Re: [PATCH net-next v5 06/20] zinc: ChaCha20 MIPS32r2 implementation

[Jason A. Donenfeld]

Hi Paul,

Thanks a bunch for the review.

On Tue, Sep 18, 2018 at 10:25 PM Paul Burton <paul.burton@xxxxxxxx> wrote:
> Should this be .set reorder?

Nice catch. Fixed here:
https://git.zx2c4.com/WireGuard/commit/?id=23d97fc333cf85dd07445a9d21a28cbef47c553c
But then...

> Even better - could we not just place the addiu before the bne & drop
> the .set noreorder, allowing the assembler to fill the delay slot with
> the addiu? Likewise in many other places throughout the patch.
>
> That would be more future proof - particularly if we ever want to adjust
> this for use with the nanoMIPS ISA which has no delay slots. It may also
> allow the assembler the choice to use compact branches (ie. branches
> without visible delay slots) when targeting MIPS32r6. I know neither of
> these will currently build this code, but I think avoiding all the
> noreorder blocks would be a nice cleanup just for the sake of
> readability anyway.

Great idea. Rene has committed that here:
https://git.zx2c4.com/WireGuard/commit/?id=5c153a59ac3aa58a3ff17c69fee63d599e5f2758

These will be in the v6 patchset whenever that's posted, and it's
already been merged into the dev tree:
https://git.kernel.org/pub/scm/linux/kernel/git/zx2c4/linux.git/log/?h=jd/wireguard

Regards,
Jason