1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (c) 2014-2015, Intel Corporation.
4 */
5
6#ifndef __NVDIMM_PFN_H
7#define __NVDIMM_PFN_H
8
9#include <linux/types.h>
10#include <linux/mmzone.h>
11
12#define PFN_SIG_LEN 16
13#define PFN_SIG "NVDIMM_PFN_INFO\0"
14#define DAX_SIG "NVDIMM_DAX_INFO\0"
15
16struct nd_pfn_sb {
17	u8 signature[PFN_SIG_LEN];
18	u8 uuid[16];
19	u8 parent_uuid[16];
20	__le32 flags;
21	__le16 version_major;
22	__le16 version_minor;
23	__le64 dataoff; /* relative to namespace_base + start_pad */
24	__le64 npfns;
25	__le32 mode;
26	/* minor-version-1 additions for section alignment */
27	/**
28	 * @start_pad: Deprecated attribute to pad start-misaligned namespaces
29	 *
30	 * start_pad is deprecated because the original definition did
31	 * not comprehend that dataoff is relative to the base address
32	 * of the namespace not the start_pad adjusted base. The result
33	 * is that the dax path is broken, but the block-I/O path is
34	 * not. The kernel will no longer create namespaces using start
35	 * padding, but it still supports block-I/O for legacy
36	 * configurations mainly to allow a backup, reconfigure the
37	 * namespace, and restore flow to repair dax operation.
38	 */
39	__le32 start_pad;
40	__le32 end_trunc;
41	/* minor-version-2 record the base alignment of the mapping */
42	__le32 align;
43	/* minor-version-3 guarantee the padding and flags are zero */
44	/* minor-version-4 record the page size and struct page size */
45	__le32 page_size;
46	__le16 page_struct_size;
47	u8 padding[3994];
48	__le64 checksum;
49};
50
51#endif /* __NVDIMM_PFN_H */
52