Re: [PATCH v2 15/15] drm/xe/nvlp: Bump maximum WOPCM size

["Bhadane, Dnyaneshwar" <dnyaneshwar.bhadane@intel.com>]

On 06-Feb-26 5:09 AM, Gustavo Sousa wrote:
> On NVL-P, the primary GT's WOPCM gained an extra 8MiB for the Memory
> URB.  As such, we need to bump the maximum size in the driver so that
> the driver is able to load without erroring out thinking that the WOPCM
> is too small.
> 
> FIXME: The wopcm code in xe driver is a bit confusing.  For the case
> where the offsets for GUC WOPCM are already locked, it appears we are
> using the maximum overall WOPCM size instead of the sizes relative to
> each type of GT.  The function __check_layout() should be checking
> against the latter.
> 
> Bspec: 67090
> Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
LGTM,
Reviewed-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_wopcm.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_wopcm.c b/drivers/gpu/drm/xe/xe_wopcm.c
> index dde4f4967ca3..900daf1d1b1b 100644
> --- a/drivers/gpu/drm/xe/xe_wopcm.c
> +++ b/drivers/gpu/drm/xe/xe_wopcm.c
> @@ -55,8 +55,6 @@
>   #define MTL_WOPCM_SIZE			SZ_4M
>   #define WOPCM_SIZE			SZ_2M
>   
> -#define MAX_WOPCM_SIZE			SZ_8M
> -
>   /* 16KB WOPCM (RSVD WOPCM) is reserved from HuC firmware top. */
>   #define WOPCM_RESERVED_SIZE		SZ_16K
>   
> @@ -186,6 +184,14 @@ u32 xe_wopcm_size(struct xe_device *xe)
>   		WOPCM_SIZE;
>   }
>   
> +static u32 max_wopcm_size(struct xe_device *xe)
> +{
> +	if (xe->info.platform == XE_NOVALAKE_P)
> +		return SZ_16M;
> +	else
> +		return SZ_8M;
> +}
> +
>   /**
>    * xe_wopcm_init() - Initialize the WOPCM structure.
>    * @wopcm: pointer to xe_wopcm.
> @@ -227,8 +233,11 @@ int xe_wopcm_init(struct xe_wopcm *wopcm)
>   		 * 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.
> +		 *
> +		 * FIXME: This is giving the maximum overall WOPCM size and not
> +		 * the size relative to each GT.
>   		 */
> -		wopcm->size = MAX_WOPCM_SIZE;
> +		wopcm->size = max_wopcm_size(xe);
>   
>   		goto check;
>   	}
>