xref: /freebsd/sys/contrib/openzfs/include/os/linux/kernel/linux/mm_compat.h (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright (c) 2023, 2024, Klara Inc.
25  * Copyright (c) 2024, Rob Norris <robn@despairlabs.com>
26  */
27 
28 #ifndef _ZFS_MM_COMPAT_H
29 #define	_ZFS_MM_COMPAT_H
30 
31 #include <linux/mm.h>
32 #include <linux/pagemap.h>
33 
34 /* 5.4 introduced page_size(). Older kernels can use a trivial macro instead */
35 #ifndef HAVE_MM_PAGE_SIZE
36 #define	page_size(p) ((unsigned long)(PAGE_SIZE << compound_order(p)))
37 #endif
38 
39 /* 6.11 removed page_mapping(). A simple wrapper around folio_mapping() works */
40 #ifndef HAVE_MM_PAGE_MAPPING
41 #define	page_mapping(p) folio_mapping(page_folio(p))
42 #endif
43 
44 /*
45  * 6.12 removed PG_error, SetPageError and ClearPageError, with no direct
46  * replacement, because page writeback errors are recorded elsewhere. Since we
47  * only use the page cache to assist with mmap(), never directly backing it
48  * with IO, it shouldn't be possible for this condition to occur on our pages
49  * anyway, even if this is the right way to report it. So it should be safe
50  * to remove, but for avoidance of doubt, we make it a no-op on 6.12 and leave
51  * it for everything else.
52  */
53 #ifndef HAVE_MM_PAGE_FLAG_ERROR
54 #define	SetPageError(p)		do {} while (0)
55 #define	ClearPageError(p)	do {} while (0)
56 #endif
57 
58 #endif /* _ZFS_MM_COMPAT_H */
59