drivers/nvdimm/pfn.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (c) 2014-2015, Intel Corporation.
0004  */
0005
0006 #ifndef __NVDIMM_PFN_H
0007 #define __NVDIMM_PFN_H
0008
0009 #include <linux/types.h>
0010 #include <linux/mmzone.h>
0011
0012 #define PFN_SIG_LEN 16
0013 #define PFN_SIG "NVDIMM_PFN_INFO\0"
0014 #define DAX_SIG "NVDIMM_DAX_INFO\0"
0015
0016 struct nd_pfn_sb {
0017     u8 signature[PFN_SIG_LEN];
0018     u8 uuid[16];
0019     u8 parent_uuid[16];
0020     __le32 flags;
0021     __le16 version_major;
0022     __le16 version_minor;
0023     __le64 dataoff; /* relative to namespace_base + start_pad */
0024     __le64 npfns;
0025     __le32 mode;
0026     /* minor-version-1 additions for section alignment */
0027     /**
0028      * @start_pad: Deprecated attribute to pad start-misaligned namespaces
0029      *
0030      * start_pad is deprecated because the original definition did
0031      * not comprehend that dataoff is relative to the base address
0032      * of the namespace not the start_pad adjusted base. The result
0033      * is that the dax path is broken, but the block-I/O path is
0034      * not. The kernel will no longer create namespaces using start
0035      * padding, but it still supports block-I/O for legacy
0036      * configurations mainly to allow a backup, reconfigure the
0037      * namespace, and restore flow to repair dax operation.
0038      */
0039     __le32 start_pad;
0040     __le32 end_trunc;
0041     /* minor-version-2 record the base alignment of the mapping */
0042     __le32 align;
0043     /* minor-version-3 guarantee the padding and flags are zero */
0044     /* minor-version-4 record the page size and struct page size */
0045     __le32 page_size;
0046     __le16 page_struct_size;
0047     u8 padding[3994];
0048     __le64 checksum;
0049 };
0050
0051 #endif /* __NVDIMM_PFN_H */