blk-integrity.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BLK_INTEGRITY_H
#define _LINUX_BLK_INTEGRITY_H

#include <linux/blk-mq.h>

struct request;

enum blk_integrity_flags {
	BLK_INTEGRITY_VERIFY		= 1 << 0,
	BLK_INTEGRITY_GENERATE		= 1 << 1,
	BLK_INTEGRITY_DEVICE_CAPABLE	= 1 << 2,
	BLK_INTEGRITY_IP_CHECKSUM	= 1 << 3,
};

struct blk_integrity_iter {
	void			*prot_buf;
	void			*data_buf;
	sector_t		seed;
	unsigned int		data_size;
	unsigned short		interval;
	unsigned char		tuple_size;
	const char		*disk_name;
};

typedef blk_status_t (integrity_processing_fn) (struct blk_integrity_iter *);
typedef void (integrity_prepare_fn) (struct request *);
typedef void (integrity_complete_fn) (struct request *, unsigned int);

struct blk_integrity_profile {
	integrity_processing_fn		*generate_fn;
	integrity_processing_fn		*verify_fn;
	integrity_prepare_fn		*prepare_fn;
	integrity_complete_fn		*complete_fn;
	const char			*name;
};

#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_integrity_register(struct gendisk *, struct blk_integrity *);
void blk_integrity_unregister(struct gendisk *);
int blk_integrity_compare(struct gendisk *, struct gendisk *);
int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
				   struct scatterlist *);
int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);

static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
{
	struct blk_integrity *bi = &disk->queue->integrity;

	if (!bi->profile)
		return NULL;

	return bi;
}

static inline struct blk_integrity *
bdev_get_integrity(struct block_device *bdev)
{
	return blk_get_integrity(bdev->bd_disk);
}

static inline bool
blk_integrity_queue_supports_integrity(struct request_queue *q)
{
	return q->integrity.profile;
}

static inline void blk_queue_max_integrity_segments(struct request_queue *q,
						    unsigned int segs)
{
	q->limits.max_integrity_segments = segs;
}

static inline unsigned short
queue_max_integrity_segments(const struct request_queue *q)
{
	return q->limits.max_integrity_segments;
}

/**
 * bio_integrity_intervals - Return number of integrity intervals for a bio
 * @bi:		blk_integrity profile for device
 * @sectors:	Size of the bio in 512-byte sectors
 *
 * Description: The block layer calculates everything in 512 byte
 * sectors but integrity metadata is done in terms of the data integrity
 * interval size of the storage device.  Convert the block layer sectors
 * to the appropriate number of integrity intervals.
 */
static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
						   unsigned int sectors)
{
	return sectors >> (bi->interval_exp - 9);
}

static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
					       unsigned int sectors)
{
	return bio_integrity_intervals(bi, sectors) * bi->tuple_size;
}

static inline bool blk_integrity_rq(struct request *rq)
{
	return rq->cmd_flags & REQ_INTEGRITY;
}

/*
 * Return the first bvec that contains integrity data.  Only drivers that are
 * limited to a single integrity segment should use this helper.
 */
static inline struct bio_vec *rq_integrity_vec(struct request *rq)
{
	if (WARN_ON_ONCE(queue_max_integrity_segments(rq->q) > 1))
		return NULL;
	return rq->bio->bi_integrity->bip_vec;
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline int blk_rq_count_integrity_sg(struct request_queue *q,
					    struct bio *b)
{
	return 0;
}
static inline int blk_rq_map_integrity_sg(struct request_queue *q,
					  struct bio *b,
					  struct scatterlist *s)
{
	return 0;
}
static inline struct blk_integrity *bdev_get_integrity(struct block_device *b)
{
	return NULL;
}
static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
{
	return NULL;
}
static inline bool
blk_integrity_queue_supports_integrity(struct request_queue *q)
{
	return false;
}
static inline int blk_integrity_compare(struct gendisk *a, struct gendisk *b)
{
	return 0;
}
static inline void blk_integrity_register(struct gendisk *d,
					 struct blk_integrity *b)
{
}
static inline void blk_integrity_unregister(struct gendisk *d)
{
}
static inline void blk_queue_max_integrity_segments(struct request_queue *q,
						    unsigned int segs)
{
}
static inline unsigned short
queue_max_integrity_segments(const struct request_queue *q)
{
	return 0;
}

static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
						   unsigned int sectors)
{
	return 0;
}

static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
					       unsigned int sectors)
{
	return 0;
}
static inline int blk_integrity_rq(struct request *rq)
{
	return 0;
}

static inline struct bio_vec *rq_integrity_vec(struct request *rq)
{
	return NULL;
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
#endif /* _LINUX_BLK_INTEGRITY_H */