drm/xe: reset mmio mappings with devm

Set our various mmio mappings to NULL. This should make it easier to
catch something rogue trying to mess with mmio after device removal. For
example, we might unmap everything and then start hitting some mmio
address which has already been unmamped by us and then remapped by
something else, causing all kinds of carnage.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522102143.128069-33-matthew.auld@intel.com

drivers/gpu/drm/xe/xe_device.c

@@ -555,7 +555,9 @@ int xe_device_probe(struct xe_device *xe)
 	if (err)
 		return err;
 
-	xe_mmio_probe_tiles(xe);
+	err = xe_mmio_probe_tiles(xe);
+	if (err)
+		return err;
 
 	xe_ttm_sys_mgr_init(xe);
 

drivers/gpu/drm/xe/xe_mmio.c

@@ -258,6 +258,21 @@ static int xe_mmio_tile_vram_size(struct xe_tile *tile, u64 *vram_size,
 	return xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
 }
 
+static void vram_fini(void *arg)
+{
+	struct xe_device *xe = 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)
+		tile->mem.vram.mapping = NULL;
+}
+
 int xe_mmio_probe_vram(struct xe_device *xe)
 {
 	struct xe_tile *tile;
@@ -334,10 +349,20 @@ int xe_mmio_probe_vram(struct xe_device *xe)
 	drm_info(&xe->drm, "Available VRAM: %pa, %pa\n", &xe->mem.vram.io_start,
 		 &available_size);
 
-	return 0;
+	return devm_add_action_or_reset(xe->drm.dev, vram_fini, xe);
 }
 
-void xe_mmio_probe_tiles(struct xe_device *xe)
+static void tiles_fini(void *arg)
+{
+	struct xe_device *xe = arg;
+	struct xe_tile *tile;
+	int id;
+
+	for_each_tile(tile, xe, id)
+		tile->mmio.regs = NULL;
+}
+
+int xe_mmio_probe_tiles(struct xe_device *xe)
 {
 	size_t tile_mmio_size = SZ_16M, tile_mmio_ext_size = xe->info.tile_mmio_ext_size;
 	u8 id, tile_count = xe->info.tile_count;
@@ -388,6 +413,8 @@ void xe_mmio_probe_tiles(struct xe_device *xe)
 			regs += tile_mmio_ext_size;
 		}
 	}
+
+	return devm_add_action_or_reset(xe->drm.dev, tiles_fini, xe);
 }
 
 static void mmio_fini(void *arg)
@@ -395,10 +422,6 @@ static void mmio_fini(void *arg)
 	struct xe_device *xe = arg;
 
 	pci_iounmap(to_pci_dev(xe->drm.dev), xe->mmio.regs);
-	if (xe->mem.vram.mapping)
-		iounmap(xe->mem.vram.mapping);
-
-	xe->mem.vram.mapping = NULL;
 	xe->mmio.regs = NULL;
 }
 

drivers/gpu/drm/xe/xe_mmio.h

@@ -14,7 +14,7 @@ struct xe_reg;
 #define LMEM_BAR		2
 
 int xe_mmio_init(struct xe_device *xe);
-void xe_mmio_probe_tiles(struct xe_device *xe);
+int xe_mmio_probe_tiles(struct xe_device *xe);
 
 u8 xe_mmio_read8(struct xe_gt *gt, struct xe_reg reg);
 u16 xe_mmio_read16(struct xe_gt *gt, struct xe_reg reg);