/* SPDX-License-Identifier: GPL-2.0 */

  /*
   * Copyright (C) 2015 IT University of Copenhagen (rrpc.h)
   * Copyright (C) 2016 CNEX Labs
   * Initial release: Matias Bjorling <matias@cnexlabs.com>
   * Write buffering: Javier Gonzalez <javier@cnexlabs.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License version
   * 2 as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that 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.
   *
   * Implementation of a Physical Block-device target for Open-channel SSDs.
   *
   */
  
  #ifndef PBLK_H_
  #define PBLK_H_
  
  #include <linux/blkdev.h>
  #include <linux/blk-mq.h>
  #include <linux/bio.h>
  #include <linux/module.h>
  #include <linux/kthread.h>
  #include <linux/vmalloc.h>
  #include <linux/crc32.h>
  #include <linux/uuid.h>
  
  #include <linux/lightnvm.h>
  
  /* Run only GC if less than 1/X blocks are free */
  #define GC_LIMIT_INVERSE 5
  #define GC_TIME_MSECS 1000
  
  #define PBLK_SECTOR (512)
  #define PBLK_EXPOSED_PAGE_SIZE (4096)

  #define PBLK_NR_CLOSE_JOBS (4)

  #define PBLK_CACHE_NAME_LEN (DISK_NAME_LEN + 16)

  /* Max 512 LUNs per device */
  #define PBLK_MAX_LUNS_BITMAP (4)
  
  #define NR_PHY_IN_LOG (PBLK_EXPOSED_PAGE_SIZE / PBLK_SECTOR)

  /* Static pool sizes */

  #define PBLK_GEN_WS_POOL_SIZE (2)

  #define PBLK_DEFAULT_OP (11)

  enum {

  	PBLK_READ		= READ,
  	PBLK_WRITE		= WRITE,/* Write from write buffer */
  	PBLK_WRITE_INT,			/* Internal write - no write buffer */

  	PBLK_READ_RECOV,		/* Recovery read - errors allowed */

  	PBLK_ERASE,
  };
  
  enum {

  	/* IO Types */
  	PBLK_IOTYPE_USER	= 1 << 0,
  	PBLK_IOTYPE_GC		= 1 << 1,
  
  	/* Write buffer flags */
  	PBLK_FLUSH_ENTRY	= 1 << 2,
  	PBLK_WRITTEN_DATA	= 1 << 3,
  	PBLK_SUBMITTED_ENTRY	= 1 << 4,
  	PBLK_WRITABLE_ENTRY	= 1 << 5,
  };
  
  enum {
  	PBLK_BLK_ST_OPEN =	0x1,
  	PBLK_BLK_ST_CLOSED =	0x2,
  };

  enum {
  	PBLK_CHUNK_RESET_START,
  	PBLK_CHUNK_RESET_DONE,
  	PBLK_CHUNK_RESET_FAILED,
  };

  struct pblk_sec_meta {
  	u64 reserved;
  	__le64 lba;
  };

  /* The number of GC lists and the rate-limiter states go together. This way the
   * rate-limiter can dictate how much GC is needed based on resource utilization.
   */

  #define PBLK_GC_NR_LISTS 4

  
  enum {

  	PBLK_RL_OFF = 0,
  	PBLK_RL_WERR = 1,
  	PBLK_RL_HIGH = 2,
  	PBLK_RL_MID = 3,
  	PBLK_RL_LOW = 4

  };

  #define pblk_dma_ppa_size (sizeof(u64) * NVM_MAX_VLBA)

  /* write buffer completion context */

  struct pblk_c_ctx {
  	struct list_head list;		/* Head for out-of-order completion */
  
  	unsigned long *lun_bitmap;	/* Luns used on current request */
  	unsigned int sentry;
  	unsigned int nr_valid;
  	unsigned int nr_padded;
  };

  /* read context */

  struct pblk_g_ctx {
  	void *private;

  	unsigned long start_time;

  	u64 lba;

  };

  /* Pad context */
  struct pblk_pad_rq {
  	struct pblk *pblk;
  	struct completion wait;
  	struct kref ref;
  };

  /* Recovery context */
  struct pblk_rec_ctx {
  	struct pblk *pblk;
  	struct nvm_rq *rqd;

  	struct work_struct ws_rec;
  };
  
  /* Write context */
  struct pblk_w_ctx {
  	struct bio_list bios;		/* Original bios - used for completion
  					 * in REQ_FUA, REQ_FLUSH case
  					 */

  	u64 lba;			/* Logic addr. associated with entry */

  	struct ppa_addr ppa;		/* Physic addr. associated with entry */
  	int flags;			/* Write context flags */
  };
  
  struct pblk_rb_entry {
  	struct ppa_addr cacheline;	/* Cacheline for this entry */
  	void *data;			/* Pointer to data on this entry */
  	struct pblk_w_ctx w_ctx;	/* Context for this entry */
  	struct list_head index;		/* List head to enable indexes */
  };
  
  #define EMPTY_ENTRY (~0U)
  
  struct pblk_rb_pages {
  	struct page *pages;
  	int order;
  	struct list_head list;
  };
  
  struct pblk_rb {
  	struct pblk_rb_entry *entries;	/* Ring buffer entries */
  	unsigned int mem;		/* Write offset - points to next
  					 * writable entry in memory
  					 */
  	unsigned int subm;		/* Read offset - points to last entry
  					 * that has been submitted to the media
  					 * to be persisted
  					 */
  	unsigned int sync;		/* Synced - backpointer that signals
  					 * the last submitted entry that has
  					 * been successfully persisted to media
  					 */

  	unsigned int flush_point;	/* Sync point - last entry that must be

  					 * flushed to the media. Used with
  					 * REQ_FLUSH and REQ_FUA
  					 */
  	unsigned int l2p_update;	/* l2p update point - next entry for
  					 * which l2p mapping will be updated to
  					 * contain a device ppa address (instead
  					 * of a cacheline
  					 */
  	unsigned int nr_entries;	/* Number of entries in write buffer -
  					 * must be a power of two
  					 */
  	unsigned int seg_size;		/* Size of the data segments being
  					 * stored on each entry. Typically this
  					 * will be 4KB
  					 */

  	unsigned int back_thres;	/* Threshold that shall be maintained by
  					 * the backpointer in order to respect
  					 * geo->mw_cunits on a per chunk basis
  					 */

  	struct list_head pages;		/* List of data pages */
  
  	spinlock_t w_lock;		/* Write lock */
  	spinlock_t s_lock;		/* Sync lock */

  #ifdef CONFIG_NVM_PBLK_DEBUG

  	atomic_t inflight_flush_point;	/* Not served REQ_FLUSH | REQ_FUA */

  #endif
  };
  
  #define PBLK_RECOVERY_SECTORS 16
  
  struct pblk_lun {
  	struct ppa_addr bppa;

  	struct semaphore wr_sem;
  };
  
  struct pblk_gc_rq {
  	struct pblk_line *line;
  	void *data;

  	u64 paddr_list[NVM_MAX_VLBA];
  	u64 lba_list[NVM_MAX_VLBA];

  	int nr_secs;
  	int secs_to_gc;
  	struct list_head list;
  };
  
  struct pblk_gc {

  	/* These states are not protected by a lock since (i) they are in the
  	 * fast path, and (ii) they are not critical.
  	 */

  	int gc_active;
  	int gc_enabled;
  	int gc_forced;

  
  	struct task_struct *gc_ts;
  	struct task_struct *gc_writer_ts;

  	struct task_struct *gc_reader_ts;
  
  	struct workqueue_struct *gc_line_reader_wq;

  	struct workqueue_struct *gc_reader_wq;

  	struct timer_list gc_timer;

  	struct semaphore gc_sem;

  	atomic_t read_inflight_gc; /* Number of lines with inflight GC reads */
  	atomic_t pipeline_gc;	   /* Number of lines in the GC pipeline -
  				    * started reads to finished writes
  				    */

  	int w_entries;

  	struct list_head w_list;

  	struct list_head r_list;

  
  	spinlock_t lock;
  	spinlock_t w_lock;

  	spinlock_t r_lock;

  };
  
  struct pblk_rl {
  	unsigned int high;	/* Upper threshold for rate limiter (free run -
  				 * user I/O rate limiter
  				 */

  	unsigned int high_pw;	/* High rounded up as a power of 2 */

  #define PBLK_USER_HIGH_THRS 8	/* Begin write limit at 12% available blks */
  #define PBLK_USER_LOW_THRS 10	/* Aggressive GC at 10% available blocks */

  
  	int rb_windows_pw;	/* Number of rate windows in the write buffer
  				 * given as a power-of-2. This guarantees that
  				 * when user I/O is being rate limited, there
  				 * will be reserved enough space for the GC to
  				 * place its payload. A window is of
  				 * pblk->max_write_pgs size, which in NVMe is
  				 * 64, i.e., 256kb.
  				 */
  	int rb_budget;		/* Total number of entries available for I/O */
  	int rb_user_max;	/* Max buffer entries available for user I/O */

  	int rb_gc_max;		/* Max buffer entries available for GC I/O */
  	int rb_gc_rsv;		/* Reserved buffer entries for GC I/O */
  	int rb_state;		/* Rate-limiter current state */

  	int rb_max_io;		/* Maximum size for an I/O giving the config */

  
  	atomic_t rb_user_cnt;	/* User I/O buffer counter */

  	atomic_t rb_gc_cnt;	/* GC I/O buffer counter */

  	atomic_t rb_space;	/* Space limit in case of reaching capacity */

  	int rsv_blocks;		/* Reserved blocks for GC */

  	int rb_user_active;

  	int rb_gc_active;

  	atomic_t werr_lines;	/* Number of write error lines that needs gc */

  	struct timer_list u_timer;

  	unsigned long total_blocks;

  
  	atomic_t free_blocks;		/* Total number of free blocks (+ OP) */
  	atomic_t free_user_blocks;	/* Number of user free blocks (no OP) */

  };

  #define PBLK_LINE_EMPTY (~0U)
  
  enum {
  	/* Line Types */
  	PBLK_LINETYPE_FREE = 0,
  	PBLK_LINETYPE_LOG = 1,
  	PBLK_LINETYPE_DATA = 2,
  
  	/* Line state */

  	PBLK_LINESTATE_NEW = 9,

  	PBLK_LINESTATE_FREE = 10,
  	PBLK_LINESTATE_OPEN = 11,
  	PBLK_LINESTATE_CLOSED = 12,
  	PBLK_LINESTATE_GC = 13,
  	PBLK_LINESTATE_BAD = 14,
  	PBLK_LINESTATE_CORRUPT = 15,
  
  	/* GC group */
  	PBLK_LINEGC_NONE = 20,
  	PBLK_LINEGC_EMPTY = 21,
  	PBLK_LINEGC_LOW = 22,
  	PBLK_LINEGC_MID = 23,
  	PBLK_LINEGC_HIGH = 24,
  	PBLK_LINEGC_FULL = 25,

  	PBLK_LINEGC_WERR = 26

  };
  
  #define PBLK_MAGIC 0x70626c6b /*pblk*/

  
  /* emeta/smeta persistent storage format versions:
   * Changes in major version requires offline migration.
   * Changes in minor version are handled automatically during
   * recovery.
   */
  
  #define SMETA_VERSION_MAJOR (0)
  #define SMETA_VERSION_MINOR (1)
  
  #define EMETA_VERSION_MAJOR (0)

  #define EMETA_VERSION_MINOR (2)

  
  struct line_header {
  	__le32 crc;
  	__le32 identifier;	/* pblk identifier */
  	__u8 uuid[16];		/* instance uuid */
  	__le16 type;		/* line type */

  	__u8 version_major;	/* version major */
  	__u8 version_minor;	/* version minor */

  	__le32 id;		/* line id for current line */
  };
  
  struct line_smeta {
  	struct line_header header;
  
  	__le32 crc;		/* Full structure including struct crc */
  	/* Previous line metadata */
  	__le32 prev_id;		/* Line id for previous line */
  
  	/* Current line metadata */
  	__le64 seq_nr;		/* Sequence number for current line */
  
  	/* Active writers */
  	__le32 window_wr_lun;	/* Number of parallel LUNs to write */
  
  	__le32 rsvd[2];

  
  	__le64 lun_bitmap[];

  };

  /*

   * Metadata layout in media:
   *	First sector:
   *		1. struct line_emeta
   *		2. bad block bitmap (u64 * window_wr_lun)

   *		3. write amplification counters

   *	Mid sectors (start at lbas_sector):
   *		3. nr_lbas (u64) forming lba list
   *	Last sectors (start at vsc_sector):
   *		4. u32 valid sector count (vsc) for all lines (~0U: free line)

   */
  struct line_emeta {
  	struct line_header header;
  
  	__le32 crc;		/* Full structure including struct crc */
  
  	/* Previous line metadata */
  	__le32 prev_id;		/* Line id for prev line */
  
  	/* Current line metadata */
  	__le64 seq_nr;		/* Sequence number for current line */
  
  	/* Active writers */
  	__le32 window_wr_lun;	/* Number of parallel LUNs to write */
  
  	/* Bookkeeping for recovery */
  	__le32 next_id;		/* Line id for next line */
  	__le64 nr_lbas;		/* Number of lbas mapped in line */
  	__le64 nr_valid_lbas;	/* Number of valid lbas mapped in line */

  	__le64 bb_bitmap[];     /* Updated bad block bitmap for line */
  };
  
  
  /* Write amplification counters stored on media */
  struct wa_counters {
  	__le64 user;		/* Number of user written sectors */
  	__le64 gc;		/* Number of sectors written by GC*/
  	__le64 pad;		/* Number of padded sectors */

  };
  
  struct pblk_emeta {
  	struct line_emeta *buf;		/* emeta buffer in media format */
  	int mem;			/* Write offset - points to next
  					 * writable entry in memory
  					 */
  	atomic_t sync;			/* Synced - backpointer that signals the
  					 * last entry that has been successfully
  					 * persisted to media
  					 */
  	unsigned int nr_entries;	/* Number of emeta entries */
  };
  
  struct pblk_smeta {
  	struct line_smeta *buf;		/* smeta buffer in persistent format */

  };

  struct pblk_w_err_gc {
  	int has_write_err;

  	int has_gc_err;

  	__le64 *lba_list;
  };

  struct pblk_line {
  	struct pblk *pblk;
  	unsigned int id;		/* Line number corresponds to the
  					 * block line
  					 */
  	unsigned int seq_nr;		/* Unique line sequence number */
  
  	int state;			/* PBLK_LINESTATE_X */
  	int type;			/* PBLK_LINETYPE_X */
  	int gc_group;			/* PBLK_LINEGC_X */
  	struct list_head list;		/* Free, GC lists */
  
  	unsigned long *lun_bitmap;	/* Bitmap for LUNs mapped in line */

  	struct nvm_chk_meta *chks;	/* Chunks forming line */

  	struct pblk_smeta *smeta;	/* Start metadata */
  	struct pblk_emeta *emeta;	/* End medatada */

  	int meta_line;			/* Metadata line id */

  	int meta_distance;		/* Distance between data and metadata */

  	u64 emeta_ssec;			/* Sector where emeta starts */
  
  	unsigned int sec_in_line;	/* Number of usable secs in line */

  	atomic_t blk_in_line;		/* Number of good blocks in line */

  	unsigned long *blk_bitmap;	/* Bitmap for valid/invalid blocks */
  	unsigned long *erase_bitmap;	/* Bitmap for erased blocks */
  
  	unsigned long *map_bitmap;	/* Bitmap for mapped sectors in line */
  	unsigned long *invalid_bitmap;	/* Bitmap for invalid sectors in line */

  	atomic_t left_eblks;		/* Blocks left for erasing */

  	atomic_t left_seblks;		/* Blocks left for sync erasing */
  
  	int left_msecs;			/* Sectors left for mapping */

  	unsigned int cur_sec;		/* Sector map pointer */

  	unsigned int nr_valid_lbas;	/* Number of valid lbas in line */
  
  	__le32 *vsc;			/* Valid sector count in line */

  
  	struct kref ref;		/* Write buffer L2P references */

  	atomic_t sec_to_update;         /* Outstanding L2P updates to ppa */

  	struct pblk_w_err_gc *w_err_gc;	/* Write error gc recovery metadata */

  	spinlock_t lock;		/* Necessary for invalid_bitmap only */
  };

  #define PBLK_DATA_LINES 4

  enum {

  	PBLK_EMETA_TYPE_HEADER = 1,	/* struct line_emeta first sector */
  	PBLK_EMETA_TYPE_LLBA = 2,	/* lba list - type: __le64 */
  	PBLK_EMETA_TYPE_VSC = 3,	/* vsc list - type: __le32 */

  };
  
  struct pblk_line_mgmt {
  	int nr_lines;			/* Total number of full lines */
  	int nr_free_lines;		/* Number of full lines in free list */
  
  	/* Free lists - use free_lock */
  	struct list_head free_list;	/* Full lines ready to use */
  	struct list_head corrupt_list;	/* Full lines corrupted */
  	struct list_head bad_list;	/* Full lines bad */
  
  	/* GC lists - use gc_lock */

  	struct list_head *gc_lists[PBLK_GC_NR_LISTS];

  	struct list_head gc_high_list;	/* Full lines ready to GC, high isc */
  	struct list_head gc_mid_list;	/* Full lines ready to GC, mid isc */
  	struct list_head gc_low_list;	/* Full lines ready to GC, low isc */

  	struct list_head gc_werr_list;  /* Write err recovery list */

  	struct list_head gc_full_list;	/* Full lines ready to GC, no valid */
  	struct list_head gc_empty_list;	/* Full lines close, all valid */
  
  	struct pblk_line *log_line;	/* Current FTL log line */
  	struct pblk_line *data_line;	/* Current data line */
  	struct pblk_line *log_next;	/* Next FTL log line */
  	struct pblk_line *data_next;	/* Next data line */

  	struct list_head emeta_list;	/* Lines queued to schedule emeta */
  
  	__le32 *vsc_list;		/* Valid sector counts for all lines */

  	/* Pre-allocated metadata for data lines */

  	struct pblk_smeta *sline_meta[PBLK_DATA_LINES];
  	struct pblk_emeta *eline_meta[PBLK_DATA_LINES];

  	unsigned long meta_bitmap;

  	/* Cache and mempool for map/invalid bitmaps */
  	struct kmem_cache *bitmap_cache;
  	mempool_t *bitmap_pool;

  	/* Helpers for fast bitmap calculations */
  	unsigned long *bb_template;
  	unsigned long *bb_aux;
  
  	unsigned long d_seq_nr;		/* Data line unique sequence number */
  	unsigned long l_seq_nr;		/* Log line unique sequence number */
  
  	spinlock_t free_lock;

  	spinlock_t close_lock;

  	spinlock_t gc_lock;
  };
  
  struct pblk_line_meta {
  	unsigned int smeta_len;		/* Total length for smeta */

  	unsigned int smeta_sec;		/* Sectors needed for smeta */
  
  	unsigned int emeta_len[4];	/* Lengths for emeta:

  					 *  [0]: Total
  					 *  [1]: struct line_emeta +
  					 *       bb_bitmap + struct wa_counters
  					 *  [2]: L2P portion
  					 *  [3]: vsc

  					 */
  	unsigned int emeta_sec[4];	/* Sectors needed for emeta. Same layout
  					 * as emeta_len
  					 */

  	unsigned int emeta_bb;		/* Boundary for bb that affects emeta */

  
  	unsigned int vsc_list_len;	/* Length for vsc list */

  	unsigned int sec_bitmap_len;	/* Length for sector bitmap in line */
  	unsigned int blk_bitmap_len;	/* Length for block bitmap in line */
  	unsigned int lun_bitmap_len;	/* Length for lun bitmap in line */
  
  	unsigned int blk_per_line;	/* Number of blocks in a full line */
  	unsigned int sec_per_line;	/* Number of sectors in a line */

  	unsigned int dsec_per_line;	/* Number of data sectors in a line */

  	unsigned int min_blk_line;	/* Min. number of good blocks in line */
  
  	unsigned int mid_thrs;		/* Threshold for GC mid list */
  	unsigned int high_thrs;		/* Threshold for GC high list */

  
  	unsigned int meta_distance;	/* Distance between data and metadata */

  };

  enum {
  	PBLK_STATE_RUNNING = 0,
  	PBLK_STATE_STOPPING = 1,
  	PBLK_STATE_RECOVERING = 2,
  	PBLK_STATE_STOPPED = 3,
  };

  /* Internal format to support not power-of-2 device formats */
  struct pblk_addrf {
  	/* gen to dev */
  	int sec_stripe;
  	int ch_stripe;
  	int lun_stripe;
  
  	/* dev to gen */
  	int sec_lun_stripe;
  	int sec_ws_stripe;
  };

  struct pblk {
  	struct nvm_tgt_dev *dev;
  	struct gendisk *disk;
  
  	struct kobject kobj;
  
  	struct pblk_lun *luns;
  
  	struct pblk_line *lines;		/* Line array */
  	struct pblk_line_mgmt l_mg;		/* Line management */
  	struct pblk_line_meta lm;		/* Line metadata */

  	struct nvm_addrf addrf;		/* Aligned address format */
  	struct pblk_addrf uaddrf;	/* Unaligned address format */

  	int addrf_len;

  
  	struct pblk_rb rwb;

  	int state;			/* pblk line state */

  	int min_write_pgs; /* Minimum amount of pages required by controller */

  	int min_write_pgs_data; /* Minimum amount of payload pages */

  	int max_write_pgs; /* Maximum amount of pages supported by controller */

  	int oob_meta_size; /* Size of OOB sector metadata */

  
  	sector_t capacity; /* Device capacity when bad blocks are subtracted */

  
  	int op;      /* Percentage of device used for over-provisioning */
  	int op_blks; /* Number of blocks used for over-provisioning */

  
  	/* pblk provisioning values. Used by rate limiter */
  	struct pblk_rl rl;

  	int sec_per_write;

  	guid_t instance_uuid;

  
  	/* Persistent write amplification counters, 4kb sector I/Os */
  	atomic64_t user_wa;		/* Sectors written by user */
  	atomic64_t gc_wa;		/* Sectors written by GC */
  	atomic64_t pad_wa;		/* Padded sectors written */
  
  	/* Reset values for delta write amplification measurements */
  	u64 user_rst_wa;
  	u64 gc_rst_wa;
  	u64 pad_rst_wa;

  	/* Counters used for calculating padding distribution */
  	atomic64_t *pad_dist;		/* Padding distribution buckets */
  	u64 nr_flush_rst;		/* Flushes reset value for pad dist.*/
  	atomic64_t nr_flush;		/* Number of flush/fua I/O */

  #ifdef CONFIG_NVM_PBLK_DEBUG

  	/* Non-persistent debug counters, 4kb sector I/Os */

  	atomic_long_t inflight_writes;	/* Inflight writes (user and gc) */
  	atomic_long_t padded_writes;	/* Sectors padded due to flush/fua */
  	atomic_long_t padded_wb;	/* Sectors padded in write buffer */

  	atomic_long_t req_writes;	/* Sectors stored on write buffer */
  	atomic_long_t sub_writes;	/* Sectors submitted from buffer */
  	atomic_long_t sync_writes;	/* Sectors synced to media */

  	atomic_long_t inflight_reads;	/* Inflight sector read requests */

  	atomic_long_t cache_reads;	/* Read requests that hit the cache */

  	atomic_long_t sync_reads;	/* Completed sector read requests */
  	atomic_long_t recov_writes;	/* Sectors submitted from recovery */
  	atomic_long_t recov_gc_writes;	/* Sectors submitted from write GC */
  	atomic_long_t recov_gc_reads;	/* Sectors submitted from read GC */
  #endif
  
  	spinlock_t lock;
  
  	atomic_long_t read_failed;
  	atomic_long_t read_empty;
  	atomic_long_t read_high_ecc;
  	atomic_long_t read_failed_gc;
  	atomic_long_t write_failed;
  	atomic_long_t erase_failed;

  	atomic_t inflight_io;		/* General inflight I/O counter */

  	struct task_struct *writer_ts;
  
  	/* Simple translation map of logical addresses to physical addresses.
  	 * The logical addresses is known by the host system, while the physical
  	 * addresses are used when writing to the disk block device.
  	 */
  	unsigned char *trans_map;
  	spinlock_t trans_lock;
  
  	struct list_head compl_list;

  	spinlock_t resubmit_lock;	 /* Resubmit list lock */
  	struct list_head resubmit_list; /* Resubmit list for failed writes*/

  	mempool_t page_bio_pool;
  	mempool_t gen_ws_pool;
  	mempool_t rec_pool;
  	mempool_t r_rq_pool;
  	mempool_t w_rq_pool;
  	mempool_t e_rq_pool;

  	struct workqueue_struct *close_wq;
  	struct workqueue_struct *bb_wq;

  	struct workqueue_struct *r_end_wq;

  	struct timer_list wtimer;
  
  	struct pblk_gc gc;
  };
  
  struct pblk_line_ws {
  	struct pblk *pblk;
  	struct pblk_line *line;
  	void *priv;
  	struct work_struct ws;
  };

  #define pblk_g_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_g_ctx))

  #define pblk_w_rq_size (sizeof(struct nvm_rq) + sizeof(struct pblk_c_ctx))

  #define pblk_err(pblk, fmt, ...)			\
  	pr_err("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
  #define pblk_info(pblk, fmt, ...)			\
  	pr_info("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
  #define pblk_warn(pblk, fmt, ...)			\
  	pr_warn("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)
  #define pblk_debug(pblk, fmt, ...)			\
  	pr_debug("pblk %s: " fmt, pblk->disk->disk_name, ##__VA_ARGS__)

  /*
   * pblk ring buffer operations
   */

  int pblk_rb_init(struct pblk_rb *rb, unsigned int size, unsigned int threshold,
  		 unsigned int seg_sz);

  int pblk_rb_may_write_user(struct pblk_rb *rb, struct bio *bio,
  			   unsigned int nr_entries, unsigned int *pos);
  int pblk_rb_may_write_gc(struct pblk_rb *rb, unsigned int nr_entries,
  			 unsigned int *pos);
  void pblk_rb_write_entry_user(struct pblk_rb *rb, void *data,
  			      struct pblk_w_ctx w_ctx, unsigned int pos);
  void pblk_rb_write_entry_gc(struct pblk_rb *rb, void *data,

  			    struct pblk_w_ctx w_ctx, struct pblk_line *line,
  			    u64 paddr, unsigned int pos);

  struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos);

  void pblk_rb_flush(struct pblk_rb *rb);

  
  void pblk_rb_sync_l2p(struct pblk_rb *rb);

  unsigned int pblk_rb_read_to_bio(struct pblk_rb *rb, struct nvm_rq *rqd,

  				 unsigned int pos, unsigned int nr_entries,
  				 unsigned int count);

  int pblk_rb_copy_to_bio(struct pblk_rb *rb, struct bio *bio, sector_t lba,

  			struct ppa_addr ppa);

  unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int entries);
  
  unsigned int pblk_rb_sync_init(struct pblk_rb *rb, unsigned long *flags);
  unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries);

  unsigned int pblk_rb_ptr_wrap(struct pblk_rb *rb, unsigned int p,
  			      unsigned int nr_entries);

  void pblk_rb_sync_end(struct pblk_rb *rb, unsigned long *flags);

  unsigned int pblk_rb_flush_point_count(struct pblk_rb *rb);

  
  unsigned int pblk_rb_read_count(struct pblk_rb *rb);

  unsigned int pblk_rb_sync_count(struct pblk_rb *rb);

  unsigned int pblk_rb_wrap_pos(struct pblk_rb *rb, unsigned int pos);
  
  int pblk_rb_tear_down_check(struct pblk_rb *rb);
  int pblk_rb_pos_oob(struct pblk_rb *rb, u64 pos);

  void pblk_rb_free(struct pblk_rb *rb);

  ssize_t pblk_rb_sysfs(struct pblk_rb *rb, char *buf);
  
  /*
   * pblk core
   */

  struct nvm_rq *pblk_alloc_rqd(struct pblk *pblk, int type);
  void pblk_free_rqd(struct pblk *pblk, struct nvm_rq *rqd, int type);

  int pblk_alloc_rqd_meta(struct pblk *pblk, struct nvm_rq *rqd);
  void pblk_free_rqd_meta(struct pblk *pblk, struct nvm_rq *rqd);

  void pblk_set_sec_per_write(struct pblk *pblk, int sec_per_write);

  int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
  			struct pblk_c_ctx *c_ctx);

  void pblk_discard(struct pblk *pblk, struct bio *bio);

  struct nvm_chk_meta *pblk_get_chunk_meta(struct pblk *pblk);

  struct nvm_chk_meta *pblk_chunk_get_off(struct pblk *pblk,
  					      struct nvm_chk_meta *lp,
  					      struct ppa_addr ppa);

  void pblk_log_write_err(struct pblk *pblk, struct nvm_rq *rqd);
  void pblk_log_read_err(struct pblk *pblk, struct nvm_rq *rqd);

  int pblk_submit_io(struct pblk *pblk, struct nvm_rq *rqd, void *buf);
  int pblk_submit_io_sync(struct pblk *pblk, struct nvm_rq *rqd, void *buf);

  int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line);

  void pblk_check_chunk_state_update(struct pblk *pblk, struct nvm_rq *rqd);

  struct pblk_line *pblk_line_get(struct pblk *pblk);
  struct pblk_line *pblk_line_get_first_data(struct pblk *pblk);

  struct pblk_line *pblk_line_replace_data(struct pblk *pblk);

  void pblk_ppa_to_line_put(struct pblk *pblk, struct ppa_addr ppa);
  void pblk_rq_to_line_put(struct pblk *pblk, struct nvm_rq *rqd);

  int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line);
  void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line);
  struct pblk_line *pblk_line_get_data(struct pblk *pblk);

  struct pblk_line *pblk_line_get_erase(struct pblk *pblk);

  int pblk_line_erase(struct pblk *pblk, struct pblk_line *line);
  int pblk_line_is_full(struct pblk_line *line);

  void pblk_line_free(struct pblk_line *line);

  void pblk_line_close_meta(struct pblk *pblk, struct pblk_line *line);

  void pblk_line_close(struct pblk *pblk, struct pblk_line *line);

  void pblk_line_close_ws(struct work_struct *work);

  void pblk_pipeline_stop(struct pblk *pblk);

  void __pblk_pipeline_stop(struct pblk *pblk);
  void __pblk_pipeline_flush(struct pblk *pblk);

  void pblk_gen_run_ws(struct pblk *pblk, struct pblk_line *line, void *priv,
  		     void (*work)(struct work_struct *), gfp_t gfp_mask,
  		     struct workqueue_struct *wq);

  u64 pblk_line_smeta_start(struct pblk *pblk, struct pblk_line *line);

  int pblk_line_smeta_read(struct pblk *pblk, struct pblk_line *line);
  int pblk_line_emeta_read(struct pblk *pblk, struct pblk_line *line,

  			 void *emeta_buf);

  int pblk_blk_erase_async(struct pblk *pblk, struct ppa_addr erase_ppa);
  void pblk_line_put(struct kref *ref);

  void pblk_line_put_wq(struct kref *ref);

  struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line);

  u64 pblk_lookup_page(struct pblk *pblk, struct pblk_line *line);
  void pblk_dealloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);

  u64 pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);

  u64 __pblk_alloc_page(struct pblk *pblk, struct pblk_line *line, int nr_secs);

  int pblk_calc_secs(struct pblk *pblk, unsigned long secs_avail,

  		   unsigned long secs_to_flush, bool skip_meta);

  void pblk_down_rq(struct pblk *pblk, struct ppa_addr ppa,

  		  unsigned long *lun_bitmap);

  void pblk_down_chunk(struct pblk *pblk, struct ppa_addr ppa);
  void pblk_up_chunk(struct pblk *pblk, struct ppa_addr ppa);

  void pblk_up_rq(struct pblk *pblk, unsigned long *lun_bitmap);

  int pblk_bio_add_pages(struct pblk *pblk, struct bio *bio, gfp_t flags,
  		       int nr_pages);

  void pblk_bio_free_pages(struct pblk *pblk, struct bio *bio, int off,
  			 int nr_pages);
  void pblk_map_invalidate(struct pblk *pblk, struct ppa_addr ppa);

  void __pblk_map_invalidate(struct pblk *pblk, struct pblk_line *line,
  			   u64 paddr);

  void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa);
  void pblk_update_map_cache(struct pblk *pblk, sector_t lba,
  			   struct ppa_addr ppa);
  void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
  			 struct ppa_addr ppa, struct ppa_addr entry_line);
  int pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa,

  		       struct pblk_line *gc_line, u64 paddr);

  void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
  			  u64 *lba_list, int nr_secs);

  int pblk_lookup_l2p_seq(struct pblk *pblk, struct ppa_addr *ppas,
  			 sector_t blba, int nr_secs, bool *from_cache);

  void *pblk_get_meta_for_writes(struct pblk *pblk, struct nvm_rq *rqd);
  void pblk_get_packed_meta(struct pblk *pblk, struct nvm_rq *rqd);

  
  /*
   * pblk user I/O write path
   */

  void pblk_write_to_cache(struct pblk *pblk, struct bio *bio,

  			unsigned long flags);

  int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq);

  
  /*
   * pblk map
   */

  int pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,

  		       unsigned int sentry, unsigned long *lun_bitmap,
  		       unsigned int valid_secs, struct ppa_addr *erase_ppa);

  int pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,

  		 unsigned long *lun_bitmap, unsigned int valid_secs,
  		 unsigned int off);
  
  /*
   * pblk write thread
   */
  int pblk_write_ts(void *data);

  void pblk_write_timer_fn(struct timer_list *t);

  void pblk_write_should_kick(struct pblk *pblk);

  void pblk_write_kick(struct pblk *pblk);

  
  /*
   * pblk read path
   */

  extern struct bio_set pblk_bio_set;

  void pblk_submit_read(struct pblk *pblk, struct bio *bio);

  int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq);

  /*
   * pblk recovery
   */

  struct pblk_line *pblk_recov_l2p(struct pblk *pblk);

  int pblk_recov_pad(struct pblk *pblk);

  int pblk_recov_check_emeta(struct pblk *pblk, struct line_emeta *emeta);

  
  /*
   * pblk gc
   */

  #define PBLK_GC_MAX_READERS 8	/* Max number of outstanding GC reader jobs */

  #define PBLK_GC_RQ_QD 128	/* Queue depth for inflight GC requests */

  #define PBLK_GC_L_QD 4		/* Queue depth for inflight GC lines */

  
  int pblk_gc_init(struct pblk *pblk);

  void pblk_gc_exit(struct pblk *pblk, bool graceful);

  void pblk_gc_should_start(struct pblk *pblk);
  void pblk_gc_should_stop(struct pblk *pblk);

  void pblk_gc_should_kick(struct pblk *pblk);

  void pblk_gc_free_full_lines(struct pblk *pblk);

  void pblk_gc_sysfs_state_show(struct pblk *pblk, int *gc_enabled,
  			      int *gc_active);

  int pblk_gc_sysfs_force(struct pblk *pblk, int force);

  void pblk_put_line_back(struct pblk *pblk, struct pblk_line *line);

  
  /*
   * pblk rate limiter
   */

  void pblk_rl_init(struct pblk_rl *rl, int budget, int threshold);

  void pblk_rl_free(struct pblk_rl *rl);

  void pblk_rl_update_rates(struct pblk_rl *rl);

  int pblk_rl_high_thrs(struct pblk_rl *rl);

  unsigned long pblk_rl_nr_free_blks(struct pblk_rl *rl);

  unsigned long pblk_rl_nr_user_free_blks(struct pblk_rl *rl);

  int pblk_rl_user_may_insert(struct pblk_rl *rl, int nr_entries);

  void pblk_rl_inserted(struct pblk_rl *rl, int nr_entries);

  void pblk_rl_user_in(struct pblk_rl *rl, int nr_entries);
  int pblk_rl_gc_may_insert(struct pblk_rl *rl, int nr_entries);
  void pblk_rl_gc_in(struct pblk_rl *rl, int nr_entries);
  void pblk_rl_out(struct pblk_rl *rl, int nr_user, int nr_gc);

  int pblk_rl_max_io(struct pblk_rl *rl);

  void pblk_rl_free_lines_inc(struct pblk_rl *rl, struct pblk_line *line);

  void pblk_rl_free_lines_dec(struct pblk_rl *rl, struct pblk_line *line,
  			    bool used);

  int pblk_rl_is_limit(struct pblk_rl *rl);

  void pblk_rl_werr_line_in(struct pblk_rl *rl);
  void pblk_rl_werr_line_out(struct pblk_rl *rl);

  /*
   * pblk sysfs
   */
  int pblk_sysfs_init(struct gendisk *tdisk);
  void pblk_sysfs_exit(struct gendisk *tdisk);

  static inline struct nvm_rq *nvm_rq_from_c_ctx(void *c_ctx)
  {
  	return c_ctx - sizeof(struct nvm_rq);
  }

  static inline void *emeta_to_bb(struct line_emeta *emeta)
  {
  	return emeta->bb_bitmap;
  }

  static inline void *emeta_to_wa(struct pblk_line_meta *lm,
  				struct line_emeta *emeta)
  {
  	return emeta->bb_bitmap + lm->blk_bitmap_len;
  }

  static inline void *emeta_to_lbas(struct pblk *pblk, struct line_emeta *emeta)
  {
  	return ((void *)emeta + pblk->lm.emeta_len[1]);
  }
  
  static inline void *emeta_to_vsc(struct pblk *pblk, struct line_emeta *emeta)

  {

  	return (emeta_to_lbas(pblk, emeta) + pblk->lm.emeta_len[2]);

  }

  static inline int pblk_line_vsc(struct pblk_line *line)
  {

  	return le32_to_cpu(*line->vsc);

  }

  static inline int pblk_ppa_to_line_id(struct ppa_addr p)

  {

  	return p.a.blk;

  }

  static inline struct pblk_line *pblk_ppa_to_line(struct pblk *pblk,
  						 struct ppa_addr p)
  {
  	return &pblk->lines[pblk_ppa_to_line_id(p)];
  }

  static inline int pblk_ppa_to_pos(struct nvm_geo *geo, struct ppa_addr p)

  {

  	return p.a.lun * geo->num_ch + p.a.ch;

  }

  static inline struct ppa_addr addr_to_gen_ppa(struct pblk *pblk, u64 paddr,
  					      u64 line_id)

