opensolaris man page for scsi_dmaget

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

NAME
       scsi_dmaget, scsi_dmafree - SCSI dma utility routines

SYNOPSIS
       #include <sys/scsi/scsi.h>

       struct scsi_pkt *scsi_dmaget(struct scsi_pkt *pkt,
	    opaque_t dmatoken, int(*callback)(void));

       void scsi_dmafree(struct scsi_pkt *pkt);

INTERFACE LEVEL
       These interfaces are obsolete. Use scsi_init_pkt(9F) instead of scsi_dmaget(). Use scsi_destroy_pkt(9F) instead of scsi_dmafree().

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

       dmatoken    Pointer to an implementation dependent object.

       callback    Pointer to a callback function, or NULL_FUNC or SLEEP_FUNC.

DESCRIPTION
       The  scsi_dmaget() function allocates DMA resources for an already allocated SCSI packet. pkt is a pointer to the previously allocated SCSI
       packet (see scsi_pktalloc(9F)).

       The dmatoken parameter is a pointer to an implementation dependent object which defines the length, direction,  and  address  of  the  data
       transfer  associated  with  this  SCSI  packet  (command).  The	dmatoken must be a pointer to a buf(9S) structure. If dmatoken is NULL, no
       resources are allocated.

       The callback parameter indicates what scsi_dmaget() 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.

       The scsi_dmafree() function frees the DMA resources associated with the SCSI packet. The packet itself remains allocated.

RETURN VALUES
       The scsi_dmaget() function returns a pointer to a scsi_pkt on success. It returns NULL if resources are not available.

CONTEXT
       If callback is SLEEP_FUNC, then this routine may only be called from user or kernel context. Otherwise, it may be called from user, kernel,
       or interrupt context. The callback function may not block or call routines that block.

       The scsi_dmafree() function can be called from user, interrupt, or kernel context.

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

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

SEE ALSO
       attributes(5), scsi_pktalloc(9F), scsi_pktfree(9F), scsi_resalloc(9F), scsi_resfree(9F), buf(9S), scsi_pkt(9S)

       Writing Device Drivers

NOTES
       The scsi_dmaget() and scsi_dmafree() functions are obsolete and will be discontinued  in  a  future  release.  These  functions	have  been
       replaced by, respectively, scsi_init_pkt(9F) and scsi_destroy_pkt(9F).

SunOS 5.11							    16 Jan 2006 						   scsi_dmaget(9F)