> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@linux-mips.org]
> Sent: Monday, October 12, 2009 9:18 AM
> To: Gandham, Raghu
> Cc: Kevin D. Kissell; linux-mips@linux-mips.org; Dearman, Chris
> Subject: Re: [PATCH 15/15] Do not rely on the initial state
> of TC/VPEbindings when doing cross VPE writes
>
> On Thu, Jul 02, 2009 at 02:46:33PM -0700, Gandham, Raghu wrote:
>
> > > From: Kevin D. Kissell [mailto:kevink@paralogos.com]
> > > Sent: Wednesday, July 01, 2009 9:02 PM
> > > To: Gandham, Raghu
> > > Cc: linux-mips@linux-mips.org; Dearman, Chris
> > > Subject: Re: [PATCH 15/15] Do not rely on the initial state of
> > > TC/VPE bindings when doing cross VPE writes
> > >
> > > Note that, regardless of the reset state, smtc_configure_tlb()
> > > should have at least temporarily bound TC 1 to VPE1, which may be
> > > why this never seemed to be a problem on the 34K. If one
> wants to
> > > support designs with more than 2 VPEs, then this is
> probably one of
> > > the things that needs to be fixed. That having been said, rather
> > > than adding a usually-redundant write_vpe_c0_vpeconf0() in that
> > > clause, wouldn't it
> > be
> > > cleaner to just move the MVP setting from the top of the
> loop to the
> > > point in the loop just after the TCs have been bound to
> the VPE in
> > > question, i.e.,
> > >
> > > 454 if (slop) {
> > > 455 if (tc != 0) {
> > > 456 smtc_tc_setup(vpe,tc, cpu);
> > > 457 cpu++;
> > > 458 }
> > > 459 printk(" %d", tc);
> > > 460 tc++;
> > > 461 slop--;
> > > 462 }
> > >
> > >
> write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0()
> > > | VPECONF0_MVP);
> > >
> > > 463 if (vpe != 0) {
> > > 464 /*
> > > 465 * Clear any stale software
> interrupts
> > from
> > > VPE's Cause
> > > 466 */
> > >
> > > This should definitely be OK for a 34K, because it's
> being executed
> > > by TC0 in VPE0 and the reset state of VPE0 has MVP set. If it
> > > weren't,
> > > smtc_configure_tlb() would have failed.
> > >
> > > Regards,
> > >
> > > Kevin K.
> >
> >
> > I will resend this patch with your suggestion.
>
> Ping? Don't think I ever received that, if you sent it.
I resent the patch and it got checked-in. It is not appended to this
mail thread though.
http://www.linux-mips.org/git?p=linux.git;a=commitdiff;h=d8e5f9fe5dab0e0
7985f2456cb6cc57788f53131
Thanks,
Raghu
>
> Ralf
>
|