linux/drivers/nvdimm/pfn.h
<<
>>
Prefs
   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