Manual Pages for UNIX Operating System command usage for man free_pktiopb

Kernel Functions for Drivers                      get_pktiopb(9F)



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

SYNOPSIS
     #include 



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


     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.




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Kernel Functions for Drivers                      get_pktiopb(9F)



DESCRIPTION
     The get_pktiopb() function 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 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 free_pktiopb() function is used for freeing  the  packet
     and its associated resources.

RETURN VALUES
     The get_pktiopb() function returns a pointer  to  the  newly
     allocated scsi_pkt or a NULL pointer.

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


     The free_pktiopb() function can be called from user,  inter-
     rupt, or kernel context.

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



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Kernel Functions for Drivers                      get_pktiopb(9F)



     ____________________________________________________________
    |       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 func-
     tions    have    been     replaced     by,     respectively,
     scsi_alloc_consistent_buf(9F)                            and
     scsi_free_consistent_buf(9F).


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





























SunOS 5.11          Last change: 16 Jan 2006                    3