96 lines
2.9 KiB
Groff
96 lines
2.9 KiB
Groff
.\"
|
|
.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd July 21, 2003
|
|
.Dt PMAP_EXTRACT 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm pmap_extract ,
|
|
.Nm pmap_extract_and_hold
|
|
.Nd map a virtual address to a physical page
|
|
.Sh SYNOPSIS
|
|
.In sys/param.h
|
|
.In vm/vm.h
|
|
.In vm/pmap.h
|
|
.Ft vm_paddr_t
|
|
.Fn pmap_extract "pmap_t pmap" "vm_offset_t va"
|
|
.Ft vm_paddr_t
|
|
.Fn pmap_extract_and_hold "pmap_t pmap" "vm_offset_t va" "vm_prot_t prot"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn pmap_extract
|
|
function maps a virtual address to a physical page.
|
|
In certain situations, callers may use
|
|
.Fn pmap_extract_and_hold
|
|
instead, to ensure that the returned page is held.
|
|
.Pp
|
|
The
|
|
.Fn pmap_extract_and_hold
|
|
function maps a virtual address to a physical page, and atomically holds
|
|
the returned page for use by the caller, only if the mapping permits
|
|
the given page protection.
|
|
.Sh IMPLEMENTATION NOTES
|
|
Currently, the page protection requested by the caller is not verified.
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn pmap_extract
|
|
function will return the physical page address associated with the
|
|
virtual address
|
|
.Fa va
|
|
inside the physical map
|
|
.Fa pmap .
|
|
If the mapping does not exist, or if the
|
|
.Fa pmap
|
|
parameter is
|
|
.Dv NULL ,
|
|
then
|
|
.Dv NULL
|
|
will be returned.
|
|
.Pp
|
|
The
|
|
.Fn pmap_extract_and_hold
|
|
function will return the physical page address associated with the
|
|
virtual address
|
|
.Fa va
|
|
inside the physical map
|
|
.Fa pmap .
|
|
If the mapping does not exist, the result is a no-op, and
|
|
.Dv NULL
|
|
will
|
|
be returned.
|
|
.Sh SEE ALSO
|
|
.Xr mutex 9 ,
|
|
.Xr pmap 9
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
The
|
|
.Fn pmap_extract_and_hold
|
|
function was implemented by
|
|
.An Alan L. Cox Aq Mt alc@imimic.com .
|
|
This manual page was written by
|
|
.An Bruce M Simpson Aq Mt bms@spc.org .
|