diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
index ab91be1405c9..2e6c94731a5a 100644
--- a/drivers/gpu/drm/xe/xe_mmio.c
+++ b/drivers/gpu/drm/xe/xe_mmio.c
@@ -300,7 +300,6 @@ void 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;
 	struct xe_gt *gt = xe_root_mmio_gt(xe);
-	const int mmio_bar = 0;
 	struct xe_tile *tile;
 	void *regs;
 	u32 mtcfg;
@@ -314,9 +313,6 @@ void xe_mmio_probe_tiles(struct xe_device *xe)
 		if (tile_count < xe->info.tile_count) {
 			drm_info(&xe->drm, "tile_count: %d, reduced_tile_count %d\n",
 					xe->info.tile_count, tile_count);
-			pci_iounmap(to_pci_dev(xe->drm.dev), xe->mmio.regs);
-			xe->mmio.size = (tile_mmio_size + tile_mmio_ext_size) * tile_count;
-			xe->mmio.regs = pci_iomap(to_pci_dev(xe->drm.dev), mmio_bar, xe->mmio.size);
 			xe->info.tile_count = tile_count;
 
 			/*
@@ -381,17 +377,17 @@ static int xe_verify_lmem_ready(struct xe_device *xe)
 int xe_mmio_init(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);
 	const int mmio_bar = 0;
 	int err;
 
 	/*
-	 * Map the maximum expected BAR size, which will get remapped later
-	 * if we determine that we're running on a reduced-tile system.
+	 * Map the entire BAR.
 	 * The first 16MB of the BAR, belong to the root tile, and include:
 	 * registers (0-4MB), reserved space (4MB-8MB) and GGTT (8MB-16MB).
 	 */
-	xe->mmio.size = (SZ_16M + xe->info.tile_mmio_ext_size) * xe->info.tile_count;
-	xe->mmio.regs = pci_iomap(to_pci_dev(xe->drm.dev), mmio_bar, xe->mmio.size);
+	xe->mmio.size = pci_resource_len(pdev, mmio_bar);
+	xe->mmio.regs = pci_iomap(pdev, mmio_bar, 0);
 	if (xe->mmio.regs == NULL) {
 		drm_err(&xe->drm, "failed to map registers\n");
 		return -EIO;