[PATCH 2/3] drm/xe: Check valid domain is passed in xe_force_wake_ref

[Michal Wajdeczko]

On 06.06.2024 14:41, Himal Prasad Ghimiray wrote:
> Assert in case of multiple or invalid domains are passed.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: Badal Nilawar <badal.nilawar at intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_force_wake.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_force_wake.h b/drivers/gpu/drm/xe/xe_force_wake.h
> index cee8ff039f83..067afcdde429 100644
> --- a/drivers/gpu/drm/xe/xe_force_wake.h
> +++ b/drivers/gpu/drm/xe/xe_force_wake.h
> @@ -24,7 +24,9 @@ static inline int
>  xe_force_wake_ref(struct xe_force_wake *fw,
>  		  enum xe_force_wake_domains domain)
>  {
> -	xe_gt_assert(fw->gt, domain);
> +	xe_gt_assert(fw->gt, domain && (domain < XE_FORCEWAKE_ALL));
> +	xe_gt_assert(fw->gt, !(domain & (domain - 1)));
> +

that should be sufficient:

	xe_gt_assert(fw->gt, domain != XE_FORCEWAKE_ALL);

but if you really want to be paranoid then add:

	xe_gt_assert(fw->gt, is_power_of_2(domain));

and then you can likely use ilog2 below:

 	return fw->domains[ilog2(domain)].ref;

>  	return fw->domains[ffs(domain) - 1].ref;
>  }
>