[PATCH 0/5] Simplify kernel-mode NEON

[Dave P Martin]

On Fri, Aug 04, 2017 at 01:25:03PM +0100, Ard Biesheuvel wrote:
> On 4 August 2017 at 13:22, Catalin Marinas <catalin.marinas at arm.com> wrote:
> > On Fri, Aug 04, 2017 at 01:08:58PM +0100, Catalin Marinas wrote:
> >> On Thu, Aug 03, 2017 at 05:23:18PM +0100, Dave P Martin wrote:
> >> > This series depends on Ard's v4.14 crypto rework [2].
> > [...]
> >> > [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-July/520664.html
> > [...]
> >> > Ard Biesheuvel (1):
> >> >   arm64: neon: replace generic definition of may_use_simd()
> >> >
> >> > Dave Martin (4):
> >> >   arm64: neon: Add missing header guard in <asm/neon.h>
> >> >   arm64: fpsimd: Consistently use __this_cpu_ ops where appropriate
> >> >   arm64: neon: Allow EFI runtime services to use FPSIMD in irq context
> >> >   arm64: neon: Remove support for nested or hardirq kernel-mode NEON
> >>
> >> Queued for 4.14. Thanks.
> >
> > ... and reverted.
> >
> > I now realised that it doesn't build without Ard's crypto series (I had
> > the wrong impression it is just a performance impact). I get errors
> > like:
> >
> > arch/arm64/crypto/sha1-ce-glue.c|41 col 2| error: implicit declaration
> > of function ‘kernel_neon_begin_partial’
> >
>
> Ah yes. Apologies for failing to mention that. Apparently, there are
> in fact build time cross-dependencies that I forgot about.

This was what I meant by "depends on", but I could have been clearer.
Apologies for that.

> To avoid delaying this unnecessarily, we just alias
> kernel_neon_begin_partial() to kernel_neon_begin() and ignore the
> argument. We can remove that again when everything has gone upstream.

We can do this to keep things buildable and mostly bootable.

Catalin, do you think that's a sufficient workaround, or do we need to
rethink this?

Do you need me to repost anything?

Cheers
---Dave
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