  {

  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	struct ppa_addr ppa;

  	if (geo->version == NVM_OCSSD_SPEC_12) {
  		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&pblk->addrf;
  
  		ppa.ppa = 0;
  		ppa.g.blk = line_id;
  		ppa.g.pg = (paddr & ppaf->pg_mask) >> ppaf->pg_offset;
  		ppa.g.lun = (paddr & ppaf->lun_mask) >> ppaf->lun_offset;
  		ppa.g.ch = (paddr & ppaf->ch_mask) >> ppaf->ch_offset;
  		ppa.g.pl = (paddr & ppaf->pln_mask) >> ppaf->pln_offset;
  		ppa.g.sec = (paddr & ppaf->sec_mask) >> ppaf->sec_offset;
  	} else {
  		struct pblk_addrf *uaddrf = &pblk->uaddrf;
  		int secs, chnls, luns;
  
  		ppa.ppa = 0;
  
  		ppa.m.chk = line_id;
  
  		paddr = div_u64_rem(paddr, uaddrf->sec_stripe, &secs);
  		ppa.m.sec = secs;
  
  		paddr = div_u64_rem(paddr, uaddrf->ch_stripe, &chnls);
  		ppa.m.grp = chnls;
  
  		paddr = div_u64_rem(paddr, uaddrf->lun_stripe, &luns);
  		ppa.m.pu = luns;
  
  		ppa.m.sec += uaddrf->sec_stripe * paddr;
  	}

  
  	return ppa;

  }

  static inline struct nvm_chk_meta *pblk_dev_ppa_to_chunk(struct pblk *pblk,
  							struct ppa_addr p)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	struct pblk_line *line = pblk_ppa_to_line(pblk, p);

  	int pos = pblk_ppa_to_pos(geo, p);
  
  	return &line->chks[pos];
  }
  
  static inline u64 pblk_dev_ppa_to_chunk_addr(struct pblk *pblk,
  							struct ppa_addr p)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  
  	return dev_to_chunk_addr(dev->parent, &pblk->addrf, p);
  }

  static inline u64 pblk_dev_ppa_to_line_addr(struct pblk *pblk,
  							struct ppa_addr p)

  {

  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	u64 paddr;

  	if (geo->version == NVM_OCSSD_SPEC_12) {
  		struct nvm_addrf_12 *ppaf = (struct nvm_addrf_12 *)&pblk->addrf;
  
  		paddr = (u64)p.g.ch << ppaf->ch_offset;
  		paddr |= (u64)p.g.lun << ppaf->lun_offset;
  		paddr |= (u64)p.g.pg << ppaf->pg_offset;
  		paddr |= (u64)p.g.pl << ppaf->pln_offset;
  		paddr |= (u64)p.g.sec << ppaf->sec_offset;
  	} else {
  		struct pblk_addrf *uaddrf = &pblk->uaddrf;
  		u64 secs = p.m.sec;
  		int sec_stripe;
  
  		paddr = (u64)p.m.grp * uaddrf->sec_stripe;
  		paddr += (u64)p.m.pu * uaddrf->sec_lun_stripe;
  
  		secs = div_u64_rem(secs, uaddrf->sec_stripe, &sec_stripe);
  		paddr += secs * uaddrf->sec_ws_stripe;
  		paddr += sec_stripe;
  	}

  
  	return paddr;

  }
  
  static inline struct ppa_addr pblk_ppa32_to_ppa64(struct pblk *pblk, u32 ppa32)
  {

  	struct nvm_tgt_dev *dev = pblk->dev;

  	return nvm_ppa32_to_ppa64(dev->parent, &pblk->addrf, ppa32);

  }

  static inline u32 pblk_ppa64_to_ppa32(struct pblk *pblk, struct ppa_addr ppa64)
  {

  	struct nvm_tgt_dev *dev = pblk->dev;

  	return nvm_ppa64_to_ppa32(dev->parent, &pblk->addrf, ppa64);

  }

  static inline struct ppa_addr pblk_trans_map_get(struct pblk *pblk,
  								sector_t lba)

  {

  	struct ppa_addr ppa;

  	if (pblk->addrf_len < 32) {

  		u32 *map = (u32 *)pblk->trans_map;

  		ppa = pblk_ppa32_to_ppa64(pblk, map[lba]);

  	} else {

  		struct ppa_addr *map = (struct ppa_addr *)pblk->trans_map;

  		ppa = map[lba];

  	}

  
  	return ppa;

  }

  static inline void pblk_trans_map_set(struct pblk *pblk, sector_t lba,
  						struct ppa_addr ppa)

  {

  	if (pblk->addrf_len < 32) {

  		u32 *map = (u32 *)pblk->trans_map;

  		map[lba] = pblk_ppa64_to_ppa32(pblk, ppa);
  	} else {
  		u64 *map = (u64 *)pblk->trans_map;

  		map[lba] = ppa.ppa;
  	}

  }
  
  static inline int pblk_ppa_empty(struct ppa_addr ppa_addr)
  {
  	return (ppa_addr.ppa == ADDR_EMPTY);
  }
  
  static inline void pblk_ppa_set_empty(struct ppa_addr *ppa_addr)
  {
  	ppa_addr->ppa = ADDR_EMPTY;
  }

  static inline bool pblk_ppa_comp(struct ppa_addr lppa, struct ppa_addr rppa)
  {

  	return (lppa.ppa == rppa.ppa);

  }

  static inline int pblk_addr_in_cache(struct ppa_addr ppa)
  {
  	return (ppa.ppa != ADDR_EMPTY && ppa.c.is_cached);
  }
  
  static inline int pblk_addr_to_cacheline(struct ppa_addr ppa)
  {
  	return ppa.c.line;
  }
  
  static inline struct ppa_addr pblk_cacheline_to_addr(int addr)
  {
  	struct ppa_addr p;
  
  	p.c.line = addr;
  	p.c.is_cached = 1;
  
  	return p;
  }

  static inline u32 pblk_calc_meta_header_crc(struct pblk *pblk,

  					    struct line_header *header)

  {
  	u32 crc = ~(u32)0;

  	crc = crc32_le(crc, (unsigned char *)header + sizeof(crc),

  				sizeof(struct line_header) - sizeof(crc));
  
  	return crc;
  }
  
  static inline u32 pblk_calc_smeta_crc(struct pblk *pblk,
  				      struct line_smeta *smeta)
  {
  	struct pblk_line_meta *lm = &pblk->lm;
  	u32 crc = ~(u32)0;
  
  	crc = crc32_le(crc, (unsigned char *)smeta +
  				sizeof(struct line_header) + sizeof(crc),
  				lm->smeta_len -
  				sizeof(struct line_header) - sizeof(crc));
  
  	return crc;
  }
  
  static inline u32 pblk_calc_emeta_crc(struct pblk *pblk,
  				      struct line_emeta *emeta)
  {
  	struct pblk_line_meta *lm = &pblk->lm;
  	u32 crc = ~(u32)0;
  
  	crc = crc32_le(crc, (unsigned char *)emeta +
  				sizeof(struct line_header) + sizeof(crc),

  				lm->emeta_len[0] -

  				sizeof(struct line_header) - sizeof(crc));
  
  	return crc;
  }

  static inline int pblk_io_aligned(struct pblk *pblk, int nr_secs)

