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_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 34#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}; 54 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 77struct 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}; 185 186bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); 187 188#endif 189