Subject: Re: [PATCH] do firmware feature fixups after features are initialised

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 11 Jul 2007 21:27:27 +1000

On Wed, 2007-07-11 at 13:06 +0200, Segher Boessenkool wrote:
> > There are two possibly solutions I see in the long run:
> >
> >  - We could set the FW features earlier on pseries, though that is  
> > a bit
> > annoying because that means doing it before the device-tree is
> > unflattened.
> >
> >  - We could constraint lmb_alloc to the first segment until the FW  
> > fixup
> > occurs, either within lmb_alloc itself, or fixup the callers such as
> > unflatten_device_tree, to pass an explicit limit.
> 
> c) use a different SLB handler during early boot;
> d) preload some SLB entries at very early boot to cover
>     the first 4GB or so.
> 
> d) sounds nice and simple, but will it work?

Nah, best to limit everything at boot to SLB 0. Thing is, 4G is not
enough, you may have more RAM and have allocations from the top.

Ben.