Move the loongarch CRC32 assembly code into the lib directory and wire
it up to the library interface.  This allows it to be used without going
through the crypto API.  It remains usable via the crypto API too via
the shash algorithms that use the library interface.  Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/loongarch/crypto/crc32-loongarch.c to
arch/loongarch/lib/crc32-loongarch.c, view this commit with
'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/20241202010844.144356-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

The LoongArch CRC32 hw acceleration is based on arch/mips/crypto/
crc32-mips.c. While the MIPS code supports both MIPS32 and MIPS64,
but LoongArch32 lacks the CRC instruction. As a result, the line
"len -= sizeof(u32)" is unnecessary.

Removing it can make context code style more unified and improve
code readability.

Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Suggested-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

This unnecessary explicit setting of cra_alignmask to 0 shows up when
grepping for shash algorithms that set an alignmask.  Remove it.  No
change in behavior.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

With a blatant copy of some MIPS bits we introduce the crc32 and crc32c
hw accelerated module to LoongArch.

LoongArch has provided these instructions to calculate crc32 and crc32c:
        * crc.w.b.w    crcc.w.b.w
        * crc.w.h.w    crcc.w.h.w
        * crc.w.w.w    crcc.w.w.w
        * crc.w.d.w    crcc.w.d.w

So we can make use of these instructions to improve the performance of
calculation for crc32(c) checksums.

As can be seen from the following test results, crc32(c) instructions
can improve the performance by 58%.

                  Software implemention    Hardware acceleration
  Buffer size     time cost (seconds)      time cost (seconds)    Accel.
   100 KB                0.000845                 0.000534        59.1%
     1 MB                0.007758                 0.004836        59.4%
    10 MB                0.076593                 0.047682        59.4%
   100 MB                0.756734                 0.479126        58.5%
  1000 MB                7.563841                 4.778266        58.5%

Signed-off-by: Min Zhou <zhoumin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>