mm: add SPDX id lines to some mm source files

Some of the memory management source files are missing
SPDX-License-Identifier lines.  Add appropriate IDs
to these files (mostly GPL-2.0, but one LGPL-2.1).

Link: https://lkml.kernel.org/r/20260204213101.1754183-1-tim.bird@sony.com
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/dmapool_test.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/device.h>
 #include <linux/dma-map-ops.h>
 #include <linux/dma-mapping.h>

mm/folio-compat.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Compatibility functions which bloat the callers too much to make inline.
  * All of the callers of these functions should be converted to use folios

mm/gup_test.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/slab.h>

mm/hugetlb_cgroup.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: LGPL-2.1
 /*
  *
  * Copyright IBM Corporation, 2012
@@ -7,14 +8,6 @@
  * Copyright (C) 2019 Red Hat, Inc.
  * Author: Giuseppe Scrivano <gscrivan@redhat.com>
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
  */
 
 #include <linux/cgroup.h>

mm/memfd.c

@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * memfd_create system call and file sealing support
  *
  * Code was originally included in shmem.c, and broken out to facilitate
  * use by hugetlbfs as well as tmpfs.
- *
- * This file is released under the GPL.
  */
 
 #include <linux/fs.h>

mm/mmu_gather.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/gfp.h>
 #include <linux/highmem.h>
 #include <linux/kernel.h>

mm/rmap.c

@@ -1,8 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * mm/rmap.c - physical to virtual reverse mappings
  *
  * Copyright 2001, Rik van Riel <riel@conectiva.com.br>
- * Released under the General Public License (GPL).
  *
  * Simple, low overhead reverse mapping scheme.
  * Please try to keep this thing as modular as possible.

mm/shmem.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Resizable virtual memory filesystem for Linux.
  *
@@ -17,8 +18,6 @@
  *
  * tiny-shmem:
  * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com>
- *
- * This file is released under the GPL.
  */
 
 #include <linux/fs.h>