[linux-block.git] / include / scsi / scsi_cmnd.h

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

#include <linux/dma-mapping.h>
#include <linux/blkdev.h>
#include <linux/t10-pi.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
#include <scsi/scsi_device.h>

struct Scsi_Host;

/*
 * MAX_COMMAND_SIZE is:
 * The longest fixed-length SCSI CDB as per the SCSI standard.
 * fixed-length means: commands that their size can be determined
 * by their opcode and the CDB does not carry a length specifier, (unlike
 * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
 * true and the SCSI standard also defines extended commands and
 * vendor specific commands that can be bigger than 16 bytes. The kernel
 * will support these using the same infrastructure used for VARLEN CDB's.
 * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
 * supports without specifying a cmd_len by ULD's
 */
#define MAX_COMMAND_SIZE 16

struct scsi_data_buffer {
	struct sg_table table;
	unsigned length;
};

/* embedded in scsi_cmnd */
struct scsi_pointer {
	char *ptr;		/* data pointer */
	int this_residual;	/* left in this buffer */
	struct scatterlist *buffer;	/* which buffer */
	int buffers_residual;	/* how many buffers left */

        dma_addr_t dma_handle;

	volatile int Status;
	volatile int Message;
	volatile int have_data_in;
	volatile int sent_command;
	volatile int phase;
};

/* for scmd->flags */
#define SCMD_TAGGED		(1 << 0)
#define SCMD_INITIALIZED	(1 << 1)
#define SCMD_LAST		(1 << 2)
#define SCMD_FAIL_IF_RECOVERING	(1 << 4)
/* flags preserved across unprep / reprep */
#define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)

/* for scmd->state */
#define SCMD_STATE_COMPLETE	0
#define SCMD_STATE_INFLIGHT	1

enum scsi_cmnd_submitter {
	SUBMITTED_BY_BLOCK_LAYER = 0,
	SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
	SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
} __packed;

struct scsi_cmnd {
	struct scsi_device *device;
	struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
	struct delayed_work abort_work;

	struct rcu_head rcu;

	int eh_eflags;		/* Used by error handlr */

	int budget_token;

	/*
	 * This is set to jiffies as it was when the command was first
	 * allocated.  It is used to time how long the command has
	 * been outstanding
	 */
	unsigned long jiffies_at_alloc;

	int retries;
	int allowed;

	unsigned char prot_op;
	unsigned char prot_type;
	unsigned char prot_flags;
	enum scsi_cmnd_submitter submitter;

	unsigned short cmd_len;
	enum dma_data_direction sc_data_direction;

	unsigned char cmnd[32]; /* SCSI CDB */

	/* These elements define the operation we ultimately want to perform */
	struct scsi_data_buffer sdb;
	struct scsi_data_buffer *prot_sdb;

	unsigned underflow;	/* Return error if less than
				   this amount is transferred */

	unsigned transfersize;	/* How much we are guaranteed to
				   transfer with each SCSI transfer
				   (ie, between disconnect / 
				   reconnects.   Probably == sector
				   size */
	unsigned resid_len;	/* residual count */
	unsigned sense_len;
	unsigned char *sense_buffer;
				/* obtained by REQUEST SENSE when
				 * CHECK CONDITION is received on original
				 * command (auto-sense). Length must be
				 * SCSI_SENSE_BUFFERSIZE bytes. */

	int flags;		/* Command flags */
	unsigned long state;	/* Command completion state */

	unsigned int extra_len;	/* length of alignment and padding */

	/*
	 * The fields below can be modified by the LLD but the fields above
	 * must not be modified.
	 */

	unsigned char *host_scribble;	/* The host adapter is allowed to
					 * call scsi_malloc and get some memory
					 * and hang it here.  The host adapter
					 * is also expected to call scsi_free
					 * to release this memory.  (The memory
					 * obtained by scsi_malloc is guaranteed
					 * to be at an address < 16Mb). */

	int result;		/* Status code from lower level driver */
};

/* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
{
	return blk_mq_rq_from_pdu(scmd);
}

