text: /*
   * Zoned block devices handling.
   *
   * Copyright (C) 2015 Seagate Technology PLC
   *
   * Written by: Shaun Tancheff <shaun.tancheff@seagate.com>
   *
   * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
   * Copyright (C) 2016 Western Digital
   *
   * This file is licensed under  the terms of the GNU General Public
   * License version 2. This program is licensed "as is" without any
   * warranty of any kind, whether express or implied.
   */
  #ifndef _BLKZONED_H
  #define _BLKZONED_H
  
  #include <linux/types.h>
  #include <linux/ioctl.h>
  
  /**
   * enum blk_zone_type - Types of zones allowed in a zoned device.
   *
   * @BLK_ZONE_TYPE_CONVENTIONAL: The zone has no write pointer and can be writen
   *                              randomly. Zone reset has no effect on the zone.
   * @BLK_ZONE_TYPE_SEQWRITE_REQ: The zone must be written sequentially
   * @BLK_ZONE_TYPE_SEQWRITE_PREF: The zone can be written non-sequentially
   *
   * Any other value not defined is reserved and must be considered as invalid.
   */
  enum blk_zone_type {
  	BLK_ZONE_TYPE_CONVENTIONAL	= 0x1,
  	BLK_ZONE_TYPE_SEQWRITE_REQ	= 0x2,
  	BLK_ZONE_TYPE_SEQWRITE_PREF	= 0x3,
  };
  
  /**
   * enum blk_zone_cond - Condition [state] of a zone in a zoned device.
   *
   * @BLK_ZONE_COND_NOT_WP: The zone has no write pointer, it is conventional.
   * @BLK_ZONE_COND_EMPTY: The zone is empty.
   * @BLK_ZONE_COND_IMP_OPEN: The zone is open, but not explicitly opened.
   * @BLK_ZONE_COND_EXP_OPEN: The zones was explicitly opened by an
   *                          OPEN ZONE command.
   * @BLK_ZONE_COND_CLOSED: The zone was [explicitly] closed after writing.
   * @BLK_ZONE_COND_FULL: The zone is marked as full, possibly by a zone
   *                      FINISH ZONE command.
   * @BLK_ZONE_COND_READONLY: The zone is read-only.
   * @BLK_ZONE_COND_OFFLINE: The zone is offline (sectors cannot be read/written).
   *
   * The Zone Condition state machine in the ZBC/ZAC standards maps the above
   * deinitions as:
   *   - ZC1: Empty         | BLK_ZONE_EMPTY
   *   - ZC2: Implicit Open | BLK_ZONE_COND_IMP_OPEN
   *   - ZC3: Explicit Open | BLK_ZONE_COND_EXP_OPEN
   *   - ZC4: Closed        | BLK_ZONE_CLOSED
   *   - ZC5: Full          | BLK_ZONE_FULL
   *   - ZC6: Read Only     | BLK_ZONE_READONLY
   *   - ZC7: Offline       | BLK_ZONE_OFFLINE
   *
   * Conditions 0x5 to 0xC are reserved by the current ZBC/ZAC spec and should
   * be considered invalid.
   */
  enum blk_zone_cond {
  	BLK_ZONE_COND_NOT_WP	= 0x0,
  	BLK_ZONE_COND_EMPTY	= 0x1,
  	BLK_ZONE_COND_IMP_OPEN	= 0x2,
  	BLK_ZONE_COND_EXP_OPEN	= 0x3,
  	BLK_ZONE_COND_CLOSED	= 0x4,
  	BLK_ZONE_COND_READONLY	= 0xD,
  	BLK_ZONE_COND_FULL	= 0xE,
  	BLK_ZONE_COND_OFFLINE	= 0xF,
  };
  
  /**
   * struct blk_zone - Zone descriptor for BLKREPORTZONE ioctl.
   *
   * @start: Zone start in 512 B sector units
   * @len: Zone length in 512 B sector units
   * @wp: Zone write pointer location in 512 B sector units
   * @type: see enum blk_zone_type for possible values
   * @cond: see enum blk_zone_cond for possible values
   * @non_seq: Flag indicating that the zone is using non-sequential resources
   *           (for host-aware zoned block devices only).
   * @reset: Flag indicating that a zone reset is recommended.
   * @reserved: Padding to 64 B to match the ZBC/ZAC defined zone descriptor size.
   *
   * start, len and wp use the regular 512 B sector unit, regardless of the
   * device logical block size. The overall structure size is 64 B to match the
   * ZBC/ZAC defined zone descriptor and allow support for future additional
   * zone information.
   */
  struct blk_zone {
  	__u64	start;		/* Zone start sector */
  	__u64	len;		/* Zone length in number of sectors */
  	__u64	wp;		/* Zone write pointer position */
  	__u8	type;		/* Zone type */
  	__u8	cond;		/* Zone condition */
  	__u8	non_seq;	/* Non-sequential write resources active */
  	__u8	reset;		/* Reset write pointer recommended */
  	__u8	reserved[36];
  };
  
  /**
   * struct blk_zone_report - BLKREPORTZONE ioctl request/reply
   *
   * @sector: starting sector of report
   * @nr_zones: IN maximum / OUT actual
   * @reserved: padding to 16 byte alignment
   * @zones: Space to hold @nr_zones @zones entries on reply.
   *
   * The array of at most @nr_zones must follow this structure in memory.
   */
  struct blk_zone_report {
  	__u64		sector;
  	__u32		nr_zones;
  	__u8		reserved[4];
  	struct blk_zone zones[0];
  } __attribute__((packed));
  
  /**
   * struct blk_zone_range - BLKRESETZONE ioctl request
   * @sector: starting sector of the first zone to issue reset write pointer
   * @nr_sectors: Total number of sectors of 1 or more zones to reset
   */
  struct blk_zone_range {
  	__u64		sector;
  	__u64		nr_sectors;
  };
  
  /**
   * Zoned block device ioctl's:
   *
   * @BLKREPORTZONE: Get zone information. Takes a zone report as argument.
   *                 The zone report will start from the zone containing the
   *                 sector specified in the report request structure.
   * @BLKRESETZONE: Reset the write pointer of the zones in the specified
   *                sector range. The sector range must be zone aligned.
   */
  #define BLKREPORTZONE	_IOWR(0x12, 130, struct blk_zone_report)
  #define BLKRESETZONE	_IOW(0x12, 131, struct blk_zone_range)
  
  #endif /* _BLKZONED_H */
  