linux/arch/arm64/crypto/speck-neon-core.S
Eric Biggers 91a2abb78f crypto: arm64/speck - add NEON-accelerated implementation of Speck-XTS
Add a NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
for ARM64.  This is ported from the 32-bit version.  It may be useful on
devices with 64-bit ARM CPUs that don't have the Cryptography
Extensions, so cannot do AES efficiently -- e.g. the Cortex-A53
processor on the Raspberry Pi 3.

It generally works the same way as the 32-bit version, but there are
some slight differences due to the different instructions, registers,
and syntax available in ARM64 vs. in ARM32.  For example, in the 64-bit
version there are enough registers to hold the XTS tweaks for each
128-byte chunk, so they don't need to be saved on the stack.

Benchmarks on a Raspberry Pi 3 running a 64-bit kernel:

   Algorithm                              Encryption     Decryption
   ---------                              ----------     ----------
   Speck64/128-XTS (NEON)                 92.2 MB/s      92.2 MB/s
   Speck128/256-XTS (NEON)                75.0 MB/s      75.0 MB/s
   Speck128/256-XTS (generic)             47.4 MB/s      35.6 MB/s
   AES-128-XTS (NEON bit-sliced)          33.4 MB/s      29.6 MB/s
   AES-256-XTS (NEON bit-sliced)          24.6 MB/s      21.7 MB/s

The code performs well on higher-end ARM64 processors as well, though
such processors tend to have the Crypto Extensions which make AES
preferred.  For example, here are the same benchmarks run on a HiKey960
(with CPU affinity set for the A73 cores), with the Crypto Extensions
implementation of AES-256-XTS added:

   Algorithm                              Encryption     Decryption
   ---------                              -----------    -----------
   AES-256-XTS (Crypto Extensions)        1273.3 MB/s    1274.7 MB/s
   Speck64/128-XTS (NEON)                  359.8 MB/s     348.0 MB/s
   Speck128/256-XTS (NEON)                 292.5 MB/s     286.1 MB/s
   Speck128/256-XTS (generic)              186.3 MB/s     181.8 MB/s
   AES-128-XTS (NEON bit-sliced)           142.0 MB/s     124.3 MB/s
   AES-256-XTS (NEON bit-sliced)           104.7 MB/s      91.1 MB/s