/*
 * Return the driver private allocation behind the command.
 * Only works if cmd_size is set in the host template.
 */
static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
{
	return cmd + 1;
}

void scsi_done(struct scsi_cmnd *cmd);
void scsi_done_direct(struct scsi_cmnd *cmd);

extern void scsi_finish_command(struct scsi_cmnd *cmd);

extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
				 size_t *offset, size_t *len);
extern void scsi_kunmap_atomic_sg(void *virt);

blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
void scsi_free_sgtables(struct scsi_cmnd *cmd);

#ifdef CONFIG_SCSI_DMA
extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
#else /* !CONFIG_SCSI_DMA */
static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
#endif /* !CONFIG_SCSI_DMA */

static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
{
	return cmd->sdb.table.nents;
}

static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
{
	return cmd->sdb.table.sgl;
}

static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
{
	return cmd->sdb.length;
}

static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
{
	cmd->resid_len = resid;
}

static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
{
	return cmd->resid_len;
}

#define scsi_for_each_sg(cmd, sg, nseg, __i)			\
	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)

static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
					   const void *buf, int buflen)
{
	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				   buf, buflen);
}

static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
					 void *buf, int buflen)
{
	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				 buf, buflen);
}

static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
{
	return blk_rq_pos(scsi_cmd_to_rq(scmd));
}

static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
{
	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;

	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
}

static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
{
	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;

	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
}

/*
 * The operations below are hints that tell the controller driver how
 * to handle I/Os with DIF or similar types of protection information.
 */
enum scsi_prot_operations {
	/* Normal I/O */
	SCSI_PROT_NORMAL = 0,

	/* OS-HBA: Protected, HBA-Target: Unprotected */
	SCSI_PROT_READ_INSERT,
	SCSI_PROT_WRITE_STRIP,

	/* OS-HBA: Unprotected, HBA-Target: Protected */
	SCSI_PROT_READ_STRIP,
	SCSI_PROT_WRITE_INSERT,

	/* OS-HBA: Protected, HBA-Target: Protected */
	SCSI_PROT_READ_PASS,
	SCSI_PROT_WRITE_PASS,
};

static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
{
	scmd->prot_op = op;
}

static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
{
	return scmd->prot_op;
}

enum scsi_prot_flags {
	SCSI_PROT_TRANSFER_PI		= 1 << 0,
	SCSI_PROT_GUARD_CHECK		= 1 << 1,
	SCSI_PROT_REF_CHECK		= 1 << 2,
	SCSI_PROT_REF_INCREMENT		= 1 << 3,
	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
};

/*
 * The controller usually does not know anything about the target it
 * is communicating with.  However, when DIX is enabled the controller
 * must be know target type so it can verify the protection
 * information passed along with the I/O.
 */
enum scsi_prot_target_type {
	SCSI_PROT_DIF_TYPE0 = 0,
	SCSI_PROT_DIF_TYPE1,
	SCSI_PROT_DIF_TYPE2,
	SCSI_PROT_DIF_TYPE3,
};

static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
{
	scmd->prot_type = type;
}

static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
{
	return scmd->prot_type;
}

static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
{
	struct request *rq = blk_mq_rq_from_pdu(scmd);

	return t10_pi_ref_tag(rq);
}

static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
{
	return scmd->device->sector_size;
}

static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
}

static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
}

static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb;
}

#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)

static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
{
	cmd->result = (cmd->result & 0xffffff00) | status;
}

static inline u8 get_status_byte(struct scsi_cmnd *cmd)
{
	return cmd->result & 0xff;
}

static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
{
	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
}

static inline u8 get_host_byte(struct scsi_cmnd *cmd)
{
	return (cmd->result >> 16) & 0xff;
}

/**
 * scsi_msg_to_host_byte() - translate message byte
 *
 * Translate the SCSI parallel message byte to a matching
 * host byte setting. A message of COMMAND_COMPLETE indicates
 * a successful command execution, any other message indicate
 * an error. As the messages themselves only have a meaning
 * for the SCSI parallel protocol this function translates
 * them into a matching host byte value for SCSI EH.
 */
static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
{
	switch (msg) {
	case COMMAND_COMPLETE:
		break;
	case ABORT_TASK_SET:
		set_host_byte(cmd, DID_ABORT);
		break;
	case TARGET_RESET:
		set_host_byte(cmd, DID_RESET);
		break;
	default:
		set_host_byte(cmd, DID_ERROR);
		break;
	}
}

static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
{
	unsigned int xfer_len = scmd->sdb.length;
	unsigned int prot_interval = scsi_prot_interval(scmd);

