Re: [PATCH] ARM: Add support for LPAE style CONTEXTIDR

[Will Deacon <will.deacon@arm.com>]

On Mon, Jun 24, 2013 at 04:15:06PM +0100, Christopher Covington wrote:
> On 06/24/2013 10:53 AM, Will Deacon wrote:
> > On Mon, Jun 24, 2013 at 03:39:09PM +0100, Christopher Covington wrote:
> >> Hi Will,
> >>
> >> On 06/24/2013 10:04 AM, Will Deacon wrote:
> >> [...]
> >>
> >>> What's the advantage of this approach, other than you get an extra byte's
> >>> worth of PID?
> >>
> >> In my view, the real advantage is that the the PID is located where people
> >> reading ARM Architecture Reference Manual are told they can find it.
> > 
> > Perhaps, but I'd usually expect a debugger or trace tools to do something
> > with the PID, and they likely expect it to be shifted, so you can't really
> > win.
> 
> But reading and implementing the architecture *is* winning! LOL. I'll file a
> ticket with the architecture folks and see what they think.

...aaand that came full circle :)

I think the conclusion is that Linux PID != CONTEXTIDR.PROCID, so there's no
architectural issue here. I'm just trying to keep it easy for the tools.

Will