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-16 23:35:41 +08:00

353 lines
9.9 KiB
ArmAsm

// SPDX-License-Identifier: GPL-2.0
/*
* ARM64 NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
*
* Copyright (c) 2018 Google, Inc
*
* Author: Eric Biggers <ebiggers@google.com>
*/
#include <linux/linkage.h>
.text
// arguments
ROUND_KEYS .req x0 // const {u64,u32} *round_keys
NROUNDS .req w1 // int nrounds
NROUNDS_X .req x1
DST .req x2 // void *dst
SRC .req x3 // const void *src
NBYTES .req w4 // unsigned int nbytes
TWEAK .req x5 // void *tweak
// registers which hold the data being encrypted/decrypted
// (underscores avoid a naming collision with ARM64 registers x0-x3)
X_0 .req v0
Y_0 .req v1
X_1 .req v2
Y_1 .req v3
X_2 .req v4
Y_2 .req v5
X_3 .req v6
Y_3 .req v7
// the round key, duplicated in all lanes
ROUND_KEY .req v8
// index vector for tbl-based 8-bit rotates
ROTATE_TABLE .req v9
ROTATE_TABLE_Q .req q9
// temporary registers
TMP0 .req v10
TMP1 .req v11
TMP2 .req v12
TMP3 .req v13
// multiplication table for updating XTS tweaks
GFMUL_TABLE .req v14
GFMUL_TABLE_Q .req q14
// next XTS tweak value(s)
TWEAKV_NEXT .req v15
// XTS tweaks for the blocks currently being encrypted/decrypted
TWEAKV0 .req v16
TWEAKV1 .req v17
TWEAKV2 .req v18
TWEAKV3 .req v19
TWEAKV4 .req v20
TWEAKV5 .req v21
TWEAKV6 .req v22
TWEAKV7 .req v23
.align 4
.Lror64_8_table:
.octa 0x080f0e0d0c0b0a090007060504030201
.Lror32_8_table:
.octa 0x0c0f0e0d080b0a090407060500030201
.Lrol64_8_table:
.octa 0x0e0d0c0b0a09080f0605040302010007
.Lrol32_8_table:
.octa 0x0e0d0c0f0a09080b0605040702010003
.Lgf128mul_table:
.octa 0x00000000000000870000000000000001
.Lgf64mul_table:
.octa 0x0000000000000000000000002d361b00
/*
* _speck_round_128bytes() - Speck encryption round on 128 bytes at a time
*
* Do one Speck encryption round on the 128 bytes (8 blocks for Speck128, 16 for
* Speck64) stored in X0-X3 and Y0-Y3, using the round key stored in all lanes
* of ROUND_KEY. 'n' is the lane size: 64 for Speck128, or 32 for Speck64.
* 'lanes' is the lane specifier: "2d" for Speck128 or "4s" for Speck64.
*/
.macro _speck_round_128bytes n, lanes
// x = ror(x, 8)
tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b
tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b
tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b
tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b
// x += y
add X_0.\lanes, X_0.\lanes, Y_0.\lanes
add X_1.\lanes, X_1.\lanes, Y_1.\lanes
add X_2.\lanes, X_2.\lanes, Y_2.\lanes
add X_3.\lanes, X_3.\lanes, Y_3.\lanes
// x ^= k
eor X_0.16b, X_0.16b, ROUND_KEY.16b
eor X_1.16b, X_1.16b, ROUND_KEY.16b
eor X_2.16b, X_2.16b, ROUND_KEY.16b
eor X_3.16b, X_3.16b, ROUND_KEY.16b
// y = rol(y, 3)
shl TMP0.\lanes, Y_0.\lanes, #3
shl TMP1.\lanes, Y_1.\lanes, #3
shl TMP2.\lanes, Y_2.\lanes, #3
shl TMP3.\lanes, Y_3.\lanes, #3
sri TMP0.\lanes, Y_0.\lanes, #(\n - 3)
sri TMP1.\lanes, Y_1.\lanes, #(\n - 3)
sri TMP2.\lanes, Y_2.\lanes, #(\n - 3)
sri TMP3.\lanes, Y_3.\lanes, #(\n - 3)
// y ^= x
eor Y_0.16b, TMP0.16b, X_0.16b
eor Y_1.16b, TMP1.16b, X_1.16b
eor Y_2.16b, TMP2.16b, X_2.16b
eor Y_3.16b, TMP3.16b, X_3.16b
.endm
/*
* _speck_unround_128bytes() - Speck decryption round on 128 bytes at a time
*
* This is the inverse of _speck_round_128bytes().
*/
.macro _speck_unround_128bytes n, lanes
