crypto: arm64/sm4-ccm - Rewrite skcipher walker loop

The fact that an error in the skcipher walker API are indicated
not only by a non-zero return value, but also by the fact that
walk->nbytes is zero, causes the layout of the skcipher walker
loop to be sufficiently different from the usual layout, which
is not a problem in itself, but it is likely to cause reading
confusion and difficulty in code maintenance.

This patch rewrites skcipher walker loop, and separates the
last chunk cryption from the loop to avoid wrong calls to the
skcipher walker API. In addition to following the usual convention
of checking walk->nbytes, it also makes the loop execute logic
clearer and easier to understand.

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

crypto: arm64/sm4 - add CE implementation for CCM mode

This patch is a CE-optimized assembly implementation for CCM mode.

Benchmark on T-Head Yitian-710 2.75 GHz, the data comes from the 223 and 225
modes of tcrypt, and compared the performance before and after this patch (the
driver used before this patch is ccm_base(ctr-sm4-ce,cbcmac-sm4-ce)).
The abscissas are blocks of different lengths. The data is tabulated and the
unit is Mb/s:

Before (rfc4309(ccm_base(ctr-sm4-ce,cbcmac-sm4-ce))):

ccm(sm4) | 16 64 256 512 1024 1420 4096 8192
-------------+---------------------------------------------------------------
CCM enc | 35.07 125.40 336.47 468.17 581.97 619.18 712.56 736.01
CCM dec | 34.87 124.40 335.08 466.75 581.04 618.81 712.25 735.89
CCM mb enc | 34.71 123.96 333.92 465.39 579.91 617.49 711.45 734.92
CCM mb dec | 34.42 122.80 331.02 462.81 578.28 616.42 709.88 734.19

After (rfc4309(ccm-sm4-ce)):

ccm-sm4-ce | 16 64 256 512 1024 1420 4096 8192
-------------+---------------------------------------------------------------
CCM enc | 77.12 249.82 569.94 725.17 839.27 867.71 952.87 969.89
CCM dec | 75.90 247.26 566.29 722.12 836.90 865.95 951.74 968.57
CCM mb enc | 75.98 245.25 562.91 718.99 834.76 864.70 950.17 967.90
CCM mb dec | 75.06 243.78 560.58 717.13 833.68 862.70 949.35 967.11

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