/* SPDX-License-Identifier: GPL-2.0 */
  #ifndef _LINUX_T10_PI_H
  #define _LINUX_T10_PI_H
  
  #include <linux/types.h>
  #include <linux/blkdev.h>
  
  /*
   * A T10 PI-capable target device can be formatted with different
   * protection schemes.	Currently 0 through 3 are defined:
   *
   * Type 0 is regular (unprotected) I/O
   *
   * Type 1 defines the contents of the guard and reference tags
   *
   * Type 2 defines the contents of the guard and reference tags and
   * uses 32-byte commands to seed the latter
   *
   * Type 3 defines the contents of the guard tag only
   */
  enum t10_dif_type {
  	T10_PI_TYPE0_PROTECTION = 0x0,
  	T10_PI_TYPE1_PROTECTION = 0x1,
  	T10_PI_TYPE2_PROTECTION = 0x2,
  	T10_PI_TYPE3_PROTECTION = 0x3,
  };
  
  /*
   * T10 Protection Information tuple.
   */
  struct t10_pi_tuple {
  	__be16 guard_tag;	/* Checksum */
  	__be16 app_tag;		/* Opaque storage */
  	__be32 ref_tag;		/* Target LBA or indirect LBA */
  };
  
  #define T10_PI_APP_ESCAPE cpu_to_be16(0xffff)
  #define T10_PI_REF_ESCAPE cpu_to_be32(0xffffffff)
  
  extern const struct blk_integrity_profile t10_pi_type1_crc;
  extern const struct blk_integrity_profile t10_pi_type1_ip;
  extern const struct blk_integrity_profile t10_pi_type3_crc;
  extern const struct blk_integrity_profile t10_pi_type3_ip;
  
  #endif