[RFC/PATCH] powerpc: Deal with 44x virtually tagged icache

[Josh Boyer]

On Wed, 31 Oct 2007 07:16:31 +1100
Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote:

> 
> > > Fortunately, we don't support SMP on these or this solution wouldn't
> > > work.
> > 
> > We should mark 44x BROKEN on SMP in Kconfig.
> 
> Can we enable SMP on 44x at all currently ?

Not without editing the Kconfig.cputypes file.  I was thinking of being
a bit proactive so people didn't just add || 44x to it and think it
would work.  But it's minor.

> > No arch/ppc fix?  I know we all want it to die as soon as possible, but
> > still... :)
> 
> Yeah, I didn't do it yet, which is one reason this patch is marked
> RFC :-)

Fair enough.

> > >  	/* interrupts are hard-disabled at this point */
> > >  restore:
> > > +#ifdef CONFIG_44x
> > > +	lis	r4,icache_44x_need_flush at ha
> > > +	lwz	r5,icache_44x_need_flush at l(r4)
> > > +	cmplwi	cr0,r5,0
> > > +	beq+	1f
> > > +	iccci	r0,r0
> > > +	li	r6,0
> > > +	iccci	r0,r0
> > > +	stw	r6,icache_44x_need_flush at l(r4)
> > > +1:
> > 
> > Why two iccci's here?
> 
> No idea... thinko/typo.

And here I thought you were being extra careful ;)

josh