Re: [PATCH v1 2/3] zinc: Introduce minimal cryptography library

From: Andy Lutomirski
Date: Tue Aug 07 2018 - 21:49:05 EST




> On Aug 7, 2018, at 4:48 PM, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
>
> Hey Andy,
>
>> On Tue, Aug 7, 2018 at 12:43 PM Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>> For "zinc: add simd helper", I think it should be in include/linux,
>> and include/linux/simd.h should (immediately or maybe in the future)
>> include <asm/simd.h> to pick up arch-specific stuff. And the patch
>> should get sent to linux-arch@xxxxxxxxxxxxxxxx
>
> I guess you saw my prompt about that in the previous commit message?
> Based on your encouragement, I implemented it:
> https://git.zx2c4.com/linux-dev/commit/?h=simd This is _far_ more
> invasive than I wanted to be, as I don't want this patch submission to
> grow unwieldy and never be merged, but I guess we can roll with this
> for now...
>

I really wish we had a way to see that we use asm-genericâs copy of a header in all cases except where an arch opts out.

>> In your blake2s_arch() implementation, you're not passing in a
>> simd_context_t. Is that still a work in progress? I thought the plan
>> was to pass it in rather than doing the check in the _arch()
>> functions.
>
> I'm inclined to do the explicit context passing only when a function
> is likely to be used in that kind of environment, and adjust as
> needed. Long term, anyway, that API will be removed once the x86 guys
> figure out lazy FPU restoration and the amortization doesn't add
> anything.

Fair enough.

>
> Jason