[PATCH 5/5] drm/i915/mtl: don't expose GSC command streamer to the user

[Matt Roper]

On Fri, Oct 28, 2022 at 10:14:05AM -0700, Ceraolo Spurio, Daniele wrote:
> 
> 
> On 10/27/2022 8:40 PM, Matt Roper wrote:
> > On Thu, Oct 27, 2022 at 03:15:54PM -0700, Daniele Ceraolo Spurio wrote:
> > > There is no userspace user for this CS yet, we only need it for internal
> > > kernel ops (e.g. HuC, PXP), so don't expose it.
> > > 
> > > Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> > > Cc: Matt Roper <matthew.d.roper at intel.com>
> > Since we never expose it to userspace, we also never get to the point of
> > doing an engine rename and removing the apostrophe.  I assume we're okay
> > with this engine continuing to show up as "other'6" in debug logs?
> 
> I don't think it matters a lot in debug logs, but anyway it wouldn't be hard
> to rename it to something different. What do you suggest to rename it to?
> Since OTHER_CLASS doesn't have a uabi_class defined we can't use a count of
> engines of that type like we do for the other classes. Just rename it
> straight to hardcoded gsc0 ?

Yeah, a hardcoded "gsc0" seems fine to me.  I agree it doesn't matter
too much either way, so I'll leave it up to you whether you add that
rename or not.


Matt

> 
> Daniele
> 
> > 
> > Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
> > 
> > > ---
> > >   drivers/gpu/drm/i915/gt/intel_engine_user.c | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> > > index 79312b734690..ca795daca116 100644
> > > --- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
> > > +++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> > > @@ -211,6 +211,10 @@ void intel_engines_driver_register(struct drm_i915_private *i915)
> > >   		if (intel_gt_has_unrecoverable_error(engine->gt))
> > >   			continue; /* ignore incomplete engines */
> > > +		/* don't expose GSC engine to user */
> > > +		if (engine->class == OTHER_CLASS)
> > > +			continue;
> > > +
> > >   		GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
> > >   		engine->uabi_class = uabi_classes[engine->class];
> > > -- 
> > > 2.37.3
> > > 
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation