Re: [Intel-gfx] [PATCH v2 5/5] drm/i915/mtl: don't expose GSC command streamer to the user

[Matt Roper <matthew.d.roper@intel.com>]

On Wed, Nov 02, 2022 at 10:10:47AM -0700, Daniele Ceraolo Spurio wrote:
> There is no userspace user for this CS yet, we only need it for internal
> kernel ops (e.g. HuC, PXP), so don't expose it.
> 
> v2: even if it's not exposed, rename the engine so it is easier to
> identify in the debug logs (Matt)
> 
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

> ---
>  drivers/gpu/drm/i915/gt/intel_engine_user.c | 27 ++++++++++++++++-----
>  1 file changed, 21 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> index 79312b734690..cd4f1b126f75 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_user.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c
> @@ -191,6 +191,15 @@ static void add_legacy_ring(struct legacy_ring *ring,
>  		ring->instance++;
>  }
>  
> +static void engine_rename(struct intel_engine_cs *engine, const char *name, u16 instance)
> +{
> +	char old[sizeof(engine->name)];
> +
> +	memcpy(old, engine->name, sizeof(engine->name));
> +	scnprintf(engine->name, sizeof(engine->name), "%s%u", name, instance);
> +	drm_dbg(&engine->i915->drm, "renamed %s to %s\n", old, engine->name);
> +}
> +
>  void intel_engines_driver_register(struct drm_i915_private *i915)
>  {
>  	struct legacy_ring ring = {};
> @@ -206,11 +215,19 @@ void intel_engines_driver_register(struct drm_i915_private *i915)
>  		struct intel_engine_cs *engine =
>  			container_of((struct rb_node *)it, typeof(*engine),
>  				     uabi_node);
> -		char old[sizeof(engine->name)];
>  
>  		if (intel_gt_has_unrecoverable_error(engine->gt))
>  			continue; /* ignore incomplete engines */
>  
> +		/*
> +		 * We don't want to expose the GSC engine to the users, but we
> +		 * still rename it so it is easier to identify in the debug logs
> +		 */
> +		if (engine->id == GSC0) {
> +			engine_rename(engine, "gsc", 0);
> +			continue;
> +		}
> +
>  		GEM_BUG_ON(engine->class >= ARRAY_SIZE(uabi_classes));
>  		engine->uabi_class = uabi_classes[engine->class];
>  
> @@ -220,11 +237,9 @@ void intel_engines_driver_register(struct drm_i915_private *i915)
>  			i915->engine_uabi_class_count[engine->uabi_class]++;
>  
>  		/* Replace the internal name with the final user facing name */
> -		memcpy(old, engine->name, sizeof(engine->name));
> -		scnprintf(engine->name, sizeof(engine->name), "%s%u",
> -			  intel_engine_class_repr(engine->class),
> -			  engine->uabi_instance);
> -		DRM_DEBUG_DRIVER("renamed %s to %s\n", old, engine->name);
> +		engine_rename(engine,
> +			      intel_engine_class_repr(engine->class),
> +			      engine->uabi_instance);
>  
>  		rb_link_node(&engine->uabi_node, prev, p);
>  		rb_insert_color(&engine->uabi_node, &i915->uabi_engines);
> -- 
> 2.37.3
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation