cregit-Linux how code gets into the kernel

Release 4.10 drivers/nvdimm/btt.h

Directory: drivers/nvdimm
/*
 * 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

Overall Contributors

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vishal vermavishal verma29675.90%266.67%
dan williamsdan williams9424.10%133.33%
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Directory: drivers/nvdimm
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