linux-stable/include/linux/t10-pi.h
Keith Busch 868e6139c5 block: move lower_48_bits() to block
The function is not generally applicable enough to be included in the core
kernel header. Move it to block since it's the only subsystem using it.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220327173316.315-1-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-11 19:18:27 -06:00

85 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_T10_PI_H
#define _LINUX_T10_PI_H
#include <linux/types.h>
#include <linux/blk-mq.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)
static inline u32 t10_pi_ref_tag(struct request *rq)
{
unsigned int shift = ilog2(queue_logical_block_size(rq->q));
#ifdef CONFIG_BLK_DEV_INTEGRITY
if (rq->q->integrity.interval_exp)
shift = rq->q->integrity.interval_exp;
#endif
return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT) & 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;
struct crc64_pi_tuple {
__be64 guard_tag;
__be16 app_tag;
__u8 ref_tag[6];
};
/**
* lower_48_bits() - return bits 0-47 of a number
* @n: the number we're accessing
*/
static inline u64 lower_48_bits(u64 n)
{
return n & ((1ull << 48) - 1);
}
static inline u64 ext_pi_ref_tag(struct request *rq)
{
unsigned int shift = ilog2(queue_logical_block_size(rq->q));
#ifdef CONFIG_BLK_DEV_INTEGRITY
if (rq->q->integrity.interval_exp)
shift = rq->q->integrity.interval_exp;
#endif
return lower_48_bits(blk_rq_pos(rq) >> (shift - SECTOR_SHIFT));
}
extern const struct blk_integrity_profile ext_pi_type1_crc64;
extern const struct blk_integrity_profile ext_pi_type3_crc64;
#endif