On big endian arm64 kernels, the xchacha20-neon and xchacha12-neon
self-tests fail because hchacha_block_neon() outputs little endian words
but the C code expects native endianness. Fix it to output the words in
native endianness (which also makes it match the arm32 version).
Fixes: cc7cf991e9 ("crypto: arm64/chacha20 - add XChaCha20 support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The change to encrypt a fifth ChaCha block using scalar instructions
caused the chacha20-neon, xchacha20-neon, and xchacha12-neon self-tests
to start failing on big endian arm64 kernels. The bug is that the
keystream block produced in 32-bit scalar registers is directly XOR'd
with the data words, which are loaded and stored in native endianness.
Thus in big endian mode the data bytes end up XOR'd with the wrong
bytes. Fix it by byte-swapping the keystream words in big endian mode.
Fixes: 2fe55987b2 ("crypto: arm64/chacha - use combined SIMD/ALU routine for more speed")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To some degree, most known AArch64 micro-architectures appear to be
able to issue ALU instructions in parellel to SIMD instructions
without affecting the SIMD throughput. This means we can use the ALU
to process a fifth ChaCha block while the SIMD is processing four
blocks in parallel.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Update the 4-way NEON ChaCha routine so it can handle input of any
length >64 bytes in its entirety, rather than having to call into
the 1-way routine and/or memcpy()s via temp buffers to handle the
tail of a ChaCha invocation that is not a multiple of 256 bytes.
On inputs that are a multiple of 256 bytes (and thus in tcrypt
benchmarks), performance drops by around 1% on Cortex-A57, while
performance for inputs drawn randomly from the range [64, 1024)
increases by around 30%.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
In preparation for adding XChaCha12 support, rename/refactor the ARM64
NEON implementation of ChaCha20 to support different numbers of rounds.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Eric Biggers