xref: /openbmc/linux/drivers/nvdimm/label.h (revision bf9bccc14c05dae8caba29df6187c731710f5380)
1 /*
2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  */
13 #ifndef __LABEL_H__
14 #define __LABEL_H__
15 
16 #include <linux/ndctl.h>
17 #include <linux/sizes.h>
18 #include <linux/io.h>
19 
20 enum {
21 	NSINDEX_SIG_LEN = 16,
22 	NSINDEX_ALIGN = 256,
23 	NSINDEX_SEQ_MASK = 0x3,
24 	NSLABEL_UUID_LEN = 16,
25 	NSLABEL_NAME_LEN = 64,
26 	NSLABEL_FLAG_ROLABEL = 0x1,  /* read-only label */
27 	NSLABEL_FLAG_LOCAL = 0x2,    /* DIMM-local namespace */
28 	NSLABEL_FLAG_BTT = 0x4,      /* namespace contains a BTT */
29 	NSLABEL_FLAG_UPDATING = 0x8, /* label being updated */
30 	BTT_ALIGN = 4096,            /* all btt structures */
31 	BTTINFO_SIG_LEN = 16,
32 	BTTINFO_UUID_LEN = 16,
33 	BTTINFO_FLAG_ERROR = 0x1,    /* error state (read-only) */
34 	BTTINFO_MAJOR_VERSION = 1,
35 	ND_LABEL_MIN_SIZE = 512 * 129, /* see sizeof_namespace_index() */
36 	ND_LABEL_ID_SIZE = 50,
37 };
38 
39 static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
40 
41 /**
42  * struct nd_namespace_index - label set superblock
43  * @sig: NAMESPACE_INDEX\0
44  * @flags: placeholder
45  * @seq: sequence number for this index
46  * @myoff: offset of this index in label area
47  * @mysize: size of this index struct
48  * @otheroff: offset of other index
49  * @labeloff: offset of first label slot
50  * @nslot: total number of label slots
51  * @major: label area major version
52  * @minor: label area minor version
53  * @checksum: fletcher64 of all fields
54  * @free[0]: bitmap, nlabel bits
55  *
56  * The size of free[] is rounded up so the total struct size is a
57  * multiple of NSINDEX_ALIGN bytes.  Any bits this allocates beyond
58  * nlabel bits must be zero.
59  */
60 struct nd_namespace_index {
61 	u8 sig[NSINDEX_SIG_LEN];
62 	__le32 flags;
63 	__le32 seq;
64 	__le64 myoff;
65 	__le64 mysize;
66 	__le64 otheroff;
67 	__le64 labeloff;
68 	__le32 nslot;
69 	__le16 major;
70 	__le16 minor;
71 	__le64 checksum;
72 	u8 free[0];
73 };
74 
75 /**
76  * struct nd_namespace_label - namespace superblock
77  * @uuid: UUID per RFC 4122
78  * @name: optional name (NULL-terminated)
79  * @flags: see NSLABEL_FLAG_*
80  * @nlabel: num labels to describe this ns
81  * @position: labels position in set
82  * @isetcookie: interleave set cookie
83  * @lbasize: LBA size in bytes or 0 for pmem
84  * @dpa: DPA of NVM range on this DIMM
85  * @rawsize: size of namespace
86  * @slot: slot of this label in label area
87  * @unused: must be zero
88  */
89 struct nd_namespace_label {
90 	u8 uuid[NSLABEL_UUID_LEN];
91 	u8 name[NSLABEL_NAME_LEN];
92 	__le32 flags;
93 	__le16 nlabel;
94 	__le16 position;
95 	__le64 isetcookie;
96 	__le64 lbasize;
97 	__le64 dpa;
98 	__le64 rawsize;
99 	__le32 slot;
100 	__le32 unused;
101 };
102 
103 /**
104  * struct nd_label_id - identifier string for dpa allocation
105  * @id: "{blk|pmem}-<namespace uuid>"
106  */
107 struct nd_label_id {
108 	char id[ND_LABEL_ID_SIZE];
109 };
110 
111 /*
112  * If the 'best' index is invalid, so is the 'next' index.  Otherwise,
113  * the next index is MOD(index+1, 2)
114  */
115 static inline int nd_label_next_nsindex(int index)
116 {
117 	if (index < 0)
118 		return -1;
119 
120 	return (index + 1) % 2;
121 }
122 
123 struct nvdimm_drvdata;
124 int nd_label_validate(struct nvdimm_drvdata *ndd);
125 void nd_label_copy(struct nvdimm_drvdata *ndd, struct nd_namespace_index *dst,
126 		struct nd_namespace_index *src);
127 size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd);
128 int nd_label_active_count(struct nvdimm_drvdata *ndd);
129 struct nd_namespace_label *nd_label_active(struct nvdimm_drvdata *ndd, int n);
130 #endif /* __LABEL_H__ */
131