linux/arch/arm64/crypto/aes-ce.S
Ard Biesheuvel 2e5d2f33d1 crypto: arm64/aes-blk - improve XTS mask handling
The Crypto Extension instantiation of the aes-modes.S collection of
skciphers uses only 15 NEON registers for the round key array, whereas
the pure NEON flavor uses 16 NEON registers for the AES S-box.

This means we have a spare register available that we can use to hold
the XTS mask vector, removing the need to reload it at every iteration
of the inner loop.

Since the pure NEON version does not permit this optimization, tweak
the macros so we can factor out this functionality. Also, replace the
literal load with a short sequence to compose the mask vector.

On Cortex-A53, this results in a ~4% speedup.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-21 13:24:50 +08:00

139 lines
3.4 KiB
ArmAsm

/*
* linux/arch/arm64/crypto/aes-ce.S - AES cipher for ARMv8 with
* Crypto Extensions
*
* 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
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#define AES_ENTRY(func) ENTRY(ce_ ## func)
#define AES_ENDPROC(func) ENDPROC(ce_ ## func)
.arch armv8-a+crypto
xtsmask .req v16
.macro xts_reload_mask, tmp
.endm
/* preload all round keys */
.macro load_round_keys, rounds, rk
cmp \rounds, #12
blo 2222f /* 128 bits */
beq 1111f /* 192 bits */
ld1 {v17.4s-v18.4s}, [\rk], #32
1111: ld1 {v19.4s-v20.4s}, [\rk], #32
2222: ld1 {v21.4s-v24.4s}, [\rk], #64
ld1 {v25.4s-v28.4s}, [\rk], #64
ld1 {v29.4s-v31.4s}, [\rk]
.endm
/* prepare for encryption with key in rk[] */
.macro enc_prepare, rounds, rk, temp
mov \temp, \rk
load_round_keys \rounds, \temp
.endm
/* prepare for encryption (again) but with new key in rk[] */
.macro enc_switch_key, rounds, rk, temp
mov \temp, \rk
load_round_keys \rounds, \temp
.endm
/* prepare for decryption with key in rk[] */
.macro dec_prepare, rounds, rk, temp
mov \temp, \rk
load_round_keys \rounds, \temp
.endm
.macro do_enc_Nx, de, mc, k, i0, i1, i2, i3
aes\de \i0\().16b, \k\().16b
aes\mc \i0\().16b, \i0\().16b
.ifnb \i1
aes\de \i1\().16b, \k\().16b
aes\mc \i1\().16b, \i1\().16b
.ifnb \i3
aes\de \i2\().16b, \k\().16b
aes\mc \i2\().16b, \i2\().16b
aes\de \i3\().16b, \k\().16b
aes\mc \i3\().16b, \i3\().16b
.endif
.endif
.endm
/* up to 4 interleaved encryption rounds with the same round key */
.macro round_Nx, enc, k, i0, i1, i2, i3
.ifc \enc, e
do_enc_Nx e, mc, \k, \i0, \i1, \i2, \i3
.else
do_enc_Nx d, imc, \k, \i0, \i1, \i2, \i3
.endif
.endm
/* up to 4 interleaved final rounds */
.macro fin_round_Nx, de, k, k2, i0, i1, i2, i3
aes\de \i0\().16b, \k\().16b
.ifnb \i1
aes\de \i1\().16b, \k\().16b
.ifnb \i3
aes\de \i2\().16b, \k\().16b
aes\de \i3\().16b, \k\().16b
.endif
.endif
eor \i0\().16b, \i0\().16b, \k2\().16b
.ifnb \i1
eor \i1\().16b, \i1\().16b, \k2\().16b
.ifnb \i3
eor \i2\().16b, \i2\().16b, \k2\().16b
eor \i3\().16b, \i3\().16b, \k2\().16b
.endif
.endif
.endm
/* up to 4 interleaved blocks */
.macro do_block_Nx, enc, rounds, i0, i1, i2, i3
cmp \rounds, #12
blo 2222f /* 128 bits */
beq 1111f /* 192 bits */
round_Nx \enc, v17, \i0, \i1, \i2, \i3
round_Nx \enc, v18, \i0, \i1, \i2, \i3
1111: round_Nx \enc, v19, \i0, \i1, \i2, \i3
round_Nx \enc, v20, \i0, \i1, \i2, \i3
2222: .irp key, v21, v22, v23, v24, v25, v26, v27, v28, v29
round_Nx \enc, \key, \i0, \i1, \i2, \i3
.endr
fin_round_Nx \enc, v30, v31, \i0, \i1, \i2, \i3
.endm
.macro encrypt_block, in, rounds, t0, t1, t2
do_block_Nx e, \rounds, \in
.endm
.macro encrypt_block2x, i0, i1, rounds, t0, t1, t2
do_block_Nx e, \rounds, \i0, \i1
.endm
.macro encrypt_block4x, i0, i1, i2, i3, rounds, t0, t1, t2
do_block_Nx e, \rounds, \i0, \i1, \i2, \i3
.endm
.macro decrypt_block, in, rounds, t0, t1, t2
do_block_Nx d, \rounds, \in
.endm
.macro decrypt_block2x, i0, i1, rounds, t0, t1, t2
do_block_Nx d, \rounds, \i0, \i1
.endm
.macro decrypt_block4x, i0, i1, i2, i3, rounds, t0, t1, t2
do_block_Nx d, \rounds, \i0, \i1, \i2, \i3
.endm
#include "aes-modes.S"