scsi_hba_pkt_alloc(9F)					   Kernel Functions for Drivers 				    scsi_hba_pkt_alloc(9F)

NAME

       scsi_hba_pkt_alloc, scsi_hba_pkt_free - allocate and free a scsi_pkt structure

SYNOPSIS

       #include <sys/scsi/scsi.h>

       struct  scsi_pkt  *scsi_hba_pkt_alloc(dev_info_t  *dip,	struct	scsi_address  *ap,  int cmdlen, int statuslen, int tgtlen, int hbalen, int
       (*callback, caddr_t arg, caddr_t arg);

       void scsi_hba_pkt_free(struct scsi_address *ap, struct scsi_pkt *pkt);

INTERFACE LEVEL

       Solaris architecture specific (Solaris DDI).

PARAMETERS

       dip	       Pointer to a dev_info_t structure, defining the HBA driver instance.

       ap	       Pointer to a scsi_address(9S) structure, defining the target instance.

       cmdlen	       Length in bytes to be allocated for the SCSI command descriptor block (CDB).

       statuslen       Length in bytes to be allocated for the SCSI status completion block (SCB).

       tgtlen	       Length in bytes to be allocated for a private data area for the target driver's exclusive use.

       hbalen	       Length in bytes to be allocated for a private data area for the HBA driver's exclusive use.

       callback        Indicates what scsi_hba_pkt_alloc() should do when resources are not available:

		       NULL_FUNC

			   Do not wait for resources.  Return a NULL pointer.

		       SLEEP_FUNC

			   Wait indefinitely for resources.

       arg	       Must be NULL.

       pkt	       A pointer to a scsi_pkt(9S) structure.

DESCRIPTION

       For scsi_hba_pkt_alloc():

       scsi_hba_pkt_alloc() allocates space for a scsi_pkt structure.  HBA drivers must use this interface when allocating a scsi_pkt  from  their
       tran_init_pkt(9E) entry point.

       If  callback is	NULL_FUNC, scsi_hba_pkt_alloc() may not sleep when allocating resources, and callers should be prepared to deal with allo-
       cation failures.

       scsi_hba_pkt_alloc() copies the scsi_address(9S) structure pointed to by ap to the pkt_address field in the scsi_pkt(9S).

       scsi_hba_pkt_alloc() also allocates memory for these scsi_pkt(9S) data areas, and sets these fields to point to the allocated memory:

       pkt_ha_private	       HBA private data area.

       pkt_private	       Target driver private data area.

       pkt_scbp 	       SCSI status completion block.

       pkt_cdbp 	       SCSI command descriptor block.

       For scsi_hba_pkt_free():

       scsi_hba_pkt_free() frees the space allocated for the scsi_pkt(9S) structure.

RETURN VALUES

       scsi_hba_pkt_alloc() returns a pointer to the scsi_pkt structure, or NULL if no space is available.

CONTEXT

       scsi_hba_pkt_alloc() can be called from user or interrupt context. Drivers must not allow scsi_hba_pkt_alloc() to sleep if called  from	an
       interrupt routine.

       scsi_hba_pkt_free() can be called from user or interrupt context.

SEE ALSO

       tran_init_pkt(9E), scsi_address(9S), scsi_pkt(9S)

       Writing Device Drivers

SunOS 5.10							    24 Feb 2003 					    scsi_hba_pkt_alloc(9F)