This is a straight port to arm64/NEON of the x86 SSE3 implementation
of the ChaCha20 stream cipher. It uses the new skcipher walksize
attribute to process the input in strides of 4x the block size.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>