[PATCH v2 2/5] drm/xe/sriov: Prepare IS_SRIOV_PF to accept const pointer

[Matt Roper]

On Mon, Feb 24, 2025 at 04:06:57PM +0100, Michal Wajdeczko wrote:
> For builds without CONFIG_PCI_IOV we have an optimized variant
> of the IS_SRIOV_PF(xe) macro that always evaluates to false,
> but we still try to validate corectness of the xe argument.
> Unfortunately typecheck() alone doesn't work well for cases
> where xe could be a const pointer. Try use _Generic() instead.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

I wonder if it would be any more intuitive to just make a static inline
function to get the type-checking?  E.g.,

  static inline bool IS_SRIOV_PF(struct xe_device *xe) { return false; }

But if _Generic works, that's fine too.

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

> ---
>  drivers/gpu/drm/xe/xe_sriov.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_sriov.h b/drivers/gpu/drm/xe/xe_sriov.h
> index 688fbabf08f1..cba6a608bf27 100644
> --- a/drivers/gpu/drm/xe/xe_sriov.h
> +++ b/drivers/gpu/drm/xe/xe_sriov.h
> @@ -38,7 +38,7 @@ static inline bool xe_device_is_sriov_vf(const struct xe_device *xe)
>  #ifdef CONFIG_PCI_IOV
>  #define IS_SRIOV_PF(xe) xe_device_is_sriov_pf(xe)
>  #else
> -#define IS_SRIOV_PF(xe) (typecheck(struct xe_device *, (xe)) && false)
> +#define IS_SRIOV_PF(xe) _Generic((xe), const struct xe_device * : false, struct xe_device * : false)
>  #endif
>  #define IS_SRIOV_VF(xe) xe_device_is_sriov_vf(xe)
>  
> -- 
> 2.47.1
> 

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