--- /dev/null
+/*
+ * Block Translation Table library
+ * Copyright (c) 2014-2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#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_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
+
+enum btt_init_state {
+ INIT_UNCHECKED = 0,
+ INIT_NOTFOUND,
+ INIT_READY
+};
+
+struct log_entry {
+ __le32 lba;
+ __le32 old_map;
+ __le32 new_map;
+ __le32 seq;
+ __le64 padding[2];
+};
+
+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;
+};
+
+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.
+ * @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.
+ *
+ * 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;
+ /* 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 btt - handle for a BTT instance
+ * @btt_disk: Pointer to the gendisk for BTT device
+ * @btt_queue: Pointer to the request queue for the 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
+ */
+struct btt {
+ struct gendisk *btt_disk;
+ struct request_queue *btt_queue;
+ 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;
+};
+
+bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super);
+
+#endif
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