Re: [Intel-gfx] [PATCH v2 3/4] drm/i915/gt: Poll aux invalidation register bit on invalidation

[Nirmoy Das <nirmoy.das@linux.intel.com>]

On 6/27/2023 11:43 AM, Andi Shyti wrote:
> From: Jonathan Cavitt <jonathan.cavitt@intel.com>
>
> For platforms that use Aux CCS, wait for aux invalidation to
> complete by checking the aux invalidation register bit is
> cleared.
>
> Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>   drivers/gpu/drm/i915/gt/gen8_engine_cs.c     | 17 +++++++++++++----
>   drivers/gpu/drm/i915/gt/intel_gpu_commands.h |  1 +
>   2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> index e10e1ad0e841f..83cddd9cb8b56 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> @@ -174,6 +174,16 @@ u32 *gen12_emit_aux_table_inv(struct intel_gt *gt, u32 *cs, const i915_reg_t inv
>   	*cs++ = AUX_INV;
>   	*cs++ = MI_NOOP;
>   
> +	*cs++ = MI_SEMAPHORE_WAIT_TOKEN |
> +		MI_SEMAPHORE_REGISTER_POLL |
> +		MI_SEMAPHORE_POLL |
> +		MI_SEMAPHORE_SAD_EQ_SDD;
> +	*cs++ = 0;
> +	*cs++ = i915_mmio_reg_offset(inv_reg) + gsi_offset;
> +	*cs++ = 0;
> +	*cs++ = 0;
> +	*cs++ = MI_NOOP;
> +
>   	return cs;
>   }
>   
> @@ -274,10 +284,9 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>   		else if (engine->class == COMPUTE_CLASS)
>   			flags &= ~PIPE_CONTROL_3D_ENGINE_FLAGS;
>   
> +		count = 8;
>   		if (!HAS_FLAT_CCS(rq->engine->i915))
> -			count = 8 + 4;
> -		else
> -			count = 8;
> +			count += 10;
>   
>   		cs = intel_ring_begin(rq, count);
>   		if (IS_ERR(cs))
> @@ -320,7 +329,7 @@ int gen12_emit_flush_xcs(struct i915_request *rq, u32 mode)
>   			aux_inv = rq->engine->mask &
>   				~GENMASK(_BCS(I915_MAX_BCS - 1), BCS0);
>   			if (aux_inv)
> -				cmd += 4;
> +				cmd += 10;
>   		}
>   	}
>   
> diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> index 5d143e2a8db03..02125a1db2796 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> @@ -121,6 +121,7 @@
>   #define   MI_SEMAPHORE_TARGET(engine)	((engine)<<15)
>   #define MI_SEMAPHORE_WAIT	MI_INSTR(0x1c, 2) /* GEN8+ */
>   #define MI_SEMAPHORE_WAIT_TOKEN	MI_INSTR(0x1c, 3) /* GEN12+ */
> +#define   MI_SEMAPHORE_REGISTER_POLL	(1 << 16)
>   #define   MI_SEMAPHORE_POLL		(1 << 15)
>   #define   MI_SEMAPHORE_SAD_GT_SDD	(0 << 12)
>   #define   MI_SEMAPHORE_SAD_GTE_SDD	(1 << 12)