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Diffstat (limited to 'drivers/nvdimm/btt.h')
| -rw-r--r-- | drivers/nvdimm/btt.h | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/nvdimm/btt.h b/drivers/nvdimm/btt.h new file mode 100644 index 000000000..0c76c0333 --- /dev/null +++ b/drivers/nvdimm/btt.h @@ -0,0 +1,239 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Block Translation Table library + * Copyright (c) 2014-2015, Intel Corporation. + */ + +#ifndef _LINUX_BTT_H +#define _LINUX_BTT_H + +#include <linux/types.h> + +#define BTT_SIG_LEN 16 +#define BTT_SIG "BTT_ARENA_INFO\0" +#define MAP_ENT_SIZE 4 +#define MAP_TRIM_SHIFT 31 +#define MAP_TRIM_MASK (1 << MAP_TRIM_SHIFT) +#define MAP_ERR_SHIFT 30 +#define MAP_ERR_MASK (1 << MAP_ERR_SHIFT) +#define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT))) +#define MAP_ENT_NORMAL 0xC0000000 +#define LOG_GRP_SIZE sizeof(struct log_group) +#define LOG_ENT_SIZE sizeof(struct log_entry) +#define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */ +#define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */ +#define RTT_VALID (1UL << 31) +#define RTT_INVALID 0 +#define BTT_PG_SIZE 4096 +#define BTT_DEFAULT_NFREE ND_MAX_LANES +#define LOG_SEQ_INIT 1 + +#define IB_FLAG_ERROR 0x00000001 +#define IB_FLAG_ERROR_MASK 0x00000001 + +#define ent_lba(ent) (ent & MAP_LBA_MASK) +#define ent_e_flag(ent) (!!(ent & MAP_ERR_MASK)) +#define ent_z_flag(ent) (!!(ent & MAP_TRIM_MASK)) +#define set_e_flag(ent) (ent |= MAP_ERR_MASK) +/* 'normal' is both e and z flags set */ +#define ent_normal(ent) (ent_e_flag(ent) && ent_z_flag(ent)) + +enum btt_init_state { + INIT_UNCHECKED = 0, + INIT_NOTFOUND, + INIT_READY +}; + +/* + * A log group represents one log 'lane', and consists of four log entries. + * Two of the four entries are valid entries, and the remaining two are + * padding. Due to an old bug in the padding location, we need to perform a + * test to determine the padding scheme being used, and use that scheme + * thereafter. + * + * In kernels prior to 4.15, 'log group' would have actual log entries at + * indices (0, 2) and padding at indices (1, 3), where as the correct/updated + * format has log entries at indices (0, 1) and padding at indices (2, 3). + * + * Old (pre 4.15) format: + * +-----------------+-----------------+ + * | ent[0] | ent[1] | + * | 16B | 16B | + * | lba/old/new/seq | pad | + * +-----------------------------------+ + * | ent[2] | ent[3] | + * | 16B | 16B | + * | lba/old/new/seq | pad | + * +-----------------+-----------------+ + * + * New format: + * +-----------------+-----------------+ + * | ent[0] | ent[1] | + * | 16B | 16B | + * | lba/old/new/seq | lba/old/new/seq | + * +-----------------------------------+ + * | ent[2] | ent[3] | + * | 16B | 16B | + * | pad | pad | + * +-----------------+-----------------+ + * + * We detect during start-up which format is in use, and set + * arena->log_index[(0, 1)] with the detected format. + */ + +struct log_entry { + __le32 lba; + __le32 old_map; + __le32 new_map; + __le32 seq; +}; + +struct log_group { + struct log_entry ent[4]; +}; + +struct btt_sb { + u8 signature[BTT_SIG_LEN]; + u8 uuid[16]; + u8 parent_uuid[16]; + __le32 flags; + __le16 version_major; + __le16 version_minor; + __le32 external_lbasize; + __le32 external_nlba; + __le32 internal_lbasize; + __le32 internal_nlba; + __le32 nfree; + __le32 infosize; + __le64 nextoff; + __le64 dataoff; + __le64 mapoff; + __le64 logoff; + __le64 info2off; + u8 padding[3968]; + __le64 checksum; +}; + +struct free_entry { + u32 block; + u8 sub; + u8 seq; + u8 has_err; +}; + +struct aligned_lock { + union { + spinlock_t lock; + u8 cacheline_padding[L1_CACHE_BYTES]; + }; +}; + +/** + * struct arena_info - handle for an arena + * @size: Size in bytes this arena occupies on the raw device. + * This