1 /* 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" 22 #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_GRP_SIZE sizeof(struct log_group) 30 #define LOG_ENT_SIZE sizeof(struct log_entry) 31 #define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */ 32 #define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */ 33 #define RTT_VALID (1UL << 31) 34 #define RTT_INVALID 0 35 #define BTT_PG_SIZE 4096 36 #define BTT_DEFAULT_NFREE ND_MAX_LANES 37 #define LOG_SEQ_INIT 1 38 39 #define IB_FLAG_ERROR 0x00000001 40 #define IB_FLAG_ERROR_MASK 0x00000001 41 42 enum btt_init_state { 43 INIT_UNCHECKED = 0, 44 INIT_NOTFOUND, 45 INIT_READY 46 }; 47 48 /* 49 * A log group represents one log 'lane', and consists of four log entries. 50 * Two of the four entries are valid entries, and the remaining two are 51 * padding. Due to an old bug in the padding location, we need to perform a 52 * test to determine the padding scheme being used, and use that scheme 53 * thereafter. 54 * 55 * In kernels prior to 4.15, 'log group' would have actual log entries at 56 * indices (0, 2) and padding at indices (1, 3), where as the correct/updated 57 * format has log entries at indices (0, 1) and padding at indices (2, 3). 58 * 59 * Old (pre 4.15) format: 60 * +-----------------+-----------------+ 61 * | ent[0] | ent[1] | 62 * | 16B | 16B | 63 * | lba/old/new/seq | pad | 64 * +-----------------------------------+ 65 * | ent[2] | ent[3] | 66 * | 16B | 16B | 67 * | lba/old/new/seq | pad | 68 * +-----------------+-----------------+ 69 * 70 * New format: 71 * +-----------------+-----------------+ 72 * | ent[0] | ent[1] | 73 * | 16B | 16B | 74 * | lba/old/new/seq | lba/old/new/seq | 75 * +-----------------------------------+ 76 * | ent[2] | ent[3] | 77 * | 16B | 16B | 78 * | pad | pad | 79 * +-----------------+-----------------+ 80 * 81 * We detect during start-up which format is in use, and set 82 * arena->log_index[(0, 1)] with the detected format. 83 */ 84 85 struct log_entry { 86 __le32 lba; 87 __le32 old_map; 88 __le32 new_map; 89 __le32 seq; 90 }; 91 92 struct log_group { 93 struct log_entry ent[4]; 94 }; 95 96 struct btt_sb { 97 u8 signature[BTT_SIG_LEN]; 98 u8 uuid[16]; 99 u8 parent_uuid[16]; 100 __le32 flags; 101 __le16 version_major; 102 __le16 version_minor; 103 __le32 external_lbasize; 104 __le32 external_nlba; 105 __le32 internal_lbasize; 106 __le32 internal_nlba; 107 __le32 nfree; 108 __le32 infosize; 109 __le64 nextoff; 110 __le64 dataoff; 111 __le64 mapoff; 112 __le64 logoff; 113 __le64 info2off; 114 u8 padding[3968]; 115 __le64 checksum; 116 }; 117 118 struct free_entry { 119 u32 block; 120 u8 sub; 121 u8 seq; 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 * @nextoff: Offset in bytes to the start of the next arena. 149 * @infooff: Offset in bytes to the info block of this arena. 150 * @dataoff: Offset in bytes to the data area of this arena. 151 * @mapoff: Offset in bytes to the map area of this arena. 152 * @logoff: Offset in bytes to the log area of this arena. 153 * @info2off: Offset in bytes to the backup info block of this arena. 154 * @freelist: Pointer to in-memory list of free blocks 155 * @rtt: Pointer to in-memory "Read Tracking Table" 156 * @map_locks: Spinlocks protecting concurrent map writes 157 * @nd_btt: Pointer to parent nd_btt structure. 158 * @list: List head for list of arenas 159 * @debugfs_dir: Debugfs dentry 160 * @flags: Arena flags - may signify error states. 161 * @log_index: Indices of the valid log entries in a log_group 162 * 163 * arena_info is a per-arena handle. Once an arena is narrowed down for an 164 * IO, this struct is passed around for the duration of the IO. 165 */ 166 struct arena_info { 167 u64 size; /* Total bytes for this arena */ 168 u64 external_lba_start; 169 u32 internal_nlba; 170 u32 internal_lbasize; 171 u32 external_nlba; 172 u32 external_lbasize; 173 u32 nfree; 174 u16 version_major; 175 u16 version_minor; 176 /* Byte offsets to the different on-media structures */ 177 u64 nextoff; 178 u64 infooff; 179 u64 dataoff; 180 u64 mapoff; 181 u64 logoff; 182 u64 info2off; 183 /* Pointers to other in-memory structures for this arena */ 184 struct free_entry *freelist; 185 u32 *rtt; 186 struct aligned_lock *map_locks; 187 struct nd_btt *nd_btt; 188 struct list_head list; 189 struct dentry *debugfs_dir; 190 /* Arena flags */ 191 u32 flags; 192 int log_index[2]; 193 }; 194 195 /** 196 * struct btt - handle for a BTT instance 197 * @btt_disk: Pointer to the gendisk for BTT device 198 * @btt_queue: Pointer to the request queue for the BTT device 199 * @arena_list: Head of the list of arenas 200 * @debugfs_dir: Debugfs dentry 201 * @nd_btt: Parent nd_btt struct 202 * @nlba: Number of logical blocks exposed to the upper layers 203 * after removing the amount of space needed by metadata 204 * @rawsize: Total size in bytes of the available backing device 205 * @lbasize: LBA size as requested and presented to upper layers. 206 * This is sector_size + size of any metadata. 207 * @sector_size: The Linux sector size - 512 or 4096 208 * @lanes: Per-lane spinlocks 209 * @init_lock: Mutex used for the BTT initialization 210 * @init_state: Flag describing the initialization state for the BTT 211 * @num_arenas: Number of arenas in the BTT instance 212 */ 213 struct btt { 214 struct gendisk *btt_disk; 215 struct request_queue *btt_queue; 216 struct list_head arena_list; 217 struct dentry *debugfs_dir; 218 struct nd_btt *nd_btt; 219 u64 nlba; 220 unsigned long long rawsize; 221 u32 lbasize; 222 u32 sector_size; 223 struct nd_region *nd_region; 224 struct mutex init_lock; 225 int init_state; 226 int num_arenas; 227 }; 228 229 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); 230 231 #endif 232