diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
index fce890b6410c..8dd818e1184c 100644
--- a/drivers/gpu/drm/xe/xe_mmio.c
+++ b/drivers/gpu/drm/xe/xe_mmio.c
@@ -101,13 +101,18 @@ int xe_mmio_probe_early(struct xe_device *xe)
 	struct xe_tile *root_tile = xe_device_get_root_tile(xe);
 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
 
-	xe->mmio.size = pci_resource_len(pdev, GTTMMADR_BAR);
 	xe->mmio.regs = pcim_iomap(pdev, GTTMMADR_BAR, 0);
 	if (!xe->mmio.regs) {
 		xe_err(xe, "Failed to map GTTMMADR_BAR\n");
 		return -EIO;
 	}
 
+	xe->mmio.size = pci_resource_len(pdev, GTTMMADR_BAR);
+	if (xe->mmio.size < SZ_16M) {
+		xe_err(xe, "GTTMMADR_BAR is too small: %zu\n", xe->mmio.size);
+		return -EIO;
+	}
+
 	/* Setup first tile; other tiles (if present) will be setup later. */
 	xe_mmio_init(&root_tile->mmio, root_tile, xe->mmio.regs, SZ_4M);