	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;

	return xfer_len;
}

extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
			     u8 key, u8 asc, u8 ascq);

struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
				   blk_mq_req_flags_t flags);

#endif /* _SCSI_SCSI_CMND_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _SCSI_SCSI_CMND_H
	3	#define _SCSI_SCSI_CMND_H
	4
	5	#include <linux/dma-mapping.h>
	6	#include <linux/blkdev.h>
	7	#include <linux/t10-pi.h>
	8	#include <linux/list.h>
	9	#include <linux/types.h>
	10	#include <linux/timer.h>
	11	#include <linux/scatterlist.h>
	12	#include <scsi/scsi_device.h>
	13
	14	struct Scsi_Host;
	15
	16	/*
	17	* MAX_COMMAND_SIZE is:
	18	* The longest fixed-length SCSI CDB as per the SCSI standard.
	19	* fixed-length means: commands that their size can be determined
	20	* by their opcode and the CDB does not carry a length specifier, (unlike
	21	* the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
	22	* true and the SCSI standard also defines extended commands and
	23	* vendor specific commands that can be bigger than 16 bytes. The kernel
	24	* will support these using the same infrastructure used for VARLEN CDB's.
	25	* So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
	26	* supports without specifying a cmd_len by ULD's
	27	*/
	28	#define MAX_COMMAND_SIZE 16
	29
	30	struct scsi_data_buffer {
	31	struct sg_table table;
	32	unsigned length;
	33	};
	34
	35	/* embedded in scsi_cmnd */
	36	struct scsi_pointer {
	37	char ptr; / data pointer */
	38	int this_residual; /* left in this buffer */
	39	struct scatterlist buffer; / which buffer */
	40	int buffers_residual; /* how many buffers left */
	41
	42	dma_addr_t dma_handle;
	43
	44	volatile int Status;
	45	volatile int Message;
	46	volatile int have_data_in;
	47	volatile int sent_command;
	48	volatile int phase;
	49	};
	50
	51	/* for scmd->flags */
	52	#define SCMD_TAGGED (1 << 0)
	53	#define SCMD_INITIALIZED (1 << 1)
	54	#define SCMD_LAST (1 << 2)
	55	#define SCMD_FAIL_IF_RECOVERING (1 << 4)
	56	/* flags preserved across unprep / reprep */
	57	#define SCMD_PRESERVED_FLAGS (SCMD_INITIALIZED \| SCMD_FAIL_IF_RECOVERING)
	58
	59	/* for scmd->state */
	60	#define SCMD_STATE_COMPLETE 0
	61	#define SCMD_STATE_INFLIGHT 1
	62
	63	enum scsi_cmnd_submitter {
	64	SUBMITTED_BY_BLOCK_LAYER = 0,
	65	SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
	66	SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
	67	} __packed;
	68
	69	struct scsi_cmnd {
	70	struct scsi_device *device;
	71	struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
	72	struct delayed_work abort_work;
	73
	74	struct rcu_head rcu;
	75
	76	int eh_eflags; /* Used by error handlr */
	77
	78	int budget_token;
	79
	80	/*
	81	* This is set to jiffies as it was when the command was first
	82	* allocated. It is used to time how long the command has
	83	* been outstanding
	84	*/
	85	unsigned long jiffies_at_alloc;
	86
	87	int retries;
	88	int allowed;
	89
	90	unsigned char prot_op;
	91	unsigned char prot_type;
	92	unsigned char prot_flags;
	93	enum scsi_cmnd_submitter submitter;
	94
	95	unsigned short cmd_len;
	96	enum dma_data_direction sc_data_direction;
	97
	98	unsigned char cmnd[32]; /* SCSI CDB */
	99
	100	/* These elements define the operation we ultimately want to perform */
	101	struct scsi_data_buffer sdb;
	102	struct scsi_data_buffer *prot_sdb;
	103
	104	unsigned underflow; /* Return error if less than
	105	this amount is transferred */
	106
	107	unsigned transfersize; /* How much we are guaranteed to
	108	transfer with each SCSI transfer
	109	(ie, between disconnect /
	110	reconnects. Probably == sector
	111	size */
	112	unsigned resid_len; /* residual count */
	113	unsigned sense_len;
	114	unsigned char *sense_buffer;
	115	/* obtained by REQUEST SENSE when
	116	* CHECK CONDITION is received on original
	117	* command (auto-sense). Length must be
	118	* SCSI_SENSE_BUFFERSIZE bytes. */
	119
	120	int flags; /* Command flags */
