Re: [PATCH V15 07/14] drm/xe/vram: Extract buddy alloc and free helpers

On 11-08-2026 18:10, Tejas Upadhyay wrote:
> Factor out xe_ttm_vram_buddy_alloc() and xe_ttm_vram_buddy_free()
> from xe_ttm_vram_mgr_new() and xe_ttm_vram_mgr_del(). These helpers
> consolidate block allocation with visible-size tracking and
> block->private tagging, making them reusable by the upcoming VRAM
> page offline reservation path.
> 
> No functional change.

Reviewed-by: Himal Prasad Ghimiray <[email protected]>

> 
> Signed-off-by: Tejas Upadhyay <[email protected]>
> ---
>   drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 82 +++++++++++++++++-----------
>   1 file changed, 51 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> index 5ab5dfdb183c..49eeec90a470 100644
> --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> @@ -46,6 +46,40 @@ static inline bool xe_is_vram_mgr_blocks_contiguous(struct gpu_buddy *mm,
>   	return true;
>   }
>   
> +static int xe_ttm_vram_buddy_alloc(struct xe_ttm_vram_mgr *mgr, u64 start,
> +				   u64 end, u64 size, u64 min_page_size,
> +				   struct list_head *blocks, unsigned long flags,
> +				   void *priv, u64 *used_visible)
> +{
> +	struct gpu_buddy *mm = &mgr->mm;
> +	struct gpu_buddy_block *block;
> +	int err;
> +
> +	err = gpu_buddy_alloc_blocks(mm, start, end, size, min_page_size, blocks, flags);
> +	if (err)
> +		return err;
> +
> +	list_for_each_entry(block, blocks, link)
> +		block->private = priv;
> +
> +	if (end <= mgr->visible_size) {
> +		*used_visible = size;
> +	} else {
> +		list_for_each_entry(block, blocks, link) {
> +			u64 blk_start = gpu_buddy_block_offset(block);
> +
> +			if (blk_start < mgr->visible_size) {
> +				u64 blk_end = blk_start + gpu_buddy_block_size(mm, block);
> +
> +				*used_visible += min(blk_end, mgr->visible_size) - blk_start;
> +			}
> +		}
> +	}
> +
> +	mgr->visible_avail -= *used_visible;
> +	return 0;
> +}
> +
>   static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>   			       struct ttm_buffer_object *tbo,
>   			       const struct ttm_place *place,
> @@ -54,7 +88,6 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>   	struct xe_ttm_vram_mgr *mgr = to_xe_ttm_vram_mgr(man);
>   	struct xe_ttm_vram_mgr_resource *vres;
>   	struct gpu_buddy *mm = &mgr->mm;
> -	struct gpu_buddy_block *block;
>   	u64 size, min_page_size;
>   	unsigned long lpfn;
>   	int err;
> @@ -115,32 +148,12 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>   		goto error_unlock;
>   	}
>   
> -	err = gpu_buddy_alloc_blocks(mm, (u64)place->fpfn << PAGE_SHIFT,
> -				     (u64)lpfn << PAGE_SHIFT, size,
> -				     min_page_size, &vres->blocks, vres->flags);
> +	err = xe_ttm_vram_buddy_alloc(mgr, (u64)place->fpfn << PAGE_SHIFT,
> +				      (u64)lpfn << PAGE_SHIFT, size,
> +				      min_page_size, &vres->blocks, vres->flags,
> +				      tbo, &vres->used_visible_size);
>   	if (err)
>   		goto error_unlock;
> -
> -	if (lpfn <= mgr->visible_size >> PAGE_SHIFT) {
> -		vres->used_visible_size = size;
> -	} else {
> -		struct gpu_buddy_block *block;
> -
> -		list_for_each_entry(block, &vres->blocks, link) {
> -			u64 start = gpu_buddy_block_offset(block);
> -
> -			if (start < mgr->visible_size) {
> -				u64 end = start + gpu_buddy_block_size(mm, block);
> -
> -				vres->used_visible_size +=
> -					min(end, mgr->visible_size) - start;
> -			}
> -		}
> -	}
> -
> -	mgr->visible_avail -= vres->used_visible_size;
> -	list_for_each_entry(block, &vres->blocks, link)
> -		block->private = tbo;
>   	mutex_unlock(&mgr->lock);
>   
>   	if (!(vres->base.placement & TTM_PL_FLAG_CONTIGUOUS) &&
> @@ -172,20 +185,27 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>   	return err;
>   }
>   
> +static void xe_ttm_vram_buddy_free(struct xe_ttm_vram_mgr *mgr,
> +				   struct list_head *blocks,
> +				   u64 used_visible)
> +{
> +	struct gpu_buddy_block *block;
> +
> +	list_for_each_entry(block, blocks, link)
> +		block->private = NULL;
> +	gpu_buddy_free_list(&mgr->mm, blocks, 0);
> +	mgr->visible_avail += used_visible;
> +}
> +
>   static void xe_ttm_vram_mgr_del(struct ttm_resource_manager *man,
>   				struct ttm_resource *res)
>   {
>   	struct xe_ttm_vram_mgr_resource *vres =
>   		to_xe_ttm_vram_mgr_resource(res);
>   	struct xe_ttm_vram_mgr *mgr = to_xe_ttm_vram_mgr(man);
> -	struct gpu_buddy *mm = &mgr->mm;
> -	struct gpu_buddy_block *block;
>   
>   	mutex_lock(&mgr->lock);
> -	list_for_each_entry(block, &vres->blocks, link)
> -		block->private = NULL;
> -	gpu_buddy_free_list(mm, &vres->blocks, 0);
> -	mgr->visible_avail += vres->used_visible_size;
> +	xe_ttm_vram_buddy_free(mgr, &vres->blocks, vres->used_visible_size);
>   	mutex_unlock(&mgr->lock);
>   
>   	ttm_resource_fini(man, res);