[Intel-gfx] [PATCH v3 1/2] drm/i915: Make for_each_engine_masked work on intel_gt

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-10-17 14:45:31)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Medium term goal is to eliminate the i915->engine[] array and to get there
> we have recently introduced equivalent array in intel_gt. Now we need to
> migrate the code further towards this state.
> 
> This next step is to eliminate usage of i915->engines[] from the
> for_each_engine_masked iterator.
> 
> For this to work we also need to use engine->id as index when populating
> the gt->engine[] array and adjust the default engine set indexing to use
> engine->legacy_idx instead of assuming gt->engines[] indexing.
> 
> v2:
>  * Populate gt->engine[] earlier.
> 
> v3:
>  * Work around the initialization order issue between default_engines()
>    and intel_engines_driver_register() which sets engine->legacy_idx for
>    now. It will be fixed properly later.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk> # v1
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_context.c |  7 +++++--
>  drivers/gpu/drm/i915/gt/intel_engine_cs.c   |  4 ++++
>  drivers/gpu/drm/i915/gt/intel_engine_user.c |  2 --
>  drivers/gpu/drm/i915/gt/intel_gt.c          |  2 +-
>  drivers/gpu/drm/i915/gt/intel_hangcheck.c   |  2 +-
>  drivers/gpu/drm/i915/gt/intel_reset.c       | 12 ++++++------
>  drivers/gpu/drm/i915/gvt/execlist.c         |  4 ++--
>  drivers/gpu/drm/i915/gvt/scheduler.c        |  2 +-
>  drivers/gpu/drm/i915/i915_active.c          |  4 ++--
>  drivers/gpu/drm/i915/i915_drv.h             |  6 +++---
>  10 files changed, 25 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 5d8221c7ba83..87d66d8faff1 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -203,14 +203,17 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx)
>         for_each_engine(engine, gt, id) {
>                 struct intel_context *ce;
>  
> +               if (engine->legacy_idx == -1)
> +                       continue;
> +
>                 ce = intel_context_create(ctx, engine);
>                 if (IS_ERR(ce)) {
>                         __free_engines(e, id);
>                         return ERR_CAST(ce);
>                 }
>  
> -               e->engines[id] = ce;
> -               e->num_engines = id + 1;
> +               e->engines[engine->legacy_idx] = ce;
> +               e->num_engines = engine->legacy_idx + 1;

e->num_engines = max(e->num_engines, engine->legacy_idx + 1);

and remove id above.

Please take the v2.5, throw in the legacy_idx=-1 and remove bits until
you are happy :)
-Chris