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Dan Williams8c2f7e82015-06-25 04:20:04 -04001/*
2 * Block Translation Table library
3 * Copyright (c) 2014-2015, Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 */
14
15#ifndef _LINUX_BTT_H
16#define _LINUX_BTT_H
17
18#include <linux/types.h>
19
20#define BTT_SIG_LEN 16
21#define BTT_SIG "BTT_ARENA_INFO\0"
Vishal Verma5212e112015-06-25 04:20:32 -040022#define MAP_ENT_SIZE 4
23#define MAP_TRIM_SHIFT 31
24#define MAP_TRIM_MASK (1 << MAP_TRIM_SHIFT)
25#define MAP_ERR_SHIFT 30
26#define MAP_ERR_MASK (1 << MAP_ERR_SHIFT)
27#define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT)))
28#define MAP_ENT_NORMAL 0xC0000000
29#define LOG_ENT_SIZE sizeof(struct log_entry)
30#define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */
31#define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */
32#define RTT_VALID (1UL << 31)
33#define RTT_INVALID 0
Vishal Verma5212e112015-06-25 04:20:32 -040034#define BTT_PG_SIZE 4096
35#define BTT_DEFAULT_NFREE ND_MAX_LANES
36#define LOG_SEQ_INIT 1
37
38#define IB_FLAG_ERROR 0x00000001
39#define IB_FLAG_ERROR_MASK 0x00000001
40
41enum btt_init_state {
42 INIT_UNCHECKED = 0,
43 INIT_NOTFOUND,
44 INIT_READY
45};
46
47struct log_entry {
48 __le32 lba;
49 __le32 old_map;
50 __le32 new_map;
51 __le32 seq;
52 __le64 padding[2];
53};
Dan Williams8c2f7e82015-06-25 04:20:04 -040054
55struct btt_sb {
56 u8 signature[BTT_SIG_LEN];
57 u8 uuid[16];
58 u8 parent_uuid[16];
59 __le32 flags;
60 __le16 version_major;
61 __le16 version_minor;
62 __le32 external_lbasize;
63 __le32 external_nlba;
64 __le32 internal_lbasize;
65 __le32 internal_nlba;
66 __le32 nfree;
67 __le32 infosize;
68 __le64 nextoff;
69 __le64 dataoff;
70 __le64 mapoff;
71 __le64 logoff;
72 __le64 info2off;
73 u8 padding[3968];
74 __le64 checksum;
75};
76
Vishal Verma5212e112015-06-25 04:20:32 -040077struct free_entry {
78 u32 block;
79 u8 sub;
80 u8 seq;
81};
82
83struct aligned_lock {
84 union {
85 spinlock_t lock;
86 u8 cacheline_padding[L1_CACHE_BYTES];
87 };
88};
89
90/**
91 * struct arena_info - handle for an arena
92 * @size: Size in bytes this arena occupies on the raw device.
93 * This includes arena metadata.
94 * @external_lba_start: The first external LBA in this arena.
95 * @internal_nlba: Number of internal blocks available in the arena
96 * including nfree reserved blocks
97 * @internal_lbasize: Internal and external lba sizes may be different as
98 * we can round up 'odd' external lbasizes such as 520B
99 * to be aligned.
100 * @external_nlba: Number of blocks contributed by the arena to the number
101 * reported to upper layers. (internal_nlba - nfree)
102 * @external_lbasize: LBA size as exposed to upper layers.
103 * @nfree: A reserve number of 'free' blocks that is used to
104 * handle incoming writes.
105 * @version_major: Metadata layout version major.
106 * @version_minor: Metadata layout version minor.
107 * @nextoff: Offset in bytes to the start of the next arena.
108 * @infooff: Offset in bytes to the info block of this arena.
109 * @dataoff: Offset in bytes to the data area of this arena.
110 * @mapoff: Offset in bytes to the map area of this arena.
111 * @logoff: Offset in bytes to the log area of this arena.
112 * @info2off: Offset in bytes to the backup info block of this arena.
113 * @freelist: Pointer to in-memory list of free blocks
114 * @rtt: Pointer to in-memory "Read Tracking Table"
115 * @map_locks: Spinlocks protecting concurrent map writes
116 * @nd_btt: Pointer to parent nd_btt structure.
117 * @list: List head for list of arenas
118 * @debugfs_dir: Debugfs dentry
119 * @flags: Arena flags - may signify error states.
120 *
121 * arena_info is a per-arena handle. Once an arena is narrowed down for an
122 * IO, this struct is passed around for the duration of the IO.
123 */
124struct arena_info {
125 u64 size; /* Total bytes for this arena */
126 u64 external_lba_start;
127 u32 internal_nlba;
128 u32 internal_lbasize;
129 u32 external_nlba;
130 u32 external_lbasize;
131 u32 nfree;
132 u16 version_major;
133 u16 version_minor;
134 /* Byte offsets to the different on-media structures */
135 u64 nextoff;
136 u64 infooff;
137 u64 dataoff;
138 u64 mapoff;
139 u64 logoff;
140 u64 info2off;
141 /* Pointers to other in-memory structures for this arena */
142 struct free_entry *freelist;
143 u32 *rtt;
144 struct aligned_lock *map_locks;
145 struct nd_btt *nd_btt;
146 struct list_head list;
147 struct dentry *debugfs_dir;
148 /* Arena flags */
149 u32 flags;
150};
151
152/**
153 * struct btt - handle for a BTT instance
154 * @btt_disk: Pointer to the gendisk for BTT device
155 * @btt_queue: Pointer to the request queue for the BTT device
156 * @arena_list: Head of the list of arenas
157 * @debugfs_dir: Debugfs dentry
158 * @nd_btt: Parent nd_btt struct
159 * @nlba: Number of logical blocks exposed to the upper layers
160 * after removing the amount of space needed by metadata
161 * @rawsize: Total size in bytes of the available backing device
162 * @lbasize: LBA size as requested and presented to upper layers.
163 * This is sector_size + size of any metadata.
164 * @sector_size: The Linux sector size - 512 or 4096
165 * @lanes: Per-lane spinlocks
166 * @init_lock: Mutex used for the BTT initialization
167 * @init_state: Flag describing the initialization state for the BTT
168 * @num_arenas: Number of arenas in the BTT instance
169 */
170struct btt {
171 struct gendisk *btt_disk;
172 struct request_queue *btt_queue;
173 struct list_head arena_list;
174 struct dentry *debugfs_dir;
175 struct nd_btt *nd_btt;
176 u64 nlba;
177 unsigned long long rawsize;
178 u32 lbasize;
179 u32 sector_size;
180 struct nd_region *nd_region;
181 struct mutex init_lock;
182 int init_state;
183 int num_arenas;
184};
Vishal Vermaab45e762015-07-29 14:58:08 -0600185
186bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super);
187
Dan Williams8c2f7e82015-06-25 04:20:04 -0400188#endif