This changes the AES core transform implementations to issue aese/aesmc
(and aesd/aesimc) in pairs. This enables a micro-architectural optimization
in recent Cortex-A5x cores that improves performance by 50-90%.
Measured performance in cycles per byte (Cortex-A57):
CBC enc CBC dec CTR
before 3.64 1.34 1.32
after 1.95 0.85 0.93
Note that this results in a ~5% performance decrease for older cores.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This adds ARMv8 implementations of AES in ECB, CBC, CTR and XTS modes,
both for ARMv8 with Crypto Extensions and for plain ARMv8 NEON.
The Crypto Extensions version can only run on ARMv8 implementations that
have support for these optional extensions.
The plain NEON version is a table based yet time invariant implementation.
All S-box substitutions are performed in parallel, leveraging the wide range
of ARMv8's tbl/tbx instructions, and the huge NEON register file, which can
comfortably hold the entire S-box and still have room to spare for doing the
actual computations.
The key expansion routines were borrowed from aes_generic.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Ard Biesheuvel