LXR linux/include/linux/t10-pi.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_T10_PI_H
   3#define _LINUX_T10_PI_H
   4
   5#include <linux/types.h>
   6#include <linux/blkdev.h>
   7
   8/*
   9 * A T10 PI-capable target device can be formatted with different
  10 * protection schemes.  Currently 0 through 3 are defined:
  11 *
  12 * Type 0 is regular (unprotected) I/O
  13 *
  14 * Type 1 defines the contents of the guard and reference tags
  15 *
  16 * Type 2 defines the contents of the guard and reference tags and
  17 * uses 32-byte commands to seed the latter
  18 *
  19 * Type 3 defines the contents of the guard tag only
  20 */
  21enum t10_dif_type {
  22        T10_PI_TYPE0_PROTECTION = 0x0,
  23        T10_PI_TYPE1_PROTECTION = 0x1,
  24        T10_PI_TYPE2_PROTECTION = 0x2,
  25        T10_PI_TYPE3_PROTECTION = 0x3,
  26};
  27
  28/*
  29 * T10 Protection Information tuple.
  30 */
  31struct t10_pi_tuple {
  32        __be16 guard_tag;       /* Checksum */
  33        __be16 app_tag;         /* Opaque storage */
  34        __be32 ref_tag;         /* Target LBA or indirect LBA */
  35};
  36
  37#define T10_PI_APP_ESCAPE cpu_to_be16(0xffff)
  38#define T10_PI_REF_ESCAPE cpu_to_be32(0xffffffff)
  39
  40static inline u32 t10_pi_ref_tag(struct request *rq)
  41{
  42        unsigned int shift = ilog2(queue_logical_block_size(rq->q));
  43
  44#ifdef CONFIG_BLK_DEV_INTEGRITY
  45        if (rq->q->integrity.interval_exp)
  46                shift = rq->q->integrity.interval_exp;
  47#endif
  48        return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT) & 0xffffffff;
  49}
  50
  51extern const struct blk_integrity_profile t10_pi_type1_crc;
  52extern const struct blk_integrity_profile t10_pi_type1_ip;
  53extern const struct blk_integrity_profile t10_pi_type3_crc;
  54extern const struct blk_integrity_profile t10_pi_type3_ip;
  55
  56#endif
  57