The CRC-T10DIF algorithm produces a 16-bit CRC, and this is reflected in
the folding coefficients, which are also only 16 bits wide.
This means that the polynomial multiplications involving these
coefficients can be performed using 8-bit long polynomial multiplication
(8x8 -> 16) in only a few steps, and this is an instruction that is part
of the base NEON ISA, which is all most real ARMv7 cores implement. (The
64-bit PMULL instruction is part of the crypto extensions, which are
only implemented by 64-bit cores)
The final reduction is a bit more involved, but we can delegate that to
the generic CRC-T10DIF implementation after folding the entire input
into a 16 byte vector.
This results in a speedup of around 6.6x on Cortex-A72 running in 32-bit
mode. On Cortex-A8 (BeagleBone White), the results are substantially
better than that, but not sufficiently reproducible (with tcrypt) to
quote a number here.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To allow an alternative version to be created of the PMULL based
CRC-T10DIF algorithm, turn the bulk of it into a macro, except for the
final reduction, which will only be used by the existing version.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
With ARCH=arm, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/arm/crypto/aes-arm-bs.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/arm/crypto/crc32-arm-ce.o
Add the missing invocation of the MODULE_DESCRIPTION() macro to all
files which have a MODULE_LICENSE().
This includes crct10dif-ce-glue.c and curve25519-glue.c which,
although they did not produce a warning with the arm allmodconfig
configuration, may cause this warning with other configurations.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace all calls to may_use_simd() in the arm crypto code with
crypto_simd_usable(), in order to allow testing the no-SIMD code paths.
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 x86, arm, and arm64 asm implementations of crct10dif are very
difficult to understand partly because many of the comments, labels, and
macros are named incorrectly: the lengths mentioned are usually off by a
factor of two from the actual code. Many other things are unnecessarily
convoluted as well, e.g. there are many more fold constants than
actually needed and some aren't fully reduced.
This series therefore cleans up all these implementations to be much
more maintainable. I also made some small optimizations where I saw
opportunities, resulting in slightly better performance.
This patch cleans up the arm version.
(Also moved the constants to .rodata as suggested by Ard Biesheuvel.)
Acked-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>
The SIMD routine ported from x86 used to have a special code path
for inputs < 16 bytes, which got lost somewhere along the way.
Instead, the current glue code aligns the input pointer to permit
the NEON routine to use special versions of the vld1 instructions
that assume 16 byte alignment, but this could result in inputs of
less than 16 bytes to be passed in. This not only fails the new
extended tests that Eric has implemented, it also results in the
code reading past the end of the input, which could potentially
result in crashes when dealing with less than 16 bytes of input
at the end of a page which is followed by an unmapped page.
So update the glue code to only invoke the NEON routine if the
input is at least 16 bytes.
Reported-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Fixes: 1d481f1cd8 ("crypto: arm/crct10dif - port x86 SSE implementation to ARM")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This is a transliteration of the Intel algorithm implemented
using SSE and PCLMULQDQ instructions that resides in the file
arch/x86/crypto/crct10dif-pcl-asm_64.S, but simplified to only
operate on buffers that are 16 byte aligned (but of any size)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
