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#ifdef CONFIG_BLK_DEV_INTEGRITY
57extern void t10_pi_prepare(struct request *rq, u8 protection_type);
58extern void t10_pi_complete(struct request *rq, u8 protection_type,
59 unsigned int intervals);
60#else
61static inline void t10_pi_complete(struct request *rq, u8 protection_type,
62 unsigned int intervals)
63{
64}
65static inline void t10_pi_prepare(struct request *rq, u8 protection_type)
66{
67}
68#endif
69
70#endif
71