Index for Section 9r

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round_page(9r)
NAME
  round_page - General: Rounds the specified address

SYNOPSIS
  #include <mach/vm_param.h>

  vm_offset_t round_page(
	  vm_offset_t address );

ARGUMENTS
  address
      Specifies the address (or byte count) that is being rounded.

DESCRIPTION
  The round_page routine rounds the specified address (or byte count) to a
  multiple of the page size. For example, round_page would round a 1-byte
  count to be equal to the size of one page.  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
  architecture. Typically, a device driver calls round_page in preparation
  for doing a DMA operation to 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 round_page routine returns the rounded address or byte count.

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

Index for Section 9r

Alphabetical listing for R

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