Manual Pages for UNIX Operating System command usage for man devmap_dup

Driver Entry Points                                devmap_dup(9E)



NAME
     devmap_dup - device mapping duplication entry point

SYNOPSIS
     #include 
     #include 


      int prefixdevmap_dup(devmap_cookie_t dhp, void *pvtp,
          devmap_cookie_t new_dhp, void **new_pvtp);


INTERFACE LEVEL
     Solaris DDI specific (Solaris DDI).

ARGUMENTS
     dhp          An opaque mapping handle that the  system  uses
                  to  describe the mapping currently being dupli-
                  cated.


     pvtp         Driver private mapping  data  for  the  mapping
                  currently being duplicated.


     new_dhp      An opaque data structure that the  system  uses
                  to describe the duplicated device mapping.


     new_pvtp     A pointer to be filled  in  by  device  drivers
                  with  the  driver  private mapping data for the
                  duplicated device mapping.


DESCRIPTION
     The system calls  devmap_dup()  when  a  device  mapping  is
     duplicated, such as during the execution of the fork(2) sys-
     tem call.  The system expects devmap_dup() to  generate  new
     driver private data for the new mapping, and to set new_pvtp
     to point to it. new_dhp is the  handle  of  the  new  mapped
     object.


     A non-zero return value  from   devmap_dup()  will  cause  a
     corresponding operation such as fork() to fail.

RETURN VALUES
     devmap_dup() returns the following values:

     0           Successful completion.




SunOS 5.11          Last change: 21 Jan 1997                    1






Driver Entry Points                                devmap_dup(9E)



     Non-zero    An error occurred.


EXAMPLES
       static int
       xxdevmap_dup(devmap_cookie_t dhp, void *pvtp, \
           devmap_cookie_t new_dhp,
           void **new_pvtp)
       {
           struct xxpvtdata    *prvtdata;
           struct xxpvtdata    *p = (struct xxpvtdata *)pvtp;
           struct xx_softc     *softc = p->softc;
           mutex_enter(&softc->mutex);
           /* Allocate a new private data structure */
           prvtdata = kmem_alloc(sizeof (struct xxpvtdata), KM_SLEEP);
           /* Return the new data */
           prvtdata->off = p->off;
           prvtdata->len = p->len;
           prvtdata->ctx = p->ctx;
           prvtdata->dhp = new_dhp;
           prvtdata->softc = p->softc;
           *new_pvtp = prvtdata;
           mutex_exit(&softc->mutex);
           return (0);
       }


SEE ALSO
     fork(2), devmap_callback_ctl(9S)


     Writing Device Drivers























SunOS 5.11          Last change: 21 Jan 1997                    2