[RFC v2 PATCH 1/1] ARM64: KGDB: Add FP/SIMD debug support

Will Deacon will.deacon at arm.com
Fri Feb 28 12:36:36 EST 2014


On Fri, Feb 28, 2014 at 11:08:58AM +0000, Vijay Kilari wrote:
> On Fri, Nov 29, 2013 at 3:27 PM, Vijay Kilari <vijay.kilari at gmail.com> wrote:
> >>> KGDB, being kernel debugger it was thought that allow
> >>> debugging only if kernel mode is supported.
> >>> In fact, I proposed (previous email)  to remove this condition and
> >>> allow to reading neon
> >>> registers always and allow write only if neon is in kernel mode.
> >>>
> >>
> >> I think KGDB is a special case here and should not considered as a
> >> user of kernel mode NEON. So even writing the registers should
> >> allowable regardless of this setting imo.
> >>
> 
>  Can we avoid checking on NEON state and allow debugger to
> access NEON registers irrespective of state to keep it simple?
> and just compile config is enough?

I'm afraid I don't follow... I think we *do* need to do the relevant
flush/sync operations, I just don't think it should be predicated on
KERNEL_MODE_NEON.

Will



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