drm/xe: Use devm_ioremap_wc for VRAM mapping and drop manual unmap

[ Upstream commit 922ae875230be91c7f05f2aa90d176b6693e2601 ]

Let's replace the manual call to ioremap_wc function with devm_ioremap_wc
function, ensuring that VRAM mappings are automatically released when
the driver is detached.
Since devm_ioremap_wc registers the mapping with the device's managed
resources, the explicit iounmap call in vram_fini is no longer needed,
so let's remove it.

Signed-off-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Suggested-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250714184818.89201-2-piotr.piorkowski@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Stable-dep-of: d30203739be7 ("drm/xe: Move rebar to be done earlier")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: piorkov

drivers/gpu/drm/xe/xe_vram.c

@@ -156,7 +156,8 @@ static int determine_lmem_bar_size(struct xe_device *xe)
 	xe->mem.vram.dpa_base = 0;
 
 	/* set up a map to the total memory area. */
-	xe->mem.vram.mapping = ioremap_wc(xe->mem.vram.io_start, xe->mem.vram.io_size);
+	xe->mem.vram.mapping = devm_ioremap_wc(&pdev->dev, xe->mem.vram.io_start,
+					       xe->mem.vram.io_size);
 
 	return 0;
 }
@@ -278,9 +279,6 @@ static void vram_fini(void *arg)
 	struct xe_tile *tile;
 	int id;
 
-	if (xe->mem.vram.mapping)
-		iounmap(xe->mem.vram.mapping);
-
 	xe->mem.vram.mapping = NULL;
 
 	for_each_tile(tile, xe, id)