[Intel-gfx] [PATCH 1/2] drm/i915/guc: Add GuC method to determine if submission is active.

[Daniele Ceraolo Spurio]

On 11/6/19 9:40 AM, don.hiatt at intel.com wrote:
> From: Don Hiatt <don.hiatt at intel.com>
> 
> Add intel_guc_submission_is_enabled() function to determine if
> GuC submission is active. Based on code by Michal Wajdeczko.
> 
> Signed-off-by: Don Hiatt <don.hiatt at intel.com>
> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c |  2 +-
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h |  1 +
>   drivers/gpu/drm/i915/i915_drv.h                   | 14 ++++++++++++++
>   3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 2498c55e0ea5..0aaef7c07879 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -1081,7 +1081,7 @@ static void guc_interrupts_release(struct intel_gt *gt)
>   	rps->pm_intrmsk_mbz &= ~ARAT_EXPIRED_INTRMSK;
>   }
>   
> -static void guc_set_default_submission(struct intel_engine_cs *engine)
> +void guc_set_default_submission(struct intel_engine_cs *engine)
>   {
>   	/*
>   	 * We inherit a bunch of functions from execlists that we'd like
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
> index 54d716828352..a0132f061ebc 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h
> @@ -63,5 +63,6 @@ void intel_guc_submission_disable(struct intel_guc *guc);
>   void intel_guc_submission_fini(struct intel_guc *guc);
>   int intel_guc_preempt_work_create(struct intel_guc *guc);
>   void intel_guc_preempt_work_destroy(struct intel_guc *guc);
> +void guc_set_default_submission(struct intel_engine_cs *engine);
>   
>   #endif
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7e0f67babe20..878d574bb1c1 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -78,8 +78,10 @@
>   
>   #include "gt/intel_lrc.h"
>   #include "gt/intel_engine.h"
> +#include "gt/intel_gt.h"
>   #include "gt/intel_gt_types.h"
>   #include "gt/intel_workarounds.h"
> +#include "gt/uc/intel_guc_submission.h"
>   #include "gt/uc/intel_uc.h"
>   
>   #include "intel_device_info.h"
> @@ -2032,4 +2034,16 @@ i915_coherent_map_type(struct drm_i915_private *i915)
>   	return HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC;
>   }
>   
> +static inline bool intel_guc_submission_is_enabled(struct intel_guc *guc)
> +{
> +	struct intel_gt *gt = guc_to_gt(guc);
> +	struct intel_engine_cs *engine;
> +	enum intel_engine_id id;
> +
> +	for_each_engine(engine, gt, id)
> +		return engine->set_default_submission ==
> +			guc_set_default_submission;
> +	return false;

It feels weird that we need to go look into the engines to understand if 
GuC submission is enabled or not. One of the patches I've sent earlier 
today ("drm/i915/guc: kill doorbell code and selftests") makes it so 
that intel_guc_submission_enable() can't fail, so after that it should 
be possible to have something like:

bool intel_guc_submission_is_enabled(struct intel_guc *guc) {
	return intel_guc_is_submission_supported(guc) &&
		intel_guc_is_running(guc);
}

AFAICS, even without my patch we do sanitize the GuC is 
intel_guc_submission_enable() fails, so the above should still work. If 
something like this doesn't fly, my preference would be to set something 
in intel_guc_submission_enable and check that instead of going inside 
the engines.
Michal, any input here?

Thanks,
Daniele

> +}
> +
>   #endif
>