xref: /openbmc/linux/drivers/nvdimm/label.h (revision 020c5260)
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 	ND_NSINDEX_INIT = 0x1,
38 };
39 
40 static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
41 
42 /**
43  * struct nd_namespace_index - label set superblock
44  * @sig: NAMESPACE_INDEX\0
45  * @flags: placeholder
46  * @seq: sequence number for this index
47  * @myoff: offset of this index in label area
48  * @mysize: size of this index struct
49  * @otheroff: offset of other index
50  * @labeloff: offset of first label slot
51  * @nslot: total number of label slots
52  * @major: label area major version
53  * @minor: label area minor version
54  * @checksum: fletcher64 of all fields
55  * @free[0]: bitmap, nlabel bits
56  *
57  * The size of free[] is rounded up so the total struct size is a
58  * multiple of NSINDEX_ALIGN bytes.  Any bits this allocates beyond
59  * nlabel bits must be zero.
60  */
61 struct nd_namespace_index {
62 	u8 sig[NSINDEX_SIG_LEN];
63 	__le32 flags;
64 	__le32 seq;
65 	__le64 myoff;
66 	__le64 mysize;
67 	__le64 otheroff;
68 	__le64 labeloff;
69 	__le32 nslot;
70 	__le16 major;
71 	__le16 minor;
72 	__le64 checksum;
73 	u8 free[0];
74 };
75 
76 /**
77  * struct nd_namespace_label - namespace superblock
78  * @uuid: UUID per RFC 4122
79  * @name: optional name (NULL-terminated)
80  * @flags: see NSLABEL_FLAG_*
81  * @nlabel: num labels to describe this ns
82  * @position: labels position in set
83  * @isetcookie: interleave set cookie
84  * @lbasize: LBA size in bytes or 0 for pmem
85  * @dpa: DPA of NVM range on this DIMM
86  * @rawsize: size of namespace
87  * @slot: slot of this label in label area
88  * @unused: must be zero
89  */
90 struct nd_namespace_label {
91 	u8 uuid[NSLABEL_UUID_LEN];
92 	u8 name[NSLABEL_NAME_LEN];
93 	__le32 flags;
94 	__le16 nlabel;
95 	__le16 position;
96 	__le64 isetcookie;
97 	__le64 lbasize;
98 	__le64 dpa;
99 	__le64 rawsize;
100 	__le32 slot;
101 	__le32 unused;
102 };
103 
104 /**
105  * struct nd_label_id - identifier string for dpa allocation
106  * @id: "{blk|pmem}-<namespace uuid>"
107  */
108 struct nd_label_id {
109 	char id[ND_LABEL_ID_SIZE];
110 };
111 
112 /*
113  * If the 'best' index is invalid, so is the 'next' index.  Otherwise,
114  * the next index is MOD(index+1, 2)
115  */
116 static inline int nd_label_next_nsindex(int index)
117 {
118 	if (index < 0)
119 		return -1;
120 
121 	return (index + 1) % 2;
122 }
123 
124 struct nvdimm_drvdata;
125 int nd_label_validate(struct nvdimm_drvdata *ndd);
126 void nd_label_copy(struct nvdimm_drvdata *ndd, struct nd_namespace_index *dst,
127 		struct nd_namespace_index *src);
128 size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd);
129 int nd_label_active_count(struct nvdimm_drvdata *ndd);
130 struct nd_namespace_label *nd_label_active(struct nvdimm_drvdata *ndd, int n);
131 u32 nd_label_alloc_slot(struct nvdimm_drvdata *ndd);
132 bool nd_label_free_slot(struct nvdimm_drvdata *ndd, u32 slot);
133 u32 nd_label_nfree(struct nvdimm_drvdata *ndd);
134 struct nd_region;
135 struct nd_namespace_pmem;
136 struct nd_namespace_blk;
137 int nd_pmem_namespace_label_update(struct nd_region *nd_region,
138 		struct nd_namespace_pmem *nspm, resource_size_t size);
139 int nd_blk_namespace_label_update(struct nd_region *nd_region,
140 		struct nd_namespace_blk *nsblk, resource_size_t size);
141 #endif /* __LABEL_H__ */
142