[Intel-gfx] [PATCH v22 04/13] drm/i915: Add intel_atomic_get_bw_*_state helpers

[Lisovskiy, Stanislav]

On Tue, Apr 14, 2020 at 08:40:44PM +0300, Ville Syrjälä wrote:
> On Thu, Apr 09, 2020 at 06:47:21PM +0300, Stanislav Lisovskiy wrote:
> > Add correspondent helpers to be able to get old/new bandwidth
> > global state object.
> > 
> > v2: - Fixed typo in function call
> > v3: - Changed new functions naming to use convention proposed
> >       by Jani Nikula, i.e intel_bw_* in intel_bw.c file.
> > v4: - Change function naming back to intel_atomic* pattern,
> >       was decided to rename in a separate patch series.
> > v5: - Fix function naming to match existing practices(Ville)
> > v6: - Removed spurious whitespace
> > 
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bw.c | 28 ++++++++++++++++++++++++-
> >  drivers/gpu/drm/i915/display/intel_bw.h |  9 ++++++++
> >  2 files changed, 36 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> > index 88f367eb28ea..96f86cfa91d4 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bw.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> > @@ -375,7 +375,33 @@ static unsigned int intel_bw_data_rate(struct drm_i915_private *dev_priv,
> >  	return data_rate;
> >  }
> >  
> > -static struct intel_bw_state *
> > +struct intel_bw_state *
> > +intel_atomic_get_old_bw_state(struct intel_atomic_state *state)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > +	struct intel_global_state *bw_state;
> > +
> > +	bw_state = intel_atomic_get_old_global_obj_state(state, &dev_priv->bw_obj);
> > +	if (!bw_state)
> > +		return NULL;
> 
> This check isn't actually needed. I think in all the other cases we just
> get_new_state()
> {
> 	return to_foo_state(get_new_state());
> }
> 
> See eg. intel_atomic_get_new_{crtc,plane}_state()
> 
> Would be nice to be consistent.

My concern was that will this to_foo_state survive NULL
being passed, i.e underlying container_of macro will
then do this pointer arithmetics with NULL, i.e:

((type *)(NULL - offsetof(type, member))); })

which doesnt look nice to me, however if you say that this is ok, 
will change that.

Stan

> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> 
> > +
> > +	return to_intel_bw_state(bw_state);
> > +}
> > +
> > +struct intel_bw_state *
> > +intel_atomic_get_new_bw_state(struct intel_atomic_state *state)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > +	struct intel_global_state *bw_state;
> > +
> > +	bw_state = intel_atomic_get_new_global_obj_state(state, &dev_priv->bw_obj);
> > +	if (!bw_state)
> > +		return NULL;
> > +
> > +	return to_intel_bw_state(bw_state);
> > +}
> > +
> > +struct intel_bw_state *
> >  intel_atomic_get_bw_state(struct intel_atomic_state *state)
> >  {
> >  	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > diff --git a/drivers/gpu/drm/i915/display/intel_bw.h b/drivers/gpu/drm/i915/display/intel_bw.h
> > index a8aa7624c5aa..ac004d6f4276 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bw.h
> > +++ b/drivers/gpu/drm/i915/display/intel_bw.h
> > @@ -24,6 +24,15 @@ struct intel_bw_state {
> >  
> >  #define to_intel_bw_state(x) container_of((x), struct intel_bw_state, base)
> >  
> > +struct intel_bw_state *
> > +intel_atomic_get_old_bw_state(struct intel_atomic_state *state);
> > +
> > +struct intel_bw_state *
> > +intel_atomic_get_new_bw_state(struct intel_atomic_state *state);
> > +
> > +struct intel_bw_state *
> > +intel_atomic_get_bw_state(struct intel_atomic_state *state);
> > +
> >  void intel_bw_init_hw(struct drm_i915_private *dev_priv);
> >  int intel_bw_init(struct drm_i915_private *dev_priv);
> >  int intel_bw_atomic_check(struct intel_atomic_state *state);
> > -- 
> > 2.24.1.485.gad05a3d8e5
> 
> -- 
> Ville Syrjälä
> Intel