0\().16b, #7
shl \out0\().16b, \in0\().16b, #1
sshr \tmp1\().16b, \in1\().16b, #7
and \tmp0\().16b, \tmp0\().16b, \const\().16b
add \out1\().16b, \in1\().16b, \in1\().16b
shl \out1\().16b, \in1\().16b, #1
and \tmp1\().16b, \tmp1\().16b, \const\().16b
eor \out0\().16b, \out0\().16b, \tmp0\().16b
eor \out1\().16b, \out1\().16b, \tmp1\().16b
.endm
.macro mix_columns_2x, in0, in1
mul_by_x_2x v8, v9, \in0, \in1, v10, v11, v14
.macro mul_by_x2_2x, out0, out1, in0, in1, tmp0, tmp1, const
ushr \tmp0\().16b, \in0\().16b, #6
shl \out0\().16b, \in0\().16b, #2
ushr \tmp1\().16b, \in1\().16b, #6
pmul \tmp0\().16b, \tmp0\().16b, \const\().16b
shl \out1\().16b, \in1\().16b, #2
pmul \tmp1\().16b, \tmp1\().16b, \const\().16b
eor \out0\().16b, \out0\().16b, \tmp0\().16b
eor \out1\().16b, \out1\().16b, \tmp1\().16b
.endm
.macro mix_columns_2x, in0, in1, enc
.if \enc == 0
/* Inverse MixColumns: pre-multiply by { 5, 0, 4, 0 } */
mul_by_x2_2x v8, v9, \in0, \in1, v10, v11, v12
eor \in0\().16b, \in0\().16b, v8.16b
rev32 v8.8h, v8.8h
eor \in1\().16b, \in1\().16b, v9.16b
rev32 v9.8h, v9.8h
eor \in0\().16b, \in0\().16b, v8.16b
eor \in1\().16b, \in1\().16b, v9.16b
.endif
mul_by_x_2x v8, v9, \in0, \in1, v10, v11, v12
rev32 v10.8h, \in0\().8h
rev32 v11.8h, \in1\().8h
eor \in0\().16b, v8.16b, \in0\().16b
eor \in1\().16b, v9.16b, \in1\().16b
shl v12.4s, v10.4s, #24
shl v13.4s, v11.4s, #24
eor v8.16b, v8.16b, v10.16b
sri v12.4s, v10.4s, #8
shl v10.4s, \in0\().4s, #24
eor v9.16b, v9.16b, v11.16b
sri v13.4s, v11.4s, #8
shl v11.4s, \in1\().4s, #24
sri v10.4s, \in0\().4s, #8
eor \in0\().16b, v8.16b, v12.16b
sri v11.4s, \in1\().4s, #8
eor \in1\().16b, v9.16b, v13.16b
eor \in0\().16b, v10.16b, \in0\().16b
eor \in1\().16b, v11.16b, \in1\().16b
eor v10.16b, v10.16b, v8.16b
eor v11.16b, v11.16b, v9.16b
eor \in0\().16b, \in0\().16b, v10.16b
eor \in1\().16b, \in1\().16b, v11.16b
tbl \in0\().16b, {\in0\().16b}, v14.16b
tbl \in1\().16b, {\in1\().16b}, v14.16b
eor \in0\().16b, \in0\().16b, v10.16b
eor \in1\().16b, \in1\().16b, v11.16b
.endm
.macro inv_mix_cols_2x, in0, in1
mul_by_x_2x v8, v9, \in0, \in1, v10, v11, v14
mul_by_x_2x v8, v9, v8, v9, v10, v11, v14
eor \in0\().16b, \in0\().16b, v8.16b
eor \in1\().16b, \in1\().16b, v9.16b
rev32 v8.8h, v8.8h
rev32 v9.8h, v9.8h
eor \in0\().16b, \in0\().16b, v8.16b
eor \in1\().16b, \in1\().16b, v9.16b
mix_columns_2x \in0, \in1
.endm
.macro inv_mix_cols_4x, in0, in1, in2, in3
mul_by_x_2x v8, v9, \in0, \in1, v10, v11, v14
mul_by_x_2x v10, v11, \in2, \in3, v12, v13, v14
mul_by_x_2x v8, v9, v8, v9, v12, v13, v14
mul_by_x_2x v10, v11, v10, v11, v12, v13, v14
eor \in0\().16b, \in0\().16b, v8.16b
eor \in1\().16b, \in1\().16b, v9.16b
eor \in2\().16b, \in2\().16b, v10.16b
eor \in3\().16b, \in3\().16b, v11.16b
rev32 v8.8h, v8.8h
rev32 v9.8h, v9.8h
rev32 v10.8h, v10.8h
rev32 v11.8h, v11.8h
eor \in0\().16b, \in0\().16b, v8.16b
eor \in1\().16b, \in1\().16b, v9.16b
eor \in2\().16b, \in2\().16b, v10.16b
eor \in3\().16b, \in3\().16b, v11.16b
