1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * Block Translation Table library |
4 | * Copyright (c) 2014-2015, Intel Corporation. |
5 | */ |
6 | |
7 | #ifndef _LINUX_BTT_H |
8 | #define _LINUX_BTT_H |
9 | |
10 | #include <linux/types.h> |
11 | |
12 | #define BTT_SIG_LEN 16 |
13 | #define BTT_SIG "BTT_ARENA_INFO\0" |
14 | #define MAP_ENT_SIZE 4 |
15 | #define MAP_TRIM_SHIFT 31 |
16 | #define MAP_TRIM_MASK (1 << MAP_TRIM_SHIFT) |
17 | #define MAP_ERR_SHIFT 30 |
18 | #define MAP_ERR_MASK (1 << MAP_ERR_SHIFT) |
19 | #define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT))) |
20 | #define MAP_ENT_NORMAL 0xC0000000 |
21 | #define LOG_GRP_SIZE sizeof(struct log_group) |
22 | #define LOG_ENT_SIZE sizeof(struct log_entry) |
23 | #define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */ |
24 | #define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */ |
25 | #define RTT_VALID (1UL << 31) |
26 | #define RTT_INVALID 0 |
27 | #define BTT_PG_SIZE 4096 |
28 | #define BTT_DEFAULT_NFREE ND_MAX_LANES |
29 | #define LOG_SEQ_INIT 1 |
30 | |
31 | #define IB_FLAG_ERROR 0x00000001 |
32 | #define IB_FLAG_ERROR_MASK 0x00000001 |
33 | |
34 | #define ent_lba(ent) (ent & MAP_LBA_MASK) |
35 | #define ent_e_flag(ent) (!!(ent & MAP_ERR_MASK)) |
36 | #define ent_z_flag(ent) (!!(ent & MAP_TRIM_MASK)) |
37 | #define set_e_flag(ent) (ent |= MAP_ERR_MASK) |
38 | /* 'normal' is both e and z flags set */ |
39 | #define ent_normal(ent) (ent_e_flag(ent) && ent_z_flag(ent)) |
40 | |
41 | enum btt_init_state { |
42 | INIT_UNCHECKED = 0, |
43 | INIT_NOTFOUND, |
44 | INIT_READY |
45 | }; |
46 | |
47 | /* |
48 | * A log group represents one log 'lane', and consists of four log entries. |
49 | * Two of the four entries are valid entries, and the remaining two are |
50 | * padding. Due to an old bug in the padding location, we need to perform a |
51 | * test to determine the padding scheme being used, and use that scheme |
52 | * thereafter. |
53 | * |
54 | * In kernels prior to 4.15, 'log group' would have actual log entries at |
55 | * indices (0, 2) and padding at indices (1, 3), where as the correct/updated |
56 | * format has log entries at indices (0, 1) and padding at indices (2, 3). |
57 | * |
58 | * Old (pre 4.15) format: |
59 | * +-----------------+-----------------+ |
60 | * | ent[0] | ent[1] | |
61 | * | 16B | 16B | |
62 | * | lba/old/new/seq | pad | |
63 | * +-----------------------------------+ |
64 | * | ent[2] | ent[3] | |
65 | * | 16B | 16B | |
66 | * | lba/old/new/seq | pad | |
67 | * +-----------------+-----------------+ |
68 | * |
69 | * New format: |
70 | * +-----------------+-----------------+ |
71 | * | ent[0] | ent[1] | |
72 | * | 16B | 16B | |
73 | * | lba/old/new/seq | lba/old/new/seq | |
74 | * +-----------------------------------+ |
75 | * | ent[2] | ent[3] | |
76 | * | 16B | 16B | |
77 | * | pad | pad | |
78 | * +-----------------+-----------------+ |
79 | * |
80 | * We detect during start-up which format is in use, and set |
81 | * arena->log_index[(0, 1)] with the detected format. |
82 | */ |
83 | |
84 | struct log_entry { |
85 | __le32 lba; |
86 | __le32 old_map; |
87 | __le32 new_map; |
88 | __le32 seq; |
89 | }; |
90 | |
91 | struct log_group { |
92 | struct log_entry ent[4]; |
93 | }; |
94 | |
95 | struct btt_sb { |
96 | u8 signature[BTT_SIG_LEN]; |
97 | u8 uuid[16]; |
98 | u8 parent_uuid[16]; |
99 | __le32 flags; |
100 | __le16 version_major; |
101 | __le16 version_minor; |
102 | __le32 external_lbasize; |
103 | __le32 external_nlba; |
104 | __le32 internal_lbasize; |
105 | __le32 internal_nlba; |
106 | __le32 nfree; |
107 | __le32 infosize; |
108 | __le64 nextoff; |
109 | __le64 dataoff; |
110 | __le64 mapoff; |
111 | __le64 logoff; |
112 | __le64 info2off; |
113 | u8 padding[3968]; |
114 | __le64 checksum; |
115 | }; |
116 | |
117 | struct free_entry { |
118 | u32 block; |
119 | u8 sub; |
120 | u8 seq; |
121 | u8 has_err; |
122 | }; |
123 | |
124 | struct aligned_lock { |
125 | union { |
126 | spinlock_t lock; |
127 | u8 cacheline_padding[L1_CACHE_BYTES]; |
128 | }; |
129 | }; |
130 | |
131 | /** |
132 | * struct arena_info - handle for an arena |
133 | * @size: Size in bytes this arena occupies on the raw device. |
134 | * This includes arena metadata. |
135 | * @external_lba_start: The first external LBA in this arena. |
