Kernel Functions for Drivers               ddimmapgetmodel(9F)



NAME
     ddimmapgetmodel -  return  data  model  type  of  current
     thread

SYNOPSIS
     #include 
     #include 



     uintt ddimmapgetmodel(void);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI).

DESCRIPTION
     ddimmapgetmodel() returns the C Language Type Model which
     the  current thread expects. ddimmapgetmodel() is used in
     combination with ddimodelconvertfrom(9F) in the  mmap(9E)
     driver  entry  point  to  determine  whether there is a data
     model mismatch between the current  thread  and  the  device
     driver.  The device driver might have to adjust the shape of
     data structures before exporting them to a user thread which
     supports a different data model.

RETURN VALUES
     DIMODELILP32     Current thread  expects  32-bit  (ILP32)
                         semantics.


     DIMODELP64      Current  thread  expects  64-bit  (LP64)
                         semantics.


     DIFAILURE         The  ddimmapgetmodel()  function  was
                         not   called  from  the  mmap(9E)  entry
                         point.


CONTEXT
     The ddimmapgetmodel() function can only  be  called  from
     the mmap(9E) driver entry point.

EXAMPLES
     Example 1 : Using ddimmapgetmodel()


     The following is an example of the mmap(9E) entry point  and
     how  to support 32-bit and 64-bit applications with the same
     device driver.




SunOS 5.11           Last change: 8 Feb 2001                    1






Kernel Functions for Drivers               ddimmapgetmodel(9F)



       struct data32 {
               int len;
               caddr32t addr;
       };

       struct data {
               int len;
               caddrt addr;
       };
       xxmmap(devt dev, offt off, int prot) {
               struct data dtc; /* a local copy for clash resolution */
               struct data *dp = (struct data *)sharedarea;

               switch (ddimodelconvertfrom(ddimmapgetmodel())) {
               case DIMODELILP32:
               {
                       struct data32 *da32p;

                       da32p = (struct data32 *)sharedarea;
                       dp = &dtc;
                       dp->len = da32p->len;
                       dp->address = da32->address;
                       break;
               }
               case DIMODELNONE:
                       break;
               }
               /* continues along using dp */
              ...
       }


SEE ALSO
     mmap(9E), ddimodelconvertfrom(9F)


     Writing Device Drivers


















SunOS 5.11           Last change: 8 Feb 2001                    2