[Intel-gfx] [PATCH 1/2] drm/i915: Wrap the protected active RCU dereference in a helper

[Daniel Vetter]

On Tue, Aug 09, 2016 at 08:08:52AM +0100, Chris Wilson wrote:
> On Tue, Aug 09, 2016 at 08:36:56AM +0200, Daniel Vetter wrote:
> > On Mon, Aug 08, 2016 at 08:28:47AM +0100, Chris Wilson wrote:
> > > As we do the lockdep protected RCU lookup in a couple of places,
> > > refactor that code to a common helper i915_gem_active_raw()..
> > > 
> > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > > ---
> > >  drivers/gpu/drm/i915/i915_gem_request.h | 21 +++++++++++++++++----
> > >  1 file changed, 17 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
> > > index 3496e28785e7..6dd01cbf4895 100644
> > > --- a/drivers/gpu/drm/i915/i915_gem_request.h
> > > +++ b/drivers/gpu/drm/i915/i915_gem_request.h
> > > @@ -360,6 +360,21 @@ __i915_gem_active_peek(const struct i915_gem_active *active)
> > >  }
> > >  
> > >  /**
> > > + * i915_gem_active_raw - return the active request
> > > + * @active - the active tracker
> > > + *
> > > + * i915_gem_active_raw() returns the current request being tracked, or NULL.
> > > + * It does not obtain a reference on the request for the caller, so the caller
> > > + * must hold struct_mutex.
> > > + */
> > > +static inline struct drm_i915_gem_request *
> > > +i915_gem_active_raw(const struct i915_gem_active *active, struct mutex *mutex)
> > 
> > There's a rcu_dereference_raw helper which doesn't bother with any lockdep
> > checking. A bit confusing naming, otoh I couldn't come up with something
> > better.
> 
> __i915_gem_active_protected()  ?

+1

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch