Re: [Intel-gfx] [PATCH V2] drm/i915/gt: Use hw_engine_masks as reset_domains

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Dec 06, 2021 at 01:40:26PM +0530, Tejas Upadhyay wrote:
> We need a way to reset engines by their reset domains.
> This change sets up way to fetch reset domains of each
> engine globally.
> 
> Changes since V1:
> 	- Use static reset domain array - Ville and Tvrtko
> 	- Use BUG_ON at appropriate place - Tvrtko
> 
> Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_engine_cs.c    | 32 ++++++++++++++++++++
>  drivers/gpu/drm/i915/gt/intel_engine_types.h |  1 +
>  drivers/gpu/drm/i915/gt/intel_reset.c        | 29 ++----------------
>  3 files changed, 35 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index f2ccd5b53d42..352254e001b4 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -325,6 +325,38 @@ static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id,
>  	engine->id = id;
>  	engine->legacy_idx = INVALID_ENGINE;
>  	engine->mask = BIT(id);
> +	if (GRAPHICS_VER(gt->i915) >= 11) {
> +		static const u32 engine_reset_domains[] = {
> +			[RCS0]  = GEN11_GRDOM_RENDER,
> +			[BCS0]  = GEN11_GRDOM_BLT,
> +			[VCS0]  = GEN11_GRDOM_MEDIA,
> +			[VCS1]  = GEN11_GRDOM_MEDIA2,
> +			[VCS2]  = GEN11_GRDOM_MEDIA3,
> +			[VCS3]  = GEN11_GRDOM_MEDIA4,
> +			[VCS4]  = GEN11_GRDOM_MEDIA5,
> +			[VCS5]  = GEN11_GRDOM_MEDIA6,
> +			[VCS6]  = GEN11_GRDOM_MEDIA7,
> +			[VCS7]  = GEN11_GRDOM_MEDIA8,
> +			[VECS0] = GEN11_GRDOM_VECS,
> +			[VECS1] = GEN11_GRDOM_VECS2,
> +			[VECS2] = GEN11_GRDOM_VECS3,
> +			[VECS3] = GEN11_GRDOM_VECS4,
> +		};
> +		GEM_BUG_ON(id >= ARRAY_SIZE(engine_reset_domains) ||

> +			   !engine_reset_domains[id]);

I was worried about this new addition to the check, but apparently
it works because no Reset domain is == 0....
Well, not sure if we won't have any in the future, but you
are right, probably better to protect the current cases than
wonder about a theoretical future one.

> +		engine->reset_domain = engine_reset_domains[id];
> +	} else {
> +		static const u32 engine_reset_domains[] = {
> +			[RCS0]  = GEN6_GRDOM_RENDER,
> +			[BCS0]  = GEN6_GRDOM_BLT,
> +			[VCS0]  = GEN6_GRDOM_MEDIA,
> +			[VCS1]  = GEN8_GRDOM_MEDIA2,
> +			[VECS0] = GEN6_GRDOM_VECS,
> +		};
> +		GEM_BUG_ON(id >= ARRAY_SIZE(engine_reset_domains) ||
> +			   !engine_reset_domains[id]);
> +		engine->reset_domain = engine_reset_domains[id];
> +	}

probably better if we could have a function for this.
engine->reset_domain = intel_reset_domain()... or something like that...

but not blocker... the patch looks good to me:

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

>  	engine->i915 = i915;
>  	engine->gt = gt;
>  	engine->uncore = gt->uncore;
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> index 5732e0d71513..36365bdbe1ee 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> @@ -318,6 +318,7 @@ struct intel_engine_cs {
>  	unsigned int guc_id;
>  
>  	intel_engine_mask_t mask;
> +	u32 reset_domain;
>  	/**
>  	 * @logical_mask: logical mask of engine, reported to user space via
>  	 * query IOCTL and used to communicate with the GuC in logical space.
> diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
> index 0fbd6dbadce7..63199f0550e6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_reset.c
> +++ b/drivers/gpu/drm/i915/gt/intel_reset.c
> @@ -297,13 +297,6 @@ static int gen6_reset_engines(struct intel_gt *gt,
>  			      intel_engine_mask_t engine_mask,
>  			      unsigned int retry)
>  {
> -	static const u32 hw_engine_mask[] = {
> -		[RCS0]  = GEN6_GRDOM_RENDER,
> -		[BCS0]  = GEN6_GRDOM_BLT,
> -		[VCS0]  = GEN6_GRDOM_MEDIA,
> -		[VCS1]  = GEN8_GRDOM_MEDIA2,
> -		[VECS0] = GEN6_GRDOM_VECS,
> -	};
>  	struct intel_engine_cs *engine;
>  	u32 hw_mask;
>  
> @@ -314,8 +307,7 @@ static int gen6_reset_engines(struct intel_gt *gt,
>  
>  		hw_mask = 0;
>  		for_each_engine_masked(engine, gt, engine_mask, tmp) {
> -			GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
> -			hw_mask |= hw_engine_mask[engine->id];
> +			hw_mask |= engine->reset_domain;
>  		}
>  	}
>  
> @@ -492,22 +484,6 @@ static int gen11_reset_engines(struct intel_gt *gt,
>  			       intel_engine_mask_t engine_mask,
>  			       unsigned int retry)
>  {
> -	static const u32 hw_engine_mask[] = {
> -		[RCS0]  = GEN11_GRDOM_RENDER,
> -		[BCS0]  = GEN11_GRDOM_BLT,
> -		[VCS0]  = GEN11_GRDOM_MEDIA,
> -		[VCS1]  = GEN11_GRDOM_MEDIA2,
> -		[VCS2]  = GEN11_GRDOM_MEDIA3,
> -		[VCS3]  = GEN11_GRDOM_MEDIA4,
> -		[VCS4]  = GEN11_GRDOM_MEDIA5,
> -		[VCS5]  = GEN11_GRDOM_MEDIA6,
> -		[VCS6]  = GEN11_GRDOM_MEDIA7,
> -		[VCS7]  = GEN11_GRDOM_MEDIA8,
> -		[VECS0] = GEN11_GRDOM_VECS,
> -		[VECS1] = GEN11_GRDOM_VECS2,
> -		[VECS2] = GEN11_GRDOM_VECS3,
> -		[VECS3] = GEN11_GRDOM_VECS4,
> -	};
>  	struct intel_engine_cs *engine;
>  	intel_engine_mask_t tmp;
>  	u32 reset_mask, unlock_mask = 0;
> @@ -518,8 +494,7 @@ static int gen11_reset_engines(struct intel_gt *gt,
>  	} else {
>  		reset_mask = 0;
>  		for_each_engine_masked(engine, gt, engine_mask, tmp) {
> -			GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
> -			reset_mask |= hw_engine_mask[engine->id];
> +			reset_mask |= engine->reset_domain;
>  			ret = gen11_lock_sfc(engine, &reset_mask, &unlock_mask);
>  			if (ret)
>  				goto sfc_unlock;
> -- 
> 2.31.1
>