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