Re: [PATCH v3 3/7] drm/xe/xe_device: Reintroduce xe_device_get_gt

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 10/14/2025 6:48 PM, Jonathan Cavitt wrote:
> Reintroduce the function xe_device_get_gt, as it was earlier renamed to
> xe_device_lookup_gt.  It performs the same functionality as
> xe_device_lookup_gt, but it guarantees the xe_gt pointer returned is not
> NULL using an assertion.

assert() does not guarantee anything, it will just WARN if cond is false 

> 
> Suggested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.h | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index 807db49a5306..af9476879454 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -97,6 +97,21 @@ static inline struct xe_gt *xe_device_lookup_gt(struct xe_device *xe, u8 gt_id)
>  	return gt;
>  }
>  
> +/**
> + * xe_device_get_gt() - Same as xe_device_lookup_gt, but return must not be NULL
> + * @xe: The XE device to search
> + * @gt_id: The ID of the GT to search for
> + *
> + * Returns a pointer to the xe_gt struct with the given gt_id.
> + */
> +static inline struct xe_gt *xe_device_get_gt(struct xe_device *xe, u8 gt_id)
> +{
> +	struct xe_gt *gt = xe_device_lookup_gt(xe, gt_id);
> +
> +	xe_assert(xe, gt);

and IMO this trick will not fool the tool as it may still say that gt returned
by the xe_device_lookup_gt() can be NULL, returned here as-is, and caller does
not check for NULL

unless you explicitly tell the tool that xe_assert() is something more than WARN
and it should stop processing at that point, but that is another abuse IMO 

> +	return gt;
> +}
> +
>  /*
>   * Provide a GT structure suitable for performing non-GT MMIO operations against
>   * the primary tile.  Primarily intended for early tile initialization, display