free_pktiopb(9f) [sunos man page]

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

NAME

       get_pktiopb, free_pktiopb - allocate/free a SCSI packet in the iopb map

SYNOPSIS

       #include <sys/scsi/scsi.h>

       struct  scsi_pkt  *get_pktiopb(struct  scsi_address  *ap, caddr_t *datap, int cdblen, int statuslen, int datalen, int readflag, int (*call-
       back);

       void free_pktiopb(struct scsi_pkt *pkt, caddr_t datap, int datalen);

INTERFACE LEVEL

       These interfaces are obsolete. Use scsi_alloc_consistent_buf(9F) instead of  get_pktiopb().  Use  scsi_free_consistent_buf(9F)  instead	of
       free_pktiopb().

PARAMETERS

       ap	       Pointer to the target's scsi_address structure.

       datap	       Pointer to the address of the packet, set by this function.

       cdblen	       Number of bytes required for the SCSI command descriptor block (CDB).

       statuslen       Number of bytes required for the SCSI status area.

       datalen	       Number of bytes required for the data area of the SCSI command.

       readflag        If non-zero, data will be transferred from the SCSI target.

       callback        Pointer to a callback function, or NULL_FUNC or SLEEP_FUNC

       pkt	       Pointer to a scsi_pkt(9S) structure.

DESCRIPTION

       get_pktiopb()  allocates a scsi_pkt structure that has a small data area allocated. It is used by some SCSI commands such as REQUEST_SENSE,
       which involve a small amount of data and require cache-consistent memory for proper operation. It uses  ddi_iopb_alloc(9F)  for	allocating
       the data area and scsi_resalloc(9F) to allocate the packet and DMA resources.

       callback indicates what get_pktiopb() should do when resources are not available:

       NULL_FUNC       Do not wait for resources. Return a NULL pointer.

       SLEEP_FUNC      Wait indefinitely for resources.

       Other Values    callback  points  to  a	function  which  is called when resources may have become available. callback must return either 0
		       (indicating that it attempted to allocate resources but failed to do so again), in which case it is put back on a  list	to
		       be  called  again later, or 1 indicating either success in allocating resources or indicating that it no longer cares for a
		       retry.

       free_pktiopb() is used for freeing the packet and its associated resources.

RETURN VALUES

       get_pktiopb() returns a pointer to the newly allocated scsi_pkt or a NULL pointer.

CONTEXT

       If callback is SLEEP_FUNC, then this routine may only be called from user-level code. Otherwise, it may	be  called  from  either  user	or
       interrupt level. The callback function may not block or call routines that block.

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

ATTRIBUTES

       See attributes(5) for a description of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Stability Level 	     |Obsolete			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       attributes(5),	ddi_iopb_alloc(9F),  scsi_alloc_consistent_buf(9F),  scsi_free_consistent_buf(9F),  scsi_pktalloc(9F),	scsi_resalloc(9F),
       scsi_pkt(9S)

       Writing Device Drivers

NOTES

       The get_pktiopb() and free_pktiopb() functions are obsolete and will be discontinued  in  a  future  release.  These  functions	have  been
       replaced by, respectively, scsi_alloc_consistent_buf(9F) and scsi_free_consistent_buf(9F).

       get_pktiopb() uses scarce resources. For this reason and its obsolescence (see above), its use is discouraged.

SunOS 5.10							    27 Sep 2002 						   get_pktiopb(9F)