mix_columns_2x \in0, \in1
mix_columns_2x \in2, \in3
.endm
.macro do_block_2x, enc, in0, in1 rounds, rk, rkp, i
.macro do_block_2x, enc, in0, in1, rounds, rk, rkp, i
ld1 {v15.4s}, [\rk]
add \rkp, \rk, #16
mov \i, \rounds
1111: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */
eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
sub_bytes_2x \in0, \in1
movi v15.16b, #0x40
tbl \in0\().16b, {\in0\().16b}, v13.16b /* ShiftRows */
tbl \in1\().16b, {\in1\().16b}, v13.16b /* ShiftRows */
ld1 {v15.4s}, [\rkp], #16
sub_bytes_2x \in0, \in1
subs \i, \i, #1
ld1 {v15.4s}, [\rkp], #16
beq 2222f
.if \enc == 1
mix_columns_2x \in0, \in1
ldr q13, .LForward_ShiftRows
.else
inv_mix_cols_2x \in0, \in1
ldr q13, .LReverse_ShiftRows
.endif
movi v12.16b, #0x40
mix_columns_2x \in0, \in1, \enc
b 1111b
2222: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */
eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
@ -262,23 +236,17 @@
eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
eor \in2\().16b, \in2\().16b, v15.16b /* ^round key */
eor \in3\().16b, \in3\().16b, v15.16b /* ^round key */
sub_bytes_4x \in0, \in1, \in2, \in3
movi v15.16b, #0x40
tbl \in0\().16b, {\in0\().16b}, v13.16b /* ShiftRows */
tbl \in1\().16b, {\in1\().16b}, v13.16b /* ShiftRows */
tbl \in2\().16b, {\in2\().16b}, v13.16b /* ShiftRows */
tbl \in3\().16b, {\in3\().16b}, v13.16b /* ShiftRows */
ld1 {v15.4s}, [\rkp], #16
sub_bytes_4x \in0, \in1, \in2, \in3
subs \i, \i, #1
ld1 {v15.4s}, [\rkp], #16
beq 2222f
.if \enc == 1
mix_columns_2x \in0, \in1
mix_columns_2x \in2, \in3
ldr q13, .LForward_ShiftRows
.else
inv_mix_cols_4x \in0, \in1, \in2, \in3
ldr q13, .LReverse_ShiftRows
.endif
movi v12.16b, #0x40
mix_columns_2x \in0, \in1, \enc
mix_columns_2x \in2, \in3, \enc
b 1111b
2222: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */
eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
@ -305,19 +273,7 @@
#include "aes-modes.S"
.text
.align 4
.LForward_ShiftRows:
CPU_LE( .byte 0x0, 0x5, 0xa, 0xf, 0x4, 0x9, 0xe, 0x3 )
CPU_LE( .byte 0x8, 0xd, 0x2, 0x7, 0xc, 0x1, 0x6, 0xb )
CPU_BE( .byte 0xb, 0x6, 0x1, 0xc, 0x7, 0x2, 0xd, 0x8 )
CPU_BE( .byte 0x3, 0xe, 0x9, 0x4, 0xf, 0xa, 0x5, 0x0 )
.LReverse_ShiftRows:
CPU_LE( .byte 0x0, 0xd, 0xa, 0x7, 0x4, 0x1, 0xe, 0xb )
CPU_LE( .byte 0x8, 0x5, 0x2, 0xf, 0xc, 0x9, 0x6, 0x3 )
CPU_BE( .byte 0x3, 0x6, 0x9, 0xc, 0xf, 0x2, 0x5, 0x8 )
CPU_BE( .byte 0xb, 0xe, 0x1, 0x4, 0x7, 0xa, 0xd, 0x0 )
.align 6
.LForward_Sbox:
.byte 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5
.byte 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76
@ -385,3 +341,12 @@ CPU_BE( .byte 0xb, 0xe, 0x1, 0x4, 0x7, 0xa, 0xd, 0x0 )
.byte 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61
.byte 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26
.byte 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
.LForward_ShiftRows:
.octa 0x0b06010c07020d08030e09040f0a0500
.LReverse_ShiftRows:
.octa 0x0306090c0f0205080b0e0104070a0d00
.Lror32by8:
.octa 0x0c0f0e0d080b0a090407060500030201