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+.\"
+.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. 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(s), this list of conditions and the following disclaimer as
+.\"    the first lines of this file unmodified other than the possible
+.\"    addition of one or more copyright notices.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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 14, 2001
+.Dt VM_PAGE_PROTECT 9
+.Os
+.Sh NAME
+.Nm vm_page_protect
+.Nd "lower a page's protection"
+.Sh SYNOPSIS
+.In sys/param.h
+.In vm/vm.h
+.In vm/vm_page.h
+.Ft void
+.Fn vm_page_protect "vm_page_t mem" "int prot"
+.Sh DESCRIPTION
+The
+.Fn vm_page_protect
+function lowers a page's protection.
+The protection is never raised by this function; therefore, if the page is
+already at
+.Dv VM_PROT_NONE ,
+the function does nothing.
+.Pp
+Its arguments are:
+.Bl -tag -width ".Fa prot"
+.It Fa mem
+The page whose protection is lowered.
+.It Fa prot
+The protection the page should be reduced to.
+If
+.Dv VM_PROT_NONE
+is specified, then the
+.Dv PG_WRITABLE
+and
+.Dv PG_MAPPED
+flags are cleared and the pmap_page's protection is set to
+.Dv VM_PROT_NONE .
+If
+.Dv VM_PROT_READ
+is specified, then the
+.Dv PG_WRITABLE
+flag is cleared and the pmap_page's protection is set to
+.Dv VM_PROT_READ .
+.El
+.Pp
+Higher protection requests are ignored.
+.Sh AUTHORS
+This manual page was written by
+.An Chad David Aq davidc@acns.ab.ca .