drm/xe: Replace xe_ttm_vram_mgr.tile with xe_mem_region

Replace the xe_ttm_vram_mgr.tile pointer with a xe_mem_region pointer
instead. The former is currently unused.
TTM VRAM regions are exposing device vram and is better to store a pointer
directly to the xe_mem_region instead of the tile. This allows to cleanup
unnecessary usage of xe_tile from xe_bo.c in later patch.

Signed-off-by: Brian Welty <[e-mail]>
Reviewed-by: Matthew Brost <[e-mail]>
Signed-off-by: Rodrigo Vivi <[e-mail]>

drivers/gpu/drm/xe/xe_ttm_vram_mgr.c

···
 int xe_ttm_vram_mgr_init(struct xe_tile *tile, struct xe_ttm_vram_mgr *mgr)
 {
 	struct xe_device *xe = tile_to_xe(tile);
+	struct xe_mem_region *vram = &tile->mem.vram;
 
-	mgr->tile = tile;
-
+	mgr->vram = vram;
 	return __xe_ttm_vram_mgr_init(xe, mgr, XE_PL_VRAM0 + tile->id,
-				      tile->mem.vram.usable_size,
-				      tile->mem.vram.io_size,
+				      vram->usable_size, vram->io_size,
 				      PAGE_SIZE);
 }
 

drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h

···
 #include <drm/drm_buddy.h>
 #include <drm/ttm/ttm_device.h>
 
-struct xe_tile;
+struct xe_mem_region;
 
 /**
  * struct xe_ttm_vram_mgr - XE TTM VRAM manager
···
  * Manages placement of TTM resource in VRAM.
  */
 struct xe_ttm_vram_mgr {
-	/** @tile: Tile which the VRAM belongs to */
-	struct xe_tile *tile;
 	/** @manager: Base TTM resource manager */
 	struct ttm_resource_manager manager;
 	/** @mm: DRM buddy allocator which manages the VRAM */
 	struct drm_buddy mm;
+	/** @vram: ptr to details of associated VRAM region */
+	struct xe_mem_region *vram;
 	/** @visible_size: Proped size of the CPU visible portion */
 	u64 visible_size;
 	/** @visible_avail: CPU visible portion still unallocated */