Re: [PATCH v3 07/11] drm/xe/xe2hpg: Remove extra allocation of CCS pages for dgfx

[Matt Roper <matthew.d.roper@intel.com>]

On Mon, Apr 08, 2024 at 10:35:41PM +0530, Balasubramani Vivekanandan wrote:
> From: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
> 
> On Xe2 dGPU, compression is only supported with VRAM. When copying from
> VRAM -> system memory the KMD uses mapping with uncompressed PAT
> so the copy in system memory is guaranteed to be uncompressed.
> When restoring such buffers from system memory -> VRAM the KMD can't
> easily know which pages were originally compressed, so we always use
> uncompressed -> uncompressed here.
> so this means that there's no need for extra CCS storage on such
> platforms.
> 
> v2: More description added to commit message
> 
> Signed-off-by: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_bo.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 6166bc715656..fdeb3691d3f6 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -2201,6 +2201,9 @@ bool xe_bo_needs_ccs_pages(struct xe_bo *bo)
>  {
>  	struct xe_device *xe = xe_bo_device(bo);
>  
> +	if (GRAPHICS_VER(xe) >= 20 && IS_DGFX(xe))
> +		return false;
> +
>  	if (!xe_device_has_flat_ccs(xe) || bo->ttm.type != ttm_bo_type_device)
>  		return false;
>  
> -- 
> 2.25.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation