Date: Fri, 7 Aug 2015 12:13:16 +0000 (UTC) From: "Jason A. Harmening" <jah@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r286411 - head/share/man/man9 Message-ID: <201508071213.t77CDGFv023251@repo.freebsd.org>
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Author: jah Date: Fri Aug 7 12:13:15 2015 New Revision: 286411 URL: https://svnweb.freebsd.org/changeset/base/286411 Log: Create man page for pmap_quick_enter_page(9) and pmap_quick_remove_page(9) Reviewed by: kib, brueffer, wblock Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D3312 Added: head/share/man/man9/pmap_quick_enter_page.9 (contents, props changed) Modified: head/share/man/man9/Makefile head/share/man/man9/pmap.9 Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Fri Aug 7 11:43:14 2015 (r286410) +++ head/share/man/man9/Makefile Fri Aug 7 12:13:15 2015 (r286411) @@ -223,6 +223,7 @@ MAN= accept_filter.9 \ pmap_pinit.9 \ pmap_protect.9 \ pmap_qenter.9 \ + pmap_quick_enter_page.9 \ pmap_release.9 \ pmap_remove.9 \ pmap_resident_count.9 \ @@ -1265,6 +1266,7 @@ MLINKS+=pmap_is_modified.9 pmap_ts_refer MLINKS+=pmap_pinit.9 pmap_pinit0.9 \ pmap_pinit.9 pmap_pinit2.9 MLINKS+=pmap_qenter.9 pmap_qremove.9 +MLINKS+=pmap_quick_enter_page.9 pmap_quick_remove_page.9 MLINKS+=pmap_remove.9 pmap_remove_all.9 \ pmap_remove.9 pmap_remove_pages.9 MLINKS+=pmap_resident_count.9 pmap_wired_count.9 Modified: head/share/man/man9/pmap.9 ============================================================================== --- head/share/man/man9/pmap.9 Fri Aug 7 11:43:14 2015 (r286410) +++ head/share/man/man9/pmap.9 Fri Aug 7 12:13:15 2015 (r286411) @@ -111,6 +111,8 @@ operation. .Xr pmap_protect 9 , .Xr pmap_qenter 9 , .Xr pmap_qremove 9 , +.Xr pmap_quick_enter_page 9 , +.Xr pmap_quick_remove_page 9 , .Xr pmap_release 9 , .Xr pmap_remove 9 , .Xr pmap_remove_all 9 , Added: head/share/man/man9/pmap_quick_enter_page.9 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/share/man/man9/pmap_quick_enter_page.9 Fri Aug 7 12:13:15 2015 (r286411) @@ -0,0 +1,103 @@ +.\" +.\" Copyright (c) 2015 Jason A. Harmening <jah@FreeBSD.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 August 6, 2015 +.Dt PMAP_QUICK_ENTER_PAGE 9 +.Os +.Sh NAME +.Nm pmap_quick_enter_page , +.Nm pmap_quick_remove_page +.Nd manage fast, single-page kernel address space mappings +.Sh SYNOPSIS +.In sys/param.h +.In vm/vm.h +.In vm/pmap.h +.Ft vm_offset_t +.Fn pmap_quick_enter_page "vm_page_t m" +.Ft void +.Fn pmap_quick_remove_page "vm_offset_t kva" +.Sh DESCRIPTION +The +.Fn pmap_quick_enter_page +function accepts a single page +.Fa m , +and enters this page into a preallocated address in kernel virtual +address (KVA) space. +This function is intended for temporary mappings that will only +be used for a very short period, for example a copy operation on +the page contents. +.Pp +The +.Fn pmap_quick_remove_page +function removes a mapping previously created by +.Fn pmap_quick_enter_page +at +.Fa kva , +making the KVA frame used by +.Fn pmap_quick_enter_page +available for reuse. +.Pp +On many architectures, +.Fn pmap_quick_enter_page +uses a per-CPU pageframe. +In those cases, it must disable preemption on the local CPU. +The corresponding call to +.Fn pmap_quick_remove_page +then re-enables preemption. +It is therefore not safe for machine-independent code to sleep +or perform locking operations while holding these mappings. +Current implementations only guarantee the availability of a single +page for the calling thread, so calls to +.Fn pmap_quick_enter_page +must not be nested. +.Pp +.Fn pmap_quick_enter_page +and +.Fn pmap_quick_remove_page +do not sleep, and +.Fn pmap_quick_enter_page +always returns a valid address. +It is safe to use these functions under all types of locks except spin mutexes. +It is also safe to use them in all thread contexts except primary interrupt +context. +.Pp +The page +.Em must +not be swapped or otherwise reused while the mapping is active. +It must be either wired or held, or it must belong to an unmanaged +region such as I/O device memory. +.Sh RETURN VALUES +The +.Fn pmap_quick_enter_page +function returns the kernel virtual address +that is mapped to the page +.Fa m . +.Sh SEE ALSO +.Xr pmap 9 +.Sh AUTHORS +This manual page was written by +.An Jason A Harmening Aq Mt jah@FreeBSD.org .
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