	121	unsigned long state; /* Command completion state */
	122
	123	unsigned int extra_len; /* length of alignment and padding */
	124
	125	/*
	126	* The fields below can be modified by the LLD but the fields above
	127	* must not be modified.
	128	*/
	129
	130	unsigned char host_scribble; / The host adapter is allowed to
	131	* call scsi_malloc and get some memory
	132	* and hang it here. The host adapter
	133	* is also expected to call scsi_free
	134	* to release this memory. (The memory
	135	* obtained by scsi_malloc is guaranteed
	136	* to be at an address < 16Mb). */
	137
	138	int result; /* Status code from lower level driver */
	139	};
	140
	141	/* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
	142	static inline struct request scsi_cmd_to_rq(struct scsi_cmnd scmd)
	143	{
	144	return blk_mq_rq_from_pdu(scmd);
	145	}
	146
	147	/*
	148	* Return the driver private allocation behind the command.
	149	* Only works if cmd_size is set in the host template.
	150	*/
	151	static inline void scsi_cmd_priv(struct scsi_cmnd cmd)
	152	{
	153	return cmd + 1;
	154	}
	155
	156	void scsi_done(struct scsi_cmnd *cmd);
	157	void scsi_done_direct(struct scsi_cmnd *cmd);
	158
	159	extern void scsi_finish_command(struct scsi_cmnd *cmd);
	160
	161	extern void scsi_kmap_atomic_sg(struct scatterlist sg, int sg_count,
	162	size_t offset, size_t len);
	163	extern void scsi_kunmap_atomic_sg(void *virt);
	164
	165	blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
	166	void scsi_free_sgtables(struct scsi_cmnd *cmd);
	167
	168	#ifdef CONFIG_SCSI_DMA
	169	extern int scsi_dma_map(struct scsi_cmnd *cmd);
	170	extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
	171	#else /* !CONFIG_SCSI_DMA */
	172	static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
	173	static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
	174	#endif /* !CONFIG_SCSI_DMA */
	175
	176	static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
	177	{
	178	return cmd->sdb.table.nents;
	179	}
	180
	181	static inline struct scatterlist scsi_sglist(struct scsi_cmnd cmd)
	182	{
	183	return cmd->sdb.table.sgl;
	184	}
	185
	186	static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
	187	{
	188	return cmd->sdb.length;
	189	}
	190
	191	static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
	192	{
	193	cmd->resid_len = resid;
	194	}
	195
	196	static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
	197	{
	198	return cmd->resid_len;
	199	}
	200
	201	#define scsi_for_each_sg(cmd, sg, nseg, __i) \
	202	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
	203
	204	static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
	205	const void *buf, int buflen)
	206	{
	207	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
	208	buf, buflen);
	209	}
	210
	211	static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
	212	void *buf, int buflen)
	213	{
	214	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
	215	buf, buflen);
	216	}
	217
	218	static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
	219	{
	220	return blk_rq_pos(scsi_cmd_to_rq(scmd));
	221	}
	222
	223	static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
	224	{
	225	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
	226
	227	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
	228	}
	229
	230	static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
	231	{
	232	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
	233
	234	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
	235	}
	236
	237	/*
	238	* The operations below are hints that tell the controller driver how
	239	* to handle I/Os with DIF or similar types of protection information.
	240	*/
	241	enum scsi_prot_operations {
	242	/* Normal I/O */
	243	SCSI_PROT_NORMAL = 0,
	244
	245	/* OS-HBA: Protected, HBA-Target: Unprotected */
	246	SCSI_PROT_READ_INSERT,
	247	SCSI_PROT_WRITE_STRIP,
	248
	249	/* OS-HBA: Unprotected, HBA-Target: Protected */
	250	SCSI_PROT_READ_STRIP,
	251	SCSI_PROT_WRITE_INSERT,
	252
