[PATCH v5] crypto: riscv/poly1305 - import OpenSSL/CRYPTOGAMS implementation

[Andy Polyakov]

> The file 'poly1305-riscv.pl' is taken straight from this upstream
> GitHub repository [0] at commit
> 5e3fba73576244708a752fa61a8e93e587f271bb.
> This patch was tested on SpacemiT X60, with 2~2.5x improvement
> over generic implementation.

Just in case. The fact that the improvement coefficient is higher than 
one quoted in the poly1305-riscv.pl should not come as a surprise. 
Baselines are simply different. The Linux baseline is 9 widening 
multiplications, while the one used for the assembly module in question 
is 4 widening multiplications plus 2 non-widening ones.

A clarification to my previous message where I mentioned that I've 
adjusted benchmark results for U74. It turned out to be some weird power 
management thing that affected the initial readings.

I've also mentioned vector implementation being developed. It's now 
committed. On a related note, ChaCha20 vector implementation is also 
optimized, though it needs a little bit more work...

Cheers.