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Ard Biesheuvel
2fffee536c
The arm64 implementation of the CRC-T10DIF algorithm uses the 64x64 bit polynomial multiplication instructions, which are optional in the architecture, and if these instructions are not available, we fall back to the C routine which is slow and inefficient. So let's reuse the 64x64 bit PMULL alternative from the GHASH driver that uses a sequence of ~40 instructions involving 8x8 bit PMULL and some shifting and masking. This is a lot slower than the original, but it is still twice as fast as the current [unoptimized] C code on Cortex-A53, and it is time invariant and much easier on the D-cache. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.