// y ^= x
eor TMP0.16b, Y_0.16b, X_0.16b
eor TMP1.16b, Y_1.16b, X_1.16b
eor TMP2.16b, Y_2.16b, X_2.16b
eor TMP3.16b, Y_3.16b, X_3.16b
// y = ror(y, 3)
ushr Y_0.\lanes, TMP0.\lanes, #3
ushr Y_1.\lanes, TMP1.\lanes, #3
ushr Y_2.\lanes, TMP2.\lanes, #3
ushr Y_3.\lanes, TMP3.\lanes, #3
sli Y_0.\lanes, TMP0.\lanes, #(\n - 3)
sli Y_1.\lanes, TMP1.\lanes, #(\n - 3)
sli Y_2.\lanes, TMP2.\lanes, #(\n - 3)
sli Y_3.\lanes, TMP3.\lanes, #(\n - 3)
// x ^= k
eor X_0.16b, X_0.16b, ROUND_KEY.16b
eor X_1.16b, X_1.16b, ROUND_KEY.16b
eor X_2.16b, X_2.16b, ROUND_KEY.16b
eor X_3.16b, X_3.16b, ROUND_KEY.16b
// x -= y
sub X_0.\lanes, X_0.\lanes, Y_0.\lanes
sub X_1.\lanes, X_1.\lanes, Y_1.\lanes
sub X_2.\lanes, X_2.\lanes, Y_2.\lanes
sub X_3.\lanes, X_3.\lanes, Y_3.\lanes
// x = rol(x, 8)
tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b
tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b
tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b
tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b
.endm
.macro _next_xts_tweak next, cur, tmp, n
.if \n == 64
/*
* Calculate the next tweak by multiplying the current one by x,
* modulo p(x) = x^128 + x^7 + x^2 + x + 1.
*/
sshr \tmp\().2d, \cur\().2d, #63
and \tmp\().16b, \tmp\().16b, GFMUL_TABLE.16b
shl \next\().2d, \cur\().2d, #1
ext \tmp\().16b, \tmp\().16b, \tmp\().16b, #8
eor \next\().16b, \next\().16b, \tmp\().16b
.else
/*
* Calculate the next two tweaks by multiplying the current ones by x^2,
* modulo p(x) = x^64 + x^4 + x^3 + x + 1.
*/
ushr \tmp\().2d, \cur\().2d, #62
shl \next\().2d, \cur\().2d, #2
tbl \tmp\().16b, {GFMUL_TABLE.16b}, \tmp\().16b
eor \next\().16b, \next\().16b, \tmp\().16b
.endif
.endm
/*
* _speck_xts_crypt() - Speck-XTS encryption/decryption
*
* Encrypt or decrypt NBYTES bytes of data from the SRC buffer to the DST buffer
* using Speck-XTS, specifically the variant with a block size of '2n' and round
* count given by NROUNDS. The expanded round keys are given in ROUND_KEYS, and
* the current XTS tweak value is given in TWEAK. It's assumed that NBYTES is a
* nonzero multiple of 128.
*/
.macro _speck_xts_crypt n, lanes, decrypting
/*
* If decrypting, modify the ROUND_KEYS parameter to point to the last
* round key rather than the first, since for decryption the round keys
* are used in reverse order.
*/
.if \decrypting
mov NROUNDS, NROUNDS /* zero the high 32 bits */
.if \n == 64
add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #3
sub ROUND_KEYS, ROUND_KEYS, #8
.else
add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #2
sub ROUND_KEYS, ROUND_KEYS, #4
.endif
.endif
// Load the index vector for tbl-based 8-bit rotates
.if \decrypting
ldr ROTATE_TABLE_Q, .Lrol\n\()_8_table
.else
ldr ROTATE_TABLE_Q, .Lror\n\()_8_table
.endif
// One-time XTS preparation
.if \n == 64
// Load first tweak
ld1 {TWEAKV0.16b}, [TWEAK]
// Load GF(2^128) multiplication table
ldr GFMUL_TABLE_Q, .Lgf128mul_table
.else
// Load first tweak
ld1 {TWEAKV0.8b}, [TWEAK]
// Load GF(2^64) multiplication table
ldr GFMUL_TABLE_Q, .Lgf64mul_table
// Calculate second tweak, packing it together with the first
ushr TMP0.2d, TWEAKV0.2d, #63
shl TMP1.2d, TWEAKV0.2d, #1
tbl TMP0.8b, {GFMUL_TABLE.16b}, TMP0.8b
eor TMP0.8b, TMP0.8b, TMP1.8b
mov TWEAKV0.d[1], TMP0.d[0]
.endif
.Lnext_128bytes_\@:
// Calculate XTS tweaks for next 128 bytes
_next_xts_tweak TWEAKV1, TWEAKV0, TMP0, \n
_next_xts_tweak TWEAKV2, TWEAKV1, TMP0, \n
_next_xts_tweak TWEAKV3, TWEAKV2, TMP0, \n
_next_xts_tweak TWEAKV4, TWEAKV3, TMP0, \n
_next_xts_tweak TWEAKV5, TWEAKV4, TMP0, \n
_next_xts_tweak TWEAKV6, TWEAKV5, TMP0, \n
_next_xts_tweak TWEAKV7, TWEAKV6, TMP0, \n
_next_xts_tweak TWEAKV_NEXT, TWEAKV7, TMP0, \n
// Load the next source blocks into {X,Y}[0-3]
ld1 {X_0.16b-Y_1.16b}, [SRC], #64
ld1 {X_2.16b-Y_3.16b}, [SRC], #64
// XOR the source blocks with their XTS tweaks
eor TMP0.16b, X_0.16b, TWEAKV0.16b
eor Y_0.16b, Y_0.16b, TWEAKV1.16b
eor TMP1.16b, X_1.16b, TWEAKV2.16b
eor Y_1.16b, Y_1.16b, TWEAKV3.16b
eor TMP2.16b, X_2.16b, TWEAKV4.16b
eor Y_2.16b, Y_2.16b, TWEAKV5.16b
eor TMP3.16b, X_3.16b, TWEAKV6.16b
eor Y_3.16b, Y_3.16b, TWEAKV7.16b
/*
* De-interleave the 'x' and 'y' elements of each block, i.e. make it so
* that the X[0-3] registers contain only the second halves of blocks,
* and the Y[0-3] registers contain only the first halves of blocks.
* (Speck uses the order (y, x) rather than the more intuitive (x, y).)
*/
uzp2 X_0.\lanes, TMP0.\lanes, Y_0.\lanes
uzp1 Y_0.\lanes, TMP0.\lanes, Y_0.\lanes
uzp2 X_1.\lanes, TMP1.\lanes, Y_1.\lanes
uzp1 Y_1.\lanes, TMP1.\lanes, Y_1.\lanes
uzp2 X_2.\lanes, TMP2.\lanes, Y_2.\lanes
uzp1 Y_2.\lanes, TMP2.\lanes, Y_2.\lanes
uzp2 X_3.\lanes, TMP3.\lanes, Y_3.\lanes
uzp1 Y_3.\lanes, TMP3.\lanes, Y_3.\lanes
// Do the cipher rounds
mov x6, ROUND_KEYS
mov w7, NROUNDS
.Lnext_round_\@:
.if \decrypting
ld1r {ROUND_KEY.\lanes}, [x6]
sub x6, x6, #( \n / 8 )
_speck_unround_128bytes \n, \lanes
.else
ld1r {ROUND_KEY.\lanes}, [x6], #( \n / 8 )
_speck_round_128bytes \n, \lanes
.endif
subs w7, w7, #1
bne .Lnext_round_\@
// Re-interleave the 'x' and 'y' elements of each block
zip1 TMP0.\lanes, Y_0.\lanes, X_0.\lanes
zip2 Y_0.\lanes, Y_0.\lanes, X_0.\lanes
zip1 TMP1.\lanes, Y_1.\lanes, X_1.\lanes
zip2 Y_1.\lanes, Y_1.\lanes, X_1.\lanes
zip1 TMP2.\lanes, Y_2.\lanes, X_2.\lanes
zip2 Y_2.\lanes, Y_2.\lanes, X_2.\lanes
zip1 TMP3.\lanes, Y_3.\lanes, X_3.\lanes
zip2 Y_3.\lanes, Y_3.\lanes, X_3.\lanes
// XOR the encrypted/decrypted blocks with the tweaks calculated earlier
eor X_0.16b, TMP0.16b, TWEAKV0.16b
eor Y_0.16b, Y_0.16b, TWEAKV1.16b
eor X_1.16b, TMP1.16b, TWEAKV2.16b
eor Y_1.16b, Y_1.16b, TWEAKV3.16b
eor X_2.16b, TMP2.16b, TWEAKV4.16b
eor Y_2.16b, Y_2.16b, TWEAKV5.16b
eor X_3.16b, TMP3.16b, TWEAKV6.16b
eor Y_3.16b, Y_3.16b, TWEAKV7.16b
mov TWEAKV0.16b, TWEAKV_NEXT.16b
// Store the ciphertext in the destination buffer
st1 {X_0.16b-Y_1.16b}, [DST], #64
st1 {X_2.16b-Y_3.16b}, [DST], #64
// Continue if there are more 128-byte chunks remaining
subs NBYTES, NBYTES, #128
bne .Lnext_128bytes_\@
// Store the next tweak and return
.if \n == 64
st1 {TWEAKV_NEXT.16b}, [TWEAK]
.else
st1 {TWEAKV_NEXT.8b}, [TWEAK]
.endif
ret
.endm
ENTRY(speck128_xts_encrypt_neon)
_speck_xts_crypt n=64, lanes=2d, decrypting=0
ENDPROC(speck128_xts_encrypt_neon)
ENTRY(speck128_xts_decrypt_neon)
_speck_xts_crypt n=64, lanes=2d, decrypting=1
ENDPROC(speck128_xts_decrypt_neon)
ENTRY(speck64_xts_encrypt_neon)
_speck_xts_crypt n=32, lanes=4s, decrypting=0
ENDPROC(speck64_xts_encrypt_neon)
ENTRY(speck64_xts_decrypt_neon)
_speck_xts_crypt n=32, lanes=4s, decrypting=1
ENDPROC(speck64_xts_decrypt_neon)