  {

  	return !(nr_secs % pblk->min_write_pgs);

  }

  #ifdef CONFIG_NVM_PBLK_DEBUG

  static inline void print_ppa(struct pblk *pblk, struct ppa_addr *p,

  			     char *msg, int error)

  {

  	struct nvm_geo *geo = &pblk->dev->geo;

  	if (p->c.is_cached) {

  		pblk_err(pblk, "ppa: (%s: %x) cache line: %llu
  ",

  				msg, error, (u64)p->c.line);

  	} else if (geo->version == NVM_OCSSD_SPEC_12) {

  		pblk_err(pblk, "ppa: (%s: %x):ch:%d,lun:%d,blk:%d,pg:%d,pl:%d,sec:%d
  ",

  			msg, error,
  			p->g.ch, p->g.lun, p->g.blk,
  			p->g.pg, p->g.pl, p->g.sec);

  	} else {

  		pblk_err(pblk, "ppa: (%s: %x):ch:%d,lun:%d,chk:%d,sec:%d
  ",

  			msg, error,
  			p->m.grp, p->m.pu, p->m.chk, p->m.sec);

  	}
  }
  
  static inline void pblk_print_failed_rqd(struct pblk *pblk, struct nvm_rq *rqd,
  					 int error)
  {
  	int bit = -1;
  
  	if (rqd->nr_ppas ==  1) {

  		print_ppa(pblk, &rqd->ppa_addr, "rqd", error);

  		return;
  	}
  
  	while ((bit = find_next_bit((void *)&rqd->ppa_status, rqd->nr_ppas,
  						bit + 1)) < rqd->nr_ppas) {

  		print_ppa(pblk, &rqd->ppa_list[bit], "rqd", error);

  	}

  	pblk_err(pblk, "error:%d, ppa_status:%llx
  ", error, rqd->ppa_status);

  }

  
  static inline int pblk_boundary_ppa_checks(struct nvm_tgt_dev *tgt_dev,
  				       struct ppa_addr *ppas, int nr_ppas)
  {
  	struct nvm_geo *geo = &tgt_dev->geo;
  	struct ppa_addr *ppa;
  	int i;
  
  	for (i = 0; i < nr_ppas; i++) {
  		ppa = &ppas[i];

  		if (geo->version == NVM_OCSSD_SPEC_12) {
  			if (!ppa->c.is_cached &&
  					ppa->g.ch < geo->num_ch &&
  					ppa->g.lun < geo->num_lun &&
  					ppa->g.pl < geo->num_pln &&
  					ppa->g.blk < geo->num_chk &&
  					ppa->g.pg < geo->num_pg &&
  					ppa->g.sec < geo->ws_min)
  				continue;
  		} else {
  			if (!ppa->c.is_cached &&
  					ppa->m.grp < geo->num_ch &&
  					ppa->m.pu < geo->num_lun &&
  					ppa->m.chk < geo->num_chk &&
  					ppa->m.sec < geo->clba)
  				continue;
  		}

  		print_ppa(tgt_dev->q->queuedata, ppa, "boundary", i);

  		return 1;
  	}
  	return 0;
  }

  static inline int pblk_check_io(struct pblk *pblk, struct nvm_rq *rqd)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;

  	struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);

  
  	if (pblk_boundary_ppa_checks(dev, ppa_list, rqd->nr_ppas)) {
  		WARN_ON(1);
  		return -EINVAL;
  	}
  
  	if (rqd->opcode == NVM_OP_PWRITE) {
  		struct pblk_line *line;

  		int i;
  
  		for (i = 0; i < rqd->nr_ppas; i++) {

  			line = pblk_ppa_to_line(pblk, ppa_list[i]);

  
  			spin_lock(&line->lock);
  			if (line->state != PBLK_LINESTATE_OPEN) {

  				pblk_err(pblk, "bad ppa: line:%d,state:%d
  ",

  							line->id, line->state);
  				WARN_ON(1);
  				spin_unlock(&line->lock);
  				return -EINVAL;
  			}
  			spin_unlock(&line->lock);
  		}
  	}
  
  	return 0;
  }
  #endif

  static inline int pblk_boundary_paddr_checks(struct pblk *pblk, u64 paddr)
  {
  	struct pblk_line_meta *lm = &pblk->lm;
  
  	if (paddr > lm->sec_per_line)
  		return 1;
  
  	return 0;
  }
  
  static inline unsigned int pblk_get_bi_idx(struct bio *bio)
  {
  	return bio->bi_iter.bi_idx;
  }
  
  static inline sector_t pblk_get_lba(struct bio *bio)
  {
  	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
  }
  
  static inline unsigned int pblk_get_secs(struct bio *bio)
  {
  	return  bio->bi_iter.bi_size / PBLK_EXPOSED_PAGE_SIZE;
  }

  static inline char *pblk_disk_name(struct pblk *pblk)
  {
  	struct gendisk *disk = pblk->disk;
  
  	return disk->disk_name;
  }

  
  static inline unsigned int pblk_get_min_chks(struct pblk *pblk)
  {
  	struct pblk_line_meta *lm = &pblk->lm;
  	/* In a worst-case scenario every line will have OP invalid sectors.
  	 * We will then need a minimum of 1/OP lines to free up a single line
  	 */
  
  	return DIV_ROUND_UP(100, pblk->op) * lm->blk_per_line;

  }

  static inline struct pblk_sec_meta *pblk_get_meta(struct pblk *pblk,
  							 void *meta, int index)
  {

  	return meta +
  	       max_t(int, sizeof(struct pblk_sec_meta), pblk->oob_meta_size)
  	       * index;

  }

  
  static inline int pblk_dma_meta_size(struct pblk *pblk)
  {

  	return max_t(int, sizeof(struct pblk_sec_meta), pblk->oob_meta_size)
  	       * NVM_MAX_VLBA;

  }

  
  static inline int pblk_is_oob_meta_supported(struct pblk *pblk)
  {
  	return pblk->oob_meta_size >= sizeof(struct pblk_sec_meta);
  }

  #endif /* PBLK_H_ */