[PATCH v3] drm/xe/xe_guc_ads: Add nonpriv registers to write list

[Dixit, Ashutosh]

On Tue, 03 Dec 2024 14:11:11 -0800, Lucas De Marchi wrote:
>
> On Tue, Dec 03, 2024 at 01:53:53PM -0800, Ashutosh Dixit wrote:
> > On Mon, 02 Dec 2024 13:11:21 -0800, Cavitt, Jonathan wrote:
> >>
> >> -----Original Message-----
> >> From: Dixit, Ashutosh <ashutosh.dixit at intel.com>
> >> Sent: Monday, December 2, 2024 12:33 PM
> >> To: Cavitt, Jonathan <jonathan.cavitt at intel.com>
> >> Cc: intel-xe at lists.freedesktop.org; Gupta, saurabhg <saurabhg.gupta at intel.com>; Zuo, Alex <alex.zuo at intel.com>; Nerlige Ramappa, Umesh <umesh.nerlige.ramappa at intel.com>; Harrison, John C <john.c.harrison at intel.com>; Roper, Matthew D <matthew.d.roper at intel.com>; De Marchi, Lucas <lucas.demarchi at intel.com>
> >> Subject: Re: [PATCH v3] drm/xe/xe_guc_ads: Add nonpriv registers to write list
> >> >
> >> > On Fri, 22 Nov 2024 10:08:26 -0800, Jonathan Cavitt wrote:
> >> > >
> >> > > When performing a guc_mmio_regset_write, we add all the registers in the
> >> > > reg_sr list to the save/restore list, but do not do the same for the
> >> > > nonpriv registers.  Add them in.
> >> > >
> >> > > v2:
> >> > > - Add all NONPRIV registers to avoid undefined behavior (Harrison)
> >> > > - s/whitelist/nonpriv
> >> > >
> >> > > v3:
> >> > > - Rebase
> >> > >
> >> > > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/issues/2249
> >> > > Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
> >> > > CC: Lucas de Marchi <lucas.demarchi at intel.com>
> >> > > CC: Matt Roper <matthew.d.roper at intel.com>
> >> > > CC: John Harrison <john.c.harrison at intel.com>
> >> > > CC: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> >> > > CC: Ashutosh Dixit <ashutosh.dixit at intel.com>
> >> > > Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

Hmm this should have had a Cc: stable at vger.kernel.org on it. Because it
didn't, now it should be sent separately following the process here:

https://www.kernel.org/doc/html/v4.15/process/stable-kernel-rules.html


> >> > > ---
> >> > >  drivers/gpu/drm/xe/xe_guc_ads.c | 7 +++++++
> >> > >  1 file changed, 7 insertions(+)
> >> > >
> >> > > diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
> >> > > index 943146e5b460..b0afb89d9d90 100644
> >> > > --- a/drivers/gpu/drm/xe/xe_guc_ads.c
> >> > > +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
> >> > > @@ -243,6 +243,8 @@ static size_t calculate_regset_size(struct xe_gt *gt)
> >> > >		xa_for_each(&hwe->reg_sr.xa, sr_idx, sr_entry)
> >> > >			count++;
> >> > >
> >> > > +	count += RING_MAX_NONPRIV_SLOTS * XE_NUM_HW_ENGINES;
> >> > > +
> >> > >	count += ADS_REGSET_EXTRA_MAX * XE_NUM_HW_ENGINES;
> >> > >
> >> > >	if (XE_WA(gt, 1607983814))
> >> > > @@ -727,6 +729,11 @@ static unsigned int guc_mmio_regset_write(struct xe_guc_ads *ads,
> >> > >	xa_for_each(&hwe->reg_sr.xa, idx, entry)
> >> > >		guc_mmio_regset_write_one(ads, regset_map, entry->reg, count++);
> >> > >
> >> > > +	for (i = 0; i < RING_MAX_NONPRIV_SLOTS; i++)
> >> > > +		guc_mmio_regset_write_one(ads, regset_map,
> >> > > +					  RING_FORCE_TO_NONPRIV(hwe->mmio_base, i),
> >> > > +					  count++);
> >> > > +
> >> >
> >> > What about the EU_PERF_CNTL registers which were there in the original
> >> > patch? Those are not needed?
> >>
> >> It turned out they weren't.  At least not for this use case.
> >> They might be needed later for a different issue, but right now we aren't
> >> observing any issues caused by their absence.
> >
> > Ok, let's keep this patch restricted to the nonprov registers.
>
> applied, thanks.
>
>
>
> Lucas De Marchi
>
> >
> >
> >>
> >> >
> >> > >	for (e = extra_regs; e < extra_regs + ARRAY_SIZE(extra_regs); e++) {
> >> > >		if (e->skip)
> >> > >			continue;
> >> > > --
> >> > > 2.43.0
> >> > >
> >> >