[Intel-xe] [PATCH] drm/xe: Use max wopcm size when validating the preset GuC wopcm size

[Matthew Brost]

On Fri, Mar 17, 2023 at 10:23:35PM +0530, Balasubramani Vivekanandan wrote:
> When the GuC wopcm base and size registers are populated by BIOS/IFWI,
> validate the parameters against the maximum allowed wopcm size.
> 
> Bpsec: 44982
> 
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>

Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_wopcm.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_wopcm.c b/drivers/gpu/drm/xe/xe_wopcm.c
> index 0f2485d9d9af..d55469e941bf 100644
> --- a/drivers/gpu/drm/xe/xe_wopcm.c
> +++ b/drivers/gpu/drm/xe/xe_wopcm.c
> @@ -54,6 +54,8 @@
>  						   for MTL, do a proper probe
>  						   sooner or later */
>  #define GEN11_WOPCM_SIZE		SZ_2M
> +
> +#define GEN12_MAX_WOPCM_SIZE            SZ_8M
>  /* 16KB WOPCM (RSVD WOPCM) is reserved from HuC firmware top. */
>  #define WOPCM_RESERVED_SIZE		SZ_16K
>  
> @@ -226,6 +228,13 @@ int xe_wopcm_init(struct xe_wopcm *wopcm)
>  	if (locked) {
>  		drm_dbg(&xe->drm, "GuC WOPCM is already locked [%uK, %uK)\n",
>  			guc_wopcm_base / SZ_1K, guc_wopcm_size / SZ_1K);
> +		/*
> +		 * When the GuC wopcm base and size are preprogrammed by
> +		 * BIOS/IFWI, check against the max allowed wopcm size to
> +		 * validate if the programmed values align to the wopcm layout.
> +		 */
> +		wopcm->size = GEN12_MAX_WOPCM_SIZE;
> +
>  		goto check;
>  	}
>  
> -- 
> 2.34.1
>