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/badblocks.h> 19 #include <linux/types.h> 20 21 #define BTT_SIG_LEN 16 22 #define BTT_SIG "BTT_ARENA_INFO\0" 23 #define MAP_ENT_SIZE 4 24 #define MAP_TRIM_SHIFT 31 25 #define MAP_TRIM_MASK (1 << MAP_TRIM_SHIFT) 26 #define MAP_ERR_SHIFT 30 27 #define MAP_ERR_MASK (1 << MAP_ERR_SHIFT) 28 #define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT))) 29 #define MAP_ENT_NORMAL 0xC0000000 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 #define ent_lba(ent) (ent & MAP_LBA_MASK) 43 #define ent_e_flag(ent) (!!(ent & MAP_ERR_MASK)) 44 #define ent_z_flag(ent) (!!(ent & MAP_TRIM_MASK)) 45 #define set_e_flag(ent) (ent |= MAP_ERR_MASK) 46 47 enum btt_init_state { 48 INIT_UNCHECKED = 0, 49 INIT_NOTFOUND, 50 INIT_READY 51 }; 52 53 struct log_entry { 54 __le32 lba; 55 __le32 old_map; 56 __le32 new_map; 57 __le32 seq; 58 __le64 padding[2]; 59 }; 60 61 struct btt_sb { 62 u8 signature[BTT_SIG_LEN]; 63 u8 uuid[16]; 64 u8 parent_uuid[16]; 65 __le32 flags; 66 __le16 version_major; 67 __le16 version_minor; 68 __le32 external_lbasize; 69 __le32 external_nlba; 70 __le32 internal_lbasize; 71 __le32 internal_nlba; 72 __le32 nfree; 73 __le32 infosize; 74 __le64 nextoff; 75 __le64 dataoff; 76 __le64 mapoff; 77 __le64 logoff; 78 __le64 info2off; 79 u8 padding[3968]; 80 __le64 checksum; 81 }; 82 83 struct free_entry { 84 u32 block; 85 u8 sub; 86 u8 seq; 87 u8 has_err; 88 }; 89 90 struct aligned_lock { 91 union { 92 spinlock_t lock; 93 u8 cacheline_padding[L1_CACHE_BYTES]; 94 }; 95 }; 96 97 /** 98 * struct arena_info - handle for an arena 99 * @size: Size in bytes this arena occupies on the raw device. 100 * This includes arena metadata. 101 * @external_lba_start: The first external LBA in this arena. 102 * @internal_nlba: Number of internal blocks available in the arena 103 * including nfree reserved blocks 104 * @internal_lbasize: Internal and external lba sizes may be different as 105 * we can round up 'odd' external lbasizes such as 520B 106 * to be aligned. 107 * @external_nlba: Number of blocks contributed by the arena to the number 108 * reported to upper layers. (internal_nlba - nfree) 109 * @external_lbasize: LBA size as exposed to upper layers. 110 * @nfree: A reserve number of 'free' blocks that is used to 111 * handle incoming writes. 112 * @version_major: Metadata layout version major. 113 * @version_minor: Metadata layout version minor. 114 * @sector_size: The Linux sector size - 512 or 4096 115 * @nextoff: Offset in bytes to the start of the next arena. 116 * @infooff: Offset in bytes to the info block of this arena. 117 * @dataoff: Offset in bytes to the data area of this arena. 118 * @mapoff: Offset in bytes to the map area of this arena. 119 * @logoff: Offset in bytes to the log area of this arena. 120 * @info2off: Offset in bytes to the backup info block of this arena. 121 * @freelist: Pointer to in-memory list of free blocks 122 * @rtt: Pointer to in-memory "Read Tracking Table" 123 * @map_locks: Spinlocks protecting concurrent map writes 124 * @nd_btt: Pointer to parent nd_btt structure. 125 * @list: List head for list of arenas 126 * @debugfs_dir: Debugfs dentry 127 * @flags: Arena flags - may signify error states. 128 * 129 * arena_info is a per-arena handle. Once an arena is narrowed down for an 130 * IO, this struct is passed around for the duration of the IO. 131 */ 132 struct arena_info { 133 u64 size; /* Total bytes for this arena */ 134 u64 external_lba_start; 135 u32 internal_nlba; 136 u32 internal_lbasize; 137 u32 external_nlba; 138 u32 external_lbasize; 139 u32 nfree; 140 u16 version_major; 141 u16 version_minor; 142 u32 sector_size; 143 /* Byte offsets to the different on-media structures */ 144 u64 nextoff; 145 u64 infooff; 146 u64 dataoff; 147 u64 mapoff; 148 u64 logoff; 149 u64 info2off; 150 /* Pointers to other in-memory structures for this arena */ 151 struct free_entry *freelist; 152 u32 *rtt; 153 struct aligned_lock *map_locks; 154 struct nd_btt *nd_btt; 155 struct list_head list; 156 struct dentry *debugfs_dir; 157 /* Arena flags */ 158 u32 flags; 159 struct mutex err_lock; 160 }; 161 162 /** 163 * struct btt - handle for a BTT instance 164 * @btt_disk: Pointer to the gendisk for BTT device 165 * @btt_queue: Pointer to the request queue for the BTT device 166 * @arena_list: Head of the list of arenas 167 * @debugfs_dir: Debugfs dentry 168 * @nd_btt: Parent nd_btt struct 169 * @nlba: Number of logical blocks exposed to the upper layers 170 * after removing the amount of space needed by metadata 171 * @rawsize: Total size in bytes of the available backing device 172 * @lbasize: LBA size as requested and presented to upper layers. 173 * This is sector_size + size of any metadata. 174 * @sector_size: The Linux sector size - 512 or 4096 175 * @lanes: Per-lane spinlocks 176 * @init_lock: Mutex used for the BTT initialization 177 * @init_state: Flag describing the initialization state for the BTT 178 * @num_arenas: Number of arenas in the BTT instance 179 */ 180 struct btt { 181 struct gendisk *btt_disk; 182 struct request_queue *btt_queue; 183 struct list_head arena_list; 184 struct dentry *debugfs_dir; 185 struct nd_btt *nd_btt; 186 u64 nlba; 187 unsigned long long rawsize; 188 u32 lbasize; 189 u32 sector_size; 190 struct nd_region *nd_region; 191 struct mutex init_lock; 192 int init_state; 193 int num_arenas; 194 struct badblocks *phys_bb; 195 }; 196 197 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); 198 int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, 199 struct btt_sb *btt_sb); 200 201 #endif 202