[RFC v2 PATCH 1/4] ARM: add support for kernel mode NEON in atomic context

[Nicolas Pitre]

On Wed, 9 Oct 2013, Ard Biesheuvel wrote:

> On 9 October 2013 21:24, Nicolas Pitre <nicolas.pitre at linaro.org> wrote:
> > On Wed, 9 Oct 2013, Ard Biesheuvel wrote:
> >
> >> +static inline void __kernel_neon_begin_atomic(struct vfp_partial_state *regs)
> >> +{
> >> +     if (!in_interrupt())
> >> +             kernel_neon_begin();
> >
> > Surely you want "if (!in_atomic())" here?
> >
> >> +     else
> >> +             vfp_save_partial_state(regs);
> >> +}
> >> +
> >> +static inline void __kernel_neon_end_atomic(struct vfp_partial_state *regs)
> >> +{
> >> +     if (!in_interrupt())
> >> +             kernel_neon_end();
> >
> > Ditto.
> >
> 
> If I am reading (and understanding) the source correctly, in_atomic()
> is also true when running with preemption disabled, and in that case,
> you should be able to just do a normal preserve / lazy restore.

Hmmm...  OK I agree.


Nicolas