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Commit 521cdde7 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
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crypto: aegis - avoid prerotated AES tables


The generic AES code provides four sets of lookup tables, where each
set consists of four tables containing the same 32-bit values, but
rotated by 0, 8, 16 and 24 bits, respectively. This makes sense for
CISC architectures such as x86 which support memory operands, but
for other architectures, the rotates are quite cheap, and using all
four tables needlessly thrashes the D-cache, and actually hurts rather
than helps performance.

Since x86 already has its own implementation of AEGIS based on AES-NI
instructions, let's tweak the generic implementation towards other
architectures, and avoid the prerotated tables, and perform the
rotations inline. On ARM Cortex-A53, this results in a ~8% speedup.

Acked-by: default avatarOndrej Mosnacek <omosnace@redhat.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 368b1bdc
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