Manual Pages for UNIX Operating System command usage for man scsi_dmaget

Kernel Functions for Drivers                      scsi_dmaget(9F)



NAME
     scsi_dmaget, scsi_dmafree - SCSI dma utility routines

SYNOPSIS
     #include 



     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 pre-
     viously 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.





SunOS 5.11          Last change: 16 Jan 2006                    1






Kernel Functions for Drivers                      scsi_dmaget(9F)



     SLEEP_FUNC      Wait indefinitely for resources.


     Other Values    callback  points  to  a  function  which  is
                     called when resources may have become avail-
                     able. callback must return either  0  (indi-
                     cating   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 indicat-
                     ing that it no longer cares for a retry.



     The scsi_dmafree() function frees the DMA resources  associ-
     ated  with  the SCSI packet. The packet itself remains allo-
     cated.

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,  inter-
     rupt, or kernel context.

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



     ____________________________________________________________
    |       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)






SunOS 5.11          Last change: 16 Jan 2006                    2






Kernel Functions for Drivers                      scsi_dmaget(9F)



     Writing Device Drivers

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     tions have been replaced by, respectively, scsi_init_pkt(9F)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
















































SunOS 5.11          Last change: 16 Jan 2006                    3