[PATCH v3 1/4] drm/i915/gt: Refactor uabi engine class/instance list creation

[Joonas Lahtinen]

Quoting Andi Shyti (2024-03-01 01:28:56)
> For the upcoming changes we need a cleaner way to build the list
> of uabi engines.
> 
> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_engine_user.c | 29 ++++++++++++---------
>  1 file changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> index 833987015b8b..cf8f24ad88f6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> @@ -203,7 +203,7 @@ static void engine_rename(struct intel_engine_cs *engine, const char *name, u16
>  
>  void intel_engines_driver_register(struct drm_i915_private *i915)
>  {
> -       u16 name_instance, other_instance = 0;
> +       u16 class_instance[I915_LAST_UABI_ENGINE_CLASS + 1] = { };

Do you mean this to be size I915_LAST_UABI_ENGINE_CLASS + 2? Because ...

<SNIP>

> @@ -222,15 +224,14 @@ void intel_engines_driver_register(struct drm_i915_private *i915)
>  
>                 GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
>                 engine->uabi_class = uabi_classes[engine->class];
> -               if (engine->uabi_class == I915_NO_UABI_CLASS) {
> -                       name_instance = other_instance++;
> -               } else {
> -                       GEM_BUG_ON(engine->uabi_class >=
> -                                  ARRAY_SIZE(i915->engine_uabi_class_count));
> -                       name_instance =
> -                               i915->engine_uabi_class_count[engine->uabi_class]++;
> -               }
> -               engine->uabi_instance = name_instance;
> +
> +               if (engine->uabi_class == I915_NO_UABI_CLASS)
> +                       uabi_class = I915_LAST_UABI_ENGINE_CLASS + 1;

.. otherwise this ...

> +               else
> +                       uabi_class = engine->uabi_class;
> +
> +               GEM_BUG_ON(uabi_class >= ARRAY_SIZE(class_instance));

.. will trigger this assertion?

Regards, Joonas