Re: [PATCH v2 1/2] drm/xe: Separate 64K physical allocation for display

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

On Tue, Jul 09, 2024 at 02:25:13PM +0200, Zbigniew Kempczyński wrote:
> In case Tile4 + compression Battlemage requires physical 64K pages
> for allocating display framebuffer. Add flag which distincts
> buffer created for scanout from other buffers which don't need this
> restriction.

I believe these 2 patches could be squashed together because this
phrase here is the explanation for the next patch as well and
that one just tell what it is doing without telling why.

> 
> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
> v2: Distinct 64K for Battlemage only (Matt)
> ---
>  drivers/gpu/drm/xe/xe_bo.c           | 9 +++++++--
>  drivers/gpu/drm/xe/xe_device_types.h | 1 +
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 31192d983d9e..fbcf77698bf1 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -1984,9 +1984,13 @@ int xe_gem_create_ioctl(struct drm_device *dev, void *data,
>  	if (args->flags & DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING)
>  		bo_flags |= XE_BO_FLAG_DEFER_BACKING;
>  
> -	if (args->flags & DRM_XE_GEM_CREATE_FLAG_SCANOUT)
> +	if (args->flags & DRM_XE_GEM_CREATE_FLAG_SCANOUT) {
>  		bo_flags |= XE_BO_FLAG_SCANOUT;
>  
> +		if (xe->info.vram_flags & XE_VRAM_FLAGS_DISPLAY_NEED64K)
> +			bo_flags |= XE_BO_NEEDS_64K;
> +	}
> +
>  	bo_flags |= args->placement << (ffs(XE_BO_FLAG_SYSTEM) - 1);
>  
>  	if (args->flags & DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM) {
> @@ -2315,8 +2319,9 @@ int xe_bo_dumb_create(struct drm_file *file_priv,
>  	uint32_t handle;
>  	int cpp = DIV_ROUND_UP(args->bpp, 8);
>  	int err;
> +	u8 flags_64k = XE_VRAM_FLAGS_NEED64K | XE_VRAM_FLAGS_DISPLAY_NEED64K;
>  	u32 page_size = max_t(u32, PAGE_SIZE,
> -		xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : SZ_4K);
> +		xe->info.vram_flags & flags_64k ? SZ_64K : SZ_4K);
>  
>  	args->pitch = ALIGN(args->width * cpp, 64);
>  	args->size = ALIGN(mul_u32_u32(args->pitch, args->height),
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index f0cf9020e463..386faaffac53 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -46,6 +46,7 @@ struct xe_pat_ops;
>  #define HAS_HECI_GSCFI(xe) ((xe)->info.has_heci_gscfi)
>  
>  #define XE_VRAM_FLAGS_NEED64K		BIT(0)
> +#define XE_VRAM_FLAGS_DISPLAY_NEED64K	BIT(1)

I was wondering if we could simply reuse the existing flag, but probably looking
at the next patch I believe that it could be intrusive and cause other issues.
So, let's go with this.

>  
>  #define XE_GT0		0
>  #define XE_GT1		1
> -- 
> 2.34.1
>