	253	/* OS-HBA: Protected, HBA-Target: Protected */
	254	SCSI_PROT_READ_PASS,
	255	SCSI_PROT_WRITE_PASS,
	256	};
	257
	258	static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
	259	{
	260	scmd->prot_op = op;
	261	}
	262
	263	static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
	264	{
	265	return scmd->prot_op;
	266	}
	267
	268	enum scsi_prot_flags {
	269	SCSI_PROT_TRANSFER_PI = 1 << 0,
	270	SCSI_PROT_GUARD_CHECK = 1 << 1,
	271	SCSI_PROT_REF_CHECK = 1 << 2,
	272	SCSI_PROT_REF_INCREMENT = 1 << 3,
	273	SCSI_PROT_IP_CHECKSUM = 1 << 4,
	274	};
	275
	276	/*
	277	* The controller usually does not know anything about the target it
	278	* is communicating with. However, when DIX is enabled the controller
	279	* must be know target type so it can verify the protection
	280	* information passed along with the I/O.
	281	*/
	282	enum scsi_prot_target_type {
	283	SCSI_PROT_DIF_TYPE0 = 0,
	284	SCSI_PROT_DIF_TYPE1,
	285	SCSI_PROT_DIF_TYPE2,
	286	SCSI_PROT_DIF_TYPE3,
	287	};
	288
	289	static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
	290	{
	291	scmd->prot_type = type;
	292	}
	293
	294	static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
	295	{
	296	return scmd->prot_type;
	297	}
	298
	299	static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
	300	{
	301	struct request *rq = blk_mq_rq_from_pdu(scmd);
	302
	303	return t10_pi_ref_tag(rq);
	304	}
	305
	306	static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
	307	{
	308	return scmd->device->sector_size;
	309	}
	310
	311	static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
	312	{
	313	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
	314	}
	315
	316	static inline struct scatterlist scsi_prot_sglist(struct scsi_cmnd cmd)
	317	{
	318	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
	319	}
	320
	321	static inline struct scsi_data_buffer scsi_prot(struct scsi_cmnd cmd)
	322	{
	323	return cmd->prot_sdb;
	324	}
	325
	326	#define scsi_for_each_prot_sg(cmd, sg, nseg, __i) \
	327	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
	328
	329	static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
	330	{
	331	cmd->result = (cmd->result & 0xffffff00) \| status;
	332	}
	333
	334	static inline u8 get_status_byte(struct scsi_cmnd *cmd)
	335	{
	336	return cmd->result & 0xff;
	337	}
	338
	339	static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
	340	{
	341	cmd->result = (cmd->result & 0xff00ffff) \| (status << 16);
	342	}
	343
	344	static inline u8 get_host_byte(struct scsi_cmnd *cmd)
	345	{
	346	return (cmd->result >> 16) & 0xff;
	347	}
	348
	349	/**
	350	* scsi_msg_to_host_byte() - translate message byte
	351	*
	352	* Translate the SCSI parallel message byte to a matching
	353	* host byte setting. A message of COMMAND_COMPLETE indicates
	354	* a successful command execution, any other message indicate
	355	* an error. As the messages themselves only have a meaning
	356	* for the SCSI parallel protocol this function translates
	357	* them into a matching host byte value for SCSI EH.
	358	*/
	359	static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
	360	{
	361	switch (msg) {
	362	case COMMAND_COMPLETE:
	363	break;
	364	case ABORT_TASK_SET:
	365	set_host_byte(cmd, DID_ABORT);
	366	break;
	367	case TARGET_RESET:
	368	set_host_byte(cmd, DID_RESET);
	369	break;
	370	default:
	371	set_host_byte(cmd, DID_ERROR);
	372	break;
	373	}
	374	}
	375
	376	static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
	377	{
	378	unsigned int xfer_len = scmd->sdb.length;
	379	unsigned int prot_interval = scsi_prot_interval(scmd);
	380
	381	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
	382	xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
	383
	384	return xfer_len;
	385	}
	386
	387	extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
	388	u8 key, u8 asc, u8 ascq);
	389
	390	struct request scsi_alloc_request(struct request_queue q, blk_opf_t opf,
	391	blk_mq_req_flags_t flags);
	392
	393	#endif /* _SCSI_SCSI_CMND_H */