[Intel-gfx] [PATCH 1/2] drm/i915/scheduler: add gvt force-single-submission for guc

[Chris Wilson]

On Tue, Mar 28, 2017 at 09:49:51AM +0800, Chuanxiao Dong wrote:
> GVT needs single submission and cannot allow merge. So when GuC submitting
> a GVT request, the next one should be submitted to guc later until the
> previous one is completed. This is following the usage when using execlist
> mode submission.
> 
> Cc: chris at chris-wilson.co.uk
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_context.h    | 20 ++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_guc_submission.c |  6 +++++-
>  drivers/gpu/drm/i915/intel_lrc.c           | 25 ++++---------------------
>  3 files changed, 29 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
> index 4af2ab94..025eba2 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.h
> +++ b/drivers/gpu/drm/i915/i915_gem_context.h
> @@ -246,6 +246,26 @@ static inline bool i915_gem_context_is_kernel(struct i915_gem_context *ctx)
>  	return !ctx->file_priv;
>  }
>  
> +static inline bool
> +i915_gem_context_single_port_submit(const struct i915_gem_context *ctx)
> +{
> +	return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
> +		i915_gem_context_force_single_submission(ctx));
> +}
> +
> +static inline bool
> +i915_gem_context_can_merge(const struct i915_gem_context *prev,
> +		const struct i915_gem_context *next)
> +{
> +	if (prev != next)
> +		return false;
> +
> +	if (i915_gem_context_single_port_submit(prev))
> +		return false;
> +
> +	return true;
> +}
> +
>  /* i915_gem_context.c */
>  int __must_check i915_gem_context_init(struct drm_i915_private *dev_priv);
>  void i915_gem_context_lost(struct drm_i915_private *dev_priv);
> diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
> index 991e76e..ad90de1 100644
> --- a/drivers/gpu/drm/i915/i915_guc_submission.c
> +++ b/drivers/gpu/drm/i915/i915_guc_submission.c
> @@ -680,10 +680,14 @@ static bool i915_guc_dequeue(struct intel_engine_cs *engine)
>  		struct drm_i915_gem_request *rq =
>  			rb_entry(rb, typeof(*rq), priotree.node);
>  
> -		if (last && rq->ctx != last->ctx) {
> +		if (last && !i915_gem_context_can_merge(last->ctx, rq->ctx)) {
>  			if (port != engine->execlist_port)
>  				break;
>  
> +			if (i915_gem_context_single_port_submit(last->ctx) ||
> +				i915_gem_context_single_port_submit(rq->ctx))
> +				break;
> +
>  			i915_gem_request_assign(&port->request, last);
>  			nested_enable_signaling(last);
>  			port++;
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index dd0e9d587..a49801e 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -377,24 +377,6 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
>  	writel(lower_32_bits(desc[0]), elsp);
>  }
>  
> -static bool ctx_single_port_submission(const struct i915_gem_context *ctx)
> -{
> -	return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
> -		i915_gem_context_force_single_submission(ctx));
> -}
> -
> -static bool can_merge_ctx(const struct i915_gem_context *prev,
> -			  const struct i915_gem_context *next)
> -{
> -	if (prev != next)
> -		return false;
> -
> -	if (ctx_single_port_submission(prev))
> -		return false;
> -
> -	return true;
> -}
> -
>  static void execlists_dequeue(struct intel_engine_cs *engine)
>  {
>  	struct drm_i915_gem_request *last;
> @@ -462,7 +444,8 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
>  		 * request, and so we never need to tell the hardware about
>  		 * the first.
>  		 */
> -		if (last && !can_merge_ctx(cursor->ctx, last->ctx)) {
> +		if (last &&
> +			!i915_gem_context_can_merge(last->ctx, cursor->ctx)) {
>  			/* If we are on the second port and cannot combine
>  			 * this request with the last, then we are done.
>  			 */
> @@ -475,8 +458,8 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
>  			 * context (even though a different request) to
>  			 * the second port.
>  			 */
> -			if (ctx_single_port_submission(last->ctx) ||
> -			    ctx_single_port_submission(cursor->ctx))
> +			if (i915_gem_context_single_port_submit(last->ctx) ||
> +			    i915_gem_context_single_port_submit(cursor->ctx))

Could you please fix gvt before this mess is propagated. There is no way
it should be caring about a non-gvt context in port[0] or port[1].
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre