[Intel-gfx] [PATCH 2/2] drm/i915: Fix up the inverse mapping for default ctx->engines[]

[Chris Wilson]

Quoting Mika Kuoppala (2019-08-08 13:59:41)
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> 
> > The order in which we store the engines inside default_engines() for the
> > legacy ctx->engines[] has to match the legacy I915_EXEC_RING selector
> > mapping in execbuf::user_map. If we present VCS2 as being the second
> > instance of the video engine, legacy userspace calls that I915_EXEC_BSD2
> > and so we need to insert it into the second video slot.
> >
> > v2: Record the legacy mapping (hopefully we can remove this need in the
> > future)
> >
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111328
> > Fixes: 2edda80db3d0 ("drm/i915: Rename engines to match their user interface")
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> > Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com> #v1
> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_context.c   |  7 +--
> >  .../drm/i915/gem/selftests/igt_gem_utils.c    |  2 +-
> >  drivers/gpu/drm/i915/gt/intel_engine_types.h  |  3 ++
> >  drivers/gpu/drm/i915/gt/intel_engine_user.c   | 52 +++++++++++++++++++
> >  drivers/gpu/drm/i915/gt/intel_gt_types.h      |  1 +
> >  drivers/gpu/drm/i915/gt/selftest_lrc.c        |  2 +-
> >  .../gpu/drm/i915/gt/selftest_workarounds.c    |  2 +-
> >  7 files changed, 63 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index 1c5bc21a80ff..b407baaf0014 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -159,7 +159,7 @@ lookup_user_engine(struct i915_gem_context *ctx,
> >               if (!engine)
> >                       return ERR_PTR(-EINVAL);
> >  
> > -             idx = engine->id;
> > +             idx = engine->legacy_idx;
> >       } else {
> >               idx = ci->engine_instance;
> >       }
> > @@ -279,6 +279,7 @@ static void free_engines_rcu(struct rcu_head *rcu)
> >  
> >  static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
> 
> clone_legacy_engines

It's not cloning :)

> create_gt_engines

Strictly it's creating the intel_context, but I felt that ctx->engines[]
was more descriptive than ctx->contexts[]. Time will tell.
-Chris