From owner-freebsd-hackers Fri Aug 30 13: 0:18 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8593337B400 for ; Fri, 30 Aug 2002 13:00:12 -0700 (PDT) Received: from rwcrmhc52.attbi.com (rwcrmhc52.attbi.com [216.148.227.88]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1B4D343E3B for ; Fri, 30 Aug 2002 13:00:12 -0700 (PDT) (envelope-from julian@elischer.org) Received: from InterJet.elischer.org ([12.232.206.8]) by rwcrmhc52.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020830200011.TNTV19514.rwcrmhc52.attbi.com@InterJet.elischer.org>; Fri, 30 Aug 2002 20:00:11 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id MAA04450; Fri, 30 Aug 2002 12:44:41 -0700 (PDT) Date: Fri, 30 Aug 2002 12:44:40 -0700 (PDT) From: Julian Elischer To: "Balaji, Pavan" Cc: "'freebsd-hackers@freebsd.org'" Subject: Re: Copying from Virtual Address Space to Physical Address In-Reply-To: <3D386AED1B47D411A94300508B11F18704AD69CF@fmsmsx116.fm.intel.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 30 Aug 2002, Balaji, Pavan wrote: > Hi, > > Is there some function using which I can copy data from the Kernel Virtual > Space to a pinned Physical Address Page. Not as such, though there are plenty of places that do such a thing. The answer is always to map the physical page somewhere into kernel space. This is true because the processer can not access pages by their physical address once it is in virtual address mode. Physio() does this.. first it finds the physical addresses of the user pages targetted, then it maps those pages into kernel space, and then it initiates IO to them. (this actually needs to change but for now it's true. > > Thanx, > > Pavan Balaji, > Intel Corporation > Email: pavan.balaji@intel.com > > "Only the Paranoid Survive" -- Andy Grove "until they die of ulcers" :-) > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message