Re: [igt-dev] [PATCH i-g-t 2/2] lib: Apply rightmost execution mask to xehp gpu walker

["Grzegorzek, Dominik" <dominik.grzegorzek@intel.com>]

On Fri, 2023-06-09 at 11:37 +0200, Christoph Manszewski wrote:
> The final thread group in each row may need partial execution (not the
> full simd16) in order to fit within the region of interest.
> 
> Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
> Signed-off-by: Christoph Manszewski <christoph.manszewski@intel.com>

Reviewed-by: Dominik Grzegorzek <dominik.grzegorzek@intel.com>
> ---
>  lib/gpu_cmds.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/gpu_cmds.c b/lib/gpu_cmds.c
> index aecba928..48fe1e13 100644
> --- a/lib/gpu_cmds.c
> +++ b/lib/gpu_cmds.c
> @@ -953,7 +953,7 @@ xehp_emit_compute_walk(struct intel_bb *ibb,
>  		       struct xehp_interface_descriptor_data *pidd,
>  		       uint8_t color)
>  {
> -	uint32_t x_dim, y_dim;
> +	uint32_t x_dim, y_dim, mask;
>  
>  	/*
>  	 * Simply do SIMD16 based dispatch, so every thread uses
> @@ -969,6 +969,12 @@ xehp_emit_compute_walk(struct intel_bb *ibb,
>  	x_dim = (x + width + 15) / 16;
>  	y_dim = y + height;
>  
> +	mask = (x + width) & 15;
> +	if (mask == 0)
> +		mask = (1 << 16) - 1;
> +	else
> +		mask = (1 << mask) - 1;
> +
>  	intel_bb_out(ibb, XEHP_COMPUTE_WALKER | 0x25);
>  
>  	intel_bb_out(ibb, 0); /* debug object */		//dw1
> @@ -980,7 +986,7 @@ xehp_emit_compute_walk(struct intel_bb *ibb,
>  	intel_bb_out(ibb, 1 << 30 | 1 << 25 | 1 << 17);		//dw4
>  
>  	/* Execution mask */
> -	intel_bb_out(ibb, 0xffffffff);				//dw5
> +	intel_bb_out(ibb, mask);				//dw5
>  
>  	/* x/y/z max */
>  	intel_bb_out(ibb, (x_dim << 20) | (y_dim << 10) | 1);	//dw6