[Intel-gfx] [PATCH v3] drm/i915/scheduler: add gvt notification for guc submission

[Tvrtko Ursulin]

On 22/03/2017 06:34, Chuanxiao Dong wrote:
> GVT request needs a manual mmio load/restore. Before GuC submit
> a request, send notification to gvt for mmio loading. And after
> the GuC finished this GVT request, notify gvt again for mmio
> restore. This follows the usage when using execlists submission.
>
> v2: use context_status_change instead of execlists_context_status_change
>     for better understanding (ZhengXiao)
> v3: remove the comment as it is obvious and not friendly to
>     the caller (Kevin)
>
> Cc: xiao.zheng at intel.com
> Cc: kevin.tian at intel.com
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_guc_submission.c |  3 +++
>  drivers/gpu/drm/i915/intel_lrc.c           | 21 +++------------------
>  drivers/gpu/drm/i915/intel_lrc.h           | 13 +++++++++++++
>  3 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
> index 055467a..0195547 100644
> --- a/drivers/gpu/drm/i915/i915_guc_submission.c
> +++ b/drivers/gpu/drm/i915/i915_guc_submission.c
> @@ -520,6 +520,8 @@ static void __i915_guc_submit(struct drm_i915_gem_request *rq)
>  	unsigned long flags;
>  	int b_ret;
>
> +	context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN);
> +
>  	/* WA to flush out the pending GMADR writes to ring buffer. */
>  	if (i915_vma_is_map_and_fenceable(rq->ring->vma))
>  		POSTING_READ_FW(GUC_STATUS);
> @@ -634,6 +636,7 @@ static void i915_guc_irq_handler(unsigned long data)
>  		rq = port[0].request;
>  		while (rq && i915_gem_request_completed(rq)) {
>  			trace_i915_gem_request_out(rq);
> +			context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);

Does GVT care that the context will still be active on the GPU for a 
small window after this notification? (User interrupt happens before 
context complete, which GuC hides from the driver.)

Regards,

Tvrtko

>  			i915_gem_request_put(rq);
>  			port[0].request = port[1].request;
>  			port[1].request = NULL;
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index eec1e71..24c69b5 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -295,21 +295,6 @@ uint64_t intel_lr_context_descriptor(struct i915_gem_context *ctx,
>  	return ctx->engine[engine->id].lrc_desc;
>  }
>
> -static inline void
> -execlists_context_status_change(struct drm_i915_gem_request *rq,
> -				unsigned long status)
> -{
> -	/*
> -	 * Only used when GVT-g is enabled now. When GVT-g is disabled,
> -	 * The compiler should eliminate this function as dead-code.
> -	 */
> -	if (!IS_ENABLED(CONFIG_DRM_I915_GVT))
> -		return;
> -
> -	atomic_notifier_call_chain(&rq->engine->context_status_notifier,
> -				   status, rq);
> -}
> -
>  static void
>  execlists_update_context_pdps(struct i915_hw_ppgtt *ppgtt, u32 *reg_state)
>  {
> @@ -350,7 +335,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
>
>  	GEM_BUG_ON(port[0].count > 1);
>  	if (!port[0].count)
> -		execlists_context_status_change(port[0].request,
> +		context_status_change(port[0].request,
>  						INTEL_CONTEXT_SCHEDULE_IN);
>  	desc[0] = execlists_update_context(port[0].request);
>  	GEM_DEBUG_EXEC(port[0].context_id = upper_32_bits(desc[0]));
> @@ -358,7 +343,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
>
>  	if (port[1].request) {
>  		GEM_BUG_ON(port[1].count);
> -		execlists_context_status_change(port[1].request,
> +		context_status_change(port[1].request,
>  						INTEL_CONTEXT_SCHEDULE_IN);
>  		desc[1] = execlists_update_context(port[1].request);
>  		GEM_DEBUG_EXEC(port[1].context_id = upper_32_bits(desc[1]));
> @@ -581,7 +566,7 @@ static void intel_lrc_irq_handler(unsigned long data)
>  			if (--port[0].count == 0) {
>  				GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED);
>  				GEM_BUG_ON(!i915_gem_request_completed(port[0].request));
> -				execlists_context_status_change(port[0].request,
> +				context_status_change(port[0].request,
>  								INTEL_CONTEXT_SCHEDULE_OUT);
>
>  				trace_i915_gem_request_out(port[0].request);
> diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
> index e8015e7..51e1be9 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.h
> +++ b/drivers/gpu/drm/i915/intel_lrc.h
> @@ -87,5 +87,18 @@ uint64_t intel_lr_context_descriptor(struct i915_gem_context *ctx,
>  /* Execlists */
>  int intel_sanitize_enable_execlists(struct drm_i915_private *dev_priv,
>  				    int enable_execlists);
> +static inline void
> +context_status_change(struct drm_i915_gem_request *rq, unsigned long status)
> +{
> +	/*
> +	 * Only used when GVT-g is enabled now. When GVT-g is disabled,
> +	 * The compiler should eliminate this function as dead-code.
> +	 */
> +	if (!IS_ENABLED(CONFIG_DRM_I915_GVT))
> +		return;
> +
> +	atomic_notifier_call_chain(&rq->engine->context_status_notifier,
> +				   status, rq);
> +}
>
>  #endif /* _INTEL_LRC_H_ */
>