scsi_pkt(9S)

NAME

scsi_pkt − SCSI packet structure

SYNOPSIS

#include <sys/scsi/scsi.h>

INTERFACE LEVEL

SPARC architecture specific (SPARC DDI).

DESCRIPTION

A scsi_pkt structure defines the packet which is allocated by scsi_init_pkt(9F). The target driver fills in some information, and passes it to scsi_transport(9F) for execution on the target. The host adapter fills in some other information as the command is processed. When the command completes (or can be taken no further) the completion function specified in the packet is called with a pointer to the packet as its argument. From fields within the packet, the target driver can determine the success or failure of the command.

STRUCTURE ELEMENTS

struct scsi_address	pkt_address;	/∗ destination packet is for ∗/
opaque_t	pkt_private;	/∗ private data for target driver ∗/
void	(∗pkt_comp)();	/∗ completion routine ∗/
long	pkt_flags;	/∗ flags ∗/
long	pkt_time;	/∗ time allotted to complete command ∗/
u_char	∗pkt_scbp;	/∗ pointer to status block ∗/
u_char	∗pkt_cdbp;	/∗ pointer to command block ∗/
long	pkt_resid;	/∗ number of bytes not transferred ∗/
u_long	pkt_state;	/∗ state of command ∗/
u_long	pkt_statistics;	/∗ statistics ∗/
u_char	pkt_reason;	/∗ reason completion called ∗/

pkt_address is initialized by scsi_init_pkt(9F) and serves to record the intended route and recipient of a request.

pkt_private is reserved for the use of the target driver and is not changed by the host adapter driver.

pkt_comp specifies the command completion callback routine. When the host adapter driver has gone as far as it can in transporting a command to a SCSI target, and the command has either run to completion, or can go no further for some other reason, the host adapter driver will call the function pointed to by this field and pass a pointer to the packet as argument. This field may contain a NULL pointer if notification of completion is not required.

pkt_flags provides additional information about how the target driver wants the command to be executed. See below.

pkt_time will be set by the target driver to represent the maximum length of time in seconds that this command should take to complete.

pkt_scbp points to the SCSI status completion block.

pkt_cdbp points to a kernel addressable buffer whose length was specified by a call to the proper resource allocation routine, scsi_init_pkt(9F).

pkt_resid contains a residual count—the number of data bytes that have not been transferred.

pkt_state has bit positions representing the five most important states that a SCSI command can go through. (see below)

pkt_statistics maintains some transport-related statistics. (see below)

pkt_reason contains a completion code that indicates why the pkt_comp function was called.

The host adapter driver will update the pkt_resid, pkt_reason, and pkt_state, pkt_statistics fields.

The definitions that are appropriate for the structure member pkt_flags are:

FLAG_NOINTR Run command without interrupts.

FLAG_NODISCON Run command without disconnects.

FLAG_SUBLUN Use the sublun field in pkt_address.

FLAG_NOPARITY Run command without parity checking.

FLAG_HTAG Run command as the head of queue tagged command.

FLAG_OTAG Run command as an ordered queue tagged command.

FLAG_STAG Run command as a simple queue tagged command.

FLAG_SENSING This command is a request sense command.

FLAG_HEAD This command should be put at the head of the queue.

The definitions that are appropriate for the structure member pkt_reason are:

CMD_CMPLT No transport errors- normal completion.

CMD_INCOMPLETE Transport stopped with abnormal state.

CMD_DMA_DERR DMA direction error.

CMD_TRAN_ERR Unspecified transport error.

CMD_RESET SCSI bus reset destroyed command.

CMD_ABORTED Command transport aborted on request.

CMD_TIMEOUT Command timed out.

CMD_DATA_OVR Data Overrun.

CMD_CMD_OVR Command Overrun.

CMD_STS_OVR Status Overrun.

CMD_BADMSG Message not Command Complete.

CMD_NOMSGOUT Target refused to go to Message Out phase.

CMD_XID_FAIL Extended Identify message rejected.

CMD_IDE_FAIL Initiator Detected Error message rejected.

CMD_ABORT_FAIL Abort message rejected.

CMD_REJECT_FAIL Reject message rejected.

CMD_NOP_FAIL No Operation message rejected.

CMD_PER_FAIL Message Parity Error message rejected.

CMD_BDR_FAIL Bus Device Reset message rejected.

CMD_ID_FAIL Identify message rejected.

CMD_UNX_BUS_FREE
Unexpected Bus Free Phase.

CMD_TAG_REJECT Target rejected the tag message.

The definitions that are appropriate for the structure member pkt_state are:

STATE_GOT_BUS Bus arbitration succeeded.

STATE_GOT_TARGET Target successfully selected.

STATE_SENT_CMD Command successfully sent.

STATE_XFERRED_DATA
Data transfer took place.

STATE_GOT_STATUS Status received.

STATE_ARQ_DONE The command resulted in a check condition and the host adapter driver executed an automatic request sense cmd.

The definitions that are appropriate for the structure member pkt_statistics are:

STAT_DISCON Device disconnect.

STAT_SYNC Command did a synchronous data transfer.

STAT_PERR SCSI parity error.

STAT_BUS_RESET
Bus reset.

STAT_DEV_RESET
Device reset.

STAT_ABORTED Command was aborted.

STAT_TIMEOUT Command timed out.

Museum