136 | * @internal_nlba: Number of internal blocks available in the arena |
137 | * including nfree reserved blocks |
138 | * @internal_lbasize: Internal and external lba sizes may be different as |
139 | * we can round up 'odd' external lbasizes such as 520B |
140 | * to be aligned. |
141 | * @external_nlba: Number of blocks contributed by the arena to the number |
142 | * reported to upper layers. (internal_nlba - nfree) |
143 | * @external_lbasize: LBA size as exposed to upper layers. |
144 | * @nfree: A reserve number of 'free' blocks that is used to |
145 | * handle incoming writes. |
146 | * @version_major: Metadata layout version major. |
147 | * @version_minor: Metadata layout version minor. |
148 | * @sector_size: The Linux sector size - 512 or 4096 |
149 | * @nextoff: Offset in bytes to the start of the next arena. |
150 | * @infooff: Offset in bytes to the info block of this arena. |
151 | * @dataoff: Offset in bytes to the data area of this arena. |
152 | * @mapoff: Offset in bytes to the map area of this arena. |
153 | * @logoff: Offset in bytes to the log area of this arena. |
154 | * @info2off: Offset in bytes to the backup info block of this arena. |
155 | * @freelist: Pointer to in-memory list of free blocks |
156 | * @rtt: Pointer to in-memory "Read Tracking Table" |
157 | * @map_locks: Spinlocks protecting concurrent map writes |
158 | * @nd_btt: Pointer to parent nd_btt structure. |
159 | * @list: List head for list of arenas |
160 | * @debugfs_dir: Debugfs dentry |
161 | * @flags: Arena flags - may signify error states. |
162 | * @err_lock: Mutex for synchronizing error clearing. |
163 | * @log_index: Indices of the valid log entries in a log_group |
164 | * |
165 | * arena_info is a per-arena handle. Once an arena is narrowed down for an |
166 | * IO, this struct is passed around for the duration of the IO. |
167 | */ |
168 | struct arena_info { |
169 | u64 size; /* Total bytes for this arena */ |
170 | u64 external_lba_start; |
171 | u32 internal_nlba; |
172 | u32 internal_lbasize; |
173 | u32 external_nlba; |
174 | u32 external_lbasize; |
175 | u32 nfree; |
176 | u16 version_major; |
177 | u16 version_minor; |
178 | u32 sector_size; |
179 | /* Byte offsets to the different on-media structures */ |
180 | u64 nextoff; |
181 | u64 infooff; |
182 | u64 dataoff; |
183 | u64 mapoff; |
184 | u64 logoff; |
185 | u64 info2off; |
186 | /* Pointers to other in-memory structures for this arena */ |
187 | struct free_entry *freelist; |
188 | u32 *rtt; |
189 | struct aligned_lock *map_locks; |
190 | struct nd_btt *nd_btt; |
191 | struct list_head list; |
192 | struct dentry *debugfs_dir; |
193 | /* Arena flags */ |
194 | u32 flags; |
195 | struct mutex err_lock; |
196 | int log_index[2]; |
197 | }; |
198 | |
199 | struct badblocks; |
200 | |
201 | /** |
202 | * struct btt - handle for a BTT instance |
203 | * @btt_disk: Pointer to the gendisk for BTT device |
204 | * @arena_list: Head of the list of arenas |
205 | * @debugfs_dir: Debugfs dentry |
206 | * @nd_btt: Parent nd_btt struct |
207 | * @nlba: Number of logical blocks exposed to the upper layers |
208 | * after removing the amount of space needed by metadata |
209 | * @rawsize: Total size in bytes of the available backing device |
210 | * @lbasize: LBA size as requested and presented to upper layers. |
211 | * This is sector_size + size of any metadata. |
212 | * @sector_size: The Linux sector size - 512 or 4096 |
213 | * @lanes: Per-lane spinlocks |
214 | * @init_lock: Mutex used for the BTT initialization |
215 | * @init_state: Flag describing the initialization state for the BTT |
216 | * @num_arenas: Number of arenas in the BTT instance |
217 | * @phys_bb: Pointer to the namespace's badblocks structure |
218 | */ |
219 | struct btt { |
220 | struct gendisk *btt_disk; |
221 | struct list_head arena_list; |
222 | struct dentry *debugfs_dir; |
223 | struct nd_btt *nd_btt; |
224 | u64 nlba; |
225 | unsigned long long rawsize; |
226 | u32 lbasize; |
227 | u32 sector_size; |
228 | struct nd_region *nd_region; |
229 | struct mutex init_lock; |
230 | int init_state; |
231 | int num_arenas; |
232 | struct badblocks *phys_bb; |
233 | }; |
234 | |
235 | bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); |
236 | int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, |
237 | struct btt_sb *btt_sb); |
238 | |
239 | #endif |
240 | |