[PATCH v3.1 6/6] drm/xe/xe_query: Use separate iterator while filling GT list

[Cavitt, Jonathan]

-----Original Message-----
From: Roper, Matthew D <matthew.d.roper at intel.com> 
Sent: Monday, June 30, 2025 3:15 PM
To: intel-xe at lists.freedesktop.org
Cc: Roper, Matthew D <matthew.d.roper at intel.com>; Cavitt, Jonathan <jonathan.cavitt at intel.com>
Subject: [PATCH v3.1 6/6] drm/xe/xe_query: Use separate iterator while filling GT list
> 
> The 'id' value updated by for_each_gt() is the uapi GT ID of the GTs
> being iterated over, and may skip over values if a GT is not present on
> the device.  Use a separate iterator for GT list array assignments to
> ensure that the array will be filled properly on future platforms where
> index in the GT query list may not match the uapi ID.
> 
> v2:
>  - Include the missing increment of the iterator.  (Jonathan)
> 
> Cc: Jonathan Cavitt <jonathan.cavitt at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>

This is just to prevent the query ioctl from changing its behavior
after the update, yes?

If that's the case:
Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
-Jonathan Cavitt

> ---
>  drivers/gpu/drm/xe/xe_query.c | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
> index e615b0916217..d517ec9ddcbf 100644
> --- a/drivers/gpu/drm/xe/xe_query.c
> +++ b/drivers/gpu/drm/xe/xe_query.c
> @@ -368,6 +368,7 @@ static int query_gt_list(struct xe_device *xe, struct drm_xe_device_query *query
>  	struct drm_xe_query_gt_list __user *query_ptr =
>  		u64_to_user_ptr(query->data);
>  	struct drm_xe_query_gt_list *gt_list;
> +	int iter = 0;
>  	u8 id;
>  
>  	if (query->size == 0) {
> @@ -385,12 +386,12 @@ static int query_gt_list(struct xe_device *xe, struct drm_xe_device_query *query
>  
>  	for_each_gt(gt, xe, id) {
>  		if (xe_gt_is_media_type(gt))
> -			gt_list->gt_list[id].type = DRM_XE_QUERY_GT_TYPE_MEDIA;
> +			gt_list->gt_list[iter].type = DRM_XE_QUERY_GT_TYPE_MEDIA;
>  		else
> -			gt_list->gt_list[id].type = DRM_XE_QUERY_GT_TYPE_MAIN;
> -		gt_list->gt_list[id].tile_id = gt_to_tile(gt)->id;
> -		gt_list->gt_list[id].gt_id = gt->info.id;
> -		gt_list->gt_list[id].reference_clock = gt->info.reference_clock;
> +			gt_list->gt_list[iter].type = DRM_XE_QUERY_GT_TYPE_MAIN;
> +		gt_list->gt_list[iter].tile_id = gt_to_tile(gt)->id;
> +		gt_list->gt_list[iter].gt_id = gt->info.id;
> +		gt_list->gt_list[iter].reference_clock = gt->info.reference_clock;
>  		/*
>  		 * The mem_regions indexes in the mask below need to
>  		 * directly identify the struct
> @@ -406,19 +407,21 @@ static int query_gt_list(struct xe_device *xe, struct drm_xe_device_query *query
>  		 * assumption.
>  		 */
>  		if (!IS_DGFX(xe))
> -			gt_list->gt_list[id].near_mem_regions = 0x1;
> +			gt_list->gt_list[iter].near_mem_regions = 0x1;
>  		else
> -			gt_list->gt_list[id].near_mem_regions =
> +			gt_list->gt_list[iter].near_mem_regions =
>  				BIT(gt_to_tile(gt)->id) << 1;
> -		gt_list->gt_list[id].far_mem_regions = xe->info.mem_region_mask ^
> -			gt_list->gt_list[id].near_mem_regions;
> +		gt_list->gt_list[iter].far_mem_regions = xe->info.mem_region_mask ^
> +			gt_list->gt_list[iter].near_mem_regions;
>  
> -		gt_list->gt_list[id].ip_ver_major =
> +		gt_list->gt_list[iter].ip_ver_major =
>  			REG_FIELD_GET(GMD_ID_ARCH_MASK, gt->info.gmdid);
> -		gt_list->gt_list[id].ip_ver_minor =
> +		gt_list->gt_list[iter].ip_ver_minor =
>  			REG_FIELD_GET(GMD_ID_RELEASE_MASK, gt->info.gmdid);
> -		gt_list->gt_list[id].ip_ver_rev =
> +		gt_list->gt_list[iter].ip_ver_rev =
>  			REG_FIELD_GET(GMD_ID_REVID, gt->info.gmdid);
> +
> +		iter++;
>  	}
>  
>  	if (copy_to_user(query_ptr, gt_list, size)) {
> -- 
> 2.49.0
> 
>