crypto: arm64/sm4 - Remove cfb(sm4)

Remove the unused CFB implementation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: arm64/sm4 - refactor and simplify NEON implementation

This patch does not add new features. The main work is to refactor and
simplify the implementation of SM4 NEON, which is reflected in the
following aspects:

The accelerated implementation supports the arbitrary number of blocks,
not just multiples of 8, which simplifies the implementation and brings
some optimization acceleration for data that is not aligned by 8 blocks.

When loading the input data, use the ld4 instruction to replace the
original ld1 instruction as much as possible, which will save the cost
of matrix transposition of the input data.

Use 8-block parallelism whenever possible to speed up matrix transpose
and rotation operations, instead of up to 4-block parallelism.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: arm64/sm4 - add ARMv8 NEON implementation

This adds ARMv8 NEON implementations of SM4 in ECB, CBC, CFB and CTR
modes. This implementation uses the plain NEON instruction set, All
S-BOX substitutions uses the tbl/tbx instructions of ARMv8, combined
with the out-of-order execution in CPU, this optimization supports
encryption of up to 8 blocks at the same time.

The performance of encrypting one block is not as good as software
implementation, so the encryption operations of CBC and CFB still
use pure software algorithms.

Benchmark on T-Head Yitian-710 2.75 GHz, the data comes from the 218
mode of tcrypt. The abscissas are blocks of different lengths. The
data is tabulated and the unit is Mb/s:

sm4-generic | 16 64 128 256 1024 1420 4096
ECB enc | 80.05 91.42 93.66 94.77 95.69 95.77 95.86
ECB dec | 79.98 91.41 93.64 94.76 95.66 95.77 95.85
CBC enc | 78.55 86.50 88.02 88.77 89.36 89.42 89.48
CBC dec | 76.82 89.06 91.52 92.77 93.75 93.83 93.96
CFB enc | 77.64 86.13 87.62 88.42 89.08 88.83 89.18
CFB dec | 77.57 88.34 90.36 91.45 92.34 92.00 92.44
CTR enc | 77.80 88.28 90.23 91.22 92.11 91.81 92.25
CTR dec | 77.83 88.22 90.22 91.22 92.04 91.82 92.28
sm4-neon
ECB enc | 28.31 112.77 203.03 209.89 215.49 202.11 210.59
ECB dec | 28.36 113.45 203.23 210.00 215.52 202.13 210.65
CBC enc | 79.32 87.02 88.51 89.28 89.85 89.89 89.97
CBC dec | 28.29 112.20 203.30 209.82 214.99 201.51 209.95
CFB enc | 79.59 87.16 88.54 89.30 89.83 89.62 89.92
CFB dec | 28.12 111.05 202.47 209.02 214.21 210.90 209.12
CTR enc | 28.04 108.81 200.62 206.65 211.78 208.78 206.74
CTR dec | 28.02 108.82 200.45 206.62 211.78 208.74 206.70

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>