Hello,
This series optimizes the Adiantum encryption mode for ARM64 by adding
an ARM64 NEON accelerated implementation of NHPoly1305, specifically the
NH part; and by modifying the existing ARM64 NEON implementation of
ChaCha20 to support XChaCha20 and XChaCha12.
This greatly improves Adiantum performance on ARM64. For example,
encrypting 4096-byte messages (single-threaded) on a Raspberry Pi 3
Model B v1.2, which has a Cortex-A53 processor:
Before After
--------- ---------
adiantum(xchacha12,aes) 44.1 MB/s 82.7 MB/s
adiantum(xchacha20,aes) 35.5 MB/s 65.7 MB/s
Decryption is almost exactly the same speed as encryption.
The biggest benefit comes from accelerating XChaCha. Accelerating NH
gives a somewhat smaller, but still significant benefit.
Performance on 512-byte inputs is also improved, though that is much
slower in the first place. When Adiantium is used with dm-crypt (or
cryptsetup), we recommend using a 4096-byte sector size.
For comparison, on the same hardware AES-256-XTS encryption is only
24.5 MB/s and decryption 21.6 MB/s, both using the NEON-bitsliced
implementation ("xts-aes-neonbs"). That is the fastest AES-256-XTS
implementation on this processor, since it doesn't have the ARMv8
Cryptography Extensions. This is despite Adiantum also being a super-
pseudorandom permutation (SPRP) over the entire sector, unlike XTS.
Note that XChaCha20 and XChaCha12 can be used for other purposes too.
Changed since v1:
- Create full stack frame in hchacha_block_neon() and
chacha_block_xor_neon().
- Use x30 instead of lr.
- Fix whitespace in nh-neon-core.S.
Eric Biggers (4):
crypto: arm64/nhpoly1305 - add NEON-accelerated NHPoly1305
crypto: arm64/chacha20 - add XChaCha20 support
crypto: arm64/chacha20 - refactor to allow varying number of rounds
crypto: arm64/chacha - add XChaCha12 support
arch/arm64/crypto/Kconfig | 7 +-
arch/arm64/crypto/Makefile | 7 +-
...hacha20-neon-core.S => chacha-neon-core.S} | 92 +++++---
arch/arm64/crypto/chacha-neon-glue.c | 207 ++++++++++++++++++
arch/arm64/crypto/chacha20-neon-glue.c | 133 -----------
arch/arm64/crypto/nh-neon-core.S | 103 +++++++++
arch/arm64/crypto/nhpoly1305-neon-glue.c | 77 +++++++
7 files changed, 461 insertions(+), 165 deletions(-)
rename arch/arm64/crypto/{chacha20-neon-core.S => chacha-neon-core.S} (90%)
create mode 100644 arch/arm64/crypto/chacha-neon-glue.c
delete mode 100644 arch/arm64/crypto/chacha20-neon-glue.c
create mode 100644 arch/arm64/crypto/nh-neon-core.S
create mode 100644 arch/arm64/crypto/nhpoly1305-neon-glue.c
--
2.19.2
