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

NAME

       hat_getkpfnum - get page frame number for kernel address

SYNOPSIS

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

       pfn_t hat_getkpfnum(caddr_t addr);

INTERFACE LEVEL

       This interface is obsolete. A driver devmap(9E) entry point should be provided instead.

PARAMETERS

       addr	The kernel virtual address for which the page frame number is to be returned.

DESCRIPTION

       hat_getkpfnum() returns the page frame number corresponding to the kernel virtual address, addr.

       addr  must  be  a  kernel  virtual  address  which maps to device memory. ddi_map_regs(9F) can be used to obtain this address. For example,
       ddi_map_regs(9F) can be called in the driver's attach(9E) routine. The resulting kernel virtual address can be saved  by  the  driver  (see
       ddi_soft_state(9F))  and  used in mmap(9E). The corresponding ddi_unmap_regs(9F) call can be made in the driver's detach(9E) routine. Refer
       to mmap(9E) for more information.

RETURN VALUES

       The page frame number corresponding to the valid, device-mapped virtual address addr. Otherwise the return value is undefined.

CONTEXT

       hat_getkpfnum() can be called only from user or kernel context.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Obsolete			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       attach(9E), detach(9E), devmap(9E), mmap(9E), ddi_map_regs(9F), ddi_soft_state(9F), ddi_unmap_regs(9F)

       Writing Device Drivers

NOTES

       For some devices, mapping device memory in the driver's attach(9E) routine and unmapping device memory in the driver's  detach(9E)  routine
       is  a  sizeable	drain  on  system  resources.  This is especially true for devices with a large amount of physical address space. Refer to
       mmap(9E) for alternative methods.

SunOS 5.10							   13 June 2004 						 hat_getkpfnum(9F)