osf1 man page for trunc_page

trunc_page(9r)															    trunc_page(9r)

NAME
       trunc_page - General: Truncates the specified address

SYNOPSIS
       #include <mach/vm_param.h>

       vm_offset_t trunc_page(
	       vm_offset_t address );

ARGUMENTS
       Specifies the address that is being truncated to a page boundary.

DESCRIPTION
       The trunc_page routine truncates the specified address to be aligned on a page boundary. This routine shields the driver writer from having
       to know the page size of the system, which could vary in different CPU architectures and on different CPU types within the  same  architec-
       ture.  Typically,  a device driver calls trunc_page in preparation for doing a DMA operation on a user's buffer. The value returned by this
       routine is used in the call to the vm_map_pageable routine. To use this routine, the  driver  writer  must  include  the  <mach/vm_param.h>
       header file in the driver.

RETURN VALUES
       The trunc_page routine returns an address truncated to a page boundary.

SEE ALSO
       Routines: current_task(9r), round_page(9r), vm_map_pageable(9r)

																    trunc_page(9r)