includes arena metadata. + * @external_lba_start: The first external LBA in this arena. + * @internal_nlba: Number of internal blocks available in the arena + * including nfree reserved blocks + * @internal_lbasize: Internal and external lba sizes may be different as + * we can round up 'odd' external lbasizes such as 520B + * to be aligned. + * @external_nlba: Number of blocks contributed by the arena to the number + * reported to upper layers. (internal_nlba - nfree) + * @external_lbasize: LBA size as exposed to upper layers. + * @nfree: A reserve number of 'free' blocks that is used to + * handle incoming writes. + * @version_major: Metadata layout version major. + * @version_minor: Metadata layout version minor. + * @sector_size: The Linux sector size - 512 or 4096 + * @nextoff: Offset in bytes to the start of the next arena. + * @infooff: Offset in bytes to the info block of this arena. + * @dataoff: Offset in bytes to the data area of this arena. + * @mapoff: Offset in bytes to the map area of this arena. + * @logoff: Offset in bytes to the log area of this arena. + * @info2off: Offset in bytes to the backup info block of this arena. + * @freelist: Pointer to in-memory list of free blocks + * @rtt: Pointer to in-memory "Read Tracking Table" + * @map_locks: Spinlocks protecting concurrent map writes + * @nd_btt: Pointer to parent nd_btt structure. + * @list: List head for list of arenas + * @debugfs_dir: Debugfs dentry + * @flags: Arena flags - may signify error states. + * @err_lock: Mutex for synchronizing error clearing. + * @log_index: Indices of the valid log entries in a log_group + * + * arena_info is a per-arena handle. Once an arena is narrowed down for an + * IO, this struct is passed around for the duration of the IO. + */ +struct arena_info { + u64 size; /* Total bytes for this arena */ + u64 external_lba_start; + u32 internal_nlba; + u32 internal_lbasize; + u32 external_nlba; + u32 external_lbasize; + u32 nfree; + u16 version_major; + u16 version_minor; + u32 sector_size; + /* Byte offsets to the different on-media structures */ + u64 nextoff; + u64 infooff; + u64 dataoff; + u64 mapoff; + u64 logoff; + u64 info2off; + /* Pointers to other in-memory structures for this arena */ + struct free_entry *freelist; + u32 *rtt; + struct aligned_lock *map_locks; + struct nd_btt *nd_btt; + struct list_head list; + struct dentry *debugfs_dir; + /* Arena flags */ + u32 flags; + struct mutex err_lock; + int log_index[2]; +}; + +struct badblocks; + +/** + * struct btt - handle for a BTT instance + * @btt_disk: Pointer to the gendisk for BTT device + * @arena_list: Head of the list of arenas + * @debugfs_dir: Debugfs dentry + * @nd_btt: Parent nd_btt struct + * @nlba: Number of logical blocks exposed to the upper layers + * after removing the amount of space needed by metadata + * @rawsize: Total size in bytes of the available backing device + * @lbasize: LBA size as requested and presented to upper layers. + * This is sector_size + size of any metadata. + * @sector_size: The Linux sector size - 512 or 4096 + * @lanes: Per-lane spinlocks + * @init_lock: Mutex used for the BTT initialization + * @init_state: Flag describing the initialization state for the BTT + * @num_arenas: Number of arenas in the BTT instance + * @phys_bb: Pointer to the namespace's badblocks structure + */ +struct btt { + struct gendisk *btt_disk; + struct list_head arena_list; + struct dentry *debugfs_dir; + struct nd_btt *nd_btt; + u64 nlba; + unsigned long long rawsize; + u32 lbasize; + u32 sector_size; + struct nd_region *nd_region; + struct mutex init_lock; + int init_state; + int num_arenas; + struct badblocks *phys_bb; +}; + +bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); +int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, + struct btt_sb *btt_sb); + +#endif |