[PATCH 5/6] ARM: Don't set TLB ops broadcasting on UP ARMv7

Tony Lindgren tony at atomide.com
Thu Sep 2 13:21:33 EDT 2010


* Russell King - ARM Linux <linux at arm.linux.org.uk> [100902 09:50]:
> On Thu, Sep 02, 2010 at 09:22:20AM -0700, Tony Lindgren wrote:
> > >From 8b22546af2ba9a0d96c2f419bfcec1f3c01a414d Mon Sep 17 00:00:00 2001
> > From: Tony Lindgren <tony at atomide.com>
> > Date: Mon, 30 Aug 2010 14:03:28 -0700
> > Subject: [PATCH 5/6] ARM: Don't set TLB ops broadcasting on UP ARMv7
> > 
> > Don't set TLB ops broadcasting on UP ARMv7. Looks like these bits
> > are also different on A8 and A9.
> 
> This is already taken care of.
> 
> > diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> > index 07fc660..51a063d 100644
> > --- a/arch/arm/mm/proc-v7.S
> > +++ b/arch/arm/mm/proc-v7.S
> > @@ -191,7 +191,8 @@ __v7_setup:
> >  	UP(mov	r0, #(1 << 6))			@ fake it for UP
> 
> If it's UP, we set r0 to 1 << 6, which...
> 
> >  	tst	r0, #(1 << 6)			@ SMP/nAMP mode enabled?
> 
> means this test produces a non-zero result.
> 
> >  	orreq	r0, r0, #(1 << 6) | (1 << 0)	@ Enable SMP/nAMP mode and
> > -	mcreq	p15, 0, r0, c1, c0, 1		@ TLB ops broadcasting
> 
> And therefore these instructions will not be executed.

AFAIK these bits are different for Cortex-A8 and A9, bit 6 is IBE on A8.

Tony



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