drivers/nvdimm/pfn.h

   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
  16 struct 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 */