[Intel-gfx] [PATCH v7 10/11] drm/i915: Support LRC context single submission

[Chris Wilson]

On Tue, Jun 07, 2016 at 11:18:46AM -0400, Zhi Wang wrote:
> This patch introduces the support of LRC context single submission.
> As GVT context may come from different guests, which require different
> configuration of render registers. It can't be combined into a dual ELSP
> submission combo.
> 
> Only GVT-g will create this kinds of GEM context currently.
> 
> v7:
> 
> - Fix typos in commit message. (Joonas)
> 
> v6:
> - Make GVT code as dead code when !CONFIG_DRM_I915_GVT. (Chris)
> 
> v5:
> 
> - Only compile this feature when CONFIG_DRM_I915_GVT=y. (Tvrtko)
> 
> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h  |  1 +
>  drivers/gpu/drm/i915/intel_lrc.c | 15 +++++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 4ab4cf7..8f8a5bc 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -882,6 +882,7 @@ struct i915_gem_context {
>  	u32 lrc_addressing_mode_bits;
>  	struct atomic_notifier_head status_notifier;
>  	bool enable_lrc_status_change_notification;
> +	bool enable_lrc_single_submission;
>  
>  	struct list_head link;
>  
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 956585d..e3cab06 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -447,6 +447,21 @@ static void execlists_context_unqueue(struct intel_engine_cs *engine)
>  			i915_gem_request_unreference(req0);
>  			req0 = cursor;
>  		} else {
> +			/* Compiler will do the dead-code elimination */
> +			if (IS_ENABLED(CONFIG_DRM_I915_GVT)) {
> +				/*
> +				 * req0 (after merged) ctx requires single
> +				 * submission, stop picking
> +				 */
> +				if (req0->ctx->enable_lrc_single_submission)

enable_ is a bad verb here, force_ would be more apt.

s/lrc/execlists/

ctx->execlists_force_single_submission
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre