[PATCH 2/16] add hypervisor support for SPU

[Ishizaki Kou]

Hi Arnd-san,

> On Wednesday 15 November 2006 19:26, Christoph Hellwig wrote:
> > On Wed, Nov 15, 2006 at 06:28:46PM +0900, Ishizaki Kou wrote:
> > > This patch adds hypervisor support for spu.
> > >
> > > Linux(GuestOS) needs to designate SPE ID number when it uses SPE on Beat,
> > > and must read the number from DT.
> >
> > In addition to the comments from Arnd which I'd like to second, what
> > do you need int_mask_lock for?  It's initialized but never used.
> 
> It's used in patch 14/16 for the hypervisor access. As far as I can
> see, it should be possible to use the existing register lock in it's
> place though. We should hold that lock before calling any of the
> priv1 accessors. In order to verify if this is done right,
> you could add BUG_ON(!spin_is_locked(&spu->register_lock));
> in the beat version of int_mask_{and,or,get,set}.

Should we hold spu->register_lock before calling 
int_mask_{and,or,get,set}, like as accessing registers?

If it's true, we will replace spu->int_mask_lock by spu->register_lock.
So we remove spu->int_mask_lock.  But we found a problem that
spu_irq_class_0_bottom calls int_mask_get without holding
spu->register_lock. We suspect that similar problems may exist.


Thank you,
Kou Ishizaki
Toshiba