[Intel-gfx] [PATCH 11/40] drm/i915: Extend I915_CONTEXT_PARAM_SSEU to support local ctx->engine[]

[Tvrtko Ursulin]

On 08/05/2019 09:06, 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.
> 
> Note that due to the ambiguity in using class:instance with
> ctx->engines[], if a user supplied engine map is active the user must
> specify the engine to alter by its index into the ctx->engines[].
> 
> 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 21bfcd529097..5fdb44714a5c 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -1363,6 +1363,7 @@ static int set_sseu(struct i915_gem_context *ctx,
>   	struct drm_i915_gem_context_param_sseu user_sseu;
>   	struct intel_context *ce;
>   	struct intel_sseu sseu;
> +	unsigned long lookup;
>   	int ret;
>   
>   	if (args->size < sizeof(user_sseu))
> @@ -1375,10 +1376,17 @@ 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;
>   
> -	ce = lookup_user_engine(ctx, 0, &user_sseu.engine);
> +	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;
> +
> +	ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
>   	if (IS_ERR(ce))
>   		return PTR_ERR(ce);
>   
> @@ -1795,6 +1803,7 @@ static int get_sseu(struct i915_gem_context *ctx,
>   {
>   	struct drm_i915_gem_context_param_sseu user_sseu;
>   	struct intel_context *ce;
> +	unsigned long lookup;
>   	int err;
>   
>   	if (args->size == 0)
> @@ -1806,10 +1815,17 @@ 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;
>   
> -	ce = lookup_user_engine(ctx, 0, &user_sseu.engine);
> +	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;
> +
> +	ce = lookup_user_engine(ctx, lookup, &user_sseu.engine);
>   	if (IS_ERR(ce))
>   		return PTR_ERR(ce);
>   
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 8e1bb22926e4..82bd488ed0d1 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -1576,9 +1576,10 @@ struct drm_i915_gem_context_param_sseu {
>   	struct i915_engine_class_instance engine;
>   
>   	/*
> -	 * 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
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko