ddi_mmap_get_model(9F)

NAME

     ddi_mmap_get_model -  return  data  model  type  of  current
     thread

SYNOPSIS

     #include <sys/ddi.h>
     #include <sys/sunddi.h>

     uint_t ddi_mmap_get_model(void);

INTERFACE LEVEL

     Solaris DDI specific (Solaris DDI).

DESCRIPTION

     ddi_mmap_get_model() returns the C Language Type Model which
     the  current thread expects. ddi_mmap_get_model() is used in
     combination with ddi_model_convert_from(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

     DDI_MODEL_ILP32
           Current thread expects 32-bit (ILP32) semantics.

     DDI_MODEL_LP64
           Current thread expects 64-bit (LP64) semantics.

     DDI_FAILURE
           The ddi_mmap_get_model() function was not called  from
           the mmap(9E) entry point.

CONTEXT

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

EXAMPLES

     Example 1: : Using ddi_mmap_get_model()

     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.

     struct data32 {
             int len;
             caddr32_t addr;
     };

     struct data {
             int len;
             caddr_t addr;
     };
     xxmmap(dev_t dev, off_t off, int prot) {
             struct data dtc; /* a local copy for clash resolution */
             struct data *dp = (struct data *)shared_area;

             switch (ddi_model_convert_from(ddi_mmap_get_model())) {
             case DDI_MODEL_ILP32:
             {
                     struct data32 *da32p;

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

SEE ALSO

     mmap(9E), ddi_model_convert_from(9F)

     Writing Device Drivers