[Intel-gfx] [PATCH 09/13] drm/i915: Extend I915_CONTEXT_PARAM_SSEU to support local ctx->engine[]

[Tvrtko Ursulin]

On 08/03/2019 14:12, Chris Wilson wrote:
> Allow the user to specify a local engine index (as opposed to
> class:index) that they can use to refer to a preset engine inside the
> ctx->engine[] array defined by an earlier I915_CONTEXT_PARAM_ENGINES.
> This will be useful for setting SSEU parameters on virtual engines that
> are local to the context and do not have a valid global class:instance
> lookup.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem_context.c | 24 ++++++++++++++++++++----
>   include/uapi/drm/i915_drm.h             |  3 ++-
>   2 files changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index 86d9bea6f275..a581c01ffff1 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -1313,6 +1313,7 @@ static int set_sseu(struct i915_gem_context *ctx,
>   	struct drm_i915_gem_context_param_sseu user_sseu;
>   	struct intel_engine_cs *engine;
>   	struct intel_sseu sseu;
> +	unsigned long lookup;

Poor 32-bit builds. ;) And in lookup_user_engine as well.

>   	int ret;
>   
>   	if (args->size < sizeof(user_sseu))
> @@ -1325,10 +1326,17 @@ static int set_sseu(struct i915_gem_context *ctx,
>   			   sizeof(user_sseu)))
>   		return -EFAULT;
>   
> -	if (user_sseu.flags || user_sseu.rsvd)
> +	if (user_sseu.rsvd)
>   		return -EINVAL;
>   
> -	engine = lookup_user_engine(ctx, 0,
> +	if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
> +		return -EINVAL;
> +
> +	lookup = 0;
> +	if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
> +		lookup |= LOOKUP_USER_INDEX;
> +
> +	engine = lookup_user_engine(ctx, lookup,
>   				    user_sseu.engine_class,
>   				    user_sseu.engine_instance);
>   	if (!engine)
> @@ -1807,6 +1815,7 @@ static int get_sseu(struct i915_gem_context *ctx,
>   	struct drm_i915_gem_context_param_sseu user_sseu;
>   	struct intel_engine_cs *engine;
>   	struct intel_context *ce;
> +	unsigned long lookup;
>   
>   	if (args->size == 0)
>   		goto out;
> @@ -1817,10 +1826,17 @@ static int get_sseu(struct i915_gem_context *ctx,
>   			   sizeof(user_sseu)))
>   		return -EFAULT;
>   
> -	if (user_sseu.flags || user_sseu.rsvd)
> +	if (user_sseu.rsvd)
>   		return -EINVAL;
>   
> -	engine = lookup_user_engine(ctx, 0,
> +	if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
> +		return -EINVAL;
> +
> +	lookup = 0;
> +	if (user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX)
> +		lookup |= LOOKUP_USER_INDEX;
> +
> +	engine = lookup_user_engine(ctx, lookup,
>   				    user_sseu.engine_class,
>   				    user_sseu.engine_instance);
>   	if (!engine)
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 00147b990e63..a609619610f2 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -1565,9 +1565,10 @@ struct drm_i915_gem_context_param_sseu {
>   	__u16 engine_instance;
>   
>   	/*
> -	 * Unused for now. Must be cleared to zero.
> +	 * Unknown flags must be cleared to zero.
>   	 */
>   	__u32 flags;
> +#define I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX (1u << 0)
>   
>   	/*
>   	 * Mask of slices to enable for the context. Valid values are a subset
> 

Looks okay. But one more thing is needed:

https://cgit.freedesktop.org/~tursulin/drm-intel/commit/?h=media&id=38266bfe99469de9e13774a13fa641c377988c67

If you don't disagree with this patch feel free to adopt it into your tree.

Regards,

Tvrtko