ddi_mmap_get_model(9f) [sunos man page]

ddi_mmap_get_model(9F)					   Kernel Functions for Drivers 				    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

       "small and bold">DDI_MODCurrent2thread 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

SunOS 5.10							    8 Feb 2001						    ddi_mmap_get_model(9F)

ddi_model_convert_from(9F)				   Kernel Functions for Drivers 				ddi_model_convert_from(9F)

NAME

       ddi_model_convert_from - determine data model type mismatch

SYNOPSIS

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

	uint_tddi_model_convert_from(uint_t model);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

PARAMETERS

       model	       The data model type of the current thread.

DESCRIPTION

       ddi_model_convert_from()  is  used  to  determine  if the current thread uses a different C Language Type Model than the device driver. The
       64-bit version of Solaris will require a 64-bit kernel to support both 64-bit and 32-bit user  mode  programs.  The  difference	between  a
       32-bit  program	and  a 64-bit program is in its C Language Type Model: a 32-bit program is ILP32 (integer, longs, and pointers are 32-bit)
       and a 64-bit program is LP64 (longs and pointers are 64-bit). There are a number of driver entry points	such  as  ioctl(9E)  and  mmap(9E)
       where  it  is  necessary  to  identify the C Language Type Model of the user-mode originator of an kernel event. For example any data which
       flows between programs and the device driver or vice versa need to be identical in format. A 64-bit device driver may need  to  modify  the
       format  of the data before sending it to a 32-bit application. ddi_model_convert_from() is used to determine if data that is passed between
       the device driver and the application requires reformatting to any non-native data model.

RETURN VALUES

       DDI_MODEL_ILP32		       A conversion to/from ILP32 is necessary.

       DDI_MODEL_NONE		       No conversion is necessary. Current thread and driver use the same data model.

CONTEXT

       ddi_model_convert_from() can be called from any context.

EXAMPLES

       Example 1: : Using ddi_model_convert_from() in the ioctl() entry point to support both 32-bit and 64-bit applications.

       The following is an example how to use ddi_model_convert_from() in the ioctl() entry point to support both 32-bit and 64-bit applications.

       struct passargs32 {
	       int len;
	       caddr32_t addr;
       };

       struct passargs {
	       int len;
	       caddr_t addr;
       };
       xxioctl(dev_t dev, int cmd, intptr_t arg, int mode,
	   cred_t *credp, int *rvalp) {
	       struct passargs pa;

	       switch (ddi_model_convert_from(mode & FMODELS)) {
		   case DDI_MODEL_ILP32:
		   {
		       struct passargs32 pa32;

		       ddi_copyin(arg, &pa32, sizeof (struct passargs32), mode);
		       pa.len = pa32.len;
		       pa.address = pa32.address;
		       break;
		   }
		   case DDI_MODEL_NONE:
		       ddi_copyin(arg, &pa, sizeof (struct passargs), mode);
		       break;
	       }

	       do_ioctl(&pa);
	       ....
       }

SEE ALSO

       ioctl(9E), mmap(9E), ddi_mmap_get_model(9F)

       Writing Device Drivers

SunOS 5.10							    8 Feb 2001						ddi_model_convert_from(9F)